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Selected AbstractsTextured Microstructure and Dielectric Properties Relationship of BaNd2Ti5O14 Thick Films Prepared by Electrophoretic DepositionADVANCED FUNCTIONAL MATERIALS, Issue 7 2009Zhi Fu Abstract An alternative approach to tailor the temperature coefficient of permittivity (TC,r) of high Q dielectric BaO,Re2O3,TiO2 (Re: rare earth elements) thick films is presented. 10- to 80-µm-thick BaNd2Ti5O14 (BNT) films are fabricated by electrophoretic deposition on Pt foils under different processing conditions. Observed anisotropic grain growth is facilitated by constrained sintering. The increase of the sintering temperature increases markedly the aspect ratio of the grains, decreases the dielectric permittivity and TC,r changes from ,114 to +12,ppm °C,1. By controlling the sintering temperature, near-zero TC,r, high Q thick films can be fabricated with 45,<,,r,<,70. These findings are of technological relevance since they demonstrate that control of substrate constraint and sintering conditions can be used to control grain anisotropy and thus microwave properties of the BaO,Re2O3,TiO2. The thick films facilitate scaling to small device sizes for high frequency operation. Similar observations are expected in other microwave systems thus opening further technological opportunities. [source] Amantadine for traumatic brain injury: does it improve cognition and reduce agitation?JOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 2 2005H. Leone PharmD Summary Objective:, To review the available literature pertaining to amantadine as therapy for improving cognition and reducing agitation following a non-penetrating traumatic brain injury (TBI). Data sources:, Clinical literature was accessed through MEDLINE (from 1966 to February 2004) and bibliographic searches. Key search terms included ,amantadine', ,traumatic brain injury', ,cognition', and ,agitation'. Data synthesis:, Amantadine is primarily used for treatment and prophylaxis of influenza A. Its ability to improve mentation and motor function in patients with head injury remains questionable. An evaluation of five clinical trials, two case reports, and one case series is conducted focusing on the use of amantadine following TBI. Patients in clinical trials were assessed using a variety of neuropsychological tools aimed at, among other things, assessing cognition and agitation. Although individual patient results varied, the majority of patients studied showed improved neuropsychological test scores. Similar observations are noted in the case reports and case series. Improvement in cognition and reduced agitation seems to occur with post-injury amantadine therapy. Conclusions:, Amantadine is a reasonable option for improving cognition and reducing agitation following a TBI but confirmatory evidence of the efficacy the drug is necessary. [source] ,, T cell receptor repertoire in blood and colonic mucosa of rhesus macaquesJOURNAL OF MEDICAL PRIMATOLOGY, Issue 6 2000Eva Rakasz Although their precise roles are not well defined, ,, T lymphocytes are recognized as regular components of immune responses. These cells express a limited T cell receptor repertoire and they can be stimulated by soluble ligands without conventional processing and presentation by major histocompatibility antigens. Progress in this area has been limited by the substantial differences between murine and human ,, T cells and the lack of knowledge about these cells in nonhuman primates. We used molecular analysis of T cell receptor diversity to characterize ,, T cell populations from peripheral blood and colon of rhesus macaques (Macaca mulatta). The ,, T cell receptor diversity was limited and distinct for these tissue compartments, particularly in the TCRGV2 family. Furthermore, the TCRDV1+ subset of peripheral blood ,, T cells showed signs of progressive oligoclonalization as a function of age. Similar observations have been reported for human tissue samples and our results validate rhesus macaques as an appropriate animal model for studying primate ,, T cell populations. [source] Plasminogen activator inhibitor-1 contributes to the deleterious effect of obesity on the outcome of thrombotic ischemic stroke in miceJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 8 2007N. NAGAI Summary.,Background:,It is widely accepted that obesity is a risk factor for ischemic heart disease, but the association with stroke is less clear. Adipose tissue is an important source of plasminogen activator inhibitor-1 (PAI-1), the main inhibitor of plasminogen activation. Objective:,To test the hypothesis that elevated PAI-1 levels associated with obesity negatively affect the outcome of thrombotic ischemic stroke. Methods:,Middle