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Research Center (research + center)
Kinds of Research Center Selected AbstractsAn experimental investigation of water level effects on the dynamic behaviour of a large arch damEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 8 2001Jean Proulx Abstract The need for full-scale dynamic tests, which are recognized as the most reliable method to evaluate a structure's vibration properties, is increasing as new analysis techniques are developed that take into account the complex interaction phenomenons that occur in dam,reservoir,foundation systems. They are extremely useful to obtain reliable data for the calibration of newly developed numerical methods. The Earthquake Engineering and Structural Dynamics Research Center (CRGP) at the University of Sherbrooke has been developing and applying dynamic testing methods for large structures in the past 10 years. This paper presents the experimental evaluation of the effects of the varying water level on the dynamic response of the 180 m Emosson arch dam in Switzerland. Repeated forced-vibration tests were carried out on the dam during four different periods of the reservoir's filling cycle during a one-year span. Acceleration and hydrodynamic pressure frequency responses were obtained at several locations while the dam was subjected to horizontal harmonic loading. The variation of the resonant frequencies as a function of the reservoir level is investigated. A summary of the ongoing numerical correlation phase with a three-dimensional finite element model for the dam,reservoir,foundation system is also presented. Copyright © 2001 John Wiley & Sons, Ltd. [source] University of Michigan Addiction Research Center (UMARC): development, evolution, and directionADDICTION, Issue 6 2010Robert A. Zucker ABSTRACT A historical summary is provided of the evolution of the University of Michigan Addiction Research Center (UMARC) since its origins in 1988. Begun as an National Institutes of Health (NIH) research center within a Department of Psychiatry and focused solely upon alcohol and aging, early work emphasized treatment efficacy, differential outcome studies and characterization of the neurophysiological and behavioral manifestations of chronic alcoholism. Over the last 15 years, UMARC has extended its research focus along a number of dimensions: its developmental reach has been extended etiologically by studies of risk early in the life span, and by way of work on earlier screening and the development of early, brief treatment interventions. The addiction focus has expanded to include other drugs of abuse. Levels of analysis have also broadened, with work on the molecular genetics and brain neurophysiology underlying addictive processes, on one hand, and examination of the role of the social environment in long-term course of disorder on the other hand. Activities have been facilitated by several research training programs and by collaborative relationships with other universities around the United States and in Poland. Since 2002, a program for research infrastructure development and collaboration has been ongoing, initially with Poland and more recently with Ukraine, Latvia and Slovakia. A blueprint for the future includes expanded characterization of the neurobiology and genetics of addictive processes, the developmental environment, as well as programmatic work to address the public health implications of our ability to identify risk for disorder very early in life. [source] The effects of binge drinking on college students' next-day academic test-taking performance and mood stateADDICTION, Issue 4 2010Jonathan Howland ABSTRACT Aim To assess the effects of binge drinking on students' next-day academic test-taking performance. Design A placebo-controlled cross-over design with randomly assigned order of conditions. Participants were randomized to either alcoholic beverage [mean = 0.12 g% breath alcohol concentration (BrAC)] or placebo on the first night and then received the other beverage a week later. The next day, participants were assessed on test-taking, neurocognitive performance and mood state. Participants A total of 196 college students (,21 years) recruited from greater Boston. Setting The trial was conducted at the General Clinical Research Center at the Boston Medical Center. Measurements The Graduate Record Examinations© (GREs) and a quiz on a lecture presented the previous day measured test-taking performance; the Neurobehavioral Evaluation System (NES3) and the Psychomotor Vigilance Test (PVT) measured neurocognitive performance; and the Profile of Mood States (POMS) measured mood. Findings Test-taking performance was not affected on the morning after alcohol administration, but mood state and attention/reaction-time were affected. Conclusion Drinking to a level of 0.12 g% BrAC does not affect next-day test-taking performance, but does affect some neurocognitive measures and mood state. [source] Reduced nicotine content cigarettes: effects on toxicant exposure, dependence and cessationADDICTION, Issue 2 2010Dorothy K. Hatsukami ABSTRACT Aims To examine the effects of reduced nicotine cigarettes on smoking behavior, toxicant exposure, dependence and abstinence. Design Randomized, parallel arm, semi-blinded study. Setting University of Minnesota Tobacco Use Research Center. Interventions Six weeks of: (i) 0.05 mg nicotine yield cigarettes; (ii) 0.3 mg nicotine yield cigarettes; or (iii) 4 mg nicotine lozenge; 6 weeks of follow-up. Measurements Compensatory smoking behavior, biomarkers of exposure, tobacco dependence, tobacco withdrawal and abstinence rate. Findings Unlike the 0.3 mg cigarettes, 0.05 mg cigarettes were not associated with compensatory smoking behaviors. Furthermore, the 0.05 mg cigarettes and nicotine lozenge were associated with reduced carcinogen exposure, nicotine dependence and product withdrawal scores. The 0.05 mg cigarette was associated with greater relief of withdrawal from usual brand cigarettes than the nicotine lozenge. The 0.05 mg cigarette led to a significantly higher rate of cessation than the 0.3 mg cigarette and a similar rate as nicotine lozenge. Conclusion The 0.05 mg nicotine yield cigarettes may be a tobacco product that can facilitate cessation; however, future research is clearly needed to support these preliminary findings. [source] Effects of fires on butterfly assemblages in lowland dipterocarp forest in East KalimantanENTOMOLOGICAL SCIENCE, Issue 2 2007Toshiya HIROWATARI Abstract The post-fire butterfly fauna in lowland dipterocarp forest of the Bukit Soeharto Education Forest (BSEF), East Kalimantan, Indonesia, was assessed during the period November 1998,April 2000 by means of consecutive Malaise trap samples, with supplementary field observations for March,April 1999. A total of 514 butterflies belonging to 61 species and representing six families were caught in the traps. Melanitis leda (Nymphalidae: Satyrinae), Charaxes bernardus (Nymphalidae: Charaxinae), and Danaus genutia (Nymphalidae: Danainae) were the species most frequently caught (60, 52 and 47 individuals, respectively), representing 31% of the total. These three species are generalists and "disturbance indicators" for tropical rainforest, being characteristic of disturbed or secondary forests, being distributed