Bacteriophage Life Cycle Animation

Bacteriophage Life Cycle Animation Bacteriophages are viruses that infect​ bacteria. A bacteriophage can have a protein tail attached to the capsid (protein coat that envelopes the genetic material), which is used to infect the host bacteria. All About Viruses Scientists have long sought to uncover the structure and function of viruses. Viruses are unique they have been classified as both living and nonliving at various points in the history of biology. A virus particle, also known as a virion, is essentially a nucleic acid (DNA or RNA) enclosed in a protein shell or coat. Viruses are extremely small, approximately 15 - 25 nanometers in diameter. Virus Replication Viruses are intracellular obligate parasites, which means that they cannot reproduce or express their genes without the help of a living cell. Once a virus has infected a cell, it will use the cells ribosomes, enzymes, and much of the cellular machinery to reproduce. Viral replication produces many progeny that leave the host cell to infect other cells. Bacteriophage Life Cycle A bacteriophage reproduces by one of two types of life cycles. These cycles are the lysogenic life cycle and the lytic life cycle. In the lysogenic cycle, bacteriophages reproduce without killing the host. Genetic recombination occurs between the viral DNA and the bacterial genome as the viral DNA is inserted into the bacterial chromosome. In the lytic life cycle, the virus breaks open or lyses the host cell. This results in the death of the host. Bacteriophage Life Cycle Animation Below are animations of the lytic life cycle of a bacteriophage.Animation AThe bacteriophage attaches to the cell wall of a bacterium.Animation BThe bacteriophage injects its genome into the bacterium.Animation CThis animation shows the replication of the viral genome.Animation DBacteriophages are released by lysis.Animation ESummary of the entire lytic life cycle of a bacteriophage.

How Express Opinions in French

How Express Opinions in French If you want to have a debate in French or discuss your opinions, you need to know the relevant vocabulary and expressions. This page offers suggestions for offering, supporting, asking for, and avoiding opinions in French.Of course, the subject pronoun je, object pronoun me, stressed pronoun moi, and possessive adjective mon in these expressions can all be replaced to express other opinions than your own. Offering an Opinion   Ã‚  Ã‚   mon avisIn my opinionCest du moins mon opinion.At least, thats my opinion.Daprà ¨s moiIn my viewEn ce qui me concerneAs far as Im concernedIl est / Cest certain queIts certainIl est / Cest clair queIts clearIl est / Cest à ©vident queIts obviousIl est / Cest impossible queIts impossibleIl est / Cest injuste queIts unfairIl est / Cest juste queIts fairIl est / Cest possible queIts possibleIl est / Cest probable queIts probableIl est / Cest sà »r queIts surelyIl est / Cest vrai queIts trueIl me semble queIt seems to meJai lidà ©e queI have the impressionJai limpression queI have a feelingJe considà ¨re queI feelJe crains quil ne soitI fear that it isJe crois queI believeJe dois dire queI must sayJestime queI consider itJimagine queI imagineJe pense queI think (that)Je suppose queI supposeJe ne pense pas.I dont think so.Je ne peux pas mempà ªcher de penser queI cant help thinkingJe suis certain queIm certain thatJe suis convaincu queIm convinced thatJe suis davis queI m of the opinionJe suis persuadà © queIm convinced thatJe suis sà »r queIm sureJe trouve queI find, I feelMoi, je... As for me, I...PersonnellementPersonallyPour ma partFor my partPour moiIn my viewQuant moiAs for meSans vouloir vous contredireWithout meaning to contradict youSelon moiIn my viewSi vous voulez mon opinion/avisIf you want my opinionTelle est mon opinion sur...Thats my view of/on... Supporting an Opinion   Ã‚  Ã‚  Jai entendu dire que dependent clauseI heard thatJai entendu parler de nounI heard aboutJe sais / Nous savons queI / We know thatOn dit queOne says, They sayPar exempleFor example Asking for an Opinion   Ã‚   votre avisIn your opinionAvez-vous une opinion surDo you have an opinion aboutComment percevez-vousHow do you viewJaimerais connaà ®tre / avoir votre avis / opinion surId like (to know) your opinion onJaimerais connaà ®tre / avoir votre rà ©action face Id like (to know) your reaction toJaimerais / Je voudrais savoir ce que vous pensez deId like to know what you think aboutJe voudrais connaà ®tre / avoir votre avis / opinion surId like (to know) your opinion on/aboutJe voudrais  connaà ®tre / avoir votre rà ©action face Id like (to know) your reaction toPourriez-vous me donner / faire  savoir votre avis/opinion surCould you give me your opinion aboutPourriez-vous me donner / faire  savoir votre rà ©action face Could you give me your reaction toPourriez-vous me dire ce que vous pensez deCould you tell me what you think aboutQuelle est votre attitude là ©gard deWhat is your attitude toward/toQuelle est votre opinion/avis surWhat is your opinion aboutQue pensez-vo us deWhat do you think aboutSelon vousIn your opinion Avoiding Expressing an Opinion   Ã‚  Ã‚  Cela dà ©pend deThat depends onCest une question de point de vue.It all depends on your point of view.Il est / Cest difficile deIts hard toIl mest impossible de donner un avis (dà ©finitif) surI cant express a (definite) opinion onJe nai jamais vraiment rà ©flà ©chi I have never really thought aboutJe nai pas dopinion bien prà ©cise / arrà ªtà ©e surI dont have strong feelings aboutJe ne me le suis jamais demandà ©.Ive never wondered about it.Je ne me suis jamais vraiment posà © la question.Ive never asked myself that question.Je ne suis pas mà ªme de dire siIm not in a position to say whetherJe prà ©fà ©rerais ne pas (avoir ) me prononcer surId rather not commentJe prà ©fà ©rerais ne pas mengagerId rather not commit myselfJignore tout deI know nothing aboutTout dà ©pend deIt all depends on

