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Selected AbstractsMedial temporal lobe function and structure in mild cognitive impairmentANNALS OF NEUROLOGY, Issue 1 2004Bradford C. Dickerson MD Functional magnetic resonance imaging (fMRI) was used to study memory-associated activation of medial temporal lobe (MTL) regions in 32 nondemented elderly individuals with mild cognitive impairment (MCI). Subjects performed a visual encoding task during fMRI scanning and were tested for recognition of stimuli afterward. MTL regions of interest were identified from each individual's structural MRI, and activation was quantified within each region. Greater extent of activation within the hippocampal formation and parahippocampal gyrus (PHG) was correlated with better memory performance. There was, however, a paradoxical relationship between extent of activation and clinical status at both baseline and follow-up evaluations. Subjects with greater clinical impairment, based on the Clinical Dementia Rating Sum of Boxes, recruited a larger extent of the right PHG during encoding, even after accounting for atrophy. Moreover, those who subsequently declined over the 2.5 years of clinical follow-up (44% of the subjects) activated a significantly greater extent of the right PHG during encoding, despite equivalent memory performance. We hypothesize that increased activation in MTL regions reflects a compensatory response to accumulating AD pathology and may serve as a marker for impending clinical decline. Ann Neurol 2004;56:27,35 [source] Irritant threshold and histological response of epidermis to irritant applicationCONTACT DERMATITIS, Issue 5-6 2004H. R. Smith Individuals vary in their ability to react to irritants, which can be demonstrated for sodium lauryl sulfate (SLS) using the irritant threshold (IT) test. We aimed to study whether the histological and immunohistochemical features of the skin following SLS exposure varied with subject's IT. 8 subjects were recruited. Their IT was measured. Biopsies were taken after 2 hr and 4 hr of occlusion with 20% SLS and control. The specimens were stained with haematoxylin and eosin and for Langerhans cells. At 4-hr, low-threshold subjects developed changes to a greater extent than high-threshold subjects. The relationship of histological reaction to IT could be related to a differential pro-inflammatory cytokine response in subjects. Low IT has been previously associated with a tumour necrosis factor alpha promoter region polymorphism. [source] Overload-induced skeletal muscle extracellular matrix remodelling and myofibre growth in mice lacking IL-6ACTA PHYSIOLOGICA, Issue 4 2009J. P. White Abstract Aim:, Overloading healthy skeletal muscle produces myofibre hypertrophy and extracellular matrix remodelling, and these processes are thought to be interdependent for producing muscle growth. Inflammatory cytokine interleukin-6 (IL-6) gene expression is induced in overloaded skeletal muscle, and the loss of this IL-6 induction can attenuate the hypertrophic response to overload (OV). Although the OV induction of IL-6 in skeletal muscle may be an important regulator of inflammatory processes and satellite cell proliferation, less is known about its role in the regulation of extracellular matrix remodelling. The purpose of the current study was to examine if OV-induced extracellular matrix remodelling, muscle growth, and associated gene expression were altered in mice that lack IL-6, when compared with wild-type mice. Methods:, Male C57/BL6 (WT) and C57/BL6 × IL-6,/, (IL-6,/,) mice (10 weeks of age) were assigned to either a sham control or synergist ablation OV treatments for 3, 21 or 56 days. Result:, Plantaris muscle mass increased 59% in WT and 116% in IL-6,/, mice after 21 day OV. Myofibre CSA was also increased by 21 day OV in both WT and IL-6,/, mice. OV induced a twofold greater increase in the volume of non-contractile tissue in IL-6,/, muscle compared to WT. OV also induced a significantly greater accumulation of hydroxyproline and procollagen-1 mRNA in IL-6,/, muscle, when compared with WT muscle after 21 day OV. Transforming growth factor-, and insulin-like growth factor-1 mRNA expression were also induced to a greater extent in IL-6,/, muscle when compared with WT muscle after 21 day OV. There was no effect of IL-6 loss on the induction of myogenin, and cyclin D1 mRNA expression after 3 day OV. However, MyoD mRNA expression in 3 day OV IL-6,/, muscle was attenuated when compared with WT OV mice. Conclusion:, IL-6 appears to be necessary for the normal regulation of extracellular matrix remodelling during OV-induced growth. [source] The World Has Changed,Have Analytical Procedure Practices?CONTEMPORARY ACCOUNTING RESEARCH, Issue 2 2010GREG TROMPETER M1; M42 Analytical Procedures (APs) provide a means for auditors to evaluate the "reasonableness" of financial disclosures by comparing a client's reported performance to expectations gained through knowledge of the client based on past experience and developments within the company and its industry. Thus, APs are fundamentally different than other audit tests in taking a broader perspective of an entity's performance vis-à-vis its environment. As such, APs have been found to be a cost-effective means to detect misstatements, and many have argued that a number of prior financial frauds would have been detected had auditors employed effective APs. With several dramatic and far-reaching developments over the past decade, the current study examines whether and how APs have changed during this period. In particular, we focus on the impact of significant "enablers" and "drivers" of change such as technological advancements and the enactment of the Sarbanes-Oxley Act. We also compare our findings to an influential study of the practices of APs by Hirst and Koonce (1996) that was conducted over 10 years ago. We interview 36 auditors (11 seniors, 13 managers, and 12 partners) from all of the Big 4 firms using a structured questionnaire. The data reveal some similarities in findings when compared to prior research (e.g., auditors continue to use fairly simple analytical procedures). However, there are a number of significant differences reflecting changes in AP practices. For instance, as a result of technology auditors now rely more extensively on industry and analyst data than previously. Further, auditors report that they develop more precise quantitative expectations and use more non-financial information. They also appear to rely more on lower level audit staff to perform APs, conduct greater inquiry of non-accounting