Food Is More Than What We Eat Essay Example for Free

Food Is More Than What We Eat Essay The food we consume everyday has more to it than a source of fuel and part of our human essentials. Though we may not realise, food plays a part of many people’s culture, religion and even employment, where food plays a significant role in their everyday lives. Today, food serves a fairly major role in our society. Due to globalisation and other global factors, there has now been a mix and harmonious diversity in cultures around the world and food is one of the main evidence of that. This can just be seen by walking to your local stores where there are at least two or more food stores/ restaurants from different cultures. This is particularly evident in Australia, as immigrants from across the globe bring with them to Australia their cultures, beliefs and lifestyles to their new homes- with food being one of them. Many of these different cultures are now welcomed, accepted and shared, which provides employment for many people. This is not only evident in the Western continents, but many other Asian countries, where you would see many restaurants, snacks stores and street stores. Food is also used to distinguish the ‘classes of certain groups and/or areas. For example, in the city where there are more higher classed people, majority of the restaurants and cuisines tend to be a lot more expensive than those in the outer suburban areas. The functions of food in cultures vary between cultures, but majority of the time plays a significant role. There are different beliefs and morals, religious and food rules/ etiquettes that are associated with food of different cultures. An example of a food belief/moral would be in China noodles represent longevity, therefore it should not to be broken off or bitten off but put all into your mouth to chew to swallow. Food has not only been applied in beliefs and morals, but also religion. This can be seen in the Buddhism, where vegetarian dietary is preferred for serious believers. Sometimes food etiquette is incorporated into the religious side of food. For example in China it is considered extremely rude and impolite to stick your chopsticks upright in your rice as it is how it appears in funerals and is disrespectful to the elderly. The use of food in traditions and celebrations is another way to show how food has a deeper meaning that being sustenance. Traditions vary between cultures, but even families and individuals. Everyone has their own ‘style’ that they live with and pass on to their family who if they decide to continue the tradition passes on to future generations. Some of these traditions in terms of culture can be having rice has your main staple for most Asian cultures, while in Australia they have many different staples ranging from bread to grain foods. Food is also a big role player in celebrations. Many cultures have special foods that are only eaten or mostly eaten on certain days or events. For example in China on Chinese New Year, moon cakes are eaten, while in Australia, citizens have BBQs on Australia Day and eat ANZAC biscuits on ANZAC day. Food has also been a reason for unity of people. People like to eat whether it is at home or in restaurants in groups, where they not only enjoy the food together but can also start up conversations. For some families during dinner time may be the only time where they sit together and talk about their day. On a larger scale, food and global factors has allowed people of different backgrounds and cultures to accept and understand each other’s cultures. As previously mentioned, where we can now have food that are not from your culture. Because of food being eaten by many cultures, there are modifications to some foods so that more people can eat them. For example, there are now many vegetarian foods such as vegetarian pies and noodles for people with vegetarian diets.

Impact of Frailty on Depression

Impact of Frailty on Depression Background With increasing life expectancy, diseases associated with old age have increased in growing proportion in recent decades. (1) The integration of frailty measures in clinical practice is crucial for the development of interventions against age-related conditions (in particular, disability) in older persons. Multiple instruments have been developed over the last years in order to capture this geriatric multidimensional syndrome characterized by decreased reserve and diminished resistance to stressors and render it objectively measurable. (2) Frailty is not uncommon to the medical contemporary research nowadays. Several possible definitions were given by different researchers in the past to define frailty. One and commonly used definition of physical frailty was given by Fried et al, Frailty was defined as a clinical syndrome in which three or more of the following criteria were present; unintentional weight loss (10lbs in past year), self-reported exhaustion, weakness (grip strength), slow walking speed, and low physical activity. (3) Frailty in older people was again classified into prefrail those having one or two criteria given by Fried et al, and frail elderly having three or more criteria as per Fried et al definition. Medical Syndrome like frailty, keeps older adults at increased risk of adverse health outcomes when exposed to a stressor. (4)   Stressors lead to decline across multiple physiological systems incrementally and are associated with greater depressive symptoms and disability. (5) Depression is not a normal part of ageing process (6) and is a potentially life-threatening disorder that affects hundreds of millions of people across the world. (7) Depression is commonly seen in frail older people as they may face widowhood or loss of function or independence or bereavement. Depression, if left untreated, complicates other chronic conditions such as heart disease, diabetes, stroke, etc. It may also incur health care costs and often accompanies functional impairment and disability. (6) Various systematic reviews and journal articles has demonstrated association between depression and frailty. In this review, focus has made to highlight the role of stressors that leads pathways linking depression and frailty. Prevalence of frailty, depression and their co-occurrence in older individuals Several studies have been carried out to measure the prevalence of frailty in community-dwelling older people as well as those in hospital settings. Majority of the studies have used similar criteria to measure frailty among older adults. Systematic review of frailty prevalence worldwide concluded that 10.7% of community-dwelling adults aged à ¢Ã¢â‚¬ °Ã‚ ¥65 years were frail and 41.6% pre-frail. (8) It was noted that prevalence figures varied substantially between studies (ranging from 4% to 59%) using different criteria to measure frailty. (6) Data from Survey of Health, Aging and Retirement in Europe (SHARE) in 2004 covering more than 10 European countries, showed prevalence of frailty and pre-frailty in 65+ age group as 17.0% (15.3 18.7) were frail and 42.3% (40.5 44.1) were pre-frail. (9) The prevalence of frailty in community dwelling older people ranged from 17%-31% in Brazil, 15% in Mexico, 5%-31% in China, and 21%-44% in Russia. However, prevalence of frailty was again fou nd much higher in institutionalized older patients as 32% in India and 49% in Brazil. Findings of study in outpatient clinics reported prevalence of frailty was 55-71% in Brazil and 28% in Peru. (10) Above finding suggests that older people of low- and middle-income countries were found frail in significant proportions which imply policy and health care provisions for this ageing population. Depression varies in its prevalence in different studies and settings. Prevalence of depressive symptoms was found 14% in Brazilian adults (11), 9% in United States general population (12) and 23.6% (95% CI: 20.3-27.2%) in Chinese older adults. (13) Depressive symptoms were most commonly associated with women (11) (12) (13) and single adults (i.e. divorced, unmarried or widowed) than in married older adults. (13) Prevalence of depressive illness rises further in the event of associated co-morbid condition such as cancer, diabetes, and hypertension[N1]. Median prevalence of minor depression was 14.4% and 10.4%, in medical settings and community-based setting, respectively[N2]. (14) The median global prevalence of serious depression in the elderly population is around 1% 5%. (15) (16) (17) Depressed elders show many phenotypical expressions of frailty and vice versa. Coexistence of both depression and frailty among older people has been investigated in several studies. (18) (19) (20) (21) (22) (23) A recent systematic review examined the relationship between depression and frailty found serious depression in 4 16% of frail individuals who are aged 60 and over. (6) However, this percentage rises to 35% in older population with age 75 years or more. (6) (24) A study conducted within framework of prospective cohort study, the Netherlands Study of Depression in Older Persons (NESDO) found that the prevalence of physical frailty was significantly higher in the depressed group in comparison with non-depressed (27.2% vs 9.1%, p4) was present in as