See the attachement and decide which question you are familiar with Essay

See the attachement and decide which question you are familiar with - Essay Example As stated by Lord Sainsbury, Parliamentary Under-Secretary of State at DTI, the purpose of the Act is to â€Å"to constantly update company law in response to changes in the way companies do business†1. According to Lord Sainsbury, the Act has four key objectives: It cannot be gainsaid that minority shareholders occupy a vulnerable and precarious position in the hierarchy of the corporate structure. The dilemma that of how one is to go about preserving their rights and granting them protections is akin to the dilemma that faces a democratic polity: while the will of the majority is a foremost consideration and indeed is the most equitable way to resolve disputes and frame policies, there is an equally compelling and equally valid need to have regard for the interests of those in the minority – marginalized sectors who face constant threat of being disenfranchised in a system founded on justice and fairness. The part of the Act that is most relevant to shareholder engagement is Part 11, which provides shareholders with, as stated in paragraph 480 of the Explanatory Notes, â€Å"a new procedure for bringing such an action which set down criteria for the court distilled from the Foss v Harbottle jurisprudence". 2 The Act essentially expands the existing derivative action, and allows shareholders to sue the directors for a wider range of breaches, namely in respect of an actual or proposed act or omission involving negligence, default, breach of duty or breach of trust. Another significant change is that a shareholder who has brought proceedings must apply to court for permission to continue the claim. The following criteria must be followed by the court in considering whether or not refuse permission are as follows: The Act also contains restrictive provisions on the issue of ratification by the majority. Members who are personally interested in the

Research Paper on Criminal Profiling Example | Topics and Well Written Essays - 2000 words

On Criminal Profiling - Research Paper Example This approach is used by professionals in the criminal justice system in identifying and capturing criminals. Often, criminal profiling is conducted by the forensic psychologists who provide criminal profile to the police departments to help in apprehending of the criminals (Kocsis, 2010). Statistical evidence, psychology, and crime scene analysis are combined in developing a personality type that fits well with the committed crime. Criminal profiling is in most cases used in helping investigators to apprehend serial killers and psychopaths who may otherwise go free (Canter, 2004). In addition, it helps in catching other types of offenders such as rapists and arsonists. The approach helps to label the offenders or perpetrators as disorganized, organized, or mixed. Criminal profiling is not only essential in finding potential offenders, but also in narrowing down the offenders’ list already compiled by the police (Devery, 2010). This paper will discuss criminal profiling by cri tiquing the foundations of criminal profiling and by comparing and contrasting inductive versus deductive profiling. 1) Critique the Foundations of Criminal Profiling Criminal profiling has proved to be an important tool in controlling of crime in recent years. Prior to the inception of criminal profiling, criminal investigators mainly relied on the physical evidence to identify and apprehend criminals (Holmes and Holmes, 2009). However, this changed after the inception of criminal profiling that provided advanced techniques in developing theories and compiling evidence based on the of patterns of criminal behavior, crime scene evidence, criminal’s socioeconomic background, motives of crime, and psychological aspects of violent crime (Alison et al, 2010). The foundations of criminal foundations since its inception aimed at detecting and classifying the major behavioral and personality characteristics of a person based on the crime analysis or the crimes that have been committ ed (Holmes and Holmes, 2009). The first foundation of criminal profiling is determining offender characteristics by using the process of assimilation phase where all the available information relating to crime scene, witnesses, and victim is examined. Police reports, autopsy reports, witness statements, victim profiles, and photographs of the crime scene are important aspects of this process (Kocsis, 2010). Criminal profiling is also founded on the principle of classification which involves integration of collected information into a framework that classifies the offender as organized, disorganized, or mixed. Organized offenders are those that plan their crimes, leave little forensic clues or evidence, exhibit advanced social skills, and display some element of control over the victim through the use of social skills (Canter, 2004). On the other hand, disorganized offender is the one that exhibit few social skills, has haphazard behavior, attempts to avoid detection, lack planning, impulsive, and the offenses committed are deemed opportunistic. Additionally, integration of information would classify the offender as mixed offender who exhibits some elements of organized and disorganized offenders (Alison et al, 2010). In addition to classification, criminal profiling is also founded on the notion that there is need for the reconstruction of the crime behavioral sequence. Following classification

The cultural impact of computer recording on popular music Essay

The cultural impact of computer recording on popular music - Essay Example ement of old analogue machines used in music recording by computers should be considered as unavoidable since computers ‘are able both to store and reproduce sound much more accurately than the old analogue machines’ (Dawe 2004, 125). Another important aspect of the introduction of computers in music recording is highlighted in the study of Dawe (2004); in accordance with the above researcher, the use of computers in music recording allowed the increase of production of music (Dawe 2004, 19) – reference is made specifically to the pop music which has been mostly benefited by the involvement of computers in the specific field. In any case, the introduction of computerized systems in music recording increased the potentials of music producers for the production of high quality music – referring to the advanced features available to the music producers compared to the past where the time required for the recording of a music piece could be significant mostly b ecause of the limited technical potentials of the analogue systems – which were used in music recording up to the introduction of the computer systems in the particular field (Baldauf et al 2008, 319). The above fact is also highlighted in the study of Gordon (2005) who noted that the production of music of improved quality – referring to the aesthetic aspect of each music piece, is another benefit of the use of computerized systems in music recording (Gordon 2005, 184). Moreover, it is noted that the introduction of advanced computerized systems in the music recording supported the development of certain brands – mostly those related to the clothing/ accessories of pop music; the volume of pop music produced was increased and its expansion globally made easy; industries which were depended on the pop... This "The cultural impact of computer recording on pop music" essay outlines that the involvement of computer in the production and the process of pop music changed it. Important aspect is highlighted in the study of Dawe (2004); in accordance with the above researcher, the use of computers in music recording allowed the increase of production of music (Dawe 2004, 19) – reference is made specifically to the pop music which has been mostly benefited by the involvement of computers in the specific field. The introduction of computerized systems in music recording increased the potentials of music producers for the production of high quality music – referring to the advanced features available to the music producers compared to the past where the time required for the recording of a music piece could be significant mostly because of the limited technical potentials of the analogue systems – which were used in music recording up to the introduction of the computer sy stems in the particular field. The above fact is also highlighted in the study of Gordon (2005) who noted that the production of music of improved quality is another benefit of the use of computerized systems in music recording (Gordon 2005, 184). Apart from the historical development of music recording, the sociological aspects of the specific activity are also important for understanding its cultural context, especially in regard to the freedom provided to music producers to produce and sell their music pieces in the international market.

