Qualitative Vs Quantitative Research method Article

Qualitative Vs Quantitative Research method - Article Example There is a further analysis on the strengths and limitations of the two research approaches. Debra A. Friedman (2011), presents qualitative research to contain questions that have an open approach to the subject under investigation. The questions by researcher give him the benefit to expect anything from the correspondence hence approach the topic with an open mind. The definition by James Dean Brown (1988) of Quantitative research help in understanding more on what type of questions characterize this type of research approach. James definition is based on trying to understand things that are continuous in a bid to derive patterns that arise because of the continuation factor in the aspect under study. The definition narrows the questions of Quantitative research to be Consistent that ensures dependency and verifiable through the different mathematical models employed in this type of research (mean, t-tests, mode, median and variance). The questions must have fidelity that ensures the answers are credible and aim at a meaningful result this is with the aim of being able to interpret the questions with different tools of mathematics or transferable. Qualitative research has the characteristics of the manner in which the question is, and the setting of the question is crucial in this approach of doing research. Donald Freeman (2009), states that the above characteristic makes the difference between qualitative and quantitative research questions. Freeman explains that the findings that the research aims at dictate the setting of the questions and the main reason that warrants these claims is the line separating the questions in the two types of researches. All the research questions are at finding a given inquiry that makes up the main purpose of the research. To illustrate the difference between the questions we use a common inquiry of a reporter to a correspondent on the ground about a political rally. Qualitative

Political science Research Paper Example | Topics and Well Written Essays - 500 words

Political science - Research Paper Example an Glover persuasively argues that the propensity of people in the West to attempt to explain the genocide in Rwanda by harking back to tribal divisions and historic tribal animosities is an oversimplification which does not do justice to the conflict. Accordingly, by focusing on the inevitability of such tribal animosity Western scholars have ignored important preconditions to the outbreak of genocide in Rwanda in 1994. As the poorest country in data set #9, the world-wide movement to atone for the historical injustices faced by the Tutsi people is alive and well in post-genocide Rwanda (CIA, 2009). Genocide in Rwanda did not â€Å"just happen†. The Belgian colonial experience shaped the artificial â€Å"ethnic† divisions in Rwanda which shaped politics for years to come, culminating in the genocide of 1994. Accordingly, the conflict in Rwanda was more than a civil war or short-term conflict. While estimates vary, up to one million people – largely Tutsis and moderate Hutus were killed in an incredibly short period of time. The Rwandan genocide was not a standard civil war and was an orchestrated full-scale genocide perpetuated against the Tutsi minority but extremists within the Hutu camp. A hate campaign against Tutsis and moderate Hutus was conducted through a variety of means by gà ©nocidaires intent on eradicating the Tutsi presence in Rwanda. Fearing a Tutsi-led invasion in the aftermath of Habyrimana’s death, the genocide planned by â€Å"people wanting to keep power† (Glover, 121) and a variety of means were used to coerce the Rwandan population to engage in the genocide. Instead of a mere tribal hostility, Glover argues for individual agency in attempting to account for the emergence of the genocide and argues that key players within the Hutu extremist establishment were responsible for the events that transpired after Habyrimana’s plane crashed. Instrumentalism is a theoretical paradigm which argues that things â€Å"don’t just happen†, events

Neuroimaging Research To The Understanding Of Psychopathology Psychology Essay

Neuroimaging Research To The Understanding Of Psychopathology Psychology Essay Over the last ten years, neuroimaging techniques has been employed to an ever increasing extent in the investigation of the biological substrates of psychopathology (Malhi and Lagopoulos 2008). Non-invasive brain imaging techniques such as PET and fMRI have been successfully applied in the localization of sensory functions (van Eijsden et al. 2009). For more complex psychological processes such as language, fMRI is now used to guide surgical decisions regarding hemispheric dominance in patients with refractory epilepsy (van Eijsden et al. 2009). Although still in its infancy (Crowe and Blair 2008), neuroimagings existing contribution has been hailed as significant (Linden 2008, Radaelli et al. 2008). Reliable biomarkers are not known for most, if not all psychiatric disorders (Linden 2008). Limited knowledge concerning the aetiological mechanisms underlying disorders thwart efforts at primary prevention and hamper secondary prevention due to the lack of reliable, comprehensive prognostic markers (Glahn et al. 2008). The lack of pathognomic neural markers, difficulties achieving clinical consensus regarding diagnostic definitions and symptom heterogeneity within the existing diagnostic entities have encouraged neuroimagings pursuit of biomarkers and endophenotypes (Malhi and Lagopoulos 2008); (Pan et al. 2009). The research agenda for DSM V underscores this theme working towards an aetiological and pathophysiological based diagnostic system rather than the current symptom and syndrome based approach (Pan et al. 2009). Neuroimagings contribution may be through refining, validating and augmenting existing diagnostic classifications or replacement of the existing phenomenologically d erived system with neuroanatomically defined biomarkers (Malhi and Lagopoulos 2008). Neuroimagings contribution may be constrained by limited knowledge regarding interregional connectivity and interactions within the brain (Honey et al. 2002). Furthermore, the pathways by which genetic and environmental risk factors interact and impinge upon behaviour ultimately manifesting as pathological symptoms is largely unknown (Glahn et al. 2008). Complexity is increased further by consideration of the points of discontinuity between psychopathology and normal variation (Glahn et al. 2008). To date, the majority of neuroimaging research has attempted to correlate functional, structural and chemical abnormalities of the brain with the presence and/or severity of symptoms (Radaelli et al. 2008). Critics argue that neuroimaging research encourages a segregationist approach to psychopathology, attempting