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  1. [Systematic evaluation of retention behavior of carbohydrates in hydrophilic interaction liquid chromatography].

    PubMed

    Fu, Qing; Wang, Jun; Liang, Tu; Xu, Xiaoyong; Jin, Yu

    2013-11-01

    A systematic evaluation of retention behavior of carbohydrates in hydrophilic interaction liquid chromatography (HILIC) was performed. The influences of mobile phase, stationary phase and buffer salt on the retention of carbohydrates were investigated. According to the results, the retention time of carbohydrates decreased as the proportion of acetonitrile in mobile phase decreased. Increased time of carbohydrates was observed as the concentration of buffer salt in mobile phase increased. The retention behavior of carbohydrates was also affected by organic solvent and HILIC stationary phase. Furthermore, an appropriate retention equation was used in HILIC mode. The retention equation lnk = a + blnC(B) + cC(B) could quantitatively describe the retention factors of carbohydrates of plant origin with good accuracy: the relative error of the predicted time to actual time was less than 0.3%. The evaluation results could provide guidance for carbohydrates to optimize the experimental conditions in HILIC method development especially for carbohydrate separation

  2. Innovative strategies for nurse recruitment and retention in behavioral health.

    PubMed

    Valente, Sharon M; Wright, Ileen

    2007-01-01

    Successfully recruiting licensed nurses to work in behavioral health is challenging. This article describes and illustrates methods one hospital successfully used to attract, orient, and mentor new graduate nurses to work in mental health. The New Horizons program included a paid internship for new graduate vocational nurses, a mental health curriculum, preceptorship, a state board review course, and a new graduate program. Since 2003, the program has recruited 37 new graduates for the unfilled licensed staff vacancies in mental health who continued their professional education and pursued degrees as registered nurses. The evaluations indicated that more than 100% of graduates rated the program as excellent as well as recommended it to their friends, and retention has been more than 90%. New Horizons graduates have received promotions; one has assumed a new role as a clinical resource nurse who teaches nursing orientation. All stakeholders including nurse management, patients, other disciplines, and coworkers have high praise for the program graduates. The program increased the cultural diversity of the mental health staff because the graduates included high percentages of African Americans, Hispanic Americans, and Asian Americans and less than 10% of White Americans. Adult learning technologies were used including teaching with films, role-playing, case studies, reflective thinking, evidence-based practice, and group performance improvement projects. Research-based fact sheets were used for the course and continued education. These 1-page fact sheets help nurses apply the evidence to improve nursing practice. PMID:17607135

  3. Relationship between Leadership Behaviors of High School Principals and Teacher Retention in Texas

    ERIC Educational Resources Information Center

    Aiken, Debra L.

    2010-01-01

    The study investigated the relationship between leadership behaviors of high school principals and teacher retention in Texas. A total of 88 Texas high school principals participated in the survey. Leadership behaviors were measured using the Culturally Adapted Leadership for Inspired Business Excellence and Results (CALIBER) Leadership Assessment…

  4. Multiple Family Groups for Child Behavior Difficulties: Retention Among Child Welfare-Involved Caregivers

    ERIC Educational Resources Information Center

    Gopalan, Geetha; Fuss, Ashley; Wisdom, Jennifer P.

    2015-01-01

    Purpose: The Multiple Family Group (MFG) service delivery model to reduce childhood disruptive behavior disorders has shown promise in engaging child welfare-involved families. This qualitative study examines caregivers' perceptions of factors that influence retention in MFGs among child welfare-involved families. Methods: Twenty-five…

  5. [Effect of forced swimming on the memory track retention in mice with various behavioral stereotypes].

    PubMed

    Dubrovina, N I; Loskutova, L V; Savost'ianova, D A

    2003-08-01

    The effects of forced swimming on retrieval of the passive avoidance during its extinction were found to depend on aggressive and submissive behavior. In mice without generated behavioral stereotypes, swim stress applied before or after training stabilized retention of the memory trace retrieval. The similar improved influence of forced swimming on memory storage is revealed in submissive, but not aggressive mice. The increase of resistance against extinction under the swim stress can be connected to facilitation of emotional processes.

  6. Multiple Family Groups for Child Behavior Difficulties Retention Among Child Welfare–Involved Caregivers

    PubMed Central

    Gopalan, Geetha; Fuss, Ashley; Wisdom, Jennifer P.

    2013-01-01

    Among children who remain at home with their permanent caregivers following a child welfare investigation, few who manifest emotional and behavioral difficulties actually engage in mental health treatment. The Multiple Family Group service delivery model to reduce childhood disruptive behavior disorders (MFG) has shown promise in engaging child welfare-involved families. This qualitative study examines caregiver perceptions of factors that influence retention in MFGs among child welfare-involved families. Methods Twenty-five predominantly Black and Hispanic adult (ages 26–57) female caregivers with child welfare services involvement participated in individual, in-depth interviews about their experience with MFGs. Transcribed interview data were thematically coded guided by grounded theory methodology. Emergent themes were subsequently organized into a conceptual framework. Results Within the overarching influence of child welfare services involvement, specific components of MFGs influencing retention included the quality of interaction among group members, group facilitators’ attentive approach with caregivers, supports designed to overcome logistical barriers (i.e., child care, transportation expenses, meals), and perceptions of MFG content and activities as fun and helpful. Caregiver factors, including their mental health and personal characteristics, as well as children’s behavior, (i.e., observed changes in behavioral difficulties) were also associated with retention. Conclusions High acceptability suggest utility for implementing MFGs within settings serving child welfare involved families, with additional modifications to tailor to setting and client features. PMID:26527856

  7. Improving utilization of and retention in PMTCT services: Can behavioral economics help?

    PubMed Central

    2013-01-01

    Background The most recent strategic call to action of the World Health Organization sets the elimination of pediatric HIV as a goal. While recent efforts have focused on building infrastructure and ensuring access to high-quality treatment, we must now turn our focus to the behavior change needed to eliminate vertical transmission. We make the case for the application of concepts from the field of behavioral economics to prevention of mother-to-child transmission (PMTCT) programs to more effectively address demand-side issues of uptake and retention. Discussion We introduce five concepts from the field of behavioral economics and discuss their application to PMTCT programs: 1) Mentor mothers who come from similar circumstances as PMTCT patients can serve as social references who provide temporally salient modeling of utilization of services and adherence to treatment. 2) Economic incentives, like cell phone minutes or food vouchers, that reward adherence to PMTCT protocols leverage present bias, the observation that people are generally biased toward immediate versus future awards. 3) Default bias, our preference for the default option, is already being used in many countries in the form of opt-out testing, and could be expanded to all PMTCT programs. 4) We are hardwired to avoid loss more than to pursue an equivalent gain. PMTCT programs can take advantage of loss aversion through the use of commitment contracts that incentivize mothers to return to the clinic in order to avoid both reputational and financial loss. Summary Eliminating vertical transmission of HIV is an ambitious goal. To close the remaining gap, innovations are needed to address demand for PMTCT services. Behavioral economics offers a set of tools that can be engineered into PMTCT programs to increase uptake and improve retention with minimal investment. PMID:24112440

  8. Activation, Self-management, Engagement, and Retention in Behavioral Health Care

    PubMed Central

    Alegría, Margarita; Carson, Nicholas; Flores, Michael; Li, Xinliang; Shi, Ping; Lessios, Anna Sophia; Polo, Antonio; Allen, Michele; Fierro, Mary; Interian, Alejandro; Jimenez, Aida; La Roche, Martin; Lee, Catherine; Lewis-Fernández, Roberto; Livas-Stein, Gabriela; Safar, Laura; Schuman, Catherine; Storey, Joan; Shrout, Patrick E.

    2015-01-01

    IMPORTANCE Given minority patients’ unequal access to quality care, patient activation and self-management strategies have been suggested as a promising approach to improving mental health care. OBJECTIVE To determine whether the DECIDE (Decide the problem; Explore the questions; Closed or open-ended questions; Identify the who, why, or how of the problem; Direct questions to your health care professional; Enjoy a shared solution) intervention, an educational strategy that teaches patients to ask questions and make collaborative decisions with their health care professional, improves patient activation and self-management, as well as engagement and retention in behavioral health care. DESIGN, SETTING, AND PATIENTS In this multisite randomized clinical trial performed from February 1, 2009, through October 9, 2011 (date of last follow-up interview), we recruited 647 English- or Spanish-speaking patients 18 to 70 years old from 13 outpatient community mental health clinics across 5 states and 1 US territory. A total of 722 patients were included in analyses of secondary outcomes. INTERVENTIONS Three DECIDE training sessions delivered by a care manager vs giving patients a brochure on management of behavioral health. MAIN OUTCOMES AND MEASURES Primary outcomes were patient assessment of activation (Patient Activation Scale) and self-management (Perceived Efficacy in Patient-Physician Interactions). Secondary outcomes included patient engagement (proportion of visits attended of those scheduled) and retention (attending at least 4 visits in the 6 months after the baseline research assessment), collected through medical record review or electronic records. RESULTS Patients assigned to DECIDE reported significant increases in activation (mean β = 1.74, SD = 0.58; P = .003) and self-management (mean β = 2.42, SD = 0.90; P = .008) relative to control patients, but there was no evidence of an effect on engagement or retention in care. CONCLUSIONS AND RELEVANCE The

  9. Corrosion behavior of dental alloys used for retention elements in prosthodontics.

    PubMed

    Nierlich, Judith; Papageorgiou, Spyridon N; Bourauel, Christoph; Hültenschmidt, Robert; Bayer, Stefan; Stark, Helmut; Keilig, Ludger

    2016-06-01

    The purpose of this study was to investigate the corrosion behavior of 10 different high noble gold-based dental alloys, used for prosthodontic retention elements, according to ISO 10271. Samples of 10 high-noble and noble gold-based dental alloys were subjected to: (i) static immersion tests with subsequent analysis of ion release for eight different elements using mass spectrometry; (ii) electrochemical tests, including open-circuit potential and potentiodynamic scans; and (iii) scanning electron microscopy, followed by energy-dispersive X-ray microscopy. The results were analyzed using one-way ANOVA and Sidak multiple-comparisons post-hoc test at a level of significance of α = 0.05. Significant differences were found among the 10 alloys studied for all ions (P < 0.001). The potentiodynamic analysis showed values from -82.5 to 102.8 mV for the open-circuit potential and from 566.7 to 1367.5 mV for the breakdown potential. Both the open-circuit and the breakdown potential varied considerably among these alloys. Scanning electron microscopy analysis confirmed the existence of typically small-diameter corrosion defects, whilst the energy-dispersive X-ray analysis found no significant alteration in the elemental composition of the alloys. The results of this study reveal the variability in the corrosive resistance among the materials used for retention elements in prosthodontics. PMID:27061513

  10. Understanding the behavioral determinants of retention in HIV care: a qualitative evaluation of a situated information, motivation, behavioral skills model of care initiation and maintenance.

    PubMed

    Smith, Laramie R; Fisher, Jeffrey D; Cunningham, Chinazo O; Amico, K Rivet

    2012-06-01

    The current study provides a qualitative test of a recently proposed application of an Information, Motivation, Behavioral Skills (IMB) model of health behavior situated to the social-environmental, structural, cognitive-affective, and behavioral demands of retention in HIV care. Mixed-methods qualitative analysis was used to identify the content and context of critical theory-based determinants of retention in HIV care, and to evaluate the relative fit of the model to the qualitative data collected via in-depth semi-structured interviews with a sample of inner-city patients accessing traditional and nontraditional HIV care services in the Bronx, NY. The sample reflected a diverse marginalized patient population who commonly experienced comorbid chronic conditions (e.g., psychiatric disorders, substance abuse disorders, diabetes, hepatitis C). Through deductive content coding, situated IMB model-based content was identified in all but 7.1% of statements discussing facilitators or barriers to retention in HIV care. Inductive emergent theme identification yielded a number of important themes influencing retention in HIV care (e.g., acceptance of diagnosis, stigma, HIV cognitive/physical impairments, and global constructs of self-care). Multiple elements of these themes strongly aligned with the model's IMB constructs. The convergence of the results from both sets of analysis demonstrate that participants' experiences map well onto the content and structure of the situated IMB model, providing a systematic classification of important theoretical and contextual determinants of retention in care. Future intervention efforts to enhance retention in HIV care should address these multiple determinants (i.e., information, motivation, behavioral skills) of self-directed retention in HIV care. PMID:22612447

  11. Mapping Patient–Identified Barriers and Facilitators to Retention in HIV Care and Antiretroviral Therapy Adherence to Andersen's Behavioral Model

    PubMed Central

    Holtzman, Carol W.; Shea, Judy A.; Glanz, Karen; Jacobs, Lisa M.; Gross, Robert; Hines, Janet; Mounzer, Karam; Samuel, Rafik; Metlay, Joshua P.; Yehia, Baligh R.

    2015-01-01

    Andersen's Behavioral Model (ABM) provides a framework for understanding how patient and environmental factors impact health behaviors and outcomes. We compared patient-identified barriers/facilitators to retention in care and antiretroviral therapy (ART) adherence, and evaluated how they mapped to ABM. Qualitative semi-structured interviews with 51 HIV-infected adults at HIV clinics in Philadelphia, PA in 2013 were used to explore patients’ experiences with HIV care and treatment. Interview data were analyzed for themes using a grounded theory approach. Among those interviewed, 53% were male and 88% were non-white; 49% were retained in care, 96% were on ART, and 57% were virally suppressed. Patients discussed 18 barriers/facilitators to retention in care and ART adherence: 11 common to both behaviors (stigma, mental illness, substance abuse, social support, reminder strategies, housing, insurance, symptoms, competing life activities, colocation of services, provider factors), 3 distinct to retention (transportation, clinic experiences, appointment scheduling), and 4 distinct to adherence (medication characteristics, pharmacy services, health literacy, health beliefs). Identified barriers/facilitators mapped to all ABM domains. These data support the use of ABM as a framework for classifying factors influencing HIV-specific health behaviors, and have the potential to inform the design of interventions to improve retention in care and ART adherence. PMID:25671515

  12. Prediction of salt effects on protein phase behavior by HIC retention and thermal stability.

    PubMed

    Baumgartner, Kai; Großhans, Steffen; Schütz, Juliane; Suhm, Susanna; Hubbuch, Jürgen

    2016-09-01

    In the biopharmaceutical industry it is mandatory to know and ensure the correct protein phase state as a critical quality attribute in every process step. Unwanted protein precipitation or crystallization can lead to column, pipe or filter blocking. In formulation, the formation of aggregates can even be lethal when injected into the patient. The typical methodology to illustrate protein phase states is the generation of protein phase diagrams. Commonly, protein phase behavior is shown in dependence of protein and precipitant concentration. Despite using high-throughput methods for the generation of phase diagrams, the time necessary to reach equilibrium is the bottleneck. Faster methods to predict protein phase behavior are desirable. In this study, hydrophobic interaction chromatography retention times were correlated to crystal size and form. High-throughput thermal stability measurements (melting and aggregation temperatures), using an Optim(®)2 system, were successfully correlated to glucose isomerase stability. By using hydrophobic interaction chromatography and thermal stability determinations, glucose isomerase conformational and colloidal stability were successfully predicted for different salts in a specific pH range. PMID:27268946

  13. Gas retention and release behavior in Hanford single-shell waste tanks

    SciTech Connect

    Stewart, C.W.; Brewster, M.E.; Gauglitz, P.A.; Mahoney, L.A.; Meyer, P.A.; Recknagle, K.P.; Reid, H.C.

    1996-12-01

    This report describes the current understanding of flammable gas retention and release in Hanford single-shell waste tanks based on theory, experimental results, and observations of tank behavior. The single-shell tanks likely to pose a flammable gas hazard are listed and described, and photographs of core extrusions and the waste surface are included. The credible mechanisms for significant flammable gas releases are described, and release volumes and rates are quantified as much as possible. The only mechanism demonstrably capable of producing large ({approximately}100 m{sup 3}) spontaneous gas releases is the buoyant displacement, which occurs only in tanks with a relatively deep layer of supernatant liquid. Only the double-shell tanks currently satisfy this condition. All release mechanisms believed plausible in single-shell tanks have been investigated, and none have the potential for large spontaneous gas releases. Only small spontaneous gas releases of several cubic meters are likely by these mechanisms. The reasons several other postulated gas release mechanisms are implausible or incredible are also given.

  14. The Effect of Internal Salary Increment Distributions on Retention Behaviors of Western New York Teachers

    ERIC Educational Resources Information Center

    Patterson, Michele M.

    2013-01-01

    This is a study of district internal salary distribution practices and its effect on retention. The study is a replication study as recommended by Jacobson (1986) and Lankford and Wyckoff (1997) whereby their research shows the prevalence of "back loading" and ineffectiveness relative to retention. In the case of this study, the…

  15. Retention behavior of lipids in reversed-phase ultrahigh-performance liquid chromatography-electrospray ionization mass spectrometry.

    PubMed

    Ovčačíková, Magdaléna; Lísa, Miroslav; Cífková, Eva; Holčapek, Michal

    2016-06-10

    Reversed-phase ultrahigh-performance liquid chromatography (RP-UHPLC) method using two 15cm sub-2μm particles octadecylsilica gel columns is developed with the goal to separate and unambiguously identify a large number of lipid species in biological samples. The identification is performed by the coupling with high-resolution tandem mass spectrometry (MS/MS) using quadrupole - time-of-flight (QTOF) instrument. Electrospray ionization (ESI) full scan and tandem mass spectra are measured in both polarity modes with the mass accuracy better than 5ppm, which provides a high confidence of lipid identification. Over 400 lipid species covering 14 polar and nonpolar lipid classes from 5 lipid categories are identified in total lipid extracts of human plasma, human urine and porcine brain. The general dependences of relative retention times on relative carbon number or relative double bond number are constructed and fit with the second degree polynomial regression. The regular retention patterns in homologous lipid series provide additional identification point for UHPLC/MS lipidomic analysis, which increases the confidence of lipid identification. The reprocessing of previously published data by our and other groups measured in the RP mode and ultrahigh-performance supercritical fluid chromatography on the silica column shows more generic applicability of the polynomial regression for the description of retention behavior and the prediction of retention times. The novelty of this work is the characterization of general trends in the retention behavior of lipids within logical series with constant fatty acyl length or double bond number, which may be used as an additional criterion to increase the confidence of lipid identification. PMID:27179677

  16. A Computer-Based Undergraduate Exercise Using Internet-Accessible Simulation Software for the Study of Retention Behavior and Optimization of Separation Conditions in Ion Chromatography

    ERIC Educational Resources Information Center

    Haddad, Paul R.; Shaw, Matthew J.; Madden, John E.; Dicinoski, Greg W.

    2004-01-01

    The ability to scan retention data over a wide range of eluent composition opens up the possibility of a computerized selection of the optimal separation conditions. The major characteristics of retention behavior, peak-shape effects and pH effects evident in ion chromatography (IC) using common stationary phases and eluents are illustrated.

  17. Behavior of deuterium retention and surface morphology for VPS–W/F82H

    SciTech Connect

    Yasuhisa Oya; Masashi Shimada; Tomonori Tokunaga; Hideo Watanabe; Naoaki Yoshida; Yuji Hatano; Ryuta Kasada; Takuya Nagasaka; Akihiko Kimura; Kenji Okuno

    2013-11-01

    The deuterium (D) retention for Vacuum Plasma Spray (VPS)–tungsten (W)/F82H was studied using two different implantation methods, namely D plasma exposure and View the MathML source implantation. The D retention for polished VPS–W/F82H after plasma exposure was found to be reduced compared to that for polycrystalline tungsten. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations indicated that porous structures around grain boundaries and the interface between VPS–W layers would be potential D diffusion paths, leading to low D retention. In the case of View the MathML source implantation, the shape of D2 TDS spectrum was almost the same as that for D plasma-exposed VPS–W/F82H; however, the D retention was quite high for unpolished VPS–W/F82H, indicating that most of D was trapped by the oxide layer, which was produced by the VPS process. The reduction of surface area due to the polishing process also reduces D retention for VPS–W/F82H. These results indicate that controlling the surface chemical states is important for the reduction of tritium retention for future fusion reactors.

  18. Statistical learning of peptide retention behavior in chromatographic separations: a new kernel-based approach for computational proteomics

    PubMed Central

    Pfeifer, Nico; Leinenbach, Andreas; Huber, Christian G; Kohlbacher, Oliver

    2007-01-01

    Background High-throughput peptide and protein identification technologies have benefited tremendously from strategies based on tandem mass spectrometry (MS/MS) in combination with database searching algorithms. A major problem with existing methods lies within the significant number of false positive and false negative annotations. So far, standard algorithms for protein identification do not use the information gained from separation processes usually involved in peptide analysis, such as retention time information, which are readily available from chromatographic separation of the sample. Identification can thus be improved by comparing measured retention times to predicted retention times. Current prediction models are derived from a set of measured test analytes but they usually require large amounts of training data. Results We introduce a new kernel function which can be applied in combination with support vector machines to a wide range of computational proteomics problems. We show the performance of this new approach by applying it to the prediction of peptide adsorption/elution behavior in strong anion-exchange solid-phase extraction (SAX-SPE) and ion-pair reversed-phase high-performance liquid chromatography (IP-RP-HPLC). Furthermore, the predicted retention times are used to improve spectrum identifications by a p-value-based filtering approach. The approach was tested on a number of different datasets and shows excellent performance while requiring only very small training sets (about 40 peptides instead of thousands). Using the retention time predictor in our retention time filter improves the fraction of correctly identified peptide mass spectra significantly. Conclusion The proposed kernel function is well-suited for the prediction of chromatographic separation in computational proteomics and requires only a limited amount of training data. The performance of this new method is demonstrated by applying it to peptide retention time prediction in IP

  19. Thickness-dependent retention behaviors and ferroelectric properties of BiFeO3 thin films on BaPbO3 electrodes

    NASA Astrophysics Data System (ADS)

    Lee, Chia-Ching; Wu, Jenn-Ming

    2007-09-01

    BiFeO3 (BFO) thin films produced with varied film thicknesses ranging from 100to230nm were fabricated on BaPbO3(BPO )/Pt/Ti/SiOx/Si substrates by rf-magnetron sputtering. Saturated polarization-electrical field hysteresis loops, polarization response by pulse measurement, and retention properties were obtained for BFO films with various thicknesses on BPO. The retention behaviors of BFO demonstrate logarithmic time dependence and stretched exponential law. When the thicknesses of BFO films increase, the contribution of logarithmic time dependence to retention, the stretched exponential law becomes dominant. BFO films with thinner thickness exhibit better retention properties but possess smaller remnant polarization.

  20. Sociodemographic, perinatal, behavioral, and psychosocial predictors of weight retention at 3 and 12 months postpartum.

    PubMed

    Siega-Riz, Anna Maria; Herring, Amy H; Carrier, Kathryn; Evenson, Kelly R; Dole, Nancy; Deierlein, Andrea

    2010-10-01

    Postpartum weight retention plays an important role in the pathway leading to obesity among women of childbearing age. The objective of this study was to examine predictors of moderate (1-10 pounds) and high (>10 pounds) postpartum weight retention using data from a prospective pregnancy cohort that followed women into the postpartum period; n = 688 and 550 women at 3 and 12 months, respectively. Analysis included descriptive statistics and predictive modeling using log-binomial techniques. The average weight retained at 3 and 12 months postpartum in this population was 9.4 lb (s.d. = 11.4) and 5.7 lb (s.d. = 13.2), respectively. At 3 months postpartum, prepregnancy weight, gestational weight gain, and hours slept during the night were associated with moderate or high weight retention, whereas having an infant hospitalized after going home and scoring in the upper 75th percentile of the Eating Attitudes Test (EAT) were associated only with high weight retention. At 12 months postpartum, prepregnancy weight, gestational weight gain, and maternal education were associated with moderate weight retention; and gestational weight gain, maternal age, race, employment status, and having an infant hospitalized at birth were associated with high weight retention. The results of this study illustrate the importance of prepregnancy weight and gestational weight gain in predicting postpartum weight retention. Furthermore, given the lack of successful intervention studies that exist to date to help women lose weight in the postpartum period, the results of this study may help to inform future interventions that focus on such aspects as hours of sleep, dealing with stress associated with a hospitalized infant, and nonclinical eating disorder symptomatology.

  1. Sociodemographic, Perinatal, Behavioral, and Psychosocial Predictors of Weight Retention at 3 and 12 months Postpartum

    PubMed Central

    Siega-Riz, Anna Maria; Herring, Amy H.; Carrier, Kathryn; Evenson, Kelly R.; Dole, Nancy; Deierlein, Andrea

    2010-01-01

    Postpartum weight retention plays an important role in the pathway leading to obesity among women of childbearing age. The objective of this study was to examine predictors of moderate (1–10 pounds) and high (>10 pounds) postpartum weight retention using data from a prospective pregnancy cohort that followed women into the postpartum period; n=688 and 550 women at 3 and 12 months, respectively. Analysis included descriptive statistics and predictive modeling using log-binomial techniques. The average weight retained at 3 and 12 months postpartum in this population was 9.4 lbs (SD=11.4) and 5.7 lbs (SD=13.2) respectively. At 3- months postpartum, prepregnancy weight, gestational weight gain, and hours slept during the night were associated with moderate or high weight retention while having an infant hospitalized after going home and scoring in the upper 75th percentile of the eating attitudes test were associated only with high weight retention. At 12- months postpartum, prepregnancy weight, gestational weight gain and maternal education were associated with moderate weight retention and gestational weight gain, maternal age, race, employment status, and having an infant hospitalized at birth were associated with high weight retention. The results of this study illustrate the importance of prepregnancy weight and gestational weight gain in predicting postpartum weight retention. Furthermore, given the lack of successful intervention studies that exist to date to help women lose weight in the postpartum period, the results of this study may help to inform future interventions that focus on such aspects as hours of sleep, dealing with stress associated with a hospitalized infant, and non-clinical eating disorder symptomatology. PMID:20035283

  2. Behavior of adsorbed and fluid phases versus retention properties of amino acids on the teicoplanin chiral selector.

    PubMed

    Poplewska, Izabela; Kramarz, Renata; Piatkowski, Wojciech; Seidel-Morgenstern, Andreas; Antos, Dorota

    2008-05-23

    The relationship between adsorption equilibria of two amino acids, i.e., l,d-threonine and l,d-methionine on the teicoplanin chiral selector and their phase behavior has been analyzed. The experimental and numerical methods have been proposed to determine activity coefficients of amino acids in different solvent systems. The procedure was based on the analysis of solubility properties of the amino acids in aqueous solutions of methanol, ethanol and propanol-2-ol used as the mobile phases in chromatographic elution. The solubility measured in mixed alcohol-water solutions was correlated with the non-random-two-liquid (NRTL) model for the activity coefficients. The values of activity coefficients were incorporated into the adsorption isotherm equation, which allowed the analysis of retention properties of the amino acids versus their fluid phase behavior. For the investigation the experimental data of adsorption equilibria of amino acids as well as of the mobile phase constituents acquired in a previous work were exploited. The composition of both the mobile and the adsorbed phases was found to affect the retention properties of the amino acids. For water-rich mobile phases the activity in the adsorbed phase determined the retention mechanism, while for the alcohol-rich systems activity in the mobile phase was predominant.

  3. Effect of boundary conditions on measured water retention behavior within soils

    NASA Astrophysics Data System (ADS)

    Galindo-torres, S.; Scheuermann, A.; Pedroso, D.; Li, L.

    2013-12-01

    conducted to examine how the fluids are distributed inside the porous medium. This distribution is quantified by the measurement of the interfacial area which behaves also differently between the two configurations. Hassanizadeh proposed an unique relation among saturation, suction and interfacial area, which has been validated experimentally [4]. However we found that such relation is not 'unique' and instead depends on the flow and boundary conditions. While future experimental tests on these results need to be carried out, the simulated SWCC behaviors raise serious questions about the current experimental set-up for measuring the soil water retention characteristics. References. 1. Serrano, S.E., Modeling infiltration with approximate solutions to Richard's equation. Journal of Hydrologic Engineering, 2004. 9(5): p. 421-432. 2. Galindo-Torres, S.A., et al., A Lattice Boltzmann model for studying transient effects during imbibition-drainage cycles in unsaturated soils. Computer Physics Communications, 2013. 184(4): p. 1086-1093. 3. Drake, S.S., D.M. O'Carroll, and J.I. Gerhard, Wettability contrasts between fresh and weathered diesel fuels. Journal of contaminant hydrology, 2012. 4. Culligan, K.A., et al., Interfacial area measurements for unsaturated flow through a porous medium. Water Resources Research, 2004. 40(12).

  4. Investigation into the phenomena affecting the retention behavior of basic analytes in chaotropic chromatography: Joint effects of the most relevant chromatographic factors and analytes' molecular properties.

    PubMed

    Čolović, Jelena; Kalinić, Marko; Vemić, Ana; Erić, Slavica; Malenović, Anđelija

    2015-12-18

    The aim of this study was to systematically investigate the phenomena affecting the retention behavior of structurally diverse basic drugs in ion-interaction chromatographic systems with chaotropic additives. To this end, the influence of three factors was studied: pH value of the aqueous phase, concentration of sodium hexafluorophosphate, and content of acetonitrile in the mobile phase. Mobile phase pH was found to affect the thermodynamic equilibria in the studied system beyond its effects on the analytes' ionization state. Specifically, increasing pH from 2 to 4 led to longer retention times, even with analytes which remain completely protonated. An explanation for this phenomenon was sought by studying the adsorption behavior of acetonitrile and chaotropic additive onto stationary phase. It was shown that the magnitude of the developed surface potential, which significantly affects retention - increases with pH, and that this can be attributed to the larger surface excess of acetonitrile. To study how analytes' structural properties influence their retention, quantitative structure-retention modeling was performed next. A support vector machine regression model was developed, relating mobile phase constituents and structural descriptors with retention data. While the ETA_EtaP_B_RC and XlogP can be considered as molecular descriptors which describe factors affecting retention in any RP-HPLC system, TDB9p and RDF45p are molecular descriptors which account for spatial arrangement of polarizable atoms and they can clearly relate to analytes' behavior on the stationary phase surface, where the electrostatic potential develops. Complementarity of analytes' structure with that of the electric double layer can be seen as a key factor influencing their retention behavior. Structural diversity of analytes and good predictive capabilities over a range of experimental conditions make the established model a useful tool in predicting retention behavior in the studied

  5. It's Not How Much; It's How: Characteristics of Practice Behavior and Retention of Performance Skills

    ERIC Educational Resources Information Center

    Duke, Robert A.; Simmons, Amy L.; Cash, Carla Davis

    2009-01-01

    We observed 17 graduate and advanced-undergraduate piano majors practicing a difficult, three-measure keyboard passage from a Shostakovich concerto. Participants' instructions were to practice until they were confident they could play the passage accurately at a prescribed tempo in a retention test session the following day. We analyzed the…

  6. Integration of the interaction model of client health behavior and transactional model of stress and coping as a tool for understanding retention in HIV care across the lifespan.

    PubMed

    Graham, Lucy J

    2015-01-01

    Retaining people living with HIV (PLWH) in care over the lifespan is critical to quality and longevity of life. Individual health behavior decisions that affect care retention are complicated and multifactorial. Current health behavior theories are inadequate in isolation to guide retention in care research. Two existing models, Cox's Interaction Model of Client Health Behavior, and Lazarus and Folkman's Transactional Model of Stress and Coping have both guided research with PLWH, although not related to retention in care. Integration of these models may more comprehensively inform care retention research and practice across the lifespan as it incorporates not only intra- and inter-personal characteristics and relationships but also the stress and coping experiences inevitable when living with a chronic illness such as HIV.

  7. Retention behavior on aminoethyl-modified poly(p-phenylene terephthalamide) fiber stationary phases in gas chromatography.

    PubMed

    Shirai, Shingoro; Saito, Yoshihiro; Sakurai, Yasuhiro; Ueta, Ikuo; Jinno, Kiyokatsu

    2010-01-01

    Surface derivatization of Kevlar, poly(p-phenylene terephthalamide), fiber has been studied along with the evaluation of the surface characteristics of the chemically-modified fiber as the stationary phase in packed-capillary gas chromatography (GC). Several experimental parameters in the derivatization reaction have been optimized, and the retention behavior of the surface-derivatized fibrous stationary phase has been investigated using various standard solutes, such as alkanes, alcohols and alkylbenzenes. By introducing aminoethyl functional groups onto the surface of the fibrous material, a specific selectivity for polar solutes has been observed.

  8. Surfactant retention in Berea sandstone - effects of phase behavior and temperature

    SciTech Connect

    Novosad, J.

    1981-01-01

    This study reports on laboratory investigations of surfactant retention in Berea cores with the main emphasis on the experimental differentiation between surfactant losses due to adsorption and those due to trapping in the immobile hydrocarbon phase left in the core after surfactant flooding. Surfactants investigated include pure sulfonate (Texas No. 1), petroleum sulfonate (TRS 10-80), and synthetic sulfonate (PDM 337) in systems forming lower and middle phase microemulsions. The temperature range studied was between 20 and 70 C. Results indicate that losses of surfactant caused by trapping in the immobile oil phase can be substantial and, more importantly, that minor changes in experimental conditions, such as variations in surfactant slug size, affect the measured losses substantially. Similar experiments may yield very different results in terms of total retention and, if the effects of the different types of surfactant losses cannot be experimentally determined, erroneous conclusions may be reached. 15 references.

  9. Retention behavior of isomeric polycyclic aromatic sulfur heterocycles in reversed-phase liquid chromatography.

    PubMed

    Wilson, Walter B; Sander, Lane C; de Alda, Miren Lopez; Lee, Milton L; Wise, Stephen A

    2016-08-26

    Retention indices for 70 polycyclic aromatic sulfur heterocycles (PASHs) were determined using reversed-phase liquid chromatography (LC) on a monomeric and a polymeric C18 stationary phase. Molecular shape parameters [length, breadth, thickness (T), and length-to-breadth ratio (L/B)] were calculated for all the compounds studied. Correlations between the retention on the polymeric C18 phase and PASH geometry (L/B and T) were investigated for six specific PASH isomer groups with molecular mass (MM) 184Da, 234Da, 258Da, 284Da, 334Da, and 384Da. Similar to previous studies for polycyclic aromatic hydrocarbons (PAHs), PASH elution order on the polymeric C18 phase was generally found to follow increasing L/B values. Correlation coefficients for retention vs L/B ranged from r=0.45 (MM 184Da) to r=0.89 (MM 284Da). In the case of smaller PASHs (MM≤258Da), the location of the sulfur atom in the bay-region of the structure resulted in later than expected elution of these isomers based on L/B. In the case of the larger PASHs (MM≥284Da), nonplanarity had a significant influence on earlier than predicted elution based on L/B values. PMID:27481401

  10. Capacity retention behavior and morphology evolution of SixGe1-x nanoparticles as lithium-ion battery anode.

    PubMed

    Ge, Mingyuan; Kim, Seongbeom; Nie, Anmin; Shahbazian-Yassar, Reza; Mecklenburg, Matthew; Lu, Yunhao; Fang, Xin; Shen, Chenfei; Rong, Jiepeng; Yi Park, Song; Suk Kim, Dong; Young Kim, Jin; Zhou, Chongwu

    2015-01-26

    Engineering silicon into nanostructures has been a well-adopted strategy to improve the cyclic performance of silicon as a lithium-ion battery anode. Here, we show that the electrode performance can be further improved by alloying silicon with germanium. We have evaluated the electrode performance of SixGe1-x nanoparticles (NPs) with different compositions. Experimentally, SixGe1-x NPs with compositions approaching Si50Ge50 are found to have better cyclic retention than both Si-rich and Ge-rich NPs. During the charge/discharge process, NP merging and Si-Ge homogenization are observed. In addition, a distinct morphology difference is observed after 100 cycles, which is believed to be responsible for the different capacity retention behavior. The present study on SixGe1-x alloy NPs sheds light on the development of Si-based electrode materials for stable operation in lithium-ion batteries (e.g., through a comprehensive design of material structure and chemical composition). The investigation of composition-dependent morphology evolution in the delithiated Li-SiGe ternary alloy also significantly broadens our understanding of dealloying in complex systems, and it is complementary to the well-established understanding of dealloying behavior in binary systems (e.g., Au-Ag alloys).

  11. Retention behavior of alkyl-substituted polycyclic aromatic sulfur heterocycles in reversed-phase liquid chromatography.

    PubMed

    Wilson, Walter B; Sander, Lane C; de Alda, Miren Lopez; Lee, Milton L; Wise, Stephen A

    2016-08-26

    Retention indices for 79 alkyl-substituted polycyclic aromatic sulfur heterocycles (PASHs) were determined by using reversed-phase liquid chromatography (LC) on a monomeric and polymeric octadecylsilane (C18) stationary phase. Molecular shape parameters [length, breadth, thickness (T), and length-to-breadth ratio (L/B)] were calculated for all the compounds studied. Based on separations of isomeric methylated polycyclic aromatic hydrocarbons on polymeric C18 phases, alkyl-substituted PASHs are expected to elute based on increasing L/B ratios. However, the correlation coefficients had a wide range of values from r=0.43 to r=0.93. Several structural features besides L/B ratios were identified to play an important role in the separation mechanism of PASHs on polymeric C18 phases. First, the location of the sulfur atom in a bay-like-region results in alkylated-PASHs being more retentive than non-bay-like-region alkylated-PASHs, and they elute later than expected based on L/B value. Second, the placement of the alkyl group in the k region of the structure resulted in a later elution than predicted by L/B. Third, highly nonplanar methyl-PASHs (i.e., 1-Me and 11-MeBbN12T) elute prior to the parent PASH (BbN12T).

  12. Retention behavior of hydrophobic organic chemicals as a function of temperature in soil leaching column chromatography.

    PubMed

    Liang, Xinmiao; Xu, Feng; Lin, Bingcheng; Su, Fan; Schramm, Karl-Werner; Kettrup, Antonius

    2002-11-01

    To study the transport mechanism of hydrophobic organic chemicals (HOCs) and the energy change in soil/solvent system, a soil leaching column chromatographic (SLCC) experiment at an environmental temperature range of 20-40 degrees C was carried out, which utilized a reference soil (SP 14696) packed column and a methanol-water (1:4 by volume ratio) eluent. The transport process quickens with the increase of column temperature. The ratio of retention factors at 30 and 40 degrees C (k'30/k'40) ranged from 1.08 to 1.36. The lower enthalpy change of the solute transfer in SLCC (from eluent to soil) than in conventional reversed-phase liquid chromatography (e.g., from eluent to C18) is consistent with the hypothesis that HOCs were dominantly and physically partitioned between solvent and soil. The results were also verified by the linear solvation energy relationships analysis. The chief factor controlling the retention was found to be the solute solvophobic partition, and the second important factor was the solute hydrogen-bond basicity, while the least important factors were the solute polarizability-dipolarity and hydrogen-bond acidity. With the increase of temperature, the contributions of the solute solvophobic partition and hydrogen-bond basicity gradually decrease, and the latter decreases faster than the former. PMID:12430644

  13. An Empirical Examination of Outdoor Behavioral Healthcare Field Instructor Job-Related Stress and Retention

    ERIC Educational Resources Information Center

    Marchand, Genevieve; Russell, Keith C.; Cross, Reid

    2009-01-01

    The purpose of this study was to collect and analyze demographic characteristics and job related difficulties experienced by field instructors in outdoor behavioral healthcare programs which utilized wilderness therapy as well as other treatment modalities. Three state-licensed outdoor behavioral healthcare programs in the United States provided a…

  14. A Study of Middle School Principal Behaviors and Their Impact on Teacher Retention

    ERIC Educational Resources Information Center

    Martin, Todd

    2011-01-01

    This dissertation was designed to investigate the causes behind teacher turnover and the connection between principal behavior, teacher working conditions, and rates of teacher turnover. In particular, this study examined behaviors that teachers in three North Carolina middle schools felt their principals displayed that helped encourage them to…

  15. Initial transport and retention behaviors of ZnO nanoparticles in quartz sand porous media coated with Escherichia coli biofilm.

    PubMed

    Jiang, Xujia; Wang, Xueting; Tong, Meiping; Kim, Hyunjung

    2013-03-01

    The significance of biofilm on the transport and deposition behaviors of ZnO nanoparticles were examined under a series of environmentally relevant ionic strength at two fluid velocities of 4 m-d(-1) and 8 m-d(-1). Biofilm enhanced nanoparticles retention in porous media under all examined conditions. The greater deposition was also observed in extracellular polymeric substances (EPS) coated surfaces by employment of quartz microbalance with dissipation (QCM-D) system. Derjaguin-Landau-Verwey-Overbeek (DLVO) failed to interpret more ZnO nanoparticles deposition on biofilm (EPS) coated silica surfaces. Chemical interaction and physical morphology of biofilm contributed to this greater deposition (retention). Biofilm affected the spacial distribution of retained ZnO nanoparticles as well. Relatively steeper slope of retained profiles were observed in the presence of biofilm, corresponding to the greater deviation from colloid filtration theory (CFT). Pore space constriction via biofilm induced more nanoparticle trapped in the column inlet, leading to greater deviations (σln k(f)) from the CFT.

  16. Effects of comprehensive function of factors on retention behavior of microparticles in gravitational field-flow fractionation.

    PubMed

    Guo, Shuang; Qiu, Bai-Ling; Zhu, Chen-Qi; Yang, Ya-Ya Gao; Wu, Di; Liang, Qi-Hui; Han, Nan-Yin

    2016-09-15

    Gravitational field-flow fractionation (GrFFF) is a useful technique for separation and characterization for micrometer-sized particles. Elution behavior of micrometer-sized particles in GrFFF was researched in this study. Particles in GrFFF channel are subject to hydrodynamic lift forces (HLF), fluid inertial forces and gravity, which drive them to different velocities by carrier flow, resulting in a size-based separation. Effects of ionic strength, flow rate and viscosity as well as methanol were investigated using polystyrene latex beads as model particles. This study is devoted to experimental verification of the effect of every factor and their comprehensive function. All experiments were performed to show isolated influence of every variable factor. The orthogonal design test was used to evaluate various factors comprehensively. Results suggested that retention ratio of particles increases with increasing flow rate or the viscosity of carrier liquid by adjusting external forces acting on particles. In addition, retention ratio increases as ionic strength decreases because of decreased electrostatic repulsion between particles and channel accumulation wall. As far as methanol, there is no general trend due to the change of both density and viscosity. On the basis of orthogonal design test it was found that viscosity of carrier liquid plays a significant role in determining resolution of micrometer-sized particles in GrFFF. PMID:27447927

  17. Retention behavior of long chain quaternary ammonium homologues and related nitroso-alkymethylamines

    USGS Publications Warehouse

    Abidi, S.L.

    1985-01-01

    Several chromatographic methods have been utilized to study the retentionbehavior of a homologous series of n-alkylbenzyldimethylammonium chlorides (ABDAC) and the corresponding nitroso-n-alkylmethylamines (NAMA). Linear correlation of the logarithmic capacity factor (k') with the number of carbons in the alkyl chain provides useful information on both gas chromatographic (GC) and high-performance liquid chromatographich (HPLC) retention parameters of unknown components. Under all conditions empolyed, GC methodology has proved effective in achieving complete resolution of the homologous mixture of NMA despite its obvious inadequacy in the separation of E-Z configurational isomers. Conversely, normal-phase HPLC on silica demonstrates that the selectivity (a) value for an E-Z pair is much higher than that for an adjacent homologous pair. In the reversed-phase HPLC study, three different silica-based column systems were examined under various mobile phase conditions. The extent of variation in k' was found to be a function of the organic modifier, counter-ion concentration, eluent pH, nature of counter-ion, and the polarity and type of stationary phase. The k'—[NaClO4] profiles showed similar trends between the ABDAC and the NAMA series, supporting the dipolar electronic structures of the latter compounds. Mobile phase and stationary phase effects on component separation are described. The methodology presented establishes the utility of HPLC separation techniques as versatile analytical tools for practical application.

  18. Behavior Management Skills as Predictors of Retention among South Texas Special Educators

    ERIC Educational Resources Information Center

    Mitchell, Ann; Arnold, Mitylene

    2004-01-01

    A survey of South Texas Special Education teachers was conducted to determine how they perceived their behavior management skills in the classroom and what effect, if any, this had on their job satisfaction. The majority of teachers were confident in their ability to accomplish the management demands of the classroom. The teachers who showed the…

  19. Influence of preferential adsorption of mobile phase on retention behavior of amino acids on the teicoplanin chiral selector.

    PubMed

    Poplewskaa, Izabela; Kramarz, Renata; Piatkowski, Wojciech; Seidel-Morgenstern, Andreas; Antos, Dorota

    2007-11-30

    The adsorption behavior of two amino acids, i.e., l,d-threonine and l,d-methionine has been investigated on the chiral stationary phase (CSP)column packed with teicoplanin bonded to a silica support. The study has been performed under non-linear conditions of adsorption isotherm for various types of organic modifiers (methanol, ethanol, propan-2-ol and acetonitrile) in the reversed-phase mode. A heterogeneous adsorption mechanism of amino acids has been identified that was strongly affected by the nature of organic modifier. Generally, isotherm non-linearity and retention decreased with decrease of the modifier content in the mobile phase exhibiting a minimum at water-rich mobile phases. These trends were suggested to result from a combined effect of the mobile as well as the adsorbed phase composition. To determine the composition of the adsorbed phase the excess adsorption of modifiers in aqueous solutions has been measured and their binary adsorption equilibria have been quantified and compared. Strongly non-ideal behavior of solvents in the mobile phase and the adsorbed phase has been accounted for by activity coefficients. The fraction of the modifiers in the adsorbed phase decreased in the sequence: methanol, ethanol, propan-2-ol and acetonitrile.

  20. Forced egg retention and oviposition behavior of malaria, dengue and filariasis vectors to a topical repellent diethyl-phenylacetamide.

    PubMed

    Seenivasagan, T; Iqbal, S Thanvir; Guha, Lopamudra

    2015-07-01

    Egg retention and oviposition behavior of four species of mosquito vectors viz., Anopheles stephensi, Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus to a topical insect repellent diethyl-phenylacetamide (DEPA) at 0.1-1000 mg/L was investigated under laboratory conditions. Based on oviposition activity indices, DEPA demonstrated concentration dependent oviposition deterrent effect to A. stephensi (-0.18 to -0.97), A. aegypti (-0.18 to -0.91) and A. albopictus (-0.50 to -0.98) females. In contrast, positive oviposition response by C. quinquefasciatus (+0.39 and +0.70) was observed respectively at 0.1 and 1 ppm, while 10 ppm of DEPA on water received 50% lesser egg rafts than control. Gravid Culex females laid no egg rafts at 100 and 1000 ppm DEPA treated bowls effecting 100% oviposition deterrence. Test mosquito females deposited most of their eggs (> 90%) in the absence of repellent odour, while DEPA odour on water surface forced them to retain huge numbers of eggs. Females of A. aegypti, A. albopictus and A. stephensi retained 49, 67 and 50% of total eggs, respectively throughout the experiment. Egg retention by Culex females due to DEPA on the water surface was ca. 65%, equivalent to 4 egg rafts. Therefore, DEPA at lower concentrations could effectively disturb the oviposition by these vectors. Application of repellents in small water bodies would help in reducing the population build up of mosquitoes near human households and could be useful in the integrated management of mosquito vectors. PMID:26245028

  1. Forced egg retention and oviposition behavior of malaria, dengue and filariasis vectors to a topical repellent diethyl-phenylacetamide.