personnel, and are willing to reduce substantive testing to a greater extent as a result of APs conducted in the planning phase. Finally, the Sarbanes-Oxley Act has had an impact in greater consideration and knowledge of internal controls, which is seen as the most important factor driving the use and reliance on APs. [source] Skeletal muscle HSP72 response to mechanical unloading: influence of endurance trainingACTA PHYSIOLOGICA, Issue 4 2004D. Desplanches Abstract Aims:, It has been shown that increased contractile activity results in heat shock protein 72 (HSP72) accumulation in various skeletal muscles. By contrast, there is no consensus for muscle HSP72 response to muscle disuse for short duration (5,8 days). On the basis of a greater constitutive HSP72 expression in slow-twitch muscles we tested the hypothesis that mechanical unloading for a longer period (2 weeks) would affect this phenotype to a greater extent. Secondly, we evaluated the effects of a physiological muscle heat shock protein (HSP) enhancer (endurance training) on HSP response to unloading and muscle remodelling. Methods:, Adult male Wistar rats were assigned randomly to four groups: (1) sedentary weight-bearing; (2) hindlimb-unloaded (HU) via tail suspension for 2 week; (3) trained on a treadmill (6 week) and (4) trained 6 week and then HU for 2 week. Results:, Unloading resulted in a preferential atrophy of slow muscles [soleus (SOL), adductor longus (AL)] and a slow-to-fast fibre transition with no change in HSP72 level. HSP72 levels were significantly lower in fast muscles [extensor digitorum longus (EDL) and plantaris (PLA)], and did not change with mechanical unloading. Endurance training was accompanied by a small (SOL) or a large (EDL, PLA) increase in HSP72 level with no change in AL. Training-induced accumulation of HSP72 disappeared with subsequent unloading in the SOL and PLA whereas HSP72 content remained elevated in EDL. Conclusion:, The results of this study indicate that (1) after 2 weeks of unloading no change occurred in HSP72 protein levels of slow-twitch muscles despite a slow-to-fast fibre transition; and (2) the training-induced increase of HSP72 content in skeletal muscles did not attenuate fibre transition. [source] ,-synuclein has a dynamic intracellular localizationCYTOSKELETON, Issue 8 2006Irina Surgucheva Abstract ,-Synuclein is a member of the synuclein family consisting of three proteins. Within the last several years increasing attention has focused on these proteins because of their role in human diseases. ,-Synuclein relevance to Parkinson's disease is based on mutations found in familial cases of the disease and its presence in filaments and inclusion bodies in sporadic cases. ,-Synuclein is implicated in some forms of cancer and ocular diseases, while ,-synuclein may antagonize their pathological functions. In this paper we present data on the localization and properties of ,-synuclein in several neuronal and nonneuronal cell cultures. We show that contrary to the current opinion, ,-synuclein is not an exclusively cytoplasmic protein, but has a dynamic localization and can associate with subcellular structures. It is present in the perinuclear area and may be associated to centrosomes. On late steps of mitosis ,-synuclein is not found in the centrosomes, and redistributes to the midbody in telophase. Under stress conditions a translocation of ,-synuclein from the perinuclear area to the nucleus occurs exhibiting nucleocytoplasmic shuttling. ,-Synuclein overexpression reduces neurite outgrowth in a greater extent then ,-synuclein overexpression. These data support the view that ,-synuclein may change its intracellular localization and associate with subcellular structures in response to intracellular signaling or stress. Cell Motil. Cytoskeleton 2006. © 2006 Wiley-Liss, Inc. [source] Do mood disorders alter crying? a pilot investigationDEPRESSION AND ANXIETY, Issue 5 2008Jonathan Rottenberg Ph.D. Abstract Clinical commentators widely interpret crying as a sign of depressed mood. However, there is virtually no empirical data on this topic, and the evidence that mood disorders alter crying is surprisingly weak. This study compared mood disordered patients to a nonpsychiatric reference group on the frequency, antecedents, and consequences of crying behavior using a well-validated questionnaire measure of crying. Forty-four outpatients diagnosed with three forms of mood pathology were age and gender matched to a reference group of 132 participants sampled to be representative of the Dutch population. Both groups completed the Adult Crying Inventory, which provides estimates of the self-reported frequency, antecedents, and consequences of crying behavior. Depression severity and psychiatric symptom severity data were also collected from patients. Compared with the reference group, patients with mood pathology reported increased cry proneness to negative antecedents. By contrast, patients and controls did not differ in reported cry proneness to positive antecedents. Patients reported less mood improvement after crying than did controls. Among male patients, but not female patients, depression severity was associated with increased crying proneness and increased crying frequency. This pilot investigation suggests that mood disorders increase the frequency of negative emotional crying, and may also alter the functions of this behavior. Mood disorders may influence male crying to a greater extent than female crying. Future directions designed to clarify the causal pathways between mood disorders and alterations in crying behavior are discussed. Depression and Anxiety 0:1,7, 2007. © 2007 Wiley-Liss, Inc. [source] Is treatment with growth hormone effective in children with cerebral palsy?DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 8 2004Melanie L Shim MD Children with cerebral palsy (CP) often have poor linear growth during childhood, resulting in a diminished final adult height. Here we report a female with CP and short stature but without growth hormone (GH) deficiency who exhibited increased growth during treatment with GH. We also report two other children with CP who were treated with GH: one female with a history of leukemia, and a male with Klinefelter syndrome. These two children were both found to be GH-deficient by insulin provocative GH testing and responded to treatment with increased growth rate. Growth improved to a greater extent in the two children with apparent GH deficiency. In summary, it is felt that GH therapy might be beneficial for children with CP and warrants further