27,444 research outputs found

    Identification of Hindbrain Neural Substrates for Motor Initiation in the hatchling Xenopus laevis Tadpole

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    Animal survival profoundly depends on the ability to detect stimuli in the environment, process them and respond accordingly. In this respect, motor responses to a sensory stimulation evolved into a variety of coordinated movements, which involve the control of brain centres over spinal locomotor circuits. The hatchling Xenopus tadpole, even in its embryonic stage, is able to detect external sensory information and to swim away if the stimulus is considered noxious. To do so, the tadpole relies on well-known ascending sensory pathway, which carries the sensory information to the brain. When the stimulus is strong enough, descending interneurons are activated, leading to the excitation of spinal CPG neurons, which causes the undulatory movement of swimming. However, the activation of descending interneurons that marks the initiation of motor response appears after a long delay from the sensory stimulation. Furthermore, the long-latency response is variable in time, as observed in the slow-summating excitation measured in descending interneurons. These two features, i.e. long-latency and variability, cannot be explained by the firing time and pattern of the ascending sensory pathway of the Xenopus tadpole. Therefore, a novel neuronal population has been proposed to lie in the hindbrain of the tadpole, and being able to 'hold' the sensory information, thus accounting for the long and variable delay of swim initiation. In this work, the role of the hindbrain in the maintenance of the long and variable response to trunk skin stimulation is investigated in the Xenopustadpole at developmental stage 37/38. A multifaceted approach has been used to unravel the neuronal mechanisms underlying the delayed motor response, including behavioural experiments, electrophysiology analysis of fictive swimming, hindbrain extracellular recordings and imaging experiments. Two novel neuronal populations have been identified in the tadpole's hindbrain, which exhibit activation patterns compatible with the role of delaying the excitation of the spinal locomotor circuit. Future work on cellular properties and synaptic connections of these newly discovered populations might shed light on the mechanism of descending control active at embryonic stage. Identifying supraspinal neuronal populations in an embryonic organism could aid in understanding mechanisms of descending motor control in more complex vertebrates

    The applied psychology of addictive orientations : studies in a 12-step treatment context.

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    The clinical data for the studies was collected at The PROMIS Recovery Centre, a Minnesota Model treatmentc entre for addictions,w hich encouragesth e membership and use of the 12 step Anonymous Fellowships, and is abstinence based. The area of addiction is contextualised in a review chapter which focuses on research relating to the phenomenon of cross addiction. A study examining the concept of "addictive orientations" in male and female addicts is described, which develops a study conductedb y StephensonM, aggi, Lefever, & Morojele (1995). This presents study found a four factor solution which appeared to be subdivisions of the previously found Hedonism and Nurturance factors. Self orientated nurturance (both food dimensions, shopping and caffeine), Other orientated nurturance (both compulsive helping dimensions and work), Sensation seeking hedonism (Drugs, prescription drugs, nicotine and marginally alcohol), and Power related hedonism (Both relationship dimensions, sex and gambling. This concept of "addictive orientations" is further explored in a non-clinical population, where again a four factor solution was found, very similar to that in the clinical population. This was thought to indicate that in terms of addictive orientation a pattern already exists in this non-clinical population and that consideration should be given to why this is the case. These orientations are examined in terms of gender differences. It is suggested that the differences between genders reflect power-related role relationships between the sexes. In order to further elaborate the significance and meaning behind these orientations, the next two chapters look at the contribution of personality variables and how addictive orientations relate to psychiatric symptomatology. Personality variables were differentially, and to a considerable extent predictably involved with the four factors for both males and females.Conscientiousness as positively associated with "Other orientated Nurturance" and negatively associated with "Sensation seeking hedonism" (particularly for men). Neuroticism had a particularly strong association with the "Self orientated Nurturance" factor in the female population. More than twice the symptomatology variance was explained by the factor scores for females than it was for males. The most important factorial predictors for psychiatric symptomatology were the "Power related hedonism" factor for males, and "Self oriented nurturance" for females. The results are discussed from theoretical and treatment perspectives

