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Research Hypotheses (research + hypothesis)
Selected AbstractsTheories of drug craving, ancient and modernADDICTION, Issue 1 2001D. Colin Drummond This paper reviews the principal theoretical models of drug craving and provides some directions for future research. The main models are classified broadly into three categories: (1) phenomenological models; based on clinical observation and description; these have been influential in classification systems of addictive disorders and in the development of pharmacological therapies; (2) conditioning models: based on conditioning theory; these have been influential in the development of cue exposure treatments; (3) cognitive theories; based on cognitive social learning theory: these have been influential in the development of cognitive therapies of addiction. It is concluded that no one specific theory provides a complete explanation of the phenomenon of craving. However, theories of craving grounded in general theories of human behaviour offer greatest promise, and generate more specific and testable research hypotheses. Theories that do not require craving to be present for relapse to occur have more empirical support than those that provide simplistic causal explanations. The cue-reactivity model shows promise in the exploration of the relationship between craving and relapse. However, further attention to the phenomenology of craving could help to advise the future measurement and study of drug craving, particularly in the context of research in which drugs are available to human subjects, with adequate ethical safeguards. There is a need for further study of the temporal dynamics of craving and consensus in the field on the most appropriate methods of measurement. Finally, new psychotherapies such as cue exposure and pharmacotherapies that aim to attenuate drinking behaviour, such as naltrexone and acamprosate, provide opportunities to improve understanding of the nature and significance of craving. However, the relatively uncritical assumption that craving is the underlying basis of addiction and represents the most appropriate target for treatment is challenged. [source] Offer and demand: proliferation and survival of neurons in the dentate gyrusEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2005Konrad Lehmann Abstract The proliferation and survival of new cells in the dentate gyrus of mammals is a complex process that is subject to numerous influences, presenting a confusing picture. We suggest regarding these processes on the level of small networks, which can be simulated in silico and which illustrate in a nutshell the influences that proliferating cells exert on plasticity and the conditions they require for survival. Beyond the insights gained by this consideration, we review the available literature on factors that regulate cell proliferation and neurogenesis in the dentate gyrus in vivo. It turns out that the rate of cell proliferation and excitatory afferents via the perforant path interactively determine cell survival, such that the best network stability is achieved when either of the two is increased whereas concurrent activation of the two factors lowers cell survival rates. Consequently, the mitotic activity is regulated by systemic parameters in compliance with the hippocampal network's requirements. The resulting neurogenesis, in contrast, depends on local factors, i.e. the activity flow within the network. In the process of cell differentiation and survival, each cell's spectrum of afferent and efferent connections decides whether it will integrate into the network or undergo apoptosis, and it is the current neuronal activity which determines the synaptic spectrum. We believe that this framework will help explain the biology of dentate cell proliferation and provide a basis for future research hypotheses. [source] Empathy in medical students as related to academic performance, clinical competence and genderMEDICAL EDUCATION, Issue 6 2002M Hojat Context, Empathy is a major component of a satisfactory doctor,patient relationship and the cultivation of empathy is a learning objective proposed by the Association of American Medical Colleges (AAMC) for all American medical schools. Therefore, it is important to address the measurement of empathy, its development and its correlates in medical schools. Objectives, We designed this study to test two hypotheses: firstly, that medical students with higher empathy scores would obtain higher ratings of clinical competence in core clinical clerkships; and secondly, that women would obtain higher empathy scores than men. Materials and subjects, A 20-item empathy scale developed by the authors (Jefferson Scale of Physician Empathy) was completed by 371 third-year medical students (198 men, 173 women). Methods, Associations between empathy scores and ratings of clinical competence in six core clerkships, gender, and performance on objective examinations were studied by using t -test, analysis of variance, chi-square and correlation coefficients. Results, Both research hypotheses were confirmed. Empathy scores were associated with ratings of clinical competence and gender, but not with performance in objective examinations such as the Medical College Admission Test (MCAT), and Steps 1 and 2 of the US Medical Licensing Examinations (USMLE). Conclusions, Empathy scores are associated with ratings of clinical competence and gender. The operational measure of empathy used in this study provides opportunities to further examine educational and clinical correlates of empathy, as well as stability and changes in empathy at different stages of undergraduate and graduate medical education. [source] How integrating industrial design in the product development process impacts on company performanceTHE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 1 2001Gerda Gemser There is a growing belief that investing in industrial design is beneficial to company performance. This article sheds more light on how and when integrating industrial design in the product development process can enhance a company's competitive position. The basic premise is that the impact of industrial design on company performance is not unconditional, but dependent on industry evolution and design strategy. We opted to define industrial design in a general