high as 46.5% of the frail subjects. Depressed patients often exhibit symptoms that interfere with their ability to function normally for longer duration which facilitates progression of frailty syndrome. (6) Therefore, in order to improve health and preventing frailty depression in elderly, it is essential for researchers and practitioners to understand the linking phenomena for further research and developing treatment options. Main pathways linking frailty and depression Several studies have identified the possible physiological pathways that link between frailty and depression in older adults. Of which, the main hypothetical pathways identified were vascular depression, chronic inflammation, Hypothalamus-Pituitary-Adrenal (HPA) axis dysregulation and accelerated cellular ageing. Vascular depression hypothesis Alexopoulos et al. (26) proposed that cerebrovascular disease may predispose, precipitate, or perpetuate some geriatric depressive syndromes. This statement was supported by another study of vascular depression based on magnetic resonance imaging (MRI) conducted by Krishnan KR et al. (27). Bivariate analyses and a fully adjusted logistic regression model in MRI study revealed that older age, late age at onset, and nonpsychotic subtype occurred more often in patients with vascular depression than in those with nonvascular depression. He also observed that anhedonia and functional disability were seen somewhat more often in patients with vascular depression. There are several clinical studies that examined vascular disease in depression. Some studies (28) found a highly significant increase in physical illness and vascular risk factors in the late onset group, after adjusting for age when they compared early and late onset late-life depression. (29) On the other hand, several others found no association of depression with cerebrovascular score (30) and vascular disease (31). Depression may occur as a result of vascular disease in a significant subpopulation of elderly persons. (32) Depression has a bidirectional association with vascular diseases and plausible mechanisms exist which explain how depression might increase these vascular diseases and vice versa. Thomas AJ et al summarized that coronary artery disease (CAD) and stroke are all associated with high rates of depression and depression is an independent risk factor for the subsequent development of CAD and stroke. (29) Mechanism of vascular depression can be hypothesized as reduced cerebral blood flow (CBF) in response to given stressors. Normal CBF in adult humans is about 60ml/100 grams/min and regionally, about 70ml/100g/min in gray matter and 20ml/100g/min in white matter. Between the ages of 20 to 65, normal CBF generally declines about 15-20%. It is generally accepted that when CBF reaches 30ml/100g/min, neurologic symptoms can appear and when CBF falls to 15-20ml/100g/min, electrical failure or irreversible neuronal damage can occur even within minutes. (33) Blood flow to the brain is influenced by systemic hemodynamics and cerebro-vascular auto-regulation, with cerebral arteries contracting or dilating as arterial pressure changes. These processes interact to maintain stable perfusion. (33) However, these processes are impaired in the context of vascular disease: hypertension, diabetes, and atherosclerosis lead to vascular wall hypertrophy, reduced arterial lumen diameter, reduced arterial distensibility, and endothelial cell dysfunction. This affects cerebral blood flow. Mild CBF reduction may impair cognitive and affective processes, while greater CBF reduction may cause ischemic injury. The subcortical white matter is particularly sensitive to these changes because it is supplied by terminal arterioles with limited collateral flow and so susceptible to infarction due to impaired autoregulation. Greater white matter hyperintensities (WMH) severity may be a marker of broader deficits in perfusion and autoregulation. Thus, risk factors for vascular disease can lead to subclinical cerebrovascular disease throughout the brain. Katz (2004) theorizes that cerebrovascular disease that causes prefrontal white-matter hyperintensities and vascular depression may also lead to posterior white matter hyperintensities, resulting in characteristics of frailty such as falls, slowness, and weakness. (34) He further stated that if the effects are anterior, the manifestations may include depression. However, if the effects are more posterior, the manifestations may be in the form of disturbances of gait and balance. Several other studies had compared depressed elderly with control group and demonstrated an increase in deep white matter hyperintensities (DWMH) in depression (35) (36) (37), but no or not significant association with peripheral vascular lesion (PVH) (36) (37). The cerebral WM contains fiber pathways that convey axons linking cerebral cortical areas with each other and with subcortical structures, facilitating the distributed neural circuits that subserve sensorimotor function, intellect, and emotion. The va scular depression hypothesis postulates that altered mood regulation and cognitive dysfunction in the elderly are due to subclinical cerebrovascular ischemia that disrupts frontostriatal neural circuits. (38) (39) This disruption of fronto-striatal neural circuits leads to disconnection syndrome that corresponds to the clinical and neuropsychological profile of LLD. (40) Prefrontal WMH also leads to executive dysfunction which affects planning, self-monitoring, attention, response inhibition, co-ordination of complex cognition (as in Trail making Test) and motor control. This leads to frailty. Chronic Inflammation hypothesis Aging- and disease-related processes promote proinflammatory states in older individuals. Administration of cytokines or induction of peripheral inflammation results in an inflammatory response, which in turn is correlated with fatigue, slowed reaction time, and mood reduction. Even without medical illness, depressed individuals exhibit increased levels of proinflammatory cytokines and reduced anti-inflammatory cytokine levels. Proinflammatory cytokines affect monoamine neurotransmitter pathways, including indoleamine 2,3-dioxygenase upregulation and kynurenine pathway activation. This results in decreased tryptophan and serotonin and increased synthesis of detrimental tryptophan catabolites that promote hippocampal damage and apoptosis. Cytokines, including IL-1ÃŽÂ ², also reduce extracellular serotonin levels by activating the serotonin transporter. Effects of the CNS inflammatory cascade on neural plasticity Microglias are primary recipients of peripheral inflammatory signals that reach the brain. Activated microglia, in turn, initiate an inflammatory cascade whereby release of relevant cytokines, chemokines, inflammatory mediators, and reactive nitrogen and oxygen species (RNS and ROS, respectively) induces mutual activation of astroglia, thereby amplifying inflammatory signals within the CNS. Cytokines, including IL-1, IL-6, and TNF-alpha, as well as IFN-alpha and IFN-gamma (from T cells), induce the enzyme, IDO, which breaks down TRP, the primary precursor of 5-HT (serotonin), into QUIN (quinolinic acid), a potent NMDA (N-methyl-D-aspartate) agonist and stimulator of GLU (glutamate) release. Astrocytic functions are compromised due to excessive exposure to cytokines, QUIN, and RNS/ROS, ultimately leading to impaired glutamate reuptake, and increased glutamate release, as well as decreased production of neurotrophic factors. Of note, oligodendroglia are especially sensitive to the CNS inflammatory cascade and suffer damage due to overexposure to cytokines such as TNF-alpha, which has a direct toxic effect on these cells, potentially contributing to apoptosis and demyelination. The confluence of excessive astrocytic glutamate release, its inadequate reuptake by astrocytes and oligodendroglia, activation of NMDA receptors by QUIN, increased glutamate binding and activation of extrasynaptic NMDA receptors (accessible to glutamate released from glial elements and associated with inhibition of BDNF (brain-derived neurotrophic factor) expression), decline in neurotrophic support, and oxidative stress ultimately disrupt neural plasticity through excitotoxicity and apoptosis. 