widely, and having larvae that feed on a wide range of host plants. In contrast, other species, such as Trogonoptera brookiana and Troides amphrysus, were recorded before the fires but were not recorded again afterwards. The pre- and post-fire butterfly fauna of East Kalimantan were compared on the basis of butterfly specimens deposited in the Tropical Rain Forest Research Center that were collected in and around the Bukit Soeharto Education Forest before the fires (1988,1995). On the basis of the post-fire survey, based on Malaise trap samples and field observations, only 43% of the butterfly species (not including Lycaenidae and Hesperiidae) were confirmed to have persisted. The data suggest that refugia that are not affected by fire are necessary for the conservation of specialist butterflies, as well as many other forms of wildlife. [source] Etoposide and merbarone are clastogenic and aneugenic in the mouse bone marrow micronucleus test complemented by fluorescence in situ hybridization with the mouse minor satellite DNA probeENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2 2003S.M. Attia Abstract The topoisomerase II (topo II) inhibitors etoposide (VP-16) and merbarone (MER) were investigated with the in vivo micronucleus test (MN test) combined with fluorescence in situ hybridization (FISH) using the mouse minor satellite DNA probe to discriminate MN of clastogenic and aneugenic origin. All experiments were performed with male (102/ElxC3H/El) F1 mice bred in the mouse colony of the GSF Research Center. The sample size per experimental group was five animals and 2,000 polychromatic erythrocytes (PCE) were scored per animal from coded slides in the conventional MN test. A separate set of coded slides was used for the FISH analysis. All treatments consisted of single intraperitoneal injections. Colchicine (COL, 3 mg/kg) and mitomycin (MMC, 1 mg/kg) were used as a positive control aneugen and clastogen, respectively, and these compounds produced the expected responses. A dose of 1 mg/kg VP-16 induced 3.44% MNPCE (compared to the concurrent solvent control of 0.37%, P < 0.001) and of these 39.9% (1.4% MNPCE) showed one or more fluorescent signals. MER (7.5,60 mg/kg) increased the MNPCE frequencies in a dose-dependent manner, with 15 mg/kg being the lowest positive dose. At the highest dose of 60 mg/kg of MER, a total of 4.26% MNPCE were found (compared to 0.31% in the concurrent solvent control, P < 0.001) and of these 46.2% (2.0% MNPCE) contained one or more fluorescent signals. The data demonstrate that VP-16 and MER induced both clastogenic and aneugenic events despite their different modes of topo II inhibition. Environ. Mol. Mutagen. 41:99,103, 2003. © 2003 Wiley-Liss, Inc. [source] GeoChip-based analysis of functional microbial communities during the reoxidation of a bioreduced uranium-contaminated aquiferENVIRONMENTAL MICROBIOLOGY, Issue 10 2009Joy D. Van Nostrand Summary A pilot-scale system was established for in situ biostimulation of U(VI) reduction by ethanol addition at the US Department of Energy's (DOE's) Field Research Center (Oak Ridge, TN). After achieving U(VI) reduction, stability of the bioreduced U(IV) was evaluated under conditions of (i) resting (no ethanol injection), (ii) reoxidation by introducing dissolved oxygen (DO), and (iii) reinjection of ethanol. GeoChip, a functional gene array with probes for N, S and C cycling, metal resistance and contaminant degradation genes, was used for monitoring groundwater microbial communities. High diversity of all major functional groups was observed during all experimental phases. The microbial community was extremely responsive to ethanol, showing a substantial change in community structure with increased gene number and diversity after ethanol injections resumed. While gene numbers showed considerable variations, the relative abundance (i.e. percentage of each gene category) of most gene groups changed little. During the reoxidation period, U(VI) increased, suggesting reoxidation of reduced U(IV). However, when introduction of DO was stopped, U(VI) reduction resumed and returned to pre-reoxidation levels. These findings suggest that the community in this system can be stimulated and that the ability to reduce U(VI) can be maintained by the addition of electron donors. This biostimulation approach may potentially offer an effective means for the bioremediation of U(VI)-contaminated sites. [source] Decomposition and parallelization strategies for solving large-scale MDO problemsGAMM - MITTEILUNGEN, Issue 2 2007M. Grauer During previous years, structural optimization has been recognized as a useful tool within the discriptines of engineering and economics. However, the optimization of large-scale systems or structures is impeded by an immense solution effort. This was the reason to start a joint research and development (R& D) project between the Institute ofMechanics and Control Engineering and the Information and Decision Sciences Institute within the Research Center for Multidisciplinary Analyses and Applied Structural Optimization (FOMAAS) on cluster computing for parallel and distributed solution of multidisciplinary optimization (MDO) problems based on the OpTiX-Workbench. Here the focus of attention will be put on coarsegrained parallelization and its implementation on clusters of workstations. A further point of emphasis was laid on the development of a parallel decomposition strategy calles PARDEC, for the solution of very complex optimization problems which cannot be solved efficiently by sequential integrated optimization. The use of the OptiX-Workbench together with the FEM ground water simulation system FEFLOWis shown for a special water management problem. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Emergence of New Mechanical Functionality in Materials via Size ReductionADVANCED FUNCTIONAL MATERIALS, Issue 18 2009Julia R. Greer Abstract Julia R. Greer received her S.B. in Chemical Engineering from the Massachusetts Institute of Technology (1997) and a Ph.D. in Materials Science from Stanford University, where she worked on the nanoscale plasticity of gold with W. D. Nix (2005). She also worked at Intel Corporation in Mask Operations (2000,03) and was a post-doctoral fellow at the Palo Alto Research Center (2005,07), where she worked on organic flexible electronics with R. A. Street. Greer is a recipient of TR-35, Technology Review's Top Young Innovator award (2008), a NSF CAREER Award (2007), a Gold Materials Research Society Graduate Student Award (2004), and an American Association of University Women Fellowship (2003). Julia joined Caltech's Materials Science department in 2007 where she is developing innovative experimental techniques to assess mechanical properties of nanometer-sized materials. One such approach involves the fabrication of nanopillars with different initial microstructures and diameters between 25,nm and 1,µm by using focused ion beam and electron-beam lithography microfabrication. The mechanical response of these pillars is subsequently measured in a custom-built in situ mechanical deformation instrument, SEMentor, comprising a scanning electron microscope and a nanoindenter. Read our interview with Prof. Greer on MaterialsViews.com [source] Rats bred for high alcohol drinking are more sensitive to delayed