to map complex functions onto discrete, localized brain areas (Honey et al. 2002). This tendency has been influenced by assumptions within cognitive psychology (van Eijsden et al. 2009), namely that mental functions are comprised of modules with identifiable, specific cognitive content processed by a computer like brain (van Eijsden et al. 2009). Thus, elements of psychological function are assumed to activate specific, reproducible brain regions, a model known as massive modularity(van Eijsden et al. 2009). Traditionally, neuroimaging techniques have been categorized according to their data acquisition methodology, focusing upon structure, function, connectivity, electrophysiology or underlying chemistry (Pine 2006). Recent advancements in multimodal imaging (MMI) enables an admixture of approaches attempting to integrate the strengths of different techniques (Malhi and Lagopoulos 2008). Rather than detecting actual neural transmission, fMRI relies on the paramagnetic properties of deoxyhaemoglobin, providing an indirect measurement of the coupling between neural activity and blood flow (Malhi and Lagopoulos 2008). Similarly, PET is an indirect measurement of neural activity measuring blood flow, metabolism or ligand-receptor interactions of particular neurotransmitters (Zimmer 2009). Compared with SPECT, PET offers increased spatial and temporal resolution and permits imaging of a greater range of brain activity than SPECT tracers (Malhi and Lagopoulos 2008). However, it does not offer equivalent spatial resolution to fMRI. DTI tractography images neural tract trajectories, enabling the modelling of white matter fibres localization, orientation, connectivity and integrity within the brain (Malhi and Lagopoulos 2008); (Honey et al. 2002); (Thai et al. 2009). Neuroimaging research can adopt either a whole brain or region of interest (ROI) approach (Malhi and Lagopoulos 2008) with important implications for interpretation. As ROI approaches examine fewer brain regions than whole brain univariate approaches such as VBM, they offer increased statistical power with a concomitant decrease in explanatory power (Ecker et al. 2010). In contrast, techniques such as VBM offer increased explanatory and moderate statistical power due to the necessity of multiple comparison corrections. Therefore, mass univariate approaches may be too conservative to detect subtle neuroanatomical abnormalities particularly with small samples (Ecker et al. 2010). Additionally, neuroimaging studies can be contrasted in terms of experimental design ranging from block, factorial to the most recently developed event-related designs. Event-related designs permit randomization of experimental conditions throughout scanning (Honey et al. 2002), allowing the response to a sing le event to be examined in a context-independent manner (Friston et al. 1998). This paper will evaluate the possible applications of neuroimaging research to the understanding of psychopathology in terms of its existing contribution and developments which may arise due to further technological innovations in the future. Initially, it will provide a brief introduction to a number of methodological considerations associated with neuroimaging research. Following this discussion, it will primarily focus upon neuroimagings contribution to aetiological research of psychopathology. In addition, it will evaluate the application of neuroimaging techniques to diagnosis, prognostic considerations and treatment. The paper will conclude with a review of recent technological developments within neuroimaging and evaluate the extent to which these innovations may further increase neuroimagings application to the understanding of psychopathology. Methodological and Technological considerations Critiques of neuroimaging research as The New Phrenology in its attempts to locate complex psychological phenomena in discrete brain regions have been described as the localization fallacy. The complexity of conducting research with patient groups and interpretation of associated results is emphasised when patient characteristics are considered (Honey et al. 2002). Psychiatric conditions are heterogenous in their presentation and difficult to define as discrete and homogenous entities. This increases the difficulty in obtaining a clinically homogenous sample for research purposes. Disorder and symptom heterogeneity manifesting as inconsistent neuroimaging findings may be a result of different aetiological pathways, variability in compensatory processes, chronicity of illness or the patients unique symptom profile (Honey et al. 2002). These inherent difficulties have been demonstrated by conflicting findings of hypofrontality in Schizophrenia (Keshavan et al. 2008) and led to the foll owing conclusion as long as we are not able to disentangle the heterogeneity question at the clinical level, it is not likely that heterogeneity at the aetiological and pathophysiological levels can be resolved (Peralta and Cuesta 2000). If a well matched sample is obtained, their symptomatic profile may be a manifestation of the final common pathway of disorder rather than representing a group matched for common aetiological mechanisms (Honey et al. 2002). To counteract these issues, many neuroimaging studies have adopted a symptom level approach, for example exclusively examining AVH (Honey et al. 2002). Critics have argued that symptom provocation studies may be imaging interference processes, compensation for diminished performance or other co-occuring symptoms (Honey et al. 2002). If the assumption that symptoms occur in isolation is correct, their location within discrete brain regions may over overly simplistic, it is more likely they are an element of complex, dynamic neural activity (Honey et al. 2002). The phenomenon of pure insertion asserts that a phenomenon of interest can be identified or manipulated in isolation from other mental processes (Honey et al. 2002). For example, linear increases in cognitive load (task demand) may not be associated with linear increases in neural activity. Furthermore, is it conceivable that ruminations in OCD can be isolated from other processes such as memory, attention and speech? (Honey et al. 2002). The subtraction technique is the most commonly employed method to identify brain areas that are active relative to one another; therefore, experimental task pairs should only differ in terms of one parameter. This is based on the assumption that by changing one parameter, that only one aspect of processing is altered (Nair 2005). Neuroimaging results may thus be misinterpreted as the cause of disorder or the disorder itself (Fuchs 2006). Thus, there are a number of important issues to consider when interpreting neuroimaging results such as whether differences reflect a symptom profile, a diagnostic entity and whether differences within these groups relate to state related