Theories and a biopsychology of addiction

Theories and a biopsychology of addiction The biopsychology of addiction examines the interaction of biological aspects associated with addictive behaviors. The word addiction comes from the Latin verb addicere meaning to enslave (Yucel, Lubman, Solowij, Brewer, 2007). The Diagnostic and Statistical Manual, Fourth Edition-Text Revision identifies drug addiction as a dependence syndrome with essential features of a lack of control over drug use despite significant drug-related problems (Kranzler Li, 2008). The prevalence and problems associated with drug addiction cost an estimated $524 billion a year, including health care, productivity loss, crime, incarceration, and drug enforcement (NIDA, 2009). Advanced research confirms that addiction is a disease because it alters the brain. It shares common attributes with other chronic diseases, such as heart disease and diabetes. The underlying concept is that there is a disruption in healthy functioning that results in serious, harmful consequences, although treatable, that can potentially last a lifetime (NIDA, 2009). Recreational drug use usually begins in adolescents at a stage in development most vulnerable to executive functioning impairment. Executive functioning impacts decision making, judgments, and emotional regulation. Brown, et al. (2008) found an increase in drinking during the age span between 16 to 20 years that fuels neurological damage and social impairments. Beckson (2005) reported an increase in adolescent drug use. Preven tion of drug addiction needs to start during adolescents because it usually begins during this stage in development. The goal of this paper is to explore multiple factors related to the biopsychology of addiction, including the molecular level of synaptic neuron communication, neurotransmitters, brain anatomy, drugs of abuse, relapse, and long-term effects of addiction. The genetic and environmental influences along with stress play significant roles in drug addiction. Theories of addiction exist with a growing agreement among experts that the Incentive Sensitization Theory of Addiction provides the best explanation. Robinson and Berridge (2003) describe several theories. Opponent Process Theory of Addiction The first theory described by Robinson and Berridge (2003), is the Opponent Process Theory of Addiction representing the traditional view of addiction. Pinel (2009) refers to this theory as the Physical-dependence Theories of Addiction. Initially drugs are taken for the positive feelings, but gradually build tolerance and dependence to the drug. Withdrawal symptoms begin and compulsive drug cravings take over. Drug use continues in an effort to avoid negative withdrawal symptoms and achieve the pleasurable effects again. Other names for this traditional theory of addiction include pleasure-pain, positive-negative reinforcement, opponent process, hedonic homeostasis, hedonic dysregulation, and reward allostasis (Robinson Berridge, 2003). Limitations exist with this theory because not all drugs, such as heroin, produce serious withdrawal symptoms. A major argument against this theory is that after a period of abstinence the rate of relapse remains high despite the lack of withdrawal s ymptoms. Positive-incentive Theory of Addiction Another theory described by Robinson and Berridge (2003) involves aberrant learning suggesting that drugs create a strong connection to natural reward centers based on learning through classical conditioning. Pinel (2009) refers to this theory as the Positive-incentive theories of drug addiction. Explicit learning as a subcategory of aberrant learning describes the learning process through declarative associations at a conscious level between actions and outcome. Explicit learning also involves the declarative predictive relationships between environmental cues and expectation or anticipation of rewards, such as drugs. Declarative learning does not sufficiently explain the transition from recreational drug use to drug addiction. Addicts do not report exaggerated declarative memories or expectations of drug pleasure because they know the pleasure gained is not worth the consequences suffered (Robinson and Berridge, 2003). Implicit learning as a second subcategory of aberrant learning describes the unconscious procedural learning that occurs automatically by pairing a stimulus and response. Drug use becomes an automatic response through the corticostriatal loops operating through the dorsal striatum (Robinson Berridge, 2003). The aberrant learning theory does not hold up under scrutiny either because implicit learning does not actually generate an automatic response, such as tying your shoe, because it is compulsion that motivates the continuation of drug use and drives the cycle of addiction. Incentive Sensitization Theory of Addiction The Incentive Sensitization Theory of Addiction best explains the transition from drug use to drug addiction. According to Robinson and Berridge (2008), the theory states that repeated drug use changes brain cells and brain neural circuitry creating a hypersensitivity to repeated drug use and associated drug cues. Incentive sensitization generates a pathological motivation or wanting of drugs that last for years, even after abstinence. The wanting of drugs may be implicit by an unconscious wanting or explicit by a conscious craving. The addicts focus on drugs is created from an interaction between incentive salience mechanisms with associated learning mechanisms. Pathological motivation generated from sensitization of brain circuits stems from a Pavlovian conditioned incentive or motivational process, known as incentive sensitization. Associative learning can trigger the motivation for drugs through incentive attributes, such as within the context of associated drug experiences and i nteractions. The pathological motivation drives the addict to seek and obtain drugs at any cost. However, the stimulus-response learned association does not fully explain the core problem of addiction. Damage or dysfunction in cortical regions creates changes in executive functioning resulting in impairments. These impairments play an important role in the addicts poor choices about drugs coupled with pathological incentive motivation for drugs triggered through incentive sensitization. Sensitization specifically refers to the increase in drug effect caused by repeated drug use. Incentive sensitization is essence of the theory. Engagement of brain incentive or reward systems, include the mesotelencephalic dopamine systems. It is the hypersensitivity in the motivation circuitry that contributes mostly to the addictive wanting of drugs. Evidence in favor of the incentive sensitization from past studies includes three features of incentive stimulus: Pavlovian conditioned approach to behavior, Pavlovian instrumental transfers, and conditioned reinforcement. The sensitization related changes in the brain are important for the transition from casual to compulsive drug use. Changes in the brain include a much larger increase in the density of dendritic spines on medium spiny neurons in the core of the nucleus accumbens. It relates to development of psychomotor sensitization. Studies further indicate that the neural changes underlying sensitization may be sufficient to promote subsequent addict-like behaviors. The essential factor in addiction is neural sensitization. Nature versus Nurture On the one hand, a genetic predisposition toward drug addiction appears evident for a substantial number of individuals. Researchers are continuing to identify specific genes related to drug addiction. The use of Quantitative Trait Locus Mapping contributes to identify specific genes for the risk and protection against addictive behavior (Crabbe, 2002). On the other hand, the learning hypothesis suggest drugs promote the learning of strong stimulus-response habits leading