and probabilistic outcomesGENES, BRAIN AND BEHAVIOR, Issue 7 2008C. J. Wilhelm Alcoholics and heavy drinkers score higher on measures of impulsivity than nonalcoholics and light drinkers. This may be because of factors that predate drug exposure (e.g. genetics). This study examined the role of genetics by comparing impulsivity measures in ethanol-naive rats selectively bred based on their high [high alcohol drinking (HAD)] or low [low alcohol drinking (LAD)] consumption of ethanol. Replicates 1 and 2 of the HAD and LAD rats, developed by the University of Indiana Alcohol Research Center, completed two different discounting tasks. Delay discounting examines sensitivity to rewards that are delayed in time and is commonly used to assess ,choice' impulsivity. Probability discounting examines sensitivity to the uncertain delivery of rewards and has been used to assess risk taking and risk assessment. High alcohol drinking rats discounted delayed and probabilistic rewards more steeply than LAD rats. Discount rates associated with probabilistic and delayed rewards were weakly correlated, while bias was strongly correlated with discount rate in both delay and probability discounting. The results suggest that selective breeding for high alcohol consumption selects for animals that are more sensitive to delayed and probabilistic outcomes. Sensitivity to delayed or probabilistic outcomes may be predictive of future drinking in genetically predisposed individuals. [source] The effect of temperature and daylength on heading in tetraploid cultivars of rhodesgrass (Chloris gayana Kunth)GRASSLAND SCIENCE, Issue 4 2005Isao Tarumoto Abstract The present study was conducted to clarify the effect of temperature and daylength on heading in tetraploid cultivars of rhodesgrass (Chloris gayana Kunth). Five cultivars, Tochiraku-kei (2,), Fords Katambora (2,), Callide (4,), Masaba (4,) and Pokot (4,), were planted on three dates at 1-month intervals (4 May, 4 June and 4 July) in three of the Ministry of Agriculture, Forestry and Fisheries research institutions in Ishigaki (Tropical Agriculture Research Center), Nishigoshi (Kyushu National Agricultural Experiment Station) and Nishinasuno (National Grassland Research Institute) in 1978. Three tetraploid cultivars were planted on three dates at 1-month intervals (4 May, 4 June and 4 July) under four daylength-treatments of natural daylength (ND), 12 h daylength [12 h], ND/12 h and 12 h/ND, and changed daylength at the eighth leaf stage, in Nishinasuno in 1978. Under natural daylength, although heading was not observed for Masaba and Pokot, heading was observed in all plots for Tochiraku-kei, Fords Katambora and Callide, and their days to heading (DH) linearly decreased with increases in daily mean temperature (DMT). The result indicated that, under natural daylength in summer, temperature was a major factor in determining DH in tetraploid Callide, which was the same as in diploid rhodesgrass cultivars. Callide reached heading under all four daylength treatments. However, Masaba and Pokot reached heading only under 12 h and ND/12 h treatments, suggesting that Masaba and Pokot have qualitative sensitivity to photoperiods that operate after the ninth leaf stage. These findings would be useful in tetraploid rhodesgrass for estimating foliage harvesting time in the field and for conducting cross-pollination in a greenhouse during winter. [source] Molecular characterization of novel progranulin (GRN) mutations in frontotemporal dementia,HUMAN MUTATION, Issue 4 2008Odity Mukherjee Abstract Frontotemporal dementia (FTD) is a clinical term encompassing dementia characterized by the presence of two major phenotypes: 1) behavioral and personality disorder, and 2) language disorder, which includes primary progressive aphasia and semantic dementia. Recently, the gene for familial frontotemporal lobar degeneration (FTLD) with ubiquitin-positive, tau-negative inclusions (FTLD-U) linked to chromosome 17 was cloned. In the present study, 62 unrelated patients from the Washington University Alzheimer's Disease Research Center and the Midwest Consortium for FTD with clinically diagnosed FTD and/or neuropathologically characterized cases of FTLD-U with or without motor neuron disease (MND) were screened for mutations in the progranulin gene (GRN; also PGRN). We discovered two pathogenic mutations in four families: 1) a single-base substitution within the 3, splice acceptor site of intron 6/exon 7 (g.5913A>G [IVS6,2A>G]) causing skipping of exon 7 and premature termination of the coding sequence (PTC); and 2) a missense mutation in exon 1 (g.4068C>A) introducing a charged amino acid in the hydrophobic core of the signal peptide at residue 9 (p.A9D). Functional analysis in mutation carriers for the splice acceptor site mutation revealed a 50% decrease in GRN mRNA and protein levels, supporting haploinsufficiency. In contrast, there was no significant difference in the total GRN mRNA between cases and controls carrying the p.A9D mutation. Further, subcellular fractionation and confocal microscopy indicate that although the mutant protein is expressed, it is not secreted, and appears to be trapped within an intracellular compartment, possibly resulting in a functional haploinsufficiency. Hum Mutat 29(4), 512,521, 2008. © 2008 Wiley-Liss, Inc. [source] IL-5-induced airway eosinophilia , the key to asthma?IMMUNOLOGICAL REVIEWS, Issue 1 2001Eckard Hamelmann Summary: Bronchial asthma is a chronic inflammatory airway disease defined by reversible airway obstruction and non-specific airway hyper-responsiveness (AHR). Although profound insights have been made into the pathophysiology of asthma, the exact mechanisms inducing and regulating the disease are still not fully understood. Yet, it is generally accepted that the pathological changes in asthma are induced by a chronic inflammatory process which is characterized by infiltration of the bronchial mucosa with lymphocytes and eosinophils, increased mucus production and submucosal edema. There is increasing evidence that an imbalance in the T-helper (Th) cell response of genetically predisposed individuals to common environmental antigens plays a pivotal role in the pathogenesis of allergic bronchial asthma and other atopic disorders. Following allergic sensitization, T cells from atopic patients tend to produce elevated levels of Th2-type cytokines, especially interleukin (IL)-4, IL-13, IL-5 and IL-6, which induce and regulate IgE production and eosinophil airway infiltration. In this review, the role of Th2-type cytokines, IgE and airway eosinophils in the induction of airway inflammation and AHR is discussed, and animal studies of asthma and AHR, mainly in rodents will be considered. A better understanding of the underlying mechanisms leading to asthma pathology may yield more specific immunological strategies for the treatment of this disease which is increasing worldwide. I thank the many colleagues in the laboratory of Dr. E. W. Gelfand, National Jewish Research Center, Denver CO, USA, for continuous support and encouragement. E.H. is a fellow of the Deutsche Forschungsgemeinschaft (DFG Ha 2162/1-1 and 2-1). [source] Metabolic phenotyping of mouse mutants in the German Mouse ClinicINTEGRATIVE ZOOLOGY (ELECTRONIC), Issue 3 2006Ralf ELVERT Abstract The German Mouse Clinic