5-HT, serotonin; BDNF, brain-derived neurotrophic factor; CNS, central nervous system; GLU, glutamate; IDO, indolamine 2,3 dioxygenase; IFN, interferon; IL, interleukin; NMDA, N-methyl-D-aspartate; QUIN, quinolinic acid; RNS, reactive nitrogen species; ROS, reactive oxygen species; TNF, tumor necrosis factor; TRP, tryptophan. Regarding LLD, the aging process disrupts immune function, increasing peripheral immune activity and shifting the CNS into a proinflammatory state. Elevated peripheral cytokine levels are associated with depressive symptoms in older adults, with the most consistent finding being for IL-6, but also implicating IL-1ÃŽÂ ², IL-8 and TNFÃŽÂ ±. Proinflammatory states in older adults are associated with cognitive deficits, including poorer executive function, poorer memory performance, worse global cognition, and steeper decline in cognition. Finally, greater IL-6 and C-reactive protein levels are associated with greater WMH burden. In LLD, ischemic lesions are also more likely to occur in the dorsolateral prefrontal cortex (DLPFC), Similarly, depressed elders exhibit increased expression of cellular adhesion molecules (CAMs) in the DLPFC. CAMs are inflammatory markers whose expression is increased by ischemia, supporting a role for ischemia in LLD and highlighting the relationship between vascular and inflammatory processes. HPA dysregulation When the HPA axis is activated by stressors, such as an immune response, high levels of glucocorticoids are released into the body and suppress immune response by inhibiting the expression of proinflammatory cytokines (e.g. IL-1, TNF alpha, and IFN gamma) and increasing the levels of anti-inflammatory cytokines (e.g. IL-4, IL-10, and IL-13) in immune cells, such as monocytes and neutrophils. Excess stress also appears to play a role in the development of depression and can cause dysregulation of the HPA axis. Patients with major depression have been found to have elevated plasma and urinary cortisol levels as well as elevated corticotropin-releasing hormone and decreased levels of BDNF. Prolonged severe stress is thought to damage hippocampal neurons and to reduce the inhibitory control exerted by the HPA axis in regulating glucocorticoid levels. During an immune response, proinflammatory cytokines (e.g. IL-1) are released into peripheral circulatory system and can pass through the blood brain barrier where they can interact with the brain and activate HPA axis. Interactions between the proinflammatory cytokines and the brain can alter the metabolic activity of neurotransmitters and cause symptoms such as fatigue, depression, and mood changes. Increased levels of aldosterone in the circulation stimulate excessive production of collagen, which leads to fibrosis of tissue or organ whereas low levels of adrenal androgen dehydroepiandrosterone sulfate and insulin-like growth factor 1 are associated with frailty. Further, cortisol may mimic the effects of aldosterone. Elevated serum levels of cortisol and aldosterone are independent predictors of mortality in patients with heart failure. Accelerated Cellular Aging hypothesis Accelerated cellular aging, as measured by telomere length (TL) shortening, might also be linked to depression and frailty. At both ends of every DNA strand in a human cell is a telomere.Telomeres prevent chromosomes from becoming frayed, fusing into rings, or binding with other DNA. Telomeres are specialized nucleoprotein structures located at the end of eukaryotic chromosomes. They play a critical role in controlling cell proliferation and maintenance of chromosomal stability. As part of bodys normal aging process, each time a cell divides the telomeres in your DNA get shorter. Add oxidative stress to the mix and telomeres shorten even more rapidly. Oxidative stress is the effect of destructive reactions in your bodys cells caused by too many free radicals or atoms/molecules that have unpaired electrons. In their search for an electron to make them whole, they destroy other cells. Free radicals come from environmental toxins, such as pollution, chemicals, drugs and radiation, and even naturally occur in your own body when you exercise. Antioxidants fight free radicals and stem the causes of oxidative stress. Eventually, bodys cells are unable to divide (or reproduce) and simply die. Eventually, this instability leads to tissue breakdown potentially leading to premature aging. Any stressful condition or anxiety leads to feeling of depression which in turn initiates physiologic body response that includes, increase in stress-induced glucocorticoid release and oxidative stress. Unhealthy behaviour will also stimulate inflammatory response which lead to release of cytokine and can affect telomere length.

Fundamental Concepts Of Ethernet Technology Information Technology Essay

Fundamental Concepts Of Ethernet Technology Information Technology Essay In this module, we will discuss the fundamental concepts of networking, Ethernet technology, and data transmission in Ethernet networks. Module Objectives At the end of this module, you will be able to: Explain the seven network layers as defined by the Open Systems Interconnection (OSI) Reference model Describe, at a high level, the history of Ethernet List physical layer characteristics of Ethernet Explain the difference between half-duplex and full-duplex transmission in an Ethernet network Describe the structure of an Ethernet frame Explain how networks can be extended and segmented using various Ethernet devices, including hubs and switches Describe how frames are forwarded in an Ethernet network Explain, at a high level, how Virtual Local Area Networks (VLANs) function Network Fundamentals This section provides a brief overview of Local Area Network (LAN) technology. We will discuss LAN architecture from a functional perspective. A network is commonly divided into seven functional layers referred to as the OSI Reference model. In addition, we will briefly discuss the use of addressing in LANs. Instructor Note Point out that this section only touches briefly on LAN concepts, and students may want to explore LAN technology in more depth on their own. Network Layers A complete LAN implementation involves a number of functions that, in combination, enable devices to communicate over a network. To understand how Ethernet fits into this overall set of functions, we can use the OSI Reference model. The OSI Reference model was developed in 1984 by the International Organization for Standardization (ISO). Instructor Note You can introduce the discussion of the OSI Reference model by comparing analysis of the model to peeling an onion. Shown in Figure 1-1, the OSI Reference model defines seven functional layers that process data when data is transmitted over a network. When devices communicate over a network, data travels through some or all of the seven functional layers. The figure shows data being transmitted from Station A, the source, to Station B, the destination. The transmission begins at the Application layer. As data (referred to as the payload) is transmitted by Station A down through the layers, each layer adds its overhead information to the data from the layer above. (The process of packaging layer-specific overhead with the payload is referred to as encapsulation discussed later in this course.) Upon reaching the Physical layer, the data is placed on the physical media for transmission. The receiving device reverses the process, unpackaging the contents layer by layer, thus allowing each layer to effectively communicate with its peer layer. Ethernet operates at Layer 2, the Data Link layer. Using Figure 1-1 as a reference, we will briefly discuss what occurs at each layer. Figure 1-1: The OSI Reference Model Application Layer The Application layer, Layer 7 (L7), is responsible for interacting with the software applications that send data to another device. These interactions are governed by Application layer protocols, such as Hypertext Transfer Protocol (HTTP), File Transfer Protocol (FTP), and Simple Mail Transfer Protocol (SMTP). Presentation Layer The Presentation layer, Layer 6 (L6), performs data translation, compression, and encryption. Data translation is required when two different types of devices are connected to each other, and both use different ways to represent the data. Compression is required to increase the transmission flow of data. Encryption is required to secure data as it moves to the lower layers of the OSI Reference model. Session Layer The Session layer, Layer 5 (L5), is responsible for creating, maintaining, and terminating communication among devices. A session is a logical link created between two software application processes to enable them to transmit data to each other for a period of time. Logical links are discussed later in this course. Transport Layer The Transport layer, Layer 4 (L4), is responsible for reliable arrival of messages and provides error checking mechanisms and data flow controls. The Transport layer also performs multiplexing to ensure that the data from various applications is transported using the same transmission channel. Multiplexing enables data from several applications to be transmitted onto a single physical link, such as a fiber optic cable. The data flow through the Transport layer is governed by transmission protocols, such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP), which are beyond the scope of this course. Network Layer The Network layer, Layer 3 (L3), is responsible for moving data across interconnected networks by comparing the L3 source address with the L3 destination address. The Network layer encapsulates the data received by higher layers to create packets. The word packet is commonly used when referring to data in the Network layer. The Network layer is also responsible for fragmentation and reassembly of packets. Data Link Layer The Data Link layer, Layer 2 (L2), responds to requests sent by the Network layer and sends service requests to the Physical layer. The Data Link layer is responsible for defining the physical addressing, establishing logical links among local devices, sequencing of frames, and error detection. The Ethernet frame is a digital