to compulsive behavior paired with rituals involved in consuming drugs (Robinson Berridge, 2008). Associative learning occurs in drug addiction through Pavlovian conditioning. The motivation for drugs becomes incentive sensitive when encountering familiar associations within the context and surrounding of the drug use, friends, location, and the like. Churchland (2004) argues that everything we know is the result of both our genetic makeup and our environmental experiences. Science has shown that development depends upon both genes and experience. Genes produce the hardware and experience provides the software. Learning occurs through genetic unfolding that generates changes in cells through memory systems of learning experiences constructed from environmental experiences. Our brain neuromodulators act upon synapses and become strengthened with repeated exposure that provides the foundation for learning. According to Kranzler and Li (2008) drug addiction stems from a combination of genetic, environmental, social, and psychological factors. The study of addiction involves multiple disciplines, including neuroscience, epidemiology, genetics, molecular biology, pharmacology, psychology, psychiatry, and sociology. It is not a matter of nature versus nurture, but more accurately nature and nurture. It is well known that addiction stems from a genetic predisposition and environmental stress and influences. Li, Mao, and Wei (2008) report that an estimated 40% to 60% of genetic factors appear responsible for drug addiction and the remaining percentage of factors relate to environmental factors. Genes and common pathways appear to underlie drug addictions. In a study conducted by Li, Mao, and Wei (2008), an extensive review of the genetic research associated with drug addiction resulted in the creation of the Knowledgebase of Addiction-Related Genes (KARG). The KARG is the first database of a bioinformatic compilation of genetic research on addiction. Through statistical analysis of the database, the authors found five common pathways in addiction, including neuroactive ligand-receptor interaction, long-term potentiation, GnRH signaling pathway, MAPK signaling pathway, and Gap junctions. Advances in science from the use of new technology, such as tillingarray and proteomics, provid e new avenues in studying the underlying pathways and genetic composition of addiction and how addiction forms from environmental influences. Brain Communication Chemical messengers called neurotransmitters carry information across tiny spaces, called synapses that exist between neurons (Cruz, Bajo, Schweitzer, Roberts, 2008). The brain communicates through electrical and chemical signals transmitted from neuron to neuron. A neuron represents the brains communication network. A neurotransmitter is released from one neuron into the synapse within 20 to 50 nanometers of the receiving neuron (Lovinger, 2008). The releasing neuron is referred to as presynaptic neuron and has at the tip of its axon terminals small pockets known as vesicles. These vesicles contain neurotransmitters that release molecules when activated by the action potential stimulated by the presynaptic neuron. The neurotransmitter is released into the synaptic gap between the two neurons. The post-synaptic neuron receives the neurotransmitter and binds it to the receptor site. According to Lovinger (2008) two major categories of neurotransmitter receptors, include the ligand-gated ion channel (LGIC) receptors and G-protein-coupled receptors (GPCR). The LGIC produces an excitatory or an inhibitory reaction depending on the action potential. The GPCRs represent proteins that bind neurotransmitter molecules and activate intercellular reactions. Once the neurotransmitter is released it becomes rapidly removed by neurotransmitter transporters. The neurotransmitter transporters are housed on the surface of the neurons cell membrane and rapidly retrieve the neurotransmitter pulling it inside the neuron. The uptake reloads the neurotransmitter into vesicles and the cycle repeats. Other brain chemicals exist, such as neurotrophins and steroid hormones. Lovington (2008) describes neurotrophins as peptides or amino acids secreted from different neuron structures, such as axon terminals and dendrites. Neurotrophins support neurons and assist in synaptic plasticity and neuron survival. Many are located within the central nervous system and the neural mechanisms that contribute to addiction (Lovinger, 2008). Steroid hormones represent small molecules that assist with intercellular communication. These hormones are found throughout the central nervous system as well. Lovinger (2008) further describes agonist as molecules that bind to and activate receptors. Antagonists also bind to neurotransmitter receptor sites by competing and blocking receptor activation. Many molecules serve as neurotransmitters, such as the amino acids, glutamate, and glycine. Histamines and different peptides also act as neurotransmitters. Neurotransmitters play a significant role in addiction. Neurotransmitters Fitzell (2007) defines neurotransmitters as molecules in the brain that transmit chemical reactions in order for neural communication to occur. There are approximately 100 billons neurons in the brain. Neurons release neurotransmitters from one neuron to the next via a presynapitc nerve terminal and receptor site at the synapse. The releasing of a neurotransmitter either triggers a message to other neurons in a chain reaction or a message to disengage signals. There are several neurotransmitters that activate specific receptors site referred to as fitting a key into a lock (Fitzell, 2007). The neurotransmitters include noradrenaline (norepinephrine), and adrenaline (epinephrine), acetylcholine, GABA, glutamate, dopamine, serotonin, opioids and other peptides, and endocannbinoids. Endorphins and enkephalins produce natural opiates in the brain related to intense pleasure. Noradrenaline (norepinephrine) has a stimulating effect on the brain. It is responsible for regulating the heart, breathing, body temperature, and blood pressure. It also may play a role in hallucinations and depression (Fitzell, 2007). Adrenaline (epinephrine) controls paranoia and the fight-or-flight response. It is also responsible for our appetite and feelings of thirst (Fitzell, 2007). Acetylcholine is responsible for muscle coordination, nerve cells, memory, and is involved in the transmission of nerve impulses in the body (Fitzell, 2007). It has a significant role in reaction to stress. GABA is found throughout the brain and in numerous sensory neurons (Cruz, Bajo, Schweitzer, Roberto, 2008). It functions as a regulator of transmitting nerve signals, and it acts on receptor sites, including GPCR, by functioning as an inhibitor. Activation of the receptor sites prohibit the release of neurotransmitters. Ethanol acts as an excitatory for the release of GABA and has a role in alcohol intoxication and contributes to the brains hyperexcitable during alcohol withdrawal. Opiods, cannabinoids, and alcohol all act on GABA through the same brain regions. Glutamate functions as a major excitatory neurotransmitter in the lower brain region (Clapp, Bhave, Hoffman, 2008). It serves most brain neurons and is found throughout the brain. Two receptors, AMPA and NMDA, appear to be involved in learning and memory. Acute alcohol consumption inhibits the release of glutamate and appears to play a role in inhibiting synaptic plasticity and impairment of memory (Lovinger, 2008). Gass and Olive (2008) studied glutamates influence on drug addiction. Studies found that all drugs of abuse utilize glutamate transmissions producing a long-term neuroplasticity in the brain. Glutamate contributes to compulsive drug-seeking behavior and drug-associated memories. Dopamine serves as the most significant neurotransmitter in the brain. It is responsible for controlling our