    The labour supply and retirement of older workers: an empirical analysis

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    This thesis examines the labour supply of older workers, their movement into retirement, and any movement out of retirement and back into work. In particular the labour force participation, labour supply and wage elasticity and other income elasticity of work hours are estimated for older workers and compared to younger workers. The thesis goes on to look at the movement into retirement for older workers as a whole by examining cohorts by gender, wave and age. The thesis also presents a descriptive and quantitative • examination of the changes in income and happiness that occur as an individual retires. Finally the thesis examines the reasons why an individual may return to work from v . retirement. The results of the findings suggest: that younger workers are significantly more responsive to wage and household income changes than older worker

    Studies of strategic performance management for classical organizations theory & practice

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    Nowadays, the activities of "Performance Management" have spread very broadly in actually every part of business and management. There are numerous practitioners and researchers from very different disciplines, who are involved in exploring the different contents of performance management. In this thesis, some relevant historic developments in performance management are first reviewed. This includes various theories and frameworks of performance management. Then several management science techniques are developed for assessing performance management, including new methods in Data Envelopment Analysis (DEA) and Soft System Methodology (SSM). A theoretical framework for performance management and its practical procedures (five phases) are developed for "classic" organizations using soft system thinking, and the relationship with the existing theories are explored. Eventually these results are applied in three case studies to verify our theoretical development. One of the main contributions of this work is to point out, and to systematically explore the basic idea that the effective forms and structures of performance management for an organization are likely to depend greatly on the organizational configuration, in order to coordinate well with other management activities in the organization, which has seemingly been neglected in the existing literature of performance management research in the sense that there exists little known research that associated particular forms of performance management with the explicit assumptions of organizational configuration. By applying SSM, this thesis logically derives some main functional blocks of performance management in 'classic' organizations and clarifies the relationships between performance management and other management activities. Furthermore, it develops some new tools and procedures, which can hierarchically decompose organizational strategies and produce a practical model of specific implementation steps for "classic" organizations. Our approach integrates popular types of performance management models. Last but not least, this thesis presents findings from three major cases, which are quite different organizations in terms of management styles, ownership, and operating environment, to illustrate the fliexbility of the developed theoretical framework

    Reforming the United Nations

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    The thesis deals with the financial crisis that the United Nations faced starting in 1985 when the US Congress decided to withhold a significant part of the US contribution to the UN regular budget in order to force a greater say for the major contributors on budgetary issues, budgetary restraint and greater efficiency. The UN responded by the adoption of resolution 41/213 of 19 December 1986 that was based on the recommendations of a Group of High-level Intergovernmental Experts ("G-18") set up a year earlier. A new system was introduced regarding the formulation of the regular budget of the United Nations Organisation and a broader process of reform was initiated including a restructuring of the Secretariat and of the intergovernmental machinery in the economic and social fields. After an introductory chapter (Chapter I), the thesis examines the UN problems at the budgetary/financial and administrative/structural levels, the solutions proposed from within and without the United Nations established framework and the actual attempts at reform (Chapters II and ifi). The realisation that the implementation of reforms is rather disjointed and often unsuccessful (e.g. the failure to restructure the intergovernmental machi.neiy) prompts a search for the deeper causes of the UN problems at the political level and the attitudes of the main actors, namely the USA, the USSR, some up-and-coming states, notably Japan, the Third World states and, finally, of the UN Secretary-General and the Secretariat (Chapter 1V). Although the financial crisis may have subsided since 1988 and the USA seem committed to paying up their dues, the deeper UN crisis of identity has not been resolved and is expected to resurface if no bold steps are taken. In that direction, some possible alternative courses for the UN in the future are discussed drawing upon theory and practice (Chapte

    The Caribbean Syzygy: a study of the novels of Edgar Mittelholzer and Wilson Harris

