The Risk Factors and Clinical Course of Asthma with Fixed Airflow Limitation.

PubMed

Pothirat, Chaicharn; Chaiwong, Warawut; Liwsrisakun, Chalerm; Bumroongkit, Chaiwat; Deesomchok, Athavudh; Theerakittikul, Theerakorn; Limsukon, Atikun; Phetsuk, Nittaya

2016-07-01

To identify risk factors and clinical course of asthma with fixed airflow limitation. A retrospective case-control study of asthma patients was conducted over a 15-month period. Asthma with fixed airflow limitation patients were defined as chronic asthmatics who had both post-bronchodilator (BD) and on-treatment ratio of forced expiratory in first second (FEV1)/forced vital capacity (FVC) persistently less than 0.7, whereas usual chronic asthma patients had post-BD and/or on-treatment ratio of FEV1/FVC more than 0.7. Serial asthma control tests (ACT), medication used, exacerbations were assessed. The risk factors were analyzed using logistic regression. Clinical characteristics between groups were compared using Student’s t-test and Fisher’s exact test. One hundred twenty from 142 eligible subjects were enrolled. They had asthma with fixed airflow limitation (n = 40) and usual chronic asthma (n = 80). Potential risk factors of asthma with fixed airflow limitation included early disease onset (age <15 years) [(adjusted odd ratio (OR) = 3.9, 95% confidence interval (CI) 1.9-8.3)] with longer disease duration (adjusted OR = 8.4, 95% CI 4.6-15.4 for >30 years). Asthma with fixed airflow limitation patients had lower ACT scores (p<0.001), lower level of asthma control (p<0.001), required more asthma medications (p = 0.002), and higher rates of hospitalization (p = 0.001) than usual chronic asthma. The potential risk factors of asthma with fixed airflow limitation were earlier disease onset and longer disease duration. They had poorer asthma control, more medications needed, and higher rates of exacerbation than usual chronic asthma.

A prospective study on the variation in falling and fall risk among community-dwelling older citizens in 12 European countries.

PubMed

Franse, Carmen B; Rietjens, Judith Ac; Burdorf, Alex; van Grieken, Amy; Korfage, Ida J; van der Heide, Agnes; Mattace Raso, Francesco; van Beeck, Ed; Raat, Hein

2017-06-30

The rate of falling among older citizens appears to vary across different countries, but the underlying aspects causing this variation are unexplained. We aim to describe between-country variation in falling and explore whether intrinsic fall risk factors can explain possible variation. Prospective study on data from the cross-national Survey of Health, Ageing and Retirement in Europe (SHARE). Twelve European countries (Austria, Belgium, Czech Republic, Denmark, Estonia, France, Germany, Italy, The Netherlands, Spain, Sweden, Switzerland). Community-dwelling persons aged ≥65 years (n=18 596). Socio-demographic factors (age, gender, education level and living situation) and intrinsic fall risk factors (less than good self-rated health (SRH), mobility limitations, limitations with activities of daily living (ADL), dizziness, impaired vision, depression and impaired cognition) were assessed in a baseline interview. Falling was assessed 2 years later by asking whether the participant had fallen within the 6 months prior to the follow-up interview. There was significant between-country variation in the rate of falling (varying from 7.9% in Switzerland to 16.2% in the Czech Republic). The prevalence of intrinsic fall risk factors varied twofold to fourfold between countries. Associations between factors age ≥80 years, less than good SRH, mobility limitations, ADL limitations, dizziness and depression, and falling were different between countries (p<0.05). Between-country differences in falling largely persisted after adjusting for socio-demographic differences but strongly attenuated after adjusting for differences in intrinsic fall risk factors. There is considerable variation in the rate of falling between European countries, which can largely be explained by between-country variation in the prevalence of intrinsic fall risk factors. There are also country-specific variations in the association between these intrinsic risk factors and falling. These findings emphasise the importance of addressing intrinsic fall risk in (inter)national fall-prevention strategies, while highlighting country-specific priorities. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

13 CFR 120.424 - What are the basic conditions a Lender must meet to securitize?

Code of Federal Regulations, 2012 CFR

2012-01-01

... performance, as determined by SBA in its discretion. The Lender's Risk Rating, among other factors, will be considered in determining satisfactory SBA performance. Other factors may include, but are not limited to, on... and loss rate), loan volume to the extent that it impacts performance measures, and other performance...

Surveys of Health Professions Trainees: Prevalence, Response Rates, and Predictive Factors to Guide Researchers.

PubMed

Phillips, Andrew W; Friedman, Benjamin T; Utrankar, Amol; Ta, Andrew Q; Reddy, Shalini T; Durning, Steven J

2017-02-01

To establish a baseline overall response rate for surveys of health professions trainees, determine strategies associated with improved response rates, and evaluate for the presence of nonresponse bias. The authors performed a comprehensive analysis of all articles published in Academic Medicine, Medical Education, and Advances in Health Sciences Education in 2013, recording response rates. Additionally, they reviewed nonresponse bias analyses and factors suggested in other fields to affect response rate including survey delivery method, prenotification, and incentives. The search yielded 732 total articles; of these, 356 were research articles, and of these, 185 (52.0%) used at least one survey. Of these, 66 articles (35.6%) met inclusion criteria and yielded 73 unique surveys. Of the 73 surveys used, investigators reported a response rate for 63.0% of them; response rates ranged from 26.6% to 100%, mean (standard deviation) 71.3% (19.5%). Investigators reported using incentives for only 16.4% of the 73 surveys. The only survey methodology factor significantly associated with response rate was single- vs. multi-institutional surveys (respectively, 74.6% [21.2%] vs. 62.0% [12.8%], P = .022). Notably, statistical power for all analyses was limited. No articles evaluated for nonresponse bias. Approximately half of the articles evaluated used a survey as part of their methods. Limited data are available to establish a baseline response rate among health professions trainees and inform researchers which strategies are associated with higher response rates. Journals publishing survey-based health professions education research should improve reporting of response rate, nonresponse bias, and other survey factors.

Factors Limiting Post-logging Seedling Regeneration by Big-leaf Mahogany (Swietenia macrophylla) in Southeastern Amazonia, Brazil, and Implications for Sustainable Management

Treesearch

James Grogan; Jurandir Galvao

2006-01-01

Post-logging seedling regeneration density by big-leaf mahogany (Swietenia macrophylla), a nonpioneer light-demanding timber species, is generally reported to be low to nonexistent. To investigate factors limiting seedling density following logging within the study region, we quantified seed production rates, germinability, dispersal patterns, and seed fates on the...

Diurnal variation in the coupling of photosynthetic electron transport and carbon fixation in iron-limited phytoplankton in the NE subarctic Pacific

NASA Astrophysics Data System (ADS)

Schuback, N.; Flecken, M.; Maldonado, M. T.; Tortell, P. D.

2015-10-01

Active chlorophyll a fluorescence approaches, including fast repetition rate fluorometry (FRRF), have the potential to provide estimates of phytoplankton primary productivity at unprecedented spatial and temporal resolution. FRRF-derived productivity rates are based on estimates of charge separation at PSII (ETRRCII), which must be converted into ecologically relevant units of carbon fixation. Understanding sources of variability in the coupling of ETRRCII and carbon fixation provides physiological insight into phytoplankton photosynthesis, and is critical for the application of FRRF as a primary productivity measurement tool. In the present study, we simultaneously measured phytoplankton carbon fixation and ETRRCII in the iron-limited NE subarctic Pacific, over the course of a diurnal cycle. We show that rates of ETRRCII are closely tied to the diurnal cycle in light availability, whereas rates of carbon fixation appear to be influenced by endogenous changes in metabolic energy allocation under iron-limited conditions. Unsynchronized diurnal oscillations of the two rates led to 3.5 fold changes in the conversion factor coupling ETRRCII and carbon fixation (Φe:C / nPSII). Consequently, diurnal variability in phytoplankton carbon fixation cannot be adequately captured with FRRF approaches if a constant conversion factor is applied. Utilizing several auxiliary photophysiological measurements, we observed that a high conversion factor is associated with conditions of excess light, and correlates with the expression of non-photochemical quenching (NPQ) in the pigment antenna, as derived from FRRF measurements. The observed correlation between NPQ and the conversion factor Φe:C / nPSII has the potential to improve estimates of phytoplankton carbon fixation rates from FRRF measurements alone.

Limitations in cooling electrons using normal-metal-superconductor tunnel junctions.

PubMed

Pekola, J P; Heikkilä, T T; Savin, A M; Flyktman, J T; Giazotto, F; Hekking, F W J

2004-02-06

We demonstrate both theoretically and experimentally two limiting factors in cooling electrons using biased tunnel junctions to extract heat from a normal metal into a superconductor. First, when the injection rate of electrons exceeds the internal relaxation rate in the metal to be cooled, the electrons do not obey the Fermi-Dirac distribution, and the concept of temperature cannot be applied as such. Second, at low bath temperatures, states within the gap induce anomalous heating and yield a theoretical limit of the achievable minimum temperature.

An approach for using general soil physical condition-root growth relationships to predict seedling growth response to site preparation tillage in loblolly pine plantations

Treesearch

L.A. Morris; K.H. Ludovici; S.J. Torreano; E.A. Carter; M.C. Lincoln; R.E. Will

2006-01-01

Tree seedling root growth rate can be limited by any one of three soil physical factors: mechanical resistance, water potential or soil aeration. All three factors vary with soil water content and, under field conditions, root growth rate will depend on the soil water content as a result of its relationship to each factor. For a specific site, the relationship between...

Unlocking Ft: Modeling thermodynamic controls and isotope fractionation factors in nutrient limited environments

NASA Astrophysics Data System (ADS)

Druhan, J. L.; Giannetta, M.; Sanford, R. A.

2017-12-01

In recent years, reactive transport principles have expanded from early applications, largely based in contaminant hydrology, to a wide range of biologically mediated redox environments including marine sedimentary diagenesis, terrestrial metal ore deposits, soils, and critical zone weathering profiles. A common observation across this diversity of systems is that they often function under energetically limited conditions in comparison to those typical of contaminated aquifers subject to engineered remediation techniques. As a result, the kinetic rate expressions traditionally employed within reactive transport frameworks to simulate microbially mediated redox transformations have required modification. This was recognized in a series of seminal papers by Jin and Bethke (2005, 2007) in which the authors expanded upon a Monod rate law to include a thermodynamic potential factor `Ft' which exerts a limitation on the overall rate based on the thermodynamic driving force of the electron transfer reaction. This new rate expression is now commonly implemented within many of the major reactive transport software packages, though appropriate application has yet to be thoroughly demonstrated. Notably, the characteristically large partitioning of stable isotopes during microbially mediated reactions, which is extensively utilized to identify and quantify these redox transformations, has yet to be simulated under conditions in which the Ft term may be expected to exert a significant mass dependent influence. Here, we develop a series of simplified simulations for the microbially mediated reduction of sulfate based on the datasets reported by Jin and Bethke, and apply appropriate mass-bias within the Ft term to consider the extent to which the resulting isotopic fractionation is consistent with that observed in energetically limited systems. We show that the Ft term can exert a significant influence on the observed fractionation factor under common environmental conditions, resulting in model behavior which is, in effect, a microbial redox analog to the variable observed fractionation factor resulting from a transition state theory rate law as derived by DePaolo (2011).

Assessment of bioavailability limitations during slurry biodegradation of petroleum hydrocarbons in aged soils.

PubMed

Huesemann, Michael H; Hausmann, Tom S; Fortman, Tim J

2003-12-01

In an effort to determine whether bioavailability limitations are responsible for the slow or incomplete hydrocarbon biodegradation in aged soils, both the rate of desorption (rdes) and biodegradation (rbio) was measured for n-alkanes and polynuclear aromatic hydrocarbons (PAHs) at different times during the slurry biotreatment of six different soils. While all n-alkanes were biodegraded to various degrees depending on their respective carbon number and the soil organic matter content, none of them were desorbed to a significant extent, indicating that these saturated hydrocarbons do not need to be transferred from the soil particles into the aqueous phase in order to be metabolized by microorganisms. Most two- and three-ring PAHs biodegraded as fast as they were desorbed (rbio = rdes); that is, desorption rates controlled biodegradation rates. By contrast, the biodegradation kinetics of four-, five-, and six-ring PAHs was limited by microbial factors during the initial phase (rbio < rdes) while becoming mass-transfer rate limited during the final phase of bioremediation treatment (rbio = rdes). Whenever PAH biodegradation stalled or did not occur at all (rbio = 0), it was never due to bioavailability limitations (rdes > 0) but was more likely caused by microbial factors. such as the absence of specific PAH degraders or cometabolic substrates. Consequently, PAHs that are found to be microbially recalcitrant in aged soils may not be so because of limited bioavailability and thus could pose a greater risk to the environment than previously thought.

Assessment of Bioavailability Limitations During Slurry Biodegradation of Petroleum Hydrocarbons in Aged Soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huesemann, Michael H.; Hausmann, Tom S.; Fortman, Timothy J.

In an effort to determine whether bioavailability limitations are responsible for the slow or incomplete hydrocarbon biodegradation in aged soils, both the rate of desorption (rdes) and biodegradation (rbio) was measured for n-alkanes and polynuclear aromatic hydrocarbons (PAHs) at different times during the slurry biotreatment of six different soils. While all n-alkanes were biodegraded to various degrees depending on their respective carbon number and the soil organic matter content, none of them were desorbed to a significant extent indicating that these saturated hydrocarbons do not need to be transferred from the soil particles into the aqueous phase in order tomore » be metabolized by microorganisms. Most 2 and 3 ring PAHs biodegraded as fast as they were desorbed (rbio=rdes), i.e., desorption rates controlled biodegradation rates. By contrast, the biodegradation kinetics of 4, 5, and 6 ring PAHs was limited by microbial factors during the initial phase (rbio < rdes) while becoming mass-transfer rate limited during the final phase of bioremediation treatment (rbio=rdes). Whenever PAH biodegradation stalled or did not occur at all (rbio=0), it was never due to bioavailability limitations (rdes >> 0) but was more likely caused by microbial factors such as the absence of specific PAH degraders or cometabolic substrates. Consequently, PAHs that are found to be microbially recalcitrant in aged soils may not be so because of limited bioavailability and thus could pose a greater risk to the environment than previously thought.« less

The Limits to Parapatric Speciation: Dobzhansky–Muller Incompatibilities in a Continent–Island Model

PubMed Central

Bank, Claudia; Bürger, Reinhard; Hermisson, Joachim

2012-01-01

How much gene flow is needed to inhibit speciation by the accumulation of Dobzhansky–Muller incompatibilities (DMIs) in a structured population? Here, we derive these limits in a classical migration–selection model with two haploid or diploid loci and unidirectional gene flow from a continent to an island. We discuss the dependence of the maximum gene-flow rate on ecological factors (exogeneous selection), genetic factors (epistasis, recombination), and the evolutionary history. Extensive analytical and numerical results show the following: (1) The maximum rate of gene flow is limited by exogeneous selection. In particular, maintenance of neutral DMIs is impossible with gene flow. (2) There are two distinct mechanisms that drive DMI evolution in parapatry, selection against immigrants in a heterogeneous environment and selection against hybrids due to the incompatibility. (3) Depending on the mechanism, opposite predictions result concerning the genetic architecture that maximizes the rate of gene flow a DMI can sustain. Selection against immigrants favors evolution of tightly linked DMIs of arbitrary strength, whereas selection against hybrids promotes the evolution of strong unlinked DMIs. In diploids, the fitness of the double heterozygotes is the decisive factor to predict the pattern of DMI stability. PMID:22542972

Identifying Facilitating Factors and Barriers to Improving Student Retention Rates in Tertiary Teaching Courses: A Systematic Review

ERIC Educational Resources Information Center

Bowles, Terence V.; Brindle, Kimberley A.

2017-01-01

Factors which impact student retention in tertiary level teaching courses are complex. This study examined facilitating factors and barriers to student retention for students studying education. Due to a limited number of studies, the search was extended to factors impacting students undertaking tertiary education. A systematic review was…

Rushing, distraction, walking on contaminated floors and risk of slipping in limited-service restaurants: a case--crossover study.

PubMed

Verma, Santosh K; Lombardi, David A; Chang, Wen Ruey; Courtney, Theodore K; Huang, Yueng-Hsiang; Brennan, Melanye J; Mittleman, Murray A; Ware, James H; Perry, Melissa J

2011-08-01

This nested case-crossover study examined the association between rushing, distraction and walking on a contaminated floor and the rate of slipping, and whether the effects varied according to weekly hours worked, job tenure and use of slip-resistant shoes. At baseline, workers from 30 limited-service restaurants in the USA reported average work hours, average weekly duration of exposure to each transient risk factor and job tenure at the current location. Use of slip-resistant shoes was determined. During the following 12 weeks, participants reported weekly their slip experience and exposures to the three transient exposures at the time of slipping. The case-crossover design was used to estimate the rate ratios using the Mantel-Haenszel estimator for person-time data. Among 396 participants providing baseline information, 210 reported one or more slips with a total of 989 slips. Rate of slipping was 2.9 times higher when rushing as compared to working at a normal pace (95% CI 2.5 to 3.3). Rate of slipping was also significantly increased by distraction (rate ratio (RR) 1.7, 95% CI 1.5 to 2.0) and walking on a contaminated floor (RR 14.6, 95% CI 12.6 to 17.0). Use of slip-resistant shoes decreased the effects of rushing and walking on a contaminated floor. Rate ratios for all three transient factors decreased monotonically as job tenure increased. The results suggest the importance of these transient risk factors, particularly floor contamination, on rate of slipping in limited-service restaurant workers. Stable characteristics, such as slip-resistant shoes, reduced the effects of transient exposures.

Insights into the enhancement of the ASB benthal solids digestion rate.

PubMed

Mahmood, Talat

2008-05-01

Aerated stabilization basins (ASB) accumulate benthal solids as they provide biotreatment to wastewaters. The accumulated solids must digest at a rate that matches the rate of settling of fresh solids in order to maintain the water column depth at the design value. In practice, however, the deposited solids digest at rates much slower than the fresh deposition rates, resulting in solids accumulation in the system. Excessive build-up of solids warrants dredging or abandoning the solids-filled cells in favour of opening new ones, often due to prohibitive dredging costs. An investigating study on factors affecting digestion rate was carried out using benthal solids from a pulp and paper ASB. The rate of digestion was not limited by the lack of macronutrients N, P, and S in the system or by toxicity due to ammonia or sulphide. Oxidation-reduction potential and pH were found conducive to anaerobic digestion throughout the 1120-day study. However, the generation of volatile organic acids from liquefaction/fermentation of solid substrate appeared to be a major factor limiting the digestion rate. Based on laboratory data, operating an ASB in the optimal mesophilic temperature range could be a practical way of enhancing the benthal solids digestion rate.

The course of physical functional limitations and occupational conditions in a middle-aged working population in France.

PubMed

de Stampa, Matthieu; Latouche, Aurélien; Derriennic, Francis; Monfort, Christine; Touranchet, Annie; Cassou, Bernard

2012-04-11

Physical functional limitations (PFL) have mainly been studied in older populations. The aim of this study was to better understand the course of PFL and associations with occupational factors by gender in a middle-aged working population. The data came from 16,950 workers in the ESTEV (Enquête Santé Travail et Vieillissement) cohort in France. PFL were assessed using the physical abilities section of the Nottingham Health Profile. Occupational conditions were measured with a self-administered questionnaire covering physical and psychosocial factors in 1990 and 1995. Multivariate analyses were used to assess the associations. The PFL appearance rate in 1995 was the same by gender (6.3%); the rate of PFL recovery was higher in men (23.9% versus 20.9%). Age was an independent factor of PFL at age 47 years or older in both genders after adjusting for confounding factors. The PFL appearance rate in 1995 was higher with physical occupational exposure in 1990, such as awkward work with a dose relation in both genders, while the PFL recovery rate decreased significantly only for men. Exposure to psychosocial occupational conditions, such as having the means to produce quality work in 1990, was significantly associated with a decreased PFL appearance rate in 1995 in both genders, and having high decision latitude in 1990 was associated with a decreased PFL appearance rate in 1995 only in men. Changes in exposure to occupational factors between 1990 and 1995 were associated with the PFL appearance and recovery rates in 1995 in both genders. After five years, the course of PFL in this working population changed and was associated with physical and psychosocial occupational factors. Relationships were stronger for the PFL appearance rate in both genders and were weaker for recovery from PFL, mainly among women.

The limits of crop productivity: validating theoretical estimates and determining the factors that limit crop yields in optimal environments

NASA Technical Reports Server (NTRS)

Bugbee, B.; Monje, O.

1992-01-01

Plant scientists have sought to maximize the yield of food crops since the beginning of agriculture. There are numerous reports of record food and biomass yields (per unit area) in all major crop plants, but many of the record yield reports are in error because they exceed the maximal theoretical rates of the component processes. In this article, we review the component processes that govern yield limits and describe how each process can be individually measured. This procedure has helped us validate theoretical estimates and determine what factors limit yields in optimal environments.

Emotional rigidity negatively impacts remission from anxiety and recovery of well-being.

PubMed

Wiltgen, Anika; Shepard, Christopher; Smith, Ryan; Fowler, J Christopher

2018-08-15

Emotional rigidity is described in clinical literature as a significant barrier to recovery; however, few there are few empirical measures of the construct. The current study had two aims: Study 1 aimed to identify latent factors that may bear on the construct of emotional rigidity while Study 2 assessed the potential impact of the latent factor(s) on anxiety remission rates and well-being. This study utilized data from 2472 adult inpatients (1176 females and 1296 males) with severe psychopathology. Study 1 utilized exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) to identify latent factors of emotional rigidity. Study 2 utilized hierarchical logistic regression analyses to assess the relationships among emotional rigidity factors and anxiety remission and well-being recovery at discharge. Study 1 yielded a two-factor solution identified in EFA was confirmed with CFA. Factor 1 consisted of neuroticism, experiential avoidance, non-acceptance of emotions, impaired goal-directed behavior, impulse control difficulties and limited access to emotion regulation strategies when experiencing negative emotions. Factor 2 consisted of lack of emotional awareness and lack of emotional clarity when experiencing negative emotions. Results of Study 2 indicated higher scores on Factor 1 was associated with lower remission rates from anxiety and poorer well-being upon discharge. Factor 2 was not predictive of outcome. Emotional rigidity appears to be a latent construct that negatively impacts remission rates from anxiety. Limitations of the present study include its retrospective design, and inefficient methods of assessing emotional rigidity. Copyright © 2018. Published by Elsevier B.V.

Response of Microbial Soil Carbon Mineralization Rates to Oxygen Limitations

NASA Astrophysics Data System (ADS)

Keiluweit, M.; Denney, A.; Nico, P. S.; Fendorf, S. E.