data transmission unit on Layer 2. The word frame is commonly used when referring to data in the Data Link layer. The Data Link layer has been subdivided into two sub-layers: Logical Link Control (LLC) and Media Access Control (MAC). LLC, defined in the Institute of Electrical and Electronics Engineers (IEEE) 802.2 specification, manages communications among devices over a link. LLC supports both connection-oriented (physical, ex an Ethernet switch) and connectionless (wireless, ex a wireless router) services. The MAC sub-level manages Ethernet frame assembly and dissembly, failure recovery, as well as access to, and routing for, the physical media. This will be discussed in more detail in this module. Physical Layer The Physical layer, Layer 1 (L1), performs hardware-specific, electrical, and mechanical operations for activating, maintaining, and deactivating the link among communicating network systems. The Physical layer is responsible for transmitting the data as raw bits over the transmission media. Now that we have reviewed the OSI Reference model, lets discuss addressing of network devices. Stations Network devices that operate at the Data Link layer or higher are referred to as stations. Stations are classified as either end stations or intermediate stations. End stations run end-user applications and are the source or final destination of data transmitted over a network. Intermediate stations relay information across the network between end stations. A characteristic of stations is that they are addressable. In the next section, we discuss the specifics of addressing. Addressing Each device in an Ethernet network is assigned an address that is used to connect with other devices in the network. This address is referred to as the MAC address and is typically a permanent address assigned by the device manufacturer. Addressing is used in the network to identify the source station and the destination station or stations of transmitted data. As shown in Figure 1-2, the MAC address consists of 48 bits (6 bytes), typically expressed as colon-separated, hexadecimal pairs. Figure 1-2: MAC Address Structure The MAC address consists of the following: Individual / Group (I/G) Bit: For destination address, if the I/G bit = 0, the destination of the frame is a single station. This is referred to as a unicast address. If the I/G bit = 1, the destination is a group of stations. This is referred to as a multicast address. In source addresses, the I/G bit = 1. Universal / Local (U/L) Bit: The U/L bit identifies whether the MAC address is universally unique (U/L bit = 0) or only unique in the LAN in which it is located. Vendor-assigned MAC addresses are always universally unique. A locally unique MAC address is assigned by the network administrator. Organizationally Unique Identifier (OUI): This typically identifies the network equipment manufacturer. OUIs are assigned to organizations by the IEEE. To locate information on the OUI associated with a manufacturer go to the following website: http://standards.ieee.org/regauth/oui/index.shtml Vendor-Assigned Bits: These bits are assigned by the vendor to uniquely identify a specific device. Following is an example of a MAC address: 00:1B:38:7C:BE:66 Later in this module, we discuss how MAC addresses are used in Ethernet networks. Introduction to Ethernet Ethernet is an internationally-accepted, standardized LAN technology. It is one of the simplest and most cost-effective LAN networking technologies in use today. Ethernet has grown through the development of a set of standards that define how data is transferred among computer networking devices. Although several other networking methods are used to implement LANs, Ethernet remains the most common method in use today. While Ethernet has emerged as the most common LAN technology for a variety of reasons, the primary reasons include the following: Ethernet is less expensive than other networking options. Easy is easy to install and provision the various components. Ethernet is faster and more robust than the other LAN technologies. Ethernet allows for an efficient and flexible network implementation. History of Ethernet Ethernet was invented in 1973 by Bob Metcalfe and David Boggs at the Xerox Palo Alto Research Center (PARC). Ethernet was originally designed as a high-speed LAN technology for connecting Xerox Palo Alto graphical computing systems and high-speed laser printers. In 1979, Xerox ® began work with Digital Equipment Corporation (DEC) and Intel ® to develop a standardized, commercial version of Ethernet. This partnership of DEC, Intel, and Xerox (DIX) developed Ethernet Version 1.0, also known as DIX80. Further refinements resulted in Ethernet Version 2, or DIX82, which is still in use today. Project 802 In 1980, the Institute of Electrical and Electronics Engineers (IEEE) formed Project 802 to create an international standard for LANs. Due to the complexity of the technology and the emergence of competing LAN technologies and physical media, five working groups were initially formed. Each working group developed standards for a particular area of LAN technology. The initial working groups consisted of the following: IEEE 802.1: Overview, Architecture, Internetworking, and Management IEEE 802.2: Logical Link Control IEEE 802.3: Carrier Sense Multiple Access / Collision Detection (CSMA/CD) Media Access Control (MAC) IEEE 802.4: Token Bus MAC and Physical (PHY) IEEE 802.5: Token Ring MAC and PHY Additional working groups have since been added to address other areas of LAN technology. The standards developed by these working groups are discussed as we move through this course. However, lets look at IEEE 802.3, which addresses standards specific to Ethernet. IEEE 802.3 IEEE 802.3 was published in 1985 and is now supported with a series of supplements covering new features and capabilities. Like all IEEE standards, the contents of supplements are added to the standard when it is revised. Now adopted by almost all computer vendors, IEEE 802.3 consists of standards for three basic elements: The physical media (fiber or copper) used to transport Ethernet signals over a network MAC rules that enable devices connected to the same transmission media to share the transmission channel Format of the Ethernet frame, which consists of a standardized set of frame fields We will discuss the transmission media used in Ethernet networks, the MAC rules, and the Ethernet frame later in this module. Instructor Note Tell the class that we will discuss the transmission media used in Ethernet networks, the MAC rules, and the Ethernet frame later in this module. You can briefly explain the differences among LANs, WANs, and MANs to the students. Ethernet Transmission Fundamentals This section covers basic fundamentals of data transmission on Ethernet networks. Specifically, we will cover the following topics: Physical layer characteristics Communication modes Ethernet frames Repeaters and hubs Ethernet bridges and switches Multilayer switches and routers Ethernet Virtual LANs (VLANs) Ethernet beyond the LAN Physical Layer Characteristics Our discussion of physical layer characteristics covers both the physical media over which network communications flow and the rate at which communications occur. In fact, the nomenclature for the various types of Ethernet is based on both of these characteristics. The Ethernet type is referred to in the following format: n-BASE-phy, such as 10BASE-T where: n is the data rate in megabits per second (Mbps). BASE indicates that the media is dedicated to only Ethernet services. phy is a code assigned to a specific type of media. A variety of media and transmission rates are available for Ethernet networks. The major media types used today are: Unshielded Twisted Pair (UTP) copper cable Shielded Twisted Pair (STP) copper cable Fiber optic cables The IEEE 802.3 standard identifies the following types of media for an Ethernet connection: 10BASE2: Defined in IEEE 802.3a, 10BASE2 Ethernet uses thin wire coaxial cable. It allows cable runs of up to 185 meters (607 feet). A maximum of 30 workstations can be supported on a single segment. This Ethernet type is no longer in use for new installations. 10BASE-T: Defined in IEEE 802.3i, 10BASE-T uses UTP copper cable and RJ-45 connectors to connect devices to an Ethernet LAN. The RJ-45 is a very common 8-pin connector. Fast Ethernet: Defined in IEEE 802.3u, Fast Ethernet is used for transmission at a rate of 100 Mbps. It includes 100BASE-TX, which uses UTP copper cable. With this type of cable, each segment can run up to 100 meters (328 feet). Another media option specified in this standard is 100BASE-FX, which uses optical fiber supporting data rates of up to 100 Mbps. Gigabit Ethernet (GbE): Defined in IEEE 802.3z, GbE uses fiber for transmitting Ethernet frames at a rate of 1000 Mbps or 1 Gbps. GbE includes 1000BASE-SX for transmission over Multi-Mode Fiber (MMF), and 1000BASE-LX for transmission over Single-Mode Fiber (SMF). The differences between Multi-Mode and Single-Mode are the physical makeup of the fiber itself and the light source that is normally used multi-mode normally uses an LED while single-mode uses a laser. Multi-mode has limited distance capability when compared to single-mode. 1000BASE-T: Defined in IEEE 802.3ab, 1000BASE-T provides GbE service over twisted pair copper cable. 