investigation. [source] Social grooming in the kindergarten: the emergence of flattery behaviorDEVELOPMENTAL SCIENCE, Issue 2 2007Genyue Fu The present study examined the emergence of flattery behavior in young children and factors that might affect whether and how it is displayed. Preschool children between the ages of 3 and 6 years were asked to rate drawings produced by either a present or absent adult stranger (Experiments 1 and 2), child stranger (Experiments 2 and 3), classmate, or the children's own teacher (Experiment 3). Young preschoolers gave consistent ratings to the same drawing by the person regardless of whether the person was absent or present. In contrast, many older preschoolers gave more flattering ratings to the drawing when the person was present than in the person's absence. Also, older preschoolers displayed flattery regardless of whether the recipient was an adult or a child. However, they displayed flattery to a greater extent towards familiar individuals than unfamiliar ones, demonstrating an emerging sensitivity to social contexts in which flattery is used. These findings suggest that preschoolers have already learned not to articulate bluntly their true feelings and thoughts about others. Rather, they are able to manipulate their communications according to social context. [source] Twice daily biphasic insulin aspart improves postprandial glycaemic control more effectively than twice daily NPH insulin, with low risk of hypoglycaemia, in patients with type 2 diabetesDIABETES OBESITY & METABOLISM, Issue 6 2003J. S. Christiansen Objective:, Biphasic insulin aspart 30 (BIAsp30) is a dual release formulation, containing 30% soluble and 70% protamine-crystallized insulin aspart. This study compared the glycaemic control and safety profiles achieved with either twice daily BIAsp30 or NPH insulin in patients with type 2 diabetes not optimally controlled by oral hypoglycaemic agents (OHAs), NPH insulin or a combination of both. Methods:, In this 16-week multinational, parallel-group, double-blind trial, 403 such patients were randomized to receive either BIAsp30 or NPH insulin immediately before breakfast and evening meals. OHAs were discontinued at randomization. Efficacy was assessed by glycosylated haemoglobin (HbA1c) and self-recorded daily 8-point blood glucose (BG) profiles. Hypoglycaemic and other adverse events were the chosen safety parameters. Results:, HbA1c concentration decreased by >0.6% (p < 0.0001 vs. baseline) in both groups, with metabolic control continuing to improve throughout the trial without reaching a stable level. Patients who switched from once or twice daily NPH monotherapy to twice daily BIAsp30 achieved a significantly greater reduction in HbA1c (0.78%) than those randomized to twice daily NPH insulin (0.58%; p = 0.03). BIAsp30 decreased mean daily postprandial glycaemic exposure to a greater extent than NPH insulin (mean difference = 0.69 mmol/l; p < 0.0001), reflecting greater decreases in the postbreakfast and postdinner increments (of 1.26 and 1.33 mmol/l, respectively), although postlunch increment was relatively increased (by 0.56 mmol/l). Despite the greater reduction in overall postprandial glycaemic exposure in the BIAsp30 group, the overall safety profile of BIAsp30 was equivalent to that of NPH insulin with <2% of patients experiencing major hypoglycaemia, and approximately 33% reporting minor hypoglycaemic episodes, in both groups. Conclusion:, Twice daily BIAsp30 reduced postprandial glucose exposure to a significantly greater extent than NPH insulin and was at least as effective at reducing HbA1c in patients with type 2 diabetes. Both insulins were well tolerated. In patients poorly controlled on OHAs or NPH alone, glycaemic control can be improved by switching to twice daily BIAsp30, without increasing hypoglycaemic risk. [source] Weathering the escarpment: chemical and physical rates and processes, south-eastern AustraliaEARTH SURFACE PROCESSES AND LANDFORMS, Issue 6 2009Benjamin C. Burke Abstract Differences in chemical weathering extent and character are expected to exist across topographic escarpments due to spatial gradients of climatic and/or tectonic forcing. The passive margin escarpment of south-eastern Australia has a debated but generally accepted model of propagation in which it retreated (within 40 Ma) to near its current position following rifting between Australia and New Zealand 85,100 Ma before present. We focus on this escarpment to quantify chemical weathering rates and processes and how they may provide insight into scarp evolution and retreat. We compare chemical weathering extents and rates above and below the escarpment using a mass balance approach coupling major and trace element analyses with previous measurements of denudation rates using cosmogenic nuclides (10Be and 26Al). We find a slight gradient in saprolite chemical weathering rate as a percentage of total weathering rate across the escarpment. The lowlands area, encompassing the region extending from the base of the escarpment to the coast, experiences a greater extent of chemical weathering than the highland region above the escarpment. Percents of denudation attributable to saprolite weathering average 57 ± 6% and 47 ± 7% at low and high sites respectively. Furthermore, the chemical index of alteration (CIA), a ratio of immobile to mobile oxides in granitic material that increases with weathering extent, have corresponding average values of 73·7 ± 3·9 and 65·5 ± 3·4, indicating lower extents of weathering above the escarpment. Finally, we quantify variations in the rates and extent of chemical weathering at the hillslope scale across the escarpment to suggest new insight into how climate differences and hillslope topography help drive landscape evolution, potentially overprinting longer term tectonic forcing. Copyright © 2009 John Wiley & Sons, Ltd. [source] Functional response and size-dependent foraging on aquatic and terrestrial prey by brown trout (Salmo trutta L.)ECOLOGY OF FRESHWATER FISH, Issue 2 2010P. Gustafsson Gustafsson P, Bergman E, Greenberg LA. Functional response and size-dependent foraging on aquatic and terrestrial prey by brown trout (Salmo trutta L.).Ecology of Freshwater Fish 2010: 19: 170,177. © 2010 John Wiley & Sons A/S Abstract ,, Terrestrial invertebrate subsidies are believed to be important energy sources for drift-feeding salmonids. Despite this, size-specific use of and efficiency in procuring this resource have not been studied to any great extent. Therefore, we measured the functional responses of three size classes