2014-12-01

The rate of soil organic matter (SOM) mineralization is known to be controlled by climatic factors as well as molecular structure, mineral-organic associations, and physical protection. What remains elusive is to what extent oxygen (O2) limitations impact overall rates of microbial SOM mineralization (oxidation) in soils. Even within upland soils that are aerobic in bulk, factors limiting O2 diffusion such as texture and soil moisture can result in an abundance of anaerobic microsites in the interior of soil aggregates. Variation in ensuing anaerobic respiration pathways can further impact SOM mineralization rates. Using a combination of (first) aggregate model systems and (second) manipulations of intact field samples, we show how limitations on diffusion and carbon bioavailability interact to impose anaerobic conditions and associated respiration constraints on SOM mineralization rates. In model aggregates, we examined how particle size (soil texture) and amount of dissolved organic carbon (bioavailable carbon) affect O2 availability and distribution. Monitoring electron acceptor profiles (O2, NO3-, Mn and Fe) and SOM transformations (dissolved, particulate, mineral-associated pools) across the resulting redox gradients, we then determined the distribution of operative microbial metabolisms and their cumulative impact on SOM mineralization rates. Our results show that anaerobic conditions decrease SOM mineralization rates overall, but those are partially offset by the concurrent increases in SOM bioavailability due to transformations of protective mineral phases. In intact soil aggregates collected from soils varying in texture and SOM content, we mapped the spatial distribution of anaerobic microsites. Optode imaging, microsensor profiling and 3D tomography revealed that soil texture regulates overall O2 availability in aggregate interiors, while particulate SOM in biopores appears to control the fine-scale distribution of anaerobic microsites. Collectively, our results suggest that texture and particulate organic matter content are useful predictors for the impact of O2 limitations on SOM mineralization rates.

Shape-Independent Limits to Near-Field Radiative Heat Transfer

NASA Astrophysics Data System (ADS)

Miller, Owen D.; Johnson, Steven G.; Rodriguez, Alejandro W.

2015-11-01

We derive shape-independent limits to the spectral radiative heat transfer rate between two closely spaced bodies, generalizing the concept of a blackbody to the case of near-field energy transfer. Through conservation of energy and reciprocity, we show that each body of susceptibility χ can emit and absorb radiation at enhanced rates bounded by |χ |2/Im χ , optimally mediated by near-field photon transfer proportional to 1 /d2 across a separation distance d . Dipole-dipole and dipole-plate structures approach restricted versions of the limit, but common large-area structures do not exhibit the material enhancement factor and thus fall short of the general limit. By contrast, we find that particle arrays interacting in an idealized Born approximation (i.e., neglecting multiple scattering) exhibit both enhancement factors, suggesting the possibility of orders-of-magnitude improvement beyond previous designs and the potential for radiative heat transfer to be comparable to conductive heat transfer through air at room temperature, and significantly greater at higher temperatures.

Interacting Effects of Light and Iron Availability on the Coupling of Photosynthetic Electron Transport and CO2-Assimilation in Marine Phytoplankton

PubMed Central

Schuback, Nina; Schallenberg, Christina; Duckham, Carolyn; Maldonado, Maria T.; Tortell, Philippe D.

2015-01-01

Iron availability directly affects photosynthesis and limits phytoplankton growth over vast oceanic regions. For this reason, the availability of iron is a crucial variable to consider in the development of active chlorophyll a fluorescence based estimates of phytoplankton primary productivity. These bio-optical approaches require a conversion factor to derive ecologically-relevant rates of CO2-assimilation from estimates of electron transport in photosystem II. The required conversion factor varies significantly across phytoplankton taxa and environmental conditions, but little information is available on its response to iron limitation. In this study, we examine the role of iron limitation, and the interacting effects of iron and light availability, on the coupling of photosynthetic electron transport and CO2-assimilation in marine phytoplankton. Our results show that excess irradiance causes increased decoupling of carbon fixation and electron transport, particularly under iron limiting conditions. We observed that reaction center II specific rates of electron transport (ETRRCII, mol e- mol RCII-1 s-1) increased under iron limitation, and we propose a simple conceptual model for this observation. We also observed a strong correlation between the derived conversion factor and the expression of non-photochemical quenching. Utilizing a dataset from in situ phytoplankton assemblages across a coastal – oceanic transect in the Northeast subarctic Pacific, this relationship was used to predict ETRRCII: CO2-assimilation conversion factors and carbon-based primary productivity from FRRF data, without the need for any additional measurements. PMID:26171963

Interacting Effects of Light and Iron Availability on the Coupling of Photosynthetic Electron Transport and CO2-Assimilation in Marine Phytoplankton.

PubMed

Schuback, Nina; Schallenberg, Christina; Duckham, Carolyn; Maldonado, Maria T; Tortell, Philippe D

2015-01-01

Iron availability directly affects photosynthesis and limits phytoplankton growth over vast oceanic regions. For this reason, the availability of iron is a crucial variable to consider in the development of active chlorophyll a fluorescence based estimates of phytoplankton primary productivity. These bio-optical approaches require a conversion factor to derive ecologically-relevant rates of CO2-assimilation from estimates of electron transport in photosystem II. The required conversion factor varies significantly across phytoplankton taxa and environmental conditions, but little information is available on its response to iron limitation. In this study, we examine the role of iron limitation, and the interacting effects of iron and light availability, on the coupling of photosynthetic electron transport and CO2-assimilation in marine phytoplankton. Our results show that excess irradiance causes increased decoupling of carbon fixation and electron transport, particularly under iron limiting conditions. We observed that reaction center II specific rates of electron transport (ETR(RCII), mol e- mol RCII(-1) s(-1)) increased under iron limitation, and we propose a simple conceptual model for this observation. We also observed a strong correlation between the derived conversion factor and the expression of non-photochemical quenching. Utilizing a dataset from in situ phytoplankton assemblages across a coastal--oceanic transect in the Northeast subarctic Pacific, this relationship was used to predict ETR(RCII): CO2-assimilation conversion factors and carbon-based primary productivity from FRRF data, without the need for any additional measurements.

Microbial Factors Rather Than Bioavailability Limit the Rate and Extent of PAH Biodegradation in Aged Crude Oil Contaminated Model Soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huesemann, Michael H.; Hausmann, Tom S.; Fortman, Timothy J.

The rate and extent of PAH biodegradation in a set of aged, crude oil contaminated model soils were measured in 90-week slurry bioremediation experiments. Soil properties such as organic matter content, mineral type, particle diameter, surface area, and porosity did not significantly influence the PAH biodegradation kinetics among the ten different model soils. A comparison of aged and freshly spiked soils indicates that aging affects the biodegradation rates and extents only for higher molecular weight PAHs while the effects of aging are insignificant for 3-ring PAHs and total PAHs. In all model soils with the exception of kaolinite clay, themore » rate of abiotic desorption was faster than the rate of biodegradation during the initial phase of bioremediation treatment indicating that PAH biodegradation was limited by microbial factors. Similarly, any of the higher molecular weight PAHs that were still present after 90 weeks of treatment were released rapidly during abiotic desorption tests which demonstrates that bioavailability limitations were not responsible for the recalcitrance of these hydrocarbons. Indeed, an analysis of microbial counts indicates that a severe reduction in hydrocarbon degrader populations may be responsible for the observed incomplete PAH biodegradation. It can therefore be concluded that the recalcitrance of PAHs during bioremediation is not necessarily due to bioavailability limitations and that these residual contaminants might, therefore, pose a greater risk to environmental receptors than previously thought.« less

Diurnal variation in the coupling of photosynthetic electron transport and carbon fixation in iron-limited phytoplankton in the NE subarctic Pacific

NASA Astrophysics Data System (ADS)

Schuback, Nina; Flecken, Mirkko; Maldonado, Maria T.; Tortell, Philippe D.

2016-02-01

Active chlorophyll a fluorescence approaches, including fast repetition rate fluorometry (FRRF), have the potential to provide estimates of phytoplankton primary productivity at an unprecedented spatial and temporal resolution. FRRF-derived productivity rates are based on estimates of charge separation in reaction center II (ETRRCII), which must be converted into ecologically relevant units of carbon fixation. Understanding sources of variability in the coupling of ETRRCII and carbon fixation provides physiological insight into phytoplankton photosynthesis and is critical for the application of FRRF as a primary productivity measurement tool. In the present study, we simultaneously measured phytoplankton carbon fixation and ETRRCII in the iron-limited NE subarctic Pacific over the course of a diurnal cycle. We show that rates of ETRRCII are closely tied to the diurnal cycle in light availability, whereas rates of carbon fixation appear to be influenced by endogenous changes in metabolic energy allocation under iron-limited conditions. Unsynchronized diurnal oscillations of the two rates led to 3.5-fold changes in the conversion factor between ETRRCII and carbon fixation (Kc / nPSII). Consequently, diurnal variability in phytoplankton carbon fixation cannot be adequately captured with FRRF approaches if a constant conversion factor is applied. Utilizing several auxiliary photophysiological measurements, we observed that a high conversion factor is associated with conditions of excess light and correlates with the increased expression of non-photochemical quenching (NPQ) in the pigment antenna, as derived from FRRF measurements. The observed correlation between NPQ and Kc / nPSII requires further validation but has the potential to improve estimates of phytoplankton carbon fixation rates from FRRF measurements alone.

Rate dependent fractionation of sulfur isotopes in through-flowing systems

NASA Astrophysics Data System (ADS)

Giannetta, M.; Sanford, R. A.; Druhan, J. L.

2017-12-01

The fidelity of reactive transport models in quantifying microbial activity in the subsurface is often improved through the use stable isotopes. However, the accuracy of current predictions for microbially mediated isotope fractionations within open through-flowing systems typically depends on nutrient availability. This disparity arises from the common application of a single `effective' fractionation factor assigned to a given system, despite extensive evidence for variability in the fractionation factor between eutrophic environments and many naturally occurring, nutrient-limited environments. Here, we demonstrate a reactive transport model with the capacity to simulate a variable fractionation factor over a range of microbially mediated reduction rates and constrain the model with experimental data for nutrient limited conditions. Two coupled isotope-specific Monod rate laws for 32S and 34S, constructed to quantify microbial sulfate reduction and predict associated S isotope partitioning, were parameterized using a series of batch reactor experiments designed to minimize microbial growth. In the current study, we implement these parameterized isotope-specific rate laws within an open, through-flowing system to predict variable fractionation with distance as a function of sulfate reduction rate. These predictions are tested through a supporting laboratory experiment consisting of a flow-through column packed with homogenous porous media inoculated with the same species of sulfate reducing bacteria used in the previous batch reactors, Desulfovibrio vulgaris. The collective results of batch reactor and flow-through column experiments support a significant improvement for S isotope predictions in isotope-sensitive multi-component reactive transport models through treatment of rate-dependent fractionation. Such an update to the model will better equip reactive transport software for isotope informed characterization of microbial activity within energy and nutrient limited environments.

Distinguishing intrinsic from extrinsic factors underlying firing rate saturation in human motor units

PubMed Central

Lester, Rosemary A.; Johns, Richard K.

2014-01-01

During voluntary contraction, firing rates of individual motor units (MUs) increase modestly over a narrow force range beyond which little additional increase in firing rate is seen. Such saturation of MU discharge may be a consequence of extrinsic factors that limit net synaptic excitation acting on motor neurons (MNs) or may be due to intrinsic properties of the MNs. Two sets of experiments involving recording of human biceps brachii MUs were carried out to evaluate saturation. In the first set, the extent of saturation was quantified for 136 low-threshold MUs during isometric ramp contractions. Firing rate-force data were best fit by a saturating function for 90% of MUs recorded with a maximum rate of 14.8 ± 2.0 impulses/s. In the second set of experiments, to distinguish extrinsic from intrinsic factors underlying saturation, we artificially augmented descending excitatory drive to biceps MNs by activation of muscle spindle afferents through tendon vibration. We examined the change in firing rate caused by tendon vibration in 96 MUs that were voluntarily activated at rates below and at saturation. Vibration had little effect on the discharge of MUs that were firing at saturation frequencies but strongly increased firing rates of the same units when active at lower frequencies. These results indicate that saturation is likely caused by intrinsic mechanisms that prevent further increases in firing rate in the presence of increasing synaptic excitation. Possible intrinsic cellular mechanisms that limit firing rates of motor units during voluntary effort are discussed. PMID:25475356

Relative importance of column and adsorption parameters on the productivity in preparative liquid chromatography II: Investigation of separation systems with competitive Langmuir adsorption isotherms.

PubMed

Forssén, Patrik; Samuelsson, Jörgen; Fornstedt, Torgny

2014-06-20

In this study we investigated how the maximum productivity for commonly used, realistic separation system with a competitive Langmuir adsorption isotherm is affected by changes in column length, packing particle size, mobile phase viscosity, maximum allowed column pressure, column efficiency, sample concentration/solubility, selectivity, monolayer saturation capacity and retention factor of the first eluting compound. The study was performed by generating 1000 random separation systems whose optimal injection volume was determined, i.e., the injection volume that gives the largest achievable productivity. The relative changes in largest achievable productivity when one of the parameters above changes was then studied for each system and the productivity changes for all systems were presented as distributions. We found that it is almost always beneficial to use shorter columns with high pressure drops over the column and that the selectivity should be greater than 2. However, the sample concentration and column efficiency have very limited effect on the maximum productivity. The effect of packing particle size depends on the flow rate limiting factor. If the pumps maximum flow rate is the limiting factor use smaller packing, but if the pressure of the system is the limiting factor use larger packing up to about 40μm. Copyright © 2014 Elsevier B.V. All rights reserved.

The effect of interaural fluctuation rate on correlation change discrimination.

PubMed

Goupell, Matthew J; Litovsky, Ruth Y

2014-02-01

While bilateral cochlear implants (CIs) provide some binaural benefits, these benefits are limited compared to those observed in normal-hearing (NH) listeners. The large frequency-to-electrode allocation bandwidths (BWs) in CIs compared to auditory filter BWs in NH listeners increases the interaural fluctuation rate available for binaural unmasking, which may limit binaural benefits. The purpose of this work was to investigate the effect of interaural fluctuation rate on correlation change discrimination and binaural masking-level differences in NH listeners presented a CI simulation using a pulsed-sine vocoder. In experiment 1, correlation-change just-noticeable differences (JNDs) and tone-in-noise thresholds were measured for narrowband noises with different BWs and center frequencies (CFs). The results suggest that the BW, CF, and/or interaural fluctuation rate are important factors for correlation change discrimination. In experiment 2, the interaural fluctuation rate was systematically varied and dissociated from changes in BW and CF by using a pulsed-sine vocoder. Results indicated that the interaural fluctuation rate did not affect correlation change JNDs for correlated reference noises; however, slow interaural fluctuations increased correlation change JNDs for uncorrelated reference noises. In experiment 3, the BW, CF, and vocoder pulse rate were varied while interaural fluctuation rate was held constant. JNDs increased for increasing BW and decreased for increasing CF. In summary, relatively fast interaural fluctuation rates are not detrimental for detecting changes in interaural correlation. Thus, limiting factors to binaural benefits in CI listeners could be a result of other temporal and/or spectral deficiencies from electrical stimulation.

Interactive effect of warming, nitrogen and phosphorus limitation on phytoplankton cell size

PubMed Central

Peter, Kalista Higini; Sommer, Ulrich

2015-01-01

Cell size is one of the ecologically most important traits of phytoplankton. The cell size variation is frequently related to temperature and nutrient limitation. In order to disentangle the role of both factors, an experiment was conducted to determine the possible interactions of these factors. Baltic Sea water containing the natural plankton community was used. We performed a factorial combined experiment of temperature, type of nutrient limitation (N vs. P), and strength of nutrient limitation. The type of nutrient limitation was manipulated by altering the N:P ratio of the medium (balanced, N and P limitation) and strength by the dilution rate (0% and 50%) of the semicontinuous cultures. The negative effect of temperature on cell size was strongest under N limitation, intermediate under P limitation, and weakest when N and P were supplied at balanced ratios. However, temperature also influenced the intensity of nutrient imitation, because at higher temperature there was a tendency for dissolved nutrient concentrations to be lower, while the C:N or C:P ratio being higher…higher at identical dilution rates and medium composition. Analyzing the response of cell size to C:N ratios (as index of N limitation) and C:P ratios (as index of P limitation) indicated a clear dominance of the nutrient effect over the direct temperature effect, although the temperature effect was also significant. PMID:25798219

Ammonium and nitrate uptake by leaves of the seagrass Thalassia testudinum: impact of hydrodynamic regime and epiphyte cover on uptake rates

NASA Astrophysics Data System (ADS)

Cornelisen, Christopher D.; Thomas, Florence I. M.

2004-08-01

Seagrasses rely on the uptake of dissolved inorganic nitrogen (DIN) from both sediment pore water and the water column for metabolic processes. Rates at which their leaves remove nutrients from the water column may be influenced by physiological factors, such as enzyme kinetics, and physical factors, including water flow and the presence of epiphytes on the leaf surface. While there is some evidence of the individual effects of these factors on uptake rates for individual plants, there is little information on the effects of these factors on seagrasses that are situated in their natural environment. In order to isolate the combined effects of water flow and epiphyte cover on uptake rates for Thalassia testudinum leaves while they were situated in a natural canopy we applied 15N-labeled ammonium and 15N-labeled nitrate in a series of field flume experiments. Hydrodynamic parameters related to thickness of diffusive boundary layers, including bottom shear stress and the rate of turbulent energy dissipation, were estimated from velocity profiles collected with an acoustic Doppler velocimeter. Rates of NH 4+ uptake for leaves with and without epiphyte cover were proportional to bottom shear stress and energy dissipation rate, while rates of NO 3- uptake were not. For epiphytes, rates of both NH 4+ and NO 3- uptake were dependent on hydrodynamic parameters. Epiphytes covering the leaf surface reduced rates of NH 4+ uptake for seagrass leaves by an amount proportional to the spatial area covered by the epiphytes (˜90%) and although epiphytes reduced NO 3- uptake rates, the amount was not proportional to the extent of epiphyte cover. Results suggest that the rate at which seagrass leaves removed ammonium was limited by the rate of delivery to the surface of the leaves and was greatly reduced due to blockage of active uptake sites by epiphytes. Conversely, rates of nitrate uptake for the seagrass leaves were limited by the rate at which the leaves could process nitrate rather than the rate of delivery. Our findings quantitatively demonstrate the potential impact of hydrodynamic regime and epiphyte cover on rates of DIN uptake by T. testudinum leaves and how the importance of these factors in affecting uptake rates can vary depending on the form of DIN being assimilated.

Evaluation of third-degree and fourth-degree laceration rates as quality indicators.

PubMed

Friedman, Alexander M; Ananth, Cande V; Prendergast, Eri; D'Alton, Mary E; Wright, Jason D

2015-04-01

To examine the patterns and predictors of third-degree and fourth-degree laceration in women undergoing vaginal delivery. We identified a population-based cohort of women in the United States who underwent a vaginal delivery between 1998 and 2010 using the Nationwide Inpatient Sample. Multivariable log-linear regression models were developed to account for patient, obstetric, and hospital factors related to lacerations. Between-hospital variability of laceration rates was calculated using generalized log-linear mixed models. Among 7,096,056 women who underwent vaginal delivery in 3,070 hospitals, 3.3% (n=232,762) had a third-degree laceration and 1.1% (n=76,347) had a fourth-degree laceration. In an adjusted model for fourth-degree lacerations, important risk factors included shoulder dystocia and forceps and vacuum deliveries with and without episiotomy. Other demographic, obstetric, medical, and hospital variables, although statistically significant, were not major determinants of lacerations. Risk factors in a multivariable model for third-degree lacerations were similar to those in the fourth-degree model. Regression analysis of hospital rates (n=3,070) of lacerations demonstrated limited between-hospital variation. Risk of third-degree and fourth-degree laceration was most strongly related to operative delivery and shoulder dystocia. Between-hospital variation was limited. Given these findings and that the most modifiable practice related to lacerations would be reduction in operative vaginal deliveries (and a possible increase in cesarean delivery), third-degree and fourth-degree laceration rates may be a quality metric of limited utility.

Net growth rate of continuum heterogeneous biofilms with inhibition kinetics.

PubMed

Gonzo, Elio Emilio; Wuertz, Stefan; Rajal, Veronica B

2018-01-01

Biofilm systems can be modeled using a variety of analytical and numerical approaches, usually by making simplifying assumptions regarding biofilm heterogeneity and activity as well as effective diffusivity. Inhibition kinetics, albeit common in experimental systems, are rarely considered and analytical approaches are either lacking or consider effective diffusivity of the substrate and the biofilm density to remain constant. To address this obvious knowledge gap an analytical procedure to estimate the effectiveness factor (dimensionless substrate mass flux at the biofilm-fluid interface) was developed for a continuum heterogeneous biofilm with multiple limiting-substrate Monod kinetics to different types of inhibition kinetics. The simple perturbation technique, previously validated to quantify biofilm activity, was applied to systems where either the substrate or the inhibitor is the limiting component, and cases where the inhibitor is a reaction product or the substrate also acts as the inhibitor. Explicit analytical equations are presented for the effectiveness factor estimation and, therefore, the calculation of biomass growth rate or limiting substrate/inhibitor consumption rate, for a given biofilm thickness. The robustness of the new biofilm model was tested using kinetic parameters experimentally determined for the growth of Pseudomonas putida CCRC 14365 on phenol. Several additional cases have been analyzed, including examples where the effectiveness factor can reach values greater than unity, characteristic of systems with inhibition kinetics. Criteria to establish when the effectiveness factor can reach values greater than unity in each of the cases studied are also presented.

An empirical model of the phytoplankton chlorophyll : carbon ratio-the conversion factor between productivity and growth rate

USGS Publications Warehouse

Cloern, James E.; Grenz, Christian; Vidergar-Lucas, Lisa

1995-01-01

We present an empirical model that describes the ratio of phytoplankton chlorophyll a to carbon, Chl: C, as a function of temperature, daily irradiance, and nutrient-limited growth rate. Our model is based on 219 published measurements of algal cultures exposed to light-limited or nutrient-limited growth conditions. We illustrate an approach for using this estimator of Chl: C to calculate phytoplankton population growth rate from measured primary productivity. This adaptive Chl: C model gives rise to interactive light-nutrient effects in which growth efficiency increases with nutrient availability under low-light conditions. One implication of this interaction is the enhancement of phytoplankton growth efficiency, in addition to enhancement of biomass yield, as a response to eutrophication.

Contribution of liver alcohol dehydrogenase to metabolism of alcohols in rats.

PubMed

Plapp, Bryce V; Leidal, Kevin G; Murch, Bruce P; Green, David W

2015-06-05

The kinetics of oxidation of various alcohols by purified rat liver alcohol dehydrogenase (ADH) were compared with the kinetics of elimination of the alcohols in rats in order to investigate the roles of ADH and other factors that contribute to the rates of metabolism of alcohols. Primary alcohols (ethanol, 1-propanol, 1-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol) and diols (1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol) were eliminated in rats with zero-order kinetics at doses of 5-20 mmol/kg. Ethanol was eliminated most rapidly, at 7.9 mmol/kgh. Secondary alcohols (2-propanol-d7, 2-propanol, 2-butanol, 3-pentanol, cyclopentanol, cyclohexanol) were eliminated with first order kinetics at doses of 5-10 mmol/kg, and the corresponding ketones were formed and slowly eliminated with zero or first order kinetics. The rates of elimination of various alcohols were inhibited on average 73% (55% for 2-propanol to 90% for ethanol) by 1 mmol/kg of 4-methylpyrazole, a good inhibitor of ADH, indicating a major role for ADH in the metabolism of the alcohols. The Michaelis kinetic constants from in vitro studies (pH 7.3, 37 °C) with isolated rat liver enzyme were used to calculate the expected relative rates of metabolism in rats. The rates of elimination generally increased with increased activity of ADH, but a maximum rate of 6±1 mmol/kg h was observed for the best substrates, suggesting that ADH activity is not solely rate-limiting. Because secondary alcohols only require one NAD(+) for the conversion to ketones whereas primary alcohols require two equivalents of NAD(+) for oxidation to the carboxylic acids, it appears that the rate of oxidation of NADH to NAD(+) is not a major limiting factor for metabolism of these alcohols, but the rate-limiting factors are yet to be identified. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Contribution of Liver Alcohol Dehydrogenase to Metabolism of Alcohols in Rats

PubMed Central

Plapp, Bryce V.; Leidal, Kevin G.; Murch, Bruce P.; Green, David W.