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    The problem of racial inheritance - the "search for identity" - is a recurring theme in the criticism of Caribbean literature. It is a pre-occupation with Caribbean writers, affecting both subject matter and literary quality, as FM. Birbalsingh, for example, has shown with reference to the novels of John Hearne and E,R. Braithwaite (Caribbean quarterly Vols. 14, December 1968 and 16, March 1970). This study of the work of Edgar Mittelholzer and Wilson Harris will attempt to show that there are important areas still to be explored relating Caribbean literature to its complex racial and cultural background. Both Mittelholzer and Harris deserve close, critical study in their own right; but a parallel examination reveals similarities and differences which bring into sharper focus wider concerns of Caribbean literature. The two important directions of West Indian writing are more clearly seen: the one, pioneered by Mittelholzer, in which the writer looks outward towards a "parent" culture, and the other looking inward, seeking in its own, complex inheritance the raw material for new and original growth. Mittelholzer and Harris are both Guyanese of mixed racial stock, both deeply concerned with the psychological effects of this mixture, and both writers have a profound awareness of the Guyanese historical and cultural heritage. They also share a deep feeling for the Guyenese landscape which appears in their work as a brooding presence affecting radically -the lives of those who live within i-t. Mittelholzer's attitude to his mixed racial and cultural origins, however, produces in his work a schizophrenic Imbalance while Harris, by accepting racial and cultural complexity as a starting-point, initiates a uniquely creative and experimental art. Mittelholzer, in his approach to history, human character eM landscape, remains a vi "coastal" writer never really concerned (as Harris is) with. the deeper significance of the "Interior" and all that this implies, both in a geographical and psychological sense. The fact that Mittelbolzer's work reflects a psychological imbalance induced by a pre-occupation with racial identity has been demonstrated by Denis Williams in the 1968 Mittelholzer Lectures, and by Joyce Sparer in a series of articles in the Guyana Graphic. Mittelholzer's awareness of this imbalance, however, and his attempt to come to terms with it in his art remain to be examined and documented, as does Harris's attempt to create am "associative" art aimed at healing the breach in the individual consciousness of Caribbean Man. The aim of this study is to demonstrate that Mitteholzer and. Harris, although antithetical in impact and style (each representing an approach to fiction directly opposed to the other) are, in fact, the opposite elements of a dichotomy. Their work illustrates the negative and positive aspects of the racial and cultural schizophrenia of the Caribbean, for both writers in their different ways are preoccupied with (and therefore have embodied in their work) the juxtaposition and, contrasting of apparently irreconcilable emotional and intellectual qualities - the Caribbean Syzygy

    Stimulating Non‐Energy Exports in Trinidad and Tobago: Evidence from a Small Petroleum‐Exporting Economy Experiencing the Dutch Disease

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    The motivation for this study hinges around the fact that Trinidad and Tobago (T&T) is suffering from the Dutch disease which inadvertently hinders the growth of non-energy exports. This paper examines measures that can be adopted for a small petroleum-exporting economy to dampen the effect of Dutch disease by promoting non-energy trade. This paper is novel and contributes to the literature in using panel data for the T&T case, as it investigates the effect of a devaluation of the TT dollar in order to stimulate non-energy exports (a combination of agriculture and manufacturing trade). Note that previous studies would have examined the Marshall–Lerner condition on the aggregate trade balance which is heavily influenced by energy revenues. The panel autoregressive distributed lag (ARDL) method is used for ten of T&T’s main trading partners for the period 1991 to 2019 to establish findings. The results show that the Marshall–Lerner condition does not hold for aggregate trade in the long run, as expected. However, when non-energy trade is isolated, it is found that a devaluation of the TT dollar does have a positive impact on non-energy trade and the Marshall–Lerner condition holds. Other measures are also recommended to stimulate non-energy exports in the long run