10 GbE: Defined in IEEE 802.3ae, 10 GbE transmits Ethernet frames at data rates up to 10 Gbps. Communication Modes Ethernet can operate in either of two communication modes, half-duplex or full-duplex. Ethernet MAC establishes procedures that all devices sharing a communication channel must follow. Half-duplex mode is used when devices on a network share a communication channel. Full-duplex mode is used when devices have no contention from other devices on a network connection. Lets discuss each of these modes in more detail. Half-Duplex Mode As shown in Figure 1-3, a device operating in half-duplex mode can send or receive data but cannot do both at the same time. Originally, as specified in the DIX80 standard, Ethernet only supported half-duplex operation. Figure 1-3: Half-Duplex Transmission Half-duplex Ethernet uses the CSMA/CD protocol to control media access in shared media LANs. With CSMA/CD, devices can share media in an orderly way. Devices that contend for shared media on a LAN are members of the same collision domain. In a collision domain, a data collision occurs when two devices on the LAN transmit data at the same time. The CSMA/CD protocol enables recovery from data collisions. With CSMA/CD, a device that has data to transmit performs carrier sense. Carrier sense is the ability of a device to monitor the transmission media for the presence of any data transmission. If the device detects that another device is using the transmission media, the device waits for the transmission to end. When the device detects that the transmission media is not being used, the device starts transmitting data. Figure 1-4 shows how CSMA/CD handles a data collision. When a collision occurs, the transmitting device stops the transmission and sends a jamming signal to all other devices to indicate the collision. After sending the jamming signal, each device waits for a random period of time, with each device generating its own time to wait, and then begins transmitting again. Figure 1-4: CSMA/CD Operation Full-Duplex Mode In the full-duplex communication mode, a device can send and receive data at the same time as shown in Figure 1-5. In this mode, the device must be connected directly to another device using a Point-to-Point (P2P) link that supports independent transmit and receive paths. (P2P is discussed later in this course.) Figure 1-5: Full-Duplex Transmission Full-duplex operation is restricted to links meeting the following criteria: The transmission media must support the simultaneous sending and receiving of data. Twisted pair and fiber cables are capable of supporting full-duplex transmission mode. These include Fast Ethernet, GbE, and 10 GbE transmission media. The connection can be a P2P link connecting only two devices, or multiple devices can be connected to each other through an Ethernet switch. The link between both devices needs to be capable of, and configured for, full-duplex operation. CSMA/CD is not used for full-duplex communications because there is no possibility of a data collision. And, since each device can both send and receive data at the same time, the aggregate throughput of the link is doubled. (Throughput is the amount of data that can be transmitted over a certain period of time.) Ethernet Frames Lets discuss another fundamental aspect of Ethernet transmission the Ethernet frame. The Ethernet frame is used to exchange data between two Data Link layer points via a direct physical or logical link in an Ethernet LAN. The minimum size of an Ethernet frame is 64 bytes. Originally, the maximum size for a standard Ethernet frame was 1518 bytes; however, it is now possible that an Ethernet frame can be as large as 10,000 bytes (referred to as a jumbo frame). As shown in Figure 1-6, an Ethernet frame consists of the following fields: (NOTE: The first two fields are added/stripped at Layer 1 and are not counted as part of the 1518 byte standard frame.) Preamble: This 7-byte field establishes bit synchronization with the sequence of 10101010 in each byte. Start Frame Delimiter: This 1-byte field indicates the start of the frame at the next byte using a bit sequence of 10101011. Destination MAC Address: This field contains the MAC hardware address of the Ethernet frames destination. Source MAC Address: This field contains the MAC hardware address of the device sending the frame. Type / Length: The specific use of this field depends on how the frame was encapsulated. When type-encapsulation is used, the field identifies the nature of the client protocol running above the Ethernet. When using length-encapsulation, this field indicated the number of bytes in the Data field. The IEEE maintains a list of accepted values for this field, the list may be viewed at: http://standards.ieee.org/regauth/ethertype/ Data: This field contains the data or payload that has been sent down from Layer 3 for packaging to Layer 2. Frame Check Sequence (FCS): This 32-bit field is used for checking the Ethernet frame for errors in bit transmission. FCS is also known as Cyclical Redundancy Check (CRC). Figure 1-6: Ethernet Frame Now that we have defined the basic structure of an Ethernet frame, lets see how we can use the destination MAC address to create three different types of Ethernet frames. Unicast Frames An Ethernet frame intended for a single device on the network is a unicast frame. An example is shown in Figure 1-7. In this example, Station A is transmitting an FTP request to a specific FTP server on the network. The destination MAC address in the frames being sent for this request is the MAC address assigned to the FTP server by its manufacturer. Therefore, these frames are unicast frames, only intended specifically for one device on the network, the FTP server. Figure 1-7: Unicast Frame Transmission Multicast Frames Multicast is a mechanism that provides the ability to send frames to a specific group of devices on a network one sender to all who are set to receive. This is done by setting a frames destination MAC address to a multicast address assigned by a higher level protocol or application. However, devices must be enabled to receive frames with this multicast address. An example of multicast frames is shown in Figure 1-8. In this example, the video server is transmitting the same video channel, via an Ethernet switch, to a group of video display devices on the network. The destination MAC address is the multicast address assigned by the video application. The receiving stations are configured to accept Ethernet frames with this multicast address. Figure 1-8: Multicast Frame Transmission Broadcast Frames Broadcasting is a mechanism for sending data in broadcast frames to all the devices in a broadcast domain. A broadcast domain is defined as a set of devices that can communicate with each other at the Data Link layer. Therefore, in a network that does not include higher layer devices, all of the network devices are in the same broadcast domain. In broadcast frames, the hexadecimal destination MAC address is always ff:ff:ff:ff:ff:ff which, in binary notation, is a series of 48 bits, each set to a value of 1. All devices in the broadcast domain recognize and accept frames with this destination MAC address. Instructor Note Be sure that students understand hexadecimal vs. binary notation, but do not take this topic beyond the scope of this course. Since broadcasting reaches all devices within a broadcast domain, Ethernet can use this capability to perform various device setup and control functions. This is a very useful feature, allowing implementation and growth of a LAN with little intervention from a network administrator. Figure 1-9 shows a broadcast transmission in which Station A is transmitting frames with this broadcast destination MAC address. All devices in the same broadcast domain as Station A receive and process the broadcast frames. Figure 1-9: Broadcast Frame Now that we have covered some basic concepts for LANs and Ethernet transmission, lets continue by discussing how devices on Ethernet LANs are connected. Instructor Note Check the existing knowledge of students on the differences among switches, hubs, routers, and gateways. Initiate a discussion around the differences among these devices and their suitability to different applications. Repeaters and Hubs A very simple LAN topology consists of network devices that are all connected directly to a shared medium as shown in Figure 1-10. If we need to connect more devices to the LAN, we are limited by the characteristics of the shared media. Devices such as repeaters and hubs can be used to overcome distance limitations of the media, allowing the reach of the network to be extended. Figure 1-10: Simple LAN Topology Repeaters are Physical layer devices that regenerate a signal, which effectively allows the network segment to extend a greater distance. As shown in Figure 1-11, we can use the additional segment length to add more devices to the LAN. Keep in mind that devices added through implementation of repeaters are still in the same collision domain as the original devices. This results in more contention for access to the