moods, energy, and feelings of pleasure (Fizell, 2007). Dopamine influences brain mechanisms of reward, evaluation of environmental stimuli, general behavioral activity level, and some brain disorders. According to Cruz, Bajo, Schweitzer, and Roberto (2008), dopamine becomes pervasive throughout the brain and is produced by only a few neurons. It is considered a pure neuromodulator because it becomes activated only by GPCRs. There are five dopamine receptor sites, D1 through D5. Half of the neurons connect to the substantia nigra pars reticulate forming the direct pathway to activating the cortex (Cruz, Bajo, Schweitzer, Roberto, 2008). The other half connect to the globus pallidus internal segmane forming the indirect pathway to slow down cortical output. Dopamine controls performance of action, including the intoxication from alcohol and other drugs (Cruz, Bajo, Schweitzer, Roberto, 2008). Many drugs target dopamine transmission, and dopamine plays a significant role with all drugs. Cocaine, amphetamine and other stimulant drugs either block or reverse the action of the dopamine transporter (Lovington, 2008). As a result, the level of dopamine in the synapse increases. Research shows that interference with dopamine transmission generates an intoxicating and addictive effect with drugs and alcohol Nicotine and alcohol stimulate dopamine. Morphine and other opiates slow GABA activity and indirectly increase the activity of dopamine. It also contributes to learning environmental cues in relation to the context of drug use that encourages drug and alcohol use. Fitzell (2007) describes serotonins role in the brain as relating to the five senses, sleep, aggressive behavior, eating, and hunger. Its release brings about a sense of calm, happiness, peace, satisfaction, signals of fullness, and reduced appetite. A decrease of serotonin or blockage in the brain cells results in aggression and violent behavior. Low levels of serotonin are associated with depression and increased appetite. Serotonin is a very powerful mood enhancer and appetite regulator located in the base of the brain (Fitzell, 2007). According to Lovinger (2008), neurons connect to other neurons through the central nervous system, including the cerebral cortex and other forebrain structures. Serotonin influences sensations related to environmental stimuli, perception, learning and memory, and sleep and mood. Serotonin activity involves 15 CPCRs that either increase or decrease neuron output. It is the target of psychoactive drugs, such as LSD, mescaline, and psilocybin that serve as agonists of serotonin. Amphetamines, such as MDMA also known as ecstasy, interfere with serotonin transporters and increase serotonin levels. It is suspected that the effect may result in sensory-enhanced effects. Alcohol appears to cause a reduction of serotonin uptake. Opioids and other peptides contribute to the brains communication by decreasing excitatory glutamate and inhibitory GABA at the cell level (Cruz, Bajo, Schweitzer, Roberto, 2008). However, GABA continues to have an excitatory effect throughout the brain producing the pain-relieving effect of opioids as well as opioid dependence. Peptides help neuromodulation of the brain through GPCRs. These peptides serve as agonists to receptor sites for morphine, heroine, and other opiate drugs (Lovington, 2008). Three opiate receptors of importance include mu-type, delta-type, and kappa-type (Befort, et al., 2008). Reduction in opioid peptide actions interfere with promoting an increase in dopamine. Lovinger (2008) describes another hormone of particular importance, the corticotrophin-releasing hormone (CRH). CRH communicates signals of stress, mood, and changes in bodily functions. CRH and its receptors play a role in stress, drug addiction, and relapse. The opioid peptides, endorphins, and enk ephalins affect mood, produce intense feelings of pleasure, and can reduce and relieve pain. Endorphins also help in managing stress. Enkephalins help the body fight pain (Fitzell, 2007). Wand (2008) describes a the stress response as involving a glucocorticoid response generated from the hypothalamic pituitary-adrenal (HPA), activation of peptides corticotrophin-releasing factor (CRF), and activation of the sympathetic nervous system releasing epinephrine and nonrepinephrine. Endocannabinoids (endogenously formed cannabinoids) and other lipid-derived neuromodulators are involved in synaptic communication and acute reinforcing effects of drugs (Cruz, Bajo, Schweitzer, Roberto, 2008). Lovinger (2008) describes the receptor site CB1 linked to GPCR as functioning to inhibit the release of neurotransmitters. CB1 acts as agonists and influences both inhibitory and excitatory synaptic transmissions (Cruz, Bajo, Schweitzer, Roberto, 2008). As a result, a decrease in several neurotransmitters occurs, including GABA and glutamate. A long-term synaptic depression may occur produced by retrograde endocannabinoid signaling. A consequence of this occurrence plays a key role in learning and memory and associated addiction (Lovinger, 2008). Brain Anatomy of Addiction The brain attempts to counteract the chemical changes caused by drug addiction. The process of neuroadaption or neuromodulation strives to reinstate homeostasis in the brain. Drug addiction influences all aspects of the brain with several significant regions serving more dominant roles. The mesotelencephalic dopamine system is a diffuse pathway consisting of dopamine neurons associated with pleasure (Pinel, 1998). Its cell bodies are connected to two structures in the midbrain tegmentum: substantia nigra or the ventral tegmental area. The axons of these two structures extend into different structures in the telencephalic sites. These structures include frontal cortex, striatum, septum, cingulated cortex, amygdala, and nucleus accumbens. The mesotelencephalic dopamine system is associated with motivation of behaviors and self-administering addictive drugs, sexual behavior, and eating (Pinel, 1998) The substania nigra is a midbrain nucleus of the tegmentum and contains cell bodies of many of the neurons of the mesotelencephalic dopamine system. Its dopaminergic neurons terminate in the striatum (Pinel, 1998). The nigrostriatal pathway is a dopaminergic tract from the substantia nigra to the striatum. The striatum is composed of the caudate and putamen and serves as the terminal of the dopaminergic nigrostriatal pathway. The ventral tegmental area is located medial to the substania nigra and contains cell body of many neurons in the mesotelecephalic dopamine system (Pinel, 1998). The nucleus accumbens is a nucleus located between the striatum and the basal forebrain. It is a major terminal in the mesotelencephalic dopamine system. It plays a critical role in the experience of pleasure (Pinel, 1998). Koob and Simon (2009) indicate that the mesocorticolimbic pathway is the brain circuit that transmits dopamine in the rewarding effects of alcohol and other drugs. The mesocorticolimbic dopamine system represents the reward system in the brain. Neural inputs and outputs interact with the dopamine projections from the ventral tegmental area to the basal forebrain (Koob Simon, 2009; Ikemoto, 2007). Pinel (1998) describes the prefrontal cortex as the large area of the frontal cortex anterior to the primary and secondary motor cortex. It consists of three large areas: dorsolateral prefrontal cortex, orbitofrontal cortex, and medial prefrontal cortex (Pinel, 1998). The dorsolateral prefrontal cortex is the large area on the lateral surface of the prefrontal lobes and plays a role in memory for temporal sequence of events but not the actual events, response sequencing, inhibiting incorrect but previously correct responses, developing and following plans of action, and creative thinking. Pinel (1998), indicates that the orbitofrontal cortex is the large area of prefrontal cortex on its anterior