    PubMed

    Seenivasagan, T; Iqbal, S Thanvir; Guha, Lopamudra

    2015-07-01

    Egg retention and oviposition behavior of four species of mosquito vectors viz., Anopheles stephensi, Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus to a topical insect repellent diethyl-phenylacetamide (DEPA) at 0.1-1000 mg/L was investigated under laboratory conditions. Based on oviposition activity indices, DEPA demonstrated concentration dependent oviposition deterrent effect to A. stephensi (-0.18 to -0.97), A. aegypti (-0.18 to -0.91) and A. albopictus (-0.50 to -0.98) females. In contrast, positive oviposition response by C. quinquefasciatus (+0.39 and +0.70) was observed respectively at 0.1 and 1 ppm, while 10 ppm of DEPA on water received 50% lesser egg rafts than control. Gravid Culex females laid no egg rafts at 100 and 1000 ppm DEPA treated bowls effecting 100% oviposition deterrence. Test mosquito females deposited most of their eggs (> 90%) in the absence of repellent odour, while DEPA odour on water surface forced them to retain huge numbers of eggs. Females of A. aegypti, A. albopictus and A. stephensi retained 49, 67 and 50% of total eggs, respectively throughout the experiment. Egg retention by Culex females due to DEPA on the water surface was ca. 65%, equivalent to 4 egg rafts. Therefore, DEPA at lower concentrations could effectively disturb the oviposition by these vectors. Application of repellents in small water bodies would help in reducing the population build up of mosquitoes near human households and could be useful in the integrated management of mosquito vectors.

  2. Increased weight gain, nitrogen retention and muscle protein synthesis following treatment of diabetic rats with insulin-like growth factor (IGF)-I and des(1-3)IGF-I.

    PubMed Central

    Tomas, F M; Knowles, S E; Owens, P C; Read, L C; Chandler, C S; Gargosky, S E; Ballard, F J

    1991-01-01

    We have examined the effects of infusing recombinant human growth hormone (hGH), insulin-like growth factor-I (IGF-I), the truncated IGF-I analogue, des(1-3)IGF-I, and insulin over a 7-day period in streptozotocin-induced diabetic rats. IGF-I at a dose of 1.05 or 1.08 mg/kg per day in two experiments increased body weight and nitrogen retention above those of vehicle-infused controls to about 30% of the improvement achieved with 25 or 30 units of insulin/kg per day, but only in the second experiment were the differences statistically significant (P less than 0.05). A 2.5-fold higher IGF-I dose, or des(1-3)IGF-I at 1.08 mg/kg per day, gave effects that were approx. 70% of those obtained with insulin. hGH at 1.38 mg/kg per day was not effective. The IGF peptides, unlike insulin, did not ameliorate the diabetic glucosuria. The improvements in nitrogen balance could be accounted for in part by increases in muscle protein synthesis. Muscle protein breakdown, as assessed by 3-methylhistidine excretion, was inhibited by insulin, but not by the IGF peptides. Carcass fat increased substantially following insulin administration. This did not occur with the IGF peptides, suggesting that IGF predominantly stimulates the growth of lean tissue. IGF-I concentrations and IGF-I-binding proteins in plasma were increased by IGF-I, especially at the higher dose, whereas hGH produced only a transient increase in IGF-I. Des(1-3)IGF-I induced binding proteins, but had only a slight effect on measured IGF-I concentrations. We conclude that IGF peptides stimulate muscle protein synthesis and improve nitrogen balance in diabetes without obviously influencing the abnormal carbohydrate metabolism. Moreover, des(1-3)IGF-I is at least as potent as the full-length IGF-I. Images Fig. 2. PMID:1710892

  3. Strength retention behavior of oriented PLLA, 96L/4D PLA, and 80L/20D,L PLA

    PubMed Central

    Huttunen, Mikko; Kellomäki, Minna

    2013-01-01

    The strength retention characteristics of oriented semicrystalline polylactides were monitored during hydrolytic degradation in vitro. The effects of the polymer type, the material’s initial inherent viscosity (iv), the sample diameter and the residual monomer content on strength retention were analyzed. The analyzed polylactides had similar, but not identical, strength retention characteristics. It was concluded that a higher degree of initial crystallinity was a major variable determining the earlier and more profound strength loss of PLLA than 96L/4D PLA and 80L/20 D,L PLA. Samples with a higher initial iv were found to have a longer strength retention time than lower iv samples. Size-dependency was observed, as the strength retention time was shorter for the smaller diameter samples. This size-dependency was caused by faster iv decay. The amount of residual monomer content had a remarkable impact on strength retention. Neither the sample diameter, initial iv or residual monomer content were found to have an effect on the iv range in which there was a rapid decline in strength properties. Therefore, it was concluded that the inherent viscosity and/or molecular weight of oriented PLLA, 96L/4D PLA and 80L/20 D,L PLA is a major variable determining the strength retention of these materials. PMID:24025528

  4. Parent recruitment and retention in a universal prevention program for child behavior and emotional problems: barriers to research and program participation.

    PubMed

    Heinrichs, Nina; Bertram, Heike; Kuschel, Annett; Hahlweg, Kurt

    2005-12-01

    Despite the potential of parent training as a prevention and behavioral family intervention strategy, there are a number of important issues related to implementation (e.g., recruitment and retention of families). This paper presents recruitment and retention data from families enrolling in a randomized controlled universal prevention trial for child behavior problems conducted in Germany. The recruitment rate averaged 31% (general project participation), with families of lower socioeconomic status (SES) participating at a lower rate. Project-declining families most often reported intrusion of privacy as their primary concern. In contrast, once parents were enrolled in the project, participation among those randomized to the parent training group averaged 77% (program/intervention participation); non-participation was mostly due to logistical issues. Parents accepting the offer of parent training were more likely to report child behavior problems than did declining parents. Although parents from more disadvantaged areas had a lower overall level of participation in the project once recruited, parents with children having higher levels of behavior problems indeed were more likely to participate in the intervention. Different recruitment methods may be required to engage high-risk families from socioeconomically disadvantaged areas to further improve community-level impact on child mental health.

  5. Rationalization of retention and overloading behavior of basic compounds in reversed-phase HPLC using low ionic strength buffers suitable for mass spectrometric detection.

    PubMed

    McCalley, David V

    2003-07-15

    The retention and overloading behavior of some basic (and acidic) compounds has been studied on different RP-HPLC columns in buffers of varying ionic strength. Anomalous retention patterns of acids and bases were found on one phase in low-pH, volatile buffers such as formic acid, favored for mass spectrometric analysis. Unusual retention compared to that in higher ionic strength phosphate buffers is attributed to the presence of positively charged sites existing on this phase at low pH. Overloading of bases as well as acids is shown to be a function of mobile-phase ionic strength. This result is a logical consequence of previous suggestions that mutual repulsion of ions held on the hydrophobic surface of the stationary phase, rather than overload of silanols, is largely responsible for overloading on pure silica RP columns. Thus, overloading occurs much more readily in low ionic strength formic acid buffers. Appreciable loss of efficiency can occur in such buffers when only 50 ng of some bases is analyzed on a standard-sized column. PMID:14570190

  6. Polycyclic aromatic hydrocarbons as test probes to investigate the retention behavior of 1,3-alternate calix[4]arene silica-bonded stationary phases.

    PubMed

    Sliwka-Kaszyńska, Magdalena; Slebioda, Marek

    2014-03-01

    A series of polycyclic aromatic hydrocarbons (PAHs) of different size and shape has been used to characterize the chromatographic behavior of five calix[4]arene stationary phases in 1,3-alternate conformation synthesized in our laboratory. The selection of linear, four-ring nonlinear, and five-ring PAHs gave data on selectivity changes across range of the calix[4]arene columns. Retention of the 12 aromatic solutes has been evaluated at various methanol contents in the mobile phase (70-100% v/v) and column temperatures (20-45°C). The thermodynamic parameters underlying the retention mechanisms revealed that each of the five calix[4]arene columns exhibited variation in selectivity and retention of PAHs caused by enthalpy and entropy effects. The calixarene stationary phases substituted with electron-withdrawing groups exhibit enhanced selectivity toward PAHs in comparison to the rest of the investigated columns. The observed divergences are due to differences in solute-stationary phase interactions and originate in π-π and π-electron transfer specific to the analytes and the type of calix[4]arene functionalization at the upper rim, as well as steric and sorption phenomena.

  7. Inductively coupled plasma mass spectrometry study of the retention behavior of arsenic species on various solid phase extraction cartridges and its application in arsenic speciation

    NASA Astrophysics Data System (ADS)

    Yu, Chunhai; Cai, Qiantao; Guo, Zhong-Xian; Yang, Zhaoguang; Khoo, Soo Beng

    2003-07-01

    Inductively coupled plasma mass spectrometry (ICP-MS) was used to investigate the retention behavior of arsenite, arsenate, monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AsB), arsenocholine (AsC), trimethylarsine oxide (TMAO) and tetramethylarsonium ion (TMAI) on various silica-based solid phase extraction (SPE) cartridges. A method for arsenic speciation is then developed on the basis of selective SPE separation of arsenic species and highly sensitive ICP-MS detection. Factors affecting the retention and elution of arsenic species were examined. Results showed that the retention of arsenic species depended on the chemical characteristics of arsenic species and the types of sorbent materials. Change of pH in the range of 2.0-9.0 did not show significant effects on the retention of DMA, AsB, AsC, TMAI and TMAO on an ethylbenzene sulfonic acid-based strong cation exchange (SCX-3) cartridge. pH also did not influence the retention of AsB, AsC, TMAI and TMAO on a mixed-mode (M-M) cartridge containing non-polar, strong cation exchange and strong anion exchange (SAX) functional groups. However, the retentions of As(V) and MMA on the SAX and the M-M cartridge changed with pH. As(V) and MMA were completely retained on the SAX cartridge and sequentially selectively eluted with 1.0 mol l -1 acetic acid (for MMA). DMA, AsB, AsC, TMAI and TMAO were completely retained on the SCX-3 cartridge and sequentially selectively eluted with 1.0 mol l -1 HNO 3 (for DMA). As(V), MMA, AsB, AsC, TMAI and TMAO were completely retained on the M-M cartridge. As(III) was not retained on either cartridge and remained in solution. Arsenic species in solution and those eluted from the cartridges were subsequently determined by ICP-MS. A detection limit of 8 ng l -1 arsenic in water sample was obtained. This method was successfully applied to arsenic speciation in various sources of water samples (drinking water, waste water, raw water, etc.) and US National Institute of

  8. Study of thermal behavior of vitamin D3 by pyrolysis-GC-MS in combination with boiling point-retention time correlation.

    PubMed

    Sun, Yu'an; Liu, Baoxia; Wang, Guoqing; Zhang, Rongjie; Xie, Bing

    2005-01-01

    The thermal behavior of vitamin D3 was studied based on pyrolysis-GC-MS technique. It was pyrolyzed at 600 degrees C, 750 degrees C, 900 degrees C, respectively. The pyrolysis product were separated With an HP-5 column and identified by the NIST mass spectral search program in combination with the correlation of boiling point and retention time (BP-RT). There are totally 50 components, including mono aromatics and polycyclic aromatic hydrocarbons (PAHs), were determined. It is shown that the contents of the PAHs are increasing with the increasing of the pyrolysis temperature. The contents of the determined components vary from 0.04% to 37.08%.

  9. Lipophilicity indices derived from the liquid chromatographic behavior observed under bimodal retention conditions (reversed phase/hydrophilic interaction): application to a representative set of pyridinium oximes.

    PubMed

    Voicu, Victor; Sârbu, Costel; Tache, Florentin; Micăle, Florina; Rădulescu, Ştefan Flavian; Sakurada, Koichi; Ohta, Hikoto; Medvedovici, Andrei

    2014-05-01

    The liquid chromatographic behavior observed under bimodal retention conditions (reversed phase and hydrophilic interaction) offers a new basis for the determination of some derived lipophilicity indices. The experiments were carried out on a representative group (30 compounds) of pyridinium oximes, therapeutically tested in acetylcholinesterase reactivation, covering a large range of lipophilic character. The chromatographic behavior was observed on a mixed mode acting stationary phase, resulting from covalent functionalization of high purity spherical silica with long chain alkyl groups terminated by a polar environment created through the vicinal diol substitution at the lasting carbon atoms (Acclaim Mixed Mode HILIC 1 column). Elution was achieved by combining different proportions of 5 mM ammonium formiate solutions in water and acetonitrile. The derived lipophilicity indices were compared with logP values resulting from different computational algorithms. The correlations between experimental and computed data sets are significant. To obtain a better insight on the transition from reversed phase to hydrophilic interaction retention mechanisms, the variation of the thermodynamic parameters determined through the van׳t Hoff approach was also discussed. PMID:24720980

  10. Retention of Motor Skills: Review.

    ERIC Educational Resources Information Center

    Schendel, J. D.; And Others

    A summary of an extensive literature survey deals with the variables known or suspected to affect the retention of learned motor behaviors over lengthy no-practice intervals. Emphasis was given to research conducted by or for the military. The variables that may affect the retention of motor skills were dichotomized into task variables and…

  11. Effects of episodic variations in web-based avian influenza education: influence of fear and humor on perception, comprehension, retention and behavior.

    PubMed

    Kim, Paul; Sorcar, Piya; Um, Sujung; Chung, Heedoo; Lee, Young Sung

    2009-06-01

    In order to provide empirical evidence on the role of a web-based avian influenza (AI) education program for mass communication and also ultimately help young children learn and develop healthy behaviors against AI and all types of influenza, an education program with two episodic variations (i.e. fear and humor) has been developed and examined with 183 fifth-grade elementary students. A quasi-experimental design was employed to find potential differential effects on the context-specific risk perception, AI knowledge acquisition, retention and behavior. The study results reveal that the fear appealed AI web-based education program was much more effective than the humor-based program in improving risk perception and educating the students about healthy behaviors (i.e. against influenza infection). However, a significant behavior change or improvement of health practices was not apparent on the post-tests (i.e. 1 month after the treatment) in either episode of the program. PMID:18524758

  12. American Recovery and Reinvestment Act of 2009. Interim Report on Customer Acceptance, Retention, and Response to Time-Based Rates from the Consumer Behavior Studies

    SciTech Connect

    Cappers, Peter; Hans, Liesel; Scheer, Richard

    2015-06-01

    Time-based rate programs1, enabled by utility investments in advanced metering infrastructure (AMI), are increasingly being considered by utilities as tools to reduce peak demand and enable customers to better manage consumption and costs. There are several customer systems that are relatively new to the marketplace and have the potential for improving the effectiveness of these programs, including in-home displays (IHDs), programmable communicating thermostats (PCTs), and web portals. Policy and decision makers are interested in more information about customer acceptance, retention, and response before moving forward with expanded deployments of AMI-enabled new rates and technologies. Under the Smart Grid Investment Grant Program (SGIG), the U.S. Department of Energy (DOE) partnered with several utilities to conduct consumer behavior studies (CBS). The goals involved applying randomized and controlled experimental designs for estimating customer responses more precisely and credibly to advance understanding of time-based rates and customer systems, and provide new information for improving program designs, implementation strategies, and evaluations. The intent was to produce more robust and credible analysis of impacts, costs, benefits, and lessons learned and assist utility and regulatory decision makers in evaluating investment opportunities involving time-based rates. To help achieve these goals, DOE developed technical guidelines to help the CBS utilities estimate customer acceptance, retention, and response more precisely.

  13. [Influences of ion-suppressors on retention behaviors of nine food additives in reversed-phase high performance liquid chromatographic separation].

    PubMed

    Zhao, Yonggang; Chen, Xiaohong; Li, Xiaoping; Yao, Shanshan; Jin, Micong

    2011-10-01

    The influences of ion-suppressors on retention behaviors of nine food additives, i.e., acesulfame, saccharin, caffeine, aspartame, benzoic acid, sorbic acid, stevioside, dehydroacetic acid and neotame in reversed-phase high performance liquid chromatographic (RP-HPLC) separation were investigated. The organic modification effects of acids, i. e. , trifluoroacetic acid (TFA) and buffer salts, i. e. , TFA-ammonium acetate (AmAc) were studied emphatically. The relationships between retention factors of solutes and volume percentages of ion-suppressors in the mobile phase systems of acetonitrile-TFA aqueous solution and acetonitrile-TFA-AmAc aqueous solution were quantitatively established, separately. The separation of nine food additives was completed by a gradient elution with acetonitrile-TFA (0.01%, v/v)-AmAc (2. 5 mmol/L) aqueous solution as the mobile phases. An RP-HPLC method was established for the simultaneous determination of nine food additives in red wine. In the range of 10. 0 - 100. 0 mg/L, nine food additives showed good linearity with the correlation coefficients ( r2 ) larger than 0. 999 1. The limits of detection (LODs) were in the range of 0. 33 - 2. 36 mg/L and the limits of quantification (LOQs) were in the range of 1. 11 - 7. 80 mg/L. The spiked recoveries were between 87. 61% and 108. 4% with the relative standard deviations (RSDs) of 2. 2% -9. 4%. These results are of referential significance for the rapid establishment and accu- rate optimization of RP-HPLC separation for the simultaneous determination of food additives in other foods.

  14. Occurrence of pharmaceuticals and endocrine disruptors in raw sewage and their behavior in UASB reactors operated at different hydraulic retention times.

    PubMed

    Queiroz, F B; Brandt, E M F; Aquino, S F; Chernicharo, C A L; Afonso, R J C F

    2012-01-01

    This work investigated the occurrence of pharmaceuticals and endocrine disrupting compounds (EDCs) in raw sewage (from Belo Horizonte city, Minas Gerais state, Brazil) and assessed their behavior in demo-scale upflow anaerobic sludge blanket reactors (UASB reactors) operated at different hydraulic retention times (HRT). The dissolved concentration of the studied micropollutants in the raw and treated sewage was obtained using solid phase extraction (SPE) followed by analysis in a liquid chromatography system coupled to a hybrid high resolution mass spectrometer consisting of an ion-trap and time of flight (LC-MS-IT-TOF). The natural (estradiol) and synthetic (ethinylestradiol) estrogens were hardly detected; when present, however, their concentrations were lower than the method quantification limits. The concentrations of bisphenol A and miconazole in raw sewage were similar to that reported in the literature (around 200 ng L⁻¹ and hardly detected, respectively). The antibiotics sulfamethoxazole (median 13.0 ng L⁻¹) and trimethoprim (median 61.5 ng L⁻¹), and the other pharmaceutical compounds (diclofenac and bezafibrate, with median 99.9 and 94.4 ng L⁻¹, respectively) were found in lower concentrations when compared with reports in the literature, which might indicate a lower consumption of such drugs in Brazil. The UASB reactors were inefficient in the removal of bisphenol A, and led to an increased concentration of nonylphenol in the effluent. The anaerobic reactors were also inefficient in the removal of diclofenac, and led to a partial removal of bezafibrate; whereas, for sulfamethoxazole there seemed to be a direct relationship between the HRT and removal efficiencies. For trimethoprim the sludge retention time (SRT) seemed to play an important role, although it was only partially removed in the UASB reactors. PMID:23109571

  15. Effect of antisera to beta and gamma goldfish brain proteins on the retention of a newly acquired behavior.

    PubMed

    Shashoua, V E; Moore, M E

    1978-06-16

    The metabolism of 3 brain cytoplasmic proteins (alpha, beta, and gamma) increases markedly when goldfish acquire a new pattern of behavior. Antisera specific to beta and beta + gamma proteins were prepared and injected into the fourth ventricle of the brains of trained animals at 8 and 24 h after the initiation of training. When tested 3 days later, such goldfish (N = 98) could not recall the training; whereas trained goldfish (N = 97) receiving non-immunized rabbit serum had complete recall of the behavior. Also no amnesia was obtained in control experiments in which trained goldfish were injected with an antiserum to a neural surface membrane protein NS-6. The fact that antisera to beta + gamma had no toxic effects was demonstrated by injecting them prior to training; no effects on the rate of acquisition and recall of the behavior was found. The antisera to beta + gamma were effective in inhibiting recall of the training when they were injected any time between 3 h up to 48 h after training; no effect was obtained at 72 h post training. These results are consistent with the hypothesis that beta and gamma might have some functional role in the plasticity of the CNS.

  16. Investigation of Phase and Emulsion Behavior, Surfactant Retention and Condensate Recovery for Condensate/Water/Ethanol Mixtures

    SciTech Connect

    Ramanathan Sampath

    2003-03-31

    This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FG26-02NT15447 during the period October 01, 2002 to April 01, 2003 which covers the first six months of the project. Presently work is in progress to characterize phase and emulsion behavior for condensate/water/ethanol system. Temperature and salinity scans are planned to identify the optimal salinity and temperature, and the temperature and salinity intervals in which all three phases coexist for this system. Test matrix to perform salinity and temperature scans has been established. Supply requests to obtain hydrocarbons, surfactant, etc., were processed and supplies obtained. Current literature in the subject area, and modeling efforts that were established in our previous studies to predict electrical conductivities and inversion phenomena were reviewed. Based on the review a computer model to predict electrical conductivities of the ethylbenzene (that has the equivalent carbon number of the condensate)/water/ethanol system is being developed. These activities resulted in one published conference abstract during this reporting period.

  17. Investigation of Phase and Emulsion Behavior, Surfactant Retention and Condensate Recovery for Condensate/Water/Ethanol Mixtures

    SciTech Connect

    Ramanathan Sampath

    2005-03-31

    This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FG26-02NT15447 during the period October 01, 2004 to March 31, 2005 which covers the fifth six months of the project. Presently work is in progress to characterize phase and emulsion behavior for ethylbenzene/water/ethanol system. Ethylbenzene that has the equivalent carbon number is used as the model condensate. During this reporting period, electrical conductivity measurements for bottom, and top phases, as well as bottom/top, and top/bottom conjugate pair phases of the ethylbenzene/water/ethanol system were performed for various ethanol volume percentage of the mixtures starting from 2% to 60%. Preliminary findings are that electrical conductivity of the bottom phase decreased as ethanol volume fraction of the mixture increased. Conductivity of the top phase was small and remained almost the same for variations in ethanol volume fraction of the mixture. Conductivity of the emulsion of the conjugate pair phases decreased as the fraction of volume of the top phase was increased and vice versa. Also inversion phenomena was observed. Detailed analyses are in progress including the prediction of conductivity data using the theoretical model already developed in this project.

  18. Investigation of Phase and Emulsion Behavior, Surfactant Retention and Condensate Recovery for Condensate/Water/Ethanol Mixtures

    SciTech Connect

    Ramanathan Sampath

    2005-09-30

    This semi-annual technical progress report describes work performed at Morehouse College under DOE Grant No. DE-FG26-02NT15447 during the period April 01, 2005 to September 30, 2005 which covers the sixth six months of the project. Presently work is in progress to characterize phase and emulsion behavior for ethylbenzene/water/ethanol system. Ethylbenzene that has the equivalent carbon number is used as the model condensate. In the last reporting period, electrical conductivity measurements for bottom/top, and top/bottom conjugate pair phases of the ethylbenzene/water/ethanol system were performed for various ethanol volume percentage in the mixture: 2,10,20,33,43,50, and 56. During this reporting period, prediction of electrical conductivity data obtained in the past was conducted employing a theoretical model already developed in this project. Results of the comparisons for 2, and 10% ethanol volume in the mixture are presented here. A good agreement was obtained between the predicted emulsion conductivities and the measured values. To date about 99% of the proposed work has been completed. Conductivity prediction for 56% ethanol volume in the mixture is in progress. Following this prediction, a final report will be developed describing the research activities conducted through the entire project period including results and conclusions.

  19. Transport, retention, and long-term release behavior of ZnO nanoparticle aggregates in saturated quartz sand: Role of solution pH and biofilm coating

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The transport, retention, and long-term fate of zinc oxide nanoparticles (ZnO-NPs) were investigated in saturated, bare and biofilm (Pseudomonas putida) coated sand packed columns. Almost complete retention of ZnO-NPs occurred in bare and biofilm coated sand when the influent solution pH was 9 and t...

  20. Pulmonary retention of coal dusts

    SciTech Connect

    Morrow, P.E.; Gibb, F.R.; Beiter, H.; Amato, F.; Yuile, C.; Kilpper, R.W.

    1980-01-01

    The principal objectives of this study were: to determine, quantitatively, coal dust retention times in the dog lung; to test the appropriateness of a pulmonary retention model which incorporates first order rate coefficients obtained from in vitro and in vivo experiments on neutron-activated coal; to acquire a temporal description of the pulmonary disposition of the retained coal dust, and to compare the behavior of two different Pennsylvania coals in the foregoing regards. The principal findings include: retention half-times for both coals of approximately 2 years following single, hour-long exposures; a vivid association of the retained coal dust with the pulmonic lymphatics; and a general validation of the retention model.

  1. Managing retention.

    PubMed

    Carter, Tony

    2007-01-01

    To build this process it is necessary to consult customers for preferences, build familiarity and knowledge to build a relationship and conduct business in a customized fashion. The process takes every opportunity to build customer satisfaction with each customer contact. It is an important process to have, since customers today are more demanding, sophisticated, educated and comfortable speaking to the company as an equal (Belk, 2003). Customers have more customized expectations so they want to be reached as individuals (Raymond and Tanner, 1994). Also, a disproportionate search for new business is costly. The cost to cultivate new customers is more than maintaining existing customers (Cathcart, 1990). Other reasons that customer retention is necessary is because many unhappy customers will never buy again from a company that dissatisfied them and they will communicate their displeasure to other people. These dissatisfied customers may not even convey their displeasure but without saying anything just stop doing business with that company, which may keep them unaware for some time that there is any problem (Cathcart, 1990). PMID:18453139

  2. Classroom Management for Student Retention.

    ERIC Educational Resources Information Center

    Santa Rita, Emilio

    This guidebook recommends methods for teachers to use to improve teacher-student interaction in the classroom, as a means of increasing student retention. Chapter I introduces eight major systems of classroom management which teachers may use as their values and the classroom situation dictate: "Behavior Modification,""Reality Therapy,""Discipline…

  3. Retentivity, selectivity and thermodynamic behavior of polycyclic aromatic hydrocarbons on charge-transfer and hypercrosslinked stationary phases under conditions of normal phase high performance liquid chromatography.

    PubMed

    Jiang, Ping; Lucy, Charles A

    2016-03-11

    Charge-transfer and hypercrosslinked polystyrene phases offer retention and separation for polycyclic aromatic hydrocarbons (PAHs) and thus have potential for petroleum analysis. The size, shape and planarity selectivity for PAH standards on charge-transfer (DNAP column) and hypercrosslinked polystyrene (HC-Tol and 5HGN columns) phases are different under normal phase liquid chromatography (NPLC). The HC-Tol column behaves like a conventional NPLC column with low retention of PAHs. Retention of PAHs on the DNAP and 5HGN are strong and increases with the number of aromatic rings. The main retention mechanism is through π-π interactions and dipole-induced dipole interaction. Thermodynamics indicates that the retention mechanism of PAHs remains unchanged over the temperature range 20-60°C. In addition, on either DNAP or 5HGN column, both linear and bent PAHs are retained through the same mechanism. But DNAP possesses smaller π-π interaction and higher planarity selectivity than 5HGN for PAHs. This is suggestive that DNAP interacts with PAHs through a disordered phase arrangement, while 5HGN behaves as an ordered adsorption phase.

  4. Transport, retention, and long-term release behavior of ZnO nanoparticle aggregates in saturated quartz sand: Role of solution pH and biofilm coating.

    PubMed

    Han, Yosep; Hwang, Gukhwa; Kim, Donghyun; Bradford, Scott A; Lee, Byoungcheun; Eom, Igchun; Kim, Pil Je; Choi, Siyoung Q; Kim, Hyunjung

    2016-03-01

    The transport, retention, and long-term release of zinc oxide nanoparticle aggregates (denoted below as ZnO-NPs) were investigated in saturated, bare and biofilm (Pseudomonas putida) coated sand packed columns. Almost complete retention of ZnO-NPs occurred in bare and biofilm coated sand when the influent solution pH was 9 and the ionic strength (IS) was 0.1 or 10 mM NaCl, and the retention profiles were always hyper-exponential. Increasing the solution IS and biofilm coating produced enhanced retention of ZnO-NPs near the column inlet. The enhanced NPs retention at high IS was attributed to more favorable NP-silica and NP-NP interactions; this was consistent with the interaction energy calculations. Meanwhile, the greater NPs retention in the presence of biofilm was attributed to larger roughness heights which alter the mass transfer rate, the interaction energy profile, and lever arms associated with the torque balance; e.g., scanning electron and atomic force microscopy was used to determine roughness heights of 33.4 nm and 97.8 nm for bare sand and biofilm-coated sand, respectively. Interactions between NPs and extracellular polymeric substances may have also contributed to enhanced NP retention in biofilm-coated sand at low IS. The long-term release of retained ZnO-NPs was subsequently investigated by continuously injecting NP-free solution at pH 6, 9, or 10 and keeping the IS constant at 10 mM. The amount and rate of retained ZnO-NP removal was strongly dependent on the solution pH. Specifically, almost complete removal of retained ZnO-NPs was observed after 627 pore volumes when the solution pH was 6, whereas much less Zn was recovered when the eluting solution pH was buffered to pH = 9 and especially 10. This long-term removal was attributed to pH-dependent dissolution of retained ZnO-NPs because: (i) the solubility of ZnO-NPs increases with decreasing pH; and (ii) ZnO-NPs were not detected in the effluent. The presence of biofilm also decreased the

  5. Transport, retention, and long-term release behavior of ZnO nanoparticle aggregates in saturated quartz sand: Role of solution pH and biofilm coating.

    PubMed

    Han, Yosep; Hwang, Gukhwa; Kim, Donghyun; Bradford, Scott A; Lee, Byoungcheun; Eom, Igchun; Kim, Pil Je; Choi, Siyoung Q; Kim, Hyunjung

    2016-03-01

    The transport, retention, and long-term release of zinc oxide nanoparticle aggregates (denoted below as ZnO-NPs) were investigated in saturated, bare and biofilm (Pseudomonas putida) coated sand packed columns. Almost complete retention of ZnO-NPs occurred in bare and biofilm coated sand when the influent solution pH was 9 and the ionic strength (IS) was 0.1 or 10 mM NaCl, and the retention profiles were always hyper-exponential. Increasing the solution IS and biofilm coating produced enhanced retention of ZnO-NPs near the column inlet. The enhanced NPs retention at high IS was attributed to more favorable NP-silica and NP-NP interactions; this was consistent with the interaction energy calculations. Meanwhile, the greater NPs retention in the presence of biofilm was attributed to larger roughness heights which alter the mass transfer rate, the interaction energy profile, and lever arms associated with the torque balance; e.g., scanning electron and atomic force microscopy was used to determine roughness heights of 33.4 nm and 97.8 nm for bare sand and biofilm-coated sand, respectively. Interactions between NPs and extracellular polymeric substances may have also contributed to enhanced NP retention in biofilm-coated sand at low IS. The long-term release of retained ZnO-NPs was subsequently investigated by continuously injecting NP-free solution at pH 6, 9, or 10 and keeping the IS constant at 10 mM. The amount and rate of retained ZnO-NP removal was strongly dependent on the solution pH. Specifically, almost complete removal of retained ZnO-NPs was observed after 627 pore volumes when the solution pH was 6, whereas much less Zn was recovered when the eluting solution pH was buffered to pH = 9 and especially 10. This long-term removal was attributed to pH-dependent dissolution of retained ZnO-NPs because: (i) the solubility of ZnO-NPs increases with decreasing pH; and (ii) ZnO-NPs were not detected in the effluent. The presence of biofilm also decreased the

  6. Des Moines.

    ERIC Educational Resources Information Center

    Gore, Deborah, Ed.

    1988-01-01

    This document, intended for elementary students, contains articles and activities designed to acquaint young people with the history of Des Moines, Iowa. The articles are short, and new or difficult words are highlighted and defined for young readers. "The Raccoon River Indian Agency" discusses the archeological exploration of the indian…

  7. Difference equation model for isothermal gas chromatography expresses retention behavior of homologues of n-alkanes excluding the influence of holdup time.

    PubMed

    Wu, Liejun; Chen, Yongli; Caccamise, Sarah A L; Li, Qing X

    2012-10-19

    A difference equation (DE) model is developed using the methylene retention increment (Δtz) of n-alkanes to avoid the influence of gas holdup time (tM). The effects of the equation orders (1st-5th) on the accuracy of a curve fitting show that a linear equation (LE) is less satisfactory and it is not necessary to use a complicated cubic or higher order equation. The relationship between the logarithm of Δtz and the carbon number (z) of the n-alkanes under isothermal conditions closely follows the quadratic equation for C3-C30n-alkanes at column temperatures of 24-260 °C. The first and second order forward differences of the expression (Δlog Δtz and Δ2log Δtz, respectively) are linear and constant, respectively, which validates the DE model. This DE model lays a necessary foundation for further developing a retention model to accurately describe the relationship between the adjusted retention time and z of n-alkanes.

  8. Mechanisms of gas bubble retention

    SciTech Connect

    Gauglitz, P.A.; Mahoney, L.A.; Mendoza, D.P.; Miller, M.C.

    1994-09-01

    Retention and episodic release of flammable gases are critical safety concerns regarding double-shell tanks (DSTs) containing waste slurries. Previous investigations have concluded that gas bubbles are retained by the slurry that has settled at the bottom of the DST. However, the mechanisms responsible for the retention of these bubbles are not well understood. In addition, the presence of retained gas bubbles is expected to affect the physical properties of the sludge, but essentially no literature data are available to assess the effect of these bubbles. The rheological behavior of the waste, particularly of the settled sludge, is critical to characterizing the tendency of the waste to retain gas bubbles. The objectives of this study are to elucidate the mechanisms contributing to gas bubble retention and release from sludge such as is in Tank 241-SY-101, understand how the bubbles affect the physical properties of the sludge, develop correlations of these physical properties to include in computer models, and collect experimental data on the physical properties of simulated sludges with bubbles. This report presents a theory and experimental observations of bubble retention in simulated sludge and gives correlations and new data on the effect of gas bubbles on sludge yield strength.

  9. Clay particle retention in small constructed wetlands.

    PubMed

    Braskerud, B C

    2003-09-01

    Constructed wetlands (CWs) can be used to mitigate non-point source pollution from arable fields. Previous investigations have shown that the relative soil particle retention in small CWs increases when hydraulic load increases. This paper investigates why this phenomenon occurs, even though common retention models predict the opposite, by studying clay and silt particle retention in two Norwegian CWs. Retention was measured with water flow proportional sampling systems in the inlet and outlet of the wetlands, and the texture of the suspended solids was analyzed. The surface area of the CWs was small compared to the watershed area (approximately 0.07%), giving high average hydraulic loads (1.1 and 2.0 md(-1)). One of the watersheds included only old arable land, whereas the other included areas with disturbed topsoil after artificial land leveling. Clay particle retention was 57% for the CW in the first watershed, and 22% for the CW in the disturbed watershed. The different behavior of the wetlands could be due to differences in aggregate size and stability of the particles entering the wetlands. Results showed that increased hydraulic loads did affect CW retention negatively. However, as runoff increased, soil particles/aggregates with higher sedimentation velocities entered the CWs (e.g., the clay particles behaved as silt particles). Hence, clay particle settling velocity is not constant as assumed in many prediction models. The net result was increased retention.

  10. Measuring Graduate Student Retention.

    ERIC Educational Resources Information Center

    Isaac, Paul D.

    1993-01-01

    The conceptual and technical problems that need to be considered when studying graduate student retention and degree progress are examined, and practical suggestions for the institutional researcher are offered. Terms are defined, retention measures are explained, and different types of analysis are outlined. Ideas are given for database…

  11. The Effect of Voice Ambulatory Biofeedback on the Daily Performance and Retention of a Modified Vocal Motor Behavior in Participants with Normal Voices

    ERIC Educational Resources Information Center

    Van Stan, Jarrad H.; Mehta, Daryush D.; Hillman, Robert E.

    2015-01-01

    Purpose: Ambulatory biofeedback has potential to improve carryover of newly established vocal motor behaviors into daily life outside of the clinic and warrants systematic research that is lacking in the literature. This proof-of-concept study was designed to establish an empirical basis for future work in this area by formally assessing whether…

  12. The Costly Consequences of Not Being Socially and Behaviorally Ready by Kindergarten: Associations with Grade Retention, Receipt of Academic Support Services, and Suspensions/Expulsions

    ERIC Educational Resources Information Center

    Bettencourt, Amie; Gross, Deborah; Ho, Grace

    2016-01-01

    In 2014-15, over 50% of kindergarten children in Baltimore City Public Schools (City Schools) did not meet benchmarks for social-behavior readiness. These include the readiness skills children need to follow directions, comply with rules, manage emotions, solve problems, organize and complete tasks, and get along with others. Social-behavioral…

  13. Effects of Episodic Variations in Web-Based Avian Influenza Education: Influence of Fear and Humor on Perception, Comprehension, Retention and Behavior

    ERIC Educational Resources Information Center

    Kim, Paul; Sorcar, Piya; Um, Sujung; Chung, Heedoo; Lee, Young Sung

    2009-01-01

    In order to provide empirical evidence on the role of a web-based avian influenza (AI) education program for mass communication and also ultimately help young children learn and develop healthy behaviors against AI and all types of influenza, an education program with two episodic variations (i.e. fear and humor) has been developed and examined…

  14. Teacher Beliefs regarding Grade Retention in an Urban Elementary School

    ERIC Educational Resources Information Center

    Gilmore-Hook, Toni

    2011-01-01

    The purpose of this study was to determine if exposure to a research-based presentation on grade retention, including the academic, socio-emotional and behavioral outcomes, would yield a change in teacher beliefs regarding retention as an intervention strategy. Teachers from a small urban school district were asked to complete a pre-survey, view a…

  15. Perceptions of the Impact of School Administrators on Teacher Retention

    ERIC Educational Resources Information Center

    Knight, Zsa Zsa L.

    2012-01-01

    This qualitative study investigated the behaviors of administrators and their impact on teacher retention. Teachers' perceptions were obtained in order to gain further understanding of the impact that administrators have on teachers' job satisfaction as well as of administrators' motivation to increase teacher retention. According…

  16. Drug Retention Times

    SciTech Connect

    Center for Human Reliability Studies

    2007-05-01

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user.

  17. Drug Retention Times

    SciTech Connect

    Center for Human Reliability Studies

    2007-05-01

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user

  18. Retention in Tough Times.

    ERIC Educational Resources Information Center

    Kaye, Beverly; Jordan-Evans, Sharon

    2002-01-01

    Interviews with 25 global talent leaders discuss keeping good people and the challenges and emerging practices for retaining employees. Sidebars discuss retention tips and what keeps people on the job. (JOW)

  19. Alternatives to Social Promotion and Retention

    ERIC Educational Resources Information Center

    Lynch, Matthew

    2013-01-01

    Studies indicate that retention negatively impacts students' behavior, attitude, and attendance, but it is still practiced in schools around the country. Social promotion undermines students' futures when they fail to develop critical study and job-related skills; however, it too is still practiced in many schools throughout the United…

  20. Fuel retention in tokamaks

    NASA Astrophysics Data System (ADS)

    Loarer, T.

    2009-06-01

    Tritium retention constitutes an outstanding problem for ITER operation and future fusion reactors, particularly for the choice of the first wall materials. In present day tokamaks, fuel retention is evaluated by two complementary methods. The in situ gas balance allows evaluation of how much fuel is retained during a discharge and, typically, up to one day of experiments. Post-mortem analysis is used to determine where the fuel is retained, integrated over an experimental campaign. In all the carbon clad devices, using the two methods, the retention is demonstrated to be very closely related to the carbon net erosion. This results from plasma-wall interaction with ion and charge-exchange fluxes, ELMs and is proportional to the pulse duration. The fuel retention by implantation saturates at high wall temperatures and limits the D/C ratio in the deposited layers but, as far as a carbon source exists, the dominant retention process remains the co-deposition of carbon with deuterium. In full metallic device, in the absence of wall conditioning with boron, co-deposition is strongly reduced and fuel retention below 1% can be achieved. Extrapolation to ITER shows that removing the carbon from the plasma-facing components would increase the number of discharges to 2500 before reaching the maximum tritium limit of 700 g.

  1. Foraging behavior of the mangrove sesarmid crab Neosarmatium trispinosum enhances food intake and nutrient retention in a low-quality food environment

    NASA Astrophysics Data System (ADS)

    Harada, Yota; Lee, S. Y.

    2016-06-01

    The large sesarmid crab Neosarmatium trispinosum has been reported to actively collect freshly fallen mangrove leaves and store them in its burrow where they are assumed to age prior to consumption. This leaf-catching behavior was hypothesized to improve the palatability and nutritional quality of leaves through leaching of feeding deterrent and microbial enrichment during storage. Earlier studies also hypothesized that N. trispinosum feeds on sediment or animal material to meet their N needs. A series of experiments was carried out to investigate the foraging behavior of N. trispinosum against these hypotheses. Study of foraging behavior using remotely operated cameras indicated that this crab spends the far majority of time (97.5 ± 2.5%, SD) underground and only a small percentage of time outside its burrow foraging (2.2 ± 2.3%). Collection of fresh mangrove litter was swift but no record of predation was evident over 31 h of video records. A field leaf tethering experiment showed that this crab started to consume the leaves immediately after collection rather than storing whole leaves, refuting the leaf-aging hypothesis. N. trispinosum also showed a preference for senescent yellow leaves over decaying brown leaves. This behavior may only aim to stock leaves (i.e. to ensure food availability) rather than conditioning them through decay (i.e. to improve food quality). Analysis of gut contents showed that vascular plant material was the dominant food item (83.3 ± 4.6%), followed by sediment (9.2 ± 4.6%) but no animal materials were recorded. N. trispinosum therefore relies minimally on animal food but are capable of removing 50% of the daily leaf litter production. Elemental C, N analysis shows that sediment inside the burrow is a sufficient potential food source (C/N = 13 to 15). While having a lower C/N ratio than fresh green or yellow leaves, the N content of sediment (∼0.1%) was significantly lower than those of mangrove leaves (0.3-0.9%), and may thus

  2. Fluence dependence of deuterium retention in oxidized SS-316

    NASA Astrophysics Data System (ADS)

    Oya, Yasuhisa; Suzuki, Sachiko; Matsuyama, Masao; Hayashi, Takumi; Yamanishi, Toshihiko; Asakura, Yamato; Okuno, Kenji

    2011-10-01

    The ion fluence dependence of deuterium retention in SS-316 during oxidation at a temperature of 673 K was studied to evaluate the dynamics of deuterium retention in the oxide layer of SS-316. The correlation between the chemical state of stainless steel and deuterium retention was evaluated using XPS and TDS. It was found that the major deuterium desorption temperatures were located at around 660 K and 935 K, which correspond to the desorption of deuterium trapped as hydroxide. The deuterium retention increased with increasing deuterium ion fluence, since the deuterium retention as hydroxide increased significantly. However, retention saturated at an ion fluence of ˜2.5 × 10 21 D + m -2. The XPS result showed that FeOOD was formed on the surface, although pure Fe also remained in the oxide layer. These facts indicate the nature of the oxide layer have a key role in deuterium trapping behavior.

  3. Principals Retention. Research Brief

    ERIC Educational Resources Information Center

    Muir, Mike

    2005-01-01

    Many districts are struggling with the problem of administrator retention. Hoffman (2004) identifies some of the reasons for this: (1) Increased accountability expectations; (2) Diminished or static levels of resources to support reform efforts; (3) Greater administrator vulnerability to sanctions; (4) The complex demands of government and the…

  4. Improving College Freshman Retention

    ERIC Educational Resources Information Center

    Yu, Winnie Y.

    2012-01-01

    In recent years, access to higher education was greatly improved through public funding. This improvement is not matched by a similar increase in graduation rate. The purpose of this study is to examine what postsecondary institutions can do to improve college freshman retention. The conceptual framework was based on research on college student…

  5. Data Show Retention Disparities

    ERIC Educational Resources Information Center

    Adams, Caralee J.; Robelen, Erik W.; Shah, Nirvi

    2012-01-01

    New nationwide data collected by the U.S. Department of Education's civil rights office reveal stark racial and ethnic disparities in student retentions, with black and Hispanic students far more likely than white students to repeat a grade, especially in elementary and middle school. The contrast is especially strong for African-Americans. In the…

  6. How work environment impacts retention.

    PubMed

    Christmas, Kate

    2008-01-01

    Work environment is a major aspect of the day-to-day grind that drives the retention (or turnover) of RNs. When opportunities abound, it is easy to jump ship, and when turnover begins, it is usually the best and brightest who are first to depart. Recent research reported a whopping 27.1% average voluntary turnover rate among new graduate nurses during their first year of employment. Aging of the nurse workforce may be the largest factor impacting health care work environments, as employers struggle to diminish the physical effect of lifting thousands of pounds and walking several miles during each shift. Every influence on the work environment (management, peer behavior, patient acuity, equipment availability, the physical plant) should be assessed for impact on the workforce. While we cannot hope to create paradise in each work setting, we can promote an environment that is healing both to patient and to caregiver. PMID:18979696

  7. How work environment impacts retention.

    PubMed

    Christmas, Kate

    2008-01-01

    Work environment is a major aspect of the day-to-day grind that drives the retention (or turnover) of RNs. When opportunities abound, it is easy to jump ship, and when turnover begins, it is usually the best and brightest who are first to depart. Recent research reported a whopping 27.1% average voluntary turnover rate among new graduate nurses during their first year of employment. Aging of the nurse workforce may be the largest factor impacting health care work environments, as employers struggle to diminish the physical effect of lifting thousands of pounds and walking several miles during each shift. Every influence on the work environment (management, peer behavior, patient acuity, equipment availability, the physical plant) should be assessed for impact on the workforce. While we cannot hope to create paradise in each work setting, we can promote an environment that is healing both to patient and to caregiver.

  8. Mobile Learning and Student Retention

    ERIC Educational Resources Information Center

    Fozdar, Bharat Inder; Kumar, Lalita S.

    2007-01-01

    Student retention in open and distance learning (ODL) is comparatively poor to traditional education and, in some contexts, embarrassingly low. Literature on the subject of student retention in ODL indicates that even when interventions are designed and undertaken to improve student retention, they tend to fall short. Moreover, this area has not…

  9. The Principles of Effective Retention.

    ERIC Educational Resources Information Center

    Tinto, Vincent

    An overview is provided of the problem of student attrition and the essential components of effective retention programs. Following introductory arguments that the secret of retention is in the development of communities committed to education rather than retention, the paper discusses several major causes of student attrition, including academic…

  10. Effect of Grade Retention in First Grade on Psychosocial Outcomes

    ERIC Educational Resources Information Center

    Wu, Wei; West, Stephen G.; Hughes, Jan N.