of wild brown trout Salmo trutta (0+, 1+ and ,2+) when fed either benthic- (Gammarus sp.) or surface-drifting prey (Musca domestica) in laboratory experiments. To test for size-specific prey preferences, both benthic and surface prey were presented simultaneously by presenting the fish with a constant density of benthic prey and a variable density of surface prey. The results showed that the functional response of 0+ trout differed significantly from the larger size classes, with 0+ fish having the lowest capture rates. Capture rates did not differ significantly between prey types. In experiments when both prey items were presented simultaneously, capture rate differed significantly between size classes, with larger trout having higher capture rates than smaller trout. However, capture rates within each size class did not change with prey density or prey composition. The two-prey experiments also showed that 1+ trout ate significantly more surface-drifting prey than 0+ trout. In contrast, there was no difference between 0+ and ,2+ trout. Analyses of the vertical position of the fish in the water column corroborated size-specific foraging results: larger trout remained in the upper part of the water column between attacks on surface prey more often than smaller trout, which tended to seek refuge at the bottom between attacks. These size-specific differences in foraging and vertical position suggest that larger trout may be able to use surface-drifting prey to a greater extent than smaller conspecifics. [source] LABOUR MARKET REGULATION: SOME COMPARATIVE LESSONSECONOMIC AFFAIRS, Issue 3 2005W. S. Siebert Labour market regulation that undermines freedom of contract leads to fewer, higher productivity jobs with employment being across a narrower range of ages. More people are excluded from the labour market, in highly regulated countries and they remain unemployed for longer. This seems to be damaging to welfare. It is possible that the extent of regulation is explained by the relative ability of those who gain from regulation (those in work) to influence the outcome of political processes to a greater extent than those who lose (the unemployed). However, the legal framework and legal traditions may also play a part. [source] Placing Progress: Contextual Inequality and Immigrant Incorporation in the United StatesECONOMIC GEOGRAPHY, Issue 3 2008Jamie Goodwin-White Abstract This article contributes to the growing body of research on the economic incorporation of immigrants by considering the relative wages of immigrants, the adult children of immigrants, and the U.S.-born children of U.S. parentage. By disaggregating these three groups racially, comparing entire wage distributions, and comparing the immigrant cities of New York and Los Angeles with the United States overall, it presents a perspective on the complicated contexts of the intergenerational progress of immigrants. In addition to comparing the groups' relative positions in 1990 and 2000, the article decomposes relative wages such that differences in the educational composition of groups can be isolated from residual wage inequality. This research is of interest because consideration of the U.S.-born or educated children of immigrants invokes questions of social mobility and the persistence of ethnic inequality more generally. The article also contributes to a theoretical debate over place and immigrants' progress by examining the second generation, for whom residence in immigrant cities is often theorized as detrimental to economic incorporation. Finally, it introduces a substantial analysis of local wage structures to questions of immigrants' intergenerational economic progress to a much greater extent than has previously been the case. The results suggest that prospects for immigrants' economic incorporation are geographically specific and should be assessed across multiple generations as a result of the continuing contexts of racial wage inequality [source] Resistance of apple trees to Cydia pomonella egg-laying due to leaf surface metabolitesENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2008Nadia Lombarkia Abstract During host plant selection and particularly after alighting on a plant, chemical cues from the plant surface influence an insect's acceptance of the plant and, subsequently, its egg-laying behaviour. Primary metabolites in the phylloplane may be more important than hitherto known. We have shown that soluble carbohydrates, such as glucose, fructose, and sucrose, and sugar alcohols, such as sorbitol, quebrachitol, and myo -inositol, can be detected by insects after contacting the plant and that they positively influence egg-laying of the codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), on apple trees. We addressed the question whether a lack of these substances could also explain apple tree resistance to C. pomonella in terms of reduced egg-laying. Leaf surface washings were collected in an apple orchard by spraying water on the resistant cultivar X65-11 and on the susceptible cultivar P5R50A4. The washings were tested on a nylon cloth on isolated females under no-choice conditions. The washings were analysed and synthetic blends, each consisting of the six metabolites in the proportions established in the leaf surface washings of both cultivars, were then tested for their effect on egg-laying of C. pomonella. Dose,response egg-laying tests were carried out on substrates impregnated with the X65-11 leaf surface blend at 1, 100, 1 000, and 10 000 times the natural dose. Egg-laying behaviour in the bioassays with leaf surface washings of both cultivars closely resembled egg-laying in the orchard. Washings of P5R50A4 stimulated egg-laying to a greater extent than those of X65-11 and the water control. Synthetic blends reduced substrate acceptance and egg-laying, compared to the washings of X65-11. Ratios between components within the blend are responsible for this resistance. In conclusion, quantities and ratios of the six primary metabolites found on the leaf surface may influence host preference of C. pomonella as well as their egg-laying behaviour, thus they may play a role in the trees' resistance to the codling moth. [source] The sublethal effects of tebufenozide on the precopulatory and copulatory activities of Choristoneura fumiferana and C. rosaceanaENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2004Renée Dallaire Abstract The sublethal effects of tebufenozide, an ecdysone agonist, on the reproductive biology of Choristoneura fumiferana (Clem) and of Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae), treated