pole and inferior surface. Damage to the orbitofrontal cortex results in marked personality changes, an inability to inhibit inappropriate behaviors, and influences social behaviors. The medial prefrontal cortex is the area of the prefrontal cortex on the medial surface of the prefrontal lobe s that when damaged, produces a blunting affect (Pinel, 1998). Amygdala is a major structure in the limbic system. It is an almond-shaped nucleus of the anterior temporal lobe. The central nucleus of the amygdala has the highest density of enkephalins. Enkephalins are found in the cell bodies of GABA neurons, the most abundant type of neuron in the nucleus of the amygdala (Cruz, Bajo, Schweitzer, Roberto, 2008). The amygdala is responsible for the fight or flight emotional reaction. The extended amygdala signifies brain structures located near the front of the lower brain region, referred to as the basal forebrain (Befort, et al.). The extended amygdala is comprised of a number of structures, including the nucleus accumbens (NAcc), the central nucleus of the amygdala (CeA), and the bed nucleus of stria terminals (BNST). It plays a role in relation to the acute reinforcing effects of drugs and the negative effects of compulsive drug use and reward. The CeA consists mostly of GABA as inhibitory neurons with neuron connections or project to the brainstem or BNST. It is considered the gate that controls information through the intra-amygdaloidal circuits. Befort, et al. (2008) describes the central extended amygdala (EAc) as a network formed by the central amygdala and the BNST controls. It plays a significant role in drug cravings, drug-seeking behaviors, drug rewards, and drug dependence. Hippocampus is the allocortical limbic system structure of the medial temporal lobes and extends from the amygdala at its anterior end to the cingulated cortex and fornix at itsposterior end (Pinel, 1998). The basolateral amygdala mediates motivational effects of drug use and the context associated with drug use in forming emotional memories (Koob, 2009). It plays a major role in learning and memory, particularly in relation to associated drug behaviors. Feltenstein and See (2008) provide a depiction of the brain anatomy and drug related connections in the mesocorticolimbic system. Dopamine projects from cell bodies in the VTA and connect to limbic structures via the mesolimbic pathway (amaygdala, ventral pallidum, hippocampus, and NAcc, and cortical areas (mesocortical pathway, including the prefrontal cortex, the orbitofrontal cortex, and the anterior cingulated gyrus) (Feltenstein See, 2008); Ikemoto, 2007). The NAcc and ventral pallidum serve as the primary effects of drug abuse. The amygdala and hippocampus serve a role in learning as it relates to the process of addiction. The amygdala and ventral hippocampus impact learning in discrete stimulus-response associations. The amygdala and dorsal hippocampus impact learning through stimulus-to-stimulus associations important in contextual learning. The prefrontal cortex, orbitofrontal cortex, and anterior cingulate gyrus regulate emotional responses, cognitive control, and executive functioning (Feltenstein See, 2008). Feltenstein See (2008) further indicated that repeated drug exposure leads to neuroadaptions at the cellular level of the prefrontal NAcc glutamatergic pathway that contributes to the persistent addictive behaviors, including diminished cognitive control and hyper-responsiveness to drug-associated stimuli. The mesolimbic pathway is involved in the acute reinforcing effects of drugs and various conditioned responses related to drug cravings and relapse. Cycle of Addiction Drug addiction forms through progressive stages of drug use, impulsivity, and compulsion. Addiction begins with the choice to use drugs for a variety of reasons, such as peer pressure or curiosity; however not everyone who uses drugs develop an addiction. As the drug begins to change neuron interactions, the brain develops neuroadaptive reactions to the drugs invasion. Drug use gradually shifts from recreational drug use to a compulsive drug need based on changes in the brain circuitry. Everitt, et al. (2008) discovered that low levels of dopamine receptors in the nucleus accumbens predict the propensity to escalate cocaine intake and the shift to compulsive drug-seeking and drug addiction. Kobb (2009) describes three stages of addiction: preoccupation/anticipation, binge intoxication, and withdrawal/negative effect. The three stages feed into each other, become intensified over time, and shift from positive reinforcement to negative reinforcement (Kobb, 2009). Drug use starts with experimentation and enjoying the pleasurable attributes of the drug. In time the addict focuses more on obtaining and using drugs that begins to shift impulsivity to tolerance and cravings in the drug relationship. As the drug begins to control the addict, the positive emotions begin to shift to negative emotions. The addict requires continued use of the drug in order to avoid negative reinforcement and to achieve positive reinforcement. The addict shifts into a compulsive need for the drug. According to Koob and Simon (2009), the binge/intoxication stage of addiction involves the nucleus accumbens-amygdala reward system, dopamine inputs from the ventral tegmental area, local opioid peptide circuits, and opioid peptide inputs in the arcuate nucleus of the hypothalamus. The stage of negative withdrawal involves a decrease in function of the reward system and the brain stress neurocircuitry. The preoccupation/anticipation (craving) stage involves key afferent projections to the extended amygdala and nucleus accumbens, specifically the prefrontal cortex (for drug-induced reinstatement), and the basolateral amygdala (for cue-induced reinstatement). Compulsvie drug-seeking behavior appears driven by ventral striatal-ventral pallidalthalamic-cortical loops. In particular, the orbitofrontal cortex in the prefrontal cortex area influences impulsivity and compulsivity in drug addiction (Torregrossa, Quinn, Taylor, 2008). It is also critical in decision making and response selection. The orbitofrontal cortex influences impulsivity in three specific ways: delaying gratification, inability to inhibit strengthened motor responses, and an inability to reflect on potential consequences of action (Torregrossa, Quinn, Taylor, 2008). Schoenbaum and Shaham (2008) concur with the concept of an altered orbitofrontal cortex in drug addicts with a lasting decline in plasticity or the ability to encode new information. Drugs Classifications Commonly Abused Drugs commonly abused change the brains chemistry by interfering with the neurotransmitters and receptor sites. Different classes of drugs appear to affect different receptors either through overproducing a neurotransmitter or blocking the production of a neurotransmitter. All drugs of abuse share enhancement in the mesocorticolimbic dopamine activity, although at different levels. Depressants Ethanol is the primary drug in alcochol. It changes serotonin levels, and acts as a substitute for endorphins. According to Frezell (2007), behaviors that occur when under the influence of the drug include sleepiness, possible violence or aggression, depression, and a dulling of psychological pain. After the effect of alcohol wears off, sleep disturbance, depression, lack of endorphins to relieve normal pain, and cravings for more alcohol occur in reaction to the brains reduction in producing endorphins. Cruz, Bajo, Schweitzer, and Roberto (2008), indicate that alcohol increases the inhibitory effect of GABA and decreases the excitatory action of glutamate. GABA is involved with the intoxication effects of alcohol and the long-term effects, including tolerance and dependence. The CeA adapts to the changes as alcohol dependence forms. Feltenstein and See (2008) indicate that ethanol interacts with a wide variety o