    2010-01-01

    In a 4-year longitudinal study, the authors investigated effects of retention in first grade on children's externalizing and internalizing behaviors; social acceptance; and behavioral, cognitive, and affective engagement. From a large multiethnic sample (n = 784) of children below the median on literacy at school entrance, 124 retained children…

  11. Floating nut retention system

    NASA Technical Reports Server (NTRS)

    Charles, J. F.; Theakston, H. A. (Inventor)

    1980-01-01

    A floating nut retention system includes a nut with a central aperture. An inner retainer plate has an opening which is fixedly aligned with the nut aperture. An outer retainer member is formed of a base plate having an opening and a surface adjacent to a surface of the inner retainer plate. The outer retainer member includes a securing mechanism for retaining the inner retainer plate adjacent to the outer retainer member. The securing mechanism enables the inner retainer plate to float with respect to the outer retainer number, while simultaneously forming a bearing surface for inner retainer plate.

  12. Behaviorism

    ERIC Educational Resources Information Center

    Moore, J.

    2011-01-01

    Early forms of psychology assumed that mental life was the appropriate subject matter for psychology, and introspection was an appropriate method to engage that subject matter. In 1913, John B. Watson proposed an alternative: classical S-R behaviorism. According to Watson, behavior was a subject matter in its own right, to be studied by the…

  13. Mechanisms of deterioration of nutrients. [retention of flavor during freeze drying

    NASA Technical Reports Server (NTRS)

    Karel, M.; Flink, J. M.

    1975-01-01

    The retention of flavor during freeze drying was studied with model systems. Mechanisms by which flavor retention phenomena is explained were developed and process conditions specified so that flavor retention is optimized. The literature is reviewed and results of studies of the flavor retention behavior of a number of real food products, including both liquid and solid foods are evaluated. Process parameters predicted by the mechanisms to be of greatest significance are freezing rate, initial solids content, and conditions which result in maintenance of sample structure. Flavor quality for the real food showed the same behavior relative to process conditions as predicted by the mechanisms based on model system studies.

  14. Boulder Valley Kindergarten Study: Retention Practices and Retention Effects.

    ERIC Educational Resources Information Center

    Shepard, Lorrie A.; Smith, Mary Lee

    Having implemented a policy that allowed schools to retain children in kindergarten an extra year, the Boulder Valley Public School District in Colorado conducted a study to determine the cognitive and emotional benefits of retention in kindergarten and the characteristics that led to decisions about retention. The study involved a research review…

  15. Des ballons pour demain

    NASA Astrophysics Data System (ADS)

    Régipa, R.

    A partir d'une théorie sur la détermination des formes et des contraintes globales d'un ballon de révolution, ou s'en rapprochant, une nouvelle famille de ballons a été définie. Les ballons actuels, dits de ``forme naturelle'', sont calculés en général pour une tension circonférencielle nulle. Ainsi, pour une mission donnée, la tension longitudinale et la forme de l'enveloppe sont strictement imposées. Les ballons de la nouvelle génération sont globalement cylindriques et leurs pôles sont réunis par un câble axial, chargé de transmettre une partie des efforts depuis le crochet (pôle inférieur), directement au pôle supérieur. De plus, la zone latérale cylindrique est soumise à un faible champ de tensions circonférencielles. Ainsi, deux paramètres permettent de faire évoluer la distribution des tensions et la forme de l'enveloppe: - la tension du câble de liaison entre pôles (ou la longueur de ce câble) - la tension circonférencielle moyenne désirée (ou le rayon du ballon). On peut donc calculer et réaliser: - soit des ballons de forme adaptée, comme les ballons à fond plat pour le bon fonctionnement des montgolfières infrarouge (projet MIR); - soit des ballons optimisés pour une bonne répartition des contraintes et une meilleure utilisation des matériaux d'enveloppe, pour l'ensemble des programmes stratosphériques. Il s'ensuit une économie sensible des coûts de fabrication, une fiabilité accrue du fonctionnement de ces ballons et une rendement opérationnel bien supérieur, permettant entre autres, d'envisager des vols à très haute altitude en matériaux très légers.

  16. Molten core retention assembly

    DOEpatents

    Lampe, Robert F.

    1976-06-22

    Molten fuel produced in a core overheating accident is caught by a molten core retention assembly consisting of a horizontal baffle plate having a plurality of openings therein, heat exchange tubes having flow holes near the top thereof mounted in the openings, and a cylindrical, imperforate baffle attached to the plate and surrounding the tubes. The baffle assembly is supported from the core support plate of the reactor by a plurality of hanger rods which are welded to radial beams passing under the baffle plate and intermittently welded thereto. Preferably the upper end of the cylindrical baffle terminates in an outwardly facing lip to which are welded a plurality of bearings having slots therein adapted to accept the hanger rods.

  17. A high-temperature liquid chromatographic reactor approach for investigating the solvolytic stability of a pharmaceutical compound and an investigation of its retention behavior on a C18-modified zirconia stationary phase.

    PubMed

    Skrdla, Peter J; Bopra, Angela; Chasse, Tyson; Wang, Tao

    2008-06-01

    The solvolysis kinetics of a developmental active pharmaceutical ingredient (API) were investigated using a high temperature (HT)-HPLC reactor approach to determine whether it might be possible to use the technique to efficiently screen the relative stabilities of typical APIs (particularly those that are stable at the column temperatures achievable on most HPLC systems and over durations of less than 60 min-a reasonable upper limit for typical method run time). It was discovered that the on-column API degradation kinetics better obeyed a second-order model than a first-order one. Employing a newly developed mathematical treatment, the apparent activation energy for the process was determined to be 85.7+/-1.6 kJ/mol; the apparent frequency factor was found to be (3.9+/-0.4)x10(4) s(-1). The retention mechanism of the API on the C18-modified zirconia column (ZirChrom) Diamondbond-C18) was investigated using a van't Hoff analysis. It was discovered that the logarithm of the retention factor (following correction for the gradient elution of the assay method) exhibited a quadratic dependence on the reciprocal of the absolute temperature. While the retention was found to be predominantly enthalpically driven over the majority of temperatures investigated in this study (ranging from 40 to 200 degrees C), a regression fit of the curve predicted a maximum at approximately 20 degrees C, indicative of a transition from predominantly enthalpically controlled retention to a mainly entropically driven mechanism. A table summarizing the thermodynamic retention parameters at each experimental column temperature is provided. Finally, the preliminary application of the HT-HPLC reactor approach to the study of degradation kinetics of other APIs is discussed in terms of some unexpected findings obtained using the zirconia column.

  18. Research Synopsis: Spring 1983 Retention.

    ERIC Educational Resources Information Center

    Peralta Community Coll. District, Oakland, CA. Office of Research, Planning and Development.

    An analysis of spring 1983 retention rates and grade distributions within the Peralta Community College District (PCCD) revealed: (1) College of Alameda had the highest successful retention rate in the PCCD, defined as the total of all students who completed the term with a grade of A, B, C, D, or CR (credit); (2) the PCCD's successful retention…

  19. Toward a Record Retention Policy

    ERIC Educational Resources Information Center

    Vaughan, Jason

    2007-01-01

    An academic library working group was charged in 2005 to create a records retention schedule and policy applicable to records containing personally identifiable information of library patrons. This group conducted a survey and extensive research, culminating in an adopted library records retention schedule and policy implemented in 2006.

  20. The Effects of a Suggestive Learning Climate, Synchronized Breathing and Music on the Learning and Retention of Spanish Words

    ERIC Educational Resources Information Center

    Benitez-Bordon, R.; Schuster, Donald H.

    1976-01-01

    This study found that the three variables, suggestion, synchronized music and breathing, had a large positive effect on the learning and retention of 50 Spanish words. Available from: Society for Suggestive-Accelerative Learning and Teaching, 2740 Richmond Avenue, Des Moines, Iowa 50319. (CFM)

  1. Effect of Grade Retention in First Grade on Psychosocial Outcomes

    PubMed Central

    Wu, Wei; West, Stephen G.; Hughes, Jan N.

    2010-01-01

    In a 4-year longitudinal study, the authors investigated effects of retention in first grade on children’s externalizing and internalizing behaviors; social acceptance; and behavioral, cognitive, and affective engagement. From a large multiethnic sample (n = 784) of children below the median on literacy at school entrance, 124 retained children were matched with 251 promoted children on the basis of propensity scores (probability of being retained in first grade estimated from 72 baseline variables). Relative to promoted children, retained children were found to benefit from retention in both the short and longer terms with respect to decreased teacher-rated hyperactivity, decreased peer-rated sadness and withdrawal, and increased teacher-rated behavioral engagement. Retained children had a short-term increase in mean peer-rated liking and school belongingness relative to promoted children, but this advantage showed a substantial decrease in the longer term. Retention had a positive short-term effect on children’s perceived school belonging and a positive longer term effect on perceived academic self-efficacy. Retention may bestow advantages in the short-term, but longer term detrimental effects on social acceptance may lead to the documented longer term negative effects of retention. PMID:20448829

  2. Data Retention and Anonymity Services

    NASA Astrophysics Data System (ADS)

    Berthold, Stefan; Böhme, Rainer; Köpsell, Stefan

    The recently introduced legislation on data retention to aid prosecuting cyber-related crime in Europe also affects the achievable security of systems for anonymous communication on the Internet. We argue that data retention requires a review of existing security evaluations against a new class of realistic adversary models. In particular, we present theoretical results and first empirical evidence for intersection attacks by law enforcement authorities. The reference architecture for our study is the anonymity service AN.ON, from which we also collect empirical data. Our adversary model reflects an interpretation of the current implementation of the EC Directive on Data Retention in Germany.

  3. Early-Grade Retention and Children's Reading and Math Learning in Elementary Years

    ERIC Educational Resources Information Center

    Hong, Guanglei; Yu, Bing

    2007-01-01

    Many schools have adopted early-grade retention as an intervention strategy for children displaying academic or behavioral problems. Previous analyses of the Early Childhood Longitudinal Study Kindergarten Cohort data have found evidence of negative effects of kindergarten retention on academic learning during the repeated year. Will kindergarten…

  4. Percutaneous tibial nerve stimulation for treatment of overactive bladder and urinary retention in an elderly population.

    PubMed

    Zinkgraf, Kristine; Quinn, Annette O'Leary; Ketterhagen, Debra; Kreuziger, Betty; Stevenson, Katherine

    2009-01-01

    Percutaneous tibial nerve stimulation (PTNS) is a treatment option for patients who present with urinary urgency, frequency, urge incontinence, or urinary retention. When behavior modification and/or pharmacotherapy did not adequately relieve symptoms, this treatment was found to decrease incidence of overactive bladder or retention symptoms in the authors' patient population.

  5. EA Shuttle Document Retention Effort

    NASA Technical Reports Server (NTRS)

    Wagner, Howard A.

    2010-01-01

    This slide presentation reviews the effort of code EA at Johnson Space Center (JSC) to identify and acquire databases and documents from the space shuttle program that are adjudged important for retention after the retirement of the space shuttle.

  6. Skill Retention and Relearning--A Proposed Cyclical Model.

    ERIC Educational Resources Information Center

    Ginzburg, S.; Dar-El, E. M.

    2000-01-01

    The relationship between relearning and retention was examined during refresher training for 53 Israeli soldiers operating an electronic system. The longer the training interval, the lower the operator's performance level. Partial simulation was suitable for retraining in complex tasks. A cyclical behavior model of learning, forgetting, and…

  7. Retention, Persistence, and Enrollment Management: An Exploration of Organizational Models

    ERIC Educational Resources Information Center

    Bartlett, Stacy A.

    2013-01-01

    Low student retention and persistence continues to be a major problem within American higher education (Elkins, Braxton, & James, 2000; Kalsbeek & Hossler, 2010; Kezar, 2004; Tinto, 2006-2007). Less is known about the institutional organizational behavior influence on student persistence (Berger, 2001-2002); and while enrollment management…

  8. Professional Development and Mentoring in Support of Teacher Retention

    ERIC Educational Resources Information Center

    Rodgers, Christopher; Skelton, Jillian

    2014-01-01

    The authors' discussion will describe how teacher retention is in jeopardy. Many novice teachers are ill-prepared to handle the rigorous school days and challenging students academically and behaviorally (Stansbury & Zimmerman, 2002). Novice teachers need guidance and support to ease tensions and stress levels which arise during teaching…

  9. Des Vents et des Jets Astrophysiques

    NASA Astrophysics Data System (ADS)

    Sauty, C.

    well expected result from the theory. Although, collimation may be conical, paraboloidal or cylindrical (Part 4), cylindrical collimation is the more likely to occur. The shape of outflows may then be used as a tool to predict physical conditions on the flows or on their source. L'éjection continue de plasma autour d'objets massifs est un phénomène largement répandu en astrophysique, que ce soit sous la forme du vent solaire, de vents stellaires, de jets d'étoiles en formation, de jets stellaires autour d'objets compacts ou de jets extra-galactiques. Cette zoologie diversifiée fait pourtant l'objet d'un commun effort de modélisation. Le but de cette revue est d'abord de présenter qualitativement le développement, depuis leur origine, des diverses théories de vents (Partie 1) et l'inter disciplinarité dans ce domaine. Il s'agit d'une énumération, plus ou moins exhaustive, des idées proposées pour expliquer l'accélération et la morphologie des vents et des jets, accompagnée d'une présentation sommaire des aspects observationnels. Cette partie s'abstient de tout aspect faisant appel au formalisme mathématique. Ces écoulements peuvent être décrits, au moins partiellement, en résolvant les équations magnétohydrodynamiques, axisymétriques et stationnaires. Ce formalisme, à la base de la plupart des théories, est exposé dans la Partie 2. Il permet d'introduire quantitativement les intégrales premières qu'un tel système possède. Ces dernières sont amenées à jouer un rôle important dans la compréhension des phénomènes d'accélération ou de collimation, en particulier le taux de perte de masse, le taux de perte de moment angulaire ou l'énergie du rotateur magnétique. La difficulté de modélisation réside dans l'existence de points critiques, propres aux équations non linéaires, qu'il faut franchir. La nature physique et la localisation de ces points critiques fait l'objet d'un débat important car ils sont la clef de voute de la r

  10. Influence of hydrologic loading rate on phosphorus retention and ecosystem productivity in created wetlands. Final report

    SciTech Connect

    Mitsch, W.J.; Cronk, J.K.

    1995-01-01

    Four 2- to 3-ha constructed freshwater riparian wetlands in Lake County, Illinois, were subjected to two hydrologic regimes of pumped river water to simulate nonpoint source pollution. The experimental wetlands at the Des Plaines River Wetland Demonstration Project were designed to develop and test wetland design principles, construction methods, and management programs needed to create and maintain wetlands for the purposes of water quality management, flood control, and fish and wildlife habitat. High-flow wetlands (HFW) with short retention times received 34 to 38 cm of river water per week, and low-flow wetlands (LFW) with high retention times received 10 to 15 cm per week. This report summarizes research results for phosphorus dynamics and retention, macrophyte development, periphyton productivity, and overall water column metabolism through 1992. All of these functions were hypothesized to be related to hydrologic conditions.

  11. Injectabilite des coulis de ciment dans des milieux fissures

    NASA Astrophysics Data System (ADS)

    Mnif, Thameur

    Le travail presente ici est un bilan du travaux de recherche effectues sur l'injectabilite des coulis de ciment dans lu milieux fissures. Un certain nombre de coulis a base de ciment Portland et microfin ont ete selectionnes afin de caracteriser leur capacite a penetrer des milieux fissures. Une partie des essais a ete menee en laboratoire. L'etude rheologique des differents melanges a permis de tester l'influence de l'ajout de superplastifiant et/ou de fumee de silice sur la distribution granulometrique des coulis et par consequent sur leur capacite a injecter des colonnes de sable simulant un milieu fissure donne. La classe granulometrique d'un coulis, sa stabilite et sa fluidite sont apparus comme les trois facteurs principaux pour la reussite d'une injection. Un facteur de finesse a ete defini au cours de cette etude: base sur la classe granulometrique du ciment et sa stabilite, il peut entrer dans la formulation theorique du debit d'injection avant application sur chantier. La deuxieme et derniere partie de l'etude presente les resultats de deux projets de recherche sur l'injection realises sur chantier. L'injection de dalles de beton fissurees a permis le suivi de l'evolution des pressions avec la distance au point d'injection. L'injection de murs de maconnerie a caractere historique a montre l'importance de la definition de criteres de performance des coulis a utiliser pour traiter un milieu donne et pour un objectif donne. Plusieurs melanges peuvent ainsi etre predefinis et mis a disposition sur le chantier. La complementarite des ciments traditionnels et des ciments microfins devient alors un atout important. Le choix d'utilisation de ces melanges est fonction du terrain rencontre. En conclusion, cette recherche etablit une methodologie pour la selection des coulis a base de ciment et des pressions d'injection en fonction de l'ouverture des fissures ou joints de construction.

  12. Genetic programming based quantitative structure-retention relationships for the prediction of Kovats retention indices.

    PubMed

    Goel, Purva; Bapat, Sanket; Vyas, Renu; Tambe, Amruta; Tambe, Sanjeev S

    2015-11-13

    The development of quantitative structure-retention relationships (QSRR) aims at constructing an appropriate linear/nonlinear model for the prediction of the retention behavior (such as Kovats retention index) of a solute on a chromatographic column. Commonly, multi-linear regression and artificial neural networks are used in the QSRR development in the gas chromatography (GC). In this study, an artificial intelligence based data-driven modeling formalism, namely genetic programming (GP), has been introduced for the development of quantitative structure based models predicting Kovats retention indices (KRI). The novelty of the GP formalism is that given an example dataset, it searches and optimizes both the form (structure) and the parameters of an appropriate linear/nonlinear data-fitting model. Thus, it is not necessary to pre-specify the form of the data-fitting model in the GP-based modeling. These models are also less complex, simple to understand, and easy to deploy. The effectiveness of GP in constructing QSRRs has been demonstrated by developing models predicting KRIs of light hydrocarbons (case study-I) and adamantane derivatives (case study-II). In each case study, two-, three- and four-descriptor models have been developed using the KRI data available in the literature. The results of these studies clearly indicate that the GP-based models possess an excellent KRI prediction accuracy and generalization capability. Specifically, the best performing four-descriptor models in both the case studies have yielded high (>0.9) values of the coefficient of determination (R(2)) and low values of root mean squared error (RMSE) and mean absolute percent error (MAPE) for training, test and validation set data. The characteristic feature of this study is that it introduces a practical and an effective GP-based method for developing QSRRs in gas chromatography that can be gainfully utilized for developing other types of data-driven models in chromatography science

  13. Genetic programming based quantitative structure-retention relationships for the prediction of Kovats retention indices.

    PubMed

    Goel, Purva; Bapat, Sanket; Vyas, Renu; Tambe, Amruta; Tambe, Sanjeev S

    2015-11-13

    The development of quantitative structure-retention relationships (QSRR) aims at constructing an appropriate linear/nonlinear model for the prediction of the retention behavior (such as Kovats retention index) of a solute on a chromatographic column. Commonly, multi-linear regression and artificial neural networks are used in the QSRR development in the gas chromatography (GC). In this study, an artificial intelligence based data-driven modeling formalism, namely genetic programming (GP), has been introduced for the development of quantitative structure based models predicting Kovats retention indices (KRI). The novelty of the GP formalism is that given an example dataset, it searches and optimizes both the form (structure) and the parameters of an appropriate linear/nonlinear data-fitting model. Thus, it is not necessary to pre-specify the form of the data-fitting model in the GP-based modeling. These models are also less complex, simple to understand, and easy to deploy. The effectiveness of GP in constructing QSRRs has been demonstrated by developing models predicting KRIs of light hydrocarbons (case study-I) and adamantane derivatives (case study-II). In each case study, two-, three- and four-descriptor models have been developed using the KRI data available in the literature. The results of these studies clearly indicate that the GP-based models possess an excellent KRI prediction accuracy and generalization capability. Specifically, the best performing four-descriptor models in both the case studies have yielded high (>0.9) values of the coefficient of determination (R(2)) and low values of root mean squared error (RMSE) and mean absolute percent error (MAPE) for training, test and validation set data. The characteristic feature of this study is that it introduces a practical and an effective GP-based method for developing QSRRs in gas chromatography that can be gainfully utilized for developing other types of data-driven models in chromatography science.

  14. Course Retention Analysis. Focus Study.

    ERIC Educational Resources Information Center

    Mount San Antonio Coll., Walnut, CA.

    A study was conducted at Mount San Antonio College (MSAC), California, to analyze patterns in credit course retention between fall 1986 and spring 1989. The study investigated the development of course prerequisites based on faculty perceptions of the skills necessary for success and minimal skill levels associated with success; student assessment…

  15. Retention-Oriented Curricular Design

    ERIC Educational Resources Information Center

    Milanovic, Ivana; Eppes, Tom A.; Girouard, Janice; Townsend, Lee

    2010-01-01

    This paper presents a retention-oriented approach to the educational value stream within the STEM undergraduate area. Faced with several strategic challenges and opportunities, a Flex Advantage Plan was developed to enhance the undergraduate engineering technology programs and better utilize the curricular flexibilities inherent in the current…

  16. A Successful College Retention Program.

    ERIC Educational Resources Information Center

    Dale, Paul M.

    This study assessed the impact of the HORIZONS Student Support Program on participating college freshmen at Purdue University (Indiana). HORIZONS is a federally funded program designed to increase retention of first generation, low income, or physically disabled students. The cornerstone of the project and the vehicle through which most services…

  17. Teacher Retention: An Appreciative Approach

    ERIC Educational Resources Information Center

    Pesavento-Conway, Jennifer Jean

    2010-01-01

    Nationally, the problem of teacher retention compounds the unstable nature of the educational situation, especially in urban, high-needs schools. Much of the instability of urban schools is due to teacher movement, the migration of teachers from school to another school within or between school districts, particularly from high-needs schools.…

  18. Maslow's Hierarchy and Student Retention.

    ERIC Educational Resources Information Center

    Brookman, David M.

    1989-01-01

    Abraham Maslow's hierarchy of needs offers perspective on student motivation and a rationale for college retention programing. Student affairs and faculty interventions addressing student safety needs and engaging students' sense of purpose reinforce persistence. A mentor program is a possible cooperative effort between student personnel and…

  19. A Research Study in Retention.

    ERIC Educational Resources Information Center

    Knibbe, Marie Vannozzi; Dusewicz, Russell A.

    A study of the Center for Literacy's (CFL) program was conducted to provide information on retention and attrition in an urban, open-entry/open-exit, individualized, goal-based literacy program. An exploratory analysis that used student and tutor records from 1985 through 1989 provided a summary of demographics and attendance patterns. This…

  20. Exploring General Education Development Retention

    ERIC Educational Resources Information Center

    Grover, Sharon D.

    2013-01-01

    According to the instructors and administrators at a local adult education (AE) program in Houston, Texas, retaining and graduating general education development (GED) students has been a constant challenge. Locating GED attendance barriers could enable AE programs to develop techniques that increase student retention and graduation rates. The…

  1. Grundlagen des Tissue Engineering

    NASA Astrophysics Data System (ADS)

    Mayer, Jörg; Blum, Janaki; Wintermantel, Erich

    Die Organtransplantation stellt eine verbreitete Therapie dar, um bei krankheitsoder unfallbedingter Schädigung eines Organs die Gesamtheit seiner Funktionen wieder herzustellen, indem es durch ein Spenderorgan ersetzt wird. Organtransplantationen werden für die Leber, die Niere, die Lunge, das Herz oder bei schweren grossflächigen Verbrennungen der Haut vorgenommen. Der grosse apparative, personelle und logistische Aufwand und die Risiken der Transplantationschirurgie (Abstossungsreaktionen) sowie die mangelnde Verfügbarkeit von immunologisch kompatiblen Spenderorganen führen jedoch dazu, dass der Bedarf an Organtransplantaten nur zu einem sehr geringen Teil gedeckt werden kann. Sind Spenderorgane nicht verfügbar, können in einzelnen Fällen lebenswichtige Teilfunktionen, wie beispielsweise die Filtrationsfunktion der Niere durch die Blutreinigung mittels Dialyse ersetzt oder, bei mangelnder Funktion der Bauchspeicheldrüse (Diabetes), durch die Verabreichung von Insulin ein normaler Zustand des Gesamtorganismus auch über Jahre hinweg erhalten werden. Bei der notwendigen lebenslangen Anwendung apparativer oder medikamentöser Therapie können für den Patienten jedoch häufig schwerwiegende, möglicherweise lebensverkürzende Nebenwirkungen entstehen. Daher werden in der Forschung Alternativen gesucht, um die Funktionen des ausgefallenen Organs durch die Implantation von Zellen oder in vitro gezüchteten Geweben möglichst umfassend wieder herzustellen. Dies erfordert biologisch aktive Implantate, welche die für den Stoffwechsel des Organs wichtigen Zellen enthalten und einen organtypischen Stoffwechsel entfalten.

  2. Managing Chemotherapy Side Effects: Swelling (Fluid Retention)

    MedlinePlus

    ... ancer I nstitute Managing Chemotherapy Side Effects Swelling (Fluid retention) “My hands and feet were swollen and ... at one time. Managing Chemotherapy Side Effects: Swelling (Fluid retention) Weigh yourself. l Weigh yourself at the ...

  3. Reticulation des fibres lignocellulosiques

    NASA Astrophysics Data System (ADS)

    Landrevy, Christel

    Pour faire face à la crise économique la conception de papier à valeur ajoutée est développée par les industries papetières. Le but de se projet est l'amélioration des techniques actuelles de réticulation des fibres lignocellulosiques de la pâte à papier visant à produire un papier plus résistant. En effet, lors des réactions de réticulation traditionnelles, de nombreuses liaisons intra-fibres se forment ce qui affecte négativement l'amélioration anticipée des propriétés physiques du papier ou du matériau produit. Pour éviter la formation de ces liaisons intra-fibres, un greffage sur les fibres de groupements ne pouvant pas réagir entre eux est nécessaire. La réticulation des fibres par une réaction de « click chemistry » appelée cycloaddition de Huisgen entre un azide et un alcyne vrai, catalysée par du cuivre (CuAAC) a été l'une des solutions trouvée pour remédier à ce problème. De plus, une adaptation de cette réaction en milieux aqueux pourrait favoriser son utilisation en milieu industriel. L'étude que nous désirons entreprendre lors de ce projet vise à optimiser la réaction de CuAAC et les réactions intermédiaires (propargylation, tosylation et azidation) sur la pâte kraft, en milieu aqueux. Pour cela, les réactions ont été adaptées en milieu aqueux sur la cellulose microcristalline afin de vérifier sa faisabilité, puis transférée à la pâte kraft et l'influence de différents paramètres comme le temps de réaction ou la quantité de réactifs utilisée a été étudiée. Dans un second temps, une étude des différentes propriétés conférées au papier par les réactions a été réalisée à partir d'une série de tests papetiers optiques et physiques. Mots Clés Click chemistry, Huisgen, CuAAC, propargylation, tosylation, azidation, cellulose, pâte kraft, milieu aqueux, papier.

  4. Designing Online Courses to Promote Student Retention

    ERIC Educational Resources Information Center

    Dietz-Uhler, Beth; Fisher, Amy; Han, Andrea

    2008-01-01

    Although the issue of student retention is a campus-wide one, it is of special interest in online distance learning courses, where retention rates are reported to be lower than in face-to-face classes. Among the explanations and theories of retention rates in online courses, one that struck us as most useful is a structural one, namely, course…

  5. Persistence-Retention. Snapshot™ Report, Spring 2015

    ERIC Educational Resources Information Center

    National Student Clearinghouse, 2015

    2015-01-01

    This Snapshot Report offers information on student persistence and retention rates for 2009-2013. It offers data on the following: (1) First-Year Persistence and Retention Rates for Students Who Start College at Four-Year Private Nonprofit Institutions; (2) First-Year Persistence and Retention Rates for Students Who Start College at Four-Year…

  6. Persistence-Retention. Snapshot™ Report, Spring 2014

    ERIC Educational Resources Information Center

    National Student Clearinghouse, 2014

    2014-01-01

    This snapshot report provides information on student persistence and retention rates for Spring 2014. Data is presented in tabular format on the following: (1) First-Year Persistence and Retention Rates by Starting Enrollment Intensity (all institutional sectors); (2) First-Year Persistence and Retention Rates by Age at College Entry (all…

  7. 5 CFR 351.404 - Retention register.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... FORCE Scope of Competition § 351.404 Retention register. (a) When a competing employee is to be released from a competitive level under this part, the agency shall establish a separate retention register for... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Retention register. 351.404 Section...

  8. Reframing Retention Strategy: A Focus on Profile

    ERIC Educational Resources Information Center

    Kalsbeek, David H.; Zucker, Brian

    2013-01-01

    Over 35 years of retention theory and literature have acknowledged the importance of institutional and student profiles in accounting for cross-sectional differences in retention and completion rates between types of colleges and universities. The first "P" within a 4 Ps framework of student retention--"profile"--recognizes that an institution's…

  9. Reframing Retention Strategy: A Focus on Progress

    ERIC Educational Resources Information Center

    Spittle, Brian

    2013-01-01

    Few words have dominated the vocabulary of college retention as has the word "persistence." Many institutions still struggle to engage faculty and administrators in building campuswide retention efforts, to find the organizational levers that translate the abstractions and complexities of retention theory into scalable and durable initiatives, and…

  10. Enhanced methodology for porting ion chromatography retention data.

    PubMed

    Park, Soo Hyun; Shellie, Robert A; Dicinoski, Greg W; Schuster, Georg; Talebi, Mohammad; Haddad, Paul R; Szucs, Roman; Dolan, John W; Pohl, Christopher A

    2016-03-01

    Porting is a powerful methodology to recalibrate an existing database of ion chromatography (IC) retention times by reflecting the changes of column behavior resulting from either batch-to-batch variability in the production of the column or the manufacture of new versions of a column. This approach has been employed to update extensive databases of retention data of inorganic and organic anions forming part of the "Virtual Column" software marketed by Thermo Fisher Scientific, which is the only available commercial optimization tool for IC separation. The current porting process is accomplished by performing three isocratic separations with two representative analyte ions in order to derive a porting equation which expresses the relationship between old and new data. Although the accuracy of retention prediction is generally enhanced on new columns, errors were observed on some columns. In this work, the porting methodology was modified in order to address this issue, where the porting equation is now derived by using six representative analyte ions (chloride, bromide, iodide, perchlorate, sulfate, and thiosulfate). Additionally, the updated porting methodology has been applied on three Thermo Fisher Scientific columns (AS20, AS19, and AS11HC). The proposed approach showed that the new porting methodology can provide more accurate and robust retention prediction on a wide range of columns, where average errors in retention times for ten test anions under three eluent conditions were less than 1.5%. Moreover, the retention prediction using this new approach provided an acceptable level of accuracy on a used column exhibiting changes in ion-exchange capacity.

  11. Oxygen plasma immersion ion implantation treatment to enhance data retention of tungsten nanocrystal nonvolatile memory

    SciTech Connect

    Wang, Jer-Chyi Chang, Wei-Cheng; Lai, Chao-Sung; Chang, Li-Chun; Ai, Chi-Fong; Tsai, Wen-Fa

    2014-03-15

    Data retention characteristics of tungsten nanocrystal (W-NC) memory devices using an oxygen plasma immersion ion implantation (PIII) treatment are investigated. With an increase of oxygen PIII bias voltage and treatment time, the capacitance–voltage hysteresis memory window is increased but the data retention characteristics become degraded. High-resolution transmission electron microscopy images show that this poor data retention is a result of plasma damage on the tunneling oxide layer, which can be prevented by lowering the bias voltage to 7 kV. In addition, by using the elevated temperature retention measurement technique, the effective charge trapping level of the WO{sub 3} film surrounding the W-NCs can be extracted. This measurement reveals that a higher oxygen PIII bias voltage and treatment time induces more shallow traps within the WO{sub 3} film, degrading the retention behavior of the W-NC memory.

  12. Prediction of contaminant retention and transport in soils using kinetic multireaction models.

    PubMed Central

    Selim, H M

    1989-01-01

    Mathematical models that describe the retention reactions of contaminants in the soil system are presented. Single and multireaction-type models for simultaneous retention and transport in the soil profile are discussed. Single retention models are classified into two types: equilibrium and kinetic models. Emphasis is given to the nonlinearity and kinetic behavior of solute retention processes in soils. Two-site models that include the equilibrium-kinetic types as well as the fully kinetic type are also examined. A multireaction-type model is also presented, which includes reversible and irreversible retention processes of the equilibrium and kinetic types. Advantages of the multireaction approach over the single or two-site models are discussed. The predictive capability of the two-site model and the multireaction model for their description of experimental results for phosphorus and two heavy metals (Cd and Cr) are examined. PMID:2695326

  13. Acute urinary retention among astronauts.

    PubMed

    Stepaniak, Philip C; Ramchandani, Suneil R; Jones, Jeffrey A

    2007-04-01

    Although acute urinary retention (AUR) is not commonly thought of as a life-threatening condition, its presentation in orbit can lead to a number of medical complications that could compromise a space mission. We report on a middle-aged astronaut who developed urinary retention during two spaceflights. On the first mission of note, the astronaut initially took standard doses of promethazine and scopolamine before launch, and developed AUR immediately after entering orbit. For the first 3 d, the astronaut underwent intermittent catheterizations with a single balloon-tipped catheter. Due to the lack of iodine solution on board and the need for the astronaut to complete certain duties without interruption, the catheter was left in place for a total of 4 d. Although the ability to void returned after day 7, a bout of AUR reemerged on day 10, 1 d before landing. On return to Earth, a cystometrogram was unremarkable. During the astronaut's next mission, AUR again recurred for the first 24 h of microgravity exposure, and the astronaut was subsequently able to void spontaneously while in space. This report details the presentation of this astronaut, the precautions that were taken for space travel subsequent to the initial episode of AUR, and the possible reasons why space travel can predispose astronauts to urinary retention while in orbit. The four major causes of AUR--obstructive, pharmacologic, psychogenic, and neurogenic-are discussed, with an emphasis on how these may have played a role in this case.

  14. Retention Study of Flavonoids Under Different Chromatographic Modes.

    PubMed

    Sentkowska, Aleksandra; Biesaga, Magdalena; Pyrzynska, Krystyna

    2016-04-01

    The goal of this study was to investigate the chromatographic behavior of selected flavonoids from their different subgroups (flavonols, flavanones, flavones and isoflavones) in hydrophilic interaction liquid chromatography (HILIC). Chromatographic measurements were made on two different HILIC columns: cross-linked DIOL (Luna HILIC) and zwitterionic sulfoalkylbetaine (SeQuant ZIC-HILIC). Separation parameters such as the content of acetonitrile and pH of an eluent were studied. On the ZIC column, the retention factors of flavonoids increased with decreasing water content in the mobile phase. The increase in pH of the aqueous component mainly affects the polarity of the analytes. DIOL stationary phase shows more or less apparent dual retention mechanism, HILIC at the acetonitrile (ACN) content ≥75% and reversed phase (RP) with lower content of organic modifier. In the presence of ammonium acetate in the mobile phase, the retention of flavonoids onto the DIOL column increases without change in the selectivity of the separations. The similar effect, but considerably smaller was observed for aglycones on the ZIC column. The retention of studied glycosides (hesperidin, rutin) decreases in the presence of salt in the mobile phase. The significantly higher mass spectrometry sensitivity was observed under HILIC conditions in comparison with the most often used RP LC due to much higher content of ACN in the mobile phase. Finally, under optimal chromatographic conditions, the method was validated and applied for the determination of flavonoids in chamomile (Matricaria chamomilla L.) infusion. PMID:26668302

  15. Neckband retention for lesser snow geese in the western Arctic

    USGS Publications Warehouse

    Samuel, M.D.; Goldberg, D.R.; Smith, A.E.; Baranyuk, W.; Cooch, E.G.

    2001-01-01

    Neckbands are commonly used in waterfowl studies (especially geese) to identify individuals for determination of movement and behavior and to estimate population parameters. Substantial neckband loss can adversely affect these research objectives and produce biased survival estimates. We used capture, recovery, and observation histories for lesser snow geese (Chen caerulescens caerulescens) banded in the western Arctic, 1993-1996, to estimate neckband retention. We found that neckband retention differed between snow goose breeding colonies at Wrangel Island, Russia, and Banks Island, Northwest Territories, Canada. Male snow geese had higher neckband loss than females, a pattern similar to that found for Canada geese (Branta canadensis) and lesser snow geese in Alaska. We found that the rate of neckband loss increased with time, suggesting that neckbands are lost as the plastic deteriorates. Survival estimates for geese based on resighting neckbands will be biased unless estimates are corrected for neckband loss. We recommend that neckband loss be estimated using survival estimators that incorporate recaptures, recoveries, and observations of marked birds. Research and management studies using neckbands should be designed to improve neckband retention and to include the assessment of neckband retention.

  16. A float mechanism of retention in reversed-phase chromatography

    NASA Astrophysics Data System (ADS)

    Deineka, V. I.; Deineka, L. A.; Saenko, I. I.; Chulkov, A. N.

    2015-07-01

    A float mechanism of retention in reversed-phase HPLC is proposed as an alternative to the known mechanisms of the distribution and hydrophobic expulsion of sorbate to the surface of a sorbent. Experimental data that the sorption of a flavylium structure is poorly sensitive to the position of OH groups, and that the retention of anthocyanins depends on the length of bonded alkyl radicals of reversed phase, form the basis of the proposed hypothesis. It is noted that the retention of anthocyanins depends on the orientation of hydroxyl groups in carbohydrate radicals, due to which the chromatographic behavior of anthocyanins is different for glucosides and galactosides, for arabinosides and xylosides, and so on. In other words, retention is a reliable indicator of the composition of a carbohydrate fragment. It is concluded that carbohydrate radicals serve as unique floats, while flat flavilic ions penetrate into the bonded phase. The existence of floats is the main reason for the lower efficiency (of the number of theoretical plates) of the peaks of anthocyanins. It is shown that if two carbohydrate radicals are present at different sites of aglycone (a two-float sorbate), the peaks of the substance are characterized by substantial additional broadening.

  17. Nanoscale retention-loss dynamics of polycrystalline PbTiO{sub 3} nanotubes.

    SciTech Connect

    Choi, H.; Kim, Y.; Hong, S.; Sung, T.-H.; Shin, H.; No, K.

    2011-07-01

    We observed the nanoscale retention dynamics of polycrystalline PbTiO{sub 3} nanotubes using piezoresponse force microscopy. We found that the retention loss of the nanodot domains on the nanotubes showed the stretched exponential relaxation behaviors with stretched exponential factor n being less than 1 (0.523 and 0.692), which are similar to the thin films. In addition, the nanodot domains showed a diverse relaxation time constant {tau} due to different remnant polarization of each dot domains.

  18. Gastro retention using polymer cocoons.

    PubMed

    Arnold, Julien; Hunkeler, David

    2015-02-01

    A gastro-retentive capsule has been prepared which is retained in the stomach for a period of 24h, providing a vehicle for the controlled delivery to the upper intestines. These "gastro cocoons" can resist passage through the sphincter of the stomach, and can retain a high drug payload (30%). They are made from oppositely charged polyelectrolytes and can swell to twice their initial volume. They are strong and also can resist 550 N of compressive force. They are based on filled pharmaceutical capsules which are visible to X-rays. Using ambroxol hydrochloride as a model drug linear, zero-order, release curves were obtained. PMID:25078789

  19. Gastro retention using polymer cocoons.

    PubMed

    Arnold, Julien; Hunkeler, David

    2015-02-01

    A gastro-retentive capsule has been prepared which is retained in the stomach for a period of 24h, providing a vehicle for the controlled delivery to the upper intestines. These "gastro cocoons" can resist passage through the sphincter of the stomach, and can retain a high drug payload (30%). They are made from oppositely charged polyelectrolytes and can swell to twice their initial volume. They are strong and also can resist 550 N of compressive force. They are based on filled pharmaceutical capsules which are visible to X-rays. Using ambroxol hydrochloride as a model drug linear, zero-order, release curves were obtained.

  20. Médecine des voyages

    PubMed Central

    Aw, Brian; Boraston, Suni; Botten, David; Cherniwchan, Darin; Fazal, Hyder; Kelton, Timothy; Libman, Michael; Saldanha, Colin; Scappatura, Philip; Stowe, Brian

    2014-01-01

    Résumé Objectif Définir la pratique de la médecine des voyages, présenter les éléments fondamentaux d’une consultation complète préalable aux voyages à des voyageurs internationaux et aider à identifier les patients qu’il vaudrait mieux envoyer en consultation auprès de professionnels de la médecine des voyages. Sources des données Les lignes directrices et les recommandations sur la médecine des voyages et les maladies liées aux voyages publiées par les autorités sanitaires nationales et internationales ont fait l’objet d’un examen. Une recension des ouvrages connexes dans MEDLINE et EMBASE a aussi été effectuée. Message principal La médecine des voyages est une spécialité très dynamique qui se concentre sur les soins préventifs avant un voyage. Une évaluation exhaustive du risque pour chaque voyageur est essentielle pour mesurer avec exactitude les risques particuliers au voyageur, à son itinéraire et à sa destination et pour offrir des conseils sur les interventions les plus appropriées en gestion du risque afin de promouvoir la santé et prévenir les problèmes médicaux indésirables durant le voyage. Des vaccins peuvent aussi être nécessaires et doivent être personnalisés en fonction des antécédents d’immunisation du voyageur, de son itinéraire et du temps qu’il reste avant son départ. Conclusion La santé et la sécurité d’un voyageur dépendent du degré d’expertise du médecin qui offre le counseling préalable à son voyage et les vaccins, au besoin. On recommande à ceux qui donnent des conseils aux voyageurs d’être conscients de l’ampleur de cette responsabilité et de demander si possible une consultation auprès de professionnels de la médecine des voyages pour tous les voyageurs à risque élevé.

  1. Retention and excretion of 95Zr-95Nb in humans.

    PubMed

    Thind, K S

    1995-12-01

    This note describes the retention and excretion of 95Zr-95Nb in humans based on a recent CANDU experience and a literature survey of reported cases. Two data bases, QUEST and INIS were used for the survey. Three reported cases were discovered: two for occupational exposures and one for public exposure from nuclear weapons fallout. Human lung retention from these three cases, plus whole body retention and some limited fecal excretion data from a recently occurred exposure at a CANDU station, were reviewed and tested against predictions based on ICRP Publication 30 model. Based on the fits of this model to the reported data it seems that the three occupational exposures exhibit class Y behavior while the public exposure exhibits class W behavior. For only one case is the chemical compound known with certainty: ZrO2. Zirconium oxides are currently classified as class W in ICRP Publications 30 and 54. This work confirms a suggestion that oxides of zirconium be classified as class Y and should be taken into account by the ICRP in its future publications.

  2. Radionuclide Retention in Concrete Wasteforms

    SciTech Connect

    Wellman, Dawn M.; Jansik, Danielle P.; Golovich, Elizabeth C.; Cordova, Elsa A.

    2012-09-24

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of LLW and MLLW, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

  3. Preheating temperature effect on tritium retention in VPS-W

    SciTech Connect

    Sato, M.; Uchimura, H.; Toda, K.; Oya, Y.; Okuno, K.; Tokunaga, T.; Watanabe, H.; Yoshida, N.; Hatano, Y.; Kasada, R.; Kimura, A.; Nagasaka, T.

    2015-03-15

    The W coating by Vacuum Plasma Spraying (VPS) technology is thought to be reasonable for most plasma facing components in future fusion reactors. In this paper the deuterium retention behavior for the Vacuum Plasma Spraying (VPS) tungsten (W) coating has been studied to demonstrate the tritium retention as a function of heating temperature. It has been found that two major deuterium desorption stages were observed at the temperature regions of 400 - 700 K (Stage 1) and 900 - 1100 K (Stage 2), considering that Stage 1 has been linked to the desorption of deuterium trapped by near surface and intrinsic defects, and Stage 2 has been related to the desorption of deuterium bound to impurities as C-D bonds. By heating the sample above 673 K, the major peak of C-1s shifted from C-O bond to C-C bond, where the retention of deuterium as Stage 2 has increased. Therefore it indicates that the hydrogen isotope retention was controlled by the amount of C-C bond in VPS, most of which was contaminated during the VPS coating process. The comparison of several samples (VPS-W with shading, VPS-W without shading and Polycrystalline W (PCW)) shows that the carbon impurity has a large affinity with deuterium and makes stable trapping states compared to that with intrinsic defects and grain boundaries. However, most of them was reduced by heating at 1173 K. Therefore, heating treatment is quite important to get rid of carbon impurities and refrain higher tritium retention in VPS. (authors)

  4. Fission-product retention in HTGR fuels

    SciTech Connect

    Homan, F.J.; Kania, M.J.; Tiegs, T.N.

    1982-01-01

    Retention data for gaseous and metallic fission products are presented for both Triso-coated and Biso-coated HTGR fuel particles. Performance trends are established that relate fission product retention to operating parameters, such as temperature, burnup, and neutron exposure. It is concluded that Biso-coated particles are not adequately retentive of fission gas or metallic cesium, and Triso-coated particles which retain cesium still lose silver. Design implications related to these performance trends are identified and discussed.

  5. Therapeutic Alliance and Retention in Brief Strategic Family Therapy: A Mixed-Methods Study.

    PubMed

    Sheehan, Alyson H; Friedlander, Myrna L

    2015-10-01

    We explored how the therapeutic alliance contributed to retention in Brief Strategic Family Therapy by analyzing videotapes of eight-first sessions in which four therapists worked with one family that stayed in treatment and one family that dropped out. Although behavioral exchange patterns between clients and therapists did not differ by retention status, positive therapist alliance-related behavior followed negative client alliance behavior somewhat more frequently in the retained cases. In the qualitative aspect of the study, four family therapy experts each viewed two randomly assigned sessions and commented on their quality without knowing the families' retention status. A qualitative analysis of the audiotaped commentaries revealed 18 alliance-related themes that were more characteristic of either the retained or the nonretained cases. PMID:25640754

  6. Therapeutic Alliance and Retention in Brief Strategic Family Therapy: A Mixed-Methods Study.

    PubMed

    Sheehan, Alyson H; Friedlander, Myrna L

    2015-10-01

    We explored how the therapeutic alliance contributed to retention in Brief Strategic Family Therapy by analyzing videotapes of eight-first sessions in which four therapists worked with one family that stayed in treatment and one family that dropped out. Although behavioral exchange patterns between clients and therapists did not differ by retention status, positive therapist alliance-related behavior followed negative client alliance behavior somewhat more frequently in the retained cases. In the qualitative aspect of the study, four family therapy experts each viewed two randomly assigned sessions and commented on their quality without knowing the families' retention status. A qualitative analysis of the audiotaped commentaries revealed 18 alliance-related themes that were more characteristic of either the retained or the nonretained cases.

  7. Radionuclide Retention in Concrete Wasteforms

    SciTech Connect

    Bovaird, Chase C.; Jansik, Danielle P.; Wellman, Dawn M.; Wood, Marcus I.