during the larval stage, were evaluated using two treatment methods: the force-feeding method and the diet method. The percentage of mortality and the developmental time of survivors increased linearly with the concentration of tebufenozide used. This ecdysone analogue proved to be more toxic to C. fumiferana than to C. rosaceana. In C. rosaceana, the weight of males and females decreased proportionally with the dose ingested, but females were affected to a greater extent. This difference might be due to a greater consumption of the treated diet, or to a differential vulnerability to tebufenozide. Tebufenozide did not modify the pre-copulatory activities associated with chemical communication in the females. However, the consumption of tebufenozide delayed ovarian maturation, causing a reduction in the fecundity of females. Treated males had smaller spermatophores and fewer eupyrene sperms in their bursa copulatrix and spermatheca, along with lower mating success. In C. fumiferana, tebufenozide delayed the females' onset time of calling the first night after emergence, but did not affect the mean time spent calling or the production of the main component of the sex pheromone. The males showed significantly greater difficulty in executing oriented flight in a wind tunnel, although their mating success was not affected. We concluded that tebufenozide interferes with various aspects of the reproductive biology of males and females of C. fumiferana and C. rosaceana, including some pre-copulatory behaviors associated with sex pheromone communication. [source] DNA damage assessment by comet assay of human lymphocytes exposed to jet propulsion fuelsENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 1 2002Shawna M. Jackman Abstract Exposure to jet fuel damages DNA and results in a number of physiological changes in liver, lung, immune, and neurological tissue. In this study the single-cell gel electrophoresis assay or comet assay was used to compare the DNA damage in human peripheral lymphocytes produced by three jet propulsion fuels: JP-8, JP-5, and JP-8+100. These fuels consist of complex mixtures of aliphatic, aromatic, and substituted naphthalene hydrocarbons. Two exposure times were investigated which correspond to estimated occupational exposure times and concentrations of fuels were used that were based on previous fuel toxicity studies. Analysis of samples for the extent of DNA damage as determined by tail moment and percent tail DNA was performed on exposed cells following a brief recovery time. All fuels produced significant increases in DNA damage; however, only JP-8+100 was genotoxic at the lowest exposure concentration (1:500). At the highest exposure concentration (1:75), the mean tail moments for JP-8 and JP-8+100 (32.041 ± 2.599 and 45.774 ± 4.743, respectively) were significantly greater than for JP-5 (1.314 ± 0.474). These results indicate that JP-8+100 is the most potent inducer of DNA damage in human peripheral lymphocytes and that both JP-8+100 and JP-8 are capable of damaging lymphocyte DNA to a greater extent than JP-5. Environ. Mol. Mutagen. 40:18,23, 2002. © 2002 Wiley-Liss, Inc. [source] Dietary accumulation of perfluorinated acids in juvenile rainbow trout (Oncorhynchus mykiss)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2003Jonathan W. Martin Abstract Perfluorinated acids (PFAs) recently have emerged as persistent global contaminants after their detection in wildlife and humans from various geographic locations. The highest concentrations of perfluorooctane sulfonate are characteristically observed in high trophic level organisms, indicating that PFAs may have a significant bioaccumulation potential. To examine this phenomenon quantitatively, we exposed juvenile rainbow trout (Oncorhynchus mykiss) simultaneously to a homologous series of perfluoroalkyl carboxylates and sulfonates for 34 d in the diet, followed by a 41-d depuration period. Carcass and liver concentrations were determined by using liquid chromatography-tandem mass spectrometry, and kinetic rates were calculated to determine compound-specific bioaccumulation parameters. Depuration rate constants ranged from 0.02 to 0.23/d, and decreased as the length of the fluorinated chain increased. Assimilation efficiency was greater than 50% for all test compounds, indicating efficient absorption from food. Bioaccumulation factors (BAFs) ranged from 0.038 to 1.0 and increased with length of the perfluorinated chain; however, BAFs were not statistically greater than 1 for any PFA. Sulfonates bioaccumulated to a greater extent than carboxylates of equivalent perfluoroalkyl chain length, indicating that hydrophobicity is not the sole determinant of PFA accumulation potential and that the acid function must be considered. Dietary exposure will not result in biomagnification of PFAs in juvenile trout, but extrapolation of these bioaccumulation parameters to larger fish and homeothermic organisms should not be performed. [source] Comparative measures of the toxicity of component chemicals in aircraft deicing fluidENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2000Jeffrey S. Cornell Abstract Acraft deicingoperationsarea necessarypart of safe air travel, but release large quantities of aircraft deicing fluids (ADFs) to the environment. Effective measures to mitigate the environmental impacts of deicing operations are hindered because of the negative effects some ADF chemicals have on treatment systems and because of the poorly characterized toxicity of ADF components. This research investigated the contributions of environmentally significant concentrations of selected ADF components to the toxicity of ADF-containing waste streams, and to the inhibition of biodegradation of propylene glycol (PG), the most important component of ADF. The component chemicals studied were PG, the corrosion inhibitor 4(5)-methylbenzotriazole (MeBT; common name: tolyltriazole), and proprietary mixes of corrosion inhibitors, buffers, and surfactants referred to as the additive package or AdPack. Relative to PG alone, the different additives increased the toxicity of ADF and decreased PG biodegradation rates. In enrichments of soil microorganisms acclimated to ADF, the MeBT component significantly decreased cell growth rates and yields, and inhibited PG biodegradation to a greater extent than the AdPack. Microtox® tests indicated that MeBT is the ADF component most toxic to microorganisms. However, acute aquatic toxicity tests indicated that the AdPack components were more toxic than MeBT to Ceriodaphnia dubia and Pimephales