phenomena or underlying aetiological differences at the genotype level (Honey et al. 2002). These ambiguities have led some researchers to question neuroimagings utility to aetiological research advocating a focus upon diagnostic imaging (Honey et al. 2002). Recent shifts towards a focus upon systems level, dynamic connectivity within the brain appears to be counteracting neuroimagings characterisation as the new phrenology (Zhou et al. 2009). The complexity of neuronal function has important implications for the analysis and interpretation of neuroimaging results. It is necessary to quantify both the relationship between neuronal activity and indirect measures of it via the haemodynamic responses and the associated temporal delay (Honey et al. 2002). It has been shown that BOLD signals are more responsive to increases rather than decreases in blood flow, known as the haemodynamic rectification effect (Keri and Gulyas 2003). These matters become increasingly complex when the contribution of neurotransmitter release and reuptake, receptor binding and electrical activity to rCBF, metabolic changes and behaviour are considered (Keri and Gulyas 2003). For example, low levels of neuronal activity may not be accompanied by rCBF changes, in a PET experiment, the lack of activation in this area does not exclude the area from being involved in the response under examination (Keri and Gulyas 2003). In contrast to sustained stimulati on, rapid changes in the brains functional state result in a brief uncoupling of perfusion from oxidative metabolism (Keri and Gulyas 2003). Imaging procedures must also model the effect of major blood vessels draining activated brain regions (Honey et al. 2002). Existing technology does not offer equivalent spatial resolution across the whole brain, there are also inherent difficulties differentiating between excitatory and inhibitory activation when using the proxy of the haemodynamic response (Honey et al. 2002). The complexity is further increased when the impact of experimental design is considered. fMRI images particularly those based on block designs frequently are static representations of haemodynamic activity averaged over time (Nair 2005). Furthermore, activity in some regions may only be detectable with more sophisticated event-related rather than block designs (Fusar-Poli et al. 2007). However, it has been shown that even in event-related fMRI paradigms that short inter stimulus intervals result in an overlap of haemodynamic responses to individual events (Ecker et al. 2008), thereby precluding confident analysis of condition specific activity. It has also been demonstrated that path co-efficients within SEM fMRI reflect changes in the temporal characteristics of the HFR induced by experimental design (Ecker et al. 2008) emphasising the effect of experimental design on effective connectivity studies. Recent developments In recent years there has been increased interest in furthering understanding of interactions between brain regions known as connectivity analysis (Sato et al. 2009b). Functional connectivity refers to the dynamic relationships between brain regions typically based upon correlational analyses (Thai et al. 2009). Effective connectivity studies infer causal or modulatory relationships between brain regions or networks and their directional, temporal interactions (Thai et al. 2009). SEM and DCM are the most commonly employed methods to investigate connectivity within fMRI data (Sato et al. 2009b). In SEM, the strength of an interaction is provided by a path co-efficient measuring the average influence of one ROI on another in a specified time period (Ecker et al. 2008). For example, using effective connectivity, it was demonstrated that the sACC and pACC had a strong directional influence on the right amygdale during an emotional processing task (Zhou et al. 2009). Rather than occurring as functionally distinct, feedforward sequential processing stages, it was shown that mental rotation performance includes both feedforward and feedback connections with indirect evidence of parallel processing (Ecker et al. 2008). Machine learning and pattern recognition methodologies, such as SVM are powerful techniques for the classification and prediction of mental states so called brain reading or decoding (Sato et al. 2009a); (Sato et al. 2009a). SVMs are used to identify statistical properties of imaging data which discriminate between groups of participants or brain states (Sato et al. 2009b), essentially, whether a new observation belongs to a training data set or otherwise. Not only do they offer the potential to categorize, their ability to anatomically localize discriminative information generated by the classification process presents the possibility of brain mapping (Sato et al. 2009a). Potentially, this methodology could be used to describe a healthy population, measuring the distance of subsequently tested participants from normative fMRI data (Sato et al. 2009b). For example, SVMs ability to distinguish between visual and auditory stimulation was 95.34% +/- 18.77 (Sato et al. 2009a). ANN and SV M based tools have employed in the identification and classification of pathology of patients with Alzheimers or Parkinsons disease from control participants (Bose et al. 2008). The development of imaging genetics offers the possibility of mapping the biological pathways and mechanisms whereby individual differences in brain function emerge and potentially predispose individuals to risk of psychological dysfunction (Viding et al. 2006). It enables the evaluation of the functional impact of brain relevant genetic polymorphisms with a view to understanding their impact on behaviour (Viding et al. 2006). For example, studies of healthy adult 5-HTTLPR S allele carriers found increased amygdala activation, reduced grey matter volume of the perigenual ACC and amygdale and altered functional connectivity of the pACC and amygdale relative to the LL genotype. Furthermore, 30% of variance in behavioural harm avoidance scores during this fMRI challenge paradigm was predicted by amygdala pACC functional connectivity (Viding et al. 2006). Aetiology Significant ambiguity remains surrounding the pathogenesis of schizophrenia (Keshavan et al. 2008). Although the majority of psychological disorders are thought to be multifactorial in origin (Glahn et al. 2008), genetic factors appear to exert a significant aetiological influence on the major psychoses, twin studies estimating heritability at 80% (van Os and Kapur 2009). Structural MRI studies have revealed reductions in whole brain and grey matter volume as well as increases in ventricular volume (Keshavan et al. 2008; van Os and Kapur 2009). Reductions have been observed in temporal lobe structures (in particular the hippocampus, amygdala and the superior temporal gyrus) and the prefrontal cortex, thalamus, AC and corpus callosum. There