    2011-09-30

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. The information present in the report provides data that (1) measures the effect of concrete wasteform properties likely to influence radionuclide migration; and (2) quantifies the rate of carbonation of concrete materials in a simulated vadose zone repository.

  8. Formation and retention of methane in coal

    SciTech Connect

    Hucka, V.J.; Bodily, D.M.; Huang, H.

    1992-05-15

    The formation and retention of methane in coalbeds was studied for ten Utah coal samples, one Colorado coal sample and eight coal samples from the Argonne Premium Coal Sample Bank.Methane gas content of the Utah and Colorado coals varied from zero to 9 cm{sup 3}/g. The Utah coals were all high volatile bituminous coals. The Colorado coal was a gassy medium volatile bituminous coal. The Argonne coals cover a range or rank from lignite to low volatile bituminous coal and were used to determine the effect of rank in laboratory studies. The methane content of six selected Utah coal seams and the Colorado coal seam was measured in situ using a special sample collection device and a bubble desorbometer. Coal samples were collected at each measurement site for laboratory analysis. The cleat and joint system was evaluated for the coal and surrounding rocks and geological conditions were noted. Permeability measurements were performed on selected samples and all samples were analyzed for proximate and ultimate analysis, petrographic analysis, {sup 13}C NMR dipolar-dephasing spectroscopy, and density analysis. The observed methane adsorption behavior was correlated with the chemical structure and physical properties of the coals.

  9. Retention of New Teachers in California

    ERIC Educational Resources Information Center

    Reed, Deborah; Rueben, Kim S.; Barbour, Elisa

    2006-01-01

    In the continuing effort to raise the academic performance of public schools, improving teacher retention could be an important strategy for California. Keeping new teachers in the classroom could improve academic performance, because experienced teachers are, on average, more effective at raising student test scores. Better retention of teachers…

  10. Positive Youth Development and Undergraduate Student Retention

    ERIC Educational Resources Information Center

    Demetriou, Cynthia; Powell, Candice

    2014-01-01

    The primary theoretical tradition in the study of college retention has been sociological. A review and synthesis of common themes of development among traditional-age, college students suggests that a developmental perspective on the retention of youth in college may have more to offer than the dominant sociological paradigm. This article argues…

  11. 10 CFR 37.103 - Record retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Record retention. 37.103 Section 37.103 Energy NUCLEAR REGULATORY COMMISSION PHYSICAL PROTECTION OF CATEGORY 1 AND CATEGORY 2 QUANTITIES OF RADIOACTIVE MATERIAL Records § 37.103 Record retention. Licensees shall maintain the records that are required by...

  12. The Psychology Underlying Successful Retention Practices.

    ERIC Educational Resources Information Center

    Bean, John; Eaton, Shevawn Bogdan

    2002-01-01

    Describes the psychological processes that lead to academic and social integration based on a retention model proposed by the authors. Describes how successful retention programs such as learning communities, freshman interest groups, tutoring, and orientation rely on psychological processes. Four psychological theories form the basis for…

  13. The Grade Retention/Social Promotion Debate.

    ERIC Educational Resources Information Center

    Lindelow, John

    1985-01-01

    This publication focuses on the retention/promotion debate regarding failing and low-achieving students. An introductory essay describes the inherent limitation in the research done on this issue--the impossibility of obtaining an appropriate control group--and suggests that the retention/promotion quandary can best be resolved by accommodating…

  14. Measuring Student Retention: A National Analysis.

    ERIC Educational Resources Information Center

    Rosenfeld, Peri

    1988-01-01

    The authors analyzed class-by-class enrollment data from the 1985-86 annual survey of nursing education programs to report retention rates in different types of nursing education programs nationwide. They also present results from a survey addendum in which program directors were asked which factors contribute to their retention problems. (CH)

  15. Faculty Personality: A Factor of Student Retention

    ERIC Educational Resources Information Center

    Shaw, Cassandra S.; Wu, Xiaodong; Irwin, Kathleen C.; Patrizi, L. A. Chad

    2016-01-01

    The purpose of this study was to determine the relationship between student retention and faculty personality as it was hypothesized that faculty personality has an effect on student retention. The methodology adopted for this study was quantitative and in two parts 1) using linear regression models to examine the impact or causality of faculty…

  16. 7 CFR 4280.136 - Minimum retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Minimum retention. 4280.136 Section 4280.136 Agriculture Regulations of the Department of Agriculture (Continued) RURAL BUSINESS-COOPERATIVE SERVICE AND... Efficiency Improvements Program Section B. Guaranteed Loans § 4280.136 Minimum retention. Minimum...

  17. 7 CFR 4280.136 - Minimum retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Minimum retention. 4280.136 Section 4280.136 Agriculture Regulations of the Department of Agriculture (Continued) RURAL BUSINESS-COOPERATIVE SERVICE AND... Efficiency Improvements Program Section B. Guaranteed Loans § 4280.136 Minimum retention. Minimum...

  18. 12 CFR 609.945 - Records retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Records retention. 609.945 Section 609.945 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ELECTRONIC COMMERCE Standards for Boards and Management § 609.945 Records retention. Records stored electronically must be accurate,...

  19. A Model for Freshman Engineering Retention

    ERIC Educational Resources Information Center

    Veenstra, Cindy P.; Dey, Eric L.; Herrin, Gary D.

    2009-01-01

    With the current concern over the growing need for more engineers, there is an immediate need to improve freshman engineering retention. A working model for freshman engineering retention is needed. This paper proposes such a model based on Tinto's Interactionalist Theory. Emphasis in this model is placed on pre-college characteristics as…

  20. 5 CFR 293.511 - Retention schedule.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Retention schedule. 293.511 Section 293.511 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PERSONNEL RECORDS Employee Medical File System Records § 293.511 Retention schedule. (a) Temporary EMFS records...

  1. Factors Affecting Students' Retention at Kuwait University

    ERIC Educational Resources Information Center

    AlKandari, Nabila

    2008-01-01

    This article addresses the factors that affect students' retention at Kuwait University. Five hundred seventy students participated in the study. A survey of 22 retention factors was designed to measure student perceptions. Students presented their agreement on factors which included: achieving personal aspiration, getting jobs, free-of-charge…

  2. Minority Teacher Recruitment and Retention Strategies

    ERIC Educational Resources Information Center

    Kearney-Gissendaner, Janet E.

    2010-01-01

    The tools and resources in this book help school leaders seamlessly incorporate minority teacher recruitment and retention programs into current human-resources activities. With details about exemplary minority teacher recruitment and retention programs, this book also showcases strategies for how to replicate such programs in your own school or…

  3. 12 CFR 226.25 - Record retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 3 2011-01-01 2011-01-01 false Record retention. 226.25 Section 226.25 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM TRUTH IN LENDING (REGULATION Z) Miscellaneous § 226.25 Record retention. (a) General rule. A creditor...

  4. Black Student Retention in Higher Education.

    ERIC Educational Resources Information Center

    Lang, Marvel, Ed.; Ford, Clinita A., Ed.

    This collection focuses on problems in the recruitment, enrollment and retention of Blacks in higher education in America. The following chapters are provided: "The Black Student Retention Problem in Higher Education: Some Introductory Perspectives" (Marvel Lang); "Early Acceptance and Institutional Linkages in a Model Program of Recruitment,…

  5. Effective Teacher Retention Bonuses: Evidence From Tennessee

    ERIC Educational Resources Information Center

    Springer, Matthew G.; Swain, Walker A.; Rodriguez, Luis A.

    2016-01-01

    We report findings from a quasi-experimental evaluation of the recently implemented US$5,000 retention bonus program for effective teachers in Tennessee's Priority Schools. We estimate the impact of the program on teacher retention using a fuzzy regression discontinuity design by exploiting a discontinuity in the probability of treatment…

  6. 12 CFR 226.25 - Record retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Record retention. 226.25 Section 226.25 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM TRUTH IN LENDING (REGULATION Z) Miscellaneous § 226.25 Record retention. (a) General rule. A creditor...

  7. Novel Word Retention in Sequential Bilingual Children

    ERIC Educational Resources Information Center

    Kan, Pui Fong

    2014-01-01

    Children's ability to learn and retain new words is fundamental to their vocabulary development. This study examined word retention in children learning a home language (L1) from birth and a second language (L2) in preschool settings. Participants were presented with sixteen novel words in L1 and in L2 and were tested for retention after…

  8. Managing human resources to improve employee retention.

    PubMed

    Arnold, Edwin

    2005-01-01

    Managers face increased challenges as the demand for health care services increases while the supply of employees with the requisite skills continues to lag. Employee retention will become more important in the effort to service health care needs. Appropriate human resource management strategies and policies implemented effectively can significantly assist managers in dealing with the employee retention challenges ahead.

  9. Profile in Action: Linking Admission and Retention

    ERIC Educational Resources Information Center

    Cortes, Carla M.

    2013-01-01

    A profile-oriented retention strategy embraces the admission process as a powerful lever in improving retention and completion rates and recognizes that the student profile can be shaped by changes in admission policies or priorities--even within the current market position of the institution. In addition, the student body can be oriented toward…

  10. Measuring Up: Benchmarking Graduate Retention. IES Report.

    ERIC Educational Resources Information Center

    Tyers, C.; Perryman, S.; Barber, L.

    Retention of college graduates by employers across the United Kingdom was examined. Data were collected through a survey of 362 organizations and interviews with 36 employers and their graduate employees. Most employers were unworried by their levels of graduate retention; two-thirds expected to keep new recruits for the foreseeable future. Rates…

  11. Retention Revisited: R=E, Id+E & In, Iv.

    ERIC Educational Resources Information Center

    Seidman, Alan

    1996-01-01

    Recent research on college student attrition is examined for trends, and it is suggested that the common perspective on retention and attrition is too narrow; it should be viewed from three perspectives: within-course retention; program retention; and institutional retention rate. Recommended for retention (R) is early (E) identification (Id) plus…

  12. 5 CFR 536.201 - Mandatory grade retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AND PAY RETENTION Grade Retention § 536.201 Mandatory grade retention. (a) Subject to the requirements in this section and in §§ 536.102 and 536.203, an agency must provide grade retention to an employee... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Mandatory grade retention....

  13. Predicting health plan member retention from satisfaction surveys: the moderating role of intention and complaint voicing.

    PubMed

    Huppertz, John W

    2008-01-01

    Many health plans have tried to increase member retention by improving their scores on customer satisfaction surveys. However, prior research has demonstrated weak relationships between member satisfaction and retention, suggesting that other variables are needed to understand how satisfaction impacts member retention. In a longitudinal study 4,806 health plan members who completed satisfaction surveys were re-assessed three years later; we compared measures of satisfaction, intention, and complaining behavior from voluntary disenrollees and retained members. The relationship between satisfaction and retention was moderated by members' intentions to disenroll. The findings suggest that health plans can enhance the predictive validity of their satisfaction surveys by including measures of both satisfaction and intentions. PMID:19064478

  14. Peste des petits ruminants.

    PubMed

    Parida, S; Muniraju, M; Mahapatra, M; Muthuchelvan, D; Buczkowski, H; Banyard, A C

    2015-12-14

    Peste des petits ruminants virus causes a highly infectious disease of small ruminants that is endemic across Africa, the Middle East and large regions of Asia. The virus is considered to be a major obstacle to the development of sustainable agriculture across the developing world and has recently been targeted by the World Organisation for Animal Health (OIE) and the Food and Agriculture Organisation (FAO) for eradication with the aim of global elimination of the disease by 2030. Fundamentally, the vaccines required to successfully achieve this goal are currently available, but the availability of novel vaccine preparations to also fulfill the requisite for differentiation between infected and vaccinated animals (DIVA) may reduce the time taken and the financial costs of serological surveillance in the later stages of any eradication campaign. Here, we overview what is currently known about the virus, with reference to its origin, updated global circulation, molecular evolution, diagnostic tools and vaccines currently available to combat the disease. Further, we comment on recent developments in our knowledge of various recombinant vaccines and on the potential for the development of novel multivalent vaccines for small ruminants.

  15. Peste des petits ruminants.

    PubMed

    Parida, S; Muniraju, M; Mahapatra, M; Muthuchelvan, D; Buczkowski, H; Banyard, A C

    2015-12-14

    Peste des petits ruminants virus causes a highly infectious disease of small ruminants that is endemic across Africa, the Middle East and large regions of Asia. The virus is considered to be a major obstacle to the development of sustainable agriculture across the developing world and has recently been targeted by the World Organisation for Animal Health (OIE) and the Food and Agriculture Organisation (FAO) for eradication with the aim of global elimination of the disease by 2030. Fundamentally, the vaccines required to successfully achieve this goal are currently available, but the availability of novel vaccine preparations to also fulfill the requisite for differentiation between infected and vaccinated animals (DIVA) may reduce the time taken and the financial costs of serological surveillance in the later stages of any eradication campaign. Here, we overview what is currently known about the virus, with reference to its origin, updated global circulation, molecular evolution, diagnostic tools and vaccines currently available to combat the disease. Further, we comment on recent developments in our knowledge of various recombinant vaccines and on the potential for the development of novel multivalent vaccines for small ruminants. PMID:26443889

  16. Peste des petits ruminants

    PubMed Central

    Parida, S.; Muniraju, M.; Mahapatra, M.; Muthuchelvan, D.; Buczkowski, H.; Banyard, A.C.

    2015-01-01

    Peste des petits ruminants virus causes a highly infectious disease of small ruminants that is endemic across Africa, the Middle East and large regions of Asia. The virus is considered to be a major obstacle to the development of sustainable agriculture across the developing world and has recently been targeted by the World Organisation for Animal Health (OIE) and the Food and Agriculture Organisation (FAO) for eradication with the aim of global elimination of the disease by 2030. Fundamentally, the vaccines required to successfully achieve this goal are currently available, but the availability of novel vaccine preparations to also fulfill the requisite for differentiation between infected and vaccinated animals (DIVA) may reduce the time taken and the financial costs of serological surveillance in the later stages of any eradication campaign. Here, we overview what is currently known about the virus, with reference to its origin, updated global circulation, molecular evolution, diagnostic tools and vaccines currently available to combat the disease. Further, we comment on recent developments in our knowledge of various recombinant vaccines and on the potential for the development of novel multivalent vaccines for small ruminants. PMID:26443889

  17. Practice and retention of nonwords in adults who stutter

    PubMed Central

    Sasisekaran, Jayanthi; Weisberg, Sanford

    2014-01-01

    Purpose We investigated short-term practice and retention of nonwords in 10 adults who stutter (Mean age = 30.7 years, SD = 15.1) and age and sex-matched 10 control participants (Mean age = 30.8 years, SD = 14.9). Methods Participants were required to repeat nonwords varying in length (3, 4, 6 syllables), phonotactic constraint (PC vs. NPC, on 3-syllable nonwords only), and complexity (simple, complex). They were tested twice with one hour gap between sessions. Results Logistic mixed model of speech accuracy revealed that the AWS showed a significantly lower probability of correct responses with increasing length and complexity. Analysis of speech kinematics revealed practice effects within Session 1 in AWS seen as a reduction in movement variability for the 3-syllable nonwords; the control group was performing at ceiling at this length. For the 4-syllable nonwords, the control group showed a significant reduction in movement variability with practice, and retained this reduction in Session 2, while the AWS group did not show practice or retention. Group differences were not evident at the 6-syllable level. Conclusions Group differences in speech accuracy suggest differences in phonemic encoding and/or speech motor processes. Group differences in changes in movement variability within and between sessions suggest reduced practice and retention in AWS. Relevance of the combined use of both behavioral and kinematic measures to interpret the nature of the skill acquisition deficit in persons who stutter is discussed. PMID:25173457

  18. Quantifying colloid retention in partially saturated porous media

    NASA Astrophysics Data System (ADS)

    Zevi, Yuniati; Dathe, Annette; Gao, Bin; Richards, Brian K.; Steenhuis, Tammo S.

    2006-12-01

    The transport of colloid-contaminant complexes and colloid-sized pathogens through soil to groundwater is of concern. Visualization and quantification of pore-scale colloid behavior will enable better description and simulation of retention mechanisms at individual surfaces, in contrast to breakthrough curves which only provide an integrated signal. We tested two procedures for quantifying colloid movement and retention as observed in pore-scale image sequences. After initial testing with static images, three series of images of synthetic microbead suspensions passing through unsaturated sand were examined. The region procedure (implemented in ImageJ) and the Boolean procedure (implemented in KS400) yielded nearly identical results for initial test images and for total colloid-covered areas in three image series. Because of electronic noise resulting in pixel-level brightness fluctuations the Boolean procedure tended to underestimate attached colloid counts and conversely overestimate mobile colloid counts. The region procedure had a smaller overestimation error of attached colloids. Reliable quantification of colloid retention at pore scale can be used to improve current understanding on the transport mechanisms of colloids in unsaturated porous media. For example, attachment counts at individual air/water meniscus/solid interface were well described by Langmuir isotherms.

  19. Retention force measurement of telescopic crowns.

    PubMed

    Bayer, Stefan; Stark, Helmut; Mues, Sebastian; Keilig, Ludger; Schrader, Anja; Enkling, Norbert

    2010-10-01

    This study deals with the determination of the retentive force between primary and secondary telescopic crowns under clinical conditions. Forty-three combined fixed-removable prostheses with a total of 140 double crowns were used for retention force measurement of the telescopic crowns prior to cementation. The crowns had a preparation of 1-2°. A specifically designed measuring device was used. The retentive forces were measured with and without lubrication by a saliva substitute. The measured values were analyzed according to the type of tooth (incisors, canines, premolars, and molars). Additionally, a comparison between lubricated and unlubricated telescopic crowns was done. As maximum retention force value 29.98 N was recorded with a telescopic crown on a molar, while the minimum of 0.08 N was found with a specimen on a canine. The median value of retention force of all telescopic crowns reached 1.93 N with an interquartile distance of 4.35 N. No statistically significant difference between lubricated and unlubricated specimens was found. The results indicate that retention force values of telescopic crowns, measured in clinical practice, are often much lower than those cited in the literature. The measurements also show a wide range. Whether this proves to be a problem for the patient's quality of life or not can however only be established by a comparison of the presented results with a follow-up study involving measurement of intraoral retention and determination by e.g. oral health impact profile.

  20. Fractal processes in soil water retention

    SciTech Connect

    Tyler, S.W.; Wheatcraft, S.W. )

    1990-05-01

    The authors propose a physical conceptual model for soil texture and pore structure that is based on the concept of fractal geometry. The motivation for a fractal model of soil texture is that some particle size distributions in granular soils have already been shown to display self-similar scaling that is typical of fractal objects. Hence it is reasonable to expect that pore size distributions may also display fractal scaling properties. The paradigm that they used for the soil pore size distribution is the Sierpinski carpet, which is a fractal that contains self similar holes (or pores) over a wide range of scales. The authors evaluate the water retention properties of regular and random Sierpinski carpets and relate these properties directly to the Brooks and Corey (or Campbell) empirical water retention model. They relate the water retention curves directly to the fractal dimension of the Sierpinski carpet and show that the fractal dimension strongly controls the water retention properties of the Sierpinski carpet soil. Higher fractal dimensions are shown to mimic clay-type soils, with very slow dewatering characteristics and relatively low fractal dimensions are shown to mimic a sandy soil with relatively rapid dewatering characteristics. Their fractal model of soil water retention removes the empirical fitting parameters from the soil water retention models and provides paramters which are intrinsic to the nature of the fractal porous structure. The relative permeability functions of Burdine and Mualem are also shown to be fractal directly from fractal water retention results.

  1. Causes and implications of colloid and microorganism retention hysteresis.

    PubMed

    Bradford, Scott A; Kim, Hyunjung

    2012-09-01

    Experiments were designed to better understand the causes and implications of colloid and microorganism retention hysteresis with transients in solution ionic strength (IS). Saturated packed column experiments were conducted using two sizes of carboxyl modified latex (CML) microspheres (0.1 and 1.1 μm) and microorganisms (coliphage φX174 and E. coli D21g) under various transient solution chemistry conditions, and 360 μm Ottawa sand that was subject to different levels of cleaning, namely, a salt cleaning procedure that removed clay particles, and a salt+acid cleaning procedure that removed clay and reduced microscopic heterogeneities due to metal oxides and surface roughness. Comparison of results from the salt and salt+acid treated sand indicated that microscopic heterogeneity was a major contributor to colloid retention hysteresis. The influence of this heterogeneity increased with IS and decreasing colloid/microbe size on salt treated sand. These trends were not consistent with calculated mean interaction energies (the secondary minima), but could be explained by the size of the electrostatic zone of influence (ZOI) near microscopic heterogeneities. In particular, the depth of local minima in the interaction energy has been predicted to increase with a decrease in the ZOI when the colloid size and/or the Debye length decreased (IS increased). The adhesive interaction was therefore largely irreversible for smaller sized 0.1 μm CML colloids, whereas it was reversible for larger 1.1 μm CML colloids. Similarly, the larger E. coli D21g exhibited greater reversibility in retention than φX174. However, direct comparison of CML colloids and microbes was not possible due to differences in size, shape, and surface properties. Retention and release behavior of CML colloids on salt+acid treated sand was much more consistent with mean interaction energies due to reduction in microscopic heterogeneities.

  2. Average Soil Water Retention Curves Measured by Neutron Radiography

    SciTech Connect

    Cheng, Chu-Lin; Perfect, Edmund; Kang, Misun; Voisin, Sophie; Bilheux, Hassina Z; Horita, Juske; Hussey, Dan

    2011-01-01

    Water retention curves are essential for understanding the hydrologic behavior of partially-saturated porous media and modeling flow transport processes within the vadose zone. In this paper we report direct measurements of the main drying and wetting branches of the average water retention function obtained using 2-dimensional neutron radiography. Flint sand columns were saturated with water and then drained under quasi-equilibrium conditions using a hanging water column setup. Digital images (2048 x 2048 pixels) of the transmitted flux of neutrons were acquired at each imposed matric potential (~10-15 matric potential values per experiment) at the NCNR BT-2 neutron imaging beam line. Volumetric water contents were calculated on a pixel by pixel basis using Beer-Lambert s law after taking into account beam hardening and geometric corrections. To remove scattering effects at high water contents the volumetric water contents were normalized (to give relative saturations) by dividing the drying and wetting sequences of images by the images obtained at saturation and satiation, respectively. The resulting pixel values were then averaged and combined with information on the imposed basal matric potentials to give average water retention curves. The average relative saturations obtained by neutron radiography showed an approximate one-to-one relationship with the average values measured volumetrically using the hanging water column setup. There were no significant differences (at p < 0.05) between the parameters of the van Genuchten equation fitted to the average neutron radiography data and those estimated from replicated hanging water column data. Our results indicate that neutron imaging is a very effective tool for quantifying the average water retention curve.

  3. Etude des Abondances de MG et de fe dans la Composante Stellaire des Disques des Galaxies Spirales

    NASA Astrophysics Data System (ADS)

    Beauchamp, Dominique

    Je presente ici une technique d'observation par imagerie des disques stellaires des galaxies spirales. Je tente, a l'aide d'un modele evolutif multiphase, de determiner les abondances de fer et de magnesium dans les disques. Dans ce but, je mesure les indices Mg2 et Fe5270 du systeme de Lick. Ces elements representent un choix judicieux d'indicateurs car ils sont formes par des supernovae de deux types differents ayant des durees de vie differentes. Le rapport d'abondances de ces deux elements est un indicateur du taux de formation des populations stellaires. Je decris, en premier lieu, les observations, la technique de mesure, ainsi que son application. J'analyse ensuite les indices mesures. A partir du modele multiphase, j'explore differents parametres physiques des spirales comme le taux de formation stellaire, l'evolution des abondances, les effets possibles de la presence de la barre, etc.

  4. Classification of 20 DES Supernova with OzDES

    NASA Astrophysics Data System (ADS)

    Davis, T. M.; Kim, A. G.; Macualay, E.; Lidman, C.; Sharp, R.; Tucker, B. E.; Yuan, F.; Zhang, B.; Lewis, G. F.; Sommer, N. E.; Martini, P.; Mould, J.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.

    2015-12-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  5. Classification of 8 DES Supernova with OzDES

    NASA Astrophysics Data System (ADS)

    King, A.; Moller, A.; Sommer, N. E.; Tucker, B. E.; Childress, M. J.; Lewis, G. F.; Lidman, C.; OâNeill, C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; D'Andrea, C.; Prajs, S.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.

    2016-09-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  6. Classification of 13 DES supernova with OzDES

    NASA Astrophysics Data System (ADS)

    Sommer, N.; Tucker, B. E.; Moller, A.; Zhang, B.; Macualay, E.; Lidman, C.; Gshwend, J.; Martini, P.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Prajs, S.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.

    2016-09-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  7. Classification of 3 DES Supernovae with OzDES

    NASA Astrophysics Data System (ADS)

    Moller, A.; Tucker, B. E.; Yuan, F.; Lewis, G.; Lidman, C.; Macaulay, E.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.

    2016-02-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  8. Classification of 2 DES supernova with OzDES

    NASA Astrophysics Data System (ADS)

    O'Neill, C. R.; Moller, A.; Sommer, N. E.; Tucker, B. E.; Childress, M. J.; Lewis, G. F.; Lidman, C.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; D'Andrea, C.; Gladney, L.; March, M.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Macaulay, E.; Nichol, R.; Prajs, S.; Smith, M.; Sullivan, M.; Maartens, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Gupta, R.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Papadopoulos, A.; Morganson, E.

    2016-10-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  9. Academic Dishonesty: Behaviors, Sanctions, and Retention of Adjudicated College Students

    ERIC Educational Resources Information Center

    Olafson, Lori; Schraw, Gregory; Kehrwald, Nicholas

    2014-01-01

    Academic dishonesty, also known as academic misconduct, includes a variety of actions such as plagiarism, cheating on tests using text messaging or concealed notes, exchanging work with other students, buying essays from students or on the Internet, and having other students write examinations (Diekhoff, LaBeff, Shinohara, & Yasukawa, 1999;…

  10. The Causal Effects of Grade Retention on Behavioral Outcomes

    ERIC Educational Resources Information Center

    Mariano, Lou; Martorell, Paco

    2015-01-01

    Requiring a failing student to repeat a grade is, of course, not a novel idea. The theory behind test-based promotion policies is that students who fail to demonstrate a sufficient understanding of their current grade's curriculum lack the prerequisite proficiency to fully engage in the following grade. This view recognizes the cumulative nature…

  11. Application of a quantitative structure retention relationship approach for the prediction of the two-dimensional gas chromatography retention times of polycyclic aromatic sulfur heterocycle compounds.

    PubMed

    Gieleciak, Rafal; Hager, Darcy; Heshka, Nicole E

    2016-03-11

    Information on the sulfur classes present in petroleum is a key factor in determining the value of refined products and processing behavior in the refinery. A large part of the sulfur present is included in polycyclic aromatic sulfur heterocycles (PASHs), which in turn are difficult to desulfurize. Furthermore, some PASHs are potentially more mutagenic and carcinogenic than polycyclic aromatic hydrocarbons, PAHs. All of this calls for improved methods for the identification and quantification of individual sulfur species. Recent advances in analytical techniques such as comprehensive two-dimensional gas chromatography (GC×GC) have enabled the identification of many individual sulfur species. However, full identification of individual components, particularly in virgin oil fractions, is still out of reach as standards for numerous compounds are unavailable. In this work, a method for accurately predicting retention times in GC×GC using a QSRR (quantitative structure retention relationship) method was very helpful for the identification of individual sulfur compounds. Retention times for 89 saturated, aromatic, and polyaromatic sulfur-containing heterocyclic compounds were determined using two-dimensional gas chromatography. These retention data were correlated with molecular descriptors generated with CODESSA software. Two independent QSRR relationships were derived for the primary as well as the secondary retention characteristics. The predictive ability of the relationships was tested by using both independent sets of compounds and a cross-validation technique. When the corresponding chemical standards are unavailable, the equations developed for predicting retention times can be used to identify unknown chromatographic peaks by matching their retention times with those of sulfur compounds of known molecular structure.

  12. Retention and leaching of nitrite by municipal solid waste incinerator bottom ash under the landfill circumstance.

    PubMed

    Yao, Jun; Kong, Qingna; Zhu, Huayue; Long, Yuyang; Shen, Dongsheng

    2015-01-01

    The retention and leaching of nitrite by municipal solid waste incinerator (MSWI) bottom ash could affect its migration in the landfill. In this study, the effect of the dosage of MSWI bottom ash as well as the variation of the landfill environmental parameters including pH, anions and organic matter on the nitrite retention and leaching behavior was investigated by batch experiments. The highest removal percentage (73.0%) of nitrite was observed when the dosage of MSWI bottom ash was 10 g L(-1) in 2 mg L(-1) nitrite solution. Further increase of the dosage would retard the retention, as the nitrite leaching from MSWI bottom ash was enhanced. The optimum retention of nitrite was observed when the pH was 5.0, while the leaching of nitrite showed a consistent reduction with the increase of pH. Besides, the presence of Cl(-), SO4(2)(-) and acetic acid could enhance the leaching of nitrite and mitigate the retention process. However, the retention of nitrite was enhanced by PO4(3)(-), which was probably due to the formation of the apatite, an active material for the adsorption of the nitrite. These results suggested that MSWI bottom ash could affect the migration of nitrite in the landfill, which was related to the variation of the landfill circumstance. PMID:25033242

  13. Effect of temperature on the chromatographic retention of ionizable compounds. II. Acetonitrile-water mobile phases.

    PubMed

    Gagliardi, Leonardo G; Castells, Cecilia B; Ràfols, Clara; Rosés, Martí; Bosch, Elisabeth

    2005-06-10

    The retentive behavior of weak acids and bases in reversed-phase liquid chromatography (RPLC) upon changes in column temperature has been theoretically and experimentally studied. The study focuses on examining the temperature dependence of the retention of various solutes at eluent pH close to their corresponding pKa values, and on the indirect role exerted by the buffer ionization equilibria on retention and selectivity. Retention factors of several ionizable compounds in a typical octadecylsilica column and using buffer solutions dissolved in 30% (v/v) acetonitrile as eluent at five temperatures in the range from 25 to 50 degrees C were carefully measured. Six buffer solutions were prepared from judiciously chosen conjugated pairs of different chemical nature. Their pKa values in this acetonitrile-water composition and within the range of 15-50 degrees C were determined potentiometrically. These compounds exhibit very different standard ionization enthalpies within this temperature range. Thus, whenever they are used to control mobile phase pH, the column temperature determines their final pH. Predictive equations of retention that take into account the temperature effect on both the transfer and the ionization processes are evaluated. This study demonstrates the significant role that the selected buffer would have on retention and selectivity in RPLC at temperatures higher than 25 degrees C, particularly for solutes that coelute. PMID:16001552

  14. Magnitude and distribution of stresses in composite resin and sound dentine interface with mechanical retentions

    PubMed Central

    Borie, Eduardo; Orsi, Iara-Augusta; Del Sol, Mariano

    2015-01-01

    Background Adhesive systems are constantly subjected to mechanical and chemical stresses that negatively impact the integrity and durability of the dentine-adhesive interface. Despite the lack of evidence to support or reject the clinical indication for mechanical retention, the potential further contribution of these preparations to the behavior of the composite resin-sound dentine bond has been rarely addressed. The authors evaluated by finite element analysis the effect of mechanical retention on the magnitude and distribution of stresses in a composite resin-sound dentin bonding interface when subjected to tensile and shear forces. Material and Methods A three-dimensional model was created based on three cylindrical volumes representing the sound dentin, adhesive system, and composite resin. From this main model, two models were designed to simulate dentine bonding: 1) a model with no mechanical retention, which considered flat adhesion; and 2) a model with retention, which considered four hemispherical holes on the dentine surface. Both groups were subjected to linear static analysis under tensile and shear loading of 200N. Results At the model with retentions’ bonding interface under tensile and shear loading, a concentration of Von Mises equivalent stress was observed within the retentions, with a reduction of those stresses on the bonding boundary surface. Conclusions Additional mechanical retention increases the tensile strength of the sound dentin-composite resin bonding interface, promoting a decrease in the magnitude of the stresses and their redistribution under tensile and shear loading. Key words:Adhesion, composite resins, dentine, finite element analysis. PMID:26155338

  15. Online Mate-Retention Tactics on Facebook Are Associated With Relationship Aggression.

    PubMed

    Brem, Meagan J; Spiller, Laura C; Vandehey, Michael A

    2015-10-01

    A measure of Facebook-related mate-retention tactics was developed to investigate the relationship between online behaviors and intimate partner aggression. One hundred and seventy-seven young adults (65 men, 112 women) completed questionnaires that included measures of online and offline mate-retention tactics, Facebook jealousy, Facebook surveillance, and intimate partner violence. A factor analysis yielded four subscales for the Facebook Mate-Retention Tactic Inventory (FMRTI): Care and Affection, Jealousy and Surveillance, Possession Signals, and Punishment of Infidelity Threat. The FMRTI total scores were positively correlated with Facebook jealousy, Facebook surveillance, and use of offline mate-retention tactics. The Jealousy and Surveillance subscale uniquely predicted intimate partner psychological and physical aggression over and above existing measures. Facebook mate-retention tactics fully mediated the relation between Facebook jealousy and both intimate partner psychological and physical aggression. The current study provides preliminary evidence for conceptualizing Facebook as an environment for the use of mate-retention tactics that have real-life implications for intimate partner violence. PMID:25339609

  16. Online Mate-Retention Tactics on Facebook Are Associated With Relationship Aggression.

    PubMed

    Brem, Meagan J; Spiller, Laura C; Vandehey, Michael A

    2015-10-01

    A measure of Facebook-related mate-retention tactics was developed to investigate the relationship between online behaviors and intimate partner aggression. One hundred and seventy-seven young adults (65 men, 112 women) completed questionnaires that included measures of online and offline mate-retention tactics, Facebook jealousy, Facebook surveillance, and intimate partner violence. A factor analysis yielded four subscales for the Facebook Mate-Retention Tactic Inventory (FMRTI): Care and Affection, Jealousy and Surveillance, Possession Signals, and Punishment of Infidelity Threat. The FMRTI total scores were positively correlated with Facebook jealousy, Facebook surveillance, and use of offline mate-retention tactics. The Jealousy and Surveillance subscale uniquely predicted intimate partner psychological and physical aggression over and above existing measures. Facebook mate-retention tactics fully mediated the relation between Facebook jealousy and both intimate partner psychological and physical aggression. The current study provides preliminary evidence for conceptualizing Facebook as an environment for the use of mate-retention tactics that have real-life implications for intimate partner violence.

  17. Effect of temperature on the chromatographic retention of ionizable compounds. II. Acetonitrile-water mobile phases.

    PubMed

    Gagliardi, Leonardo G; Castells, Cecilia B; Ràfols, Clara; Rosés, Martí; Bosch, Elisabeth

    2005-06-10

    The retentive behavior of weak acids and bases in reversed-phase liquid chromatography (RPLC) upon changes in column temperature has been theoretically and experimentally studied. The study focuses on examining the temperature dependence of the retention of various solutes at eluent pH close to their corresponding pKa values, and on the indirect role exerted by the buffer ionization equilibria on retention and selectivity. Retention factors of several ionizable compounds in a typical octadecylsilica column and using buffer solutions dissolved in 30% (v/v) acetonitrile as eluent at five temperatures in the range from 25 to 50 degrees C were carefully measured. Six buffer solutions were prepared from judiciously chosen conjugated pairs of different chemical nature. Their pKa values in this acetonitrile-water composition and within the range of 15-50 degrees C were determined potentiometrically. These compounds exhibit very different standard ionization enthalpies within this temperature range. Thus, whenever they are used to control mobile phase pH, the column temperature determines their final pH. Predictive equations of retention that take into account the temperature effect on both the transfer and the ionization processes are evaluated. This study demonstrates the significant role that the selected buffer would have on retention and selectivity in RPLC at temperatures higher than 25 degrees C, particularly for solutes that coelute.

  18. Retention and leaching of nitrite by municipal solid waste incinerator bottom ash under the landfill circumstance.

    PubMed

    Yao, Jun; Kong, Qingna; Zhu, Huayue; Long, Yuyang; Shen, Dongsheng

    2015-01-01

    The retention and leaching of nitrite by municipal solid waste incinerator (MSWI) bottom ash could affect its migration in the landfill. In this study, the effect of the dosage of MSWI bottom ash as well as the variation of the landfill environmental parameters including pH, anions and organic matter on the nitrite retention and leaching behavior was investigated by batch experiments. The highest removal percentage (73.0%) of nitrite was observed when the dosage of MSWI bottom ash was 10 g L(-1) in 2 mg L(-1) nitrite solution. Further increase of the dosage would retard the retention, as the nitrite leaching from MSWI bottom ash was enhanced. The optimum retention of nitrite was observed when the pH was 5.0, while the leaching of nitrite showed a consistent reduction with the increase of pH. Besides, the presence of Cl(-), SO4(2)(-) and acetic acid could enhance the leaching of nitrite and mitigate the retention process. However, the retention of nitrite was enhanced by PO4(3)(-), which was probably due to the formation of the apatite, an active material for the adsorption of the nitrite. These results suggested that MSWI bottom ash could affect the migration of nitrite in the landfill, which was related to the variation of the landfill circumstance.

  19. 21 CFR 107.280 - Records retention.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... HUMAN CONSUMPTION INFANT FORMULA Infant Formula Recalls § 107.280 Records retention. Each manufacturer of an infant formula shall make and retain such records respecting the distribution of the infant... the shelf life of the infant formula....

  20. Tritium retention and removal on TFTR

    SciTech Connect

    Mueller, D.; Blanchard, W.; Doyle, B.L.

    1997-11-01

    Tritium retention and removal are critical issues for the success of ITER or any DT fusion reactor. The Tokamak Fusion Test Reactor, TFTR, is the first fusion facility to afford the opportunity to study the tritium retention and removal over an extended period. In TFTR, tritium accumulates on all surfaces with line of sight to the plasma by codeposition of tritium with carbon. Measurements of both deuterium and tritium retention fractions have yielded retention between 0.2 and 0.6 of the injected fuel in the torus. Tritium has been successfully removed from TFTR by glow discharge cleaning and by air purges. The in-vessel inventory was reduced by a factor of 2, facilitating machine maintenance. In TFTR, the amount of dust recovered from the TFTR vacuum vessel has varied from several grams to a few kilograms.

  1. Tritium retention and removal on TFTR

    SciTech Connect

    Mueller, D.; Blanchard, W.; Doyle, B.L.

    1997-10-01

    Tritium retention and removal are critical issues for the success of ITER or any DT fusion reactor. The Tokamak Fusion Test Reactor, TFTR, is the first fusion facility to afford the opportunity to study the tritium retention and removal over an extended period. In TFTR, tritium accumulates on all surfaces with line of sight to the plasma by codeposition of tritium with carbon. Measurements of both deuterium and tritium retention fractions have yielded retention between 0.2 and 0.6 of the injected fuel in the torus. Tritium has been successfully removed from TFTR by glow discharge cleaning and by air purges. The in-vessel inventory was reduced by a factor of 2, facilitating machine maintenance. In TFTR, the amount of dust recovered from the TFTR vacuum vessel has varied from several grams to a few kilograms.

  2. 21 CFR 107.280 - Records retention.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... HUMAN CONSUMPTION INFANT FORMULA Infant Formula Recalls § 107.280 Records retention. Each manufacturer... monitor recalls of the formula. Such records shall be retained for at least 1 year after the expiration...

  3. 21 CFR 107.280 - Records retention.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... HUMAN CONSUMPTION INFANT FORMULA Infant Formula Recalls § 107.280 Records retention. Each manufacturer... monitor recalls of the formula. Such records shall be retained for at least 1 year after the expiration...

  4. Gage measures electrical connector pin retention force

    NASA Technical Reports Server (NTRS)

    1965-01-01

    The retention force of a female connector pin is measured by observing the action of a calibrated spring in a gage consisting of housing, a plunger terminating in a male subminiature connector pin, and the tension spring.

  5. Taking a Holistic Approach to Retention.

    ERIC Educational Resources Information Center

    Fields, Cheryl D.

    2002-01-01

    Describes how, at the University of Kansas, many students of color are excelling at a rate that has outpaced their peers. Campus officials credit the HAWK Link program and its comprehensive approach to retention. (EV)

  6. 21 CFR 107.280 - Records retention.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... HUMAN CONSUMPTION INFANT FORMULA Infant Formula Recalls § 107.280 Records retention. Each manufacturer... formula through any establishment owned or operated by such manufacturer as may be necessary to effect...

  7. Spinal morphine anesthesia and urinary retention.

    PubMed

    Mahan, K T; Wang, J

    1993-11-01

    Spinal anesthetic is a common form of surgical anesthetic used in foot and ankle surgery. Spinal morphine anesthetic is less common, but has the advantage of providing postoperative analgesia for 12 to 24 hr. A number of complications can occur with spinal anesthesia, including urinary retention that may be a source of severe and often prolonged discomfort and pain for the patient. Management of this problem may require repeated bladder catheterization, which may lead to urinary tract infections or impairment of urethrovesicular function. This study reviews the incidence of urinary retention in 80 patients (40 after general anesthesia and 40 after spinal anesthesia) who underwent foot and ankle surgery at Saint Joseph's Hospital, Philadelphia, PA. Twenty-five percent of the patients who had spinal anesthesia experienced urinary retention, while only 7 1/2% of the group who had general anesthesia had this complication. Predisposing factors, treatment regimen, and recommendations for the prevention and management of urinary retention are presented.

  8. A REVIEW OF EFFORTS TO ORGANIZE INFORMATION ABOUT HUMAN LEARNING, TRANSFER, AND RETENTION.

    ERIC Educational Resources Information Center

    GINSBERG, ROSE; AND OTHERS

    FOURTEEN EFFORTS TO ORGANIZE AVAILABLE INFORMATION ON HUMAN LEARNING, TRANSFER, AND RETENTION ARE SUMMARIZED AND EVALUATED ON SIX CRITERIA--BEHAVIORAL SIGNIFICANCE OF CATEGORIES, SCOPE, OBJECTIVITY AND RELIABILITY OF CATEGORIES, PROGNOSIS FOR THE SYSTEM, LOGICAL STRUCTURE, AND HEURISTIC VALUE OF THE SYSTEM. ATTENTION IS GIVEN TO OTHER SOURCES OF…

  9. Demonstrating the importance of polymer-conjugate conformation in solution on its therapeutic output: Diethylstilbestrol (DES)-polyacetals as prostate cancer treatment.

    PubMed

    Giménez, Vanessa; James, Craig; Armiñán, Ana; Schweins, Ralf; Paul, Alison; Vicent, María J

    2012-04-30

    The design of improved polymeric carriers to be used in the next generation of polymer therapeutics is an ongoing challenge. Biodegradable systems present potential advantages regarding safety benefit apart from the possibility to use higher molecular weight (Mw) carriers allowing PK optimization, by exploiting the enhanced permeability and retention (EPR)-mediated tumor targeting. Within this context, we previously designed pH-responsive polyacetalic systems, tert-polymers, where a drug with the adequate diol-functionality was incorporated within the polymer mainchain. The synthetic, non-steroidal estrogen, diethylstilboestrol (DES) clinically used for the treatment of advanced prostate cancer was chosen as drug. In order to improve the properties of this tert-polymer, novel polyacetalic systems as block-co-polymers, with more defined structure have been obtained. This second generation polyacetals allowed higher drug capacity than the tert-polymer, a biphasic DES release profile at acidic pH and due to its controlled amphiphilic character readily formed micelle-like structures in solution. These features result in an enhancement of conjugate therapeutic value in selected prostate cancer cell models. Exhaustive physico-chemical characterization focusing on nanoconjugate solution behavior and using advanced techniques, such as, pulsed-gradient spin-echo NMR (PGSE-NMR) and small-angle neutron scattering (SANS), has been carried out in order to demonstrate this hypothesis. Clear evidence of significantly different conformation in solution has been obtained for both polyacetals. These results demonstrate that an adequate control on molecular or supramolecular conformation in solution with polymer therapeutics is crucial in order to achieve the desired therapeutic output.

  10. L'astronomie des Anciens

    NASA Astrophysics Data System (ADS)

    Nazé, Yaël

    2009-04-01

    Quelle que soit la civilisation à laquelle il appartient, l'être humain cherche dans le ciel des réponses aux questions qu'il se pose sur son origine, son avenir et sa finalité. Le premier mérite de ce livre est de nous rappeler que l'astronomie a commencé ainsi à travers les mythes célestes imaginés par les Anciens pour expliquer l'ordre du monde et la place qu'ils y occupaient. Mais les savoirs astronomiques passés étaient loin d'être négligeables et certainement pas limités aux seuls travaux des Grecs : c'est ce que l'auteur montre à travers une passionnante enquête, de Stonehenge à Gizeh en passant par Pékin et Mexico, fondée sur l'étude des monuments anciens et des sources écrites encore accessibles. Les tablettes mésopotamiennes, les annales chinoises, les chroniques médiévales, etc. sont en outre d'une singulière utilité pour les astronomes modernes : comment sinon remonter aux variations de la durée du jour au cours des siècles, ou percer la nature de l'explosion qui a frappé tant d'observateurs en 1054 ? Ce livre offre un voyage magnifiquement illustré à travers les âges, entre astronomie et archéologie.

  11. Improving Student Retention in Ontario Secondary Schools. Student Retention and Transition Series.

    ERIC Educational Resources Information Center

    King, A. J. C.; And Others

    The purpose of this study was to evaluate retention efforts in Ontario (Canada) secondary schools in order to develop policy and support initiatives designed to reduce dropouts and improve retention rates. The study had four parts: (1) an analysis of credit accumulation for four cohorts and academic achievement patterns over 4 years in 16 schools;…

  12. Considering Student Retention as a Complex System: A Possible Way forward for Enhancing Student Retention

    ERIC Educational Resources Information Center

    Forsman, Jonas; van den Bogaard, Maartje; Linder, Cedric; Fraser, Duncan

    2015-01-01

    This study uses multilayer minimum spanning tree analysis to develop a model for student retention from a complex system perspective, using data obtained from first-year engineering students at a large well-regarded institution in the European Union. The results show that the elements of the system of student retention are related to one another…

  13. Nursing Student Retention in Associate Degree Nursing Programs Utilizing a Retention Specialist

    ERIC Educational Resources Information Center

    Schrum, Ronna A.

