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Sample records for vfa turnover rates

  1. Achilles tendinosis - Changes in biochemical composition and collagen turnover rate

    NARCIS (Netherlands)

    de Mos, Marieke; van El, Benno; DeGroot, Jeroen; Jahr, Holger; van Schie, Hans T. M.; van Arkel, Ewoud R.; Tol, Hans; Heijboer, Rien; van Osch, Gerjo J. V. M.; Verhaar, Jan A. N.

    Background: Understanding biochemical and structural changes of the extracellular matrix in Achilles tendinosis might be important for developing mechanism-based therapies. Hypothesis: In Achilles tendinosis, changes occur in biochemical composition and collagen turnover rate. Study Design:

  2. Achilles tendinosis: Changes in biochemical composition and collagen turnover rate

    NARCIS (Netherlands)

    Mos, M. de; El, B. van; Groot, J. de; Jahr, H.; Schie, H.T.M. van; Arkel, E.R. van; Tol, H.; Heijboer, R.; Osch, G.J.V.M. van; Verhaar, J.A.N.

    2007-01-01

    Background: Understanding biochemical and structural changes of the extracellular matrix in Achilles tendinosis might be important for developing mechanism-based therapies. Hypothesis: In Achilles tendinosis, changes occur in biochemical composition and collagen turnover rate. Study Design:

  3. Biotic turnover rates during the Pleistocene-Holocene transition

    Science.gov (United States)

    Stivrins, Normunds; Soininen, Janne; Amon, Leeli; Fontana, Sonia L.; Gryguc, Gražyna; Heikkilä, Maija; Heiri, Oliver; Kisielienė, Dalia; Reitalu, Triin; Stančikaitė, Miglė; Veski, Siim; Seppä, Heikki

    2016-11-01

    The Northern Hemisphere is currently warming at the rate which is unprecedented during the Holocene. Quantitative palaeoclimatic records show that the most recent time in the geological history with comparable warming rates was during the Pleistocene-Holocene transition (PHT) about 14,000 to 11,000 years ago. To better understand the biotic response to rapid temperature change, we explore the community turnover rates during the PHT by focusing on the Baltic region in the southeastern sector of the Scandinavian Ice Sheet, where an exceptionally dense network on microfossil and macrofossil data that reflect the biotic community history are available. We further use a composite chironomid-based summer temperature reconstruction compiled specifically for our study region to calculate the rate of temperature change during the PHT. The fastest biotic turnover in the terrestrial and aquatic communities occurred during the Younger Dryas-Holocene shift at 11,700 years ago. This general shift in species composition was accompanied by regional extinctions, including disappearance of mammoth (Mammuthus primigenius) and reindeer (Rangifer tarandus) and many arctic-alpine plant taxa, such as Dryas octopetala, Salix polaris and Saxifraga aizoides, from the region. This rapid biotic turnover rate occurred when the rate of warming was 0.17 °C/decade, thus slightly lower than the current Northern Hemisphere warming of 0.2 °C/decade. We therefore conclude that the Younger Dryas-Holocene shift with its rapid turnover rates and associated regional extinctions represents an important palaeoanalogue to the current high latitude warming and gives insights about the probable future turnover rates and patterns of the terrestrial and aquatic ecosystem change.

  4. Growth rate correlates negatively with protein turnover in Arabidopsis accessions.

    Science.gov (United States)

    Ishihara, Hirofumi; Moraes, Thiago Alexandre; Pyl, Eva-Theresa; Schulze, Waltraud X; Obata, Toshihiro; Scheffel, André; Fernie, Alisdair R; Sulpice, Ronan; Stitt, Mark

    2017-08-01

    Previous studies with Arabidopsis accessions revealed that biomass correlates negatively to dusk starch content and total protein, and positively to the maximum activities of enzymes in photosynthesis. We hypothesized that large accessions have lower ribosome abundance and lower rates of protein synthesis, and that this is compensated by lower rates of protein degradation. This would increase growth efficiency and allow more investment in photosynthetic machinery. We analysed ribosome abundance and polysome loading in 19 accessions, modelled the rates of protein synthesis and compared them with the observed rate of growth. Large accessions contained less ribosomes than small accessions, due mainly to cytosolic ribosome abundance falling at night in large accessions. The modelled rates of protein synthesis resembled those required for growth in large accessions, but were up to 30% in excess in small accessions. We then employed 13 CO2 pulse-chase labelling to measure the rates of protein synthesis and degradation in 13 accessions. Small accessions had a slightly higher rate of protein synthesis and much higher rates of protein degradation than large accessions. Protein turnover was negligible in large accessions but equivalent to up to 30% of synthesised protein day-1 in small accessions. We discuss to what extent the decrease in growth in small accessions can be quantitatively explained by known costs of protein turnover and what factors may lead to the altered diurnal dynamics and increase of ribosome abundance in small accessions, and propose that there is a trade-off between protein turnover and maximisation of growth rate. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  5. High triacylglycerol turnover rate in human skeletal muscle

    DEFF Research Database (Denmark)

    Sacchetti, Massimo; Saltin, Bengt; Olsen, David B

    2004-01-01

    could be due to the observed decline in plasma insulin concentration (-74%, P skeletal muscle in post-absorptive healthy individuals is esterified into IMTAG, due to its high turnover rate (29 h pool(-1)). An increase in FA level...... into IMTAG in vastus lateralis muscle was determined during two consecutive 4-h periods (2-6 h and 6-10 h). Fifty to sixty per cent of the FA taken up from the circulation were esterified into IMTAG, whereas 32 and 42% were oxidized between 2-6 and 6-10 h, respectively. IMTAG fractional synthesis rate was 3...

  6. Unsteady Flows Control Hydrologic Turnover Rates in Antarctic Hyporheic Zones

    Science.gov (United States)

    Wlostowski, A. N.; Gooseff, M. N.; McKnight, D. M.; Lyons, W. B.; Saelens, E.

    2016-12-01

    Hydrologic turnover of the hyporheic zone (HZ) is the process of HZ flowpaths receiving water and solutes from the stream channel while simultaneously contributing water and solutes from the HZ back to the stream channel. The influence of hydrologic turnover on HZ solute storage depends on the relative magnitude of hyporheic exchange rates (i.e. physical transport) and biogeochemical reaction rates. Because both exchange rates and reaction rates are unsteady in natural systems, the availability of solutes in the HZ is controlled by the legacy of hydraulic and biological conditions. In this study, we quantify the influence of unsteady flows on hydrologic turnover of the HZ. We study a glacial melt stream in the McMurdo Dry Valleys of Antarctica (MDVs). The MDVs provide an ideal setting for investigating hydrologic and chemical storage characteristics of HZs, because nearly all streamflow is generated from glacier melt and the HZ is vertically bounded by continuous permafrost. A dense network of shallow groundwater wells and piezometers was installed along a 60-meter reach of Von Guerard Stream. 12 days of continuous water level data in each well was used to compute the magnitude and direction of 2D hydraulic gradients between the stream channel and lateral hyporheic aquifer. Piezometers were sampled daily for stable isotope abundances. The direction and magnitude of the cross-valley (CV), perpendicular to the thalweg, component of hydraulic gradients is sensitive to daily flood events and exhibits significant spatial heterogeneity. CV gradients are consistently oriented from the hyporheic aquifer towards the stream channel on 2 sections of the study reach, whereas CV gradients are consistently oriented from the stream channel towards the hyporheic aquifer on 1 section. Three sections show diel changes in orientation of CV gradients, coincident with the passage of daily flood events. During a 4-day period of low flows, the HZ is isotopically distinct from the stream

  7. Impact of euthanasia rates, euthanasia practices, and human resource practices on employee turnover in animal shelters.

    Science.gov (United States)

    Rogelberg, Steven G; Reeve, Charlie L; Spitzmüller, Christiane; DiGiacomo, Natalie; Clark, Olga L; Teeter, Lisa; Walker, Alan G; Starling, Paula G; Carter, Nathan T

    2007-03-01

    To examine the effects of euthanasia rates, euthanasia practices, and human resource practices on the turnover rate among employees with euthanasia responsibilities at animal shelters. Cross-sectional original study. 36 shelters across the United States that employed at least 5 full-time employees and performed euthanasia on site. By mail, 1 survey was sent to each shelter. Surveys were completed by a senior member of management and were returned by mail. Questions assessed characteristics (eg, euthanasia rates) and practices of the animal shelter, along with employee turnover rates. By use of correlation coefficients and stepwise regression analyses, key predictors of turnover rates among employees with euthanasia responsibilities were investigated. Employee turnover rates were positively related to euthanasia rate. Practices that were associated with decreased turnover rates included provision of a designated euthanasia room, exclusion of other live animals from vicinity during euthanasia, and removal of euthanized animals from a room prior to entry of another animal to be euthanized. Making decisions regarding euthanasia of animals on the basis of factors other than behavior and health reasons was related to increased personnel turnover. With regard to human resources practices, shelters that used a systematic personnel selection procedure (eg, standardized testing) had comparatively lower employee turnover. Data obtained may suggest several specific avenues that can be pursued to mitigate turnover among employees with euthanasia responsibilities at animal shelters and animal control or veterinary medical organizations.

  8. Dicty_cDB: VFA444 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available library) VFA444 (Link to dictyBase) - - - Contig-U15823-1 VFA444E (Link to Original site) VFA444F 579 VFA444Z...VFA444Z 737 VFA444P 1316 VFA444E 1046 Show VFA444 Library VF (Link to library) Clone ID VFA444 (Link to...tsukuba.ac.jp/CSM/VF/VFA4-B/VFA444Q.Seq.d/ Representative seq. ID VFA444E (Link to Original site) Representative...Representative DNA sequence >VFA444 (VFA444Q) /CSM/VF/VFA4-B/VFA444Q.Seq.d/ ATAAATGGAGGCCGATCCGAGCTTAGT...significant alignments: (bits) Value VFA444 (VFA444Q) /CSM/VF/VFA4-B/VFA444Q.Seq.d/ 1608 0.0 VFM332 (VFM332Q)

  9. Dynamic structure of stock communities: a comparative study between stock returns and turnover rates

    Science.gov (United States)

    Su, Li-Ling; Jiang, Xiong-Fei; Li, Sai-Ping; Zhong, Li-Xin; Ren, Fei

    2017-07-01

    The detection of community structure in stock market is of theoretical and practical significance for the study of financial dynamics and portfolio risk estimation. We here study the community structures in Chinese stock markets from the aspects of both price returns and turnover rates, by using a combination of the PMFG and infomap methods based on a distance matrix. An empirical study using the overall data set shows that for both returns and turnover rates the largest communities are composed of specific industrial or conceptional sectors and the correlation inside a sector is generally larger than the correlation between different sectors. However, the community structure for turnover rates is more complex than that for returns, which indicates that the interactions between stocks revealed by turnover rates may contain more information. This conclusion is further confirmed by the analysis of the changes in the dynamics of community structures over five sub-periods. Sectors like banks, real estate, health care and New Shanghai take turns to comprise a few of the largest communities in different sub-periods, and more interestingly several specific sectors appear in the communities with different rank orders for returns and turnover rates even in the same sub-period. To better understand their differences, a comparison between the evolution of the returns and turnover rates of the stocks from these sectors is conducted. We find that stock prices only had large changes around important events while turnover rates surged after each of these events relevant to specific sectors, which shows strong evidence that the turnover rates are more susceptible to exogenous shocks than returns and its measurement for community detection may contain more useful information about market structure.

  10. Soil respiration and rates of soil carbon turnover differ among six common European tree species

    DEFF Research Database (Denmark)

    Vesterdal, Lars; Elberling, Bo; Christiansen, Jesper Riis

    2012-01-01

    The knowledge of tree species effects on soil organic carbon (C) turnover based on rigorous experimental designs is limited for common European deciduous tree species. We assessed soil respiration, and rates of C turnover in six tree species in a more than 30-year-old common garden experiment...... of C turnover were estimated by (i) the ratio of estimated soil heterotrophic respiration (R h) to C stock in forest floor and top mineral soil, (ii) the ratio of litterfall C to forest floor C, (iii) foliar mass loss in litterbags, and (iv) mineral soil C turnover assessed by laboratory incubation....... Soil respiration differed significantly among several species and increased in the order beechSoil respiration was temperature limited with no significant species difference in Q10. Norway spruce soils were significantly driest, and soil respiration was also limited by soil...

  11. Cesium-134 and strontium-85 turnover rates in the centipede Scolopocryptops nigridia McNeill

    Energy Technology Data Exchange (ETDEWEB)

    Yates, L R; Crossley, Jr, D A

    1979-07-01

    Radioactive tracers are providing significant information about the ecology of food chains, including such phenomena as accumulation of radioactive fission products, movement of materials along food chains, assimilation and ingestion rates, and nutrient accumulation and turnover. In this study the ingestion, assimilation and turnover to two radioactive tracers were investigated for Scolopocryptops nigridia, an abundant species in forests of the southeastern United States. The two tracers utilized, cesium-134 and strontium-85, are metabolic analogs of potassium and calcium, respectively. The research was performed as part of a larger investigation on the population ecology of the centipede species, emphasizing its relations to nutrient cycling and energy flow in a forest floor system.

  12. Relationship between Emotional Intelligence and Employees Turnover Rate in FMCG Organizations

    Directory of Open Access Journals (Sweden)

    Razi Sultan Siddiqui

    2013-05-01

    Full Text Available The study has been designed to determine the impact of emotional intelligence on turnover rate of first line managers of FMCG organizations in Karachi. It is generally believed that low emotional intelligence is a determinant of high turnover rate in first line managers of the FMCG organization. A sample of 40 employees from different FMCG organizations of Karachi who are performing their duties at first line management level falling within the age range of 20–40 years, with education level from Intermediate to Masters has been drawn randomly. Personal information of the participants is collected through demographic information sheet. TEIQue (Petrides and Furnhm, 2003 questionnaire is used to measure the variables of employees’ turnover and trait emotional intelligence. All participants have to respond on a seven point Likert scale. A higher score on this scale indicates higher level of emotional intelligence. In order to analyze the data, Statistical Package for Social Science (SPSS, V, 12 is applied. Descriptive statistics (mean and standard deviation is applied to study the sample characteristics and linear regression analysis and Karl Pearson’s Coefficient of Correlation (Pearson’s product moment correlation coefficient is calculated. This analysis shows strong relation of low emotional intelligence with increased employee job turnover rate.

  13. Growth rate controls mRNA turnover in steady and non-steady states.

    Science.gov (United States)

    García-Martínez, José; Troulé, Kevin; Chávez, Sebastián; Pérez-Ortín, José E

    2016-12-01

    Gene expression has been investigated in relation with growth rate in the yeast Saccharomyces cerevisiae, following different experimental strategies. The expression of some specific gene functional categories increases or decreases with growth rate. Our recently published results have unveiled that these changes in mRNA concentration with growth depend on the relative alteration of mRNA synthesis and decay, and that, in addition to this gene-specific transcriptomic signature of growth, global mRNA turnover increases with growth rate. We discuss here these results in relation with other previous and concurrent publications, and we add new evidence which indicates that growth rate controls mRNA turnover even under non-steady-state conditions.

  14. Turnover rates of B cells, T cells, and NK cells in simian immunodeficiency virus-infected and uninfected rhesus macaques

    NARCIS (Netherlands)

    Boer, R.J. de; Mohri, H.; Ho, D.D.; Perelson, A.S.

    2003-01-01

    We determined average cellular turnover rates by fitting mathematical models to 5-bromo-2'-deoxyuridine measurements in SIV-infected and uninfected rhesus macaques. The daily turnover rates of CD4(+) T cells, CD4(-) T cells, CD20(+) B cells, and CD16(+) NK cells in normal uninfected rhesus macaques

  15. Plasma Protein Turnover Rates in Rats Using Stable Isotope Labeling, Global Proteomics, and Activity-Based Protein Profiling

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jordan N.; Tyrrell, Kimberly J.; Hansen, Joshua R.; Thomas, Dennis G.; Murphree, Taylor A.; Shukla, Anil K.; Luders, Teresa; Madden, James M.; Li, Yunying; Wright, Aaron T.; Piehowski, Paul D.

    2017-12-06

    Protein turnover is important for general health on cellular and organism scales providing a strategy to replace old, damaged, or dysfunctional proteins. Protein turnover also informs of biomarker kinetics, as a better understanding of synthesis and degradation of proteins increases the clinical utility of biomarkers. Here, turnover rates of plasma proteins in rats were measured in vivo using a pulse-chase stable isotope labeling experiment. During the pulse, rats (n=5) were fed 13C6-labeled lysine (“heavy”) feed for 23 days to label proteins. During the chase, feed was changed to an unlabeled equivalent feed (“light”), and blood was repeatedly sampled from rats over 10 time points for 28 days. Plasma samples were digested with trypsin, and analyzed with liquid chromatography-tandem mass spectrometry (LC-MS/MS). MaxQuant was used to identify peptides and proteins, and quantify heavy:light lysine ratios. A system of ordinary differential equations was used to calculate protein turnover rates. Using this approach, 273 proteins were identified, and turnover rates were quantified for 157 plasma proteins with half-lives ranging 0.3-103 days. For the ~70 most abundant proteins, variability in turnover rates among rats was low (median coefficient of variation: 0.09). Activity-based protein profiling was applied to pooled plasma samples to enrich serine hydrolases using a fluorophosphonate (FP2) activity-based probe. This enrichment resulted in turnover rates for an additional 17 proteins. This study is the first to measure global plasma protein turnover rates in rats in vivo, measure variability of protein turnover rates in any animal model, and utilize activity-based protein profiling for enhancing measurements of targeted, low-abundant proteins, such as those commonly used as biomarkers. Measured protein turnover rates will be important for understanding of the role of protein turnover in cellular and organism health as well as increasing the utility of protein

  16. Greater soil carbon stocks and faster turnover rates with increasing agricultural productivity

    Science.gov (United States)

    Sanderman, Jonathan; Creamer, Courtney; Baisden, W. Troy; Farrell, Mark; Fallon, Stewart

    2017-01-01

    Devising agricultural management schemes that enhance food security and soil carbon levels is a high priority for many nations. However, the coupling between agricultural productivity, soil carbon stocks and organic matter turnover rates is still unclear. Archived soil samples from four decades of a long-term crop rotation trial were analyzed for soil organic matter (SOM) cycling-relevant properties: C and N content, bulk composition by nuclear magnetic resonance (NMR) spectroscopy, amino sugar content, short-term C bioavailability assays, and long-term C turnover rates by modeling the incorporation of the bomb spike in atmospheric 14C into the soil. After > 40 years under consistent management, topsoil carbon stocks ranged from 14 to 33 Mg C ha-1 and were linearly related to the mean productivity of each treatment. Measurements of SOM composition demonstrated increasing amounts of plant- and microbially derived SOM along the productivity gradient. Under two modeling scenarios, radiocarbon data indicated overall SOM turnover time decreased from 40 to 13 years with increasing productivity - twice the rate of decline predicted from simple steady-state models or static three-pool decay rates of measured C pool distributions. Similarly, the half-life of synthetic root exudates decreased from 30.4 to 21.5 h with increasing productivity, indicating accelerated microbial activity. These findings suggest that there is a direct feedback between accelerated biological activity, carbon cycling rates and rates of carbon stabilization with important implications for how SOM dynamics are represented in models.

  17. Turnover rates in microorganisms by laser ablation electrospray ionization mass spectrometry and pulse-chase analysis

    Energy Technology Data Exchange (ETDEWEB)

    Stopka, Sylwia A.; Mansour, Tarek R.; Shrestha, Bindesh [Department of Chemistry, W.M. Keck Institute for Proteomics Technology and Applications, The George Washington University, Washington, DC 20052 (United States); Maréchal, Éric; Falconet, Denis [Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, CEA-CNRS-INRA-Univ. Grenoble Alpes, Grenoble (France); Vertes, Akos, E-mail: vertes@gwu.edu [Department of Chemistry, W.M. Keck Institute for Proteomics Technology and Applications, The George Washington University, Washington, DC 20052 (United States)

    2016-01-01

    Biochemical processes rely on elaborate networks containing thousands of compounds participating in thousands of reaction. Rapid turnover of diverse metabolites and lipids in an organism is an essential part of homeostasis. It affects energy production and storage, two important processes utilized in bioengineering. Conventional approaches to simultaneously quantify a large number of turnover rates in biological systems are currently not feasible. Here we show that pulse-chase analysis followed by laser ablation electrospray ionization mass spectrometry (LAESI-MS) enable the simultaneous and rapid determination of metabolic turnover rates. The incorporation of ion mobility separation (IMS) allowed an additional dimension of analysis, i.e., the detection and identification of isotopologs based on their collision cross sections. We demonstrated these capabilities by determining metabolite, lipid, and peptide turnover in the photosynthetic green algae, Chlamydomonas reinhardtii, in the presence of {sup 15}N-labeled ammonium chloride as the main nitrogen source. Following the reversal of isotope patterns in the chase phase by LAESI-IMS-MS revealed the turnover rates and half-lives for biochemical species with a wide range of natural concentrations, e.g., chlorophyll metabolites, lipids, and peptides. For example, the half-lives of lyso-DGTS(16:0) and DGTS(18:3/16:0), t{sub 1/2} = 43.6 ± 4.5 h and 47.6 ± 2.2 h, respectively, provided insight into lipid synthesis and degradation in this organism. Within the same experiment, half-lives for chlorophyll a, t{sub 1/2} = 24.1 ± 2.2 h, and a 2.8 kDa peptide, t{sub 1/2} = 10.4 ± 3.6 h, were also determined. - Highlights: • High-throughput pulse-chase analysis using direct sampling of biological cells. • Ion mobility separation for the elucidation of isotopologs. • Identification of isotopologs in difference heat plots of DT vs. m/z. • Simultaneous determination of turnover rates for lipids and

  18. Probing the Jet Turnover Frequency Dependence on Mass and Mass Accretion Rate

    Science.gov (United States)

    Hammerstein, Erica; Gültekin, Kayhan; King, Ashley

    2018-01-01

    We have examined a sample of 15 sub-Eddington supermassive black holes (SMBHs) in a variety of galaxy classifications to further understand the proposed fundamental plane of black hole activity and scaling relations between black hole masses and their radio and X-ray luminosities. This plane describes black holes from stellar-mass to supermassive. The physics probed by these sub-Eddington systems is thought to be a radiatively inefficient, jet-dominated accretion flow. By studying black holes in this regime, we can learn important information on the disk-jet connection for accreting black holes.A key factor in studying the fundamental plane is the turnover frequency — the frequency at which emission transitions from optically thick at lower frequencies to optically thin at higher frequencies. This turnover point can be measured by observing the source in both radio and X-ray. Our project aims to test the dependence of the turnover frequency on mass and mass accretion rate.Radio observations of the sample were obtained using the Karl G. Jansky Very Large Array (VLA) in the range of 5-40 GHz across four different frequency bands in A configuration to give the highest spatial resolution to focus on the core emission. Our carefully chosen sample of SMBHs with dynamically measured masses consists of two sub-samples: those with approximately constant mass accretion rate (LX/LEdd ~ 10‑7) and those with approximately constant mass (MBH ~ 108 Msun). X-ray data were obtained from archival Chandra observations. To find the turnover frequency, we used Markov Chain Monte Carlo methods to fit two power laws to the radio data and the archival X-ray data. The intersection of the radio and X-ray fits is the turnover frequency.We present the results for both subsamples of SMBHs and their relationship between the turnover frequency and X-ray luminosity, which we take to scale with mass accretion rate, and jet power derived from both radio and X-ray properties.

  19. Estimating Population Turnover Rates by Relative Quantification Methods Reveals Microbial Dynamics in Marine Sediment.

    Science.gov (United States)

    Kevorkian, Richard; Bird, Jordan T; Shumaker, Alexander; Lloyd, Karen G

    2018-01-01

    The difficulty involved in quantifying biogeochemically significant microbes in marine sediments limits our ability to assess interspecific interactions, population turnover times, and niches of uncultured taxa. We incubated surface sediments from Cape Lookout Bight, North Carolina, USA, anoxically at 21°C for 122 days. Sulfate decreased until day 68, after which methane increased, with hydrogen concentrations consistent with the predicted values of an electron donor exerting thermodynamic control. We measured turnover times using two relative quantification methods, quantitative PCR (qPCR) and the product of 16S gene read abundance and total cell abundance (FRAxC, which stands for "fraction of read abundance times cells"), to estimate the population turnover rates of uncultured clades. Most 16S rRNA reads were from deeply branching uncultured groups, and ∼98% of 16S rRNA genes did not abruptly shift in relative abundance when sulfate reduction gave way to methanogenesis. Uncultured Methanomicrobiales and Methanosarcinales increased at the onset of methanogenesis with population turnover times estimated from qPCR at 9.7 ± 3.9 and 12.6 ± 4.1 days, respectively. These were consistent with FRAxC turnover times of 9.4 ± 5.8 and 9.2 ± 3.5 days, respectively. Uncultured Syntrophaceae , which are possibly fermentative syntrophs of methanogens, and uncultured Kazan-3A-21 archaea also increased at the onset of methanogenesis, with FRAxC turnover times of 14.7 ± 6.9 and 10.6 ± 3.6 days. Kazan-3A-21 may therefore either perform methanogenesis or form a fermentative syntrophy with methanogens. Three genera of sulfate-reducing bacteria, Desulfovibrio , Desulfobacter , and Desulfobacterium , increased in the first 19 days before declining rapidly during sulfate reduction. We conclude that population turnover times on the order of days can be measured robustly in organic-rich marine sediment, and the transition from sulfate-reducing to methanogenic conditions stimulates

  20. Unit-level voluntary turnover rates and customer service quality: implications of group cohesiveness, newcomer concentration, and size.

    Science.gov (United States)

    Hausknecht, John P; Trevor, Charlie O; Howard, Michael J

    2009-07-01

    Despite substantial growth in the service industry and emerging work on turnover consequences, little research examines how unit-level turnover rates affect essential customer-related outcomes. The authors propose an operational disruption framework to explain why voluntary turnover impairs customers' service quality perceptions. On the basis of a sample of 75 work units and data from 5,631 employee surveys, 59,602 customer surveys, and organizational records, results indicate that unit-level voluntary turnover rates are negatively related to service quality perceptions. The authors also examine potential boundary conditions related to the disruption framework. Of 3 moderators studied (group cohesiveness, group size, and newcomer concentration), results show that turnover's negative effects on service quality are more pronounced in larger units and in those with a greater concentration of newcomers.

  1. Effect of Different Organic Material Turnover on Soil Structure and Maize Photosynthetic Rate

    Directory of Open Access Journals (Sweden)

    ZHANG Jiu-ming

    2014-02-01

    Full Text Available The effect of different organic material turnover on soil structure and maize photosynthetic rate was researched in this paper. The results showed that comparing the control treatment, the soil bulk density of two treatments of shallow reversing and chiseling plow with straw returning and organic fertilizer were decreased by 0.13 g·cm-3and 0.09 g·cm-3, respectively. The application of shallow reversing and chiseling plow with straw turnover,organic fertilizer, green organic fertilizer and bio-fertilizer could reduce soil hardness, change the soil three phase state, improve the soil physics structure. Organic fertilizer and green organic fertilizer and bio-fertilizer increased the maize photosynthetic rate at trumpet period by 2.1~7.6 μmol·m-2·s-1. The transpiration rate of straw turnover and bio-fertilizer treatments was decreased by57% and 56% separately. Conductances of all treatments were lower than that of the control treatment at trumpet period. Meanwhile stomatal conductance was increased at filling stage which may lead to the decreasing CO2concentration with the reason that reducing of stomatal booster caused the lower CO2concentration. Returning of organic materials could reduce soil bulk density and com paction, make the soil three phase state having a reasonable range, improve crop photosynthetic rate, decrease the transpiration rate, especially the treatments of straw returning and organic fertilize. In short, protection tillage and organic materials returning to field play a positive role for improving soil fertility, soil physical characteristics, crop photosynthetic rate and crop yields.

  2. Capital's Pons Asinorum: the Rate of Turnover in Karl Marx's Analysis of Capitalist Valorisation

    OpenAIRE

    Passarella, Marco; Baron, Hervé

    2013-01-01

    This article aims to shed light on the role played by the ‘rate of turnover’ of capital within the Marxian analysis of the working laws of capitalism. Oddly enough, that concept has been neglected by the most part of Karl Marx’s scholars and exegetes, as is demonstrated proved by the small number of scientific works dealing with it. Yet, the rate of turnover plays a crucial role in Marx’s economic thought, since it allows Marx to address the impact of the improvement in finance, transportatio...

  3. Dicty_cDB: VFA114 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VF (Link to library) VFA114 (Link to dictyBase) - - - Contig-U13991-1 VFA114P (Link to Original site) VFA114F...(Link to library) Clone ID VFA114 (Link to dictyBase) Atlas ID - NBRP ID - dictyBase ID - Link to Contig...Contig-U13991-1 Original site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VF/VFA1-A/VFA114Q.Seq.d/ Representative...Representative seq. ID VFA114P (Link to Original site) Representative DNA sequence >VFA114 (VFA114Q) /CSM/VF/VFA1-A/VFA114Q....Seq.d/ TAGAATCCACACATTATAATTTTATAATGGGAAAAAGAAAAACTATGCAATCATTTAACC TTGAATCCTTTGGAAAAAATTTAGAAAAAAA

  4. Turnover rate of cerebrospinal fluid in female sheep: changes related to different light-dark cycles

    Directory of Open Access Journals (Sweden)

    Malpaux Benoit

    2009-08-01

    Full Text Available Abstract Background Sheep are seasonal breeders. The key factor governing seasonal changes in the reproductive activity of the ewe is increased negative feedback of estradiol at the level of the hypothalamus under long-day conditions. It has previously been demonstrated that when gonadotropin secretions are inhibited during long days, there is a higher concentration of estradiol in the cerebrospinal fluid (CSF than during short days. This suggests an involvement of the CSF and choroid plexus in the neuroendocrine regulatory loop, but the mechanisms underlying this phenomenon remain unknown. One possible explanation of this difference in hormonal content is an effect of concentration or dilution caused by variations in CSF secretion rate. The aim of this study was thus to investigate changes in the CSF turnover rate related to light-dark cycles. Methods The turnover rate of the CSF was estimated by measuring the time taken for the recovery of intraventricular pressure (IVP after removal of a moderate volume (0.5 to 2 ml of CSF (slope in mmHg/min. The turnover rate was estimated three times in the same group of sheep: during a natural period of decreasing day-length corresponding to the initial period when gonadotropin activity is stimulated (SG1, during a long-day inhibitory period (IG, and finally during a short-day stimulatory period (SG2. Results The time taken and the speed of recovery of initial IVP differed between groups: 8 min 30 sec, 0.63 ± 0.07 mmHg/min(SG1, 11 min 1 sec, 0.38 ± 0.06 mmHg/min (IG and 9 min 0 sec, 0.72 ± 0.15 mmHg/min (SG2. Time changes of IVP differed between groups (ANOVA, p p p = 0.41, but was significantly different from IG: 71.33 ± 16.59 μl/min (p = 0.016. Conclusion This study shows that the turnover rate of CSF in ewes changes according to the light-dark cycle; it is increased during short day periods and reduced in long day periods. This phenomenon could account for differences in hormonal concentrations in

  5. Dicty_cDB: VFA458 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VF (Link to library) VFA458 (Link to dictyBase) - - - Contig-U16349-1 VFA458P (Link... to Original site) VFA458F 602 VFA458Z 403 VFA458P 1005 - - Show VFA458 Library VF (Link to library) Clone ID VFA458 (Link to dict...yBase) Atlas ID - NBRP ID - dictyBase ID - Link to Contig Contig-U16349-1 Original site URL http://dict...SCNQESSTSGICDPFSILGDSCLHDMPGMSGCNNF KKLCASGSVVEQCSTVDSVTDLPTTMKMWANIKSICNEMTMTGCEKCTILNATCDVLTVY STLCLAMPEMGQCANWTQMC--- ---ICT...lpifqlq*kcgqilkvfvmk*q*qvvknaqy*mplvmy*qfi plfvlqcqrwvnvptgpkcv--- ---ICTEMAMDGCEKCSGNSPTTTCDVLPVYSSLCMAMPDM

  6. Tissue turnover rates and isotopic trophic discrimination factors in the endothermic teleost, pacific bluefin tuna (Thunnus orientalis.

    Directory of Open Access Journals (Sweden)

    Daniel J Madigan

    Full Text Available Stable isotope analysis (SIA of highly migratory marine pelagic animals can improve understanding of their migratory patterns and trophic ecology. However, accurate interpretation of isotopic analyses relies on knowledge of isotope turnover rates and tissue-diet isotope discrimination factors. Laboratory-derived turnover rates and discrimination factors have been difficult to obtain due to the challenges of maintaining these species in captivity. We conducted a study to determine tissue- (white muscle and liver and isotope- (nitrogen and carbon specific turnover rates and trophic discrimination factors (TDFs using archived tissues from captive Pacific bluefin tuna (PBFT, Thunnus orientalis, 1-2914 days after a diet shift in captivity. Half-life values for (15N turnover in white muscle and liver were 167 and 86 days, and for (13C were 255 and 162 days, respectively. TDFs for white muscle and liver were 1.9 and 1.1‰ for δ(15N and 1.8 and 1.2‰ for δ(13C, respectively. Our results demonstrate that turnover of (15N and (13C in bluefin tuna tissues is well described by a single compartment first-order kinetics model. We report variability in turnover rates between tissue types and their isotope dynamics, and hypothesize that metabolic processes play a large role in turnover of nitrogen and carbon in PBFT white muscle and liver tissues. (15N in white muscle tissue showed the most predictable change with diet over time, suggesting that white muscle δ(15N data may provide the most reliable inferences for diet and migration studies using stable isotopes in wild fish. These results allow more accurate interpretation of field data and dramatically improve our ability to use stable isotope data from wild tunas to better understand their migration patterns and trophic ecology.

  7. Dicty_cDB: VFA347 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available cant alignments: (bits) Value VFA347 (VFA347Q) /CSM/VF/VFA3-B/VFA347Q.Seq.d/ 373 e-103 SFE418 (SFE418Q...) /CSM/SF/SFE4-A/SFE418Q.Seq.d/ 367 e-101 VFG876 (VFG876Q) /CSM/VF/VFG8-D/VFG876Q.Seq.d

  8. Estimating rates of local species extinction, colonization and turnover in animal communities

    Science.gov (United States)

    Nichols, James D.; Boulinier, T.; Hines, J.E.; Pollock, K.H.; Sauer, J.R.

    1998-01-01

    Species richness has been identified as a useful state variable for conservation and management purposes. Changes in richness over time provide a basis for predicting and evaluating community responses to management, to natural disturbance, and to changes in factors such as community composition (e.g., the removal of a keystone species). Probabilistic capture-recapture models have been used recently to estimate species richness from species count and presence-absence data. These models do not require the common assumption that all species are detected in sampling efforts. We extend this approach to the development of estimators useful for studying the vital rates responsible for changes in animal communities over time; rates of local species extinction, turnover, and colonization. Our approach to estimation is based on capture-recapture models for closed animal populations that permit heterogeneity in detection probabilities among the different species in the sampled community. We have developed a computer program, COMDYN, to compute many of these estimators and associated bootstrap variances. Analyses using data from the North American Breeding Bird Survey (BBS) suggested that the estimators performed reasonably well. We recommend estimators based on probabilistic modeling for future work on community responses to management efforts as well as on basic questions about community dynamics.

  9. Initial turnover rates of two standard wood substrates following land-use change in subalpine ecosystems in the Swiss Alps

    Science.gov (United States)

    Anita C. Risch; Martin F. Jurgensen; Deborah S. Page-Dumroese; Martin Schutz

    2013-01-01

    Forest cover has increased in mountainous areas of Europe over the past decades because of the abandonment of agricultural areas (land-use change). For this reason, understanding how land-use change affects carbon (C) source-sink strength is of great importance. However, most studies have assessed mountainous systems C stocks, and less is known about C turnover rates,...

  10. Large centric diatoms allocate more cellular nitrogen to photosynthesis to counter slower RUBISCO turnover rates

    Directory of Open Access Journals (Sweden)

    Yaping eWu

    2014-12-01

    Full Text Available Diatoms contribute ~40% of primary production in the modern ocean and encompass the largest cell size range of any phytoplankton group. Diatom cell size influences their nutrient uptake, photosynthetic light capture, carbon export efficiency, and growth responses to increasing pCO2. We therefore examined nitrogen resource allocations to the key protein complexes mediating photosynthesis across six marine centric diatoms, spanning 5 orders of magnitude in cell volume, under past, current and predicted future pCO2 levels, in balanced growth under nitrogen repletion. Membrane bound photosynthetic protein concentrations declined with cell volume in parallel with cellular concentrations of total protein, total nitrogen and chlorophyll. Larger diatom species, however, allocated a greater fraction (by 3.5 fold of their total cellular nitrogen to the soluble RUBISCO carbon fixation complex than did smaller species. Carbon assimilation per unit of RUBISCO large subunit (C RbcL-1 s-1 decreased with cell volume, from ~8 to ~2 C RbcL-1 s-1 from the smallest to the largest cells. Whilst a higher allocation of cellular nitrogen to RUBISCO in larger cells increases the burden upon their nitrogen metabolism, the higher RUBISCO allocation buffers their lower achieved RUBISCO turnover rate to enable larger diatoms to maintain carbon assimilation rates per total protein comparable to small diatoms. Individual species responded to increased pCO2, but cell size effects outweigh pCO2 responses across the diatom species size range examined. In large diatoms a higher nitrogen cost for RUBISCO exacerbates the higher nitrogen requirements associated with light absorption, so the metabolic cost to maintain photosynthesis is a cell size-dependent trait.

  11. Estimating soil turnover rate from tree uprooting during hurricanes in Puerto Rico

    Science.gov (United States)

    Melanie T. Lenart; D.A. Falk; F.N. Scatena; W.R. Osterkamp

    2010-01-01

    Soil turnover by tree uprooting in primary and secondary forests on the island of Puerto Rico was measured in 42 study plots in the months immediately after the passage of a Category 3 hurricane. Trunk basal area explained 61% of the variability of mound volume and 53% of the variability of mound area. The proportion of uprooted trees, the number of uprooted trees, or...

  12. Predicting VFA formation by dark fermentation of particulate substrates.

    Science.gov (United States)

    Arudchelvam, Yalini; Perinpanayagam, Malarmagal; Nirmalakhandan, Nagamany

    2010-10-01

    This study presents a mathematical model for predicting volatile fatty acid (VFA) production by dark fermentation of complex particulate substrates of biomass origin. This model is based on the premise that degradable components of such substrates are first hydrolyzed into soluble monomers, which are then fermented to liquid and gaseous end products. The model considered cellulose and hemicellulose as the degradable components of typical biomass-based organic substrates; and volatile fatty acids, hydrogen, and carbon dioxide as the end products. Hydrolysis of the particulate forms of the components is modeled by a surface-limiting rate equation, and the formation of end products is modeled following the guidelines of the anaerobic digestion model (ADM1). The model was calibrated and validated using experimental COD and VFA data from six batch reactors where, cattle manure was tested as a representative biomass-based substrate. The model predictions agreed well with the temporal trend in the experimental data, with overall r(2) of 0.85 for COD, 0.82 for acetic acid, 0.72 for butyric acid, and 0.42 for propionic acid. Copyright 2010 Elsevier Ltd. All rights reserved.

  13. Partial bioaugmentation to remove 3-chloroaniline slows bacterial species turnover rate in bioreactors.

    Science.gov (United States)

    Falk, Michael W; Seshan, Hari; Dosoretz, Carlos; Wuertz, Stefan

    2013-12-01

    Bioaugmentation is a potentially powerful tool to direct community structure and metabolic capacities in bioreactors. Yet the outcome of bioaugmentation studies is usually unpredictable and effects on microbial community dynamics are poorly understood. We asked the question whether bioaugmentation could prevent a diversity shift induced by a model toxin, 3-chloroaniline (3-CA), regardless of whether 3-CA was degraded. Four replicate membrane bioreactors (MBRs) operating in parallel were amended with Pseudomonas putida UWC3 (pWDL7::rfp), a strain that carries the upper pathway genes necessary for partial degradation of 3-CA on its plasmid. Two MBRs served as controls and two MBRs were exposed to 3-CA for 71 days. Despite the selective pressure imposed by 3-CA, there was little or no 3-CA removal and neither the 16S rRNA gene of the augmented strain UWC3 nor the plasmid pWDL7::rfp proliferated in any of the reactors. Yet both host strain and plasmid were maintained at reduced levels (~10(4) host strain cells ml(-1)) in all reactors compared to the initial inoculum (~10(7) cells ml(-1); 1% of active cells). Additionally, the microbial community dynamics were evaluated for each MBR via terminal restriction fragment length polymorphism (T-RFLP) analysis (n = 15 per reactor) that targeted a portion of the 16S rRNA gene. Analysis comprised of a suite of multivariate statistics coupled with a theoretical microbial ecological approach, 'Island Biogeography', using a bacterial species time relationship (STR), within each MBR. Control MBRs had a wider range in w values than the treatment MBRs, which is attributed to the lack of a toxin selecting for biota that can withstand its toxic nature. Bioaugmentation alone strongly slowed the bacterial species turnover rate (as revealed by very low w scaling components), compared to non-bioaugmented reactors from a previous study, but did not protect the microbial community from a diversity shift caused by the toxin. Nonmetric

  14. Quantifying nitrate and oxygen reduction rates in the hyporheic zone using 222Rn to upscale biogeochemical turnover in rivers

    Science.gov (United States)

    Frei, Sven; Gilfedder, Benjamin; Pittroff, Marco

    2017-04-01

    Quantifying and upscaling chemical turnover in the hyporheic zone (HZ) is difficult due to limited reaction rate data, unknown site specific characteristics, and few methods for upscaling local measurements to river networks. Here we present a method for quantifying reaction kinetics in-situ in the HZ and upscaling biogeochemical turnover to catchment scales. Radon-222 was used to quantify water residence times in the HZ of the Roter Main River (RM), Germany. Residence times were then combined with O2, NO3-, CO2, DOC and carbon quality (EEMs, SUVA) data to estimate Monod and first-order reaction rates. Carbon quality was highly bioavailable in the HZ and is unlikely to be limiting. Reaction kinetics were incorporated into the FINIFLUX model to upscale NO3- mass loss over a 32 km reach of the RM. The aim was to (1) estimate hyporheic efficiency in terms of nitrate turnover, and (2) calculate nitrate- mass loss in the HZ over at the reach scale. Damköhler analysis, based on characteristic transport and reaction times, suggests that the hyporheic zone is inefficient for nitrate processing, however this is somewhat misleading as the largest NO3- mass loss occurs at the shortest residence times where Da<<1. This is due to the largest water flux occurring in the uppermost part of the sediment profile. Total nitrate processing in the HZ for the 32 km reach accounted for 24 kg nitrate per hour, which was 20 % of the nitrate flux from the catchment.

  15. Absorption and Turnover Rates of Iron Measured by the Whole Body Counter

    Energy Technology Data Exchange (ETDEWEB)

    Price, D. C.; Cohn, S. H.

    1962-09-05

    Human iron metabolism has been extensively studied in the past twenty-five years with the radioisotopes iron55 and iron59. Before the availability of the whole body counter, however, iron absorption studies were performed by the indirect methods of fecal assay of unabsorbed radioiron, and estimation of red cell incorporation of absorbed tracer. The few long-term excretion studies performed required numerous assumptions, since human iron excretion was less well understood. Whole body counting provides a simple and accurate method of measuring the total body retention of administrative tracer iron59, thus making absorption and subsequent excretion determinations possible with a single radioiron study. The energetic gamma emissions of iron59 permit ready external detection with small quantities of isotope, Normal radioiron distribution is uniform throughout the circulating red cell mass and thus minimize geometry influences on the counting efficiency, 0nly the 45.1 day half-life of iron59 limits long term iron turnover studies. Measurements of iron59 absorption and long-term body turnover have been under way at Brookhaven National Laboratory for over two years. The present paper outlines some of the results of these studies, and discusses some implications of the method. (auth)

  16. Escape from a cavity through a small window: turnover of the rate as a function of friction constant.

    Science.gov (United States)

    Berezhkovskii, Alexander M; Makhnovskii, Yurii A; Zitserman, Vladimir Yu

    2006-11-21

    To escape from a cavity through a small window the particle has to overcome a high entropy barrier to find the exit. As a consequence, its survival probability in the cavity decays as a single exponential and is characterized by the only parameter, the rate constant. We use simulations to study escape of Langevin particles from a cubic cavity through a small round window in the center of one of the cavity walls with the goal of analyzing the friction dependence of the escape rate. We find that the rate constant shows the turnover behavior as a function of the friction constant, zeta: The rate constant grows at very small zeta, reaches a maximum value which is given by the transition-state theory (TST), and then decreases approaching zero as zeta-->infinity. Based on the results found in simulations and some general arguments we suggest a formula for the rate constant that predicts a turnover of the escape rate for ergodic cavities in which collisions of the particle with the cavity walls are defocusing. At intermediate-to-high friction the formula describes transition between two known results for the rate constant: the TST estimation and the high friction limiting behavior that characterizes escape of diffusing particles. In this range of friction the rate constants predicted by the formula are in good agreement with those found in simulations. At very low friction the rate constants found in simulations are noticeably smaller than those predicted by the formula. This happens because the simulations were run in the cubic cavity which is not ergodic.

  17. Measurement of the rates of oxindole-3-acetic acid turnover, and indole-3-acetic acid oxidation in Zea mays seedlings

    Science.gov (United States)

    Nonhebel, H. M.; Bandurski, R. S. (Principal Investigator)

    1986-01-01

    Oxindole-3-acetic acid is the principal catabolite of indole-3-acetic acid in Zea mays seedlings. In this paper measurements of the turnover of oxindole-3-acetic acid are presented and used to calculate the rate of indole-3-acetic acid oxidation. [3H]Oxindole-3-acetic acid was applied to the endosperm of Zea mays seedlings and allowed to equilibrate for 24 h before the start of the experiment. The subsequent decrease in its specific activity was used to calculate the turnover rate. The average half-life of oxindole-3-acetic acid in the shoots was found to be 30 h while that in the kernels had an average half-life of 35h. Using previously published values of the pool sizes of oxindole-3-acetic acid in shoots and kernels from seedlings of the same age and variety, and grown under the same conditions, the rate of indole-3-acetic acid oxidation was calculated to be 1.1 pmol plant-1 h-1 in the shoots and 7.1 pmol plant-1 h-1 in the kernels.

  18. Fossils and a large molecular phylogeny show that the evolution of species richness, generic diversity, and turnover rates are disconnected.

    Science.gov (United States)

    Xing, Yaowu; Onstein, Renske E; Carter, Richard J; Stadler, Tanja; Peter Linder, H

    2014-10-01

    The magnitude and extent of global change during the Cenozoic is remarkable, yet the impacts of these global changes on the biodiversity and evolutionary dynamics of species diversification remain poorly understood. To investigate this question, we combine paleontological and neontological data for the angiosperm order Fagales, an ecologically important clade of about 1370 species of trees with an exceptional fossil record. We show differences in patterns of accumulation of generic diversity, species richness, and turnover rates for Fagales. Generic diversity evolved rapidly since the Late Cretaceous and peaked during the Eocene or Oligocene. Turnover rates were high during periods of extreme global climate change, but relatively low when the climate remained stable. Species richness accumulated gradually throughout the Cenozoic, possibly at an accelerated pace after the Middle Miocene. Species diversification occurred in new environments: Quercoids radiating in Oligocene subtropical seasonally arid habitats, Casuarinaceae in Australian pyrophytic biomes, and Betula in Late Neogene holarctic habitats. These radiations were counterbalanced by regional extinctions in Late Neogene mesic warm-temperate forests. Thus, the overall diversification at species level is linked to regional radiations of clades with appropriate ecologies exploiting newly available habitats. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  19. Isotopic discrimination factors and nitrogen turnover rates in reared Atlantic bluefin tuna larvae (Thunnus thynnus: effects of maternal transmission

    Directory of Open Access Journals (Sweden)

    Amaya Uriarte

    2016-11-01

    Full Text Available The use of stable isotope analysis to study animal diets requires estimates of isotopic turnover rates (half time, t50 and discrimination factors (Δ for an accurate interpretation of trophic patterns. The stable isotopes of carbon and nitrogen were analysed for eggs and reared larvae of Thunnus thynnus, as well as for the different diets supplied during the experiment. The results showed high values of δ15N in eggs and larvae (n=646 until 4 DAH. After this time lapse, the stable isotope values declined progressively until 12 DAH, when notochord flexion began. The δ13C showed an inverse trend, suggesting that maternal inheritance of the stable isotopes is evident until pre-flexion stages. This study proposes a model for estimating maternal isotopic signatures of bluefin broodstock. After notochord flexion, larvae were fed with aquaculture-bred gilthead seabream, which resulted in a rapid increase of bluefin larvae δ15N values together with a rapid decrease in δ13C values. The estimated nitrogen half-time to reach the steady state from the diet was 2.5±0.3 days and the discrimination factor was 0.4±0.3(‰. These results represent the first data set that has allowed isotopic nitrogen turnover rates and discrimination factors of the larval stages of bluefin tuna to be estimated.

  20. Can transformational managers control turnover intention?

    National Research Council Canada - National Science Library

    Massad A Alatawi

    2017-01-01

    .... The purpose of this study was to measure the correlation between transformational leadership style and turnover intention to control the employee turnover rate in organisations. Research method...

  1. PENGARUH PROFIT MARGIN, ASSETS TURNOVER DAN LEVERAGE TERHADAP SUSTAINABLE GROWTH RATE PADA PERUSAHAAN SEKTOR JASA YANG TERDAFTAR DI BURSA EFEK INDONESIA PERIODE 2010-2012

    Directory of Open Access Journals (Sweden)

    Arim Nasim

    2015-04-01

    Full Text Available This study aims to determine the effect of Profit Margin, Assets Turnover and Leverage on Sustainable Growth Rate. The variables used are profit margin, asset turnover and leverage as independent variable and sustainable growth rate as dependent variable. This study also aims to describe the state of profit margin projected by Net Profit Margin (NPM, asset turnover proxied by Total Assets Turnover (TATO, leverage which is proxied by Debt to Equity Ratio (DER and Sustainable Growth Rate (SGR Service sector. This research was conducted on service sector companies listed in Indonesia Stock Exchange 2010-2012.Data obtained from website Bursa Efek Indonesia.Teknik data analysis used is multiple linear regression and use t-statistics to test the influence of each independent variable to variable Dependent partially.Previously done classical assumption test that includes data normality test, multicolinierity test, heteroskedastisitas test and autocorrelation test.Based on data normality test, multicolinierity test, heteroscedasticity test and autocorrelation test did not found any variables that deviate from the classical assumption.From the results of research Shows that profit margin positively affect sustainable growth rate, asset turnover have positive effect to sustainable growth rate, and leverage have positive effect to sustainable growth rate.

  2. High Gene Family Turnover Rates and Gene Space Adaptation in the Compact Genome of the Carnivorous Plant Utricularia gibba.

    Science.gov (United States)

    Carretero-Paulet, Lorenzo; Librado, Pablo; Chang, Tien-Hao; Ibarra-Laclette, Enrique; Herrera-Estrella, Luis; Rozas, Julio; Albert, Victor A

    2015-05-01

    Utricularia gibba is an aquatic carnivorous plant with highly specialized morphology, featuring fibrous floating networks of branches and leaf-like organs, no recognizable roots, and bladder traps that capture and digest prey. We recently described the compressed genome of U. gibba as sufficient to control the development and reproduction of a complex organism. We hypothesized intense deletion pressure as a mechanism whereby most noncoding DNA was deleted, despite evidence for three independent whole-genome duplications (WGDs). Here, we explore the impact of intense genome fractionation in the evolutionary dynamics of U. gibba's functional gene space. We analyze U. gibba gene family turnover by modeling gene gain/death rates under a maximum-likelihood statistical framework. In accord with our deletion pressure hypothesis, we show that the U. gibba gene death rate is significantly higher than those of four other eudicot species. Interestingly, the gene gain rate is also significantly higher, likely reflecting the occurrence of multiple WGDs and possibly also small-scale genome duplications. Gene ontology enrichment analyses of U. gibba-specific two-gene orthogroups, multigene orthogroups, and singletons highlight functions that may represent adaptations in an aquatic carnivorous plant. We further discuss two homeodomain transcription factor gene families (WOX and HDG/HDZIP-IV) showing conspicuous differential expansions and contractions in U. gibba. Our results 1) reconcile the compactness of the U. gibba genome with its accommodation of a typical number of genes for a plant genome, and 2) highlight the role of high gene family turnover in the evolutionary diversification of U. gibba's functional gene space and adaptations to its unique lifestyle and highly specialized body plan. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Preliminary results on the influence of mineralogy on the turnover rates of SOM from different Hungarian soils

    Science.gov (United States)

    Zacháry, Dóra; Szalai, Zoltán; Jakab, Gergely; Németh, Tibor; Sipos, Péter; Filep, Tibor

    2016-04-01

    Fine textured soils generally considered containing more microbial biomass, and having a lower rate of biomass turnover and organic matter decomposition than coarse textured soils. In spite of this, several recent studies have shown contradicting trends. For example, the relative importance of different clay minerals for stabilizing SOM remains an open question. The aim of this study is to evaluate soil mineralological effect on the turnover of SOM by identifying and quantifying soil phyllosilicates. Our samples are derived from C3 forests and C3 croplands from different sites of Hungary. C4 maize residues are added to the soils in order to get natural 13C enrichment as tracer for the young carbon. Bulk samples of the soils from 0 to 20 cm depth were collected. The samples were dried at room temperature and preincubated in the dark for 4 months at 20 °C. The basic soil properties (pH, cation exchange capacity) were analysed after 2 mm sieving and homogenization. The amount of total C and N in the soils and maize residues were analysed using NDIR-chemiluminescent analyzer (Tekmar Dohrman Apollo 9000N). Particle size distribution was determined by laser diffraction (Fritsch Analysette MicroTec 22 plus) and particle imaging method (Malvern Morphologi G3-ID). The mineralological composition of the samples was determined by X-ray diffraction (Philips PW 1730 X-ray diffractometer). Moist soil equivalent to 400 g dry soil mixed with 2 g maize leaves is kept in air tight glass chambers for 183 days at 20°C. The leaves had previously been dried at 60 °C, were cut into pieces and sieved through a 2 mm mesh. The evolved CO2 is trapped by 10 mL 2 M NaOH, which is exchanged on day 1, 3, 5, 7, 10, 14, 21, 28 and subsequently every 31 days. The fractional abundance of 13C of the soils, the plant material and the evolved CO2 is measured with isotope ratio mass spectrometer (Thermo Scientific Delta V IRMS). Our work show the preliminary results on the link between phyllosilicate

  4. High rates of microbial carbon turnover in sediments in the deepest oceanic trench on Earth

    DEFF Research Database (Denmark)

    Glud, Ronnie N.; Wenzhöfer, Frank; Middelboe, Mathias

    2013-01-01

    extent of the abyss, deep-sea sediments are quantitatively important for the global carbon cycle(2,3). However, the deepest regions of the ocean have remained virtually unexplored(4). Here, we present observations of microbial activity in sediments at Challenger Deep in the Mariana Trench in the central...... west Pacific, which at almost 11,000 m depth represents the deepest oceanic site on Earth. We used an autonomous micro-profiling system to assess benthic oxygen consumption rates. We show that although the presence of macrofauna is restricted at Challenger Deep, rates of biological consumption......Microbes control the decomposition of organic matter in marine sediments. Decomposition, in turn, contributes to oceanic nutrient regeneration and influences the preservation of organic carbon(1). Generally, rates of benthic decomposition decline with increasing water depth, although given the vast...

  5. Validation of a tracer technique to determine nonsteady-state ketone body turnover rates in man

    Energy Technology Data Exchange (ETDEWEB)

    Keller, U.; Sonnenberg, G.E.; Stauffacher, W.

    1981-03-01

    The features of a single-compartment model of total ketone bodies were evaluated using primed constant infusions of (3-14C)acetoacetate (AcAc) and of D-(3-14C)beta-hydroxybutyrate (beta OHB) in 12 postabsorptive subjects. The volume of distribution (VD) of AcAc was 0.18 +- 0.01 liter/kg (n = 9), and that of beta OHB was similar, 0.18 +- 0.02 liter/kg (n = 3). The production rate of total ketone bodies was calculated using the combined specific activity of AcAc and of beta OHB. The mean basal total ketone body production rates were similar using either (14C)AcAc (6.5 mumol . kg-1 . min-1) or (14C)beta OHB (6.8 mumol . kg-1 . min-1). To determine the pool fraction that was rapidly mixed during nonsteady state of ketone body inflow, unlabeled AcAc was infused with stepwise increasing and decreasing rates between 5 and 25 mumol . kg-1 . m-1 to mimic nonsteady-state ketone body production rates. The functional pool fraction P was determined as the pool fraction that provided the best match between tracer-determined rates of ketone production and rates of AcAc infusion. P of total ketone bodies was almost equal to 1 using either (14C)AcAc (1.05 +- 0.16) or (14C)beta OHB (1.00 +- 0.06), suggesting rapid mixing of ketone bodies throughout the entire pool. The described pool model may be used to determine total ketone body kinetics during acute perturbations of the steady state.

  6. High turnover rates of copepod fecal pellets due to Noctiluca scintillans grazing

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2003-01-01

    %) of the pellets produced in the overlying water column reached sediment traps positioned at 30 to 60 m depth, and specific sinking losses computed from steady-state considerations varied inversely with trap depth between 0.3 and 2.9 d-1. Total specific losses varied between 0.6 and 16 d-1, and the major part...... for fecal pellets at about 0.6 l cell-1 d-1. A simple encounter model suggests that such high clearance rates are feasible. Since N. scintillans occurs at typical abundances of about 106 cells m-2 in temperate seas during spring, summer and autumn, it may contribute significantly to the recycling of rapidly...

  7. Selective logging: do rates of forest turnover in stems, species composition and functional traits decrease with time since disturbance? – A 45 year perspective

    Science.gov (United States)

    Osazuwa-Peters, Oyomoare L.; Jiménez, Iván; Oberle, Brad; Chapman, Colin A.; Zanne, Amy E.

    2015-01-01

    Selective logging, the targeted harvesting of timber trees in a single cutting cycle, is globally rising in extent and intensity. Short-term impacts of selective logging on tropical forests have been widely investigated, but long-term effects on temporal dynamics of forest structure and composition are largely unknown. Understanding these long-term dynamics will help determine whether tropical forests are resilient to selective logging and inform choices between competing demands of anthropogenic use versus conservation of tropical forests. Forest dynamics can be studied within the framework of succession theory, which predicts that temporal turnover rates should decline with time since disturbance. Here, we investigated the temporal dynamics of a tropical forest in Kibale National Park, Uganda over 45 years following selective logging. We estimated turnover rates in stems, species composition, and functional traits (wood density and diameter at breast height), using observations from four censuses in 1989, 1999, 2006, and 2013, of stems ≥ 10 cm diameter within 17 unlogged and 9 logged 200 × 10 m vegetation plots. We used null models to account for interdependencies among turnover rates in stems, species composition, and functional traits. We tested predictions that turnover rates should be higher and decrease with increasing time since the selective logging event in logged forest, but should be less temporally variable in unlogged forest. Overall, we found higher turnover rates in logged forest for all three attributes, but turnover rates did not decline through time in logged forest and was not less temporally variable in unlogged forest. These results indicate that successional models that assume recovery to pre-disturbance conditions are inadequate for predicting the effects of selective logging on the dynamics of the tropical forest in Kibale. Selective logging resulted in persistently higher turnover rates, which may compromise the carbon storage capacity

  8. Selective logging: do rates of forest turnover in stems, species composition and functional traits decrease with time since disturbance? - A 45 year perspective.

    Science.gov (United States)

    Osazuwa-Peters, Oyomoare L; Jiménez, Iván; Oberle, Brad; Chapman, Colin A; Zanne, Amy E

    2015-12-01

    Selective logging, the targeted harvesting of timber trees in a single cutting cycle, is globally rising in extent and intensity. Short-term impacts of selective logging on tropical forests have been widely investigated, but long-term effects on temporal dynamics of forest structure and composition are largely unknown. Understanding these long-term dynamics will help determine whether tropical forests are resilient to selective logging and inform choices between competing demands of anthropogenic use versus conservation of tropical forests. Forest dynamics can be studied within the framework of succession theory, which predicts that temporal turnover rates should decline with time since disturbance. Here, we investigated the temporal dynamics of a tropical forest in Kibale National Park, Uganda over 45 years following selective logging. We estimated turnover rates in stems, species composition, and functional traits (wood density and diameter at breast height), using observations from four censuses in 1989, 1999, 2006, and 2013, of stems ≥ 10 cm diameter within 17 unlogged and 9 logged 200 × 10 m vegetation plots. We used null models to account for interdependencies among turnover rates in stems, species composition, and functional traits. We tested predictions that turnover rates should be higher and decrease with increasing time since the selective logging event in logged forest, but should be less temporally variable in unlogged forest. Overall, we found higher turnover rates in logged forest for all three attributes, but turnover rates did not decline through time in logged forest and was not less temporally variable in unlogged forest. These results indicate that successional models that assume recovery to pre-disturbance conditions are inadequate for predicting the effects of selective logging on the dynamics of the tropical forest in Kibale. Selective logging resulted in persistently higher turnover rates, which may compromise the carbon storage capacity

  9. A new VFA sensor technique for anaerobic reactor systems

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær

    2003-01-01

    to monitor VFA online in one of the most difficult media: animal slurry or manure. A novel in situ filtration technique has made it possible to perform microfiltration inside a reactor system. This filter enables sampling from closed reactor systems without large-scale pumping and filters. Furthermore, due...... to its small size it can be placed in lab-scale reactors without disturbing the process. Using this filtration technique together with commercially available membrane filters we have constructed a VFA sensor system that can perform automatic analysis of animal slurry at a frequency as high as every 15...... filtration technique are being presented is this article....

  10. The Immune Response to a Vesicular Stomatitis Virus Vaccine Vector Is Independent of Particulate Antigen Secretion and Protein Turnover Rate

    Science.gov (United States)

    Cobleigh, Melissa A.; Bradfield, Clinton; Liu, Yuanjie; Mehta, Anand

    2012-01-01

    Vesicular stomatitis virus (VSV) is a highly cytopathic virus being developed as a vaccine vector due to its ability to induce strong protective T cell and antibody responses after a single dose. However, little is known regarding the mechanisms underlying the potent immune responses elicited by VSV. We previously generated a VSV vector expressing the hepatitis B virus middle envelope surface glycoprotein (MS) that induces strong MS-specific T cell and antibody responses in mice. After synthesis in the cytoplasm, the MS protein translocates to the endoplasmic reticulum, where it forms subviral particles that are secreted from the cell. To better understand the contributions of secreted and intracellular protein to the VSV-induced immune response, we produced a vector expressing a secretion-deficient MS mutant (MSC69A) and compared the immunogenicity of this vector to that of the wild-type VSV-MS vector in mice. As expected, the MSC69A protein was not secreted from VSV-infected cells and displayed enhanced proteasome-mediated degradation. Surprisingly, despite these differences in intracellular protein processing, the T cell and antibody responses generated to MSC69A were comparable to those elicited by virus expressing wild-type MS protein. Therefore, when it is expressed from VSV, the immune responses to MS are independent of particulate antigen secretion and the turnover rate of cytoplasmic protein. These results are consistent with a model in which the immune responses to VSV are strongly influenced by the replication cycle of the vector and demonstrate that characteristics of the vector have the capacity to affect vaccine efficacy more than do the properties of the antigen itself. PMID:22345454

  11. Decreased brain serotonin turnover rate following administration of Sharbat-e-Ahmed Shah produces antidepressant and anxiolytic effect in rats.

    Science.gov (United States)

    Ahmed, Muhammad; Azmat, Aisha

    2017-07-07

    Sharbat-e-Ahmed Shah (SAS) has usually been used in Traditional Unani Medicine (TUM) for depression and insomnia but still not evaluated for its anti-depressant and Neuropharmacological activity. In the present study, a Human dose of SAS (0.6 ml/kg/d) was administered orally to the rats for 15 consecutive days. Antidepressant and anxiolytic were screened scientifically in rats by using Forced swim test and light and dark box test. At the end of study high-performance liquid chromatographic (HPLC) method with electrochemical (EC) detector was used for the measurement of blood and brain tryptophan and brain serotonin levels. The present reported results are according to what is known in TUM, where is prescribed as an antidepressant agent. After the administration, SAS (at a human dose for 15 days) reduced the immobility time in rats analogous to Imipramine (positive control) indicating the antidepressant effect of SAS. In the present study, Diazepam or SAS (0.6 ml/kg/day) treated rats stayed in the illuminated side of the light-dark box, as compare to control rats (Veh, 134.62 ± 4.430 s; SAS 0.6 ml/kg, 192.2 ± 8.11 s; DZP 1.0 mg/kg, 205.21.20 ± 10.26 s, p < 0.05). It was also observed that SAS increased the availability of tryptophan in blood and brain and hence increases 5-hydroxytryptamine (Serotonin: 5HT) in the brain. At the end, it was concluded that SAS contains some active principles which increase the availability of neurochemical (tryptophan and 5HT) and decrease the 5HT turnover rate thus causes antidepressant and anxiolytic effects in experimental animals.

  12. High species richness of Chironomidae (Diptera) in temporary flooded wetlands associated with high species turn-over rates.

    Science.gov (United States)

    Lundström, J O; Brodin, Y; Schäfer, M L; Vinnersten, T Z Persson; Ostman, O

    2010-08-01

    Species richness and species turn-over of Chironomidae was studied in irregularly flooded wetlands of the River Dalälven flood-plains in central Sweden. The chironomid fauna, sampled with emergence traps in six wetlands over six summers, contained as much as 135 species, and the cumulative species curves indicated that the regional species pool contain several more species. Recurrent irregular floods may have induced this high chironomid species richness and the high species turn-over in the temporary wetlands, as the dominance between terrestrial and aquatic species shifted between years. Half of the wetlands were treated with Bacillus thuringiensis var. israelensis (Bti) against larvae of the flood-water mosquito Aedes sticticus. These treatments had no significant effect on chironomid species richness, but there was a higher species turn-over between years of primarily low abundance species in the treated wetlands. The cumulative number of species was also higher in the Bti-treated experimental wetlands than in the untreated reference wetlands. Thus, Bti treatment against mosquito larvae seemed to have only small effects on chironomid species richness but seemed to increase the colonisation-extinction dynamics.

  13. Toasting of cereal grains: effects on in vitro rumen gas production and VFA yield

    Directory of Open Access Journals (Sweden)

    Seerp Tamminga

    2010-01-01

    Full Text Available The fermentation properties of the following feeds: pelleted barley (PB, toasted and pelleted barley (TPB, pelleted maize (PM and toasted and pelleted maize (TPM were studied using an in vitro gas production (GP technique. Each feed sample (0.5g was incubated (3 replications, with rumen fluid collected from 3 grazing lactating dairy cows. The kinetics of GP were automatically recorded for 72h. The amounts of DM disappeared (DMd and the volatile fatty acid yields (VFA were measured. On barley, compared to simple pelleting, toasting significantly (P<0.05 reduced DMd (87.5 vs. 86.2%, the asymptotic GP (A, 388 vs. 367ml/g DMd and slightly increased the time of maximum GP rate (TRmax, 2.89 vs. 3.15h. On maize toasting did not affect DMd and A, but significantly reduced T1/2 (9.71 vs. 8.57; P<0.05 and TRmax (5.04 vs. 4.49, P<0.05. Toasting significantly reduced the VFA yields both of barley and maize. These results, in agreement with previous in sacco and in vivo observations, suggest that toasting might reduce the amount of potential fermentable substrate of barley, whereas it might increase the rate of fermentation of maize.

  14. A new method combining soil oxygen concentration measurements with the quantification of gross nitrogen turnover rates and associated formation of N2O and N2 emissions

    Science.gov (United States)

    Gütlein, Adrian; Dannenmann, Michael; Sörgel, Christoph; Meier, Rudi; Meyer, Astrid; Kiese, Ralf

    2014-05-01

    Climate change and the expansion of land use have led to significant changes in terrestrial ecosystems. These include changes in the biogeochemical cycle of nitrogen and therewith implications for biodiversity, water cycle and pedosphere-atmosphere exchange. To understand these impacts detailed research on nitrogen turnover and fluxes are conducted at various (semi-) natural and managed ecosystems in the Mt. Kilimanjaro region. In this context, we execute 15N tracing analyses on soil samples in our stable isotope laboratory including a new experimental setup. The soils were sampled from different forest ecosystems of Mt. Kilimanjaro varying in altitude (1600 - 4500 m) and will be analyzed for gross rates of ammonification and nitrification, gross rates of microbial inorganic N uptake as well as for the gaseous losses of ^15N2 and ^15N2O using ^15NH4+ and ^15NO3- tracing and pool dilution approaches. Since nitrogen turnover of nitrification and denitrification is dependent on soil oxygen concentrations we developed an incubation method which allows to adjust soil samples to different oxygen concentrations. For this purpose, soil is incubated in glass bottles with side tubes to ensure a constant gas flow over the whole incubation time. To adjust the oxygen levels in the laboratory experiment as close as possible to the natural conditions, we started to monitor soil oxygen concentrations with a FirestingO2 Sensor (Pyroscience) connected to a timer and a datalogger (MSR 145 IP 60 E3333) at a Mt. Kilimanjaro rainforest site. The equipment is complemented with soil temperature, moisture and pressure sensors (MSR 145 IP 60). A solar panel connected to an energy source guarantees a working time for over 2 years by a measuring frequency of 20 seconds each 30 minutes. The new laboratory incubation method together with in-situ oxygen concentration measurements in soils will facilitate laboratory incubations with realistic oxygen concentrations and thus will allow for a better

  15. A hybrid cascade control scheme for the VFA and COD regulation in two-stage anaerobic digestion processes.

    Science.gov (United States)

    Méndez-Acosta, H O; Campos-Rodríguez, A; González-Álvarez, V; García-Sandoval, J P; Snell-Castro, R; Latrille, E

    2016-10-01

    A hybrid (continuous-discrete) cascade control is proposed to regulate both, volatile fatty acids (VFA) and chemical oxygen demand (COD) concentrations in two-stage (acidogenic-methanogenic) anaerobic digestion (TSAD) processes. The outer loop is a discrete controller that regulates the COD concentration of the methanogenic bioreactor by using a daily off-line measurement and that modifies the set-point tracked by inner loop, which manipulates the dilution rate to regulate the VFA concentration of the acidogenic bioreactor, estimated by continuous on-line conductivity measurements, avoiding acidification. The experimental validation was conducted in a TSAD process for the treatment of tequila vinasses during 110days. Results showed that the proposed cascade control scheme was able to achieve the VFA and COD regulation by using conventional measurements under different set-point values in spite of adverse common scenarios in full-scale anaerobic digestion processes. Microbial composition analysis showed that the controller also favors the abundance and diversity toward methane production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Comparison of VFA titration procedures used for monitoring the biogas process

    DEFF Research Database (Denmark)

    Lützhøft, Hans-Christian Holten; Boe, Kanokwan; Fang, Cheng

    2014-01-01

    titration procedures. Currently, no standardized procedure is used and it is therefore difficult to compare the performance among plants. The aim of this study was to evaluate four titration procedures (for determination of VFA-levels of digested manure samples) and compare results with gas chromatographic...... (GC) analysis. Two of the procedures are commonly used in biogas plants and two are discussed in literature. The results showed that the optimal titration results were obtained when 40mL of four times diluted digested manure was gently stirred (200rpm). Results from samples with different VFA...... concentrations (1-11g/L) showed linear correlation between titration results and GC measurements. However, determination of VFA by titration generally overestimated the VFA contents compared with GC measurements when samples had low VFA concentrations, i.e. around 1g/L. The accuracy of titration increased when...