is evidence of a relationship between superior temporal gyrus volume and positive symptoms; medial temporal lobe reductions correlating with memory impairment. Qualitatively similar but less marked structural changes have been observed in the affec tive disorders. Whilst structural abnormalities may be consistently found in Schizophrenia, they are diagnostically non-specific and may be common amongst patients across diagnostic classifications. Evidence of progressive brain changes during the course of schizophrenia suggests that structural abnormalities may be a result of early and later developmental dysfunction (Karlsgodt et al. 2008). The onset of frank symptoms has been associated with progressive changes. Using longitudinal research designs, deviations from normative development can be examined (Serene et al. 2007). For example, longitudinal studies of early onset schizophrenia demonstrated progressive grey matter loss across the lateral surface of the brain, with treatment refractory patients displaying the most pronounced and rapid cortical grey matter loss. However, the explanatory power of progressive brain structural changes as the primary pathophysiological process within schizophrenia is diminished due to the prese nce of potentially confounding factors secondary to the illness such as symptom profile, severity, medication history and status and the duration of illness (Karlsgodt et al. 2008). Furthermore, structural changes are generally subtle and of relatively small effect sizes (Keshavan et al. 2008). Inconsistency has mired findings of hypofrontality in Schizophrenia, functional imaging meta-analysis have calculated moderate effect sizes for activated and resting state conditions. Conversely, once performance differences are controlled for, patients have shown increased prefrontal activation relative to controls perhaps indicative of an inefficient frontal response to task demands. There have been similarly inconsistent findings regarding other brain regions. Functional imaging research has found alterations in prefrontal and occasionally temporal lobe function (Shergill et al. 2007), with speculation regarding a specific abnormality in the reciprocal modulatory interaction of frontal areas and the hippocampus (van Os and Kapur 2009). Hyper- and hypoactive network responses have been demonstrated depending on experimental paradigm (van Os and Kapur 2009). Inconsistencies in the functional imaging literature may be a result of the diverse experimental designs employed, non-uniform standardization of resting state conditions, lack of control for performance differences, typically small sample sizes and medication confounds which curtail the interpretability of these results (Keshavan et al. 2008). MRS studies have corroborated regions implicated by structural and functional imaging results demonstrating reductions in neuronal and membrane integrity in at risk and early schizophrenic groups. However, it can be concluded that many of schizophrenias putative biomarkers are of less than robust effect sizes, non-specific and too time consuming or expensive to consider implementing as potential diagnostic biomarkers (Keshavan et al. 2008). It is proving difficult if not impossible to explain the features of this disorder and its associated functional deficits in terms of selective, focal abnormalities (Fusar-Poli et al. 2007). The disconnectivity hypothesis of the pathophysiological basis of vulnerability to psychosis implicates abnormal interaction/disconnectivity of the prefrontal cortex, temporal lobe and subcortical regions (Fusar-Poli et al. 2007). Findings of disturbed functional connectivity of the medial prefrontal, thalamic and cerebellar regions in relatives of patients with schizophrenia have provided support for this view (Fusar-Poli et al. 2007). Although evidence for disconnectivity in schizophrenia is strong, its relationship to aetiology, pathophysiology and implications for symptomatic behaviour remain unclear (Stephan et al. 2009). AVH have been found to activate a wide network of language areas in the frontal and temporal lobes and limbic areas such as the amygdale and hippocampus (Vercammen et al. 2009). The subjective intensity of AVH has been correlated with activation of the primary auditory cortex. Schizophrenic patients who experience AVH have been found to activate differential brain areas relative to healthy controls and non-hallucinating patients with schizophrenia, displaying altered activation of the anterior cingulate and superior temporal regions bilaterally (Mechelli et al. 2007; Shergill et al. 2007). DTI studies have demonstrated differences in the orientation of white matter fibres relative to patients without AVH and healthy controls. Examining the effective connectivity of AVH using DCM demonstrated a specific impairment of functional integration between the left superior temporal cortex and the dorsal part of the ACC during the evaluation of self and alien generated speech in patients with AVH (Mechelli et al. 2007). This implies a relationship between impaired functional integration and AVH experiences, Mechelli et al, speculate that a similar impairment in effective connectivity may diminish patients ability to process their own inner speech. Furthermore, a whole brain DTI study illustrated that propensity to experience AVH was associated with increased fractional anisotrophy (FA) within lateral aspects of the superior longitudinal fasciculi bilaterally, the main connection area between Wernickes and Brocas areas (Shergill et al. 2007). Similar differences in FA have been reported in at risk and first episode patients. However, it is possible that these connectivity changes may be a result of experiencing AVH rather than being causative in nature. Increased frequency of AVH may enhance connectivity in these regions. Studies conducted during the prodromal phase permit the prospective investigation of the pathophysiological processes underlying vulnerability and development of the disorder (Fusar-Poli et al. 2009; Pantelis et al. 2003).Neuroimaging studies have demonstrated qualitatively similar abnormalities to those evident in established schizophrenia and bipolar to those present in first episode psychosis and individuals without psychosis but with a strong familial risk (Pantelis et al. 2003). At risk individuals who subsequently developed psychosis had smaller grey matter volumes in the right medial temporal region, including the hippocampus and parahippocampal cortex, in a right lateral temporal region encompassing the superior temporal gyrus, a right inferior frontal region including the orbital portion of the inferior frontal gyrus and adjacent parts of the insula and basal ganglia and a cingulate region including the anterior and posterior cingulate gyrus bilaterally which mimics findings in probands of MZ twin pairs discordant for schizophrenia, first