shared transmission media. Such devices are in little use today. Figure 1-11: LAN Extended with a Repeater As shown in Figure 1-12, hubs can also be used to extend the distance of a LAN segment. Hubs are Layer 1 (physical) devices. The advantage of a hub versus a repeater is that hubs provide more ports. Increased contention for media access still exists since the additional devices connected to the hub(s) are still in the same collision domain. Figure 1-12: LAN Extended with a Hub Ethernet Bridges and Switches Ethernet bridges and switches are Layer 2 (Data Link) devices that provide another option for extending the distance and broadcast domain of a network. Unlike repeaters and hubs, bridges and switches keep the collision domains of connected LAN segments isolated from each other as shown in Figure 1-13. Therefore, the devices in one segment do not contend with devices in another segment for media access. Figure 1-13: LAN Extended with an Ethernet Switch Frame Forwarding with Ethernet Switches As Layer 2 devices, Ethernet switches make frame-forwarding decisions based on source and destination MAC addresses. One of the processes used in making these decisions is MAC learning. To make efficient use of the data pathways that are dynamically cross connected within an Ethernet switch, the switch keeps track of the location of as many active devices as its design allows. When an Ethernet frame ingresses (enters) a switch, the switch inspects the frames source address to learn the location of the sender and inspects the destination address to learn the location of the recipient. This knowledge is kept in a MAC address table. Figure 1-14 shows an example of a MAC address table. As long as the sender remains connected to the same physical port that their MAC address was learned on, the switch will know which port to forward frames to that are destined for that particular senders address. Figure 1-14: MAC Address Table MAC address information stored in a MAC address table is not retained indefinitely. Each entry is time stamped; and if no activity is sensed for a period of time, referred to as an aging period, the inactive entry is removed. This is done so that only active devices occupy space in the table. This keeps the MAC address table from overloading and facilitates address lookup. The default aging period is typically five minutes. Figure 1-15 shows how an Ethernet switch forwards frames based on entries in the MAC address table. The forwarding process consists of the following steps: Inspect the incoming frames MAC destination address: If the MAC destination address is a broadcast address, flood it out all ports within the broadcast domain. If the MAC destination address is a unicast address, look for it in the MAC address table. If the address is found, forward the frame on the egress (exit) port where the NE knows the device can be reached. If not, flood it. Flooding allows communication even when MAC destination addresses are unknown. Along with multicast, which is actually a large set of special-purpose MAC addresses, network traffic can be directed to any number of devices on a network. Inspect the incoming frames MAC source address: If the MAC source address is already in the MAC address table, update the aging timer. This is an active device on the port through which it is connected. If the MAC source address is not currently in the MAC address table, add it in the list and set the aging timer. This is also an active device. Periodically check for MAC address table entries that have expired. These are no longer active devices on the port on which they were learned, and these table entries are removed. If a device is moved from one port to another, the device becomes active on the new ports MAC table. This is referred to as MAC motion. An Ethernet switch will purposely filter (drop) certain frames. Whether a frame is dropped or forwarded can depend on the switch configuration, but normal switch behavior drops any frame containing a destination address that the switch knows can be reached through the same port where the frame was received. This is done to prevent a device from receiving duplicate frames. Figure 1-15: Frame-Forwarding Process A MAC Learning and Broadcast Domain Analogy Mail Delivery Consider this following analogy to understand the concept of MAC learning and broadcast domain: Consider a situation where your friend wants to send you a birthday party invitation (the invitation represents an Ethernet frame). You and your friend live on the same street (the street represents a broadcast domain). However, there is a problem. Your friend does not know your house address so she writes her return (source) address on the birthday party invitation card and writes the street name as your (destination) address. Your friend drops the envelope in her mail box (your friends mail box represents a LAN) as shown in Figure 1-16. Figure 1-16: Broadcast Analogy, Part 1 When the mail carrier picks up the mail, he notices that the destination address is unknown. The postman goes to a copier and makes enough copies so that he can deliver one copy to each possible destination address on the street. This would mean every house on the street, except for your friends house, will get a copy of the invitation. After the postman has delivered the envelopes to all the houses (this process is analogous to a broadcast transmission), you receive the birthday party invitation and recognize your name on the envelope. So, you open the envelope and read the invitation. Figure 1-17: Broadcast Analogy, Part 2 All of your neighbors receive copies of the same envelope, but they see that the name is not theirs so they simply discard it. After reading the invitation, you send a thank you card back to your friend with your friends address; and you include a return (source) address. The postman sees that this envelope has a specific destination address so it can be delivered without broadcasting. It also has a source address, so the postman now knows your address. It is now possible to exchange mail directly with your friend without broadcasting letters to your neighbors. In other words, you can communicate using unicast transmission. If you and your friend were on different streets (broadcast domains), you would have never received your invitation card; and communication could have never occurred. Multilayer Switches and Routers In this course, our discussion of switching focuses on switching at the Data Link level since Ethernet is a Layer 2 technology. However, switching can also be

Transnational Race and the Black Movement Essay -- Race History

The United States and Latin America have seen their fair shares of inequality and hardships when it comes to those of the minority status. Minorities have successfully fought back in the timeless battle to achieve equality, rather it be with those of their own race, or from different ethnic backgrounds. When groups are able to coexist, their ideologies are expressed to one another and at times are able to influence different groups on their attitudes toward different subjects. Now that immigration has astronomically increased to the United States, the idea of this country as a â€Å"melting pot† has never been more correct. Being that more individuals are turning to the United States for permanent residence, race has obtained multiple definitions over the course of history, resulting from the ever-changing racial makeup of the United States and Latin America. The black movement has also contributed to the change in racial identification from the early 20th century up until to day, resulting in transnational ideologies of race. These two changes have culminated into the current culture that is taking over America, and making it into a more diversified nation. As the election of President Barack Obama proved to America and others around the world that this country was moving past race, the importance of transnational ideologies and race in America have led to a society that does not turn to race first, but instead looks at the beliefs and attitudes of those around it. When looking around the world at different races, it is easy to compare some of the sentiment toward these races to the very same attitudes American citizens have against them in the United States. Mark Anderson discusses how certain stereotypes about blacks have diffuse... ...rican American president, how far will we go in ensuring that race is a thing of the past? Works Cited Anderson, Mark. "Bad Boys and Peaceful Garifuna." In Neither Enemies nor Friends, by Anani Dzidzienyo and Oboler Suzanne, 101-115. New York: Palgrave Macmillian, 2005. DeScipio, Louis. "Transnational politics and civic engagement : do home-country political ties limit Latino immigrant pursuit of US civic engagement and citizenship?" In Transforming politics, transforming America : the political and civic incorporation of immigrants in the United States, by S. Karthick Ramakrishnan, and Ricardo Ramà ­rez Taeku Lee, n/a. Charlottesville: UVA Press, 2006. Lewis, Hope. "Transnational Dimensions of Race in America." Albany Law Review, 2009: 999-1028. Sawyer, Mark Q. Racial Politics in Post-Revolutionary Cuba. New York City: Cambridge University Press, 2006.