cerebral artery (MCA) occlusion was induced photochemically in mice with nutritionally induced or genetically determined obesity and their lean counterparts. Results:,The MCA occlusion time (to obtain complete occlusion) was significantly shorter in obese (nutritionally induced) than in lean wild-type (WT) C57Bl/6 mice, whereas the infarct size was significantly larger and intracranial hemorrhage (ICH) was enhanced (all P < 0.05). Similar observations were made in genetically obese ob/ob mice, as compared to lean WT littermates. In both strains, obesity was associated with markedly elevated circulating PAI-1 levels, probably originating from the fat tissue. In contrast, PAI-1-deficient lean and obese mice did not display significant differences in MCA occlusion time, infarct volume or ICH. Conclusions:,Plasminogen activator inhibitor-1 may play a functional role in the deleterious effect of obesity on the outcome of thrombotic ischemic stroke in mice. [source] Endocytosis of plasma-derived factor V by megakaryocytes occurs via a clathrin-dependent, specific membrane binding eventJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 3 2005B. A. BOUCHARD Summary., Megakaryocytes were analyzed for their ability to endocytose factor V to define the cellular mechanisms regulating this process. In contrast to fibrinogen, factor V was endocytosed by megakaryocytes derived from CD34+ cells or megakaryocyte-like cell lines, but not by platelets. CD41+ex vivo -derived megakaryocytes endocytosed factor V, as did subpopulations of the megakaryocyte-like cells MEG-01, and CMK. Similar observations were made for fibrinogen. Phorbol diester-induced megakaryocytic differentiation of the cell lines resulted in a substantial increase in endocytosis of both proteins as compared to untreated cells that did not merely reflect their disparate plasma concentrations. Factor IX, which does not associate with platelets or megakaryocytes, was not endocytosed by any of the cells examined. Endocytosis of factor V by megakaryocytes proceeds through a specific and independent mechanism as CHRF-288 cells endocytosed fibrinogen but not factor V, and the presence of other plasma proteins had no effect on the endocytosis of factor V by MEG-01 cells. Furthermore, as the endocytosis of factor V was also demonstrated to occur through a clathrin-dependent mechanism, these combined data demonstrate that endocytosis of factor V by megakaryocytes occurs via a specific, independent, and most probably receptor-mediated, event. [source] Chain Transfer to Polymer and Branching in Controlled Radical Polymerizations of n -Butyl AcrylateMACROMOLECULAR RAPID COMMUNICATIONS, Issue 23 2009Nasir M. Ahmad Abstract Chain transfer to polymer (CTP) in conventional free-radical polymerizations (FRPs) and controlled radical polymerizations (ATRP, RAFT and NMP) of n -butyl acrylate (BA) has been investigated using 13C NMR measurements of branching in the poly(n -butyl acrylate) produced. The mol-% branches are reduced significantly in the controlled radical polymerizations as compared to conventional FRPs. Several possible explanations for this observation are discussed critically and all except one refuted. The observations are explained in terms of differences in the concentration of highly reactive short-chain radicals which can be expected to undergo both intra- and inter-molecular CTP at much higher rates than long-chain radicals. In conventional FRP, the distribution of radical concentrations is broad and there always is present a significant proportion of short-chain radicals, whereas in controlled radical polymerizations, the distribution is narrow with only a small proportion of short-chain radicals which diminishes as the living chains grow. Hence, irrespective of the type of control, controlled radical polymerizations give rise to lower levels of branching, when performed under otherwise similar conditions to conventional FRP. Similar observations are expected for other acrylates and monomers that undergo chain transfer to polymer during radical polymerization. [source] KATP Channels Are an Important Component of the Shear-Sensing Mechanism in the Pulmonary MicrovasculatureMICROCIRCULATION, Issue 8 2006S. CHATTERJEE ABSTRACT Objective: To investigate the role of a KATP channel in sensing shear, specifically its cessation, in the endothelial cells of the pulmonary microvasculature. Methods: Endothelial cells isolated from the pulmonary microvasculature of wild-type and KATP channel knockout (KIR6.2,/,) mice were either statically cultured (non-flow-adapted) or kept under flow (flow-adapted) and the KIR currents in these cells were monitored by whole-cell patch-clamp technique during flow and its cessation. Membrane