2015-01-01

The kinetics of oxidation of various alcohols by purified rat liver alcohol dehydrogenase (ADH) were compared with the kinetics of elimination of the alcohols in rats in order to investigate the roles of ADH and other factors that contribute to the rates of metabolism of alcohols. Primary alcohols (ethanol, 1-propanol, 1-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol) and diols (1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol) were eliminated in rats with zero-order kinetics at doses of 5–20 mmole/kg. Ethanol was eliminated most rapidly, at 7.9 mmole/kg•h. Secondary alcohols (2-propanol-d7, 2-propanol, 2-butanol, 3-pentanol, cyclopentanol, cyclohexanol) were eliminated with first order kinetics at doses of 5–10 mmole/kg, and the corresponding ketones were formed and slowly eliminated with zero or first order kinetics. The rates of elimination of various alcohols were inhibited on average 73% (55% for 2-propanol to 90% for ethanol) by 1 mmole/kg of 4-methylpyrazole, a good inhibitor of ADH, indicating a major role for ADH in the metabolism of the alcohols. The Michaelis kinetic constants from in vitro studies (pH 7.3, 37 °C) with isolated rat liver enzyme were used to calculate the expected relative rates of metabolism in rats. The rates of elimination generally increased with increased activity of ADH, but a maximum rate of 6 ± 1 mmole/kg•h was observed for the best substrates, suggesting that ADH activity is not solely rate-limiting. Because secondary alcohols only require one NAD+ for the conversion to ketones whereas primary alcohols require two equivalents of NAD+ for oxidation to the carboxylic acids, it appears that the rate of oxidation of NADH to NAD+ is not a major limiting factor for metabolism of these alcohols, but the rate-limiting factors are yet to be identified. PMID:25641189

Tenax TA extraction to understand the rate-limiting factors in methyl-β-cyclodextrin-enhanced bioremediation of PAH-contaminated soil.

PubMed

Sun, Mingming; Luo, Yongming; Teng, Ying; Christie, Peter; Jia, Zhongjun; Li, Zhengao

2013-06-01

The effectiveness of many bioremediation systems for PAH-contaminated soil may be constrained by low contaminant bioaccessibility due to limited aqueous solubility or large sorption capacity. Information on the extent to which PAHs can be readily biodegraded is of vital importance in the decision whether or not to remediate a contaminated soil. In the present study the rate-limiting factors in methyl-β-cyclodextrin (MCD)-enhanced bioremediation of PAH-contaminated soil were evaluated. MCD amendment at 10 % (w/w) combined with inoculation with the PAH-degrading bacterium Paracoccus sp. strain HPD-2 produced maximum removal of total PAHs of up to 35 %. The desorption of PAHs from contaminated soil was determined before and after 32 weeks of bioremediation. 10 % (w/w) MCD amendment (M2) increased the Tenax extraction of total PAHs from 12 to 30 % and promoted degradation by up to 26 % compared to 6 % in the control. However, the percentage of Tenax extraction for total PAHs was much larger than that of degradation. Thus, in the control and M2 treatment it is likely that during the initial phase the bioaccessibility of PAHs is high and biodegradation rates may be limited by microbial processes. On the other hand, when the soil was inoculated with the PAH-degrading bacterium (CKB and MB2), the slowly and very slowly desorbing fractions (F sl and F vl ) became larger and the rate constants of slow and very slow desorption (k sl and k vl ) became extremely small after bioremediation, suggesting that desorption is likely rate limiting during the second, slow phase of biotransformation. These results have practical implications for site risk assessment and cleanup strategies.

Hawaii's public mental health system.

PubMed

VanderVoort, Debra J

2005-03-01

The following article addresses the nature of and problems with the public mental health system in Hawaii. It includes a brief history of Hawaii's public mental health system, a description and analysis of this system, economic factors affecting mental health, as well as a needs assessment of the elderly, individuals with severe mental illness, children and adolescents, and ethnically diverse individuals. In addition to having the potential to increase suicide rates and unnecessarily prolong personal suffering, problems in the public mental health system such as inadequate services contribute to an increase in social problems including, but not limited to, an increase in crime rates (e.g., domestic violence, child abuse), divorce rates, school failure, and behavioral problems in children. The population in need of mental health services in Hawaii is under served, with this inadequacy of services due to economic limitations and a variety of other factors.

Biodegradation of airborne acetone/styrene mixtures in a bubble column reactor.

PubMed

Vanek, T; Silva, A; Halecky, M; Paca, J; Ruzickova, I; Kozliak, E; Jones, K

2017-07-29

The ability of a bubble column reactor (BCR) to biodegrade a mixture of styrene and acetone vapors was evaluated to determine the factors limiting the process efficiency, with a particular emphasis on the presence of degradation intermediates and oxygen levels. The results obtained under varied loadings and ratios were matched with the dissolved oxygen levels and kinetics of oxygen mass transfer, which was assessed by determination of k L a coefficients. A 1.5-L laboratory-scale BCR was operated under a constant air flow of 1.0 L.min -1 , using a defined mixed microbial population as a biocatalyst. Maximum values of elimination capacities/maximum overall specific degradation rates of 75.5 gC.m -3 .h -1 /0.197 gC.gdw -1 .h -1 , 66.0 gC.m -3 .h -1 /0.059 gC.gdw -1 .h -1 , and 45.8 gC.m -3 .h -1 /0.027 gC.gdw -1 .h -1 were observed for styrene/acetone 2:1, styrene-rich and acetone-rich mixtures, respectively, indicating significant substrate interactions and rate limitation by biological factors. The BCR removed both acetone and styrene near-quantitatively up to a relatively high organic load of 50 g.m -3 .h -1 . From this point, the removal efficiencies declined under increasing loading rates, accompanied by a significant drop in the dissolved oxygen concentration, showing a process transition to oxygen-limited conditions. However, the relatively efficient pollutant removal from air continued, due to significant oxygen mass transfer, up to a threshold loading rate when the accumulation of acetone and degradation intermediates in the aqueous medium became significant. These observations demonstrate that oxygen availability is the limiting factor for efficient pollutant degradation and that accumulation of intermediates may serve as an indicator of oxygen limitation. Microbial (activated sludge) analyses revealed the presence of amoebae and active nematodes that were not affected by variations in operational conditions.

Socioeconomic factors outweigh climate in the regional difference of suicide death rate in Taiwan.

PubMed

Tsai, Jui-Feng

2010-09-30

The present study explored both socioeconomic and climatic factors to obtain a more comprehensive view of the asymmetric regional suicide death rate during 1998-2006 in Taiwan. The annual suicide death rate, population and meteorological data from 19 cities/counties in Taiwan were analysed by multiple regression. Five socioeconomic (sex ratio, no spouse, aged, unemployment and low income) and three climatic (temperature, rainfall and sunshine) factors were identified as significant, explaining 59.0% of the variance in the total suicide death rate. 'Without spouse' and 'aged' were associated with the highest risk, while 'low income with financial aids' was strongly protective. The most influential climatic factor was 'temperature,' which was negatively correlated with suicide. 'Sunshine' was positively associated with suicide. The socioeconomic and climatic factors contributed 52.7% and 6.8%, respectively, to the variance of the total suicide death rate. Limitations of the study included the fact that no individual events were considered, the study was of relatively short duration and it was confined to the territory of Taiwan. Socioeconomic factors outweighed climatic factors in explaining regional differences in the suicide death rate in Taiwan. Temperature weighed more than sunshine. 'Thermotherapy' seems more clinically relevant than the popular light therapy, at least in Taiwan. Copyright © 2008 Elsevier Ltd. All rights reserved.

Data collection in IMS: It's not as easy as it looks

NASA Technical Reports Server (NTRS)

Davis, Dennis M.; Maswadeh, Waleed; Shoff, Donald B.; Harden, Charles S.; Snyder, A. Peter

1995-01-01

Data collection in Ion Mobility Spectrometry (IMS) is not as easy an endeavor as it appears. Despite the advent of high speed personal computers and fast analog-to-digital converters (ADC's), care must be taken to ensure that reliable data are obtained in a timely fashion. This is especially true in hyphenated techniques, e.g. GC-IMS, where the amount of data increases dramatically when gas chromatography-ion mobility spectrometry (GC-IMS) data is being collected. Using the Graseby GC-IMS, with a gate repetition rate of 33 Hz, it is theoretically possible to collect 33 spectra per second. This collection rate is not realistically obtained due to a number of factors. Among these factors are inaccuracy of the timing signal from the IMS, the necessity to store the data, disk input/output limitations, disk operating system limitations, and program overhead. Taking these factors into account, we have achieved a data collection rate of 20 spectra per second. This paper will describe these problems, demonstrate the practical effects these problems present, and present methods for minimizing these effects.

Teacher Education in Central Equatoria, South Sudan

ERIC Educational Resources Information Center

Hahs Brinkley, Catherine

2016-01-01

Without education, many South Sudanese will continue living in poverty. There are numerous factors that limit their educational opportunities including tribal warfare, colonialism, missionary malpractice, civil wars, a high illiteracy rate, low government funding, and threats of war. These factors have left a substantial deficiency in available…

Parsing the heterogeneity of depression: An exploratory factor analysis across commonly used depression rating scales.

PubMed

Ballard, Elizabeth D; Yarrington, Julia S; Farmer, Cristan A; Lener, Marc S; Kadriu, Bashkim; Lally, Níall; Williams, Deonte; Machado-Vieira, Rodrigo; Niciu, Mark J; Park, Lawrence; Zarate, Carlos A

2018-04-15

Due to the heterogeneity of depressive symptoms-which can include depressed mood, anhedonia, negative cognitive biases, and altered activity levels-researchers often use a combination of depression rating scales to assess symptoms. This study sought to identify unidimensional constructs measured across rating scales for depression and to evaluate these constructs across clinical trials of a rapid-acting antidepressant (ketamine). Exploratory factor analysis (EFA) was conducted on baseline ratings from the Beck Depression Inventory (BDI), the Hamilton Depression Rating Scale (HAM-D), the Montgomery-Asberg Depression Rating Scale (MADRS), and the Snaith-Hamilton Pleasure Rating Scale (SHAPS). Inpatients with major depressive disorder (n = 76) or bipolar depression (n = 43) were participating in clinical ketamine trials. The trajectories of the resulting unidimensional scores were evaluated in 41 subjects with bipolar depression who participated in clinical ketamine trials. The best solution, which exhibited excellent fit to the data, comprised eight factors: Depressed Mood, Tension, Negative Cognition, Impaired Sleep, Suicidal Thoughts, Reduced Appetite, Anhedonia, and Amotivation. Various response patterns were observed across the clinical trial data, both in treatment effect (ketamine versus placebo) and in degree of placebo response, suggesting that use of these unidimensional constructs may reveal patterns not observed with traditional scoring of individual instruments. Limitations include: 1) small sample (and related inability to confirm measurement invariance); 2) absence of an independent sample for confirmation of factor structure; and 3) the treatment-resistant nature of the population, which may limit generalizability. The empirical identification of unidimensional constructs creates more refined scores that may elucidate the connection between specific symptoms and underlying pathophysiology. Published by Elsevier B.V.

Limiting factors of four rare plant species in `Ōla`A Forest of Hawai'i Volcanoes National Park

USGS Publications Warehouse

VanDeMark, Joshua R.; Pratt, Linda W.; Euaparadorn, Melody

2010-01-01

In conclusion, 2 of the 3 regularly-monitored rare plant species of `Ōla`a Forest appeared to have more than 1 limiting factor inhibiting the natural increase in their populations, while for P. floribunda the most important factor was high seedling mortality. Most plants of the monitored C. giffardii population appeared to be hybrids, probably with the more common species C. lysiosepala. Seed germination rates were low, and natural seedlings were not observed. Pollinators were not seen in many hours of observation, indicating that cross pollination is a rare or uncommon event. The re-introduced population of P. floribunda had relatively low mortality, and reproduction was successful with high rates of fruit formation from abundant flowers. Seed germination rates were high, and a soil seed bank was detected. Natural seedling recruitment was observed, but high seedling mortality indicated that this life stage was the most vulnerable in the species. The population of S. alba was small and the vine life form precluded an accurate estimate of the number of adult plants in `Ōla`a Forest. Natural dormancy was likely a factor in the observed low rate of seed germination. No soil seed bank was detected, and alien rodents were implicated as seed predators. Natural recruitment was observed at multiple sites in `Ōla`a, but seedling mortality was high. The cause of seedling mortality was not identified.

Turnover and vacancy rates for registered nurses: do local labor market factors matter?

PubMed

Rondeau, Kent V; Williams, Eric S; Wagar, Terry H

2008-01-01

Turnover of nursing staff is a significant issue affecting health care cost, quality, and access. In recent years, a worldwide shortage of skilled nurses has resulted in sharply higher vacancy rates for registered nurses in many health care organizations. Much research has focused on the individual, group, and organizational determinants of turnover. Labor market factors have also been suggested as important contributors to turnover and vacancy rates but have received limited attention by scholars. This study proposes and tests a conceptual model showing the relationships of organization-market fit and three local labor market factors with organizational turnover and vacancy rates. The model is tested using ordinary least squares regression with data collected from 713 Canadian hospitals and nursing homes. Results suggest that, although modest in their impact, labor market and the organization-market fit factors do make significant yet differential contributions to turnover and vacancy rates for registered nurses. Knowledge of labor market factors can substantially shape an effective campaign to recruit and retain nurses. This is particularly true for employers who are perceived to be "employers-of-choice."

Observations on the action of limit dextrinases on amylopectin-like polysaccharides (Short Communication)

PubMed Central

Dunn, Graham; Hardie, D. Grahame; Manners, David J.

1973-01-01

The rate of hydrolysis of amylopectin by three different limit dextrinase preparations is only about 15–23% of that of amylopectin β-limit dextrin under similar conditions. On dilution of the enzymes there was no change in specificity. The factors controlling the specificity of the enzyme and the possible significance in vivo of the results are discussed. PMID:4734116

Roles of conformational stability and colloidal stability in the aggregation of recombinant human granulocyte colony-stimulating factor

PubMed Central

Chi, Eva Y.; Krishnan, Sampathkumar; Kendrick, Brent S.; Chang, Byeong S.; Carpenter, John F.; Randolph, Theodore W.

2003-01-01

We studied the non-native aggregation of recombinant human granulocyte stimulating factor (rhGCSF) in solution conditions where native rhGCSF is both conformationally stable compared to its unfolded state and at concentrations well below its solubility limit. Aggregation of rhGCSF first involves the perturbation of its native structure to form a structurally expanded transition state, followed by assembly process to form an irreversible aggregate. The energy barriers of the two steps are reflected in the experimentally measured values of free energy of unfolding (ΔGunf) and osmotic second virial coefficient (B22), respectively. Under solution conditions where rhGCSF conformational stability dominates (i.e., large ΔGunf and negative B22), the first step is rate-limiting, and increasing ΔGunf (e.g., by the addition of sucrose) decreases aggregation. In solutions where colloidal stability is high (i.e., large and positive B22 values) the second step is rate-limiting, and solution conditions (e.g., low pH and low ionic strength) that increase repulsive interactions between protein molecules are effective at reducing aggregation. rhGCSF aggregation is thus controlled by both conformational stability and colloidal stability, and depending on the solution conditions, either could be rate-limiting. PMID:12717013

Mark-recapture estimation of snag standing rates in northern Arizona mixed-conifer and ponderosa pine forests

Treesearch

Joseph L. Ganey; Gary C. White; Jeffrey S. Jenness; Scott C. Vojta

2015-01-01

Snags (standing dead trees) are important components of forests that provide resources for numerous species of wildlife and contribute to decay dynamics and other ecological processes. Managers charged with managing populations of snags need information about standing rates of snags and factors influencing those rates, yet such data are limited for ponderosa pine (...

Impacts of Daily Bag Limit Reductions on Angler Effort in Wisconsin Walleye Lakes

USGS Publications Warehouse

Beard, T.D.; Cox, S.P.; Carpenter, S.R.

2003-01-01

Angler effort is an important factor affecting recreational fisheries. However, angler responses are rarely incorporated into recreational fisheries regulations or predictions. Few have attempted to examine how daily bag limit regulations affect total angling pressure and subsequent stock densities. Our paper develops a theoretical basis for predicting angler effort and harvest rate based on stock densities and bag limit regulations. We examined data from a management system that controls the total exploitation of walleyes Sander vitreus (formerly Stizostedion vitreum) in northern Wisconsin lakes and compared these empirical results with the predictions from a theoretical effort and harvest rate response model. The data indicated that higher general angler effort occurs on lakes regulated with a 5-walleye daily limit than on lakes regulated with either a 2- or 3-walleye daily limit. General walleye catch rates were lower on lakes with a 5-walleye limit than on lakes with either a 2- or 3-walleye daily limit. An effort response model predicted a logarithmic relationship between angler effort and adult walleye density and that an index of attractiveness would be greater on lakes with high bag limits. Predictions from the harvest rate model with constant walleye catchability indicated that harvest rates increased nonlinearly with increasing density. When the effort model was fitted to data from northern Wisconsin, we found higher lake attractiveness at 5-walleye-limit lakes. We conclude that different groups of anglers respond differently to bag limit changes and that reliance on daily bag limits may not be sufficient to maintain high walleye densities in some lakes in this region.

Coping with Drinking Pressures: Adolescent Versus Parent Perspectives.

ERIC Educational Resources Information Center

Brown, Sandra A.; Stetson, Barbara A.

1988-01-01

Fifteen techniques to limit or stop alcohol consumption were rated by 94 adolescents, aged 12 to 19, and their parents. Factor analysis of effectiveness ratings demonstrated consistency in appraisal of adult options for coping strategies, but significant differences in adolescent and parent views of how teenagers should cope with drinking…

Exploring Incomplete Rating Designs with Mokken Scale Analysis

ERIC Educational Resources Information Center

Wind, Stefanie A.; Patil, Yogendra J.

2018-01-01

Recent research has explored the use of models adapted from Mokken scale analysis as a nonparametric approach to evaluating rating quality in educational performance assessments. A potential limiting factor to the widespread use of these techniques is the requirement for complete data, as practical constraints in operational assessment systems…

Egg maturation by the glassy-winged sharpshooter (Hemiptera: Cicadellidae); a vector of Xylella fastidiosa

USDA-ARS?s Scientific Manuscript database

Rates of spread of insect-transmitted plant pathogens are a function of vector abundance. Despite this, factors affecting population growth rates of insects that transmit plant pathogens have received limited attention. The glassy-winged sharpshooter (Homalodisca vitripennis) feeds on xylem-sap and ...

Factors Influencing Latino Participation in Community-Based Diabetes Education

ERIC Educational Resources Information Center

Francis, Sarah L.; Noterman, Amber; Litchfield, Ruth

2014-01-01

An Extension diabetes program (DP) was revised for Latinos; however, participation was limited. Factors influencing low participation rates were examined. Five Latinos interested in the DP participated in a focus group discussion. Transcripts were analyzed for themes. Preferred education programs were multi-session, local, group classes led by an…

13 CFR 120.451 - How does a Lender become a PLP Lender?

Code of Federal Regulations, 2010 CFR

2010-01-01

... for final decision. (b) In making its decision, SBA considers whether the Lender: (1) Has the required.... The Lender's Risk Rating, among other factors, will be considered in determining satisfactory SBA performance. Other factors may include, but are not limited to, on-site review/examination assessments...

13 CFR 120.812 - Probationary period for newly certified CDCs.

Code of Federal Regulations, 2010 CFR

2010-01-01

... its recommendation to the D/FA, who will make the final decision. SBA will determine permanent CDC... discretion. The CDC's Risk Rating, among other factors, will be considered in determining satisfactory SBA performance. Other factors may include, but are not limited to, on-site review/examination assessments...

Speed Variance and Its Influence on Accidents.

ERIC Educational Resources Information Center

Garber, Nicholas J.; Gadirau, Ravi

A study was conducted to investigate the traffic engineering factors that influence speed variance and to determine to what extent speed variance affects accident rates. Detailed analyses were carried out to relate speed variance with posted speed limit, design speeds, and other traffic variables. The major factor identified was the difference…

The Association between Regional Environmental Factors and Road Trauma Rates: A Geospatial Analysis of 10 Years of Road Traffic Crashes in British Columbia, Canada

PubMed Central

Brubacher, Jeffrey R.; Chan, Herbert; Erdelyi, Shannon; Schuurman, Nadine; Amram, Ofer

2016-01-01

Background British Columbia, Canada is a geographically large jurisdiction with varied environmental and socio-cultural contexts. This cross-sectional study examined variation in motor vehicle crash rates across 100 police patrols to investigate the association of crashes with key explanatory factors. Methods Eleven crash outcomes (total crashes, injury crashes, fatal crashes, speed related fatal crashes, total fatalities, single-vehicle night-time crashes, rear-end collisions, and collisions involving heavy vehicles, pedestrians, cyclists, or motorcyclists) were identified from police collision reports and insurance claims and mapped to police patrols. Six potential explanatory factors (intensity of traffic law enforcement, speed limits, climate, remoteness, socio-economic factors, and alcohol consumption) were also mapped to police patrols. We then studied the association between crashes and explanatory factors using negative binomial models with crash count per patrol as the response variable and explanatory factors as covariates. Results Between 2003 and 2012 there were 1,434,239 insurance claim collisions, 386,326 police reported crashes, and 3,404 fatal crashes. Across police patrols, there was marked variation in per capita crash rate and in potential explanatory factors. Several factors were associated with crash rates. Percent roads with speed limits ≤ 60 km/hr was positively associated with total crashes, injury crashes, rear end collisions, and collisions involving pedestrians, cyclists, and heavy vehicles; and negatively associated with single vehicle night-time crashes, fatal crashes, fatal speeding crashes, and total fatalities. Higher winter temperature was associated with lower rates of overall collisions, single vehicle night-time collisions, collisions involving heavy vehicles, and total fatalities. Lower socio-economic status was associated with higher rates of injury collisions, pedestrian collisions, fatal speeding collisions, and fatal collisions. Regions with dedicated traffic officers had fewer fatal crashes and fewer fatal speed related crashes but more rear end crashes and more crashes involving cyclists or pedestrians. The number of traffic citations per 1000 drivers was positively associated with total crashes, fatal crashes, total fatalities, fatal speeding crashes, injury crashes, single vehicle night-time crashes, and heavy vehicle crashes. Possible explanations for these associations are discussed. Conclusions There is wide variation in per capita rates of motor vehicle crashes across BC police patrols. Some variation is explained by factors such as climate, road type, remoteness, socioeconomic variables, and enforcement intensity. The ability of explanatory factors to predict crash rates would be improved if considered with local traffic volume by all travel modes. PMID:27099930

Identifying the Safety Factors over Traffic Signs in State Roads using a Panel Quantile Regression Approach.

