230 resultados para French, Steven: Key concepts in philosophy
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Alfred Schütz original contribution to the social sciences refers to his analysis of the structure of the "life-world". This article aims to invigorate interest in the work of this author, little known in the field of health psychology. Key concepts of Schütz' approach will be presented in relation to their potential interest to the understanding of the experience of illness. In particular, we develop the main characteristics of the everyday life and its cognitive style, that is, its finite province of meaning. We propose to adopt this notion to define the experience of chronic or serious illness when the individual is confronted to the medical world. By articulating this analysis with literature in health psychology, we argue that Schütz's perspective brings useful insight to the field, namely because of its ability to study meaning constructions by overcoming the trap of solipsism by embracing intersubjectivity. The article concludes by outlining both, the limitations and research perspectives brought by this phenomenological analysis of the experiences of health and illness.
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Studies on niche evolution allow us to establish how species niches have changed over time as well as to identify how long-term evolutionary processes have led to present-day species distributions. Here, we investigate the patterns of climatic niche evolution in Tynanthus (Bignonieae, Bignoniaceae), a genus comprising narrowly distributed species. We test the hypothesis that niche conservatism has played an important role in the diversification history of this group of Neotropical lianas. For that, we perform univariate and multivariate comparisons between species' climatic niches and associated environmental data with information on species' phylogenetic relationships. We encountered considerable divergence in niches among species, indicating that niche conservatism in climatic variables has does not seem to havenot played a key role in the diversification of the genus. Our results are used as a basis to discuss patterns of ecological niche evolution in the group and to suggest novel approaches for future analyses.
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Stereochemical factors are known to play a significant role in the metabolism of drugs and other xenobiotics. Following Prelog's lead, types of metabolic stereoselectivity can be categorized as (i) substrate stereoselectivity (the differential metabolism of two or more stereoisomeric substrates) and (ii) product stereoselectivity (the differential formation of two or more stereoisomeric metabolites from a single substrate). Combinations of the two categories exist as (iii) substrate-product stereoselectivities, meaning that product stereoselectivity itself is substrate stereoselective. Here, published examples of metabolic stereoselectivities are examined in the light of these concepts. In parallel, a graphical scheme is presented with a view to facilitate learning and help researchers to solve classification problems.
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Lactate, a product of glycolysis, has been shown to play a key role in the metabolic support of neurons/axons in the CNS by both astrocytes and oligodendrocytes through monocarboxylate transporters (MCTs). Despite such importance in the CNS, little is known about MCT expression and lactate function in the PNS. Here we show that mouse MCT1, MCT2, and MCT4 are expressed in the PNS. While DRG neurons express MCT1, myelinating Schwann cells (SCs) coexpress MCT1 and MCT4 in a domain-specific fashion, mainly in regions of noncompact myelin. Interestingly, SC-specific downregulation of MCT1 expression in rat neuron/SC cocultures led to increased myelination, while its downregulation in neurons resulted in a decreased amount of neurofilament. Finally, pure rat SCs grown in the presence of lactate exhibited an increase in the level of expression of the main myelin regulator gene Krox20/Egr2 and the myelin gene P0. These data indicate that lactate homeostasis participates in the regulation of the SC myelination program and reveal that similar to CNS, PNS axon-glial metabolic interactions are most likely mediated by MCTs.
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Understanding the basis on which recruiters form hirability impressions for a job applicant is a key issue in organizational psychology and can be addressed as a social computing problem. We approach the problem from a face-to-face, nonverbal perspective where behavioral feature extraction and inference are automated. This paper presents a computational framework for the automatic prediction of hirability. To this end, we collected an audio-visual dataset of real job interviews where candidates were applying for a marketing job. We automatically extracted audio and visual behavioral cues related to both the applicant and the interviewer. We then evaluated several regression methods for the prediction of hirability scores and showed the feasibility of conducting such a task, with ridge regression explaining 36.2% of the variance. Feature groups were analyzed, and two main groups of behavioral cues were predictive of hirability: applicant audio features and interviewer visual cues, showing the predictive validity of cues related not only to the applicant, but also to the interviewer. As a last step, we analyzed the predictive validity of psychometric questionnaires often used in the personnel selection process, and found that these questionnaires were unable to predict hirability, suggesting that hirability impressions were formed based on the interaction during the interview rather than on questionnaire data.
