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Active Development (active + development)
Selected AbstractsHyperthermia in utero due to maternal influenza is an environmental risk factor for schizophreniaCONGENITAL ANOMALIES, Issue 3 2007Marshall J. Edwards ABSTRACT A hypothesis is presented that the association between maternal influenza and other causes of fever during the second trimester of pregnancy and the subsequent development of schizophrenia in the child is due to the damage caused by hyperthermia to the developing amygdalohippocampal complex and associated structures in the fetal brain. Hyperthermia is a known cause of congenital defects of the central nervous system and other organs after sufficiently severe exposures during early organogenesis. The pathogenic mechanisms include death of actively dividing neuroblasts, disruption of cell migration and arborization and vascular damage. In experimental studies, hyperthermia during later stages of central nervous system development also caused damage to the developing brainstem that was associated with functional defects. This damage usually results in hypoplasia of the parts undergoing active development at the time of exposure. Recent studies have shown no evidence of direct invasion of the fetus by the influenza virus. Factors that might interact with hyperthermia include familial liability to schizophrenia, season of birth, maternal nutrition, severe stress and medications used to alleviate the symptoms of fevers. The time of the development of the fetal amygdalohippocampal complex and the changes found in its structure and associated areas of the brain are compatible with the known effects of hyperthermia. [source] Phototrophs in high iron microbial mats: microstructure of mats in iron-depositing hot springsFEMS MICROBIOLOGY ECOLOGY, Issue 3 2000Beverly K Pierson Abstract Chocolate Pots Hot Springs in Yellowstone National Park are high in ferrous iron, silica and bicarbonate. The springs are contributing to the active development of an iron formation. The microstructure of photosynthetic microbial mats in these springs was studied with conventional optical microscopy, confocal laser scanning microscopy and transmission electron microscopy. The dominant mats at the highest temperatures (48,54°C) were composed of Synechococcus and Chloroflexus or Pseudanabaena and Mastigocladus. At lower temperatures (36,45°C), a narrow Oscillatoria dominated olive green cyanobacterial mats covering most of the iron deposit. Vertically oriented cyanobacterial filaments were abundant in the top 0.5 mm of the mats. Mineral deposits accumulated beneath this surface layer. The filamentous microstructure and gliding motility may contribute to binding the iron minerals. These activities and heavy mineral encrustation of cyanobacteria may contribute to the growth of the iron deposit. Chocolate Pots Hot Springs provide a model for studying the potential role of photosynthetic prokaryotes in the origin of Precambrian iron formations. [source] Preparation for Crisis Management: A Proposed Model and Empirical EvidenceJOURNAL OF CONTINGENCIES AND CRISIS MANAGEMENT, Issue 3 2004S. Elsubbaugh This article explores the forces restricting effective crisis management in a crisis ridden industry. Models of crisis preparedness have typically been developed based upon research in US or Western business. This study is based upon the Egyptian industry which, until the 1990s was state owned and heavily state supported. Changes in government policy, combined with external forces, not in the least the loss of markets in the previous Soviet bloc, had plunged the industry into serious crisis. Crisis is a cultural embarrassment to most Egyptian managers and this, combined with the depth of economic difficulties faced by the industry, makes it extraordinarily difficult for any level of crisis preparedness to be achieved. Based on interview and questionnaire data, this article extends existing models of crisis preparedness to better accommodate conditions in crisis prone industries outside the West. New dimensions in the proposed model are the stress on national culture and how this limits the range of managerial responses. This in turn requires the active development of an organisational culture to counteract these limitations. [source] Impact of Policy Shifts on South Asian Carers in the United KingdomJOURNAL OF POLICY AND PRACTICE IN INTELLECTUAL DISABILITIES, Issue 1 2005Elizabeth Hensel Abstract, The aim of this study was to assess how the introduction of new service policies in the United Kingdom , such as person-centered planning and the active development of support networks , was impacting the lives of carers of people with intellectual disability from South Asian backgrounds. Using a semistructured interview schedule, 19 families of South Asian background living in an urban conurbation were interviewed about their service use and needs with respect to providing care for their family member with an intellectual disability. The families experienced material disadvantage, poor health, and did not access services to the same extent as did the general population in the UK. Overall, community participation was low and only two individuals with an intellectual disability had a care plan as outlined in the latest UK government policies. The introduction of these new policies did not appear to have positively impacted the lives of the individuals interviewed in this study. The results were similar to findings of studies in other parts of Britain: that is, the culture of caring and protecting the individual with an intellectual disability, combined with the importance of family life over an outside social life, ran somewhat counter to the underlying principles of current national disability policy (i.e., promoting individual rights and independent living). It is suggested that attempts to implement these policies risks alienating carers of South