PubMed

Šarić, Željko; Xu, Xuecai; Duan, Li; Babić, Darko

2018-06-20

This study intended to investigate the interactions between accident rate and traffic signs in state roads located in Croatia, and accommodate the heterogeneity attributed to unobserved factors. The data from 130 state roads between 2012 and 2016 were collected from Traffic Accident Database System maintained by the Republic of Croatia Ministry of the Interior. To address the heterogeneity, a panel quantile regression model was proposed, in which quantile regression model offers a more complete view and a highly comprehensive analysis of the relationship between accident rate and traffic signs, while the panel data model accommodates the heterogeneity attributed to unobserved factors. Results revealed that (1) low visibility of material damage (MD) and death or injured (DI) increased the accident rate; (2) the number of mandatory signs and the number of warning signs were more likely to reduce the accident rate; (3)average speed limit and the number of invalid traffic signs per km exhibited a high accident rate. To our knowledge, it's the first attempt to analyze the interactions between accident consequences and traffic signs by employing a panel quantile regression model; by involving the visibility, the present study demonstrates that the low visibility causes a relatively higher risk of MD and DI; It is noteworthy that average speed limit corresponds with accident rate positively; The number of mandatory signs and the number of warning signs are more likely to reduce the accident rate; The number of invalid traffic signs per km are significant for accident rate, thus regular maintenance should be kept for a safer roadway environment.

Clinical Opinion: "Doing Something" About the Cesarean Delivery Rate.

PubMed

Clark, S L; Garite, T J; Hamilton, E J; Belfort, M A; Hankins, G D

2018-05-04

There is a general consensus that the cesarean delivery rate in the U.S. is too high, and that practice patterns of obstetricians are largely to blame for this situation. In reality, the U.S. cesarean delivery rate is the result of 3 forces largely beyond the control of the practicing clinician: patient expectations and misconceptions regarding the safety of labor, the medical-legal system, and limitations in technology. Efforts to "do something" about the cesarean delivery rate by promulgating practice directives which are marginally evidence-based or influenced by social pressures are both ineffective and potentially harmful. We examine both the recent ACOG/SMFM Care Consensus Statement "Safe Prevention of Primary Cesarean Delivery" document and the various iterations of the ACOG guidelines for vaginal birth after cesarean delivery in this context. Adherence to arbitrary time limits for active phase or second stage arrest without incorporating other clinical factors into the decision making process is unwise. In a similar manner, ever-changing practice standards for vaginal birth after cesarean driven by factors other than changing data are unlikely to be effective in lowering the cesarean delivery rate. Whether too high or too low, the current U.S. cesarean delivery rate is the expected result of the unique demographic, geographic and social forces driving it and is unlikely to change significantly given the limitations of current technology to otherwise satisfy the demands of these forces. Copyright © 2018 Elsevier Inc. All rights reserved.

Twenty-year follow-up study of long-term survival of limited-stage small-cell lung cancer and overview of prognostic and treatment factors.

PubMed

Tai, Patricia; Tonita, Jon; Yu, Edward; Skarsgard, David

2003-07-01

To predict the long-term survival results of clinical trials earlier than using actuarial methods and to assess the factors predictive of long-term cure in patients with limited-stage small-cell lung cancer. Between 1981 and 1998, 1417 new cases of small-cell lung cancer were diagnosed in Saskatchewan, Canada, of which 244 were limited stage and treated with curative intent. They were followed to the end of February 2002. A parametric lognormal statistical model was retrospectively validated to determine whether long-term survival rates could be estimated several years earlier than is possible using the standard life-table actuarial method. The survival time of the uncured group followed a lognormal distribution. Four 2-year periods of diagnosis were combined, and patients were followed as a cohort for an additional 2 years. The estimated 10-year cause-specific survival rate was 13% by the lognormal model. The Kaplan-Meier calculation for 10-year cause-specific survival rate was 15% +/- 3%. The data also showed that the absence of mediastinal lymphadenopathy and higher chest radiotherapy dose were significant prognostic factors on multivariate analysis (p < 0.05). Among the 163 patients given prophylactic cranial irradiation, a higher biologically effective dose to the brain did not improve survival or decrease the incidence of brain metastases. The lognormal model has been validated for the estimation of survival in patients with limited-stage small-cell lung cancer. A higher biologically effective dose to the brain did not improve survival or decrease the incidence of brain metastases.

Reappraising factors affecting mourning dove perch coos

USGS Publications Warehouse

Sayre, M.W.; Atkinson, R.D.; Baskett, T.S.; Haas, G.H.

1978-01-01

Results confirmed pairing as the primary factor influencing perch-cooing rates of wild mourning doves (Zenaida macroura). Marked unmated males cooed at substantially higher rates (6.2x) than mated males, had greater probability of cooing (2.3x) during 3-minute periods, and continued cooing longer each morning than mated males. Population density was not a major factor affecting cooing. Unmated males cooed more frequently in the presence of other cooing doves (P < 0.05) than when alone, but the number of additional doves above 1 was unimportant. Cooing rates of both mated and unmated males on areas with dissimilar dove densities were not significantly different. Within limits of standard call-count procedure, weather exerted no detectable influence on cooing.

Compact binary merger rates: Comparison with LIGO/Virgo upper limits

DOE PAGES

Belczynski, Krzysztof; Repetto, Serena; Holz, Daniel E.; ...

2016-03-03

Here, we compare evolutionary predictions of double compact object merger rate densities with initial and forthcoming LIGO/Virgo upper limits. We find that: (i) Due to the cosmological reach of advanced detectors, current conversion methods of population synthesis predictions into merger rate densities are insufficient. (ii) Our optimistic models are a factor of 18 below the initial LIGO/Virgo upper limits for BH–BH systems, indicating that a modest increase in observational sensitivity (by a factor of ~2.5) may bring the first detections or first gravitational wave constraints on binary evolution. (iii) Stellar-origin massive BH–BH mergers should dominate event rates in advanced LIGO/Virgo and can be detected out to redshift z sime 2 with templates including inspiral, merger, and ringdown. Normal stars (more » $$\\lt 150\\;{M}_{\\odot }$$) can produce such mergers with total redshifted mass up to $${M}_{{\\rm{tot,z}}}\\simeq 400\\;{M}_{\\odot }$$. (iv) High black hole (BH) natal kicks can severely limit the formation of massive BH–BH systems (both in isolated binary and in dynamical dense cluster evolution), and thus would eliminate detection of these systems even at full advanced LIGO/Virgo sensitivity. We find that low and high BH natal kicks are allowed by current observational electromagnetic constraints. (v) The majority of our models yield detections of all types of mergers (NS–NS, BH–NS, BH–BH) with advanced detectors. Numerous massive BH–BH merger detections will indicate small (if any) natal kicks for massive BHs.« less

Oxygen Consumption by Postfermentation Wine Yeast Lees: Factors Affecting Its Rate and Extent under Oenological Conditions

PubMed Central

Müller, Jonas; Schmidt, Dominik

2016-01-01

Summary Postfermentation wine yeast lees show antioxidant properties based on their ability to consume dissolved oxygen. The oxygen consumption capacity of suspended yeast lees obtained after fermentations with six commercial active dry yeast strains was investigated in model, white and red wines using fluorescence-based oxygen sensors operating in a nondestructive way. In model solution, the oxygen consumption rate of yeast lees was shown to depend on their amount, yeast strain, sulfur dioxide and temperature. It is slightly lower in red than in white wines. It is strongly decreased by current levels of free sulfur dioxide, thus excluding the complementary use of both as antioxidants in wine. However, in 25 randomly sampled white wines produced under commercial conditions, the rate and extent of oxygen consumption during the first six months of postfermentation had no significant correlation with any of these interacting factors, making it difficult to predict the actual antioxidant effect of yeast lees. In these wines, yeast lees consumed 0 to 47% of the dissolved oxygen. Although total oxygen consumption capacity of yeast lees is not a limiting factor under commercial winemaking conditions, their oxygen consumption proceeds at a limited rate that reduces but cannot totally prevent concomitant chemical oxidation of the wine. PMID:28115896

Oxygen Consumption by Postfermentation Wine Yeast Lees: Factors Affecting Its Rate and Extent under Oenological Conditions.

PubMed

Schneider, Volker; Müller, Jonas; Schmidt, Dominik

2016-12-01

Postfermentation wine yeast lees show antioxidant properties based on their ability to consume dissolved oxygen. The oxygen consumption capacity of suspended yeast lees obtained after fermentations with six commercial active dry yeast strains was investigated in model, white and red wines using fluorescence-based oxygen sensors operating in a nondestructive way. In model solution, the oxygen consumption rate of yeast lees was shown to depend on their amount, yeast strain, sulfur dioxide and temperature. It is slightly lower in red than in white wines. It is strongly decreased by current levels of free sulfur dioxide, thus excluding the complementary use of both as antioxidants in wine. However, in 25 randomly sampled white wines produced under commercial conditions, the rate and extent of oxygen consumption during the first six months of postfermentation had no significant correlation with any of these interacting factors, making it difficult to predict the actual antioxidant effect of yeast lees. In these wines, yeast lees consumed 0 to 47% of the dissolved oxygen. Although total oxygen consumption capacity of yeast lees is not a limiting factor under commercial winemaking conditions, their oxygen consumption proceeds at a limited rate that reduces but cannot totally prevent concomitant chemical oxidation of the wine.

Induction of microcin B17 formation in Escherichia coli ZK650 by limitation of oxygen and glucose is independent of glucose consumption rate

NASA Technical Reports Server (NTRS)

Gao, Q.; Fang, A.; Demain, A. L.

2001-01-01

We examined the consumption of glucose from the media in which Escherichia coli ZK650 was grown. This organism, which produces the polypeptide antibiotic microcin B17 best under conditions of limiting supplies of glucose and air, was grown with a low level of glucose (0.5 mg/ml) as well as a high level (5.0 mg/ml) under both high and low aeration. Glucose consumption rates were virtually identical under both high and low aeration. Thus, glucose consumption rate is not a regulating factor in microcin B17 formation.

The contribution of perceptual factors and training on varying audiovisual integration capacity.

PubMed

Wilbiks, Jonathan M P; Dyson, Benjamin J

2018-06-01

The suggestion that the capacity of audiovisual integration has an upper limit of 1 was challenged in 4 experiments using perceptual factors and training to enhance the binding of auditory and visual information. Participants were required to note a number of specific visual dot locations that changed in polarity when a critical auditory stimulus was presented, under relatively fast (200-ms stimulus onset asynchrony [SOA]) and slow (700-ms SOA) rates of presentation. In Experiment 1, transient cross-modal congruency between the brightness of polarity change and pitch of the auditory tone was manipulated. In Experiment 2, sustained chunking was enabled on certain trials by connecting varying dot locations with vertices. In Experiment 3, training was employed to determine if capacity would increase through repeated experience with an intermediate presentation rate (450 ms). Estimates of audiovisual integration capacity (K) were larger than 1 during cross-modal congruency at slow presentation rates (Experiment 1), during perceptual chunking at slow and fast presentation rates (Experiment 2), and, during an intermediate presentation rate posttraining (Experiment 3). Finally, Experiment 4 showed a linear increase in K using SOAs ranging from 100 to 600 ms, suggestive of quantitative rather than qualitative changes in the mechanisms in audiovisual integration as a function of presentation rate. The data compromise the suggestion that the capacity of audiovisual integration is limited to 1 and suggest that the ability to bind sounds to sights is contingent on individual and environmental factors. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Injury rates and injury risk factors among Federal Bureau of Investigation new agent trainees.

PubMed

Knapik, Joseph J; Grier, Tyson; Spiess, Anita; Swedler, David I; Hauret, Keith G; Graham, Bria; Yoder, James; Jones, Bruce H

2011-12-13

A one-year prospective examination of injury rates and injury risk factors was conducted in Federal Bureau of Investigation (FBI) new agent training. Injury incidents were obtained from medical records and injury compensation forms. Potential injury risk factors were acquired from a lifestyle questionnaire and existing data at the FBI Academy. A total of 426 men and 105 women participated in the project. Thirty-five percent of men and 42% of women experienced one or more injuries during training. The injury incidence rate was 2.5 and 3.2 injuries/1,000 person-days for men and women, respectively (risk ratio (women/men) = 1.3, 95% confidence interval = 0.9-1.7). The activities most commonly associated with injuries (% of total) were defensive tactics training (58%), physical fitness training (20%), physical fitness testing (5%), and firearms training (3%). Among the men, higher injury risk was associated with older age, slower 300-meter sprint time, slower 1.5-mile run time, lower total points on the physical fitness test (PFT), lower self-rated physical activity, lower frequency of aerobic exercise, a prior upper or lower limb injury, and prior foot or knee pain that limited activity. Among the women higher injury risk was associated with slower 300-meter sprint time, slower 1.5-mile run time, lower total points on the PFT, and prior back pain that limited activity. The results of this investigation supported those of a previous retrospective investigation emphasizing that lower fitness and self-reported pain limiting activity were associated with higher injury risk among FBI new agents.

Of lemmings and snowshoe hares: the ecology of northern Canada

PubMed Central

Krebs, Charles J.

2011-01-01

Two population oscillations dominate terrestrial community dynamics in northern Canada. In the boreal forest, the snowshoe hare (Lepus americanus) fluctuates in cycles with an 8–10 year periodicity and in tundra regions lemmings typically fluctuate in cycles with a 3–4 year periodicity. I review 60 years of research that has uncovered many of the causes of these population cycles, outline areas of controversy that remain and suggest key questions to address. Lemmings are keystone herbivores in tundra ecosystems because they are a key food resource for many avian and mammalian predators and are a major consumer of plant production. There remains much controversy over the role of predation, food shortage and social interactions in causing lemming cycles. Predation is well documented as a significant mortality factor limiting numbers. Food shortage is less likely to be a major limiting factor on population growth in lemmings. Social interactions might play a critical role in reducing the rate of population growth as lemming density rises. Snowshoe hares across the boreal forest are a key food for many predators and their cycles have been the subject of large-scale field experiments that have pinpointed predation as the key limiting factor causing these fluctuations. Predators kill hares directly and indirectly stress them by unsuccessful pursuits. Stress reduces the reproductive rate of female hares and is transmitted to their offspring who also suffer reduced reproductive rates. The maternal effects produced by predation risk induce a time lag in the response of hare reproductive rate to density, aiding the cyclic dynamics. PMID:20980307

Evaporation rate of nucleating clusters.

PubMed

Zapadinsky, Evgeni

2011-11-21

The Becker-Döring kinetic scheme is the most frequently used approach to vapor liquid nucleation. In the present study it has been extended so that master equations for all cluster configurations are included into consideration. In the Becker-Döring kinetic scheme the nucleation rate is calculated through comparison of the balanced steady state and unbalanced steady state solutions of the set of kinetic equations. It is usually assumed that the balanced steady state produces equilibrium cluster distribution, and the evaporation rates are identical in the balanced and unbalanced steady state cases. In the present study we have shown that the evaporation rates are not identical in the equilibrium and unbalanced steady state cases. The evaporation rate depends on the number of clusters at the limit of the cluster definition. We have shown that the ratio of the number of n-clusters at the limit of the cluster definition to the total number of n-clusters is different in equilibrium and unbalanced steady state cases. This causes difference in evaporation rates for these cases and results in a correction factor to the nucleation rate. According to rough estimation it is 10(-1) by the order of magnitude and can be lower if carrier gas effectively equilibrates the clusters. The developed approach allows one to refine the correction factor with Monte Carlo and molecular dynamic simulations.

Dropout is a problem in lifestyle intervention programs for overweight and obese infertile women: a systematic review.

PubMed

Mutsaerts, M A Q; Kuchenbecker, W K H; Mol, B W; Land, J A; Hoek, A

2013-04-01

What are the dropout rates in lifestyle intervention programs (LIPs) for overweight and obese infertile women and can intervention- or patient-related baseline factors associated with dropout be identified in these women? The median dropout rate was 24% in overweight and obese infertile women who participated in a LIP; clinical useful intervention or patient-related factors associated with dropout could not be identified. Overweight and obese infertile women might improve their chance of conception when they improve their lifestyle and lose weight. Dropout from LIPs reduces the chance of losing considerable weight and is therefore considered to be an important limiting factor of the success of LIPs. This systematic review included 15 studies published between January 1980 and December 2012. The included studies investigated the effect of LIPs for overweight and obese infertile women with infertility. From these studies, dropout rates and intervention- and patient-related baseline factors associated with dropout, as well as weight loss and pregnancy rates, were recorded. There were 15 studies identified, of which 10 reported dropout rates. The median dropout rate was 24% (range: 0-31%). Four studies reported baseline characteristics of women who dropped out, but modifiable predictors of dropout could not be identified. Weight loss and pregnancy rates were lower in women who dropped out than in women who completed the LIPs. There were limited numbers of studies investigating patient-related factors associated with dropout. The heterogeneity in the studies precluded us from drawing firm conclusions on the relation between the type of intervention and dropout. Dropout from LIPs is a major drawback because it predisposes to less weight loss and lower pregnancy rates. Identification of predictors of dropout is needed to identify overweight and obese infertile women who are prone for dropout. These women might benefit from extra support and monitoring, to potentially increasing adherence rates, weight loss and pregnancy chances. M.A.Q.M. was supported by a research grant from the Dutch Organization for Health Research and Development (ZonMw). The department of obstetrics and gynaecology received research grants from Merck Sharpe and Dohme BV, feering pharmaceuticals, Merck Serono, the Netherlands.

Using Epidemiological Survey Data to Examine Factors Influencing Participation in Parent-Training Programmes

ERIC Educational Resources Information Center

Morawska, Alina; Dyah Ramadewi, Mikha; Sanders, Matthew R.

2014-01-01

Evidence-based parent-training programmes aim to reduce child behaviour problems; however, the effects of these programmes are often limited by poor participation rates. This study proposes a model of parent, child and family factors related to parental participation in parenting interventions. A computer-assisted telephone interview was used to…

Work-Related Musculoskeletal Disorders in Physical Therapists: A Prospective Cohort Study With 1-Year Follow-up

PubMed Central

Campo, Marc; Weiser, Sherri; Koenig, Karen L; Nordin, Margareta

2008-01-01

Background: Work-related musculoskeletal disorders (WMSDs) have a significant impact on physical therapists, but few studies have addressed the issue. Research is needed to determine the scope of the problem and the effects of specific risk factors. Objectives: The objectives of this study were: (1) to determine the 1-year incidence rate of WMSDs in physical therapists and (2) to determine the effects of specific risk factors. Design: This was a prospective cohort study with 1-year follow-up. Methods: Subjects were randomly selected American Physical Therapy Association members (N=882). Exposure assessment included demographic data, physical risk factors, job strain, and specific physical therapy tasks. The primary outcome was WMSDs, with a severity rating of at least 4/10 and present at least once a month or lasting longer than a week. Results: The response rate to the baseline questionnaire was 67%. Ninety-three percent of the subjects who responded to the baseline questionnaire responded to the follow-up questionnaire. The 1-year incidence rate of WMSDs was 20.7%. Factors that increased the risk for WMSDs included patient transfers, patient repositioning, bent or twisted postures, joint mobilization, soft tissue work, and job strain. Limitations: The primary limitation of this study was the number of therapists who had a change in their job situation during the follow-up year. Conclusions: Work-related musculoskeletal disorders are prevalent in physical therapists. Physical therapy exposures, patient handling, and manual therapy, in particular, increase the risk for WMSDs. PMID:18276935

43 CFR 3482.1 - Exploration and resource recovery and protection plans.

Code of Federal Regulations, 2012 CFR

2012-10-01

...; earth- or debris-disposal areas; existing bodies of surface water; and topographic and drainage features... to, mining sequence, production rate, estimated recovery factors, stripping ratios, highwall limits...

Outcomes of limited period of adalimumab treatment in moderate to severe Crohn's disease patients: Taiwan Society of Inflammatory Bowel Disease Study

PubMed Central

Lin, Wei-Chen; Chou, Jen-Wei; Yen, Hsu-Heng; Hsu, Wen-Hung; Lin, Hung-Hsin; Lin, Jen-Kou; Chuang, Chiao-Hsiung; Huang, Tien-Yu; Wang, Horng-Yuan; Wong, Jau-Min

2017-01-01

Background/Aims In Taiwan, due to budget limitations, the National Health Insurance only allows for a limited period of biologics use in treating moderate to severe Crohn's disease (CD). We aimed to access the outcomes of CD patients following a limited period use of biologics, specifically focusing on the relapse rate and remission duration; also the response rate to second use when applicable. Methods This was a multicenter, retrospective, observational study and we enrolled CD patients who had been treated with adalimumab (ADA) according to the insurance guidelines from 2009 to 2015. Results A total of 54 CD patients, with follow-up of more than 6 months after the withdrawal of ADA, were enrolled. The average period of treatment with ADA was 16.7±9.7 months. After discontinuing ADA, 59.3% patients suffered a clinical relapse. In the univariate analysis, the reason for withdrawal was a risk factor for relapse (P=0.042). In the multivariate analysis, current smoker became an important risk factor for relapse (OR, 3.9; 95% CI, 1.2−14.8; P=0.044) and male sex was another risk factor (OR, 2.9; 95% CI, 1.1−8.6; P=0.049). For those 48 patients who received a second round of biologics, the clinical response was seen in 60.4%, and 1 anaphylaxis occurred. Conclusions Fifty-nine percent of patients experienced a relapse after discontinuing the limited period of ADA treatment, and most of them occurred within 1 year following cessation. Male sex and current smoker were risk factors for relapse. Though 60.4% of the relapse patients responded to ADA again. PMID:29142516

Escape rate for nonequilibrium processes dominated by strong non-detailed balance force

NASA Astrophysics Data System (ADS)

Tang, Ying; Xu, Song; Ao, Ping

2018-02-01

Quantifying the escape rate from a meta-stable state is essential to understand a wide range of dynamical processes. Kramers' classical rate formula is the product of an exponential function of the potential barrier height and a pre-factor related to the friction coefficient. Although many applications of the rate formula focused on the exponential term, the prefactor can have a significant effect on the escape rate in certain parameter regions, such as the overdamped limit and the underdamped limit. There have been continuous interests to understand the effect of non-detailed balance on the escape rate; however, how the prefactor behaves under strong non-detailed balance force remains elusive. In this work, we find that the escape rate formula has a vanishing prefactor with decreasing friction strength under the strong non-detailed balance limit. We both obtain analytical solutions in specific examples and provide a derivation for more general cases. We further verify the result by simulations and propose a testable experimental system of a charged Brownian particle in electromagnetic field. Our study demonstrates that a special care is required to estimate the effect of prefactor on the escape rate when non-detailed balance force dominates.

On the derivation of flow rating curves in data-scarce environments

NASA Astrophysics Data System (ADS)

Manfreda, Salvatore

2018-07-01

River monitoring is a critical issue for hydrological modelling that relies strongly on the use of flow rating curves (FRCs). In most cases, these functions are derived by least-squares fitting which usually leads to good performance indices, even when based on a limited range of data that especially lack high flow observations. In this context, cross-section geometry is a controlling factor which is not fully exploited in classical approaches. In fact, river discharge is obtained as the product of two factors: 1) the area of the wetted cross-section and 2) the cross-sectionally averaged velocity. Both factors can be expressed as a function of the river stage, defining a viable alternative in the derivation of FRCs. This makes it possible to exploit information about cross-section geometry limiting, at least partially, the uncertainty in the extrapolation of discharge at higher flow values. Numerical analyses and field data confirm the reliability of the proposed procedure for the derivation of FRCs.

International migration and caesarean birth: a systematic review and meta-analysis.