was established as a phenotyping center to provide the scientific community with systematic standardized phenotyping of mouse models from various genetic backgrounds. We found metabolic phenotypes in nine out of 20 mutant lines screened in a primary screen. Based on these findings, the mutants were analyzed in secondary and tertiary screens. Mice of a sample mutant line, isolated from the ENU-screen at the National Research Center for Environment and Health in Munich, were found to have lower body weight, consume less food, but have higher ratios of metabolized energy per unit body weight compared with their wild-type littermates. Basal metabolic rate and heat production were simultaneously increased by 16,18%, whereas body fat content was reduced by 11,16%. The combination of various parameters of energy consumption, expenditure and energy storage illustrate the metabolic demands of the sample mutant mouse line and demonstrate the utility of the powerful phenotyping tool used at the German Mouse Clinic. [source] Advantages of Different Tillage Systems and Their Effects on the Economically Important Pests, Thrips tabaci Lind. and Aphis gossypii Glov. in Cotton FieldsJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 6 2004I. Gencsoylu Abstract An experiment to assess advantages of different tillage and their effects on Aphis gossypii Glov. and Thrips tabaci Lind was conducted during the 2000 and 2001 cotton growing seasons in cotton fields at Adnan Menderes University, Agricultural Faculty Research Center, located in Ayd,n Province, Turkey. The tillage systems examined were conventional, strip, precision and ridge tillage. Two insect population densities were not affected by the type of tillage systems during either year. However, significant differences in populations were observed in thrips populations on 31 May 2000 and 18 May 2001 and aphid populations on 24 May 2000 and 11 May 2001. The results show that the highest yield was observed in all conservation tillage systems in 2000 and ridge tillage system in 2001. Early maturity was higher in both precision and ridge tillage systems. In addition, tillage systems did not affect fibre properties. As a result, the application of conservation tillage is more advantageous in cotton in respect of early maturity and total yield. [source] The Relationship Between the Action of Arginine Vasopressin and Responsiveness to Oral Desmopressin in Older Men: A Pilot StudyJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 4 2007Theodore M. Johnson II OBJECTIVES: To identify whether oral desmopressin (ddAVP) reduced nocturnal urine volume (NUV) in older men with nocturia without obvious bladder outlet obstruction and to determine whether deficiencies in arginine vasopressin (AVP) release and action demonstrated using water deprivation testing predicted responsiveness to ddAVP. DESIGN: Participants had a 2-day Clinical Research Center (CRC) evaluation followed by a double-blinded, placebo-controlled, crossover trial of individually titrated oral ddAVP. SETTING: Participants were from a single Department of Veterans Affairs Medical Center. MEASUREMENTS: Maximum urine osmolality and percentage increase in osmolality were measured after subjects received aqueous vasopressin as part of the overnight water deprivation study; these data were used to categorize participants as normal, having partial central AVP deficiency, or having impaired renal responsiveness to AVP. Response to ddAVP was assessed using data from frequency-volume records. RESULTS: Fourteen participants completed the CRC stay and ddAVP trial. Subjects given ddAVP reduced NUV significantly from baseline (P=.02) and had significantly lower NUV than when on placebo (P=.01). The mean net reduction in NUV from ddAVP compared to placebo was 14±18%. Using water deprivation testing to categorize participants, 10 were normal, two had partial central AVP deficiency, and two had impaired renal responsiveness. The mean net reduction in NUV for those with abnormal water deprivation tests was 11±25%, versus 15±16% for those with normal water deprivation testing (P=.70). CONCLUSION: In this small randomized, controlled trial in older men with nocturia, ddAVP reduced NUV. Counter to expectations, participants deemed normal according to water deprivation tests had approximately equivalent responsiveness to ddAVP. Although this study cannot offer definitive conclusions on the lack of prediction of water deprivation testing for ddAVP benefit, these data offer additional information that may help clarify the pathophysiology and optimal treatment of nocturia in older men. [source] Estimating Cardiorespiratory Fitness in Well-Functioning Older Adults: Treadmill Validation of the Long Distance Corridor WalkJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 1 2006Eleanor M. Simonsick PhD Objectives: To determine criterion validity of the 400-m walk component of the Long Distance Corridor Walk (LDCW) and develop equations for estimating peak oxygen consumption (VO2) from 400-m time and factors intrinsic to test performance (e.g., heart rate (HR) and systolic blood pressure (SBP) response) in older adults. Design: Cross-sectional validation study. Setting: Gerontology Research Center, National Institute on Aging, Baltimore, Maryland. Participants: Healthy volunteers (56 men and 46 women) aged 60 to 91 participating in the Baltimore Longitudinal Study of Aging between August 1999 and July 2000. Measurements: The LDCW, consisting of a 2-minute walk followed immediately by a 400-m walk "done as quickly as possible" over a 20-m course was administered the day after maximal treadmill testing. HR and SBP were measured before testing and at the end of the 400-m walk. Weight, height, activity level, perceived effort, and stride length were also acquired. Results: Peak VO2 ranged from 12.2 to 31.1 mL oxygen/kg per minute, and 400-m time ranged from 2 minutes 52 seconds to 6 minutes 18 seconds. Correlation between 400-m time and peak VO2 was ,0.79. The estimating equation from linear regression included 400-m time (partial coefficient of determination (R2)=0.625), long versus short stride (partial R2=0.090), ending SBP (partial R2=0.019), and a correction factor for fast 400-m time (<240 seconds; partial R2=0.020) and explained 75.5% of the variance in peak VO2 (correlation coefficient=0.87). Conclusion: A 400-m walk performed as part of the LDCW provides a valid estimate of peak VO2 in older adults. Incorporating low-cost, safe assessments of fitness in clinical and research settings can identify early evidence of physical decline and individuals who may benefit from therapeutic interventions. [source] Job Satisfaction and Subjective Well-Being in a Sample of NursesJOURNAL OF APPLIED SOCIAL PSYCHOLOGY, Issue 5 2005Stephen A. Sparks It is surprising that there are no published studies exploring job satisfaction and subjective well-being (SWB) in nurses given the current shortage (Clark & Clark, 2002). For the present study, 152 nurses completed measures of job satisfaction, SWB, and social desirability. The Dimensions of Satisfaction scale was designed for this study and demonstrated acceptable reliability and validity. Results indicated that the most important aspect to nurses' job satisfaction is pay, followed by staffing and benefits. When entering