  17. Response of the Fine Root Production, Phenology, and Turnover Rate of Six Shrub Species from a Subtropical Forest to a Soil Moisture Gradient and Shading

    Science.gov (United States)

    Fu, X.; Dai, X.; Wang, H.

    2015-12-01

    Knowledge of the fine root dynamics of different life forms in forest ecosystems is critical to understanding how the overall belowground carbon cycling is affected by climate change. However, our current knowledge regarding how endogenous or exogenous factors regulate the root dynamics of understory vegetation is limited. We selected a suite of study sites representing different habitats with gradients of soil moisture and solar radiation (shading or no shading). We assessed the fine root production phenology, the total fine root production, and the turnover among six understory shrub species in a subtropical climate, and examined the responses of the fine root dynamics to gradients in the soil moisture and solar radiation. The shrubs included three evergreen species, Loropetalum chinense, Vaccinium bracteatum, and Adinandra millettii, and three deciduous species, Serissa serissoides, Rubus corchorifolius, and Lespedeza davidii. We observed that variations in the annual fine root production and turnover among species were significant in the deciduous group but not in the evergreen group. Notably, V. bracteatum and S. serissoides presented the greatest responses in terms of root phenology to gradients in the soil moisture and shading: high-moisture habitat led to a decrease and shade led to an increase in fine root production during spring. Species with smaller fine roots of the 1st+2nd-order diameter presented more sensitive responses in terms of fine root phenology to a soil moisture gradient. Species with a higher fine root nitrogen-to -carbon ratio exhibited more sensitive responses in terms of fine root annual production to shading. Soil moisture and shading did not change the annual fine root production as much as the turnover rate. The fine root dynamics of some understory shrubs varied significantly with soil moisture and solar radiation status and may be different from tree species. Our results emphasize the need to study the understory fine root dynamics

  18. Environmental and historical imprints on beta diversity: insights from variation in rates of species turnover along gradients

    DEFF Research Database (Denmark)

    Fitzpatrick, Matthew C Fitzpatrick; Sanders, Nathan J.; Normand, Signe

    2013-01-01

    A common approach for analysing geographical variation in biodiversity involves using linear models to determine the rate at which species similarity declines with geographical or environmental distance and comparing this rate among regions, taxa or communities. Implicit in this approach are weak...

  19. A conserved degron containing an amphipathic helix regulates the cholesterol-mediated turnover of human squalene monooxygenase, a rate-limiting enzyme in cholesterol synthesis.

    Science.gov (United States)

    Chua, Ngee Kiat; Howe, Vicky; Jatana, Nidhi; Thukral, Lipi; Brown, Andrew J

    2017-12-08

    Cholesterol biosynthesis in the endoplasmic reticulum (ER) is tightly controlled by multiple mechanisms to regulate cellular cholesterol levels. Squalene monooxygenase (SM) is the second rate-limiting enzyme in cholesterol biosynthesis and is regulated both transcriptionally and post-translationally. SM undergoes cholesterol-dependent proteasomal degradation when cholesterol is in excess. The first 100 amino acids of SM (designated SM N100) are necessary for this degradative process and represent the shortest cholesterol-regulated degron identified to date. However, the fundamental intrinsic characteristics of this degron remain unknown. In this study, we performed a series of deletions, point mutations, and domain swaps to identify a 12-residue region (residues Gln-62-Leu-73), required for SM cholesterol-mediated turnover. Molecular dynamics and circular dichroism revealed an amphipathic helix within this 12-residue region. Moreover, 70% of the variation in cholesterol regulation was dependent on the hydrophobicity of this region. Of note, the earliest known Doa10 yeast degron, Deg1, also contains an amphipathic helix and exhibits 42% amino acid similarity with SM N100. Mutating SM residues Phe-35/Ser-37/Leu-65/Ile-69 into alanine, based on the key residues in Deg1, blunted SM cholesterol-mediated turnover. Taken together, our results support a model whereby the amphipathic helix in SM N100 attaches reversibly to the ER membrane depending on cholesterol levels; with excess, the helix is ejected and unravels, exposing a hydrophobic patch, which then serves as a degradation signal. Our findings shed new light on the regulation of a key cholesterol synthesis enzyme, highlighting the conservation of critical degron features from yeast to humans. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Addressing employee turnover and retention: keeping your valued performers.

    Science.gov (United States)

    McConnell, Charles R

    2011-01-01

    Employee turnover and employee retention are inextricably linked; to control turnover is to enhance retention. Turnover is a relatively simple concept; however, considerable confusion often results when addressing turnover because of differences in how it is defined; that is, what is counted, how it is counted, and how the turnover rates are expressed. Turnover is also costly, although not enough attention is paid to its cost because so much of it is indirect and thus not readily visible. There are a variety of causes of turnover, some that can be corrected and some that cannot be avoided. Reducing or otherwise controlling turnover requires continuing management attention to its causes and constant recognition of what can and should be controlled and what cannot be controlled. Ongoing attention to turnover is an essential part of the department manager's role; every improvement in turnover is a direct improvement in retention, with eventual positive effects on the bottom line.

  1. A novel in-situ sampling and VFA sensor technique for anaerobic systems

    DEFF Research Database (Denmark)

    Pind, Peter Frode; Angelidaki, Irini; Ahring, Birgitte Kiær

    2002-01-01

    that has made it possible to monitor VFA on-line in one of the most difficult media: animal slurry or manure. A novel in-situ filtration technique has made it possible to perform microfiltration inside the reactor system. This filter enables sampling from closed reactor systems without large scale pumping...... and filtering. Using this filtration technique together with commercially available membrane filters we have constructed a VFA sensor system that can perform automatic analysis on animal slurry at a frequency as high as every 15 minutes. The VFA sensor has been tested for a period of more than 60 days with more...

  2. Efeitos da independência do banco central e da taxa de rotatividade sobre a inflação brasileira The effects of central bank independence and the rate of turnover on the Brazilian inflation

    Directory of Open Access Journals (Sweden)

    Helder Ferreira de Mendonça

    2006-12-01

    Full Text Available Nowadays, the belief is strong in the Brazilian federal government that operational central bank independence is a basic condition to assure price stability. The literature concerning this subject highlights that a high degree of independence and a low turnover of central bank governor are associated with low inflation. This paper analyzes the relation between central bank independence and inflation in Brazil during 1980-2002. The findings denote that there is no effect on inflation due to an increase in degree of independence and a fall in turnover rate.

  3. PENGARUH TURNOVER INTENTIONS, SELF RATE EMPLOYEE PERFORMANCE, DAN SELF ESTEEM TERHADAP PENERIMAAN DYSFUNCTIONAL BEHAVIOR IN AUDIT DALAM PRESPEKTIF GENDER (Studi padaKantorAkuntanPublik Se- JawaTengah

    Directory of Open Access Journals (Sweden)

    Hj. Falikhatun ,

    2009-12-01

    Full Text Available The objective of this research are: first, examining the effect of turnover intentions, self rate employee performance and self esteem on acceptance of dysfunctional behavior in audit, and second tested the differences on acceptance of dysfunctional behavior in audit for male and female auditor Hypotheses that proposed are turnover intentions and self esteem will have positive effect on acceptance of dysfunctional behavior in audit, while, self rate employee performance will has negative effect on acceptance of dysfunctional behavior in audit. The next hypotheses is the difference of acceptance of dysfunctional behavior in audit for male and female auditor. The population is auditors working in public accountant firm located in Central Java. Purposive random sampling used to take the samples. Data collection method that used is mail questionnaires method. Data analyze method is validity and reliability analysis, classic assumption analysis and hypotheses analysis that used multiple regression and independent sample t test. The results are all variables valid and reliable and fulfil classic assumption. The result of hypotheses analysis show that self rate employee performance will has positive significantly effect on acceptance of dysfunctional behavior in audit, while turnover intentions, and self esteem have insignificant positive effect on acceptance dysfunctional behavior. For gender prespective, acceptance of dysfunctional behavior in audit for male and female auditor isn 't different. Keywords: turnover intentions, self rate employee performanc, self esteem, acceptance of dysfunctional behavior in audit, gender.

  4. Lack of 13C-label incorporation suggests low turnover rates of thaumarchaeal intact polar tetraether lipids in sediments from the Iceland shelf

    Science.gov (United States)

    Lengger, S. K.; Lipsewers, Y. A.; de Haas, H.; Sinninghe Damsté, J. S.; Schouten, S.

    2014-01-01

    Thaumarchaeota are amongst the most abundant microorganisms in aquatic environments, however, their metabolism in marine sediments is still debated. Labeling studies in marine sediments have previously been undertaken, but focused on complex organic carbon substrates which Thaumarchaeota have not yet been shown to take up. In this study, we investigated the activity of Thaumarchaeota in sediments by supplying different 13C-labeled substrates which have previously been shown to be incorporated into archaeal cells in water incubations and/or enrichment cultures. We determined the incorporation of 13C-label from bicarbonate, pyruvate, glucose and amino acids into thaumarchaeal intact polar lipid-glycerol dibiphytanyl glycerol tetraethers (IPL-GDGTs) during 4-6 day incubations of marine sediment cores from three sites on the Iceland shelf. Thaumarchaeal intact polar lipids, in particular crenarchaeol, were detected at all stations and concentrations remained constant or decreased slightly upon incubation. No 13C incorporation in any IPL-GDGT was observed at stations 2 (clay-rich sediment) and 3 (organic-rich sediment). In bacterial/eukaryotic IPL-derived fatty acids at station 3, contrastingly, a large uptake of 13C label (up to + 80‰ ) was found. 13C was also respired during the experiment as shown by a substantial increase in the 13C content of the dissolved inorganic carbon. In IPL-GDGTs recovered from the sandy sediments at station 1, however, some enrichment in δ13C (1-4‰ ) was detected after incubation with bicarbonate and pyruvate. The low incorporation rates suggest a low activity of Thaumarchaeota in marine sediments and/or a low turnover rate of thaumarchaeal IPL-GDGTs due to their low degradation rates. Cell numbers and activity of sedimentary Thaumarchaeota based on IPL-GDGT measurements may thus have previously been overestimated.

  5. Comparison of VFA titration procedures used for monitoring the biogas process.

    Science.gov (United States)

    Lützhøft, Hans-Christian Holten; Boe, Kanokwan; Fang, Cheng; Angelidaki, Irini

    2014-05-01

    Titrimetric determination of volatile fatty acids (VFAs) contents is a common way to monitor a biogas process. However, digested manure from co-digestion biogas plants has a complex matrix with high concentrations of interfering components, resulting in varying results when using different titration procedures. Currently, no standardized procedure is used and it is therefore difficult to compare the performance among plants. The aim of this study was to evaluate four titration procedures (for determination of VFA-levels of digested manure samples) and compare results with gas chromatographic (GC) analysis. Two of the procedures are commonly used in biogas plants and two are discussed in literature. The results showed that the optimal titration results were obtained when 40 mL of four times diluted digested manure was gently stirred (200 rpm). Results from samples with different VFA concentrations (1-11 g/L) showed linear correlation between titration results and GC measurements. However, determination of VFA by titration generally overestimated the VFA contents compared with GC measurements when samples had low VFA concentrations, i.e. around 1 g/L. The accuracy of titration increased when samples had high VFA concentrations, i.e. around 5 g/L. It was further found that the studied ionisable interfering components had lowest effect on titration when the sample had high VFA concentration. In contrast, bicarbonate, phosphate and lactate had significant effect on titration accuracy at low VFA concentration. An extended 5-point titration procedure with pH correction was best to handle interferences from bicarbonate, phosphate and lactate at low VFA concentrations. Contrary, the simplest titration procedure with only two pH end-points showed the highest accuracy among all titration procedures at high VFA concentrations. All in all, if the composition of the digested manure sample is not known, the procedure with only two pH end-points should be the procedure of

  6. Can transformational managers control turnover intention?

    Directory of Open Access Journals (Sweden)

    Massad A. Alatawi

    2017-01-01

    Full Text Available Orientation and research purpose: Employee turnover is a complex phenomenon that has negative consequences for organisations. The purpose of this study was to measure the correlation between transformational leadership style and turnover intention to control the employee turnover rate in organisations.Research method: This study utilised a two-stage clustering method and web-based survey research with a correlational design to collect the data. A total of 356 responses were collected from 14 clusters in Southern California; however, the final selected data for analysis came from 210 subjects with a cluster-sampling design of (14 × 15.Main findings and managerial implications: This study concluded that the transformational leadership style has a negative correlation with turnover intention. Managers who adopt this style of leadership can expect lower rates of turnover; thus, they can stay competitive in an unstable economy and achieve enhanced productivity, improved performance and reduction in expenses.

  7. Nucleotídeos na dieta de frangos de corte e seus efeitos sobre taxa de turnover da mucosa intestinal antes e após lesões causadas por coccidiose Nucleotides in broilers challenged diet and its effects on intestinal mucosa turnover rate before and after injuries caused by coccidiose

    Directory of Open Access Journals (Sweden)

    Vanessa Cristina Pelícia

    2011-09-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da dieta suplementada com nucleotídeos sobre taxa de turnover da mucosa intestinal de frangos antes e após lesões causadas por coccidiose por meio de análise isotópica, utilizando a variação do carbono-13 em plantas C3 e C4. Foram utilizados 264 pintos submetidos a dois tratamentos: dieta controle e dieta suplementada com 0,07% nucleotídeos. Os pintos possuíam sinais isotópicos em seus tecidos semelhantes ao de ditas C4. Após o alojamento, para avaliar taxa de turnover da mucosa, as aves receberam dietas predominantemente C3. Com 16 dias de idade, 50% das aves de cada tratamento foram inoculadas com oocistos de Eimeria acervulina e, a partir de 21 dias, para avaliar a taxa de turnover após desafio, as aves passaram a receber dieta predominantemente C4. Amostras de mucosa foram analisadas isotopicamente por espectrometria de massa. Na fase inicial, a suplementação com nucleotídeos propiciou aceleração na troca do carbono na mucosa, com meia-vida de 1,06 e 1,01 dias para dieta controle e com nucleotídeos, respectivamente, acelerando o crescimento intestinal. Na fase de 21 a 42 dias de idade, para os grupos não desafiados com coccidiose, as meias-vidas do carbono foram 1,81 e 1,80 dias para dieta controle e com nucleotídeos, respectivamente, não havendo influência dos tratamentos. Porém, nos grupos desafiados, as meias-vidas foram 1,01 dias no grupo controle e 0,75 dias no que recebeu dieta com nucleotídeos, indicando maior turnover da mucosa nesse último grupo. A adição de nucleotídeos promove aceleração no processo de renovação da mucosa intestinal e na regeneração após danos causados por coccidiose.The objective was to evaluate the effect of nucleotides supplementation diet on the intestinal mucosa turnover rate of broilers before and after injury caused by coccidiosis, through isotopic analysis, using the carbon-13 variation in C³ and C4 plants. It was used 264

  8. Selective VFA production potential from organic waste streams: Assessing temperature and pH influence.

    Science.gov (United States)

    Garcia-Aguirre, Jon; Aymerich, Enrique; González-Mtnez de Goñi, Jaime; Esteban-Gutiérrez, Myriam

    2017-11-01

    This study explored the volatile fatty acid (VFA) production potential of seven waste streams from urban and agroindustrial sources. For that purpose, batch assays were performed under acidic (pH 5.5) and alkaline (pH 10) conditions at both mesophilic (35°C) and thermophilic (55°C) temperature. Overall, the VFA yield was influenced by temperature, and it was positively affected by pH, ranging between 220 and 677mgCODg-1CODfed for liquid waste streams and between 127 and 611mgCODg-1CODfed for solid waste streams and urban sludge. The highest VFA concentration and highest VFA/sCOD ratio was obtained during the organic fraction of municipal solid waste (OFMSW) fermentation, with 8,320mgCODL-1 and 94% at alkaline pH and mesophilic temperature. The results of this study suggest that selective VFA production, i.e. via propionic, butyric and acetic acid production, might be feasible for scaling-up purposes with specific waste streams by adjusting the process parameters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Chronic Teacher Turnover in Urban Elementary Schools

    Directory of Open Access Journals (Sweden)

    Kacey Guin

    2004-08-01

    Full Text Available This study examines the characteristics of elementary schools that experience chronic teacher turnover and the impacts of turnover on a school’s working climate and ability to effectively function. Based on evidence from staff climate surveys and case studies, it is clear that high turnover schools face significant organizational challenges. Schools with high teacher turnover rates have difficulty planning and implementing a coherent curriculum and sustaining positive working relationships among teachers. The reality of these organizational challenges is particularly alarming, given that high turnover schools are more likely to serve low-income and minority students. The negative relationship between teacher turnover and school functioning, and the fact that turbulent schools are disproportionately likely to serve lowincome and minority students have important implications for both district and school-level policies. Specifically: Teacher turnover rates are one indicator of school health, which school districts should consider when focusing on school improvements. Districts need to begin by developing the means to identify individual schools that experience high levels of teacher turnover. Current district policies in implementing professional development for teachers in low-performing schools are inefficient when teachers do not remain in the schools in which they are trained. In order for low-performing schools to improve, districts need to consider providing incentive programs so that high quality teachers apply for, and remain in, these schools. Future research is needed to address the causal link between turnover, organizational functioning and student outcomes. Additionally, there is a need for research examining district policies that may facilitate teacher turnover within a district, including how districts place and transfer teachers, as well as how teachers’ salaries are budgeted.

  10. Monitoring and control of the biogas process based on propionate concentration using online VFA measurement

    DEFF Research Database (Denmark)

    Boe, Kanokwan; Steyer, J.P.; Angelidaki, Irini

    2008-01-01

    Simple logic control algorithms were tested for automatic control of a lab-scale CSTR manure digester. Using an online VFA monitoring system, propionate concentration in the reactor was used as parameter for control of the biogas process. The propionate concentration was kept below a threshold...... of 10 mM by manipulating the feed flow. Other online parameters such as pH, biogas production, total VFA, and other individual VFA were also measured to examine process performance. The experimental results showed that a simple logic control can successfully prevent the reactor from overload......, but with fluctuations of the propionate level due to the nature of control approach. The fluctuation of propionate concentration could be reduced, by adding a lower feed flow limit into the control algorithm to prevent undershooting of propionate response. It was found that use of the biogas production as a main...

  11. MANAGEMENT OF PERSONNEL TURNOVER

    Directory of Open Access Journals (Sweden)

    Vyara Slavyanska

    2014-09-01

    Full Text Available Personnel turnover is a problem of great importance and increasing actuality for the business practice both on a world scale and in Bulgaria. This provokes a search of effective instruments for its management. The paper presents a summary of a monograph examining the specificity of personnel turnover management.

  12. Managing teacher turnover

    African Journals Online (AJOL)

    Erna Kinsey

    ticular those students who have also done well in Mathematics and. Physical Science ... ". This plea, in part, does address a concern over one of the consequences of teacher turnover, that is, teacher shortages. However, the situation regarding teacher turnover and attrition in. South Africa seems complex due a variety of ...

  13. CONTROL PARAMETERS FOR UNDERSTANDING AND PREVENTING PROCESS IMBALANCES IN BIOGAS PLANTS. EMPHAS IS ON VFA DYNAMICS

    DEFF Research Database (Denmark)

    Bangsø Nielsen, Henrik

    H. The experiments were carried out in lab-scale thermophilic continuously stirred tank reactors (CSTR) treating livestock waste. The imbalances included inhibition by long chain fatty acids (LCFA), inhibition by ammonia, organic overloading with proteins and organic overloading with industrial waste, i.e. meat...... and bone meal and lipids. During the main part of the experiments one reactor was connected to an online VFA sensor giving a detailed profile of the VFA dynamics during the process imbalances. Based on the results it was concluded, that propionate was the most reliable single parameter for indication...

  14. The Visiting Forces Agreement (VFA in the Philippines: Insights on Issues of Sovereignty, Security and Foreign Policy

    Directory of Open Access Journals (Sweden)

    Mark Anthony M. Velasco

    2015-11-01

    Full Text Available The study intends to compare the Visiting Forces Agreement (VFA between the Philippines and the United States of America and the VFA between the Philippines and Australia. The research piece is arranged in the following flow of ideas. The first and the second part provides the foundations by highlighting issues on definition, historical background, provisions of the agreement and concerns faced by the agreement of the Visiting Forces Agreement (VFA between the Republic of the Philippines and the United States of America and the Status of the Visiting Forces Agreement (SOVFA between the Republic of the Philippines and Australia. The third part is an analysis of the VFA and the SOVFA under the tutelage of the framework on the non-intervention principle. As a result, the provisions of SOVFA were in consonance with the legal arrangement in the Philippines than the VFA with the United States of America.

  15. The island-mainland species turnover relationship.

    Science.gov (United States)

    Stuart, Yoel E; Losos, Jonathan B; Algar, Adam C

    2012-10-07

    Many oceanic islands are notable for their high endemism, suggesting that islands may promote unique assembly processes. However, mainland assemblages sometimes harbour comparable levels of endemism, suggesting that island biotas may not be as unique as is often assumed. Here, we test the uniqueness of island biotic assembly by comparing the rate of species turnover among islands and the mainland, after accounting for distance decay and environmental gradients. We modelled species turnover as a function of geographical and environmental distance for mainland (M-M) communities of Anolis lizards and Terrarana frogs, two clades that have diversified extensively on Caribbean islands and the mainland Neotropics. We compared mainland-island (M-I) and island-island (I-I) species turnover with predictions of the M-M model. If island assembly is not unique, then the M-M model should successfully predict M-I and I-I turnover, given geographical and environmental distance. We found that M-I turnover and, to a lesser extent, I-I turnover were significantly higher than predicted for both clades. Thus, in the first quantitative comparison of mainland-island species turnover, we confirm the long-held but untested assumption that island assemblages accumulate biodiversity differently than their mainland counterparts.

  16. Evaluating 5 and 8 pH-point titrations for measuring VFA in full-scale ...

    African Journals Online (AJOL)

    The comparison showed that the VFA concentrations measured with the two titration methods were higher than those obtained via gas chromatography, differing by 9 and 13 mg COD∙ℓ-1 for the hydrolysate and by 5 and 6 mg COD∙ℓ-1 for the ordinary primary settler effluent. No improvement in the accuracy of VFA ...

  17. Empirical Prediction of Turnovers in NFL Football

    Directory of Open Access Journals (Sweden)

    Joel R. Bock

    2016-12-01

    Full Text Available Turnovers in the National Football League (NFL occur whenever a team loses possession of the ball due to a fumble, or an interception. Turnovers disrupt momentum of the offensive team, and represent lost opportunities to advance downfield and score. Teams with a positive differential turnover margin in a given game win 70 % of the time. Turnovers are statistically rare events, occurring apparently randomly. These characteristics make them difficult to predict. This investigation advances the hypothesis that turnovers are predictable in NFL football. Machine learning models are developed to learn the concept: At any point within a football game, what is the likelihood that a turnover will be observed on the next play from scrimmage? NFL play-by-play data for 32 teams spanning seven full seasons were used to train the models. Results presented suggest evidence to support the working hypothesis. Under certain conditions, both fumbles and interceptions can be anticipated at low false discovery rates (less than 15 % . When a turnover is predicted on the impending play from scrimmage, a high degree of confidence is associated with that prediction. The ability to anticipate catastrophic in-game events may lead to their management and control, ultimately improving the performance of individual athletes and their teams. This investigation contributes to the sports science literature by demonstrating the predictability of in-game events often considered to be essentially random in their occurrence. To the author’s knowledge, direct prediction of turnovers has not previously appeared in the literature, which has focused on retrospective statistical analyses of turnover margin in football games.

  18. Determinants of CEO Turnover in Publicand Private Firms in Denmark - CEO and Firm Characteristics

    DEFF Research Database (Denmark)

    Sponholtz, Carina

    turnover across a variety of firm types that di¤er with re-spect to the corporate governance issues they face. Our simple methodol-ogy to define CEO turnover results in turnover rates similar to those foundpreviously. Our results indicate that CEO characteristics are an important factor in explaining CEO...... governance issues they face. Our simple methodology to define CEO turnover results in turnover rates similar to those foundpreviously. Our results indicate that CEO characteristics are an important factor in explaining CEO turnover. Finally, the inverse relationshipbetween firm performance and CEO turnover......-employee data to study CEO turnover. Using this data we contribute tothe existing literature by examining the effect of previously unstudied individual characteristics on CEO turnover. Additionally, we are able toexamine CEO turnover across a variety of firm types that di¤er with respect to the corporate...

  19. Pilot-scale application of an online VFA sensor for monitoring and control of a manure digester

    DEFF Research Database (Denmark)

    Boe, Kanokwan; Angelidaki, Irini

    2012-01-01

    A volatile fatty acids (VFA) sensor based on headspace chromatography was tested for online monitoring and control of a pilot-scale manure digester. The sensor showed satisfying results in terms of sensitivity and reliability for monitoring of the digester. The online VFA and biogas production data...... were used for automatic control of the digester based on feed flow manipulation. The control approach was based on optimization of biogas production while using VFA concentration as the alarm threshold. A rule-based supervisory system with a cascade controller was used to optimize the biogas production...

  20. Turnover in health care: the mediating effects of employee engagement.

    Science.gov (United States)

    Collini, Stevie A; Guidroz, Ashley M; Perez, Lisa M

    2015-03-01

    This study aimed to understand the interaction between interpersonal respect, diversity climate, mission fulfilment and engagement to better predict turnover in health care. Registered nurse turnover has averaged 14% and current nursing shortages are expected to spread. Few studies have studied employee engagement as a mediator between organisational context and turnover. Study participants were employees working within 185 departments across ten hospitals within a large healthcare organisation in the USA. Although a total of 5443 employees work in these departments, employee opinion survey responses were aggregated by department before being linked to turnover rates gathered from company records. Engagement fully mediated the relationship between respect and turnover and the relationship between mission fulfilment and turnover. Diversity climate was not related to turnover. Turnover in health care poses a significant threat to the mission of creating a healing environment for patients and these results demonstrate that workplace respect and connection to the mission affect turnover by decreasing engagement. The findings demonstrated that to increase engagement, and improve turnover rates in health care, it would be beneficial for organisations, and nurse management to focus on improving mission fulfilment and interpersonal relationships. © 2013 John Wiley & Sons Ltd.

  1. Health workforce acquisition, retention and turnover in southwest ...

    African Journals Online (AJOL)

    Background: Skill mix of health professionals, staff acquisition and turnover rate are among the major challenges for the delivery of quality health care. This study assessed the health workforce acquisition, retention, turnover rate and their intention to leave. Methods: A cross-sectional survey with quantitative and qualitative ...

  2. Vertical flow immunoassay (VFA) biosensor for a rapid one-step immunoassay.

    Science.gov (United States)

    Oh, Young Kyoung; Joung, Hyou-Arm; Kim, Sanghyo; Kim, Min-Gon

    2013-03-07

    A highly rapid, one-step immunoassay of high sensitivity C-reactive protein (hsCRP) using a biosensor with a vertical flow immunoassay (VFA) was developed. The VFA biosensor was primarily composed of a sample pad, conjugate pad, FTH film and nitrocellulose (NC) membrane, which were all vertically stacked upon one another. Anti-hsCRP and secondary antibodies were consecutively immobilized on the NC membrane at the position below the holes. Gold nanoparticles (AuNPs) conjugated with another anti-hsCRP antibody were encapsulated in the conjugation pad. Various assay conditions, including the size of the hole and the sample volume, were optimized. Under optimized conditions, hsCRP concentrations from 0.01 to 10 μg mL(-1) were detected within 2 min. In comparison with a lateral flow assay (LFA) system, the VFA sensor showed a gradual increase of signal in a concentration-dependent manner without a hook effect in the tested range.

  3. Does Judge Turnover Affect Judicial Performance?

    DEFF Research Database (Denmark)

    Guerra, Alice; Tagliapietra, Claudio

    2017-01-01

    office to another after three years of mandate, and the law prescribes their transfer after ten years to guarantee their independence. Flaws in the process managing the backlog of outbound judges and the existence of asynchrony between outbound and inbound transfers produce a chain of delays...... to the disposition of court cases. Using a novel dataset on Court of Appeal Districts in Italy (2008–2012), we provide evidence of a strong negative relation between high turnover rates and judicial performance. We find that marginal increases in judge turnover rates lead to a statistically significant decrease...... in judicial performance over two years of time...

  4. Costs of employee turnover

    Directory of Open Access Journals (Sweden)

    Jiří Duda

    2013-01-01

    Full Text Available The aim of this paper is to establish a general methodology for calculating the costs incurred by employee turnover. This paper deals with identification of costs incurred by the departure of an employee, and does not deal with the cost of recruitment of a new employee. Economic calculations are adjusted to the tax policy in the Czech Republic. The costs of employee turnover (according to Bliss, 2012 include the costs of substitution of the unoccupied position, costs of conducting the exit interview and termination of the contract. The cost of an executive’s time to understand the causes of leaving and costs of the leaving employee’s training were also determined. Important factors in the costs of employee turnover also include the loss of knowledge and possibly also a loss of customers. Costs of lost employee and department productiveness represent an important part of the costs of employee turnover, as well. For all of these costs there have been proposed general calculations formulas.

  5. Explaining turnover intention in Korean public community hospitals: occupational differences.

    Science.gov (United States)

    Hwang, Jee-In; Chang, Hyejung

    2008-01-01

    Personnel in public hospitals had relatively low job satisfaction despite of tenure employment. High turnover rates degrade hospital image and incur additional costs related to recruitment and training. The purposes of this study were to describe the occupational differences and to identify factors affecting turnover intention among public hospital personnel. A questionnaire survey was conducted as part of Administrative Services Quality Evaluation Program by Seoul metropolitan municipality from 1 November to 1 December in 2003. The subjects were 1251 entire hospital personnel in four hospitals. The questionnaire was designed to measure job satisfaction, organizational commitment, turnover intention, and demographic characteristics. Logistic regression analysis was performed to determine factors influencing turnover intention. There were significant differences in job satisfaction, organizational commitment, and turnover intention according to the occupations. The turnover intention rates were highest among physicians, followed by paramedicals and nursing staffs and then administrators. The significant factors affecting turnover intention were involvement and loyalty among physicians, hospital type, satisfaction with systems and loyalty among nursing staffs, satisfaction with relationship and loyalty among administrators, and loyalty among paramedicals. There were different moderators that influence turnover intentions of hospital personnel. Loyalty had the most important effect upon turnover intention in all occupations. 2007 John Wiley & Sons, Ltd

  6. Glucose turnover during pregnancy in anaesthetized post-absorptive rats

    OpenAIRE

    Leturque, Armelle; Gilbert, Marc; Girard, Jean

    1981-01-01

    During pregnancy the decline in blood [glucose] does not result from the increased distribution space of glucose. The absolute rate of glucose turnover increases in late pregnancy in parallel with the rise in the mass of the conceptus. Nevertheless, glucose turnover per kg body wt. is not increased in late pregnancy, since the lower blood [glucose] decreases glucose utilization by maternal tissues.

  7. Agglomeration and Firm Turnover

    OpenAIRE

    Marjan Nasir

    2013-01-01

    The geographic and industrial concentration of firms affects firm turnover, as highlighted in research on industrial organization. This study conducts a firm-level analysis to determine the impact of agglomeration on firm entry and exit in domestic industries in Punjab, Pakistan. The study also illustrates how some industries exist in clusters while others are highly dispersed. The results suggest that firm entry and exit is higher in highly agglomerated industries.

  8. Seasonal groundwater turnover

    OpenAIRE

    Nordell, Bo; Engström, Maria

    2006-01-01

      Seasonal air temperature variations and corresponding changes in groundwater temperature cause convective movements in groundwater similar to the seasonal turnover in lakes. Numerical simulations were performed to investigate the natural conditions for thermally driven groundwater convection to take place. Thermally driven convection could be triggered by a horizontal groundwater flow, Convection then starts at a considerably lower Rayleigh number (Ra) than the general critical Rayleigh ...

  9. Changes of Protein Turnover in Aging Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Dhondt, Ineke; Petyuk, Vladislav A.; Bauer, Sophie; Brewer, Heather M.; Smith, Richard D.; Depuydt, Geert; Braeckman, Bart P.

    2017-07-05

    Protein turnover rates severely decline in aging organisms, including C. elegans. However, limited information is available on turnover dynamics at the individual protein level during aging. We followed changes in protein turnover at one-day resolution using a multiple-pulse 15Nlabeling and accurate mass spectrometry approach. Forty percent of the proteome shows gradual slowdown in turnover with age, whereas only few proteins show increased turnover. Decrease in protein turnover was consistent for only a minority of functionally related protein subsets, including tubulins and vitellogenins, whereas randomly diverging turnover patterns with age were the norm. Our data suggests increased heterogeneity of protein turnover of the translation machinery, whereas protein turnover of ubiquitin-proteasome and antioxidant systems are well-preserved over time. Hence, we presume that maintenance of quality control mechanisms is a protective strategy in aging worms, although the ultimate proteome collapse is inescapable.

  10. Pilot-scale application of an online VFA sensor for monitoring and control of a manure digester.

    Science.gov (United States)

    Boe, K; Angelidaki, I

    2012-01-01

    A volatile fatty acids (VFA) sensor based on headspace chromatography was tested for online monitoring and control of a pilot-scale manure digester. The sensor showed satisfying results in terms of sensitivity and reliability for monitoring of the digester. The online VFA and biogas production data were used for automatic control of the digester based on feed flow manipulation. The control approach was based on optimization of biogas production while using VFA concentration as the alarm threshold. A rule-based supervisory system with a cascade controller was used to optimize the biogas production from the digester. The alarm state was set at 40 mM total VFA and 10 mM propionate concentration. The control algorithms could successfully maximize the biogas production without overloading the process. However, as the algorithm was based on a fixed biogas yield parameter and only used the biogas parameter for optimization, it could not distinguish between the decreases of biogas production from inhibition and from lower organic content in the substrate, which resulted in undesired decreasing of the control gas setpoint when the substrate was diluted. It was necessary to adjust the yield parameter in order to get this control approach to function properly, which is not suitable for the full-scale biogas plant where the organic content of waste streams can vary. An alternative approach could be a modified rule-based algorithm that includes VFA parameters to help distinguish between different process scenarios.

  11. How Employee Turnover Affects Productivity

    DEFF Research Database (Denmark)

    Eriksen, Bo

    Research on employee turnover suggests that turnover results in negative organization-level outcomes. This paper provides a firm-level analysis of the impact of the in- and outflows of human resources on productivity and how the presence of organizational slack resources moderates the effects...... of employee turnover. Drawing on a unique longitudinal dataset of 2,926 Danish manufacturing firms that combine individual-level data with firm-level data, the paper shows that job turnover has a substantial negative effect on total productivity but that the firm’s size, its capital intensity, and its age...

  12. Quantification of isotopic turnover in agricultural systems

    Science.gov (United States)

    Braun, A.; Auerswald, K.; Schnyder, H.

    2012-04-01

    The isotopic turnover, which is a proxy for the metabolic rate, is gaining scientific importance. It is quantified for an increasing range of organisms, from microorganisms over plants to animals including agricultural livestock. Additionally, the isotopic turnover is analyzed on different scales, from organs to organisms to ecosystems and even to the biosphere. In particular, the quantification of the isotopic turnover of specific tissues within the same organism, e.g. organs like liver and muscle and products like milk and faeces, has brought new insights to improve understanding of nutrient cycles and fluxes, respectively. Thus, the knowledge of isotopic turnover is important in many areas, including physiology, e.g. milk synthesis, ecology, e.g. soil retention time of water, and medical science, e.g. cancer diagnosis. So far, the isotopic turnover is quantified by applying time, cost and expertise intensive tracer experiments. Usually, this comprises two isotopic equilibration periods. A first equilibration period with a constant isotopic input signal is followed by a second equilibration period with a distinct constant isotopic input signal. This yields a smooth signal change from the first to the second signal in the object under consideration. This approach reveals at least three major problems. (i) The input signals must be controlled isotopically, which is almost impossible in many realistic cases like free ranging animals. (ii) Both equilibration periods may be very long, especially when the turnover rate of the object under consideration is very slow, which aggravates the first problem. (iii) The detection of small or slow pools is improved by large isotopic signal changes, but large isotopic changes also involve a considerable change in the input material; e.g. animal studies are usually carried out as diet-switch experiments, where the diet is switched between C3 and C4 plants, since C3 and C4 plants differ strongly in their isotopic signal. The

  13. Global Distribution of Root Turnover in Terrestrial Ecosystems

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Estimates of root turnover rates were calculated from measurements of live root standing crop and belowground net primary production (BNPP) compiled from...

  14. Relaxation of nonproductive binding and increased rate of coenzyme release in an alcohol dehydrogenase increases turnover with a nonpreferred alcohol enantiomer.

    Science.gov (United States)

    Hamnevik, Emil; Enugala, Thilak Reddy; Maurer, Dirk; Ntuku, Siphosethu; Oliveira, Ana; Dobritzsch, Doreen; Widersten, Mikael

    2017-11-01

    Alcohol dehydrogenase A (ADH-A) from Rhodococcus ruber DSM 44541 is a promising biocatalyst for redox transformations of arylsubstituted sec-alcohols and ketones. The enzyme is stereoselective in the oxidation of 1-phenylethanol with a 300-fold preference for the (S)-enantiomer. The low catalytic efficiency with (R)-1-phenylethanol has been attributed to nonproductive binding of this substrate at the active site. Aiming to modify the enantioselectivity, to rather favor the (R)-alcohol, and also test the possible involvement of nonproductive substrate binding as a mechanism in substrate discrimination, we performed directed laboratory evolution of ADH-A. Three targeted sites that contribute to the active-site cavity were exposed to saturation mutagenesis in a stepwise manner and the generated variants were selected for improved catalytic activity with (R)-1-phenylethanol. After three subsequent rounds of mutagenesis, selection and structure-function analysis of isolated ADH-A variants, we conclude: (a) W295 has a key role as a structural determinant in the discrimination between (R)- and (S)-1-phenylethanol and a W295A substitution fundamentally changes the stereoselectivity of the protein. One observable effect is a faster rate of NADH release, which changes the rate-limiting step of the catalytic cycle from coenzyme release to hydride transfer. (b) The obtained change in enantiopreference, from the (S)- to the (R)-alcohol, can be partly explained by a shift in the nonproductive substrate-binding modes. Structural data are available in the Protein Data Bank with accession codes 5o8q for A2, 5o8h for A2C2, 5o9f for A2C3, and 5o9d for A2C2B1. © 2017 Federation of European Biochemical Societies.

  15. Electron spray ionization mass spectrometry and 2D {sup 31}P NMR for monitoring {sup 18}O/{sup 16}O isotope exchange and turnover rates of metabolic oligophosphates

    Energy Technology Data Exchange (ETDEWEB)

    Nemutlu, Emirhan [Mayo Clinic, Division of Cardiovascular Diseases, Department of Medicine, Rochester, MN (United States); University of Hacettepe, Department of Analytical Chemistry, Faculty of Pharmacy, Ankara (Turkey); Juranic, Nenad; Macura, Slobodan [Mayo Clinic, Department of Biochemistry and Molecular Biology, Rochester, MN (United States); Mayo Clinic, Analytical NMR Core Facility, Rochester, MN (United States); Zhang, Song; Terzic, Andre; Dzeja, Petras P. [Mayo Clinic, Division of Cardiovascular Diseases, Department of Medicine, Rochester, MN (United States); Ward, Lawrence E. [Mayo Clinic, CTSA Metabolomic Core Facility, Rochester, MN (United States); Dutta, Tumpa; Nair, K.S. [Mayo Clinic, CTSA Metabolomic Core Facility, Rochester, MN (United States); Mayo Clinic, Division of Endocrinology and Endocrine Research Unit, Rochester, MN (United States)

    2012-05-15

    A new method was here developed for the determination of {sup 18}O-labeling ratios in metabolic oligophosphates, such as ATP, at different phosphoryl moieties ({alpha}-, {beta}-, and {gamma}-ATP) using sensitive and rapid electrospray ionization mass spectrometry (ESI-MS). The ESI-MS-based method for monitoring of {sup 18}O/{sup 16}O exchange was validated with gas chromatography-mass spectrometry and 2D {sup 31}P NMR correlation spectroscopy, the current standard methods in labeling studies. Significant correlation was found between isotopomer selective 2D {sup 31}P NMR spectroscopy and isotopomer less selective ESI-MS method. Results demonstrate that ESI-MS provides a robust analytical platform for simultaneous determination of levels, {sup 18}O-labeling kinetics and turnover rates of {alpha}-, {beta}-, and {gamma}-phosphoryls in ATP molecule. Such method is advantageous for large scale dynamic phosphometabolomic profiling of metabolic networks and acquiring information on the status of probed cellular energetic system. (orig.)

  16. Managing voluntary turnover through challenging assignments

    NARCIS (Netherlands)

    Preenen, P.T.Y.; de Pater, I.E.; van Vianen, A.E.M.; Keijzer, L.

    2011-01-01

    This study examines employees’ challenging assignments as manageable means to reduce turnover intentions, job search behaviors, and voluntary turnover. Results indicate that challenging assignments are negatively related to turnover intentions and job search behaviors and that these relationships

  17. Managing voluntary turnover through challenging assignments

    NARCIS (Netherlands)

    Preenen, P.T.Y.; Pater, I.E. de; Vianen, A.E.M. van; Keijzer, L.

    2011-01-01

    This study examines employees' challenging assignments as manageable means to reduce turnover intentions, job search behaviors, and voluntary turnover. Results indicate that challenging assignments are negatively related to turnover intentions and job search behaviors and that these relationships

  18. Work and Career considerations in Understanding Employee Turnover Intentions and Turnover: Development of the Turnover Diagnostic.

    Science.gov (United States)

    1984-08-01

    researchers have noted that organizations perceived not to link rewards to performance had higher turnover ( Hellriegel & White, 1973; Hulln, 1966, 1968...Telly, French, & Scott, 1971). Similarly, some company policy and administrative Issues related to pay and promotion ( Hellriegel & White, 1973...practices are a strong correlate of turnover (Dansereau, Cashman, & Graen, 1973; Fleishman & Harris, 1962; Graen & Ginsburgh, 1977; Hellriegel & White

  19. Collagen turnover after tibial fractures

    DEFF Research Database (Denmark)

    Joerring, S; Krogsgaard, M; Wilbek, H

    1994-01-01

    Collagen turnover after tibial fractures was examined in 16 patients with fracture of the tibial diaphysis and in 8 patients with fracture in the tibial condyle area by measuring sequential changes in serological markers of turnover of types I and III collagen for up to 26 weeks after fracture....... The markers were the carboxy-terminal extension peptide of type I procollagen (PICP), the amino-terminal extension peptide of type III procollagen (PIIINP), and the pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP). The latter is a new serum marker of degradation of type I...... collagen. A group comparison showed characteristic sequential changes in the turnover of types I and III collagen in fractures of the tibial diaphysis and tibial condyles. The turnover of type III collagen reached a maximum after 2 weeks in both groups. The synthesis of type I collagen reached a maximum...

  20. [Turnover Experience of Male Nurses].

    Science.gov (United States)

    Kim, Hyunsu; Lee, Jeongseop

    2017-02-01

    The aim of this study was to identify turnover experiences of men in nursing and to derive a substantive theory on the turnover experience of men who are nurses. Data were collected through in-depth interviews with 13 men who had worked as a nurse for 1 year or more, and had a turnover experience during that period. Collected data were analyzed on the basis of Strauss and Corbin's grounded theory. The core category in the turnover experiences of the respondents was 'seeking a stable place for me'. In the analysis of the core category, types of 'contentment', 'seeking', 'survival' and 'confusion' were identified. The sequential stages of these nurses' turnover experience were 'confrontation', 'incertitude', 'retrying' and 'realization'. However, when a problem arose in the process, they returned to the stage of confusion. Thus, these stages could occur in a circular fashion. These findings provide a deep understanding of the turnover experience of men in nursing and offers new information about how they adapt to nursing practice. The findings should be useful as foundational data for men who hope to become nurses and also for managers responsible for nurses who are men.

  1. Job turnover and regional attrition among physiotherapists in northern Ontario.

    Science.gov (United States)

    Noh, S; Beggs, C E

    1993-01-01

    Results of an initial study indicated that the most significant factor affecting retention for Physiotherapists in Northern Ontario was perceived opportunity for career development. A follow-up study was completed two years later to determine: 1) actual job turnover and regional attrition among physiotherapists in Northern Ontario; and 2) the predictive validity of variables identified in the first study regarding job turnover and regional attrition. Job turnover occurred in 29.5% of those sampled and the regional attrition rate was 12%. Discriminant function analysis revealed factors affecting job turnover and regional attrition including professional experience, practice location, opportunity for career development and size of community of residence. Based on previous intention, indicated by participants, follow-up revealed that the initial study correctly predicted 77.5% of those who changed their jobs and 74.1% of those who left Northern Ontario. Identified factors provide direction for the development of strategies for recruitment and retention of physiotherapists.

  2. Quantitative analysis of protein turnover in plants.

    Science.gov (United States)

    Nelson, Clark J; Li, Lei; Millar, A Harvey

    2014-03-01

    Proteins are constantly being synthesised and degraded as plant cells age and as plants grow, develop and adapt the proteome. Given that plants develop through a series of events from germination to fruiting and even undertake whole organ senescence, an understanding of protein turnover as a fundamental part of this process in plants is essential. Both synthesis and degradation processes are spatially separated in a cell across its compartmented structure. The majority of protein synthesis occurs in the cytosol, while synthesis of specific components occurs inside plastids and mitochondria. Degradation of proteins occurs in both the cytosol, through the action of the plant proteasome, and in organelles and lytic structures through different protease classes. Tracking the specific synthesis and degradation rate of individual proteins can be undertaken using stable isotope feeding and the ability of peptide MS to track labelled peptide fractions over time. Mathematical modelling can be used to follow the isotope signature of newly synthesised protein as it accumulates and natural abundance proteins as they are lost through degradation. Different technical and biological constraints govern the potential for the use of (13)C, (15)N, (2)H and (18)O for these experiments in complete labelling and partial labelling strategies. Future development of quantitative protein turnover analysis will involve analysis of protein populations in complexes and subcellular compartments, assessing the effect of PTMs and integrating turnover studies into wider system biology study of plants. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. High efficient ethanol and VFA production from gas fermentation: effect of acetate, gas and inoculum microbial composition

    DEFF Research Database (Denmark)

    El-Gammal, Maie; Abou-Shanab, Reda; Angelidaki, Irini

    2017-01-01

    In bioindustry, syngas fermentation is a promising technology for biofuel production without the use of plant biomass as sugar-based feedstock. The aim of this study was to identify optimal conditions for high efficient ethanol and volatile fatty acids (VFA) production from synthetic gas...... fermentation. Therefore, the effect of different gases (pure CO, H2, and a synthetic syngas mixture), media (acetate medium and acetate-free medium), and biocatalyst (pure and mixed culture) were studied. Acetate was the most dominant product independent on inoculum type. The maximum concentration of volatile...... fatty acids and ethanol was achieved by the pure culture (Clostridium ragsdalei). Depending on the headspace gas composition, VFA concentrations were up to 300% higher after fermentation with Clostridium ragsdalei compared to fermentation with mixed culture. The preferred gas composition with respect...

  4. Listening to the Voices of Children in Foster Care: Youths Speak out about Child Welfare Workforce Turnover and Selection

    Science.gov (United States)

    Strolin-Goltzman, Jessica; Kollar, Sharon; Trinkle, Joanne

    2010-01-01

    Child welfare workforce turnover rates across private and public child welfare agencies are concerning. Although research about the causes of child welfare workforce turnover has been plentiful, empirical studies on the effects of turnover on child outcomes are sparse. Furthermore, the voices and experiences of youths within the system have been…

  5. Health insurance, cost expectations, and adverse job turnover.

    Science.gov (United States)

    Ellis, Randall P; Albert Ma, Ching-To

    2011-01-01

    Because less healthy employees value health insurance more than the healthy ones, when health insurance is newly offered job turnover rates for healthier employees decline less than turnover rates for the less healthy. We call this adverse job turnover, and it implies that a firm's expected health costs will increase when health insurance is first offered. Health insurance premiums may fail to adjust sufficiently fast because state regulations restrict annual premium changes, or insurers are reluctant to change premiums rapidly. Even with premiums set at the long run expected costs, some firms may be charged premiums higher than their current expected costs and choose not to offer insurance. High administrative costs at small firms exacerbate this dynamic selection problem. Using 1998-1999 MEDSTAT MarketScan and 1997 Employer Health Insurance Survey data, we find that expected employee health expenditures at firms that offer insurance have lower within-firm and higher between-firm variance than at firms that do not. Turnover rates are systematically higher in industries in which firms are less likely to offer insurance. Simulations of the offer decision capturing between-firm health-cost heterogeneity and expected turnover rates match the observed pattern across firm sizes well. 2010 John Wiley & Sons, Ltd.

  6. Job turnover and labor turnover : a taxonomy of employment dynamics

    NARCIS (Netherlands)

    Hassink, Wolter H.J.; Hamermesh, Daniel S.

    1994-01-01

    We present an organized set of stylized facts on the relations among flows of workers,changes in employment and changes in the numer of jobs at the firm level. Job turnover isusually measured by comparing stocks of employment in each firm at two points in time andadding up the absolute employment

  7. Protein turnover methods in single-celled organisms: dynamic SILAC.

    Science.gov (United States)

    Claydon, Amy J; Beynon, Robert J

    2011-01-01

    Early achievements in proteomics were qualitative, typified by the identification of very small quantities of proteins. However, as the subject has developed, there has been a pressure to develop approaches to define the amounts of each protein--whether in a relative or an absolute sense. A further dimension to quantitative proteomics embeds the behavior of each protein in terms of its turnover. Virtually every protein in the cell is in a dynamic state, subject to continuous synthesis and degradation, the relative rates of which control the expansion or the contraction of the protein pool, and the absolute values of which dictate the temporal responsiveness of the protein pool. Strategies must therefore be developed to assess the turnover of individual proteins in the proteome. Because a protein can be turning over rapidly even when the protein pool is in steady state, the only acceptable approach to measure turnover is to use metabolic labels that are incorporated or lost from the protein pool as it is replaced. Using metabolic labeling on a proteome-wide scale in turn requires metabolic labels that contain stable isotopes, the incorporation or loss of which can be assessed by mass spectrometry. A typical turnover experiment is complex. The choice of metabolic label is dictated by several factors, including abundance in the proteome, metabolic redistribution of the label in the precursor pool, and the downstream mass spectrometric analytical protocols. Key issues include the need to control and understand the relative isotope abundance of the precursor, the optimization of label flux into and out of the protein pool, and a sampling strategy that ensures the coverage of the greatest range of turnover rates. Finally, the informatics approaches to data analysis will not be as straightforward as in other areas of proteomics. In this chapter, we will discuss the principles and practice of workflow development for turnover analysis, exemplified by the development of

  8. Employee Turnover in MFIs: Reasons & Remedies

    OpenAIRE

    Sk. Mahmudul Alam, Mahmud

    2015-01-01

    At present day’s employee turnover is one of the challenging issues in microfinance sector of Bangladesh. Excessive turnover is not only pricey, but it can create a bad reputation in the MFI sector and among the job seekers. Excessive turnover may be harmful to an MFI's productivity if experienced and efficient employees are often departing and the employee encompasses a high percentage of beginners. The impact of turnover has received substantial attention by the senior management and human ...

  9. Optimization and evaluation of reference region variable flip angle (RR-VFA) B1+ and T1 Mapping in the Prostate at 3T.

    Science.gov (United States)

    Rangwala, Novena A; Dregely, Isabel; Wu, Holden H; Sung, Kyunghyun

    2017-03-01

    To optimize and evaluate the reference region variable flip angle (RR-VFA) technique for simultaneous B1+ and T1 mapping of the prostate at 3 Tesla (T). The fat region surrounding the prostate was first identified using a fractional fat segmentation constant (tF ) and a signal fat-fraction threshold (rF ), and the relative flip angle (FA) was characterized using an effective fat T1 (T1f ) within the fat region. Optimal values of tF , rF , and T1f were chosen by comparing relative FA maps using RR-VFA (ARR-VFA ) with a reference relative FA maps (AREF ) in the surrounding fat and evaluating interpolation errors within the prostate. The optimized RR-VFA was evaluated in volunteers at 3T on a single scanner (n = 10) and across three scanners (n = 4). tF , rF and T1f were optimized as 0.5, 90%, and 320 ms, respectively. Prostate ARR-VFA showed differences of 30% among volunteers on one scanner, with no significant differences between ARR-VFA and AREF (P = 0.41). Prostate T1 after B1+ correction was 1998 ± 113 ms with significantly (P = 0.004) lower standard deviation than T1 before B1+ correction. The average coefficient of variation of prostate T1 across multiple scanners decreased from 15% to 5% after B1+ correction. The optimized RR-VFA can simultaneously measure B1+ and T1 in the prostate without the need for an additional scan and improve T1 consistency within and across MRI scanners at 3T. 3 J. Magn. Reson. Imaging 2017;45:751-760. © 2016 International Society for Magnetic Resonance in Medicine.

  10. Nurse Knowledge, Work Environment, and Turnover in Highly Specialized Pediatric End-of-Life Care.

    Science.gov (United States)

    Lindley, Lisa C; Cozad, Melanie J

    2017-07-01

    To examine the relationship between nurse knowledge, work environment, and registered nurse (RN) turnover in perinatal hospice and palliative care organizations. Using nurse intellectual capital theory, a multivariate analysis was conducted with 2007 National Home and Hospice Care Survey data. Perinatal hospice and palliative care organizations experienced a 5% turnover rate. The professional experience of advanced practice nurses (APNs) was significantly related to turnover among RNs (β = -.032, P < .05). Compared to organizations with no APNs professional experience, clinical nurse specialists and nurse practitioners significantly reduced RN turnover by 3 percentage points. No other nurse knowledge or work environment variables were associated with RN turnover. Several of the control variables were also associated with RN turnover in the study; Organizations serving micropolitan (β = -.041, P < .05) and rural areas (β = -.037, P < .05) had lower RN turnover compared to urban areas. Organizations with a technology climate where nurses used electronic medical records had a higher turnover rate than those without (β = .036, P < .05). The findings revealed that advanced professional experience in the form of APNs was associated with reductions in RN turnover. This suggests that having a clinical nurse specialist or nurse practitioner on staff may provide knowledge and experience to other RNs, creating stability within the organization.

  11. Acetate, lactate, propionate, and isobutyrate as electron donors for iron and sulfate reduction in Arctic marine sediments, Svalbard

    DEFF Research Database (Denmark)

    Finke, Niko; Vandieken, Verona; Jørgensen, Bo Barker

    2007-01-01

    . Inhibition of sulfate reduction with selenate resulted in the accumulation of acetate, propionate, and isobutyrate. The acetate turnover rates determined by radiotracer and accumulation after inhibition were similar. VFA turnover accounted for 21% and 52% of the mineralization through sulfate reduction...... by alternative e--donors. The accumulation of VFA in the selenate-inhibited 0-2 cm slurry did not enhance iron reduction, indicating that iron reducers were not limited by VFA availability....

  12. Nursing Home Staff Turnover: Impact on Nursing Home Compare Quality Measures

    Science.gov (United States)

    Castle, Nicholas G.; Engberg, John; Men, Aiju

    2007-01-01

    Purpose: We used data from a large sample of nursing homes to examine the association between staff turnover and quality. Design and Methods: The staff turnover measures came from primary data collected from 2,840 nursing homes in 2004 (representing a 71% response rate). Data collection included measures for nurse aides, licensed practical nurses,…

  13. The Teacher Labour Market, Teacher Turnover and Disadvantaged Schools: New Evidence for England

    Science.gov (United States)

    Allen, Rebecca; Burgess, Simon; Mayo, Jennifer

    2018-01-01

    We study the market for teachers in England, in particular teacher turnover. We show that there is a positive raw association between the level of school disadvantage and the turnover rate of its teachers. This association diminishes as we control for school, pupil and local teacher labour market characteristics, but is not eliminated. The…

  14. Investigating the adequacy of the Competence-Turnover Intention Model: how does nursing competence affect nurses' turnover intention?

    Science.gov (United States)

    Takase, Miyuki; Teraoka, Sachiko; Kousuke, Yabase

    2015-03-01

    The aim of this study was to test the adequacy of the Competence-Turnover Intention Model, which was developed to identify how nursing competence could affect nurses' turnover intention (nurses' intention to voluntarily leave an organisation). Recent studies have suggested that the level of nursing competence is negatively related to nurses' intention to leave their jobs, suggesting that a lack of competence threatens both the quality and quantity of the nursing workforce. However, the mechanism of how nursing competence affects nurses' turnover intention has not been explored previously. A cross-sectional survey design was used. Surveys were distributed to 1337 Japanese registered nurses/midwives in October, 2013. The adequacy of the model was analysed using structural equation modelling. In total, 766 questionnaires were returned, with a return rate of 57%. The model fitted well with the data. The results showed that the level of nursing competence was related positively to the quantity of organisational rewards they felt they had received, and negatively related to the level of exhaustion they experienced. Moreover, the perceived organisational rewards and exhaustion were correlated with nurses' turnover intention through affective commitment. The Competence-Turnover Intention Model is useful for explaining how nursing competence impacts on their turnover intention. Clinical implications derived from the findings are that: promoting nursing competence is key to improving not only the quality of care provided by nurses, but also to retaining the nursing workforce, and the model can be used to develop strategies that would mitigate their turnover intention. © 2014 John Wiley & Sons Ltd.

  15. The rapid yet uneven turnover of Earth's groundwater

    Science.gov (United States)

    Befus, Kevin M.; Jasechko, Scott; Luijendijk, Elco; Gleeson, Tom; Bayani Cardenas, M.

    2017-06-01

    The turnover of groundwater through recharge drives many processes throughout Earth's surface and subsurface. Yet groundwater turnover rates and their relationship to regional climate and geology remain largely unknown. We estimated that over 200 × 106 km3 of groundwater has recharged since the Last Glacial Maximum (LGM), which is 10 times the volume of global groundwater storage. However, flushing is very unevenly distributed throughout Earth's one million watersheds, with some aquifers turned over thousands of times to others with global groundwater turnover of 5 ± 3 times since the LGM highlights groundwater's active role in Earth system processes. Incomplete groundwater turnover since the LGM beneath a third of land areas reveals the imprint of relict climate conditions on modern-day groundwater resources. The bulk groundwater turnover calculated here enables better quantification of groundwater's impact in dynamic global water budgets and the transport of nutrients, contaminants, and geologic weathering products.Plain Language SummaryThe duration groundwater spends in an aquifer sets how long it is sequestered from the rest of the hydrologic cycle, where it can interact with the surrounding matrix and transport dissolved chemicals to and from the land surface. Over geologic timescales, these interactions transform landscapes, affect global climate, and regulate water resource sustainability and quality. We present how much groundwater has recharged since the Last Glacial Maximum and where groundwater on Earth is associated with previous climate conditions.

  16. Epitope mapping of recombinant Leishmania donovani virulence factor A2 (recLdVFA2 and canine leishmaniasis diagnosis using a derived synthetic bi-epitope.

    Directory of Open Access Journals (Sweden)

    Thais Melo Mendes

    2017-05-01

    Full Text Available Leishmaniasis is one of the most important zoonotic diseases spread in Latin America. Since many species are involved in dog infection with different clinical manifestations, the development of specific diagnostic tests is mandatory for more accurate disease control and vaccine strategies.Seventy-five 15-mer peptides covering the sequence of recombinant Leishmania donovani virulence factor A2 (recLdVFA2 protein were prepared by Spot synthesis. Membrane-bound peptides immunoreactivity with sera from dogs immunized with recLdVFA2 and with a specific anti-recLdVFA2 monoclonal antibody allowed mapping of continuous B-cell epitopes. Five epitopes corresponding to the N-terminal region of recLdVFA2 (MKIRSVRPLVVLLVC, RSVRPLVVLLVCVAA, RPLVVLLVCVAAVLA, VVLLVCVAAVLALSA and LVCVAAVLALSASAE, region 1-28 and one located within the repetitive units (PLSVGPQAVGLSVG, regions 67-81 and 122-135 were identified. A 34-mer recLdVFA2-derived bi-epitope containing the sequence MKIRSVRPLVVLLVC linked to PLSVGPQAVGLSVG by a Gly-Gly spacer was chemically synthesized in its soluble form. The synthetic bi-epitope was used as antigen to coat ELISA plates and assayed with dog sera for in vitro diagnosis of canine visceral leishmaniasis (CVL. The assay proved to be highly sensitive (98% and specific (99%.Our work suggests that synthetic peptide-based ELISA strategy may be useful for the development of a sensitive and highly specific serodiagnosis for CVL or other parasitic diseases.

  17. Dynamics of Adipocyte Turnover in Humans

    Energy Technology Data Exchange (ETDEWEB)

    Spalding, K; Arner, E; Westermark, P; Bernard, S; Buchholz, B; Bergmann, O; Blomqvist, L; Hoffstedt, J; Naslund, E; Britton, T; Concha, H; Hassan, M; Ryden, M; Frisen, J; Arner, P

    2007-07-16

    Obesity is increasing in an epidemic fashion in most countries and constitutes a public health problem by enhancing the risk for cardiovascular disease and metabolic disorders such as type 2 diabetes. Owing to the increase in obesity, life expectancy may start to decrease in developed countries for the first time in recent history. The factors determining fat mass in adult humans are not fully understood, but increased lipid storage in already developed fat cells is thought to be most important. We show that adipocyte number is a major determinant for the fat mass in adults. However, the number of fat cells stays constant in adulthood in lean and obese and even under extreme conditions, indicating that the number of adipocytes is set during childhood and adolescence. To establish the dynamics within the stable population of adipocytes in adults, we have measured adipocyte turnover by analyzing the integration of {sup 14}C derived from nuclear bomb tests in genomic DNA. Approximately 10% of fat cells are renewed annually at all adult ages and levels of body mass index. Neither adipocyte death nor generation rate is altered in obesity, suggesting a tight regulation of fat cell number that is independent of metabolic profile in adulthood. The high turnover of adipocytes establishes a new therapeutic target for pharmacological intervention in obesity.

  18. Measuring worker turnover in long-term care: lessons from the better jobs better care demonstration.

    Science.gov (United States)

    Barry, Theresa Teta; Kemper, Peter; Brannon, S Diane

    2008-06-01

    Turnover among direct-care workers (DCWs) continues to be a challenge in long-term care. Both policy makers and provider organizations recognize this issue as a major concern and are designing efforts to reduce turnover among these workers. However, there is currently no standardized method of measuring turnover to define the scope of the problem or to assess the effectiveness of interventions. This article draws on our experience of the Better Jobs Better Care Demonstration (BJBC) to explicate some important issues in measuring and interpreting turnover related to interventions designed to improve DCW jobs. We used turnover data from a selected group of BJBC providers (N = 9) to demonstrate some of the measurement issues we uncovered in developing a turnover tracking system for BJBC. We also illustrate how the data elements collected in the tracking system make it possible to construct measures that are useful at both policy and practice levels. Differences in definitions of turnover and the data elements used to construct the measure can have large effects on turn over rates, how they are used, and what they mean. Policy makers, researchers, and managers who need comparative turnover information to address the impending demand for DCWs should be aware that turnover measures differ, and they should take steps to ensure that measures they use have common definitions and data elements.

  19. On-call work and physicians' turnover intention: the moderating effect of job strain.

    Science.gov (United States)

    Heponiemi, Tarja; Presseau, Justin; Elovainio, Marko

    2016-01-01

    Physician shortage and turnover are major problems worldwide. On-call duties may be among the risk factors of high turnover rates among physicians. We investigated whether having on-call duties is associated with physicians' turnover intention and whether job strain variables moderate this association. The present study was a cross-sectional questionnaire study among 3324 (61.6% women) Finnish physicians. The analyses were conducted using analyses of covariance adjusted for age, gender, response format, specialization status and employment sector. The results showed that job strain moderated the association between being on-call and turnover intention. The highest levels of turnover intention were among those who had on-call duties and high level of job strain characterized by high demands and low control opportunities. The lowest levels of turnover intention were among those who were not on-call and who had low strain involving low demands and high control. Also, job demands moderated the association between being on-call and turnover intention; turnover intention levels were higher among those with on-call duties and high demands than those being on-call and low demands. To conclude, working on-call was related to physicians' turnover intention particularly in those with high job strain. Health care organizations should focus more attention on working arrangements and scheduling of on-call work, provide a suitable working pace and implement means to increase physicians' participation and control over their job.

  20. Semi-aerobic fermentation as a novel pre-treatment to obtain VFA and increase methane yield from primary sludge.

    Science.gov (United States)

    Peces, M; Astals, S; Clarke, W P; Jensen, P D

    2016-01-01

    There is a growing trend to consider organic wastes as potential sources of renewable energy and value-add products. Fermentation products have emerged as attractive value-add option due to relative easy production and broad application range. However, pre-fermentation and extraction of soluble products may impact down-stream treatment processes, particularly energy recovery by anaerobic digestion. This paper investigates primary sludge pre-fermentation at different temperatures (20, 37, 55, and 70°C), treatment times (12, 24, 48, and 72h), and oxygen availability (semi-aerobic, anaerobic); and its impact on anaerobic digestion. Pre-fermentation at 20 and 37°C succeeded for VFA production with acetate and propionate being major products. Pre-fermentation at 37, 55, and 70°C resulted in higher solubilisation yield but it reduced sludge methane potential by 20%. Under semi-aerobic conditions, pre-fermentation allowed both VFA recovery (43gCODVFAkg(-1)VS) and improved methane potential. The latter phenomenon was linked to fungi that colonised the sludge top layer during pre-fermentation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. KECENDERUNGAN KEPUASAN KERJA SEBAGAI TRIGGER TURNOVER

    Directory of Open Access Journals (Sweden)

    Raditya Adi Saputra

    2017-06-01

    Full Text Available The purpose of this study are: (1 To determine the effect of job satisfaction on turnover intention; (2 To determine the effect of work stress on turnover intention; (3 To determine the effect of compensation on turnover intention; (4 To determine the effect of organizational climate on turnover intention; and (5 To determine the stress of work, compensation, organizational climate and job satisfaction effect on turnover intention. The population in this study are employees of the Cooperative KOKAPURA AVIA totaling 180 people, while employees who have worked more than three years as many as 128 people. Samples were taken 97 people. The technique of collecting data using questionnaires. The analysis used is multiple regression analysis and path analysis using PLS 3.0 Smart program. Based on the results of the study concluded that: (1 Job satisfaction significantly influence employee turnover intention; (2 Work stress significantly influence employee turnover intention; (3 Compensation incentives significantly influence employee turnover intention; (4 organizational climate significantly influence employee turnover intention; and (5 Work stress, incentive compensation, organizational climate and job satisfaction simultaneously significantly influence employee turnover intention.

  2. Hybrid mathematical model of cardiomyocyte turnover in the adult human heart.

    Directory of Open Access Journals (Sweden)

    Jeremy A Elser

    Full Text Available The capacity for cardiomyocyte regeneration in the healthy adult human heart is fundamentally relevant for both myocardial homeostasis and cardiomyopathy therapeutics. However, estimates of cardiomyocyte turnover rates conflict greatly, with a study employing C14 pulse-chase methodology concluding 1% annual turnover in youth declining to 0.5% with aging and another using cell population dynamics indicating substantial, age-increasing turnover (4% increasing to 20%.Create a hybrid mathematical model to critically examine rates of cardiomyocyte turnover derived from alternative methodologies.Examined in isolation, the cell population analysis exhibited severe sensitivity to a stem cell expansion exponent (20% variation causing 2-fold turnover change and apoptosis rate. Similarly, the pulse-chase model was acutely sensitive to assumptions of instantaneous incorporation of atmospheric C14 into the body (4-fold impact on turnover in young subjects while numerical restrictions precluded otherwise viable solutions. Incorporating considerations of primary variable sensitivity and controversial model assumptions, an unbiased numerical solver identified a scenario of significant, age-increasing turnover (4-6% increasing to 15-22% with age that was compatible with data from both studies, provided that successive generations of cardiomyocytes experienced higher attrition rates than predecessors.Assignment of histologically-observed stem/progenitor cells into discrete regenerative phenotypes in the cell population model strongly influenced turnover dynamics without being directly testable. Alternatively, C14 trafficking assumptions and restrictive models in the pulse-chase model artificially eliminated high-turnover solutions. Nevertheless, discrepancies among recent cell turnover estimates can be explained and reconciled. The hybrid mathematical model provided herein permits further examination of these and forthcoming datasets.

  3. 'Memory and molecular turnover,' 30 years after inception.

    Science.gov (United States)

    Meagher, Richard B

    2014-01-01

    In 1984 Sir Francis Crick hypothesized that memory is recorded in the brain as reversible modifications to DNA and protein, but acknowledged that most biomolecules turn over too rapidly to account for long-term memories. To accommodate this possible paradox he modeled an enzymatic mechanism to maintain modifications on hemi-modified multimeric symmetrical molecules. While studies on the turnover of chromatin modifications that may be involved in memory are in their infancy, an exploration of his model in the light of modern epigenetics produced somewhat surprising results. The molecular turnover rates for two classes of chromatin modifications believed to record and store durable memories were approximated from experiments using diverse approaches and were found to be remarkably short. The half-lives of DNA cytosine methylation and post-translationally modified nucleosomal histones are measured in hours and minutes, respectively, for a subset of sites on chromatin controlling gene expression. It appears likely that the turnover of DNA methylation in the brain and in neurons, in particular, is even more rapid than in other cell types and organs, perhaps accommodating neuronal plasticity, learning, and memory. The machinery responsible for the rapid turnover of DNA methylation and nucleosomal histone modifications is highly complex, partially redundant, and appears to act in a sequence specific manner. Molecular symmetry plays an important part in maintaining site-specific turnover, but its particular role in memory maintenance is unknown. Elucidating Crick's paradox, the contradiction between rapid molecular turnover of modified biomolecules and long-term memory storage, appears fundamental to understanding cognitive function and neurodegenerative disease.

  4. Using Absenteeism and Performance To Predict Employee Turnover: Early Detection through Company Records.

    Science.gov (United States)

    Morrow, Paula C.; McElroy, James C.; Laczniak, Kathleen S.; Fenton, James B.

    1999-01-01

    Results of a comparison of 113 insurance company employees who left voluntarily with 113 who stayed supported a relationship between absenteeism, performance ratings, and voluntary turnover. There was no significant interaction effect. (SK)

  5. Sildenafil Stimulates Aqueous Humor Turnover in Rabbits

    Science.gov (United States)

    Alvarez, Lawrence J.; Zamudio, Aldo C.; Candia, Oscar A.