PubMed

Merry, Lisa; Small, Rhonda; Blondel, Béatrice; Gagnon, Anita J

2013-01-30

Perinatal health disparities including disparities in caesarean births have been observed between migrant and non-migrant women and some literature suggests that non-medical factors may be implicated. A systematic review was conducted to determine if migrants in Western industrialized countries consistently have different rates of caesarean than receiving-country-born women and to identify the reasons that explain these differences. Reports were identified by searching 12 literature databases (from inception to January 2012; no language limits) and the web, by bibliographic citation hand-searches and through key informants. Studies that compared caesarean rates between international migrants and non-migrants living in industrialized countries and that did not have a 'fatal flaw' according to the US Preventative Services Task Force criteria were included. Studies were summarized, analyzed descriptively and where possible, meta-analyzed. Seventy-six studies met inclusion criteria. Caesarean rates between migrants and non-migrants differed in 69% of studies. Meta-analyses revealed consistently higher overall caesarean rates for Sub-Saharan African, Somali and South Asian women; higher emergency rates for North African/West Asian and Latin American women; and lower overall rates for Eastern European and Vietnamese women. Evidence to explain the consistently different rates was limited. Frequently postulated risk factors for caesarean included: language/communication barriers, low SES, poor maternal health, GDM/high BMI, feto-pelvic disproportion, and inadequate prenatal care. Suggested protective factors included: a healthy immigrant effect, preference for a vaginal birth, a healthier lifestyle, younger mothers and the use of fewer interventions during childbirth. Certain groups of international migrants consistently have different caesarean rates than receiving-country-born women. There is insufficient evidence to explain the observed differences.

International migration and caesarean birth: a systematic review and meta-analysis

PubMed Central

2013-01-01

Background Perinatal health disparities including disparities in caesarean births have been observed between migrant and non-migrant women and some literature suggests that non-medical factors may be implicated. A systematic review was conducted to determine if migrants in Western industrialized countries consistently have different rates of caesarean than receiving-country-born women and to identify the reasons that explain these differences. Methods Reports were identified by searching 12 literature databases (from inception to January 2012; no language limits) and the web, by bibliographic citation hand-searches and through key informants. Studies that compared caesarean rates between international migrants and non-migrants living in industrialized countries and that did not have a ‘fatal flaw’ according to the US Preventative Services Task Force criteria were included. Studies were summarized, analyzed descriptively and where possible, meta-analyzed. Results Seventy-six studies met inclusion criteria. Caesarean rates between migrants and non-migrants differed in 69% of studies. Meta-analyses revealed consistently higher overall caesarean rates for Sub-Saharan African, Somali and South Asian women; higher emergency rates for North African/West Asian and Latin American women; and lower overall rates for Eastern European and Vietnamese women. Evidence to explain the consistently different rates was limited. Frequently postulated risk factors for caesarean included: language/communication barriers, low SES, poor maternal health, GDM/high BMI, feto-pelvic disproportion, and inadequate prenatal care. Suggested protective factors included: a healthy immigrant effect, preference for a vaginal birth, a healthier lifestyle, younger mothers and the use of fewer interventions during childbirth. Conclusion Certain groups of international migrants consistently have different caesarean rates than receiving-country-born women. There is insufficient evidence to explain the observed differences. PMID:23360183

[Ecologic factors and risk of rehospitalization of psychotic patients].

PubMed

Klusmann, D; Angermeyer, M C

1986-01-01

The present study investigates the relationship between ecological factors and the community tenure patients with functional psychoses. Data were gathered from the records of three psychiatric hospitals in the city of Hamburg. The analysis controls for the effects of sociodemographic variables and variables pertaining to the last impatient treatment. Variations in readmission rates can be explained by the latter to a certain extent, but only poorly by sociodemographic variables and hardly at all by ecological factors. These findings are discussed with respect to the methodological limitations of the study and as substantive results. Two lines of interpretation are offered. Firstly, equal readmission rates may have been caused by different sets of ecological factors; secondly, patients released from mental hospital may be relatively insusceptible to the impact of ecological factors.

Perceptual and Cognitive Factors Imposing “Speed Limits” on Reading Rate: A Study with the Rapid Serial Visual Presentation

PubMed Central

Spinelli, Donatella; Zoccolotti, Pierluigi; De Luca, Maria; Martelli, Marialuisa

2016-01-01

Adults read at high speed, but estimates of their reading rate vary greatly, i.e., from 100 to 1500 words per minute (wpm). This discrepancy is likely due to different recording methods and to the different perceptual and cognitive processes involved in specific test conditions. The present study investigated the origins of these notable differences in RSVP reading rate (RR). In six experiments we investigated the role of many different perceptual and cognitive variables. The presence of a mask caused a steep decline in reading rate, with an estimated masking cost of about 200 wpm. When the decoding process was isolated, RR approached values of 1200 wpm. When the number of stimuli exceeded the short-term memory span, RR decreased to 800 wpm. The semantic context contributed to reading speed only by a factor of 1.4. Finally, eye movements imposed an upper limit on RR (around 300 wpm). Overall, data indicate a speed limit of 300 wpm, which corresponds to the time needed for eye movement execution, i.e., the most time consuming mechanism. Results reconcile differences in reading rates reported by different laboratories and thus provide suggestions for targeting different components of reading rate. PMID:27088226

Efforts to estimate pesticide degradation rates in subsurface ...

EPA Pesticide Factsheets

When pesticides are used in real-world settings, the objective is to be effective in pest eradication at the site of application, but also it is desired that the pesticide have minimal persistence and mobility as it migrates away from the application site. At the site of application, sorption on soil and surface-soil degradation rates both factor into the pesticides' persistence. But once it migrates to the subsurface vadose zone and/or aquifers, subsurface degradation rate is a factor as well. Unfortunately, numerous soil properties that might affect pesticide degradation rate vary by orders of magnitude in the subsurface environment, both spatially and temporally, e.g., organic-carbon concentration, oxygen concentration, redox conditions, pH and soil mineralogy. Consequently, estimation of subsurface pesticide degradation rates and, in tum, pesticide persistence and mobility in the environment, has remained a challenge. To address this intransigent uncertainty, we surveyed peer-reviewed literature to identify > 100 data pairs in which investigators reported pesticide degradation rates in both surface and subsurface soils, using internally consistent experimental methods. These > 100 data pairs represented >30 separate pesticides. When the > 100 subsurface half-lives were plotted against surface half-lives, a limiting line could be defined for which all subsurface half-lives but three fe ll below the line. Of the three data points plotting above the limiting li

Miscoding-induced stalling of substrate translocation on the bacterial ribosome.

PubMed

Alejo, Jose L; Blanchard, Scott C

2017-10-10

Directional transit of the ribosome along the messenger RNA (mRNA) template is a key determinant of the rate and processivity of protein synthesis. Imaging of the multistep translocation mechanism using single-molecule FRET has led to the hypothesis that substrate movements relative to the ribosome resolve through relatively long-lived late intermediates wherein peptidyl-tRNA enters the P site of the small ribosomal subunit via reversible, swivel-like motions of the small subunit head domain within the elongation factor G (GDP)-bound ribosome complex. Consistent with translocation being rate-limited by recognition and productive engagement of peptidyl-tRNA within the P site, we now show that base-pairing mismatches between the peptidyl-tRNA anticodon and the mRNA codon dramatically delay this rate-limiting, intramolecular process. This unexpected relationship between aminoacyl-tRNA decoding and translocation suggests that miscoding antibiotics may impact protein synthesis by impairing the recognition of peptidyl-tRNA in the small subunit P site during EF-G-catalyzed translocation. Strikingly, we show that elongation factor P (EF-P), traditionally known to alleviate ribosome stalling at polyproline motifs, can efficiently rescue translocation defects arising from miscoding. These findings help reveal the nature and origin of the rate-limiting steps in substrate translocation on the bacterial ribosome and indicate that EF-P can aid in resuming translation elongation stalled by miscoding errors.

Miscoding-induced stalling of substrate translocation on the bacterial ribosome

PubMed Central

Alejo, Jose L.; Blanchard, Scott C.

2017-01-01

Directional transit of the ribosome along the messenger RNA (mRNA) template is a key determinant of the rate and processivity of protein synthesis. Imaging of the multistep translocation mechanism using single-molecule FRET has led to the hypothesis that substrate movements relative to the ribosome resolve through relatively long-lived late intermediates wherein peptidyl-tRNA enters the P site of the small ribosomal subunit via reversible, swivel-like motions of the small subunit head domain within the elongation factor G (GDP)-bound ribosome complex. Consistent with translocation being rate-limited by recognition and productive engagement of peptidyl-tRNA within the P site, we now show that base-pairing mismatches between the peptidyl-tRNA anticodon and the mRNA codon dramatically delay this rate-limiting, intramolecular process. This unexpected relationship between aminoacyl-tRNA decoding and translocation suggests that miscoding antibiotics may impact protein synthesis by impairing the recognition of peptidyl-tRNA in the small subunit P site during EF-G–catalyzed translocation. Strikingly, we show that elongation factor P (EF-P), traditionally known to alleviate ribosome stalling at polyproline motifs, can efficiently rescue translocation defects arising from miscoding. These findings help reveal the nature and origin of the rate-limiting steps in substrate translocation on the bacterial ribosome and indicate that EF-P can aid in resuming translation elongation stalled by miscoding errors. PMID:28973849

Developmental Trajectories of Aggression from Late Childhood through Adolescence: Similarities and Differences across Gender

PubMed Central

Xie, Hongling; Drabick, Deborah A. G.; Chen, Diane

2015-01-01

Although numerous investigations of overt aggressive and antisocial trajectories have been undertaken, there is a dearth of literature examining gender differences and similarities in trajectory patterns and their correlates. To address these gaps, we investigated gender differences in the prevalence rates, predictive validity during transition to adulthood, childhood risk factors, and adolescent correlates of different trajectories of teacher-reported overt aggression (i.e., fights, argues, gets in trouble) among 220 participants (116 girls and 104 boys) evaluated annually from grade 4 to grade 12. Four patterns of trajectories were identified: low, increasing (i.e., adolescent-onset), decreasing (i.e., childhood-limited), and high (i.e., childhood-onset). majority large proportion of youth, particularly girls, displayed low levels of aggression over time. A small proportion followed the childhood-onset trajectory. Across gender, the childhood-onset trajectory was associated with the highest rates of maladjustment during the transition to adulthood, the highest number of childhood risk factors, and multiple problems during adolescence. The adolescent-onset trajectory was associated with few childhood risk factors, but with high levels of independent status during adolescence. In contrast, the childhood-limited trajectory was associated with several childhood risk factors, but high levels of parental monitoring and school engagement during adolescence. Romantic involvement differentiated the adolescent-onset and childhood-limited trajectories among girls. PMID:21748751

Developmental trajectories of aggression from late childhood through adolescence: similarities and differences across gender.

PubMed

Xie, Hongling; Drabick, Deborah A G; Chen, Diane

2011-01-01

Although numerous investigations of overt aggressive and antisocial trajectories have been undertaken, there is a dearth of literature examining gender differences and similarities in trajectory patterns and their correlates. To address these gaps, we investigated gender differences in the prevalence rates, predictive validity during transition to adulthood, childhood risk factors, and adolescent correlates of different trajectories of teacher-reported overt aggression (i.e., fights, argues, gets in trouble) among 220 participants (116 girls and 104 boys) evaluated annually from grade 4 to grade 12. Four patterns of trajectories were identified: low, increasing (i.e., adolescent-onset), decreasing (i.e., childhood-limited), and high (i.e., childhood-onset). A large proportion of youth, particularly girls, displayed low levels of aggression over time. A small proportion followed the childhood-onset trajectory. Across gender, the childhood-onset trajectory was associated with the highest rates of maladjustment during the transition to adulthood, the highest number of childhood risk factors, and multiple problems during adolescence. The adolescent-onset trajectory was associated with few childhood risk factors, but with high levels of independent status during adolescence. In contrast, the childhood-limited trajectory was associated with several childhood risk factors, but high levels of parental monitoring and school engagement during adolescence. Romantic involvement differentiated the adolescent-onset and childhood-limited trajectories among girls. © 2011 Wiley-Liss, Inc.

Nursing home bed capacity in the States, 1978-86

PubMed Central

Harrington, Charlene; Swan, James H.; Grant, Leslie A.

1988-01-01

Trends in nursing home bed supply in the States show large variations in beds per population and a gradual decline in supply per aged population. A cross-sectional time-series regression analysis was used to examine some factors associated with nursing home bed supply. Variation was accounted for by economic factors, supply of alternative services, and climate. State Medicaid reimbursement rates had negative coefficients, with supply suggesting States may be increasing rates to improve access where supply is limited. Medicaid waiver policy was not found to be significant. PMID:10312634

African-American Male Student Perceptions about Factors Related to Why Black Boys Drop out of Secondary School

ERIC Educational Resources Information Center

Edwards, Anntwanique DeVonne

2012-01-01

African-American males are overwhelmingly represented in the nation's dropout rates. Dropping out of school has serious social and economic consequences for our society. The dropout rate is overwhelmingly represented by African-American male students, but limited attention is given to student voice. This study examines African-American male…

Teacher ratings of DSM-III-R symptoms for the disruptive behavior disorders.

PubMed

Pelham, W E; Gnagy, E M; Greenslade, K E; Milich, R

1992-03-01

Ratings were collected on a rating scale comprised of the DSM-III-R diagnostic criteria for disruptive behavior disorders. Teacher ratings were obtained for 931 boys in regular classrooms in grades K through 8 from around North America. Means and standard deviations for attention-deficit hyperactivity disorder (ADHD), oppositional-defiant disorder (ODD), and conduct disorder (CD) scales are reported by age. Frequencies of DSM-III-R symptoms are reported by age, and suggested diagnostic cutoffs are discussed. A factor analysis revealed three factors: one reflecting ODD and several CD symptoms, one on which ADHD symptoms of inattention loaded, and one comprised of ADHD impulsivity/overactivity symptoms. Conditional probability analyses revealed that several hallmark symptoms of ADHD had very poor predictive power, whereas combinations of symptoms from the two ADHD factors had good predictive power. Combinations of ODD symptoms also had very high predictive power. The limited utility of teacher ratings in assessing symptoms of conduct disorder in this age range is discussed.

WOMEN’S EMPOWERMENT AS A PROTECTIVE FACTOR AGAINST INTIMATE PARTNER VIOLENCE IN BANGLADESH: A QUALITATIVE EXPLORATION OF THE PROCESS AND LIMITATIONS OF ITS INFLUENCE

PubMed Central

Schuler, Sidney Ruth; Lenzi, Rachel; Badal, Shamsul Huda; Bates, Lisa M.

2016-01-01

Literature on the relationship between intimate partner violence (IPV) against women and women’s empowerment is contradictory. Findings from a recent survey in rural Bangladesh suggest that empowerment is becoming protective even though IPV rates remain high. We construct qualitative case studies exploring factors and social processes underlying relationships between empowerment and IPV in four villages. Empowerment may be protective against IPV in the aggregate, but this relationship can be subverted at the micro-level. Interventions are needed to reinforce the potential of empowerment to reduce IPV and counteract factors like geographic isolation and limited employment opportunities that inhibit empowerment. PMID:27486126

"It's almost expected": rural Australian Aboriginal women's reflections on smoking initiation and maintenance: a qualitative study.

PubMed

Passey, Megan E; Gale, Jennifer T; Sanson-Fisher, Robert W

2011-12-09

Despite declining smoking rates among the general Australian population, rates among Indigenous Australians remain high, with 47% of the Indigenous population reporting daily smoking - twice that of other Australians. Among women, smoking rates are highest in younger age groups, with more than half of Aboriginal women smoking during pregnancy. A lack of research focused on understanding the social context of smoking by Aboriginal women in rural Australia limits our ability to reduce these rates. This study aimed to explore the factors contributing to smoking initiation among rural Aboriginal women and girls and the social context within which smoking behaviour occurs. We conducted three focus groups with 14 Aboriginal women and service providers and 22 individual interviews with Aboriginal women from four rural communities to explore their perceptions of the factors contributing to smoking initiation among Aboriginal girls. Four inter-related factors were considered important to understanding the social context in which girls start smoking: colonisation and the introduction of tobacco; normalization of smoking within separate Aboriginal social networks; disadvantage and stressful lives; and the importance of maintaining relationships within extended family and community networks. Within this context, young girls use smoking to attain status and as a way of asserting Aboriginal identity and group membership, a way of belonging, not of rebelling. Family and social structures were seen as providing strong support, but limited the capacity of parents to influence children not to smoke. Marginalization was perceived to contribute to limited aspirations and opportunities, leading to pleasure-seeking in the present rather than having goals for the future. The results support the importance of addressing contextual factors in any strategies aimed at preventing smoking initiation or supporting cessation among Aboriginal girls and women. It is critical to acknowledge Aboriginal identity and culture as a source of empowerment; and to recognise the role of persistent marginalization in contributing to the high prevalence and initiation of smoking.

"It's almost expected": rural Australian Aboriginal women's reflections on smoking initiation and maintenance: a qualitative study

PubMed Central

2011-01-01

Background Despite declining smoking rates among the general Australian population, rates among Indigenous Australians remain high, with 47% of the Indigenous population reporting daily smoking - twice that of other Australians. Among women, smoking rates are highest in younger age groups, with more than half of Aboriginal women smoking during pregnancy. A lack of research focused on understanding the social context of smoking by Aboriginal women in rural Australia limits our ability to reduce these rates. This study aimed to explore the factors contributing to smoking initiation among rural Aboriginal women and girls and the social context within which smoking behaviour occurs. Methods We conducted three focus groups with 14 Aboriginal women and service providers and 22 individual interviews with Aboriginal women from four rural communities to explore their perceptions of the factors contributing to smoking initiation among Aboriginal girls. Results Four inter-related factors were considered important to understanding the social context in which girls start smoking: colonisation and the introduction of tobacco; normalization of smoking within separate Aboriginal social networks; disadvantage and stressful lives; and the importance of maintaining relationships within extended family and community networks. Within this context, young girls use smoking to attain status and as a way of asserting Aboriginal identity and group membership, a way of belonging, not of rebelling. Family and social structures were seen as providing strong support, but limited the capacity of parents to influence children not to smoke. Marginalization was perceived to contribute to limited aspirations and opportunities, leading to pleasure-seeking in the present rather than having goals for the future. Conclusions The results support the importance of addressing contextual factors in any strategies aimed at preventing smoking initiation or supporting cessation among Aboriginal girls and women. It is critical to acknowledge Aboriginal identity and culture as a source of empowerment; and to recognise the role of persistent marginalization in contributing to the high prevalence and initiation of smoking. PMID:22152218

Injury rates and injury risk factors among federal bureau of investigation new agent trainees

PubMed Central

2011-01-01

Background A one-year prospective examination of injury rates and injury risk factors was conducted in Federal Bureau of Investigation (FBI) new agent training. Methods Injury incidents were obtained from medical records and injury compensation forms. Potential injury risk factors were acquired from a lifestyle questionnaire and existing data at the FBI Academy. Results A total of 426 men and 105 women participated in the project. Thirty-five percent of men and 42% of women experienced one or more injuries during training. The injury incidence rate was 2.5 and 3.2 injuries/1,000 person-days for men and women, respectively (risk ratio (women/men) = 1.3, 95% confidence interval = 0.9-1.7). The activities most commonly associated with injuries (% of total) were defensive tactics training (58%), physical fitness training (20%), physical fitness testing (5%), and firearms training (3%). Among the men, higher injury risk was associated with older age, slower 300-meter sprint time, slower 1.5-mile run time, lower total points on the physical fitness test (PFT), lower self-rated physical activity, lower frequency of aerobic exercise, a prior upper or lower limb injury, and prior foot or knee pain that limited activity. Among the women higher injury risk was associated with slower 300-meter sprint time, slower 1.5-mile run time, lower total points on the PFT, and prior back pain that limited activity. Conclusion The results of this investigation supported those of a previous retrospective investigation emphasizing that lower fitness and self-reported pain limiting activity were associated with higher injury risk among FBI new agents. PMID:22166096

Self-inhibition can limit biologically enhanced TCE dissolution from a TCE DNAPL.

PubMed

Haest, P J; Springael, D; Seuntjens, P; Smolders, E

2012-11-01

Biodegradation of trichloroethene (TCE) near a Dense Non Aqueous Phase Liquid (DNAPL) can enhance the dissolution rate of the DNAPL by increasing the concentration gradient at the DNAPL-water interface. Two-dimensional flow-through sand boxes containing a TCE DNAPL and inoculated with a TCE dechlorinating consortium were set up to measure this bio-enhanced dissolution under anaerobic conditions. The total mass of TCE and daughter products in the effluent of the biotic boxes was 3-6 fold larger than in the effluent of the abiotic box. However, the mass of daughter products only accounted for 19-55% of the total mass of chlorinated compounds in the effluent, suggesting that bio-enhanced dissolution factors were maximally 1.3-2.2. The enhanced dissolution most likely primarily resulted from variable DNAPL distribution rather than biodegradation. Specific dechlorination rates previously determined in a stirred liquid medium were used in a reactive transport model to identify the rate limiting factors. The model adequately simulated the overall TCE degradation when predicted resident microbial numbers approached observed values and indicated an enhancement factor for TCE dissolution of 1.01. The model shows that dechlorination of TCE in the 2D box was limited due to the short residence time and the self-inhibition of the TCE degradation. A parameter sensitivity analysis predicts that the bio-enhanced dissolution factor for this TCE source zone can only exceed a value of 2 if the TCE self-inhibition is drastically reduced (when a TCE tolerant dehalogenating community is present) or if the DNAPL is located in a low-permeable layer with a small Darcy velocity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Activation rates for nonlinear stochastic flows driven by non-Gaussian noise

NASA Astrophysics Data System (ADS)

van den Broeck, C.; Hänggi, P.

1984-11-01

Activation rates are calculated for stochastic bistable flows driven by asymmetric dichotomic Markov noise (a two-state Markov process). This noise contains as limits both a particular type of non-Gaussian white shot noise and white Gaussian noise. Apart from investigating the role of colored noise on the escape rates, one can thus also study the influence of the non-Gaussian nature of the noise on these rates. The rate for white shot noise differs in leading order (Arrhenius factor) from the corresponding rate for white Gaussian noise of equal strength. In evaluating the rates we demonstrate the advantage of using transport theory over a mean first-passage time approach for cases with generally non-white and non-Gaussian noise sources. For white shot noise with exponentially distributed weights we succeed in evaluating the mean first-passage time of the corresponding integro-differential master-equation dynamics. The rate is shown to coincide in the weak noise limit with the inverse mean first-passage time.

"Very Good" Ratings in a Survey of Maternity Care: Kindness and Understanding Matter to Australian Women.

PubMed

Todd, Angela L; Ampt, Amanda J; Roberts, Christine L

2017-03-01

Surveys have shown that women are highly satisfied with their maternity care. Their satisfaction has been associated with various demographic, personal, and care factors. Isolating the factors that most matter to women about their care can guide quality improvement efforts. This study aimed to identify the most significant factors associated with high ratings of care by women in the three maternity periods (antenatal, birth, and postnatal). A survey was sent to 2,048 women who gave birth at seven public hospitals in New South Wales, Australia, exploring their expectations of, and experiences with maternity care. Women's overall ratings of care for the antenatal, birth, and postnatal periods were analyzed, and a number of maternal characteristics and care factors examined as potential predictors of "Very good" ratings of care. Among 886 women with a completed survey, 65 percent assigned a "Very good" rating for antenatal care, 74 percent for birth care, 58 percent for postnatal care, and 44 percent for all three periods. One factor was strongly associated with care ratings in all three maternity periods: women who were "always or almost always" treated with kindness and understanding were 1.8-2.8 times more likely to rate their antenatal, birth, and postnatal care as "Very good." A limited number of other factors were significantly associated with high care ratings for one or two of the maternity periods. Women's perceptions about the quality of their interpersonal interactions with health caregivers have a significant bearing on women's views about their maternity care journey. © 2016 Wiley Periodicals, Inc.