way, namely as the activity that transforms a set of product requirements into a configuration of materials, elements and components. This activity can have an impact on a product's appearance, user friendliness, ease of manufacture, efficient use of materials, functional performance, and so on. The empirical data incorporated in this study stems from two Dutch manufacturing industries, namely home furniture and precision instruments. Home furniture and precision instruments were selected because the strategy of integrating industrial design in the product development process is rather mature in the first-named industry and emerging in the second. We collected data from firms investing considerably in industrial design (n = 23) and firms investing little to nothing in industrial design (n = 24), using a semistructured questionnaire that was administrated during face-to-face sessions with senior managers. Two out of the three research hypotheses were supported. It was found that the extent to which firms integrate industrial design in new product development projects has a significant and positive influence on company performance (Hla), in particular when the strategy of investing in industrial design is relatively new for the industry involved (Hlb). There was no systematic pattern indicating that design innovation is more important in industries where the use of design is mature than in industries where the use of design is emerging (H2). Instead, we found that design innovation has significant positive performance effects in both types of industries. One important managerial inference from our study is that new product development managers should consider the changing nature of competition during industry evolution while developing strategies that encompass the use of industrial design in new product development. Another important managerial inference is that, besides being innovative in the field of products, being innovative with respect to design and design strategy can help to enhance competitiveness regardless of industry evolution. [source] Use of inhaled nitric oxide in the new born period: results from the European inhaled nitric oxide registryACTA PAEDIATRICA, Issue 6 2010Chris Dewhurst Abstract Aims:, The aim of this study was to present data relating to the use of inhaled nitric oxide (iNO) in newborn infants included in the European Inhaled Nitric Oxide Registry. Methods:, Demographic, clinical and therapeutic data from seven European centres are reported. Univariate analyses were performed to identify factors associated with acute response to iNO and survival without extra corporeal membrane oxygenation (ECMO). Results:, A total of 112 newborn infants received iNO, with 40% being less than 34 weeks gestational age. The commonest indication for iNO was secondary pulmonary hypertension. Acute response to iNO was more common in infants with a higher oxygenation index (median OI 32.7 vs 22.6, p = 0.040), although acute response did not predict survival without ECMO. Infants who survived without ECMO had a lower OI prior to therapy (median OI 24 vs 43, p = 0.009), were commenced on a higher starting dose (median dose 20 ppm vs 10 ppm p = 0.013) and received a lower maintenance dose (median dose 10 vs 17 ppm, p = 0.027) than those who died or received ECMO. Conclusion:, Collating and reporting data about iNO therapy in neonates across a number of European centres using a web-based system is feasible. These data may be used to monitor the clinical use of iNO, identify adverse effects, generate research hypotheses and promote high standards in the clinical use of iNO. [source] Voluntary Disclosure of Good and Bad Earnings News in a Low Litigation Setting,ACCOUNTING PERSPECTIVES, Issue 4 2008Philip T. Sinnadurai ABSTRACT This study uses a historical setting in which expected litigation costs were low (i.e., Australia, from 1993 to 1996) to investigate whether companies with good news were more likely to preempt annual earnings than their counterparts with bad news. Empirical tests compare the probability of preemption conditional on having good news with the probability of preemption conditional on having bad news. The models control for other potential determinants of disclosure policy that have been documented in the literature. The results do not support the research hypothesis that companies with good news were more likely to preempt annual earnings than companies with bad news. This finding suggests that there may be other factors driving disclosure of bad news, in addition to those acknowledged in the extant literature. The evidence also indicates that in Australia during the investigation period, the probability of preemption was positively associated with firm size and analyst following and differed as a function of industry membership. [source] At what degree of belief in a research hypothesis is a trial in humans justified?JOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 2 2002Benjamin Djulbegovic MD Abstract Rationale, aims and objectives,Randomized controlled trials (RCTs) have emerged as the most reliable method of assessing the effects of health care interventions in clinical medicine. However, RCTs should be undertaken only if there is substantial uncertainty about which of the trial treatments would benefit a patient most. The purpose of this study is to determine the degree of uncertainty in a research hypothesis before it can empirically be tested in an RCT. Methods,We integrated arguments from three independent lines of research , on ethics, principles of the design and conduct of clinical trials, and medical decision making , to develop a decision model to help solve the dilemma of under which circumstances innovative treatments should be tested in an RCT. Results,We showed that RCTs are the preferable option to resolve uncertainties about competing treatment alternatives whenever we desire reliable, undisputed, high-quality evidence with a low likelihood of false-positive or false-negative results. Conclusions When the expected benefit : risk ratio of a new treatment is small, an RCT is justified to resolve uncertainties over a wide range of prior belief (e.g. 10,90%) in the accuracy of the research hypothesis. Randomized controlled trials represent the best means for resolving uncertainties about health care interventions. [source] | |||||||||||||