    2013-01-01

    Sildenafil citrate increases ocular blood flow and accelerates the rate of anterior chamber refilling after paracentesis. The latter effect could have resulted from a reduction in outflow facility or from an increase in aqueous humor (AH) production. In this study, we used scanning ocular fluorophotometry to examine the effects of sildenafil on AH turnover, and thus, AH production in eyes of live normal rabbits. For this, the rate of aqueous humor flow (AHF) was quantified with a commercially available fluorophotometer that measured the rate of fluorescein clearance from the anterior segment, which predominantly occurs via the trabecular meshwork. After ≈ 2 hrs of control scans to determine the baseline rate of AHF, the rabbits were fed 33 mg of sildenafil and allowed ≈ 45 min for the drug to enter the systemic circulation. Thereafter, fluorescence scans were retaken for an additional 90–120 min. Sildenafil ingestion increased AHF by about 36%, from 2.31 μL/min to 3.14 μL/min (PViagra, Revatio), stimulates AHF in rabbits. Our results seem consistent with reports indicating that the drug dilates intraocular arteries and augments intraocular vascular flow. These physiological responses to the agent apparently led to increased fluid entry into the anterior chamber. As such, the drug might have utility in patients with ocular hypotony resulting from insufficient AH formation. PMID:23562660

  6. Pattern and process in Amazon tree turnover, 1976-2001.

    Science.gov (United States)

    Phillips, O L; Baker, T R; Arroyo, L; Higuchi, N; Killeen, T J; Laurance, W F; Lewis, S L; Lloyd, J; Malhi, Y; Monteagudo, A; Neill, D A; Vargas, P Núñez; Silva, J N M; Terborgh, J; Martínez, R Vásquez; Alexiades, M; Almeida, S; Brown, S; Chave, J; Comiskey, J A; Czimczik, C I; Di Fiore, A; Erwin, T; Kuebler, C; Laurance, S G; Nascimento, H E M; Olivier, J; Palacios, W; Patiño, S; Pitman, N C A; Quesada, C A; Saldias, M; Lezama, A Torres; Vinceti, B

    2004-01-01

    Previous work has shown that tree turnover, tree biomass and large liana densities have increased in mature tropical forest plots in the late twentieth century. These results point to a concerted shift in forest ecological processes that may already be having significant impacts on terrestrial carbon stocks, fluxes and biodiversity. However, the findings have proved controversial, partly because a rather limited number of permanent plots have been monitored for rather short periods. The aim of this paper is to characterize regional-scale patterns of 'tree turnover' (the rate with which trees die and recruit into a population) by using improved datasets now available for Amazonia that span the past 25 years. Specifically, we assess whether concerted changes in turnover are occurring, and if so whether they are general throughout the Amazon or restricted to one region or environmental zone. In addition, we ask whether they are driven by changes in recruitment, mortality or both. We find that: (i) trees 10 cm or more in diameter recruit and die twice as fast on the richer soils of southern and western Amazonia than on the poorer soils of eastern and central Amazonia; (ii) turnover rates have increased throughout Amazonia over the past two decades; (iii) mortality and recruitment rates have both increased significantly in every region and environmental zone, with the exception of mortality in eastern Amazonia; (iv) recruitment rates have consistently exceeded mortality rates; (v) absolute increases in recruitment and mortality rates are greatest in western Amazonian sites; and (vi) mortality appears to be lagging recruitment at regional scales. These spatial patterns and temporal trends are not caused by obvious artefacts in the data or the analyses. The trends cannot be directly driven by a mortality driver (such as increased drought or fragmentation-related death) because the biomass in these forests has simultaneously increased. Our findings therefore indicate that

  7. Relationship between Job Satisfaction and Turnover Intention ...

    African Journals Online (AJOL)

    This study explores the association between job satisfaction and turnover intentions among lecturers in three public universities in Tanzania. It had three objectives: (1) to determine the level of perceived job satisfaction among lecturers; (2) to determine the association between job satisfaction and turnover intention; and (3) ...

  8. PENGARUH TEPUNG DAUN GAMAL DAN DAUN KELOR DALAM UREA CASSAVA BLOK (UCB TERHADAP KECERNAAN, KADAR VFA, DAN NH3 IN-VITRO

    Directory of Open Access Journals (Sweden)

    N M. WITARIADI

    2012-09-01

    Full Text Available ABSTRAK Penelitian telah dilakukan dengan tujuan untuk mendapatkan informasi tentang pengaruh tepung daun gamal dan daun kelor sebagai sumber protein dalam urea cassava blok (UCB terhadap kecernaan bahan kering, bahan organik, kadar VFA, dan NH3 cairan rumen pakan jerami padi secara invitro. Penelitian dilaksanakan dengan mempergunakan rancangan acak lengkap (RAL dengan 3 perlakuan dan 5 ulangan. Sehingga secara keseluruhan terdapat 15 unit penelitian. Adapun ketiga perlakuan tersebut adalah: Perlakuan A (jerami padi + UCB yang ditambah tepung daun kelor; B (jerami padi + UCB yang ditambah tepung daun gamal, dan C (jerami padi + UCB yang ditambah tepung daun kelor dan daun gamal. Varibel yang diamati adalah kecernaan bahan kering (KCBK , kecernaan bahan organik (KCBO in-vitro, produksi vollatile fatty acid (VFA, produksi NH3, dan pH supernatan. Hasil penelitian mendapatkan bahwa KCBK, KCBO invitro, VFA, NH3, dan pH supernatan pada ketiga perlakuan berbeda nyata (P<0,05. Penggunaan daun gamal sebagai sumber protein pada UCB menghasilkan KCBK, KCBO, VFA, NH3, tertinggi dibandingkan dengan daun kelor maupun kombinasi antara daun gamal dan daun kelor. EFFECT OF USING GLIRICIDIA (Gliricidia sepium AND MORINGA (Moringa oleifera LEAVES MEALS IN UREA CASSAVA BLOCK (UCB ON DIGESTIBILITY, VOLLATILE FATTY ACID, AND NH3 IN-VITRO. ABSTRACT The experiment has been conducted in order to now the effect of Gliricidia sepium and Moringa oleifera leaves meal a source of protein in urea cassava block (UCB to the digestibility dray matter and organic matter , VFA and ammonia concentration with rice straw diet. The experiment set in completely randomized design using three treatment. The treatment are: A (rise straw + UCB with Moringa; B (rise straw + UCB with Gliricidia sepium, and C (rise straw + UCB with Moringa and Gliricidia sepium. The observed variable are: dry matter, organic matter digestibility, volatile fatty acid, ammonia concentration, and pH rumen juice

  9. Microbial carbon turnover in the plant-rhizosphere-soil continuum

    Science.gov (United States)

    Malik, Ashish; Dannert, Helena; Griffiths, Robert; Thomson, Bruce; Gleixner, Gerd

    2014-05-01

    Soil microbial biomass contributes significantly to maintenance of soil organic matter (SOM). It is well known that biochemical fractions of soil microorganisms have varying turnover and therefore contribute differentially to soil C storage. Here we compare the turnover rates of different microbial biochemical fractions using a pulse chase 13CO2 plant labelling experiment. The isotope signal was temporally traced into rhizosphere soil microorganisms using the following biomarkers: DNA, RNA, fatty acids and chloroform fumigation extraction derived microbial biomass size classes. C flow into soil microbial functional groups was assessed through phospholipid and neutral lipid fatty acid (PLFA/NLFA) analyses. Highest 13C enrichment was seen in the low molecular weight (LMW) size class of microbial biomass (Δδ13C =151) and in nucleic acids (DNA: 38o RNA: 66) immediately after the pulse followed by a sharp drop. The amount of 13C in the high molecular weight (HMW) microbial biomass (17-81) and total fatty acids (32-54) was lower initially and stayed relatively steady over the 4 weeks experimental period. We found significant differences in turnover rates of different microbial biochemical and size fractions. We infer that LMW cytosolic soluble compounds are rapidly metabolized and linked to respiratory C fluxes, whereas mid-sized products of microbial degradation and HMW polymeric compounds have lower renewal rate in that order. The turnover of cell wall fatty acids was also very slow. DNA and RNA showed faster turnover rate; and as expected RNA renewal was the fastest due to its rapid production by active microorganisms independent of cell replication. 13C incorporation into different functional groups confirmed that mutualistic arbuscular mycorrhizal fungi rely on root C and are important in the initial plant C flux. We substantiated through measurements of isotope incorporation into bacterial RNA that rhizosphere bacteria are also important in the initial C conduit

  10. Turnover of nonessential fatty acids in cardiolipin from the rat heart

    Science.gov (United States)

    Wahjudi, Paulin N.; K. Yee, Jennifer; Martinez, Steven R.; Zhang, Jin; Teitell, Michael; Nikolaenko, Liana; Swerdloff, Ronald; Wang, Christina; Lee, W. N. Paul

    2011-01-01

    Cardiolipin (CL) is a unique phospholipid (PL) found in the mitochondria of mammalian cells. CL remodeling is accompanied by turnover of its fatty acid acyl groups. Abnormalities in CL remodeling have been found in Barth's syndrome, diabetes, and obesity. The objective of this study was to determine nonessential fatty acid turnover in CL and phosphatidylethanolamine (PE) in the rat heart in vivo. Sprague-Dawley rats were fed either a regular chow or a high-fat diet for 15 weeks, and consumed 6% deuterium-enriched drinking water as a tracer for 14 days. CL and PE were extracted from cardiac tissue and isolated by TLC. Fatty acids from CL, PE, and plasma were analyzed by GC/MS for deuterium incorporation. Results showed oleate and vaccenate turnover were the highest in CL whereas palmitate and stearate turnover were low. Among the nonessential fatty acids in PE, turnover of stearate and vaccenate were the highest. The high turnover rate in vaccenate was unexpected, because vaccenate previously had no known metabolic or physiologic function. In conclusion, the similarly high turnover rates of both oleate and vaccenate readily suggest that remodeling is an important functional aspect of PL metabolism in CL. PMID:21957203

  11. Radiocarbon dating reveals minimal collagen turnover in both healthy and osteoarthritic human cartilage

    DEFF Research Database (Denmark)

    Heinemeier, Katja M; Schjerling, Peter; Heinemeier, Jan

    2016-01-01

    The poor regenerative capacity of articular cartilage presents a major clinical challenge and may relate to a limited turnover of the cartilage collagen matrix. However, the collagen turnover rate during life is not clear, and it is debated whether osteoarthritis (OA) can influence it. Using......, no replacement of the collagen matrix happened after skeletal maturity and that neither OA nor tissue damage, per se, influenced collagen turnover. Regional differences in (14)C content across the joint surface showed that cartilage collagen located centrally on the joint surface is formed several years earlier...

  12. The validation of the turnover intention scale

    Directory of Open Access Journals (Sweden)

    Chris F.C. Bothma

    2013-01-01

    Full Text Available Orientation: Turnover intention as a construct has attracted increased research attention in the recent past, but there are seemingly not many valid and reliable scales around to measure turnover intention.Research purpose: This study focused on the validation of a shortened, six-item version of the turnover intention scale (TIS-6.Motivation for the study: The research question of whether the TIS-6 is a reliable and a valid scale for measuring turnover intention and for predicting actual turnover was addressed in this study.Research design, approach and method: The study was based on a census-based sample (n= 2429 of employees in an information, communication and technology (ICT sector company (N= 23 134 where the TIS-6 was used as one of the criterion variables. The leavers (those who left the company in this sample were compared with the stayers (those who remained in the employ of the company in this sample in respect of different variables used in the study.Main findings: It was established that the TIS-6 could measure turnover intentions reliably (α= 0.80. The TIS-6 could significantly distinguish between leavers and stayers (actual turnover, thereby confirming its criterion-predictive validity. The scale also established statistically significant differences between leavers and stayers in respect of a number of the remaining theoretical variables used in the study, thereby also confirming its differential validity. These comparisons were conducted for both the 4-month and the 4-year period after the survey was conducted.Practical/managerial implications: Turnover intention is related to a number of variables in the study which necessitates a reappraisal and a reconceptualisation of existing turnover intention models.Contribution/value-add: The TIS-6 can be used as a reliable and valid scale to assess turnover intentions and can therefore be used in research to validly and reliably assess turnover intentions or to

  13. AN ECONOMETRIC APPROACH ABOUT VOLUNTARY TURNOVER

    Directory of Open Access Journals (Sweden)

    ADALET EREN

    2013-06-01

    Full Text Available This study analyzes individual and organizational variables that affect voluntary turnover are determined in the special defence and security companies. A binomial logistic regression model is used to estimate voluntary turnover.  Binomial Logistic regression, reliability test (scale alfa, variance (ANOVA, Post-hoc/Tukey, correlation (Pearson and other basic statistical techniques  with SPSS 13 statistical packet program was used in the analyzes ofresearch data. The study finds that; situation of suppose working, number of child, number of death child, number of home’s moving, support of rent, total monthly income of household, last work’s region, number of prizes, affect voluntary turnover are determined.

  14. Collagen turnover in normal and degenerate human intervertebral discs as determined by the racemization of aspartic acid

    NARCIS (Netherlands)

    Sivan, S.-S.; Wachtel, E.; Tsitron, E.; Sakkee, N.; Ham, F. van der; Groot, J.de; Roberts, S.; Maroudas, A.

    2008-01-01

    Knowledge of rates of protein turnover is important for a quantitative understanding of tissue synthesis and catabolism. In this work, we have used the racemization of aspartic acid as a marker for the turnover of collagen obtained from healthy and pathological human intervertebral disc matrices. We

  15. Effects of role stress on nurses' turnover intentions: The mediating effects of organizational commitment and burnout.

    Science.gov (United States)

    Han, Sang-Sook; Han, Jeong-Won; An, Young-Suk; Lim, So-Hee

    2015-10-01

    This paper was designed to extend the extant research regarding factors related to nurses' turnover intentions. This survey-based study was based on a path analysis designed to verify a hypothesized causal model involving nurses' role stress, organizational commitment, turnover intentions, and burnout. This study distributed 500 questionnaires to nurses in general hospitals with more than 500 beds located in Seoul, Korea, during 16-30 April 2012. Role conflict, an underlying factor in role stress, had no significant effect on role stress, but the results showed that role ambiguity reduced organizational commitment. On the other hand, role conflict and role ambiguity increased the level of burnout. Organizational commitment reduced turnover intentions, and burnout increased turnover intentions. Role conflict and role ambiguity had no direct effect on turnover intentions, but they had indirect effects on organizational commitment and burnout. To reduce nurses' turnover rate, this study recommends developing plans to improve their organizational commitment because it mediates role stress and turnover intention. © 2014 The Authors. Japan Journal of Nursing Science © 2014 Japan Academy of Nursing Science.

  16. MHC class II protein turnover in vivo and its relevance for autoimmunity in nonobese diabetic mice

    Directory of Open Access Journals (Sweden)

    Robert eBusch

    2013-11-01

    Full Text Available MHCII proteins are loaded with endosomal peptides and reside at the surface of antigen-presenting cells (APCs for a time before being degraded. In vitro, MHCII protein levels and turnover are affected by peptide loading and by rates of ubiquitin-dependent internalization from the cell surface, which is in turn affected by APC type and activation state. Prior work suggested that fast turnover of disease-associated MHCII alleles may contribute to autoimmunity. We recently developed novel stable isotope tracer techniques to test this hypothesis in vivo. In nonobese diabetic (NOD mice, a model of type 1 diabetes (T1D, MHCII turnover was affected by APC type, but unaffected by disease-associated structural polymorphism. Differences in MHCII turnover were observed between NOD colonies with high and low T1D incidence, but fast turnover was dispensable for autoimmunity. Moreover, NOD mice with gene knockouts of peptide loading cofactors do not develop T1D. Thus, fast turnover does not appear pathogenic, and conventional antigen presentation is critical for autoimmunity in NOD mice. However, shared environmental factors may underpin colony differences in MHCII protein turnover, immune regulation, and pathogenesis.

  17. Impact of work environment and work-related stress on turnover intention in physical therapists

    OpenAIRE

    Lee, Byoung-kwon; Seo, Dong-kwon; Lee, Jang-Tae; Lee, A-Ram; Jeon, Ha-Neul; Han, Dong-Uk

    2016-01-01

    [Purpose] This study was conducted to provide basic data for solutions to reduce the turnover rate of physical therapists. It should help create efficient personnel and organization management by exploring the impact of the work environment and work-related stress on turnover intention and analyzing the correlation between them. [Subjects and Methods] A survey was conducted with 236 physical therapists working at medical institutions in the Daejeon and Chungcheong areas. For the analysis on t...

  18. Organisational Commitment, Job Satisfaction and Turnover ...

    African Journals Online (AJOL)

    This study investigated organisational commitment, job satisfaction and turnover intentions among records management personnel in Ondo State Civil Service, Akure, Nigeria. Simple random sampling technique was used to draw 240 subjects from a population size of 275 records management personnel.

  19. Effects of work environment and job characteristics on the turnover intention of experienced nurses: The mediating role of work engagement.

    Science.gov (United States)

    Wan, Qiaoqin; Li, Zhaoyang; Zhou, Weijiao; Shang, Shaomei

    2018-01-19

    To assess turnover intention among experienced nurses and explore the effects of work environment, job characteristics and work engagement on turnover intention. The nursing shortage is an urgent concern in China. A high turnover rate of experienced nurses could have serious effects on the quality of care, costs and the efficiency of hospitals. It is crucial to explore the predictors of turnover intention and develop strategies tailored to experienced nurses. A descriptive, cross-sectional survey design. A total of 778 experienced nurses from 7 hospitals was surveyed on their work engagement, job characteristics, work environment and turnover intention in March-May 2017. Structural equation modelling was used to test a theoretical model and the hypotheses. The results showed 35.9% of experienced nurses had high-level turnover intention. The final model explained 50% of the variance in experienced nurses' turnover intention and demonstrated that: (1) work environment was positively associated with higher work engagement and lower turnover intention and work engagement partially mediated the relationship between work environment and turnover intention; and (2) job characteristics were positively related to higher work engagement and lower turnover intention and work engagement fully mediated the relationship between job characteristics and turnover intention. The study confirms the intrinsic and extrinsic motivators on work engagement posited by job demands-resources model. Theory-driven strategies to improve work environment, enhance job characteristics and promote wok engagement are needed to address the nursing shortage and high turnover intention among experienced nurses. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  20. Kinetics of corneal epithelium turnover in vivo. Studies of lovastatin

    Energy Technology Data Exchange (ETDEWEB)

    Cenedella, R.J.; Fleschner, C.R. (Kirksville College of Osteopathic Medicine, MO (USA))

    1990-10-01

    The authors developed a direct chemical approach for estimating the rate of turnover of the corneal epithelium in vivo. The method was used to examine the effects of lovastatin, a potent inhibitor of cholesterol biosynthesis, on proliferation and turnover of the epithelium. Corneal DNA was labeled by pulse injection (IP) of the rat with 3H-thymidine, and 3H-labeled DNA was recovered from peripheral and central corneas over the next 15 days. Only the epithelium became labeled, and the loss of label by cell desquamation began 3 days after injection. The loss of 3H-DNA from the cornea (peripheral plus central region) followed first-order kinetics. The half-life of the disappearance was about 3 days. The peripheral cornea became more highly labeled than the central cornea and began to lose 3H-DNA before the central cornea. These observations support the possibility of a higher mitotic rate in the peripheral region and the centripetal movement of a population of peripheral epithelial cells in the normal cornea. The half-lives of the disappearance of 3H-DNA from peripheral and central corneas measured between days 5 and 15 postinjection were identical, both at 3 days. Complete turnover of the corneal epithelium would, therefore, require about 2 weeks (4-5 half-lives). Treatment of the rat with lovastatin had no obvious effects upon the proliferation or turnover of the corneal epithelium. Although lovastatin inhibited corneal 3-hydroxy-3-methylglutaryl coenzyme A reductase, the key regulatory enzyme of cholesterol synthesis, the cornea compensated by induction of this enzyme so that there was no net inhibition of cholesterol synthesis in the cornea.

  1. SNR efficiency of combined bipolar gradient echoes: Comparison of three-dimensional FLASH, MPRAGE, and multiparameter mapping with VFA-FLASH and MP2RAGE.

    Science.gov (United States)

    Jutras, Jean-David; Wachowicz, Keith; Gilbert, Guillaume; De Zanche, Nicola

    2017-06-01

    High-bandwidth bipolar multiecho gradient echo sequences are increasingly popular in structural brain imaging because of reduced water-fat shifts, lower susceptibility effects, and improved signal-to-noise ratio (SNR) efficiency. In this study, we investigated the performance of three three-dimensional multiecho sequences (MPRAGE, MP2RAGE, and FLASH) with scan times 3T. We also compared the performance of multiparameter mapping (PD, T1 , and T2*) with bipolar multiecho MP2RAGE versus the variable flip angle technique with multiecho FLASH (VFA-FLASH). Multiecho sequences were optimized to yield equivalent contrast and improved SNR compared with their single-echo counterparts. Theoretical SNR gains were verified with measurements in a multilayered phantom. Robust image processing pipelines extracted PD, T1 , and T2* maps from MP2RAGE or VFA-FLASH, and the corresponding SNR was measured with varying SENSE accelerations (R = 1-5) and number of echoes (N = 1-12). All sequences were tested on four healthy volunteers. Multiecho sequences achieved SNR gains of 1.3-1.6 over single-echo sequences. MP2RAGE yielded comparable T1 -to-noise ratio to VFA-FLASH, but significantly lower SNR (maps. Measured SNR gains agreed with the theoretical predictions for SENSE accelerations ≤3. Multiecho sequences achieve higher SNR efficiency over conventional single-echo sequences, despite three-fold higher sampling bandwidths. VFA-FLASH surpasses MP2RAGE in its ability to map three parameters with high SNR and 1-mm isotropic resolution in a clinically relevant scan time (∼8:30 min), whereas MP2RAGE yields lower intersubject variability in T1 . Magn Reson Med 77:2186-2202, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  2. Norepinephrine turnover in heart and spleen of 7-, 22-, and 34 C-acclimated hamsters

    Science.gov (United States)

    Jones, S. B.; Musacchia, X. J.

    1976-01-01

    The relationship of norepinephrine (NE) concentration and endogenous turnover rates in both myocardial and spleen tissues in the golden hamster is examined as a function of chronic exposure to either high or low ambient temperatures. Changes in myocardial and spleen NE turnover values are discussed in terms of functional alterations in sympathetic nerve activity and the importance of such changes in temperature acclimation. It is found that acclimation of hamsters to 7 C for 7-10 weeks results in decreased myocardial NE concentration and an apparent increase in myocardial NE turnover. In contrast, exposure to 34 C for 6-8 weeks results in increased myocardial NE concentration and an apparent decrease in NE turnover in both myocardial and spleen tissues. The implication of altered NE synthesis is that sympathetic nerve activity is reduced with heat acclimation and is enhanced with cold acclimation.

  3. New Insights into the Protein Turnover Regulation in Ethylene Biosynthesis.

    Science.gov (United States)

    Yoon, Gyeong Mee

    2015-07-01

    Biosynthesis of the phytohormone ethylene is under tight regulation to satisfy the need for appropriate levels of ethylene in plants in response to exogenous and endogenous stimuli. The enzyme 1-aminocyclopropane-1-carboxylic acid synthase (ACS), which catalyzes the rate-limiting step of ethylene biosynthesis, plays a central role to regulate ethylene production through changes in ACS gene expression levels and the activity of the enzyme. Together with molecular genetic studies suggesting the roles of post-translational modification of the ACS, newly emerging evidence strongly suggests that the regulation of ACS protein stability is an alternative mechanism that controls ethylene production, in addition to the transcriptional regulation of ACS genes. In this review, recent new insight into the regulation of ACS protein turnover is highlighted, with a special focus on the roles of phosphorylation, ubiquitination, and novel components that regulate the turnover of ACS proteins. The prospect of cross-talk between ethylene biosynthesis and other signaling pathways to control turnover of the ACS protein is also considered.

  4. Bone turnover markers: Emerging tool in the management of osteoporosis

    Directory of Open Access Journals (Sweden)

    Sahana Shetty

    2016-01-01

    Full Text Available Bone is a dynamic tissue which undergoes constant remodeling throughout the life span. Bone turnover is balanced with coupling of bone formation and resorption at various rates leading to continuous remodeling of bone. A study of bone turnover markers (BTMs provides an insight of the dynamics of bone turnover in many metabolic bone disorders. An increase in bone turnover seen with aging and pathological states such as osteoporosis leads to deterioration of bone microarchitecture and thus contributes to an increase in the risk of fracture independent of low bone mineral density (BMD. These microarchitectural alterations affecting the bone quality can be assessed by BTMs and thus may serve as a complementary tool to BMD in the assessment of fracture risk. A systematic search of literature regarding BTMs was carried out using the PubMed database for the purpose of this review. Various reliable, rapid, and cost-effective automated assays of BTMs with good sensitivity are available for the management of osteoporosis. However, BTMs are subjected to various preanalytical and analytical variations necessitating strict sample collection and assays methods along with utilizing ethnicity-based reference standards for different populations. Estimation of fracture risk and monitoring the adherence and response to therapy, which is a challenge in a chronic, asymptomatic disease such as osteoporosis, are the most important applications of measuring BTMs. This review describes the physiology of bone remodeling, various conventional and novel BTMs, and BTM assays and their role in the assessment of fracture risk and monitoring response to treatment with antiresorptive or anabolic agents.

  5. Turnover of Stable Isotopes Due to Growth and Metabolism in Zebrafish, Danio Rerio

    Science.gov (United States)

    Tarboush, R.; MacAvoy, S.; Macko, S.; Connaughton, V.

    2002-05-01

    Stable isotope ratios of carbon (13C/12C), nitrogen (15 N/14N) and sulfur (34S/32S) in animal tissues can be used as tracers of the nutrient sources of organisms' diets and determining trophic interactions in ecosystems. The isotopic turnover of these elements in a predator's tissues reflects the isotopic signature of the predator's diet (the prey). The rate at which an organism takes up the isotopic signature of its food is correlated with its growth rate and/or metabolism. Hence unless baseline isotopic turnover rates are known, the isotopic signature of a consumer may lead to misinterpretation of predator-prey relationships. Laboratory studies provide isotopic turnover rates of organisms under controlled conditions, which serve as models for understanding the rates at which organisms in the field isotopically incorporate new diets. This study examines the isotopic turnover rates of carbon, nitrogen and sulfur in response to a dietary switch in young zebrafish, Danio rerio. Zebrafish, raised on commercial fish food (8.2 ñ 0.5%, d34S; were fed a new, isotopically distinct diet (2.9 ñ 0.5%, d34S) and the rate at which zebra fish muscle tissues changed towards the isotopic signature of their new food was monitored. Preliminary results show a change in the fish sulfur isotope composition of roughly 0.03% per day towards the sulfur isotope ratio of the new food. At the observed turnover rate, approximately 180 days would be required for the zebrafish muscle tissue to resemble a new food. The study is also investigating the importance of growth versus metabolism as a predictor of isotope turnover rate in zebra fish tissues.

  6. Nurse turnover: the mediating role of burnout.

    Science.gov (United States)

    Leiter, Michael P; Maslach, Christina

    2009-04-01

    This study tested whether the mediation model of burnout could predict nurses' turnover intentions. A better understanding of what factors support a commitment to a nursing career could inform both policies and workplace practices. The mediation model of burnout provides a way of linking the quality of a nurse's worklife to various outcomes, such as turnover. Data on areas of worklife, burnout, and turnover intentions were collected by surveying 667 Canadian nurses in the Atlantic Provinces. The findings supported the mediation model of burnout, in which areas of worklife predicted burnout, which in turn predicted turnover intentions. Cynicism was the key burnout dimension for turnover, and the most critical areas of worklife were value conflicts and inadequate rewards. The results of this study provide some new insights into how the intention of nurses to leave their job is related to particular aspects of their worklife and to burnout. These results suggest what may be the most appropriate areas to target for interventions to reduce the risk of nurses exiting early from their chosen career.

  7. Impact of work environment and work-related stress on turnover intention in physical therapists.

    Science.gov (United States)

    Lee, Byoung-Kwon; Seo, Dong-Kwon; Lee, Jang-Tae; Lee, A-Ram; Jeon, Ha-Neul; Han, Dong-Uk

    2016-08-01

    [Purpose] This study was conducted to provide basic data for solutions to reduce the turnover rate of physical therapists. It should help create efficient personnel and organization management by exploring the impact of the work environment and work-related stress on turnover intention and analyzing the correlation between them. [Subjects and Methods] A survey was conducted with 236 physical therapists working at medical institutions in the Daejeon and Chungcheong areas. For the analysis on the collected data, correlational and linear regression analyses were conducted using the SPSS 18.0 program and Cronbach's alpha coefficient. [Results] The results showed a statistically significant positive correlation between turnover intention and work-related stress but a statistically significant negative correlation respectively between turnover intention and work environment. Work-related stress (β=0.415) had a significant positive impact on turnover intention and work environment (β=-0.387) had a significant negative impact on turnover intention. [Conclusion] To increase satisfaction level with the profession as well as the workplace for physical therapists, improvement of the work environment was the most necessary primary improvement.

  8. The Effect of Primary Care Provider Turnover on Patient Experience of Care and Ambulatory Quality of Care.

    Science.gov (United States)

    Reddy, Ashok; Pollack, Craig E; Asch, David A; Canamucio, Anne; Werner, Rachel M

    2015-07-01

    Primary care provider (PCP) turnover is common and can disrupt patient continuity of care. Little is known about the effect of PCP turnover on patient care experience and quality of care. To measure the effect of PCP turnover on patient experiences of care and ambulatory care quality. Observational, retrospective cohort study of a nationwide sample of primary care patients in the Veterans Health Administration (VHA). We included all patients enrolled in primary care at the VHA between 2010 and 2012 included in 1 of 2 national data sets used to measure our outcome variables: 326,374 patients in the Survey of Healthcare Experiences of Patients (SHEP; used to measure patient experience of care) associated with 8441 PCPs and 184,501 patients in the External Peer Review Program (EPRP; used to measure ambulatory care quality) associated with 6973 PCPs. Whether a patient experienced PCP turnover, defined as a patient whose provider (physician, nurse practitioner, or physician assistant) had left the VHA (ie, had no patient encounters for 12 months). Five patient care experience measures (from SHEP) and 11 measures of quality of ambulatory care (from EPRP). Nine percent of patients experienced a PCP turnover in our study sample. Primary care provider turnover was associated with a worse rating in each domain of patient care experience. Turnover was associated with a reduced likelihood of having a positive rating of their personal physician of 68.2% vs 74.6% (adjusted percentage point difference, -5.3; 95% CI, -6.0 to -4.7) and a reduced likelihood of getting care quickly of 36.5% vs 38.5% (adjusted percentage point difference, -1.1; 95% CI, -2.1 to -0.1). In contrast, PCP turnover was not associated with lower quality of ambulatory care except for a lower likelihood of controlling blood pressure of 78.7% vs 80.4% (adjusted percentage point difference, -1.44; 95% CI, -2.2 to -0.7). In 9 measures of ambulatory care quality, the difference between patients who experienced no

  9. The Magnitude, Destinations and Determinants of Mathematics and Science Teacher Turnover

    Science.gov (United States)

    Ingersoll, Richard; May, Henry

    2010-01-01

    The objective of this study is to use nationally representative data to examine the rates, destinations and sources of math and science teacher turnover. There are four sets of research questions the authors address concerning the departure of mathematics and science teachers from their schools: (1) At what rates do mathematics/science teachers…

  10. Development of hydraulic properties and nitrate turnover processes in minerotrophic fen soil on differnet scales

    Science.gov (United States)

    Kleimeier, Christian; Lennartz, Bernd

    2014-05-01

    Generally, it is recommended to remove the uppermost highly degraded peat layer from fens prior to rewetting to eliminate a potential source of organic pollutants for downstream water bodies. We investigated this material as a potential medium for denitrifying filters to further use the organic material. We are aiming to remove nitrate from tile drainage runoff at the outlet drainage dominated catchments to fullfill the requirements of the European Water Framework Directive. In a lysimeter scale long term mesocosm experiments we were aiming to reveal the peats behavior after disturbing and rewetting under constant flow conditions. Tracer experiments revealed a restructuring of the peat ending up at 20/80 percentage of mobile immobile pore volume. Additionally we observed the nitrate turnover. The turnover rate was determined by the hydraulic load. Absolute turnover rates were equal at lower and higher concentrations as well as flow rates, whereas the turnover reached higher percentages at lower concentrations. To further reveal the nitrate turnover processes flow through rector experiments were conducted in an anaerobic environment. We found that strongly reducing conditions can be created in peat even at the presence of nitrate. Thus we can conclude that the minerotrophic peat with its high iron and sulfur concentrations also enables autotrophic denitrification oxidizing iron and sulfur. While the conditions are favorable to re-reduce iron and sulfur,thus an electron shuttling system developed transporting electrons from the organic material as initial e- donor to nitrate as terminal e- acceptor.

  11. Duodenal juice total protein and pancreatic enzyme synthesis, turnover, and secretion in patients after acute pancreatitis.

    Science.gov (United States)

    Ogden, J M; O'Keefe, S J; Louw, J A; Adams, G; Marks, I N

    1993-09-01

    It is controversial whether acute pancreatitis has longterm effects on pancreatic function. Pancreatic enzyme synthesis, turnover, and secretion were measured in 10 patients in clinical remission who had had one or more (one to six) attacks of acute alcoholic pancreatitis. The studies were done between two and 29 months after the most recent attack. A control group included five patients with no evidence of pancreatic disease. A four hour primed/continuous intravenous infusion of [14C]L-leucine tracer was given with secretin (2 U/kg/h) and cholecystokinin (0.5 U/kg/h) and secreted duodenal juice aspirated. Amylase and trypsin were extracted from duodenal juice by affinity chromatography, permitting measurement of the rate of isotope incorporation into total protein, amylase, and trypsin. The results showed non-parallel changes in enzyme synthesis and turnover with decreases in total enzyme protein and amylase synthesis and turnover but preservation of trypsin synthesis and turnover. The low turnover rates may be ascribed to continuing pancreatic cell malfunction after recovery from acute alcoholic pancreatitis and suggest that the decreased amylase secretion rates are partly a consequence of impaired amylase synthesis and not simply because of loss of pancreatic tissue.

  12. Antecedents of Norwegian Beginning Teachers' Turnover Intentions

    Science.gov (United States)

    Tiplic, Dijana; Brandmo, Christian; Elstad, Eyvind

    2015-01-01

    This study aims at exploring several individual, organizational, and contextual factors that may affect beginning teachers' turnover intentions during their first years of practice. The sample consists of 227 beginning teachers (69% female and 31% male) from 133 schools in Norway. The results show four important antecedents of beginning teachers'…

  13. A Turnover Model for the Mexican Maquiladoras.

    Science.gov (United States)

    Maertz, Carl P.; Stevens, Michael J.; Campion, Michael A.

    2003-01-01

    From interviews with 47 Mexican maquiladora workers, a model of voluntary turnover was created and compared with models from the United States, Canada, England, and Australia. Despite similarities, the cultural and economic environment affected the precise content of antecedents in the Mexican model. (Contains 63 references.) (SK)

  14. Home Visitor Job Satisfaction and Turnover.

    Science.gov (United States)

    Buchbinder, Sharon B.; Duggan, Anne K.; Young, Elizabeth; Fuddy, Loretta; Sia, Cal

    This paper summarizes findings of a 3-year study of the job satisfaction and turnover of home visitors, both professional and paraprofessional, in programs which link families-at-risk for impaired functioning to medical home care and other resources. Specifically, the study examined: (1) home visitor personal characteristics that influence…

  15. Health care workplace discrimination and physician turnover.

    Science.gov (United States)

    Nunez-Smith, Marcella; Pilgrim, Nanlesta; Wynia, Matthew; Desai, Mayur M; Bright, Cedric; Krumholz, Harlan M; Bradley, Elizabeth H

    2009-12-01

    To examine the association between physician race/ ethnicity, workplace discrimination, and physician job turnover. Cross-sectional, national survey conducted in 2006-2007 of practicing physicians (n = 529) randomly identified via the American Medical Association Masterfile and the National Medical Association membership roster. We assessed the relationships between career racial/ethnic discrimination at work and several career-related dependent variables, including 2 measures of physician turnover, career satisfaction, and contemplation of career change. We used standard frequency analyses, odds ratios and chi2 statistics, and multivariate logistic regression modeling to evaluate these associations. Physicians who self-identified as nonmajority were significantly more likely to have left at least 1 job because of workplace discrimination (black, 29%; Asian, 24%; other race, 21%; Hispanic/Latino, 20%; white, 9%). In multivariate models, having experienced racial/ethnic discrimination at work was associated with high job turnover (adjusted odds ratio, 2.7; 95% CI, 1.4-4.9). Among physicians who experienced workplace discrimination, only 45% of physicians were satisfied with their careers (vs 88% among those who had not experienced workplace discrimination, p value workplace discrimination, p value Workplace discrimination is associated with physician job turnover, career dissatisfaction, and contemplation of career change. These findings underscore the importance of monitoring for workplace discrimination and responding when opportunities for intervention and retention still exist.

  16. University Lecturers' Professional Empowerment and Turnover in ...

    African Journals Online (AJOL)

    Hitherto, attention has not been paid to whether professional empowerment of the lecturers explains this phenomenon and whether it can help to curb it. Therefore, this study was conducted to analyse the level of professional empowerment provided to the lecturers and the way it relates to their turnover. Data was collected ...

  17. Developmental Climate: A Cross-level Analysis of Voluntary Turnover and Job Performance.

    Science.gov (United States)

    Spell, Hannah B; Eby, Lillian T; Vandenberg, Robert J

    2014-06-01

    This research investigates the influence of shared perceptions of developmental climate on individual-level perceptions of organizational commitment, engagement, and perceived competence, and whether these attitudes mediate the relationship between developmental climate and both individual voluntary turnover and supervisor-rated job performance. Survey data were collected from 361 intact employee-supervisory mentoring dyads and matched with employee turnover data collected one year later to test the proposed framework using multilevel modeling techniques. As expected, shared perceptions of developmental climate were significantly and positively related to all three individual work attitudes. In addition, both organizational commitment and perceived competence were significant mediators of the positive relationship between shared perceptions of developmental climate and voluntary turnover, as well as shared perceptions of developmental climate and supervisor-rated job performance. By contrast, no significant mediating effects were found for engagement. Theoretical implications, limitations, and future research are discussed.

  18. Developmental Climate: A Cross-level Analysis of Voluntary Turnover and Job Performance

    Science.gov (United States)

    Spell, Hannah B.; Eby, Lillian T.; Vandenberg, Robert J.

    2014-01-01

    This research investigates the influence of shared perceptions of developmental climate on individual-level perceptions of organizational commitment, engagement, and perceived competence, and whether these attitudes mediate the relationship between developmental climate and both individual voluntary turnover and supervisor-rated job performance. Survey data were collected from 361 intact employee-supervisory mentoring dyads and matched with employee turnover data collected one year later to test the proposed framework using multilevel modeling techniques. As expected, shared perceptions of developmental climate were significantly and positively related to all three individual work attitudes. In addition, both organizational commitment and perceived competence were significant mediators of the positive relationship between shared perceptions of developmental climate and voluntary turnover, as well as shared perceptions of developmental climate and supervisor-rated job performance. By contrast, no significant mediating effects were found for engagement. Theoretical implications, limitations, and future research are discussed. PMID:24748681

  19. Pemberian Pakan Serat Sisa Tanaman Pertanian (Jerami Kacang Tanah, Jerami Jagung, Pucuk Tebu Terhadap Evolusi pH, N-NH3 dan VFA Di dalam Rumen Sapi

    Directory of Open Access Journals (Sweden)

    Yunasri Usman

    2013-10-01

    Full Text Available (Feeding agricultural crop residues (groundnut straw, corn straw, sugarcane straw to the pH evolution, N-NH3 and VFA in the cow rumen ABSTRACT. The goal of this study is to evaluate the condition of fermentation in the rumen of cows by administration of 3 types of feed fiber agricultural crop residues (Groundnut Straw (GS, Corn Straw (CS and Sugarcane Tops (ST. Single feeding wascarried out at 2 Holstein Friesian Crossbred (HFC cows with the age of 4-5 by fistula rumen.This study was conducted 20 days and with a 14-dayadaptation period.At the end of the adaptation period, rumen fluid was collected to measure pH, N-NH3and VFA based on feed treatment percow.Collection of rumen fluid was simultanous conducted for 24 hours at 27 time points decision.The results of the experiment showed that the level of pH for GS, CS and ST was 7.02 + 0.29; 6.54 + 0.16 and 6.54 + 0.14 respectively. The level of N-NH3 was 4.90 + 2.10 mg/100 ml of rumen fluid; 7.36 + 3.10 mg/100 ml of rumen fluid; 2.26 + 0.85 mg/100 ml of rumen fluidfor GS, CS and ST, respectively. Meanwile, the level of VFA was 57.44 + 12.75 mmol/l ml, 64.84 + 10.82 mmol/l and 44.13 + 6.66 mmol/l ml of rumen fluid, respectively.

  20. Parametric study of effects of collagen turnover on the natural history of abdominal aortic aneurysms.

    Science.gov (United States)

    Wilson, J S; Baek, S; Humphrey, J D

    2013-02-08

    Abdominal aortic aneurysms (AAAs) are characterized by significant changes in the architecture of the aortic wall, notably, loss of functional elastin and smooth muscle. Because collagen is the principal remaining load-bearing constituent of the aneurysmal wall, its turnover must play a fundamental role in the natural history of the lesion. Nevertheless, detailed investigations of the effects of different aspects of collagen turnover on AAA development are lacking. A finite-element membrane model of the growth and remodelling of idealized AAAs was thus used to investigate parametrically four of the primary aspects of collagen turnover: rates of production, half-life, deposition stretch (prestretch) and material stiffness. The predicted rates of aneurysmal expansion and spatio-temporal changes in wall thickness, biaxial stresses and maximum collagen fibre stretch at the apex of the lesion depended strongly on all four factors, as did the predicted clinical endpoints (i.e. arrest, progressive expansion or rupture). Collagen turnover also affected the axial expansion, largely due to mechanical changes within the shoulder region of the lesion. We submit, therefore, that assessment of rupture risk could be improved by future experiments that delineate and quantify different aspects of patient-specific collagen turnover and that such understanding could lead to new targeted therapeutics.

  1. Effects of water and nitrogen addition on species turnover in temperate grasslands in northern China.

    Directory of Open Access Journals (Sweden)

    Zhuwen Xu

    Full Text Available Global nitrogen (N deposition and climate change have been identified as two of the most important causes of current plant diversity loss. However, temporal patterns of species turnover underlying diversity changes in response to changing precipitation regimes and atmospheric N deposition have received inadequate attention. We carried out a manipulation experiment in a steppe and an old-field in North China from 2005 to 2009, to test the hypothesis that water addition enhances plant species richness through increase in the rate of species gain and decrease in the rate of species loss, while N addition has opposite effects on species changes. Our results showed that water addition increased the rate of species gain in both the steppe and the old field but decreased the rates of species loss and turnover in the old field. In contrast, N addition increased the rates of species loss and turnover in the steppe but decreased the rate of species gain in the old field. The rate of species change was greater in the old field than in the steppe. Water interacted with N to affect species richness and species turnover, indicating that the impacts of N on semi-arid grasslands were largely mediated by water availability. The temporal stability of communities was negatively correlated with rates of species loss and turnover, suggesting that water addition might enhance, but N addition would reduce the compositional stability of grasslands. Experimental results support our initial hypothesis and demonstrate that water and N availabilities differed in the effects on rate of species change in the temperate grasslands, and these effects also depend on grassland types and/or land-use history. Species gain and loss together contribute to the dynamic change of species richness in semi-arid grasslands under future climate change.

  2. Quantitative Gd-DOTA uptake from cerebrospinal fluid into rat brain using 3D VFA-SPGR at 9.4T

    DEFF Research Database (Denmark)

    Lee, Hedok; Mortensen, Kristian; Sanggaard, Simon

    2017-01-01

    gadolinium concentration maps are derived. METHODS: We implemented a 3D variable flip angle spoiled gradient echo (VFA-SPGR) longitudinal relaxation time (T1) technique, the accuracy of which was cross-validated by way of inversion recovery rapid acquisition with relaxation enhancement (IR-RARE) using...... phantoms. Normal Wistar rats underwent Gd-DOTA infusion into CSF via the cisterna magna and continuous MRI for approximately 130 min using T1-weighted imaging. Dynamic Gd-DOTA concentration maps were calculated and parenchymal uptake was estimated. RESULTS: In the phantom study, T1 discrepancies between...... states. Magn Reson Med, 2017. © 2017 International Society for Magnetic Resonance in Medicine....

  3. Investigating the turnover of middle and senior managers in the pharmaceutical industry in South Africa

    Directory of Open Access Journals (Sweden)

    Abofele Khoele

    2014-02-01

    Full Text Available Orientation: Today, knowledge is a commodity and thus skilled knowledge workers, particularly in management positions, are vital for organisations’ success; their increased turnover has an adverse effect on productivity and profitability. High staff turnover is a cause for alarm, not only because of the costs associated with recruitment, selection and training, but also due to the increasing scarcity of experienced talent.Research purpose: This research investigates the reasons for the turnover of middle and senior managers in the pharmaceutical industry in South Africa in order to identify the possible reasons and formulate solutions to address the issue.Motivation for the study: In South Africa, employment, retention and turnover occur against the backdrop of a history of discrimination and inequality and attempts by government and organisations at redress. The significance of this background cannot be underestimated.Research approach, design and method: This study was qualitative and inductive to allow dominant themes to emerge from the raw data. Data was collected through in-depth, semi-structured one-on-one interviews as well as a review of company turnover reports and employment equity reports.Main findings: The study found that in the sampled organisations, employee turnover averaged almost 22% per annum between 2007 and 2010. Reasons for the turnover include a range of industry, company and personal factors.Practical/managerial implications: The overall turnover rate remains high, particularly amongst black knowledge workers, the attraction, recruitment and retention of whom is as important for addressing historical inequities in the local industry as it is for ensuring the diversity that companies need to reach a bigger market and gain a competitive edge. Further, as government is a significant purchaser of pharmaceutical goods and services, companies must ensure that the required Black Economic Empowerment (BEE rating level is

  4. Bone Turnover in Postmenopausal Women with Bone Loss - Original Investigation

    Directory of Open Access Journals (Sweden)

    Nurdan Paker

    2005-12-01

    Full Text Available Osteoporosis is characterized by decrease in bone strength due to decreased bone mass and disruption of bone microstructure and eventually increase in fracture risk. Increased bone turnover in postmenopausal period results in bone loss and osteoporosis. Aim of our study was to investigate the rate of bone turnover in postmenopausal women. Postmenopausal women were included in this study. Dual energy X ray absorbtiometry( Dexa was used for the measurement of BMD of the lumbar spine and proximal femur. Serum osteocalcin and type 1 collagen cross-linked C-telopeptide (Ctx levels were measured in blood. 32 postmenopausal women with bone loss were included in our study. The mean age was 61,5 ± 9,6 years, mean menopause duration 14,7± 9,5 years. The mean value of L2- L4 BMD was 0,910 ±0,143 gr/cm2 , femur neck BMD 0,734± 0,134 gr/cm2. Mean blood osteocalcin level was 23,34± 10,9 ng/ml(normal range <20, Ctx level was 0,70± 0,27 (normal range <0.75 ng/ml. There was statistically significant negative relationship between the menopause duration and serum Ctx levels (R =0,382, p<0,05. Mean serum Ctx level was 0,83 ±0,11 ng/ml in the patients whose menopause duration was less than 5 years and was 0,7 ±0,3 ng/ml in the patients whose menopause duration was more than 5 years. There was no relationship between serum osteocalcin and Ctx levels with age, body mass index(BMI, menopause duration, L2- L4 and femur neck BMD values. There was statistically significant relation between BMI(body mass index and L2 - L4 and femur neck BMD values( p < 0.05. There was no relationship between regular walking activity with BMD, serum osteocalcin and Ctx levels. In this study increased bone turnover rate in early postmenopausal period has been shown. It was known that bone loss increases due to the estrogen deficiency in postmenopausal period. Therefore, bone turnover markers of postmenopausal women should be measured in addition to bone mineral density who had bone

  5. Accelerated extracellular matrix turnover during exacerbations of COPD

    DEFF Research Database (Denmark)

    Sand, Jannie M B; Knox, Alan J; Lange, Peter

    2015-01-01

    progression. Extracellular matrix (ECM) turnover reflects activity in tissues and consequently assessment of ECM turnover may serve as biomarkers of disease activity. We hypothesized that the turnover of lung ECM proteins were altered during exacerbations of COPD. METHODS: 69 patients with COPD hospitalised...

  6. Library infrastructure as predictor of turnover intentions of librarians ...

    African Journals Online (AJOL)

    The result revealed that library infrastructure is a predictor of turnover intentions of librarians (r = 0.647, p < 0.05) which indicates that an improvement in library infrastructure will reduce turnover intentions of librarians. The result showed that inadequate/unavailability of library infrastructure increase turnover intentions of ...

  7. Effect of Fe(0) addition on volatile fatty acids evolution on anaerobic digestion at high organic loading rates.

    Science.gov (United States)

    Kong, Xin; Yu, Shuyao; Xu, Shuang; Fang, Wen; Liu, Jianguo; Li, Huan

    2017-03-17

    Excessive acidification frequently occurs in the anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) at high organic loading rates (OLR), due to the accumulation of non-acetic volatile fatty acids (VFA). In this study, the performance of Fe(0) in enhancing various VFA production and metabolism was investigated. The butyric acid concentration in a high OLR reactor with Fe(0) addition decreased from 7200 to 0mg/L after a short lag phase, and the total VFA (TVFA) concentration also decreased substantially. The corresponding dominant acidogenesis type also changed from butyric type to propionic type fermentation. Furthermore, the CH4 yield of the reactor with added Fe(0) was approximately 595ml CH4/g VSadded, which was an increase of 41.7% compared with the biochemical methane potential (BMP) test results in controls without added ZVI. A microbial diversity analysis, using high throughput sequencing, showed that Methanofollis and Methanosarcina were dominant in terms of the archaeal structures of the Fe(0) reactor at the butyric converting stage; however, Methanosaeta was predominant in the reactor during the control BMP test. These results suggested that Fe(0) can convert non-acetic VFA to acetic VFA and improve the CH4 yield by enhancing the activity of methanogens. Copyright © 2017. Published by Elsevier Ltd.

  8. Serum concentration of biochemical bone turnover markers in vegetarian children.

    Science.gov (United States)

    Ambroszkiewicz, J; Klemarczyk, W; Gajewska, J; Chełchowska, M; Laskowska-Klita, T

    2007-01-01

    In general, most children on well-planed vegetarian diets can achieve normal growth and development. However, elimination of animal products from the diet decreases the intake of some essential nutrients, such as calcium and vitamin D, and may influence bone metabolism. This is especially important in childhood and adolescence, when growth and bone turnover are most intensive. The aim of this study was to investigate the serum concentrations of biochemical bone turnover markers in prepubertal vegetarian children. We examined 50 children on vegetarian and 50 on omnivorous diets aged 2-10 years. Dietary constituents were analyzed using a local nutritional program. Serum bone formation (OC, BALP) and resorption (CTX) markers were determined by specific enzyme immunoassays (ELISA) and 25-hydroxyvitamin D by the chemiluminescence method (CLIA). The average daily energetic value and the percentage of energy from protein, fat and carbohydrates in the diets were similar in both groups of children and were within the recommended range. The vegetarian children showed about a two-fold lower daily intake of calcium and vitamin D than their omnivorous counterparts. The level of 25-hydroxyvitamin D in the serum of vegetarian children was also nearly 2-fold lower compared with omnivores. In vegetarians, as compared to non-vegetarians, mean serum concentrations of OC, BALP and CTX were lower by about 20%, 10% and 15%, respectively. Our preliminary results suggest that an inadequate dietary intake of calcium and vitamin D may impair bone turnover rate in vegetarian children. The parameters of bone metabolism should be monitored in these children in order to prevent bone abnormalities.

  9. Soil microbial carbon turnover decreases with increasing molecular size

    Science.gov (United States)

    Malik, Ashish; Gleixner, Gerd

    2014-05-01

    It is well established that soil microorganisms play an important role in respiration of newly fixed plant carbon. Recent results show that they also contribute significantly to soil organic matter (SOM) formation. We hypothesized that different molecular size classes of compounds in soil microbial biomass (SMB) have variable turnover time and in consequence influence SOM formation differentially. Here we used natural differences in carbon stable isotope signatures (δ13C values) after C3-C4 vegetation change to track newly fixed C4 plant carbon into SMB molecular size classes. SMB was obtained by chloroform fumigation extraction and δ13C values of its size classes were measured using size exclusion chromatography coupled online to liquid chromatography-isotope ratio mass spectrometry (SEC-LC-IRMS). Resolved SMB was assigned to 5 size classes: 1800-9800 Da, 800-1800 Da, 380-800 Da, 180-380 Da and 50-180 Da. The contribution of recent C4 plant carbon to size classes of SMB decreased with increasing molecular weight (MW). It ranged from 77±19% in the lowest MW size class size class to 41±14% in the 1800-9800 Da size class in 'Sandy' soil and from 59±18% in the lowest MW size class to 8±15% in the highest MW size class in 'Clayey' soil. A decreasing carbon turnover of compounds in SMB extracts along a continuum of molecular size from small to large implies that low molecular weight microbial compounds are rapidly metabolized products that link to fast respiratory carbon fluxes, whereas high molecular weight ones could be products of microbial synthesis like structural compounds that have slower turnover rates and link to slower SOM formation.

  10. Survival analysis to measure turnover of the medical education workforce in Ethiopia.

    Science.gov (United States)

    Assefa, Tsion; Haile Mariam, Damen; Mekonnen, Wubegzier; Derbew, Miliard

    2017-03-14

    Until recently, there were only a few medical schools in Ethiopia. However, currently, in response to the apparent shortage in physician workforce, the country has made huge progress with respect to the expansion of medical schools, by adopting the so-called flooding strategy. Nevertheless, the effectiveness of the intended strategy also relies on physician accessibility and turnover. Therefore, the aim of this study was to examine the distribution of physicians in the medical schools of Ethiopia and to quantify the magnitude and identify factors associated with physician turnover. This organizational faculty physician workforce survey was conducted in seven government-owned medical schools in Ethiopia. Longitudinal medical workforce data set of about 6 years (between September 2009 and June 2015) were retrospectively collected from each of the medical schools. The observation time begins with the date of employment (time zero) and ends at the date on which the physician leaves the appointment/or the data collection date. Kaplan-Meier survival method was used to describe the duration of stay of physicians in the academic health care settings. A Cox proportional hazards (CPH) model was fitted to identify the risk factors for physician turnover. In this study, a total of 1258 faculty physicians were observed in seven medical schools which resulted in 6670.5 physician-years. Of the total, there were 198 (15.7%) turnover events and the remaining 1060 (84.3%) were censored. The average turnover rate is about 29.7 per 1000 physician-years of observations. Multivariate modeling revealed no statistical significant difference in the rate of turnover between males and females (adjusted hazard ratio (AHR), 1.12; 95%CI, 0.71, 1.80). However, a lower rate of physician turnover was observed among those who were born before 1975 (AHR, 0.37; 95%CI, 0.20, 0.69) compared with those who were born after 1985. Physicians with the academic rank of associate professor and above had a

  11. Bone mass and turnover in fibromyalgia

    DEFF Research Database (Denmark)

    Jacobsen, Søren; Gam, A; Egsmose, C

    1993-01-01

    Physical inactivity accelerates bone loss. Since patients with fibromyalgia are relatively physically inactive, bone mass and markers of bone metabolism were determined in 12 premenopausal women with fibromyalgia and in healthy age matched female control subjects. No differences were found in lum.......01. This was linked to lower urinary creatinine excretion (p = 0.02) probably reflecting lower physical activity in the patients with fibromyalgia. We conclude that bone mass and turnover are generally not affected in premenopausal women with fibromyalgia....

  12. Rapid turnover of glycogen in memory formation.

    Science.gov (United States)

    Gibbs, Marie E; Hutchinson, Dana S

    2012-11-01

    The influence of noradrenaline acting at α(2)-AR and β(2)-ARs on the turnover of glycogen after learning has been investigated. The role of glycogen turnover in memory formation was examined using weakly-reinforced, single trial bead discrimination training in day-old domestic chickens. This study follows our previous work that focused on the need for glycogen breakdown (glycogenolysis) during learning. Inhibition of glycogenolysis by 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) prevented the consolidation of strongly-reinforced learning and inhibited memory. The action of DAB could be prevented by stimulating glycogenolysis with the selective β(2)-AR agonist, zinterol. Stimulation of α(2)-ARs has been shown to lead to an increase in the turnover and synthesis of glycogen. In the present study, we examined the effect of inhibition of α(2)-AR stimulated glycogen turnover (measured as(14)C-glucose incorporation into glycogen) on the ability of zinterol to promote the consolidation of weakly reinforced memory. In astrocytes, the selective α(2)-AR agonist clonidine stimulated (14)C-glucose incorporation into glycogen in chick astrocytes and this was inhibited by the selective α(2)-AR antagonist, ARC239. The critical importance of the timing of ARC239 injection relative to training and intracerebral administration of zinterol was examined. It is concluded that our data provides evidence for a readily accessible labile pool of glycogen in brain astrocytes. If glycogen synthesis is inhibited, the can be depleted within 10 min, thus preventing zinterol from promoting consolidation.

  13. Bone mass and turnover in fibromyalgia

    DEFF Research Database (Denmark)

    Jacobsen, Søren; Gam, A; Egsmose, C

    1993-01-01

    Physical inactivity accelerates bone loss. Since patients with fibromyalgia are relatively physically inactive, bone mass and markers of bone metabolism were determined in 12 premenopausal women with fibromyalgia and in healthy age matched female control subjects. No differences were found.......01. This was linked to lower urinary creatinine excretion (p = 0.02) probably reflecting lower physical activity in the patients with fibromyalgia. We conclude that bone mass and turnover are generally not affected in premenopausal women with fibromyalgia....

  14. High bone turnover in Irish professional jockeys.

    LENUS (Irish Health Repository)

    Waldron-Lynch, F

    2012-02-01

    SUMMARY: Professional jockeys are routinely exposed to high impact trauma and sustain fractures frequently. We found that jockeys restrict their caloric intake in order to maintain regulation weights, and that bone turnover is high. There are significant health and safety implications for the racing industry. INTRODUCTION: Professional jockeys routinely sustain fractures from high impact falls. Jockeys maintain a low percentage body fat and a low body mass index (BMI) to achieve low weight targets in order to race. We evaluated dietary habits and bone metabolism in jockeys. METHODS: Bone mineral density (BMD) was measured in 27 male jockeys of the 144 jockeys licensed in Ireland. Fourteen (52%) had BMD T score below -1.0, of whom 12 consented to clinical review, nutritional survey, endocrine studies, and bone turnover markers (BTM). BTM were compared to age- and sex-matched controls (n = 16). RESULTS: BMI was 20.6 +\\/- 1.7 kg\\/m(2); previous fracture frequency was 3.2 +\\/- 2.0 per rider. All had normal endocrine axes. The jockeys\\' diet as determined by a 7-day dietary recall was deficient in energy, calcium, and vitamin D intake. Compared with the control group, the jockey group had evidence of increased bone turnover. CONCLUSIONS: A substantial proportion of the professional jockeys in Ireland have low-normal BMD, low BMI, and high bone turnover that may result from weight and dietary restrictions. These factors seem to have a deleterious effect on their bone health and predispose the jockeys to a high fracture risk that should be remediated.

  15. TURNOVER AND JOB EMBEDDEDNESS IN TIJUANA MEXICO

    OpenAIRE

    Blanca Rosa García Rivera; Peter W Hom; Ignacio Alejandro Mendoza Martínez; Sonia Elizabeth Maldonado Radillo; Concepción Ramírez Barón

    2013-01-01

    In this paper we analyze the relationship between family and community links and future intentions to quit from employees at the export processing zone (EPZ) in Tijuana, Mexico. With survey data gathered in an organization belonging to a Tijuana EPZ, we applied the theory of embededdness to identify the causes behind turnover. A questionnaire with 125 items using a 4-points Likert scale was developed to assess job embeddedness, family embeddedness, satisfaction with benefits, and affective co...

  16. Differential turnover of tyrosinated and detyrosinated microtubules.

    OpenAIRE

    Webster, D. R.; Gundersen, G G; Bulinski, J C; Borisy, G G

    1987-01-01

    Turnover of tyrosinated and detyrosinated microtubules ([Tyr]MTs and [Glu]MTs, respectively) was analyzed by the combined use of hapten-mediated immunocytochemistry and peptide-specific antibodies. Cells were microinjected with hapten-labeled tubulin and then processed for triple-label immunofluorescence to determine the pattern of incorporation of the injected subunits into [Tyr]- and [Glu]-MTs. Within 2 min of microinjection, hapten-labeled domains were present at the ends of virtually all ...

  17. Bypass of an anesthesiologist-directed preoperative evaluation clinic results in greater first-case tardiness and turnover times.

    Science.gov (United States)

    Epstein, Richard H; Dexter, Franklin; Schwenk, Eric S; Witkowski, Thomas A

    2017-09-01

    We evaluated 4 hypotheses related to bypass of an anesthesiologist-directed preoperative evaluation clinics (APEC): 1) first-case tardiness and turnover times increased; 2) turnover times increased more than first-case tardiness; and higher American Society of Anesthesiologists Physical Status (ASA PS) resulted in both an ordered increase among ASA PS and within ASA PS in 3) first-case tardiness; and 4) turnover times. Retrospective observational study using electronic health records. One large, teaching hospital. An average of 14,310 patients per year undergoing elective surgery in the hospital's main opera rating rooms who were not inpatients preoperatively between 2006 and 2016. None. Average increases in first-case tardiness and turnover times between patients seen or not seen preoperatively in the APEC. APEC bypass increased first-case tardiness 2.58 min per case (CI 1.55-3.61; PAPEC, the increase in total minutes OR- 1 workday- 1 for turnover times would have been larger than the increase in first-case tardiness (difference=5.71, CI 3.17-4.72; PAPEC bypass for both first-case tardiness and turnover times with increasing ASA PS (PAPEC bypass. All 4 hypotheses were accepted. Overall and with control for ASA PS, APEC bypass increases first-case tardiness and turnover times. A strategy of selective bypass of ASA PS 1-2 patients would not be effective economically because of substantial delays from ASA PS 2 patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Generational differences in registered nurse turnover.

    Science.gov (United States)

    LeVasseur, Sandra A; Wang, Chen-Yen; Mathews, Barbara; Boland, Mary

    2009-08-01

    The chronic nature of the nursing workforce shortage in the United States is a continuing concern. As the nationwide gap between supply and demand grows, it remains unknown what impact turnover will have on nursing, access to care, and efforts to improve quality and safety of health care. It also remains unclear whether the recent turnover trends among new graduate registered nurses differ from past generational cohorts of new nurses. The aims of this study were to identify the reasons why registered nurses turnover by generational cohort (Veterans, Baby Boomers, and GenXMs) and to compare the length of time nurses were employed in their first five nursing positions by generational cohort. The findings suggest the three generational cohorts displayed similar reasons for leaving nursing positions with relocation, career advancement, and personal/family reasons reported most frequently. Except for the first nursing position, significant generational effects were found in the length of time Veterans, Baby Boomer, and GenXMs stayed employed in their nursing positions. It remains unknown why the GenXMs displayed a significantly shorter length of employment time in their second, third, fourth, and fifth nursing positions. The decline in length of employment time displayed in both the Baby Boomers and GenXMs may be an issue of concern requiring future research.

  19. Constituent attachment and voluntary turnover in low-wage/low-skill service work.

    Science.gov (United States)

    Ellingson, Jill E; Tews, Michael J; Dachner, Alison M

    2016-01-01

    This paper draws on life stage theory, ethnographic research conducted in the service sector, and evidence for secondary segmentation within the low-wage/low-skill labor force to offer evidence that social bond development with coworkers can help reduce the high rate of turnover observed in low-wage/low-skill service work. Contrary to the belief that these employees will leave before social ties can develop, constituent attachment was found to be the only significant predictor of turnover in 2 samples of front-line service workers in a casual dining, national restaurant chain after controlling for other aspects of work that can create a sense of attachment to a job, and other job attitudes, such as satisfaction and commitment. However, the effect was dependent on developmental life stage. Constituent attachment reduced turnover among workers classified as emerging adults, whereas constituent attachment did little to affect turnover among nonemerging adults. Implications of the results are discussed with respect to the value of considering segmentation in future research on turnover in the service sector and the use of life stage theory for understanding the leaving behavior of workers in different stages of adulthood. (c) 2016 APA, all rights reserved).

  20. PERAN STRES KERJA DAN KEPUASAN KERJA UNTUK MENGURANGI TURNOVER INTENTION

    Directory of Open Access Journals (Sweden)

    Syarifah Nazenin

    2014-09-01

    Full Text Available Tujuan penelitian ini untuk menguji pengaruh variabel stres kerja dan kepuasan kerja pada turnover intention karyawan tetap bagian produksi. Sampel penelitian ini adalah 86 responden, menggunakan metode Slovin dengan teknik probability sampling dengan jenis proportionate random sampling. Berdasarkan hasil penelitian, menunjukkan bahwa stres kerja berpengaruh positif signifikan pada turnover intention. Kemudian, kepuasan kerja berpengaruh negatif signifikan. Penelitian ini menyimpulkan, bahwa stres kerja berpengaruh positif dan signifikan pada turnover intention karyawan dan kepuasan kerja berpengaruh negatif dan signifikan terhadap turnover intention karyawan. Implikasi manajerial yang bisa dilakukan adalah dengan pengurangan tingkat stres karyawan dan membuat program untuk tujuan menekan turnover intention, seperti kesempatan promosi dan meningkatkan reward karyawan. The purpose of this study conducted to examine the effect of work stress and job satisfaction on turnover intention of employee in production department. The sample was 86 respondent, using Slovin method with proportionate random sampling technique. The result showed that job stress has a positive effect on turnover intention while job satisfaction has a negative effect on turnover intention. This study conclude that job stress has positive and significant impact on employee turnover intention and job satisfaction significantly and negatively related to turnover intention of employees. Therefore, it is recommended to managerial level people to reduce stress levels in employees and to create a program for pressing turnover intention, such as promotional opportunities and improve employee rewards.

  1. The Causes and Effects of English Teachers' Turnover: A Case from Afghanistan

    Science.gov (United States)

    Khawary, Omidullah; Ali, Sajid

    2015-01-01

    One of the challenging issues that educational organizations in developing countries face in staffing classrooms with qualified teachers is the high rate of teachers' turnover. It creates problems for schools, which eventually leads to substandard instruction and low student achievement. This research explores the causes of English teachers'…

  2. Comparing antecedents of voluntary job turnover among majority and minority employees

    NARCIS (Netherlands)

    Hofhuis, J.; van der Zee, K.I.; Otten, S.

    2014-01-01

    Purpose Cultural minority employees often display higher rates of voluntary turnover than majority employees, which reduces organizations’ ability to benefit from diversity in the workplace. The purpose of this paper is to identify specific job domains which are responsible for this difference.

  3. Blood Lead, Bone Turnover, and Survival in Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Fang, Fang; Peters, Tracy L; Beard, John D; Umbach, David M; Keller, Jean; Mariosa, Daniela; Allen, Kelli D; Ye, Weimin; Sandler, Dale P; Schmidt, Silke; Kamel, Freya

    2017-11-01

    Blood lead and bone turnover may be associated with the risk of amyotrophic lateral sclerosis (ALS). We aimed to assess whether these factors were also associated with time from ALS diagnosis to death through a survival analysis of 145 ALS patients enrolled during 2007 in the National Registry of Veterans with ALS. Associations of survival time with blood lead and plasma biomarkers of bone resorption (C-terminal telopeptides of type I collagen (CTX)) and bone formation (procollagen type I amino-terminal peptide (PINP)) were estimated using Cox models adjusted for age at diagnosis, diagnostic certainty, diagnostic delay, site of onset, and score on the Revised ALS Functional Rating Scale. Hazard ratios were calculated for each doubling of biomarker concentration. Blood lead, plasma CTX, and plasma PINP were mutually adjusted for one another. Increased lead (hazard ratio (HR) = 1.38; 95% confidence interval (CI): 1.03, 1.84) and CTX (HR = 2.03; 95% CI: 1.42, 2.89) were both associated with shorter survival, whereas higher PINP was associated with longer survival (HR = 0.59; 95% CI: 0.42, 0.83), after ALS diagnosis. No interactions were observed between lead or bone turnover and other prognostic indicators. Lead toxicity and bone metabolism may be involved in ALS pathophysiology. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  4. How to reduce turnover by creating a positive work climate.

    Science.gov (United States)

    Kushell, R E

    1979-08-01

    Despite company attempts to reduce employee turnover by offering attractive salaries and benefits, Kushell notes that attrition continues at an alarming rate. He states that more than one of every three employees will change jobs over the next five years, a transition that will take its toll on company morale and productivity. The underlying factor, according to the author, is the quality of the working environment. A 1969 University of Michigan survey of 1,533 workers, at every occupation level, reported that all respondents ranked interesting work and authority to get the job done far ahead of good pay and job security. Sources of employee frustration include a stifling bureaucracy, excessive job expectations, and unsuitable jobs. The author suggests that top managers ask themselves whether they are missing out on or losing talented employees. If this is the case, there are several guidelines management should follow: improve communication between employees and top management; define expectations of the employee; and promote candor in the job interview. Kushell concludes that top executives can have an impact on turnover by paying attention to what employees really want rather than what management thinks they want.

  5. Turnover and organizational performance: a comparative analysis of the effects of voluntary, involuntary, and reduction-in-force turnover.

    Science.gov (United States)

    McElroy, J C; Morrow, P C; Rude, S N

    2001-12-01

    Data were collected from 31 regional subunits of a national financial services company to examine differential effects of 3 types of turnover (voluntary, involuntary, and reduction-in-force) on measures of organizational subunit performance. Although each form of turnover exhibited adverse effects on subunit performance when examined separately, partial correlation results revealed greater and more pervasive adverse effects for reduction-in-force turnover (i.e., downsizing) in comparison with the effects of voluntary and involuntary turnover. The results confirm the negative effects of downsizing, suggesting the need to move beyond the traditional voluntary-involuntary classification scheme used in turnover research.

  6. Work-to-family conflict as a mediator of the relationship between job satisfaction and turnover intention.

    Science.gov (United States)

    Chen, I-Hui; Brown, Roger; Bowers, Barbara J; Chang, Wen-Yin

    2015-10-01

    To investigate the mediating effect of work-to-family conflict on the relationship between job satisfaction and turnover intention among licensed nurses in long-term care settings. The considerable research on turnover in long-term care has primarily focused on the impact of job satisfaction on turnover intention. Given the well-documented high turnover rate in nursing home staffing, dissatisfaction is expected to continue. Alternatives (e.g. reduction in work-to-family conflict) for reducing turnover under the circumstance of job dissatisfaction have not been investigated extensively. A cross-sectional mailed survey. A convenience sample comprising 200 nurses from 25 private nursing homes in Central Taiwan was created. Data were collected from nurses about their level of turnover intention, job satisfaction and work-to-family conflict in 2012. A composite indicator structural equation model was used to examine the mediation model of this study. Overall, 186 nurses (93%) returned the completed questionnaires. Consistent with published research from other countries, turnover intention in our study was significantly and negatively associated with job satisfaction and significantly and positively associated with work-to-family conflict. In addition, job dissatisfaction indirectly influenced turnover intention through high work-to-family conflict. Findings from this study indicate the importance of work-to-family conflict to nurse turnover. While work setting has a strong, well-documented influence on job satisfaction, limiting job satisfaction efforts to work setting improvements may not yield the hoped-for results unless work-to-family conflict is also considered and addressed. © 2015 John Wiley & Sons Ltd.