Mechanistic kinetic models of enzymatic cellulose hydrolysis-A review.

PubMed

Jeoh, Tina; Cardona, Maria J; Karuna, Nardrapee; Mudinoor, Akshata R; Nill, Jennifer

2017-07-01

Bioconversion of lignocellulose forms the basis for renewable, advanced biofuels, and bioproducts. Mechanisms of hydrolysis of cellulose by cellulases have been actively studied for nearly 70 years with significant gains in understanding of the cellulolytic enzymes. Yet, a full mechanistic understanding of the hydrolysis reaction has been elusive. We present a review to highlight new insights gained since the most recent comprehensive review of cellulose hydrolysis kinetic models by Bansal et al. (2009) Biotechnol Adv 27:833-848. Recent models have taken a two-pronged approach to tackle the challenge of modeling the complex heterogeneous reaction-an enzyme-centric modeling approach centered on the molecularity of the cellulase-cellulose interactions to examine rate limiting elementary steps and a substrate-centric modeling approach aimed at capturing the limiting property of the insoluble cellulose substrate. Collectively, modeling results suggest that at the molecular-scale, how rapidly cellulases can bind productively (complexation) and release from cellulose (decomplexation) is limiting, while the overall hydrolysis rate is largely insensitive to the catalytic rate constant. The surface area of the insoluble substrate and the degrees of polymerization of the cellulose molecules in the reaction both limit initial hydrolysis rates only. Neither enzyme-centric models nor substrate-centric models can consistently capture hydrolysis time course at extended reaction times. Thus, questions of the true reaction limiting factors at extended reaction times and the role of complexation and decomplexation in rate limitation remain unresolved. Biotechnol. Bioeng. 2017;114: 1369-1385. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

A Spread-Spectrum SQUID Multiplexer

NASA Astrophysics Data System (ADS)

Irwin, K. D.; Chaudhuri, S.; Cho, H.-M.; Dawson, C.; Kuenstner, S.; Li, D.; Titus, C. J.; Young, B. A.

2018-06-01

The transition-edge sensor (TES) is a mature, high-resolution x-ray spectrometer technology that provides a much higher efficiency than dispersive spectrometers such as gratings and crystal spectrometers. As larger arrays are developed, time-division multiplexing schemes operating at MHz frequencies are being replaced by microwave SQUID multiplexers using frequency-division multiplexing at GHz frequencies. However, the multiplexing factor achievable with microwave SQUIDs is limited by the high slew rate on the leading edge of x-ray pulses. In this paper, we propose a new multiplexing scheme for high-slew-rate TES x-ray calorimeters: the spread-spectrum SQUID multiplexer, which has the potential to enable higher multiplexing factors, especially in applications with lower photon-arrival rates.

Organizational Factors and the Cancer Screening Process

PubMed Central

Zapka, Jane; Edwards, Heather; Taplin, Stephen H.

2010-01-01

Cancer screening is a process of care consisting of several steps and interfaces. This article reviews what is known about the association between organizational factors and cancer screening rates and examines how organizational strategies can address the steps and interfaces of cancer screening in the context of both intraorganizational and interorganizational processes. We reviewed 79 studies assessing the relationship between organizational factors and cancer screening. Screening rates are largely driven by strategies to 1) limit the number of interfaces across organizational boundaries; 2) recruit patients, promote referrals, and facilitate appointment scheduling; and 3) promote continuous patient care. Optimal screening rates can be achieved when health-care organizations tailor strategies to the steps and interfaces in the cancer screening process that are most critical for their organizations, the providers who work within them, and the patients they serve. PMID:20386053

Organizational factors and the cancer screening process.

PubMed

Anhang Price, Rebecca; Zapka, Jane; Edwards, Heather; Taplin, Stephen H

2010-01-01

Cancer screening is a process of care consisting of several steps and interfaces. This article reviews what is known about the association between organizational factors and cancer screening rates and examines how organizational strategies can address the steps and interfaces of cancer screening in the context of both intraorganizational and interorganizational processes. We reviewed 79 studies assessing the relationship between organizational factors and cancer screening. Screening rates are largely driven by strategies to 1) limit the number of interfaces across organizational boundaries; 2) recruit patients, promote referrals, and facilitate appointment scheduling; and 3) promote continuous patient care. Optimal screening rates can be achieved when health-care organizations tailor strategies to the steps and interfaces in the cancer screening process that are most critical for their organizations, the providers who work within them, and the patients they serve.

Child poverty and changes in child poverty.

PubMed

Chen, Wen-Hao; Corak, Miles

2008-08-01

This article offers a cross-country overview of child poverty, changes in child poverty, and the impact of public policy in North America and Europe. Levels and changes in child poverty rates in 12 Organisation for Economic Co-operation and Development (OECD) countries during the 1990s are documented using data from the Luxembourg Income Study project, and a decomposition analysis is used to uncover the relative role of demographic factors, labor markets, and income transfers from the state in determining the magnitude and direction of the changes. Child poverty rates fell noticeably in only three countries and rose in three others. In no country were demographic factors a force for higher child poverty rates, but these factors were also limited in their ability to cushion children from adverse shocks originating in the labor market or the government sector. Increases in the labor market engagement of mothers consistently lowered child poverty rates, while decreases in the employment rates and earnings of fathers were a force for higher rates. Finally, there is no single road to lower child poverty rates. Reforms to income transfers intended to increase labor supply may or may not end up lowering the child poverty rate.

Child Poverty and Changes in Child Poverty

PubMed Central

CHEN, WEN-HAO; CORAK, MILES

2008-01-01

This article offers a cross-country overview of child poverty, changes in child poverty, and the impact of public policy in North America and Europe. Levels and changes in child poverty rates in 12 Organisation for Economic Co-operation and Development (OECD) countries during the 1990s are documented using data from the Luxembourg Income Study project, and a decomposition analysis is used to uncover the relative role of demographic factors, labor markets, and income transfers from the state in determining the magnitude and direction of the changes. Child poverty rates fell noticeably in only three countries and rose in three others. In no country were demographic factors a force for higher child poverty rates, but these factors were also limited in their ability to cushion children from adverse shocks originating in the labor market or the government sector. Increases in the labor market engagement of mothers consistently lowered child poverty rates, while decreases in the employment rates and earnings of fathers were a force for higher rates. Finally, there is no single road to lower child poverty rates. Reforms to income transfers intended to increase labor supply may or may not end up lowering the child poverty rate. PMID:18939660

Browse evaluation of tall shrubs based on direct measurement of a management objective

USGS Publications Warehouse

Keigley, R.B.; Frisina, M.R.; Kitchen, Stanley G.; Pendleton, Rosemary L.; Monaco, Thomas A.; Vernon, Jason

2008-01-01

The monitoring of Geyer willow was based on the following management objective: Browsing will prevent fewer than 50 percent of Geyer willow shrubs from growing taller than 3 m . Three questions were addressed: (1) Is browsing a potential factor? (2) If so, can young plants grow taller than 3 meters? (3) If not, is browsing the dominant factor? All shrubs were intensely browsed. With a post-browsing growth rate of 5.0 cm per yr, no shrub could grow 3 m tall. Analyses of stem growth rate excluded dominant roles for climate and plant vigor. Browsing and stem age were the dominant factors that limited growth to 3 m tall.

Impact of measurement uncertainty from experimental load distribution factors on bridge load rating

NASA Astrophysics Data System (ADS)

Gangone, Michael V.; Whelan, Matthew J.

2018-03-01

Load rating and testing of highway bridges is important in determining the capacity of the structure. Experimental load rating utilizes strain transducers placed at critical locations of the superstructure to measure normal strains. These strains are then used in computing diagnostic performance measures (neutral axis of bending, load distribution factor) and ultimately a load rating. However, it has been shown that experimentally obtained strain measurements contain uncertainties associated with the accuracy and precision of the sensor and sensing system. These uncertainties propagate through to the diagnostic indicators that in turn transmit into the load rating calculation. This paper will analyze the effect that measurement uncertainties have on the experimental load rating results of a 3 span multi-girder/stringer steel and concrete bridge. The focus of this paper will be limited to the uncertainty associated with the experimental distribution factor estimate. For the testing discussed, strain readings were gathered at the midspan of each span of both exterior girders and the center girder. Test vehicles of known weight were positioned at specified locations on each span to generate maximum strain response for each of the five girders. The strain uncertainties were used in conjunction with a propagation formula developed by the authors to determine the standard uncertainty in the distribution factor estimates. This distribution factor uncertainty is then introduced into the load rating computation to determine the possible range of the load rating. The results show the importance of understanding measurement uncertainty in experimental load testing.

Oxygen Consumption Rates of Bacteria under Nutrient-Limited Conditions

PubMed Central

Riedel, Timothy E.; Nealson, Kenneth H.; Finkel, Steven E.

2013-01-01

Many environments on Earth experience nutrient limitation and as a result have nongrowing or very slowly growing bacterial populations. To better understand bacterial respiration under environmentally relevant conditions, the effect of nutrient limitation on respiration rates of heterotrophic bacteria was measured. The oxygen consumption and population density of batch cultures of Escherichia coli K-12, Shewanella oneidensis MR-1, and Marinobacter aquaeolei VT8 were tracked for up to 200 days. The oxygen consumption per CFU (QO2) declined by more than 2 orders of magnitude for all three strains as they transitioned from nutrient-abundant log-phase growth to the nutrient-limited early stationary phase. The large reduction in QO2 from growth to stationary phase suggests that nutrient availability is an important factor in considering environmental respiration rates. Following the death phase, during the long-term stationary phase (LTSP), QO2 values of the surviving population increased with time and more cells were respiring than formed colonies. Within the respiring population, a subpopulation of highly respiring cells increased in abundance with time. Apparently, as cells enter LTSP, there is a viable but not culturable population whose bulk community and per cell respiration rates are dynamic. This result has a bearing on how minimal energy requirements are met, especially in nutrient-limited environments. The minimal QO2 rates support the extension of Kleiber's law to the mass of a bacterium (100-fg range). PMID:23770901

A prospective study of floor surface, shoes, floor cleaning and slipping in US limited-service restaurant workers.

PubMed

Verma, Santosh K; Chang, Wen Ruey; Courtney, Theodore K; Lombardi, David A; Huang, Yueng-Hsiang; Brennan, Melanye J; Mittleman, Murray A; Ware, James H; Perry, Melissa J

2011-04-01

Slips and falls are a leading cause of injury at work. Few studies, however, have systematically examined risk factors of slipping outside the laboratory environment. This study examined the association between floor surface characteristics, slip-resistant shoes, floor cleaning frequency and the risk of slipping in limited-service restaurant workers. 475 workers from 36 limited-service restaurants from three major chains in six states in the USA were recruited to participate in a prospective cohort study of workplace slipping. Kitchen floor surface roughness and coefficient of friction (COF) were measured in eight working areas and then averaged within each restaurant. The use of slip-resistant shoes was determined by examining the participant's shoes and noting the presence of a 'slip-resistant' marking on the sole. Restaurant managers reported the frequency of daily kitchen floor cleaning. Participants reported their slip experience and work hours weekly for up to 12 weeks. The survey materials were made available in three languages: English, Spanish and Portuguese. The associations between rate of slipping and risk factors were assessed using a multivariable negative binomial generalised estimating equation model. The mean of individual slipping rate varied among the restaurants from 0.02 to 2.49 slips per 40 work hours. After adjusting for age, gender, BMI, education, primary language, job tenure and restaurant chain, the use of slip-resistant shoes was associated with a 54% reduction in the reported rate of slipping (95% CI 37% to 64%), and the rate of slipping decreased by 21% (95% CI 5% to 34%) for each 0.1 increase in the mean kitchen COF. Increasing floor cleaning frequency was significantly associated with a decreasing rate of slipping when considered in isolation but not after statistical adjustment for other factors. These results provide support for the use of slip-resistant shoes and measures to increase COF as preventive interventions to reduce slips, falls and injuries.

Factors influencing deprescribing habits among geriatricians.

PubMed

Ní Chróinín, Danielle; Ní Chróinín, Chantelle; Beveridge, Alexander

2015-07-01

deprescribing habits among physicians managing older, frailer, cognitively impaired patients have not been well investigated. an anonymised electronic survey was disseminated to all members of an international geriatric society/local advanced trainee network (N = 930). This comprised a Likert-scale analysis of factors influencing desprescribing, and five case vignettes, detailing a patient with progressive cognitive impairment and dependency, on a background of ischaemic heart disease and hypertension. among 134 respondents (response rate 14.4%), 47.4% were female, 48.9% aged 36-50 years and 84.1% specialists (15.9% trainees). Respondents commonly rated limited life expectancy (96.2%) and cognitive impairment (84.1%) as very/extremely important to deprescribing practices. On multivariable analysis, older respondents less commonly rated functional dependency (odds ratio [OR] 0.22 per change in age category; P < 0.001) and limited life expectancy (OR 0.09, P = 0.04) important when deprescribing, while female participants (OR 3.03, P < 0.001) and trainees (versus specialists OR 14.29, P < 0.001) more often rated adherence to evidence-based guidelines important. As vignettes described increasing dependency and cognitive impairment, physicians were more likely to stop donepezil, aspirin, atorvastatin and antihypertensives (all P < 0.001 for trend). Aspirin (93.6%) and ramipril (94.1%) were most commonly deprescribed. Commonest reasons cited for deprescribing medications were 'dementia severity', followed by pill burden. in this exploratory analysis, geriatricians rated limited life expectancy and cognitive impairment very important in driving deprescribing practices. Geriatricians more often deprescribed multiple medications in the setting of advancing dependency and cognitive impairment, driven by dementia severity and pill burden concerns. Physician characteristics also influence deprescribing practices. Further exploration of factors influencing deprescribing patterns, and patient outcomes, is needed. © The Author 2015. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Characteristics of right-sided colonic neoplasia and colonoscopy barriers limiting their early detection and prognosis: a review of the literature.

PubMed

Fischbach, Wolfgang; Elsome, Rory; Amlani, Bharat

2018-06-05

Colonoscopy provides less protection from colorectal cancer in the right colon than the left. Areas covered: This review examines patient outcomes and colonoscopy success rates to identify factors that limit the protective effect of colonoscopy in the right colon. The MEDLINE and Embase databases were searched for literature from 2000 onwards, on the long-term outcomes and differences in screening practice between the right and left colon. In total, 12 systematic reviews (including nine meta-analyses) and 44 primary data records were included. Differences in patient outcomes and colonoscopy practice were identified between the right and left colon, suggesting that several factors, many of which disproportionally affect the right colon, impact lesion detection rates. Shorter withdrawal times reduce detection rates, while longer times significantly increase detection; mostly of adenomas in the right colon. Colonoscope attachments often only show a significant improvement in detection rates in the right colon, suggesting detection is more challenging due to visibility of the right colonic mucosa. Higher bowel cleansing grades significantly improve detection rates in the right colon compared to the left. Expert commentary: These findings confirm the need for continued improvement of colonoscopy effectiveness, and obligatory quality assessment, overall and especially in the right colon.

Improvement of CSCW Software Implementation in NPD: The CAM Mechanism for a Better Adoption by Users

ERIC Educational Resources Information Center

Restrepo, Tomas; Arbelaez, Natalia; Millet, Dominique; Gidel, Thierry

2010-01-01

Cooperation between disseminated actors is a key factor in improving new product development (NPD) performance. In the last years, numerous CSCW software applications have been introduced in the industry to support NPD with a low success rate. This is partly due to the limited insight of the organisational and human factors influencing user…

Contrasting patterns of nest survival and postfledging survival in ovenbirds and Acadian flycatchers in Missouri forest fragments

Treesearch

Julianna M. A. Jenkins; Frank R. Thompson; John Faaborg

2016-01-01

We can improve our ability to assess population viability and forecast population growth under different scenarios by understanding factors that limit population parameters in each stage of the annual cycle. Postfledging mortality rates may be as variable as nest survival across regions and fragmentation gradients, although factors that negatively impact nest survival...

IL-2 and Beyond in Cancer Immunotherapy.

PubMed

Wrangle, John M; Patterson, Alicia; Johnson, C Bryce; Neitzke, Daniel J; Mehrotra, Shikhar; Denlinger, Chadrick E; Paulos, Chrystal M; Li, Zihai; Cole, David J; Rubinstein, Mark P

2018-02-01

The development of the T- and natural killer (NK) cell growth factor IL-2 has been a sentinel force ushering in the era of immunotherapy in cancer. With the advent of clinical grade recombinant IL-2 in the mid-1980s, oncologists could for the first time directly manipulate lymphocyte populations with systemic therapy. By itself, recombinant IL-2 can induce clinical responses in up to 15% of patients with metastatic cancer or renal cell carcinoma. When administered with adoptively transferred tumor-reactive lymphocytes, IL-2 promotes T cell engraftment and response rates of up to 50% in metastatic melanoma patients. Importantly, these IL-2-driven responses can yield complete and durable responses in a subset of patients. However, the use of IL-2 is limited by toxicity and concern of the expansion of T regulatory cells. To overcome these limitations and improve response rates, other T cell growth factors, including IL-15 and modified forms of IL-2, are in clinical development. Administering T cell growth factors in combination with other agents, such as immune checkpoint pathway inhibitors, may also improve efficacy. In this study, we review the development of T- and NK cell growth factors and highlight current combinatorial approaches based on these reagents.

Ethnic disparities in disability among middle-aged and older israeli adults: the role of socioeconomic disadvantage and traumatic life events.

PubMed

Osman, Amira; Walsemann, Katrina M

2013-04-01

We examined the contribution of socioeconomic disadvantage and traumatic life events to ethnic disparities in disability among Israeli adults. We used data from the Survey of Health, Aging and Retirement in Europe (SHARE-Israel), a sample of Israeli adults aged 50 or older (N = 1,546). Disability measures included functional limitations, limitations in activities of daily living (ADL), and limitations in instrumental activities of daily living (IADL). Arabs and immigrants from the Former Soviet Union (FSU) experienced higher rates of functional limitations and limitations in IADLs compared to veteran Jews. The rate of having limitations in ADLs was similar for Arabs and veteran Jews, but was higher for FSU immigrants compared to veteran Jews. Inclusion of education, income, and traumatic life events attenuated, but did not eliminate ethnic disparities in disability. Identifying factors driving ethnic health disparities in Israel is imperative if we hope to achieve health equity.

Comparison of PAH Biodegradation and Desorption Kinetics During Bioremediation of Aged Petroleum Hydrocarbon Contaminated Soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huesemann, Michael H.; Hausmann, Tom S.; Fortman, Timothy J.

It is commonly assumed that mass-transfer limitations are the cause for slow and incomplete biodegradation of PAHs in aged soils. In order to test this hypothesis, the biodegradation rate and the abiotic release rate were measured and compared for selected PAHs in three different soils. It was found that PAH biodegradation was not mass-transfer limited during slurry bioremediation of an aged loamy soil. By contrast, PAH biodegradation rates were much larger than abiotic release rates in kaolinite clay indicating that sorbed-phase PAHs can apparently be biodegraded directly from mineral surfaces without prior desorption or dissolution into the aqueous phase. Amore » comparison of PAH biodegradation rates and abiotic release rates at termination of the slurry bioremediation treatment revealed that abiotic release rates are much larger than the respective biodegradation rates. In addition, it was found that the number of hydrocarbon degraders decreased by four orders of magnitude during the bioremediation treatment. It can therefore be concluded that the slow and incomplete biodegradation of PAHs is not caused by mass-transfer limitations but rather by microbial factors. Consequently, the residual PAHs that remain after extensive bioremediation treatment are still bioavailable and for that reason could pose a greater risk to environmental receptors than previously thought.« less

Probing the rate-limiting step for intramolecular transfer of a transcription factor between specific sites on the same DNA molecule by (15)Nz-exchange NMR spectroscopy.

PubMed

Ryu, Kyoung-Seok; Tugarinov, Vitali; Clore, G Marius

2014-10-15

The kinetics of translocation of the homeodomain transcription factor HoxD9 between specific sites of the same or opposite polarities on the same DNA molecule have been studied by (15)Nz-exchange NMR spectroscopy. We show that exchange occurs by two facilitated diffusion mechanisms: a second-order intermolecular exchange reaction between specific sites located on different DNA molecules without the protein dissociating into free solution that predominates at high concentrations of free DNA, and a first-order intramolecular process involving direct transfer between specific sites located on the same DNA molecule. Control experiments using a mixture of two DNA molecules, each possessing only a single specific site, indicate that transfer between specific sites by full dissociation of HoxD9 into solution followed by reassociation is too slow to measure by z-exchange spectroscopy. Intramolecular transfer with comparable rate constants occurs between sites of the same and opposing polarity, indicating that both rotation-coupled sliding and hopping/flipping (analogous to geminate recombination) occur. The half-life for intramolecular transfer (0.5-1 s) is many orders of magnitude larger than the calculated transfer time (1-100 μs) by sliding, leading us to conclude that the intramolecular transfer rates measured by z-exchange spectroscopy represent the rate-limiting step for a one-base-pair shift from the specific site to the immediately adjacent nonspecific site. At zero concentration of added salt, the intramolecular transfer rate constants between sites of opposing polarity are smaller than those between sites of the same polarity, suggesting that hopping/flipping may become rate-limiting at very low salt concentrations.

Interdependence of specialization and biodiversity in Phanerozoic marine invertebrates.

PubMed

Nürnberg, Sabine; Aberhan, Martin

2015-03-17

Studies of the dynamics of biodiversity often suggest that diversity has upper limits, but the complex interplay between ecological and evolutionary processes and the relative role of biotic and abiotic factors that set upper limits to diversity are poorly understood. Here we statistically assess the relationship between global biodiversity and the degree of habitat specialization of benthic marine invertebrates over the Phanerozoic eon. We show that variation in habitat specialization correlates positively with changes in global diversity, that is, times of high diversity coincide with more specialized faunas. We identify the diversity dynamics of specialists but not generalists, and origination rates but not extinction rates, as the main drivers of this ecological interdependence. Abiotic factors fail to show any significant relationship with specialization. Our findings suggest that the overall level of specialization and its fluctuations over evolutionary timescales are controlled by diversity-dependent processes--driven by interactions between organisms competing for finite resources.

Health-Related Quality of Life Among US Workers: Variability Across Occupation Groups.

PubMed

Shockey, Taylor M; Zack, Matthew; Sussell, Aaron

2017-08-01

To examine the health-related quality of life among workers in 22 standard occupation groups using data from the 2013-2014 US Behavioral Risk Factor Surveillance System. We examined the health-related quality of life measures of self-rated health, frequent physical distress, frequent mental distress, frequent activity limitation, and frequent overall unhealthy days by occupation group for 155 839 currently employed adults among 17 states. We performed multiple logistic regression analyses that accounted for the Behavioral Risk Factor Surveillance System's complex survey design to obtain prevalence estimates adjusted for potential confounders. Among all occupation groups, the arts, design, entertainment, sports, and media occupation group reported the highest adjusted prevalence of frequent physical distress, frequent mental distress, frequent activity limitation, and frequent overall unhealthy days. The personal care and service occupation group had the highest adjusted prevalence for fair or poor self-rated health. Workers' jobs affect their health-related quality of life.

Survey of Expert Opinion on Intelligence: Causes of International Differences in Cognitive Ability Tests

PubMed Central

Rindermann, Heiner; Becker, David; Coyle, Thomas R.