promelas, although both components were more toxic than PG alone. [source] Ecological research in the office of research and development at the U.S. Environmental Protection Agency: An overview of new directions,,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2000Rick A. Linthurst Abstract In virtually every major environmental act, Congress has required that the U.S. Environmental Protection Agency (U.S. EPA) ensure not only that the air be safe to breathe, the water safe to drink, and the food supply free of contamination, but also that the environment be protected. In response, the U.S. EPA's Office of Research and Development (ORD) has established research to improve ecosystem risk assessment and management, identifying it as one of the highest priority research areas for investment over the next 10 years. The research is intended to provide environmental managers with new tools and flexible guidance that reflect a holistic environmental management perspective of science and that can be applied both to common and unique problems. In keeping with its responsibility to provide the U.S. EPA with science that supports a dynamic changing regulatory agenda, the ORD has set the goal of its Ecological Research Program to "provide the scientific understanding required to measure, model, maintain and/or restore, at multiple scales, the integrity and sustainability of ecosystems now, and in the future." In the context of this program, ecological integrity is defined in relative terms as the maintenance of ecosystem structure and function characteristic of a reference condition deemed appropriate for its use by society, and sustainability is defined as the ability of an ecosystem to maintain relative ecological integrity into the future. Therefore, the research program will emphasize relative risk and consider the impact of multiple stressors, at multiple scales and at multiple levels of biological organization. The program will also shift from chemical to biological and physical stressors to a far greater extent than in the past. The purpose of this paper is to provide an introduction to the U.S. EPA's changing ecological research program. [source] Nitric oxide synthase inhibition in Thoroughbred horses augments O2 extraction at rest and submaximal exercise, but not during short-term maximal exerciseEQUINE VETERINARY JOURNAL, Issue S36 2006M. MANOHAR Summary Reason for performing study: Work is required to establish the role of endogenous nitric oxide (NO) in metabolism of resting and exercising horses. Objectives: To examine the effects of NO synthase inhibition on O2 extraction and anaerobic metabolism at rest, and during submaximal and maximal exertion. Methods: Placebo and NO synthase inhibition (with N,-nitro-L-arginine methyl ester [l -NAME] administered at 20 mg/kg bwt i.v.) studies were performed in random order, 7 days apart on 7 healthy, exercise-trained Thoroughbred horses at rest and during incremental exercise leading to 120 sec of maximal exertion at 14 m/sec on a 3.5% uphill grade. Results: At rest, NO synthase inhibition significantly augmented the arterial to mixed-venous blood O2 content gradient and O2 extraction as mixed-venous blood O2 tension and saturation decreased significantly. While NO synthase inhibition did not affect arterial blood-gas tensions in exercising horses, the exercise-induced increment in haemoglobin concentration and arterial O2 content was attenuated. In the l -NAME study, during submaximal exercise, mixed-venous blood O2 tension and haemoglobin-O2 saturation decreased to a greater extent causing O2 extraction to increase significantly. During maximal exertion, arterial hypoxaemia, desaturation of haemoglobin and hypercapnia of a similar magnitude developed in both treatments. Also, the changes in mixed-venous blood O2 tension and haemoglobin-O2 saturation, arterial to mixed-venous blood O2 content gradient, O2 extraction and markers of anaerobic metabolism (lactate and ammonia production, and metabolic acidosis) were not different from those in the placebo study. Conclusion: Endogenous NO production augments O2 extraction at rest and during submaximal exertion, but not the during short-term maximal exercise. Also, NO synthase inhibition does not affect anaerobic metabolism at rest or during exertion. Potential relevance: It is unlikely that endogenous NO release modifies aerobic or anaerobic metabolism in horses performing short-term maximal exertion. [source] CD30 ligation differentially affects CXCR4-dependent HIV-1 replication and soluble CD30 secretion in non-Hodgkin cell lines and in ,,,,T,lymphocytesEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2003Priscilla Biswas Abstract We studied whether signaling through CD30, a member of the TNF receptor family, affected acute infection with HIV-1, encompassing its entire replicative cycle. Several non-Hodgkin cell lines, targets of CXCR4-dependent (X4) HIV-1 infection, were positive for CD30 expression. CD30 ligation induced up-regulation of viral replication only in certain CD30+ cell lines. Enhancement ofX4 virus replication by CD30 engagement inversely correlated with both CD30 surface density and constitutive NF-,B activation. Conversely, expression of CD30, but not of other members of the TNF receptor family, was proportional to constitutive NF-,B binding. Concomitantly, secretion of soluble (s) CD30 increased in all cell lines by CD30 ligation. sCD30 release was enhanced by engagement of CD30 alone and, to a greater extent, by co-engagement of CD3 also in primary ,,,,T,lymphocytes, along with complementary modulations of their surface CD30 expression. sCD30-containing supernatant specifically inhibited HIV-1 expression induced by CD30 engagement in chronically infected ACH-2 T,cells; thus sCD30 may act as a negative feed-back molecule. In conclusion, we have delineated novel features of CD30 biology and underline the peculiar link of CD30 expression to constitutive NF-,B activation which is pivotal to both HIV replication and cell survival. [source] Facial nerve injury-induced disinhibition in the primary motor cortices of both hemispheresEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2000Tamás Farkas Abstract Unilateral facial nerve transection induces plastic reorganization of the somatotopic order in the primary motor cortex area (MI). This process is biphasic and starts with a transient disinhibition of connections between cortical areas in both hemispheres. Little is known about the underlying mechanisms. Here, cortical excitability has been studied by paired pulse electrical