  7. The relationships between organisational citizenship behaviour, job satisfaction and turnover intention.

    Science.gov (United States)

    Tsai, Yafang; Wu, Shih-Wang

    2010-12-01

    This study aims to explore the relationships between organisational citizenship behaviour, job satisfaction and turnover intention. Because of the changing health policies landscape, Taiwan's hospital administrators are facing major cost reduction challenges. Specifically, the high turnover rate of nurses represents a hindrance and a human resource cost. This study focuses on ways of reducing the employee turnover rate through enhanced organisational citizenship behaviour and job satisfaction. A cross-sectional study. This study focuses on hospital nurses in Taiwan. Our research samples were obtained from one medical centre, three regional hospitals and seven district hospitals. Out of 300 questionnaires distributed among samples, 237 were completed and returned. Pearson's correlation was used to test for relationships among the main variables. One-way analysis of variance and Scheffé's post hoc analysis were employed to test the influence of demographic data on the main variables. The results reveal that the nurses' job satisfaction has a significantly positive correlation with organisational citizenship behaviour and a negative correlation with turnover intention. This study has proven that the turnover intention of clinical nurses is related to their organisational citizenship behaviour and job satisfaction. Hospital administrators can reduce the turnover intention by meeting nurses' needs and by promoting their organisational citizenship behaviour. Organisational citizenship behaviour involves behaviour that encourages staff to endeavour to voluntarily improve organisational performance without lobbying for compensation. Employees' job satisfaction includes satisfaction with the working environment or welfare programme in the context of human resource initiatives. Similarly, human resource protocols may serve as the starting point for promoting staff organisational citizenship behaviour. Administrators in clinical healthcare are encouraged to meet their

  8. Turnover of grain legume N rhizodeposits and effect of rhizodeposition on the turnover of crop residues

    DEFF Research Database (Denmark)

    Mayer, J.; Buegger, F.; Jensen, E.S.

    2004-01-01

    The turnover of N derived from rhizodeposition of faba bean (Vicia faba L.), pea (Pisum sativum L.) and white lupin (Lupinus albus L.) and the effects of the rhizodeposition on the subsequent C and N turnover of its crop residues were investigated in an incubation experiment (168 days, 15 degrees....... In the experiment the turnover of C and N was compared in soils with and without previous growth of three legumes and with and without incorporation of crop residues. After 168 days, 21% (lupin), 26% (faba bean) and 27% (pea) of rhizodeposition N was mineralised in the treatments without crop residues. A smaller......C). A sandy loam soil for the experiment was either stored at 6 degreesC or planted with the respective grain legume in pots. Legumes were in situ N-15 stem labelled during growth and visible roots were removed at maturity. The remaining plant-derived N in soil was defined as N rhizodeposition...

  9. Active G protein-coupled receptors (GPCR), matrix metalloproteinases 2/9 (MMP2/9), heparin-binding epidermal growth factor (hbEGF), epidermal growth factor receptor (EGFR), erbB2, and insulin-like growth factor 1 receptor (IGF-1R) are necessary for trenbolone acetate-induced alterations in protein turnover rate of fused bovine satellite cell cultures.

    Science.gov (United States)

    Thornton, K J; Kamanga-Sollo, E; White, M E; Dayton, W R

    2016-06-01

    Trenbolone acetate (TBA), a testosterone analog, increases protein synthesis and decreases protein degradation in fused bovine satellite cell (BSC) cultures. However, the mechanism through which TBA alters these processes remains unknown. Recent studies indicate that androgens improve rate and extent of muscle growth through a nongenomic mechanism involving G protein-coupled receptors (GPCR), matrix metalloproteinases (MMP), heparin-binding epidermal growth factor (hbEGF), the epidermal growth factor receptor (EGFR), erbB2, and the insulin-like growth factor-1 receptor (IGF-1R). We hypothesized that TBA activates GPCR, resulting in activation of MMP2/9 that releases hbEGF, which activates the EGFR and/or erbB2. To determine whether the proposed nongenomic pathway is involved in TBA-mediated alterations in protein turnover, fused BSC cultures were treated with TBA in the presence or absence of inhibitors for GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R, and resultant protein synthesis and degradation rates were analyzed. Assays were replicated at least 9 times for each inhibitor experiment utilizing BSC cultures obtained from at least 3 different steers that had no previous exposure to steroid compounds. As expected, fused BSC cultures treated with 10 n TBA exhibited increased ( GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R suppressed ( GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R in the presence of 10 n TBA each had no ( > 0.05) effect on TBA-mediated decreases in protein degradation. However, inhibition of both EGFR and erbB2 in the presence of 10 n TBA resulted in decreased ( GPCR, MMP2/9, hbEGF, EGFR, erbB2, and IGF-1R. However, the mechanism through which TBA mediates changes in protein degradation is different and appears to involve only the EGFR and erbB2. Furthermore, it appears the protein kinase B pathway is involved in TBA's effects on fused BSC cultures.

  10. Uncertainties on Root C Turnover and Decomposition and its Impact on Soil C Sequestration Potential

    Science.gov (United States)

    Matamala, R.; Gonzalez-Meler, M. A.; Jastrow, J. D.

    2005-12-01

    Roots provide a path for movement of carbon and energy from plant canopies to soils; thus, root production and turnover directly impact the biogeochemical cycle of C and nutrients in terrestrial ecosystems. Uncertainties in estimates of production, mortality and decomposition of roots prevent proper quantification of net primary productivity (NPP), belowground C allocation and inputs to soil organic matter. Our study compares the ecosystem C sequestration potential of two distinct forest types, a pine and a sweetgum forest, growing under FACE (Free Air CO2-Enrichment) conditions that allow for the use of 13CO2 as a tracer in the tissues and soils. Using this technique root C turnover measurements have showed that although fine roots have often been assumed to have MRT of about one year, the MRT of the fine root C varies from 1 to 9 years depending on root diameter and tree species. The relative importance of a slow or a fast root C turnover is shown on the C accrual rate of the soil, slow root turnover rates appears to reduce the sequestration potential of C in soil supporting pine trees, while fast root C turnover in a sweetgum forest sustained significant increases in soil C after being exposed to elevated CO2 for five to six years. The rate of root decomposition and root inputs are calculated for both forest types and compared with the rate of soil organic matter accrual. Our results suggest that C sequestration in soils is strongly affected by root production and the MRT of C of the root system.

  11. Metabolic Turnover of Synaptic Proteins: Kinetics, Interdependencies and Implications for Synaptic Maintenance

    Science.gov (United States)

    Cohen, Laurie D.; Zuchman, Rina; Sorokina, Oksana; Müller, Anke; Dieterich, Daniela C.; Armstrong, J. Douglas; Ziv, Tamar; Ziv, Noam E.

    2013-01-01

    Chemical synapses contain multitudes of proteins, which in common with all proteins, have finite lifetimes and therefore need to be continuously replaced. Given the huge numbers of synaptic connections typical neurons form, the demand to maintain the protein contents of these connections might be expected to place considerable metabolic demands on each neuron. Moreover, synaptic proteostasis might differ according to distance from global protein synthesis sites, the availability of distributed protein synthesis facilities, trafficking rates and synaptic protein dynamics. To date, the turnover kinetics of synaptic proteins have not been studied or analyzed systematically, and thus metabolic demands or the aforementioned relationships remain largely unknown. In the current study we used dynamic Stable Isotope Labeling with Amino acids in Cell culture (SILAC), mass spectrometry (MS), Fluorescent Non–Canonical Amino acid Tagging (FUNCAT), quantitative immunohistochemistry and bioinformatics to systematically measure the metabolic half-lives of hundreds of synaptic proteins, examine how these depend on their pre/postsynaptic affiliation or their association with particular molecular complexes, and assess the metabolic load of synaptic proteostasis. We found that nearly all synaptic proteins identified here exhibited half-lifetimes in the range of 2–5 days. Unexpectedly, metabolic turnover rates were not significantly different for presynaptic and postsynaptic proteins, or for proteins for which mRNAs are consistently found in dendrites. Some functionally or structurally related proteins exhibited very similar turnover rates, indicating that their biogenesis and degradation might be coupled, a possibility further supported by bioinformatics-based analyses. The relatively low turnover rates measured here (∼0.7% of synaptic protein content per hour) are in good agreement with imaging-based studies of synaptic protein trafficking, yet indicate that the metabolic load

  12. Endogenous Turnover of Cyanogenic Glycosides in Plants

    DEFF Research Database (Denmark)

    Picmanova, Martina

    with noncyanogenic compounds glaringly resembling their structures. In order to examine the spatial as well as temporal presence and abundance of the putative turnover products of CNglcs, comparative metabolic profiling using LC-MS/MS was performed in three cyanogenic crops – cassava, almond and sorghum. This work...... of the proposed catabolic route, even though the enzymes involved remain elusive. Testing of heterologously expressed and purified nitrilases and nitrilase-related enzymes from cassava and almond, including NIT4s, glutamine-dependent NAD+ synthetase (QNS) and a newly discovered nucleus-localized nitrilase...

  13. Analysis of Soil Structure Turnover with Garnet Particles and X-Ray Microtomography.

    Science.gov (United States)

    Schlüter, Steffen; Vogel, Hans-Jörg

    2016-01-01

    Matter turnover in soil is tightly linked to soil structure which governs the heterogeneous distribution of habitats, reaction sites and pathways in soil. Thereby, the temporal dynamics of soil structure alteration is deemed to be important for essential ecosystem functions of soil but very little is known about it. A major reason for this knowledge gap is the lack of methods to study soil structure turnover directly at microscopic scales. Here we devise a conceptual approach and an image processing workflow to study soil structure turnover by labeling some initial state of soil structure with small garnet particles and tracking their fate with X-ray microtomography. The particles adhere to aggregate boundaries at the beginning of the experiment but gradually change their position relative to the nearest pore as structure formation progresses and pores are destructed or newly formed. A new metric based on the contact distances between particles and pores is proposed that allows for a direct quantification of soil structure turnover rates. The methodology is tested for a case study about soil compaction of a silty loam soil during stepwise increase of bulk density (ρ = {1.1, 1.3, 1.5} g/cm3). We demonstrate that the analysis of mean contact distances provides genuinely new insights about changing diffusion pathways that cannot be inferred neither from conventional pore space attributes (porosity, mean pore size, pore connectivity) nor from deformation analysis with digital image correlation. This structure labeling approach to quantify soil structure turnover provides a direct analogy to stable isotope labeling for the analysis of matter turnover and can be readily combined with each other.

  14. Job satisfaction, burnout and turnover intention in occupational therapists working in mental health.

    Science.gov (United States)

    Scanlan, Justin Newton; Still, Megan

    2013-10-01

    Employee wellbeing is an important issue for mental health services. Poor employee wellbeing (i.e., high levels of burnout or low job satisfaction) is associated with poorer consumer outcomes and higher staff turnover. This study set out to examine factors related to job satisfaction, turnover intention and burnout in a group of occupational therapists in mental health. Thirty-four occupational therapists (response rate approximately 60%) in a metropolitan public mental health service participated in a whole-of-service workforce survey. The survey included measures of job satisfaction, turnover intention, burnout, job hindrances, job challenges and job resources and questions about positive and negative aspects of positions and factors that attracted employees to their current position. Burnout was associated with lower job satisfaction and higher turnover intention. Higher job satisfaction was associated with rewards (remuneration and recognition) as well as cognitively challenging work. The variables most significantly associated with poorer wellbeing (higher turnover intention and burnout) were recipient contact demands (perception that contact with service users or families was demanding), and feelings of stress or fatigue. This study provides a detailed analysis of factors associated with job satisfaction, turnover intention and burnout in a group of occupational therapists working in mental health. To promote workforce wellbeing and enhanced retention, interventions to minimise burnout should be implemented and evaluated. These strategies should focus on enhancing job resources such as supervisor support, feedback and participation in decision making as well as building the personal resilience of occupational therapists working in mental health. © 2013 Occupational Therapy Australia.

  15. Analysis of Soil Structure Turnover with Garnet Particles and X-Ray Microtomography.

    Directory of Open Access Journals (Sweden)

    Steffen Schlüter

    Full Text Available Matter turnover in soil is tightly linked to soil structure which governs the heterogeneous distribution of habitats, reaction sites and pathways in soil. Thereby, the temporal dynamics of soil structure alteration is deemed to be important for essential ecosystem functions of soil but very little is known about it. A major reason for this knowledge gap is the lack of methods to study soil structure turnover directly at microscopic scales. Here we devise a conceptual approach and an image processing workflow to study soil structure turnover by labeling some initial state of soil structure with small garnet particles and tracking their fate with X-ray microtomography. The particles adhere to aggregate boundaries at the beginning of the experiment but gradually change their position relative to the nearest pore as structure formation progresses and pores are destructed or newly formed. A new metric based on the contact distances between particles and pores is proposed that allows for a direct quantification of soil structure turnover rates. The methodology is tested for a case study about soil compaction of a silty loam soil during stepwise increase of bulk density (ρ = {1.1, 1.3, 1.5} g/cm3. We demonstrate that the analysis of mean contact distances provides genuinely new insights about changing diffusion pathways that cannot be inferred neither from conventional pore space attributes (porosity, mean pore size, pore connectivity nor from deformation analysis with digital image correlation. This structure labeling approach to quantify soil structure turnover provides a direct analogy to stable isotope labeling for the analysis of matter turnover and can be readily combined with each other.

  16. Analysis of Soil Structure Turnover with Garnet Particles and X-Ray Microtomography

    Science.gov (United States)

    Schlüter, Steffen; Vogel, Hans-Jörg

    2017-04-01

    Matter turnover in soil is tightly linked to soil structure which governs the heterogeneous distribution of habitats, reaction sites and pathways in soil. Thereby, the temporal dynamics of soil structure alteration is deemed to be important for essential ecosystem functions of soil but very little is known about it. A major reason for this knowledge gap is the lack of methods to study soil structure turnover directly at microscopic scales. Here we devise a conceptual approach and an image processing workflow to study soil structure turnover by labeling some initial state of soil structure with small garnet particles and tracking their fate with X-ray microtomography. The particles adhere to aggregate boundaries at the beginning of the experiment but gradually change their position relative to the nearest pore as structure formation progresses and pores are destructed or newly formed. A new metric based on the contact distances between particles and pores is proposed that allows for a direct quantification of soil structure turnover rates. The methodology is tested for two case studies: (1) soil compaction of a silty loam soil in steps of 1.1, 1.3 and 1.5 g/cm3 and (2) wetting/drying cycles at different bulk densities in the same soil. We demonstrate that the analysis of mean contact distances provides genuinely new insights about changing diffusion pathways that cannot be inferred neither from conventional pore space attributes (porosity, mean pore size, pore connectivity) nor from deformation analysis with digital image correlation. This structure labeling approach to quantify soil structure turnover provides a direct analogy to stable isotope labeling for the analysis of matter turnover and can be readily combined with each other.

  17. Factors influencing turnover intention among primary care doctors: a cross-sectional study in Chongqing, China.

    Science.gov (United States)

    Wen, Tong; Zhang, Yan; Wang, Xue; Tang, Guo

    2018-02-13

    The intention to leave a job, known as turnover intention, among primary care doctors has a significant impact on primary health care service delivery. We investigated primary care doctors' turnover intention and analysed associated factors involved in primary health facilities in Chongqing, China. A total of 440 doctors were interviewed, they were selected using a multi-stage stratified random sampling method. The survey instrument was a self-administered questionnaire which assessed socio-demographic and work-related characteristics, job satisfaction and turnover intention. The data were analysed using χ 2 test, one-way analysis of variance, exploratory factor analysis and linear regression analysis. Our study found that 42.3% of the primary care doctors we sampled in Chongqing, China, intended to resign. Location, age, job title, doctor's position level, work pressure and job satisfaction were associated with turnover intention. Job satisfaction included both employment-related job satisfaction (including "your chance of promotion", "your rate of pay" and two other items) and satisfaction with the job itself (including "the freedom to choose your own method of working", "your job safety" and two other items). Improving job satisfaction, in terms of salary, promotion and job safety, is crucial for reducing turnover intention among primary care doctors. Therefore, we suggest that the government increase its financial investment in primary care facilities, especially in less-developed areas, and reform incentive mechanisms to improve the job satisfaction of primary care doctors. The government should consider policies such as establishing a social pension programme for village-level doctors and providing more opportunities for job promotion among primary care doctors, especially township-level doctors. Attention should also be paid to the impact of rapid urbanization, which could lead to increased workload or increased opportunities for career development, thus

  18. Bone turnover markers do not predict stress fracture in elite combat recruits.

    Science.gov (United States)

    Yanovich, Ran; Evans, Rachel K; Friedman, Eitan; Moran, Daniel S

    2013-04-01

    With bone resorption rates greater than formation, stress fracture pathogenesis plausibly involves bone remodeling imbalance. If this is the case, one would anticipate serum levels of bone turnover markers would be higher in patients with stress fractures than in those without. We therefore asked whether: (1) bone turnover markers differ between soldiers who will or will not have stress fractures during basic training; (2) bone turnover markers change during basic training; and (3) serial bone formation or bone resorption markers differ between subjects with and without stress fractures during basic training? We performed serial determinations of serum bone formation (bone alkaline phosphatase [BAP] and procollagen type I amino-terminal propeptide [PINP]), and resorption (tartrate-resistant acid phosphatase [TRAP5b] and cross-linked collagen telopeptide [CTx]) biomarkers, measured at 2- to 4-week intervals (during 18 weeks) in 69 male soldiers in the Israeli Defense Forces during elite basic training. Twenty-two soldiers (32%) were diagnosed with stress fractures. The mean training week at diagnosis was 8.0±2.0 weeks. We observed no differences in bone turnover markers between soldiers with and without stress fractures. During basic training, the mean values of all subjects for bone turnover markers (BAP, PINP, and CTx) changed in comparison to their mean levels at induction (43.9 versus 37.3 μg/L, 110.4 versus 78.0 μg/L, 1.4 versus 1.1 ng/mL, respectively). We found no changes in bone formation and resorption markers between subjects with and without stress fractures. These specific bone turnover markers cannot be considered as either diagnostic or predictive tools for stress fracture detection in young male military recruits. Level II prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

  19. Evaluating nurse turnover: comparing attitude surveys and exit interviews.

    Science.gov (United States)

    Fottler, M D; Crawford, M A; Quintana, J B; White, J B

    1995-01-01

    High turnover rates among hospital nurses demand rigorous and valid processes of research to determine the reasons motivating such attrition. In most hospitals, the exit interview often provides the only relevant data. The case study reported here examines the relative effectiveness of exit interviews and an employee attitude survey in generating data that are useful in managing nurse retention. The conclusion reached is that the attitude survey generates more data and higher-quality data. Further, the study shows that the use of open-ended questions can provide useful information and probably should be the starting point in developing or supplementing an attitude survey for nurses. Recommendations for improving the usefulness and validity of nurse attitude surveys and exit interviews in managing nurse retention are provided.

  20. Protein turnover during in vitro tissue engineering.

    Science.gov (United States)

    Li, Qiyao; Chang, Zhen; Oliveira, Gisele; Xiong, Maiyer; Smith, Lloyd M; Frey, Brian L; Welham, Nathan V

    2016-03-01

    Repopulating acellular biological scaffolds with phenotypically appropriate cells is a promising approach for regenerating functional tissues and organs. Under this tissue engineering paradigm, reseeded cells are expected to remodel the scaffold by active protein synthesis and degradation; however, the rate and extent of this remodeling remain largely unknown. Here, we present a technique to measure dynamic proteome changes during in vitro remodeling of decellularized tissue by reseeded cells, using vocal fold mucosa as the model system. Decellularization and recellularization were optimized, and a stable isotope labeling strategy was developed to differentiate remnant proteins constituting the original scaffold from proteins newly synthesized by reseeded cells. Turnover of matrix and cellular proteins and the effects of cell-scaffold interaction were elucidated. This technique sheds new light on in vitro tissue remodeling and the process of tissue regeneration, and is readily applicable to other tissue and organ systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Nitrogen turnover in soil and global change.

    Science.gov (United States)

    Ollivier, Julien; Töwe, Stefanie; Bannert, Andrea; Hai, Brigitte; Kastl, Eva-Maria; Meyer, Annabel; Su, Ming Xia; Kleineidam, Kristina; Schloter, Michael

    2011-10-01

    Nitrogen management in soils has been considered as key to the sustainable use of terrestrial ecosystems and a protection of major ecosystem services. However, the microorganisms driving processes like nitrification, denitrification, N-fixation and mineralization are highly influenced by changing climatic conditions, intensification of agriculture and the application of new chemicals to a so far unknown extent. In this review, the current knowledge concerning the influence of selected scenarios of global change on the abundance, diversity and activity of microorganisms involved in nitrogen turnover, notably in agricultural and grassland soils, is summarized and linked to the corresponding processes. In this context, data are presented on nitrogen-cycling processes and the corresponding microbial key players during ecosystem development and changes in functional diversity patterns during shifts in land use. Furthermore, the impact of increased temperature, carbon dioxide and changes in precipitation regimes on microbial nitrogen turnover is discussed. Finally, some examples of the effects of pesticides and antibiotics after application to soil for selected processes of nitrogen transformation are also shown. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  2. Relationships between Bone Turnover and Energy Metabolism

    Directory of Open Access Journals (Sweden)

    Tânia A. P. Fernandes

    2017-01-01

    Full Text Available It is well established that diabetes can be detrimental to bone health, and its chronic complications have been associated with an increased risk of osteoporotic fracture. However, there is growing evidence that the skeleton plays a key role in a whole-organism approach to physiology. The hypothesis that bone may be involved in the regulation of physiological functions, such as insulin sensitivity and energy metabolism, has been suggested. Given the roles of insulin, adipokines, and osteocalcin in these pathways, the need for a more integrative conceptual approach to physiology is emphasized. Recent findings suggest that bone plays an important role in regulating intermediary metabolism, being possibly both a target of diabetic complications and a potential pathophysiologic factor in the disease itself. Understanding the relationships between bone turnover and glucose metabolism is important in order to develop treatments that might reestablish energy metabolism and bone health. This review describes new insights relating bone turnover and energy metabolism that have been reported in the literature.

  3. Current practice and perspectives in CRO oversight based on a survey performed among members of the German Association of Research-Based Pharmaceutical Companies (vfa).

    Science.gov (United States)

    Hennig, Michael; Hundt, Ferdinand; Busta, Susanne; Mikus, Stefan; Sanden, Per-Holger; Sörgel, Andrea; Ruppert, Thorsten

    2017-01-01

    In recent years, the number and scope of outsourced activities in the pharmaceutical industry have increased heavily. In addition, also the type of outsourcing has changed significantly in that time. This raises the question of whether and how sponsors retain the capability to select and to control the contract research organizations (CROs) involved and what expertise still has to be present in the development department as well as other relevant departments to ensure adequate oversight, also in line with the expectations of regulators and health authorities. In order to answer these questions, a survey was conducted among the German vfa member companies. The survey describes the latest developments and experiences in outsourcing by 18 German vfa member companies. It concentrates on measures how to implement Quality Assurance (QA) when performing outsourced clinical studies. This study shows that the majority of companies apply a full-outsourcing, preferred-provider model of clinical trial services, with the clinical research department playing the major role in this process. A large amount of guiding documents, processes and tools are used to ensure an adequate oversight of the services performed by the CRO(s). Finally the guiding principles for all oversight processes should be transparent communication, a clearly established expectation for quality, a precise definition of accountability and responsibility while avoiding silo mentality, and a comprehensive documentation of the oversight's evidence. For globally acting and outsourcing sponsors, oversight processes need to be aligned with regards to local and global perspectives. This survey shows that the current implementation of oversight processes in the participating companies covers all relevant areas to ensure highest quality and integrity of the data produced by the outsourced clinical trial.

  4. Current practice and perspectives in CRO oversight based on a survey performed among members of the German Association of Research-Based Pharmaceutical Companies (vfa

    Directory of Open Access Journals (Sweden)

    Hennig, Michael

    2017-01-01

    Full Text Available In recent years, the number and scope of outsourced activities in the pharmaceutical industry have increased heavily. In addition, also the type of outsourcing has changed significantly in that time. This raises the question of whether and how sponsors retain the capability to select and to control the contract research organizations (CROs involved and what expertise still has to be present in the development department as well as other relevant departments to ensure adequate oversight, also in line with the expectations of regulators and health authorities. In order to answer these questions, a survey was conducted among the German vfa member companies. The survey describes the latest developments and experiences in outsourcing by 18 German vfa member companies. It concentrates on measures how to implement Quality Assurance (QA when performing outsourced clinical studies.This study shows that the majority of companies apply a full-outsourcing, preferred-provider model of clinical trial services, with the clinical research department playing the major role in this process. A large amount of guiding documents, processes and tools are used to ensure an adequate oversight of the services performed by the CRO(s.Finally the guiding principles for all oversight processes should be transparent communication, a clearly established expectation for quality, a precise definition of accountability and responsibility while avoiding silo mentality, and a comprehensive documentation of the oversight’s evidence. For globally acting and outsourcing sponsors, oversight processes need to be aligned with regards to local and global perspectives. This survey shows that the current implementation of oversight processes in the participating companies covers all relevant areas to ensure highest quality and integrity of the data produced by the outsourced clinical trial.

  5. Current practice and perspectives in CRO oversight based on a survey performed among members of the German Association of Research-Based Pharmaceutical Companies (vfa)

    Science.gov (United States)

    Hennig, Michael; Hundt, Ferdinand; Busta, Susanne; Mikus, Stefan; Sanden, Per-Holger; Sörgel, Andrea; Ruppert, Thorsten

    2017-01-01

    In recent years, the number and scope of outsourced activities in the pharmaceutical industry have increased heavily. In addition, also the type of outsourcing has changed significantly in that time. This raises the question of whether and how sponsors retain the capability to select and to control the contract research organizations (CROs) involved and what expertise still has to be present in the development department as well as other relevant departments to ensure adequate oversight, also in line with the expectations of regulators and health authorities. In order to answer these questions, a survey was conducted among the German vfa member companies. The survey describes the latest developments and experiences in outsourcing by 18 German vfa member companies. It concentrates on measures how to implement Quality Assurance (QA) when performing outsourced clinical studies. This study shows that the majority of companies apply a full-outsourcing, preferred-provider model of clinical trial services, with the clinical research department playing the major role in this process. A large amount of guiding documents, processes and tools are used to ensure an adequate oversight of the services performed by the CRO(s). Finally the guiding principles for all oversight processes should be transparent communication, a clearly established expectation for quality, a precise definition of accountability and responsibility while avoiding silo mentality, and a comprehensive documentation of the oversight’s evidence. For globally acting and outsourcing sponsors, oversight processes need to be aligned with regards to local and global perspectives. This survey shows that the current implementation of oversight processes in the participating companies covers all relevant areas to ensure highest quality and integrity of the data produced by the outsourced clinical trial. PMID:28163667

  6. Effect of Maillard reaction products on ruminal and fecal acid-resistant E. coli, total coliforms, VFA profiles, and pH in steers.

    Science.gov (United States)

    Sindt, J J; Drouillard, J S; Thippareddi, H; Phebus, R K; Coetzer, C M; Kerr, K D; Lambert, D L; Farran, T B; Montgomery, S P; LaBrune, H J

    2004-04-01

    Six ruminally cannulated Angus-cross steers (362 kg) were used in a replicated 3 x 3 Latin square design to determine effects of supplementing Maillard reaction products (MRP) on acid-resistant E. coli and coliform populations. Steers were fed roughage-based diets supplemented (DM basis) with either 10% soybean meal (SBM), 10% nonenzymatically browned SBM (NESBM), or 10% SBM top-dressed with 45 g of a lysine-dextrose Maillard reaction product (LD-MRP). Equal weights of dextrose, lysine hydrochloride, and deionized water were refluxed to produce the LD-MRP. The NESBM was manufactured by treating SBM with invertase enzyme, followed by heating to induce nonenzymatic browning. Steers were allowed slightly less than ad libitum access to diets fed twice daily and were adapted to their respective treatments within 10 d. On d 11, ruminal and fecal samples were collected at 0, 2, 4, 6, 8, and 12 h after feeding from each of the steers and transported to the laboratory for microbial analysis. Ruminal samples and feces were analyzed for pH and VFA, and both ruminal fluid and feces were tested for acid-resistant E. coli and total coliforms by incubating samples in tryptic soy broth adjusted to pH 2, 4, and 7. Ruminal pH and total VFA concentrations did not differ among treatments. The molar proportion of ruminal acetate was higher (P coliforms than steers that received SBM. No differences were observed for ruminal E. coli and total coliforms at pH 2 and 7. Fecal pH was lower (P coliforms at pH 2 and 7 did not differ among treatments. Dietary MRP had limited effectiveness at decreasing acid-resistant coliforms in the rumen and feces of cattle. Acid resistance in coliforms may depend on protein availability.

  7. Effect of substrate and cation requirement on anaerobic volatile fatty acid conversion rates at elevated biogas pressure

    NARCIS (Netherlands)

    Lindeboom, R.E.F.; Ferrer, I.; Weijma, J.; Lier, van J.B.

    2013-01-01

    This work studied the anaerobic conversion of neutralized volatile fatty acids (VFA) into biogas under Autogenerative High Pressure Digestion (AHPD) conditions. The effects of the operating conditions on the biogas quality, and the substrate utilisation rates were evaluated using 3 AHPD reactors

  8. Job embeddedness, work engagement and turnover intention of staff in a higher education institution: An exploratory study

    Directory of Open Access Journals (Sweden)

    Ndayiziveyi Takawira

    2014-02-01

    Full Text Available Orientation: The world economy is becoming increasingly knowledge driven, and intellectual capital is now considered as a human resource that affords organisations a competitive advantage. A high turnover rate in higher education and the importance of retaining staff are concerns that have resulted in increased interest in psychological variables, such as job embeddedness and work engagement that may influence employee retention.Research purpose: The objective of this study was to explore the relationship between job embeddedness, work engagement and turnover intention of staff in a higher education institution.Motivation for the study: Research on how employees’ job embeddedness and work engagement influence their turnover intention is important in the light of organisational concerns about retaining knowledgeable staff in the current higher education environment.Research design, approach and method: A cross-sectional quantitative survey was conducted on a non-probability purposive sample (N = 153 of academic and non-academic staff in a South African higher education institution.Main findings: Correlational analyses revealed significant relationships between job embeddedness, work engagement and turnover intention. Multiple regression analyses showed that organisational links and dedication significantly and negatively predict turnover intention.Practical/managerial implications: When designing retention strategies, management and human resource practitioners need to recognise how job embeddedness and work engagement influence the turnover intention of higher education staff.Contribution: These findings contribute valuable new knowledge that can be applied in the retention of staff in the higher education environment.

  9. Using the Job-Demands-Resources model to predict turnover in the information technology workforce – General effects and gender

    Directory of Open Access Journals (Sweden)

    Peter Hoonakker

    2014-01-01

    Full Text Available High employee turnover has always been a major issue for Information Technology (IT. In particular, turnover of women is very high. In this study, we used the Job Demand/Resources (JD-R model to examine the relationship between job demands and job resources, stress/burnout and job satisfaction/commitment, and turnover intention and tested the model for gender differences. Data were collected in five IT companies. A sample of 624 respondents (return rate: 56%; 54% males; mean age: 39.7 years was available for statistical analyses. Results of our study show that relationships between job demands and turnover intention are mediated by emotional exhaustion (burnout and relationships between job resources and turnover intention are mediated by job satisfaction. We found noticeable gender differences in these relationships, which can explain differences in turnover intention between male and female employees. The results of our study have consequences for organizational retention strategies to keep men and women in the IT work force.

  10. Listening to the voices of children in foster care: youths speak out about child welfare workforce turnover and selection.

    Science.gov (United States)

    Strolin-Goltzman, Jessica; Kollar, Sharon; Trinkle, Joanne

    2010-01-01

    Child welfare workforce turnover rates across private and public child welfare agencies are concerning. Although research about the causes of child welfare workforce turnover has been plentiful, empirical studies on the effects of turnover on child outcomes are sparse. Furthermore, the voices and experiences of youths within the system have been largely overlooked.The purpose ofthis study was, first, to explore the experiences and opinions about child welfare workforce turnover and retention of youths in the child welfare system; second, to explore a relationship between the number of caseworkers a youth has had and his or her number of foster care placements; and third, to harness the suggestions of youths in resolving the turnover problem. Youths in the child welfare system (N = 25) participated in focus groups and completed a small demographic survey. Findings suggest that youths experience multiple effects of workforce turnover, such as lack of stability; loss of trusting relationships; and, at times, second chances. The article concludes with suggestions for caseworkers, state trainers, local and state administrators, and social work researchers on engaging with youths in relationships that facilitate genuine systems change around social work practice and the child welfare workforce crisis.

  11. Ethical Climate and Job Attitude in Fashion Retail Employees’ Turnover Intention, and Perceived Organizational Sustainability Performance: A Cross-Sectional Study

    National Research Council Canada - National Science Library

    Stacy H Lee; Jung Ha-Brookshire

    2017-01-01

    The relationship between the fashion retail industry’s working environment and the high rate of employee turnover has been highlighted as one of the key concerns for negative organizational performance in both the short and long term...

  12. Acute effects of dichloroacetate in the depancreatized dog: glucose synthesis and turnover.

    Science.gov (United States)

    Searle, G L; Felts, J M; Shakelford, R

    1982-07-01

    Blood glucose turnover (entry and removal rates) and the rate of recycling of radiolabelled glucose carbon into newly synthesized blood glucose have been evaluated before and acutely after the administration of dichloroacetate to depancreatized dogs. Blood glucose concentration began to decline immediately after dichloroacetate administration and fell to new steady state levels within 1.5-3 h. Analysis of blood glucose kinetics during the decline demonstrated a 52% (average) reduction in the rate of hepatic glucose supply. Glucose supply remained reduced over the duration of these studies (3-4.5 h). Glucose turnover in the steady state following dichloroacetate administration averaged 62% of pretreatment values. Cori cycle activity was depressed by 63% after dichloroacetate administration. The results of these studies are consistent with the hypothesis that a major mechanism underlying the hypoglycaemic action of this drug is the inhibition of glucose synthesis.

  13. Relationship between turnover and periodic health check-up data among Japanese hospital nurses: a three-year follow-up study.

    Science.gov (United States)

    Shimizu, Takashi; Eto, Risa; Horiguchi, Itsuko; Obata, Yasuko; Feng, Qiaolian; Nagata, Shoji

    2005-07-01

    The present study explored the relationship between turnover and periodic health check-up data among Japanese hospital nurses. The subjects were 379 registered nurses in a Japanese hospital and the duration of our study period was three years. By the proportional hazard model, we investigated the relative risks (RRs) of the turnover rate associated with the following: lifestyles (irregularity of meals, taking breakfast), work environment (working hours, work schedule), and health status (body mass index [BMI], serum total cholesterol [T-cho], taking medication, sleep disturbance). We obtained the data on turnover from October, 1997 to September, 2000. During the observed period we were able to follow up on 363 female nurses (96%) and the turnover total amongst them was 100. We divided the subjects into a younger (21-25-yr-old) and an older (>25-yr-old) group because of the interaction between age and turnover. In the younger group, we found that sleep disturbance influenced turnover significantly. On the other hand, in the older nurses, BMI and T-cho contributed to turnover significantly. Our results imply the possibility of a partial association between turnover and periodic health check-up data among the nurses.

  14. Investigation on the turnover of plant proteins. 2. Protein turnover in epicotyl segments of Pisum sativum L. influenced by 2'-methyl-4'-chlorophenoxy acetic acid (MCPA)

    Energy Technology Data Exchange (ETDEWEB)

    Becker, R.; Winkler, E.; Jung, K.; Huebner, G. (Akademie der Wissenschaften der DDR, Leipzig. Zentralinstitut fuer Isotopen- und Strahlenforschung)

    1981-01-01

    Based on kinetic analyses of amino acid and protein turnover by means of compartment models the synthesis and degradation of the soluble proteins in etiolated epicotyl segments of Pisum sativum L. as well as their dependence on the herbicide 2'-methyl-4'-chlorophenoxyacetic acid (MCPA) were determined quantitatively. The segments were incubated for 10 h in a medium containing /sup 14/C-leucine and subsequently placed in an inactive medium. The radioactivity in the soluble proteins and in the amino acid fraction was followed up for a total of 24 h. A 3-pool model in which the total measurable amino acid pool was divided into a direct precursor pool for protein synthesis and into a degradation pool was best suited to interpret the data. The turnover rate for the soluble proteins of untreated epicotyl segments was determined to be 0.058 h/sup -1/; at an MCPA concentration of 10/sup -4/ M this value was nearly doubled. An increased proteolytic activity in the epicotyl segments ran parallel to the change of the turnover rate in dependence on MCPA concentration. The heterogeneity of the soluble protein with respect to the turnover rate was investigated by means of /sup 3/H//sup 14/C double labelling for individual protein fractions separated by gel electrophoresis. The results obtained in this way were comparable with those of the total pool turnover.

  15. The need for power, brain norepinephrine turnover and learning.

    Science.gov (United States)

    McClelland, D C; Davidson, R; Saron, C; Floor, E

    1980-03-01

    This experiment was designed to explore whether brain norepinephrine (NE) serves as a specific reward system for the power drive. Previous research has indicated that 3-methoxy-4-hydroxyphenyl glycol (MHPG), a urinary metabolite reflecting central NE turnover, is positively correlated with features of assertiveness which one might expect of a person high in the need for power (n power) or in a state of aroused power motivation. Twenty-seven male undergraduates, 13 of whom were high and 14 of whom were low in n power as assessed by a TAT measure, were recruited as subjects. Before and after the laboratory session, subjects voided all urine and concentrations of epinephrine, norepinephrine and MHPG were obtained from samples. The laboratory task consisted of 20 picture-word pairs in which the subject had to learn to anticipate the word associated with each picture before the word was presented. Five pairs of stimuli in each of the following picture-word combinations were presented 12 times: neutral-neutral, neutral-power, power-neutral and power-power. The results revealed that, as predicted, subjects high in n power learn most power-related material faster than subjects low in n power. The need for achievement is unrelated to the learning of any picture-word pairs. The neurochemical data indicated that subjects maintaining a relatively high MHPG excretion rate during the experiment who were also high in n power showed the greatest mastery of power related compared with neutral picture-word pairs. These findings are consistent with the hypothesis that brain NE turnover is specifically related to the learning of power-related responses in subjects high in n power.

  16. Single Turnover Autophosphorylation Cycle of the PKA RIIβ Holoenzyme.

    Science.gov (United States)

    Zhang, Ping; Knape, Matthias J; Ahuja, Lalima G; Keshwani, Malik M; King, Charles C; Sastri, Mira; Herberg, Friedrich W; Taylor, Susan S

    2015-07-01

    To provide tight spatiotemporal signaling control, the cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) holoenzyme typically nucleates a macromolecular complex or a "PKA signalosome." Using the RIIβ holoenzyme as a prototype, we show how autophosphorylation/dephosphorylation of the RIIβ subunit, as well as cAMP and metal ions, contribute to the dynamics of PKA signaling. While we showed previously that the RIIβ holoenzyme could undergo a single turnover autophosphorylation with adenosine triphosphate and magnesium (MgATP) and trap both products in the crystal lattice, we asked here whether calcium could trap an ATP:RIIβ holoenzyme since the RIIβ holoenzyme is located close to ion channels. The 2.8Å structure of an RIIβp2:C2:(Ca2ADP)2 holoenzyme, supported by biochemical and biophysical data, reveals a trapped single phosphorylation event similar to MgATP. Thus, calcium can mediate a single turnover event with either ATP or adenosine-5'-(β,γ-imido)triphosphate (AMP-PNP), even though it cannot support steady-state catalysis efficiently. The holoenzyme serves as a "product trap" because of the slow off-rate of the pRIIβ subunit, which is controlled by cAMP, not by phosphorylation of the inhibitor site. By quantitatively defining the RIIβ signaling cycle, we show that release of pRIIβ in the presence of cAMP is reduced by calcium, whereas autophosphorylation at the phosphorylation site (P-site) inhibits holoenzyme reassociation with the catalytic subunit. Adding a single phosphoryl group to the preformed RIIβ holoenzyme thus creates a signaling cycle in which phosphatases become an essential partner. This previously unappreciated molecular mechanism is an integral part of PKA signaling for type II holoenzymes.

  17. An application of Six Sigma methodology to turnover intentions in health care.

    Science.gov (United States)

    Taner, Mehmet

    2009-01-01

    The purpose of this study is to show how the principles of Six Sigma can be applied to the high turnover problem of doctors in medical emergency services and paramedic backup. Six Sigma's define-measure-analyse-improve-control (DMAIC) is applied for reducing the turnover rate of doctors in an organisation operating in emergency services. Variables of the model are determined. Explanatory factor analysis, multiple regression, analysis of variance (ANOVA) and Gage R&R are employed for the analysis. Personal burnout/stress and dissatisfaction from salary were found to be the "vital few" variables. The organisation took a new approach by improving its initiatives to doctors' working conditions. Sigma level of the process is increased. New policy and process changes have been found to effectively decrease the incidence of turnover intentions. The improved process is gained, standardised and institutionalised. This study is one of the few papers in the literature that elaborates the turnover problem of doctors working in the emergency and paramedic backup services.

  18. Two-color fluorescent analysis of connexin 36 turnover: relationship to functional plasticity.

    Science.gov (United States)

    Wang, Helen Yanran; Lin, Ya-Ping; Mitchell, Cheryl K; Ram, Sripad; O'Brien, John

    2015-11-01

    Gap junctions formed of connexin 36 (Cx36, also known as Gjd2) show tremendous functional plasticity on several time scales. Changes in connexin phosphorylation modify coupling in minutes through an order of magnitude, but recent studies also imply involvement of connexin turnover in regulating cell-cell communication. We utilized Cx36 with an internal HaloTag to study Cx36 turnover and trafficking in cultured cells. Irreversible, covalent pulse-chase labeling with fluorescent HaloTag ligands allowed clear discrimination of newly formed and pre-existing Cx36. Cx36 in junctional plaques turned over with a half-life of 3.1 h, and the turnover rate was unchanged by manipulations of protein kinase A (PKA) activity. In contrast, changes in PKA activity altered coupling within 20 min. New Cx36 in cargo vesicles was added directly to existing gap junctions and newly made Cx36 was not confined to points of addition, but diffused throughout existing gap junctions. Existing connexins also diffused into photobleached areas with a half-time of less than 2 s. In conclusion, studies of Cx36-HaloTag revealed novel features of connexin trafficking and demonstrated that phosphorylation-based changes in coupling occur on a different time scale than turnover. © 2015. Published by The Company of Biologists Ltd.

  19. Suboptimal provision of preventive healthcare due to expected enrollee turnover among private insurers.

    Science.gov (United States)

    Herring, Bradley

    2010-04-01

    Many preventive healthcare procedures are widely recognized as cost-effective but have relatively low utilization rates in the US. Because preventive care is a present-period investment with a future-period expected financial return, enrollee turnover among private insurers lowers the expected return of this investment. In this paper, I present a simple theoretical model to illustrate the suboptimal provision of preventive healthcare that results from insurers 'free riding' off of the provision from others. I also provide an empirical test of this hypothesis using data from the Community Tracking Study's Household Survey. I use lagged market-level measures of employment-induced insurer turnover to identify variation in insurers' expectations and test for the effect of turnover on several different measures of medical utilization. As expected, I find that turnover has a significantly negative effect on the utilization of preventive services and has no effect on the utilization of acute services used as a control. Copyright (c) 2009 John Wiley & Sons, Ltd.

  20. Evaluation of clinical trials by Ethics Committees in Germany – results and a comparison of two surveys performed among members of the German Association of Research-Based Pharmaceutical Companies (vfa

    Directory of Open Access Journals (Sweden)

    Russ, Hagen

    2015-01-01

    Full Text Available [english] Objective: The objective of this project was to evaluate the quality and quantity of initial applications for a clinical trial according to § 7 of the German Good Clinical Practice (GCP ordinance (German: GCP-Verordnung, GCP-V, the quality of evaluations of those applications by Ethics Committees (ECs/Investigational Review Boards (IRBs in Germany as well as the pattern of EC objections in their reasoned opinions (vote. In order to identify a change over time, the results of the present survey were also compared with a survey performed in 2008.Methods: Based on reasoned opinions issued by the respective EC in charge of the coordinating principle investigator (coordinating EC in 2011, a written survey among members of the German Association of Research-Based Pharmaceutical Companies (vfa was conducted in 2012. The answers to the questionnaire were analyzed descriptively. Since the data set collected in 2011 was structurally identical with the data set gained in 2007 both surveys were compared.Results: Of the 24 companies represented on the vfa Clinical Research/Quality Assurance Subcommittee, 75% (18 took part in the survey. Survey evaluation was based on a total of 251 applications of these 18 companies submitted to 43 ECs. These account for about 21% of 1,214 applications for authorization of commercial and non-commercial phase I–IV clinical trials submitted to the regulatory authorities (BfArM and PEI in 2011.In comparison to 2007, a lower amount of applications (n=251 in 2011 vs. n=288 in 2007 was submitted to a slightly higher number of ECs (43 in 2011 vs. 40 in 2007. The amount of objections increased by 21% from 1,299 (2007 to 1,574 (2011 resulting in an average of 4.5 (2007 vs. 6.3 (2011 objections per application. Overall, the analysis of both formal and content related objections revealed almost the same pattern as in the previous survey. In total, the most frequent objections applied to the patient information and consent

  1. Bone mass and turnover in fibromyalgia

    DEFF Research Database (Denmark)

    Jacobsen, Søren; Gam, A; Egsmose, C

    1993-01-01

    Physical inactivity accelerates bone loss. Since patients with fibromyalgia are relatively physically inactive, bone mass and markers of bone metabolism were determined in 12 premenopausal women with fibromyalgia and in healthy age matched female control subjects. No differences were found...... in lumbar bone mineral density, femoral neck bone mineral density, serum levels of alkaline phosphatase, osteocalcin, ionized calcium and phosphate. The urinary excretion of both hydroxyproline and calcium relative to urinary creatinine excretion was significantly higher in patients with fibromyalgia, p = 0.......01. This was linked to lower urinary creatinine excretion (p = 0.02) probably reflecting lower physical activity in the patients with fibromyalgia. We conclude that bone mass and turnover are generally not affected in premenopausal women with fibromyalgia....

  2. Organizational commitment and turnover intentions in humanitarian organizations

    NARCIS (Netherlands)

    Wijnmalen, Julia; Heyse, Liesbet; Voordijk, Hans

    2016-01-01

    Unwanted staff turnover is a prominent HRM problem in humanitarian organisations. In the profit sector, HRM tools such as pay, benefits, socialisation and training have proven to be effective in increasing organisational commitment and decreasing staff turnover. This study explores whether such

  3. How Multiple Interventions Influenced Employee Turnover: A Case Study.

    Science.gov (United States)

    Hatcher, Timothy

    1999-01-01

    A 3-year study of 46 textile industry workers identified causes of employee turnover (supervision, training, organizational communication) using performance analysis. A study of multiple interventions based on the analysis resulted in changes in orientation procedures, organizational leadership, and climate, reducing turnover by 24%. (SK)

  4. Survey of pay satisfaction, job satisfaction and employee turnover in ...

    African Journals Online (AJOL)

    Survey of pay satisfaction, job satisfaction and employee turnover in selected business organisations in Lagos, Nigeria. ... Global Journal of Social Sciences ... The study was an attempt at investigating the relatedness of pay satisfaction, job satisfaction and employee turnover in business organizations in Lagos Nigeria.

  5. Performance and turnover intentions: a social exchange perspective

    NARCIS (Netherlands)

    Biron, M.; Boon, C.

    2013-01-01

    Purpose - Prior research has yielded mixed results regarding the relationship between performance and turnover intentions. Drawing from social exchange theory, the purpose of this paper is to propose that the performance-turnover intentions association may be contingent upon individuals' exchange

  6. Managing teacher turnover | Xaba | South African Journal of Education

    African Journals Online (AJOL)

    Concerns about educator turnover and attrition are reported widely as a global phenomenon. Turnover translates, amongst other things, into shortages in educator supply, costs in recruitment, training and mentoring, poor learner performance due to disruption of planning programmes and continuity, as well as overcrowded ...

  7. Below the Surface of Special Education Administrator Turnover

    Science.gov (United States)

    Meeks, Amy

    2016-01-01

    The field of special education administration has experienced a shortage of high quality special education leadership candidates for several decades. If school districts are to effectively address the turnover of educational leaders, they must know what is happening that affects turnover of their leadership team. The intent of this study was to…

  8. The Link between Training Satisfaction, Work Engagement and Turnover Intention

    Science.gov (United States)

    Memon, Mumtaz Ali; Salleh, Rohani; Baharom, Mohamed Noor Rosli

    2016-01-01

    Purpose: The purpose of this paper is to examine the casual relationship between training satisfaction, work engagement (WE) and turnover intention and the mediating role of WE between training satisfaction and turnover intention. Design/methodology/approach: Data were collected from 409 oil and gas professionals using an email survey…

  9. Regulatory mechanisms of skeletal muscle protein turnover during exercise

    DEFF Research Database (Denmark)

    Rose, Adam John; Richter, Erik

    2009-01-01

    Skeletal muscle protein turnover is a relatively slow metabolic process that is altered by various physiological stimuli such as feeding/fasting and exercise. During exercise, catabolism of amino acids contributes very little to ATP turnover in working muscle. With regards to protein turnover......, there is now consistent data from tracer studies in rodents and humans showing that global protein synthesis is blunted in working skeletal muscle. Whether there is altered skeletal muscle protein breakdown during exercise remains unclear. The blunting of protein synthesis is believed to be mediated...... downstream of changes in intracellular Ca(2+) and energy turnover. In particular, a signaling cascade involving Ca(2+)-calmodulin-eEF2 kinase-eEF2 is implicated. The possible functional significance of altered protein turnover in working skeletal muscle during exercise is discussed. Further work...

  10. Pitfalls in quantifying species turnover: the residency effect

    Directory of Open Access Journals (Sweden)

    Kevin Chase Burns

    2014-03-01

    Full Text Available The composition of ecological communities changes continuously through time and space. Understanding this turnover in species composition is a central goal in biogeography, but quantifying species turnover can be problematic. Here, I describe an underappreciated source of bias in quantifying species turnover, namely ‘the residency effect’, which occurs when the contiguous distributions of species across sampling domains are small relative to census intervals. I present the results of a simulation model that illustrates the problem theoretically and then I demonstrate the problem empirically using a long-term dataset of plant species turnover on islands. Results from both exercises indicate that empirical estimates of species turnover may be susceptible to significant observer bias, which may potentially cloud a better understanding of how the composition of ecological communities changes through time.

  11. Sexual selection affects local extinction and turnover in bird communities

    Science.gov (United States)

    Doherty, P.F.; Sorci, G.; Royle, J. Andrew; Hines, J.E.; Nichols, J.D.; Boulinier, T.

    2003-01-01

    Predicting extinction risks has become a central goal for conservation and evolutionary biologists interested in population and community dynamics. Several factors have been put forward to explain risks of extinction, including ecological and life history characteristics of individuals. For instance, factors that affect the balance between natality and mortality can have profound effects on population persistence. Sexual selection has been identified as one such factor. Populations under strong sexual selection experience a number of costs ranging from increased predation and parasitism to enhanced sensitivity to environmental and demographic stochasticity. These findings have led to the prediction that local extinction rates should be higher for species/populations with intense sexual selection. We tested this prediction by analyzing the dynamics of natural bird communities at a continental scale over a period of 21 years (1975-1996), using relevant statistical tools. In agreement with the theoretical prediction, we found that sexual selection increased risks of local extinction (dichromatic birds had on average a 23% higher local extinction rate than monochromatic species). However, despite higher local extinction probabilities, the number of dichromatic species did not decrease over the period considered in this study. This pattern was caused by higher local turnover rates of dichromatic species, resulting in relatively stable communities for both groups of species. Our results suggest that these communities function as metacommunities, with frequent local extinctions followed by colonization. Anthropogenic factors impeding dispersal might therefore have a significant impact on the global persistence of sexually selected species.

  12. Pancreatic enzyme synthesis and turnover in human subjects.

    Science.gov (United States)

    O'Keefe, S J; Bennet, W M; Zinsmeister, A R; Haymond, M W

    1994-05-01

    Animal studies have shown that pancreatic enzyme secretion is independent of enzyme synthesis. To investigate this relationship in humans, we have coinfused 14C-labeled leucine tracer with cholecystokinin octapeptide in nine healthy adults for 4 h and measured the rate of appearance of secreted and newly labeled enzymes in the duodenum. Enzyme secretion was well maintained throughout, but newly labeled enzymes only appeared in juice between 75 and 101 min (median time, 86 min), indicating that initial secretion was dependent on the release of zymogen stores and that the median production time for new enzymes was 86 min. Between 85 and 225 min there was a curvilinear increase in the enrichment of secreted enzymes with newly synthesized enzymes, suggesting a median turnover rate of zymogen stores of 29%/h (range 12-47%/h). In conclusion, our results suggest that in healthy humans, postprandial pancreatic enzyme secretion is maintained by the export of a large stored pool and is not rate limited by enzyme synthesis, since it takes approximately 86 min for newly synthesized enzymes to take part in the digestive process.

  13. Global Proteome Turnover Analyses of the Yeasts S. cerevisiae and S. pombe

    Directory of Open Access Journals (Sweden)

    Romain Christiano

    2014-12-01

    Full Text Available How cells maintain specific levels of each protein and whether that control is evolutionarily conserved are key questions. Here, we report proteome-wide steady-state protein turnover rate measurements for the evolutionarily distant but ecologically similar yeasts, Saccharomyces cerevisiae and Schizosaccharomyces pombe. We find that the half-life of most proteins is much longer than currently thought and determined to a large degree by protein synthesis and dilution due to cell division. However, we detect a significant subset of proteins (∼15% in both yeasts that are turned over rapidly. In addition, the relative abundances of orthologous proteins between the two yeasts are highly conserved across the 400 million years of evolution. In contrast, their respective turnover rates differ considerably. Our data provide a high-confidence resource for studying protein degradation in common yeast model systems.

  14. Increased precipitation accelerates soil organic matter turnover associated with microbial community composition in topsoil of alpine grassland on the eastern Tibetan Plateau.

    Science.gov (United States)

    Han, Conghai; Wang, Zongli; Si, Guicai; Lei, Tianzhu; Yuan, Yanli; Zhang, Gengxin

    2017-10-01

    Large quantities of carbon are stored in alpine grassland of the Tibetan Plateau, which is extremely sensitive to climate change. However, it remains unclear whether soil organic matter (SOM) in different layers responds to climate change analogously, and whether microbial communities play vital roles in SOM turnover of topsoil. In this study we measured and collected SOM turnover by the (14)C method in alpine grassland to test climatic effects on SOM turnover in soil profiles. Edaphic properties and microbial communities in the northwestern Qinghai Lake were investigated to explore microbial influence on SOM turnover. SOM turnover in surface soil (0-10 cm) was more sensitive to precipitation than that in subsurface layers (10-40 cm). Precipitation also imposed stronger effects on the composition of microbial communities in the surface layer than that in deeper soil. At the 5-10 cm depth, the SOM turnover rate was positively associated with the bacteria/fungi biomass ratio and the relative abundance of Acidobacteria, both of which are related to precipitation. Partial correlation analysis suggested that increased precipitation could accelerate the SOM turnover rate in topsoil by structuring soil microbial communities. Conversely, carbon stored in deep soil would be barely affected by climate change. Our results provide valuable insights into the dynamics and storage of SOM in alpine grasslands under future climate scenarios.

  15. Turnover intention among intensive care unit nurses in Alexandria, Egypt.

    Science.gov (United States)

    Mosallam, Rasha; Hamidi, Samer; Elrefaay, Manal

    2015-06-01

    Given the difficulty in recruiting new nurses, it is imperative to retain those already in the profession. This cross-sectional study explored the relationship of demographic and work-related factors, burnout, conflict management and relationship between nurses and physicians on turnover intentions among ICU nurses in eight major hospitals in Alexandria, Egypt. Data on burnout, conflict management, nurse-physician communication, and turnover intention were collected by surveying 100 nurses in eight hospitals in Alexandria governorate. All nurses at the ICU of selected hospitals were approached (n=100) and a 47-item Likert scale questionnaire was administered to explore the factors affecting the turnover intention of ICU nurses in Alexandria. ICU nurses exhibited a mean score for turnover intention of 3.23 (mean score percentage 65.0%). There was a moderately positive statistically significant correlation between turnover intention and emotional exhaustion (r=0.29, P<0.05), nurse-physician communication (r=0.25, P<0.05), and age (r=0.21, P<0.05). The predicting factors for turnover intention were emotional exhaustion and age. Nurses turnover intention at the ICU of the selected hospitals is high and is significantly associated with nurses' emotional exhaustion, poor nurse-physician communication, and nurses age.

  16. Dynamics of human adipose lipid turnover in health and metabolic disease.

    Science.gov (United States)

    Arner, Peter; Bernard, Samuel; Salehpour, Mehran; Possnert, Göran; Liebl, Jakob; Steier, Peter; Buchholz, Bruce A; Eriksson, Mats; Arner, Erik; Hauner, Hans; Skurk, Thomas; Rydén, Mikael; Frayn, Keith N; Spalding, Kirsty L

    2011-09-25

    Adipose tissue mass is determined by the storage and removal of triglycerides in adipocytes. Little is known, however, about adipose lipid turnover in humans in health and pathology. To study this in vivo, here we determined lipid age by measuring (14)C derived from above ground nuclear bomb tests in adipocyte lipids. We report that during the average ten-year lifespan of human adipocytes, triglycerides are renewed six times. Lipid age is independent of adipocyte size, is very stable across a wide range of adult ages and does not differ between genders. Adipocyte lipid turnover, however, is strongly related to conditions with disturbed lipid metabolism. In obesity, triglyceride removal rate (lipolysis followed by oxidation) is decreased and the amount of triglycerides stored each year is increased. In contrast, both lipid removal and storage rates are decreased in non-obese patients diagnosed with the most common hereditary form of dyslipidaemia, familial combined hyperlipidaemia. Lipid removal rate is positively correlated with the capacity of adipocytes to break down triglycerides, as assessed through lipolysis, and is inversely related to insulin resistance. Our data support a mechanism in which adipocyte lipid storage and removal have different roles in health and pathology. High storage but low triglyceride removal promotes fat tissue accumulation and obesity. Reduction of both triglyceride storage and removal decreases lipid shunting through adipose tissue and thus promotes dyslipidaemia. We identify adipocyte lipid turnover as a novel target for prevention and treatment of metabolic disease.

  17. Employee turnover and productivity among small business entities in Nigeria

    Directory of Open Access Journals (Sweden)

    John N. N. Ugoani

    2016-12-01

    Full Text Available This study was designed to evaluate the problems of employee turnover on productivity among small business entities in Nigeria, and recommend remedial actions. Employee turnover is the separation of employees from employers and replacement with other employees. Productive manpower is a critical element for the economic survival of any small business entity. The survey research design was used for the study. The sample comprised of 320 respondents. Data generated were analyzed by using descriptive, and Z-test statistical techniques. It was found that employee turnover adversely affects productivity in small business entities.

  18. Higher Dissatisfaction Higher Turnover in the Hospitality Industry

    OpenAIRE

    Ahmad Rasmi AlBattat; Ahmad Puad Mat Som; Abdullah Saleh Helalat

    2014-01-01

    Turnover crisis reducing has been highlighted as a remarkable research theme in the hospitality industry. Regardless of the significant number of studies on employee turnover, it remains a vague issue and requires further research, It is well known that the service industry is highly dependent on the “human factor” which has become a major part of the hospitality product. The aim of this study is to give a clearer idea of enhancing employment factors to reduce the turnover crisis, Mobley`s mo...

  19. Plant traits and environment: floating leaf blade production and turnover of waterlilies.

    Science.gov (United States)

    Klok, Peter F; van der Velde, Gerard

    2017-01-01

    Floating leaf blades of waterlilies fulfill several functions in wetland ecosystems by production, decomposition and turnover as well as exchange processes. Production and turnover rates of floating leaf blades of three waterlily species, Nuphar lutea (L.) Sm., Nymphaea alba L. and Nymphaea candida Presl, were studied in three freshwater bodies, differing in trophic status, pH and alkalinity. Length and percentages of leaf loss of marked leaf blades were measured weekly during the growing season. Area and biomass were calculated based on leaf length and were used to calculate the turnover rate of floating leaf blades. Seasonal changes in floating leaf production showed that values decreased in the order: Nymphaea alba , Nuphar lutea , Nymphaea candida . The highest production was reached for Nuphar lutea and Nymphaea alba in alkaline, eutrophic water bodies. The production per leaf was relatively high for both species in the acid water body. Nymphaea candida showed a very short vegetation period and low turnover rates. The ratio Total potential leaf biomass/Maximum potential leaf biomass (P/B max ) of the three species ranged from 1.35-2.25. The ratio Vegetation period (Period with floating leaves)/Mean leaf life span ranged from 2.94-4.63, the ratio Growth period (Period with appearance of new floating leaves)/Vegetation period from 0.53-0.73. The clear differences between Nymphaea candida versus Nuphar lutea and Nymphaea alba , may be due to adaptations of Nymphaea candida to an Euro-Siberic climate with short-lasting summer conditions.

  20. Plant traits and environment: floating leaf blade production and turnover of waterlilies

    Directory of Open Access Journals (Sweden)

    Peter F. Klok

    2017-04-01

    Full Text Available Floating leaf blades of waterlilies fulfill several functions in wetland ecosystems by production, decomposition and turnover as well as exchange processes. Production and turnover rates of floating leaf blades of three waterlily species, Nuphar lutea (L. Sm., Nymphaea alba L. and Nymphaea candida Presl, were studied in three freshwater bodies, differing in trophic status, pH and alkalinity. Length and percentages of leaf loss of marked leaf blades were measured weekly during the growing season. Area and biomass were calculated based on leaf length and were used to calculate the turnover rate of floating leaf blades. Seasonal changes in floating leaf production showed that values decreased in the order: Nymphaea alba, Nuphar lutea, Nymphaea candida. The highest production was reached for Nuphar lutea and Nymphaea alba in alkaline, eutrophic water bodies. The production per leaf was relatively high for both species in the acid water body. Nymphaea candida showed a very short vegetation period and low turnover rates. The ratio Total potential leaf biomass/Maximum potential leaf biomass (P/Bmax of the three species ranged from 1.35–2.25. The ratio Vegetation period (Period with floating leaves/Mean leaf life span ranged from 2.94–4.63, the ratio Growth period (Period with appearance of new floating leaves/Vegetation period from 0.53–0.73. The clear differences between Nymphaea candida versus Nuphar lutea and Nymphaea alba, may be due to adaptations of Nymphaea candida to an Euro-Siberic climate with short-lasting summer conditions.

  1. Level of dietary protein intake affects glucose turnover in endurance-trained men

    Directory of Open Access Journals (Sweden)

    Pasiakos Stefan M

    2011-11-01

    Full Text Available Abstract Background To examine the effects of higher-protein diets on endogenous glucose metabolism in healthy, physically active adults, glucose turnover was assessed in five endurance-trained men (age 21.3 ± 0.3 y, VO2peak 70.6 ± 0.1 mL kg-1 min-1 who consumed dietary protein intakes spanning the current dietary reference intakes. Findings Using a randomized, crossover design, volunteers consumed 4 week eucaloric diets providing either a low (0.8 g kg-1 d-1; LP, moderate (1.8 g kg-1 d-1; MP, or high (3.6 g kg-1 d-1; HP level of dietary protein. Glucose turnover (Ra, glucose rate of appearance; and Rd glucose rate of disappearance was assessed under fasted, resting conditions using primed, constant infusions of [6,6-2H2] glucose. Glucose Ra and Rd (mg kg-1 min-1 were higher for MP (2.8 ± 0.1 and 2.7 ± 0.1 compared to HP (2.4 ± 0.1 and 2.3 ± 0.2, P P P > 0.05 between LP (4.6 ± 0.1, MP (4.8 ± 0.1, and HP (4.7 ± 0.1 diets. Conclusions Level of protein consumption influenced resting glucose turnover in endurance athletes in a state of energy balance with a higher rate of turnover noted for a protein intake of 1.8 g kg-1 d-1. Findings suggest that consumption of protein in excess of the recommended dietary allowance but within the current acceptable macronutrient distribution range may contribute to the regulation of blood glucose when carbohydrate intake is reduced by serving as a gluconeogenic substrate in endurance-trained men.

  2. Turnover of microbial groups and cell components in soil: 13C analysis of cellular biomarkers

    Science.gov (United States)

    Gunina, Anna; Dippold, Michaela; Glaser, Bruno; Kuzyakov, Yakov

    2017-01-01

    Microorganisms regulate the carbon (C) cycle in soil, controlling the utilization and recycling of organic substances. To reveal the contribution of particular microbial groups to C utilization and turnover within the microbial cells, the fate of 13C-labelled glucose was studied under field conditions. Glucose-derived 13C was traced in cytosol, amino sugars and phospholipid fatty acid (PLFA) pools at intervals of 3, 10 and 50 days after glucose addition into the soil. 13C enrichment in PLFAs ( ˜ 1.5 % of PLFA C at day 3) was an order of magnitude greater than in cytosol, showing the importance of cell membranes for initial C utilization. The 13C enrichment in amino sugars of living microorganisms at day 3 accounted for 0.57 % of total C pool; as a result, we infer that the replacement of C in cell wall components is 3 times slower than that of cell membranes. The C turnover time in the cytosol (150 days) was 3 times longer than in PLFAs (47 days). Consequently, even though the cytosol pool has the fastest processing rates compared to other cellular compartments, intensive recycling of components here leads to a long C turnover time. Both PLFA and amino-sugar profiles indicated that bacteria dominated in glucose utilization. 13C enrichment decreased with time for bacterial cell membrane components, but it remained constant or even increased for filamentous microorganisms. 13C enrichment of muramic acid was the 3.5 times greater than for galactosamine, showing a more rapid turnover of bacterial cell wall components compared to fungal. Thus, bacteria utilize a greater proportion of low-molecular-weight organic substances, whereas filamentous microorganisms are responsible for further C transformations. Thus, tracing 13C in cellular compounds with contrasting turnover rates elucidated the role of microbial groups and their cellular compartments in C utilization and recycling in soil. The results also reflect that microbial C turnover is not restricted to the death or

  3. Continuous liquid fermentation of pretreated waste activated sludge for high rate volatile fatty acids production and online nutrients recovery.

    Science.gov (United States)

    Zhang, Lihui; Liu, He; Zheng, Zhiyong; Ma, Huijun; Yang, Meng; Liu, Hongbo

    2017-11-04

    Raw sludge was pretreated, and the separated sludge liquid was used as substrate in a continuous operated up-flow anaerobic sludge blanket reactor to produce volatile fatty acids (VFAs). The highest VFA productivity of continuous fermentation with sludge liquid at an organic loading rate (OLR) of 10.0 kg COD/m3/d was about 5.0-fold and 4.0-fold higher than batch and semi-continuous fermentation with pretreated sludge slurry, respectively. Moreover, the liquid fermentation with an OLR of 10.0 kg COD/m3/d consumed the least energy, which was about 10.57% and 12.12% of batch and semi-continuous sludge fermentation, respectively. When combined with online nitrogen and phosphorus recovery, VFA production further increased by 20.67% and struvite recovery efficiency reached 1.98  ±  0.28 g/g PO43-. The process showed high VFA production, low energy consumption and good nutrients recovery by continuous liquid anaerobic fermentation, significantly increasing the economic potential of VFA production from waste activated sludge. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Organic loading rate effect on the acidogenesis of cheese whey: a comparison between UASB and SBR reactors.

    Science.gov (United States)

    Calero, R; Iglesias-Iglesias, R; Kennes, C; Veiga, M C

    2017-09-16

    Volatile fatty acids (VFA) production and degree of acidification (DA) were investigated in the anaerobic treatment of cheese whey by comparison of two processes: a continuous process using a laboratory upflow anaerobic sludge blanket (UASB) reactor and a discontinuous process using a sequencing batch reactor (SBR). The main purpose of this work was to study the organic loading rate (OLR) effect on the yield of VFA in two kinds of reactors. The predominant products in the acidogenic process in both reactors were: acetate, propionate, butyrate and valerate. The maximum DA obtained was 98% in an SBR at OLR of 2.7 g COD L-1 d-1, and 97% in the UASB at OLR at 15.1 g COD L-1 d-1. The results revealed that the UASB reactor was more efficient at a medium OLR with a higher VFA yield, while with the SBR reactor, the maximum acidification was obtained at a lower OLR with changes in the VFA profile at different OLRs applied.

  5. An Infraspec VFA-IR spectrometer analysis of Trans-fat content in glazed donuts purchased from supermarkets, convenience stores and bakeries

    Directory of Open Access Journals (Sweden)

    Sharron Jenkins

    2015-05-01

    Full Text Available Most packaged food products must contain trans-fat labelling; however unpackaged snacks such as cookies, donuts, and muffins at supermarkets, gas station convenience stores, and bakeries often do not have or require nutrition fact labels. Hence, consumers are not aware of the trans-fat content in unpackaged food products. It is well-known within the health and scientific community that diets high in trans-fat can lead to a host of health problems, namely coronary heart disease (CHD. The purpose of this study is to conduct a preliminary study of the trans-fat content in unpackaged baked goods, particularly unpackaged glazed donuts. To accomplish our objective, we determined the % trans-fat in oil extracted from glazed donuts obtained from several supermarkets, gas stations and bakeries across Northwest, Indiana. Variable Filter Array (VFA IR spectroscopy was used to assess the trans-fat content of oil extracted from food samples. In this paper, we present our preliminary findings.

  6. Nurse turnover in substance abuse treatment programs affiliated with the National Drug Abuse Treatment Clinical Trials Network.

    Science.gov (United States)

    Knudsen, Hannah K; Abraham, Amanda J; Roman, Paul M; Studts, Jamie L

    2011-04-01

    Voluntary nurse turnover, which is costly and disrupts patient care, has not been studied as an organizational phenomenon within substance abuse treatment organizations. In this exploratory study, we examined the frequency and correlates of nurse turnover within treatment programs affiliated with the National Drug Abuse Treatment Clinical Trials Network. During face-to-face interviews conducted in 2005-2006, 215 program administrators reported the number of nurses currently employed. Leaders of programs with nursing staff then described the number of nurses who had voluntarily quit in the past year, the degree to which filling vacant nursing positions was difficult, and the average number of days to fill a vacant position. About two thirds of these programs had at least one nurse on staff. In programs with nurses, the average rate of voluntary turnover was 15.0%. Turnover was significantly lower in hospital-based programs and programs offering adolescent treatment but higher in facilities offering residential treatment. Most of the administrators indicated that filling vacant nurse positions was difficult and took more than 2 months to complete. These findings suggest that nurse turnover is a significant issue facing many substance abuse treatment facilities. Efforts to improve retention of the addiction treatment workforce should be expanded to include nursing professionals. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. FOXO/DAF-16 Activation Slows Down Turnover of the Majority of Proteins in C. elegans

    Energy Technology Data Exchange (ETDEWEB)

    Dhondt, Ineke; Petyuk, Vladislav A.; Cai, Huaihan; Vandemeulebroucke, Lieselot; Vierstraete, Andy; Smith, Richard D.; Depuydt, Geert; Braeckman, Bart P.