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Store-operated Ca(2+) channels (SOCs) are voltage-independent Ca(2+) channels activated upon depletion of the endoplasmic reticulum Ca(2+) stores. Early studies suggest the contribution of such channels to Ca(2+) homeostasis in insulin-secreting pancreatic β-cells. However, their composition and contribution to glucose-stimulated insulin secretion (GSIS) remains unclear. In this study, endoplasmic reticulum Ca(2+) depletion triggered by acetylcholine (ACh) or thapsigargin stimulated the formation of a ternary complex composed of Orai1, TRPC1, and STIM1, the key proteins involved in the formation of SOCs. Ca(2+) imaging further revealed that Orai1 and TRPC1 are required to form functional SOCs and that these channels are activated by STIM1 in response to thapsigargin or ACh. Pharmacological SOCs inhibition or dominant negative blockade of Orai1 or TRPC1 using the specific pore mutants Orai1-E106D and TRPC1-F562A impaired GSIS in rat β-cells and fully blocked the potentiating effect of ACh on secretion. In contrast, pharmacological or dominant negative blockade of TRPC3 had no effect on extracellular Ca(2+) entry and GSIS. Finally, we observed that prolonged exposure to supraphysiological glucose concentration impaired SOCs function without altering the expression levels of STIM1, Orai1, and TRPC1. We conclude that Orai1 and TRPC1, which form SOCs regulated by STIM1, play a key role in the effect of ACh on GSIS, a process that may be impaired in type 2 diabetes.
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Imaging plays a key role in the detection of a diaphragmatic pathology in utero. US is the screening method, but MRI is increasingly performed. Congenital diaphragmatic hernia is by far the most often diagnosed diaphragmatic pathology, but unilateral or bilateral eventration or paralysis can also be identified. Extralobar pulmonary sequestration can be located in the diaphragm and, exceptionally, diaphragmatic tumors or secondary infiltration of the diaphragm from tumors originating from an adjacent organ have been observed in utero. Congenital abnormalities of the diaphragm impair normal lung development. Prenatal imaging provides a detailed anatomical evaluation of the fetus and allows volumetric lung measurements. The comparison of these data with those from normal fetuses at the same gestational age provides information about the severity of pulmonary hypoplasia and improves predictions about the fetus's outcome. This information can help doctors and families to make decisions about management during pregnancy and after birth. We describe a wide spectrum of congenital pathologies of the diaphragm and analyze their embryological basis. Moreover, we describe their prenatal imaging findings with emphasis on MR studies, discuss their differential diagnosis and evaluate the limits of imaging methods in predicting postnatal outcome.
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The phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway regulates multiple cellular processes. An overactivation of the pathway is frequently present in human malignancies and plays a key role in cancer progression. Hence, its inhibition has become a promising approach in cancer therapy. However, the development of resistances, such as the abrogation of negative feedback mechanisms or the activation of other proliferative signaling pathways, has considerably limited the anticancer efficacy of PI3K/AKT inhibitors. In addition, emerging evidence points out that although AKT is acknowledged as the major downstream effector of PI3K, both PI3K and AKT can operate independently of each other in cancer, revealing another level of complexity in this pathway. Here, we highlight the complex relationship between PI3K and AKT in cancer and further discuss the consequences of this relationship for cancer therapy.
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INTRODUCTION: Dispatch-assisted cardiopulmonary resuscitation (DA-CPR) plays a key role in out-of-hospital cardiac arrests. We sought to measure dispatchers' performances in a criteria-based system in recognizing cardiac arrest and delivering DA-CPR. Our secondary purpose was to identify the factors that hampered dispatchers' identification of cardiac arrests, the factors that prevented them from proposing DA-CPR, and the factors that prevented bystanders from performing CPR. METHODS AND RESULTS: We reviewed dispatch recordings for 1254 out-of-hospital cardiac arrests occurring between January 1, 2011 and December 31, 2013. Dispatchers correctly identified cardiac arrests in 71% of the reviewed cases and 84% of the cases in which they were able to assess for patient consciousness and breathing. The median time to recognition of the arrest was 60s. The median time to start chest compression was 220s. CONCLUSIONS: This study demonstrates that performances from a criteria-based dispatch system can be similar to those from a medical-priority dispatch system regarding out-of-hospital cardiac arrest (OHCA) time recognition and DA-CPR delivery. Agonal breathing recognition remains the weakest link in this sensitive task in both systems. It is of prime importance that all dispatch centers tend not only to implement DA-CPR but also to have tools to help them reach this objective, as today it should be mandatory to offer this service to the community. In order to improve benchmarking opportunities, we completed previously proposed performance standards as propositions.
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The amyloid-β peptide or Aβ is the key player in the amyloid-cascade hypothesis of Alzheimer's disease. Aβ appears to trigger cell death but also production of double-strand breaks (DSBs) in aging and Alzheimer's disease. All-trans retinoic acid (RA), a derivative of vitamin A, was already known for its neuroprotective effects against the amyloid cascade. It diminishes, for instance, the production of Aβ peptides and their oligomerisation. In the present work we investigated the possible implication of RA receptor (RAR) in repair of Aβ-induced DSBs. We demonstrated that RA, as well as RAR agonist Am80, but not AGN 193109 antagonist, repair Aβ-induced DSBs in SH-SY5Y cells and an astrocytic cell line as well as in the murine cortical tissue of young and aged mice. The nonhomologous end joining pathway and the Ataxia Telangiectasia Mutated kinase were shown to be involved in RA-mediated DSBs repair in the SH-SY5Y cells. Our data suggest that RA, besides increasing cell viability in the cortex of young and even of aged mice, might also result in targeted DNA repair of genes important for cell or synaptic maintenance. This phenomenon would remain functional up to a point when Aβ increase and RA decrease probably lead to a pathological state.