2016-01-01

Following Snyderman and Rothman (1987, 1988), we surveyed expert opinions on the current state of intelligence research. This report examines expert opinions on causes of international differences in student assessment and psychometric IQ test results. Experts were surveyed about the importance of culture, genes, education (quantity and quality), wealth, health, geography, climate, politics, modernization, sampling error, test knowledge, discrimination, test bias, and migration. The importance of these factors was evaluated for diverse countries, regions, and groups including Finland, East Asia, sub-Saharan Africa, Southern Europe, the Arabian-Muslim world, Latin America, Israel, Jews in the West, Roma (gypsies), and Muslim immigrants. Education was rated by N = 71 experts as the most important cause of international ability differences. Genes were rated as the second most relevant factor but also had the highest variability in ratings. Culture, health, wealth, modernization, and politics were the next most important factors, whereas other factors such as geography, climate, test bias, and sampling error were less important. The paper concludes with a discussion of limitations of the survey (e.g., response rates and validity of expert opinions). PMID:27047425

High Data Rate Quantum Cryptography

NASA Astrophysics Data System (ADS)

Kwiat, Paul; Christensen, Bradley; McCusker, Kevin; Kumor, Daniel; Gauthier, Daniel

2015-05-01

While quantum key distribution (QKD) systems are now commercially available, the data rate is a limiting factor for some desired applications (e.g., secure video transmission). Most QKD systems receive at most a single random bit per detection event, causing the data rate to be limited by the saturation of the single-photon detectors. Recent experiments have begun to explore using larger degree of freedoms, i.e., temporal or spatial qubits, to optimize the data rate. Here, we continue this exploration using entanglement in multiple degrees of freedom. That is, we use simultaneous temporal and polarization entanglement to reach up to 8.3 bits of randomness per coincident detection. Due to current technology, we are unable to fully secure the temporal degree of freedom against all possible future attacks; however, by assuming a technologically-limited eavesdropper, we are able to obtain 23.4 MB/s secure key rate across an optical table, after error reconciliation and privacy amplification. In this talk, we will describe our high-rate QKD experiment, with a short discussion on our work towards extending this system to ship-to-ship and ship-to-shore communication, aiming to secure the temporal degree of freedom and to implement a 30-km free-space link over a marine environment.

Position Matters: Network Centrality Considerably Impacts Rates of Protein Evolution in the Human Protein–Protein Interaction Network

PubMed Central

Feyertag, Felix; Chakraborty, Sandip

2017-01-01

Abstract The proteins of any organism evolve at disparate rates. A long list of factors affecting rates of protein evolution have been identified. However, the relative importance of each factor in determining rates of protein evolution remains unresolved. The prevailing view is that evolutionary rates are dominantly determined by gene expression, and that other factors such as network centrality have only a marginal effect, if any. However, this view is largely based on analyses in yeasts, and accurately measuring the importance of the determinants of rates of protein evolution is complicated by the fact that the different factors are often correlated with each other, and by the relatively poor quality of available functional genomics data sets. Here, we use correlation, partial correlation and principal component regression analyses to measure the contributions of several factors to the variability of the rates of evolution of human proteins. For this purpose, we analyzed the entire human protein–protein interaction data set and the human signal transduction network—a network data set of exceptionally high quality, obtained by manual curation, which is expected to be virtually free from false positives. In contrast with the prevailing view, we observe that network centrality (measured as the number of physical and nonphysical interactions, betweenness, and closeness) has a considerable impact on rates of protein evolution. Surprisingly, the impact of centrality on rates of protein evolution seems to be comparable, or even superior according to some analyses, to that of gene expression. Our observations seem to be independent of potentially confounding factors and from the limitations (biases and errors) of interactomic data sets. PMID:28854629

Position Matters: Network Centrality Considerably Impacts Rates of Protein Evolution in the Human Protein-Protein Interaction Network.

PubMed

Alvarez-Ponce, David; Feyertag, Felix; Chakraborty, Sandip

2017-06-01

The proteins of any organism evolve at disparate rates. A long list of factors affecting rates of protein evolution have been identified. However, the relative importance of each factor in determining rates of protein evolution remains unresolved. The prevailing view is that evolutionary rates are dominantly determined by gene expression, and that other factors such as network centrality have only a marginal effect, if any. However, this view is largely based on analyses in yeasts, and accurately measuring the importance of the determinants of rates of protein evolution is complicated by the fact that the different factors are often correlated with each other, and by the relatively poor quality of available functional genomics data sets. Here, we use correlation, partial correlation and principal component regression analyses to measure the contributions of several factors to the variability of the rates of evolution of human proteins. For this purpose, we analyzed the entire human protein-protein interaction data set and the human signal transduction network-a network data set of exceptionally high quality, obtained by manual curation, which is expected to be virtually free from false positives. In contrast with the prevailing view, we observe that network centrality (measured as the number of physical and nonphysical interactions, betweenness, and closeness) has a considerable impact on rates of protein evolution. Surprisingly, the impact of centrality on rates of protein evolution seems to be comparable, or even superior according to some analyses, to that of gene expression. Our observations seem to be independent of potentially confounding factors and from the limitations (biases and errors) of interactomic data sets. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Factors limiting sulfolane biodegradation in contaminated subarctic aquifer substrate.

PubMed

Kasanke, Christopher P; Leigh, Mary Beth

2017-01-01

Sulfolane, a water-soluble organosulfur compound, is used industrially worldwide and is associated with one of the largest contaminated groundwater plumes in the state of Alaska. Despite being widely used, little is understood about the degradation of sulfolane in the environment, especially in cold regions. We conducted aerobic and anaerobic microcosm studies to assess the biological and abiotic sulfolane degradation potential of contaminated subarctic aquifer groundwater and sediment from Interior Alaska. We also investigated the impacts of nutrient limitations and hydrocarbon co-contamination on sulfolane degradation. We found that sulfolane underwent biodegradation aerobically but not anaerobically under nitrate, sulfate, or iron-reducing conditions. No abiotic degradation activity was detectable under either oxic or anoxic conditions. Nutrient addition stimulated sulfolane biodegradation in sediment slurries at high sulfolane concentrations (100 mg L-1), but not at low sulfolane concentrations (500 μg L-1), and nutrient amendments were necessary to stimulate sulfolane biodegradation in incubations containing groundwater only. Hydrocarbon co-contamination retarded aerobic sulfolane biodegradation rates by ~30%. Our study is the first to investigate the sulfolane biodegradation potential of subarctic aquifer substrate and identifies several important factors limiting biodegradation rates. We concluded that oxygen is an important factor limiting natural attenuation of this sulfolane plume, and that nutrient amendments are unlikely to accelerate biodegradation within in the plume, although they may biostimulate degradation in ex situ groundwater treatment applications. Future work should be directed at elucidating the identity of indigenous sulfolane-degrading microorganisms and determining their distribution and potential activity in the environment.

Factors limiting sulfolane biodegradation in contaminated subarctic aquifer substrate

PubMed Central

2017-01-01

Sulfolane, a water-soluble organosulfur compound, is used industrially worldwide and is associated with one of the largest contaminated groundwater plumes in the state of Alaska. Despite being widely used, little is understood about the degradation of sulfolane in the environment, especially in cold regions. We conducted aerobic and anaerobic microcosm studies to assess the biological and abiotic sulfolane degradation potential of contaminated subarctic aquifer groundwater and sediment from Interior Alaska. We also investigated the impacts of nutrient limitations and hydrocarbon co-contamination on sulfolane degradation. We found that sulfolane underwent biodegradation aerobically but not anaerobically under nitrate, sulfate, or iron-reducing conditions. No abiotic degradation activity was detectable under either oxic or anoxic conditions. Nutrient addition stimulated sulfolane biodegradation in sediment slurries at high sulfolane concentrations (100 mg L-1), but not at low sulfolane concentrations (500 μg L-1), and nutrient amendments were necessary to stimulate sulfolane biodegradation in incubations containing groundwater only. Hydrocarbon co-contamination retarded aerobic sulfolane biodegradation rates by ~30%. Our study is the first to investigate the sulfolane biodegradation potential of subarctic aquifer substrate and identifies several important factors limiting biodegradation rates. We concluded that oxygen is an important factor limiting natural attenuation of this sulfolane plume, and that nutrient amendments are unlikely to accelerate biodegradation within in the plume, although they may biostimulate degradation in ex situ groundwater treatment applications. Future work should be directed at elucidating the identity of indigenous sulfolane-degrading microorganisms and determining their distribution and potential activity in the environment. PMID:28727811

Food limitation and the recovery of sea otters following the 'Exxon Valdez' oil spill

USGS Publications Warehouse

Dean, Thomas A.; Bodkin, James L.; Fukuyama, Allan K.; Jewett, Stephen C.; Monson, Daniel H.; O'Clair, Charles E.; VanBlaricom, Glenn R.

2002-01-01

We examined the potential role of food limitation in constraining the recovery of sea otters Enhydra lutris in Prince William Sound, Alaska, following the 'Exxon Valdez' oil spill. The spill resulted in the removal of a large number of sea otters in 1989, and as of 1998, the portion of the population in the heavily oiled northern Knight Island region had not fully recovered. Between 1996 and 1998, prey consumption rate was higher and the condition of sea otters was better at northern Knight Island than in an unoiled area of the sound (Montague Island). Estimates of prey energy available per unit mass of sea otter were about 4 times higher at Knight than Montague Island, albeit not significantly different between the 2 areas. Over this same period, the number of sea otters remained constant at northern Knight Island but increased at Montague Island. These data suggest that food was at least as abundant at Knight than at Montague Island, and that recovery of sea otters via intrinsic population growth was limited by factors other than food. However, the availability of food, the prey consumption rate, and the condition of sea otters were all much lower at both Knight and Montague Islands than in areas newly occupied by sea otters where the population growth rate was near the theoretical maximum. It is possible that the relatively short supply of food (compared to areas where sea otter population growth rate was high) may have inhibited immigration or interacted with other factors (e.g. oil-induced mortality or predation) to restrict sea otter population growth. Nonetheless, these data suggest that impacts of anthropogenic disturbances on large, often food-limited vertebrate predators can persist in spite of the availability of food resources that are sufficient for intrinsic population growth.

Engine Performance and Knock Rating of Fuels for High-output Aircraft Engines

NASA Technical Reports Server (NTRS)

Rothbrock, A M; Biermann, Arnold E

1938-01-01

Data are presented to show the effects of inlet-air pressure, inlet-air temperature, and compression ratio on the maximum permissible performance obtained on a single-cylinder test engine with aircraft-engine fuels varying from a fuel of 87 octane number to one 100 octane number plus 1 ml of tetraethyl lead per gallon. The data were obtained on a 5-inch by 5.75-inch liquid-cooled engine operating at 2,500 r.p.m. The compression ratio was varied from 6.50 to 8.75. The inlet-air temperature was varied from 120 to 280 F. and the inlet-air pressure from 30 inches of mercury absolute to the highest permissible. The limiting factors for the increase in compression ratio and in inlet-air pressure was the occurrence of either audible or incipient knock. The data are correlated to show that, for any one fuel,there is a definite relationship between the limiting conditions of inlet-air temperature and density at any compression ratio. This relationship is dependent on the combustion-gas temperature and density relationship that causes knock. The report presents a suggested method of rating aircraft-engine fuels based on this relationship. It is concluded that aircraft-engine fuels cannot be satisfactorily rated by any single factor, such as octane number, highest useful compression ratio, or allowable boost pressure. The fuels should be rated by a curve that expresses the limitations of the fuel over a variety of engine conditions.

Strong climate and tectonic control on plagioclase weathering in granitic terrain

USGS Publications Warehouse

Rasmussen, C.; Brantley, S.; Richter, D.D.B.; Blum, A.; Dixon, J.; White, A.F.

2011-01-01

Investigations to understand linkages among climate, erosion and weathering are central to quantifying landscape evolution. We approach these linkages through synthesis of regolith data for granitic terrain compiled with respect to climate, geochemistry, and denudation rates for low sloping upland profiles. Focusing on Na as a proxy for plagioclase weathering, we quantified regolith Na depletion, Na mass loss, and the relative partitioning of denudation to physical and chemical contributions. The depth and magnitude of regolith Na depletion increased continuously with increasing water availability, except for locations with mean annual temperature <5??C that exhibited little Na depletion, and locations with physical erosion rates <20gm-2yr-1 that exhibited deep and complete regolith Na depletion. Surface Na depletion also tended to decrease with increasing physical erosion. Depth-integrated Na mass loss and regolith depth were both three orders of magnitude greater in the fully depleted, low erosion rate sites relative to other locations. These locations exhibited strong erosion-limitation of Na chemical weathering rates based on correlation of Na chemical weathering rate to total Na denudation. Sodium weathering rates in cool locations with positive annual water balance were strongly correlated to total Na denudation and precipitation, and exhibited an average apparent activation energy (Ea) of 69kJmol-1 Na. The remaining water-limited locations exhibited kinetic limitation of Na weathering rates with an Ea of 136kJmol-1 Na, roughly equivalent to the sum of laboratory measures of Ea and dissolution reaction enthalpy for albite. Water availability is suggested as the dominant factor limiting rate kinetics in the water-limited systems. Together, these data demonstrate marked transitions and nonlinearity in how climate and tectonics correlate to plagioclase chemical weathering and Na mass loss. ?? 2010 Elsevier B.V.

Constraint of the Astrophysical Al 26 g ( p , γ ) Si 27 Destruction Rate at Stellar Temperatures

DOE PAGES

Pain, S. D.; Bardayan, D. W.; Blackmon, J. C.; ...

2015-05-28

The Galactic 1.809-MeV γ-ray signature from the β decay of 26gAl is a dominant target of γ-ray astronomy, of which a significant component is understood to originate from massive stars. The 26gAl(p,γ) 27Si reaction is a major destruction pathway for 26gAl at stellar temperatures, but the reaction rate is poorly constrained due to uncertainties in the strengths of low-lying resonances in 27Si. The 26gAl (d,p) 27Al reaction has been employed in inverse kinematics to determine the spectroscopic factors, and hence resonance strengths, of proton resonances in 27Si via mirror symmetry. Finally, the strength of the 127-keV resonance is found tomore » be a factor of 4 higher than the previously adopted upper limit, and the upper limit for the 68-keV resonance has been reduced by an order of magnitude, considerably constraining the 26gAl destruction rate at stellar temperatures.« less

Prognostic indicators of outcomes in patients with lung metastases from differentiated thyroid carcinoma during long-term follow-up.

PubMed

Sohn, Seo Young; Kim, Hye In; Kim, Young Nam; Kim, Tae Hyuk; Kim, Sun Wook; Chung, Jae Hoon

2018-02-01

Distant metastases, although uncommon, represent maximum disease-related mortality in differentiated thyroid carcinoma (DTC). Lungs are the most frequent sites of metastases. We aimed to evaluate long-term outcomes and identify prognostic factors in metastatic DTC limited to the lungs. This retrospective study included 89 patients with DTC and metastases limited to the lungs, who were treated between 1996 and 2012 at Samsung Medical Center. Progression-free survival (PFS) and cancer-specific survival (CSS) rates were evaluated according to clinicopathologic factors. Cox regression analysis was used to identify independent factors associated with structural progressive disease (PD) and cancer-specific death. With a median follow-up of 84 months, the 5- and 10-year CSS rates were 78% and 73%, respectively. Older age at diagnosis (≥55 years), radioactive iodine (RAI) nonavidity, preoperative or late diagnosis of metastasis and macro-nodular metastasis (≥1 cm) were predictive of decreased PFS and CSS. Multivariate analysis identified older age (P = .002), RAI nonavidity (P = .045) and preoperative (P = .030) or late diagnosis (P = .026) as independent predictors of structural PD. RAI avidity was also independent predictor of cancer-specific death (P = .025). Patients with DTC and metastatic disease limited to the lungs had favourable long-term outcomes. Age, RAI avidity and timing of metastasis were found to be major factors for predicting prognosis. © 2017 John Wiley & Sons Ltd.

Inter-hospital variations in caesarean sections. A risk adjusted comparison in the Valencia public hospitals

PubMed Central

Librero, J.; Peiro, S.; Calderon, S. M.

2000-01-01

BACKGROUND—The aim of this study was to describe the variability in caesarean rates in the public hospitals in the Valencia Region, Spain, and to analyse the association between caesarean sections and clinical and extra-clinical factors.
METHODS—Analysis of data contained in the Minimum Basic Data Set (MBDS) compiled for all births in 11 public hospitals in Valencia during 1994-1995 (n=36 819). Bivariate and multivariate analyses were used to evaluate the association between caesarean section rates and specific risk factors. The multivariate model was used to construct predictions about caesarean rates for each hospital, for comparison with rates observed.
RESULTS—Caesarean rates were 17.6% (inter-hospital range: 14.7% to 25.0%), with ample variability between hospitals in the diagnosis of maternal-fetal risk factors (particularly dystocia and fetal distress), and the indication for caesarean in the presence of these factors. Multivariate analysis showed that maternal-fetal risk factors correlated strongly with caesarean section, although extra-clinical factors, such as the day of the week, also correlated positively. After adjusting for the risk factors, the inter-hospital variation in caesarean rates persisted.
CONCLUSIONS—Although certain limitations (imprecision of some diagnoses and information biases in the MBDS) make it impossible to establish unequivocal conclusions, results show a high degree of variability among hospitals when opting for caesarean section. This variability cannot be justified by differences in obstetric risks.


Keywords: hospital utilisation; medical practice variation; caesarean section; administrative databases PMID:10890876

Some growth factors stimulate cultured adult rabbit ventricular myocyte hypertrophy in the absence of mechanical loading

NASA Technical Reports Server (NTRS)

Decker, R. S.; Cook, M. G.; Behnke-Barclay, M.; Decker, M. L.

1995-01-01

Cultured adult rabbit cardiac myocytes treated with recombinant growth factors display enhanced rates of protein accumulation (ie, growth) in response to insulin and insulin-like growth factors (IGFs), but epidermal growth factor, acidic or basic fibroblast growth factor, and platelet-derived growth factor failed to increase contractile protein synthesis or growth of the heart cells. Insulin and IGF-1 increased growth rates by stimulating anabolic while simultaneously inhibiting catabolic pathways, whereas IGF-2 elevated growth modestly by apparently inhibiting lysosomal proteolysis. Neutralizing antibodies directed against either IGF-1 or IGF-2 or IGF binding protein 3 blocked protein accumulation. A monoclonal antibody directed against the IGF-1 receptor also inhibited changes in protein turnover provoked by recombinant human IGF-1 but not IGF-2. Of the other growth factors tested, only transforming growth factor-beta 1 increased the fractional rate of myosin heavy chain (MHC) synthesis, with beta-MHC synthesis being elevated and alpha-MHC synthesis being suppressed. However, the other growth factors were able to modestly stimulate the rate of DNA synthesis in this preparation. Bromodeoxyuridine labeling revealed that these growth factors increased DNA synthesis in myocytes and nonmyocytes alike, but the heart cells displayed neither karyokinesis or cytokinesis. In contrast, cocultures of cardiac myocytes and nonmyocytes and nonmyocyte-conditioned culture medium failed to enhance the rate of cardiac MHC synthesis or its accumulation, implying that quiescent heart cells do not respond to "conditioning" by cardiac nonmyocytes. These findings demonstrated that insulin and the IGFs promote passively loaded cultured adult rabbit heart cells to hypertrophy but suggest that other growth factors tested may be limited in this regard.

Cyclic voltammetry of fast conducting electrocatalytic films.

PubMed

Costentin, Cyrille; Savéant, Jean-Michel

2015-07-15

In the framework of contemporary energy challenges, cyclic voltammetry is a particularly useful tool for deciphering the kinetics of catalytic films. The case of fast conducting films is analyzed, whether conduction is of the ohmic type or proceeds through rapid electron hopping. The rate-limiting factors are then the diffusion of the substrate in solution and through the film as well as the catalytic reaction itself. The dimensionless combination of the characteristics of these factors allows reducing the number of actual parameters to a maximum of two. The kinetics of the system may then be fully analyzed with the help of a kinetic zone diagram. Observing the variations of the current-potential responses with operational parameters such as film thickness, the potential scan rate and substrate concentration allows a precise assessment of the interplay between these factors and of the values of the rate controlling factors. A series of thought experiments is described in order to render the kinetic analysis more palpable.

Assessing children's perceptions of academic interventions: The Kids Intervention Profile.

PubMed

Eckert, Tanya L; Hier, Bridget O; Hamsho, Narmene F; Malandrino, Rigby D

2017-06-01

The psychometric properties of the Kids Intervention Profile (KIP), a rating scale designed to measure academic intervention acceptability from the perspective of students, were examined as well as the influence of background factors on students' acceptability ratings. Data were extracted from 4 randomized controlled trials investigating the effects of a performance feedback intervention on third-grade students' writing fluency (n = 228). Results indicated that the KIP contains 2 factors (General Intervention Acceptability, Skill Improvement) and has adequate internal consistency and stability across a 3-week period. There were gender differences in students' acceptability ratings, with female students rating the intervention as significantly more acceptable than males. In addition, results suggested a modest, positive relationship between students' intervention acceptability ratings and their intervention outcomes. Considerations regarding the use of the KIP, as well as limitations of the study, are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The Limits of Natural Selection in a Nonequilibrium World.

PubMed

Brandvain, Yaniv; Wright, Stephen I

2016-04-01

Evolutionary theory predicts that factors such as a small population size or low recombination rate can limit the action of natural selection. The emerging field of comparative population genomics offers an opportunity to evaluate these hypotheses. However, classical theoretical predictions assume that populations are at demographic equilibrium. This assumption is likely to be violated in the very populations researchers use to evaluate selection's limits: populations that have experienced a recent shift in population size and/or effective recombination rates. Here we highlight theory and data analyses concerning limitations on the action of natural selection in nonequilibrial populations and argue that substantial care is needed to appropriately test whether species and populations show meaningful differences in selection efficacy. A move toward model-based inferences that explicitly incorporate nonequilibrium dynamics provides a promising approach to more accurately contrast selection efficacy across populations and interpret its significance. Copyright © 2016 Elsevier Ltd. All rights reserved.

Limited socioeconomic opportunities and Latina teen childbearing: a qualitative study of family and structural factors affecting future expectations.

PubMed

Minnis, Alexandra M; Marchi, Kristen; Ralph, Lauren; Biggs, M Antonia; Combellick, Sarah; Arons, Abigail; Brindis, Claire D; Braveman, Paula

2013-04-01

The decrease in adolescent birth rates in the United States has been slower among Latinas than among other ethnic/racial groups. Limited research has explored how socioeconomic opportunities influence childbearing among Latina adolescents. We conducted in-depth interviews with 65 pregnant foreign- and US-born Latina women (31 adolescents; 34 adults) in two California counties. We assessed perceived socioeconomic opportunities and examined how family, immigration and acculturation affected the relationships between socioeconomic opportunities and adolescent childbearing. Compared with women who delayed childbearing into adulthood, pregnant adolescents described having few resources for educational and career development and experiencing numerous socioeconomic and social barriers to achieving their goals. Socioeconomic instability and policies limiting access to education influenced childbearing for immigrant adolescents. In contrast, family disintegration tied to poverty figured prominently in US-born adolescents' childbearing. Limited socioeconomic opportunities may play a large role in persistently high pregnancy rates among Latina adolescents.

A comparative meta-analysis of maximal aerobic metabolism of vertebrates: implications for respiratory and cardiovascular limits to gas exchange.