potential changes, generation of reactive oxygen species (ROS), and Ca2+ influx with flow cessation were evaluated by the use of fluorescent dyes. Lungs isolated from wild-type mice were imaged to visualize ROS generation in the subpleural endothelium. Results: By patch-clamp analysis, reduction in the KIR current with cessation of flow occurred only in wild-type cells that were flow-adapted and not in flow-adapted KIR6.2,/, cells. Similar observations were made using changes in bisoxonol fluorescence as an index of cell membrane potential. Generation of ROS and Ca2+ influx that follow membrane depolarization were significantly lower in statically cultured and in KIR6.2,/, cells as compared to flow-adapted wild-type cells. Imaging of subpleural endothelial cells of the whole lung showed that the KATP antagonist glyburide caused the production of ROS in the absence of flow cessation. Conclusions: The responses to stop of flow (viz. membrane depolarization, KIR currents, ROS, Ca2+) were significantly altered with knockout of KATP channels, which indicates that this channel is an important component of the pulmonary endothelial response to abrupt loss of shear stress. [source] Vasotocin and mesotocin in the brains of amphibians: State of the artMICROSCOPY RESEARCH AND TECHNIQUE, Issue 3 2001Wilhelmus J.A.J. Smeets Abstract Immunohistochemical studies during the last decade have revealed elaborate systems of vasotocinergic (AVT) and mesotocinergic (MST) neuronal elements in the brain of a variety of amphibians including anurans, urodeles, and gymnophionans. Apart from a well-developed hypothalamo-hypophysial system, the antibodies demonstrated the existence of extrahypothalamic AVT- and MST-immunoreactive cell groups as well as extensive extrahypothalamic networks of immunoreactive fibers. The wide distribution of AVT- and MST-immunoreactive fibers throughout the brains of amphibians suggests that the two neuropeptidergic systems are involved not only in hypothalamo-hypophysial interactions, but also in a variety of other brain functions. Moreover, there is now evidence that sex-related differences occur in amphibians as previously shown for amniotes. It should be noted, however, that substantial variation occurs in the relative densities of AVT- and MST-immunoreactive fibers and number of cells between species, even within a single order of amphibians. Similar observations have been made in other classes of vertebrates and prompt us, therefore, to critically evaluate conclusions with respect to specific functions of AVT and MST in the central nervous system of vertebrates. Microsc. Res. Tech. 54:125,136, 2001. © 2001 Wiley-Liss, Inc. [source] Z -scores and the birthweight paradoxPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 5 2009Enrique F. Schisterman Summary Investigators have long puzzled over the observation that low-birthweight babies of smokers tend to fare better than low-birthweight babies of non-smokers. Similar observations have been made with regard to factors other than smoking status, including socio-economic status, race and parity. Use of standardised birthweights, or birthweight z -scores, has been proposed as an approach to resolve the crossing of the curves that is the hallmark of the so-called birthweight paradox. In this paper, we utilise directed acyclic graphs, analytical proofs and an extensive simulation study to consider the use of z -scores of birthweight and their effect on statistical analysis. We illustrate the causal questions implied by inclusion of birthweight in statistical models, and illustrate the utility of models that include birthweight or z -scores to address those questions. Both analytically and through a simulation study we show that neither birthweight nor z -score adjustment may be used for effect decomposition. The z -score approach yields an unbiased estimate of the total effect, even when collider-stratification would adversely impact estimates from birthweight-adjusted models; however, the total effect could have been estimated more directly with an unadjusted model. The use of z -scores does not add additional information beyond the use of unadjusted models. Thus, the ability of z -scores to successfully resolve the paradoxical crossing of mortality curves is due to an alteration in the causal parameter being estimated (total effect), rather than adjustment for confounding or effect decomposition or other factors. [source] ,Thawing' of ,frozen' variation in an adventive, facultatively apomictic, clonal weedPLANT SPECIES BIOLOGY, Issue 2 2001Hazel Chapman Abstract Radiation of adventive, sexually reproducing organisms into a new environment has been well documented, but less is understood about the patterns and processes of