The Great Depression Essay -- Economics Finance History Economy Essays

The Great Depression The Great Depression was an economic slump in North America, Europe, and other industrialized areas of the world that began in 1929 and lasted until about 1939. There were a few main areas of focus during the Great Depression. The key areas were the Crash of the Stock Market, Unemployment Rate, the effect on the rest of the world, World War II and our political out look and the way different countries handle themselves today. The Great Depression was the longest and most severe depression ever experienced by the industrialized Western world. Though the U.S. economy had gone into depression six months earlier, the Great Depression may be said to have begun with a catastrophic collapse of stock-market prices on the New York Stock Exchange in October 1929, when President Hoover came in office. During the next three years stock prices in the United States continued to fall, until by late 1932 they had dropped to only about 20 percent of their value in 1929 (www.english.uiuc.edu). Some of the stock figures I received from (www.huppi.com) indicate the changes of the Gross National Product from 1930 until 1939. The Gross National Product, or GNP, for 1930 had a negative change of 9.4 percent. In 1931, the GNP continued to decline another 8.5 percent. In 1932 it dropped another 13.4 percent and continued to drop 2.1 percent in 1933. In 1934 the GNP made a turn for the better and started to increase by 7.7 percent and continued to rise in 1935 with an increase of 8.1 percent. During 1936 and 1937 the GNP rose for a combined amoun t of 19.1 percent but do to the beginning of recession in 1938 it had a drop of 4.5 percent. Once Recession ended the GNP went up 7.9 percent in 1939. (Www.english.uiuc.edu) tells us that besides ruining many thousands of individual investors, this precipitous decline in the value of assets greatly strained banks and other financial institutions, particularly those holding stocks in their portfolios. Many banks were consequently forced into insolvency; by 1933, 11,000 of the United States' 25,000 banks had failed. The failure of so many banks, combined with a general and nationwide loss of confidence in the economy, led to much-reduced levels of spending and demand and hence of production, thus aggravating the downward spiral. â€Å"The result was drastically falling output and drastically rising unemployment; ... ...its were contracting it; The Fed's inaction was the reason why the initial recession turned into a prolonged depression; The economy continually sank throughout Hoover's entire term. Under Roosevelt's New Deal, it rose five out of seven years. Attempts to blame Big Government for the Depression do not withstand serious scrutiny; The Smoot-Hawley Tariff had a minor impact because trade formed only 6 percent of the U.S. economy, and reducing trade gave Americans only that much more money to spend domestically. Hoover's other attempts at government intervention came mostly during his last year in office, when the Depression was already at its depth; The first nations to come out of the Great Depression were Sweden, Germany, Great Britain, and then everyone else did so after they adopted the Keynesian solution of heavy deficit government spending and the Keynesian economic policies have eliminated the depression from the world's economies in the six decades that have followed. Works Cited WWW.huppi.com WWW.english.uiuc.edu Nelson Cary Kennedy, David Freedom From Fear: The American People in Depression and War Oxford, New York 1999 Oxford University Press   Ã‚  Ã‚  Ã‚  Ã‚  

My Educational Philosophy :: Philosophy of Education Teaching

My Educational Philosophy ABC†¦123†¦, think about all the times throughout the day that the use of something as simple as the ABC’s and the 123’s. Who was it that teaches those things that we deem as so simple now? It was teachers, all through out school they teach children not only the basics like reading writing and arithmetic, but they also teach how to grow up and be a functioning person in the complex world that is all around. In this paper I will explain why I want to teach, the philosophies that I plan to use and my educational goals. Many people in the teacher education program have known all their lives that they wanted to teach, but not me. I have changed my mind numerous times and each time the reason is because I can’t imagine myself doing that given profession for the rest of my life. However, I had never actually considered teaching until the summer before my senior year. I got the opportunity to volunteer at a local day care center and work with children from the ages of 3 months through 12 years. It is that summer that completely changed my mind on what I wanted to do the rest of my life. The first reason that I decided that I want to teach is for the simple fact of getting to shape young minds and change lives. The influence that teachers have over their pupils is amazing, I can remember all of my teachers individually and how many people do you meet and can remember them 12 or 13 years later? It is not only an awesome opportunity is an enormous responsibility, one that I am excited and also a little scared about taking on. Not only do teachers teach children, they also have an influence on the parents that they come in contact with. Getting the parents involved is a vital part of teaching, if you can get the parents excited about the child’s learning then they will encourage the child. In the elementary years children tend to look towards their parents and react in the same ways they do about situations that they encounter. Having the parents involved not only gives the children encouragement, teachers can change the ways that parents do things. If the child’s parent didn’t have guidance as children then they probably don’t know how to encourage and guide their own children, but teachers can change all that by keeping them involved and interested.

The Business Activities Study

This case study is related to the business activities of a hedge fund which performs a macro investment strategy. Its investment manager Troy Dexter seeks for profits which arise from shifts in the real economy. As he considers an end of the Australian housing market boom as likely, he anticipates that Australia's overall economic growth will slow down, whereas the prices for energy will go up. In reaction to those expectations he decides to purchase treasury bonds and stocks of energy companies Against this background Case Study 1 is aimed at classifying Troy Dexter's two investment decisions as either direct or indirect investments. Such a classification provides different results depending on the party from whose perspective it is assessed. Thus, it is the purpose of the following section of this work to distinguish between the terms direct and indirect investment based on the corresponding point of view using practical illustrations whenever possible. This is to be done after clarifying key terms associated therewith first. Term definition A hedge fund is an alternative investment vehicle which excessively uses financial instruments such as derivatives and leverage and in which an aggressive management strategy is usually applied (Fung & Hsieh, 2004). As Capocci and Hà ¼bner (2004) state, a hedge fund's major purpose is to generate active return (called alpha) for its typically wealthy investor base. As hedge funds are less exposed to capital market regulation than other fund types, they are able to generate – on average – higher returns, but associated with higher levels of risk as well (Lederman, 2012). Troy's decision to purchase energy stocks is related to his expectation of rising oil prices. Given his expectation turns out to be correct, the share price of oil producing companies will increase. The term â€Å"energy stock market†, however, comprises not only oil producing companies, but all other kinds of energy producing firms, as well as energy infrastructure and energy service providers, too (Henriques & Sadorsky, 2008). As Henriques and Sadorsky (2008) note, a rise in the oil price will not only increase the share price of oil and gas producers, but also the market value of those firms which offer substitutes (e.g. solar and wind energy) will increase. This holds as their products become more competitive in such an environment and their turnover is likely to increase. Stockholders who have purchased such stocks directly for their own stock portfolio before a rise in the oil price has taken place, will profit. Their profits, on the one hand, consist of the 4 chance to sell those shares at a higher price at the stock market and, on the other hand, of (increased) dividend payments (Bodie, 2013). Treasury bonds purchased in the debt market are usually characterized by less risk than any kind of stock market investment (Sharpe et al., 1999). Given Troy's expectation about the future economic environment of Australia, his decision to purchase such long-term fixed interest debt instruments is reasonable. This holds as they are issued by the Australian government which is very unlikely to default (Chaudhuri ; Smiles, 2004). On the contrary, as the Australian government has several tools at hand which allows it to make interest payments as promised (e.g. increase taxes), a treasury bond is considered as one of the safest investment forms available in the market (Hull et al., 2005). Investors who have decided to hold treasury bonds in their stock portfolio (direct security investment) can expect a fixed interest on their investment. The historic development of the Australian 10-year treasury bond is illustrated below.   