Drug Abuse in Nigeria Essays -- Nigerian Society Illegal Narcotics

Drug Abuse in Nigeria Today, you only have to switch on your television, radio or open a newspaper or magazine to be aware that the structure of our society is being contaminated by the growing evil plague of drug abuse. Drug abuse, is one of the major problems in the Nigerian society. Actually, almost every country faces such problem today. A lot of measures are taken to struggle against drug abuse, and, definitely, some changes for the better are evident. However, this problem is not eliminated and perhaps, will never be completely stopped. The repetitive death of drug users today has become an everyday event, that most of us had used it. The numbers of the victims is more and more increasing rapidly in such a degree that makes us have fear on what our society will turn into. Prospectively, there was an alarming increase in drug abuse at our country. Many students take cocaine, heroine, hash, crack, and other drugs. Problem of drug abuse has made a way through the society. Overprotection some times makes a gateway for the beginning of drug abuse. The imitation of musicians and actors can lead many young people to drugs, as they are trying to look alike them. However, as we know, today this entire teenage is all about being ‘cool’. This affects most young people and it is more obvious in places where there are many people, like in college. The society today has become a place where drugs are gotten easily in the college, whenever and whatever drug you want. Finally, a disappointment from a relationship or school, for example a fail in the finals, can be a good reason for those young people to turn into drugs. For this bad situation that exists in Nigeria today, many teachers and counselors have tried to let pe... ... the past 10 months.†(p.19) In the 80s Nigerian citizens are caught on daily bases due to drug trafficking. At a moment like this what the country should do is to apply a policy that would reduce drug trafficking. Another way to control this issue is to put roadblocks and checkpoints where violence is common and also in airports and seaports. The N.D.L.E.A should also make sure that all pharmacies issue people drugs on prescription only. The problem of drug abuse is not something that can be controlled while sitting down, the country has to work together to prevent this harmful act. If the whole country will seek and use the knowledge they have to fight drug abuse then the society would be a better place to live .Now that we know the effects of drug abuse, it is time to put our hands together as a family to fight drug abuse in Nigeria and all over the world.

Marketing Mix (Research Paper) Essay

Business magazines and websites are abuzz with news about the value of marketing mix modeling as a way to help companies maximize returns on their marketing investments (ROMI). Despite the currency of this topic in the media, the concepts and tools of marketing mix modeling date back at least 30 to 40 years. The topic is of growing interest partly because of the corporate world’s interest in growing topline revenue. The last couple of decades have witnessed unparalleled cost cutting and staff reductions among the Fortune 500 in the U.S. The opportunities for further cost reductions are diminishing in number and scale, so the pressure for long-term financial performance from public markets can only be met by renewed emphasis on new products and revenue growth. A second reason for the growing interest in marketing mix modeling is the proliferation of new media (i.e., new ways to spend the marketing budget), including the Internet, online communities, search engines, event marketing, sports marketing, viral marketing, cell phones, and text messaging, etc. No one knows how to accurately measure the potential value of these many new ways to spend one’s marketing dollars. To grow revenue and profits, corporate executives need to understand the types of marketing investments that are most likely to produce viable, long-term revenue growth. That is, what combination of marketing and advertising investments will generate the greatest sales growth and/or maximize profits? Eureka! Marketing mix modeling might provide some answers to these challenging problems. What exactly is marketing mix modeling? The term is widely used and applied indiscriminately to a broad range of marketing models used to evaluate different components of marketing plans, such as advertising, promotion, packaging, media weight levels, sales force numbers, etc. These models can be of many types, but multiple regression is the workhorse of most marketing mix modeling. Regression is based on a number of inputs (or independent variables) and how these relate to an outcome (or dependent variable) such as sales or profits or both. Once the model is built and validated, the input variables (advertising, promotion, etc.) can be manipulated to determine the net effect on a company’s sales or profits. If the president of a company knows that sales will go up $10 million for every $1 million he spends on a particular advertising campaign, he can quickly determine if additional advertising investment makes economic sense. But, in a broader sense, a deep understanding of the variables that drive sales and profits upwards is essential to determining an optimal strategy for the corporation. So, marketing mix modeling can assist in making specific marketing decisions and tradeoffs, but it can also create a broad platform of knowledge to guide strategic planning. From a conceptual perspective, there are two main strategies to pursue in marketing mix modeling. One is longitudinal; the other is cross-sectional or side-by-side analysis. In longitudinal analyses, the corporation looks at sales and profits over a number of time periods (months, quarters, years), compared to the marketing inputs in each of those time periods. In the cross-sectional approach, the corporation’s various sales territories each receive different marketing inputs at the same time, or these inputs are systematically varied across the sales territories, and are compared to the sales and profit outcomes. Both methods are sound, and both have their place. Often, some combination of the two methods is the most efficient. .