    2014-01-01

    The purpose of this study was to examine specific variables associated with nursing student retention in Associate Degree Nursing (ADN) Programs. Jeffreys (2004) Nursing Undergraduate Retention and Success (NURS) conceptual model provided the framework for this descriptive correlational study. One hundred sixty eight pre-licensure associate degree…

  14. Retention in care and medication adherence: current challenges to antiretroviral therapy success.

    PubMed

    Holtzman, Carol W; Brady, Kathleen A; Yehia, Baligh R

    2015-04-01

    Health behaviors such as retention in HIV medical care and adherence to antiretroviral therapy (ART) pose major challenges to reducing new HIV infections, addressing health disparities, and improving health outcomes. Andersen's Behavioral Model of Health Service Use provides a conceptual framework for understanding how patient and environmental factors affect health behaviors and outcomes, which can inform the design of intervention strategies. Factors affecting retention and adherence among persons with HIV include patient predisposing factors (e.g., mental illness, substance abuse), patient-enabling factors (e.g., social support, reminder strategies, medication characteristics, transportation, housing, insurance), and healthcare environment factors (e.g., pharmacy services, clinic experiences, provider characteristics). Evidence-based recommendations for improving retention and adherence include (1) systematic monitoring of clinic attendance and ART adherence; (2) use of peer or paraprofessional navigators to re-engage patients in care and help them remain in care; (3) optimization of ART regimens and pharmaceutical supply chain management systems; (4) provision of reminder devices and tools; (5) general education and counseling; (6) engagement of peer, family, and community support groups; (7) case management; and (8) targeting patients with substance abuse and mental illness. Further research is needed on effective monitoring strategies and interventions that focus on improving retention and adherence, with specific attention to the healthcare environment. PMID:25792300

  15. Retention in Care and Medication Adherence: Current Challenges to Antiretroviral Therapy Success

    PubMed Central

    Holtzman, Carol W.; Brady, Kathleen A.; Yehia, Baligh R.

    2015-01-01

    Health behaviors, such as retention in HIV medical care and adherence to antiretroviral therapy (ART), pose major challenges to reducing new HIV infections, addressing health disparities, and improving health outcomes. Andersen's Behavioral Model of Health Service Use provides a conceptual framework for understanding how patient and environmental factors affect health behaviors and outcomes, which can inform the design of intervention strategies. Factors affecting retention and adherence among persons with HIV include patient predisposing factors (e.g. mental illness, substance abuse), patient enabling factors (e.g. social support, reminder strategies, medication characteristics, transportation, housing, insurance), and health care environment factors (e.g. pharmacy services, clinic experiences, provider characteristics). Evidence-based recommendations for improving retention and adherence include 1) systematic monitoring of clinic attendance and ART adherence; 2) use of peer or paraprofessional navigators to re-engage patients in care and help them remain in care; 3) optimization of ART regimens and pharmaceutical supply chain management systems 4) provision of reminder devices and tools; 5) general education and counseling; 6) engagement of peer, family, and community support groups; 7) case management; and 8) targeting patients with substance abuse and mental illness. Further research is needed on effective monitoring strategies and interventions that focus on improving retention and adherence, with specific attention to the health care environment. PMID:25792300

  16. Assessing Chemical Retention Process Controls in Ponds

    NASA Astrophysics Data System (ADS)

    Torgersen, T.; Branco, B.; John, B.

    2002-05-01

    Small ponds are a ubiquitous component of the landscape and have earned a reputation as effective chemical retention devices. The most common characterization of pond chemical retention is the retention coefficient, Ri= ([Ci]inflow-[Ci] outflow)/[Ci]inflow. However, this parameter varies widely in one pond with time and among ponds. We have re-evaluated literature reported (Borden et al., 1998) monthly average retention coefficients for two ponds in North Carolina. Employing a simple first order model that includes water residence time, the first order process responsible for species removal have been separated from the water residence time over which it acts. Assuming the rate constant for species removal is constant within the pond (arguable at least), the annual average rate constant for species removal is generated. Using the annual mean rate constant for species removal and monthly water residence times results in a significantly enhanced predictive capability for Davis Pond during most months of the year. Predictive ability remains poor in Davis Pond during winter/unstratified periods when internal loading of P and N results in low to negative chemical retention. Predictive ability for Piedmont Pond (which has numerous negative chemical retention periods) is improved but not to the same extent as Davis Pond. In Davis Pond, the rate constant for sediment removal (each month) is faster than the rate constant for water and explains the good predictability for sediment retention. However, the removal rate constant for P and N is slower than the removal rate constant for sediment (longer water column residence time for P,N than for sediment). Thus sedimentation is not an overall control on nutrient retention. Additionally, the removal rate constant for P is slower than for TOC (TOC is not the dominate removal process for P) and N is removed slower than P (different in pond controls). For Piedmont Pond, sediment removal rate constants are slower than the removal

  17. Retention Projection Enables Accurate Calculation of Liquid Chromatographic Retention Times Across Labs and Methods

    PubMed Central

    Abate-Pella, Daniel; Freund, Dana M.; Ma, Yan; Simón-Manso, Yamil; Hollender, Juliane; Broeckling, Corey D.; Huhman, David V.; Krokhin, Oleg V.; Stoll, Dwight R.; Hegeman, Adrian D.; Kind, Tobias; Fiehn, Oliver; Schymanski, Emma L.; Prenni, Jessica E.; Sumner, Lloyd W.; Boswell, Paul G.

    2015-01-01

    Identification of small molecules by liquid chromatography-mass spectrometry (LC-MS) can be greatly improved if the chromatographic retention information is used along with mass spectral information to narrow down the lists of candidates. Linear retention indexing remains the standard for sharing retention data across labs, but it is unreliable because it cannot properly account for differences in the experimental conditions used by various labs, even when the differences are relatively small and unintentional. On the other hand, an approach called “retention projection” properly accounts for many intentional differences in experimental conditions, and when combined with a “back-calculation” methodology described recently, it also accounts for unintentional differences. In this study, the accuracy of this methodology is compared with linear retention indexing across eight different labs. When each lab ran a test mixture under a range of multi-segment gradients and flow rates they selected independently, retention projections averaged 22-fold more accurate for uncharged compounds because they properly accounted for these intentional differences, which were more pronounced in steep gradients. When each lab ran the test mixture under nominally the same conditions, which is the ideal situation to reproduce linear retention indices, retention projections still averaged 2-fold more accurate because they properly accounted for many unintentional differences between the LC systems. To the best of our knowledge, this is the most successful study to date aiming to calculate (or even just to reproduce) LC gradient retention across labs, and it is the only study in which retention was reliably calculated under various multi-segment gradients and flow rates chosen independently by labs. PMID:26292625

  18. Safeguards Workforce Repatriation, Retention and Utilization

    SciTech Connect

    Gallucci, Nicholas; Poe, Sarah

    2015-10-01

    Brookhaven National Laboratory was tasked by NA-241 to assess the transition of former IAEA employees back to the United States, investigating the rate of retention and overall smoothness of the repatriation process among returning safeguards professionals. Upon conducting several phone interviews, study authors found that the repatriation process went smoothly for the vast majority and that workforce retention was high. However, several respondents expressed irritation over the minimal extent to which their safeguards expertise had been leveraged in their current positions. This sentiment was pervasive enough to prompt a follow-on study focusing on questions relating to the utilization rather than the retention of safeguards professionals. A second, web-based survey was conducted, soliciting responses from a larger sample pool. Results suggest that the safeguards workforce may be oversaturated, and that young professionals returning to the United States from Agency positions may soon encounter difficulties finding jobs in the field.

  19. Variables affecting athletes' retention of coaches' feedback.

    PubMed

    Januário, Nuno M S; Rosado, Antonio F; Mesquita, Isabel

    2013-10-01

    Athletes' retention of information conveyed in coaches' feedback during training was examined, considering the nature of the information transmitted by each coach (extensions, total number of ideas transmitted, and total number of repeated ideas), athletes' characteristics, (ages, genders, school levels, and practice levels), and athletes' perceptions (relevance and acceptance of coaches' information, task motivational levels, and athletes' attention levels). Participants were 193 athletes (79 boys, 114 girls; 9 to 13 years of age) and 6 coaches. Feedback was both audio and video recorded and all athletes were interviewed. All coaches' feedback and athletes' recollections were subjected to content analysis. Information was completely retained in 31.60% of feedback episodes. Athletes' mean per-episode information retention was 63.0%. Three variables appeared to b e predictiveathletes' retention: athletes' practice levels (p = -.25), attention to coaches' provision of feedback (P = .17), and the number of different ideas transmitted by each coach (P = -.90).

  20. Deuterium Retention in NSTX with Lithium Conditioning

    SciTech Connect

    C.H. Skinner, J.P. Allain, W. Blanchard, H.W. Kugel, R. Maingi, L. Roquemore, V. Soukhanovskii, C.N. Taylor

    2010-06-02

    High (≈ 90%) deuterium retention was observed in NSTX gas balance measurements both withand without lithiumization of the carbon plasma facing components. The gas retained in ohmic discharges was measured by comparing the vessel pressure rise after a discharge to that of a gasonly pulse with the pumping valves closed. For neutral beam heated discharges the gas input and gas pumped by the NB cryopanels were tracked. The discharges were followed by outgassing of deuterium that reduced the retention. The relationship between retention and surface chemistry was explored with a new plasma-material interface probe connected to an in-vacuo surface science station that exposed four material samples to the plasma. XPS and TDS analysis showed that the binding of D atoms is fundamentally changed by lithium - in particular atoms are weakly bonded in regions near lithium atoms bound to either oxygen or the carbon matrix.

  1. Combustion characteristics and arsenic retention during co-combustion of agricultural biomass and bituminous coal.

    PubMed

    Zhou, Chuncai; Liu, Guijian; Wang, Xudong; Qi, Cuicui; Hu, Yunhu

    2016-08-01

    A combination of thermogravimetric analysis (TG) and laboratory-scale circulated fluidized bed combustion experiment was conducted to investigate the thermochemical, kinetic and arsenic retention behavior during co-combustion bituminous coal with typical agricultural biomass. Results shown that ignition performance and thermal reactivity of coal could be enhanced by adding biomass in suitable proportion. Arsenic was enriched in fly ash and associated with fine particles during combustion of coal/biomass blends. The emission of arsenic decreased with increasing proportion of biomass in blends. The retention of arsenic may be attributed to the interaction between arsenic and fly ash components. The positive correlation between calcium content and arsenic concentration in ash suggesting that the arsenic-calcium interaction may be regarded as the primary mechanism for arsenic retention. PMID:27136608

  2. Combustion characteristics and arsenic retention during co-combustion of agricultural biomass and bituminous coal.

    PubMed

    Zhou, Chuncai; Liu, Guijian; Wang, Xudong; Qi, Cuicui; Hu, Yunhu

    2016-08-01

    A combination of thermogravimetric analysis (TG) and laboratory-scale circulated fluidized bed combustion experiment was conducted to investigate the thermochemical, kinetic and arsenic retention behavior during co-combustion bituminous coal with typical agricultural biomass. Results shown that ignition performance and thermal reactivity of coal could be enhanced by adding biomass in suitable proportion. Arsenic was enriched in fly ash and associated with fine particles during combustion of coal/biomass blends. The emission of arsenic decreased with increasing proportion of biomass in blends. The retention of arsenic may be attributed to the interaction between arsenic and fly ash components. The positive correlation between calcium content and arsenic concentration in ash suggesting that the arsenic-calcium interaction may be regarded as the primary mechanism for arsenic retention.

  3. Use of mucolytics to enhance magnetic particle retention at a model airway surface

    NASA Astrophysics Data System (ADS)

    Ally, Javed; Roa, Wilson; Amirfazli, A.

    A previous study has shown that retention of magnetic particles at a model airway surface requires prohibitively strong magnetic fields. As mucus viscoelasticity is the most significant factor contributing to clearance of magnetic particles from the airway surface, mucolytics are considered in this study to reduce mucus viscoelasticity and enable particle retention with moderate strength magnetic fields. The excised frog palate model was used to simulate the airway surface. Two mucolytics, N-acetylcysteine (NAC) and dextran sulfate (DS) were tested. NAC was found to enable retention at moderate field values (148 mT with a gradient of 10.2 T/m), whereas DS was found to be effective only for sufficiently large particle concentrations at the airway surface. The possible mechanisms for the observed behavior with different mucolytics are also discussed based on aggregate formation and the loading of cilia.

  4. JT8D engine performance retention

    NASA Technical Reports Server (NTRS)

    James, A. D.; Weisel, D. R.

    1981-01-01

    The attractive performance retention characteristics of the JT8D engine are described. Because of its moderate bypass ratio and turbine temperature, and stiff structural design, the performance retention versus flight cycles of the JT8D engine sets a standard that is difficult for other engines to equal. In addition, the significant benefits of refurbishment of the JT8D engine are presented. Cold section refurbishment offers thrust specific fuel consumption improvements of up to 2 percent and payback in less than a year, making a very attractive investment option for the airlines.

  5. Nitrogen Saturation in Highly Retentive Watersheds?

    NASA Astrophysics Data System (ADS)

    Daley, M. L.; McDowell, W. H.

    2009-12-01

    Watershed managers are often concerned with minimizing the amount of N delivered to N-limited estuaries and coastal zones. A major concern is that watersheds might reach N saturation, in which N delivered to coastal zones increases due to declines in the efficiency of N retention despite constant or even reduced N inputs. We have quantified long-term changes in N inputs (atmospheric deposition, imported food and agricultural fertilizers), outputs (N concentration and export) and retention in the urbanizing Lamprey River watershed in coastal NH. Overall, the Lamprey watershed is 70% forested, receives about 13.5 kg N/ha/yr and has a high rate of annual N retention (85%). Atmospheric deposition (8.7 kg/ha/yr) is the largest N input to the watershed. Of the 2.2 kg N/ha/yr exported in the Lamprey River, dissolved organic N (DON) is the dominant form (50% of total) and it varies spatially throughout the watershed with wetland cover. Nitrate accounts for 30% of the N exported, shows a statistically significant increase from 1999 to 2009, and its spatial variability in both concentration and export is related to human population density. In sub-basins throughout the Lamprey, inorganic N retention is high (85-99%), but the efficiency of N retention declines sharply with increased human population density and associated anthropogenic N inputs. N assimilation in the vegetation, denitrification to the atmosphere and storage in the groundwater pool could all be important contributors to the current high rates of N retention. The temporal and spatial patterns that we have observed in nitrate concentration and export are driven by increases in N inputs and impervious surfaces over time, but the declining efficiency of N retention suggests that the watershed may also be reaching N saturation. The downstream receiving estuary, Great Bay, already suffers from low dissolved oxygen levels and eelgrass loss in part due to N loading from the Lamprey watershed. Targeting and reducing

  6. Critical role of surface roughness on colloid retention and release in porous media.

    PubMed

    Torkzaban, Saeed; Bradford, Scott A

    2016-01-01

    This paper examines the critical role of surface roughness (both nano- and micro-scale) on the processes of colloid retention and release in porous media under steady-state and transient chemical conditions. Nanoscale surface roughness (NSR) in the order of a few nanometers, which is common on natural solid surfaces, was incorporated into extended-DLVO calculations to quantify the magnitudes of interaction energy parameters (e.g. the energy barrier to attachment, ΔΦa , and detachment, ΔΦd , from a primary minimum). This information was subsequently used to explain the behavior of colloid retention and release in column and batch experiments under different ionic strength (IS) and pH conditions. Results demonstrated that the density and height of NSR significantly influenced the interaction energy parameters and consequently the extent and kinetics of colloid retention and release. In particular, values of ΔΦa and ΔΦd significantly decreased in the presence of NSR. Therefore, consistent with findings of column experiments, colloid retention in the primary minimum was predicted to occur at some specific locations on the sand surface, even at low IS conditions. However, NSR yielded a much weaker primary minimum interaction compared with that of smooth surfaces. Colloid release from primary minima upon decreasing IS and increasing pH was attributed to the impact of NSR on the values of ΔΦd . Pronounced differences in the amount of colloid retention in batch and column experiments indicated that primary minimum interactions were weak even at high IS conditions. Negligible colloid retention in batch experiments was attributed to hydrodynamic torques overcoming adhesive torques, whereas significant colloid retention in column experiments was attributed to nano- and micro-scale roughness which would dramatically alter the lever arms associated with hydrodynamic and adhesive torques.

  7. A practical methodology to measure unbiased gas chromatographic retention factor vs. temperature relationships.

    PubMed

    Peng, Baijie; Kuo, Mei-Yi; Yang, Panhia; Hewitt, Joshua T; Boswell, Paul G

    2014-12-29

    Compound identification continues to be a major challenge. Gas chromatography-mass spectrometry (GC-MS) is a primary tool used for this purpose, but the GC retention information it provides is underutilized because existing retention databases are experimentally restrictive and unreliable. A methodology called "retention projection" has the potential to overcome these limitations, but it requires the retention factor (k) vs. T relationship of a compound to calculate its retention time. Direct methods of measuring k vs. T relationships from a series of isothermal runs are tedious and time-consuming. Instead, a series of temperature programs can be used to quickly measure the k vs. T relationships, but they are generally not as accurate when measured this way because they are strongly biased by non-ideal behavior of the GC system in each of the runs. In this work, we overcome that problem by using the retention times of 25 n-alkanes to back-calculate the effective temperature profile and hold-up time vs. T profiles produced in each of the six temperature programs. When the profiles were measured this way and taken into account, the k vs. T relationships measured from each of two different GC-MS instruments were nearly as accurate as the ones measured isothermally, showing less than two-fold more error. Furthermore, temperature-programmed retention times calculated in five other laboratories from the new k vs. T relationships had the same distribution of error as when they were calculated from k vs. T relationships measured isothermally. Free software was developed to make the methodology easy to use. The new methodology potentially provides a relatively fast and easy way to measure unbiased k vs. T relationships.

  8. Critical role of surface roughness on colloid retention and release in porous media.

    PubMed

    Torkzaban, Saeed; Bradford, Scott A

    2016-01-01

    This paper examines the critical role of surface roughness (both nano- and micro-scale) on the processes of colloid retention and release in porous media under steady-state and transient chemical conditions. Nanoscale surface roughness (NSR) in the order of a few nanometers, which is common on natural solid surfaces, was incorporated into extended-DLVO calculations to quantify the magnitudes of interaction energy parameters (e.g. the energy barrier to attachment, ΔΦa , and detachment, ΔΦd , from a primary minimum). This information was subsequently used to explain the behavior of colloid retention and release in column and batch experiments under different ionic strength (IS) and pH conditions. Results demonstrated that the density and height of NSR significantly influenced the interaction energy parameters and consequently the extent and kinetics of colloid retention and release. In particular, values of ΔΦa and ΔΦd significantly decreased in the presence of NSR. Therefore, consistent with findings of column experiments, colloid retention in the primary minimum was predicted to occur at some specific locations on the sand surface, even at low IS conditions. However, NSR yielded a much weaker primary minimum interaction compared with that of smooth surfaces. Colloid release from primary minima upon decreasing IS and increasing pH was attributed to the impact of NSR on the values of ΔΦd . Pronounced differences in the amount of colloid retention in batch and column experiments indicated that primary minimum interactions were weak even at high IS conditions. Negligible colloid retention in batch experiments was attributed to hydrodynamic torques overcoming adhesive torques, whereas significant colloid retention in column experiments was attributed to nano- and micro-scale roughness which would dramatically alter the lever arms associated with hydrodynamic and adhesive torques. PMID:26512805

  9. Effects of polymer retention on dynamics of single phase flow

    NASA Astrophysics Data System (ADS)

    Parsa, Shima; Weitz, David

    2014-11-01

    We study the effect of adsorption of polymer solution on dynamics of a single phase flow in a model porous medium. We use confocal microscopy to fully visualize the flow of fluid in 3D micromodel of porous media. Polymer flooding is known to be an effective method for enhanced oil recovery. However, the physical mechanism is not clearly understood. We study the effect of polymer retention on the dynamics of single phase flow using particle image velocimetery. The distribution of velocities in the medium changes greatly after flow of high concentrations of polymer through the medium. Comparing the magnitude of velocities before and after the polymer flow, we observe reduction of accessible pores to the fluid at similar injection rates. Independent measurement of the permeability of the medium confirms the decrease in the porosity. Measurements of the retention of polymer in porous media shows a weak dependence on the hydrodynamic radius of the polymer. In these experiments, the viscoelastic behavior of the polymer is isolated from velocity measurements.

  10. Brain-derived neurotrophic factor enhances conditioned taste aversion retention.

    PubMed

    Castillo, Diana V; Figueroa-Guzmán, Yazmín; Escobar, Martha L

    2006-01-01

    Brain-derived neurotrophic factor (BDNF) has recently emerged as one of the most potent molecular mediators of not only central synaptic plasticity, but also behavioral interactions between an organism and its environment. Our previous studies on the insular cortex (IC), a region of the temporal cortex implicated in the acquisition and storage of conditioned taste aversion (CTA), have demonstrated that induction of long-term potentiation (LTP) in the projection from the basolateral nucleus of the amygdala (Bla) to the IC, previous to CTA training, enhances the retention of this task. Recently, we found that intracortical microinfusion of BDNF induces a lasting potentiation of synaptic efficacy in the Bla-IC projection of adult rats in vivo. In this work, we present experimental data showing that intracortical microinfusion of BDNF previous to CTA training enhances the retention of this task. These findings support the concept that BDNF may contribute to memory-related functions performed by a neocortical area, playing a critical role in long-term synaptic plasticity.

  11. Interaction of retention interval with CS-preexposure and extinction treatments: symmetry with respect to primacy.

    PubMed

    Wheeler, Daniel S; Stout, Steven C; Miller, Ralph R

    2004-08-01

    Imposition of a retention interval between cue-outcome pairings and testing can alleviate the retardation of conditioned responding induced by pretraining exposure to the cue (i.e., the CS-preexposure effect). However, recent studies have reported an enhanced effect of CS-preexposure treatment with longer retention intervals (De la Casa & Lubow, 2000, 2002; Lubow & De la Casa, 2002). In a series of conditioned barpress suppression studies with rats, we examined the effects of imposing a retention interval just prior to testing following either CS-preexposure (cue alone before cue-outcome pairings) or extinction (cue alone after cue-outcome pairings) treatments. Experiment 1 replicated in a different preparation recent reports of CS-preexposure treatment effects increasing with longer retention intervals. Experiment 2 showed that spontaneous recovery of stimulus control of behavior after extinction can be obtained with the same parameters as those used to observe the augmented effect of CS-preexposure treatment. In Experiment 3, both the augmented effect of CS-preexposure treatment and spontaneous recovery from extinction were found when we used, in place of a retention interval, an associative priming manipulation.

  12. Application of hydrophilic interaction chromatography retention coefficients for predicting peptide elution with TFA and methanesulfonic acid ion-pairing reagents.

    PubMed

    Wujcik, Chad E; Tweed, Joseph; Kadar, Eugene P

    2010-03-01

    Hydrophilic retention coefficients for 17 peptides were calculated based on retention coefficients previously published for TSKgel silica-60 and were compared with the experimental elution profile on a Waters Atlantis HILIC silica column using TFA and methanesulfonic acid (MSA) as ion-pairing reagents. Relative peptide retention could be accurately determined with both counter-ions. Peptide retention and chromatographic behavior were influenced by the percent acid modifier used with increases in both retention and peak symmetry observed at increasing modifier concentrations. The enhancement of net peptide polarity through MSA pairing shifted retention out by nearly five-fold for the earliest eluting peptide, compared with TFA. Despite improvements in retention and efficiency (N(eff)) for MSA over TFA, a consistent reduction in calculated selectivity (alpha) was observed. This result is believed to be attributed to the stronger polar contribution of MSA masking and diminishing the underlying influence of the amino acid residues of each associated peptide. Finally, post-column infusion of propionic acid and acetic acid was evaluated for their potential to recover signal intensity for TFA and MSA counter-ions for LC-ESI-MS applications. Acetic acid generally yielded more substantial signal improvements over propionic acid on the TFA system while minimal benefits and some further reductions were noted with MSA.

  13. Transport quantique dans des nanostructures

    NASA Astrophysics Data System (ADS)

    Naud, C.

    2002-09-01

    structure des oscillations de conductance en fonction du flux du champ magnétique de période h/e dont l'amplitude est beaucoup plus importante que celle mesurée sur un réseau carré de même dimension. Cette différence constitue une signature d'un effet de localisation induit par le champ magnétique sur la topologie mathcal{T}3. Pour des valeurs spécifiques du champ magnétique, du fait des interférences destructives Aharonov-Bohm, la propagation des fonctions d'ondes est limitée à un ensemble fini de cellule du réseau appelé cage. De la dépendance en température des oscillations de période h/e mesurées sur le réseau mathcal{T}3 nous avons tiré une longueur caractéristique qui peut être rattachée au périmètre des cages. Un phénomène inattendu fut l'observation, pour des champs magnétiques plus importants, d'un doublement de fréquence des oscillations. Ces oscillations de période h/2e pouvant avoir une amplitude supérieure aux oscillations de période h/e, une interprétation en terme d'harmonique n'est pas possible. Enfin, l'influence de la largeur électrique des fils constituant le réseau et donc celle du nombre de canaux par brin a été étudiée en réalisant des grilles électrostatique. Les variations de l'amplitude des signaux en h/e et h/2e en fonction de la tension de grille ont été mesurés.

  14. Seed Implant Retention Score Predicts the Risk of Prolonged Urinary Retention After Prostate Brachytherapy

    SciTech Connect

    Lee, Hoon K.; Adams, Marc T.; Shi, Qiuhu; Basillote, Jay; LaMonica, Joanne; Miranda, Luis; Motta, Joseph

    2010-04-15

    Purpose: To risk-stratify patients for urinary retention after prostate brachytherapy according to a novel seed implant retention score (SIRS). Patients and Methods: A total of 835 patients underwent transperineal prostate seed implant from March 1993 to January 2007; 197 patients had {sup 125}I and 638 patients had {sup 103}Pd brachytherapy. Four hundred ninety-four patients had supplemental external-beam radiation. The final downsized prostate volume was used for the 424 patients who had neoadjuvant hormone therapy. Retention was defined as reinsertion of a Foley catheter after the implant. Results: Retention developed in 7.4% of patients, with an average duration of 6.7 weeks. On univariate analysis, implant without supplemental external-beam radiation (10% vs. 5.6%; p = 0.02), neoadjuvant hormone therapy (9.4% vs. 5.4%; p = 0.02), baseline alpha-blocker use (12.5% vs. 6.3%; p = 0.008), and increased prostate volume (13.4% vs. 6.9% vs. 2.9%, >45 cm{sup 3}, 25-45 cm{sup 3}, <25 cm{sup 3}; p = 0.0008) were significantly correlated with increased rates of retention. On multivariate analysis, implant without supplemental external-beam radiation, neoadjuvant hormone therapy, baseline alpha-blocker use, and increased prostate volume were correlated with retention. A novel SIRS was modeled as the combined score of these factors, ranging from 0 to 5. There was a significant correlation between the SIRS and retention (p < 0.0001). The rates of retention were 0, 4%, 5.6%, 9%, 20.9%, and 36.4% for SIRS of 0 to 5, respectively. Conclusions: The SIRS may identify patients who are at high risk for prolonged retention after prostate brachytherapy. A prospective validation study of the SIRS is planned.

  15. Impact de la preparation des anodes crues et des conditions de cuisson sur la fissuration dans des anodes denses

    NASA Astrophysics Data System (ADS)

    Amrani, Salah

    La fabrication de l'aluminium est realisee dans une cellule d'electrolyse, et cette operation utilise des anodes en carbone. L'evaluation de la qualite de ces anodes reste indispensable avant leur utilisation. La presence des fissures dans les anodes provoque une perturbation du procede l'electrolyse et une diminution de sa performance. Ce projet a ete entrepris pour determiner l'impact des differents parametres de procedes de fabrication des anodes sur la fissuration des anodes denses. Ces parametres incluent ceux de la fabrication des anodes crues, des proprietes des matieres premieres et de la cuisson. Une recherche bibliographique a ete effectuee sur tous les aspects de la fissuration des anodes en carbone pour compiler les travaux anterieurs. Une methodologie detaillee a ete mise au point pour faciliter le deroulement des travaux et atteindre les objectifs vises. La majorite de ce document est reservee pour la discussion des resultats obtenus au laboratoire de l'UQAC et au niveau industriel. Concernant les etudes realisees a l'UQAC, une partie des travaux experimentaux est reservee a la recherche des differents mecanismes de fissuration dans les anodes denses utilisees dans l'industrie d'aluminium. L'approche etait d'abord basee sur la caracterisation qualitative du mecanisme de la fissuration en surface et en profondeur. Puis, une caracterisation quantitative a ete realisee pour la determination de la distribution de la largeur de la fissure sur toute sa longueur, ainsi que le pourcentage de sa surface par rapport a la surface totale de l'echantillon. Cette etude a ete realisee par le biais de la technique d'analyse d'image utilisee pour caracteriser la fissuration d'un echantillon d'anode cuite. L'analyse surfacique et en profondeur de cet echantillon a permis de voir clairement la formation des fissures sur une grande partie de la surface analysee. L'autre partie des travaux est basee sur la caracterisation des defauts dans des echantillons d'anodes crues

  16. Effect of physicochemical parameters on the retention of some monoamine oxidase inhibitory drugs on a porous graphitized carbon column.

    PubMed

    Forgács, E; Cserháti, T

    1996-05-31

    The retention of sixteen monoamine oxidase inhibitory drugs (proparlgylamine derivatives) was determined on a porous graphitized carbon (PGC) column using ethanol-water mixtures as eluents. The HPLC retention characteristics of drugs were correlated with their physicochemical properties using stepwise regression analysis and principal component (PC) analysis. The dimensions of the matrices for PC loadings and variables was reduced using a non-linear mapping technique, varimax rotation and cluster analysis. It has been established that the drugs can be well separated on the PGC column in ethanol-water eluents. Calculations proved that the retention behavior of monoamine oxidase drugs on PGC column is of mixed character: both steric and electronic parameters influence the retention.

  17. 9 CFR 354.73 - Retention labels.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Retention labels. 354.73 Section 354.73 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF...

  18. 9 CFR 354.73 - Retention labels.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Retention labels. 354.73 Section 354.73 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION...

  19. 7 CFR 400.412 - Record retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Social Security Account Numbers and Employer Identification Numbers § 400.412 Record retention. (a) FCIC... years from the date of final action on a policy for the crop year, unless further maintenance of specific records is requested by FCIC. Final actions on insurance policies include conclusion of...

  20. Predicting Student Retention in Teacher Education Programs.

    ERIC Educational Resources Information Center

    Vare, Jonatha W.; Dewalt, Mark W.; Dockery, E. Ray

    This paper describes the preliminary results from a longitudinal study of student teacher attrition and retention. The sample consisted of 316 students in an initial course in teacher education. Data collection included the following: high school grade point ratio (GPR); SAT scores; other demographic information, such as education of father and…

  1. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  2. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  3. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  4. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  5. 10 CFR 490.810 - Record retention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Record retention. 490.810 Section 490.810 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Compliance § 490... documentation pertaining to its waiver application and alternative compliance, including petroleum...

  6. 5 CFR 353.302 - Retention protections.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Retention protections. 353.302 Section 353.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RESTORATION... protections. An injured employee enjoys no special protection in a reduction in force. Separation by...

  7. 5 CFR 353.302 - Retention protections.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Retention protections. 353.302 Section 353.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RESTORATION... protections. An injured employee enjoys no special protection in a reduction in force. Separation by...

  8. 5 CFR 353.302 - Retention protections.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Retention protections. 353.302 Section 353.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RESTORATION... protections. An injured employee enjoys no special protection in a reduction in force. Separation by...

  9. 5 CFR 353.302 - Retention protections.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Retention protections. 353.302 Section 353.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RESTORATION... protections. An injured employee enjoys no special protection in a reduction in force. Separation by...

  10. 5 CFR 353.209 - Retention protections.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Retention protections. 353.209 Section 353.209 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RESTORATION... protections. (a) During uniformed service. An employee may not be demoted or separated (other than...

  11. 5 CFR 353.209 - Retention protections.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Retention protections. 353.209 Section 353.209 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RESTORATION... protections. (a) During uniformed service. An employee may not be demoted or separated (other than...

  12. 5 CFR 353.302 - Retention protections.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Retention protections. 353.302 Section 353.302 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RESTORATION... protections. An injured employee enjoys no special protection in a reduction in force. Separation by...

  13. 5 CFR 353.209 - Retention protections.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Retention protections. 353.209 Section 353.209 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RESTORATION... protections. (a) During uniformed service. An employee may not be demoted or separated (other than...

  14. 5 CFR 353.209 - Retention protections.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Retention protections. 353.209 Section 353.209 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RESTORATION... protections. (a) During uniformed service. An employee may not be demoted or separated (other than...

  15. 5 CFR 353.209 - Retention protections.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Retention protections. 353.209 Section 353.209 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RESTORATION... protections. (a) During uniformed service. An employee may not be demoted or separated (other than...

  16. Freshman Learning Communities, College Performance, and Retention

    ERIC Educational Resources Information Center

    Hotchkiss, Julie L.; Moore, Robert E.; Pitts, M. Melinda

    2006-01-01

    This paper applies a standard treatment effects model to determine that participation in Freshman Learning Communities improves academic performance and retention. Not controlling for individual self-selection into Freshman Learning Communities participation leads one to incorrectly conclude that the impact is the same across race and gender…

  17. 1978-79 Recruitment & Retention Program.

    ERIC Educational Resources Information Center

    DeCosmo, Richard

    The Moraine Valley Community College (MVCC) 1978-79 Recruitment Program seeks to increase the pool of students who wish to attend college rather than compete more aggressively for those students who have already decided to participate in higher education. A special adjunct Retention Program has been developed to enhance the entire recruitment…

  18. Online Student Retention: Can It Be Done?

    ERIC Educational Resources Information Center

    O'Brien, Barbara S.; Renner, Alice L.

    Retention has been indicated as one of the greatest weaknesses in online instruction. While a preponderance of literature about online instruction is available, concrete ideas about how to retain students are lacking. A DHHS grant for over one million dollars made it possible for the Wright State University College of Nursing and Health (Dayton,…

  19. 5 CFR 9701.356 - Pay retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Pay retention. 9701.356 Section 9701.356 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN...

  20. 5 CFR 293.511 - Retention schedule.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... RECORDS Employee Medical File System Records § 293.511 Retention schedule. (a) Temporary EMFS records must not be placed in a newly-created EMF for a separating employee and must be removed from an already existing EMF before its transfer to another agency or to the NPRC. Such records must be disposed of...

  1. 40 CFR 35.6705 - Records retention.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... STATE AND LOCAL ASSISTANCE Cooperative Agreements and Superfund State Contracts for Superfund Response Actions Records Requirements Under A Cooperative Agreement § 35.6705 Records retention. (a) Applicability... Cooperative Agreement, or are otherwise reasonably considered as pertinent to program regulations or...

  2. 7 CFR 56.38 - Retention authorities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) VOLUNTARY GRADING OF SHELL EGGS Grading of Shell Eggs Identifying and Marking Products § 56.38 Retention authorities. A grader may... identification and control of shell eggs which are not in compliance with the regulations or are held for...

  3. Illinois Valley Industry Retention Program. Final Report.

    ERIC Educational Resources Information Center

    Allen, John P.

    The Illinois Valley Industry Retention Program was conceived with the goals of retaining existing industries in the area and saving presently available jobs for the area's citizens. A program committee, formed in March 1982 of representatives from state government, Illinois Valley Community College (IVCC), and local businesses, undertook a survey…

  4. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  5. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  6. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  7. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  8. 33 CFR 133.21 - Records retention.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Records retention. 133.21 Section 133.21 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS §...

  9. Recruitment and Retention with a Spin

    ERIC Educational Resources Information Center

    Lindgren, Rita; Hixson, Carla Braun

    2010-01-01

    Strategic planning and innovation at Bismarck State College (BSC) found common ground in the college's goal to recruit and retain employees in an environment of low unemployment and strong competition for skilled employees. BSC's strategic plan for 2007-09 included the objective "to increase retention of employees." One of the strategies connected…

  10. Healthcare Learning Community and Student Retention

    ERIC Educational Resources Information Center

    Johnson, Sherryl W.

    2014-01-01

    Teaching, learning, and retention processes have evolved historically to include multifaceted techniques beyond the traditional lecture. This article presents related results of a study using a healthcare learning community in a southwest Georgia university. The value of novel techniques and tools in promoting student learning and retention…

  11. 9 CFR 354.73 - Retention labels.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Retention labels. 354.73 Section 354.73 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF...

  12. 9 CFR 354.73 - Retention labels.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Retention labels. 354.73 Section 354.73 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF...

  13. 9 CFR 354.73 - Retention labels.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Retention labels. 354.73 Section 354.73 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF...

  14. Relationship of Personality Traits to Student Retention

    ERIC Educational Resources Information Center

    Liang, John Paul

    2010-01-01

    Carl Jung's theory of psychological types has been the basis for the development of personality categorization, including tests such as Myers-Briggs Type Indicator (MBTI). This study analyzed the extent of the relationship between MBTI and Tinto (1993) retention factors that influence Oriental medicine students' choice of staying or dropping out…

  15. 14 CFR 291.23 - Record retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... § 291.23 Record retention. (a) The provisions of 14 CFR part 249, Preservation of air carrier accounts... the Department. Each carrier shall retain for 1 year a copy of any formula based on standard weight... Management and Budget under control number 3024-0022)...

  16. 16 CFR 437.7 - Record retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Record retention. 437.7 Section 437.7 Commercial Practices FEDERAL TRADE COMMISSION TRADE REGULATION RULES BUSINESS OPPORTUNITY RULE § 437.7 Record... opportunity sellers and their principals must prepare, retain, and make available for inspection by...

  17. 16 CFR 437.7 - Record retention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Record retention. 437.7 Section 437.7 Commercial Practices FEDERAL TRADE COMMISSION TRADE REGULATION RULES BUSINESS OPPORTUNITY RULE § 437.7 Record... opportunity sellers and their principals must prepare, retain, and make available for inspection by...

  18. 5 CFR 9701.356 - Pay retention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Pay retention. 9701.356 Section 9701.356 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN...

  19. 5 CFR 9701.356 - Pay retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Pay retention. 9701.356 Section 9701.356 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN...

  20. 39 CFR 946.10 - Record retention.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... MAIL MATTER AND PROPERTY ACQUIRED BY THE POSTAL INSPECTION SERVICE FOR USE AS EVIDENCE § 946.10 Record retention. Records regarding property subject to this part will be retained for a period of 3 years following return of the property to its owner or a determination that the property is abandoned....

  1. 39 CFR 946.10 - Record retention.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... MAIL MATTER AND PROPERTY ACQUIRED BY THE POSTAL INSPECTION SERVICE FOR USE AS EVIDENCE § 946.10 Record retention. Records regarding property subject to this part will be retained for a period of 3 years following return of the property to its owner or a determination that the property is abandoned....

  2. 39 CFR 946.10 - Record retention.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... MAIL MATTER AND PROPERTY ACQUIRED BY THE POSTAL INSPECTION SERVICE FOR USE AS EVIDENCE § 946.10 Record retention. Records regarding property subject to this part will be retained for a period of 3 years following return of the property to its owner or a determination that the property is abandoned....

  3. Tallahassee Community College Retention Study. Final Report.

    ERIC Educational Resources Information Center

    Johnston, Archie B.

    A retention study was conducted at Tallahassee Community College (TCC) to determine reasons student withdrew from TCC prior to meeting their educational objectives. The survey population consisted of all students, apart from graduates and those who had been academically suspended, who were enrolled in winter 1981 but had not returned by winter…

  4. 5 CFR 9701.356 - Pay retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM Pay and Pay Administration Pay Administration § 9701.356 Pay retention. (a) Subject to...

  5. Structural Information Retention in Visual Art Processing.

    ERIC Educational Resources Information Center

    Koroscik, Judith Smith

    The accuracy of non-art college students' longterm retention of structural information presented in Leonardo da Vinci's "Mona Lisa" was tested. Seventeen female undergraduates viewed reproductions of the painting and copies that closely resembled structural attributes of the original. Only 3 of the 17 subjects reported having viewed a reproduction…

  6. 5 CFR 293.404 - Retention schedule.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... RECORDS Employee Performance File System Records § 293.404 Retention schedule. (a)(1) Except as provided... in this system, including transfer with the employee who changes positions, shall be as agencies... performance-related documents five years old or less shall be forwarded in the Employee Performance File...

  7. 40 CFR 35.6705 - Records retention.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... concerning Federal Government records (36 CFR parts 1220 through 1234) and EPA records management... the starting dates for records retention described in 40 CFR 31.42(c) (1) and (2). ... been started before the expiration of the ten-year period, the records must be retained...

  8. 76 FR 34010 - Credit Risk Retention

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-10

    ..., 2011, at 76 FR 24090, is extended. Comments on the Credit Risk NPR must be received on or before August... 76 FR 24090. The Credit Risk NPR would specify credit risk retention requirements for securitizers of...-AA43 DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT 24 CFR Part 267 RIN 2501-AD53 Credit Risk...

  9. 78 FR 57927 - Credit Risk Retention

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-20

    ... proposal, as described in more detail below. \\5\\ Credit Risk Retention; Proposed Rule, 76 FR 24090 (April... legislation.''). \\24\\ See 78 FR 6408 (January 30, 2013), as amended by 78 FR 35430 (June 12, 2013). These two... Federal Register. See 76 FR 27390 (May 11, 2011). The Board had initial responsibility for...

  10. Procurement and Retention of Black Officers.

    ERIC Educational Resources Information Center

    Miller, Clarence A., Jr.

    A study was made of the history of the black officer in the Army, the sources and procedures the Army uses to procure black officers and the retention of black officers in the Army. Data was gathered by interviews with Department of Army personnel and black junior officers; questionnaires were used to gather information from professors of Military…

  11. Retention--A Pseudo-Problem?

    ERIC Educational Resources Information Center

    Geis, George L.

    1999-01-01

    Discusses retention of learning; training methods; maintenance issues; the effect of punishment; reinforcement; the performance environment; transfer of training; forgetting; implications for designers of instructional materials or designers of training programs; and the division between training and on-the-job performance. (LRW)

  12. Metals Retention in Constructed Wetland Sediments

    SciTech Connect

    KNOX, ANNA

    2004-10-27

    The A-01 wetland treatment system (WTS) was designed to remove metals from the effluent at the A-01 NPDES outfall at the Savannah River Site, Aiken, SC. Sequential extraction data was used to evaluate remobilization and retention of Cu, Pb, Zn, Mn, and Fe in the wetland sediment. Remobilization of metals was determined by the Potentially Mobile Fraction (PMF) and metal retention by the Recalcitrant Factor (RF). The PMF, which includes water soluble, exchangeable, and oxides fractions, is the contaminant fraction that has the potential to enter into the mobile aqueous phase under changeable environmental conditions. PMF values were low for Cu, Zn and Pb (about 20 percent) and high for Fe and Mn (about 60 to 70 percent). The RF, which includes crystalline oxides, sulfides or silicates and aluminosilicates, is the ratio of strongly bound fractions to the total concentration of elements in sediment. RF values were about 80 percent for Cu, Zn and Pb, indicating high retention in the sediment and 30 percent to above 40 percent for Fe and Mn indication low retention.

  13. Does Retention Help? Perspectives after Three Years.

    ERIC Educational Resources Information Center

    Schuyler, Nancy Baenen

    The Austin Independent School District Office of Research and Evaluation (AISD-ORE) has recently completed a three year study of the effects of retention on elementary students. As in other studies comparing the academic achievement of elementary retainees and similar students not retained, findings indicated that promoted students generally show…

  14. Retention of Electronic Fundamentals: Differences Among Topics.

    ERIC Educational Resources Information Center

    Johnson, Kirk A.

    Criterion-referenced tests were used to measure the learning and retention of a sample of material taught by means of programed instruction in the Avionics Fundamentals Course, Class A. It was found that the students knew about 30 percent of the material before reading the programs, that mastery rose to a very high level on the immediate posttest,…

  15. COMPARTMENTAL MODEL OF NITRATE RETENTION IN STREAMS

    EPA Science Inventory

    A compartmental modeling approach is presented to route nitrate retention along a cascade of stream reach sections. A process transfer function is used for transient storage equations with first order reaction terms to represent nitrate uptake in the free stream, and denitrifica...

  16. Foster Family Resources, Psychosocial Functioning, and Retention.

    ERIC Educational Resources Information Center

    Rhodes, Kathryn W.; Orme, John G.; Cox, Mary Ellen; Buehler, Cheryl

    2003-01-01

    This longitudinal study examined the effect of family resources and psychosocial problems on retention for foster families. Almost 50 percent of families who started preservice training did not complete it. Families with more psychosocial problems and fewer resources were more likely to express uncertainly about continuing. These results have…

  17. Testing to Enhance Retention in Human Anatomy

    ERIC Educational Resources Information Center

    Logan, Jessica M.; Thompson, Andrew J.; Marshak, David W.

    2011-01-01

    Recent work in cognitive psychology has shown that repeatedly testing one's knowledge is a powerful learning aid and provides substantial benefits for retention of the material. To apply this in a human anatomy course for medical students, 39 fill-in-the-blank quizzes of about 50 questions each, one for each region of the body, and four about the…

  18. Retention of First Year Community College Students

    ERIC Educational Resources Information Center

    Windham, Melissa H.

    2012-01-01

    Although close to half of all community college students leave before obtaining their stated goals, most retention studies are still being conducted at the four-year college and university level. There is still little research conducted at the community college level. In order to determine what student characteristics increase community college…

  19. Personnel Recruitment and Retention in Rural America.

    ERIC Educational Resources Information Center

    Helge, Doris; Marrs, Lawrence W.

    Recruitment and retention of special education teachers and related services staff have been persistent problems of rural school districts nationwide. High teacher attrition rates have serious ramifications for personnel development and program stability. Effective recruitment strategies for rural areas have four main components: (1) emphasis on…

  20. Effective Retention Strategies for Diverse Employees.

    ERIC Educational Resources Information Center

    Musser, Linda R.

    2001-01-01

    Discusses methods to determine why employees leave or stay, based on experiences at Pennsylvania State University libraries. Considers retention tools that work best to retain diverse employees, including mentoring, networking, career and learning opportunities, balance between work and home life, a welcoming climate, and support for research.…

  1. Employee Retention: A Challenge of the Nineties.

    ERIC Educational Resources Information Center

    Zeiss, Tony

    1990-01-01

    Considers ways in which community colleges can help employers implement programs to improve the work environment and retain trained workers. Presents a model for employee retention that has worked effectively in Pueblo, Colorado. Describes Pueblo Community College's cooperative program with the Wats Marketing Group to help reduce employee…

  2. Reframing Retention Strategy: A Focus on Process

    ERIC Educational Resources Information Center

    Schroeder, Charles C.

    2013-01-01

    When institutions engage in discussions regarding improving retention and graduation rates, invariably the conversation focuses on entering student characteristics, especially ACT and SAT scores and high school grades. Clearly, attracting and enrolling well-prepared and motivated high-ability students will certainly improve institutional measures…

  3. An Examination of Master's Student Retention & Completion

    ERIC Educational Resources Information Center

    Barry, Melissa; Mathies, Charles

    2011-01-01

    This study was conducted at a research-extensive public university in the southeastern United States. It examined the retention and completion of master's degree students across numerous disciplines. Results were derived from a series of descriptive statistics, T-tests, and a series of binary logistic regression models. The findings from binary…

  4. High temperature ceramic composition for hydrogen retention

    DOEpatents

    Webb, R.W.