    2016-09-01

    Cellular protein quality can be maintained by proteolytic elimination of damaged proteins and replacing them with newly synthesized copies, a process called protein turnover (Ward, 2000). Protein turnover rates have been estimated using SILAC (stable isotope labeling by amino acids in cell culture) in prokaryotes and eukaryotes. The last decade has witnessed a growing interest in the analysis of whole-organism proteome dynamics in metazoans using the same approach (Claydon and Beynon, 2012). In recent work, SILAC was applied to monitor protein synthesis throughout life in adult Caenorhabditis elegans (Vukoti et al., 2015) and to investigate food intake (Gomez-Amaro et al., 2015

  8. Volatile fatty acid cycling in organic-rich marine sediments

    Science.gov (United States)

    Sansone, Francis J.; Martens, Christopher S.

    1982-09-01

    Volatile fatty acid (VFA) apparent turnover rates were determined by measuring whole sediment VFA concentrations and the corresponding reaction rate constants. The following ranges of VFA concentrations were measured in Cape Lookout Bight, N.C. sediments (μmole·l s-1): acetate 54-660, propionate 1-24, butyrate iso-butyrate <0.5-6. Apparent turnover rates measured over a one-year period ranged from 18-600 μmole·l s-1·h -1 for acetate and 0.7-7 μmole·l s-1·h -1 for the carboxyl carbon of propionate. Methane production was observed only with acetate and only in sulfatedepleted sediments; total acetate turnover attained approximately the same maximum value in both sulfate-reducing and sulfate-depleted sediments. Apparent turnover rates for acetate and propionate appeared to be controlled by similar factors: in sulfate-reducing (surface) sediments the turnover rates were stimulated by autumn storm-mediated deposition/resuspension events; in deeper sulfate-depleted sediments the turnover rates followed changes in the ambient temperature. Changes in VFA poolsizes were proportionally much larger than changes in corresponding rate constants. The ratio of CO 2 to CH 4 produced from acetate vs. depth suggested that non-methanogenic bacteria accounted for 60% of the acetate turnover in sulfate-depleted sediments. VFA concentrations were much lower in N.C. continental slope mud than in Cape Lookout sediments; acetate was the only VFA detectable throughout the top 40 cm of the slope sediments. The estimated production rate of CO 2 from acetate decreased rapidly with depth. The surface rate was approximately 20 times less than that measured at similar temperatures in sulfate-reducing Cape Lookout sediments.

  9. Protection of myocytes against free radical-induced damage by accelerated turnover of the glutathione redox cycle

    NARCIS (Netherlands)

    Le, C. T.; Hollaar, L.; van der Valk, E. J.; Franken, N. A.; van Ravels, F. J.; Wondergem, J.; van der Laarse, A.

    1995-01-01

    The primary defence mechanism of myocytes against peroxides and peroxide-derived peroxyl and alkoxyl radicals is the glutathione redox cycle. The purpose of the present study was to increase the turnover rate of this cycle by stimulating the glutathione peroxidase catalysed reaction (2GSH-->GSSG),

  10. Report: Remedial Project Manager Turnover at Superfund Sites

    Science.gov (United States)

    Report #2001-M-000015, June 15, 2001. We determined that EPA Region III did not have formal procedures in place to mitigate continuity problems caused by turnover of EPA personnel in the Superfund program.

  11. Higher molecular weight dissolved organic nitrogen turnover as affected by soil management history

    DEFF Research Database (Denmark)

    Lønne Enggrob, Kirsten

    High molecular weight dissolved organic nitrogen turnover as affected by soil management history *Kirsten Lønne Enggrob,1 Lars Elsgaard,1 and Jim Rasmussen1 1Aarhus University, Dept. of Agroecology, Foulum, Denmark 1. Introduction Dissolved organic nitrogen (DON) play an important role in soil N...... cycling. DON, as a collective term, refers to a diversity of organic N compounds which can operationally be grouped into high molecular weight (Mw) DON (Mw > 1 kDa) and low Mw DON (... are presented for 14CO2 evolution during 14 days of incubation. 4. Results and conclusion Results showed that the turnover rate of high Mw DON was dependent on both the Mw size of DON and on the soil liming history. Evidence showing where in the DON Mw sizes the bottleneck lies will be presented....

  12. Exploring Relationships Among Occupational Safety, Job Turnover, and Age Among Home Care Aides in Maine.

    Science.gov (United States)

    Butler, Sandra S

    2017-01-01

    As the U.S. population ages, the number of people needing personal assistance in the home care setting is increasing dramatically. Personal care aides and home health workers are currently adding more jobs to the economy than any other single occupation. Home health workers face physically and emotionally challenging, and at times unsafe, work conditions, with turnover rates ranging from 44 percent to 65 percent annually. As part of a mixed-method, longitudinal study in Maine examining turnover, interviews with 252 home care aides were analyzed thematically. Responses to interview questions regarding the job's impact on health and safety, the adequacy of training, and the level of agency responsiveness were examined. Emergent themes, indicating some contradictory perspectives on workplace safety, quality of training, and agency support, were compared across three variables: job termination, occupational injury, and age. Implications for increasing occupational safety and job retention are discussed.

  13. The relationship between perceptions of organizational functioning and voluntary counselor turnover: A four-wave longitudinal study

    Science.gov (United States)

    Eby, Lillian T.; Rothrauff-Laschober, Tanja C.

    2011-01-01

    Using data from a nationwide study, we annually track a cohort of 598 substance use disorder counselors over a 4-wave period to (1) document the cumulative rates of voluntary turnover and (2) examine how counselor perceptions of the organizational environment (procedural justice, distributive justice, perceived organizational support, job satisfaction) and clinical supervisor leadership effectiveness (relationship quality, in-role performance, extra-role performance) predict voluntary turnover over time. Survey data were collected from counselors in year 1 and actual turnover data were collected from organizational records in year 2, 3, and 4. Findings reveal that 25% of the original counselors turned over by year 2, 39% by year 3, and 47% by year 4. Counselors with more favorable perceptions of the organizational environment are between 13.8% – 22.8% less likely to turn over than those with less favorable perceptions. None of the leadership effectiveness variables are significant. PMID:22116013

  14. Corporate governance mechanisms in family firms: Evidence from CEO turnovers

    OpenAIRE

    González, Maximiliano; Guzmán, Alexander; Pombo, Carlos; Trujillo, María Andréa

    2013-01-01

    Research Question/Issue: How sensitive is CEO turnover to firm performance in the context of family firms? Research Findings/Insights: Using a detailed database of mostly non-listed Colombian firms, we found that family ownership (direct and indirect through pyramidal structures) reduces the probability of CEO turnover when financial performance has been poor; however, we found that the opposite effect is true when families participate actively on the board of directors. These results hold tr...

  15. Predicted Relative Metabolomic Turnover (PRMT): determining metabolic turnover from a coastal marine metagenomic dataset.

    Science.gov (United States)

    Larsen, Peter E; Collart, Frank R; Field, Dawn; Meyer, Folker; Keegan, Kevin P; Henry, Christopher S; McGrath, John; Quinn, John; Gilbert, Jack A

    2011-06-14

    The world's oceans are home to a diverse array of microbial life whose metabolic activity helps to drive the earth's biogeochemical cycles. Metagenomic analysis has revolutionized our access to these communities, providing a system-scale perspective of microbial community interactions. However, while metagenome sequencing can provide useful estimates of the relative change in abundance of specific genes and taxa between environments or over time, this does not investigate the relative changes in the production or consumption of different metabolites. We propose a methodology, Predicted Relative Metabolic Turnover (PRMT) that defines and enables exploration of metabolite-space inferred from the metagenome. Our analysis of metagenomic data from a time-series study in the Western English Channel demonstrated considerable correlations between predicted relative metabolic turnover and seasonal changes in abundance of measured environmental parameters as well as with observed seasonal changes in bacterial population structure. The PRMT method was successfully applied to metagenomic data to explore the Western English Channel microbial metabalome to generate specific, biologically testable hypotheses. Generated hypotheses linked organic phosphate utilization to Gammaproteobactaria, Plantcomycetes, and Betaproteobacteria, chitin degradation to Actinomycetes, and potential small molecule biosynthesis pathways for Lentisphaerae, Chlamydiae, and Crenarchaeota. The PRMT method can be applied as a general tool for the analysis of additional metagenomic or transcriptomic datasets.

  16. Roles of stem cells in tissue turnover and radiation carcinogenesis.

    Science.gov (United States)

    Niwa, Ohtsura

    2010-12-01

    Radiation research has its foundation on the target and hit theories, which assume that the initial stochastic deposition of energy on a sensitive target in a cell determines the final biological outcome. This assumption is rather static in nature but forms the foundation of the linear no-threshold (LNT) model of radiation carcinogenesis. The stochastic treatment of radiation carcinogenesis by the LNT model enables easy calculation of radiation risk, and this has made the LNT model an indispensable tool for radiation protection. However, the LNT model sometimes fails to explain some of the biological and epidemiological data, and this suggests the need for insight into the mechanisms of radiation carcinogenesis. Recent studies have identified unique characteristics of the tissue stem cells and their roles in tissue turnover. In the present report, some important issues of radiation protection such as the risk of low-dose-rate exposures and in utero exposures are discussed in light of the recent advances of stem cell biology.

  17. Telaah Hubungan Kepuasan Kerja Dan Komitmen Organisasional Terhadap Turnover Intention

    Directory of Open Access Journals (Sweden)

    Ali Amran

    2017-04-01

    ABSTRACT       Employees are the most important resources of company. They are human resources to do and move all of the activities of company. Therefore, company needs to keep and maintain their job satisfaction and organizational commitment in order to reduce the intention to leave the company (turnover intention. It is necessary to study the relationship among job satisfaction, organizational commitment and turnover intention. This will give benefit to determine the important values of employees’ job satisfaction and organizational commitment and its influences on turnover intention. The research methods are descriptive survey and verificative survey that is used to assess the performance of independent variables: those are job satisfaction and organizational commitment,  and dependent variable: that is turnover intention with doing observation to employees of PT. Alexindo Bekasi. The result of this research is there is influence of job satisfaction and organizational commitment on turnover intention. This research is the improvement of existing researches which can be applied in the other companies specially for the human resource or employee behavior field.   Keywords: Job Satisfaction, Organizational Commitment, Turnover Intention

  18. Evaluation of climate-related carbon turnover processes in global vegetation models for boreal and temperate forests.

    Science.gov (United States)

    Thurner, Martin; Beer, Christian; Ciais, Philippe; Friend, Andrew D; Ito, Akihiko; Kleidon, Axel; Lomas, Mark R; Quegan, Shaun; Rademacher, Tim T; Schaphoff, Sibyll; Tum, Markus; Wiltshire, Andy; Carvalhais, Nuno

    2017-08-01

    Turnover concepts in state-of-the-art global vegetation models (GVMs) account for various processes, but are often highly simplified and may not include an adequate representation of the dominant processes that shape vegetation carbon turnover rates in real forest ecosystems at a large spatial scale. Here, we evaluate vegetation carbon turnover processes in GVMs participating in the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP, including HYBRID4, JeDi, JULES, LPJml, ORCHIDEE, SDGVM, and VISIT) using estimates of vegetation carbon turnover rate (k) derived from a combination of remote sensing based products of biomass and net primary production (NPP). We find that current model limitations lead to considerable biases in the simulated biomass and in k (severe underestimations by all models except JeDi and VISIT compared to observation-based average k), likely contributing to underestimation of positive feedbacks of the northern forest carbon balance to climate change caused by changes in forest mortality. A need for improved turnover concepts related to frost damage, drought, and insect outbreaks to better reproduce observation-based spatial patterns in k is identified. As direct frost damage effects on mortality are usually not accounted for in these GVMs, simulated relationships between k and winter length in boreal forests are not consistent between different regions and strongly biased compared to the observation-based relationships. Some models show a response of k to drought in temperate forests as a result of impacts of water availability on NPP, growth efficiency or carbon balance dependent mortality as well as soil or litter moisture effects on leaf turnover or fire. However, further direct drought effects such as carbon starvation (only in HYBRID4) or hydraulic failure are usually not taken into account by the investigated GVMs. While they are considered dominant large-scale mortality agents, mortality mechanisms related to insects and

  19. Further examination of predictors of turnover intention among mental health professionals.

    Science.gov (United States)

    Yanchus, N J; Periard, D; Osatuke, K

    2017-02-01

    rates within this workforce are concerning. We used United States of America Veterans Health Administration data to add to the limited knowledge about this topic. Aim We examined predictors of turnover intention, or an employee's cognitive withdrawal from their job, in a large sample of direct care mental health professionals, separating among occupations to increase the pragmatic relevance of our findings. Method Survey data from 10 997 mental health employees working in direct patient contact (2432 registered nurses, 3769 social workers, 2520 psychologists and 1276 psychiatrists) were used in a cross-sectional design with structural equation modelling techniques for model testing. Results Job satisfaction was predicted by civility (courteous and respectful workplace behaviours) and supervisory support. Job satisfaction predicted emotional exhaustion which predicted turnover intention. Job satisfaction also directly predicted turnover intention and turnover plans. Discussion Predictors of job satisfaction included civility and supervisory support. Emotional exhaustion predicted turnover intention. Results inform organizational actions to address these work environment characteristics. Implications for practice Organizations can initiate culture changes to improve civility and develop supervisors' 'soft skills' in conjunction with technical expertise. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  20. Lignin as a molecular marker of land management impacts on soil C storage and turnover

    Science.gov (United States)

    Panettieri, Marco; Rumpel, Cornelia; Dignac, Marie-France; Billiou, Daniel; Chabbi, Abad

    2017-04-01

    purified with the CuO oxidation method, then their molecular isotopic content was analyzed with a gas chromatograph coupled with an isotopic ratio mass spectrometer. Turnover of each monomer was evaluated using the values obtained for maize and grass biomass as a reference. Results showed that for syringyl units, the acid monophenols had a faster turnover than their aldehydic form, whereas differences were less pronounced for vanillyl units. The fast degradation of cinnamyl units impeded a reliable determination of their turnover rates. Ley grassland reduced the turnover rates of lignin monophenols within macroaggregates and microaggregates, main contributors of total soil mass, and for vanillyl units of bulk soil. For finer fractions, similar turnover rates were detected under ley grassland and permanent cropland. A possible explanation is the preferential binding of lignin to silt in a first step, followed by a degradation of monophenols and their transformation into compounds that are not detected by the CuO oxidation method. Thus, turnover of SOM compounds constitutes a complex mosaic of different interactions and factor, such as litter origin, land use. Our molecular isotopic study also evidenced that spatial variability must be taken into account to evaluate carbon storage at long-term.

  1. Reviewing Employee Turnover: Focusing on Proximal Withdrawal States and an Expanded Criterion

    Science.gov (United States)

    Hom, Peter W.; Mitchell, Terence R.; Lee, Thomas W.; Griffeth, Rodger W.

    2012-01-01

    We reconceptualize employee turnover to promote researchers' understanding and prediction of why employees quit or stay in employing institutions. A literature review identifies shortcomings with prevailing turnover dimensions. In response, we expand the conceptual domain of the turnover criterion to include multiple types of turnover (notably,…

  2. Effects of organic loading rate on hydrogen and volatile fatty acid production and microbial community during acidogenic hydrogenesis in a continuous stirred tank reactor using molasses wastewater.

    Science.gov (United States)

    Yun, J; Cho, K-S

    2016-12-01

    Microbial community associated with hydrogen production and volatile fatty acids (VFAs) accumulation was characterized in acidogenic hydrogenesis using molasses wastewater as a feedstock. Hydrogen and VFAs production were measured under an organic loading rate (OLR) from 19 to 35 g-COD l(-1)  day(-1) . The active microbial community was analysed using RNA-based massively parallel sequencing technique, and their correlation patterns were analysed using networking analysis. The continuous stirred tank reactor achieved stable hydrogen production at different OLR conditions, and the maximum hydrogen production rate (HPR) was 1·02 L-H2  l(-1)  day(-1) at 31·0 g-COD l(-1)  day(-1) . Butyrate (50%) and acetate (38%) positively increased with increase in OLR. Total VFA production stayed around 7135 mg l(-1) during the operation period. Although Clostridiales and Lactobacillales were relatively abundant, the HPR was positively associated with Pseudomonadaceae and Micrococcineae. Total VFA and acetate, butyrate and propionate concentrations were positively correlated with lactic acid bacteria (LAB) such as Bacillales, Sporolactobacillus and Lactobacillus. The close relationship between Pseudomonadaceae and Micrococcineae, and LAB play important roles for stable hydrogen and VFA production from molasses wastewater. Microbial information on hydrogen and VFA production can be useful to design and operate for acidogenic hydrogenesis using high strength molasses wastewater. © 2016 The Society for Applied Microbiology.

  3. The ways to improve state regulation of land turnover which are in a government and municipal property in Ukraine

    Directory of Open Access Journals (Sweden)

    S. A. Serdyuk

    2016-09-01

    Full Text Available After comprehensive scientific exploration the ways of improvement of state regulation of land turnover which are in a government and state municipal property in Ukraine have been identified. Also it was proposed and justified the conceptual bases of strategy in development of state regulation. As a result of scientific exploration the directions of improvement of organizational mechanism have been formed also and wich a viev to improve legal mechanism of state regulation of land turnover it was suggested the modern approach of it. The main problem that constrains mechanical development of state regulation is non-compliance with legal principles, corruption and low motivation of officials. Approach to improvement is necessity of strategic development by the way of compliance law principles, realization of identified steps in development, using the practice of international regulation in land turnover. Strategic goals are in improvement of procedure of land turnover in public property by the way of advance mechanisms of state regulation; in a finding of effective approaches to improvement components of the legal mechanism; to produce and to offer propositions about development of components legal mechanism; to create clear and understandable procedure of land turnover for all participants in relationships in accordance with European legal traditions etc.Scenario of development that was elected is strategic and directed to solve the problems, perfection of economic, organizational and legal mechanisms of land turnover and also system development. But there are some risks that can interfere realization of strategic priorities. They are in outside threat, political instability, the economic downturn and corruption. We have chosen the next evaluation criteria: the level of investment attractiveness; the level of perception corruption in the society; the level of rating and satisfying quality of in land turnover process by the market participants with

  4. Modeling the effects of hypoxia on ATP turnover in exercising muscle

    Science.gov (United States)

    Arthur, P. G.; Hogan, M. C.; Bebout, D. E.; Wagner, P. D.; Hochachka, P. W.

    1992-01-01

    Most models of metabolic control concentrate on the regulation of ATP production and largely ignore the regulation of ATP demand. We describe a model, based on the results of Hogan et al. (J. Appl. Physiol. 73: 728-736, 1992), that incorporates the effects of ATP demand. The model is developed from the premise that a unique set of intracellular conditions can be measured at each level of ATP turnover and that this relationship is best described by energetic state. Current concepts suggest that cells are capable of maintaining oxygen consumption in the face of declines in the concentration of oxygen through compensatory changes in cellular metabolites. We show that these compensatory changes can cause significant declines in ATP demand and result in a decline in oxygen consumption and ATP turnover. Furthermore we find that hypoxia does not directly affect the rate of anaerobic ATP synthesis and associated lactate production. Rather, lactate production appears to be related to energetic state, whatever the PO2. The model is used to describe the interaction between ATP demand and ATP supply in determining final ATP turnover.

  5. Non-invasive quantification of collagen turnover in renal transplant recipients.

    Directory of Open Access Journals (Sweden)

    Elisabeth G D Stribos

    Full Text Available Kidney allograft failure due to chronic injury/rejection remains the main cause of graft loss in renal transplant recipients (RTR. Here, we investigated whether specific biomarkers of extracellular matrix (ECM turnover are associated with allograft function and chronic kidney disease (CKD stage in RTR. Seventy-eight patients who attended the University Medical Center Groningen for a routine check-up after kidney transplantation were enrolled in the study. Plasma and/or 24h-urine samples were collected and specific matrix-metalloproteinase-generated neo-epitope fragments of collagens were measured by enzyme-linked immunosorbent assay. Our results demonstrated that urinary levels of C3M, a marker for collagen type III degradation, correlated with estimated glomerular filtration rate (eGFR; r = 0.58, p<0.0001, with lower levels detected in the urine of patients with advanced CKD. In addition, plasma levels of Pro-C6, a marker for collagen type VI formation, significantly increased with disease progression and correlated with eGFR (r = -0.72, p<0.0001. Conversely, plasma C3M and urinary Pro-C6 levels showed no correlation with renal function. We identified two neo-epitope biomarkers of tissue turnover associated with ECM remodeling and fibrosis that can stratify patients by CKD stage. This is as promising first step towards non-invasive monitoring of ECM turnover in the kidneys.

  6. Actin filament turnover drives leading edge growth during myelin sheath formation in the central nervous system.

    Science.gov (United States)

    Nawaz, Schanila; Sánchez, Paula; Schmitt, Sebastian; Snaidero, Nicolas; Mitkovski, Mišo; Velte, Caroline; Brückner, Bastian R; Alexopoulos, Ioannis; Czopka, Tim; Jung, Sang Y; Rhee, Jeong S; Janshoff, Andreas; Witke, Walter; Schaap, Iwan A T; Lyons, David A; Simons, Mikael

    2015-07-27

    During CNS development, oligodendrocytes wrap their plasma membrane around axons to generate multilamellar myelin sheaths. To drive growth at the leading edge of myelin at the interface with the axon, mechanical forces are necessary, but the underlying mechanisms are not known. Using an interdisciplinary approach that combines morphological, genetic, and biophysical analyses, we identified a key role for actin filament network turnover in myelin growth. At the onset of myelin biogenesis, F-actin is redistributed to the leading edge, where its polymerization-based forces push out non-adhesive and motile protrusions. F-actin disassembly converts protrusions into sheets by reducing surface tension and in turn inducing membrane spreading and adhesion. We identified the actin depolymerizing factor ADF/cofilin1, which mediates high F-actin turnover rates, as an essential factor in this process. We propose that F-actin turnover is the driving force in myelin wrapping by regulating repetitive cycles of leading edge protrusion and spreading. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. The influence of vegan diet on bone mineral density and biochemical bone turnover markers.

    Science.gov (United States)

    Ambroszkiewicz, Jadwiga; Klemarczyk, Witold; Gajewska, Joanna; Chełchowska, Magdalena; Franek, Edward; Laskowska-Klita, Teresa

    2010-01-01

    Vegetarian diets can be healthy when they are well balanced and if a variety of foods is consumed. However, elimination of animal products from the diet (vegan diets) decreases the intake of some essential nutrients and may influence the bone metabolism. This is especially important in childhood and adolescence, when growth and bone turnover are most intensive. The aim of the study was to assess the effect of vegan diet on bone density (BMD) density and serum concentrations of bone metabolism markers. We examined a family on vegan diet which consisted of parents and two children. Dietary constituents were analysed using a nutritional program. Total and regional BMD were measured by dual-energy X-ray absorptiometry. Concentrations of calcium and phosphate in serum obtained from fasting patients were determined by colorimetric methods, 25-hydroxyvitamin D by the chemiluminescence method and bone turnover markers by specific enzyme immunoassays. In studied vegans, the dietary intake of phosphate was adequate while calcium and vitamin D were below the recommended range. Concentrations of calcium, phosphate and bone turnover markers in the serum of all subjects were within the physiological range, but 25-hydroxyvitamin D level was low. Age-matched Z-score total BMD was between -0.6 and 0.3 in adults, however in children it was lower (-0.9 and -1.0). Z-score BMD lumbar spine (L2-L4) was between -0.9 to -1.9 in parents and -1.5 to -1.7 in children. Our results suggest that an inadequate dietary intake of calcium and vitamin D may impair the bone turnover rate and cause a decrease in bone mineral density in vegans. The parameters of bone density and bone metabolism should be monitored in vegans, especially children, in order to prevent bone abnormalities.

  8. Short organic carbon turnover time and narrow 14C age spectra in early Holocene wetland paleosols

    Science.gov (United States)

    Vetter, Lael; Rosenheim, Brad E.; Fernandez, Alvaro; Törnqvist, Torbjörn E.

    2017-01-01

    Paleosols contain information about the rates of soil organic carbon turnover when the soil was actively forming. However, this temporal information is often difficult to interpret without tight stratigraphic control on the age of the paleosol. Here we apply ramped pyrolysis/oxidation (Ramped PyrOx) 14C analyses to evaluate age spectra of transgressive early Holocene paleosols from the Mississippi Delta in southeastern Louisiana, USA. We find 14C age spectra from soil organic matter (SOM) in both paleosols and overlying basal peats that represent variability in age that is close to, or only slightly greater than, analytical uncertainty of 14C measurements, despite different sources of carbon with likely disparate ages. Such age spectra have not previously been observed in the sedimentary record. Here they indicate vigorous soil carbon turnover prior to burial, which homogenized 14C ages within SOM across the entire thermochemical spectrum. The weighted bulk 14C ages from Ramped PyrOx of paleosols and overlying peats are identical within analytical and process-associated uncertainty, and corroborate 14C ages from charcoal fragments and plant macrofossils from the overlying peat. The youngest ages from Ramped PyrOx age spectra may also potentially be applied as chronometers for stratigraphic burial ages. Our results suggest rapid turnover (≪300 years) of carbon in these soils relative to input of allochthonous carbon, indicating that the 14C age of different soil components is decoupled from thermochemical stability and instead reflects vigorous turnover processes. The concurrence of paleosol and peat 14C ages also suggests that pedogenic processes were linked with the development of coastal marshes, and that the priming effect potentially masked the signal of allochthonous carbon inputs during sea level rise.

  9. Factors that contribute to public sector nurses’ turnover in Limpopo province of South Africa

    Directory of Open Access Journals (Sweden)

    Takalani G. Tshitangano

    2013-01-01

    Full Text Available Background: The ongoing worldwide phenomenon of a shortage of about 4.3 million nurses and midwives poses a threat to health service delivery. Limpopo province had the worst nurse shortage of over 60% in 2010. Authors attribute this shortage to turnover of nurses. The quest to describe factors contributing to nurses’ turnover led to this study in Limpopo province,South Africa.Objectives: To explore and describe factors that contribute to nurses’ turnover in Limpopo province of South Africa by assessing public sector nurses’ job satisfaction in relation to common determinants of job satisfaction.Method: A descriptive cross-sectional approach used primary quantitative data collected from 141 of 380 respondents (31.1% response rate contacted incidentally. Self-administered hand delivered questionnaires were used to gather ordinal data, which were analysed in terms off requency and percentage tables using the Statistical Package for Social Sciences version 6. The sum of positive and negative effects was used to determine satisfaction; if positive effects were greater than negative effects respondents were judged to be satisfied and vice versa.Results: Frequency and percentage tables revealed that nurses in Limpopo province were more dissatisfied (53.9% than satisfied (37.8% with their jobs. Factors which respondents were found to be dissatisfied with included staffing (85.2%, availability of workplace resources(83.7%, salaries (78.8%, workplace safety (73.7%, career development opportunities (64.5% and hours of work (47.6%.Conclusion: Nurses’ turnover is attributed to nurses’ dissatisfaction with staffing, resources, salaries and workplace safety. Attention needs to be given to these specific issues if retentionof nurses is to be achieved.

  10. Team climate, intention to leave and turnover among hospital employees: Prospective cohort study

    Directory of Open Access Journals (Sweden)

    Virtanen Marianna

    2007-10-01

    Full Text Available Abstract Background In hospitals, the costs of employee turnover are substantial and intentions to leave among staff may manifest as lowered performance. We examined whether team climate, as indicated by clear and shared goals, participation, task orientation and support for innovation, predicts intention to leave the job and actual turnover among hospital employees. Methods Prospective study with baseline and follow-up surveys (2–4 years apart. The participants were 6,441 (785 men, 5,656 women hospital employees under the age of 55 at the time of follow-up survey. Logistic regression with generalized estimating equations was used as an analysis method to include both individual and work unit level predictors in the models. Results Among stayers with no intention to leave at baseline, lower self-reported team climate predicted higher likelihood of having intentions to leave at follow-up (odds ratio per 1 standard deviation decrease in team climate was 1.6, 95% confidence interval 1.4–1.8. Lower co-worker assessed team climate at follow-up was also association with such intentions (odds ratio 1.8, 95% confidence interval 1.4–2.4. Among all participants, the likelihood of actually quitting the job was higher for those with poor self-reported team climate at baseline. This association disappeared after adjustment for intention to leave at baseline suggesting that such intentions may explain the greater turnover rate among employees with low team climate. Conclusion Improving team climate may reduce intentions to leave and turnover among hospital employees.

  11. EFFECT OF FEED PROCESSING ON VOLATILE FATTY ACID PRODUCTION RATES MEASURED WITH 13C-ACETATE IN GRAZING LACTATING DAIRY COWS

    Directory of Open Access Journals (Sweden)

    R. Tothi

    2007-06-01

    Full Text Available The effect of processed cereal grain supplementation on volatile fatty acid (VFA production rates of grazing, lactating Holstein-Friesian cows were measured in a 5x5 Latin square experiment. The experimental treatments were as follows: control (only grazing, no supplement addition, NS, pelleted barley (PB, pelleted maize (PM, toasted and subsequently pelleted barley (TPB, and toasted and subsequently pelleted maize (TPM as supplements. An isotope dilution technique using stable isotope of carbon (13C as an internal marker was employed for the estimation of VFA production. At the beginning of a 3-hour long allowed grazing time, 100 mg of 99% enriched 13C2 Na-acetate were introduced in the rumen and repeated after grazing with 50 mg isotope, after which the cows were starved for 6 hours until evening milking. During grazing disappearance rate (kdis and production rate (kprod of acetate, propionate and butyrate were significantly higher (P≤0.05 in supplemented than in NS cows. Moreover the effect of barley grain and pelleting treatment was higher than the effect of maize grain and toasting. During starvation significantly higher (P≤0.05 kdis and kprod of VFAs were observed in PM and TPM treatments. Total VFA production for the experimental period (grazing + starvation were 49.5, 78.7, 69.9, 88.5, 80.8 mol/day for NS, PB, TPB, PM and TPM, respectively. The higher VFA productions measured in supplemented animals emphasis the extensive digestion that occurs in the rumen after feeding processed grains. In methodological terms, 13C2 Na-acetate labelling appears to be a useful means for examining the VFA acetate production in ruminants.

  12. Effect of the Organic Loading Rate Increase and the Presence of Zeolite on Microbial Community Composition and Process Stability During Anaerobic Digestion of Chicken Wastes.

    Science.gov (United States)

    Ziganshina, Elvira E; Belostotskiy, Dmitry E; Ilinskaya, Olga N; Boulygina, Eugenia A; Grigoryeva, Tatiana V; Ziganshin, Ayrat M

    2015-11-01

    This study investigates the effect of the organic loading rate (OLR) increase from 1.0 to 3.5 g VS L(-1) day(-1) at constant hydraulic retention time (HRT) of 35 days on anaerobic reactors' performance and microbial diversity during mesophilic anaerobic digestion of ammonium-rich chicken wastes in the absence/presence of zeolite. The effects of anaerobic process parameters on microbial community structure and dynamics were evaluated using a 16S ribosomal RNA gene-based pyrosequencing approach. Maximum 12 % of the total ammonia nitrogen (TAN) was efficiently removed by zeolite in the fixed zeolite reactor (day 87). In addition, volatile fatty acids (VFA) in the fixed zeolite reactor accumulated in lower concentrations at high OLR of 3.2-3.5 g VS L(-1) day(-1). Microbial communities in the fixed zeolite reactor and reactor without zeolite were dominated by various members of Bacteroidales and Methanobacterium sp. at moderate TAN and VFA levels. The increase of the OLR accompanied by TAN and VFA accumulation and increase in pH led to the predominance of representatives of the family Erysipelotrichaceae and genera Clostridium and Methanosarcina. Methanosarcina sp. reached relative abundances of 94 and 57 % in the fixed zeolite reactor and reactor without zeolite at the end of the experimental period, respectively. In addition, the diminution of Synergistaceae and Crenarchaeota and increase in the abundance of Acholeplasmataceae in parallel with the increase of TAN, VFA, and pH values were observed.

  13. Impact of severity, duration, and etiology of hyperthyroidism on bone turnover markers and bone mineral density in men

    Directory of Open Access Journals (Sweden)

    El Gawad Soma

    2011-08-01

    Full Text Available Abstract Background Hyperthyroidism is accompanied by osteoporosis with higher incidence of fracture rates. The present work aimed to study bone status in hyperthyroidism and to elucidate the impact of severity, duration, and etiology of hyperthyroidism on biochemical markers of bone turnover and bone mineral density (BMD. Methods Fifty-two male patients with hyperthyroidism, 31 with Graves' disease (GD and 21 with toxic multinodular goiter (TNG, with an age ranging from 23 to 65 years were included, together with 25 healthy euthyroid men with matched age as a control group. In addition to full clinical examination, patients and controls were subjected to measurement of BMD using dual-energy X-ray absorptiometery scanning of the lower half of the left radius. Also, some biochemical markers of bone turnover were done for all patients and controls. Results Biochemical markers of bone turnover: included serum bone specific alkaline phosphatase, osteocalcin, carboxy terminal telopeptide of type l collagen also, urinary deoxypyridinoline cross-links (DXP, urinary DXP/urinary creatinine ratio and urinary calcium/urinary creatinine ratio were significantly higher in patients with GD and TNG compared to controls (P 0.05. BMD was significantly lower in GD and TNG compared to controls, but the Z-score of BMD at the lower half of the left radius in patients with GD (-1.7 ± 0.5 SD was not significantly different from those with TNG (-1.6 ± 0.6 SD (>0.05. There was significant positive correlation between free T3 and free T4 with biochemical markers of bone turnover, but negative correlation between TSH and those biochemical markers of bone turnover. The duration of the thyrotoxic state positively correlated with the assessed bone turnover markers, but it is negatively correlated with the Z-score of BMD in the studied hyperthyroid patients (r = -0.68, P Conclusion Men with hyperthyroidism have significant bone loss with higher biochemical markers of bone

  14. PENGARUH JOB SATISFACTION TERHADAP OCB DAN TURNOVER INTENTION

    Directory of Open Access Journals (Sweden)

    Febru Rida Ningsih

    2015-06-01

    Full Text Available This article aims to provide the impact of job satisfaction to OCB and turnover intention. This study used a quantitative method with a statistical analysis. Simple analysis regression used to test each hypotheses. The object of this research is a branch of national bank. Population in this research are entire employees of a brach of national bank that is e non frontliner employees. Non-probability sampling is used of this reseach. The measurement of job satiafaction and turnover intention variables used likert scale that developed by Rinaldi (2008 and measurement of OCB variable adopted from  Organ (1988.  The result of this research has shown that hypotheses one is rejected and hypotheses two is accepted. Eventually, through this article, an understanding that job satisfaction does not significantly influence to OCB but job satisfaction has significant influence to turnover intention.

  15. Estimation of Employee Turnover with Competing Risks Models

    Directory of Open Access Journals (Sweden)

    Grzenda Wioletta

    2015-12-01

    Full Text Available Employee turnover accompanies every business organization, regardless of the industry and size. Nowadays, many companies struggle with problems related to the lack of sufficient information about the nature of employee turnover processes. Therefore, comprehensive analysis of these processes is necessary. This article aims to examine the turnover of employees from a big manufacturing company using competing risks models with covariates and without covariates. This technique allows to incorporate the information about the type of employment contract termination. Moreover, Cox proportional hazard model enables the researcher to analyse simultaneously multiple factors that affect employment duration. One of the major observations is that employee remuneration level differentiates most strongly the risk of job resignation.

  16. Taxonomic and functional turnover are decoupled in European peat bogs.

    Science.gov (United States)

    Robroek, Bjorn J M; Jassey, Vincent E J; Payne, Richard J; Martí, Magalí; Bragazza, Luca; Bleeker, Albert; Buttler, Alexandre; Caporn, Simon J M; Dise, Nancy B; Kattge, Jens; Zając, Katarzyna; Svensson, Bo H; van Ruijven, Jasper; Verhoeven, Jos T A

    2017-10-27

    In peatland ecosystems, plant communities mediate a globally significant carbon store. The effects of global environmental change on plant assemblages are expected to be a factor in determining how ecosystem functions such as carbon uptake will respond. Using vegetation data from 56 Sphagnum-dominated peat bogs across Europe, we show that in these ecosystems plant species aggregate into two major clusters that are each defined by shared response to environmental conditions. Across environmental gradients, we find significant taxonomic turnover in both clusters. However, functional identity and functional redundancy of the community as a whole remain unchanged. This strongly suggests that in peat bogs, species turnover across environmental gradients is restricted to functionally similar species. Our results demonstrate that plant taxonomic and functional turnover are decoupled, which may allow these peat bogs to maintain ecosystem functioning when subject to future environmental change.

  17. The relationship between bone turnover and insulin sensitivity and secretion

    DEFF Research Database (Denmark)

    Frost, Morten; Balkau, Beverley; Hatunic, Mensud

    2018-01-01

    Bone metabolism appears to influence insulin secretion and sensitivity, and insulin promotes bone formation in animals, but similar evidence in humans is limited. The objectives of this study are to explore if bone turnover markers were associated with insulin secretion and sensitivity...... and to determine if bone turnover markers predict changes in insulin secretion and sensitivity. The study population encompassed 576 non-diabetic adult men with normal glucose tolerance (NGT; n=503) or impaired glucose regulation (IGR; n=73). Baseline markers of bone resorption (CTX) and formation (P1NP) were......, baseline bone turnover markers were neither associated with insulin sensitivity (assessed using hyperinsulinaemic euglycaemic clamp and OGTT) nor with insulin secretion capacity (based on IVGTT and OGTT) at baseline or at follow-up. Although inverse associations between fasting glucose and markers of bone...

  18. Cultural turnover among Galápagos sperm whales.

    Science.gov (United States)

    Cantor, Mauricio; Whitehead, Hal; Gero, Shane; Rendell, Luke

    2016-10-01

    While populations may wax and wane, it is rare for an entire population to be replaced by a completely different set of individuals. We document the large-scale relocation of cultural groups of sperm whale off the Galápagos Islands, in which two sympatric vocal clans were entirely replaced by two different ones. Between 1985 and 1999, whales from two clans (called Regular and Plus-One) defined by cultural dialects in coda vocalizations were repeatedly photo-identified off Galápagos. Their occurrence in the area declined through the 1990s; by 2000, none remained. We reassessed Galápagos sperm whales in 2013-2014, identifying 463 new females. However, re-sighting rates were low, with no matches with the Galápagos 1985-1999 population, suggesting an eastward shift to coastal areas. Their vocal repertoires matched those of two other clans (called Short and Four-Plus) found across the Pacific but previously rare or absent around Galápagos. The mechanisms behind this cultural turnover may include large-scale environmental regime shifts favouring clan-specific foraging strategies, and a response to heavy whaling in the region involving redistribution of surviving whales into high-quality habitats. The fall and rise of sperm whale cultures off Galápagos reflect the structuring of the Pacific population into large, enduring clans with dynamic ranges. Long-lasting clan membership illustrates how culture can be bound up in the structure and dynamics of animal populations and so how tracking cultural traits can reveal large-scale population shifts.

  19. Modelling carbon and nitrogen turnover in variably saturated soils

    Science.gov (United States)

    Batlle-Aguilar, J.; Brovelli, A.; Porporato, A.; Barry, D. A.

    2009-04-01

    Natural ecosystems provide services such as ameliorating the impacts of deleterious human activities on both surface and groundwater. For example, several studies have shown that a healthy riparian ecosystem can reduce the nutrient loading of agricultural wastewater, thus protecting the receiving surface water body. As a result, in order to develop better protection strategies and/or restore natural conditions, there is a growing interest in understanding ecosystem functioning, including feedbacks and nonlinearities. Biogeochemical transformations in soils are heavily influenced by microbial decomposition of soil organic matter. Carbon and nutrient cycles are in turn strongly sensitive to environmental conditions, and primarily to soil moisture and temperature. These two physical variables affect the reaction rates of almost all soil biogeochemical transformations, including microbial and fungal activity, nutrient uptake and release from plants, etc. Soil water saturation and temperature are not constants, but vary both in space and time, thus further complicating the picture. In order to interpret field experiments and elucidate the different mechanisms taking place, numerical tools are beneficial. In this work we developed a 3D numerical reactive-transport model as an aid in the investigation the complex physical, chemical and biological interactions occurring in soils. The new code couples the USGS models (MODFLOW 2000-VSF, MT3DMS and PHREEQC) using an operator-splitting algorithm, and is a further development an existing reactive/density-dependent flow model PHWAT. The model was tested using simplified test cases. Following verification, a process-based biogeochemical reaction network describing the turnover of carbon and nitrogen in soils was implemented. Using this tool, we investigated the coupled effect of moisture content and temperature fluctuations on nitrogen and organic matter cycling in the riparian zone, in order to help understand the relative

  20. Human turnover dynamics during sleep: Statistical behavior and its modeling

    Science.gov (United States)

    Yoneyama, Mitsuru; Okuma, Yasuyuki; Utsumi, Hiroya; Terashi, Hiroo; Mitoma, Hiroshi

    2014-03-01

    Turnover is a typical intermittent body movement while asleep. Exploring its behavior may provide insights into the mechanisms and management of sleep. However, little is understood about the dynamic nature of turnover in healthy humans and how it can be modified in disease. Here we present a detailed analysis of turnover signals that are collected by accelerometry from healthy elderly subjects and age-matched patients with neurodegenerative disorders such as Parkinson's disease. In healthy subjects, the time intervals between consecutive turnover events exhibit a well-separated bimodal distribution with one mode at ⩽10 s and the other at ⩾100 s, whereas such bimodality tends to disappear in neurodegenerative patients. The discovery of bimodality and fine temporal structures (⩽10 s) is a contribution that is not revealed by conventional sleep recordings with less time resolution (≈30 s). Moreover, we estimate the scaling exponent of the interval fluctuations, which also shows a clear difference between healthy subjects and patients. We incorporate these experimental results into a computational model of human decision making. A decision is to be made at each simulation step between two choices: to keep on sleeping or to make a turnover, the selection of which is determined dynamically by comparing a pair of random numbers assigned to each choice. This decision is weighted by a single parameter that reflects the depth of sleep. The resulting simulated behavior accurately replicates many aspects of observed turnover patterns, including the appearance or disappearance of bimodality and leads to several predictions, suggesting that the depth parameter may be useful as a quantitative measure for differentiating between normal and pathological sleep. These findings have significant clinical implications and may pave the way for the development of practical sleep assessment technologies.

  1. Problematics of high employee turnover in hotel Thermal

    OpenAIRE

    Gistinger, Petr

    2016-01-01

    Bachelor´s thesis is focused on high employee turnover in a specific company. Thesis is divided into two parts. The first part consists of definitions, theoretical starting-points and methods connected with employee turnover. In the beginning of the second part the hotel is briefly introduced. In the main body of second part I have analysed the situation in the hotel based on internal documents, hotel´s official web page, official statistics and an interview with company´s manager. Using the ...

  2. Nonlicensed employee turnover in a long-term care facility.

    Science.gov (United States)

    Gaddy, T; Bechtel, G A

    1995-06-01

    The purpose of this study was to analyze nonlicensed employee turnover in a long-term care facility using Maslow's hierarchy of needs as a framework. During exit interviews, a convenience sample of 34 employees completed an attitudes and beliefs survey regarding their work environment. Findings were mixed; 39.6 percent of the employees stated positive personal relationships were a strength of the organization, although 24.3 percent resigned because of personal/staff conflicts. Financial concerns were not a major factor in their resignations. The study suggests that decreasing nonlicensed employee stress and increasing their personal satisfaction with patient care may decrease employee turnover.

  3. Dystropathology increases energy expenditure and protein turnover in the mdx mouse model of duchenne muscular dystrophy.

    Directory of Open Access Journals (Sweden)

    Hannah G Radley-Crabb

    Full Text Available The skeletal muscles in Duchenne muscular dystrophy and the mdx mouse model lack functional dystrophin and undergo repeated bouts of necrosis, regeneration, and growth. These processes have a high metabolic cost. However, the consequences for whole body energy and protein metabolism, and on the dietary requirements for these macronutrients at different stages of the disease, are not well-understood. This study used juvenile (4- to 5- wk-old and adult (12- to 14-wk-old male dystrophic C57BL/10ScSn-mdx/J and age-matched C57BL/10ScSn/J control male mice to measure total and resting energy expenditure, food intake, spontaneous activity, body composition, whole body protein turnover, and muscle protein synthesis rates. In juvenile mdx mice that have extensive muscle damage, energy expenditure, muscle protein synthesis, and whole body protein turnover rates were higher than in age-matched controls. Adaptations in food intake and decreased activity were insufficient to meet the increased energy and protein needs of juvenile mdx mice and resulted in stunted growth. In (non-growing adult mdx mice with less severe dystropathology, energy expenditure, muscle protein synthesis, and whole body protein turnover rates were also higher than in age-matched controls. Food intake was sufficient to meet their protein and energy needs, but insufficient to result in fat deposition. These data show that dystropathology impacts the protein and energy needs of mdx mice and that tailored dietary interventions are necessary to redress this imbalance. If not met, the resultant imbalance blunts growth, and may limit the benefits of therapies designed to protect and repair dystrophic muscles.

  4. Measurement of ribosomal RNA turnover in vivo by use of deuterium-labeled glucose.

    Science.gov (United States)

    Defoiche, Julien; Zhang, Yan; Lagneaux, Laurence; Pettengell, Ruth; Hegedus, Andrea; Willems, Luc; Macallan, Derek C

    2009-10-01

    Most methods for estimation of rates of RNA production are not applicable in human in vivo clinical studies. We describe here an approach for measuring ribosomal RNA turnover in vivo using [6,6-(2)H(2)]-glucose as a precursor for de novo RNA synthesis. Because this method involves neither radioactivity nor toxic metabolites, it is suitable for human studies. For method development in vitro, a lymphocyte cell line (PM1) was cultured in the presence of [6,6-(2)H(2)]-glucose. RNA was extracted, hydrolyzed enzymatically to ribonucleosides, and derivatized to either the aldonitrile tetra-acetate or the pentafluoro triacetate derivative of the pentose before GC-MS. We identified optimum derivatization and analysis conditions and demonstrated quantitative incorporation of deuterium from glucose into RNA of dividing cells. Pilot clinical studies demonstrated the applicability of this approach to blood leukocytes and solid tissues. A patient with chronic lymphocytic leukemia received [6,6-(2)H(2)]-glucose (1 g/kg) orally in aliquots administered every 30 min for a period of 10 h. When we analyzed CD3(-) B cells that had been purified by gradient centrifugation and magnetic-bead adhesion, we observed deuterium enrichment, a finding consistent with a ribosomal RNA production rate of about 7%/day, despite the slow division rates observed in concurrent DNA-labeling analysis. Similarly, in 2 patients with malignant infiltration of lymph nodes, administration of [6,6-(2)H(2)]-glucose (by intravenous infusion for 24 h) before excision biopsy allowed estimation of DNA and RNA turnover in lymph node samples. Our study results demonstrate the proof-of-principle that deuterium-labeled glucose may be used to analyze RNA turnover, in addition to DNA production/cell proliferation, in clinical samples.

  5. Control of mRNA turnover as a mechanism of glucose repression in Saccharomyces cerevisiae.

    Science.gov (United States)

    Scheffler, I E; de la Cruz, B J; Prieto, S

    1998-11-01

    The phenomenon of glucose repression in yeast is concerned with the repression of a large number of genes when glucose is an abundant carbon source and almost all of the energy requirements of the cell can be satisfied from glycolysis. Prominent among the repressed genes are those encoding mitochondrial proteins required for respiration and oxidative phosphorylation. Past studies have characterized a pathway by which a signal generated from extracellular glucose is transmitted to the nucleus. The ultimate outcome is the repression of transcription of numerous genes, but also the induction of a limited number of others. The emphasis has been almost exclusively on transcriptional control mechanisms. A discovery made originally with the transcript of the SDH2 gene prompted an investigation of post-transcriptional mechanisms, and more specifically a study of the turnover rate of this mRNA in the absence and presence of glucose. SDH2 mRNA has a very short half-life in medium with glucose (YPD) and a significantly longer half-life in medium with glycerol (YPG). Experimental evidence and recent progress in understanding of (1) mRNA turnover in yeast and (2) initiation of translation on the 5' untranslated region of mRNAs, lead to a working hypothesis with the following major features: the carbon source, via a signaling pathway involving kinase/phosphatase activities, controls the rate of initiation, and thus influences a competition between eukaryotic initiation factors (prominently eIF4E, eIF4G, eIF3) binding to the capped mRNA and a decapping activity (DCP1) which is one of the rate limiting activities in the turnover of such mRNAs.

  6. pH and VFA

    African Journals Online (AJOL)

    Dr.Choi

    2012-07-10

    Jul 10, 2012 ... 3Department of Companion Animal and Animal Resources Sciences, Joongbu University, Kumsan-gun 312-702, South. Korea. ... The treatments included an untreated control, 100 g of alum ... amendments (P < 0.05) in the litter over time compared with the controls except for NH3 emissions at 1 through 3 ...

  7. Quantitative analysis of endocytosis and turnover of epidermal growth factor (EGF) and EGF receptor.

    Science.gov (United States)

    Sorkin, Alexander; Duex, Jason E

    2010-03-01

    Binding of epidermal growth factor (EGF) to the EGF receptor (EGFR) initiates signal transduction, ultimately leading to altered gene expression. Ligand-activated EGFR is also rapidly internalized and then targeted to lysosomes for degradation or recycled back to the plasma membrane. Endocytosis is a major regulator of EGFR signaling. Therefore, elucidation of the mechanisms of EGFR endocytosis is essential for a better understanding of EGFR biology. In order to achieve a comprehensive analysis of these mechanisms, reliable methods for measuring the rates of EGFR protein turnover and the rate parameters for individual steps of EGFR endocytic trafficking must be employed. The protocols in this unit describe methodologies to measure the rates of EGFR synthesis and degradation, to monitor EGF-induced down-regulation of surface EGFR, to measure the kinetic rate parameters of internalization, recycling, and degradation of radiolabeled EGF, and to perform radioiodination of EGF by the chloramine T method.

  8. Firm-level innovation activity, employee turnover and HRM practices

    DEFF Research Database (Denmark)

    Eriksson, Tor; Qin, Zhihua; Wang, Wenjing

    2014-01-01

    This paper examines the relationship between employee turnover, HRM practices and innovation in Chinese firms in five high technology sectors. We estimate hurdle negative binomial models for count data on survey data allowing for analyses of the extensive as well as intensive margins of firms...

  9. Work-life balance, job satisfaction and turnover intention amongst ...

    African Journals Online (AJOL)

    Talent retention is of particular concern in the information technology (IT) sector owing to globalisation, the skills shortage and rapidly advancing technology. Employee turnover has signifi cant costs and negative consequences for organisations. The objective of this study was to explore the association between employees' ...

  10. Exercise Enhances Whole-Body Cholesterol Turnover in Mice

    NARCIS (Netherlands)

    Meissner, Maxi; Havinga, Rick; Boverhof, Renze; Kema, Ido; Groen, Albert K.; Kuipers, Folkert

    MEISSNER, M., R. HAVINGA, R. BOVERHOF, I. KEMA, A. K. GROEN, and F. KUIPERS. Exercise Enhances Whole-Body Cholesterol Turnover in Mice. Med. Sci. Sports Exerc., Vol. 42, No. 8, pp. 1460-1468, 2010. Purpose: Regular exercise reduces cardiovascular risk in humans by reducing cholesterol levels, but

  11. Oxidative Criteria And Somebone Turnover Markers In Beta ...

    African Journals Online (AJOL)

    Bone disease in beta-thalassemic patients has multifactorial etiology; increased iron stores and per-oxidative stress are involved factors. This study aimed to investigate the relationship between some bone turnover markers and some oxidants, antioxidants parameters of betathalassemic patients. The study included 50 ...

  12. Organisational culture of hospitals to predict turnover intentions of ...

    African Journals Online (AJOL)

    The objective of this study was to determine if organisational culture predicts turnover intentions of professional nurses. A predictive model with organisational culture and various proposed mediating variables, namely knowledge sharing, organisational commitment, organisational citisenship behaviour and job satisfaction, ...

  13. 41 CFR 109-27.5002 - Stores inventory turnover ratio.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Stores inventory....5002 Stores inventory turnover ratio. Comparison of investment in stores inventories to annual issues... ratio of 2.0, shall be established for each stores using activity. It is recognized, however, that...

  14. Effects of ractopamine and gender on protein turnover in skeletal ...

    African Journals Online (AJOL)

    Effects of the β-agonist, ractopamine-HCl (ractopamine), on skeletal muscle protein turnover were evaluated in 16 steers (512 kg) and 16 heifers (473 kg). Treatments were arranged in a 2 × 2 factorial design and included gender (steer vs. heifer) and ractopamine (0 or 200 mg/d). Steers were implanted with 120 mg ...

  15. The Effects of Turnover: What We Know about Teacher Attrition

    Science.gov (United States)

    DeAngelis, Karen

    2012-01-01

    School business officials are likely to know better than anyone else about the financial costs to districts and schools associated with teacher attrition. Perhaps less well-known, though, is what else has been learned about this issue in recent years--information that may affect how one thinks about teacher turnover. Here is some of that research:…

  16. Bone turnover biomarkers in obese postmenopausal Saudi women ...

    African Journals Online (AJOL)

    Background: There is a high prevalence of diabetes mellitus type-2 (T2DM) and osteoporosis are problems worldwide. In this study, we evaluated the correlation between T2DM and bone turnover in diabetic obese postmenopausal Saudi women. Subjects and Methods: The present study included total of 65 T2-DM obese ...

  17. Prediction of Military Turnover Using Intentions, Satisfaction, and Performance.

    Science.gov (United States)

    Knapp, Deirdre J.; And Others

    Although researchers have examined the link between job attitudes and turnover, some studies claim that civilian samples may not be generalizable to military personnel. This paper addresses two central questions: (1) To what extent does job satisfaction, job performance, and reenlistment intentions predict reenlistment behavior?; (2) To what…

  18. Influence of Religiosity on Turnover Intention: Empirical Evidence ...

    African Journals Online (AJOL)

    This study examined the influence of employees' religiosity on their turnover intentions. The ex-post facto research design and the convenient sampling technique were employed in this study. A hundred and forty-nine (149) employees in Lagos and Ogun States of Nigeria were sampled as the study participants.

  19. Turnover of nursing employees in a Gauteng hospital group

    Directory of Open Access Journals (Sweden)

    Japie Greyling

    2010-03-01

    Full Text Available Orientation: The South African nursing profession is in a crisis as professional nurses leave the country in search of lucrative work overseas.Research purpose: The purpose of this study was to investigate individual determinants of voluntary turnover to identify a risk-group profile.Motivation for the study: Nursing employers should have a clearer understanding of the dynamics around nurses’ turnover behaviour and embark on strategies to retain their talent.Research design, approach and method: A survey measuring voluntary turnover was conducted among 262 professional and assistant nurses in three selected hospitals in Gauteng province using the McCarthy, Tyrrell and Cronin (2002 instrument. Pearson’s chi square with Yates’s continuity correction tested the relationship among the variables presented in a contingency table, in other words the risk group and each of the individual determinants.Main findings: Discontent with salaries was the major determinant of the nurses’ resignation. Organisational causes were nursing practices, the work environment, physical-emotional costs and employment opportunities after resignation.Practical/managerial implications: Hospital management could indeed establish a good rapport with nursing staff while facilitating respectful and ethical conduct by doctors towards nursing staff. Putting into place effective labour practices and business strategies could improve job satisfaction in the workplace.Contribution/value-add: This study contributed to a greater understanding of the personal and organisational determinants of the turnover of nurses in South African hospitals.

  20. Resilience, job satisfaction and anticipated turnover in nurse leaders.

    Science.gov (United States)

    Hudgins, Tracy Ann

    2016-01-01

    The aim was to identify relationships between resilience, job satisfaction and anticipated turnover among nurse leaders. Despite the reported value of resilience, there is a lack of research on resilience in nurse leaders. This study examined how nurse leaders describe their resilience and the relationship it has with job satisfaction and anticipated turnover. This quantitative study used a sample of 89 nurse leaders (bedside, department, division and organisational) from a multi-hospital health-care system in southwestern Virginia. There are significant relationships between resilience, job satisfaction and anticipated turnover. Additionally, it was found that the variables of job satisfaction and anticipated turnover significantly overlapped in their meaning and created a new construct of intent to remain (ITR) that has a statistically significant relationship with resilience. A stable nursing team has a positive impact on improving patient outcomes. To mitigate the impact of a nursing shortage, nurse leaders can enhance their own resilience and then recruit, hire and retain resilient staff nurses in an effort to improve nurses' ITR. With higher resilience, nurse leaders are more likely to intend to remain in their leadership positions. © 2015 John Wiley & Sons Ltd.

  1. Chinese Teachers' Work Stress and Their Turnover Intention

    Science.gov (United States)

    Liu, Shujie; Onwuegbuzie, Anthony J.

    2012-01-01

    This survey study employed qualitative dominant mixed research to explore the sources of teacher stress in China and the possible reasons for Chinese teachers' turnover intention. The data were collected in Jilin Province of China, and 510 teachers participated in the survey. Quantitatively, 40.4% of the surveyed teachers reported that they…

  2. Effects of ractopamine and gender on protein turnover in skeletal ...

    African Journals Online (AJOL)

    p2492989

    Effects of the β-agonist, ractopamine-HCl (ractopamine), on skeletal muscle protein turnover were evaluated in ... The increase in shear force of m. longissimus from cattle fed β-agonists suggests that muscle protein degradation is ..... Cimaterol-induced muscle hypertrophy and altered endocrine status in lambs. J. Anim. Sci.

  3. Teacher Turnover: An Issue of Workgroup Racial Diversity

    Science.gov (United States)

    Sohn, Kitae

    2009-01-01

    One neglected aspect of the teacher labor supply is a recent increase in the proportion of minority teachers. Using the Schools and Staffing Survey and the Teacher Follow-up Survey, one can estimate the relationship between workgroup racial diversity and the turnover of White teachers. This approach finds that young White teachers are more likely…

  4. Employees as Customers: Exploring Service Climate, Employee Patronage, and Turnover

    Science.gov (United States)

    Abston, Kristie A.; Kupritz, Virginia W.

    2011-01-01

    The role of retail employees as customers was explored by quantitatively examining the influence of service climate and employee patronage on employee turnover intentions. Employees representing all shifts in two stores of a national retailer participated. Results indicated that employee patronage partially mediates the effects of service climate…

  5. Increased loss and decreased synthesis of hepatic glutathione after acute ethanol administration. Turnover studies.

    Science.gov (United States)

    Speisky, H; MacDonald, A; Giles, G; Orrego, H; Israel, Y

    1985-01-01

    The effect of acute ethanol administration on rates of synthesis and utilization of hepatic glutathione (GSH) was studied in rats after a pulse of [35S]cysteine. A 35% decrease in hepatic GSH content 5h after administration of 4 g of ethanol/kg body wt. was accompanied by a 33% increase in the rate of GSH utilization. The decrease occurred without increases in hepatic oxidized glutathione (GSSG) or in the GSH/GSSG ratio. The rate of non-enzymic condensation of GSH with acetaldehyde could account for only 6% of the rate of hepatic GSH disappearance. The increased loss of [35S]GSH induced by ethanol was not accompanied by an increased turnover; rather, a 30% inhibition of GSH synthesis balanced the increased rate of loss, leaving the turnover rate unchanged. The rate of acetaldehyde condensation with cysteine in vitro occurred at about one-third of the rate of GSH loss in ethanol-treated animals. However, ethanol induced only a minor decrease in liver cysteine content, which did not precede, but followed, the decrease in GSH. The characteristics of 2-methylthiazolidine-4-carboxylic acid, the condensation product between acetaldehyde and cysteine, were studied and methodologies were developed to determine its presence in tissues. It was not found in the liver of ethanol-treated animals. Ethanol administration led to a marked increase (47%) in plasma GSH in the post-hepatic inferior vena cava, but not in its pre-hepatic segment. Data suggest that an increased loss of GSH from the liver constitutes an important mechanism for the decrease in GSH induced by ethanol. In addition, an inhibition of GSH synthesis is observed. PMID:3977847

  6. A tentative model for (D)-glucose turnover in human saliva.

    Science.gov (United States)

    Cetik, Sibel; Zhang, Ying; Hupkens, Emeline; Jurysta, Cedric; Malaisse, Willy J; Sener, Abdullah

    2013-10-01

    The aim of the present study is to propose a tentative model for d-glucose turnover in human saliva. The whole saliva and the saliva from parotid and submandibular/sublingual glands were collected by use of the Salivette™. The saliva glucose concentration was measured by the hexokinase method, saliva bacteria glycolysis by use of d-[5-(3)H] glucose, and the saliva ATP content by the luciferase method. The concentration of glucose amounted to 43.9±6.3 (n=29), 197.5±17.3 (n=29), 104.0±12.4 (n=27) μM in whole saliva, parotid saliva and submandibular/sublingual saliva, respectively. The rate of d-glucose utilization by oral bacteria at a physiological concentration of d-glucose in saliva (50μM) was estimated at 0.047±0.003 (n=11) nmol/min per 10(6) bacteria. Unstimulated salivary d-glucose turnover rate, as calculated from the amount of glucose secreted in saliva which comes from parotid and submandibular and sublingual glands represented 214.6±19.1%/min. In order for salivary d-glucose production to match bacterial utilization of the hexose, the total number of oral bacteria was estimated at about 2.0×10(9) bacteria, in fair agreement with previously published data. This study thus provides support for a tentative model for d-glucose turnover in human saliva. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Carbon stock and carbon turnover in boreal and temperate forests - Integration of remote sensing data and global vegetation models

    Science.gov (United States)

    Thurner, Martin; Beer, Christian; Carvalhais, Nuno; Forkel, Matthias; Tito Rademacher, Tim; Santoro, Maurizio; Tum, Markus; Schmullius, Christiane

    2016-04-01

    Long-term vegetation dynamics are one of the key uncertainties of the carbon cycle. There are large differences in simulated vegetation carbon stocks and fluxes including productivity, respiration and carbon turnover between global vegetation models. Especially the implementation of climate-related mortality processes, for instance drought, fire, frost or insect effects, is often lacking or insufficient in current models and their importance at global scale is highly uncertain. These shortcomings have been due to the lack of spatially extensive information on vegetation carbon stocks, which cannot be provided by inventory data alone. Instead, we recently have been able to estimate northern boreal and temperate forest carbon stocks based on radar remote sensing data. Our spatially explicit product (0.01° resolution) shows strong agreement to inventory-based estimates at a regional scale and allows for a spatial evaluation of carbon stocks and dynamics simulated by global vegetation models. By combining this state-of-the-art biomass product and NPP datasets originating from remote sensing, we are able to study the relation between carbon turnover rate and a set of climate indices in northern boreal and temperate forests along spatial gradients. We observe an increasing turnover rate with colder winter temperatures and longer winters in boreal forests, suggesting frost damage and the trade-off between frost adaptation and growth being important mortality processes in this ecosystem. In contrast, turnover rate increases with climatic conditions favouring drought and insect outbreaks in temperate forests. Investigated global vegetation models from the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), including HYBRID4, JeDi, JULES, LPJml, ORCHIDEE, SDGVM, and VISIT, are able to reproduce observation-based spatial climate - turnover rate relationships only to a limited extent. While most of the models compare relatively well in terms of NPP, simulated

  8. A Social Network Perspective on Turnover Intentions : The Role of Distributive Justice and Social Support

    NARCIS (Netherlands)

    Soltis, Scott M.; Agneessens, Filip; Sasovova, Zuzana; Labianca, Giuseppe (Joe)

    Organizations are increasingly concerned about retaining human talent, particularly within knowledge-based industries where turnover is expensive. Our study employs a social network perspective to explore the influence of employees' formal and informal workplace relationships on their turnover

  9. Prostate Cancer Metastases to Bone: Role of High Bone Turnover Induced by Androgen Deprivation

    National Research Council Canada - National Science Library

    Padalecki, Susan

    2002-01-01

    .... Treatment with androgen deprivation therapy leads to an increase in bone turnover as indicated by the loss of bone mineral density and the increase in markers of bone turnover in patients on treatment...

  10. Nitric oxide turnover in permeable river sediment

    DEFF Research Database (Denmark)

    Schreiber, Frank; Stief, Peter; Kuypers, Marcel M M

    2014-01-01

    We measured nitric oxide (NO) microprofiles in relation to oxygen (O2) and all major dissolved N-species (ammonium, nitrate, nitrite, and nitrous oxide [N2O]) in a permeable, freshwater sediment (River Weser, Germany). NO reaches peak concentrations of 0.13 μmol L-1 in the oxic zone and is consumed...... in the oxic-anoxic transition zone. Apparently, NO is produced by ammonia oxidizers under oxic conditions and consumed by denitrification under microoxic conditions. Experimental percolation of sediment cores with aerated surface water resulted in an initial rate of NO production that was 12 times higher than...

  11. The relationship between occupational stress, burnout, and turnover intention among managerial staff from a Sino-Japanese joint venture in Guangzhou, China.

    Science.gov (United States)

    Lin, Qiu-Hong; Jiang, Chao-Qiang; Lam, Tai Hing

    2013-01-01

    The aim of this study was to analyze the associations between occupational stress, burnout and turnover intention and explore their associated factors among managerial staff in Guangzhou, China. This cross-sectional study recruited 288 managerial employees from a Sino-Japanese joint venture automobile manufacturing enterprise in Guangzhou. The questionnaire included questions about sociodemographic characteristics, smoking, drinking and physical activity and the Chinese versio ns of the Occupational Stress Indicator (OSI), Maslach Burnout Inventory (MBI), Eysenck Personality Questionnaire (EPQ), Simplified Coping Style Questionnaire (SCSQ) and Social Support Rating Scale (SSRS). The response rate was 57.6%. Stepwise regression analysis was performed to examine the associations between burnout and occupational stress and turnover intention and related factors. The respondents had a high level burnout on the personal accomplishment subscale and had a high prevalence of turnover intention. Neuroticism, psychoticism, job satisfaction, occupational stress and social support were strong predictors of emotional exhaustion. Psychoticism, passive coping, occupational stress, objective support, utilization of support, male gender and job satisfaction were strong predictors of depersonalization. Active and passive coping and job satisfaction were strong predictors of personal accomplishment. Job dissatisfaction and emotional exhaustion were strong predictors of turnover intention. High occupational stress and low job satisfaction were associated with high burnout, particularly in the emotional exhaustion and depersonalization dimensions. Low job satisfaction and high emotional exhaustion were associated with high turnover intention among employees. Personality traits, social support and coping style were also found to be associated with burnout.

  12. Impact Event and Radiolarian Faunal Turnover across the Middle-upper Norian Transition in the Upper Triassic of Japan

    Science.gov (United States)

    Onoue, T.; Sato, H.; Yamashita, D.; Uno, K.

    2014-12-01

    It has long been recognized that marine biotic turnover events took place at around the Norian/Rhaetian boundary in the Late Triassic. Although the causes of these Norian to Rhaetian biotic turnover events are still the subject of debate, extraterrestrial impacts have been proposed to account for the biotic turnover. A Norian impact event has been inferred from a platinum group element (PGE) concentration anomaly, Os isotope negative excursion, and the presence of Ni-rich magnetite and microspherules, in claystone layer within middle to upper Norian bedded chert succession in the Sakahogi section, Mino Belt, central Japan. Previous osmium isotope studies have revealed that the anomalously high PGE abundances resulted from a large chondritic impactor (3.3-7.8 km in diameter). To evaluate the biotic and environmental effects of such an impact event, we report on new micropaleontological data from the Sakahogi section across the ejecta layer. Detailed high-resolution sampling and biostratigraphic data showed that the ejecta layer occurs at the base of the radiolarian Trialatus robustus-Lysemelas olbia zone and is correlated with the middle to late Norian boundary. The biostratigraphc analysis revealed that no mass extinction of radiolarians occurred at the impact event horizon. Only one species became extinct at the ejecta horizon and the extinction rate of radiolarians is estimated to be about 5% at the horizon. However, major turnovers in radiolarians occur above the ejecta horizon, in the Trialatus robustus-Lysemelas olbia zone; this turnover is associated with deposition of a spicular chert, suggesting temporal changes in marine ecosystems after the impact event.

  13. Endospore abundance and D:L-amino acid modeling of bacterial turnover in holocene marine sediment (Aarhus Bay)

    Science.gov (United States)

    Langerhuus, Alice T.; Røy, Hans; Lever, Mark A.; Morono, Yuki; Inagaki, Fumio; Jørgensen, Bo B.; Lomstein, Bente Aa.

    2012-12-01

    In order to study bacterial activity, and turnover times of bacterial necromass and biomass in marine sediment, two stations from the Aarhus Bay, Denmark were analyzed. Sediment cores were up to 11 m deep and covered a timescale from the present to ˜11,000 years ago. Sediment was analyzed for total hydrolysable amino acids (THAA), total hydrolysable amino sugars, the bacterial endospore marker dipicolinic acid (DPA), and amino acid enantiomers (L- and D-form) of aspartic acid. Turnover times of bacterial necromass and vegetative cells, as well as carbon oxidation rates were estimated by use of the D:L-amino acid racemization model. Diagenetic indicators were applied to evaluate the diagenetic state of the sedimentary organic matter. The contribution of amino acids to total organic carbon, and the ratio between the amino acids aspartic acid and glutamic acid, and their respective non protein degradation products, β-alanine and γ-amino butyric acid, all indicated increasing degradation state of the organic matter with sediment depth and age. Quantification of DPA showed that endospores were abundant, and increased with depth relative to vegetative cells. Most of the amino acids (97%) could be ascribed to microbial necromass, i.e. the remains of dead bacterial cells. Model estimates showed that the turnover times of microbial necromass were in the range of 0.5-1 × 105 years, while turnover times of vegetative cells were in the range of tens to hundreds of years. The turnover time of the TOC pool increased with depth in the sediment, indicating that the TOC pool became progressively more refractory and unavailable to microorganisms with depth and age of the organic matter.

  14. Hubungan Stres Kerja dengan Intensi Turnover Pada Karyawan Bank di Medan

    OpenAIRE

    Salim, Melinda

    2017-01-01

    Human is important resources in industry or organizational sector. Human resources become one of the most important successors in an organization. Number of turnovers that are increasing from time to time show that turnover intention between workers has increased too. The sector with higher turnover is financial sectors. Turnover intention is caused by work related stress that happened to the bank workers. The aim of this research is to see whether there is correlation betwe...

  15. Different land use intensities in grassland ecosystems drive ecology of microbial communities involved in nitrogen turnover in soil

    OpenAIRE

    Meyer, A.; Focks, A.; Radl, V.; Keil, D.; Welzl, G.; Schoning, I.; Boch, S.