stimulation, applied either within the MI or peripherally to the trigeminal nerve, while the responses were recorded bilaterally in the MI. The ratios between the amplitudes of the second and first evoked potentials (EPs or fEPSPs) were taken as measures of the inhibitory capacity in the MI ipsilateral or contralateral to the nerve injury. A skin wound or unilateral facial nerve exposure immediately caused a transient facilitation, which was followed by a reset to some level of inhibition in the MI on both sides. After facial nerve transection, the first relatively mild reduction of inhibition started shortly (within 10 min) after denervation. This was followed by a second step, involving a stronger decrease in inhibition, 40,45 min later. Previous publications have proved that sensory nerve injury (deafferentation) induces disinhibition in corresponding areas of the sensory cortex. It is now demonstrated that sham operation and, to an even greater extent, unilateral transection of the purely motoric facial nerve (deefferentation), each induce extended disinhibition in the MIs on both sides. [source] What matters most to prejudice: Big Five personality, Social Dominance Orientation, or Right-Wing Authoritarianism?EUROPEAN JOURNAL OF PERSONALITY, Issue 6 2004Bo Ekehammar Whereas previous research has studied the relation of either (i) personality with prejudice, (ii) personality with social dominance orientation (SDO) and right-wing authoritarianism (RWA), or (iii) SDO and RWA with prejudice, the present research integrates all approaches within the same model. In our study (N,=,183), various causal models of the relationships among the Big Five, SDO, RWA, and Generalized Prejudice are proposed and tested. Generalized Prejudice scores were obtained from a factor analysis of the scores on various prejudice instruments (racism, sexism, prejudice toward homosexuals, and mentally disabled people), which yielded a one-factor solution. The best-fitting causal model, which was our suggested hypothetical model, showed that Big Five personality had no direct effect on Generalized Prejudice but an indirect effect transmitted through RWA and SDO, where RWA seems to capture personality aspects to a greater extent than SDO. Specifically, Generalized Prejudice was affected indirectly by Extraversion, Openness to Experience, and Conscientiousness through RWA, and by Agreeableness through SDO, whereas Neuroticism had no effect at all. The results are discussed against the background of previous research and the personality and social psychology approaches to the study of prejudice. Copyright © 2004 John Wiley & Sons, Ltd. [source] Acute signalling responses to intense endurance training commenced with low or normal muscle glycogenEXPERIMENTAL PHYSIOLOGY, Issue 2 2010Wee Kian Yeo We have previously demonstrated that well-trained subjects who completed a 3 week training programme in which selected high-intensity interval training (HIT) sessions were commenced with low muscle glycogen content increased the maximal activities of several oxidative enzymes that promote endurance adaptations to a greater extent than subjects who began all training sessions with normal glycogen levels. The aim of the present study was to investigate acute skeletal muscle signalling responses to a single bout of HIT commenced with low or normal muscle glycogen stores in an attempt to elucidate potential mechanism(s) that might underlie our previous observations. Six endurance-trained cyclists/triathletes performed a 100 min ride at ,70% peak O2 uptake (AT) on day 1 and HIT (8 × 5 min work bouts at maximal self-selected effort with 1 min rest) 24 h later (HIGH). Another six subjects, matched for fitness and training history, performed AT on day 1 then 1,2 h later, HIT (LOW). Muscle biopsies were taken before and after HIT. Muscle glycogen concentration was higher in HIGH versus LOW before the HIT (390 ± 28 versus 256 ± 67 ,mol (g dry wt),1). After HIT, glycogen levels were reduced in both groups (P < 0.05) but HIGH was elevated compared with LOW (229 ± 29 versus 124 ± 41 ,mol (g dry wt),1; P < 0.05). Phosphorylation of 5,AMP-activated protein kinase (AMPK) increased after HIT, but the magnitude of increase was greater in LOW (P < 0.05). Despite the augmented AMPK response in LOW after HIT, selected downstream AMPK substrates were similar between groups. Phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) was unchanged for both groups before and after the HIT training sessions. We conclude that despite a greater activation AMPK phosphorylation when HIT was commenced with low compared with normal muscle glycogen availability, the localization and phosphorylation state of selected downstream targets of AMPK were similar in response to the two interventions. [source] Selective Long-Term Electrical Stimulation of Fast Glycolytic Fibres Increases Capillary Supply but not Oxidative Enzyme Activity in Rat Skeletal MusclesEXPERIMENTAL PHYSIOLOGY, Issue 5 2000S. Egginton Glycolytic fibres in rat extensor digitorum longus (EDL) and tibialis anterior (TA) were selectively activated, as demonstrated by glycogen depletion, by indirect electrical stimulation via electrodes implanted in the vicinity of the peroneal nerve using high frequency (40 Hz) trains (250 ms at 1 Hz) and low voltage (threshold of palpable contractions). This regime was applied 10 times per day, each bout being of 15 min duration with 60 min recovery, for 2 weeks. Cryostat sections of muscles were stained for alkaline phosphatase to depict capillaries, succinate dehydrogenase (SDH) to demonstrate oxidative fibres, and periodic acid-Schiff reagent (PAS) to verify glycogen depletion. Specific activity of hexokinase (HK), 6-phosphofructokinase, pyruvate kinase, glycogen phosphorylase and cytochrome c oxidase (COX) were estimated separately in homogenates of the EDL and the predominantly glycolytic cortex and oxidative core of the TA. Stimulation increased the activity of HK but not that of oxidative enzymes in fast muscles. Comparison of changes in oxidative capacity and capillary supply showed a dissociation in the predominantly glycolytic TA cortex. Here, COX was 3.9 ± 0.68 ,M min-1 (g wet wt)-1 in stimulated muscles compared with 3.7 ± 0.52 ,M min-1 (g wet wt)-1 in contralateral muscles (difference not significant), while the percentage of oxidative fibres (those positively stained for SDH) was also similar in stimulated (14.0 ± 2.8%) and contralateral (12.2 ± 1.9%) muscles. In contrast, the capillary to fibre ratio was significantly increased (2.01 ± 0.12 vs. 1.55 ± 0.04, P < 0.01). We conclude that capillary supply can be increased independently of oxidative capacity, possibly due to haemodynamic factors, and serves metabolite removal to a greater extent than substrate delivery. [source] Allometric scaling of maximum metabolic rate: the influence of temperatureFUNCTIONAL ECOLOGY, Issue 4 2008C. R. White Summary 1Maximum aerobic metabolic rate, measured in terms of rate of oxygen consumption during exercise (), is well known to scale to body mass (M) with an exponent greater than the value of 0·75 predicted by models based on the geometry of systems that supply nutrients. 