geographical radiation in adventive species with uniparental reproduction (parthenogenesis or apomixis), usually associated with ,frozen' variation within maternal lineages. In this study we have used Pilosella officinarum to test the hypothesis that sexual reproduction becomes important in the radiation of adventive facultatively apomictic species. Within its native Europe P. officinarum is an extremely variable species, with eight subspecies and a range of ploidy levels. Pentaploids are always apomictic. However, early chromosome analyses of New Zealand adventive populations, carried out during the 1980s, discovered only pentaploid, apomictic clones. Similar observations were made in an early 1990s study of the same sites. Since then, a range of ploidy levels, including aneuploids, and a plethora of morphological variation, has been recorded. In this paper, we use a combination of image analysis and chromosome counts to show that sexual reproduction has become an important avenue for adaptive radiation in New Zealand populations of P. officinarum. Current populations probably comprise complex among-subspecies hybrids, and possibly among-species hybrids, which are at least partially capable of sexual reproduction and various forms of back-crossing. Somatic mutation may also play an important role in creating morphological variation. DNA fingerprinting did not contribute to this study because this technique failed to distinguish between morphological types observed in the field. [source] Neurodevelopmental sequelae of postnatal maternal care in rodents: clinical and research implications of molecular insightsTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 3-4 2007Arie Kaffman Parental care plays an important role in the emotional and cognitive development of the offspring. Children who have been exposed to abuse or neglect are more likely to develop numerous psychopathologies, while good parent,infant bonding is associated with improved resiliency to stress. Similar observations have also been reported in non-human primates and rodents, suggesting that at least some neurodevelopmental aspects of parent,offspring interactions are conserved among mammals and could therefore be studied in animals. We present data to suggest that frequency of licking and grooming provided by the dam during a critical period in development plays an important role in modifying neurodevelopment. These findings are examined in the broader context in which exposure to other sensory modalities such as vision or hearing during a specific period in development shapes brain development with functional consequences that persist into adulthood. We also discuss recent rodent work showing that increased frequency of licking and grooming provided by the dam during the first week of life is associated with changes in DNA methylation of promoter elements that control expression of these genes and behavior. The stability of DNA methylation in postmitotic cells provides a possible molecular scaffold by which changes in gene expression and behavioral traits induced by postnatal maternal care are maintained throughout life. Finally, the relevance of findings reported in rodents to those noted in non-human primates and humans are assessed and the research and clinical implications of these observations for future work are explored. [source] Malformation of True Bug (Heteroptera): a Phenotype Field Study on the Possible Influence of Artificial Low-Level RadioactivityCHEMISTRY & BIODIVERSITY, Issue 4 2008Cornelia Hesse-Honegger Abstract The results of extensive field studies on the malformation of Western European true bugs (Heteroptera) are reviewed. More than 16,000 individuals were collected over two decades, and subjected to detailed visual inspection. Various types of disturbances were found and illustrated in detail. Depending on country, region, as well as local influences, severe disturbances and high degrees of malformation were noticed, especially in the sphere of nuclear-power installations in Switzerland (Aargau), France (La Hague), and Germany (Gundremmingen). Malformation reached values as high as 22 and 30% for morphological (MD) and total disturbance (TD), respectively. This is far above the values expected for natural populations (ca. 1%) or those determined for true bugs living in biotopes considered as relatively ,intact' (1,3%). A detailed chi-square test of the malformation data obtained for 650 true bugs from 13 collection sites near the nuclear-reprocessing plant La Hague showed a highly significant correlation (p=0.003) between malformation and wind exposure/local topography. Similar observations were made for other study sites. Currently, our data are best rationalized by assuming a direct