the field, nurses most valued pay, followed by personal fulfillment and respect. A majority of the sample (59%) indicated satisfaction with their job, but this is well below the national average for American workers (85%; National Opinion Research Center, 2000). Nurses indicated higher SWB than the general population (Myers & Diener, 1996). However, the correlation between job satisfaction and SWB was lower than that of the general population (Tail, Padgett, & Baldwin, 1989). [source] Effects of Low-Dose Prednisone on Bone Metabolism,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 3 2005Francine N Ton MD Abstract Prednisone 5 mg/day suppresses multiple indices of bone formation in a randomized placebo-controlled trial in healthy postmenopausal females. This suggests that even low doses of prednisone may reduce bone repair or renewal and may have adverse effects on bone mass and/or bone strength. Introduction: High doses of chronic glucocorticoids are known to have adverse effects on bone, and measures to prevent bone loss are well established for doses >7.5 mg daily, because these doses can cause premature or exaggerated osteoporosis. However, it is unclear if chronic prednisone doses of 5 mg daily have the same effects on bone. There are no established recommendations for preventing glucocorticoid-induced osteoporosis in people taking prednisone 5 mg daily, a dose used frequently in medical practice to treat diseases of the lungs, joints, skin, muscles, eyes, nerves, etc. Our primary objective was to test whether prednisone 5 mg daily affects serum and urine indices of bone metabolism in healthy postmenopausal women. Our secondary objectives were to determine if prednisone 5 mg affected systolic or diastolic blood pressure or causes side effects. Materials and Methods: A double-blinded randomized placebo-controlled 8-week trial in 50 healthy postmenopausal women was conducted at the Massachusetts General Hospital Outpatient General Clinical Research Center. Patients were randomly assigned to prednisone 5 mg daily or matching placebo for 6 weeks, followed by a 2-week recovery phase. Markers of bone formation and resorption were determined at weeks 0, 2, 4, 6, and 8. Indices of osteoblast activity included serum propeptide of type I N-terminal procollagen (PINP), propeptide of type I C-terminal procollagen (PICP), osteocalcin, and bone-specific alkaline phosphatase (BSALP). Indices of osteoclast activity included urine and serum type I collagen N-telopeptide (NTX) and free urinary deoxypyridinoline (DPD). Results and Conclusions: Prednisone rapidly and significantly decreased serum PINP (p < 0.01), PICP (p < 0.01), and osteocalcin (p < 0.01) and free urinary deoxypyridinoline (p = 0.017). These changes were largely reversed during the recovery period. Side effects were indistinguishable in the two groups. Neither systolic nor diastolic blood pressure changed significantly throughout the study between the two groups. In conclusion, low-dose prednisone significantly decreases indices of bone formation and may decrease indices of bone resorption in postmenopausal women. Further studies are needed to assess the effects of low-dose prednisone on BMD and fracture risk. [source] Roundtable Discussion: Problems in the Management of HypertensionJOURNAL OF CLINICAL HYPERTENSION, Issue 3 2002Marvin Moser MD Following a symposium on hypertension sponsored by the National Heart, Lung, and Blood Institute in Chicago, IL on October 3, 2001, a panel was convened to discuss various aspects of hypertension treatment. Moderating the panel was Dr. Marvin Moser, Clinical Professor of Medicine at The Yale University School of Medicine. Panel members included Dr. George Bakris, Professor of Preventive Medicine and Director, Hypertension/Clinical Research Center at the Rush-Presbyterian-St. Luke's Medical Center in Chicago, Illinois and Dr. Henry Black, Professor of Medicine, Associate Vice President for Research, and Chairman of the Department of Preventive Medicine at Rush-Presbyterian. [source] Obesity , is it a genetic disorder?JOURNAL OF INTERNAL MEDICINE, Issue 5 2003R. J. F. Loos Abstract., Loos RJF, Bouchard C (Human Genomics Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA, USA). Obesity , is it a genetic disorder? (Review). J Intern Med 2003; 254: 401,425. Obesity is one of the most pressing problems in the industrialized world. Twin, adoption and family studies have shown that genetic factors play a significant role in the pathogenesis of obesity. Rare mutations in humans and model organisms have provided insights into the pathways involved in body weight regulation. Studies of candidate genes indicate that some of the genes involved in pathways regulating energy expenditure and food intake may play a role in the predisposition to obesity. Amongst these genes, sequence variations in the adrenergic receptors, uncoupling proteins, peroxisome proliferator-activated receptor, and the leptin receptor genes are of particular relevance. Results that have been replicated in at least three genome-wide scans suggest that key genes are located on chromosomes 2p, 3q, 5p, 6p, 7q, 10p, 11q, 17p and 20q. We conclude that the currently available evidence suggests four levels of genetic determination of obesity: genetic obesity, strong genetic predisposition, slight genetic predisposition, and genetically resistant. This growing body of research may help in the development of anti-obesity agents and perhaps genetic tests to predict the risk for obesity. [source] Fitness, fatness and activity as predictors of bone mineral density in older personsJOURNAL OF INTERNAL MEDICINE, Issue 5 2002K. J. Stewart Abstract. Stewart KJ, DeRegis JR, Turner KL, Bacher AC, Sung J, Hees PS, Tayback M, Ouyang P (Johns Hopkins Bayview Medical Center, Johns Hopkins University, School of Medicine, Baltimore, MD, USA). Fitness, fatness, and activity as predictors of bone mineral density in older persons. J Intern Med 2002; 252: 381,388. Objectives. To determine relationships of bone mineral density (BMD) with fitness, physical activity, and body composition and fat distribution. Design. Cross-sectional. Setting. General Clinical Research Center, Johns Hopkins Bayview Medical Center, Baltimore, Maryland. Subjects. Men (n = 38) and women (n = 46), aged 55,75 years with high normal blood pressure or mild hypertension but otherwise healthy. Methods. Aerobic fitness (oxygen uptake) on a treadmill, muscle strength by one-repetition maximum, activity by questionnaire, abdominal obesity by magnetic resonance imaging; anthropometrics, and body composition by dual energy X-ray absorptiometry (DXA) which measured total fat and lean mass, and BMD for the total skeleton, lumbar spine (L1,L4) and total hip. Results. Aerobic fitness did not correlate with BMD. Using multivariate analysis to ascertain independent contributions to the variance in BMD, in women, with adjustment for hormone replacement therapy (HRT), total skeleton BMD was independently related to muscle strength and abdominal total fat; total hip BMD to body weight; lumbar spine BMD to abdominal total fat. HRT also influenced BMD in the lumbar spine. In men, lumbar spine BMD was independently related to abdominal total fat physical activity and total hip BMD related to lower body strength. P < 0.05 for all of these