2Recently, the observed scaling for (,M0·872) has been hypothesized to arise because of the temperature dependence of biological processes, and because large species show a greater increase in muscle temperature when exercising than do small species. 3Based on this hypothesis, we predicted that will be positively related to ambient temperature, because heat loss is restricted at high temperatures and body temperature is likely to be elevated to a greater extent than during exercise in the cold. 4This prediction was tested using a comparative phylogenetic generalized least-squares (PGLS) approach, and 34 measurements of six species of rodent (20·5,939 g) maximally exercising at temperatures from ,16 to 30 °C. 5 is unrelated to testing temperature, but is negatively related to acclimation temperature. We conclude that prolonged cold exposure increases exercise-induced by acting as a form of aerobic training in mammals, and that elevated muscle temperatures of large species do not explain the scaling of across taxa. [source] Geography's Emerging Cross-Disciplinary Links: Process, Causes, Outcomes and ChallengesGEOGRAPHICAL RESEARCH, Issue 1 2002J.H. Holmes In Australian universities the discipline of Geography has been the pace-setter in forging cross-disciplinary links to create multidisciplinary departments and schools, well ahead of other disciplines in humanities, social sciences and sciences, and also to a greater extent than in comparable overseas university systems. Details on all cross-disciplinary links and on immediate outcomes have been obtained by surveys of all heads of departments/schools with undergraduate Geography programs. These programs have traced their own distinctive trajectories, with ramifying links to cognate fields of enquiry, achieved through mergers, transfers, internal initiatives and, more recently, faculty-wide restructuring to create supradisciplinary schools. Geography's ,exceptionalism' has proved short-lived. Disciplinary flux is now extending more widely within Australian universities, driven by a variety of internal and external forces, including: intellectual questioning and new ways of constituting knowledge; technological change and the information revolution; the growth of instrumentalism and credentialism, and managerialism and entre-preneurial imperatives; reinforced by a powerful budgetary squeeze. Geographers are proving highly adaptive in pursuit of cross-disciplinary connections, offering analytical tools and selected disciplinary insights useful to non-geographers. However, this may be at cost to undergraduate programs focussing on Geography's intellectual core. Whereas formerly Geography had high reproductive capacity but low instrumental value it may now be in a phase of enhanced utility but perilously low reproductive capacity. [source] The stress dependent elastic properties of thermally induced microfractures in aeolian Rotliegend sandstoneGEOPHYSICAL PROSPECTING, Issue 3 2007Colin MacBeth ABSTRACT The impact of thermally induced microfractures on the stress-sensitive elastic wave properties of aeolian Rotliegend sandstone samples is analysed. It is found that to identify the effects of the microfracture contribution accurately, a correction must first be made to account for water loss (representing a mass loss of 4,6%) from the pore throats and clays due to the heating process, despite care being taken to ensure that the thermally fractured samples re-adsorb room moisture. Both the original and thermally fractured rocks are stress-sensitive at the ultrasonic wave frequencies of the laboratory. However, a distinct shift in the estimated distribution of internal rock compliance indicates that the population of thermal microfractures differs in nature from that caused solely by core-plug extraction damage. In particular, the ratio of normal to tangential compliance is observed to be higher for the thermally generated microfractures than for the broken grain-grain contacts created by extraction unloading. This can be explained by the intragranular thermal-fracture surfaces being smoother when compared to the intergranular boundaries. Mechanical hysteresis is observed between the up- and downgoing test cycles for both the original and, to a greater extent, the thermally fractured rock. This indicates that there is compaction-induced movement of the fractures in the samples during application of stress in the laboratory. [source] Comparison of hematologic or biochemical parameters among elderly hospital patients, institution-dwelling residents, and health check-up examineesGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 3 2003Ryuichi Yamamoto Background: The purpose of the present paper was to examine the differences in the levels of hematological or biochemical parameters among elderly hospital patients, nursing home residents, and mass health check-up recipients. Methods: One hundred and 44 geriatric inpatients (aged , 65 years), 237 outpatients, 146 nursing home residents, 120 aged examinees from mass health check-ups, and 512 younger health check-up examinees (controls) were included in the present study. They were divided into five male and five female subgroups, respectively. The levels of hemoglobin (Hb), white blood cells (WBC), serum albumin (Alb), Ca, albumin-corrected Ca, Na, creatinine (Cr), and total cholesterol (TC) were determined and compared. Results: There were significantly lower levels of Hb, Alb, Ca, Na, and TC in inpatients than in other groups in both sexes. In contrast, higher levels of WBC and Cr were found in inpatients. Among women there was no difference in the level of any parameter between nursing home residents, health check-up examinees, and controls. Conclusion: The data indicate that the levels of these parameters are affected to a greater extent in inpatients, and that female nursing home residents and health check-up examinees show values similar to those of controls. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||