Source: Reserve Bank of Australia, 2017. From this graph it can be derived that the long term trend of Australian treasury bonds is downward sloping. Starting from a level of more than 10.0% in 1995, the interest rate went down to about 3.0% in 2013. Interest rates in the short run are stagnating on a relatively low level of about 3.0%. Based on the fact that Troy Dexter has founded the hedge fund in 2009, it can be stated that his decision was right in the short run: Interest rates, indeed, went up from 4.0% to 6.0% between January 2009 and January 2010. However, it has to be noted that in the subsequent years his expectation turned out to be incorrect: Starting from January 2011, interest rates on the Australian 10-year treasury bond went down to about 3.0% in January 2013. This implies for Troy Dexter as the fund manager that his hedge fund may have generated losses from 2011 onwards as the interest rate of Australian treasury bonds have lacked his expectations. The figure adds value to the topic of this work as it illustrates that the fund manager's decision to invest in treasury bonds could not have been a smart decision in the long run: Fund investors are indirectly suffering from this decision as they have decided to provide Troy Dexter with parts of their funds which are now invested in a non-optimal security. 1. Direct vs. indirect securities – Northwest Capital Management perspective In order to classify Northwest Capital Management's investments in treasury bonds and energy stocks from the firm's perspective, one has to understand the business concept of capital management firms first. Firms such as Troy Dexter's hedge fund business aim at professionally managing private investor's funds. They do so by investing customers' money in a broad range of asset classes, restricted by particular investment goals (Fung ; Hsieh, 2001). However, as Brav et al. (2010) notice, the service such firms provide is not just related to the optimum asset allocation, but financial statement analysis as well as the monitoring of existing investments plays an important role, too. Hedge funds – in contrast to more conservative capital management firms – invest a relatively high percentage of its assets in risky asset classes such as the stock market of even emerging market economies (Jansen et al., 1998). The portfolio composition of an exemplary hedge fund is illustrated in the graph below. Source: Blair, 2001. The figure above already reveals that it is the hedge fund manager Troy Dexter who is responsible for the investment decisions of his fund and who chooses between the above asset classes (asset allocation). It is important to understand that the private investor is not involved in the daily investment process of the hedge fund, but hands over any responsibility for the invested amount of money to Troy Dexter. 0.50% 0.50% 31% 19% 15% 14% 7% 6% 3% 2% 2% Strategy composition of a hedge fund Short selling Other Equity long/short Macro Relative value arbitrage Event driven Fixed income Convertible arbitrage Distressed securities/high yield Equity markets neutral Emerging markets 6 Derived from this line of reasoning it can be stated that Troy Dexter's intended purchase of treasury bonds and energy stocks can be considered as a direct securities investment from the firm's point of view. This holds, because there is no third party involved in Troy's securities acquisition process (Bodie, 2013). In contrast, it is likely to be assumed that Troy himself owns a trading platform which he can use to exercise any stock market transactions personally and immediately. Even if Troy does not own such a trading platform, the consultation of a stock broker can still be considered as a direct securities investment from Northwest Capital Management's point of view. This holds because a stock broker can simply be considered as an entity which executes buy and sell orders on behalf of someone else for a particular fee or commission (Pollock et al., 2004). As Pollock et al. (2014) note, brokers are not allowed to alter the order, but execute the transaction only. 2. Direct vs. indirect securities – Investor perspective Taking the viewpoint of an investor in Troy Dexter's hedge fund, Troy's investment decisions can clearly be considered as indirect investments. As stated above, the fund manager decides about the allocation across available asset classes. The investor knows about the financial risks tied to Troy's investment decisions from the prospectus and may have expectations about a desired return, but cannot alter Troy's daily sell and buy orders. However, this would be a vitally important characteristic of a direct securities investment. As soon as customers have decided to invest in the fund, they have to sign a declaration of consent in which they transfer the responsibility for managing their funds to the portfolio management team (in our case to Troy Dexter) (Philpot ; Jonson, 2007). Not the investors themselves engage a broker who carries out financial market transactions, but Troy Dexter does that on behalf of them using his financial market knowledge. In this context it is important to note that – although restrictions are less strict in a hedge fund – fund managers have to stick to the proposed fund objective and are not allowed to invest in anything which is not related to the praised goal of the fund, although it may be a lucrative investment (Philpot ; Jonson, 2007). This assignment of any kind of right to alter the investment decision related to maximizing investors' own monetary wealth underpins the indirect nature of a fund investment from an investor's point of view. The incentives for customers of Northwest Capital Management to provide Troy Dexter with the rights to manage their savings on behalf of them (indirect investment) is related to Troy Dexter's expertise about financial markets (Capon et al., 1996). Additionally, as Capon et al. (1996) state, the pooling of large amounts of money in the hedge fund provides customers with a lot more market power than they would have when investing on their own. This shows that although private investors cannot actively decide about each investment decision on their own, the indirect securities investment through Troy Dexter's Northwest Capital Management is utterly worthwhile for its investor base. It can be summarized that investing in a hedge fund implies no direct securities investment from the private investors' perspective. This is compounded by the fact that private investors of a hedge fund do not own any securities themselves (Droms & Walker, 1996). Instead, those securities are entirely controlled by the fund managers who either own a trading platform themselves or contact brokers to carry out deals which are likely to benefit the fund's investor base. Shareholders are not able to access the fund's existing investments on a daily basis, but have to rely on the fund managers' expertise (Droms ; Walker, 1996). This trust, however, may be the basis for higher returns compared to investing individually on any kind of capital market. 7 Furthermore, the indirect securities investment from the investor's point of view implies that each single investor gains or loses proportionally to his or her investment in Troy Dexter's hedge fund. This fact stands in sharp contrast to a direct securities investment in which an investor is on his own and has a claim on any gains and losses related to this investment (Bodie, 2013). Instead of having the chance to convert profits right away in a direct securities investment, an indirect investment via a fund prohibits an investor from this right and makes him dependent on the decisions of the fund manager. Recommendations: A common way of how to classify securities is to divide them into either direct or indirect securities. In this context it is of particular importance to distinguish between either an investment manager's or a private investor's perspective (Davis, 2004). Conclusion: The statements above have shown that the classification of any kind of investment as being either direct or indirect depends on the party from whose perspective such a classification is made. In the case of a hedge fund one can categorize an investment as an indirect one from the investor perspective and as a direct one from the fund manager's perspective. This holds as it is not the investor who makes any kind of investment decision, but the fund manager on his behalf. The investor puts trust in the fund manager's capital market expertise when deciding to invest in a fund and – at the same time – cedes any kind of rights to alter the fund manager's perspective on the future development of the capital market. In contrast, the fund manager, on a daily basis, has to directly â€Å"step† in the capital market and has to sell or buy certain types of investments. References Blair, F. (2001): Managing the equity portfolio: South-Western College Publishing. Bodie, Z. (2013): Investments: McGraw-Hill. Brav, A.; Jiang, W.; Kim, H. (2010): Hedge fund activism. A review. In: Foundations and Trends in Finance 4(3), p. 185–246. Capocci, D.; Hà ¼bner, G. 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