correlations. Conclusions. Abdominal obesity and muscle strength emerge as predominant correlates of BMD in older persons with stronger relationships seen in women. Body weight and HRT also explained portions of the variance in BMD in women. Whether abdominal obesity is simply a marker for general obesity or has independent protective effects on bone is yet to be determined. [source] Assessment of progestin-only therapy for endometriosis in macaqueJOURNAL OF MEDICAL PRIMATOLOGY, Issue 2008G. Maginnis Abstract Background, Endometriosis is a condition where endometrium-like tissue forms lesions at ectopic sites outside the uterus. In women, oral contraceptive pills and progestins are often prescribed as therapy for early stage endometriosis. In contrast, in macaques the disease is frequently advanced at the time of diagnosis and ovariectomy is the standard therapy. However, surgery is contraindicated in many patients. A review of 15 endometriosis cases over the past 10 years at the Oregon National Primate Research Center (ONPRC) revealed that 5 failed to show improvement after ovariectomy and were subsequently euthanized. Therefore, our goal was to assess the feasibility of treating endometriosis in macaques with chronic progesterone (P) as an alternative therapy for the disease. Methods, Seven adult rhesus macaques with advanced endometriosis were identified by clinical symptoms and endometriosis was confirmed by abdominal palpation, ultrasound examination, and/or aspiration of menstrual blood from abdominal cysts. The patients were chronically treated with Silastic capsules that released 5,7 ng P /ml in blood for up to 20 months. During treatment the patients were assessed daily and scored numerically for appetite, activity, attitude, abdominal discomfort and menstruation by the Clinical Veterinary staff. The patients were then re-examined by abdominal palpation and ultrasound for the disease at the end of treatment. Results, During the first 2 weeks of treatment, endometriotic symptoms improved significantly in all the patients (P < 0.05). This was associated with a significant increase in body weight and significant reduction in abdominal discomfort and menstrual bleeding. Two of the patients gradually developed increased symptoms of the disease after 5 months of treatment. Post-treatment abdominal examination revealed that 2/5 patients continued to have an abdominal mass even though symptoms were suppressed. Conclusions, We conclude that continuous P treatment of rhesus monkeys provides therapeutic benefit to reduce symptoms of endometriosis and may provide an option for cases where ovariectomy is contraindicated. Supported by RR-00163. [source] Herpes B-virus seroreactivity in a colony of Macaca mulatta: data from the Sabana Seca Field Station, a new Specific Pathogen-Free ProgramJOURNAL OF MEDICAL PRIMATOLOGY, Issue 1 2005Carlos A. Sariol Abstract:, The demand for B-virus-free animals for biomedical research is increasing, while at the same time the availability of such animals is decreasing. The establishment of Specific Pathogen-Free (SPF) breeding macaque colonies is a priority of the National Institutes of Health. Nevertheless, it is well known that seroreactivity to B-virus can be difficult to interpret, particularly as it can vary over time in a single animal. The aim of the present study was to implement a reliable algorithm to examine B-virus reactivity among the rhesus monkey population of the Caribbean Primate Research Center. The sensitivity and specificity of our assay were determined using reports from two different laboratories as references. Whereas 95.4% of animals showed consistent serological status and 4.6% of animals recruited to this SPF program showed serovariability to B-virus over the initial 2 years of examination. Implications for all SPF programs are discussed in this article. [source] Leptin, body composition, adrenal and gonadal hormones among captive male baboonsJOURNAL OF MEDICAL PRIMATOLOGY, Issue 6 2003M.P. Muehlenbein Abstract:, Morphometric and hormonal measures were collected from 21 captive savanna baboons (Papio cynocephalus) maintained at the Tulane National Primate Research Center in order to determine age-related patterns in leptin levels over the life course as well as their relationships to body composition and adrenal and gonadal steroids. Comparison of leptin levels between peri-pubertal, adolescent, young adult, and fully mature males show lower levels among adolescent as compared with young adult males (P = 0.05 by Kruskal,Wallis ANOVA). In addition, abdominal fat varied among age groups (P = 0.003 by Kruskal,Wallis ANOVA) with the peri-pubertal animals lower than the adolescents, young adults, and prime adults. However leptin was not related to any measure of body composition, including abdominal fat, or to adrenal hormones (dehydroepiandrosterone, dehydroepiandrosterone-sulfate, and cortisol) or gonadal hormones (testosterone and estradiol). Age-related changes in leptin appear similar to those reported for captive rhesus macaques, while the failure to find an association between leptin and abdominal fat is interestingly different. These results confirm elevated levels of leptin in captive baboons compared with their wild counterparts and suggest that they result from changes in fetal development. [source] Hematology and blood biochemistry in infant baboons (Papio hamadryas)JOURNAL OF MEDICAL PRIMATOLOGY, Issue 3 2003L.M. Havill Abstract: Although published normative reference standards for hematologic and clinical chemistry measures are available for adult baboons, their applicability to infants has not been addressed. We analyzed these measures in 110 infant baboons (55 females and 55 males) from a large breeding colony at the Southwest Regional Primate Research Center in San Antonio, Texas. The sample consists of olive baboons and olive/yellow baboon hybrids, 1 week to 12 months of age. We produced cross-sectional reference values and examined the effects of age, sex, and subspecies on these variables. Hematology reference ranges for infant baboons are similar to, but wider than, those for adults. Reference ranges for blood biochemistry measures are generally more dissimilar to adults, indicating that for many variables, reference ranges for adult baboons are not adequate for infants. Although sex and subspecies differences are rare, age accounts for more than 10% of the variance in many of the variables. [source] Identity and Pathogenicity of Fungi Associated with Root and Crown Rot of Soft Red Winter Wheat Grown on the Upper Coastal Plain Land Resource Area of MississippiJOURNAL OF PHYTOPATHOLOGY, Issue 2 2000M. S. Gonzalez Seedling stand, disease severity and fungal incidence were determined from untreated ,Wakefield' soft red winter wheat planted on a Leeper silty clay loam in field tests conducted at the Mississippi Agricultural and Forestry Experiment Station, Plant Science Research Center, Mississippi State University, Starkville, Mississippi during the 1996,97 and 1997,98 growing seasons. Seedling stand was reduced by 40% each year in plots established with untreated seed. Cochliobolus sativus was the most frequently isolated fungus. Fusarium acuminatum, Fusarium equiseti and Fusarium solani were the most prevalent Fusarium spp. Seven other Fusarium spp. and 23 