    2013-01-01

    Understanding factors driving the ecology of N cycling microbial communities is of central importance for sustainable land use. In this study we report changes of abundance of denitrifiers, nitrifiers and nitrogen-fixing microorganisms (based on qPCR data for selected functional genes) in response to different land use intensity levels and the consequences for potential turnover rates. We investigated selected grassland sites being comparable with respect to soil type and climatic conditions,...

  16. Different Land Use Intensities in Grassland Ecosystems Drive Ecology of Microbial Communities Involved in Nitrogen Turnover in Soil

    OpenAIRE

    Meyer, Annabel; Focks, Andreas; Radl, Viviane; Keil, Daniel; Welzl, Gerhard; Schöning, Ingo; Boch, Steffen; Marhan, Sven; Kandeler, Ellen; Schloter, Michael

    2013-01-01

    Understanding factors driving the ecology of N cycling microbial communities is of central importance for sustainable land use. In this study we report changes of abundance of denitrifiers, nitrifiers and nitrogen-fixing microorganisms (based on qPCR data for selected functional genes) in response to different land use intensity levels and the consequences for potential turnover rates. We investigated selected grassland sites being comparable with respect to soil type and climatic conditions,...

  17. Protein turnover and cellular autophagy in growing and growth-inhibited 3T3 cells

    Energy Technology Data Exchange (ETDEWEB)

    Papadopoulos, T.; Pfeifer, U. (Univ. of Wuerzburg (West Germany))

    1987-07-01

    The relationship between growth, protein degradation, and cellular autophagy was tested in growing and in growth-inhibited 3T3 cell monolayers. For the biochemical evaluation of DNA and protein metabolism, growth-inhibited 3T3 cell monolayers with high cell density and growing 3T3 cell monolayers with low cell density were labeled simultaneously with ({sup 14}C)thymidine and ({sup 3}H)leucine. The evaluation of the DNA turnover and additional ({sup 3}H)thymidine autoradiography showed that 24 to 5% of 3T3 cells continue to replicate even in the growth-inhibited state, where no accumulation of protein and DNA can be observed. Cell loss, therefore, has to be assumed to compensate for the ongoing cell proliferation. When the data of protein turnover were corrected for cell loss, it was found that the rate constant of protein synthesis in nongrowing monolayers was reduced to half the value found in growing monolayers. Simultaneously, the rate constant of protein degradation in nongrowing monolayers was increased to about 1.5-fold the value of growing monolayers. These data are in agreement with the assumption that cellular autophagy represents a major pathway of regulating protein degradation in 3T3 cells and that the regulation of autophagic protein degradation is of relevance for the transition from a growing to a nongrowing state.

  18. A mathematical model of actin filament turnover for fitting FRAP data.

    Science.gov (United States)

    Halavatyi, Aliaksandr A; Nazarov, Petr V; Al Tanoury, Ziad; Apanasovich, Vladimir V; Yatskou, Mikalai; Friederich, Evelyne

    2010-03-01

    A novel mathematical model of the actin dynamics in living cells under steady-state conditions has been developed for fluorescence recovery after photobleaching (FRAP) experiments. As opposed to other FRAP fitting models, which use the average lifetime of actins in filaments and the actin turnover rate as fitting parameters, our model operates with unbiased actin association/dissociation rate constants and accounts for the filament length. The mathematical formalism is based on a system of stochastic differential equations. The derived equations were validated on synthetic theoretical data generated by a stochastic simulation algorithm adapted for the simulation of FRAP experiments. Consistent with experimental findings, the results of this work showed that (1) fluorescence recovery is a function of the average filament length, (2) the F-actin turnover and the FRAP are accelerated in the presence of actin nucleating proteins, (3) the FRAP curves may exhibit both a linear and non-linear behaviour depending on the parameters of actin polymerisation, and (4) our model resulted in more accurate parameter estimations of actin dynamics as compared with other FRAP fitting models. Additionally, we provide a computational tool that integrates the model and that can be used for interpretation of FRAP data on actin cytoskeleton.

  19. Faster turnover of new soil carbon inputs under increased atmospheric CO2.

    Science.gov (United States)

    van Groenigen, Kees Jan; Osenberg, Craig W; Terrer, César; Carrillo, Yolima; Dijkstra, Feike A; Heath, James; Nie, Ming; Pendall, Elise; Phillips, Richard P; Hungate, Bruce A

    2017-10-01

    Rising levels of atmospheric CO2 frequently stimulate plant inputs to soil, but the consequences of these changes for soil carbon (C) dynamics are poorly understood. Plant-derived inputs can accumulate in the soil and become part of the soil C pool ("new soil C"), or accelerate losses of pre-existing ("old") soil C. The dynamics of the new and old pools will likely differ and alter the long-term fate of soil C, but these separate pools, which can be distinguished through isotopic labeling, have not been considered in past syntheses. Using meta-analysis, we found that while elevated CO2 (ranging from 550 to 800 parts per million by volume) stimulates the accumulation of new soil C in the short term (soil C pool over either temporal scale. Our results are inconsistent with predictions of conventional soil C models and suggest that elevated CO2 might increase turnover rates of new soil C. Because increased turnover rates of new soil C limit the potential for additional soil C sequestration, the capacity of land ecosystems to slow the rise in atmospheric CO2 concentrations may be smaller than previously assumed. © 2017 John Wiley & Sons Ltd.

  20. Is high employee turnover really harmful?: An empirical test using company records

    NARCIS (Netherlands)

    Glebbeek, A.C.; Bax, E.H.

    2004-01-01

    We tested the hypothesis that employee turnover and firm performance have an inverted U-shaped relationship: overly high or low turnover is harmful. Our analysis was based on economic performance data from 110 offices of a temporary employment agency. These offices had high variation in turnover but

  1. When the Going Gets Tough: Direct, Buffering and Indirect Effects of Social Support on Turnover Intention

    Science.gov (United States)

    Pomaki, Georgia; DeLongis, Anita; Frey, Daniela; Short, Kathy; Woehrle, Trish

    2010-01-01

    We examined the role of social support in turnover intention among new teachers. First, we tested and found evidence for a direct negative relationship between social support and turnover intention. Second, we tested the social support buffer hypothesis, and found that teachers with higher social support had lower turnover intention in the face of…

  2. To leave or not to leave : When receiving interpersonal citizenship behavior influences an employee's turnover intention

    NARCIS (Netherlands)

    Regts, Gerdien; Molleman, Eric

    Given that few studies have examined relational bases for voluntary employee turnover, the purpose of the article is to examine whether work relationships explain employee turnover intention. Adopting a social relational perspective on employee turnover, we investigated the effect of receiving

  3. Disaturated-phosphatidylcholine and surfactant protein-B turnover in human acute lung injury and in control patients.

    Science.gov (United States)

    Simonato, Manuela; Baritussio, Aldo; Ori, Carlo; Vedovelli, Luca; Rossi, Sandra; Dalla Massara, Lorenza; Rizzi, Sabina; Carnielli, Virgilio P; Cogo, Paola E

    2011-03-24

    Patients with adult respiratory distress syndrome (ARDS) and acute lung injury (ALI) have low concentrations of disaturated-phosphatidylcholine and surfactant protein-B in bronchoalveolar lavage fluid. No information is available on their turnover. To analyze disaturated-phosphatidylcholine and surfactant protein-B turnover in patients with ARDS/ALI and in human adults with normal lungs (controls). 2H2O as precursor of disaturated-phosphatidylcholine-palmitate and 113C-Leucine as precursor of surfactant protein-B were administered intravenously to 12 patients with ARDS/ALI and to 8 controls. Disaturated-phosphatidylcholine and surfactant protein-B were isolated from serial tracheal aspirates, and their fractional synthetic rate was derived from the 2H and 13C enrichment curves, obtained by gas chromatography mass spectrometry. Disaturated-phosphatidylcholine, surfactant protein-B, and protein concentrations in tracheal aspirates were also measured. 1) Surfactant protein-B turned over at faster rate than disaturated-phosphatidylcholine both in ARDS/ALI patients and in controls. 2) In patients with ARDS/ALI the fractional synthesis rate of disaturated-phosphatidylcholine was 3.1 times higher than in controls (p phosphatidylcholine and surfactant protein-B in tracheal aspirates were markedly and significantly reduced (17% and 40% of the control values respectively). 1) Disaturated-phosphatidylcholine and surfactant protein-B have a different turnover both in healthy and diseased lungs. 2) In ARDS/ALI the synthesis of these two surfactant components may be differently regulated.

  4. Therapist turnover and new program sustainability in mental health clinics as a function of organizational culture, climate, and service structure.

    Science.gov (United States)

    Glisson, Charles; Schoenwald, Sonja K; Kelleher, Kelly; Landsverk, John; Hoagwood, Kimberly Eaton; Mayberg, Stephen; Green, Philip

    2008-03-01

    The present study incorporates organizational theory and organizational characteristics in examining issues related to the successful implementation of mental health services. Following the theoretical foundations of socio-technical and cultural models of organizational effectiveness, organizational climate, culture, legal and service structures, and workforce characteristics are examined as correlates of therapist turnover and new program sustainability in a nationwide sample of mental health clinics. Results of General Linear Modeling (GLM) with the organization as the unit of analysis revealed that organizations with the best climates as measured by the Organizational Social Context (OSC) profiling system, had annual turnover rates (10%) that were less than half the rates found in organizations with the worst climates (22%). In addition, organizations with the best culture profiles sustained new treatment or service programs over twice as long (50 vs. 24 months) as organizations with the worst cultures. Finally, clinics with separate children's services units had higher turnover rates than clinics that served adults and children within the same unit. The findings suggest that strategies to support the implementation of new mental health treatments and services should attend to organizational culture and climate, and to the compatibility of organizational service structures with the demand characteristics of treatments.

  5. Disaturated-phosphatidylcholine and Surfactant protein-B turnover in human acute lung injury and in control patients

    Directory of Open Access Journals (Sweden)

    Rizzi Sabina

    2011-03-01

    Full Text Available Abstract Background Patients with Adult Respiratory Distress Syndrome (ARDS and Acute Lung Injury (ALI have low concentrations of disaturated-phosphatidylcholine and surfactant protein-B in bronchoalveolar lavage fluid. No information is available on their turnover. Objectives To analyze disaturated-phosphatidylcholine and surfactant protein-B turnover in patients with ARDS/ALI and in human adults with normal lungs (controls. Methods 2H2O as precursor of disaturated-phosphatidylcholine-palmitate and 113C-Leucine as precursor of surfactant protein-B were administered intravenously to 12 patients with ARDS/ALI and to 8 controls. Disaturated-phosphatidylcholine and surfactant protein-B were isolated from serial tracheal aspirates, and their fractional synthetic rate was derived from the 2H and 13C enrichment curves, obtained by gas chromatography mass spectrometry. Disaturated-phosphatidylcholine, surfactant protein-B, and protein concentrations in tracheal aspirates were also measured. Results 1 Surfactant protein-B turned over at faster rate than disaturated-phosphatidylcholine both in ARDS/ALI patients and in controls. 2 In patients with ARDS/ALI the fractional synthesis rate of disaturated-phosphatidylcholine was 3.1 times higher than in controls (p Conclusions 1 Disaturated-phosphatidylcholine and surfactant protein-B have a different turnover both in healthy and diseased lungs. 2 In ARDS/ALI the synthesis of these two surfactant components may be differently regulated.

  6. Methane and carbon monoxide production, oxidation, and turnover times in the Caribbean Sea as influenced by the Orinoco River

    Energy Technology Data Exchange (ETDEWEB)

    Jones, R.D.; Amador, J.A. (Florida International Univ., Miami (United States))

    1993-02-15

    The surface distribution of CH[sub 4], photoproduction capacity of seawater for CO, and CH[sub 4] and CO microbial oxidation rates and turnover times were determined for the surface waters of the southeastern Carribean Sea and Gulf of Paria as affected by the Orinoco River. Measurements were made during the spring (low river flow) and the fall (high river flow) in order to determine the influence of Orinoco River discharge on these parameters. Methane concentrations were generally lower in the fall than in the spring. Low CH[sub 4] oxidation rates and similar surface distributions were observed during both seasons. Methane oxidation in the river plume was significantly higher in the fall. Potential CO photoproduction and CO oxidation rates were generally higher during the fall. Possible effects of the Orinoco River on potential CO photoproduction capacity were observed as far as Puerto Rico. Turnover times for CH[sub 4] were in the order of years, whereas CO turnover times were in the order of hours. The Orinoco River has a significant impact on the consumption of CO and CH[sub 4] and the photoproduction of CO in the southeastern Caribbean Sea, presumably resulting from inputs of riverine carbon and nutrients. 22 refs., 2 figs., 2 tabs.

  7. The roles of unit leadership and nurse-physician collaboration on nursing turnover intention.

    Science.gov (United States)

    Galletta, Maura; Portoghese, Igor; Battistelli, Adalgisa; Leiter, Michael P

    2013-08-01

    To report a study of the relationship between variables at the group and individual level with nurses' intention to leave their unit. Workplaces are collective environments where workers constantly interact with each other. The quality of working relationship employees develop at the unit-level influences both employee outcomes and unit performance by shaping employee attitudes. The study was a cross-sectional design with self-administered questionnaires. A questionnaire including measures of leader-member exchange and nurse-physician collaboration analysed at group-level and affective commitment and turnover intention analysed at individual level, was administered individually to 1018 nurses in five Italian hospitals. Data were collected in 2009. A total of 832 nurses (81·7% response rate) completed questionnaires. The results showed that affective commitment at individual level completely mediated the relationship between leader-member exchange at group-level and nursing turnover intention. Furthermore, the cross-level interaction was significant: at individual level, the nurses with high levels of individual affective commitment towards their unit showed low levels of turnover intention and this relationship was stronger when the nurse-physician collaboration at group-level was high. This study showed the importance for organizations to implement management practices that promote both high-quality nurse-supervisor and nurse-physician relationships, because they increase nurses' identification with their units. Individual affective commitment is an important quality for retaining a workforce and good nurses' relationship at group-level relationships with both supervisors and physicians are instrumental in developing identification with the work unit. Thus, the quality of relationship among staff members is an important factor in nurses' decision to leave. © 2012 Blackwell Publishing Ltd.

  8. A new approach for evaluating bone turnover in chronic kidney disease.

    Science.gov (United States)

    Tolouian, Ramin; Hernandez, German T; Chiang, Wen-Yuan; Gupta, Ajay

    2010-06-01

    The validity of serum parathyroid hormone (PTH) as a surrogate marker of bone turnover in chronic kidney disease (CKD) is limited by several factors such as relative resistance of bone to PTH, hyperphosphatemia, diabetes, gender, age, race and vitamin D analog action on the PTH-bone axis. Urinary collagen N-terminal telopeptide X (NTx), a bone collagen degradation product, expressed as bone collagen equivalents (BCE) per mM of creatinine (NTx/Cr ratio), is routinely used to estimate bone turnover in osteoporosis. The purpose of this study is to evaluate NTx as a marker of bone turnover in CKD. We studied the relationship between bone-specific alkaline phosphatase (BSAP), PTH and urine NTx/Cr in 37 CKD out-patients. In a multivariate model, PTH had a positive correlation with BSAP (r=0.44, P<0.19) and U-NTx/Cr (r=0.55, P<0.30), after adjusting for age, gender, estimated glomerular filtration rate (GFR), serum phosphorus, corrected calcium, and race. However, the strongest correlation was found between the two direct markers of bone resorption and formation (U-NTx vs. BSAP; r=0.80; P<0.0001), suggesting a tight coupling of bone resorption and formation in CKD. The effect of gender on U-NTx/Cr was studied in a multivariate model after adjusting for age, race, GFR, serum calcium, phosphorus and PTH. Females had a higher U-NTx/Cr than males. Our findings indicate that urinary NTx, a promising marker of bone resorption in CKD patients, exhibits a strong positive correlation with other markers used to assess renal osteodystrophy i.e. PTH and BSAP. Unlike PTH and BSAP, urine NTx also measures bone loss secondary to osteoporosis. Published by Elsevier B.V.

  9. Nursing assistant turnover in nursing homes and need satisfaction.

    Science.gov (United States)

    Caudill, M; Patrick, M

    1989-06-01

    1. Level of Maslow's Hierarchy of Needs is basic physiological needs measured by salary, adequate housing, and food. Attainment of these needs increased the length of stay of nursing assistants in nursing homes. 2. Safety and security (level 2) influenced length of stay of nursing assistants. Those with benefits of retirement, vacation, and holiday pay tended to have less turnover. 3. Praise by the patient and family was most important to nursing assistants. Belonging to a peer group and praise by charge nurse also decreased turnover of nursing assistants (level 3). 4. Level 4, self-esteem measured by input into decisions and being able to criticize, increased length of stay of nursing assistants.

  10. Keratin dynamics: modeling the interplay between turnover and transport.

    Science.gov (United States)

    Portet, Stéphanie; Madzvamuse, Anotida; Chung, Andy; Leube, Rudolf E; Windoffer, Reinhard

    2015-01-01

    Keratin are among the most abundant proteins in epithelial cells. Functions of the keratin network in cells are shaped by their dynamical organization. Using a collection of experimentally-driven mathematical models, different hypotheses for the turnover and transport of the keratin material in epithelial cells are tested. The interplay between turnover and transport and their effects on the keratin organization in cells are hence investigated by combining mathematical modeling and experimental data. Amongst the collection of mathematical models considered, a best model strongly supported by experimental data is identified. Fundamental to this approach is the fact that optimal parameter values associated with the best fit for each model are established. The best candidate among the best fits is characterized by the disassembly of the assembled keratin material in the perinuclear region and an active transport of the assembled keratin. Our study shows that an active transport of the assembled keratin is required to explain the experimentally observed keratin organization.

  11. Methane conversion efficiency as a simple control parameter for an anaerobic digester at high loading rates.

    Science.gov (United States)

    Charles, W; Carnaje, N P; Cord-Ruwisch, R

    2011-01-01

    The anaerobic digestion process is globally applied to the treatment of highly concentrated wastes such as industrial and rural effluents, and sewage sludge. However, it is known to be relatively unstable. When loaded with high concentrations of organic material, unwanted volatile fatty acids (VFA) are often produced rather than methane (CH4) gas which can lead to digester acidification and failure. This study investigated digester behaviour under high loading rates, testing the usefulness of stoichiometric methane conversion efficiency as a digester control parameter at high loading rates. Our results show that, in general, the CH4 production rate was proportional to the feed rate (loading rate). However, at very high loading rates, the CH4 production rate was not proportional to the increase in the feeding rate. Consequently, VFA accumulated and the H2 partial pressure increased. The proportionality of the loading rate and gas production rate is stoichiometrically expressed as the conversion efficiency. We found that conversion efficiency was a useful indicator as an early warning of digester imbalance. The digester remained stable at conversion efficiencies above 75%. Dropping below 70% signified the onset of digester failure. As loading rate and methane production data are readily available on-line in most anaerobic digestion plants, the conversion efficiency can be monitored on-line and used as an efficient control technique to maintain safe operation of anaerobic digesters at high loading rates.

  12. Matrix metalloproteinases in fish biology and matrix turnover.

    Science.gov (United States)

    Pedersen, Mona E; Vuong, Tram T; Rønning, Sissel B; Kolset, Svein O

    2015-01-01

    Matrix metalloproteinases have important functions for tissue turnover in fish, with relevance both for the fish industry and molecular and cellular research on embryology, inflammation and tissue repair. These metalloproteinases have been studied in different fish types, subjected to both aquaculture and experimental conditions. This review highlights studies on these metalloproteinases in relation to both fish quality and health and further, the future importance of fish for basic research studies. Copyright © 2015. Published by Elsevier B.V.

  13. Effects of carbon turnover time on terrestrial ecosystem carbon storage

    Science.gov (United States)

    Yan, Yaner; Zhou, Xuhui; Jiang, Lifeng; Luo, Yiqi

    2017-12-01

    Carbon (C) turnover time is a key factor in determining C storage capacity in various plant and soil pools as well as terrestrial C sink in a changing climate. However, the effects of C turnover time on ecosystem C storage have not been well explored. In this study, we compared mean C turnover times (MTTs) of ecosystem and soil, examined their variability to climate, and then quantified the spatial variation in ecosystem C storage over time from changes in C turnover time and/or net primary production (NPP). Our results showed that mean ecosystem MTT based on gross primary production (GPP; MTTEC_GPP = Cpool/GPP, 25.0 ± 2.7 years) was shorter than soil MTT (MTTsoil = Csoil/NPP, 35.5 ± 1.2 years) and NPP-based ecosystem MTT (MTTEC_NPP = Cpool/NPP, 50.8 ± 3 years; Cpool and Csoil referred to ecosystem or soil C storage, respectively). On the biome scale, temperature is the best predictor for MTTEC (R2 = 0.77, p < 0.001) and MTTsoil (R2 = 0.68, p < 0.001), while the inclusion of precipitation in the model did not improve the performance of MTTEC (R2 = 0.76, p < 0.001). Ecosystem MTT decreased by approximately 4 years from 1901 to 2011 when only temperature was considered, resulting in a large C release from terrestrial ecosystems. The resultant terrestrial C release caused by the decrease in MTT only accounted for about 13.5 % of that due to the change in NPP uptake (159.3 ± 1.45 vs. 1215.4 ± 11.0 Pg C). However, the larger uncertainties in the spatial variation of MTT than temporal changes could lead to a greater impact on ecosystem C storage, which deserves further study in the future.

  14. Stoichiometry and Turnover of the Stator and Rotor.

    Science.gov (United States)

    Morimoto, Yusuke V; Minamino, Tohru

    2017-01-01

    Fluorescence imaging techniques using green fluorescent protein (GFP) and related fluorescent proteins are utilized to monitor and analyze a wide range of biological processes in living cells. Stepwise photobleaching experiments can determine the stoichiometry of protein complexes. Fluorescence recovery after photobleaching (FRAP) experiments can reveal in vivo dynamics of biomolecules. In this chapter, we describe methods to detect the subcellular localization, stoichiometry, and turnovers of stator and rotor components of the Salmonella flagellar motor.

  15. Alpine grassland soils contain large proportion of labile carbon but indicate long turnover times

    Directory of Open Access Journals (Sweden)

    K. Budge

    2011-07-01

    Full Text Available Alpine soils are expected to contain large amounts of labile carbon (C which may become a further source of atmospheric carbon dioxide (CO2 as a result of global warming. However, there is little data available on these soils, and understanding of the influence of environmental factors on soil organic matter (SOM turnover is limited. We extracted 30 cm deep cores from five grassland sites along a small elevation gradient from 2285 to 2653 m a.s.l. in the central Swiss Alps. Our aim was to determine the quantity, allocation, degree of stabilization and mean residence time (MRT of SOM in relation to site factors such as soil pH, vegetation, and SOM composition. Soil fractions obtained by size and density fractionation revealed a high proportion of labile C in SOM, mostly in the uppermost soil layers. Labile C in the top 20 cm across the gradient ranged from 39.6–57.6 % in comparison to 7.2–29.6 % reported in previous studies for lower elevation soils (810–1960 m a.s.l.. At the highest elevation, MRTs measured by means of radiocarbon dating and turnover modelling, increased between fractions of growing stability from 90 years in free POM (fPOM to 534 years in the mineral associated fraction (mOM. Depending on elevation and pH, plant community data suggested considerable variation in the quantity and quality of organic matter input, and these patterns could be reflected in the dynamics of soil C. 13C NMR data confirmed a relationship of SOM composition to MRT. While low temperature in alpine environments is likely to be a major cause for the slow turnover rate observed, other factors such as residue quality and soil pH, as well as the combination of all factors, play an important role in causing small scale variability of SOM turnover. Failing to incorporate this interplay of controlling factors into models may impair the performance of models to project SOM responses to environmental change.

  16. Mechanisms in intracellular turnover of stable and labile enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Kenney, F. T.; Pomato, N.; Lee, K. L.

    1977-01-01

    We have focused on two proteins of rat liver, one representative of the stable class and probably of reaction mechanisms operative in degradation of all proteins, the other unusually labile and possibly subject to uncommon as well as common mechanisms in turnover. The proteins chosen, tyrosine aminotransferase (E.C. 2.6.1.5) and alanine aminotransferase (E.C. 2.6.1.2) are similar in many respects. They catalyze similar reactions and share a substrate pair (glutamic acid and ..cap alpha..-ketoglutarate). Both are located in the soluble fraction of liver cytoplasm. Molecular weights are comparable (tyrosine aminotransferase, 100,000; alanine aminotransferase, 115,000) and both enzymes are structurally dimers of apparently identical subunits each of which binds one molecule of the common coenzyme, pyridoxal phosphate. Metabolically both are inducible by glucocorticoid hormones. But there the resemblance ends, for on the other, degradative side of the metabolic coin the two enzymes are sharply divergent. Tyrosine aminotransferase is among the most labile of liver enzymes, undergoing turnover with a half-life of 1.5 h, while turnover of alanine aminotransferase (half-life about 3 days) is virtually identical to that of the bulk of soluble liver proteins. Recent experimentation designed to determine the mechanistic basis for this difference in metabolism of otherwise quite similar enzymes is reviewed.

  17. Bone turnover markers in epileptic patients under chronic valproate therapy

    Directory of Open Access Journals (Sweden)

    Mohammad Zare

    2013-01-01

    Full Text Available Background: The effects of chronic valproic acid administration on bone health have been a matter of concern and controversy. In this study, the bone status following valproate intake was assessed by using several bone-related biochemical markers. Materials and Methods: In this case-control study, 62 epileptic patients and 40 age- and gender-matched controls were enrolled. The patients had been under chronic valproate therapy (758 ± 29 mg/day for at least the past 6 months, without any vitamin D/or calcium supplementation. Serum markers of bone turnover (carboxy-terminal telopeptide of type I collagen (CTX and bone-specific alkaline phosphatase [BALP], calcium, phosphorus, total alkaline phosphatase, and parathyroid hormone levels were measured in both groups. Results: The markers of bone turnover as well as other measured bone biochemical parameters did not statistically differ between the two groups. Conclusion: Valproate therapy at the mentioned doses does not seem to change bone turnover in adult epileptic patients.

  18. KEAHLIAN AUDITOR DAN TURNOVER INTENTION SEBAGAI MEDIASI DETERMINAN KINERJA AUDITOR

    Directory of Open Access Journals (Sweden)

    Ceacilia Srimindarti

    2015-12-01

    Full Text Available This research aims to examine the effect of locus of control and organizational commitment on auditors’ performance as well as to examine whether auditors’ expertise and turnover intention mediate the effect of locus of control and organizational commitment on auditors’ performance. Samples of this study were auditors who worked at audit firms in Semarang. Samples were selected using the purposive sampling method. The data were analyzed using SEM with AMOS program. This study found that locus of control had a negative effect on auditors’ performance, organizational commitment had a positive effect on auditors’ performance, and auditors’ expertise and turnover intention had no effect on auditors’ performance. Furthermore, locus of control had a negative effect on auditors’ expertise, and organizational commitment had a negative effect on turnover intention. Based on this result, managers of public accounting firm (partners should provide some trainings to the auditors who had the external locus of control so that they can achieve the standardized performances. They should also confirm the company’s values to the auditor to increase emotional attachment to the company as well as try to comply to the demands of the company thus its performance will be in accordance with company’s expectations.

  19. Examining the temporal relationship between psychological climate, work attitude, and staff turnover.

    Science.gov (United States)

    Garner, Bryan R; Hunter, Brooke D

    2013-02-01

    Relative to the broader industrial-organizational (I-O) psychology field, research on the turnover of substance use disorder (SUD) treatment staff is in its infancy. Despite its long and rich history, recent reviews of the turnover literature within I-O psychology have noted that there remains considerable room for improvement. In particular, recommendations have been made for research that considers time in the turnover process and explores more distal causes of staff turnover. Addressing these gaps, this article examined the temporal relationship between latent measures of psychological climate, work attitude, and staff turnover. Using data from 95 SUD treatment staff clustered within 29 treatment organizations, multilevel discrete-time survival analyses revealed that a latent measure of work attitude (e.g., job satisfaction, pay satisfaction, turnover intentions) fully mediated the temporal relationship between latent measures of psychological climate (e.g., supervisor support, coworker support, role conflict) and subsequent staff turnover. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Beyond safety outcomes: An investigation of the impact of safety climate on job satisfaction, employee engagement and turnover using social exchange theory as the theoretical framework.

    Science.gov (United States)

    Huang, Yueng-Hsiang; Lee, Jin; McFadden, Anna C; Murphy, Lauren A; Robertson, Michelle M; Cheung, Janelle H; Zohar, Dov

    2016-07-01

    Safety climate, a measure of the degree to which safety is perceived by employees to be a priority in their company, is often implicated as a key factor in the promotion of injury-reducing behavior and safe work environments. Using social exchange theory as a theoretical basis, this study hypothesized that safety climate would be related to employees' job satisfaction, engagement, and turnover rate, highlighting the beneficial effects of safety climate beyond typical safety outcomes. Survey data were collected from 6207 truck drivers from two U.S. trucking companies. The objective turnover rate was collected one year after the survey data collection. Results showed that employees' safety climate perceptions were linked to employees' level of job satisfaction, engagement, and objective turnover rate, thus supporting the application of social exchange theory. Job satisfaction was also a significant mediator between safety climate and the two human resource outcomes (i.e., employee engagement and turnover rate). This study is among the first to assess the impact of safety climate beyond safety outcomes among lone workers (using truck drivers as an exemplar). Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Predicting TUrnover Intentions of Hotel Employees: The Influence of Employee Development Human Resource Management Practices and Trust in Organization

    Directory of Open Access Journals (Sweden)

    Mohamad Abdullah Hemdi

    2006-01-01

    Full Text Available This study investigates the variables that may be predictive of hotel employees’ turnover intentions. The influence of trust in organization as a mediator in the proposed relationship is also examined. A total of 380 operational employees from 5-star rated hotels completed the questionnaires. Hierarchical regression analysis was used to test the relationships hypothesized in the model. Most of the hypotheses were supported. It is suggested that to enhance employees’ trust in organization and subsequently to reduce turnover intentions, hotels need to continue to provide training and development programs to their employees, conduct fair and formal appraisal system, and provide ample and clear career advancement to their employees. Limitations and suggestions for future studies are forwarded.

  2. Substrate turnover at low carbon concentrations in a model drinking water distribution system

    DEFF Research Database (Denmark)

    Boe-Hansen, Rasmus; Albrechtsen, Hans-Jørgen; Arvin, Erik

    2002-01-01

    utilisation and bacterial growth at low nutrient conditions in a model distribution system. The model system consisted of two loops in series, where flow rate and retention time were controlled independently. Spiking the drinking water of the model system with two different environmentally realistic......Water quality changes caused by microbial activity in the distribution network can cause serious problems. Reducing the amount of microbial available substrate may be an effective way to control bacterial aftergrowth. The purpose of the present study was to study the kinetics of substrate...... concentrations of carbon allowed for a close monitoring of the kinetics of substrate turnover (less than 10 μg C/L 14C-benzoic acid was added). The mineralisation of benzoic acid was rapid and could be modelled by a no-growth Monod expression using a maximum degradation rate of 0.59 μg C/L/h and a half...

  3. Decoherence and quantum interference in a four-site model system: mechanisms and turnovers.

    Science.gov (United States)

    Zarea, Mahdi; Powell, Daniel; Renaud, Nicolas; Wasielewski, Michael R; Ratner, Mark A

    2013-01-31

    We study quantum interference effects in a four-level system which can be used as a minimal model to understand such behavior in systems from synthetic molecular structures to the photosystem-1 reaction center. The effects of environmental decoherence and relaxation on the electron transfer rate are investigated for several types of decoherence processes. The rate as a function of decoherence amplitude shows Kramers turnover, as expected. However, various decoherence processes affect the quantum interference differently. It is shown that when the bridge sites are not dephased the superexchange transfer is enhanced by constructive quantum interference. Dephasing on bridge sites opens a (classical) diffusive channel for fast electron transfer, which can dominate the superexchange current and reduce the constructive quantum interference.

  4. Actin turnover is required for myosin-dependent mitochondrial movements in Arabidopsis root hairs.

    Directory of Open Access Journals (Sweden)

    Maozhong Zheng

    Full Text Available BACKGROUND: Previous studies have shown that plant mitochondrial movements are myosin-based along actin filaments, which undergo continuous turnover by the exchange of actin subunits from existing filaments. Although earlier studies revealed that actin filament dynamics are essential for many functions of the actin cytoskeleton, there are little data connecting actin dynamics and mitochondrial movements. METHODOLOGY/PRINCIPAL FINDINGS: We addressed the role of actin filament dynamics in the control of mitochondrial movements by treating cells with various pharmaceuticals that affect actin filament assembly and disassembly. Confocal microscopy of Arabidopsis thaliana root hairs expressing GFP-FABD2 as an actin filament reporter showed that mitochondrial distribution was in agreement with the arrangement of actin filaments in root hairs at different developmental stages. Analyses of mitochondrial trajectories and instantaneous velocities immediately following pharmacological perturbation of the cytoskeleton using variable-angle evanescent wave microscopy and/or spinning disk confocal microscopy revealed that mitochondrial velocities were regulated by myosin activity and actin filament dynamics. Furthermore, simultaneous visualization of mitochondria and actin filaments suggested that mitochondrial positioning might involve depolymerization of actin filaments on the surface of mitochondria. CONCLUSIONS/SIGNIFICANCE: Base on these results we propose a mechanism for the regulation of mitochondrial speed of movements, positioning, and direction of movements that combines the coordinated activity of myosin and the rate of actin turnover, together with microtubule dynamics, which directs the positioning of actin polymerization events.

  5. Building America Case Study: Philadelphia Housing Authority Energy-Efficiency Turnover Protocols, Philadelphia, Pennsylvania

    Energy Technology Data Exchange (ETDEWEB)

    2016-02-01

    Over one million HUD-supported public housing units provide rental housing for eligible low-income families across the country. A survey of over 100 public housing authorities (PHAs) across the country indicated that there is a high level of interest in developing low-cost solutions that improve energy efficiency and can be seamlessly included in the refurbishment process. Further, PHAs, have incentives (both internal and external) to reduce utility bills. ARIES worked with four PHAs to develop packages of energy efficiency retrofit measures the PHAs can cost-effectively implement with their own staffs in the normal course of housing operations at the time when units are refurbished between occupancies. The energy efficiency turnover protocols emphasized air infiltration reduction, duct sealing, and measures that improve equipment efficiency. ARIES documented implementation in 18 housing units. Reductions in average air leakage were 16 percent and duct leakage reductions averaged 23 percent. Total source energy consumption savings due to implemented measures was estimated at 3-10 percent based on BEopt modeling with a simple payback of 1.6 to 2.5 years. Implementation challenges were encountered mainly related to required operational changes and budgetary constraints. Nevertheless, simple measures can feasibly be accomplished by PHA staff at low or no cost. At typical housing unit turnover rates, these measures could impact hundreds of thousands of units per year nationally.

  6. Influence of renal function and platelet turnover on the antiplatelet effect of aspirin.

    Science.gov (United States)

    Würtz, Morten; Wulff, Lise N; Grove, Erik L; Kristensen, Steen D; Hvas, Anne-Mette

    2012-04-01

    Kidney disease predisposes to cardiovascular events. This study investigated the influence of renal function and platelet turnover on the antiplatelet effect of aspirin in patients with coronary artery disease. We included 124 aspirin-treated patients with coronary artery disease and normal to moderately reduced renal function. All tests were performed one hour after aspirin ingestion. Renal function was assessed using creatinine, estimated glomerular filtration rate (eGFR), and cystatin C. The antiplatelet effect of aspirin was evaluated using the VerifyNow Aspirin assay and multiple electrode aggregometry (MEA, Multiplate) induced by collagen (1.0 μg/mL) and arachidonic acid (1.0 mmol/L). Von Willebrand factor was measured as a marker of endothelial dysfunction. Platelet turnover was evaluated by measurements of immature, reticulated platelets. Renal function did not influence the antiplatelet effect of aspirin evaluated by MEA (r=-0.2-0.09, p=0.03-0.77) or the VerifyNow (r=-0.12-0.11, all p-values>0.1). In contrast, renal function correlated inversely with von Willebrand factor levels (r(creatinine)=0.48, pantiplatelet effect of aspirin may be explained by an increased number of immature platelets. Moderately impaired renal function was associated with high levels of von Willebrand factor, but not with a reduced antiplatelet effect of aspirin. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Workplace stress, job satisfaction, job performance, and turnover intention of health care workers in rural Taiwan.

    Science.gov (United States)

    Chao, Ming-Che; Jou, Rong-Chang; Liao, Cing-Chu; Kuo, Chung-Wei

    2015-03-01

    Workplace stress (WS) has been found to affect job satisfaction (JS), performance, and turnover intentions (TIs) in developed countries, but there is little evidence from other countries and especially rural areas. In rural Taiwan, especially, there is an insufficient health care workforce, and the situation is getting worse. To demonstrate the relationship, we used a cross-sectional structured questionnaire, and data from 344 licensed professionals in 1 rural regional hospital were analyzed using the structural equation model. The results showed that WS had a positive effect on both TI and job performance (JP) but a negative effect on satisfaction. JS did improve performance. For the staff with an external locus of control, stress affected JP and satisfaction significantly. For the staff with lower perceived job characteristics, JS affected performance significantly. The strategies to decrease stress relating to work load, role conflict, family factors, and working environment should be focused and implemented urgently to lower the turnover rate of health care workers in rural Taiwan. © 2013 APJPH.

  8. Soil carbon stabilization and turnover at alley-cropping systems, Eastern Germany

    Science.gov (United States)

    Medinski, T.; Freese, D.

    2012-04-01

    Alley-cropping system is seen as a viable land-use practice for mitigation of greenhouse gas CO2, energy-wood production and soil carbon sequestration. The extent to which carbon is stored in soil varies between ecosystems, and depends on tree species, soil types and on the extent of physical protection of carbon within soil aggregates. This study investigates soil carbon sequestration at alley-cropping systems presented by alleys of fast growing tree species (black locust and poplar) and maize, in Brandenburg, Eastern Germany. Carbon accumulation and turnover are assessed by measuring carbon fractions differing in decomposition rates. For this purpose soil samples were fractionated into labile and recalcitrant soil-size fractions by wet-sieving: macro (>250 µm), micro (53-250 µm) and clay + silt (LiCor automated device LI-8100A. No differences for the total and stable (clay+silt, <53 µm) carbon fraction were observed between treatment. While cold water-extractable carbon was significantly higher at maize alley compared to black locust alley. This may indicate faster turnover of organic matter at maize alley due to tillage, which influenced greater incorporation of plant residues into the soil, greater soil respiration and microbial activity.

  9. The effect of fertilization levels and genetic deployment on soil organic matter chemistry and turnover in managed loblolly pine forests

    Science.gov (United States)

    Vogel, J. G.; Jokela, E. J.; He, D.; Hockaday, W. C.; Schuur, E. A.

    2013-12-01

    Soil organic matter (SOM) dynamics were examined for two managed loblolly pine forests (Pinus taeda L.) located in north-central Florida on sandy Spodosols. The study designs were split-plots with the whole plots designated as fertilization levels, and the split-plots full-sib families of loblolly pine. The forests were aged 9 and 10 years at sampling. Roots, wood, and charcoal were hand-picked from SOM and density fractionation (1.6 g/ml) used to further separate SOM into a light (LF) and heavy fraction (HF). LF turnover rates were estimated using radiocarbon and LF chemistry determined with nuclear magnetic resonance (NMR). Family or fertilization level effects on the mass of SOM components were not significant at both sites. The largest proportions of SOM were in the LF (83% and 85%) and wood (6% and 9%). Varying in relative contributions were charcoal (2% and 3%) and the HF (4% and 1%) while fine dead roots were between 1-2% of total SOM. Higher fertilization levels generally depressed fine root (family and soil horizon. The turnover rate for one family under low fertilization was significantly slower (14 yrs) than the other treatments. This treatment also had a greater proportion of lignin, and given the slow turnover, the results suggest this lignin derived from the previous stand. At the other site lignin and lipids differed significantly (pfamilies. These results suggest that tree genetics in forests can influence SOM chemistry, but that family and the degree of fertilization have little net effect on SOM chemistry and turnover.

  10. Performance and carbon turnover in fast- and slow-growing broilers submitted to cyclic heat stress and fed on high-protein diets.

    Science.gov (United States)

    Campos, D M B; Macari, M; Fernadez-Alarcon, M F; Nogueira, W C L; de Souza, F A; Hada, F H; Lunedo, R; Denadai, J C

    2016-01-01

    Two experiments were conducted to test the hypothesis that when using similar protein/amino acid diets and environment temperature conditions, the performance and carbon turnover in muscle and liver tissues, as measured by the incorporation of stable isotopes ((13)C/(12)C), must be different between fast-growing Cobb 500® and slow-growing Label Rouge broilers. For both experiments (Cobb and Label Rouge), 21-d-old birds were distributed in a completely randomised, 3 × 3 factorial design; three environmental temperatures (cyclic heat stress ad libitum, 22°C ad libitum, and 22°C restricted) and three crude protein concentrations (189.1, 210 and 220 g/kg CP) were used. The Cobb 500® had better performance with higher concentrations of crude protein. Cyclic heat stress (a temperature factor), negatively affected this genetic strain's performance. For the Label Rouge birds, the crude protein concentrations in the diet presented inconsistent results and cyclic heat stress did not affect the performance. The carbon turnover rate was affected in the Cobb 500® strain, with a high protein content reducing carbon turnover in the evaluated tissues (liver and muscles). Feed intake had a greater impact on carbon turnover rates than cyclic heat stress. The Label Rouge birds were not affected by the evaluated factors, suggesting that genetic improvement has a leading role on tissue carbon turnover. There is a genetic influence on carbon turnover in the liver and muscle tissues of broiler chickens. In addition, genetically fast-growing broilers are more susceptible to variations in diet composition and environmental temperature than less rapidly growing animals.

  11. How the Timing of Climate Change Policy Affects Infrastructure Turnover in the Electricity Sector: Engineering, Economic and Policy Considerations

    Science.gov (United States)

    Izard, Catherine Finlay

    The electricity sector is responsible for producing 35% of US greenhouse gas (GHG) emissions. Estimates suggest that ideally, the electricity sector would be responsible for approximately 85% of emissions abatement associated with climate polices such as America's Clean Energy and Security Act (ACES). This is equivalent to ˜50% cumulative emissions reductions below projected cumulative business-as-usual (BAU) emissions. Achieving these levels of emissions reductions will require dramatic changes in the US electricity generating infrastructure: almost all of the fossil-generation fleet will need to be replaced with low-carbon sources and society is likely to have to maintain a high build rate of new capacity for decades. Unfortunately, the inertia in the electricity sector means that there may be physical constraints to the rate at which new electricity generating capacity can be built. Because the build rate of new electricity generating capacity may be limited, the timing of regulation is critical---the longer the U.S. waits to start reducing GHG emissions, the faster the turnover in the electricity sector must occur in order to meet the same target. There is a real, and thus far unexplored, possibility that the U.S. could delay climate change policy implementation for long enough that it becomes infeasible to attain the necessary rate of turnover in the electricity sector. This dissertation investigates the relationship between climate policy timing and infrastructure turnover in the electricity sector. The goal of the dissertation is to answer the question: How long can we wait before constraints on infrastructure turnover in the electricity sector make achieving our climate goals impossible? Using the Infrastructure Flow Assessment Model, which was developed in this work, this dissertation shows that delaying climate change policy increases average retirements rates by 200-400%, increases average construction rates by 25-85% and increases maximum construction

  12. Paleocommunity turnover in an Early Pliocene seamount from southeastern Spain

    Science.gov (United States)

    García-Ramos, Diego Antonio; Zuschin, Martin

    2017-04-01

    Seamounts are topographic elevations under the sea, regardless of their size and relief. They support rich living communities and are important biodiversity hotspots, but many of the fundamental ecological processes that maintain seamount communities remain poorly understood. In contrast to snapshot observations conducted on extant seamounts, fossil examples may provide the opportunity to assess how temporal changes in physico-chemical parameters relate to paleocommunity turnovers in these particular biotopes. Here we deal with an Early Pliocene (Zanclean) small seamount in southeastern Spain. This classic locality is extremely rich in fossil macroinvertebrates and was subject to studies of some taxonomic groups in the late seventies. However, the detailed stratigraphy is herein outlined for the first time. The overall feature is a shallowing upward succession about 35 m thick which onlaps a Miocene volcanic ridge. The occurrence of the planktonic foraminifera Globorotalia margaritae and G. puncticulata allow attribution to the MPl3 biozone of the Mediterranean Pliocene. We measured two sections that can be divided in a lower interval of fine-grained bryozoan-rich deposits and a upper interval of biocalcarenite increasingly rich in rhodoliths upsection. The whole series is bioturbated, with Thalassinoides traces being more common upsection. Biofabrics comprise mostly densely-packed suites of disarticulated and fragmented shells of calcitic fauna (large oysters are often bioeroded by clionid sponges), suggesting relatively low sedimentation rates and reworking by storms (e.g., channelized shell-beds, tubular tempestites). The prevailing taxonomic groups are cheilostome bryozoans, oysters, brachiopods, pectinids, echinoderms, cirripedes and corals. The lower interval contains octocoral internodes (Isididae) (only recorded at the base of the section). Scleratinians like Balanophyllia? decrease in abundance upsection. Bryozoans are extremely abundant and diverse, with

  13. Rhizosphere bacterial carbon turnover is higher in nucleic acids than membrane lipids: implications for understanding soil carbon cycling

    Science.gov (United States)

    Malik, Ashish A.; Dannert, Helena; Griffiths, Robert I.; Thomson, Bruce C.; Gleixner, Gerd

    2015-01-01

    Using a pulse chase 13CO2 plant labeling experiment we compared the flow of plant carbon into macromolecular fractions of rhizosphere soil microorganisms. Time dependent 13C dilution patterns in microbial cellular fractions were used to calculate their turnover time. The turnover times of microbial biomolecules were found to vary: microbial RNA (19 h) and DNA (30 h) turned over fastest followed by chloroform fumigation extraction-derived soluble cell lysis products (14 days), while phospholipid fatty acids (PLFAs) had the slowest turnover (42 days). PLFA/NLFA 13C analyses suggest that both mutualistic arbuscular mycorrhizal and saprophytic fungi are dominant in initial plant carbon uptake. In contrast, high initial 13C enrichment in RNA hints at bacterial importance in initial C uptake due to the dominance of bacterial derived RNA in total extracts of soil RNA. To explain this discrepancy, we observed low renewal rate of bacterial lipids, which may therefore bias lipid fatty acid based interpretations of the role of bacteria in soil microbial food webs. Based on our findings, we question current assumptions regarding plant-microbe carbon flux and suggest that the rhizosphere bacterial contribution to plant assimilate uptake could be higher. This highlights the need for more detailed quantitative investigations with nucleic acid biomarkers to further validate these findings. PMID:25914679

  14. Factors Influencing Job Satisfaction and Anticipated Turnover among Nurses in Sidama Zone Public Health Facilities, South Ethiopia

    Science.gov (United States)

    Belachew, Tefera; Yimam, Ebrahim

    2014-01-01

    Background. Workplace turnover is destructive to nursing and patient outcomes as it leads to losing competent and qualified nurses. However, developments of coping strategies demand a clear understanding of workplace variables that either motivate nurses to remain employed or lead them to leave their current jobs. Objective. This study was designed toassess factors influencing job satisfaction and intention to turnover among nurses in Sidama zone public health facilities, in Southern Ethiopia. Method. Cross-sectional study design was carried out on 278 nurses using both qualitative and quantitative data collection methods from May 12 to June 05, 2010. Result. A total of 242 nurses were interviewed giving a response rate of 87%. Nearly two-third (68.6%) of the participants were female, and the mean age was 28 (±6.27) years for both sexes. All job satisfaction subscale except benefit and salary subscale were significant predictors of overall job satisfaction. Satisfactions with work environment and group cohesion (AOR: 0.25 [95% CI: 0.12, 0.51]), single cohesion (AOR: 2.56 [95% CI: 1.27, 5.13]), and working in hospital (AOR: 2.19 [95% CI: 1.12, 4.30]) were the final significant predictors of anticipated turnover of Sidama zone nurses. Conclusions. More than any factors managers should consider the modification of working environment and group cohesions rather than trying to modify nurses to retain and maintain more experienced nurses for the organizations. PMID:24707397

  15. Factors Influencing Job Satisfaction and Anticipated Turnover among Nurses in Sidama Zone Public Health Facilities, South Ethiopia

    Directory of Open Access Journals (Sweden)

    Agezegn Asegid

    2014-01-01

    Full Text Available Background. Workplace turnover is destructive to nursing and patient outcomes as it leads to losing competent and qualified nurses. However, developments of coping strategies demand a clear understanding of workplace variables that either motivate nurses to remain employed or lead them to leave their current jobs. Objective. This study was designed toassess factors influencing job satisfaction and intention to turnover among nurses in Sidama zone public health facilities, in Southern Ethiopia. Method. Cross-sectional study design was carried out on 278 nurses using both qualitative and quantitative data collection methods from May 12 to June 05, 2010. Result. A total of 242 nurses were interviewed giving a response rate of 87%. Nearly two-third (68.6% of the participants were female, and the mean age was 28 (±6.27 years for both sexes. All job satisfaction subscale except benefit and salary subscale were significant predictors of overall job satisfaction. Satisfactions with work environment and group cohesion (AOR: 0.25 [95% CI: 0.12, 0.51], single cohesion (AOR: 2.56 [95% CI: 1.27, 5.13], and working in hospital (AOR: 2.19 [95% CI: 1.12, 4.30] were the final significant predictors of anticipated turnover of Sidama zone nurses. Conclusions. More than any factors managers should consider the modification of working environment and group cohesions rather than trying to modify nurses to retain and maintain more experienced nurses for the organizations.

  16. Arabidopsis actin-depolymerizing factor7 severs actin filaments and regulates actin cable turnover to promote normal pollen tube growth.

    Science.gov (United States)

    Zheng, Yiyan; Xie, Yurong; Jiang, Yuxiang; Qu, Xiaolu; Huang, Shanjin

    2013-09-01

    Actin filaments are often arranged into higher-order structures, such as the longitudinal actin cables that generate the reverse fountain cytoplasmic streaming pattern present in pollen tubes. While several actin binding proteins have been implicated in the generation of these cables, the mechanisms that regulate their dynamic turnover remain largely unknown. Here, we show that Arabidopsis thaliana actin-depolymerizing factor7 (ADF7) is required for turnover of longitudinal actin cables. In vitro biochemical analyses revealed that ADF7 is a typical ADF that prefers ADP-G-actin over ATP-G-actin. ADF7 inhibits nucleotide exchange on actin and severs filaments, but its filament severing and depolymerizing activities are less potent than those of the vegetative ADF1. ADF7 primarily decorates longitudinal actin cables in the shanks of pollen tubes. Consistent with this localization pattern, the severing frequency and depolymerization rate of filaments significantly decreased, while their maximum lifetime significantly increased, in adf7 pollen tube shanks. Furthermore, an ADF7-enhanced green fluorescent protein fusion with defective severing activity but normal G-actin binding activity could not complement adf7, providing compelling evidence that the severing activity of ADF7 is vital for its in vivo functions. These observations suggest that ADF7 evolved to promote turnover of longitudinal actin cables by severing actin filaments in pollen tubes.

  17. Rhizosphere bacterial carbon turnover is higher in nucleic acids than membrane lipids: implications for understanding soil carbon cycling

    Directory of Open Access Journals (Sweden)

    Ashish A. Malik

    2015-04-01

    Full Text Available Using a pulse-chase 13CO2 plant labeling experiment we compared the flow of plant carbon into macromolecular fractions of root-associated soil microorganisms. Time dependent 13C dilution patterns in microbial cellular fractions were used to calculate their turnover time. The turnover times of microbial biomolecules were found to vary: microbial RNA (19 h and DNA (30 h turned over fastest followed by chloroform fumigation extraction-derived soluble cell lysis products (14 d, while phospholipid fatty acids (PLFAs had the slowest turnover (42 d. PLFA/NLFA 13C analyses suggest that both mutualistic arbuscular mycorrhizal and saprophytic fungi are dominant in initial plant carbon uptake. In contrast, high initial 13C enrichment in RNA hints at bacterial importance in initial C uptake due to the dominance of bacterial derived RNA in total extracts of soil RNA. To explain this discrepancy, we observed low renewal rate of bacterial lipids, which may therefore bias lipid fatty acid based interpretations of the role of bacteria in soil microbial food webs. Based on our findings, we question current assumptions regarding plant-microbe carbon flux and suggest that the rhizosphere bacterial contribution to plant assimilate uptake could be higher. This highlights the need for more detailed quantitative investigations with nucleic acid biomarkers to further validate these findings.

  18. Fat Cell and Fatty Acid Turnover in Obesity.

    Science.gov (United States)

    Engin, Atilla

    2017-01-01

    The ratio of free fatty acid (FFA) turnover decreases significantly with the expansion of white adipose tissue. Adipose tissue and dietary saturated fatty acid levels significantly correlate with an increase in fat cell size and number. Inhibition of adipose triglyceride lipase leads to an accumulation of triglyceride, whereas inhibition of hormone-sensitive lipase leads to the accumulation of diacylglycerol. The G0/G1 switch gene 2 increases lipid content in adipocytes and promotes adipocyte hypertrophy through the restriction of triglyceride turnover. Excess triacylglycerols (TAGs), sterols and sterol esters are surrounded by the phospholipid monolayer surface and form lipid droplets. Following the release of lipid droplets from endoplasmic reticulum, cytoplasmic lipid droplets increase their volume either by local TAG synthesis or by homotypic fusion. The number and the size of lipid droplet distribution is correlated with obesity. Obesity-associated adipocyte death exhibits feature of necrosis-like programmed cell death. NOD-like receptors family pyrin domain containing 3 (NLRP3) inflammasome-dependent caspase-1 activation in hypertrophic adipocytes induces obese adipocyte death by pyroptosis. Actually adipocyte death may be a prerequisite for the transition from hypertrophic to hyperplastic obesity. Major transcriptional factors, CCAAT/enhancer-binding proteins beta and delta, play a central role in the subsequent induction of critical regulators, peroxisome-proliferator-activated receptor gamma, CCAAT/enhancer-binding protein alpha and sterol regulatory element-binding protein 1, in the transcriptional control of adipogenesis in obesity.Collectively, in this chapter the concept of adipose tissue remodeling in response to adipocyte death or adipogenesis, and the complexity of lipid droplet interactions with the other cellular organelles are reviewed. Furthermore, in addition to lipid droplet growth, the functional link between the adipocyte-specific lipid

  19. Centennial black carbon turnover observed in a Russia steppe soil

    Energy Technology Data Exchange (ETDEWEB)

    Hammes, K.; Torn, M.S.; Lapenas, A.G.; Schmidt, M.W.I.

    2008-09-15

    Black carbon (BC), from incomplete combustion of fuels and biomass, has been considered highly recalcitrant and a substantial sink for carbon dioxide. Recent studies have shown that BC can be degraded in soils. We use two soils with very low spatial variability sampled 100 years apart in a Russian steppe preserve to generate the first whole-profile estimate of BC stocks and turnover in the field. Quantities of fire residues in soil changed significantly over a century. Black carbon stock was 2.5 kg m{sup -2}, or about 7-10% of total organic C in 1900. With cessation of biomass burning, BC stocks decreased 25% over a century, which translates into a centennial soil BC turnover (293 years best estimate; range 182-541 years), much faster than so-called inert or passive carbon in ecosystem models. The turnover time presented here is for loss by all processes, namely decomposition, leaching, and erosion, although the latter two were probably insignificant in this case. Notably, at both time points, the peak BC stock was below 30 cm, a depth interval, which is not typically accounted for. Also, the quality of the fire residues changed with time, as indicated by the use benzene poly carboxylic acids (BPCA) as molecular markers. The proportions of less-condensed (and thus more easily degradable) BC structures decreased, whereas the highly condensed (and more recalcitrant) BC structures survived unchanged over the 100-year period. Our results show that BC cannot be assumed chemically recalcitrant in all soils, and other explanations for very old soil carbon are needed.

  20. Influence of orlistat on bone turnover and body composition

    DEFF Research Database (Denmark)

    Gotfredsen, A; Westergren Hendel, H; Andersen, T

    2001-01-01

    OBJECTIVE: To investigate the influence of the pancreas lipase inhibitor orlistat (OLS) on calcium metabolism, bone turnover, bone mass, bone density and body composition when given for obesity as adjuvant to an energy- and fat-restricted diet. DESIGN: Randomized controlled double-blinded trial...... of treatment with OLS 120 mg three times daily or placebo for 1 y. SUBJECTS: Thirty obese subjects with a mean body mass index (BMI) of 36.9+/-3.7 kg/m(2) and a mean age of 41+/-11 y. Sixteen patients were assigned to OLS and 14 to placebo. MEASUREMENTS: Dual energy X-ray absorptiometry (DXA) measurements...

  1. Clinical usefulness of bone turnover marker concentrations in osteoporosis

    DEFF Research Database (Denmark)

    Morris, H A; Eastell, R; Rye Jørgensen, Niklas

    2017-01-01

    Current evidence continues to support the potential for bone turnover markers (BTM) to provide clinically useful information particularly for monitoring the efficacy of osteoporosis treatment. Many of the limitations identified earlier remain, principally in regard to the relationship between BTM...... of combining such data for meta-analyses. Harmonization of units for reporting serum/plasma CTX (ng/L) and PINP (μg/L) is recommended. The development of international collaborations continues with an important initiative to combine BTM results from clinical trials in osteoporosis in a meta...

  2. Bilateral Anterior Rectus Sheath Turnover Flap for Abdominal Closure

    Directory of Open Access Journals (Sweden)

    Bulent Kaya

    2013-10-01

    Full Text Available The management of abdominal wall hernias with tissue loss is a difficult subject.Several surgical techniques have been used in the treatment. Sometimes closure of the abdomen with primary sutures may be impossible. Dual meshes, component separation technique, usculofascial flaps can be used for closure of the abdomen.In this case report a patient with complex abdominal wall hernia was presented.The abdomen was successfully closed with anterior rectus sheath turnover flap.We discussed this surgical technique with literature review.

  3. Species turnover and geographic distance in an urban river network

    DEFF Research Database (Denmark)

    Rouquette, James R.; Dallimer, Martin; Armsworth, Paul R.

    2013-01-01

    of the habitat or topographic features of the landscape and the means of dispersal of the organism. River networks, in particular in human-modified landscapes, are a striking example of such a situation. Here, we use data for both aquatic and terrestrial organisms across an urban river network to examine...... patterns of species turnover and to determine whether these patterns differ between different taxonomic groups. LocationSheffield area, UK. MethodsAquatic (macroinvertebrates, diatoms) and terrestrial (birds, plants, butterflies) organisms were surveyed at 41 sites across an urban river network. We...

  4. Hydrologic and biologic influences on stream network nutrient concentrations: Interactions of hydrologic turnover and concentration-dependent nutrient uptake

    Science.gov (United States)

    Mallard, John; McGlynn, Brian; Covino, Tim

    2016-04-01

    Stream networks lie in a crucial landscape position between terrestrial ecosystems and downstream water bodies. As such, whether inferring terrestrial watershed processes from watershed outlet nutrient signals or predicting the effect of observed terrestrial processes on stream nutrient signals, it is requisite to understand how stream networks can modulate terrestrial nutrient inputs. To date integrated understanding and modeling of physical and biological influences on nutrient concentrations at the stream network scale have been limited. However, watershed scale groundwater - surface water exchange (hydrologic turnover), concentration-variable biological uptake, and the interaction between the two can strongly modify stream water nutrient concentrations. Stream water and associated nutrients are lost to and replaced from groundwater with distinct nutrient concentrations while in-stream nutrients can also be retained by biological processes at rates that vary with concentration. We developed an empirically based network scale model to simulate the interaction between hydrologic turnover and concentration-dependent nutrient uptake across stream networks. Exchange and uptake parameters were measured using conservative and nutrient tracer addition experiments in the Bull Trout Watershed, central Idaho. We found that the interaction of hydrologic turnover and concentration-dependent uptake combined to modify and subsequently stabilize in-stream concentrations, with specific concentrations dependent on the magnitude of hydrologic turnover, groundwater concentrations, and the shape of nutrient uptake kinetic curves. We additionally found that by varying these physical and biological parameters within measured ranges we were able to generate a spectrum of stream network concentration distributions representing a continuum of shifting magnitudes of physical and biological influences on in-stream concentrations. These findings elucidate the important and variable role of

  5. Increasing job satisfaction and motivation while reducing nursing turnover through the implementation of shared governance.

    Science.gov (United States)

    Relf, M

    1995-11-01

    In today's cost-conscious, changing health care environment, health care agencies must identify and implement strategies to promote fiscal responsibility while maintaining employee satisfaction and retention. The cost to recruit professional nurses is high. Therefore, the business objective is to retain the productive employee. Through the implementation of shared governance, employees find the workplace rewarding and stimulating--motivating factors as described by Herzberg. The Secretary's Commission on Nursing identified 16 strategies for the reduction of the nursing shortage and retention of professional nurses. One recommendation reinforces a report by the American Academy of Nursing that states work satisfaction among nurses in higher and turnover rates lower when organizational climates provide for nursing's involvement in decision making relating not only to nursing practice and unit management but also patient care. Through shared governance, staff nurse involvement in nursing and patient care policy is advanced.

  6. Employee Turnover and Organizational Performance: a Study of the Brazilian Retail Sector

    Directory of Open Access Journals (Sweden)

    Luciana Carvalho de Mesquita Ferreira

    2015-01-01

    Full Text Available This study investigates the relationship between employee turnover and performance in retailing. To achieve this aim, we used data from a single company with several comparable branches and tested whether stores with lower employee turnover have better financial and organizational results (sales and workplace accidents, respectively. This study also analyzes whether Human resources practices, such as rewards, recognition and training, affect employee turnover. The empirical results indicate a strong relationship between employee turnover and sales, supporting results from previous studies. However, the additional relationships were not confirmed. The results do not rule out some hypotheses about the relationship between employee turnover and labor accidents, and further suggest that human resources management practices may increase employee turnover, depending on their motivation and strategic alignment.

  7. Transformational leadership moderates the relationship between emotional exhaustion and turnover intention among community mental health providers.

    Science.gov (United States)

    Green, Amy E; Miller, Elizabeth A; Aarons, Gregory A

    2013-08-01

    Public sector mental health care providers are at high risk for burnout and emotional exhaustion which negatively affect job performance and client satisfaction with services. Few studies have examined ways to reduce these associations, but transformational leadership may have a positive effect. We examine the relationships between transformational leadership, emotional exhaustion, and turnover intention in a sample of 388 community mental health providers. Emotional exhaustion was positively related to turnover intention, and transformational leadership was negatively related to both emotional exhaustion and turnover intention. Transformational leadership moderated the relationship between emotional exhaustion and turnover intention, indicating that having a transformational leader may buffer the effects of providers' emotional exhaustion on turnover intention. Investing in transformational leadership development for supervisors could reduce emotional exhaustion and turnover among public sector mental health providers.

  8. Transformational Leadership Moderates the Relationship between Emotional Exhaustion and Turnover Intention among Community Mental Health Providers

    Science.gov (United States)

    Green, Amy E.; Miller, Elizabeth A.; Aarons, Gregory A.

    2014-01-01

    Public sector mental health care providers are at high risk for burnout and emotional exhaustion which negatively affect job performance and client satisfaction with services. Few studies have examined ways to reduce these associations, but transformational leadership may have a positive effect. We examine the relationships between transformational leadership, emotional exhaustion, and turnover intention in a sample of 388 community mental health providers. Emotional exhaustion was positively related to turnover intention, and transformational leadership was negatively related to both emotional exhaustion and turnover intention. Transformational leadership moderated the relationship between emotional exhaustion and turnover intention, indicating that having a transformational leader may buffer the effects of providers’ emotional exhaustion on turnover intention. Investing in transformational leadership development for supervisors could reduce emotional exhaustion and turnover among public sector mental health providers. PMID:22052429

  9. Hospital Mergers in Norway: Employee Health and Turnover to Three Destinations

    Directory of Open Access Journals (Sweden)

    Mari Holm Ingelsrud

    2017-03-01

    Full Text Available This article investigates the probability of turnover to three destinations following hospital merg- ers: within the hospital sector, out of the hospital sector, and out of work. It is hypothesized that mergers increase turnover to nonemployment among employees with poor health and increase turnover to employment outside of the hospital sector among healthy employees. Discrete-time survival analyses show that mergers increase turnover within the hospital sector for all employ- ees, regardless of health. Turnover to other sectors and out of work does not increase. Possible explanations for the limited turnover out of the sector associated with mergers are aspects of the Norwegian labor market such as the institution of employee participation, low unemployment, and labor shortages within hospitals.

  10. Organizational turnover as endogenous precursor of industry dynamics and organizational dissolution

    OpenAIRE

    Cattani, Gino; Johannes M. Pennings; Wezel, Filippo Carlo

    2002-01-01

    This paper studies the effect of organizational turnover on firm survival within the Dutch accounting service industry during the period 1880-1986. We address three issues: (1) estimating the effect of organizational turnover on organizational dissolution; (2) showing the significance of propinquity in isolating that effect; (3) exposing population dynamics through different levels of analysis. The results of our analysis confirm that turnover is an important endogenous force shaping the evol...

  11. Employee Turnover and Organizational Performance: a Study of the Brazilian Retail Sector

    OpenAIRE

    Luciana Carvalho de Mesquita Ferreira; Ciro Barbosa de Aquino Almeida

    2015-01-01

    This study investigates the relationship between employee turnover and performance in retailing. To achieve this aim, we used data from a single company with several comparable branches and tested whether stores with lower employee turnover have better financial and organizational results (sales and workplace accidents, respectively). This study also analyzes whether Human resources practices, such as rewards, recognition and training, affect employee turnover. The empirical results indic...

  12. Organizational Demography and Turnover: An Examination of Multiform and Non-Linear Heterogeneity

    OpenAIRE

    Alexander,Jeffrey; Nuchols, Beverly; Bloom, Joan; Lee, Shoou-Yih D

    1993-01-01

    This paper advances the study of organizational demography and its relationship to organizational turnover by examining two of Blau's concepts of social structure: non-linear and multiform heterogeneity. In a sample of 383 community hospitals, nursing turnover was examined in relation to four dimensions of demographic heterogeneity among nursing staff in those hospitals. The form of the relationships between turnover and heterogeneity was specified to test whether heterogeneity relates to hig...

  13. Factors Involved in Extracellular Matrix Turnover in Human Derived Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Gregori Casals

    2013-11-01

    Full Text Available Background: The molecular mechanisms by which myocardial ischemia translates into ventricular remodeling remain unclear. Methods: We investigated whether hypoxia and proinflammatory cytokines are specific inducers of remodeling signals in an in vitro model of cultured adult human ventricular myocytes (AC16 cells. Results:Hypoxia modified the ratio of matrix remodeling factors by increasing the aminoterminal propeptide of type III procollagen (PIIINP and reducing tissue inhibitor of matrix metalloproteinase type 1 (TIMP-1 secretion in AC16 cells. These effects, however, were not associated with either modifications in expression of matrix metalloproteinase type 2, collagen-I or metalloproteinase activity. Hypoxia does, actually increase the production of the cardiac antifibrogenic growth factors, Apelin and VEGF, through an Hypoxia Inducible Factor type 1-dependent mechanism. Concerning proinflammatory signaling pathways, IL1β emerged as a powerful inducer of matrix turnover, since it significantly enhanced PIIINP, TIMP-1 and hyaluronic acid production and increased metalloproteinase activity. In contrast, TNFα did not modify matrix turnover but markedly induced the production of Apelin and VEGF. Conclusion: Hypoxia and increased TNFα activity likely exert cardioprotective actions by activating the cardiac antifibrogenic factors Apelin and VEGF. In contrast, IL1β is a strong promoter of interstitial collagen remodeling that may contribute to ventricular dilation and heart failure in the ischemic myocardium.

  14. Liquid Crystal Gel Reduces Age Spots by Promoting Skin Turnover

    Directory of Open Access Journals (Sweden)

    Mina Musashi

    2014-07-01

    Full Text Available Studies have shown that liquid crystals structurally resembling the intercellular lipids in the stratum corneum can beneficially affect the skin when applied topically by stimulating the skin’s natural regenerative functions and accelerating epidermal turnover. In the present study, the effects of applying low concentrations of a liquid crystal gel of our own creation were evaluated using epidermal thickening in mouse skin as an assay for effective stimulation of epidermal turnover. A liquid crystal gel was also applied topically to human facial skin, and analysis was conducted using before-and-after photographs of age spots, measurements of L* values that reflect degree of skin pigmentation, single-layer samples of the stratum corneum obtained via tape-stripping, and measurements of trans-epidermal water loss that reflect the status of the skin’s barrier function. The results suggested that cost-effective creams containing as low as 5% liquid crystal gel might be effective and safely sold as skin care products targeting age spots and other problems relating to uneven skin pigmentation.

  15. The Natural Resource Management Implications of Rural Property Turnover

    Directory of Open Access Journals (Sweden)

    Emily Mendham

    2012-12-01

    Full Text Available One aspect of recent rural change is in-migration, which is challenging the traditional dominance of production values in some areas. We explored the natural resource management implications of property turnover in two Australian regions. Our mixed-methods approach combined analysis of property sales records and spatially referenced landholder survey data with data from key informant interviews. Close to 50% of rural properties are expected to change hands between 2006 and 2016, double the change in the previous decade. This change is linked to the transformation of these rural areas, including the influx of non-farming rural landholders seeking amenity values. Our research suggests that property turnover of this scale has important implications for natural resource management. Newer and longer term owners were very different in terms of their values, attitudes, knowledge, land use, and management practices. A substantial proportion of these new property owners are absentees, which further complicates natural resource management, and our view is that a "business as usual" approach to the engagement of the new cohort of rural land managers is unlikely to be effective.

  16. HUMAN RESOURCE PRACTICES AS DETERMINANTS OF EMPLOYEE TURNOVER: AN EMPIRICAL INVESTIGATION

    Directory of Open Access Journals (Sweden)

    Muhammad Aminu Bawa

    2005-01-01

    Full Text Available The volume of literature on the causes of employee turnover continues to grow. In spite of this, attempts to distinguish between the causes of voluntary and involuntary turnover in organizations, though recognized for quite some time, receive little attention from researchers. The two phenomena seem to be influenced by a different set of factors. There are clear-cut theoretical and empirical reasons for this assertion. The objective of this paper is to investigate the relationship between human resource (HR practices and employee turnover in Malaysia where companies are generally experiencing labour shortage and labour turnover. Using data collected from a census of managers, the study utilized Analysis of Variance (ANOVA and simple regression and tested hypotheses developed to investigate the relationship between HR practices and employee voluntary and involuntary turnover. The results show that (1 staffing process and employee monitoring were effective in reducing involuntary turnover, and (2 none of the HR practices were effective in reducing voluntary turnover. In other words, workers continue to leave or quit irrespective of the type of HR practices implemented. The paper concludes that economic factors such as availability of alternative jobs are most likely relevant in explaining the turnover process. Based on these findings, various strategies were suggested which have wider managerial and policy implications for the management of turnover in similar settings.