influence between the release of anthropogenic radionuclides such as tritium (3H), carbon-14 (14C), or iodine-131 (131I), constantly emitted by nuclear-power and nuclear-reprocessing plants, as well as by Chernobyl and bomb-testing fallout, which is rich in caesium-137 (137Cs) and other long-lived noxious isotopes that have entered the food chain. The present work supports the growing evidence that low-level radiation, especially in the form of randomly scattered ,hot' , - and , -particles, mainly transported via aerosols, puts a heavy burden on the biosphere in general, and on true bugs in particular. These insects could, thus, serve as sensitive ,bio-indicators' for future studies. [source] IN VITRO INHIBITORY EFFECTS OF ATORVASTATIN ON CARDIAC FIBROBLASTS: IMPLICATIONS FOR VENTRICULAR REMODELLINGCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 9 2005Jennifer Martin SUMMARY 1.,Hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors (statins) reduce mortality after myocardial infarction (MI). Although this may be predominantly due to their known anti-ischaemic actions, these drugs are known to have other beneficial effects. 2.,Because pathological deposition of extracellular matrix (ECM) material is a key component of remodelling after MI, we sought to determine whether atorvastatin could inhibit ECM production in vitro. 3.,The addition of atorvastatin to rat cardiac fibroblasts stimulated with either transforming growth factor (TGF)-,1 (TGF-,1) or angiotensin (Ang) II reduced collagen synthesis in a dose-dependent manner (3.7-fold reduction (95% confidence interval (CI) 1.8,15; P < 0.01) and 5.3-fold reduction (95% CI 1.8,7.7; P < 0.01), respectively, compared with stimulant alone). Similar observations were made in human cardiac fibroblast cell culture. Atorvastatin also dose-dependently reduced TGF-,1 and AngII-induced increases in ,(I)-procollagen mRNA (P < 0.01 for both), as well as gene expression of the profibrotic peptide connective tissue growth factor. 4.,Atorvastatin appears to directly inhibit collagen production by cardiac fibroblasts. This antifibrotic action may contribute to the antiremodelling effect of statins. [source] Role of Sulfate in Structural Modifications of Sodium Barium Borosilicate Glasses Developed for Nuclear Waste ImmobilizationJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2008Raman K. Mishra A sodium barium borosilicate glass matrix with a higher solubility of sulfate has been developed recently at Bhabha Atomic Research Centre for vitrification of sulfate bearing high-level nuclear waste. We report here the studies carried out to understand the influence of sulfate ion on the three-dimensional borosilicate network. Experiments were carried out with sodium barium borosilicate base glass samples loaded with varying amounts of SO42, (0,5 mol%). Phase separation studies on the samples revealed that as much as 3 mol% of SO42, can be loaded within the base glass without any phase separation, however, beyond this limit BaSO4 (barite) crystallizes within the matrix. Thermal analyses of the samples indicated a shift in glass transition temperature from 534° (0 mol% SO42,) to 495°C (3 mol% SO42,) and it remained more or less unaltered afterwards even with high SO42, loading. A similar observation of structure stabilization was obtained from 29Si MAS,NMR studies also, which showed that with 2 mol% of SO42, loading, the Q2:Q3 ratio changed from 59:41 (for samples with 0 mol% SO42, loading) to 62:38 and it remained almost the same afterwards even with higher SO42, loading. 11B MAS NMR patterns of the glass samples, however, remained unchanged with SO42, loading ([BO4]:[BO3]=38:62). Based on 29Si and 11B MAS NMR studies, the authors propose two different ways of interaction of SO42, ions with the borosilicate network: (i) the network modifying action of SO42, ions with -Si,O,Si- linkages, at low SO42, ion concentration (<2 mol%) and (ii) the preferential interaction of SO42, with the Ba2+ ions at high SO42, concentration (>2 mol%). [source] Theory development and convergence of human resource fields: Implications for human performance technologyPERFORMANCE IMPROVEMENT QUARTERLY, Issue 3 2010Yonjoo Cho PhD This study examines major theory developments in human resource (HR) fields and discusses implications for human performance technology (HPT). Differentiated HR fields are converging to improve organizational performance through knowledge-based innovations. Ruona and Gibson (2004) made a similar observation and analyzed the historical evolution and convergence of three HR-related fields: human resource management (HRM), human resource development (HRD), and organization development (OD). A field left out in their analysis is HPT. Many learning