Asian descent from service providers and their implementation must be done in a culturally sensitively context. [source] Lead Zirconate Titanate Particle Dispersion in Thick-Film Ink FormulationsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2000Erik S. Thiele Diverse device applications for lead zirconate titanate (PZT) ceramics in thick-film form are currently in active development. In the present study, the particle dispersion properties of thick-film ink formulations containing PZT powder have been determined using rheological measurements. Although all of the eight commercially available dispersants tested are more effective than the terpineol solvent alone in decreasing attractive interparticle forces in suspensions, the best dispersant identified for hard and soft PZT powders is a phosphate ester oligomer. This dispersant is extremely efficient, and its use in thick-film ink formulations results in viscosity decreases of 50% at low shear rates (10 s,1) and 30% at high shear rates (100 s,1) compared with current ink formulations containing no dispersant. The effects upon rheology of the order of addition of components in the processing of inks have been studied, with the most effective processing route using a fugitive solvent that probably facilitates uniform coverage of the particle surfaces by the dispersant molecules. Modeling of the rheological profiles of inks indicates that the use of a dispersant decreases the depth of the primary minimum in the interparticle potential by a factor of 3. Demonstrated advantages of the use of a dispersant in PZT thick-film inks include improved microstructural homogeneity in the green body and the ability to formulate printable inks with higher solids loadings. No adverse effects of the dispersant upon the dielectric and piezoelectric properties of bulk PZT samples are found following burnout and sintering. [source] Determination of Sample Sizes for Demonstrating Efficacy of Radiation CountermeasuresBIOMETRICS, Issue 1 2010Ralph L. Kodell Summary In response to the ever increasing threat of radiological and nuclear terrorism, active development of nontoxic new drugs and other countermeasures to protect against and/or mitigate adverse health effects of radiation is ongoing. Although the classical LD50 study used for many decades as a first step in preclinical toxicity testing of new drugs has been largely replaced by experiments that use fewer animals, the need to evaluate the radioprotective efficacy of new drugs necessitates the conduct of traditional LD50 comparative studies (FDA, 2002,,Federal Register,67, 37988,37998). There is, however, no readily available method to determine the number of animals needed for establishing efficacy in these comparative potency studies. This article presents a sample-size formula based on Student's,t,for comparative potency testing. It is motivated by the U.S. Food and Drug Administration's (FDA's) requirements for robust efficacy data in the testing of response modifiers in total body irradiation experiments where human studies are not ethical or feasible. Monte Carlo simulation demonstrated the formula's performance for Student's,t, Wald, and likelihood ratio tests in both logistic and probit models. Importantly, the results showed clear potential for justifying the use of substantially fewer animals than are customarily used in these studies. The present article may thus initiate a dialogue among researchers who use animals for radioprotection survival studies, institutional animal care and use committees, and drug regulatory bodies to reach a consensus on the number of animals needed to achieve statistically robust results for demonstrating efficacy of radioprotective drugs. [source] WHAT MAKES A CGRP2 RECEPTOR?CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 10 2007DL Hay SUMMARY 1Heterogeneity in the receptors for the neuropeptide calcitonin gene-related peptide (CGRP) has been apparent for nearly 20 years. This is most clearly manifested in the observation of CGRP8,37 -sensitive and -insensitive populations of CGRP-activated receptors. The pA2 values for CGRP8,37 in excess of 7 are widely considered to be the result of antagonism of CGRP1 receptors, whereas those below 7 are believed to be the consequence of antagonism of a second population of receptors, namely CGRP2 receptors. 2However, a multitude of pA2 values exist for CGRP8,37, spanning several log units, and as such no obvious clusters of values are apparent. Understanding the molecular nature of the receptors that underlie this phenomenon is likely to aid the development of selective pharmacological tools to progress our understanding of the physiology of CGRP and related peptides. Because there is active development of CGRP agonists and antagonists as therapeutics, such information would also further this pursuit. 3The CGRP1 receptor is pharmacologically and molecularly well defined as a heterodimer of the calcitonin receptor-like receptor (CL) and receptor activity modifying protein (RAMP) 1. The CL/RAMP1 complex is highly sensitive to CGRP8,37. Conversely, the constituents of the CGRP2 receptor have not been identified. In fact, there is little evidence for a distinct molecular entity that represents the CGRP2 receptor. 4Recent pharmacological characterization of receptors related to CGRP1 has revealed that some of these receptors may explain CGRP2 receptor pharmacology. Specifically, AMY1(a) (calcitonin receptor/RAMP1) and AM2 (CL/RAMP3) receptors can be activated by CGRP but are relatively insensitive to CGRP8,37. 5This, along with other supporting data, suggests that the ,CGRP2 receptor' that has been extensively reported in the literature may, in fact, be an amalgamation of contributions from a variety of CGRP-activated receptors. The use of appropriate combinations of agonists and antagonists, along with receptor expression studies, could allow such receptors to be separated. [source] | |||||||||||||