  17. Workplace Bullying and Turnover Intention: Exploring Work Engagement as a Potential Mediator.

    Science.gov (United States)

    Coetzee, Melinde; van Dyk, Jeannette

    2017-01-01

    Employees' turnover intentions may entail expensive consequences for companies. The study examined the mediating effect of work engagement in the relationship between workplace bullying and turnover intention. Using a cross-sectional sample of 373 employees, structural equation modeling and mediation analysis showed that perceptions of work- and person-related bullying were linked to low levels of vigor and dedication which in turn were associated with high turnover intention. Work engagement partially mediated the effect of high workplace bullying on high turnover intention. The results were interpreted from a social cognitive perspective and recommendations for practice were made.

  18. The stability of a stochastic CaMKII switch: dependence on the number of enzyme molecules and protein turnover.

    Directory of Open Access Journals (Sweden)

    Paul Miller

    2005-04-01

    Full Text Available Molecular switches have been implicated in the storage of information in biological systems. For small structures such as synapses, these switches are composed of only a few molecules and stochastic fluctuations are therefore of importance. Such fluctuations could potentially lead to spontaneous switch reset that would limit the lifetime of information storage. We have analyzed a model of the calcium/calmodulin-dependent protein kinase II (CaMKII switch implicated in long-term memory in the nervous system. The bistability of this switch arises from autocatalytic autophosphorylation of CaMKII, a reaction that is countered by a saturable phosphatase-1-mediated dephosphorylation. We sought to understand the factors that control switch stability and to determine the functional relationship between stability and the number of molecules involved. Using Monte Carlo simulations, we found that the lifetime of states of the switch increase exponentially with the number of CaMKII holoenzymes. Switch stability requires a balance between the kinase and phosphatase rates, and the kinase rate must remain high relative to the rate of protein turnover. Thus, a critical limit on switch stability is set by the observed turnover rate (one per 30 h on average. Our computational results show that, depending on the timescale of fluctuations in enzyme numbers, for a switch composed of about 15 CaMKII holoenzymes, the stable persistent activation can span from a few years to a human lifetime.

  19. The Stability of a Stochastic CaMKII Switch: Dependence on the Number of Enzyme Molecules and Protein Turnover

    Directory of Open Access Journals (Sweden)

    Miller Paul

    2005-01-01

    Full Text Available Molecular switches have been implicated in the storage of information in biological systems. For small structures such as synapses, these switches are composed of only a few molecules and stochastic fluctuations are therefore of importance. Such fluctuations could potentially lead to spontaneous switch reset that would limit the lifetime of information storage. We have analyzed a model of the calcium/calmodulin-dependent protein kinase II (CaMKII switch implicated in long-term memory in the nervous system. The bistability of this switch arises from autocatalytic autophosphorylation of CaMKII, a reaction that is countered by a saturable phosphatase-1-mediated dephosphorylation. We sought to understand the factors that control switch stability and to determine the functional relationship between stability and the number of molecules involved. Using Monte Carlo simulations, we found that the lifetime of states of the switch increase exponentially with the number of CaMKII holoenzymes. Switch stability requires a balance between the kinase and phosphatase rates, and the kinase rate must remain high relative to the rate of protein turnover. Thus, a critical limit on switch stability is set by the observed turnover rate (one per 30 h on average. Our computational results show that, depending on the timescale of fluctuations in enzyme numbers, for a switch composed of about 15 CaMKII holoenzymes, the stable persistent activation can span from a few years to a human lifetime.

  20. Effects of breeder turnover and harvest on group composition and recruitment in a social carnivore

    Science.gov (United States)

    Ausband, David E.; Mitchell, Michael S.; Waits, Lisette P.

    2017-01-01

    Breeder turnover can influence population growth in social carnivores through changes to group size, composition and recruitment.Studies that possess detailed group composition data that can provide insights about the effects of breeder turnover on groups have generally been conducted on species that are not subject to recurrent annual human harvest. We wanted to know how breeder turnover affects group composition and how harvest, in turn, affects breeder turnover in cooperatively breeding grey wolves (Canis lupus Linnaeus 1758).We used noninvasive genetic sampling at wolf rendezvous sites to construct pedigrees and estimate recruitment in groups of wolves before and after harvest in Idaho, USA.Turnover of breeding females increased polygamy and potential recruits per group by providing breeding opportunities for subordinates although resultant group size was unaffected 1 year after the turnover. Breeder turnover had no effect on the number of nonbreeding helpers per group. After breeding male turnover, fewer female pups were recruited in the new males’ litters. Harvest had no effect on the frequency of breeder turnover.We found that breeder turnover led to shifts in the reproductive hierarchies within groups and the resulting changes to group composition were quite variable and depended on the sex of the breeder lost. We hypothesize that nonbreeding females direct help away from non-kin female pups to preserve future breeding opportunities for themselves. Breeder turnover had marked effects on the breeding opportunities of subordinates and the number and sex ratios of subsequent litters of pups. Seemingly subtle changes to groups, such as the loss of one individual, can greatly affect group composition, genetic content, and short-term population growth when the individual lost is a breeder.

  1. Effects of breeder turnover and harvest on group composition and recruitment in a social carnivore.

    Science.gov (United States)

    Ausband, David E; Mitchell, Michael S; Waits, Lisette P

    2017-09-01

    Breeder turnover can influence population growth in social carnivores through changes to group size, composition and recruitment. Studies that possess detailed group composition data that can provide insights about the effects of breeder turnover on groups have generally been conducted on species that are not subject to recurrent annual human harvest. We wanted to know how breeder turnover affects group composition and how harvest, in turn, affects breeder turnover in cooperatively breeding grey wolves (Canis lupus Linnaeus 1758). We used noninvasive genetic sampling at wolf rendezvous sites to construct pedigrees and estimate recruitment in groups of wolves before and after harvest in Idaho, USA. Turnover of breeding females increased polygamy and potential recruits per group by providing breeding opportunities for subordinates although resultant group size was unaffected 1 year after the turnover. Breeder turnover had no effect on the number of nonbreeding helpers per group. After breeding male turnover, fewer female pups were recruited in the new males' litters. Harvest had no effect on the frequency of breeder turnover. We found that breeder turnover led to shifts in the reproductive hierarchies within groups and the resulting changes to group composition were quite variable and depended on the sex of the breeder lost. We hypothesize that nonbreeding females direct help away from non-kin female pups to preserve future breeding opportunities for themselves. Breeder turnover had marked effects on the breeding opportunities of subordinates and the number and sex ratios of subsequent litters of pups. Seemingly subtle changes to groups, such as the loss of one individual, can greatly affect group composition, genetic content, and short-term population growth when the individual lost is a breeder. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  2. Distribution and turnover of carbon in natural and constructed wetlands in the Florida Everglades

    Energy Technology Data Exchange (ETDEWEB)

    Stern, J. [Department of Geological Sciences, Florida State University and National High Magnetic Field Laboratory, Tallahassee, FL 32306-4100 (United States); NASA Ames Research Center, Moffett Field, CA 94035 (United States); Wang, Y. [Department of Geological Sciences, Florida State University and National High Magnetic Field Laboratory, Tallahassee, FL 32306-4100 (United States)], E-mail: ywang@magnet.fsu.edu; Gu, B.; Newman, J. [Everglades Division, South Florida Water Management District, West Palm Beach, FL 33406 (United States)

    2007-09-15

    Stable and radiocarbon isotopic contents of dissolved organic C (DOC), dissolved inorganic C (DIC), particulate organic C (POC) and plants were used to examine the source and turnover rate of C in natural and constructed wetlands in the Florida Everglades. DOC concentrations decreased, with P concentrations, along a water quality gradient from the agriculturally impacted areas in the northern Everglades to the more pristine Everglades National Park. {delta}{sup 13}C values of DOC in the area reflect contributions of both wetland vegetation and sugarcane from agriculture. Radiocarbon ages of DOC, POC and DIC in the Everglades ranged from 2.01 ka BP to '>modern'. The old {sup 14}C ages of DOC and POC were found in impacted areas near the Everglades Agricultural Area (EAA) in the northern Everglades. In contrast, DOC and POC in pristine marsh areas had near modern or '>modern'{sup 14}C ages. These data indicate that a major source of POC and DOC in impacted areas is the degradation of historic peat deposits in the EAA. In the pristine areas of the marsh, DOC represents a mix of modern and historic C sources, whereas POC comes from modern primary production as indicated by positive {delta}{sup 14}C values, suggesting that DOC is transported farther away from its source than POC. High {delta}{sup 14}C values of DIC indicate that dissolution of limestone bedrock is not a significant source of DIC in the Everglades wetlands. As a restored wetland moves towards its 'original' or 'natural' state, the {sup 14}C signatures of DOC should approach that of modern atmosphere. In addition, measurements of concentration and C isotopic composition of DOC in two small constructed wetlands (i.e., test cells) indicate that these freshwater wetland systems contain a labile DOC pool with rapid turnover times of 26-39 days and that the test cells are overall net sinks of DOC.

  3. Protein turnover, amino acid requirements and recommendations for athletes and active populations.

    Science.gov (United States)

    Poortmans, J R; Carpentier, A; Pereira-Lancha, L O; Lancha Jr, A

    2012-10-01

    Skeletal muscle is the major deposit of protein molecules. As for any cell or tissue, total muscle protein reflects a dynamic turnover between net protein synthesis and degradation. Noninvasive and invasive techniques have been applied to determine amino acid catabolism and muscle protein building at rest, during exercise and during the recovery period after a single experiment or training sessions. Stable isotopic tracers ((13)C-lysine, (15)N-glycine, ²H5-phenylalanine) and arteriovenous differences have been used in studies of skeletal muscle and collagen tissues under resting and exercise conditions. There are different fractional synthesis rates in skeletal muscle and tendon tissues, but there is no major difference between collagen and myofibrillar protein synthesis. Strenuous exercise provokes increased proteolysis and decreased protein synthesis, the opposite occurring during the recovery period. Individuals who exercise respond differently when resistance and endurance types of contractions are compared. Endurance exercise induces a greater oxidative capacity (enzymes) compared to resistance exercise, which induces fiber hypertrophy (myofibrils). Nitrogen balance (difference between protein intake and protein degradation) for athletes is usually balanced when the intake of protein reaches 1.2 g · kg(-1) · day(-1) compared to 0.8 g · kg(-1) · day(-1) in resting individuals. Muscular activities promote a cascade of signals leading to the stimulation of eukaryotic initiation of myofibrillar protein synthesis. As suggested in several publications, a bolus of 15-20 g protein (from skimmed milk or whey proteins) and carbohydrate (± 30 g maltodextrine) drinks is needed immediately after stopping exercise to stimulate muscle protein and tendon collagen turnover within 1 h.

  4. Protein turnover, amino acid requirements and recommendations for athletes and active populations

    Energy Technology Data Exchange (ETDEWEB)

    Poortmans, J.R.; Carpentier, A. [Laboratory for Biometry and Sport Nutrition, Faculty of Motor Sciences, Free University of Brussels, Brussels (Belgium); Pereira-Lancha, L.O. [Departamento de Nutrição, Instituto Vita, São Paulo, SP (Brazil); Lancha, A. Jr. [Laboratório de Nutrição Aplicada à Atividade Motora, Escola de Educação Física e Esporte, Universidade de São Paulo, São Paulo, SP (Brazil)

    2012-06-08

    Skeletal muscle is the major deposit of protein molecules. As for any cell or tissue, total muscle protein reflects a dynamic turnover between net protein synthesis and degradation. Noninvasive and invasive techniques have been applied to determine amino acid catabolism and muscle protein building at rest, during exercise and during the recovery period after a single experiment or training sessions. Stable isotopic tracers ({sup 13}C-lysine, {sup 15}N-glycine, {sup 2}H{sub 5}-phenylalanine) and arteriovenous differences have been used in studies of skeletal muscle and collagen tissues under resting and exercise conditions. There are different fractional synthesis rates in skeletal muscle and tendon tissues, but there is no major difference between collagen and myofibrillar protein synthesis. Strenuous exercise provokes increased proteolysis and decreased protein synthesis, the opposite occurring during the recovery period. Individuals who exercise respond differently when resistance and endurance types of contractions are compared. Endurance exercise induces a greater oxidative capacity (enzymes) compared to resistance exercise, which induces fiber hypertrophy (myofibrils). Nitrogen balance (difference between protein intake and protein degradation) for athletes is usually balanced when the intake of protein reaches 1.2 g·kg{sup −1}·day{sup −1} compared to 0.8 g·kg{sup −1}·day{sup −1} in resting individuals. Muscular activities promote a cascade of signals leading to the stimulation of eukaryotic initiation of myofibrillar protein synthesis. As suggested in several publications, a bolus of 15-20 g protein (from skimmed milk or whey proteins) and carbohydrate (± 30 g maltodextrine) drinks is needed immediately after stopping exercise to stimulate muscle protein and tendon collagen turnover within 1 h.

  5. Nicotinic Acid Accelerates HDL Cholesteryl Ester Turnover in Obese Insulin-Resistant Dogs.

    Directory of Open Access Journals (Sweden)

    Jérôme Le Bloc'h

    Full Text Available Nicotinic acid (NA treatment decreases plasma triglycerides and increases HDL cholesterol, but the mechanisms involved in these change are not fully understood. A reduction in cholesteryl ester transfer protein (CETP activity has been advanced to explain most lipid-modulating effects of NA. However, due to the central role of CETP in reverse cholesterol transport in humans, other effects of NA may have been hidden. As dogs have no CETP activity, we conducted this study to examine the specific effects of extended-release niacin (NA on lipids and high-density lipoprotein (HDL cholesteryl ester (CE turnover in obese Insulin-Resistant dogs with increase plasma triglycerides.HDL kinetics were assessed in fasting dogs before and four weeks after NA treatment through endogenous labeling of cholesterol and apolipoprotein AI by simultaneous infusion of [1,2 13C2] acetate and [5,5,5 2H3] leucine for 8 h. Kinetic data were analyzed by compartmental modeling. In vitro cell cholesterol efflux of serum from NA-treated dogs was also measured.NA reduced plasma total cholesterol, low-density lipoprotein cholesterol, HDL cholesterol, triglycerides (TG, and very-low-density lipoprotein TG concentrations (p < 0.05. The kinetic study also showed a higher cholesterol esterification rate (p < 0.05. HDL-CE turnover was accelerated (p < 0.05 via HDL removal through endocytosis and selective CE uptake (p < 0.05. We measured an elevated in vitro cell cholesterol efflux (p < 0.05 with NA treatment in accordance with a higher cholesterol esterification.NA decreased HDL cholesterol but promoted cholesterol efflux and esterification, leading to improved reverse cholesterol transport. These results highlight the CETP-independent effects of NA in changes of plasma lipid profile.

  6. Protein turnover, amino acid requirements and recommendations for athletes and active populations

    Directory of Open Access Journals (Sweden)

    J.R. Poortmans

    2012-10-01

    Full Text Available Skeletal muscle is the major deposit of protein molecules. As for any cell or tissue, total muscle protein reflects a dynamic turnover between net protein synthesis and degradation. Noninvasive and invasive techniques have been applied to determine amino acid catabolism and muscle protein building at rest, during exercise and during the recovery period after a single experiment or training sessions. Stable isotopic tracers (13C-lysine, 15N-glycine, ²H5-phenylalanine and arteriovenous differences have been used in studies of skeletal muscle and collagen tissues under resting and exercise conditions. There are different fractional synthesis rates in skeletal muscle and tendon tissues, but there is no major difference between collagen and myofibrillar protein synthesis. Strenuous exercise provokes increased proteolysis and decreased protein synthesis, the opposite occurring during the recovery period. Individuals who exercise respond differently when resistance and endurance types of contractions are compared. Endurance exercise induces a greater oxidative capacity (enzymes compared to resistance exercise, which induces fiber hypertrophy (myofibrils. Nitrogen balance (difference between protein intake and protein degradation for athletes is usually balanced when the intake of protein reaches 1.2 g·kg-1·day-1 compared to 0.8 g·kg-1·day-1 in resting individuals. Muscular activities promote a cascade of signals leading to the stimulation of eukaryotic initiation of myofibrillar protein synthesis. As suggested in several publications, a bolus of 15-20 g protein (from skimmed milk or whey proteins and carbohydrate (± 30 g maltodextrine drinks is needed immediately after stopping exercise to stimulate muscle protein and tendon collagen turnover within 1 h.

  7. The Relationship Between the FRAX Tool and Bone Turnover Markers in Postmenopausal Osteoporosis

    Directory of Open Access Journals (Sweden)

    Murat Uludağ

    2013-08-01

    Full Text Available Aim: In this study, we aimed to show the correlation between the ten-year fracture risk, calculated with FRAX and bone turnover markers (BTM in a group of postmenopausal women with osteoporosis. Material and Methods: Twenty-four postmenopausal women diagnosed as osteoporosis were included. Patients were assessed for duration of menopause, secondary diseases, medication, habits of nutrition, previous fracture, and family history of fracture. Weight and height measurements were obtained. Bone mineral density (BMD was measured by dual-energy X-ray absorptiometry (DXA, with a Hologic-QDR 4500 plus device. The ten-year risk for major as well as hip fractures were calculated with the FRAX tool. Serum calcium, phosphorus, magnesium, 25-OH Vitamin D, parathormone (PTH, alkaline phosphatase (ALP, and biochemical markers of bone formation (Osteocalcin, Bone-ALP and resorption ( N-terminal collagen type 1 and C terminal collagen type 1 were determined. Results: The mean age of patients was 64.3±8.6 (46-80 years. The mean ten-year major fracture and hip fracture risks were 19.5±6.2% and 16.0±5.1%, respectively. There was a strong correlation between the duration of menopause and hip fracture risk (r: 0.878, p=0.022. There was also a strong relationship between hip fracture risk and NTX (r: 0.759, p=0.042. Conclusion: Resorption markers of bone turnover are relevant components in determining fracture risk. Rate of bone remodeling is a parameter which is not included in the FRAX tool. Since FRAX is an established tool for assessing the ten-year fracture risk, we assessed and found a correlation between hip fracture risk and NTX. Further studies, in larger groups of patients need to make clear the impact of BTM in this tool. (Turkish Journal of Osteoporosis 2013;19: 38-41

  8. Enhanced Fasting Glucose Turnover in Mice with Disrupted Action of TUG Protein in Skeletal Muscle*

    Science.gov (United States)

    Löffler, Michael G.; Birkenfeld, Andreas L.; Philbrick, Katerina M.; Belman, Jonathan P.; Habtemichael, Estifanos N.; Booth, Carmen J.; Castorena, Carlos M.; Choi, Cheol Soo; Jornayvaz, Francois R.; Gassaway, Brandon M.; Lee, Hui-Young; Cartee, Gregory D.; Philbrick, William; Shulman, Gerald I.; Samuel, Varman T.; Bogan, Jonathan S.

    2013-01-01

    Insulin stimulates glucose uptake in 3T3-L1 adipocytes in part by causing endoproteolytic cleavage of TUG (tether containing a ubiquitin regulatory X (UBX) domain for glucose transporter 4 (GLUT4)). Cleavage liberates intracellularly sequestered GLUT4 glucose transporters for translocation to the cell surface. To test the role of this regulation in muscle, we used mice with muscle-specific transgenic expression of a truncated TUG fragment, UBX-Cter. This fragment causes GLUT4 translocation in unstimulated 3T3-L1 adipocytes. We predicted that transgenic mice would have GLUT4 translocation in muscle during fasting. UBX-Cter expression caused depletion of PIST (PDZ domain protein interacting specifically with TC10), which transmits an insulin signal to TUG. Whereas insulin stimulated TUG proteolysis in control muscles, proteolysis was constitutive in transgenic muscles. Fasting transgenic mice had decreased plasma glucose and insulin concentrations compared with controls. Whole-body glucose turnover was increased during fasting but not during hyperinsulinemic clamp studies. In muscles with the greatest UBX-Cter expression, 2-deoxyglucose uptake during fasting was similar to that in control muscles during hyperinsulinemic clamp studies. Fasting transgenic mice had increased muscle glycogen, and GLUT4 targeting to T-tubule fractions was increased 5.7-fold. Whole-body oxygen consumption (VO2), carbon dioxide production (VCO2), and energy expenditure were increased by 12–13%. After 3 weeks on a high fat diet, the decreased fasting plasma glucose in transgenic mice compared with controls was more marked, and increased glucose turnover was not observed; the transgenic mice continued to have an increased metabolic rate. We conclude that insulin stimulates TUG proteolysis to translocate GLUT4 in muscle, that this pathway impacts systemic glucose homeostasis and energy metabolism, and that the effects of activating this pathway are maintained during high fat diet

  9. Enhanced fasting glucose turnover in mice with disrupted action of TUG protein in skeletal muscle.

    Science.gov (United States)

    Löffler, Michael G; Birkenfeld, Andreas L; Philbrick, Katerina M; Belman, Jonathan P; Habtemichael, Estifanos N; Booth, Carmen J; Castorena, Carlos M; Choi, Cheol Soo; Jornayvaz, Francois R; Gassaway, Brandon M; Lee, Hui-Young; Cartee, Gregory D; Philbrick, William; Shulman, Gerald I; Samuel, Varman T; Bogan, Jonathan S

    2013-07-12

    Insulin stimulates glucose uptake in 3T3-L1 adipocytes in part by causing endoproteolytic cleavage of TUG (tether containing a ubiquitin regulatory X (UBX) domain for glucose transporter 4 (GLUT4)). Cleavage liberates intracellularly sequestered GLUT4 glucose transporters for translocation to the cell surface. To test the role of this regulation in muscle, we used mice with muscle-specific transgenic expression of a truncated TUG fragment, UBX-Cter. This fragment causes GLUT4 translocation in unstimulated 3T3-L1 adipocytes. We predicted that transgenic mice would have GLUT4 translocation in muscle during fasting. UBX-Cter expression caused depletion of PIST (PDZ domain protein interacting specifically with TC10), which transmits an insulin signal to TUG. Whereas insulin stimulated TUG proteolysis in control muscles, proteolysis was constitutive in transgenic muscles. Fasting transgenic mice had decreased plasma glucose and insulin concentrations compared with controls. Whole-body glucose turnover was increased during fasting but not during hyperinsulinemic clamp studies. In muscles with the greatest UBX-Cter expression, 2-deoxyglucose uptake during fasting was similar to that in control muscles during hyperinsulinemic clamp studies. Fasting transgenic mice had increased muscle glycogen, and GLUT4 targeting to T-tubule fractions was increased 5.7-fold. Whole-body oxygen consumption (VO2), carbon dioxide production (VCO2), and energy expenditure were increased by 12-13%. After 3 weeks on a high fat diet, the decreased fasting plasma glucose in transgenic mice compared with controls was more marked, and increased glucose turnover was not observed; the transgenic mice continued to have an increased metabolic rate. We conclude that insulin stimulates TUG proteolysis to translocate GLUT4 in muscle, that this pathway impacts systemic glucose homeostasis and energy metabolism, and that the effects of activating this pathway are maintained during high fat diet

  10. Actin turnover-mediated gravity response in maize root apices: gravitropism of decapped roots implicates gravisensing outside of the root cap.

    Science.gov (United States)

    Mancuso, Stefano; Barlow, Peter W; Volkmann, Dieter; Baluska, Frantisek

    2006-03-01

    The dynamic actin cytoskeleton has been proposed to be linked to gravity sensing in plants but the mechanistic understanding of these processes remains unknown. We have performed detailed pharmacological analyses of the role of the dynamic actin cytoskeleton in gravibending of maize (Zea mays) root apices. Depolymerization of actin filaments with two drugs having different mode of their actions, cytochalasin D and latrunculin B, stimulated root gravibending. By contrast, drug-induced stimulation of actin polymerization and inhibition of actin turnover, using two different agents phalloidin and jasplakinolide, compromised the root gravibending. Importantly, all these actin drugs inhibited root growth to similar extents suggesting that high actin turnover is essential for the gravity-related growth responses rather than for the general growth process. Both latrunculin B and cytochalasin D treatments inhibited root growth but restored gravibending of the decapped root apices, indicating that there is a strong potential for effective actin-mediated gravity sensing outside the cap. This elusive gravity sensing outside the root cap is dependent not only on the high rate of actin turnover but also on weakening of myosin activities, as general inhibition of myosin ATPases induced stimulation of gravibending of the decapped root apices. Collectively, these data provide evidence for the actin turnover-mediated gravity sensing outside the root cap.

  11. Carbon turnover and sequestration potential of fodder radish cover crop

    DEFF Research Database (Denmark)

    Mutegi, James; Petersen, Bjørn Molt; Munkholm, Lars Juhl

    2013-01-01

    We studied fodder radish carbon turnover as affected by soil tillage in Foulum, Denmark. Actively growing fodder radish monoliths from direct-drilled (DD) and conventionally tilled (CT) plots were extracted and labelled regularly with 14C isotope across their entire growth period. At the end...... of the fodder radish growth cycle, labelled biomass was harvested and incorporated into the same monolith. These monoliths were destructively sampled at biomass incorporation, 4, 8 and 18 months after incorporation. For each sampling period, soil and root samples were taken at 0- to 10-, 10- to 25-, and 25......-SIM model forecast, we estimated that over a 30-yr period of continuous autumn fodder radish establishment, at least 4.9 t C/ha fodder radish C with a residence time of more than 20 yr could be stored in the soil....

  12. System wide cofactor turnovers can propagate metabolic stability between pathways

    DEFF Research Database (Denmark)

    Yang, Y.; Guan, Y.H.; Villadsen, John

    2016-01-01

    the metabolic networks studied were invariably associated with living cells. Nowadays, there are needs to reconstruct metabolic networks, and so metabolic homeostasis cannot be taken for granted. For metabolic steady state, enzyme feedback control has been known to explain why metabolites in metabolic pathways......Metabolic homeostasis, or low-level metabolic steady state, has long been taken for granted in metabolic engineering, and research priority has always been given to understand metabolic flux control and regulation of the reaction network. In the past, this has not caused concerns because....... Furthermore, we elaborated the criteria to tell if a multi-enzyme over-all reaction path is of in vivo nature or not at the metabolic level. As new findings, we discovered that there are interactions between the enzyme feedback inhibition and the CI turnover, and such interactions may well lead to metabolic...

  13. Serum leptin is correlated to high turnover in osteoporosis.

    Science.gov (United States)

    Hipmair, Gunter; Böhler, Nikolaus; Maschek, Wilma; Soriguer, Federico; Rojo-Martínez, Gemma; Schimetta, Wolfgang; Pichler, Robert

    2010-01-01

    Clinical data have suggested that obesity protects against osteoporosis. Leptin, mainly secreted by white adipose tissue, might be involved by mediating an effect on bone metabolism. This study was conducted to investigate a possible relationship of leptin and bone turn-over in postmenopausal women with osteoporosis. We measured bone mineral density (BMD), serum leptin levels and markers of bone metabolism, including osteocalcin and cross-laps in 44 patients with osteoporosis. The main group consisted of 32 postmenopausal women. Mean serum leptin was 13.1 microg/L and showed no statistically significant difference to the levels measured in a collective of normal persons adjusted for age and BMI. When related to serum cross-laps as markers of bone resorption, a positive correlation (posteoporosis.

  14. Feasibility of protein turnover studies in prototroph Saccharomyces cerevisiae strains.

    Science.gov (United States)

    Martin-Perez, Miguel; Villén, Judit

    2015-04-07

    Quantitative proteomics studies of yeast that use metabolic labeling with amino acids rely on auxotrophic mutations of one or more genes on the amino acid biosynthesis pathways. These mutations affect yeast metabolism and preclude the study of some biological processes. Overcoming this limitation, it has recently been described that proteins in a yeast prototrophic strain can also be metabolically labeled with heavy amino acids. However, the temporal profiles of label incorporation under the different phases of the prototroph's growth have not been examined. Labeling trajectories are important in the study of protein turnover and dynamics, in which label incorporation into proteins is monitored across many time points. Here we monitored protein labeling trajectories for 48 h after a pulse with heavy lysine in a yeast prototrophic strain and compared them with those of a lysine auxotrophic yeast. Labeling was successful in prototroph yeast during exponential growth phase but not in stationary phase. Furthermore, we were able to determine the half-lives of more than 1700 proteins during exponential phase of growth with high accuracy and reproducibility. We found a median half-life of 2 h in both strains, which corresponds with the cellular doubling time. Nucleolar and ribosomal proteins showed short half-lives, whereas mitochondrial proteins and other energy production enzymes presented longer half-lives. Except for some proteins involved in lysine biosynthesis, we observed a high correlation in protein half-lives between prototroph and auxotroph strains. Overall, our results demonstrate the feasibility of using prototrophs for proteomic turnover studies and provide a reliable data set of protein half-lives in exponentially growing yeast.

  15. Cereal aphid colony turnover and persistence in winter wheat.

    Directory of Open Access Journals (Sweden)

    Linton Winder

    Full Text Available An understanding of spatial and temporal processes in agricultural ecosystems provides a basis for rational decision-making with regards to the management and husbandry of crops, supporting the implementation of integrated farming strategies. In this study we investigated the spatial and temporal distribution of aphid pests (Sitobion avenae and Metopolophium dirhodum within winter wheat fields. Using an intensive sampling programme we investigated distributions at both the small (single shoot and large (field scales. Within two fields, a grid with 82 locations was established (area 120 m by 168 m. At each location, 25 shoots were individually marked and aphid counts by observation conducted on 21 and 22 occasions as the crop matured, resulting in 43,050 and 45,100 counts being conducted in the two fields respectively. We quantified field scale spatial distributions, demonstrating that spatial pattern generally emerged, with temporal stability being both species- and field- dependent. We then measured turnover of colonies at the small (individual shoot and large (field scales by comparing consecutive pairs of sampling occasions. Four turnover categories were defined: Empty (no aphids recorded on either occasion; Colonised (aphids recorded on the second occasion but not the first; Extinction (aphids recorded on the first occasion but not the second; Stable (aphids recorded on both occasions. At the field scale, population stability soon established, but, at the small scale there was a consistently high proportion of unoccupied shoots with considerable colonisation and extinction and low stability. The redistribution of aphids within the crop at the local scale is a vulnerability which could be used to disrupt population development--by mediating exposure to ground-active natural enemies and by incurring a metabolic cost caused by the physiological demands to re-establish on a nearby host plant.

  16. Sclerostin as a novel marker of bone turnover in athletes

    Directory of Open Access Journals (Sweden)

    A Zagrodna

    2016-02-01

    Full Text Available Sclerostin is a protein secreted by osteocytes that acts as an inhibitor of bone formation. It has been shown that physical activity affects sclerostin concentration and thus bone remodelling. The aim of the study was to evaluate serum concentrations of sclerostin, selected bone turnover markers (PTH, P1NP, 25(OH D3 and the intake of calcium and vitamin D in physically active versus sedentary men. A total of 59 healthy men aged 17-37 were enrolled in the study (43 athletes and 16 non-athletes. The mean sclerostin concentration in the group of athletes (A was significantly higher than in non-athletes (NA (35.3±8.9 vs 28.0±5.6 pmol• l-1, p= 0.004. A compared with NA had higher concentrations of P1NP (145.6±77.5 vs 61.2±22.3 ng• ml-1, p= <0.0001 and 25(OHD3 (16.9±8.4 vs 10.3±4.3 ng • ml-1, p= 0.004 and lower concentrations of PTH (25.8±8.3 vs 38.2±11.5 pg• ml-1, p= <0.0001. Vitamin D deficiency was found in 77% of A and 100% of NA. A and NA had similar daily energy intake. They did not differ as to the intake of calcium and vitamin D. We observed a negative correlation between the serum concentrations of sclerostin and calcium in the studied subjects. Our results suggest that regular, long-lasting physical training may be associated with higher concentration of sclerostin. It seems that increased sclerostin is not related to other bone turnover markers (PTH, P1NP.

  17. Turnover of sex chromosomes in the stickleback fishes (gasterosteidae.

    Directory of Open Access Journals (Sweden)

    Joseph A Ross

    2009-02-01

    Full Text Available Diverse sex-chromosome systems are found in vertebrates, particularly in teleost fishes, where different systems can be found in closely related species. Several mechanisms have been proposed for the rapid turnover of sex chromosomes, including the transposition of an existing sex-determination gene, the appearance of a new sex-determination gene on an autosome, and fusions between sex chromosomes and autosomes. To better understand these evolutionary transitions, a detailed comparison of sex chromosomes between closely related species is essential. Here, we used genetic mapping and molecular cytogenetics to characterize the sex-chromosome systems of multiple stickleback species (Gasterosteidae. Previously, we demonstrated that male threespine stickleback fish (Gasterosteus aculeatus have a heteromorphic XY pair corresponding to linkage group (LG 19. In this study, we found that the ninespine stickleback (Pungitius pungitius has a heteromorphic XY pair corresponding to LG12. In black-spotted stickleback (G. wheatlandi males, one copy of LG12 has fused to the LG19-derived Y chromosome, giving rise to an X(1X(2Y sex-determination system. In contrast, neither LG12 nor LG19 is linked to sex in two other species: the brook stickleback (Culaea inconstans and the fourspine stickleback (Apeltes quadracus. However, we confirmed the existence of a previously reported heteromorphic ZW sex-chromosome pair in the fourspine stickleback. The sex-chromosome diversity that we have uncovered in sticklebacks provides a rich comparative resource for understanding the mechanisms that underlie the rapid turnover of sex-chromosome systems.

  18. Modelling nitrate transport and turnover in a lowland catchment system

    Science.gov (United States)

    Wriedt, Gunter; Rode, Michael

    2006-08-01

    SummaryNitrate transport in groundwater dominated lowland catchment systems is influenced by complex and spatially distributed physical and chemical interactions. A modelling approach was developed combining a distributed soil nitrogen model with a three-dimensional groundwater model and a reactive transport model linking nitrate turnover and availability of reaction partners such as pyrite and organic matter. The modelling approach was applied to a hypothetical case study based on data from the pleistocene lowland catchment "Schaugraben" (20 km 2) in the North of Saxony-Anhalt, with focus on the investigation of interactions of spatially distributed transport and chemical processes. The modelling approach could successfully simulate transport and turnover of nitrate in a groundwater dominated catchment. The advancement of the nitrate front and the corresponding depletion of pyrite as well as the distribution of seepage fluxes and nitrate concentrations in seepage water in the channel system showed distinct spatial variation. Surface water nitrate concentrations corresponding to the average soil leachate concentrations were not completely reached after a simulation period of 200 years for a conservative transport simulation. Under reactive conditions, about 80% of the nitrate was lost due to denitrification. Given a uniformly distributed input of nitrate, drain loads developed in a sigmoidal curve defined only by travel time distribution. The average travel time was 93 years. A distributed input of nitrate resulted in reduction of travel time to 80 years due to the different arrangement of source areas and flow. The modelling approach is a step towards bridging the gap between simple large scale models and detailed small scale studies, maintaining process orientation while allowing to consider landscape heterogeneity.

  19. Functional divergence and evolutionary turnover in mammalian phosphoproteomes.

    Directory of Open Access Journals (Sweden)

    Luca Freschi

    2014-01-01

    Full Text Available Protein phosphorylation is a key mechanism to regulate protein functions. However, the contribution of this protein modification to species divergence is still largely unknown. Here, we studied the evolution of mammalian phosphoregulation by comparing the human and mouse phosphoproteomes. We found that 84% of the positions that are phosphorylated in one species or the other are conserved at the residue level. Twenty percent of these conserved sites are phosphorylated in both species. This proportion is 2.5 times more than expected by chance alone, suggesting that purifying selection is preserving phosphoregulation. However, we show that the majority of the sites that are conserved at the residue level are differentially phosphorylated between species. These sites likely result from false-negative identifications due to incomplete experimental coverage, false-positive identifications and non-functional sites. In addition, our results suggest that at least 5% of them are likely to be true differentially phosphorylated sites and may thus contribute to the divergence in phosphorylation networks between mouse and humans and this, despite residue conservation between orthologous proteins. We also showed that evolutionary turnover of phosphosites at adjacent positions (in a distance range of up to 40 amino acids in human or mouse leads to an over estimation of the divergence in phosphoregulation between these two species. These sites tend to be phosphorylated by the same kinases, supporting the hypothesis that they are functionally redundant. Our results support the hypothesis that the evolutionary turnover of phosphorylation sites contributes to the divergence in phosphorylation profiles while preserving phosphoregulation. Overall, our study provides advanced analyses of mammalian phosphoproteomes and a framework for the study of their contribution to phenotypic evolution.

  20. An Exploratory Study of the Role of Human Resource Management in Models of Employee Turnover

    Science.gov (United States)

    Ozolina-Ozola, Iveta

    2016-01-01

    The purpose of this paper is to present the study results of the human resource management role in the voluntary employee turnover models. The mixed methods design was applied. On the basis of the results of the search and evaluation of publications, the 16 models of employee turnover were selected. Applying the method of content analysis, the…

  1. Team turnover and task conflict: A longitudinal study on the moderating effects of collective experience

    NARCIS (Netherlands)

    Kuypers, A.P.A.; Günter, H.; van Emmerik, I.H.

    2015-01-01

    Team turnover can be harmful to a team in many ways. This study examined whether a team’s collective experience (team organizational tenure) attenuates the association between team turnover and task conflict changes. Differing from prior research, our study used a longitudinal design to assess the

  2. Labour turnover and its effects on performance : an empirical test using firm data

    NARCIS (Netherlands)

    Glebbeek, A.C.; Bax, E.H.

    2002-01-01

    In this article we test the hypothesis that the relationship between labour turnover and the economic performance of the firm is bell-shaped: a turnover level too low has a negative effect and likewise does a level too high. Our analysis is based on economic performance data of 110 offices of a temp

  3. Academic Staff Turnover Intention in Madda Walabu University, Bale Zone, South-East Ethiopia

    Science.gov (United States)

    Yimer, Ibrahim; Nega, Rahel; Ganfure, Gemechu

    2017-01-01

    Turnover is a voluntary cessation of membership of an organization by an employee. Employee retention is one of the challenges facing several organizations in both the developed and developing countries of the world. It is profitable to proactively react for possible staff turnover intentions. This research was carried out to determine the…

  4. Why turnover matters in self-managing work teams : Learning, social integration, and task flexibility

    NARCIS (Netherlands)

    van der Vegt, G.S.; Bunderson, S.; Kuipers, B.

    This study considers how turnover in self-managing work teams influences the team interaction processes that promote effective task accomplishment. Drawing from research on self-managing work teams and group process, the authors propose that team turnover affects performance in self-managing teams

  5. Impact of transamination reactions and protein turnover on labeling dynamics in C-13-labeling experiments

    DEFF Research Database (Denmark)

    Grotkjær, Thomas; Åkesson, M.; Christensen, Bjarke

    2004-01-01

    that carbon exchange due to transamination and protein turnover can significantly increase the required time needed for metabolites in the TCA cycle to reach isotopic steady state, which is in agreement with published experimental observations. On the other hand, transamination and protein turnover will speed...

  6. An Unfolding Model of Voluntary Turnover of Air Force Reservists and Air National Guard Members

    Science.gov (United States)

    2004-03-01

    variables and turnover intentions. Journal of Managerial Issues , 15, 175-190. Cohen, A. (1995). An examination of the relationship between work...organizational commitment, intention to leave and voluntary turnover. Journal of Managerial Issues , 11, 493-513. Lee, T. W., & Mitchell, T. R. (1994

  7. An Analysis of Turnover Intentions: A Reexamination of Air Force Civil Engineering Company Grade Officers

    Science.gov (United States)

    2012-03-01

    Approved: ________//SIGNED//_________________ _2-Mar-2012_ Alfred E. Thal, Jr., PhD (Chairman) Date ________//SIGNED...OPTEMPO) and turnover intentions might have a curvilinear relationship (Castro & Adler , 1999). This curvilinear relationship could change the...home deployment cycle. Additionally, OPTEMPO and turnover intentions might have a curvilinear relationship (Castro & Adler , 1999). The curvilinear

  8. Organizational turnover as endogenous precursor of industry dynamics and organizational dissolution

    NARCIS (Netherlands)

    Cattani, Gino; Pennings, Johannes M.; Wezel, Filippo Carlo

    2002-01-01

    This paper studies the effect of organizational turnover on firm survival within the Dutch accounting service industry during the period 1880-1986. We address three issues: (1) estimating the effect of organizational turnover on organizational dissolution; (2) showing the significance of propinquity

  9. Dynamic Effects of Teacher Turnover on the Quality of Instruction. Working Paper 170

    Science.gov (United States)

    Hanushek, Eric A.; Rivkin, Steven G.; Schiman, Jeffrey C.

    2016-01-01

    It is widely believed that teacher turnover adversely affects the quality of instruction in urban schools serving predominantly disadvantaged children, and a growing body of research investigates various components of turnover effects. The evidence at first seems contradictory, as the quality of instruction appears to decline following turnover…

  10. Toward a Theoretical Model of Employee Turnover: A Human Resource Development Perspective

    Science.gov (United States)

    Peterson, Shari L.

    2004-01-01

    This article sets forth the Organizational Model of Employee Persistence, influenced by traditional turnover models and a student attrition model. The model was developed to clarify the impact of organizational practices on employee turnover from a human resource development (HRD) perspective and provide a theoretical foundation for research on…

  11. A Study on the Employee Turnover Antecedents in ITES/BPO Sector

    Science.gov (United States)

    Sree Rekha, K. R.; Kamalanabhan, T. J.

    2010-01-01

    This paper aims at testing a conceptual model connecting variables of the internal and external work environment to ITES/BPO employee turnover. Based on the gaps identified from the literature that no single model explains in a comprehensive way as to why, people choose to leave and the lack of turnover studies on call centers located in India.…

  12. Short-Term Effects of Midseason Coach Turnover on Team Performance in Soccer

    Science.gov (United States)

    Balduck, Anne-Line; Buelens, Marc; Philippaerts, Renaat

    2010-01-01

    The present study addressed the issue of short-term performance effects of midseason coach turnover in soccer. The goal of this study was to examine this effect on subsequent short-term team performance. The purposes of this study were to (a) examine whether midseason coach turnover improved results in the short term, and (b) examine how team…

  13. Why Agriculture Teachers Leave: A National Examination of Turnover Intentions and Work-Family Conflict

    Science.gov (United States)

    Sorensen, Tyson J.; McKim, Aaron J.; Velez, Jonathan J.

    2016-01-01

    Using data from a random sample of secondary school agriculture teachers in the United States, this study explored the work-family conflict and turnover intentions of agriculture teachers. Additionally, this study sought to determine the relationship between work-family conflict and turnover intentions among agriculture teachers. Work-family…

  14. Controls on terrestrial carbon feedbacks by productivity versus turnover in the CMIP5 Earth System Models

    Science.gov (United States)

    Koven, C. D.; Chambers, J. Q.; Georgiou, K.; Knox, R.; Negron-Juarez, R.; Riley, W. J.; Arora, V. K.; Brovkin, V.; Friedlingstein, P.; Jones, C. D.

    2015-09-01

    To better understand sources of uncertainty in projections of terrestrial carbon cycle feedbacks, we present an approach to separate the controls on modeled carbon changes. We separate carbon changes into four categories using a linearized, equilibrium approach: those arising from changed inputs (productivity-driven changes), and outputs (turnover-driven changes), of both the live and dead carbon pools. Using Coupled Model Intercomparison Project Phase 5 (CMIP5) simulations for five models, we find that changes to the live pools are primarily explained by productivity-driven changes, with only one model showing large compensating changes to live carbon turnover times. For dead carbon pools, the situation is more complex as all models predict a large reduction in turnover times in response to increases in productivity. This response arises from the common representation of a broad spectrum of decomposition turnover times via a multi-pool approach, in which flux-weighted turnover times are faster than mass-weighted turnover times. This leads to a shift in the distribution of carbon among dead pools in response to changes in inputs, and therefore a transient but long-lived reduction in turnover times. Since this behavior, a reduction in inferred turnover times resulting from an increase in inputs, is superficially similar to priming processes, but occurring without the mechanisms responsible for priming, we call the phenomenon "false priming", and show that it masks much of the intrinsic changes to dead carbon turnover times as a result of changing climate. These patterns hold across the fully coupled, biogeochemically coupled, and radiatively coupled 1 % yr-1 increasing CO2 experiments. We disaggregate inter-model uncertainty in the globally integrated equilibrium carbon responses to initial turnover times, initial productivity, fractional changes in turnover, and fractional changes in productivity. For both the live and dead carbon pools, inter-model spread in

  15. Numbers of simultaneous turnovers calculated from anesthesia or operating room information management system data.

    Science.gov (United States)

    Dexter, Franklin; Marcon, Eric; Aker, John; Epstein, Richard H

    2009-09-01

    More personnel are needed to turn over operating rooms (ORs) promptly when there are more simultaneous turnovers. Anesthesia and/or OR information management system data can be analyzed statistically to quantify simultaneous turnovers to evaluate whether to add an additional turnover team. Data collected for each case at a six OR facility were room, date of surgery, time of patient entry into the OR, and time of patient exit from the OR. The number of simultaneous turnovers was calculated for each 1 min of 122 4-wk periods. Our end point was the reduction in the daily minutes of simultaneous turnovers exceeding the number of teams caused by the addition of a team. Increasing from two turnover teams to three teams reduced the mean daily minutes of simultaneous turnovers exceeding the numbers of teams by 19 min. The ratio of 19 min to 8 h valued the time of extra personnel as 4.0% of the time of OR staff, surgeons, and anesthesia providers. Validity was suggested by other methods of analyses also suggesting staffing for three simultaneous turnovers. Discrete-event simulation showed that the reduction in daily minutes of turnover times from the addition of a team would likely match or exceed the reduction in the daily minutes of simultaneous turnovers exceeding the numbers of teams. Confidence intervals for daily minutes of turnover times achieved by increasing from two to three teams were calculated using successive 4-wk periods. The distribution was sufficiently close to normal that accurate confidence intervals could be calculated using Student's t distribution (Lilliefors' test P = 0.58). Analysis generally should use 13 4-wk periods as increasing the number of periods from 6 to 13 significantly reduced the coefficient of variation of the averages but not increasing the number of periods from 6 to 9 or from 9 to 13. The number of simultaneous turnovers can be calculated for each 1 min over 1 yr. The reduction in the daily minutes of simultaneous turnovers

  16. The right friends in the right places: Understanding network structure as a predictor of voluntary turnover.

    Science.gov (United States)

    Ballinger, Gary A; Cross, Rob; Holtom, Brooks C

    2016-04-01

    Research examining the relationship between social networks and employee retention has focused almost exclusively on the number of direct links and generally found that having more ties decreases the likelihood of turnover. The present research moves beyond simple measures of network centrality to investigate the relationship between 2 additional, and theoretically distinct, facets of social capital and voluntary turnover. In 2 organizations, we found consistent evidence of a negative relationship between reputation, as measured by relationships with highly sought-out others (incoming eigenvector centrality) and voluntary turnover. Further, we found that the negative relationship between brokerage (structural holes) and turnover is significant, but only for higher-level employees. The theoretical and practical implications of expanding the suite of social capital measures to understand voluntary turnover are discussed. (c) 2016 APA, all rights reserved).

  17. Roles of perceived exchange quality and organisational identification in predicting turnover intention

    Directory of Open Access Journals (Sweden)

    Manish Kumar

    2012-03-01

    Full Text Available This paper explores whether the perceived quality of the leader–member exchange and the general environment of exchange could predict turnover intention. It further examines the role of organisational identification as an explanatory variable mediating between exchange relationships and turnover intention. The authors used three-step hierarchical linear regressions on a data set collected in two time waves. The results supported the mediating role of organisational identification for the leader–member exchange and turnover intention relationship as well as the general environment of exchange and turnover intention relationship. Moreover, as was expected, the general exchange quality had a greater impact on organisational identification compared to the leader–member exchange quality. However, the findings did not confirm the expected trend in the case of two exchange variables predicting turnover intention.

  18. The effects of autonomy and empowerment on employee turnover: test of a multilevel model in teams.

    Science.gov (United States)

    Liu, Dong; Zhang, Shu; Wang, Lei; Lee, Thomas W

    2011-11-01

    Extending research on voluntary turnover in the team setting, this study adopts a multilevel self-determination theoretical approach to examine the unique roles of individual and social-contextual motivational precursors, autonomy orientation and autonomy support, in reducing team member voluntary turnover. Analysis of multilevel time-lagged data collected from 817 employees on 115 teams indicates that psychological empowerment mediates the main effect of autonomy orientation and the interactive effect of autonomy support and its differentiation on a team member's voluntary turnover. The findings have meaningful implications for the turnover and self-determination literatures as well as for managers who endeavor to prevent voluntary turnover in teams. (c) 2011 APA, all rights reserved.

  19. The relationship between family-to-work conflict of employee and co-workers' turnover intention

    Directory of Open Access Journals (Sweden)

    Tavakol Sharafi

    2012-01-01

    Full Text Available Previous studies have convincingly shown that employees' family lives can affect their work outcomes. We investigate whether family-to-work conflict (FWC experienced by the employee also affects the turnover intention of a co-worker. We predict that the employee's FWC has an effect on the co-worker's turnover intention through the crossover of positive and negative work attitudes. Using a sample of 154 co-worker dyads, we found that the employee FWC was positively related to co-worker turnover intention through the crossover of (reduced work engagement. Results show that family matters at work, affecting employee. In addition, employee's job engagement was positively related to his (her co-worker job engagement and it was negatively related co-worker turnover intention and employee's FWC was not positively related to co-worker turnover intention trough the crossover of (reduced feelings of engagement.

  20. Antecedents and consequence of employee turnover intention: Empirical evidence from Ghana

    Directory of Open Access Journals (Sweden)

    Michael A. Gyensare

    2015-08-01

    Full Text Available Guided by the theory of reasoned action, this study found support for the hypothesized inverse relationship between work-related factors and employee turnover intention on the one hand, and turnover intention and perceptions of accountable absence legitimacy on the other hand. Specifically, the higher employees’ turnover intent, the lower their perceptions about the accountability of their absence behavior and vice versa. The findings highlight the need to consider turnover intention as a salient construct that plays a dual role, first as a consequence variable to job satisfaction, affective and normative commitments, and next as an antecedent to accountable absence legitimacy in the workplace. The article concludes with a discussion on the significance of lessening employee turnover intent as a means of mitigating the perceptions of absence legitimacy in the workplace.

  1. Impact of peat mining, and restoration on methane turnover potentials and methane-cycling microorganisms in a northern bog.

    Science.gov (United States)

    Reumer, Max; Harnisz, Monika; Lee, Hyo Jung; Reim, Andreas; Grunert, Oliver; Putkinen, Anuliina; Fritze, Hannu; Bodelier, Paul L E; Ho, Adrian

    2017-11-27

    Ombrotrophic peatlands are a recognized global carbon reservoir. Without restoration and peat regrowth, harvested peatlands are dramatically altered, impairing its carbon sink function, with consequences for methane turnover. Previous studies determined the impact of commercial mining on the peat physico-chemical properties, and the effects on methane turnover. However, the response of the underlying microbial communities catalyzing methane production and oxidation have so far received little attention. We hypothesize that with the return of Sphagnum post-harvest, methane turnover potentials and the corresponding microbial communities will converge in a natural and restored peatland. To address our hypothesis, we determined the potential methane production and oxidation rates in a natural (as a reference), actively mined, abandoned, and restored peatland over two consecutive years. In all sites, the methanogenic and methanotrophic population size were enumerated using qPCR assays targeting the mcrA and pmoA genes, respectively. Shifts in the community composition was determined using Illumina MiSeq sequencing of the mcrA gene, and a pmoA-based t-RFLP analysis, complemented by cloning and sequence analysis of the mmoX gene. Peat mining adversely affected methane turnover potentials, but rates recovered in the restored site. The recovery in potential activity was reflected in the methanogenic and methanotrophic abundances. However, the microbial community composition was altered, more pronounced for the methanotrophs. Overall, we observed a lag between the recovery of the methanogenic/methanotrophic activity and the return of the corresponding microbial communities, suggesting a longer duration (>15 years) is needed to reverse mining-induced effects on the methane-cycling microbial communities.ImportanceOmbrotrophic peatlands are a crucial carbon sink, but this environment is also a source of methane, an important greenhouse gas. Methane emission in peatlands is

  2. Turnover Rates of Fall Migrating Pectoral Sandpipers Through the Lower Mississippi Alluvial Valley

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Mississippi Alluvial Valley (MA V) is the historic alluvial floodplain of the Lower Mississippi River. Most of the MAV is located in Arkansas, Louisiana, and...

  3. Fate and turnover rate of ovarian follicular cysts in dairy cattle.

    Science.gov (United States)

    Cook, D L; Smith, C A; Parfet, J R; Youngquist, R S; Brown, E M; Garverick, H A

    1990-09-01

    Non-lactating, multiparous dairy cows diagnosed as having cysts by palpation per rectum were used. Cysts were induced with oestradiol-17 beta (15 mg) and progesterone (37.5 mg) dissolved in ethanol and injected s.c. twice daily for 7 days. Following initial diagnosis of cysts, ovaries were exposed by midventral laparotomy, and the perimeter of the base of each cyst was marked with subepithelial injections of charcoal. Ovaries were removed from cows by transvaginal incision at 10 days (Group 1; N = 8), 20 days (Group 2; N = 8), or 40 days (Group 3; N = 7) after marking of cysts. Ovaries were examined for structures present and their relationship to the marked site. Corpora lutea with ovulation papilla were present in 7/23 cows (1/8, 4/8 and 2/7, for Groups 1, 2 and 3, respectively). In these 7 cows, corpora lutea were at a site different from the original structure that was marked. Marked structures persisted for the duration of the experimental period in 1 and 2 cows, in Groups 1 and 3, respectively. In the remaining 13 cows, new large follicular structures (cysts) were present at a site other than that marked with charcoal. These structures developed on the ovary contralateral to the one originally marked in 9 of 13 cows. Cysts are therefore dynamic in nature and may persist or may be replaced by others.

  4. The Effects of Intradistrict School Mobility and High Student Turnover Rates on Early Reading Achievement

    Science.gov (United States)

    LeBoeuf, Whitney A.

    2013-01-01

    A number of studies have identified school mobility as one form of school disengagement that is disproportionately harmful for young children enrolled in large urban districts. However, there is substantial variation in these findings, with some studies actually evidencing positive associations between school mobility and academic outcomes (Mehana…

  5. Are Fast Food “Trans-Fat” Claims True? An Infraspec VFA-IR Spectrometer Analysis of Trans-fat content in select food items purchased from Long John Silver’s

    Directory of Open Access Journals (Sweden)

    Sharron Jenkins

    2014-10-01

    Full Text Available Studies linking high trans-fat diets to coronary heart disease (CHD have prompted the need to regulate, limit, or completely ban trans-fat from all commercial food products, including fast foods. Many U.S. fast food chains now claim that their food items, particularly French fries, have "no trans-fat". In a previous study, our lab tested the validity of trans-fat claims made by several popular fast food restaurants by experimentally determining the %trans-fat in oil extracted from fast food French fries. In some cases, the trans-fat content was nearly twice as high as the amount reported by the restaurant in their literature. Long John Silver's, for example, reported a trans-fat content of 25% for their French fries, while our lab actually found over 40% trans-fat. The purpose of this study is to broaden our study of Long John Silver's trans-fat claims by analyzing a variety of their food items and comparing our findings with the %trans-fat reported by the restaurant literature (nutrition fact tables. Variable Filter Array (VFA IR spectroscopy was used to assess the trans-fat content of oil extracted from food samples. Our preliminary findings suggest that nearly every food item under study contained considerably more trans-fat than the amount reported in the restaurant’s literature.

  6. Complete assessment of whole-body n-3 and n-6 PUFA synthesis-secretion kinetics and DHA turnover in a rodent model.

    Science.gov (United States)

    Metherel, Adam H; Lacombe, R J Scott; Chouinard-Watkins, Rapha Eumll; Hopperton, Kathryn E; Bazinet, Richard P

    2017-12-11

    Previous assessments of the PUFA biosynthesis pathway have focused on DHA and arachidonic acid synthesis. Here, we determined whole-body synthesis-secretion kinetics for all downstream products of PUFA metabolism, including direct measurements of DHA and n-6 docosapentaenoic acid (DPAn-6, 22:5n-6) turnover, and compared n-6 and n-3 homologue kinetics. We infused labeled α-linolenic acid (ALA, 18:3n-3), linoleic acid (LNA, 18:2n-6), DHA and DPAn-6 as 2H5-ALA, 13C18-LNA, 13C22-DHA or 13C22-DPAn-6. Eight 11-week-old Long Evans rats fed a 10% fat diet were infused with the labeled PUFAs over 3 h, and plasma enrichment of labeled products was measured every 30 min. The DHA synthesis-secretion rate (94 +/- 34 nmol/day) did not differ from other PUFA products (range, 21.8 +/- 4.3 to 408 +/- 116 nmol/day). Synthesis-secretion rates of n-6 and n-3 PUFA homologues were similar, except 22:4n-6 and DPAn-6 had lower synthesis rates. However, daily turnover from newly synthesized DHA (0.067% +/- 0.023%) was 56-fold to 556-fold slower than all other PUFA turnover and was 130-fold slower than that determined directly from the total plasma unesterified DHA pool. In conclusion, n-6 and n-3 PUFA synthesis-secretion kinetics suggest that differences in turnover, not in synthesis-secretion rates, primarily determine PUFA plasma levels. Copyright © 2017, The American Society for Biochemistry and Molecular Biology.

  7. Timescales of carbon turnover in soils with mixed crystalline mineralogies

    Science.gov (United States)

    Khomo, Lesego; Trumbore, Susan; Bern, Carleton R.; Chadwick, Oliver A.

    2017-01-01

    Organic matter-mineral associations stabilize much of the carbon (C) stored globally in soils. Metastable short-range-order (SRO) minerals such as allophane and ferrihydrite provide one mechanism for long-term stabilization of organic matter in young soil. However, in soils with few SRO minerals and a predominance of crystalline aluminosilicate or Fe (and Al) oxyhydroxide, C turnover should be governed by chemisorption with those minerals. Here, we correlate mineral composition from soils containing small amounts of SRO minerals with mean turnover time (TT) of C estimated from radiocarbon (14C) in bulk soil, free light fraction and mineral-associated organic matter. We varied the mineral amount and composition by sampling ancient soils formed on different lithologies in arid to subhumid climates in Kruger National Park (KNP), South Africa. Mineral contents in bulk soils were assessed using chemical extractions to quantify Fe oxyhydroxides and SRO minerals. Because of our interest in the role of silicate clay mineralogy, particularly smectite (2 : 1) and kaolinite (1 : 1), we separately quantified the mineralogy of the clay-sized fraction using X-ray diffraction (XRD) and measured 14C on the same fraction. Density separation demonstrated that mineral associated C accounted for 40-70 % of bulk soil organic C in A and B1 horizons for granite, nephelinite and arid-zone gabbro soils, and > 80 % in other soils. Organic matter strongly associated with the isolated clay-sized fraction represented only 9-47 % of the bulk soil C. The mean TT of C strongly associated with the clay-sized fraction increased with the amount of smectite (2 : 1 clays); in samples with > 40 % smectite it averaged 1020 ± 460 years. The C not strongly associated with clay-sized minerals, including a combination of low-density C, the C associated with minerals of sizes between 2 µm and 2 cm (including Fe oxyhydroxides as coatings), and C removed from clay-sized material by 2 % hydrogen peroxide had

  8. Timescales of carbon turnover in soils with mixed crystalline mineralogies

    Science.gov (United States)

    Khomo, Lesego; Trumbore, Susan E.; Bern, Carleton R.; Chadwick, Oliver A.

    2017-01-01

    Organic matter–mineral associations stabilize much of the carbon (C) stored globally in soils. Metastable short-range-order (SRO) minerals such as allophane and ferrihydrite provide one mechanism for long-term stabilization of organic matter in young soil. However, in soils with few SRO minerals and a predominance of crystalline aluminosilicate or Fe (and Al) oxyhydroxide, C turnover should be governed by chemisorption with those minerals. Here, we correlate mineral composition from soils containing small amounts of SRO minerals with mean turnover time (TT) of C estimated from radiocarbon (14C) in bulk soil, free light fraction and mineral-associated organic matter. We varied the mineral amount and composition by sampling ancient soils formed on different lithologies in arid to subhumid climates in Kruger National Park (KNP), South Africa. Mineral contents in bulk soils were assessed using chemical extractions to quantify Fe oxyhydroxides and SRO minerals. Because of our interest in the role of silicate clay mineralogy, particularly smectite (2 : 1) and kaolinite (1 : 1), we separately quantified the mineralogy of the clay-sized fraction using X-ray diffraction (XRD) and measured 14C on the same fraction. Density separation demonstrated that mineral associated C accounted for 40–70 % of bulk soil organic C in A and B1 horizons for granite, nephelinite and arid-zone gabbro soils, and > 80 % in other soils. Organic matter strongly associated with the isolated clay-sized fraction represented only 9–47 % of the bulk soil C. The mean TT of C strongly associated with the clay-sized fraction increased with the amount of smectite (2 : 1 clays); in samples with > 40 % smectite it averaged 1020 ± 460 years. The C not strongly associated with clay-sized minerals, including a combination of low-density C, the C associated with minerals of sizes between 2 µm and 2 cm (including Fe oxyhydroxides as coatings), and C removed from clay

  9. Storage and turnover of organic matter in soil

    Energy Technology Data Exchange (ETDEWEB)

    Torn, M.S.; Swanston, C.W.; Castanha, C.; Trumbore, S.E.

    2008-07-15

    Historically, attention on soil organic matter (SOM) has focused on the central role that it plays in ecosystem fertility and soil properties, but in the past two decades the role of soil organic carbon in moderating atmospheric CO{sub 2} concentrations has emerged as a critical research area. This chapter will focus on the storage and turnover of natural organic matter in soil (SOM), in the context of the global carbon cycle. Organic matter in soils is the largest carbon reservoir in rapid exchange with atmospheric CO{sub 2}, and is thus important as a potential source and sink of greenhouse gases over time scales of human concern (Fischlin and Gyalistras 1997). SOM is also an important human resource under active management in agricultural and range lands worldwide. Questions driving present research on the soil C cycle include: Are soils now acting as a net source or sink of carbon to the atmosphere? What role will soils play as a natural modulator or amplifier of climatic warming? How is C stabilized and sequestered, and what are effective management techniques to foster these processes? Answering these questions will require a mechanistic understanding of how and where C is stored in soils. The quantity and composition of organic matter in soil reflect the long-term balance between plant carbon inputs and microbial decomposition, as well as other loss processes such as fire, erosion, and leaching. The processes driving soil carbon storage and turnover are complex and involve influences at molecular to global scales. Moreover, the relative importance of these processes varies according to the temporal and spatial scales being considered; a process that is important at the regional scale may not be critical at the pedon scale. At the regional scale, SOM cycling is influenced by factors such as climate and parent material, which affect plant productivity and soil development. More locally, factors such as plant tissue quality and soil mineralogy affect

  10. Rapid turnover of dissolved DMS and DMSP by defined bacterioplankton communities in the stratified euphotic zone of the North Sea

    Science.gov (United States)

    Zubkov, Mikhail V.; Fuchs, Bernhard M.; Archer, Stephen D.; Kiene, Ronald P.; Amann, Rudolf; Burkill, Peter H.

    Bacterioplankton-driven turnover of the algal osmolyte, dimethylsulphoniopropionate (DMSP), and its degradation product, dimethylsulphide (DMS) the major natural source of atmospheric sulphur, were studied during a Lagrangian SF 6-tracer experiment in the North Sea (60°N, 3°E). The water mass sampled within the euphotic zone was characterised by a surface mixed layer (from 0 m to 13-30 m) and a subsurface layer (from 13-30 m to 45-58 m) separated by a 2°C thermocline spanning 2 m. The fluxes of dissolved DMSP (DMSPd) and DMS were determined using radioactive tracer techniques. Rates of the simultaneous incorporation of 14C-leucine and 3H-thymidine were measured to estimate bacterioplankton production. Flow cytometry was employed to discriminate subpopulations and to determine the numbers and biomass of bacterioplankton by staining for nucleic acids and proteins. Bacterioplankton subpopulations were separated by flow cytometric sorting and their composition determined using 16S ribosomal gene cloning/sequencing and fluorescence in situ hybridisation with designed group-specific oligonucleotide probes. A subpopulation, dominated by bacteria related to Roseobacter-( α-proteobacteria), constituted 26-33% of total bacterioplankton numbers and 45-48% of biomass in both surface and subsurface layers. The other abundant prokaryotes were a group within the SAR86 cluster of γ-proteobacteria and bacteria from the Cytophaga-Flavobacterium—cluster. Bacterial consumption of DMSPd was greater in the subsurface layer (41 nM d -1) than in the surface layer (20 nM d -1). Bacterioplankton tightly controlled the DMSPd pool, particularly in the subsurface layer, with a turnover time of 2 h, whereas the turnover time of DMSPd in the surface layer was 10 h. Consumed DMSP satisfied the majority of sulphur demands of bacterioplankton, even though bacterioplankton assimilated only about 2.5% and 6.0% of consumed DMSPd sulphur in the surface and subsurface layers, respectively

  11. Further Clarifying Proximal Withdrawal States and the Turnover Criterion Space: Comment on Hom, Mitchell, Lee, and Griffeth (2012)

    Science.gov (United States)

    Maertz, Carl P., Jr.

    2012-01-01

    In "Reviewing Employee Turnover: Focusing on Proximal Withdrawal States and an Expanded Criterion," Hom, Mitchell, Lee, and Griffeth (2012) brought together many of the most important content and process factors in the employee turnover literature. In this paper, I attempt to clarify the true contributions of this framework for the turnover area…

  12. Microbial communities mediating algal detritus turnover under anaerobic conditions

    Directory of Open Access Journals (Sweden)

    Jessica M. Morrison

    2017-01-01

    Full Text Available Background Algae encompass a wide array of photosynthetic organisms that are ubiquitously distributed in aquatic and terrestrial habitats. Algal species often bloom in aquatic ecosystems, providing a significant autochthonous carbon input to the deeper anoxic layers in stratified water bodies. In addition, various algal species have been touted as promising candidates for anaerobic biogas production from biomass. Surprisingly, in spite of its ecological and economic relevance, the microbial community involved in algal detritus turnover under anaerobic conditions remains largely unexplored. Results Here, we characterized the microbial communities mediating the degradation of Chlorella vulgaris (Chlorophyta, Chara sp. strain IWP1 (Charophyceae, and kelp Ascophyllum nodosum (phylum Phaeophyceae, using sediments from an anaerobic spring (Zodlteone spring, OK; ZDT, sludge from a secondary digester in a local wastewater treatment plant (Stillwater, OK; WWT, and deeper anoxic layers from a seasonally stratified lake (Grand Lake O’ the Cherokees, OK; GL as inoculum sources. Within all enrichments, the majority of algal biomass was metabolized within 13–16 weeks, and the process was accompanied by an increase in cell numbers and a decrease in community diversity. Community surveys based on the V4 region of the 16S rRNA gene identified different lineages belonging to the phyla Bacteroidetes, Proteobacteria (alpha, delta, gamma, and epsilon classes, Spirochaetes, and Firmicutes that were selectively abundant under various substrate and inoculum conditions. Within all kelp enrichments, the microbial communities structures at the conclusion of the experiment were highly similar regardless of the enrichment source, and were dominated by the genus Clostridium, or family Veillonellaceae within the Firmicutes. In all other enrichments the final microbial community was dependent on the inoculum source, rather than the type of algae utilized as substrate

  13. Microbial communities mediating algal detritus turnover under anaerobic conditions

    Science.gov (United States)

    Morrison, Jessica M.; Murphy, Chelsea L.; Baker, Kristina; Zamor, Richard M.; Nikolai, Steve J.; Wilder, Shawn; Elshahed, Mostafa S.

    2017-01-01

    Background Algae encompass a wide array of photosynthetic organisms that are ubiquitously distributed in aquatic and terrestrial habitats. Algal species often bloom in aquatic ecosystems, providing a significant autochthonous carbon input to the deeper anoxic layers in stratified water bodies. In addition, various algal species have been touted as promising candidates for anaerobic biogas production from biomass. Surprisingly, in spite of its ecological and economic relevance, the microbial community involved in algal detritus turnover under anaerobic conditions remains largely unexplored. Results Here, we characterized the microbial communities mediating the degradation of Chlorella vulgaris (Chlorophyta), Chara sp. strain IWP1 (Charophyceae), and kelp Ascophyllum nodosum (phylum Phaeophyceae), using sediments from an anaerobic spring (Zodlteone spring, OK; ZDT), sludge from a secondary digester in a local wastewater treatment plant (Stillwater, OK; WWT), and deeper anoxic layers from a seasonally stratified lake (Grand Lake O’ the Cherokees, OK; GL) as inoculum sources. Within all enrichments, the majority of algal biomass was metabolized within 13–16 weeks, and the process was accompanied by an increase in cell numbers and a decrease in community diversity. Community surveys based on the V4 region of the 16S rRNA gene identified different lineages belonging to the phyla Bacteroidetes, Proteobacteria (alpha, delta, gamma, and epsilon classes), Spirochaetes, and Firmicutes that were selectively abundant under various substrate and inoculum conditions. Within all kelp enrichments, the microbial communities structures at the conclusion of the experiment were highly similar regardless of the enrichment source, and were dominated by the genus Clostridium, or family Veillonellaceae within the Firmicutes. In all other enrichments the final microbial community was dependent on the inoculum source, rather than the type of algae utilized as substrate. Lineages enriched

  14. Provincial Variations in Divorce Rates: A Canadian Case.

    Science.gov (United States)

    Makabe, Tomoko

    1980-01-01

    Examines differentials in divorce rates in Canada. Provinces with higher population turnover are characterized by lower degrees of social integration and lower social costs attached to divorce, reflected in higher divorce rates. The hypothesis that divorce rates are higher where more economic opportunities are available for women is explored.…

  15. On the controlling mechanism of the upper turnover states in the NTC regime

    KAUST Repository

    Ji, Weiqi

    2015-12-18

    Using n-butane, n-heptane and iso-octane as representative fuels exhibiting NTC (negative temperature coefficient) behavior, comprehensive computational studies with detailed mechanisms and theoretical analysis were performed to investigate the upper stationary point, denoted as turnover states, on the NTC curve near the higher temperature regime, where the ignition delay τ exhibits a local maximum. It is found that the global behavior of the turnover states exhibits distinctive thermodynamic and kinetic characteristics under different pressures, in that the ignition delay at the turnover states shows an Arrhenius dependence on the temperature T and an approximate inverse quadratic power law dependence on the pressure P. These global behaviors imply that the temperature and pressure of the turnover states are not independent and can be correlated by Arrhenius dependence, as ln P ∝ 1/T. Further theoretical analyses demonstrate that such turnover states result from the competition between the low-temperature chain branching reactions and the decomposition of the intermediate species, and therefore correspond to a critical value, α, of the ratio of OH production from low-temperature chemistry. In addition, the ignition delay at the turnover state can be well correlated by the analytical expression derived by Peters et al., with the further demonstration that the pressure dependence of the turnover ignition delay mainly result from the H2O2 decomposition reaction. Comparison of the present results with the literature experimental data of n-heptane ignition delay time shows very good agreement.

  16. The mediating effect of emotional intelligence between emotional labour, job stress, burnout and nurses' turnover intention.