professionals recognize HPT as a more comprehensive approach to improving organizational performance issues (Molenda & Pershing, 2008; Pershing, 2006). However, little research has been done to advance the theory development of HPT and discuss its relationships within HR fields. This study adds a new perspective to that of Ruona and Gibson's historical analysis of HR fields by examining convergence issues from a theory development perspective. [source] Association Between Ethanol and Sucrose Intake in the Laboratory Mouse: Exploration Via Congenic Strains and Conditioned Taste AversionALCOHOLISM, Issue 3 2000David A. Blizard Background: A substantial body of literature indicates that intakes of "sweet' solutions and ethanol are positively correlated across inbred strains of rats and mice but there has been speculation that the correlation is fortuitous and there is no agreement on the underlying mechanism. Methods and Results: We assessed the correlation between intake of sucrose and ethanol in congenic mice created by backcrossing alleles favoring sucrose intake from the BXD RI-5 strain into DBA/2J. In addition, to probe more specifically the interrelationship between intake of the two solutions, we examined aversion generalization from sucrose to ethanol in C57BL/6J mice. Among the congenic mice, a statistically significant product-moment correlation of r= 0.36 (p < 0.02) was found between 6-hr intake of sucrose corrected for differences in baseline water intake and preference for 10% ethanol presented in a 96-hr 2-bottle test. Furthermore, C57BL/6J male mice conditioned to avoid a 0.2 M sucrose solution generalized their aversion to a 10% ethanol solution presented in the same 2-bottle test, drinking 42.1 ± 9.38% (mean ± SE) of their total fluid intake from the ethanol tube, compared with the control group mean of 69.86 ± 8.84%. Conclusions: The positive association between intake of sucrose and ethanol in congenic mice provides strong evidence that the previously demonstrated genetic correlation between intake of these solutions is not the result of fortuitous fixation of unrelated alleles and provides suggestive evidence that, at least in the B6/D2 lineage, the genetic association between intakes of the two solutions reflects close linkage or the pleiotropic effects of the same genes. The demonstration that a conditioned taste aversion to sucrose generalized to ethanol in the C57BL/6J inbred mouse strain is an extension of similar observations in outbred rats and specifically demonstrates that intake of the two solutions is controlled by some of the same physiologic or neurological processes and thus is consistent with the pleiotropic interpretation of the genetic correlation. [source] A search for high-redshift molecular absorption lines towards millimetre-loud, optically faint quasarsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2003M. T. Murphy ABSTRACT We describe initial results of a search for redshifted molecular absorption towards four millimetre-loud, optically faint quasars. A wide frequency bandwidth of up to 23 GHz per quasar was scanned using the Swedish,ESO Submillimetre Telescope at La Silla. Using a search list of commonly detected molecules, we obtained nearly complete redshift coverage up to zabs= 5. The sensitivity of our data is adequate to have revealed absorption systems with characteristics similar to those seen in the four known redshifted millimetre-band absorption systems, but none were found. Our frequency-scan technique nevertheless demonstrates the value of wide-band correlator instruments for searches such as these. We suggest that a somewhat larger sample of similar observations should lead to the discovery of new millimetre-band absorption systems. [source] Photodegradation mechanism and stabilization of polyphenylene oxide and rigid-rod polymersPOLYMER INTERNATIONAL, Issue 2 2006Ying-Hung So Abstract Poly(2,4-dimethyl-1,4-phenylene oxide) (PPO), poly(benzo[1,2- d:5,4- d,]bisoxazole-2,6-diyl-1,4-phenylene) (PBO) and poly(benzo[1,2- d:4,5- d,]bisthiazole-2,6-diyl-1,4-phenylene) (PBZT), which are polymers with extended conjugated structures, undergo a self-sensitized photo-induced electron-transfer reaction. A second component is not required. This article presents many similar observations on these polymers when they are exposed to light and evidence to support the proposed photo-induced electron-transfer mechanism. Methods to stabilize these polymers against photo-oxidation are also described. Workers investigating other conjugated polymeric systems may find the experimental methods, observations and polymer stabilization approaches discussed in this review useful. Copyright © 2005 Society of Chemical Industry [source] | ||||||||||||||||