    The transformation of the Foreign Office 1900-1907

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    The Foreign Office underwent an important transformation at the beginning of the twentieth century. This development coincided with the new course of British foreign policy which has been called "the end of isolation." One reason for this transformation was the rapid promotion of new men with new ideas to fill the senior posts both in the Foreign Office and the Diplomatic Service. Two men in particular, Sir Francis Bertie and Sir Charles Hardinge, benefited from Royal influence to become, respectively, Ambassador at Paris and Permanent Under-Secretary at the Foreign Office. These two men, and a number of their contemporaries, began to wield more influence than their predecessors, and attempted with some success to bring about the promotion of men of whom they approved in preference to those of whom they did not approve. Their activities introduced a new body of men at the top of the Foreign Office and brought about an atmosphere of intrigue and rivalry which had not previously been present. Another reason for this transformation was the reform and consequent reorganisation of the Foreign Office. This development brought about a devolution of responsibility and encouraged the permanent officials to begin to put forward their own views and to influence the execution of British foreign policy. The men who were being promoted to the important senior posts were, therefore, provided with an administrative machinery which facilitated their desire for a more active role in the formulation of policy. -2- The other reason for the transformation was the rise of "anti-German" feeling in the Foreign Office, which came to a head at exactly the same time. Towards the close of the nineteenth century the important members of the Office began first to criticise the methods of German diplomacy, and then to see the aims of German foreign policy as inimical to British interests. This mounting criticism was dramatically affected by the collapse of Russia and the aggressive policy pursued by Germany shortly after. Some of the more influential members of the Foreign Office began to suspect that Germany was attempting to impose a hegemony over Europe. They were divided about the importance which they felt should be attached to the potential threat from Russia, but so long as that Power remained weak they began to regard Anglo-German relations as the most important factor to be taken into account when considering British foreign policy. The men at the forefront of this opinion were by and large the same men who were able to take advantage of the new organisation of the Foreign Office to exploit their new positions to the full. When a general consensus was finally reached that Germany was moving towards a bid for hegemony the transformation of the Foreign Office was complete. The Foreign Secretary was surrounded by a body of forceful senior officials, who took advantage of the new and efficient organisation to advance the same overall policy. The Foreign Secretary did not always follow the advice that he was given, but after this time that advice was something which he had to take into consideration. The transformation of the Foreign Office was the watershed between the nineteenth century office and the twentieth century bureaucrac

    Mandatory detention and treatment of drug users in Malaysia : The implications for the principles of human rights

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    The research framework is founded upon a critical analysis of the extent to which the legal process involved in the mandatory treatment and rehabilitation of drug users in Malaysia is consistent with the principles of human rights according to the national and international human rights instruments; the Malaysian Constitution and the UDHR respectively. The mandatory treatment is based upon the principles of punishment rather than rehabilitation. The arrest and detention of these drug users, which are salient features of the legal process raises the issue of serious violations of the human rights principles. To fulfill the true objective of the government's Drug Intervention Programme (DIP) through treatment and rehabilitation at Puspen centres, by reducing drug dependency and preventing relapse, treatment must be consistent with the principles of human rights for it to be effective. Data and information were gathered from empirical research through the application of various qualitative methods: these include a case study, direct observation, semistructured and unstructured interviews with key stakeholders, focus group with former drug users and an analysis of case files. Findings revealed that the legal process of funneling 'suspected drug dependants' into treatment involved a series of breaches of the fundamental human rights principles that could not be justified. The scope of police powers with regard to the arrest and detention of 'suspected drug dependants' has been widely abused and such exercise of power has been without proper statutory safeguards to protect the rights of these individuals from such arbitrary arrest. Unnecessary prolonged period of detention have led to grave infringement of individual liberty whilst conditions of confinement and failure to provide medical assistance and medication-assisted treatment particularly during withdrawal symptoms have amounted to inhuman, cruel and degrading treatment. Lack of due process including denying the right to legal representation has caused severe legal implications upon the drug users. As a consequence, the flaw in the legal system has deprived them of their constitutional rights and in contravention of the international human rights principles. Recommendations are proposed for an immediate reform to the drug policies and procedures with paramount consideration towards a more humane and effective treatment

    Your ID, please? The effect of facemasks and makeup on perceptions of age of young adult female faces

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    During the COVID-19 pandemic, wearing facemasks was mandatory in the United Kingdom except for individuals with medical exemptions. Facemasks cover the full lower half of the face, however the effect of facemasks on age perception is not yet known. The present study examined whether age estimation accuracy of unfamiliar young adult women is impaired when the target is wearing a facemask. This study also examined whether makeup, which has previously been shown to increase error bias, further impairs age estimation accuracy when paired with a facemask. The findings indicate that both facemasks and makeup tend to result in over-estimation of the young women's age compared to neutral faces, but the combination of both is not additive. Individual level analysis also revealed large individual differences in age estimation accuracy ranging from estimates within 1 year of the target's actual age, and age estimates which deviated by up to 20 years
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