    Science.gov (United States)

    Hong, Eunyoung; Lee, Young Sook

    2016-12-01

    This study was designed to construct and test the structural equation modelling on nurses' turnover intention including emotional labour, job stress, emotional intelligence and burnout in order to identify the mediating effect of emotional intelligence between those variables. Emotional labour, job stress and burnout increase turnover intention of nurses. However, emotional intelligence is negatively correlated with emotional labour and reduces job stress, burnout and turnover intention. Structural equation modelling was used to analyse the goodness of fit of the hypothetical model of nurses' turnover intention. Research data were collected via questionnaires from 4 to 22 August 2014 and analysed using SPSS version 18.0 and AMOS version 20.0. The model fit indices for the hypothetical model were suitable for recommended. Emotional intelligence has decreasing effect on turnover intention through burnout, although its direct effect on turnover intention is not significant. Emotional intelligence has mediation effect between emotional labour and burnout. This study's results suggest that increasing emotional intelligence might critically decrease nurses' turnover intention by reducing the effect of emotional labour on burnout. © 2016 John Wiley & Sons Australia, Ltd.

  17. Decreased bone turnover with balanced resorption and formation prevent cortical bone loss during disuse (hibernation) in grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    McGee, Meghan E; Maki, Aaron J; Johnson, Steven E; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

    2008-02-01

    Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and subsequently recover it at a faster rate than other animals. Here we show decreased cortical bone turnover during hibernation with balanced formation and resorption in grizzly bear femurs. Hibernating grizzly bear femurs were less porous and more mineralized, and did not demonstrate any changes in cortical bone geometry or whole bone mechanical properties compared to active grizzly bear femurs. The activation frequency of intracortical remodeling was 75% lower during hibernation than during periods of physical activity, but the normalized mineral apposition rate was unchanged. These data indicate that bone turnover decreases during hibernation, but osteons continue to refill at normal rates. There were no changes in regional variation of porosity, geometry, or remodeling indices in femurs from hibernating bears, indicating that hibernation did not preferentially affect one region of the cortex. Thus, grizzly bears prevent bone loss during disuse by decreasing bone turnover and maintaining balanced formation and resorption, which preserves bone structure and strength. These results support the idea that bears possess a biological mechanism to prevent disuse osteoporosis.

  18. Carbon Turnover during Effluent Application to the Land: A Potential Role for Vegetation?

    Directory of Open Access Journals (Sweden)

    Vasileios A. Tzanakakis

    2015-01-01

    Full Text Available This work investigates the effect of plant species (Eucalyptus camaldulensis vs. Arundo donax on carbon (C turnover during wastewater application to the land. The study was carried out in 40-liter pots under field conditions and plant species were treated either with pre-treated municipal wastewater or freshwater. Plant species had a strong effect on soil organic matter with pots planted with E. camaldulensis showing greater values than pots planted with A. donax. In accordance, greater respiration rates were measured in E. camaldulensis pots compared to those planted with A. donax. The respiration rate followed a decreasing trend with the progress of the season for both species. These findings suggest differences in soil microbial community composition and/or activity in the rhizosphere of plant species. Minor effects of plant species or effluent were observed in dissolved organic carbon, protein, and hexoses content. In conclusion, the results of the present study reveal an important role of plant species on C cycling in terrestrial environments with potential implications on the sequestration of C and release of nutrients and pollutants.

  19. Rapid Turnover of Effector–Memory CD4+ T Cells in Healthy Humans

    Science.gov (United States)

    Macallan, Derek C.; Wallace, Diana; Zhang, Yan; de Lara, Catherine; Worth, Andrew T.; Ghattas, Hala; Griffin, George E.; Beverley, Peter C.L.; Tough, David F.

    2004-01-01

    Memory T cells can be divided into central–memory (TCM) and effector–memory (TEM) cells, which differ in their functional properties. Although both subpopulations can persist long term, it is not known whether they are maintained by similar mechanisms. We used in vivo labeling with deuterated glucose to measure the turnover of CD4+ T cells in healthy humans. The CD45R0+CCR7− TEM subpopulation was shown to have a rapid proliferation rate of 4.7% per day compared with 1.5% per day for CD45R0+CCR7+ TCM cells; these values are equivalent to average intermitotic (doubling) times of 15 and 48 d, respectively. In contrast, the CD45RA+CCR7+ naive CD4+ T cell population was found to be much longer lived, being labeled at a rate of only 0.2% per day (corresponding to an intermitotic time of approximately 1 yr). These data indicate that human CD4+ TEM cells constitute a short-lived cell population that requires continuous replenishment in vivo. PMID:15249595

  20. Benthic Carbon Mineralization and Nutrient Turnover in a Scottish Sea Loch

    DEFF Research Database (Denmark)

    Glud, Ronnie N.; Berg, Peter; Stahl, Henrik

    2016-01-01

    Based on in situ microprofiles, chamber incubations and eddy covariance measurements, we investigated the benthic carbon mineralization and nutrient regeneration in a ~65-m-deep sedimentation basin of Loch Etive, UK. The sediment hosted a considerable amount of infauna that was dominated by the b......Based on in situ microprofiles, chamber incubations and eddy covariance measurements, we investigated the benthic carbon mineralization and nutrient regeneration in a ~65-m-deep sedimentation basin of Loch Etive, UK. The sediment hosted a considerable amount of infauna that was dominated...... ascribed to enhanced ventilation of infauna burrows during periods of elevated flow rates. The ratio in exchange rates of ΣCO2 and O2 was close to unity, confirming that the O2 uptake was a good proxy for the benthic carbon mineralization in this setting. The infauna activity resulted in highly dynamic...... for bioavailable nitrogen. Furthermore, bioturbation mediated a high efflux of dissolved phosphorus and silicate. The study documents a high spatial and temporal variation in benthic solute exchange with important implications for benthic turnover of organic carbon and nutrients. However, more long-term in situ...

  1. Large-scale turnover of functional transcription factor bindingsites in Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Moses, Alan M.; Pollard, Daniel A.; Nix, David A.; Iyer, VenkyN.; Li, Xiao-Yong; Biggin, Mark D.; Eisen, Michael B.

    2006-07-14

    The gain and loss of functional transcription-factor bindingsites has been proposed as a major source of evolutionary change incis-regulatory DNA and gene expression. We have developed an evolutionarymodel to study binding site turnover that uses multiple sequencealignments to assess the evolutionary constraint on individual bindingsites, and to map gain and loss events along a phylogenetic tree. Weapply this model to study the evolutionary dynamics of binding sites ofthe Drosophila melanogaster transcription factor Zeste, using genome-widein vivo (ChIP-chip) binding data to identify functional Zeste bindingsites, and the genome sequences of D. melanogaster, D. simulans, D.erecta and D. yakuba to study their evolution. We estimate that more than5 percent of functional Zeste binding sites in D. melanogaster weregained along the D. melanogaster lineage or lost along one of the otherlineages. We find that Zeste bound regions have a reduced rate of bindingsite loss and an increased rate of binding site gain relative to flankingsequences. Finally, we show that binding site gains and losses areasymmetrically distributed with respect to D. melanogaster, consistentwith lineage-specific acquisition and loss of Zeste-responsive regulatoryelements.

  2. Organic matter turnover in a tropical floodplain shows hysteresis during a flood cycle

    Science.gov (United States)

    Zuijdgeest, Alissa; Baumgartner, Simon; Wehrli, Bernhard

    2016-04-01

    Tropical inland waters are increasingly recognized for their role in the global carbon cycle, but uncertainty about the effects of such systems on the transported organic matter remains. The seasonal interactions between river, floodplain, and vegetation result in highly dynamic systems, which can exhibit markedly different biogeochemical patterns throughout a flood cycle. In this study, we investigated patterns and rates of organic matter turnover, and determined responsible processes. Multi-probes upstream and downstream of the Barotse Plains, a pristine floodplain in the Upper Zambezi (Zambia), provided a high-resolution data set over the course of a hydrological cycle. Concentrations of oxygen, carbon dioxide, dissolved organic carbon, and suspended particulate matter in water column of the main channel showed clear hysteresis trends relative to hydrological parameters. Considering that the respiration rate in the river water remained rather low and stable throughout the year, these patterns indicated that degradation of the terrestrial organic matter was mainly occurring on the floodplain. We suggest that the main location of terrestrially-derived organic matter degradation in river-floodplain systems shifts during a flood cycle from the water of the main channel, to the soil-water interface on the floodplain when the water spends more time on the floodplain.

  3. Energy turnover during 24 hours and 6 days of adventure racing.

    Science.gov (United States)

    Enqvist, Jonas K; Mattsson, C Mikael; Johansson, Patrik H; Brink-Elfegoun, Thibault; Bakkman, Linda; Ekblom, Björn T

    2010-07-01

    Energy turnover was assessed in two conditions of mixed ultra-endurance exercise. In Study 1, energy expenditure and intake were measured in nine males in a laboratory over 24 h. In Study 2, energy expenditure was assessed in six males during an 800-km Adventure race (mean race time 152.5 h). Individual correlations between heart rate and oxygen uptake (VO(2)) were established during pre-tests when kayaking, cycling, and running. During exercise, energy expenditure was estimated from continuous heart rate recordings. Heart rate and VO(2) were measured regularly during fixed cycling work rates to correct energy expenditure for drift in oxygen pulse. Mean energy expenditure was 18,050 +/- 2,390 kcal (750 +/- 100 kcal h(-1)) and 80,000 +/- 18,000 kcal (500 +/- 100 kcal h(-1)) in Study 1 and Study 2 respectively, which is higher than previously reported. Energy intake in Study 1 was 8,450 +/- 1,160 kcal, resulting in an energy deficit of 9,590 +/- 770 kcal. Body mass decreased in Study 1 (-2.3 +/- 0.8 kg) but was unchanged in Study 2. Fat mass decreased in Study 2 (-2.3 +/- 1.5 kg). In Study 1, muscle glycogen content decreased by only 60%. Adventure racing requires a high energy expenditure, with large inter-individual variation. A large energy deficit is caused by inadequate energy intake, possibly due to suppressed appetite and gastrointestinal problems. The oxygen pulse, comparing start to 12 h of exercise and beyond, increased by 10% and 5% in Study 1 and Study 2 respectively. Hence, estimations of energy expenditure from heart rate recordings should be corrected according to this drift.

  4. Threats or violence from patients was associated with turnover intention among foreign-born GPs - a comparison of four workplace factors associated with attitudes of wanting to quit one's job as a GP.

    Science.gov (United States)

    Eneroth, Mari; Gustafsson Sendén, Marie; Schenck Gustafsson, Karin; Wall, Maja; Fridner, Ann

    2017-06-01

    General practitioners (GPs) are crucial in medical healthcare, but there is currently a shortage of GPs in Sweden and elsewhere. Recruitment of GPs from abroad is essential, but foreign-born physicians face difficulties at work that may be related to turnover intention, i.e. wanting to quit one's job. The study aims to explore the reasons to why foreign-born GPs may intend to quit their job. Survey data were used to compare four work-related factors that can be associated with turnover intentions; patient-related stress, threats or violence from patients, control of work pace, and empowering leadership, among native-born and foreign-born GPs. These work-related factors were subsequently examined in relation to turnover intention among the foreign-born GPs by means of linear hierarchical regression analyses. The questionnaire consisted of items from the QPS Nordic and items constructed by the authors. A primary care setting in a central area of Sweden. Native-born (n = 208) and foreign-born GPs (n = 73). Turnover intention was more common among foreign-born GPs (19.2% compared with 14.9%), as was the experience of threats or violence from patients (22% compared with 3% of the native-born GPs). Threats or violence was also associated with increased turnover intention. Control of work pace and an empowering leadership was associated with reduced turnover intention. The organisations need to recognise that foreign-born GPs may face increased rates of threats and/or violence from patients, which may ultimately cause job turnover and be harmful to the exposed individual.

  5. Dietary glutamine, glutamic acid and nucleotide supplementation accelerate carbon turnover (δ13C on stomach of weaned piglets

    Directory of Open Access Journals (Sweden)

    Amanda D. Assoni

    2017-09-01

    Full Text Available The use of stable isotope analysis as a tool for characterization of carbon turnover (δ13C in piglet's tissues by tracing its feeding system has drawn attention. Thus, this study aimed at evaluating the influence of dietary glutamine, glutamic acid and nucleotides supplementation on carbon turnover in fundic-stomach region of weaned piglets at an average age of 21 days. The diets consisted of additive-free diet – control (C; 1% glutamine (G; 1% glutamic acid (GA and 1% nucleotides (Nu. At weaning day (day 0: baseline, 3 piglets were slaughtered to quantify the δ13C of stomach. The remaining 120 piglets were blocked by weight and sex, randomly assigned to pens with 3 piglets slaughtered per treatment at days 1, 2, 4, 5, 7, 9, 13, 20, 27 and 49 after weaning in order to verify the fundic-stomach isotopic composition by treatments. Samples were analyzed in terms of 13C/12C ratio by mass spectrometry and converted to relative isotopic enrichment values (δ13C ‰ used to plot the first order exponential curves over time using OriginPro 8.0 software. The inclusion of glutamine, glutamate and nucleotides in piglet's diets has accelerated the carbon turnover in stomach during the post-weaning period, demonstrating also that glutamate has guaranteed fastest 13C incorporation rate on fundic-stomach region and pH-lowering. Besides that, stable isotopes technique (δ13C has proved to be an important methodology to determine the time-scales at which piglets shift among diets with different isotopic values, characterizing the trophic effects of additives and the phenotypic flexibility of stomach.

  6. Turnover intentions in a call center: The role of emotional dissonance, job resources, and job satisfaction.

    Science.gov (United States)

    Zito, Margherita; Emanuel, Federica; Molino, Monica; Cortese, Claudio Giovanni; Ghislieri, Chiara; Colombo, Lara

    2018-01-01

    Turnover intentions refer to employees' intent to leave the organization and, within call centers, it can be influenced by factors such as relational variables or the perception of the quality of working life, which can be affected by emotional dissonance. This specific job demand to express emotions not felt is peculiar in call centers, and can influence job satisfaction and turnover intentions, a crucial problem among these working contexts. This study aims to detect, within the theoretical framework of the Job Demands-Resources Model, the role of emotional dissonance (job demand), and two resources, job autonomy and supervisors' support, in the perception of job satisfaction and turnover intentions among an Italian call center. The study involved 318 call center agents of an Italian Telecommunication Company. Data analysis first performed descriptive statistics through SPSS 22. A path analysis was then performed through LISREL 8.72 and tested both direct and indirect effects. Results suggest the role of resources in fostering job satisfaction and in decreasing turnover intentions. Emotional dissonance reveals a negative relation with job satisfaction and a positive relation with turnover. Moreover, job satisfaction is negatively related with turnover and mediates the relationship between job resources and turnover. This study contributes to extend the knowledge about the variables influencing turnover intentions, a crucial problem among call centers. Moreover, the study identifies theoretical considerations and practical implications to promote well-being among call center employees. To foster job satisfaction and reduce turnover intentions, in fact, it is important to make resources available, but also to offer specific training programs to make employees and supervisors aware about the consequences of emotional dissonance.

  7. Use of ABC–XYZ–analysis in cost management of the cargo turnover in transport logistics

    OpenAIRE

    Chukurna O.; Davydova A.

    2017-01-01

    This article focuses on the relevance of the use of ABC–XYZ–analysis in the management of cargo turnover costs in the implementation of transport and logistics operations. It proposed by using the ABC analysis to rank suppliers or customers of freight turnover and the cost of each logistics operation (or profitability of the logistics services). On the basis of the received data to optimise logistics costs. It is proposed to use the XYZ–analysis to predict the volume of cargo turnover and a l...

  8. The collagen turnover profile is altered in patients with inguinal and incisional hernia

    DEFF Research Database (Denmark)

    Henriksen, Nadia A; Mortensen, Joachim H; Sorensen, Lars T

    2015-01-01

    in the interstitial matrix (types I, III, and V collagens) and in the basement membrane (type IV collagen). MATERIAL AND METHODS: Patients with 3 different types of hernias were included: Primary unilateral inguinal hernia (n = 17), multiple hernias defined as ≥3 hernias (n = 21), and incisional hernia (n = 25......, and C4M) were measured in serum by validated, solid-phase competitive assays. RESULTS: In inguinal hernia patients, the turnover of the interstitial matrix collagens type III (P ... turnover profile of type IV collagens may predict the presence of inguinal and incisional hernia. Regulation of type IV collagen turnover may be crucial for hernia development....

  9. The Relationship between Managerial Satisfaction and Job Turnover Intention: The Mediating Role of Job Satisfaction

    Directory of Open Access Journals (Sweden)

    Rüveyda Öztürk Basol

    2017-09-01

    Full Text Available The growth of service sector in Turkey occurs faster than the other sectors and the number of shopping malls increases correspondingly. The rapid growth of the number of shopping malls has necessitated the measurement of the attitudes of the employees in this sector. This study demonstrated that the gender, marital status and age were not the significant variables on job satisfaction, managerial satisfaction and job turnover intention; however, education status and income status were found to be significant variables on job satisfaction and job turnover intention. In addition, job satisfaction fully mediated the relationship between managerial satisfaction and job turnover intention.

  10. Menguji Konsistensi Korelasi Job Satisfaction dengan Intensi Turnover: Studi Meta-Analisis

    Directory of Open Access Journals (Sweden)

    Ferdinand - Hindiarto

    2017-12-01

    Full Text Available Abstract This study examines the correlation between job satisfaction and turnover intention from various studies in 2009-2016, with meta-analysis method. The used samples consist of 25 studies from 21 research journal which is found by searching on online database: ProQuest, EBSCO and EmeraldInsight via www.lib.ugm.ac.id. Analysis conduct on 2 artefacts, correction on error sampling and on error measuring. Result of the study shows that correlation between job satisfaction and turnover intention in 1st artefact is -0,46 and in 2nd artefact is -0,56. Keyword: meta-analysis, job satisfaction, turnover intention

  11. THE EFFECT OF JOB SATISFACTION ON IT EMPLOYEES TURNOVER INTENTION IN ISRAEL

    Directory of Open Access Journals (Sweden)

    Ladelsky Limor

    2014-07-01

    Full Text Available Employee voluntary turnover is very costly for companies, particularly for the Hi-Tech sector, where the costs of their IT labor force is expensive. Employees\\' voluntary turnover has substantial negative impacts on the companies especially costs, potential loss of valuable knowledge, skills and organizational knowledge.That is why it becomes a critical issue to take address. Studies have been carried out on the reasons which lead to this tendency, however the ability to explain and predict it remains restricted.The objective of this paper is to present the reasons for voluntary turnover of employees in the IT sector in Israel from the IT employees` perspective. A broad analysis of the field literature led to the following groups of causes affecting voluntary turnover: organizational causes: Human Resource Management (HRM related, organizational culture, job related, leadership and internal marketing related; extra organizational causes: individual and, respectively, labor market related causes. This could be approached as n light of this review this article will focus on one of the extra organizational causes of voluntary turnover, i.e. the effect of job satisfaction on voluntary turnover intention among IT employees in Hi-Tech companies in Israel. This correlation was researched in an extensive empirical study among two population groups: IT employees and IT managers and by using mixed method research (combination of quantitative and qualitative research.The findings that supported the literature show job satisfaction has a negative effect on voluntary turnover intention among IT employees in Hi-Tech companies in Israel. Additionally, it was found that job satisfaction indirectly affects voluntary turnover intentions and that emotional variables such as commitment, motivation and loyalty mediate voluntary turnover intention.This finding is supported partially in the literature which only pointed out commitment as a mediating factor in the

  12. Improving operating room turnover time: a systems based approach.

    Science.gov (United States)

    Bhatt, Ankeet S; Carlson, Grant W; Deckers, Peter J

    2014-12-01

    Operating room (OR) turnover time (TT) has a broad and significant impact on hospital administrators, providers, staff and patients. Our objective was to identify current problems in TT management and implement a consistent, reproducible process to reduce average TT and process variability. Initial observations of TT were made to document the existing process at a 511 bed, 24 OR, academic medical center. Three control groups, including one consisting of Orthopedic and Vascular Surgery, were used to limit potential confounders such as case acuity/duration and equipment needs. A redesigned process based on observed issues, focusing on a horizontally structured, systems-based approach has three major interventions: developing consistent criteria for OR readiness, utilizing parallel processing for patient and room readiness, and enhancing perioperative communication. Process redesign was implemented in Orthopedics and Vascular Surgery. Comparisons of mean and standard deviation of TT were made using an independent 2-tailed t-test. Using all surgical specialties as controls (n = 237), mean TT (hh:mm:ss) was reduced by 0:20:48 min (95 % CI, 0:10:46-0:30:50), from 0:44:23 to 0:23:25, a 46.9 % reduction. Standard deviation of TT was reduced by 0:10:32 min, from 0:16:24 to 0:05:52 and frequency of TT≥30 min was reduced from 72.5to 11.7 %. P systems-based focus should drive OR TT design.

  13. Degradation of asialoprothrombin and its relevance to prothrombin turnover

    Energy Technology Data Exchange (ETDEWEB)

    Vostal, J.G.

    1986-01-01

    As a part of their turnover, serum glycoproteins have been thought to be cleared from plasma and degraded after an initial conversion to an asialogylcoprotein intermediate. The authors have examined this possibility with the plasma protein prothrombin. Bovine prothrombin and its asialo derivative were prepared and radioiodinated by conventional methods. In vivo plasma half lives of trichloroacetic acid (TCA) precipitable radioactivity were estimated in heparinized and anesthetized rats following and injection of the individual proteins into the femoral vein. For prothrombin, the half life was 3.2 hours with very little plasma TCA soluble radioactive products formed over 3 hours. Asialo-prothrombin's half life was only 1.1 minutes with soluble radioactive material increasing greatly during the initial 30 minutes. Simultaneous administration of competing doses of asialofetuin greatly increased the apparent half life of asialoprothrombin. The uptake and the release of TCA soluble radioactivity from liver was also delayed. Studies with isolated hepatocytes further demonstrated that asialoprothrombin was taken up by the cells and eventually degraded in the lysosomes. However, single or multiple injections of the highest dose of asialofetuin had no effect on /sup 125/I-prothrombin half life plasma soluble radioactivity or accumulation in the liver. The data indicate that while exogenously administered asialoprothrombin is apparently cleared from circulation by a hepatic asialoglycoprotein receptor, prothrombin, even though accumulated by the liver, is not.

  14. Bone growth and turnover in progesterone receptor knockout mice.

    Energy Technology Data Exchange (ETDEWEB)

    Rickard, David J.; Iwaniec, Urszula T.; Evans, Glenda; Hefferan, Theresa E.; Hunter, Jaime C.; Waters, Katrina M.; Lydon, John P.; O' Malley, Bert W.; Khosla, Sundeep; Spelsberg, Thomas C.; Turner, Russell T.

    2008-05-01

    The role of progesterone receptor (PR) signaling in skeletal metabolism is controversial. To address whether signaling through the PR is necessary for normal bone growth and turnover, we performed histomorphometric and mCT analyses of bone from homozygous female PR knockout (PRKO) mice at 6, 12, and 26 weeks of age. These mice possess a null mutation of the PR locus, which blocks the gene expression of A and B isoforms of PR. Body weight gain, uterine weight gain and tibia longitudinal bone growth was normal in PRKO mice. In contrast, total and cortical bone mass were increased in long bones of post-pubertal (12 and 26-week-old) PRKO mice, whereas cancellous bone mass was normal in the tibia but increased in the humerus. The striking 57% decrease in cancellous bone from the proximal tibia metaphysis which occurred between 6 and 26 weeks in WT mice was abolished in PRKO mice. The improved bone balance in aging PRKO mice was associated with elevated bone formation and a tendency toward reduced osteoclast perimeter. Taken together, these findings suggest that PR signaling in mice attenuates the accumulation of cortical bone mass during adolescence and is required for early age-related loss of cancellous bone.

  15. Employee Turnover and Knowledge Management in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Lucie Vnoučková

    2015-01-01

    Full Text Available Knowledge economy regards employee knowledge as a most important asset. It is a priority task to ensure systematic knowledge continuity of those employees who are the holders of critical knowledge. The aim of the article is to analyse the causes of mobility of knowledge workers and categorise types of employees and mobility according to the future development of an employee’s career. The research areas, i.e. ensuring knowledge continuity and employee turnover were analysed based on the premise of significant relation between those two areas. The data were collected in organizations in the Czech Republic. Surveys were drawn across sectors to ensure representativeness of the outcomes. The outputs revealed two basic approaches to maintaining knowledge inside organizations. Employees can be divided into knowledge workers and remainder, who seek only security. A knowledge worker who decides to transfer is not motivated by the amount of salary (they do not mind a lower level of remuneration; on the contrary they suffer due to an unclear vision on the part of the organization, where they used to work; they cannot stay in conditions where there is no possibility to participate on personal growth. Future research in this area should focus on the return of investments in the knowledge and employee learning, training and retention.

  16. Kindlin-1 regulates integrin dynamics and adhesion turnover.

    Science.gov (United States)

    Margadant, Coert; Kreft, Maaike; Zambruno, Giovanna; Sonnenberg, Arnoud

    2013-01-01

    Loss-of-function mutations in the gene encoding the integrin co-activator kindlin-1 cause Kindler syndrome. We report a novel kindlin-1-deficient keratinocyte cell line derived from a Kindler syndrome patient. Despite the expression of kindlin-2, the patient's cells display several hallmarks related to reduced function of β1 integrins, including abnormal cell morphology, cell adhesion, cell spreading, focal adhesion assembly, and cell migration. Defective cell adhesion was aggravated by kindlin-2 depletion, indicating that kindlin-2 can compensate to a certain extent for the loss of kindlin-1. Intriguingly, β1 at the cell-surface was aberrantly glycosylated in the patient's cells, and its expression was considerably reduced, both in cells in vitro and in the patient's epidermis. Reconstitution with wild-type kindlin-1 but not with a β1-binding defective mutant restored the aberrant β1 expression and glycosylation, and normalized cell morphology, adhesion, spreading, and migration. Furthermore, the expression of wild-type kindlin-1, but not of the integrin-binding-defective mutant, increased the stability of integrin-mediated cell-matrix adhesions and enhanced the redistribution of internalized integrins to the cell surface. Thus, these data uncover a role for kindlin-1 in the regulation of integrin trafficking and adhesion turnover.

  17. Kindlin-1 regulates integrin dynamics and adhesion turnover.

    Directory of Open Access Journals (Sweden)

    Coert Margadant

    Full Text Available Loss-of-function mutations in the gene encoding the integrin co-activator kindlin-1 cause Kindler syndrome. We report a novel kindlin-1-deficient keratinocyte cell line derived from a Kindler syndrome patient. Despite the expression of kindlin-2, the patient's cells display several hallmarks related to reduced function of β1 integrins, including abnormal cell morphology, cell adhesion, cell spreading, focal adhesion assembly, and cell migration. Defective cell adhesion was aggravated by kindlin-2 depletion, indicating that kindlin-2 can compensate to a certain extent for the loss of kindlin-1. Intriguingly, β1 at the cell-surface was aberrantly glycosylated in the patient's cells, and its expression was considerably reduced, both in cells in vitro and in the patient's epidermis. Reconstitution with wild-type kindlin-1 but not with a β1-binding defective mutant restored the aberrant β1 expression and glycosylation, and normalized cell morphology, adhesion, spreading, and migration. Furthermore, the expression of wild-type kindlin-1, but not of the integrin-binding-defective mutant, increased the stability of integrin-mediated cell-matrix adhesions and enhanced the redistribution of internalized integrins to the cell surface. Thus, these data uncover a role for kindlin-1 in the regulation of integrin trafficking and adhesion turnover.

  18. Increased hypothalamic serotonin turnover in inflammation-induced anorexia.

    Science.gov (United States)

    Dwarkasing, J T; Witkamp, R F; Boekschoten, M V; Ter Laak, M C; Heins, M S; van Norren, K

    2016-05-20

    Anorexia can occur as a serious complication of disease. Increasing evidence suggests that inflammation plays a major role, along with a hypothalamic dysregulation characterized by locally elevated serotonin levels. The present study was undertaken to further explore the connections between peripheral inflammation, anorexia and hypothalamic serotonin metabolism and signaling pathways. First, we investigated the response of two hypothalamic neuronal cell lines to TNFα, IL-6 and LPS. Next, we studied transcriptomic changes and serotonergic activity in the hypothalamus of mice after intraperitoneal injection with TNFα, IL-6 or a combination of TNFα and IL-6. In vitro, we showed that hypothalamic neurons responded to inflammatory mediators by releasing cytokines. This inflammatory response was associated with an increased serotonin release. Mice injected with TNFα and IL-6 showed decreased food intake, associated with altered expression of inflammation-related genes in the hypothalamus. In addition, hypothalamic serotonin turnover showed to be elevated in treated mice. Overall, our results underline that peripheral inflammation reaches the hypothalamus where it affects hypothalamic serotoninergic metabolism. These hypothalamic changes in serotonin pathways are associated with decreased food intake, providing evidence for a role of serotonin in inflammation-induced anorexia.

  19. Geographical variation in mutualistic networks: similarity, turnover and partner fidelity.

    Science.gov (United States)

    Trøjelsgaard, Kristian; Jordano, Pedro; Carstensen, Daniel W; Olesen, Jens M

    2015-03-07

    Although species and their interactions in unison represent biodiversity and all the ecological and evolutionary processes associated with life, biotic interactions have, contrary to species, rarely been integrated into the concepts of spatial β-diversity. Here, we examine β-diversity of ecological networks by using pollination networks sampled across the Canary Islands. We show that adjacent and distant communities are more and less similar, respectively, in their composition of plants, pollinators and interactions than expected from random distributions. We further show that replacement of species is the major driver of interaction turnover and that this contribution increases with distance. Finally, we quantify that species-specific partner compositions (here called partner fidelity) deviate from random partner use, but vary as a result of ecological and geographical variables. In particular, breakdown of partner fidelity was facilitated by increasing geographical distance, changing abundances and changing linkage levels, but was not related to the geographical distribution of the species. This highlights the importance of space when comparing communities of interacting species and may stimulate a rethinking of the spatial interpretation of interaction networks. Moreover, geographical interaction dynamics and its causes are important in our efforts to anticipate effects of large-scale changes, such as anthropogenic disturbances. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  20. TRENDS OF THE FACTORING TURNOVER IN INTERNATIONAL COMPARISONS

    Directory of Open Access Journals (Sweden)

    Éva DARABOS

    2017-05-01

    Full Text Available The factoring scheme was developed by the competition between the market operators and the need for the most favourable conditions of sale. The seller is constrained to provide loans on a broad scale therefore the seller may have liquidity problems. In cases of this kind, the seller can apply to a factoring company in order to access sources, instead of a bank loan. The factoring service has a price. Decision of the financial managers can largely contribute to choosing the appropriate funding form to retain the continuous liquidity situation of an enterprise. Aim of the article is to present the main tendencies of the factoring turnover in international comparisons, highlighting the characteristics of the financial service by its direction, sectorial distribution and customer size in Hungary. It has been estimated that the factoring financing approaches 10% of the short-term loan stocks of SMEs required from banks which indicates that the factoring is now far beyond the marginal financial service but it is an essential element of the short-term financing toolkit.

  1. A model of voluntary turnover among hospital CEOs.

    Science.gov (United States)

    Weil, P A; Kimball, P A

    1995-01-01

    This study examines factors contributing to hospital CEOs' voluntary decisions to leave their positions in 1990. Using a longitudinal design, we contrast 49 leavers with 1,362 stayers. We view turnover as influenced by both "push" factors that promote leaving (dissatisfaction with the position) and "hump" factors that need to be overcome (the cost of job change). Push factors giving rise to dissatisfaction include lower compensation, the predecessor's termination, and value incongruity between the CEO and the hospital. Testing the impact of key variables from Fiedler's contingency theory of leadership, we show that task-oriented leaders are relatively less satisfied when compared with relationship-oriented leaders. CEOs also express less satisfaction in low-situational control settings, a measure heavily influenced by perceived inadequate support from medical staff and subordinates. "Hump" factors that deterred leaving included family-related obstacles such as spouse's work or children's school, features mentioned most often by younger CEOs. The study suggests that boards should structure competitively paid positions with opportunities to generate support from the medical staff and subordinates. Recruiters for CEO positions are apprised of the importance of nonwork features in CEOs' willingness to consider new positions.

  2. Effects of drought on nitrogen turnover and abundances of ammonia-oxidizers in mountain grassland

    Science.gov (United States)

    Fuchslueger, L.; Kastl, E.-M.; Bauer, F.; Kienzl, S.; Hasibeder, R.; Ladreiter-Knauss, T.; Schmitt, M.; Bahn, M.; Schloter, M.; Richter, A.; Szukics, U.

    2014-11-01

    Future climate scenarios suggest an increased frequency of summer drought periods in the European Alpine Region. Drought can affect soil nitrogen (N) cycling, by altering N transformation rates, as well as the abundances of ammonia-oxidizing bacteria and archaea. However, the extent to which drought affects N cycling under in situ conditions is still controversial. The goal of this study was to analyse effects of drought on soil N turnover and ammonia-oxidizer abundances in soil without drought history. To this end we conducted rain-exclusion experiments at two differently managed mountain grassland sites, an annually mown and occasionally fertilized meadow and an abandoned grassland. Soils were sampled before, during and after drought and were analysed for potential gross rates of N mineralization, microbial uptake of inorganic N, nitrification, and the abundances of bacterial and archaeal ammonia-oxidizers based on gene copy numbers of the amoA gene (AOB and AOA, respectively). Drought induced different responses at the two studied sites. At the managed meadow drought increased NH4+ immobilization rates and NH4+ concentrations in the soil water solution, but led to a reduction of AOA abundance compared to controls. At the abandoned site gross nitrification and NO3- immobilization rates decreased during drought, while AOB and AOA abundances remained stable. Rewetting had only minor, short-term effects on the parameters that had been affected by drought. Seven weeks after the end of drought no differences to control plots could be detected. Thus, our findings demonstrated that in mountain grasslands drought had distinct transient effects on soil nitrogen cycling and ammonia-oxidizers, which could have been related to a niche differentiation of AOB and AOA with increasing NH4+ levels. However, the effect strength of drought was modulated by grassland management.

  3. An engine for global plant diversity: Highest evolutionary turnover and emigration in the American tropics

    Directory of Open Access Journals (Sweden)

    Alexandre eAntonelli

    2015-04-01

    Full Text Available Understanding the processes that have generated the latitudinal biodiversity gradient and the continental differences in tropical biodiversity remains a major goal of evolutionary biology. Here we estimate the timing and direction of range shifts of extant flowering plants (angiosperms between tropical and non-tropical zones, and into and out of the major tropical regions of the world. We then calculate rates of speciation and extinction taking into account incomplete taxonomic sampling. We use a recently published fossil calibrated phylogeny and apply novel bioinformatic tools to code species into user-defined polygons. We reconstruct biogeographic history using stochastic character mapping to compute relative numbers of range shifts in proportion to the number of available lineages through time. Our results, based on the analysis of c. 22,600 species and c. 20 million geo-referenced occurrence records, show no significant differences between the speciation and extinction of tropical and non-tropical angiosperms. This suggests that at least in plants, the tropical biodiversity gradient primarily derives from other factors than differential rates of diversification. In contrast, the outstanding species richness found today in the American tropics (the Neotropics, as compared to tropical Africa and tropical Asia, is associated with significantly higher speciation and extinction rates. This suggests an exceedingly rapid evolutionary turnover, i.e. Neotropical species being formed and replaced by one another at unparalleled rates. In addition, tropical America stands out from other continents by having ‘pumped out’ more species than it received through most of the last 66 million years. These results imply that the Neotropics have acted as an engine for global plant diversity.

  4. Time-Series Radiocarbon Measurements Indicate Carbon Turnover Across Soil Fractions is Correlated With Productivity in a Long-Term Agricultural Experiment

    Science.gov (United States)

    Sanderman, J.; Baisden, W. T.; Creamer, C.; Farrell, M.; Fallon, S.

    2016-12-01

    Devising agricultural management schemes that enhance food security and soil carbon levels is a high priority for many nations. However, the coupling between agricultural productivity, soil carbon stocks and organic matter turnover rates is still unclear. Archived soil samples from four decades (1963-1993) of a long-term crop rotation trial were analyzed for soil organic matter (SOM) cycling relevant properties. Trial treatments ranged from wheat-long fallow to crop-pasture rotations to permanent pasture. We focus on tracing the bomb-spike in atmospheric 14CO2 through various soil pools in the upper 10 cm of soil to better understand how changes in carbon inputs effects the turnover of different soil carbon fractions that can be isolated in the laboratory. In particular, we analyzed bulk SOM (fast as simple steady-state considerations would suggest to result in the observed SOC stocks. Further modeling work using the fraction data suggest a nuanced picture of SOM cycling where 1) there appears to be a direct feedback between increased C inputs and SOM turnover rates, and 2) physically isolated fractions while roughly approximating conceptual model pools are likely composed of a small but fast cycling component and a larger slower cycling component.

  5. A methodology to measure the effectiveness of academic recruitment and turnover

    DEFF Research Database (Denmark)

    Abramo, Giovanni; D’Angelo, Ciriaco Andrea; Rosati, Francesco

    2016-01-01

    of effectiveness used, and between the indicators andthe universities’ overall research performance. In countries that conduct regular nationalassessment exercises, the evaluation of effectiveness in recruitment and turnover couldcomplement the overall research assessments. In particular, monitoring...

  6. ORGANIZATIONAL JUSTICE, COUNTERPRODUCTIVE WORK BEHAVIOR AND TURNOVER INTENTIONS RELATION: MEDIATION BY DEHUMANIZATION AND MODERATION BY GENDER

    National Research Council Canada - National Science Library

    Ishfaq Ahmed; Muhammad Khalid Khan

    2016-01-01

      The core aim of this study is to find the effects of organizational justice on employees' counter productive work behavior and turnover intentions considering the explanatory and moderating roles...

  7. Effects of meclofenoxate on the level and turnover of biogenic monoamines in the rat brain.

    Science.gov (United States)

    Petkov, V V; Grahovska, T; Petkov, V D; Konstantinova, E

    1985-01-01

    The level and turnover of biogenic monoamines in some rat brain structures were determined after treatment with meclofenoxate at a dose of 50 mg/kg administered i.p. two times a day (9 a.m. and 5 p.m.) for 5 days. Meclofenoxate decreased dopamine (DA) turnover in the frontal cortex and striatum and highly increased it in the hypothalamus. The DA level significantly declined in the striatum, tended to decline in the cortex and significantly rose in the hypothalamus. The noradrenaline (NA) turnover and level in the cortex and striatum were decreased. Meclofenoxate decreased serotonin (5-HT) turnover in the cortex, striatum and hypothalamus and increased it in the pons. At the same time, the 5-HT level rose in the cortex, striatum and pons and declined in the hypothalamus. These results suggest the neurochemical basis of the psychotropic and neuroendocrine effects of meclofenoxate.

  8. The Role Of LMX In Employees Job Motivation, Satisfaction, Empowerment, Stress And Turnover: Cross Country Analysis

    National Research Council Canada - National Science Library

    Maria Malik; Difang Wan; Muhammad Ishfaq Ahmad; Muhammad Akram Naseem; Ramiz ur Rehman

    2015-01-01

      We investigated the effect of Leader Member Exchange (LMX) quality relationship on employee motivation, stress, turnover, satisfaction and Psychological Empowerment with a sample of 1500 employees across four countries...

  9. Dynamics of psychological contracts with work engagement and turnover intention: the influence of organizational tenure

    NARCIS (Netherlands)

    Bal, P.M.; de Cooman, R.; Mol, S.T.

    2013-01-01

    This study investigated the interrelations of the psychological contract with work engagement and turnover intention, which has hitherto been a largely overlooked topic in psychological contract research. Although previous research has mainly focused on how psychological contracts influence job

  10. Impact of work environment and work-related stress on turnover intention in physical therapists

    National Research Council Canada - National Science Library

    Lee, Byoung-kwon; Seo, Dong-kwon; Lee, Jang-Tae; Lee, A-Ram; Jeon, Ha-Neul; Han, Dong-Uk

    2016-01-01

    .... It should help create efficient personnel and organization management by exploring the impact of the work environment and work-related stress on turnover intention and analyzing the correlation between them...

  11. Factors affecting employee turnover and sound retention strategies in business organization: a conceptual view

    Directory of Open Access Journals (Sweden)

    Chowdhury Abdullah Al Mamun

    2017-03-01

    Full Text Available “Employee turnover” as an expression is broadly used in business organization. Despite the fact that several studies have been performed on this topic, little research has been conducted on examining the causes and leading factors of turnover as well, as advising some feasible approaches, which can be applied by bosses to ensure that employees will continue in their respective organizations to enhance organizational effectiveness and productivity. The main purpose of this study is to determine the reasons and key factors in the perspectives of the relevant literature and identify to the intention of employee turnover. This conceptual paper also suggests various possible strategies on how to minimize the turnover and retain employees in the organizations. Hence, the paper has proposed a conceptual framework that shows the major variables in explaining the phenomenon of employee turnover and addressing sound retention strategies to handle these issues.

  12. The Effect of Organizational Justice on Accountants’ Job Satisfaction and Turnover Intention

    Directory of Open Access Journals (Sweden)

    Gökhan ÖZER

    2010-12-01

    Full Text Available The purpose of this study is to investigate how the accounting profession members’ who work dependently in accounting firms (vocational trainees, CAs and CPAs perception of organizational justice effect the formation of job satisfaction and turnover intention in order to understand and put forward the phenomenon of turnover among accountants. Organizational justice has been investigated under the sub-dimensions as distributive and procedurel justice. According to the findings attained as a result of the analysis of the data obtained from the survey that was carried out with 240 accountants working in different regions of Turkey and who were chosen randomly for this study; 1 as procedural justice perception increase accountants’ job satisfaction increase as well but their turnover intention decrease 2 as job satisfaction increase accountant’ turnover intention decrease

  13. WORK OVERLOAD AND TURNOVER INTENTION OF JUNIOR AUDITORS IN GREATER JAKARTA, INDONESIA

    Directory of Open Access Journals (Sweden)

    Andika Pradana

    2015-11-01

    Full Text Available This paper aims to analyze how work overload influences turnover intentions of newly hired junior auditors in public accounting offices. Job satisfaction, work related stress and work life conflicts are used as mediating variables between work overload and turnover intention. This study employed 141 auditors from several accounting firms operating in the Greater Jakarta region. The sample was selected using purposive sampling. Three mediation hypotheses were tested using Structural Equation Modeling (SEM. The results show that work overload has a significant effect on increas- ing turnover intention through both job satisfaction and work related stress. In comparison, work overload does not influence turnover intention through work life balance. This may be due to the nature of the respondents, in which a majority of the newly hired accountants employed in this study are unmarried.

  14. The Impact of Staff Turnover on Workplace Demands and Coworker Relationships

    Science.gov (United States)

    Knight, Danica K.; Becan, Jennifer E.; Flynn, Patrick M.

    2016-01-01

    Turnover among clinical staff can have detrimental effects on service provision and organizational efficiency. But how does it affect staff who remain employed at the agency? Researchers at the Institute of Behavioral Research at Texas Christian University sought to answer this question by examining the impact of staff turnover on perceptions of workplace demands and support among 353 clinical staff members from 63 outpatient substance abuse treatment programs. Study results documented that counselors in high-turnover programs reported higher demands (job stress, inadequate staffing) and lower support (communication, collaboration) within their organization, even after controlling for other factors such as decreasing budgets, increasing census, and individual measures of workload. Findings underscore the need to intentionally promote workplace communication and collaboration among staff following the departure of a coworker in order to reduce stress and minimize subsequent turnover among remaining clinical staff. PMID:27540331

  15. Phagocytosis and intracellular digestion of collagen, its role in turnover and remodelling

    NARCIS (Netherlands)

    Everts, V.; van der Zee, E.; Creemers, L.; Beertsen, W.

    1996-01-01

    Collagens of most connective tissues are subject to continuous remodelling and turnover, a phenomenon which occurs under both physiological and pathological conditions. Degradation of these proteins involves participation of a variety of proteolytic enzymes including members of the following

  16. Effects of immobilization and whole-body vibration on rat serum Type I collagen turnover

    Directory of Open Access Journals (Sweden)

    Gürhan Dönmez

    2016-08-01

    Conclusion: Although 1 week of WBV had a positive effect on type I collagen turnover in controls, it is not an efficient method for repairing tissue damage in the early stage following immobilization.

  17. Millisecond dynamics in glutaredoxin during catalytic turnover is dependent on substrate binding and absent in the resting states

    DEFF Research Database (Denmark)

    Jensen, Kristine Steen; Winther, Jakob R; Teilum, Kaare

    2011-01-01

    tuned to exchange on the millisecond time scale. The conformational changes of the protein backbone during catalysis were followed by (15)N nuclear spin relaxation dispersion experiments. A conformational transition that is well described by a two-state process with an exchange rate corresponding...... to the glutathione exchange rate was observed for 23 residues. Binding of reduced glutathione resulted in competitive inhibition of the reduced enzyme having kinetics similar to that of the reaction. This observation couples the motions observed during catalysis directly to substrate binding. Backbone motions......Conformational dynamics is important for enzyme function. Which motions of enzymes determine catalytic efficiency and whether the same motions are important for all enzymes, however, are not well understood. Here we address conformational dynamics in glutaredoxin during catalytic turnover...

  18. Predicting voluntary turnover in employees using demographic characteristics: A South African case study

    Directory of Open Access Journals (Sweden)

    Anton F. Schlechter

    2016-03-01

    Full Text Available Purpose: Employee turnover presents arguably the biggest threat to business sustainability and is a dynamic challenge faced by businesses globally. In South Africa, organisations compete to attract and retain skilled employees in an environment characterised by a burgeoning skills deficit. Turnover risk management is becoming an important strategy to ensure organisational stability and promote the effective retention of employees. The purpose of this research was to contribute to the practice of turnover risk management by proposing an approach and constructing a model to predict employee turnover based on demographic characteristics readily available in a human resource information system.Design: An exploratory research design was employed. Secondary quantitative data were extracted from an existing human resources database and analysed. Data obtained for 2592 employees in a general insurance company based in South Africa and Namibia formed the basis for the analysis. Logistic regression analysis was employed to predict employee turnover using various demographic characteristics available within the database. A likelihood ratio test was used to build a predictive model and the Akaike information criterion and Schwarz criterion were used to test how much value each variable added to the model and if its inclusion was warranted. The model was tested by conducting statistical tests of the significance of the coefficients. Deviance and Pearson goodness-of-fit statistics as well as the R-square test of significance were used. The overall goodness-of-fit of the model was also tested using the Hosmer and Lemeshow goodness-of-fit test.Findings: The current findings provide partial support for a predictive model explaining employee turnover. The model tested 14 demographic variables and the following five variables were found to have statistically significant predictive value: age, years of service, cost centre, performance score and the interaction

  19. A structural equation model of turnover for a longitudinal survey among early career registered nurses.

    Science.gov (United States)

    Brewer, Carol S; Chao, Ying-Yu; Colder, Craig R; Kovner, Christine T; Chacko, Thomas P

    2015-11-01

    Key predictors of early career nurses' turnover are job satisfaction, organizational commitment, job search, intent to stay, and shock (back injuries) based on the literature review and our previous research. Existing research has often omitted one of these key predictors. The purpose of this study in a sample of early career nurses was to compare predictors of turnover to nurses' actual turnover at two time points in their careers. A multi-state longitudinal panel survey of early career nurses was used to compare a turnover model across two time periods. The sample has been surveyed five times. The sample was selected using a two-stage sample of registered nurses nested in 51 metropolitan areas and nine non-metropolitan, rural areas in 34 states and the District of Columbia. The associations between key predictors of turnover were tested using structural equation modeling and data from the earliest and latest panels in our study. We used predictors from the respondents who replied to the Wave-1 survey in 2006 and their turnover status from Wave 2 in 2007 (N=2386). We compared these results to the remaining respondents' predictors from Wave 4 in 2011 and their turnover status in Wave 5 in 2013 (N=1073). We tested and found no effect for missingness from Wave 1-5 and little evidence of attrition bias. Strong support was found for the relationships hypothesized among job satisfaction, organizational commitment, intent to stay, and turnover, with some support for shock and search in the Wave 1-2 sample. However, for Wave 4-5 sample (n=1073), none of the paths through search were significant, nor was the path from shock to turnover. Nurses in the second analysis who had matured longer in their career did not have a significant response to search or shock (back injuries), which may indicate how easily experienced registered nurses find new jobs and/or accommodation to jobs requiring significant physicality. Nurse turnover is a major concern for healthcare organizations

  20. Daytime pattern of post-exercise protein intake affects whole-body protein turnover in resistance-trained males

    Directory of Open Access Journals (Sweden)

    Moore Daniel R

    2012-10-01

    Full Text Available Abstract Background The pattern of protein intake following exercise may impact whole-body protein turnover and net protein retention. We determined the effects of different protein feeding strategies on protein metabolism in resistance-trained young men. Methods Participants were randomly assigned to ingest either 80g of whey protein as 8x10g every 1.5h (PULSE; n=8, 4x20g every 3h (intermediate, INT; n=7, or 2x40g every 6h (BOLUS; n=8 after an acute bout of bilateral knee extension exercise (4x10 repetitions at 80% maximal strength. Whole-body protein turnover (Q, synthesis (S, breakdown (B, and net balance (NB were measured throughout 12h of recovery by a bolus ingestion of [15N]glycine with urinary [15N]ammonia enrichment as the collected end-product. Results PULSE Q rates were greater than BOLUS (~19%, P Conclusion We conclude that the pattern of ingested protein, and not only the total daily amount, can impact whole-body protein metabolism. Individuals aiming to maximize NB would likely benefit from repeated ingestion of moderate amounts of protein (~20g at regular intervals (~3h throughout the day.

  1. Persistence of subclinical deformed wing virus infections in honeybees following Varroa mite removal and a bee population turnover.

    Directory of Open Access Journals (Sweden)

    Barbara Locke

    Full Text Available Deformed wing virus (DWV is a lethal virus of honeybees (Apis mellifera implicated in elevated colony mortality rates worldwide and facilitated through vector transmission by the ectoparasitic mite Varroa destructor. Clinical, symptomatic DWV infections are almost exclusively associated with high virus titres during pupal development, usually acquired through feeding by Varroa mites when reproducing on bee pupae. Control of the mite population, generally through acaricide treatment, is essential for breaking the DWV epidemic and minimizing colony losses. In this study, we evaluated the effectiveness of remedial mite control on clearing DWV from a colony. DWV titres in adult bees and pupae were monitored at 2 week intervals through summer and autumn in acaricide-treated and untreated colonies. The DWV titres in Apistan treated colonies was reduced 1000-fold relative to untreated colonies, which coincided with both the removal of mites and also a turnover of the bee population in the colony. This adult bee population turnover is probably more critical than previously realized for effective clearing of DWV infections. After this initial reduction, subclinical DWV titres persisted and even increased again gradually during autumn, demonstrating that alternative non-Varroa transmission routes can maintain the DWV titres at significant subclinical levels even after mite removal. The implications of these results for practical recommendations to mitigate deleterious subclinical DWV infections and improving honeybee health management are discussed.

  2. Evaluation of clinical trials by Ethics Committees in Germany: Experience of applicants with the review of requests for opinion of the Ethics Committees - results of a survey among members of the German Association of Research-Based Pharmaceutical Companies (VFA

    Directory of Open Access Journals (Sweden)

    Russ, Hagen

    2009-07-01

    Full Text Available The review of requests for a positive opinion of the ethics committees (application procedure as a requirement to start a clinical trial in Germany has been completely redesigned with the transposition of EU Directive 2001/20/EC in the 12th Amendment of the German Medicines Act in August 2004. The experience of applicants (sponsors, legal representatives of sponsors in the EU and persons or organizations authorized by the sponsors to make the application, respectively in terms of interactions with the ethics committees in Germany has been positive overall, especially with respect to ethics committee adherence to the statutory timelines applicable for review of requests. However, inconsistencies between ethics committees exist in terms of the form and content of the requirements for application documents and their evaluation.With the objective of further improving both the quality of applications and the evaluation of those applications by ethics committees, a survey among members of the German Association of Research-Based Pharmaceutical Companies (VFA was conducted from January to April 2008. Based on reasoned opinions issued by the respective ethics committee in charge of the coordinating principal investigator (coordinating ethics committee, the type and frequency of formal and content-related objections to applications according to § 7 of the German Good Clinical Practice (GCP Regulation were systematically documented, and qualitative and quantitative analyses performed. 21 out of 44 members of the VFA participated in the survey. 288 applications for Phase I–IV studies submitted between January and December 2007 to 40 ethics committees were evaluated.This survey shows that about one in six applications is incomplete and has formal and/or content objections, respectively, especially those that pertain to documents demonstrating the qualification of the investigator and/or suitability of the facilities. These objections are attributable to

  3. Job Demand and Job Satisfaction in Latent Groups of Turnover Intention Among Licensed Nurses in Taiwan Nursing Homes.

    Science.gov (United States)

    Chen, I-Hui; Brown, Roger; Bowers, Barbara J; Chang, Wen-Yin

    2015-10-01

    Nurses' turnover intention is not dichotomous; it may reflect intent to leave the profession, intent to leave a type of facility, or intent to leave a specific workplace. In a latent class analysis (LCA) of data from 186 licensed nurses (RNs and LPNs) recruited from 25 nursing homes (NHs) in Taiwan, we classified nurses into turnover intention subgroups based on seven questionnaire items and used a multilevel contrast analysis to characterize the subgroups according to demographic and facility factors, job demand, and job satisfaction. A multilevel probit model was used to examine how job demand and job satisfaction influenced subgroup membership. Three turnover subgroups were identified: high turnover intention (12%), middle turnover intention (57%), and low turnover intention (31%). The high turnover intention subgroup comprised the youngest nurses and had the lowest percentage of registered nurses (RNs); nurses in this subgroup had worked the longest at the current NH and had the greatest likelihood of working at a for-profit facility. Nurses in the middle turnover intention subgroup had the lowest likelihood of working at a for-profit facility. Nurses in the low turnover intention subgroup were primarily RNs and had the shortest work experience in the current facility. Nurses in the high and middle turnover intention subgroups reported lower intrinsic job satisfaction than those with low turnover intention. Extrinsic job satisfaction mediated the relationship between job demand and turnover intention subgroup assignment. The results of this LCA can help target interventions to address heterogeneity of turnover intention and ultimately lessen turnover. © 2015 Wiley Periodicals, Inc.

  4. Intention to leave and employee turnover: expanding understanding of key antecedents in the modern workforce

    OpenAIRE

    Voigt, Emily Anne

    2017-01-01

    This research expanded understanding of the key antecedents of intention to leave and employee turnover in a sample of retail banking employees from a large Australian-based financial institution. In three empirical studies, this research provided unique insights into today‘s workforce and deepened understanding of how work related factors influence intention to leave and turnover. The first study compared the relationships between work attitudes and intention to leave for part-time and f...

  5. Recreational football improves bone mineral density and bone turnover marker profile in elderly men

    DEFF Research Database (Denmark)

    Helge, Eva Wulff; Rostgaard Andersen, Thomas; Schmidt, Jakob Friis

    2014-01-01

    This study examined the effect of recreational football and resistance training on bone mineral density (BMD) and bone turnover markers (BTMs) in elderly men. Twenty-six healthy sedentary men (age 68.2 ± 3.2 years) were randomized into three groups: football (F; n = 9) and resistance training (R; n...... training had no effect. The anabolic response may be due to increased bone turnover, especially improved bone formation....

  6. Work–family climate, organizational commitment, and turnover: Multilevel contagion effects of leaders ⋆

    OpenAIRE

    O’Neill, John W.; Harrison, Michelle M.; Cleveland, Jeannette; Almeida, David; Stawski, Robert; Crouter, Anne C.

    2009-01-01

    This paper presents empirical research analyzing the relationship between work–family climate (operationalized in terms of three work–family climate sub-scales), organizational leadership (i.e., senior manager) characteristics, organizational commitment and turnover intent among 526 employees from 37 different hotels across the US. Using multilevel modeling, we found significant associations between work–family climate, and both organizational commitment and turnover intent, both within and b...

  7. Roles of perceived exchange quality and organisational identification in predicting turnover intention

    OpenAIRE

    Kumar, Manish; Singh, Shailendra

    2012-01-01

    This paper explores whether the perceived quality of the leader–member exchange and the general environment of exchange could predict turnover intention. It further examines the role of organisational identification as an explanatory variable mediating between exchange relationships and turnover intention. The authors used three-step hierarchical linear regressions on a data set collected in two time waves. The results supported the mediating role of organisational identification for the lead...

  8. A multistudy examination of organizational stressors, emotional labor, burnout, and turnover in sport organizations.

    Science.gov (United States)

    Larner, R J; Wagstaff, C R D; Thelwell, R C; Corbett, J

    2017-12-01

    While a growing body of research has examined the types of organizational stressors encountered by individuals and their allied responses, little is known about how such individuals manage their emotional responses to these stressors or the consequences of such behaviors. This article presents novel findings from two studies examining the moderating role that emotional labor plays in the relationship between the frequency of organizational stressor experience, burnout, turnover intentions, and actual turnover in sport. In study 1, participants (n=487) completed measures of organizational stressors (OSI-SP), emotional labor (ELS), burnout (ABQ), and turnover intentions. In study 2, a 6-month longitudinal design was used to examine measures of organizational stressors (OSI-SP), emotional labor (ELS), turnover intentions, and actual turnover. Study 1 showed that surface acting moderated the relationship between the frequency of organizational stressors and burnout in sport. Further, surface acting acted as an important mechanism through which burnout mediated the relationship between the frequency of organizational stressors and turnover intentions. Study 2 showed that surface acting moderated the relationship between the organizational stressor frequency and turnover intentions-but not actual turnover-over time. These results highlight the importance of surface acting in understanding how individuals respond to organizational stressors encountered in sport, expanding our understanding of the positive and negative responses component of the meta-model of stress, emotions, and performance. These findings also highlight potentially deleterious emotion-management behaviors that practitioners might consider when aiming to support individuals encountering organizational stressors in sport. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. The Effect of Organizational Justice on Accountants’ Job Satisfaction and Turnover Intention

    OpenAIRE

    Gökhan ÖZER; Mehmet GÜNLÜK

    2010-01-01

    The purpose of this study is to investigate how the accounting profession members’ who work dependently in accounting firms (vocational trainees, CAs and CPAs) perception of organizational justice effect the formation of job satisfaction and turnover intention in order to understand and put forward the phenomenon of turnover among accountants. Organizational justice has been investigated under the sub-dimensions as distributive and procedurel justice. According to the findings attained as a r...

  10. Rest break organization in geriatric care and turnover: a multimethod cross-sectional study.

    Science.gov (United States)

    Wendsche, Johannes; Hacker, Winfried; Wegge, Jürgen; Schrod, Nadine; Roitzsch, Katharina; Tomaschek, Anne; Kliegel, Matthias

    2014-09-01

    Various determinants of nurses' work motivation and turnover behavior have been examined in previous studies. In this research, we extend this work by investigating the impact of care setting (nursing homes vs. home care services) and the important role of rest break organization. We aimed to identify direct and indirect linkages between geriatric care setting, rest break organization, and registered nurses' turnover assessed over a period of one year. We designed a multimethod cross-sectional study. 80 nursing units (n=45 nursing homes, n=35 home care) in 51 German geriatric care services employing 597 registered nurses. We gathered documentary, interview, and observational data about the organization of rest breaks, registered nurses' turnover, and additional organizational characteristics (type of ownership, location, nursing staff, clients, and client-to-staff-ratio). The findings show that the rest break system in geriatric nursing home units is more regularly as well as collectively organized and causes less unauthorized rest breaks than in home care units. Moreover, the feasibility of collective rest breaks was, as predicted, negatively associated with registered nurses' turnover and affected indirectly the relation between care setting and registered nurses' turnover. Care setting, however, had no direct impact on turnover. Furthermore, registered nurses' turnover was higher in for-profit care units than in public or non-profit units. This study reveals significant differences in rest break organization as a function of geriatric care setting and highlights the role of collective rest breaks for nursing staff retention. Our study underlines the integration of organizational context variables and features of rest break organization for the analysis of nursing turnover. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. THE EFFECT OF ORGANIZATIONAL CULTURE ON IT EMPLOYEES TURNOVER INTENTION IN ISRAEL

    Directory of Open Access Journals (Sweden)

    Kessler Ladelsky Limor

    2014-07-01

    Full Text Available Employee voluntary turnover is very expensive from the point of view of the organization, has significant negative effects on the organization and hence remains a critical issue for organizations.Most of the causes discussed in the literature are classic causes coming from conservative theories such as psychological and sociological organizational behavior etc. Field literature review shows that these general causes affecting voluntary turnover intention could be grouped in the following broad categories: 1 organizational causes, related to: Human Resource Management (HRM, organizational culture, job structure and content, leadership style and internal marketing strategies, policies and practices; 2 extra organizational causes, related to: individual characteristics and labor market aspects. One of the classical causes of voluntary turnover that has been researched but still needing attention is organizational culture. The purpose of this paper is to present a new explanation of the phenomenon of voluntary turnover of IT employees in the IT sector in Israel, i.e. from the corporate culture perspective. It focuses on the correlations between organizational culture and voluntary turnover intention among IT employees in Hi-Tech companies in Israel. This correlation was researched in an extensive empirical study among two population groups: IT employees and IT managers and by means of mixed methods research (combination of quantitative and qualitative research.The findings show that only one type of organizational culture influences voluntary turnover intention:Type C Marketing culture, which focuses on results and objectives. It is also shown that this type of organizational culture has a positive effect on voluntary turnover intention among IT employees in Hi-Tech companies in Israel. This finding has to be adopted by IT organizations and management who have to develop a way to prevent voluntary turnover among IT employees and have to develop an

  12. A new method for calculating the average period of current assets turnover in the analyzed period

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    Kulakova Julija Nikolaevna

    2015-05-01

    Full Text Available The aim of this study is to develop a new method for calculating the average period of current assets turnover during the analyzed period without using of financial results (revenue, cost, etc.. To prove the advantages of the proposed method in comparison with the traditional method of calculating turnover the example of estimating the mean residence time in the analyzed period of working capital in the form of receivables is developed.

  13. Statistical testing of the association between annual turnover and marketing activities in SMEs using χ2

    Science.gov (United States)

    Pater, Liana; Miclea, Şerban; Izvercian, Monica

    2016-06-01

    This paper considers the impact of SMEs' annual turnover upon its marketing activities (in terms of marketing responsibility, strategic planning and budgeting). Empirical results and literature reviews unveil that SMEs managers incline to partake in planned and profitable marketing activities, depending on their turnover's level. Thus, using the collected data form 131 Romanian SMEs managers, we have applied the Chi-Square Test in order to validate or invalidate three research assumptions (hypotheses), created starting from the empirical and literature findings.

  14. A methodology to measure the effectiveness of academic recruitment and turnover

    DEFF Research Database (Denmark)

    Abramo, Giovanni; D’Angelo, Ciriaco Andrea; Rosati, Francesco

    2016-01-01

    We propose a method to measure the effectiveness of the recruitment and turnover of professors, in terms of their research performance. The method presented is applied tothe case of Italian universities over the period 2008–2012. The work then analyses thecorrelation between the indicators...... of effectiveness used, and between the indicators andthe universities’ overall research performance. In countries that conduct regular nationalassessment exercises, the evaluation of effectiveness in recruitment and turnover couldcomplement the overall research assessments. In particular, monitoring...

  15. Exploring factors influencing voluntary turnover intent of Generation X public servants: A South African case

    OpenAIRE

    Hester Nienaber; Vhusthilo Masibigiri

    2012-01-01

    Purpose: The purpose of this article is to report on the factors perceived to influence the turnover intent of Generation X public servants. The problem: The researcher investigated the factors that Generation X public servants in South Africa perceive as influencing their turnover intent. Design: The problem was studied by way of a case study. The data were collected by means of semi-structured interviews. A total of eight purposively selected Generation X public servants participated ...

  16. Health promotion funding, workforce recruitment and turnover in New Zealand.

    Science.gov (United States)

    Lovell, Sarah A; Egan, Richard; Robertson, Lindsay; Hicks, Karen

    2015-06-01

    Almost a decade on from the New Zealand Primary Health Care Strategy and amidst concerns about funding of health promotion, we undertook a nationwide survey of health promotion providers. To identify trends in recruitment and turnover in New Zealand's health promotion workforce. Surveys were sent to 160 organisations identified as having a health focus and employing one or more health promoter. Respondents, primarily health promotion managers, were asked to report budget, retention and hiring data for 1 July 2009 through 1 July 2010. Responses were received from 53% of organisations. Among respondents, government funding for health promotion declined by 6.3% in the year ended July 2010 and health promoter positions decreased by 7.5% (equalling 36.6 full-time equivalent positions). Among staff who left their roles, 79% also left the field of health promotion. Forty-two organisations (52%) reported employing health promoters on time-limited contracts of three years or less; this employment arrangement was particularly common in public health units (80%) and primary health organisations (57%). Among new hires, 46% (n=55) were identified as Maori. Low retention of health promoters may reflect the common use of limited-term employment contracts, which allow employers to alter staffing levels as funding changes. More than half the surveyed primary health organisations reported using fixed-term employment contracts. This may compromise health promotion understanding, culture and institutional memory in these organisations. New Zealand's commitment to addressing ethnic inequalities in health outcomes was evident in the high proportion of Maori who made up new hires.

  17. Mechanism of ATP turnover inhibition in the EJC

    Science.gov (United States)

    Nielsen, Klaus H.; Chamieh, Hala; Andersen, Christian B.F.; Fredslund, Folmer; Hamborg, Kristiane; Le Hir, Hervé; Andersen, Gregers R.

    2009-01-01

    The exon junction complex (EJC) is deposited onto spliced mRNAs and is involved in many aspects of mRNA function. We have recently reconstituted and solved the crystal structure of the EJC core made of MAGOH, Y14, the most conserved portion of MLN51, and the DEAD-box ATPase eIF4AIII bound to RNA in the presence of an ATP analog. The heterodimer MAGOH/Y14 inhibits ATP turnover by eIF4AIII, thereby trapping the EJC core onto RNA, but the exact mechanism behind this remains unclear. Here, we present the crystal structure of the EJC core bound to ADP-AIF3, the first structure of a DEAD-box helicase in the transition-mimicking state during ATP hydrolysis. It reveals a dissociative transition state geometry and suggests that the locking of the EJC onto the RNA by MAGOH/Y14 is not caused by preventing ATP hydrolysis. We further show that ATP can be hydrolyzed inside the EJC, demonstrating that MAGOH/Y14 acts by locking the conformation of the EJC, so that the release of inorganic phosphate, ADP, and RNA is prevented. Unifying features of ATP hydrolysis are revealed by comparison of our structure with the EJC–ADPNP structure and other helicases. The reconstitution of a transition state mimicking complex is not limited to the EJC and eIF4AIII as we were also able to reconstitute the complex Dbp5–RNA–ADP–AlF3, suggesting that the use of ADP–AlF3 may be a valuable tool for examining DEAD-box ATPases in general. PMID:19033377

  18. Radiocarbon dating of the human eye lens crystallines reveal proteins without carbon turnover throughout life.

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    Niels Lynnerup

    Full Text Available BACKGROUND: Lens crystallines are special proteins in the eye lens. Because the epithelial basement membrane (lens capsule completely encloses the lens, desquamation of aging cells is impossible, and due to the complete absence of blood vessels or transport of metabolites in this area, there is no subsequent remodelling of these fibers, nor removal of degraded lens fibers. Human tissue ultimately derives its (14C content from the atmospheric carbon dioxide. The (14C content of the lens proteins thus reflects the atmospheric content of (14C when the lens crystallines were formed. Precise radiocarbon dating is made possible by comparing the (14C content of the lens crystallines to the so-called bomb pulse, i.e. a plot of the atmospheric (14C content since the Second World War, when there was a significant increase due to nuclear-bomb testing. Since the change in concentration is significant even on a yearly basis this allows very accurate dating. METHODOLOGY/PRINCIPAL FINDINGS: Our results allow us to conclude that the crystalline formation in the lens nucleus almost entirely takes place around the time of birth, with a very small, and decreasing, continuous formation throughout life. The close relationship may be further expressed as a mathematical model, which takes into account the timing of the crystalline formation. CONCLUSIONS/SIGNIFICANCE: Such a life-long permanence of human tissue has hitherto only been described for dental enamel. In confront to dental enamel it must be held in mind that the eye lens is a soft structure, subjected to almost continuous deformation, due to lens accommodation, yet its most important constituent, the lens crystalline, is never subject to turnover or remodelling once formed. The determination of the (14C content of various tissues may be used to assess turnover rates and degree of substitution (for example for brain cell DNA. Potential targets may be nervous tissues in terms of senile or pre

  19. Glucose turnover and hormonal changes during insulin-induced hypoglycemia in trained humans

    DEFF Research Database (Denmark)

    Kjær, Michael; Mikines, K J; Christensen, N J

    1984-01-01

    .9 mmol X l-1. Glucose turnover was determined by primed constant rate infusion of 3-[3H]glucose. Basal C-peptide (0.46 +/- 0.04 vs. 0.73 +/- 0.06 pmol X ml-1) and glucagon (4 +/- 0.4 vs. 10 +/- 2 pmol X l-1) were lower (P less than 0.05) and epinephrine higher (0.30 +/- 0.06 vs. 0.09 +/- 0.03 nmol X l-1......Eight athletes (T), studied the third morning after the last exercise session, and seven sedentary males (C) (maximal O2 consumption 65 +/- 4 vs. 49 +/- 4 (SE) ml X kg-1 X min-1, for T and C men, respectively) had insulin infused until plasma glucose, at an insulin level of 1,600 pmol X l-1, was 1......) in T than in C subjects. During and after insulin infusion production, disappearance and clearance of glucose changed identically in T and C subjects. However, in spite of identical plasma glucose concentrations, epinephrine (7.88 +/- 0.99 vs. 3.97 +/- 0.40 nmol X l-1), growth hormone (97 +/- 17 vs. 64...

  20. Alpha-synuclein gene ablation increases docosahexaenoic acid incorporation and turnover in brain phospholipids

    DEFF Research Database (Denmark)

    Golovko, Mikhail Y; Rosenberger, Thad A; Feddersen, Søren

    2007-01-01

    Previously, we demonstrated that ablation of alpha-synuclein (Snca) reduces arachidonate (20:4n-6) turnover in brain phospholipids through modulation of an endoplasmic reticulum-localized acyl-CoA synthetase (Acsl). The effect of Snca ablation on docosahexaenoic acid (22:6n-3) metabolism is unknown....... In the present study, we examined the effect of Snca gene ablation on brain 22:6n-3 metabolism. We determined 22:6n-3 uptake and incorporation into brain phospholipids by infusing awake, wild-type and Snca-/- mice with [1-14C]22:6n-3 using steady-state kinetic modeling. In addition, because Snca modulates 20:4n......-6-CoA formation, we assessed microsomal Acsl activity using 22:6n-3 as a substrate. Although Snca gene ablation does not affect brain 22:6n-3 uptake, brain 22:6n-3-CoA mass was elevated 1.5-fold in the absence of Snca. This is consistent with the 1.6- to 2.2-fold increase in the incorporation rate...