degree relatives of patients with psychosis and people with schizotypal personality disorder. Longitudinal examination of patients who transitioned to psychosis, showed a significant bilateral reduction in grey matter volume between baseline and follow up in the cingulate gyri, the left parahippocampal gyrus, left fusiform gyrus and left OFC (Pantelis et al. 2003). This study demonstrated that pathophysiological anomalies predate the onset of overt psychosis but that further grey matter volume changes are associated with the first expression of frank symptoms. It is unclear however, whether these changes represent a cause or effect of psychosis. Pantelis et al conclude that MRI may in the future prove a valuable tool in the identification of ultra high risk individuals. Neurochemical PET and SPECT studies investigating the dopamine hypothesis of schizophrenia with 18 F-dopa and 11 C-raclopride have shown that schizophrenia in its acute psychotic state is associated with an increase in dopamine synthesis, dopamine release and resting state dopamine concentration (van Os and Kapur 2009). Research has also demonstrated pre-synaptic dopamine overactivity in schizophrenic patients and first episode patients (Fusar-Poli et al. 2009) Studies of prodromal patients have demonstrated elevated Striatal 18 F-dopa uptake with levels approaching those of Schizophrenic patients (Howes et al. 2009). 18 F-dopa uptake in the ARMS was directly correlated with symptom severity and the degree of neuropsychological impairment. The most pronounced dopaminergic abnormality was found in the associative subdivision of the striatum in both schizophrenic patients and individuals with an at risk mental state (Howes et al. 2009). Thus, it has been suggested that pre-synaptic striatal dopamine function may be a worthwhile target for novel drug development and that these findings may provide a neurophysiological rationale for the introduction of anti-dopaminergic preventative intervention in high risk individuals (Howes et al. 2009). Multimodal studies of a verbal fluency task during the ARMS demonstrated an association between altered prefrontal activation and striatal hyperdopimergia (Fusar-Poli et al. 2009). Controlling for performance differences, there was increased activation of the left inferior frontal gyrus and the right middle frontal gyrus suggesting reduced efficiency or a compensatory process to achieve a similar behavioural response as controls. Improvement in prodromal symptoms has been associated with a normalization of the exaggerated inferior frontal response during a verbal fluency task. Previous findings linking the degree of elevation of striatal hyperdopimergia with symptom severity suggest that striatal hyperdopaminergia may underlie both symptoms and neurocognitive dysfunction although it is possible that another pathway is responsible. The observed correlation may represent the effect of prefrontal cortex on striatal dopamine or vice versa. Crucially, this study demonstrates that abnormal ities which were heretofore regarded as key pathophysiological features of Schizophrenia are correlates of vulnerability rather than sufficient for development of the disorder (Fusar-Poli et al. 2009). Interpretation of ARMS findings is difficult due to uncertainty regarding the degree to which they reflect trait or state factors, that is, psychosis liability or prodromal symptoms (Fusar-Poli et al. 2007). Thus, neuroimaging findings indicate changes in gray matter structure indicative of connectivity deficits at the level of synaptic connections and neuropil allied with white matter changes indicative of large scale deficits in connections between cortical regions (Karlsgodt et al. 2008). Although several biological abnormalities have been replicated (abnormally large ventricles, abnormal dopamine concentration and altered P300) they are not sensitive enough (usually only seen in 40-50% of patients) or not specific enough (seen in only 30% of first degree relatives) to be of diagnostic influence (van Os and Kapur 2009). Anxiety Disorders Neuroimaging research of anxiety disorders have implicated brain areas involved in the stress response as being associated with anxiety symptoms, including the prefrontal cortex, hippocampus and amygdala (Engel et al. 2009). However, potential brain structures implicated in the pathophysiology of anxiety disorders are extremely difficult to image due to their sizes and locations these include the amydala, brainstem nuclei and periaquaductal gray (Engel et al. 2009). Neuroimaging of PTSD highlights many of the complexities involved in conducting this research. Complexities relate to symptom presentation in terms of their variable content and emotional arousal in particular during the retrieval of traumatic memories (Peres et al. 2008). Symptomatic heterogeneity is extremely difficult to control for, additional potential confounds include nature of the traumatic experience (s) and the length of time since its occurrence. It is questionable whether it is appropriate to generalize from i maging results based on a sample of war veterans to survivors of childhood abuse (Peres et al. 2008). However, the results of neuroimaging studies appear to offer support for two broad subtypes of PTSD, one being primarily dissociative, the other characterised by intrusions and hyperarousal (Malhi and Lagopoulos 2008). Structural studies have demonstrated reduced ACC and hippocampal volumes in studies across a variety of traumatic experiences. Increased amydala activation has also been observed (Crowe and Blair 2008). Impaired hippocampal function has been speculatively linked to the memory fragmentation process observed in PTSD (Peres et al. 2008). However consistent findings of structural or functional change, they do not necessarily imply a causative relationship. Depression Research investigating the pathophysiology of depression have highlighted decreased anterior paralimbic and cortical activity in both major and bipolar depression (Malhi and Lagopoulos 2008). These decreased activation patterns are found to reverse with successful treatment. For example, in studies of major depression it has been observed that diminished activation of the dorsalateral prefrontal cortex can be increased following effective treatment. PET studies of the serotonin transporter SERT have demonstrated increased thalamic SERT in depressed patients relative to controls. Across the affective disorders, findings of hyperamydala and hypofrontality have led to speculation that these abnormalities may represent a critical pathway or potential predictive biomarker for those at risk of future development of psychopathology (Viding et al. 2006). However, it remains unclear as to whether these findings represent state or trait related function. The search for trait related biomarkers offers the potential to uncover early warning signs of