Home About us Contact
|
Home About us Contact | ||
|
|
||
External Stressors (external + stressor)
Selected AbstractsAqueous exposure to 4-nonylphenol and 17,-estradiol increases stress sensitivity and disrupts ion regulatory ability of juvenile Atlantic salmonENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2007Darren T. Lerner Abstract Population declines of wild Atlantic salmon have been attributed to an array of anthropogenic disturbances, including dams, commercial and recreational fishing, habitat loss, and pollution. Environmental contaminants in particular, can act as environmental stressors on fish, typically causing disruption of ion homeostasis due to their close association with the aquatic environment. To examine the effects of the xenoestrogen 4-nonylphenol (NP) or 17,-estradiol (E2) on stress sensitivity and ion regulation, we exposed juvenile Atlantic salmon continuously for 21 d to either 10 or 100 ,g/L NP (NP-L or NP-H), 2 ,g/L E2 (positive control), or vehicle control during the parr-smolt transformation in April. After treatment, fish were sampled in freshwater (FW), transferred to 30, seawater (SW) for 24 h, or subjected to a handling stress. Estradiol and NP-H increased plasma vitellogenin in males and females, and E2 increased gonadosomatic index only in males. In FW, E2 reduced sodium potassium,activated adenosine triphosphatase activity as well as plasma levels of growth hormone, insulin-like growth factor I, and triiodothyronine. Both E2 and NP-H reduced plasma sodium in FW and increased plasma chloride in SW. Plasma Cortisol levels pre- and poststressor were significantly elevated by all treatments relative to controls, but only E2 increased plasma glucose before and after the stressor. These results indicate that exposure of anadromous salmonids to environmental estrogens heightens sensitivity to external stressors, impairs ion regulation in both FW and SW, and disrupts endocrine pathways critical for smolt development. [source] Stress and health in novice and experienced nursing studentsJOURNAL OF ADVANCED NURSING, Issue 2 2010Cristobal Jimenez jimenez c., navia-osorio p.m. & diaz c.v. (2010) Stress and health in novice and experienced nursing students. Journal of Advanced Nursing66(2), 442,455. Abstract Title.,Stress and health in novice and experienced nursing students Aim., This paper is a report of a study conducted to identify the differences in novice and experienced nursing students' reports of stress and health. Background., Stress from clinical practice and its impact are international yet culturally mediated phenomena. Nursing students are under considerable stress during clinical practice periods, putting their education and health at risk. However, there is little or no empirical evidence about the stress suffered by nursing students and its impact on their health throughout clinical practice. Methods., We performed cross-sectional research using standard information gathering tools. This study was carried out with 357 students from all 3 years of a nursing diploma programme at a Spanish nursing college (71% response rate). The data were collected over an 8-month period in 2004,2005. Findings., We identified three types of stressors (clinical, academic and external) and two categories of symptoms (physiological and psychological) linked to clinical practice. Factor analysis identified six major sources of stress and six important symptoms. Students perceived clinical stressors more intensely than academic and external stressors, and showed psychological symptoms more frequently than physiological symptoms. Nursing students from all 3 years perceived moderate stress at similar levels. Experienced students perceived more academic stressors than novices. Although the students were healthy, second year students were the most vulnerable to somatic and psychic anxiety, and common symptoms. Conclusion., We suggest informing students about possible stressors associated with their profession, and introducing interventions to support development of professionalism, social skills and coping capacity for clinical practice. [source] The clinical benefit of moisturizersJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 6 2005M Lodén ABSTRACT Moisturizing creams marketed to consumers often contain trendy ingredients and are accompanied by exciting names and attractive claims. Moisturizers are also an important part of the dermatologist's armamentarium to treat dry skin conditions and maintain healthy skin. The products can be regarded as cosmetics, but may also be regulated as medicinal products if they are marketed against dry skin diseases, such as atopic dermatitis and ichthyosis. When moisturizers are used on the so-called dry skin, many distinct disorders that manifest themselves with the generally recognized symptoms of dryness are treated. Dryness is not a single entity, but is characterized by differences in chemistry and morphology in the epidermis depending on the internal and external stressors of the skin. Patients and the society expect dermatologists and pharmacists to be able to recommend treatment for various dry skin conditions upon evidence-based medicine. Learning objective, Upon completing this paper, the reader should be aware of different types of moisturizers and their major constituents. Furthermore, s/he will know more about the relief of dryness symptoms and the functional changes of the skin induced by moisturizers. [source] Recent insights into R gene evolutionMOLECULAR PLANT PATHOLOGY, Issue 5 2006JOHN M. MCDOWELL SUMMARY Plants are under strong evolutionary pressure to maintain surveillance against pathogens. Resistance (R) gene-dependent recognition of pathogen avirulence (Avr) determinants plays a major role in plant defence. Here we highlight recent insights into the molecular mechanisms and selective forces that drive the evolution of NB-LRR (nucleotide binding-leucine-rich repeat) resistance genes. New implications for models of R gene evolution have been raised by demonstrations that R proteins can detect cognate Avr proteins indirectly by ,guarding' virulence targets, and by evidence that R protein signalling is regulated by intramolecular interactions between different R functional domains. Comparative genomic surveys of NB-LRR diversity in different species have revealed ancient NB-LRR lineages that are unequally represented among plant taxa, consistent with a Birth and Death Model of evolution. The physical distribution of NB-LRRs in plant genomes indicates that tandem and segmental duplication are important factors in R gene proliferation. The majority of R genes reside in clusters, and the frequency of recombination between clustered genes can vary strikingly, even within a single cluster. Biotic and abiotic factors have been shown to increase the frequency of recombination in reporter transgene-based assays, suggesting that external stressors can affect genome stability. Fitness penalties have been associated with some R genes, and population studies have provided evidence for maintenance of ancient R allelic diversity by balancing selection. The available data suggest that different R genes can follow strikingly distinct evolutionary trajectories, indicating that it will be difficult to formulate universally applicable models of R gene evolution. [source] Community as a factor in implementing interorganizational partnerships: Issues, constraints, and adaptationsNONPROFIT MANAGEMENT & LEADERSHIP, Issue 1 2003Elizabeth A. Mulroy This article reports findings from a community-based study of collaboration among seven nonprofit human service agencies in a very low-income urban neighborhood. The project, funded by a federal demonstration grant, was developed to prevent child abuse and neglect as an alternative to the existing public child welfare system. Findings suggest that privatization, funding uncertainties, and community-level factors posed external stressors that constrained executives' ability to collaborate. The article identifies five key stressors, analyzes how each constrained the partnership, and then discusses specific adaptations made by executive leadership in political, technical, and interpersonal areas that facilitated strategic adjustment and realignment in a very complex interorganizational arrangement and set of relationships. Finally, implications are drawn for nonprofit managers, social policy, and nonprofit research. [source] | |||||||||||||