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Literature Study (literature + study)
Selected AbstractsDietary specialization and infochemical use in carnivorous arthropods: testing a conceptENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2003Johannes L. M. Steidle Abstract For the location of hosts and prey, insect carnivores (i.e., parasitoids or predators) often use infochemical cues that may originate from the host/prey itself but also from the food of the host/prey, a food plant, or another feeding substrate. These cues can be either specific for certain host/prey complexes or generally present in various complexes, and the reaction of the carnivores to these cues is either innate or learned. According to the concept on dietary specialization and infochemical use in natural enemies, the origin and specificity of the infochemical cues used and the innateness of the behavioural response are dependent on the degree of dietary specialization of the carnivore and its host/prey species. This concept has been widely adopted and has been frequently cited since its publication. Only few studies, however, have been explicitly designed to test predictions of the concept. Thus, more than 10 years after publication and despite of its broad acceptance, the general validity of the concept is still unclear. Using data from about 140 research papers on 95 species of parasitoids and predators, the present literature study comparatively scrutinises predictions from the concept. In accordance with the concept, learning to react to infochemicals and the use of general host and host plant cues was more often found in generalists than in specialists. In addition, more specialists were using specific infochemicals than generalists. In contrast to the concept, however, there was no significant difference between specialists and generalists in the proportion of carnivore species that use infochemicals during foraging and also extreme generalists are using infochemical cues for foraging. Likewise, an innate reaction to infochemicals was found in both specialists and generalists. Several reasons why infochemical use, including an innate reaction to infochemicals, is adaptive in generalist carnivores are discussed . We conclude that the concept has been a useful paradigm in advancing the chemical ecology of arthropod carnivores, but needs to be modified: the use of infochemicals is expected in all arthropod carnivores, regardless of dietary specialization. [source] Assessing functional health status in adults with haemophilia: towards a preliminary core set of clinimetric instruments based on a literature search in Rheumatoid Arthritis and OsteoarthritisHAEMOPHILIA, Issue 4 2005P. De Kleijn Summary., People with haemophilia experience a progressive deterioration of their functional health status. Regular clinical assessment of functional health status provides insight into their process of disablement. As such, the development of a core-set of measurement tools is warranted. The aim of this study was to gather data to prepare a (preliminary) core set of clinically relevant and feasible instruments to assess the functional health status of adults with haemophilia, and to indicate their psychometric qualities. Therefore, clinimetric instruments frequently used in two haemophilia-resembling diseases (Rheumatoid Arthritis and Osteoarthritis) were reviewed from the literature. An extensive search in Medline yielded 13 relevant review articles, incorporating a total of 182 instruments, of which 40 were appropriate for haemophilia. Of these 40 instruments 3 measure body structures, 13 body functions, 19 activities (of which 5 are performance based and 14 self-report based), and 3 measure participation. This classification is based on the International Classification of Functioning, Disability and Health. Detailed information regarding the psychometrics (reliability, validity and responsiveness) of four instruments is described fully in the literature, whereas the psychometrics of the majority of the other instruments are only partly described. The results of this literature study may contribute to the formation of a (preliminary) core set of clinimetric instruments to assess the functional health status of adults with haemophilia. Decisions on the final core set should be held within the Musculoskeletal Committee of the World Federation of Haemophilia. [source] Genetic Polymorphisms Related to Delirium Tremens: A Systematic ReviewALCOHOLISM, Issue 2 2007Barbara C. Van Munster Background: Delirium tremens (DT) is one of the more severe complications of alcohol withdrawal (AW), with a 5 to 10% lifetime risk for alcohol-dependent patients. The 2 most important neurosystems involved in AW are , -aminobutyric acid and glutamate. It is unknown whether these neurosystems are involved in the pathophysiology of DT as well. The candidate gene approach in DT could contribute to this knowledge and demonstrate a possible genetic predisposition for DT. The purpose of this study is to give an overview of all studied genetic polymorphisms in the diverse candidate genes related to DT and to summarize what these studies contribute to insights into the pathophysiology of DT. Methods: The inclusion criteria for this literature study were articles in English analyzing the association between a genetic polymorphism and DT without other AW syndromes. Studies were identified until February 2006 in MEDLINE and EMBASE databases. Results: We found 25 studies dealing with 30 polymorphisms, located in 19 different genes. Positive associations were found in 3 different candidate genes involved in the dopamine transmission, 1 gene involved in the glutamate pathway, 1 neuropeptide gene, and 1 cannabinoid gene. Two candidate genes involved in the dopamine transmission, dopamine receptor D3, and solute carrier family 6, were each associated with DT in 2 different study populations. The other 4 positive associations were not replicated in other studies. Conclusions: A total of 8 positive associations out of 30 polymorphisms makes a genetic base for DT plausible. Understanding the pathophysiological process of the development of DT has, indeed, been augmented by the reviewed genetic association studies. These studies suggest that the regulation of dopaminergic neurotransmission may play an important role. [source] Individualized duration of oral anticoagulant therapy for deep vein thrombosis based on a decision modelJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 12 2003R. Vink Summary.,Background:,The optimal duration of oral anticoagulant therapy for patients with a first episode of deep vein thrombosis (DVT) is still a matter of debate. However, according to the ACCP consensus strategy a limited stratification in treatment duration is advocated, i.e. 3 months for patients with a transient risk factor and 1 year or longer for patients with recurrent disease or a consistent risk factor such as thrombophilia or cancer. This consensus strategy is founded on the mean optimal duration of therapy obtained in large cohorts of patients and is mainly based on the risk of recurrent venous thromboembolism (VTE), with only minimal consideration for the patient's bleeding risk. Objective:,The aim of this study is to optimize the anticoagulant treatment strategy with vitamin K antagonists for the individual patient with DVT. Methods:,Based on an extensive literature study, a mathematical model was constructed to balance the risk of recurrent VTE against the risk of major hemorrhagic complications. The following parameters are incorporated in the model: baseline estimates and risk factors for recurrent VTE and bleeding, clinical course of DVT, and efficacy of treatment with vitamin K antagonists. With the use of these parameters, the risk for a recurrent VTE and a bleeding episode can be calculated for the individual patient. The optimal duration of anticoagulant therapy can be defined as the timepoint at which the benefit of treatment (prevention of VTE) is counterbalanced by its risk (bleeding). Results/conclusions:,How long a patient should receive anticoagulant treatment is a matter of balancing the benefits and risks of treatment. The model shows that the optimal treatment duration varies greatly from patient to patient according to the patient's unique bleeding and recurrence risk. [source] Influencing product lifetime through product designBUSINESS STRATEGY AND THE ENVIRONMENT, Issue 5 2005Nicole van Nes Abstract This article investigates the possibility of influencing product lifetime through product design. First, the results of a literature study on consumer behavior are presented. These show that surprisingly few researchers have focused specifically on the arousal of the need to replace a product. Therefore, empirical data about motives for product replacement were acquired through a combination of qualitative investigation and a quantitative survey. This resulted in a model of factors influencing the replacement decision and in a replacement typology. Finally, possible design directions for longer lasting products were explored. It was concluded that despite the variety of replacement motivations people basically want a well functioning and up to date product that meets their altering needs. This requires the development of dynamic and flexible products, which implies designing for variability and product attachment and preparing the product for future repair or upgrading. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment. [source] | ||||||||||