impending psychological disorder as they may be present prior to symptom onset (Malhi and Lagopoulos 2008). The clarification of state related changes affords the possibility of monitoring differential responses to treatment over time (Malhi and Lagopoulos 2008). Cautious interpretation of existing neuroimaging findings is advised due to the complexity of emotional networks and lack of understanding regarding their integration with higher cognitive processes (Malhi and Lagopoulos 2008). Diagnosis As of yet there are a limited number of neuroimaging studies attempting to classify or categorize disorder (Glahn et al. 2008). Ongoing research endeavours to uncover pathophysiological biomarkers complements the development of diagnostic imaging systems. The discovery of biomarkers of schizophrenia may assist in early diagnosis and haveprognostic value (Bose et al. 2008). Initial diagnostic research efforts focused on measurement of striatal D2 receptor levels. Although it appears that striatal D2 receptor levels are elevated in schizophrenia, inconsistent and variable PET and SPECT results (possibly related to samples tested) have precluded its use as a diagnostic variable (Bose et al. 2008). Machine learning and pattern recognition techniques provide methods for analysing imaging data that may improve the sensitivity and specificity of diagnosis (Bose et al. 2008). Using ANN modelling of striatal [18F] fluro-L-DOPA influx constants, it was found that an ANN model correctly classified 84% of schizophrenic patients and 74% of controls (Bose et al. 2008). Sensitivity analysis revealed that the posterior putamen and anterior caudate nucleus were the most important areas within the ANN classification. The addition of multiple risk facto rs to the ANN classifier such as neuropsychological, genetic or structural imaging results may improve the ANN classifiers accuracy further (Bose et al. 2008). Bose et al, 2008 suggest the potential util

The Effects of Aerobic Exercise Among Adolescents with Mild to Moderate

The Effects of Aerobic Exercise Among Adolescents with Mild to Moderate Depression Kaplan and Sadock (as cited in Brollier, Hamrick & Jacobson, 1994) stated that depression, during the teen years, has become an increasing area of concern in psychiatry (Kaplan & Sadock, 1991. Kashani, Carlson, Beck, Hoeper, Corcoran, McAllister, Fallahi, Rosenberg and Reid (as cited in Brollier, Hamrick ,& Jacobson, 1994) studied the prevalence of depression in adolescents and reported that approximately 8% of adolescents experienced depressive disorders. Kaplan and Sadock (as cited in Brollier et al., 1994) suggested that new forms of treatment are needed when dealing with adolescents because adolescents often do not respond well to medications, electroconvulsive therapy, and psychotherapy, which are used on adults. Exercise, or physical activity, of an aerobic nature has been widely used as part of the recommended medical treatment for many health problems, and the physiological health benefits associated with exercise have been well documented. Brown, Ramierez,, and Taub (as cited in Mihevic, 1982) have stated that within recent years, exercise has been increasingly used for the treatment of depression as well. The results of a study conducted by Maroulakis and Zerva (1993) have shown that all dimensions of mood were positively affected by exercise to a significant extent. They went further to say that exercise is the most important natural mood modulator. Many studies have been conducted which examine the effects of aerobic exercise on depression scores of normal adult patients, and adult patients with depression. One such study, conducted by McCann and Holmes (1984), concluded that participation in a program of strenuous aerobi... ... on mood of adult women. Perceptual and Motor Skills, 76, 795-801. McCann, I.L., & Holmes, D.S. (1984). Influence of aerobic exercise on depression. Journal of Personality and Social Psychology, 46, 1142-1147. Milhevic, P.M. (1982). Anxiety, depression and exercise. Quest, 33, 140-153. Norris, R., Carroll, D., & Cochrane, R. (1990). The effects of aerobic and anaerobic training on fitness, blood pressure, and psychological stress and well-being. Journal of Psychosomatic Research, 34, 367-375. Norris, R., Carroll, D., & Cochrane, R. (1991). The effects of physical activity and exercise training on psychological stress and well-being in the adolescent population. Journal of Psychosomatic Research, 36, 55-65. Stein, P.N., & Motta, R.W. (1992). Effects of aerobic and nonaerobic exercise on depression and self-concept. Perceptual and Motor Skills, 74, 79-89.

Applied Statistics at Grand Canyon University Essay

1. Which patient scored the highest on the preoperative CVLT Acquisition? What was his or her T score? The 3rd patient scored 63 which is the highest CVLT T-score. 2. Which patient scored the lowest on postoperative CVLT Retrieval? What was this patient’s T score? The 4th patient scored the lowest on the postoperative CVLT Retrieval with a score of 23. 3. Did the patient in Question 2 have more of a memory performance decline than average on the CVLT Retrieval? Provide a rationale for your answer. Yes, because he scored 23 and the average is 38.2. 4. What is the mean ( X) and standard deviation (SD) for preoperative T score for CVLT Acquisition? The mean for preoperative T score for CVLT acquisition is 46.35, and the SD is 5.061, calculated using Excel auto sum function. 5. Is the preoperative Retrieval T score for Patient 5 above or below the mean for the norm of the group? Provide a rationale for your answer. The score for patient 5 on preoperative Retrieval T score (52) is above the mean for the norm of the group (47.36). 6. Assuming that the distribution of the preoperative CVLT Retrieval T scores is normal, the middle 68% of the patients had T scores between what two values? 7. Assuming that the distribution of scores for the postoperative CVLT Retrieval T scores is normal, the middle 68% of the patients had T scores between what two values? 8. The researchers state that it appears that the functional integrity of the left temporal lobe, despite evidence of structural abnormality, plays a considerable role when it comes to memory outcomes following left ATL. Can the findings from this study be generalized to a larger population? Provide a rationale for your answer. No, because, according to our source, the sample size is too small to generalize the results for a larger population. 9. If a patient had a raw score = 30, what would his/her postoperative CVLT Retrieval T score be? Tscore=10X/SD+(50-10Xo/SD) Tscore=10(30)/1.414+(50-10(39.294))/1.414 Tscore=-15.729 10. Did patients demonstrate more postoperative memory declines among CVLT Retrieval T scores than CVLT Acquisition T scores? Provide a rationale for your answer No, the number of declines in both postoperative categories is the same(13).