Digital World of Cellular essays

Digital World of Cellular essays Cell phones have been around for nearly 15 years and are now everywhere you look. Over a quarter of Americans and a half of Europeans own cell phones and the numbers have been increasing exponentially. With the continuing increase in technology cell phones have become smaller, cheaper, and thanks to the move from analog to digital the calls are much clearer. They offer a great amount of convenience, and can be very economically for the busy businessman on the go. Advancements in cell phones are always being made, giving a clearer sound and lighter feel, as well as a longer life. The cell phone industry has been one of the fastest growing in the world. The electronics are fairly simple, but they are so small that they are truly and engineering marvel. This paper will discuss in depth the many different components of the average cell phone, and talk about how it converts your voice into something that can be sent through a digital network. The paper will also look at how the inner workings allow for a phone to act as a microcomputer, with Internet access, address books, and even games. Finally, it will review the many exciting ideas for this growing market and look to the future of the industry, and how the industry plans on overcoming various limiting factors. Alexander Graham Bell invented the telephone in 1876, 18 years later Guglielmo Marconi created the first radio. It was only natural that these two great technologies would eventually be combined to create the cellular craze. In the 80's few people used radiophones, these phones were the precursor to cellular, but they had several limiting factors preventing them from every becoming a major part of everyday society. In the radio telephone system, there was one central antenna tower per major city, and no more than 25 channels available on that tower. Each phone needed a powerful transmitter, big enough to transmit 40 or 50 miles. It also meant that not many peo...

3 Interview Questions That You Should Answer Honestly

3 Interview Questions That You Should Answer Honestly We’ve all been there: we go into the interview feeling confident, very nearly nail it, and then get thrown off by that one question that plagues us for the rest of the day (or week, or forever). No matter how well we’ve prepared our answers to the typical questions and done research into questions that might come up at that particular interview, there’s always that questions we feel we didn’t answer  perfectly. The truth is this: there are a few questions that should not come with canned, pre-prepared answers. Here are three questions you’d be better off answering off the cuff, in an honest and authentic manner. Knowing when to go off the script can really save an interview from feeling forced.â€Å"Tell me about a time you overcame a problem or challenge in the workplace†If you plan to discuss a challenge you overcame in your professional past,  it’s good to have some idea of what you’ll say if this comes up as a follow-up question. But it’s best not to have it too rigidly scripted. What your interviewer wants to know here is how well you handle pressure and whether or not you get daunted by seemingly impossible tasks. Give an answer with a bit of nuance, which shows you’re not afraid of complex situations and detail.â€Å"What is something you feel you should have done differently?†You should prepare for this question just as much as you’d prepare for the â€Å"something you’re really proud of† question. Often it can follow that question immediately. Don’t be too practiced. It can be very effective to appear surprised by the question, and then to give an honest account of a mistake you made that you learned a lot from. Your interviewer is just making sure you can be humble enough to admit your faults- and constructive enough to evolve past them.â€Å"What do you like to do in your spare time?†The interviewer will know if you’re just tryin g to say what you think will please them. So don’t listen to that panicked voice in your head that says, â€Å"But what if the hiring manager doesn’t like what I like?† It doesn’t matter. If they do they do, and if they don’t, they’re not supposed to. The hiring manager just wants to know that you’re a person they wouldn’t be embarrassed to go to happy hour with. So be honest about your passions- not crazy, of course, but be yourself.The bottom line is this: be prepared to answer these questions, but don’t be too rehearsed. Allow for a little spontaneity, let your answers be natural, and just be yourself.

ATOD Personal Theoretical Paper Essay Example | Topics and Well Written Essays - 750 words

ATOD Personal Theoretical Paper - Essay Example As such, there is a need for prevention and treatment to avoid the condition to worsen and eventually, destroy certain parts of the body, such as the liver and kidney. Aside from its effects on a biological perspective, drug abuse also has a greater impact in the social and psychological aspects of the patient. And with this comes different perspectives interpreting the condition of drug abuse. The psychosocial aspect impacted by the condition has created several theories that allow the patient, the family and the society to understand the effects of such condition. Drug abuse is not something that affects the patient alone but it has a way of dragging the immediate circle of people that the patient is in contact with. It also extends to the people of the society since drug abuse has become a nationwide issue because of the number of cases that are reported. A recent popular approach to the study of drug abuse is the biopsychosocial approach. Compared to psychological approach, which sees drug abuse as a condition wherein the patient attaches itself to drug abuse to deal with personal needs and conflicts, the biological approach, which see drug abuse as a tendency of the body to crave for the dependency on the effects of the drugs abused, and social approach, which interprets drug abuse as something that is related to social conflicts and the need to belong, the biopsychosocial approach interprets drug abuse as a condition that combines and interrelates all three approaches. It does not deny or attempt to isolate the factors and the effects of drug abuse. It in fact seeks to understand how it creates a circular pattern that connects all three approaches. It is not a general approach to understanding drug abuse but is a specific approach that aims to see the different factors affecting all processes of the human mind and body. It may see m like a grand approach to understanding the condition and yes, it could be when interpreted wrongly. But

Social policy Essay Example | Topics and Well Written Essays - 1500 words

Social policy - Essay Example The individuals against whom those powers might be used are just those who infringe the general rules; they should not be identified in any other way. Since the point is to restrain the coercive activities of government, these general rules should not be framed so as to discriminate either against or in favour of any group of persons known in advance—against Jews or Blacks, for example. Laws against speeding lay down general rules of this kind: they apply equally to all motorists, and they do not single out particular individuals (say, BMW drivers) for special attention. Retrospective legislation is likely to violate the rule of law on this interpretation since its victims and beneficiaries usually can be identified in advance. 1 General rules of this kind that are announced in advance are a defence against the arbitrary actions of governments. They are necessary in Hayek’s view both for the proper working of the market and for the existence of liberty precisely because they allow individuals to plan their affairs secure in the knowledge that government powers will not be used deliberately to frustrate their efforts. Once governments go beyond the enforcement of certain general rules, their activities inevitably involve the coercion of particular individuals. Since general rules of the kind Hayek favours are not aimed to produce particular effects on particular people, their precise consequences cannot be known in advance. They provide a framework for the decisions and actions of individuals, but they do not determine what those decisions and actions will be. From this point of view there is no reason in principle why governments should not concern themselves with the regulation of economic affairs. B ut their interventions should take the form of a framework of laws within which markets can operate, rather than the direction of economic activity by a central authority. 2 Here and elsewhere, Hayek