    1974-01-01

    A ceramic coating for H retention in fuel elements is described. The coating has relatively low thermal neutron cross section, is not readily reduced by H at 1500 deg F, is adherent to the fuel element base metal, and is stable at reactor operating temperatures. (JRD)

  5. 39 CFR 946.10 - Record retention.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Record retention. 946.10 Section 946.10 Postal Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PROCEDURE RELATING TO THE DISPOSITION OF STOLEN MAIL MATTER AND PROPERTY ACQUIRED BY THE POSTAL INSPECTION SERVICE FOR USE AS EVIDENCE § 946.10...

  6. 39 CFR 946.10 - Record retention.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Record retention. 946.10 Section 946.10 Postal Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PROCEDURE RELATING TO THE DISPOSITION OF STOLEN MAIL MATTER AND PROPERTY ACQUIRED BY THE POSTAL INSPECTION SERVICE FOR USE AS EVIDENCE § 946.10...

  7. ORTHODONTIC RETENTION. Studies of retention capacity, cost-effectiveness and long-term stability.

    PubMed

    Tynelius, Gudrun Edman

    2014-01-01

    Retention strategies, cost-effectiveness and long-term stability of treatment outcome are essential aspects of orthodontic treatment planning. The overall aim of this thesis was to compare and evaluate three different retention strategies, with special reference to short- and long-term clinical stability and cost-effectiveness. The approach was evidence-based, hence randomized controlled methodology was used in order to generate high levels of evidence. This thesis is based on four studies: Papers I and II are based on randomized controlled trials, evaluating the stability of treatment outcome after one and two years of retention, using three different retention strategies: a maxillary vacuum-formed retainer combined with a mandibular canine-to-canine retainer; a maxillary vacuum-formed retainer combined with stripping of the mandibular anterior teeth and a prefabricated positioner. Paper III presents a cost-minimization analysis of two years of retention treatment. Paper IV is based on a randomized controlled trial documenting the results five years post-retention. The following conclusions were drawn: Papers I and II. From a clinical perspective, asssessment after one year of retention disclosed that the three retention methods were successful in retaining the orthodontic treatment results. After two years of retention, all three retention methods were equally effective in controlling relapse at a clinically acceptable level. Most of the relapse occurred during the first year of retention; only minor or negligible changes were found during the second year. The subjects were grouped according to the level of compliance (excellent or good). After two years of retention there was a negative correlation between growth in body height and relapse of mandibular LII in the group of subjects with excellent compliance. The group with good compliance showed a positive correlation (Paper II, Figure 3). After two years of retention, growth in body height, initial crowding and

  8. Everyday attention and lecture retention: the effects of time, fidgeting, and mind wandering

    PubMed Central

    Farley, James; Risko, Evan F.; Kingstone, Alan

    2013-01-01

    We have all had our thoughts wander from the immediate task at hand. The emerging embodied cognition literature emphasizes the role that the body plays in human thought, and raises the possibility that changes in attentional focus may be associated with changes in body behavior. Recent research has found that when individuals view a lecture, mind wandering increases as a function of time. In the present study we asked whether this decline in attention during lecture viewing was associated with fidgeting. Participants were filmed while they watched a 40-min lecture video, and at regular 5-min intervals provided ratings of their attentiveness. Following the lecture, participant's memory for the material was assessed. Fidgeting behavior was coded from video recordings of each session. Results indicated that attention to, and retention of, lecture material declined as a function of time on task. Critically, and as predicted, fidgeting also increased with time on task. We also found that the relation between fidgeting and retention was significant even when the role of attention was factored into the equation, suggesting that fidgeting makes a unique contribution to retention of lecture material over and above that contributed by an individual's attention. We propose a novel non-attentional stress-based account of fidgeting and how this impacts retention for lecture material over and above changes in levels in mind wandering vis-a-vis changes in attention. PMID:24065933

  9. Statistical evaluation and choice of soil water retention models

    NASA Astrophysics Data System (ADS)

    Lennartz, Franz; Müller, Hans-Otfried; Nollau, Volker; Schmitz, Gerd H.; El-Shehawy, Shaban A.

    2008-12-01

    This paper presents the results of statistical investigations for the evaluation of soil water retention models (SWRMs). We employed three different methods developed for model selection in the field of nonlinear regression, namely, simulation studies, analysis of nonlinearity measures, and resampling strategies such as cross validation and bootstrap methods. Using these methods together with small data sets, we evaluated the performance of three exemplarily chosen types of SWRMs with respect to their parameter properties and the reliability of model predictions. The resulting rankings of models show that the favorable models are characterized by few parameters with an almost linear estimation behavior and close to symmetric distributions. To further demonstrate the potential of the statistical methods in the field of model selection, a modification of the four-parameter van Genuchten model is proposed which shows significantly improved and robust statistical properties.

  10. Plastic debris retention and exportation by a mangrove forest patch.

    PubMed

    Ivar do Sul, Juliana A; Costa, Monica F; Silva-Cavalcanti, Jacqueline S; Araújo, Maria Christina B

    2014-01-15

    An experiment observed the behavior of selected tagged plastic items deliberately released in different habitats of a tropical mangrove forest in NE Brazil in late rainy (September) and late dry (March) seasons. Significant differences were not reported among seasons. However, marine debris retention varied among habitats, according to characteristics such as hydrodynamic (i.e., flow rates and volume transported) and relative vegetation (Rhizophora mangle) height and density. The highest grounds retained significantly more items when compared to the borders of the river and the tidal creek. Among the used tagged items, PET bottles were more observed and margarine tubs were less observed, being easily transported to adjacent habitats. Plastic bags were the items most retained near the releasing site. The balance between items retained and items lost was positive, demonstrating that mangrove forests tend to retain plastic marine debris for long periods (months-years).

  11. Gas-chromatographic retention indexes of organic sulfur (II) compounds

    SciTech Connect

    Garbuzov, V.G.; Aerov, A.F.; Golovnya, R.V.; Misharina, T.A.

    1985-10-01

    Despite the large number of papers on the gas chromatographyof sulfur-containing compounds, according to the authors no systematic study has been carried out of their behavior, showing the dependences of the sorptional characteristics on the structure of the molecule and on the polarity of the stationary phase. The present article systematizes the results of many years of work on the determination on four columns with different polarity of retention indexes of sulfurcontaining compounds: mercaptans, dimercaptans, di-n-alkyl sulfides, n-alkyl isoalkyl sulfides, diisoalkyl sulfides, unsaturated sulfides, di-n-alkyl disulfides, and many others, in all more than 400 compounds. The data obtained and the regularities in their change, depending on the structure and polarity of the stationary phases, were successfully used to identify sulfur-containing compounds in the study of the odor composition of salmon flesh, boiled beef, boiled-corned pork and an aromatizer with a meat aroma.

  12. Plastic debris retention and exportation by a mangrove forest patch.

    PubMed

    Ivar do Sul, Juliana A; Costa, Monica F; Silva-Cavalcanti, Jacqueline S; Araújo, Maria Christina B

    2014-01-15

    An experiment observed the behavior of selected tagged plastic items deliberately released in different habitats of a tropical mangrove forest in NE Brazil in late rainy (September) and late dry (March) seasons. Significant differences were not reported among seasons. However, marine debris retention varied among habitats, according to characteristics such as hydrodynamic (i.e., flow rates and volume transported) and relative vegetation (Rhizophora mangle) height and density. The highest grounds retained significantly more items when compared to the borders of the river and the tidal creek. Among the used tagged items, PET bottles were more observed and margarine tubs were less observed, being easily transported to adjacent habitats. Plastic bags were the items most retained near the releasing site. The balance between items retained and items lost was positive, demonstrating that mangrove forests tend to retain plastic marine debris for long periods (months-years). PMID:24321881

  13. Reliability of in-stream retention metrics

    NASA Astrophysics Data System (ADS)

    Savickis, Jevgenijs; Zaramella, Mattia; Marion, Andrea

    2016-04-01

    The temporary solute retention within transient storage zones (TSZs) has been shown to have a large effect on the transport of solute. This retention can significantly increase the overall in-stream residence time and as consequence increase the contact time of solute with aquatic interfaces (biota, sediment) and living species. An important question that arises is whether the currently available metrics adequately represent retention mechanism. This work attempts to investigate the reliability of two existing measures, the hydrological retention factor (Rh) and the fraction of median travel time due to transient storage zone (Fmed200). For this purpose, five conservative tracer tests were conducted in four European streams with distinct morphological, sediment composition, vegetation and hydraulic characteristics. The obtained breakthrough curves (BTCs) were used to derive storage zone parameters (storage zone area, storage zone exchange coefficient and mean residence time), which then were used for comparison and in the metric expressions. The storage zone parameters were computed using a single TSZ model OTIS-P and a multiple TSZ model STIR. The STIR model was applied to BTCs as an additional tool to separate TSZs into short timescale (ST) and long timescale (LT). The study results reveal correlation between Fmed200 and LT residence time T2 values, where the streams with the lowest Fmed200 (0.01-0.96) have the smallest long timescale storage zones T2 values, ranging from 912 s to 1402 s. The findings also demonstrate an influence of discharge rate on both retention metrics. The greatest Fmed200 (6.19) and Rh (0.938) values are calculated for the streams with low discharge rates (0.08-0.10 m3s‑1) and a relatively high ST storage zone residence times T1 (159 s to 351 s). Results show that the Fmed200 and Rh metrics are strongly affected by the short timescale transient storage zones, whereas the LT storage zones (hyporheic) effects are not taken into account.

  14. Reliability of in-stream retention metrics

    NASA Astrophysics Data System (ADS)

    Savickis, Jevgenijs; Zaramella, Mattia; Marion, Andrea

    2016-04-01

    The temporary solute retention within transient storage zones (TSZs) has been shown to have a large effect on the transport of solute. This retention can significantly increase the overall in-stream residence time and as consequence increase the contact time of solute with aquatic interfaces (biota, sediment) and living species. An important question that arises is whether the currently available metrics adequately represent retention mechanism. This work attempts to investigate the reliability of two existing measures, the hydrological retention factor (Rh) and the fraction of median travel time due to transient storage zone (Fmed200). For this purpose, five conservative tracer tests were conducted in four European streams with distinct morphological, sediment composition, vegetation and hydraulic characteristics. The obtained breakthrough curves (BTCs) were used to derive storage zone parameters (storage zone area, storage zone exchange coefficient and mean residence time), which then were used for comparison and in the metric expressions. The storage zone parameters were computed using a single TSZ model OTIS-P and a multiple TSZ model STIR. The STIR model was applied to BTCs as an additional tool to separate TSZs into short timescale (ST) and long timescale (LT). The study results reveal correlation between Fmed200 and LT residence time T2 values, where the streams with the lowest Fmed200 (0.01-0.96) have the smallest long timescale storage zones T2 values, ranging from 912 s to 1402 s. The findings also demonstrate an influence of discharge rate on both retention metrics. The greatest Fmed200 (6.19) and Rh (0.938) values are calculated for the streams with low discharge rates (0.08-0.10 m3s-1) and a relatively high ST storage zone residence times T1 (159 s to 351 s). Results show that the Fmed200 and Rh metrics are strongly affected by the short timescale transient storage zones, whereas the LT storage zones (hyporheic) effects are not taken into account.

  15. Calculation of Retention Time Tolerance Windows with Absolute Confidence from Shared Liquid Chromatographic Retention Data

    PubMed Central

    Boswell, Paul G.; Abate-Pella, Daniel; Hewitt, Joshua T.

    2015-01-01

    Compound identification by liquid chromatography-mass spectrometry (LC-MS) is a tedious process, mainly because authentic standards must be run on a user’s system to be able to confidently reject a potential identity from its retention time and mass spectral properties. Instead, it would be preferable to use shared retention time/index data to narrow down the identity, but shared data cannot be used to reject candidates with an absolute level of confidence because the data are strongly affected by differences between HPLC systems and experimental conditions. However, a technique called “retention projection” was recently shown to account for many of the differences. In this manuscript, we discuss an approach to calculate appropriate retention time tolerance windows for projected retention times, potentially making it possible to exclude candidates with an absolute level of confidence, without needing to have authentic standards of each candidate on hand. In a range of multi-segment gradients and flow rates run among seven different labs, the new approach calculated tolerance windows that were significantly more appropriate for each retention projection than global tolerance windows calculated for retention projections or linear retention indices. Though there were still some small differences between the labs that evidently were not taken into account, the calculated tolerance windows only needed to be relaxed by 50% to make them appropriate for all labs. Even then, 42% of the tolerance windows calculated in this study without standards were narrower than those required by WADA for positive identification, where standards must be run contemporaneously. PMID:26292624

  16. Applications of Cost Effectiveness to Counseling Center Retention Programs.

    ERIC Educational Resources Information Center

    Weiss, Steven J.; Giddan, Norman S.

    1986-01-01

    Provides a framework for considering cost-benefit analysis and cost-effectiveness analysis of college counseling centers and retention activities. Results indicated that careful evaluation techniques can improve the efficiency and effectiveness of student retention programs. (Author/BL)

  17. Effect of aging on temporary cement retention in vitro.

    PubMed

    Millstein, P L; Hazan, E; Nathanson, D

    1991-06-01

    Retention of restorations cemented with temporary cement varies. Some cements are adhesive and others are weak in retention. In addition, cement retention may vary over time. This study determined (1) the retentive properties of four temporary cements, and (2) the effects of aging on temporary cement retention. Cylindrical amalgam cores and mated stainless steel retainers with a 0.05 mm cement space were used in the study. Cores were cemented into the retainers and stored in 100% humidity at 37 degrees C until tested. Retention was measured by applying a compressive force to the cores through a rod in an Instron machine. Half the samples were tested after 1 week and half were tested after 6 weeks. The results indicate a significant difference in retentive value among the four cements, including a significant decrease in retention for one cement over the 6-week aging period.

  18. Nutrient retention in riparian floodplains on landscape scale, the necessity for a monthly retention approach.

    PubMed

    Natho, S; Venohr, M

    2012-01-01

    This study analyses the computed nitrogen retention, the distribution and the extent of riparian floodplains of three German rivers, as input data and application of the retention model has not been carried out on landscape scale so far. The Software FLYS 2.1.3 was used for the calculation of the floodplain extent and depth at certain discharges. Thus a first empirical approach is suggested to quantify the share of load that enters the floodplain (incoming load) and the extent of floodplain as variables depending on discharge ratios. Measured loads have subsequently been applied to the presented approach to calculate incoming loads on a monthly and yearly basis for the years 1999 and 2002. Finally, linear and exponential yearly retention models were applied, obtained from the literature. Large variations in the retention results were found between the years and the models and between monthly and yearly calculations. In hydrologically average years, calculated retention rates are in the range of reported values (440-670 kg N ha⁻¹ yr⁻¹), whereas for wet years, retention values account for 1,400 kg N ha⁻¹ yr⁻¹. Consequently, this approach needs to be improved to reduce overestimation by considering more complex characteristics of the floodplain, but generally its application is possible on the landscape scale.

  19. Characterizing endogenous and exogenous peroxidase activity for bleaching of fluid whey and retentate.

    PubMed

    Campbell, R E; Gerard, P D; Drake, M A

    2014-03-01

    The lactoperoxidase (LP) system may be used to achieve the desired bleaching of fluid whey with the addition of low concentrations (<50mg/kg) of hydrogen peroxide. The addition of an exogenous peroxidase (EP) to whey may also be used to aid in whey bleaching when the LP system is not fully active. The objectives of this study were to monitor LP activity in previously refrigerated or frozen milk, fluid whey, and whey retentate (10% solids) and to evaluate peroxidase activity in fluid whey and whey retentate (10% solids), with and without additional EP (2, 1, or 0.5 dairy bleaching units), over a range of pH (5.5-6.5) and temperatures (4-60°C). Subsequent experiments were conducted to determine the relationship between enzyme activity and bleaching efficacy. Raw and pasteurized milk, fat-separated pasteurized whey, and whey retentate (10% solids) were evaluated for LP activity following storage at 4 or -20°C, using an established colorimetric method. A response surface model was applied to evaluate both endogenous and EP activity at various temperatures and pH in freshly manufactured whey and retentate. Refrigerated or frozen storage at the parameters evaluated did not affect LP activity in milk, whey, or retentate. In fluid whey, with and without added EP, as pH decreased (to 5.5) and temperature increased (to 60°C), peroxidase activity increased. Retentate with EP exhibited behavior similar to that of fluid whey: as pH decreased and temperature increased, activity increased. However, in retentate without EP, as pH increased and temperature increased, activity increased. Enzyme activity was negatively correlated to bleaching time (time for >80% norbixin destruction) in fluid whey but a linear relationship was not evident in retentate. When fluid whey is bleached enzymatically, if pH is decreased and temperature is increased, the rate of reaction increases (e.g., bleaching occurs in less time). When bleaching in retentate, a higher pH (pH 6.5 vs. pH 5.5) is

  20. Hydrogen retention in deposition layers formed from type 316 stainless steel

    SciTech Connect

    Uchida, Y.; Katayama, K.; Okamura, T.; Imaoka, K.; Nishikawa, M.; Fukada, S.

    2008-07-15

    From the viewpoints of plasma control and radiation safety, tritium retention in deposition layers is an important problem. In this study, deposition layers from type 316 stainless steel were formed by a sputtering method using hydrogen RF plasma at three different temperatures. The behavior of hydrogen release from the deposition layers was observed by a thermal desorption method at argon atmosphere. It was found that hydrogen retention and release behavior greatly change depending on the temperature of a substrate where the layer is formed. The surface structure of the layer also changed depending on the temperature. However, the ratios of metallic atoms such as Fe, Cr and Ni in deposition layers were almost the same as that in type 316 stainless steel. (authors)

  1. Participant Retention in the Parents Matter! Program: Strategies and Outcome

    ERIC Educational Resources Information Center

    Armistead, Lisa P.; Clark, Heather; Barber, C. Nekol; Dorsey, Shannon; Hughley, Jennifer; Favors, Marcia; Wyckoff, Sarah C.

    2004-01-01

    We present a discussion of the literature addressing retention of ethnic minority samples in longitudinal studies. In addition, we describe the retention procedures implemented in the Parents Matter! Program (PMP), a community-based sexual risk reduction intervention for African American families. Finally, the results of PMP's retention strategies…

  2. Retention Initiatives Used by Professional Master's Athletic Training Program Directors

    ERIC Educational Resources Information Center

    Bowman, Thomas G.; Dodge, Thomas M.; Mazerolle, Stephanie M.

    2015-01-01

    Context: Many professional master's athletic training program directors believe retention is a problem facing athletic training education. However, it remains unknown what steps, if any, are taken to improve retention. Objective: To inquire with program directors about their respective methods and interventions aimed at increasing retention rates.…

  3. Policies and Practice: A Focus on Higher Education Retention.

    ERIC Educational Resources Information Center

    American Association of State Colleges and Universities, Washington, DC.

    This book, based on a discussion at an interactive videoconference, examines student diversity issues and retention strategies in the context of the Sallie Mae National Retention Project that addressed state expectations for more accountability and federal reporting requirements on graduation and retention. The eight chapters focus on equity as it…

  4. Framing Retention for Institutional Improvement: A 4 Ps Framework

    ERIC Educational Resources Information Center

    Kalsbeek, David H.

    2013-01-01

    A 4 Ps framework for student retention strategy is a construct for reframing the retention discussion in a way that enables institutional improvement by challenging some conventional wisdom and prevailing perspectives that have characterized retention strategy for years. It opens new possibilities for action and improvement by suggesting that…

  5. 48 CFR 4.704 - Calculation of retention periods.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Calculation of retention periods. 4.704 Section 4.704 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL ADMINISTRATIVE MATTERS Contractor Records Retention 4.704 Calculation of retention periods. (a) The...

  6. 49 CFR 239.203 - Retention of emergency preparedness plan.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Retention of emergency preparedness plan. 239.203... Retention of Emergency Preparedness Plans § 239.203 Retention of emergency preparedness plan. Each passenger...), shall each retain one copy of the emergency preparedness plan required by § 239.201 and one copy of...

  7. 49 CFR 239.203 - Retention of emergency preparedness plan.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Retention of emergency preparedness plan. 239.203... Retention of Emergency Preparedness Plans § 239.203 Retention of emergency preparedness plan. Each passenger...), shall each retain one copy of the emergency preparedness plan required by § 239.201 and one copy of...

  8. A Review of the Elementary School Promotion/Retention Dilemma.

    ERIC Educational Resources Information Center

    Bossing, Lewis; Brien, Phyl

    The purpose of this paper is to present different aspects of the effects of grade retention on students and to consider what is best for the total development of the child. Studies show that grade retention does not ensure significant gains in achievement. However, studies seem to be less conclusive regarding retention due to the immaturity of…

  9. Grade Retention: What are the Costs and Benefits?

    ERIC Educational Resources Information Center

    Eide, Eric R.; Goldhaber, Dan D.

    2005-01-01

    Grade retention is a common practice used when students fail to meet required benchmarks. Therefore, it is important that we understand the relative benefits and costs associated with students repeating a grade. In this article we analyze the costs and benefits of grade retention. In our examination of retention, we obtain our calculations of the…

  10. Measuring Student Retention at an Online Institution of Higher Education

    ERIC Educational Resources Information Center

    Boston, Wallace E., Jr.

    2010-01-01

    Student persistence or retention has been a documented issue in higher education in the United States since the late 1800s. While much has been written about the topic of retention at the more traditional types of institutions, little has been written about retention at the online institutions of higher learning that have developed since the early…

  11. Education for Sustainable Development and Retention: Unravelling a Research Agenda

    ERIC Educational Resources Information Center

    Lotz-Sisitka, Heila

    2010-01-01

    This paper considers the question of what education for sustainable development (ESD) research might signify when linked to the concept of "retention", and how this relation (ESD and retention) might be researched. It considers two different perspectives on retention, as revealed through educational research trajectories, drawing on existing…

  12. 48 CFR 1604.705 - Specific retention periods.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Specific retention periods... EMPLOYEES HEALTH BENEFITS ACQUISITION REGULATION GENERAL ADMINISTRATIVE MATTERS Contractor Records Retention 1604.705 Specific retention periods. Unless the contracting officer determines that there exists...

  13. 5 CFR 351.401 - Determining retention standing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... REDUCTION IN FORCE Scope of Competition § 351.401 Determining retention standing. Each agency shall determine the retention standing of each competing employee on the basis of the factors in this subpart and... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Determining retention standing....

  14. 5 CFR 536.208 - Termination of grade retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... CFR part 531, subpart B, for GS positions). An employee is not entitled to pay retention under subpart... grade retention benefits (except that, if an employee's election specifically provides that the... grade retention terminates under this section, the employee's rate of basic pay must be set...

  15. 5 CFR 351.506 - Effective date of retention standing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... the performance factor as provided in § 351.504: (a) The retention standing of each employee released... is so released. (b) The retention standing of each employee retained in a competitive level as an... been released had the exception not been used. The retention standing of each employee retained...

  16. 5 CFR 536.302 - Optional pay retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ....102 and this section, an authorized agency official may provide pay retention to an employee not... employee to pay retention under paragraph (a) of this section, the agency must apply the geographic... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Optional pay retention. 536.302...

  17. 5 CFR 575.309 - Payment of retention incentives.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... a retention incentive is subject to the aggregate limitation on pay under 5 CFR part 530, subpart B. ... retention incentive rate may not exceed— (1) 25 percent, if authorized for an individual employee; or (2) 10... example, an agency establishes a retention incentive percentage rate of 10 percent for an employee....

  18. 5 CFR 536.202 - Optional grade retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... §§ 536.102 and 536.203, an authorized agency official may provide grade retention to an employee moving... lower-graded position. (c) When an employee is offered a position with grade retention under this... entitlement to grade retention under § 536.201 if the agency actually moves the employee to the...

  19. Strategies to improve retention in randomised trials

    PubMed Central

    Brueton, Valerie C; Tierney, Jayne; Stenning, Sally; Harding, Seeromanie; Meredith, Sarah; Nazareth, Irwin; Rait, Greta

    2013-01-01

    Background Loss to follow-up from randomised trials can introduce bias and reduce study power, affecting the generalisability, validity and reliability of results. Many strategies are used to reduce loss to follow-up and improve retention but few have been formally evaluated. Objectives To quantify the effect of strategies to improve retention on the proportion of participants retained in randomised trials and to investigate if the effect varied by trial strategy and trial setting. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PreMEDLINE, EMBASE, PsycINFO, DARE, CINAHL, Campbell Collaboration's Social, Psychological, Educational and Criminological Trials Register, and ERIC. We handsearched conference proceedings and publication reference lists for eligible retention trials. We also surveyed all UK Clinical Trials Units to identify further studies. Selection criteria We included eligible retention trials of randomised or quasi-randomised evaluations of strategies to increase retention that were embedded in 'host' randomised trials from all disease areas and healthcare settings. We excluded studies aiming to increase treatment compliance. Data collection and analysis We contacted authors to supplement or confirm data that we had extracted. For retention trials, we recorded data on the method of randomisation, type of strategy evaluated, comparator, primary outcome, planned sample size, numbers randomised and numbers retained. We used risk ratios (RR) to evaluate the effectiveness of the addition of strategies to improve retention. We assessed heterogeneity between trials using the Chi2 and I2 statistics. For main trials that hosted retention trials, we extracted data on disease area, intervention, population, healthcare setting, sequence generation and allocation concealment. Main results We identified 38 eligible retention trials. Included trials evaluated six broad types of strategies to improve retention. These

  20. Etude des effets du martelage repetitif sur les contraintes residuelles

    NASA Astrophysics Data System (ADS)

    Hacini, Lyes

    L'assemblage par soudage peut engendrer des contraintes residuelles. Ces contraintes provoquent des fissurations prematurees et un raccourcissement de la duree de vie des composants. Dans ce contexte, le martelage robotise est utilise pour relaxer ces contraintes residuelles. Trois volets sont presentes: le premier est l'evaluation des effets des impacts unitaires repetes sur le champ de contraintes developpe dans des plaques d'acier inoxydable austenitique 304L vierges ou contenant des contraintes residuelles initiales. Dans la deuxieme partie de ce projet, le martelage est applique grace au robot SCOMPI. Les contraintes residuelles induites et relaxees par martelage sont ensuite mesurees par la methode des contours, qui a ete adaptee a cet effet. Dans la troisieme partie, le martelage est modelise par la methode des elements finis. Un modele axisymetrique developpe grace au logiciel ANSYS permet de simuler des impacts repetes d'un marteau elastique sur une plaque ayant un comportement elastoplastique.

  1. The Influence of Movement Initiation Deficits on the Quantification of Retention in Parkinson’s Disease

    PubMed Central

    Pendt, Lisa K.; Maurer, Heiko; Müller, Hermann

    2012-01-01

    In patients with an impaired motor system, like Parkinson’s disease (PD), deficits in motor learning are expected and results of various studies seem to confirm these expectations. However, most studies in this regard are behaviorally based and quantify learning by performance changes between at least two points in time, e.g., baseline and retention. But, performance in a retention test is also dependent on other factors than learning. Especially in patients, the functional capacity of the control system might be altered unspecific to a certain task and learning episode. The aim of the study is to test whether characteristic temporal deficits exist in PD patients that affect retention performance. We tested the confounding effects of typical PD motor control deficits, here movement initiation deficits, on retention performance in the motor learning process. 12 PD patients and 16 healthy control participants practiced a virtual throwing task over 3 days with 24 h rest between sessions. Retention was tested comparing performance before rest with performance after rest. Movement initiation deficits were quantified by the timing of throwing release that should be affected by impairments in movement initiation. To scrutinize the influence of the initiation deficits on retention performance we gave participants a specific initiation intervention prior to practice on one of the three practice days. We found that only for the PD patients, post-rest performance as well as release timing was better with intervention as compared to without intervention. Their performance could be enhanced through a tuning of release initiation. Thus, we suggest that in PD patients, performance decline after rest that might be easily interpreted as learning deficits could rather result from disease-related deficiencies in motor control. PMID:22870067

  2. Three-dimensional topographic index applied to the prediction of acyclic C5-C8 alkenes Kováts retention indices on polydimethylsiloxane and squalane columns.

    PubMed

    Ren, Yueying; Liu, Huanxiang; Yao, Xiaojun; Liu, Mancang

    2007-06-29

    A novel approach is described for the prediction of gas chromatographic Kováts retention indices of 150 acyclic C5-C8 alkenes on two stationary phases (polydimethylsiloxane, PDMS, and squalane, SQ). The heuristic method was used to build multiple linear regression models using descriptors calculated by MODLESLAB software and CODESSA program. The resulting quantitative structure-retention relationship (QSRR) models were well-correlated, with predictive R2 values of 0.970 and 0.958 for retention indices on PDMS and SQ columns, respectively. 1Omegap, a three-dimensional (3D) topographic index, was found to play the most important role in the description of the chromatographic retention behavior of the alkenes in these two stationary phases. Moreover, this index could completely distinguish different isomers of alkene. Therefore, it can also be extended to distinguish different isomers of other compounds so that can well describe their quantitative structure-retention relationships.

  3. Sulfonate retention by kaolinite at high pH - effect of inorganic anions

    SciTech Connect

    Baviere, M.; Ruaux, E.; Defives, D. )

    1993-05-01

    At high pH and with surfactant concentrations well above the critical micelle concentration (CMC), the pH-dependent part of adsorption is small. Retention depends especially on the sodium-ion activity and on the type and valence of inorganic anions. As the anionic charge increases, adsorption at a given ionic strength decreases. This behavior correlates with the effect of anions on the sulfonate activity in solution.

  4. Tritium Retention and Removal in Tokamaks

    SciTech Connect

    Skinner, Charles H.

    2009-02-19

    Management of tritium inventory remains one of the grand challenges in the development of fusion energy. Tritium is an important source term in safety assessments, it is expensive and in short supply. Tritium can be continuously retained in a tokamak by codeposition with eroded carbon or beryllium and JET and TFTR with carbon plasma facing components showed a tritium retention level that would be unacceptable in ITER or future fusion reactors. Asdex-U and Alcator C-mod have shown reduced hydrogenic retention with tungsten clad and molybdenum plasma facing components. Once the tritium inventory approaches the administrative limit, tritium must be removed to permit continued D-T plasma operations. Several candidate techniques are being considered and need to be proven at a relevant speed and efficiency in contemporary tokamaks. Projections for ITER are discussed.

  5. Retention technique #1. Developing managerial warmth.

    PubMed

    Davidhizar, R

    1989-01-01

    A manager who has interpersonal warmth is not simply gullible or naive, but instead possesses a valuable skill in reaching others. In most manager-employee relationships, some degree of limit-setting and judgment are necessary; however, warmth integrated with limit-setting is more satisfying for both employee and manager. Although warmth as an interpersonal phenomenon is affected by the employee's perception, certain managerial actions can increase the likelihood of being perceived as warm; yet, in spite of careful adherence to the guidelines for communicating warmth, managerial warmth will still be rejected in some situations. As is true of any managerial technique, the effective use of warmth requires an assessment of the employee's personality and the approach most appropriate for the situation at hand. The excellent manager is able to quickly adapt, matching the level of warmth to the situation. See Nurse Manager Retention Factors for viewpoints from nurses themselves. Interpersonal management style is an important retention factor.

  6. Improving student retention in computer engineering technology

    NASA Astrophysics Data System (ADS)

    Pierozinski, Russell Ivan

    The purpose of this research project was to improve student retention in the Computer Engineering Technology program at the Northern Alberta Institute of Technology by reducing the number of dropouts and increasing the graduation rate. This action research project utilized a mixed methods approach of a survey and face-to-face interviews. The participants were male and female, with a large majority ranging from 18 to 21 years of age. The research found that participants recognized their skills and capability, but their capacity to remain in the program was dependent on understanding and meeting the demanding pace and rigour of the program. The participants recognized that curriculum delivery along with instructor-student interaction had an impact on student retention. To be successful in the program, students required support in four domains: academic, learning management, career, and social.

  7. A model of nursing student retention.

    PubMed

    Shelton, Elisabeth N

    2012-03-18

    A model of nursing student retention was studied in nontraditional, associate degree nursing students. Student retention was defined as persistence, or choosing to continue in a nursing program, and successful academic performance, or meeting the necessary academic standards to continue in a nursing program. The model shows the interaction of background variables, internal psychological processes, and external supports, and their relationships to persistence and academic performance. Participants were 458 nontraditional associate degree nursing students. There were significant differences in background variables between students who persisted and those who withdrew voluntarily or failed academically. Perceived faculty support was related to both persistence and academic performance, such that students with higher perceived faculty support were more likely to continue in a nursing program until graduation and were more likely to be successful academically. Students with higher perceived faculty support also had higher outcome expectations of earning an associate degree in nursing.

  8. Selective Surface Modification on Lubricant Retention

    NASA Astrophysics Data System (ADS)

    Jiang, Yu; Suvanto, Mika; Pakkanen, Tapani A.

    2016-11-01

    While surface patterns are effective in improving tribological properties, nevertheless they alter the surface wettability, which will in turn affect the surface-lubricant interactions. When there is a shortage of lubricant on a patterned surface, the lubricant stored inside the cavities will be extracted to compensate the surface lubricant dissipation. Additionally, the lubricant retention effect provided by the cavities is competing with the release of the lubricant. With weak surface-lubricant interaction, the retention is limited. Therefore, the lubrication will have a sudden failure, giving a dramatic transition to abrasive wear. To improve the performance of polar lubricants on hydrophobic polymer surfaces, both topographical and selective surface modifications were incorporated on injection molded polypropylene surfaces. Distinctive lubrication improvement was observed when the surface structure density for the lubricant storage was high, and the release of the lubricant was controlled by the interaction with the selectively modified surfaces.

  9. Staff retention and empowerment: functions of leadership.

    PubMed

    Mass, Diana

    2002-01-01

    Regardless of any organization's structure and technology, the most potent leverage for exceptional performance and quality assurance resides within personnel. Retention of empowered, committed staff who believe in their organization's purpose and leadership is important to an organization's success. The Clinical Laboratory Sciences (CLS) profession faces a different kind of crisis, not only one of economics, but also one of quality because of lost professional expertise. This dilemma is because of profound neglect of the organization's greatest asset--its CLS professionals. Retention of expert CLS professionals requires a dramatic change in management's belief system regarding the value of their assets. Laboratory leaders must create a culture of empowered people with the freedom to exhibit self-direction toward achieving the organization's mission and goals. Managers must consider employees valuable enough to invest in their professional growth. A laboratory's long-term sustainability and economic performance will depend on a committed workforce.

  10. Nursing workforce retention: challenging a bullying culture.

    PubMed

    Stevens, Stella

    2002-01-01

    Discussions surrounding nursing shortages typically focus on recruitment, but retention is also a problem. Emerging research suggests that intimidation in the nursing workforce is a problem that planners need to deal with as part of an overall strategy aimed at maintaining a balance between supply and demand. This paper explores issues surrounding intimidation in the nursing workforce and looks at how one major teaching hospital in Australia attempted to address the problem. PMID:12224882

  11. 300 Area Building Retention Evaluation Mitigation Plan

    SciTech Connect

    D. J. McBride

    2007-07-03

    Evaluate the long-term retention of several facilities associated with the PNNL Capability Replacement Laboratory and other Hanfor mission needs. WCH prepared a mitigation plan for three scenarios with different release dates for specific buildings. The evaluations present a proposed plan for providing utility services to retained facilities in support of a long-term (+20 year) lifespan in addition to temporary services to buildings with specified delayed release dates.

  12. Improved motor sequence retention by motionless listening.

    PubMed

    Lahav, Amir; Katz, Tal; Chess, Roxanne; Saltzman, Elliot

    2013-05-01

    This study examined the effect of listening to a newly learned musical piece on subsequent motor retention of the piece. Thirty-six non-musicians were trained to play an unfamiliar melody on a piano keyboard. Next, they were randomly assigned to participate in three follow-up listening sessions over 1 week. Subjects who, during their listening sessions, listened to the same initial piece showed significant improvements in motor memory and retention of the piece despite the absence of physical practice. These improvements included increased pitch accuracy, time accuracy, and dynamic intensity of key pressing. Similar improvements, though to a lesser degree, were observed in subjects who, during their listening sessions, were distracted by another task. Control subjects, who after learning the piece had listened to nonmusical sounds, showed impaired motoric retention of the piece at 1 week from the initial acquisition day. These results imply that motor sequences can be established in motor memory without direct access to motor-related information. In addition, the study revealed that the listening-induced improvements did not generalize to the learning of a new musical piece composed of the same notes as the initial piece learned, limiting the effects to musical motor sequences that are already part of the individual's motor repertoire. PMID:22434336

  13. Why does atorvastatin inhibit renal crystal retention?

    PubMed

    Tsujihata, Masao; Yoshioka, Iwao; Tsujimura, Akira; Nonomura, Norio; Okuyama, Akihiko

    2011-10-01

    Recently, we reported that atorvastatin prevents renal tubular cell injury by oxalate and inhibits renal crystal retention. In this study, we investigated the mechanism by which atorvastatin inhibits renal crystal retention. Male Sprague-Dawley rats were separated into four experimental groups, and the ethylene glycol model of hyperoxaluria and the atorvastatin treatment model were analyzed. To clarify the mechanism by which atorvastatin inhibits renal crystal retention, the removed kidneys were used for the quantitative analysis of superoxide dismutase (SOD) and catalase. The subunits of the NADPH oxidase system were evaluated using real-time polymerase chain reaction analysis. Furthermore, the level of transforming growth factor-β (TGF-β) in kidney tissue was compared in each group. Atorvastatin treatment increased the SOD and catalase level compared with the stone-forming control group. Atorvastatin treatment decreased the expression of NOX-1 mRNA. Furthermore, the level of TGF-β was suppressed by atorvastatin treatment. We found that atorvastatin have inhibited calcium oxalate (CaOX) urolithiasis formation. We hypothesize that the mechanism of action of atorvastatin involves inhibiting TGF-β and NADPH oxidase, and increasing the SOD and catalase level. We believe that atorvastatin will be helpful in the treatment of CaOX urolithiasis.

  14. Maternal Stress Predicts Postpartum Weight Retention

    PubMed Central

    Whitaker, Kara; Vernon, Marlo; Wilcox, Sara

    2014-01-01

    Postpartum weight retention (PPWR) is a significant contributor to the development of overweight and obesity in women of childbearing age. Stress may be a key mechanism making it more difficult for mothers to lose weight in the year following delivery. The aim of this study was to assess whether specific aspects of parenting stress and life stress influence postpartum weight retention in new mothers. Women in late pregnancy or up to 2 months postpartum (n = 123) were enrolled in the study and followed through the first year postpartum. Linear regression models evaluated the associations of parenting stress (isolation, attachment and depressive symptoms) as well as overall life stress at 2, 6, and 12 months postpartum with PPWR at 6 and 12 months. During the first year postpartum, higher depression and life stress were significantly associated with greater PPWR. As the effect of depression diminished, the effect of life stress became significant. Contrary to hypothesized relationships, fewer problems with attachment and less social isolation were significantly associated with greater PPWR. Higher gestational weight gain and African American race were also significantly associated with greater PPWR at both 6 and 12 months. Different types of stress predict weight retention in first time mothers during the first year postpartum. Understanding the relationships between parenting stress, concurrent life stress and PPWR can enhance the development of future interventions that specifically target self-identified stressors, leading to improved weight related outcomes. PMID:24760321

  15. Testing to enhance retention in human anatomy.

    PubMed

    Logan, Jessica M; Thompson, Andrew J; Marshak, David W

    2011-01-01

    Recent work in cognitive psychology has shown that repeatedly testing one's knowledge is a powerful learning aid and provides substantial benefits for retention of the material. To apply this in a human anatomy course for medical students, 39 fill-in-the-blank quizzes of about 50 questions each, one for each region of the body, and four about the nervous system, were developed. The quizzes were optional, and no credit was awarded. They were posted online using Blackboard, which provided feedback, and they were very popular. To determine whether the quizzes had any effect on retention, they were given in a controlled setting to 21 future medical and dental students. The weekly quizzes included questions on regional anatomy and an expanded set of questions on the nervous system. Each question about the nervous system was given three times, in a slightly different form each time. The second quiz was given approximately half an hour after the first one, and the third was given one week after the second to assess retention. The quizzes were unpopular, but students showed robust improvement on the questions about the nervous system. The scores increased by almost 9% on the second quiz, with no intervention except viewing the correct answers. The scores were 29% higher on the third quiz than on the first, and there was also a positive correlation between the grades on the quizzes and the final examination. Thus, repeated testing is an effective strategy for learning and retaining information about human anatomy. PMID:21805688

  16. Measuring the value of customer retention

    SciTech Connect

    Monts, K.; Bonevac, B.; Lauer, J.; Tessema, D.

    1997-05-01

    Competition will require changes in how market research is conducted and how customers are pursued. The question remains: How does one approach customer retention in a way that provides meaningful guidelines? The conventional wisdom is that {open_quotes}the business of business is selling.{close_quotes} There is some truth to this, but the key question today is: What bearing does this have on how to run a business in a competitive environment? A recent article in the Harvard Business Review noted that, {open_quotes}Increasingly, companies are less focused on selling products and more interested in keeping customers.{close_quotes} Indeed, some observers have posited a natural societal evolutionary trend toward a shift of emphasis toward customer retention vis-a-vis customer acquisition, as a consequence of the primary marketing communication technology shifting from {open_quotes}broadcast{close_quotes} (where messages are sent out to inchoate masses) to {open_quotes}interactive{close_quotes} (where relationships are cultivated with precisely defined market niches or individual customers). The business of growing a business, then, can be framed as a matter of getting customers and keeping them so as to grow the value of the customer base to its fullest potential. In these terms, setting a marketing budget becomes the task of balancing what is spent on customer acquisition with what is spent on retention.

  17. Retention of perceptual generalization of fear extinction.

    PubMed

    Pappens, Meike; Schroijen, Mathias; Van den Bergh, Omer; Van Diest, Ilse

    2015-12-01

    Fear reduction obtained during a fear extinction procedure can generalize from the extinction stimulus to other perceptually similar stimuli. Perceptual generalization of fear extinction typically follows a perceptual gradient, with increasing levels of fear reduction the more a stimulus resembles the extinction stimulus. The current study aimed to investigate whether perceptual generalization of fear extinction can be observed also after a retention interval of 24h. Fear was acquired to three geometrical figures of different sizes (CS(+), CS1(+) and CS2(+)) by consistently pairing them with a short-lasting suffocation experience (US). Three other geometrical figures that were never followed by the US served as control stimuli (CS(-), CS1(-), CS2(-)). Next, only the CS(+) was extinguished by presenting it in the absence of the US. One day later, fear responses to all stimuli were assessed without any US-presentation. Outcome measures included startle blink EMG, skin conductance, US expectancy, respiratory rate and tidal volume. On day 2 spontaneous recovery of fear was observed in US expectancy and tidal volume, but not in the other outcomes. Evidence for the retention of fear extinction generalization was present in US expectancy and skin conductance, but a perceptual gradient in the retention of generalized fear extinction could not be observed.

  18. DRAM Weak Cell Characterization for Retention Time.

    PubMed

    Kang, Jonghyuk; Lee, Sungho; Choi, Byoungdeog

    2016-05-01

    This work proposes a sequence of tests for detecting refresh weak cells based on data retention time distribution in the main cell array of DRAMs and verify the feasibility of the proposed method through analysis of 30 nm design-rule DRAM cells with Recess Channel Array Transistor (RCAT) and Buried Channel Array Transistor (BCAT). Basic idea of the proposed mechanism is to test with different bias conditions and break down retention failures based on their root causes such as Gate Induced Drain Leakage, sub-threshold leakage and junction leakage. This categorization helps to determine the physical locations of each failure group, enabling precise Physical Failure Analysis (PFA). The characterization of data retention weak cells for 30 nm design rule DRAMs with BCAT and RCAT has been investigated. Most weak cells were classified as GIDL leaky cells in both cases. In the case of BCAT, the distance between the word line and the storage node, caused by the process distribution, is the main origin of weak cells. In the case of RCAT, the sharp corner of the active layer in the storage node is the main cause of weak cells. PMID:27483878

  19. Deuterium Retention in NSTX with Lithium Conditioning

    SciTech Connect

    Skinner, C. H.; Allain, J. P.; Blanchard, W.; Kugel, H. W.; Maingi, Rajesh; Roquemore, L.; Soukhanovskii, V. A.; Taylor, C. N.

    2011-01-01

    High (approximate to 90%) deuterium retention was observed in NSTX gas balance measurements both with- and without lithiumization of the carbon plasma-facing components. The gas retained in ohmic discharges was measured by comparing the vessel pressure rise after a discharge to that of a gas-only pulse with the pumping valves closed. For neutral beam heated discharges the gas input and gas pumped by the NB cryopanels were tracked. The discharges were followed by outgassing of deuterium that reduced the retention. The relationship between retention and surface chemistry was explored with a new plasma-material interface probe connected to an in vacuo surface science station that exposed four material samples to the plasma. XPS and TDS analysis demonstrated that binding of D atoms in graphite is fundamentally changed by lithium - in particular atoms are weakly bonded in regions near lithium atoms bound to either oxygen or the carbon matrix. This is in contrast to the strong ionic bonding that occurs between D and pure Li. (C) 2010 Elsevier B.V. All rights reserved.

  20. Retention prediction of highly polar ionizable solutes under gradient conditions on a mixed-mode reversed-phase and weak anion-exchange stationary phase.

    PubMed

    Balkatzopoulou, P; Fasoula, S; Gika, H; Nikitas, P; Pappa-Louisi, A

    2015-05-29

    In the present work the retention of three highly polar and ionizable solutes - uric acid, nicotinic acid and ascorbic acid - was investigated on a mixed-mode reversed-phase and weak anion-exchange (RP/WAX) stationary phase in buffered aqueous acetonitrile (ACN) mobile phases. A U-shaped retention behavior was observed for all solutes with respect to the eluent organic modifier content studied in a range of 5-95% (v/v). This retention behavior clearly demonstrates the presence of a HILIC-type retention mechanism at ACN-rich hydro-organic eluents and an RP-like retention at aqueous-rich hydro-organic eluents. Hence, this column should be promising for application under both RP and HILIC gradient elution modes. For this reason, a series of programmed elution runs were carried out with increasing (RP) and decreasing (HILIC) organic solvent concentration in the mobile phase. This dual gradient process was successfully modeled by two retention models exhibiting a quadratic or a cubic dependence of the logarithm of the solute retention factor (lnk) upon the organic modifier volume fraction (φ). It was found that both models produced by gradient retention data allow the prediction of solute retention times for both types of programmed elution on the mixed-mode column. Four, in the case of the quadratic model, or five, in the case of the cubic model, initial HILIC- and RP-type gradient runs gave satisfactory retention predictions of any similar kind elution program, even with different flow rate, with an overall error of only 2.5 or 1.7%, respectively.