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NlmCategory="UNASSIGNED">Alphaproteobacteria include many medically and environmentally important organisms. Despite the diversity of their niches and lifestyles, from free-living to host-associated, they usually rely on very similar mechanisms to control their cell cycles. Studies on Caulobacter crescentus still lay the foundation for understanding the molecular details of pathways regulating DNA replication and cell division and coordinating these two processes with other events of the cell cycle. This review highlights recent discoveries on the regulation and the mode of action of conserved global regulators and small molecules like c-di-GMP and (p)ppGpp, which play key roles in cell cycle control. It also describes several newly identified mechanisms that modulate cell cycle progression in response to stresses or environmental conditions.
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Renal biopsy is being increasingly proposed as a diagnostic tool to characterize small renal masses (SRM). Indeed, the wide adoption of imaging in the diagnostic workup of many diseases had led to a substantial increased incidence of SRM (diameter ≤4 cm). While modern ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) techniques have high sensitivity for detecting SRM, none is able to accurately and reliably characterize them in terms of histological features. This is currently of key importance in guiding clinical decision-making in some situations, and in these cases renal biopsy should be considered. In this review, we aim to summarize the technique, diagnostic performance, and predicting factors of nondiagnostic biopsy, as well as the future perspectives.
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Glucose is the most important metabolic substrate of the retina and maintenance of normoglycemia is an essential challenge for diabetic patients. Chronic, exaggerated, glycemic excursions could lead to cardiovascular diseases, nephropathy, neuropathy and retinopathy. We recently showed that hypoglycemia induced retinal cell death in mouse via caspase 3 activation and glutathione (GSH) decrease. Ex vivo experiments in 661W photoreceptor cells confirmed the low-glucose induction of death via superoxide production and activation of caspase 3, which was concomitant with a decrease of GSH content. We evaluate herein retinal gene expression 4 h and 48 h after insulin-induced hypoglycemia. Microarray analysis demonstrated clusters of genes whose expression was modified by hypoglycemia and we discuss the potential implication of those genes in retinal cell death. In addition, we identify by gene set enrichment analysis, three important pathways, including lysosomal function, GSH metabolism and apoptotic pathways. Then we tested the effect of recurrent hypoglycemia (three successive 4h periods of hypoglycemia spaced by 48 h recovery) on retinal cell death. Interestingly, exposure to multiple hypoglycemic events prevented GSH decrease and retinal cell death, or adapted the retina to external stress by restoring GSH level comparable to control situation. We hypothesize that scavenger GSH is a key compound in this apoptotic process, and maintaining "normal" GSH level, as well as a strict glycemic control, represents a therapeutic challenge in order to avoid side effects of diabetes, especially diabetic retinopathy.
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The World Health Organization (WHO) plans to submit the 11th revision of the International Classification of Diseases (ICD) to the World Health Assembly in 2018. The WHO is working toward a revised classification system that has an enhanced ability to capture health concepts in a manner that reflects current scientific evidence and that is compatible with contemporary information systems. In this paper, we present recommendations made to the WHO by the ICD revision's Quality and Safety Topic Advisory Group (Q&S TAG) for a new conceptual approach to capturing healthcare-related harms and injuries in ICD-coded data. The Q&S TAG has grouped causes of healthcare-related harm and injuries into four categories that relate to the source of the event: (a) medications and substances, (b) procedures, (c) devices and (d) other aspects of care. Under the proposed multiple coding approach, one of these sources of harm must be coded as part of a cluster of three codes to depict, respectively, a healthcare activity as a 'source' of harm, a 'mode or mechanism' of harm and a consequence of the event summarized by these codes (i.e. injury or harm). Use of this framework depends on the implementation of a new and potentially powerful code-clustering mechanism in ICD-11. This new framework for coding healthcare-related harm has great potential to improve the clinical detail of adverse event descriptions, and the overall quality of coded health data.
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This chapter assesses the theories and related empirical evidence regarding the factors that explain cultural innovation by cultural organizations. It begins by defining key concepts, including what is meant by a cultural organization, cultural innovation, and the innovation referent. The chapter identifies two main disciplines that have been interested in cultural innovation or innovative programming by cultural organizations: sociology and economics. The focus, contributions, and overlap of these two disciplinary approaches to cultural innovation are discussed, and the chapter concludes by identifying some gaps and putting forward some suggestions for future research.