species of other fungal genera were isolated. Pathogenicity tests with three isolates each of C. sativus, Cochliobolus spicifer, F. acuminatum, F. solani, F. equiseti, Fusarium compactum, Embellisia chlamydospora and Microdochium bolleyi were performed in test tube culture and two isolates each of C. sativus, C. spicifer, F. acuminatum, E. chlamydospora and M. bolleyi under greenhouse conditions. In test tubes and in the greenhouse, seedlings infected with isolates of C. sativus developed seedling blight, discoloration and necrosis, primarily in seminal roots and crowns. In the greenhouse, C. sativus induced lesions on the lower leaf sheath and reduced seedling height, seedling emergence, dry and fresh weight of roots and shoots. Isolates of F. acuminatum, F. solani, F. equiseti, F. compactum, E. chlamydospora and M. bolleyi induced slight to moderate orange to light-brown discoloration of crown and seminal roots in test tubes. Cochliobolus spicifer isolates had the most pre-emergence activity, inducing black root discoloration and root pruning of wheat seedlings and reducing seedling emergence, root fresh weight and shoot dry weight. In the greenhouse, F. acuminatum reduced seedling height, seedling emergence and root and shoot dry weights. Microdochium bolleyi and E. chlamydospora reduced fresh and dry weight of roots, plant emergence and shoot dry weight. Fusarium acuminatum and C. spicifer reduced the growth rate of wheat seedlings. All fungi evaluated showed increased disease severity compared to the untreated control. The high frequency of isolation of C. sativus from crown and root tissues can be partially explained by the dry, warm conditions during the early stages of wheat seedling development in the Upper Coastal Plain Land Resource Area of Mississippi. Zusammenfassung Die Auflaufrate von Sämlingen, die Stärke des Krank-heitsbefalls sowie die Häufigkeit von Pilzarten wurden bei nicht behandelten roten Weichwinterweizen der Sorte Wakefield ermittelt, welche in einem Leeper schlammigen Tonboden an der Mississippi Agricultural & Forestry Experiment Station, Plant Science Research Center, Mississippi State University, Starkville, Mississippi in der 1996,97 und 1997,98 Saison gesät worden waren. In beiden Jahren wurde die Auflaufrate von nicht behandeltem Saatgut um 40% reduziert. Cochliobolus sativus wurde am häufigsten isoliert. Fusarium acuminatum, Fusarium equiseti und Fusarium solani waren die überwiegenden Fusarium spp. Außierdem wurden sieben weitere Fusarium spp. sowie 23 weitere Pilzarten isoliert. Pathogenitätstests mit je 3 Isolaten von C. sativus, Cochliobolus spicifer, F. acuminatum, F. solani, F. equiseti, Fusarium compactum, Embellisia chlamydospora und Microdochiumbolleyi wurden in Reagenzröhrchen durchgeführt, sowie mit je 2 Isolaten von C. sativus, C. spicifer, F. acuminatum, E. chlamydospora und M. bolleyi unter Gewächshausbedingungen. Sowohl in den Reagenzröhrchen als auch im Gewächshaus entwickelten Sämlinge, die mit C. sativus inokuliert worden waren, eine Fäule, Verfärbung sowie Nekrosis, hauptsächlich in den sekundären Wurzeln und in den Halmbasen. Unter Gewächshausbedingungen verursachte C. sativus außierdem Läsionen der unteren Blattscheide sowie eine Reduzierung des Sämlingswachstums, des Sämlingsauflaufs, des Trocken-und Frischgewichts der Wurzeln und Sprossen. Im Reagenzröhrchentest induzierten Isolate von F. acuminatum, F. solani, F. equiseti, F. compactum, E. chlamydospora und M. bolleyieine schwache bis mäßiige orange bis hell braune Verfärbung des Halmbasis und der Sekundärwurzeln. Isolate von C. spicifer besaßien die höchste Vorauflaufaktivität und induzierten eine Verschwärzung und Verkürzung der Wurzeln sowie eine Reduzierung des Sämlingsauflaufs, des Wurzelfrischgewichts sowie des Sproitrockengewichts. Unter Gewächshausbedingungen reduzierte F. acuminatum die Sämlingshöhe, die Auflaufrate sowie das Trockengewicht der Wurzeln und Sproien. Microdochium bolleyi und E. chlamydospora reduzierten das Frisch-und Trockengewicht der Wurzeln, die Auflaufrate sowie das Sproßitrockengewicht. Die Wachstumsrate der Sämlinge wurde durch F. acuminatum und C. spicifer reduziert. Alle untersuchten Pilzarten erhöhten die Befallsstärke verglichen mit der unbehandelten Kontrolle. Die hohe Isolierungsrate von C. sativus aus dem Halmbasis-und Wurzelgewebe kann zum Teil dadurch erklärt werden, dass während der Frühentwicklungsphase der Sämlinge trockene und warme Wachstumsbedingungen in diesem Gebiet herrschten. [source] Glycosidases in soils as affected by cropping systemsJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 6 2005Daniel E. Dodor Abstract Glycosidases are a group of soil enzymes that play a major role in degradation of carbohydrates. This study was conducted to assess the impact of crop rotation and N fertilization on the activities of ,- and ,-glucosidases and ,- and ,-galactosidases in plots of two long-term field experiments at the Clarion-Webster Research Center (CWRC) and Northeast Research Center (NERC) in Iowa. Surface-soil (0,15 cm) samples were taken in 1996 and 1997 in corn (Zeamays L.), soybean (Glycinemax (L.) Merr.), oats (Avenasativa L.), or meadow (alfalfa) (Medicago sativa L.) plots that received 0 or 180,kg N ha,1, applied as urea before corn, and an annual application of 20,kg P ha,1 and 56,kg K ha,1. Activities of the four glycosidases were significantly affected by crop rotations in both years at the two sites but not by nitrogen application. In general, higher activities were observed in plots under meadow or oat and the lowest in continuous corn (CWRC) and soybean (NERC). Four-year rotation showed the highest activity, followed by 2-year rotation and monocropping systems. Linear-regression analyses indicated that, in general, the activities of the glycosidases were significantly correlated with microbial-biomass C (r > 0.302, p , 0.05) and microbial-biomass N (r > 0.321, p , 0.05), organic-C (r > 0.332, p , 0.05) and organic-N (r > 0.399, p , 0.01) contents of the soils. Results of this work suggest that multicropping stimulated the activities of the glycosidases. The specific activities of the glycosidases in soils of the two sites studied, expressed as g p -nitrophenol released per,kg of organic C, differed among the four enzymes. The lowest values were obtained for ,-galactosidase and ,-glucosidase, followed by ,-galactosidase and ,-glucosidase. Glycosidasen in Böden unter dem Einfluss von Bewirtschaftungssystemen Glycosidasen stellen eine Gruppe von Bodenenzymen dar, welche eine entscheidende Rolle im Abbau von Kohlenhydraten spielen. Ziel dieser Untersuchungen war die Erfassung des Einflusses von Fruchtfolge und N-Düngung auf die Aktivitäten von ,- und ,-Glucosidasen und ,- und ,-Galactosidasen in zwei Langzeitfeldversuchen, dem Clarion-Webster-Versuchsfeld (CWRC) und dem Northeast-Versuchsfeld (NERC) in Iowa. In den Jahren 1996 und 1997 wurden Oberbodenproben (0,15 cm) von Parzellen unter Mais (Zeamays L.), Sojabohne (Glycine max (L.) Merr.), Hafer (Avena sativa L.) oder Luzerne (Medicago sativa L.) entnommen, welche vor Mais 0 oder 180,kg N ha,1 in Form von Harnstoff sowie jährliche Düngergaben in Höhe von 20,kg P ha,1 und 56,kg K ha,1 erhielten. Über zwei Jahre wurden die Aktivitäten der vier Glycosidasen in beiden Feldversuchen signifikant von der