  1. Ostéosynthèse des fractures des métacarpiens et des phalanges de la main par mini plaque: à propos de 12 cas

    PubMed Central

    Moncef, Erraji; Abdelhafid, Derfoufi; Abdessamad, Kharraji; Omar, Agoumi; Najib, Abdeljaouad; Abdelkrim, Daoudi; Hicham, Yacoubi

    2016-01-01

    Le traitement des fractures instables des métacarpes et des phalanges reste un objet de controverse. Peu de séries ont été rapportées dans la littérature, rendant leur analyse difficile. Nous rapportons une étude rétrospective comportant 12 patients, opérés par cette technique, ayant eu des fractures déplacées des métacarpes ou des phalanges, sur une période de deux ans. Les résultats globaux ont été bons dans 75% des cas, moyenne dans 16,5% des cas et mauvais dans 8,5% des cas. La stabilité du montage par mini plaques des fractures instables des métacarpiens et des phalanges ont permis une mobilisation précoce des articulations de la main, évitant ainsi la raideur. PMID:27800079

  2. Dysfunctional Elimination Behaviors and Associated Complications in School-Age Children

    ERIC Educational Resources Information Center

    Kistner, Mary

    2009-01-01

    Lack of privacy, risk of bullying, limited access, lack of essential products for good hygiene, and dirty bathrooms can all contribute to encouraging a child to withhold urine and stool while in school. Withholding behaviors over time can create a condition known as dysfunctional elimination syndrome (DES). DES is any pattern of voiding or…

  3. Qualitative Insights into Faculty Use of Student Support Services with Online Students at Risk: Implications for Student Retention

    ERIC Educational Resources Information Center

    Russo-Gleicher, Rosalie J.

    2013-01-01

    This article provides qualitative insights into the ways that faculty can impact retention rates of online students. Semi-structured, in-depth interviews were conducted at random with 16 faculty who teach online courses at a community college in the Northeast. Faculty were asked to describe behaviors of online students that made them feel…

  4. Nickel migration and retention dynamics in natural soil columns

    NASA Astrophysics Data System (ADS)

    Raveh-Rubin, Shira; Edery, Yaniv; Dror, Ishai; Berkowitz, Brian

    2015-09-01

    Nickel migration measured in laboratory-scale, natural soil column experiments is shown to display anomalous (non-Fickian) transport, nonequilibrium adsorption and desorption patterns, and precipitation/dissolution. Similar experiments using a conservative tracer also exhibit anomalous behavior. The occurrence of ion exchange of nickel, mainly with calcium (but also with other soil components), is measured in both batch and flow-through column experiments; adsorption and desorption isotherms demonstrate hysteresis. Strong retention of nickel during transport in soil columns leads to delayed initial breakthrough (˜40 pore volumes), slow increase in concentration, and extended concentration tailing at long times. We describe the mechanisms of transport and retention in terms of a continuous time random walk (CTRW) model, and use a particle tracking formulation to simulate nickel migration in the column. This approach allows us to capture the non-Fickian transport and the subtle local effects of adsorption/desorption and precipitation/dissolution. Consideration also of preferential pathways accounts for the evolution of the measured breakthrough curve and measured spatial concentration profiles. The model uses non-Fickian transport parameters estimated from the conservative tracer and, as a starting point, adsorption/desorption parameters based on batch experiments and a precipitation parameter based on Ksp values. The batch parameters are found to underestimate the actual amount of adsorption. We suggest that the sorption and precipitation/dissolution dynamics, and resulting breakthrough curves, are influenced strongly by preferential pathways; such pathways significantly alter the availability of sorption sites and ion availability for precipitation. Analysis of these results provides further understanding of the interaction and dynamics among transport, precipitation, and sorption mechanisms in natural soil.

  5. Retention and release mechanisms of deuterium implanted into beryllium

    NASA Astrophysics Data System (ADS)

    Oberkofler, M.; Reinelt, M.; Linsmeier, Ch.

    2011-06-01

    The fraction of deuterium (D) that is retained upon irradiation of beryllium (Be) as well as the temperatures at which implanted D is released are of importance for the international fusion experiment ITER, where Be will be used as an armor material. The influence of single parameters on retention and release is investigated in laboratory experiments performed under well defined conditions with the aim to identify dominant underlying mechanisms and thus be able to predict the behavior of the Be wall in ITER. Recent progress in the quantification of retained fractions and release temperatures as well as in the understanding of the governing mechanisms is presented. The retained fraction upon implantation of D at 1 keV into Be(1 1 2¯ 0) to fluences far below the saturation threshold of 10 21 m -2 is almost 95%, the remaining 5% being attributed to reflection at the surface. At these low fluences, no dependence of the retained fractions on implantation energy is observed. At fluences of the order of 10 21 m -2 and higher, saturation of the irradiated material affects the retention, leading to lower retained fractions. Furthermore, at these fluences the retained fractions decrease with decreasing implantation energies. Differences in the retained fractions from implanted Be(1 1 2¯ 0) and polycrystalline Be are explained by anisotropic diffusion of interstitials during implantation, leading to an amount of surviving D-trap complexes that depends on surface-orientation. Temperature-programmed desorption (TPD) spectra are recorded after implantation of fluences of the order of 10 19 m -2 at various energies and simulated by means of a newly developed code based on coupled reaction-diffusion systems (CRDS). The asymmetric shape of the TPD peaks is reproduced by introducing a local D accumulation process into the model.

  6. Grafting zwitterionic polymer onto cryogel surface enhances protein retention in steric exclusion chromatography on cryogel monolith.

    PubMed

    Tao, Shi-Peng; Zheng, Jie; Sun, Yan

    2015-04-10

    Cryogel monoliths with interconnected macropores (10-100μm) and hydrophilic surfaces can be employed as chromatography media for protein retention in steric exclusion chromatography (SXC). SXC is based on the principle that the exclusion of polyethylene glycol (PEG) on both a hydrophilic chromatography surface and a protein favors their association, leading to the protein retention on the chromatography surface. Elution of the retained protein can be achieved by reducing PEG concentration. In this work, the surface of polyacrylamide-based cryogel monolith was modified by grafting zwitterionic poly(carboxybetaine methacrylate) (pCBMA), leading the increase in the surface hydrophilicity. Observation by scanning electron microscopy revealed the presence of the grafted pCBMA chain clusters on the cryogel surface, but pCBMA grafting did not result in the changes of the physical properties of the monolith column, and the columns maintained good recyclability in SXC. The effect of the surface grafting on the SXC behavior of γ-globulin was investigated in a wide flow rate range (0.6-12cm/min). It was found that the dynamic retention capacity increased 1.4-1.8 times by the zwitterionic polymer grafting in the flow rate range of 1.5-12cm/min. The mechanism of enhanced protein retention on the zwitterionic polymer-grafted surface was proposed. The research proved that zwitterionic polymer modification was promising for the development of new materials for SXC applications.

  7. Transport of Sulfide-Reduced Graphene Oxide in Saturated Quartz Sand: Cation-Dependent Retention Mechanisms.

    PubMed

    Xia, Tianjiao; Fortner, John D; Zhu, Dongqiang; Qi, Zhichong; Chen, Wei

    2015-10-01

    We describe how the reduction of graphene oxide (GO) via environmentally relevant pathways affects its transport behavior in porous media. A pair of sulfide-reduced GOs (RGOs), prepared by reducing 10 mg/L GO with 0.1 mM Na2S for 3 and 5 days, respectively, exhibited lower mobility than did parent GO in saturated quartz sand. Interestingly, decreased mobility cannot simply be attributed to the increased hydrophobicity and aggregation upon GO reduction because the retention mechanisms of RGOs were highly cation-dependent. In the presence of Na(+) (a representative monovalent cation), the main retention mechanism was deposition in the secondary energy minimum. However, in the presence of Ca(2+) (a model divalent cation), cation bridging between RGO and sand grains became the most predominant retention mechanism; this was because sulfide reduction markedly increased the amount of hydroxyl groups (a strong metal-complexing moiety) on GO. When Na(+) was the background cation, increasing pH (which increased the accumulation of large hydrated Na(+) ions on grain surface) and the presence of Suwannee River humic acid (SRHA) significantly enhanced the transport of RGO, mainly due to steric hindrance. However, pH and SRHA had little effect when Ca(2+) was the background cation because neither affected the extent of cation bridging that controlled particle retention. These findings highlight the significance of abiotic transformations on the fate and transport of GO in aqueous systems.

  8. Grafting zwitterionic polymer onto cryogel surface enhances protein retention in steric exclusion chromatography on cryogel monolith.

    PubMed

    Tao, Shi-Peng; Zheng, Jie; Sun, Yan

    2015-04-10

    Cryogel monoliths with interconnected macropores (10-100μm) and hydrophilic surfaces can be employed as chromatography media for protein retention in steric exclusion chromatography (SXC). SXC is based on the principle that the exclusion of polyethylene glycol (PEG) on both a hydrophilic chromatography surface and a protein favors their association, leading to the protein retention on the chromatography surface. Elution of the retained protein can be achieved by reducing PEG concentration. In this work, the surface of polyacrylamide-based cryogel monolith was modified by grafting zwitterionic poly(carboxybetaine methacrylate) (pCBMA), leading the increase in the surface hydrophilicity. Observation by scanning electron microscopy revealed the presence of the grafted pCBMA chain clusters on the cryogel surface, but pCBMA grafting did not result in the changes of the physical properties of the monolith column, and the columns maintained good recyclability in SXC. The effect of the surface grafting on the SXC behavior of γ-globulin was investigated in a wide flow rate range (0.6-12cm/min). It was found that the dynamic retention capacity increased 1.4-1.8 times by the zwitterionic polymer grafting in the flow rate range of 1.5-12cm/min. The mechanism of enhanced protein retention on the zwitterionic polymer-grafted surface was proposed. The research proved that zwitterionic polymer modification was promising for the development of new materials for SXC applications. PMID:25757821

  9. Within-river phosphorus retention: accounting for a missing piece in the watershed phosphorus puzzle.

    PubMed

    Jarvie, Helen P; Sharpley, Andrew N; Scott, J Thad; Haggard, Brian E; Bowes, Michael J; Massey, Lesley B

    2012-12-18

    The prevailing "puzzle" in watershed phosphorus (P) management is how to account for the nonconservative behavior (retention and remobilization) of P along the land-freshwater continuum. This often hinders our attempts to directly link watershed P sources with their water quality impacts. Here, we examine aspects of within-river retention of wastewater effluent P and its remobilization under high flows. Most source apportionment methods attribute P loads mobilized under high flows (including retained and remobilized effluent P) as nonpoint agricultural sources. We present a new simple empirical method which uses chloride as a conservative tracer of wastewater effluent, to quantify within-river retention of effluent P, and its contribution to river P loads, when remobilized under high flows. We demonstrate that within-river P retention can effectively mask the presence of effluent P inputs in the water quality record. Moreover, we highlight that by not accounting for the contributions of retained and remobilized effluent P to river storm-flow P loads, existing source apportionment methods may significantly overestimate the nonpoint agricultural sources and underestimate wastewater sources in mixed land-use watersheds. This has important implications for developing effective watershed remediation strategies, where remediation needs to be equitably and accurately apportioned among point and nonpoint P contributors.

  10. Peste des Petits Ruminants Virus.

    PubMed

    Baron, M D; Diallo, A; Lancelot, R; Libeau, G

    2016-01-01

    Peste des petits ruminants virus (PPRV) causes a severe contagious disease of sheep and goats and has spread extensively through the developing world. Because of its disproportionately large impact on the livelihoods of low-income livestock keepers, and the availability of effective vaccines and good diagnostics, the virus is being targeted for global control and eventual eradication. In this review we examine the origin of the virus and its current distribution, and the factors that have led international organizations to conclude that it is eradicable. We also review recent progress in the molecular and cellular biology of the virus and consider areas where further research is required to support the efforts being made by national, regional, and international bodies to tackle this growing threat. PMID:27112279

  11. Cancer risk in DES daughters

    PubMed Central

    Verloop, Janneke; van Leeuwen, Flora E.; Helmerhorst, Theo J. M.; van Boven, Hester H.

    2010-01-01

    Objective We examined long-term risk of cancer in women exposed to diethylstilbestrol (DES) in utero. Methods A total of 12,091 DES-exposed women in the Netherlands were followed prospectively from December 1992 till June 2008. Cancer incidence was assessed through linkage with the Dutch pathology database (PALGA) and the Netherlands Cancer Registry and compared with the Dutch female population. Results A total of 348 medically verified cancers occurred; median age at end of follow-up was 44.0 years. No overall increased risk of cancer was found (standardized incidence ratio [SIR] = 1.01; 95% confidence interval [CI] = 0.91, 1.13). The risk of clear cell adenocarcinoma of the vagina and cervix (CCA) was statistically significantly increased (SIR = 24.23; 95% CI = 8.89, 52.74); the elevated risk persisted above 40 years of age. The risk of melanoma diagnosed before age 40 was increased (SIR = 1.59; 95% CI = 1.08, 2.26). No excess risks were found for other sites, including breast cancer. Conclusions Except for an elevated risk of CCA, persisting at older ages, and an increased risk of melanoma at young ages, we found no increased risk of cancer. Longer follow-up is warranted to examine cancer risk at ages when cancer occurs more frequently. Electronic supplementary material The online version of this article (doi:10.1007/s10552-010-9526-5) contains supplementary material, which is available to authorized users. PMID:20204493

  12. The enhancement of existing DES Maplet interface

    NASA Astrophysics Data System (ADS)

    Abdullah, Nur Lina; Mutalip, Rasidah Abdull; Abdullah, Kamilah

    2014-07-01

    This study pertains to the process of Data Encryption Standard, DES. DES consists of encryption and decryption processes linked with mathematical elements such as algebra and number theory. Preliminary, studies revealed that most of mathematics students face a problem in understanding the complicated process of DES. In modern learning methods, learning environment becomes more interesting with the use of computer and a variety of mathematical software packages. Several mathematical softwares such as Maple, Mathematica, Mathlab and Sage were developed in order to fulfill the specific calculation requirements. Correspondingly, motivated from that, this study incorporated with Maple to enhance the existing DES Maplet interface to be more interactive and user-friendly compared to the original version.

  13. Activation of the bacterial thermosensor DesK involves a serine zipper dimerization motif that is modulated by bilayer thickness

    PubMed Central

    Cybulski, Larisa Estefanía; Ballering, Joost; Moussatova, Anastassiia; Inda, Maria Eugenia; Vazquez, Daniela B.; Wassenaar, Tsjerk A.; de Mendoza, Diego; Tieleman, D. Peter; Killian, J. Antoinette

    2015-01-01

    DesK is a bacterial thermosensor protein involved in maintaining membrane fluidity in response to changes in environmental temperature. Most likely, the protein is activated by changes in membrane thickness, but the molecular mechanism of sensing and signaling is still poorly understood. Here we aimed to elucidate the mode of action of DesK by studying the so-called “minimal sensor DesK” (MS-DesK), in which sensing and signaling are captured in a single transmembrane segment. This simplified version of the sensor allows investigation of membrane thickness-dependent protein–lipid interactions simply by using synthetic peptides, corresponding to the membrane-spanning parts of functional and nonfunctional mutants of MS-DesK incorporated in lipid bilayers with varying thicknesses. The lipid-dependent behavior of the peptides was investigated by circular dichroism, tryptophan fluorescence, and molecular modeling. These experiments were complemented with in vivo functional studies on MS-DesK mutants. Based on the results, we constructed a model that suggests a new mechanism for sensing in which the protein is present as a dimer and responds to an increase in bilayer thickness by membrane incorporation of a C-terminal hydrophilic motif. This results in exposure of three serines on the same side of the transmembrane helices of MS-DesK, triggering a switching of the dimerization interface to allow the formation of a serine zipper. The final result is activation of the kinase state of MS-DesK. PMID:25941408

  14. Strategies to improve retention in randomised trials

    PubMed Central

    Brueton, Valerie C; Tierney, Jayne; Stenning, Sally; Harding, Seeromanie; Meredith, Sarah; Nazareth, Irwin; Rait, Greta

    2013-01-01

    Background Loss to follow-up from randomised trials can introduce bias and reduce study power, affecting the generalisability, validity and reliability of results. Many strategies are used to reduce loss to follow-up and improve retention but few have been formally evaluated. Objectives To quantify the effect of strategies to improve retention on the proportion of participants retained in randomised trials and to investigate if the effect varied by trial strategy and trial setting. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PreMEDLINE, EMBASE, PsycINFO, DARE, CINAHL, Campbell Collaboration's Social, Psychological, Educational and Criminological Trials Register, and ERIC. We handsearched conference proceedings and publication reference lists for eligible retention trials. We also surveyed all UK Clinical Trials Units to identify further studies. Selection criteria We included eligible retention trials of randomised or quasi-randomised evaluations of strategies to increase retention that were embedded in 'host' randomised trials from all disease areas and healthcare settings. We excluded studies aiming to increase treatment compliance. Data collection and analysis We contacted authors to supplement or confirm data that we had extracted. For retention trials, we recorded data on the method of randomisation, type of strategy evaluated, comparator, primary outcome, planned sample size, numbers randomised and numbers retained. We used risk ratios (RR) to evaluate the effectiveness of the addition of strategies to improve retention. We assessed heterogeneity between trials using the Chi2 and I2 statistics. For main trials that hosted retention trials, we extracted data on disease area, intervention, population, healthcare setting, sequence generation and allocation concealment. Main results We identified 38 eligible retention trials. Included trials evaluated six broad types of strategies to improve retention. These

  15. Gas bubble retention and its effect on waste properties: Retention mechanisms, viscosity, and tensile and shear strengths

    SciTech Connect

    Gauglitz, P.A.; Rassat, S.D.; Powell, M.R.

    1995-08-01

    Several of the underground nuclear storage tanks at Hanford have been placed on a flammable gas watch list, because the waste is either known or suspected to generate, store, and episodically release flammable gases. Because retention and episodic release of flammable gases from these tanks containing radioactive waste slurries are critical safety concerns, Pacific Northwest Laboratory (PNL) is studying physical mechanisms and waste properties that contribute to the episodic gas release from these storage tanks. This study is being conducted for Westinghouse Hanford Company as part of the PNL Flammable Gas project. Previous investigations have concluded that gas bubbles are retained by the slurry or sludge that has settled at the bottom of the tanks; however, the mechanisms responsible for the retention of these bubbles are not well understood. Understanding the rheological behavior of the waste, particularly of the settled sludge, is critical to characterizing the tendency of the waste to retain gas bubbles and the dynamics of how these bubbles are released from the waste. The presence of gas bubbles is expected to affect the rheology of the sludge, specifically its viscosity and tensile and shear strengths, but essentially no literature data are available to assess the effect of bubbles. The objectives of this study were to conduct experiments and develop theories to understand better how bubbles are retained by slurries and sludges, to measure the effect of gas bubbles on the viscosity of simulated slurries, and to measure the effect of gas bubbles on the tensile and shear strengths of simulated slurries and sludges. In addition to accomplishing these objectives, this study developed correlations, based on the new experimental data, that can be used in large-scale computations of waste tank physical phenomena.

  16. Workforce Challenges and Retention Success Stories

    NASA Technical Reports Server (NTRS)

    Donohue, John T.

    2008-01-01

    This viewgraph document discusses the current and future challenges in building and retaining the required workforce of scientist and engineers for NASA. Specifically, the talk reviews the current situation at the Goddard Space Flight Center in Greenbelt, Maryland. Several programs at NASA for high school and college students to assist in inspiring the next generation of scientist and engineers are reviewed. The issue of retention of the best of the young scientists and engineers is also reviewed, with a brief review of several young engineers and their success with and for NASA.

  17. Nitrogen retention in urban lawns and forests.

    PubMed

    Raciti, S M; Groffman, P M; Fahey, T J

    2008-10-01

    Lawns are a dominant cover type in urban ecosystems, and there is concern about their impacts on water quality. However, recent watershed-level studies suggest that these pervious areas might be net sinks, rather than sources, for nitrogen (N) in the urban environment. A 15N pulse-labeling experiment was performed on lawn and forest plots in the Baltimore (Maryland, U.S.A.) metropolitan area to test the hypothesis that lawns are a net sink for atmospheric-N deposition and to compare and contrast mechanisms of N retention in these vegetation types. A pulse of 15N-NO3-, simulating a precipitation event, was followed through mineral soils, roots, Oi-layer/thatch, aboveground biomass, microbial biomass, inorganic N, and evolved N2 gas over a one-year period. The 15N label was undetectable in gaseous samples, but enrichment of other pools was high. Gross rates of production and consumption of NO3- and NH4+ were measured to assess differences in internal N cycling under lawns and forests. Rates of N retention were similar during the first five days of the experiment, with lawns showing higher N retention than forests after 10, 70, and 365 days. Lawns had larger pools of available NO3- and NH4+; however, gross rates of mineralization and nitrification were also higher, leading to no net differences in NO3- and NH4+ turnover times between the two systems. Levels of 15N remained steady in forest mineral soils from day 70 to 365 (at 23% of applied 15N), but continued to accumulate in lawn mineral soils over this same time period, increasing from 20% to 33% of applied 15N. The dominant sink for N in lawn plots changed over time. Immobilization in mineral soils dominated immediately (one day) after tracer application (42% of recovered 15N); plant biomass dominated the short term (10 days; 51%); thatch and mineral-soil pools together dominated the medium term (70 days; 28% and 36%, respectively); and the mineral-soil pool alone dominated long-term retention (one year; 70% of

  18. LARES Mission: Separation and Retention Subsystem

    NASA Technical Reports Server (NTRS)

    Bursi, Alessandro; Camilli, Pierluigi; Piredda, Claudio; Babini, Gianni; Mangraviti, Elio

    2014-01-01

    As part of the Lares (LAser RElativity Satellite) mission, an all-Italian scientific mission launched with the Vega maiden flight in February 2012, a mechanical separation and retention subsystem (SSEP) has been developed to retain the LARES satellite during launch and release it in the final orbit. The design flow was based on the identification of the driving requirements and critical areas to guide the trade-off, design, analysis and test activities. In particular, the SSEP had to face very high environmental loads and to minimize the contact areas with the satellite that had a spherical shape. The test activity overview is provided.

  19. Survey on workforce retention and attrition

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2013-03-01

    The Society of Petroleum Engineers (SPE) is conducting a survey to gather information on why technical professionals change jobs or quit working. The survey, prompted by concern about the retention of skilled workers, aims to provide information to employers that can assist them in addressing practices that can lead to significant workforce attrition. To participate in the survey, which is open to everyone (including those who are not SPE members), go to http://research.spe.org/se.ashx?s=705E3F1335720258 through 15 May 2013. For more information, contact speresearch@spe.org.

  20. Retention, Helpful or Harmful? A Look at How or If Grade Retention Affects Children in School.

    ERIC Educational Resources Information Center

    Rothstein, Vivian L.

    Noting that the rate of grade retention has risen nearly 40 percent over the past 20 years, this case study examines whether being retained for 1 school year helps children academically by giving them more practice and time to succeed or harms their self-esteem and causes them to eventually drop out of school. Participating in the study were five…

  1. Reframing Retention: New Evidence from within the Elementary School Classroom on Post-Retention Performance

    ERIC Educational Resources Information Center

    Gottfried, Michael A.

    2012-01-01

    This study contributes a novel perspective on grade retention by empirically examining how classroom composition relates to the standardized-testing performance of grade-retained students in their post-retained years. This evaluation employed a sample of entire cohorts of urban elementary school children in the Philadelphia School District over 6…

  2. Football and Freshmen Retention: Examining the Impact of College Football on Institutional Retention Rates

    ERIC Educational Resources Information Center

    Jones, Willis A.

    2010-01-01

    Student retention has been one of the more researched topics in the study of American higher education over the past 20 years (Braxton, Hirschy, & McClendon, 2004; Pascarella & Terenzini, 2005). Very little of this research, however, has attempted to examine the impact of college athletics on an institution's ability to retain students. This…

  3. CD44 is required for spatial memory retention and sensorimotor functions

    PubMed Central

    Raber, Jacob; Olsen, Reid H. J.; Su, Weiping; Foster, Scott; Xing, Rubing; Acevedo, Summer F.; Sherman, Larry S.

    2014-01-01

    CD44 is a transmembrane receptor for the glycosaminoglycan hyaluronan, a component of the extracellular matrix. CD44 is expressed by neural stem/progenitor cells, astrocytes, and some neurons but its function in the central nervous system is unknown. To determine the role of CD44 in brain function, we behaviorally analyzed CD44-null (KO) and wild-type (WT) mice. KO mice showed increased activity levels in the light-dark test and a trend towards increased activity in the open field. In addition, KO mice showed impaired hippocampus-dependent spatial memory retention in the probe trial following the first hidden-platform training day in the Morris water maze: WT mice showed spatial memory retention and spent more time in the target quadrant than any other quadrant, while KO mice did not. Although there were no genotype differences in swim speeds during the water maze training sessions with the visible or hidden platform, sensorimotor impairments were seen in other behavioral tests. In the inclined screen and balance beam tests, KO mice moved less than WT mice. In the wire hang test, KO mice also fell off of the wire faster than WT mice. In contrast, there was no genotype difference when emotional learning and memory were assessed in the passive avoidance test. These data support an important role for CD44 in locomotor and sensorimotor functions, and in spatial memory retention. PMID:25219362

  4. CD44 is required for spatial memory retention and sensorimotor functions.

    PubMed

    Raber, Jacob; Olsen, Reid H J; Su, Weiping; Foster, Scott; Xing, Rubing; Acevedo, Summer F; Sherman, Larry S

    2014-12-15

    CD44 is a transmembrane receptor for the glycosaminoglycan hyaluronan, a component of the extracellular matrix. CD44 is expressed by neural stem/progenitor cells, astrocytes, and some neurons but its function in the central nervous system is unknown. To determine the role of CD44 in brain function, we behaviorally analyzed CD44-null (KO) and wild-type (WT) mice. KO mice showed increased activity levels in the light-dark test and a trend toward increased activity in the open field. In addition, KO mice showed impaired hippocampus-dependent spatial memory retention in the probe trial following the first hidden-platform training day in the Morris water maze: WT mice showed spatial memory retention and spent more time in the target quadrant than any other quadrant, while KO mice did not. Although there were no genotype differences in swim speeds during the water maze training sessions with the visible or hidden platform, sensorimotor impairments were seen in other behavioral tests. In the inclined screen and balance beam tests, KO mice moved less than WT mice. In the wire hang test, KO mice also fell off of the wire faster than WT mice. In contrast, there was no genotype difference when emotional learning and memory were assessed in the passive avoidance test. These data support an important role for CD44 in locomotor and sensorimotor functions, and in spatial memory retention.

  5. Effets perturbateurs endocriniens des pesticides organochlores.

    PubMed

    Charlier, C; Plomteux, G

    2002-01-01

    Xenoestrogens such organochlorine pesticides are known to induce changes in reproductive development, function or behaviour in wildlife. Because these compounds are able to modify the estrogens metabolism, or to compete with estradiol for binding to the estrogen receptor, it may be possible that these products affect the risk of developing impaired fertility, precocious puberty or some kinds of cancer in man. Le plus ancien récit de lutte contre la pollution remonte à une légende indienne racontant que la divinité Sing-bonga était incommodée par les émanations des fours dans lesquels les Asuras fondaient leurs métaux (1). Evidemment depuis, la problématique n-a cessé de s-accroître et la contamination de la Terre par de nombreux polluants est devenue aujourd-hui un problème majeur de notre Société. La protection de notre environnement est une question capitale qui doit être respectée malgré la pression économique actuelle et qui ne cessera de croître au cours des prochaines années même si l-identification objective et indiscutable de ce qui est essentiel - donc devant être prioritairement garanti sur la planète - est difficile à cerner (2). « Un oiseau en mauvais état ne pond pas de bons oeufs » disait un proverbe grec. Mais ce n-est qu-à partir de la seconde moitié du XXème siècle que les toxicologues ont commencé à identifier les effets qu-avaient entraînés à l-échelle mondiale les pollutions émises aux XIXème siècle sur la faune sauvage et sur le cheptel (3). L-histoire contemporaine des pesticides industriels commence vers 1874 (synthèse des organochlorés) et se poursuit tout au long de ces 2 siècles en passant par la synthèse des organophosphorés (1950), des carbamates (1970) et des pyréthroïdes (1975) (4). Le dichlorodiphényltrichloroéthane (DDT) a été synthétisé pour la première fois par un étudiant en cours de préparation de sa thèse de doctorat : Othmer Zeidler. La production, reprise par les

  6. Gender differences in problem severity at assessment and treatment retention.

    PubMed

    Arfken, C L; Klein, C; di Menza, S; Schuster, C R

    2001-01-01

    Women in treatment for substance abuse have been reported to have more severe problems at assessment than men but not to differ in treatment retention. To examine gender differences in problems at assessment, 30-day retention, and treatment completion, data from Detroit's publicly funded substance abuse treatment system were used. Women had significantly more severe problems at assessment, lower 30-day retention, and lower treatment completion rates than men. These gender differences in retention remained significant even after controlling for problem severity, primary drug of abuse, and referred treatment setting. There was no evidence of improvements in women's problems at assessment or retention over time during this period. Women presented with more severe problems at assessment and were less likely to stay in treatment for 30 days or to complete treatment than men. Monitoring gender differences in problems at presentation and retention outcomes is recommended to assess local need for interventions.

  7. Mechanistic failure mode investigation and resolution of parvovirus retentive filters.

    PubMed

    LaCasse, Daniel; Lute, Scott; Fiadeiro, Marcus; Basha, Jonida; Stork, Matthew; Brorson, Kurt; Godavarti, Ranga; Gallo, Chris

    2016-07-01

    Virus retentive filters are a key product safety measure for biopharmaceuticals. A simplistic perception is that they function solely based on a size-based particle removal mechanism of mechanical sieving and retention of particles based on their hydrodynamic size. Recent observations have revealed a more nuanced picture, indicating that changes in viral particle retention can result from process pressure and/or flow interruptions. In this study, a mechanistic investigation was performed to help identify a potential mechanism leading to the reported reduced particle retention in small virus filters. Permeate flow rate or permeate driving force were varied and analyzed for their impact on particle retention in three commercially available small virus retentive filters. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:959-970, 2016.

  8. Hydrogen retention in ion irradiated steels

    SciTech Connect

    Hunn, J.D.; Lewis, M.B.; Lee, E.H.

    1998-11-01

    In the future 1--5 MW Spallation Neutron Source, target radiation damage will be accompanied by high levels of hydrogen and helium transmutation products. The authors have recently carried out investigations using simultaneous Fe/He,H multiple-ion implantations into 316 LN stainless steel between 50 and 350 C to simulate the type of radiation damage expected in spallation neutron sources. Hydrogen and helium were injected at appropriate energy and rate, while displacement damage was introduced by nuclear stopping of 3.5 MeV Fe{sup +}, 1 {micro}m below the surface. Nanoindentation measurements showed a cumulative increase in hardness as a result of hydrogen and helium injection over and above the hardness increase due to the displacement damage alone. TEM investigation indicated the presence of small bubbles of the injected gases in the irradiated area. In the current experiment, the retention of hydrogen in irradiated steel was studied in order to better understand its contribution to the observed hardening. To achieve this, the deuterium isotope ({sup 2}H) was injected in place of natural hydrogen ({sup 1}H) during the implantation. Trapped deuterium was then profiled, at room temperature, using the high cross-section nuclear resonance reaction with {sup 3}He. Results showed a surprisingly high concentration of deuterium to be retained in the irradiated steel at low temperature, especially in the presence of helium. There is indication that hydrogen retention at spallation neutron source relevant target temperatures may reach as high as 10%.

  9. Cooking utensil with improved heat retention

    DOEpatents

    Potter, Thomas F.; Benson, David K.; Burch, Steven D.

    1997-01-01

    A cooking utensil with improved heat retention includes an inner pot received within an outer pot and separated in a closely spaced-apart relationship to form a volume or chamber therebetween. The chamber is evacuated and sealed with foil leaves at the upper edges of the inner and outer pot. The vacuum created between the inner and outer pot, along with the minimum of thermal contact between the inner and outer pot, and the reduced radiative heat transfer due to low emissivity coatings on the inner and outer pot, provide for a highly insulated cooking utensil. Any combination of a plurality of mechanisms for selectively disabling and re-enabling the insulating properties of the pot are provided within the chamber. These mechanisms may include: a hydrogen gas producing and reabsorbing device such as a metal hydride, a plurality of metal contacts which can be adjusted to bridge the gap between the inner and outer pot, and a plurality of bimetallic switches which can selectively bridge the gap between the inner and outer pot. In addition, phase change materials with superior heat retention characteristics may be provided within the cooking utensil. Further, automatic and programmable control of the cooking utensil can be provided through a microprocessor and associated hardware for controlling the vacuum disable/enable mechanisms to automatically cook and save food.

  10. Cooking utensil with improved heat retention

    DOEpatents

    Potter, T.F.; Benson, D.K.; Burch, S.D.

    1997-07-01

    A cooking utensil with improved heat retention includes an inner pot received within an outer pot and separated in a closely spaced-apart relationship to form a volume or chamber there between. The chamber is evacuated and sealed with foil leaves at the upper edges of the inner and outer pot. The vacuum created between the inner and outer pot, along with the minimum of thermal contact between the inner and outer pot, and the reduced radiative heat transfer due to low emissivity coatings on the inner and outer pot, provide for a highly insulated cooking utensil. Any combination of a plurality of mechanisms for selectively disabling and re-enabling the insulating properties of the pot are provided within the chamber. These mechanisms may include: a hydrogen gas producing and reabsorbing device such as a metal hydride, a plurality of metal contacts which can be adjusted to bridge the gap between the inner and outer pot, and a plurality of bimetallic switches which can selectively bridge the gap between the inner and outer pot. In addition, phase change materials with superior heat retention characteristics may be provided within the cooking utensil. Further, automatic and programmable control of the cooking utensil can be provided through a microprocessor and associated hardware for controlling the vacuum disable/enable mechanisms to automatically cook and save food. 26 figs.

  11. Global phosphorus retention by river damming.

    PubMed

    Maavara, Taylor; Parsons, Christopher T; Ridenour, Christine; Stojanovic, Severin; Dürr, Hans H; Powley, Helen R; Van Cappellen, Philippe

    2015-12-22

    More than 70,000 large dams have been built worldwide. With growing water stress and demand for energy, this number will continue to increase in the foreseeable future. Damming greatly modifies the ecological functioning of river systems. In particular, dam reservoirs sequester nutrient elements and, hence, reduce downstream transfer of nutrients to floodplains, lakes, wetlands, and coastal marine environments. Here, we quantify the global impact of dams on the riverine fluxes and speciation of the limiting nutrient phosphorus (P), using a mechanistic modeling approach that accounts for the in-reservoir biogeochemical transformations of P. According to the model calculations, the mass of total P (TP) trapped in reservoirs nearly doubled between 1970 and 2000, reaching 42 Gmol y(-1), or 12% of the global river TP load in 2000. Because of the current surge in dam building, we project that by 2030, about 17% of the global river TP load will be sequestered in reservoir sediments. The largest projected increases in TP and reactive P (RP) retention by damming will take place in Asia and South America, especially in the Yangtze, Mekong, and Amazon drainage basins. Despite the large P retention capacity of reservoirs, the export of RP from watersheds will continue to grow unless additional measures are taken to curb anthropogenic P emissions.

  12. Retention of Halogens in Waste Glass

    SciTech Connect

    Hrma, Pavel R.

    2010-05-01

    In spite of their potential roles as melting rate accelerators and foam breakers, halogens are generally viewed as troublesome components for glass processing. Of five halogens, F, Cl, Br, I, and At, all but At may occur in nuclear waste. A nuclear waste feed may contain up to 10 g of F, 4 g of Cl, and ≤100 mg of Br and I per kg of glass. The main concern is halogen volatility, producing hazardous fumes and particulates, and the radioactive iodine 129 isotope of 1.7x10^7-year half life. Because F and Cl are soluble in oxide glasses and tend to precipitate on cooling, they can be retained in the waste glass in the form of dissolved constituents or as dispersed crystalline inclusions. This report compiles known halogen-retention data in both high-level waste (HLW) and low-activity waste (LAW) glasses. Because of its radioactivity, the main focus is on I. Available data on F and Cl were compiled for comparison. Though Br is present in nuclear wastes, it is usually ignored; no data on Br retention were found.

  13. Global phosphorus retention by river damming

    PubMed Central

    Maavara, Taylor; Parsons, Christopher T.; Ridenour, Christine; Stojanovic, Severin; Dürr, Hans H.; Powley, Helen R.; Van Cappellen, Philippe

    2015-01-01

    More than 70,000 large dams have been built worldwide. With growing water stress and demand for energy, this number will continue to increase in the foreseeable future. Damming greatly modifies the ecological functioning of river systems. In particular, dam reservoirs sequester nutrient elements and, hence, reduce downstream transfer of nutrients to floodplains, lakes, wetlands, and coastal marine environments. Here, we quantify the global impact of dams on the riverine fluxes and speciation of the limiting nutrient phosphorus (P), using a mechanistic modeling approach that accounts for the in-reservoir biogeochemical transformations of P. According to the model calculations, the mass of total P (TP) trapped in reservoirs nearly doubled between 1970 and 2000, reaching 42 Gmol y−1, or 12% of the global river TP load in 2000. Because of the current surge in dam building, we project that by 2030, about 17% of the global river TP load will be sequestered in reservoir sediments. The largest projected increases in TP and reactive P (RP) retention by damming will take place in Asia and South America, especially in the Yangtze, Mekong, and Amazon drainage basins. Despite the large P retention capacity of reservoirs, the export of RP from watersheds will continue to grow unless additional measures are taken to curb anthropogenic P emissions. PMID:26644553

  14. Radionuclide Retention in Concrete Waste Forms

    SciTech Connect

    Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.; Wood, Marcus I.

    2010-09-30

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how waste form performance is affected by the full range of environmental conditions within the disposal facility; the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of waste form aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the waste forms come in contact with groundwater. The information presented in the report provides data that 1) quantify radionuclide retention within concrete waste form materials similar to those used to encapsulate waste in the Low-Level Waste Burial Grounds (LLBG); 2) measure the effect of concrete waste form properties likely to influence radionuclide migration; and 3) quantify the stability of uranium-bearing solid phases of limited solubility in concrete.

  15. Global phosphorus retention by river damming.

    PubMed

    Maavara, Taylor; Parsons, Christopher T; Ridenour, Christine; Stojanovic, Severin; Dürr, Hans H; Powley, Helen R; Van Cappellen, Philippe

    2015-12-22

    More than 70,000 large dams have been built worldwide. With growing water stress and demand for energy, this number will continue to increase in the foreseeable future. Damming greatly modifies the ecological functioning of river systems. In particular, dam reservoirs sequester nutrient elements and, hence, reduce downstream transfer of nutrients to floodplains, lakes, wetlands, and coastal marine environments. Here, we quantify the global impact of dams on the riverine fluxes and speciation of the limiting nutrient phosphorus (P), using a mechanistic modeling approach that accounts for the in-reservoir biogeochemical transformations of P. According to the model calculations, the mass of total P (TP) trapped in reservoirs nearly doubled between 1970 and 2000, reaching 42 Gmol y(-1), or 12% of the global river TP load in 2000. Because of the current surge in dam building, we project that by 2030, about 17% of the global river TP load will be sequestered in reservoir sediments. The largest projected increases in TP and reactive P (RP) retention by damming will take place in Asia and South America, especially in the Yangtze, Mekong, and Amazon drainage basins. Despite the large P retention capacity of reservoirs, the export of RP from watersheds will continue to grow unless additional measures are taken to curb anthropogenic P emissions. PMID:26644553

  16. Radionuclide Retention in Concrete Wasteforms - FY13

    SciTech Connect

    Snyder, Michelle MV; Golovich, Elizabeth C.; Wellman, Dawn M.; Crum, Jarrod V.; Lapierre, Robert; Dage, Denomy C.; Parker, Kent E.; Cordova, Elsa A.

    2013-10-15

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of low-level waste and mixed low-level waste, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

  17. Modeling structural influences on soil water retention

    USGS Publications Warehouse

    Nimmo, J.R.

    1997-01-01

    A new model quantities the effect of soil structure, considered as the arrangement of particles in the soil, on soil water retention. The model partitions the pore space into texture-related and structure-related components, the textural component being what can be deduced to exist if the arrangement of the particles were random, and the structural component being the remainder. An existing model, based on particle-size distributions, represents the textural component, and a new model, based on aggregate-size distributions, represents the structural component. This new model makes use of generalized properties that vary little from one medium to another, thereby eliminating any need for empirically tilted parameters. It postulates a particular character of the structural pore space that in same ways resembles texture-related pore space, but with pore shape related to the breadth of the aggregate-size distribution. To predict a soil water retention curve, this model requires the soil's porosity and particle- and aggregate-size distributions. Tested with measurements for 17 samples from two sources, it fits the data much better than does a model based on texture alone. Goodness of fit indicated by correlation coefficients ranged from 0.908 to 0.998 for the new model, compared with a range of 0.686 in 0.955 for the texture-based model.

  18. High retention membrane bioreactors: challenges and opportunities.

    PubMed

    Luo, Wenhai; Hai, Faisal I; Price, William E; Guo, Wenshan; Ngo, Hao H; Yamamoto, Kazuo; Nghiem, Long D

    2014-09-01

    Extensive research has focussed on the development of novel high retention membrane bioreactor (HR-MBR) systems for wastewater reclamation in recent years. HR-MBR integrates high rejection membrane separation with conventional biological treatment in a single step. High rejection membrane separation processes currently used in HR-MBR applications include nanofiltration, forward osmosis, and membrane distillation. In these HR-MBR systems, organic contaminants can be effectively retained, prolonging their retention time in the bioreactor and thus enhancing their biodegradation. Therefore, HR-MBR can offer a reliable and elegant solution to produce high quality effluent. However, there are several technological challenges associated with the development of HR-MBR, including salinity build-up, low permeate flux, and membrane degradation. This paper provides a critical review on these challenges and potential opportunities of HR-MBR for wastewater treatment and water reclamation, and aims to guide and inform future research on HR-MBR for fast commercialisation of this innovative technology. PMID:24996563

  19. How efficient are central mechanisms for the learning and retention of coincident timing actions?

    PubMed

    Fleury, M; Bard, C; Teasdale, N; Michaud, D; Lamarre, Y

    1999-06-01

    We compared the adaptive strategy and retention capacity of a deafferented subject and control subjects when intercepting, with a sliding-throw, an apparent movement coming at various speeds. Subjects were submitted to five practice sessions (30 trials per session) and to a retention test. The throwing kinematics was analysed, and spatial and temporal performance errors were measured. With practice, the deafferented subject showed modifications in movement initiation strategies and throwing patterns. With a slow apparent movement, the deafferented subject's initial behavior was characterized by short movement initiation and movement times. With practice, she showed an important increase in movement time in session 5, allowing longer visual control and leading to better temporal and spatial accuracy than that shown in session 1. In the retention session, the deafferented patient showed a late movement initiation strategy, similar to that of the control subjects. This increased movement initiation time was accompanied by an improved temporal accuracy compared to the deafferented subject's early results. However, spatial accuracy improvement was labile and could not be maintained over the retention interval. At the fast speed, all temporal components of the response, namely, movement initiation time (MIT), movement time (MT), and disk travel time (DTT), were similar for the deafferented and control subjects. Overall, the deafferented subject reduced her temporal error through practice, though without attaining the control subjects' accuracy. However, with a fast-moving stimulus, she showed a deteriorated spatial accuracy, even doubling her spatial errors at retention. In brief, the deafferented subject achieved proper temporal (perceptivo-cognitive) lasting control of her interceptive action, whereas spatial (sensorimotor) regulation raised mnemonic problems.

  20. Sexual Behaviors in Autism: Problems of Definition and Management.

    ERIC Educational Resources Information Center

    Realmuto, George M.; Ruble, Lisa A.

    1999-01-01

    Explores the problems of definition of sexual behaviors in individuals with autism and describes a case that highlights the difficulties of management. After failure of behavioral and educational programs, a testosterone-suppressing medication was used resulting in suppression of public masturbation behaviors and retention of the participant's…

  1. Job embeddedness as a nurse retention strategy for rural hospitals.

    PubMed

    Stroth, Chandra

    2010-01-01

    RN turnover is expensive and disruptive for rural hospitals, constraining finances, impacting patient care, and stressing remaining nurses. Recent investigations have described a promising new construct related to employee retention: job embeddedness. Leaders in nonhealthcare organizations have adopted a job-embeddedness model to guide retention strategies and experienced a subsequent reduction in turnover. The author explores job embeddedness as an effective retention plan strategy for rural hospitals. PMID:20010375

  2. Manager impact on retention of hospital staff: Part 2.

    PubMed

    Taunton, R L; Krampitz, S D; Woods, C Q

    1989-04-01

    This is the second article in a two-part series based on a study of the impact of middle managers on retention of 71 hospital professionals. Research design, methods, and descriptive results were presented in Part 1 (March 1989). In Part 2, the impact of managers' motivation to manage, power, influence, and leadership style on retention is detailed. Recommendations for improving retention include interventions to increase employee job satisfaction and intent to stay, and to improve managers' performance and leadership.

  3. Gender-related behavior in women exposed prenatally to diethylstilbestrol.

    PubMed Central

    Newbold, R R

    1993-01-01

    Accumulating evidence in experimental animals over the past three decades suggests that mammalian brain development and differentiation of the central nervous system are influenced by perinatal exposure to sex hormones. Hence, changes in human behavioral patterns may be associated with prenatal exposure to estrogenic substances such as diethylstilbestrol (DES). This paper reviews relevant studies from a series of laboratories and finds that no clear-cut differences can be demonstrated to date between unexposed and DES-exposed women in gender-related behavior, although the physical and psychological impact of the problems associated with exposure to DES are well documented. If both prenatal and postnatal influences such as social, economic, and environmental factors are taken into consideration, individual variation is more apparent than differences in gender-related behavior between unexposed and DES-exposed women. In summary, gender-related behavior is determined by a complex array of interacting factors, and prenatal influences are only one of many developmental events. More studies are needed using larger populations with carefully controlled selection criteria to suggest a direct role of prenatal DES exposure on subsequent gender-related behavior. Images p208-a PMID:8404755

  4. The effect of hydrate saturation on water retention curves in hydrate-bearing sediments

    NASA Astrophysics Data System (ADS)

    Mahabadi, Nariman; Zheng, Xianglei; Jang, Jaewon

    2016-05-01

    The experimental measurement of water retention curve in hydrate-bearing sediments is critically important to understand the behavior of hydrate dissociation and gas production. In this study, tetrahydrofuran (THF) is selected as hydrate former. The pore habit of THF hydrates is investigated by visual observation in a transparent micromodel. It is confirmed that THF hydrates are not wetting phase on the quartz surface of the micromodel and occupy either an entire pore or part of pore space resulting in change in pore size distribution. And the measurement of water retention curves in THF hydrate-bearing sediments with hydrate saturation ranging from Sh = 0 to Sh = 0.7 is conducted for excess water condition. The experimental results show that the gas entry pressure and the capillary pressure increase with increasing hydrate saturation. Based on the experimental results, fitting parameters for van Genuchten equation are suggested for different hydrate saturation conditions.