Service Industry vs Manufacturing Industry in the UK

The market in which organisations find themselves is continually changing. On the other hand, trade and investments are growing rapidly and overtaking the world output and there is increasing integration of the world economy. Multilateralism is constantly threatening and regionalism is stronger in Europe, Asia and America than ever before. This continuous structural change in world economies indicates the variations in the relative size of each sector which can be seen in terms of changes in output, employment and productivity. ECONOMY STRUCTURESEconomies can be divided into three categories: Primary, Secondary and Tertiary. The primary economy includes all activities related to the extraction of natural resources e. g. mining, farming etc. The secondary economy includes activities related to the production of goods and processing of materials which have manufacturing as its major component. It also includes the construction sector and utilities sector. The tertiary sector includes b oth the private and public services such financial industry, health, defence and other services related sectors. http://tutor2u. net/business/gcse/external_environment_economic_sectors. tm accessed on 31st November 2009. MANUFACTURING INDUSTRY IN BRITAIN Industry is defined as a group of firms producing similar products with boundary of an industry determined by a gap in the chain of substitutes. All sectors of the economy can be referred to as an industry but emphasis lay with the secondary sector which is widely regarded as the manufacturing sector. Roger Cox (2009) Concerns have been raised over the competitiveness and continued decline of Britain’s manufacturing base. This de-industrialisation has continually raised questions whether it can seriously damage the country’s wealth.The concerns about manufacturing have been reflected in trends in various statistical indicators especially the shift away from manufacturing towards services, the productivity gap between B ritain and its major international competitors. Malcolm Sawyer (2009) clearly stated that the value of manufacturing output in Britain has continued to rise slowly in the last half century, but the share of manufacturing in the total output is what has declined not the absolute amount. DE-INDUSTRIALISATION IN BRITAIN The trade balance in manufactured goods moved into deficit in 1983 for the first time since the Industrial revolution of the early 90’s.This could be attributed to the gradual movement of the economy from manufacturing to more service-oriented economies. This experience is not unique to Britain alone, over the period 1970 to 1990, the share of manufacturing in the national output declined in all major industrial nations while that of services increased. By 1990, the share of manufacturing in the GDP among major economies had declined with Britain coming sixth behind Japan, Germany, USA, and France. Mark C. & Corri F. (1998) De-industrialisation can be viewed in a number of ways: ?The decline in employment, in both absolute and relative terms. The decline in the share of national output contributed by the sector. ?The decline in the country’s share of world manufacturing output or exports. ?The failure due to poor export performance or increased import penetration to generate sufficient export to finance a full employment level of imports. Office for National Statistics ONS figures for the last quarter of 2008 shows a decline of 10. 4% lower than the figures from the previous year with output decreasing in 12 out of 13 sub-sectors. Significant decreases were recorded in the metal industries, transport industries and in machinery and equipments industries 11. 4%, 10. % and 9. 8% respectively. http://www. fundstrategy. co. uk/news/british-manufacturing-slumps/182454. article accessed 25th of November 2009. In Britain, the fall in the demand for labour is associated with a reduction in output until 1987 and probably a rise in the wage le vel relative to the price of other factors. The decline in manufacturing employment means that its share of total employment has also declined over that period of time with employment in the service industry sector growing at a faster rate. A growth rate of over 7% was recorded in the 1980’s in the service sector with manufacturing falling by over 20%.Shares of world trade in manufactures and deindustrialisation. (%) 195019601970197919901991 France9. 99. 68. 710. 59. 710 Germany7. 319. 319. 820. 920. 220 Japan3. 46. 911. 713. 715. 917 UK25. 516. 510. 89. 18. 69 USA27. 321. 618. 616. 016. 018 Office for National Statistics (1991), Monthly review of External Trade statistics. London Manufacturing’s problems began with the misguided notion that Britain should become a â€Å"post-industrial† economy: that we would focus on services and the creation of ideas, with other nations taking on the less attractive task of making the finished product.The results speak for th emselves. Manufacturing now generates just 13% of GDP, compared with 32% in 1970. John Rose, http://web. ebscohost. com/ehost/detail? vid=3&hid=11&[email  protected]&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=bth&AN=35824528 accessed on 22 November 2009. In the period 1980 to 2000, the manufacturing base in Britain was on a steady decline. Government argued that the reducing contribution made by the manufacturing towards GDP will be made up for by the service industry but further researches shows that the assumption was misjudged.Figures show deficits on goods moving from +? 1. 3 billion to -? 30. 4 billion creating a ? 31. 7 billion deficit not covered by the service industry. This Industrial decline was accelerated by increased competition from cheaper imports and the outsourcing to low cost economies which saw a free fall in different high profile companies closing down, downsizing or relocating to low cost economies. http://web. ebscohost. com/ehost/detail? vid=3&hid=11&[email  p rotected]&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=bth&AN=35457939 accessed on 26th November 2009.John S & Mark S (2004) clearly states that the deindustrialisation in Britain has not being affecting the whole of the manufacturing sector, certain sectors mainly instruments and electrical engineering industries has witnessed a tremendous rise in production and they are among the fastest growing in the economy but industries like the metal industries have witnessed a substantial decline in their productivity. EMPLOYMENT FIGURES WITHIN THE INDUSTRIES This sector underwent a significant growth in the early 80’s in the EU during the post industrial phase of economic development.The doubts about manufacturing sector have been shown in various indicators with the shift to more service-oriented sector taking prominence. It has been argued that the decline in Britain’s manufacturing sector should not be a cause for concern but rather the offset of expansion of other sectors of the economy especially the Service industry. The service sector witnessed a rapid increase in employment with the financial sector gaining rapidly on the manufacturing sector. In 1971, the workforce in the manufacturing industry has shrunk by around 4 million with the service industry recording a growth of around 3. million. By 1994, while about 46 million people where employed in the manufacturing sector, about 55 million and 28 million people where employed in the private and public services sector respectively representing about 64% of the total employment figure within the EU. Andrew Taylor of financial times reported that over a century beginning from the first production in 1907 to 2007, the manufacturing sector employment figures has fallen from 7 million to 3 million while women