Bewirtschaftung beeinflusst, jedoch nicht von der N-Düngung. Im allgemeinen wurden höhere Enzymaktivitäten in Parzellen unter Luzerne oder Hafer festgestellt und die geringsten unter Maismonokultur (CWRC) bzw. Sojabohne (NERC). Vierjährige Fruchtfolgen zeigten die höchsten Aktivitäten, gefolgt von zweijährigen Fruchtfolgen und Monokulturen. Analysen mittels linearer Regression weisen auf eine Korrelation zwischen Glycosidaseaktivitäten und C (r > 0.332, p , 0.05) und N der mikrobiellen Biomasse (r > 0.321, p , 0.05) sowie den Gehalten an org. C (r > 0.332, p , 0.05) und N (r > 0.399, p , 0.01) hin. Die Ergebnisse dieser Untersuchungen deuten darauf hin, dass die Aktivitäten von Glycosidasen durch mehrjährige Fruchtfolgen stimuliert wurden. Die spezifischen Glycosidaseaktivitäten in den Böden der zwei Feldversuche, berechnet als freigesetztes p -Nitrophenol (g (kg org. C),1), variierten zwischen den vier Enzymen. Die geringsten Werte wurden für ,-Galactosidase und ,-Glucosidase festgestellt, gefolgt von ,-Galactosidase und ,-Glucosidase. [source] Effect of cropping systems on phosphatases in soilsJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 1 2003Daniel E. Dodor Abstract Phosphatases are widely distributed in nature and play a major role in phosphorus nutrition of plants. The effects of crop rotations and nitrogen fertilization on the activities of phosphatases (acid phosphatase, alkaline phosphatase, and phosphodiesterase) were studied in soils from two long-term cropping systems at the Northeast Research Center (NERC) in Nashua and the Clarion Webster Research Center (CWRC) in Kanawha, Iowa, USA. Surface soils (0,15 cm) were taken in 1996 and 1997 from replicated field plots in corn, soybeans, oats, or meadow (alfalfa) that received 0 or 180 kg N ha,1 before corn. Because of differences in organic C contents among soils of the two sites, the soils from the CWRC sites contained greater enzyme activity values than those from the NERC site. Plots under oats or meadow showed the greatest activity values, whereas those under continuous corn at the CWRC site and soybean at the NERC site showed the least activities. Analysis of variance indicated that the activities of the phosphatases were significantly affected by crop rotation (P < 0.001) in both years at the NERC site but not at the CWRC site. Nitrogen fertilization affected the activity of acid phosphatase in soils from the CWRC site in both years and alkaline phosphatase only in 1997; but it did not affect the activities of the phosphatases in the soils from the NERC site. With the exception of alkaline phosphatase (CWRC) and phosphodiesterase (NERC) in soils sampled in 1997, activities of alkaline phosphatase and phosphodiesterase were significantly correlated with microbial biomass C (C mic) in soils from both sites and years, with r values ranging from 0.366* to 0.599***. Cropping systems and N fertilization affected the specific activities of phosphomonoesterases, especially acid phosphatase, but not of phosphodiesterase. Regression analysis showed that activities of phosphatases were significantly correlated with organic C contents of soils from the NERC site but not from the CWRC site. Einfluss von Managementsystemen auf Phosphatasen in Böden Phosphatasen sind weit verbreitet in der Natur und spielen eine entscheidende Rolle in der Phosphorversorgung von Pflanzen. Die Auswirkungen von Managementsystemen und Stickstoffdüngung auf Phosphataseaktivitäten in Böden (saure und alkalische Phosphatase, Phosphodiesterase) wurden in zwei langjährigen Feldversuchen am Northeast-Research Center (NERC) in Nashua und am Clarion-Webster Research Center (CWRC) in Kanawha, Iowa, USA untersucht. In den Jahren 1996 und 1997 wurden Oberbodenproben (0,15cm) von Parzellen unter Mais, Sojabohne, Hafer und Luzerne entnommen, welche in jeweils drei Wiederholungen angelegt waren. Die Parzellen erhielten zusätzlich Düngergaben von 0 bzw. 180 kg N ha,1 , die vor Mais appliziert wurden. Infolge der unterschiedlichen Gehalte der Böden an organischem Kohlenstoff waren die Enzymaktivitäten auf den CWRC-Flächen höher als auf den NERC-Flächen. Die Parzellen unter Hafer und Luzerne wiesen die höchsten, Parzellen unter Monokulturen von Mais (CWRC) bzw. Soja (NERC) die geringsten Aktivitäten auf. Die Ergebnisse der Varianzanalyse zeigten, dass die Phosphataseaktivitäten auf den NERC-Flächen in beiden Jahren signifikant durch das Managementsystem beeinflusst wurden (P < 0, 001). Die Stickstoffdüngung hatte auf den CWRC-Flächen in beiden Jahren einen signifikanten Einfluss auf die saure Phosphataseaktivität und auf die alkalische Phosphataseaktivität im Jahr 1997. Auf den NERC-Flächen war hingegen kein Düngungseinfluss nachzuweisen. Die alkalische Phosphatase und Phosphodiesterase waren, mit Ausnahme der alkalischen Phosphatase auf den CWRC-Flächen und der Phosphodiesterase auf den NERC-Flächen, signifikant mit dem Gehalt der Böden an mikrobieller Biomasse (C mic) korreliert (r = 0, 366* bis 0, 599***). Die Management- und N-Düngungssysteme beeinflussten die spezifischen Aktivitäten von Phosphomonoesterasen, v.a. von saurer Phosphatase, jedoch nicht die spezifischen Phosphodiesteraseaktivitäten. Regressionsanalysen ergaben einen signifikanten Zusammenhang zwischen den Phosphataseaktivitäten und dem Gehalt der Böden an organischem C für die NERC-Flächen, jedoch nicht für die CWRC-Flächen. [source] A dedicated small-angle X-ray scattering beamline with a superconducting wiggler source at the NSRRCJOURNAL OF SYNCHROTRON RADIATION, Issue 1 2009Din-Goa Liu At the National Synchrotron Radiation Research Center (NSRRC), which operates a 1.5,GeV storage ring, a dedicated small-angle X-ray scattering (SAXS) beamline has been installed with an in-achromat superconducting wiggler insertion device of peak magnetic field 3.1,T. The vertical beam divergence from the X-ray source is reduced significantly by a collimating mirror. Subsequently the beam is selectively monochromated by a double Si(111) crystal monochromator with high energy resolution (,E/E, 2 × 10,4) in the energy range 5,23,keV, or by a double Mo/B4C multilayer monochromator for 10,30 times higher flux (,1011,photons,s,1) in the 6,15,keV range. These two monochromators are incorporated into one rotating cradle for fast exchange. The monochromated beam is focused by a toroidal mirror with 1:1 focusing for a small beam divergence and a beam size of ,0.9,mm × 0.3 mm (horizontal × vertical) at the focus point located 26.5,m from the radiation source. A plane mirror installed after the toroidal mirror is selectively used to deflect the beam downwards for grazing-incidence SAXS (GISAXS) from liquid surfaces. Two online beam-position monitors separated by 8,m provide an efficient feedback control for an overall beam-position stability in the 10,µm range. The beam features measured, including the flux density, energy resolution, size and divergence, are consistent with those calculated using the ray-tracing program SHADOW. With the deflectable beam of relatively high energy resolution and high flux, the new beamline meets the requirements for a wide range of SAXS applications, including anomalous SAXS for multiphase nanoparticles (e.g. semiconductor core-shell quantum dots) and GISAXS from liquid surfaces. 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