  5. Effects of Globally Waste Disturbing Activities on Gas Generation, Retention, and Release in Hanford Waste Tanks

    SciTech Connect

    Stewart, Charles W.; Fountain, Matthew S.; Huckaby, James L.; Mahoney, Lenna A.; Meyer, Perry A.; Wells, Beric E.

    2005-08-02

    Various operations are authorized in Hanford single- and double-shell tanks that disturb all or a large fraction of the waste. These globally waste-disturbing activities have the potential to release a large fraction of the retained flammable gas and to affect future gas generation, retention, and release behavior. This report presents analyses of the expected flammable gas release mechanisms and the potential release rates and volumes resulting from these activities. The background of the flammable gas safety issue at Hanford is summarized, as is the current understanding of gas generation, retention, and release phenomena. Considerations for gas monitoring and assessment of the potential for changes in tank classification and steady-state flammability are given.

  6. Treatment retention in a prison-based residential sex offender treatment program.

    PubMed

    Pelissier, Bernadette

    2007-12-01

    This study assessed the role of static factors, a dynamic factor (motivation to change sexually deviant behavior), and an administrative factor in predicting treatment retention within a prison-based sex offender treatment program. The analyses also included assessing differences in initial levels of motivation and differences in beginning-versus end-of-treatment motivation scores for various types of program discharges. The sample consisted of 251 individuals who were admitted to a residential prison-based sex offender treatment program where 46% completed the program. Paired comparison t-tests showed higher motivation scores at the end of treatment only among treatment completers. Multivariate analyses showed that treatment retention was associated with higher initial motivation scores, higher levels of education and admission to treatment within 3 months of initial commitment to prison. Implications for motivational enhancement programming as well as for changes in admission criteria are discussed.

  7. Defects in tungsten responsible for molecular hydrogen isotope retention after exposure to low energy plasmas

    NASA Astrophysics Data System (ADS)

    Causey, R. A.; Doerner, R.; Fraser, H.; Kolasinski, R. D.; Smugeresky, J.; Umstadter, K.; Williams, R.

    2009-06-01

    Recent work on hydrogen isotope retention in tungsten has shown a substantial fraction of the retained hydrogen to be in the form of molecules. It can be expected that hydrogen permeating through a material such as tungsten, that has a very low solubility for hydrogen, would come out of solution and combine into molecules at voids located throughout the bulk. The purpose of this report is to determine the type of voids responsible for the molecular retention. High purity tungsten provided by Plansee Aktiengesellschaft was first polished, annealed at 1273 K in vacuum for one hour, and then exposed to high fluxes and high fluences of deuterium in the PISCES facility. High resolution Transmission Electron Microscopy was then used to examine the samples for voids. The results of these experiments were used to interpret the expected behavior of tungsten to be used as the divertor of the ITER fusion device.

  8. Rayleigh-Taylor Instability within Sediment Layers Due to Gas Retention: Preliminary Theory and Experiments

    SciTech Connect

    Gauglitz, Phillip A.; Wells, Beric E.; Buchmiller, William C.; Rassat, Scot D.

    2013-03-21

    In Hanford underground waste storage tanks, a typical waste configuration is settled beds of waste particles beneath liquid layers. The settled beds are typically composed of layers, and these layers can have different physical and chemical properties. One postulated configuration within the settled bed is a less-dense layer beneath a more-dense layer. The different densities can be a result of different gas retention in the layers or different degrees of settling and compaction in the layers. This configuration can experience a Rayleigh-Taylor (RT) instability where the less dense lower layer rises into the upper layer. Previous studies of gas retention and release have not considered potential buoyant motion within a settle bed of solids. The purpose of this report is to provide a review of RT instabilities, discuss predictions of RT behavior for sediment layers, and summarize preliminary experimental observations of RT instabilities in simulant experiments.

  9. Human memory retention and recall processes. A review of EEG and fMRI studies.

    PubMed

    Amin, Hafeezullah; Malik, Aamir S

    2013-10-01

    Human memory is an important concept in cognitive psychology and neuroscience. Our brain is actively engaged in functions of learning and memorization. Generally, human memory has been classified into 2 groups: short-term/working memory, and long-term memory. Using different memory paradigms and brain mapping techniques, psychologists and neuroscientists have identified 3 memory processes: encoding, retention, and recall. These processes have been studied using EEG and functional MRI (fMRI) in cognitive and neuroscience research. This study reviews previous research reported for human memory processes, particularly brain behavior in memory retention and recall processes with the use of EEG and fMRI. We discuss issues and challenges related to memory research with EEG and fMRI techniques.

  10. Secondary retention of rubber dam: effective moisture control access considerations.

    PubMed

    Liebenberg, W H

    1995-04-01

    Primary rubber dam retention affects attachment of the latex sheet to the anchor teeth bordering the isolated working field. Secondary rubber dam retention is the provision of an effective seal at the dam-tooth junction, which is essential to the maintenance of adequate access and moisture control within the working field. Practical hints are offered to optimize access and moisture control through well-planned and properly executed secondary retention of classic rubber dam applications. In addition, innovative solutions to the limitations of general field isolation, which pertain mostly to secondary retention of the unrestrained buccal and lingual curtains of the slit dam, are introduced.

  11. 12 CFR Appendix A to Part 749 - Record Retention Guidelines

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... RECORDS PRESERVATION PROGRAM AND APPENDICES-RECORD RETENTION GUIDELINES; CATASTROPHIC ACT PREPAREDNESS... microfilm, microfiche, or in an electronic format, the stored records must be accurate, reproducible...

  12. Retention Indices for Frequently Reported Compounds of Plant Essential Oils

    NASA Astrophysics Data System (ADS)

    Babushok, V. I.; Linstrom, P. J.; Zenkevich, I. G.

    2011-12-01

    Gas chromatographic retention indices were evaluated for 505 frequently reported plant essential oil components using a large retention index database. Retention data are presented for three types of commonly used stationary phases: dimethyl silicone (nonpolar), dimethyl silicone with 5% phenyl groups (slightly polar), and polyethylene glycol (polar) stationary phases. The evaluations are based on the treatment of multiple measurements with the number of data records ranging from about 5 to 800 per compound. Data analysis was limited to temperature programmed conditions. The data reported include the average and median values of retention index with standard deviations and confidence intervals.

  13. Mechanical retention versus bonding of amalgam and gallium alloy restorations.

    PubMed

    Eakle, W S; Staninec, M; Yip, R L; Chavez, M A

    1994-10-01

    The retention of amalgam and gallium alloy restorations in proximal box forms was measured in vitro, and three different adhesives to conventional undercuts were compared. For control, restorations were placed without undercuts or adhesives. No significant difference was found between amalgam and gallium alloys with each of the five methods of retention used. Alloys placed without retention or adhesives were significantly less retentive than all other groups. When Tytin alloy was used, no difference was found in retention among the restorations retained with Panavia or All-Bond adhesive or an occlusal dovetail and retention grooves, but Amalgambond adhesive was less retentive than all three of these methods. When gallium alloy was used, both Panavia and All-Bond adhesive were more retentive than undercuts, but the effect of Amalgambond adhesive was more retentive than undercuts, but the effect of Amalgambond adhesive was comparable to that of undercuts. The results of this study indicate that adhesives could be used in place of traditional undercuts to retain amalgam and gallium alloys, thus saving a considerable amount of tooth structure. PMID:7990038

  14. Scoring Dawg Core Breakoff and Retention Mechanism

    NASA Technical Reports Server (NTRS)

    Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph; Bao, Xiaoqi; Backes, Paul G.

    2011-01-01

    This novel core break-off and retention mechanism consists of a scoring dawg controlled by a set of two tubes (a drill tube and an inner tube). The drill tube and the inner tube have longitudinal concentric holes. The solution can be implemented in an eccentric tube configuration as well where the tubes have eccentric longitudinal holes. The inner tube presents at the bottom two control surfaces for controlling the orientation of the scoring dawg. The drill tube presents a sunk-in profile on the inside of the wall for housing the scoring dawg. The inner tube rotation relative to the drill tube actively controls the orientation of the scoring dawg and hence its penetration and retrieval from the core. The scoring dawg presents a shaft, two axially spaced arms, and a tooth. The two arms slide on the control surfaces of the inner tube. The tooth, when rotated, can penetrate or be extracted from the core. During drilling, the two tubes move together maintaining the scoring dawg completely outside the core. After the desired drilling depth has been reached the inner tube is rotated relative to the drill tube such that the tooth of the scoring dawg moves toward the central axis. By rotating the drill tube, the scoring dawg can score the core and so reduce its cross sectional area. The scoring dawg can also act as a stress concentrator for breaking the core in torsion or tension. After breaking the core, the scoring dawg can act as a core retention mechanism. For scoring, it requires the core to be attached to the rock. If the core is broken, the dawg can be used as a retention mechanism. The scoring dawg requires a hard-tip insert like tungsten carbide for scoring hard rocks. The relative rotation of the two tubes can be controlled manually or by an additional actuator. In the implemented design solution the bit rotation for scoring was in the same direction as the drilling. The device was tested for limestone cores and basalt cores. The torque required for breaking the

  15. Novel word retention in bilingual and monolingual speakers

    PubMed Central

    Kan, Pui Fong; Sadagopan, Neeraja

    2014-01-01

    The goal of this research was to examine word retention in bilinguals and monolinguals. Long-term word retention is an essential part of vocabulary learning. Previous studies have documented that bilinguals outperform monolinguals in terms of retrieving newly-exposed words. Yet, little is known about whether or to what extent bilinguals are different from monolinguals in word retention. Participants were 30 English-speaking monolingual adults and 30 bilingual adults who speak Spanish as a home language and learned English as a second language during childhood. In a previous study (Kan et al., 2014), the participants were exposed to the target novel words in English, Spanish, and Cantonese. In this current study, word retention was measured a week after the fast mapping task. No exposures were given during the one-week interval. Results showed that bilinguals and monolinguals retain a similar number of words. However, participants produced more words in English than in either Spanish or Cantonese. Correlation analyses revealed that language knowledge plays a role in the relationships between fast mapping and word retention. Specifically, within- and across-language relationships between bilinguals' fast mapping and word retention were found in Spanish and English, by contrast, within-language relationships between monolinguals' fast mapping and word retention were found in English and across-language relationships between their fast mapping and word retention performance in English and Cantonese. Similarly, bilinguals differed from monolinguals in the relationships among the word retention scores in three languages. Significant correlations were found among bilinguals' retention scores. However, no such correlations were found among monolinguals' retention scores. The overall findings suggest that bilinguals' language experience and language knowledge most likely contribute to how they learn and retain new words. PMID:25324789

  16. Retention in HIV care among female sex workers in the Dominican Republic: implications for research, policy and programming.

    PubMed

    Zulliger, Rose; Maulsby, Cathy; Barrington, Clare; Holtgrave, David; Donastorg, Yeycy; Perez, Martha; Kerrigan, Deanna

    2015-04-01

    There are clear benefits of retention in HIV care, yet millions of people living with HIV are sub-optimally retained. This study described factors from Andersen's behavioral model that were associated with retention in HIV care among 268 female sex workers (FSWs) living with HIV in the Dominican Republic using two measures of retention: a 6-month measure of HIV clinic attendance and a measure that combined clinic attendance and missed visits. FSWs who ever attended HIV care reported high rates (92 %) of 6-month attendance, but 37 % reported missed visits. Using the combined retention measure, the odds of being retained in HIV care were higher among FSWs with more positive perceptions of HIV service providers [adjusted odds ratio (AOR) 1.17; 95 % confidence interval (CI) 01.09, 1.25] and lower among women who reported recent alcohol consumption (AOR 0.50; 95 % CI 0.28, 0.92) and self-stigmatizing beliefs related to sex work (AOR 0.93; 95 % CI 0.88, 0.98). These findings support the hypothesis that retention in HIV care may be best determined through a combined measure as missed visits are an important mechanism to identify in-care patients who require additional support.

  17. Effect of the eluent pH and acidic modifiers in high-performance liquid chromatography retention of basic analytes.

    PubMed

    LoBrutto, R; Jones, A; Kazakevich, Y V; McNair, H M

    2001-04-13

    The retention of ionogenic bases in liquid chromatography is strongly dependent upon the pH of the mobile phase. Chromatographic behavior of a series of substituted aniline and pyridine basic compounds has been studied on C18 bonded silica using acetonitrile-water (10:90) as the eluent with different pHs and at various concentrations of the acidic modifier counter anions. The effect of different acidic modifiers on solute retention over a pH range from 1.3 to 8.6 was studied. Ionized basic compounds showed increased retention with a decrease of the mobile phase pH. This increase in retention was attributed to the interaction with counter anions of the acidic modifiers. The increase in retention is dependent on the nature of the counter anion and its concentration in the mobile phase. It was shown that altering the concentration of counter anion of the acidic modifier allows the optimization of the selectivity between basic compounds as well as for neutral and acidic compounds. PMID:11355811

  18. Retention of Cationic Starch onto Cellulose Fibres

    NASA Astrophysics Data System (ADS)

    Missaoui, Mohamed; Mauret, Evelyne; Belgacem, Mohamed Naceur

    2008-08-01

    Three methods of cationic starch titration were used to quantify its retention on cellulose fibres, namely: (i) the complexation of CS with iodine and measurement of the absorbency of the ensuing blue solution by UV-vis spectroscopy; (ii) hydrolysis of the starch macromolecules followed by the conversion of the resulting sugars to furan-based molecules and quantifying the ensuing mixture by measuring their absorbance at a Ι of 490 nm, using the same technique as previous one and; finally (iii) hydrolysis of starch macromolecules by trifluoro-acetic acid and quantification of the sugars in the resulting hydrolysates by high performance liquid chromatography. The three methods were found to give similar results within the range of CS addition from 0 to 50 mg per g of cellulose fibres.

  19. Volatile species retention during metallic fuel casting

    NASA Astrophysics Data System (ADS)

    Fielding, Randall S.; Porter, Douglas L.

    2013-10-01

    Metallic nuclear fuels are candidate transmutation fuel forms for advanced fuel cycles. Through the operation of the Experimental Breeder Reactor II metallic nuclear fuels have been shown to be robust and easily manufactured. However, concerns have been raised concerning loss of americium during the casting process because of its high vapor pressure. In order to address these concerns a gaseous diffusion model was developed and a series of experiments using both manganese and samarium as surrogates for americium were conducted. The modeling results showed that volatility losses can be controlled to essentially no losses with a modest overpressure. Experimental results also showed volatile species retention down to no detectable losses through overpressure, and although the loss values varied from the model results the same trend was seen. Based on these results it is very probable that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.

  20. Volatile Species Retention During Metallic Fuel Casting

    SciTech Connect

    Randall S. Fielding; Douglas L. Proter

    2013-10-01

    Metallic nuclear fuels are candidate transmutation fuel forms for advanced fuel cycles. Through the operation of the Experimental Breeder Reactor II metallic nuclear fuels have been shown to be robust and easily manufactured. However, concerns have been raised concerning loss of americium during the casting process because of its high vapor pressure. In order to address these concerns a gaseous diffusion model was developed and a series of experiments using both manganese and samarium as surrogates for americium were conducted. The modeling results showed that volatility losses can be controlled to essentially no losses with a modest overpressure. Experimental results also showed volatile species retention down to no detectable losses through overpressure, although the loss values varied from the model results the same trend was seen. Bases on these results it is very probably that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.

  1. Quantitative structure-chromatographic retention relationships

    SciTech Connect

    Kaliszan, R.

    1987-01-01

    This book provides a wide-ranging overview of quantitative structure-retention relationships (QSRR). It brings together a great deal of information that previously was scattered in various parts of the literature. Although the book covers a lot of material, it provides the reader with sufficient background to read the related literature. In addition to QSRR, the book covers some topics related to quantitative structure-activity relationships (QSAR), where activity refers to biological activity. Overall, the book is well written and easy to understand. It would have been helpful to the reader if the chapter numbers had been included in the running heads. The book is divided by subject into 12 chapters, each with references. Works published through 1985 are included; hence, some recent literature is not covered. However, the book is heavily referenced, and each reference has the full title of the work as well as source and author information.

  2. Recruitment and Retention of LGBTIQ Astronomers

    NASA Astrophysics Data System (ADS)

    Dixon, William Van Dyke

    2012-01-01

    While lesbian, gay, bisexual, transgender, intersex, or questioning (LGBTIQ) astronomers face many of the same workplace challenges as women and racial/ethnic minorities, from implicit bias to overt discrimination, other challenges are unique to this group. An obvious example is the absence at many institutions of health insurance and other benefits for the same-sex domestic partners of their employees. More subtle is the psychological toll paid by LGBTIQ astronomers who remain "in the closet," self-censoring every statement about their personal lives. Paradoxically, the culture of the physical sciences, in which sexuality, gender identity, and gender expression are considered irrelevant, can discourage their discussion, further isolating LGBTIQ researchers. Addressing these challenges is not just a matter of fairness; it is an essential tool in the recruitment and retention of the brightest researchers and in assuring their productivity. We will discuss these issues and what individuals and departments can to make their institutions more welcoming to their LGBTIQ colleagues.

  3. Fluid Flow in Porous Media for Soil-Water Retention

    NASA Astrophysics Data System (ADS)

    Cejas, Cesare; Selva, Bertrand; Beaufret, Raphael; Hough, Larry; Fretigny, Christian; Dreyfus, Remi; CNRS / Rhodia / UPenn UMI 3254 Team

    2011-11-01

    The study aims to understand the mechanisms that determine the behavior of water in soil. In developing a better comprehension of the coupling between the various fluxes (e.g. evaporation, drainage) in soil and the surrounding environment, we elaborate strategies that permit to understand and improve particularly the water absorption by the roots. Our first approach, through direct visualization, focuses on evaporation out of a 2D model soil consisting of monolayer glass beads. Evaporation from porous media exhibits an abrupt transition from capillary-supported regime 1 to diffusion-controlled regime 2. Varying the wettability of the model soil suggests that the duration of regime 1evaporation and drying front formation in hydrophobic media are shorter than in hydrophilic media due to the absence of hydraulic continuity towards the evaporating surface. We then study how evaporation couples in the presence of roots in the model soil while being subjected to various treatment conditions (e.g. physical additives, etc.). Through this study, we would be able to quantify how the physico-chemical soil treatments affect these phenomena and inspire solutions for improving soil water retention.

  4. Formation and retention of methane in coal. Final report

    SciTech Connect

    Hucka, V.J.; Bodily, D.M.; Huang, H.

    1992-05-15

    The formation and retention of methane in coalbeds was studied for ten Utah coal samples, one Colorado coal sample and eight coal samples from the Argonne Premium Coal Sample Bank.Methane gas content of the Utah and Colorado coals varied from zero to 9 cm{sup 3}/g. The Utah coals were all high volatile bituminous coals. The Colorado coal was a gassy medium volatile bituminous coal. The Argonne coals cover a range or rank from lignite to low volatile bituminous coal and were used to determine the effect of rank in laboratory studies. The methane content of six selected Utah coal seams and the Colorado coal seam was measured in situ using a special sample collection device and a bubble desorbometer. Coal samples were collected at each measurement site for laboratory analysis. The cleat and joint system was evaluated for the coal and surrounding rocks and geological conditions were noted. Permeability measurements were performed on selected samples and all samples were analyzed for proximate and ultimate analysis, petrographic analysis, {sup 13}C NMR dipolar-dephasing spectroscopy, and density analysis. The observed methane adsorption behavior was correlated with the chemical structure and physical properties of the coals.

  5. Solute transport and retention in three-dimensional fracture networks

    NASA Astrophysics Data System (ADS)

    Cvetkovic, Vladimir; Frampton, Andrew

    2012-02-01

    Resolving the hydrodynamic control of retention is an important step in predictive modeling of transport of sorbing tracers in fractured rock. The statistics of the transport resistance parameter β [T/L] and the related effective active specific surface area sf [1/L] are studied in a crystalline rock volume on a 100 m scale. Groundwater flow and advective transport are based on generic boundary conditions and realistic discrete fracture networks inferred from the Laxemar site, southeast Sweden. The overall statistics of β are consistent with statistics of the water residence time τ; the moments of β vary linearly with distance, at least up to 100 m. The correlation between log τ and log β is predominantly linear, however, there is significant dispersion; the parameter sf strongly depends on the assumed hydraulic law (theoretical cubic or empirical quadratic). Fast and slow trajectories/segments in the network determine the shape of the β distribution that cannot be reproduced by infinitely divisible model over the entire range; the low value range and median can be reproduced reasonably well with the tempered one-sided stable density using the exponent in the range 0.35-0.7. The low percentiles of the β distribution seems to converge to a Fickian type of behavior from a 50 to 100 m scale.

  6. 33 CFR 117.439 - Des Allemands Bayou.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Des Allemands Bayou. 117.439... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.439 Des Allemands Bayou. (a) The draw of the S631 bridge, mile 13.9 at Des Allemands, shall open on signal if at least four hours notice...

  7. 33 CFR 117.439 - Des Allemands Bayou.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Des Allemands Bayou. 117.439... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.439 Des Allemands Bayou. (a) The draw of the S631 bridge, mile 13.9 at Des Allemands, shall open on signal if at least four hours notice...

  8. 75 FR 63714 - Drawbridge Operation Regulation; Des Allemands Bayou, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-18

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulation; Des Allemands Bayou, LA AGENCY: Coast... Burlington Northern Santa Fe Railway swing bridge across Des Allemands Bayou, mile 14.0, in St. Charles and... INFORMATION: The Burlington Northern Santa Fe Railway swing span drawbridge across Bayou Des Allemands,...

  9. Statutes of limitations: the special problem of DES suits.

    PubMed

    Feigin, C A

    1981-01-01

    In 1971, medical studies determined that DES causes a rare type of vaginal cancer in a small number of daughters of mothers who took DES during pregnancy. Subsequently, medical studies determined that exposure to DES can cause other vaginal abnormalities in the daughters, some of which may be precancerous. As a result of these discoveries, many lawsuits have been filed by these daughters against DES manufacturers. Many DES suits may be barred by statutes of limitations, both because the number of years between the daughters' exposure to DES in utero and the discovery that DES can cause injuries exceeds the statutory period, and because the cancer or other injuries caused by DES may not develop for many additional years. This Note discusses two methods that DES plaintiffs may be able to use to overcome the potential statutes of limitations bar: the discovery rule, and state provisions which toll the statute of limitations for minors. The Note contends that courts should apply an expanded discovery rule to DES suits to avoid the unfair result of barring a claim before the plaintiff could have known that she had a cause of action. In addition, the Note argues that the injury which causes the statute of limitations to begin to run in DES suits should not be rigidly defined. Finally, the Note urges that courts allow eligible DES plaintiffs to take advantage of applicable state provisions that toll the statute of limitations for minors.

  10. Building 310 retention tanks characterization report

    SciTech Connect

    Sholeen, C.M.; Geraghty, D.C.

    1996-12-01

    The Health Physics Section of ANL performed a characterization of the Building 310 Service Floor Retention Tank Facility during the months of July and August, 1996. The characterization included measurements for radioactivity, air sampling for airborne particles and sampling to determine the presence and quantity of hazardous materials requiring remediation. Copies of previous lead and asbestos sampling information was obtained from ESH-IH. The facility consists of ten retention tanks located in rooms, A-062A, A-050A, A-038A, A-026A, and an entry room A-068A which contained miscellaneous pumps and other scrap material. Significant contamination was found in each room except room A-068A which had two contaminated spots on the floor and a discarded contaminated pump. Room A-062A: This room had the highest radiation background. Therefore, beta readings reflected the background readings. The floor, west wall, and the exterior of tank No. 1 had areas of alpha contamination. The piping leading from the tank had elevated gamma readings. There were low levels of smearable contamination on the west wall-Room A-050A: Alpha and Beta contamination is wide spread on the floor, west wall and the lower portion of the north wall. An area near the electrical box on the west wall had alpha and beta loose contamination. The exterior of tank No. 4 also had contaminated areas. The grate in front of tank No. 4 was contaminated. The piping leading from tanks No. 2, 3, and 4 had elevated gamma readings. There were low levels of smearable contamination on tank No. 4 and on the tar paper that is glued to the floor.

  11. NASA records retention schedules: Procedures governing the retention, retirement, and destruction of agency records

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This handbook sets forth the minimum retention periods of official records of NASA. Its provisions are applicable to NASA Headquarters and all field installations. This revised edition has been correlated to the 'NASA Uniform Files Index (UFI) (NHB 1442.1B), the General Records Schedules' produced by the National Archives and Records Administration (NARA), and has been enlarged in scope to cover Privacy Act Systems of Records and record series previously omitted. Guidance is provided in the areas of record retirement, transfer, and retrieval from Federal Record Centers (FRC) and disposal actions. Included are provisions for making changes to these schedules by addition of new items or revision of current items. The NASA Records Retention Schedules (NRRS) were approved for NASA use by NARA, the General Services Administration, and the General Accounting Office.

  12. 47 CFR 73.1840 - Retention of logs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Retention of logs. 73.1840 Section 73.1840... Rules Applicable to All Broadcast Stations § 73.1840 Retention of logs. (a) Any log required to be kept by station licensees shall be retained by them for a period of 2 years. However, logs...

  13. 47 CFR 73.782 - Retention of logs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Retention of logs. 73.782 Section 73.782... International Broadcast Stations § 73.782 Retention of logs. Logs of international broadcast stations shall be retained by the licensee or permittee for a period of two years: Provided, however, That logs...

  14. What Works in Student Retention? All Survey Colleges

    ERIC Educational Resources Information Center

    Habley, Wesley R.; McClanahan, Randy

    2004-01-01

    This report reflects ACT's commitment to assist colleges and universities to better understand the impact of campus practices on college student retention and degree completion. Survey findings indicate that: (1) Only 51.7% of campuses have identified an individual responsible for coordinating retention strategies; (2) Only 47.2% of campuses have…

  15. Effects of Targeted Sales Messages on Subscription Sales and Retention.

    ERIC Educational Resources Information Center

    Gamst, Glenn; And Others

    1987-01-01

    Investigates the effects of targeted sales messages on newspaper subscription sales and retention by combining two large research projects--a demographic market segmentation scheme, and a readership-lifestyle survey. Proposes that the content of sales messages influences new subscriptions but does not affect retention. (MM)

  16. 7 CFR 7.38 - Retention of authority.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Retention of authority. 7.38 Section 7.38 Agriculture Office of the Secretary of Agriculture SELECTION AND FUNCTIONS OF AGRICULTURAL STABILIZATION AND CONSERVATION STATE, COUNTY AND COMMUNITY COMMITTEES § 7.38 Retention of authority. Nothing in this part...

  17. 7 CFR 274.5 - Record retention and forms security.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 4 2011-01-01 2011-01-01 false Record retention and forms security. 274.5 Section 274....5 Record retention and forms security. (a) Availability of records. (1) The State agency shall.... (2) In lieu of the records themselves, easily retrievable microfilm, microfiche, or computer...

  18. 7 CFR 274.5 - Record retention and forms security.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 4 2014-01-01 2014-01-01 false Record retention and forms security. 274.5 Section 274....5 Record retention and forms security. (a) Availability of records. (1) The State agency shall.... (2) In lieu of the records themselves, easily retrievable microfilm, microfiche, or computer...

  19. 7 CFR 274.5 - Record retention and forms security.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 4 2013-01-01 2013-01-01 false Record retention and forms security. 274.5 Section 274.5 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE FOOD STAMP AND FOOD DISTRIBUTION PROGRAM ISSUANCE AND USE OF PROGRAM BENEFITS § 274.5 Record retention and forms security....

  20. 7 CFR 274.5 - Record retention and forms security.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 4 2012-01-01 2012-01-01 false Record retention and forms security. 274.5 Section 274....5 Record retention and forms security. (a) Availability of records. (1) The State agency shall.... (2) In lieu of the records themselves, easily retrievable microfilm, microfiche, or computer...

  1. Student Retention and Graduation, University System of Georgia.

    ERIC Educational Resources Information Center

    University System of Georgia, Atlanta. Office of Research and Planning.

    Describing outcomes related to student retention and graduation in the University System of Georgia, this six-part report discusses definitions and assumptions pertaining to retention and compares success rates for black, white, developmental studies, and regularly-admitted freshmen students in USG senior and two-year colleges. Section 1 provides…

  2. Predictors of First-Year Retention in a Community College

    ERIC Educational Resources Information Center

    Mertes, Scott J.; Hoover, Richard E.

    2014-01-01

    Retention is a complex issue of great importance to community colleges. Several retention models have been developed to help explain this phenomenon. However, these models typically have used four-year college and university environments to build their foundations. Several researchers have attempted to identify predictor variables using…

  3. Retention in Special Education Teachers in Georgia: A Phenomenological Approach

    ERIC Educational Resources Information Center

    Jackson, Arndra N.

    2012-01-01

    The purpose of this qualitative study using a phenomenological approach was to identify and examine factors influencing the retention rate of special education teachers in rural and urban schools in middle Georgia. Provided in this study are factors that are related to retention in special education teachers. Semistructured interviews were used to…

  4. Clomipramine-induced urinary retention in a cat.

    PubMed

    Pfeiffer, E; Guy, N; Cribb, A

    1999-04-01

    A 10-year-old, female, spayed shorthair with presumed psychogenic alopecia was treated with clomipramine (1 mg/kg body weight/day). The cat developed urinary retention within 2 days. Clomipramine was discontinued. Clinical signs resolved over the next 7 days. The urinary retention was attributed to the anticholinergic effects of clomipramine.

  5. 24 CFR 990.305 - Retention of excess revenues.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Retention of excess revenues. 990... Resident Management Corporations (RMCs) § 990.305 Retention of excess revenues. (a) Any income generated by... by the PHA under the management contract. (c) Any revenues retained by an RMC under this section...

  6. Mapping a Retention Index across the Student Continuum

    ERIC Educational Resources Information Center

    van der Merwe, C. A.

    2011-01-01

    Student retention is the field of institutional research that has (deservedly) had the most attention. Besides the models proposed by Tinto (1975, 1993), there have been many theoretical and applied papers on many aspects of student retention. These include demographic characteristics, scholastic scores, financial and residential considerations,…

  7. 19 CFR 111.23 - Retention of records.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Retention of records. 111.23 Section 111.23 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY CUSTOMS BROKERS Duties and Responsibilities of Customs Brokers § 111.23 Retention of records. (a) Place and period of retention—(1)...

  8. Please, Not Another Push to Get Tough on Student Retention

    ERIC Educational Resources Information Center

    Norton, M. Scott

    2011-01-01

    Standardized academic testing, under-performing schools, demands for high standards in America's schools and current levels of student dropouts have resulted in renewed calls for "getting tough on student retention." The push for student retention is demanded by school boards and others in spite of the overwhelming research evidence that student…

  9. 27 CFR 28.45 - Retention of records.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Retention of records. 28.45 Section 28.45 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Miscellaneous Provisions Retention of Records §...

  10. 27 CFR 28.45 - Retention of records.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Retention of records. 28.45 Section 28.45 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Miscellaneous Provisions Retention of Records §...

  11. Annotated Bibliography: Black Student Retention in Higher Education Institutions.

    ERIC Educational Resources Information Center

    Dunston, F. Myron; And Others

    An annotated bibliography of 105 publications (1961-1982) on the retention of black college students is presented. Topics include: retention programs for low income and minority undergraduates; the interrelatedness of curriculum and cultural/economic reproduction; predicting academic performance in college; dropout prevention and reasons…

  12. 21 CFR 320.63 - Retention of bioequivalence samples.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 5 2012-04-01 2012-04-01 false Retention of bioequivalence samples. 320.63... (CONTINUED) DRUGS FOR HUMAN USE BIOAVAILABILITY AND BIOEQUIVALENCE REQUIREMENTS Procedures for Determining the Bioavailability or Bioequivalence of Drug Products § 320.63 Retention of bioequivalence...

  13. 21 CFR 320.63 - Retention of bioequivalence samples.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 5 2014-04-01 2014-04-01 false Retention of bioequivalence samples. 320.63... (CONTINUED) DRUGS FOR HUMAN USE BIOAVAILABILITY AND BIOEQUIVALENCE REQUIREMENTS Procedures for Determining the Bioavailability or Bioequivalence of Drug Products § 320.63 Retention of bioequivalence...

  14. 21 CFR 320.63 - Retention of bioequivalence samples.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 5 2013-04-01 2013-04-01 false Retention of bioequivalence samples. 320.63... (CONTINUED) DRUGS FOR HUMAN USE BIOAVAILABILITY AND BIOEQUIVALENCE REQUIREMENTS Procedures for Determining the Bioavailability or Bioequivalence of Drug Products § 320.63 Retention of bioequivalence...

  15. 44 CFR 321.5 - Retention of industrial facilities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true Retention of industrial..., DEPARTMENT OF ENERGY, MARITIME ADMINISTRATION) § 321.5 Retention of industrial facilities. (a) Industrial..., shall be retained in the Industrial reserves (National Industrial Reserve, Departmental...

  16. 44 CFR 321.5 - Retention of industrial facilities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 44 Emergency Management and Assistance 1 2014-10-01 2014-10-01 false Retention of industrial..., DEPARTMENT OF ENERGY, MARITIME ADMINISTRATION) § 321.5 Retention of industrial facilities. (a) Industrial..., shall be retained in the Industrial reserves (National Industrial Reserve, Departmental...

  17. 44 CFR 321.5 - Retention of industrial facilities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 44 Emergency Management and Assistance 1 2013-10-01 2013-10-01 false Retention of industrial..., DEPARTMENT OF ENERGY, MARITIME ADMINISTRATION) § 321.5 Retention of industrial facilities. (a) Industrial..., shall be retained in the Industrial reserves (National Industrial Reserve, Departmental...

  18. 46 CFR 4.05-15 - Voyage records, retention of.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Voyage records, retention of. 4.05-15 Section 4.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC MARINE CASUALTIES AND INVESTIGATIONS Notice of Marine Casualty and Voyage Records § 4.05-15 Voyage records, retention of. (a) The owner, agent, master, or...

  19. Retention of crowns cemented on implant abutments with temporary cements.

    PubMed

    Nagasawa, Yuko; Hibino, Yasushi; Nakajima, Hiroshi

    2014-01-01

    This study was to examine the retentive force of crowns to implant abutments with commercial temporary cements. Six different temporary cements were investigated. Cast crowns were cemented to the abutments using each cement and their retentive forces to abutments were determined 7 or 28 days after cementing (n=10). The retentive force of the cements to abutments varied widely among the products [27-109 N (7-day), 18-80 N (28-days)]. The retentive force of all the cements was not reduced as the time elapsed, except for two products tested. The polycarboxylate cements and paste-mixing type eugenol-free cements revealed comparable retentive force after 28 days of storage. The powder-liquid type cements showed a positive correlation (p<0.05) between the retentive force and the shear strength, while a negative correlation (p<0.05) was obtained for paste-mixing type cement between the retentive force and compressive strength. Mechanical strength of temporary cements could not be a prominent predicting factor for retention of the crowns on the abutments.

  20. Neuropathic urinary retention in the absence of neurological signs.

    PubMed

    Sylvester, P A; McLoughlin, J; Sibley, G N; Dorman, P J; Kabala, J; Ormerod, I E

    1995-12-01

    We present two cases of painless urinary retention secondary to central intervertebral disc prolapse. In neither case were there signs or symptoms suggesting an underlying neurological insult. Both patients voided spontaneously following neurosurgical intervention. The classical features of acute cauda equina compression may be absent in patients with central lumbar disc protrusion. Painless urinary retention may be the only physical sign.

  1. Study Abroad Programming: A 21st Century Retention Strategy?

    ERIC Educational Resources Information Center

    Metzger, Christy A.

    2006-01-01

    Preparing the workforce for an increasingly global economy is among the leading concerns in higher education, and retention of students is vital to successfully managing this economic shift. Study abroad programming consistently yields positive outcomes that span these three levels and may very well be a retention strategy that has been previously…

  2. 16 CFR 312.10 - Data retention and deletion requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Data retention and deletion requirements. 312.10 Section 312.10 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS CHILDREN'S ONLINE PRIVACY PROTECTION RULE § 312.10 Data retention and deletion requirements....

  3. Retention Issues: A Study of Alabama Special Education Teachers

    ERIC Educational Resources Information Center

    Plash, Shawn; Piotrowski, Chris

    2006-01-01

    This study investigated issues that impact attrition, migration and retention of special education teachers in Alabama. The sample comprised 70 teachers designated as "highly-qualified" who responded to a job satisfaction instrument, with a focus on retention issues, developed by Levine (2001). The results indicated that the major reasons for…

  4. 24 CFR 590.25 - Retention of records.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Retention of records. 590.25 Section 590.25 Housing and Urban Development Regulations Relating to Housing and Urban Development... URBAN DEVELOPMENT COMMUNITY FACILITIES URBAN HOMESTEADING § 590.25 Retention of records. The LUHA...

  5. The Retention Factor: Retaining the Distance Education Learner

    ERIC Educational Resources Information Center

    Boyd, Victoria

    2010-01-01

    The purpose of this study is focused upon retaining distance education learners. Many adult learners are returning to higher education but may not complete their chosen curriculum. Fike and Fike (2008) stated that retention is important for a variety of reasons: (a) from the institution's perspective, the retention of students is necessary for…

  6. Incorporating carbon saturation concepts and nitrogen retention theory

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent advances in soil C saturation concepts have increased our understanding of soil C storage and mineralization without explicit links to N retention and saturation theories. Here, we exploit a soil texture gradient to test hypotheses that link C saturation with soil 15N retention and nitrifica...

  7. Teacher Induction, Mentoring, and Retention: A Summary of the Research

    ERIC Educational Resources Information Center

    Strong, Michael

    2005-01-01

    This paper reviews the research literature on new teacher mentoring, focusing on issues of definition, why teachers quit, and the effects of mentoring on retention. Conclusions call for more scientific studies on the relationship between mentoring and retention, more research on the relation between mentoring and other educational outcomes, and a…

  8. Grade Retention and School Adjustment: An Explanatory Analysis.

    ERIC Educational Resources Information Center

    Reynolds, Arthur J.

    1992-01-01

    Studied effects at grade 4 of early grade retention for 1,255 low-income mostly African-American children (20.4 percent had been retained from kindergarten to grade 3). Retention negatively affected cognitive reading and mathematics achievement, had no relation to teacher ratings of school adjustment, and positively affected children's perceived…

  9. A Data-Mining Approach to Differentiate Predictors of Retention

    ERIC Educational Resources Information Center

    Yu, Chong Ho; DiGangi, Samuel A.; Jannasch-Pennell, Angel; Lo, Wenjuo; Kaprolet, Charles

    2007-01-01

    Student retention is an important issue for all university administrators and faculty due to the potential negative impact of student attrition. In this study, retention rates will be studied with data from sophomore students who initially enrolled in the 2002 academic year at Arizona State University, following these students through their junior…

  10. 49 CFR 1244.6 - Retention of files.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Retention of files. 1244.6 Section 1244.6... PROPERTY-RAILROADS § 1244.6 Retention of files. (a) Subject railroads which submit waybill sample data by... transit waybills, for a minimum period of four years. (b) This file of retained waybills shall...

  11. 32 CFR 536.69 - Retention of file.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Retention of file. 536.69 Section 536.69 National... UNITED STATES Investigation and Processing of Claims § 536.69 Retention of file. After final action has been taken, the settlement authority will retain the file until at least one month after either...

  12. 5 CFR 536.204 - Period of grade retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... from which the second reduction in grade was made for 2 years following the effective date of the second reduction in grade. (c) Notwithstanding § 536.207(a)(1), grade retention continues to apply to an... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Period of grade retention....

  13. 5 CFR 536.204 - Period of grade retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... from which the second reduction in grade was made for 2 years following the effective date of the second reduction in grade. (c) Notwithstanding § 536.207(a)(1), grade retention continues to apply to an... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Period of grade retention....

  14. 5 CFR 536.204 - Period of grade retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... from which the second reduction in grade was made for 2 years following the effective date of the second reduction in grade. (c) Notwithstanding § 536.207(a)(1), grade retention continues to apply to an... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Period of grade retention....

  15. 5 CFR 536.204 - Period of grade retention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... from which the second reduction in grade was made for 2 years following the effective date of the second reduction in grade. (c) Notwithstanding § 536.207(a)(1), grade retention continues to apply to an... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Period of grade retention....

  16. 5 CFR 536.204 - Period of grade retention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... from which the second reduction in grade was made for 2 years following the effective date of the second reduction in grade. (c) Notwithstanding § 536.207(a)(1), grade retention continues to apply to an... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Period of grade retention....

  17. 40 CFR 160.195 - Retention of records.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Retention of records. 160.195 Section 160.195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS GOOD LABORATORY PRACTICE STANDARDS Records and Reports § 160.195 Retention of records. (a) Record...

  18. Catholic School Principal Job Satisfaction: Keys to Retention and Recruitment

    ERIC Educational Resources Information Center

    Fraser, Jennifer; Brock, Barbara L.

    2006-01-01

    This article presents a study on principal retention in New South Wales, Australia. Factors in job retention included economic security, role enjoyment, and the opportunity to contribute. Disincentives to the principalship included lack of support from the employing authority, inadequate pay, isolation, growing responsibilities, difficult parents,…

  19. 21 CFR 872.3740 - Retentive and splinting pin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Retentive and splinting pin. 872.3740 Section 872.3740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3740 Retentive and splinting pin....

  20. 21 CFR 872.3740 - Retentive and splinting pin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Retentive and splinting pin. 872.3740 Section 872.3740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3740 Retentive and splinting pin....

  1. Background or Experience? Using Logistic Regression to Predict College Retention

    ERIC Educational Resources Information Center

    Synco, Tracee M.

    2012-01-01

    Tinto, Astin and countless others have researched the retention and attrition of students from college for more than thirty years. However, the six year graduation rate for all first-time full-time freshmen for the 2002 cohort was 57%. This study sought to determine the retention variables that predicted continued enrollment of entering freshmen…

  2. Assessing Retention in Online Learning: An Administrative Perspective

    ERIC Educational Resources Information Center

    Boston, Wallace E.; Ice, Phil

    2011-01-01

    As the growth of online programs continues to rapidly accelerate, concern over the retention of the online learner is increasing. Educational administrators at institutions offering online courses, those fully online or brick and mortars, are eager to promote student achievement. Retention is critically important, not just for student success, but…

  3. Comprehensive Assessment of Student Retention in Online Learning Environments

    ERIC Educational Resources Information Center

    Boston, Wallace E.; Ice, Phil; Gibson, Angela M.

    2011-01-01

    As the growth of online programs continues to rapidly accelerate, concern over the retention of the online learner is increasing. Educational administrators at institutions offering online courses, those fully online or brick and mortars, are eager to promote student achievement. Retention is critically important, not just for student success, but…

  4. Know when to Hold 'Em: Data Retention Policies

    ERIC Educational Resources Information Center

    Johnson, Jason

    2007-01-01

    While the need for a data retention policy is rapidly becoming clear to schools, little guidance is available for crafting one. Most schools depend on backup and recovery plans that generally focus on individual servers or devices. However, retention policies also need to focus on the type of data contained on those servers and how it will be…

  5. 4 CFR 5.2 - Grade and pay retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 4 Accounts 1 2010-01-01 2010-01-01 false Grade and pay retention. 5.2 Section 5.2 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM COMPENSATION § 5.2 Grade and pay retention. (a) Change of... pay system. (4) For such other purposes as the Comptroller General may provide by regulation....

  6. 10 CFR 36.81 - Records and retention periods.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Records and retention periods. 36.81 Section 36.81 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Records § 36.81 Records and retention periods. The licensee shall maintain the following records at the irradiator for the periods specified. (a) A copy of...

  7. 13 CFR 120.861 - Job creation or retention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false Job creation or retention. 120.861... Company Loan Program (504) Project Economic Development Goals § 120.861 Job creation or retention. A Project must create or retain one Job Opportunity per an amount of 504 loan funding that will be...

  8. 13 CFR 120.861 - Job creation or retention.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Job creation or retention. 120.861... Company Loan Program (504) Project Economic Development Goals § 120.861 Job creation or retention. A Project must create or retain one Job Opportunity per an amount of 504 loan funding that will be...

  9. 13 CFR 120.861 - Job creation or retention.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Job creation or retention. 120.861... Company Loan Program (504) Project Economic Development Goals § 120.861 Job creation or retention. A Project must create or retain one Job Opportunity per an amount of 504 loan funding that will be...

  10. 13 CFR 120.861 - Job creation or retention.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Job creation or retention. 120.861... Company Loan Program (504) Project Economic Development Goals § 120.861 Job creation or retention. A Project must create or retain one Job Opportunity per an amount of 504 loan funding that will be...

  11. 13 CFR 120.861 - Job creation or retention.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Job creation or retention. 120.861... Company Loan Program (504) Project Economic Development Goals § 120.861 Job creation or retention. A Project must create or retain one Job Opportunity per an amount of 504 loan funding that will be...

  12. 32 CFR 637.13 - Retention of property.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Retention of property. 637.13 Section 637.13 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.13 Retention of...

  13. 32 CFR 637.13 - Retention of property.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Retention of property. 637.13 Section 637.13 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.13 Retention of...

  14. 32 CFR 637.13 - Retention of property.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Retention of property. 637.13 Section 637.13 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.13 Retention of...

  15. 32 CFR 637.13 - Retention of property.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Retention of property. 637.13 Section 637.13 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.13 Retention of...

  16. 32 CFR 637.13 - Retention of property.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Retention of property. 637.13 Section 637.13 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MILITARY POLICE INVESTIGATION Investigations § 637.13 Retention of...

  17. A Year-Round Recruitment and Retention Plan.

    ERIC Educational Resources Information Center

    Monetti-Souply, Marta

    Catholic school educators are recognizing the necessity of marketing research for the effective planning of a long-range, proactive recruitment and retention program. A successful plan involves marketing, recruitment and retention, and public relations. Part I of this booklet outlines steps for the initiation of a marketing plan and provides…

  18. Retention Initiative for Unscheduled Sophomores and Unscheduled Readmits.

    ERIC Educational Resources Information Center

    Karp, Rashelle; Logue, Rose

    2003-01-01

    In an attempt to increase student retention, phone calls were made by a university to non-returning sophomores and students who had applied for readmission after a hiatus. The purpose was to facilitate students' registration for classes, and thus, their return to campus. The strategy proved effective as a retention device and provided useful…

  19. 50 CFR 635.22 - Recreational retention limits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... of the Atlantic EEZ, to a shark taken from or possessed in the Atlantic Ocean including the Gulf of... boundary of the EEZ. (c) Sharks. (1) The recreational retention limit for sharks applies to any person who... commercial shark vessel permit under § 635.4. The retention limit can change depending on the species...

  20. Knowledge Retention as a Latent Outcome Measure in Distance Learning.

    ERIC Educational Resources Information Center

    Wisher, Robert A.; Curnow, Christina K.; Seidel, Robert J.

    2001-01-01

    Describes two experiments that investigated the retention of knowledge as a latent measure of learning outcome in video teletraining courses, one for air traffic controllers and one for military training. Discusses the merits of knowledge retention as a construct for examining initial evidence of learning, especially for training related to the…