not account to 23% compared to the 25% at the onset.The mining sector used to account for about three-quarters of the employment with figures about 837,000 but now employs around 10,000 accounting for j ust around 1% of the employment figures. The aerospace industry, a section of the service industry which was non-existent at the beginning of the century now employs about 100,000. Mark C. & Corri F. (1998) http://web. ebscohost. com/ehost/pdf? vid=5&hid=9&[email  protected] accessed 1st December 2009.SERVICE SECTOR GROWTH IN BRITAIN In the post industrialisation era in EU, economies including the UK witness a boom in the service sector with significant growth in the financial services sector and the aerospace industries. Between 1979 and 1993, there was a rise from 7 to 13 percentages in service sector employment rate. In more recent surveys, the services industry across banking to airliners has shown growth rates in February that represent a five month high, as companies have raised their prices.This is a positive sign that suggests that the predicted slowdown as espoused by the Bank of England has yet to materialize. The Chartered Institute of Purchasing and Supply revealed tha t index prices are up by 1. 5 percent since September 2007 whilst the report also indicated that the economy has maintained its current momentum. http://www. investmentmarkets. co. uk/20080305-1705. html accessed on 23rd of November, 2009. The measurement of service industry depends on the way it is defined, either value or volume wise. Outsourcing has been a major component in promoting service sector.Manufacturing companies outsources most of its functions like finances, design and other little services to focus on its core competencies and all this in turn increases activities within the service industry and the employment figures reducing its manufacturing counterpart in correspondence. The rise of services is due also to changing economies within the EU, limited competitiveness of traditional industrial production. Financial Times. (2009) AEROSPACE INDUSTRY IN BRITAIN The UK aerospace industry (UKAI) remains one of the most successful sectors of UK manufacturing.In 2003, the UK AI accounted for 0. 6 percent of UK gross value added (GVA) and four percent of value added by the UK’s manufacturing industry as a whole. The UKAI is also one of the UK’s major export sectors, generating a trade surplus of just over ? 2. 5 billion in 2003, compared with manufacturing overall, which had a trade deficit. The UKAI provides direct and indirect employment in the UK for around 255,000 people. Although productivity levels in the UKAI are generally higher than the UK average, they Remain disappointing when compared to the industry’s main international competitors.However, there are signs that UKAI productivity growth is beginning to outpace these competitors. There are also evidences to suggest that there will be a further challenge for The UKAI as competition from emerging economies is growing. The growth of the United Kingdom aerospace industry illustrates the changing trends in globalisation, industrialisation and service delivery. From a virtually non-existent sector around a century ago, the UKAI has grown so much in the last twenty years and captured about 10% of the world market in aerospace and accounted for just over 4% of UK anufactured output and directly contributed just over ? 5. 5 billion to UK gross value added (GVA)1 in 2002. In 2003, the UKAI directly employed just fewer than 122,000 people, 0. 4% of total UK employment and 3% of total manufacturing employment. An additional 150,000 people have been estimated to be indirectly employed by the industry.UKAI productivity was ? 54,000 per head in 2001, 50% higher than the UK average and 35 percent higher than for manufacturing as a whole. http://www. publications. parliament. uk/pa/cm200405/cmselect/cmtrdind/151/151. df accessed 27th November 2009. ANALYSIS OF THE MANUFACTURING AND SERVICE SECTORS A steady growth rate has been recorded in the service industry while the contribution to the overall GDP from the manufacturing industry has witnessed a steady decline in t he last few decades. This has been well documented from various researches carried out but a serious questions still arises from the performance of the service sector and its long term sustainability and effect on the economy.David Liston asked â€Å"what will the services industry be servicing if there is no hardware? The first priority should be to stop treating manufacturing as a relic of the industrial revolution. High-value-added manufacturing brings huge benefits. It penetrates the economy of the entire country, not just London and the south-east. It pays well but avoids bewildering distortions of income. It drives and enables a broad range of skills and stimulates the growth of services. In short, it creates wealth. Curmen P et. al (1997) The UK manufacturing sector continues to decline and the subsequent loss of exports has not been replaced by revenue from the service sector as the government had originally thought.At the same time, the ownership of UK companies by foreign ers is increasing and UK companies are continuing to relocate some of their labour intensive operations to low cost economies. The cost of compensating employees who are made redundant when a company in the UK closes is one of the lowest in the European Union. So for multi-national companies with surplus capacity, the UK factories may be selected for closure. There is also a tendency for companies to consolidate research and development in their home country with the consequence that it is lost from the UK.This decline in manufacturing was triggered by some factors: ?Changes in manufacturing and materials technology and consumption patterns which affected a lot of steel, coal ship-building and power generation industries. ?Obsolete and redundant plants and inadequate investment and financial assistance to replace them. ?Diverse and intense competition from low wage nations and newly industrialised economies. ?Resistance to change at all levels of production from management to trade unions. Adverse effect of Government policies both fiscal and monetary on industries. Particularly in high interest rates and fluctuating exchange rates. With David Liston’s question in mind and the fact that service industry has not been able to replace manufacturing industries effectively producing a cushioning effect for the drop in its GDP contribution slump which is evident by the facts below: ?The interdependence on manufacturing industry as shown in the case of the aerospace, further reduction in manufacturing output will adversely affect services output also. Technical progress in manufacturing offers greater prospects of high-wage jobs able to raise standards compared to part-time low wage in the services industry. ?For each 1% decline in export of Britain’s manufacture, an excess of 2. 5% rise in export in required in services to complement the effect. Some policies which cut across all concerned parties from Government to private market solutions have been f ormulated to help halt the decline in manufacturing. Some of which include: ? Britain’s macroeconomic and industrial policy Improved management in the industrial sector ?A reform of Britain’s institutions ?Greater accumulation of both human and physical capital ?Improved innovation to accommodate mechanisation http://web. ebscohost. com/ehost/pdf? vid=5&hid=9&[email  protected] accessed on 1st of December 2009. CONCLUSION Divergent analysis from various stakeholders shows the variable effect of manufacturing and service delivery on the national income of Britain. A steady decline in manufacturing was evident and it coincided with the boom