PubMed

Hillman, Stanley S; Hancock, Thomas V; Hedrick, Michael S

2013-02-01

Maximal aerobic metabolic rates (MMR) in vertebrates are supported by increased conductive and diffusive fluxes of O(2) from the environment to the mitochondria necessitating concomitant increases in CO(2) efflux. A question that has received much attention has been which step, respiratory or cardiovascular, provides the principal rate limitation to gas flux at MMR? Limitation analyses have principally focused on O(2) fluxes, though the excess capacity of the lung for O(2) ventilation and diffusion remains unexplained except as a safety factor. Analyses of MMR normally rely upon allometry and temperature to define these factors, but cannot account for much of the variation and often have narrow phylogenetic breadth. The unique aspect of our comparative approach was to use an interclass meta-analysis to examine cardio-respiratory variables during the increase from resting metabolic rate to MMR among vertebrates from fish to mammals, independent of allometry and phylogeny. Common patterns at MMR indicate universal principles governing O(2) and CO(2) transport in vertebrate cardiovascular and respiratory systems, despite the varied modes of activities (swimming, running, flying), different cardio-respiratory architecture, and vastly different rates of metabolism (endothermy vs. ectothermy). Our meta-analysis supports previous studies indicating a cardiovascular limit to maximal O(2) transport and also implicates a respiratory system limit to maximal CO(2) efflux, especially in ectotherms. Thus, natural selection would operate on the respiratory system to enhance maximal CO(2) excretion and the cardiovascular system to enhance maximal O(2) uptake. This provides a possible evolutionary explanation for the conundrum of why the respiratory system appears functionally over-designed from an O(2) perspective, a unique insight from previous work focused solely on O(2) fluxes. The results suggest a common gas transport blueprint, or Bauplan, in the vertebrate clade.

Chemostat Studies of TCE-Dehalogenating Anaerobic Consortia under Excess and Limited Electron Donor Addition

NASA Astrophysics Data System (ADS)

Semprini, L.; Azizian, M.; Green, J.; Mayer-Blackwell, K.; Spormann, A. M.

2015-12-01

Two cultures - the Victoria Strain (VS) and the Evanite Strain (EV), enriched with the organohalide respiring bacteria Dehalococcoides mccartyi - were grown in chemostats for more than 4 years at a mean cell residence time of 50 days. The slow doubling rate represents growth likely experienced in the subsurface. The chemostats were fed formate as an electron donor and trichloroethene (TCE) as the terminal electron acceptor. Under excess formate conditions, stable operation was observed with respect to TCE transformation, steady-state hydrogen (H2) concentrations (40 nM), and the structure of the dehalogenating community. Both cultures completely transformed TCE to ethene, with minor amounts of vinyl chloride (VC) observed, along with acetate formation. When formate was limited, TCE was transformed incompletely to ethene (40-60%) and VC (60- 40%), and H2 concentrations ranged from 1 to 3 nM. The acetate concentration dropped below detection. Batch kinetic studies of TCE transformation with chemostat harvested cells found transformation rates of c-DCE and VC were greatly reduced when the cells were grown with limited formate. Upon increasing formate addition to the chemostats, from limited to excess, essentially complete transformation of TCE to ethene was achieved. The increase in formate was associated with an increase in H2 concentration and the production of acetate. Results of batch kinetic tests showed increases in transformation rates for TCE and c-DCE by factors of 3.5 and 2.5, respectively, while VC rates increased by factors of 33 to 500, over a six month period. Molecular analysis of chemostat samples is being performed to quantify the changes in copy numbers of reductase genes and to determine whether shifts in the strains of Dehalococcoides mccartyi where responsible for the observed rate increases. The results demonstrate the importance of electron donor supply for successful in-situ remediation.

Effect of outside air ventilation rate on VOC concentrations and emissions in a call center

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hodgson, A.T.; Faulkner, D.; Sullivan, D.P.

2002-01-01

A study of the relationship between outside air ventilation rate and concentrations of VOCs generated indoors was conducted in a call center. Ventilation rates were manipulated in the building's four air handling units (AHUs). Concentrations of VOCs in the AHU returns were measured on 7 days during a 13-week period. Indoor minus outdoor concentrations and emission factors were calculated. The emission factor data was subjected to principal component analysis to identify groups of co-varying compounds based on source type. One vector represented emissions of solvents from cleaning products. Another vector identified occupant sources. Direct relationships between ventilation rate and concentrationsmore » were not observed for most of the abundant VOCs. This result emphasizes the importance of source control measures for limiting VOC concentrations in buildings.« less

Hantavirus pulmonary syndrome in Argentina, 1995-2008.

PubMed

Martinez, Valeria P; Bellomo, Carla M; Cacace, Maria Luisa; Suarez, Paola; Bogni, Liliana; Padula, Paula J

2010-12-01

We report a large case series of hantavirus pulmonary syndrome (HPS) in Argentina that was confirmed by laboratory results from 1995 through 2008. The geographic and temporal distribution of cases by age, sex, fatality rate, and risk factors for HPS was analyzed. A total of 710 cases were unequally distributed among 4 of the 5 Argentine regions. Different case-fatality rates were observed for each affected region, with a maximum rate of 40.5%. The male-to-female ratio for HPS case-patients was 3.7:1.0; the case-fatality rate was significantly higher for women. Agriculture-associated activities were most commonly reported as potential risk factors, especially among men of working age. Although HPS cases occurred predominantly in isolation, we identified 15 clusters in which strong relationships were observed between members, which suggests ongoing but limited person-to-person transmission.

Replacing the CCSDS Telecommand Protocol with Next Generation Uplink

NASA Technical Reports Server (NTRS)

Kazz, Greg; Burleigh, Scott; Greenberg, Ed

2012-01-01

Better performing Forward Error Correction on the forward link along with adequate power in the data open an uplink operations trade space that enable missions to: Command to greater distances in deep space (increased uplink margin) Increase the size of the payload data (latency may be a factor) Provides space for the security header/trailer of the CCSDS Space Data Link Security Protocol Note: These higher rates could be used for relief of emergency communication margins/rates and not limited to improving top-end rate performance. A higher performance uplink could also reduce the requirements on flight emergency antenna size and/or the performance required from ground stations. Use of a selective repeat ARQ protocol may increase the uplink design requirements but the resultant development is deemed acceptable, due the factor of 4 to 8 potential increase in uplink data rate.

NAND Flash Qualification Guideline

NASA Technical Reports Server (NTRS)

Heidecker, Jason

2012-01-01

Better performing Forward Error Correction on the forward link along with adequate power in the data open an uplink operations trade space that enable missions to: Command to greater distances in deep space (increased uplink margin). Increase the size of the payload data (latency may be a factor). Provides space for the security header/trailer of the CCSDS Space Data Link Security Protocol. Note: These higher rates could be used for relief of emergency communication margins/rates and not limited to improving top-end rate performance. A higher performance uplink could also reduce the requirements on flight emergency antenna size and/or the performance required from ground stations. Use of a selective repeat ARQ protocol may increase the uplink design requirements but the resultant development is deemed acceptable, due the factor of 4 to 8 potential increase in uplink data rate.

Testing the control of mineral supply rates on chemical erosion in the Klamath Mountains

NASA Astrophysics Data System (ADS)

West, N.; Ferrier, K.

2017-12-01

The relationship between rates of chemical erosion and mineral supply is central to many problems in Earth science, including the role of tectonics in the global carbon cycle, nutrient supply to soils and streams via soil production, and lithologic controls on landscape evolution. We aim to test the relationship between mineral supply rates and chemical erosion in the forested uplands of the Klamath mountains, along a latitudinal transect of granodioritic plutons that spans an expected gradient in mineral supply rates associated with the geodynamic response to the migration of the Mendocino Triple Junction. We present 10Be-derived erosion rates and Zr-derived chemical depletion factors, as well as bulk soil and rock geochemistry on 10 ridgetops along the transect to test hypotheses about supply-limited and kinetically-limited chemical erosion. Previous studies in this area, comparing basin-averaged erosion rates and modeled uplift rates, suggest this region may be adjusted to an approximate steady state. Our preliminary results suggest that chemical erosion at these sites is influenced by both mineral supply rates and dissolution kinetics.

What is the impact of flexicurity on the chances of entry into employment for people with low education and activity limitations due to health problems? A comparison of 21 European countries using Qualitative Comparative Analysis (QCA).

PubMed

Backhans, Mona C; Mosedale, Sarah; Bruce, Daniel; Whitehead, Margaret; Burström, Bo

2016-08-19

Employment and unemployment are key determinants of health inequalities and should be a priority when discussing policies to reduce such inequalities. Our aim is to investigate how flexicurity policies across European countries impact on the employment chances for people with low education and activity limitations. The longitudinal EU-SILC dataset, pooled 2005-2010, was used to calculate labour market outcomes. The sample consisted of 25 countries and 19,881 individuals. The employment transitions of non-employed people with activity limitations was followed from one year to the next, and the outcomes were rates of return-to work (RTW) among those with low education, and relative equality of RTW between those with low and high education (rate ratio, RR). Data on flexicurity policy and labour market factors were accessed from Eurostat and the OECD. As policy data was only available for OECD countries, the sample was reduced to 21 countries. Fuzzy-set QCA (Qualitative Comparative Analysis) was used to examine how different combinations of the components of flexicurity were linked to the two outcomes. Where high rates of RTW were achieved, high employment rates were always present. In five countries (the Nordic countries and the Netherlands) these factors coexisted with high expenditure on active labour market policies and social services in old age. In three others (The Czech Republic, UK and Estonia) they were combined with low employment protection and low benefit expenditure. For equality in RTW, low unemployment rates were combined with either high benefit expenditure, or low employment protection. We found two routes that lead to high RTW: we characterise these as the high road and the low road. Taking the low road (relaxing employment protection and limiting benefits) may be a tempting option for poorly performing countries. However, without measures to stimulate female employment it may not be enough as high overall employment is so important in enabling people with activity limitations to access the labour market. To achieve equality in RTW, it seems that as long as unemployment is low, either flexibility or security is sufficient.

Rating educational quality: factors in the erosion of professional standards.

PubMed

Albanese, M

1999-06-01

Changes in the health care environment are putting increasing pressure on medical schools to make faculty accountable and to document the quality of the medical education they provide. Faculty's ratings of students' performances and students' ratings of faculty's teaching are important elements in these efforts to document educational quality. This article discusses selected research related to factors affecting raters' judgments, analyzes how changes in the health care environment are influencing such judgments, and links these influences to the system that upholds professional standards. Ratings are known to have a positive bias (generosity error), provide limited discrimination, and often fail to document serious deficits. The potential sources of these problems relate to the mechanics of the rating task, the system used to obtain ratings, and factors affecting rater judgment. As managed care demands reduce the time faculty have for teaching, as system-wide disincentives to provide negative ratings proliferate, and as social engineering challenges, such as the Americans with Disabilities Act, impose differential standards for students, the natural tendency to avoid giving negative ratings becomes even harder to resist. Ultimately, these forces compromise the capability of faculty to uphold the standards of the profession. The author calls for a national effort to stem the erosion of those standards.

Examining related influential factors for dental calculus scaling utilization among people with disabilities in Taiwan, a nationwide population-based study.

PubMed

Lai, Hsien-Tang; Kung, Pei-Tseng; Su, Hsun-Pi; Tsai, Wen-Chen

2014-09-01

Limited studies with large samples have been conducted on the utilization of dental calculus scaling among people with physical or mental disabilities. This study aimed to investigate the utilization of dental calculus scaling among the national disabled population. This study analyzed the utilization of dental calculus scaling among the disabled people, using the nationwide data between 2006 and 2008. Descriptive analysis and logistic regression were performed to analyze related influential factors for dental calculus scaling utilization. The dental calculus scaling utilization rate among people with physical or mental disabilities was 16.39%, and the annual utilization frequency was 0.2 times. Utilization rate was higher among the female and non-aboriginal samples. Utilization rate decreased with increased age and disability severity while utilization rate increased with income, education level, urbanization of residential area and number of chronic illnesses. Related influential factors for dental calculus scaling utilization rate were gender, age, ethnicity (aboriginal or non-aboriginal), education level, urbanization of residence area, income, catastrophic illnesses, chronic illnesses, disability types, and disability severity significantly influenced the dental calculus scaling utilization rate. Copyright © 2014 Elsevier Ltd. All rights reserved.

Seizures and Epilepsy in Alzheimer’s Disease

PubMed Central

Friedman, Daniel; Honig, Lawrence S.; Scarmeas, Nikolaos

2013-01-01

Introduction Many studies have shown that patients with Alzheimer’s disease (AD) are at increased risk for developing seizures and epilepsy. However, reported prevalence and incidence of seizures and relationship of seizures to disease measures such as severity, outcome and progression vary widely between studies. Methods Literature review of the available clinical and epidemiological data on the topic of seizures in patients with AD. We review seizure rates and types, risk factors for seizures, electroencephalogram (EEG)studies, and treatment responses. Finally, we consider limitations and methodological issues. Results There is considerable variability in the reported prevalence and incidence of seizures in patients with AD - with reported lifetime prevalence rates of 1.5 - 64%. More recent, prospective, and larger studies in general report lower rates. Some, but not all, studies have noted increased seizure risk with increasing dementia severity or with younger age of AD onset. Generalized convulsive seizures are the most commonly reported type, but often historical information is the only basis used to determine seizure type and the manifestation of seizures may be difficult to distinguish from other behaviors common in demented patients. EEG has infrequently been performed and reported. Data on treatment of seizures in AD are extremely limited. Similarly, the relationship between seizures and cognitive impairment in AD is unclear. Conclusions The literature on seizures and epilepsy in AD, including diagnosis, risk factors, and response to treatment suffers from methodological limitations and gaps. PMID:22070283

Coping Resources and Self-Rated Health among Latina Breast Cancer Survivors

PubMed Central

Nápoles, Anna M.; Ortíz, Carmen; O’Brien, Helen; Sereno, Andrea B.; Kaplan, Celia P.

2013-01-01

Purpose/Objectives To examine relationships between coping resources and self-rated health among Latina breast cancer survivors (BCS). Design Cross-sectional telephone survey. Setting Four Northern California counties. Sample 330 Latina BCS within 1–5 years of diagnosis. Methods Telephone survey conducted by bilingual-bicultural interviewers. Main Research Variables Predictors were sociodemographic and clinical factors, cancer self-efficacy (adapted Cancer Behavior Inventory-B, ver. 2), spirituality (Functional Assessment of Cancer Therapy Quality of Life Measurement System Spiritual Well-being Scale, ver. 4) social support from family/friends and oncologists (adapted Helgeson’s Social Support Scales). Outcomes were functional limitations and self-rated health. Findings Mean age was 58 years; 70% were Mexican; and most had ≤ a high school education. About 60% had a mastectomy; about 90% were within 2–3 years of diagnosis. Approximately one-fourth of women reported functional limitations (73; 22.1%) and poor/fair self-rated health (89; 27%). Unemployment (AOR=7.06; 95% CI 2.04, 24.46), mastectomy (AOR=2.67; 95% CI 1.06, 6.77), and comorbidity (AOR=4.09; 95% CI 1.69, 9.89) were associated with higher risk of functional limitations; cancer self-efficacy had a protective effect (AOR=0.40, 95% CI 0.18, 0.90). Comorbidity was associated with higher risk of poor/fair self-rated health (AOR=4.95; 95% CI 2.13, 11.47); cancer self-efficacy had a protective effect (AOR=0.30; 95% CI 0.13, 0.66). Conclusions Comorbidity places Latina BCS at increased risk of poor health. Cancer self-efficacy deserves more attention as a potentially modifiable protective factor. Implications for Nursing Practice Nurses need to assess the impact of comorbidity on functioning and can reinforce a sense of clinician support and control over cancer. PMID:21875840

Model-independent analysis of semileptonic B decays to D** for arbitrary new physics

NASA Astrophysics Data System (ADS)

Bernlochner, Florian U.; Ligeti, Zoltan; Robinson, Dean J.

2018-04-01

We explore semileptonic B decays to the four lightest excited charm mesons, D**={D0*,D1* ,D1 ,D2*} , for nonzero charged lepton mass and for all b →c ℓν ¯ four-Fermi interactions, including calculation of the O (ΛQCD/mc ,b) and O (αs) corrections to the heavy quark limit for all form factors. In the heavy quark limit, some form factors are suppressed at zero recoil; therefore, the O (ΛQCD/mc ,b) corrections can be very important. The D** rates exhibit sensitivities to new physics in b →c τ ν ¯ mediated decays complementary to the D and D* modes. Since they are also important backgrounds to B →D(*)τ ν ¯, the correct interpretation of future semitauonic B →D(*) rate measurements requires consistent treatment of both the D** backgrounds and the signals. Our results allow more precise and more reliable calculations of these B →D**ℓν ¯ decays and are systematically improvable by better data on the e and μ modes. As an example, we show that the D** rates are more sensitive to a new c ¯ σμ νb tensor interaction than the D(*) rates.

Cellobionic acid inhibition of cellobiohydrolase I and cellobiose dehydrogenase

USDA-ARS?s Scientific Manuscript database

End-product inhibition by cellobiose and glucose is a rate-limiting factor in cellulose hydrolysis by cellulases. While cellobiose and glucose inhibition have been extensively investigated, cellobionate inhibition has been minimally studied despite the discovery that accessory proteins such as cello...

Ecological factors associated with pandemic influenza A (H1N1) hospitalization rates in California, USA: a geospatial analysis.

PubMed

Maliszewski, Paul J; Wei, Ran

2011-11-01

The 2009 H1N1 influenza A virus subtype (H1N1) pandemic had a large impact in the United States of America (USA), causing an estimated 192,000 to 398,000 hospitalizations and 8,720 to 18,050 deaths between April 2009 and mid-March 2010. Recent research on the 2009 H1N1 pandemic has largely focused on individual, non-spatial demographic characterizations (e.g. age and race/ethnicity) associated with H1N1 hospitalizations. Broader ecological factors such as transportation use, land use and other socioeconomic factors are important aspects of influenza studies that have not been empirically examined. This research explores and identifies ecological factors associated with 2009 H1N1 pandemic hospitalization rates. We conducted a spatial regression analysis of county level hospitalization rates from 3 April to 15 September, 2009 obtained via the California Department of Public Health. Hospitalization rates were found to be spatially dependent. Public transportation usage rates and agricultural land use proportions were significant environmental factors positively related to hospitalization rates. Consistent with public health official's assumptions and existing evidence, county percentages of persons less than 18 years of age were positively associated with hospitalization. These findings help to clarify the limited consensus and dubious evidence on the role of broader ecological factors associated with pandemic influenza. A better understanding of the ecological risk factors associated with hospitalizations should also benefit public health officials with respect to their work aiming at improving emergency supply allocation and non-pharmaceutical intervention strategies in the context of an influenza pandemic.

Gaming in risk-adjusted mortality rates: effect of misclassification of risk factors in the benchmarking of cardiac surgery risk-adjusted mortality rates.

PubMed

Siregar, Sabrina; Groenwold, Rolf H H; Versteegh, Michel I M; Noyez, Luc; ter Burg, Willem Jan P P; Bots, Michiel L; van der Graaf, Yolanda; van Herwerden, Lex A

2013-03-01

Upcoding or undercoding of risk factors could affect the benchmarking of risk-adjusted mortality rates. The aim was to investigate the effect of misclassification of risk factors on the benchmarking of mortality rates after cardiac surgery. A prospective cohort was used comprising all adult cardiac surgery patients in all 16 cardiothoracic centers in The Netherlands from January 1, 2007, to December 31, 2009. A random effects model, including the logistic European system for cardiac operative risk evaluation (EuroSCORE) was used to benchmark the in-hospital mortality rates. We simulated upcoding and undercoding of 5 selected variables in the patients from 1 center. These patients were selected randomly (nondifferential misclassification) or by the EuroSCORE (differential misclassification). In the random patients, substantial misclassification was required to affect benchmarking: a 1.8-fold increase in prevalence of the 4 risk factors changed an underperforming center into an average performing one. Upcoding of 1 variable required even more. When patients with the greatest EuroSCORE were upcoded (ie, differential misclassification), a 1.1-fold increase was sufficient: moderate left ventricular function from 14.2% to 15.7%, poor left ventricular function from 8.4% to 9.3%, recent myocardial infarction from 7.9% to 8.6%, and extracardiac arteriopathy from 9.0% to 9.8%. Benchmarking using risk-adjusted mortality rates can be manipulated by misclassification of the EuroSCORE risk factors. Misclassification of random patients or of single variables will have little effect. However, limited upcoding of multiple risk factors in high-risk patients can greatly influence benchmarking. To minimize "gaming," the prevalence of all risk factors should be carefully monitored. Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Disentangling immigrant status in mental health: psychological protective and risk factors among Latino and Asian American immigrants.

PubMed

Leong, Frederick; Park, Yong S; Kalibatseva, Zornitsa

2013-01-01

This study aimed to disentangle the psychological mechanisms underlying immigrant status by testing a model of psychological protective and risk factors to predict the mental health prevalence rates among Latino and Asian American immigrants based on secondary analysis of the National Latino and Asian American Study. The first research question examined differences on the set of protective and risk factors between immigrants and their U.S.-born counterparts and found that immigrants reported higher levels of ethnic identity, family cohesion, native language proficiency, and limited English proficiency than their U.S.-born counterparts. The second research question examined the effect of the protective and risk factors on prevalence rates of depressive, anxiety, and substance-related disorders and found that social networking served as a protective factor. Discrimination, acculturative stress, and family conflict were risk factors on the mental health for both ethnic groups. Clinical implications and directions for future research are provided. © 2013 American Orthopsychiatric Association.

Determining the Limiting Factors Controlling Soil Ecosystem Regeneration After a Stand-replacing Wildfire

NASA Astrophysics Data System (ADS)

Cooperdock, S.; Breecker, D.

2016-12-01

Like all forest disturbances, wildfires remove vegetation but additionally they can remove or transform soil nutrients through volatilization due to extreme temperatures. As the stability and nutrient source for plants, soils are the key to forest regeneration after disturbances and in order to predict and mitigate damage, it is essential to understand how soils are affected by fires. In this study, soil respiration and temperature were measured in-situ at 20 sites affected by two fires that occurred during September 2011 and October 2015 in Bastrop County TX. At each site, soil samples were collected from 0-5 cm depth. These samples were incubated in the dark at 25° C and 22% water content to determine respiration rates under controlled environmental conditions. Total C, N, trace element concentrations and pH were measured in each soil sample to determine the effect of fire on soil chemistry and the effect of soil chemistry on soil activity. These methods of respiration measurement were performed to distinguish the impact of environmental and chemical factors on soil biological activity. Results show that from May to July 2016, soil temperatures increased an average of 6° C and 1° C more in burned areas than in unburned areas at depths of 5 cm and 15 cm, respectively. This likely results from fire-induced decrease in overstory cover, decrease in organic matter insulation and darkening soil color. Increasing temperatures correspond with a decrease in water content and respiration. Pearson's tests of the effect of soil moisture loss on a decrease of in-situ respiration rate show a correlation for burned soils, especially at sites burned in both fires (rho=0.90, p=0.04) and no correlation for unburned soils, suggesting a larger impact of environmental factors on soil activity in burned soils. Microcosm experiments show N concentration significantly affects respiration rate in unburned plots (rho=0.89, p=0.04) and both N (rho=0.92, p=0.03) and C concentration (rho=0.92, p=0.03) affect respiration rate in plots burned in 2011. No correlation was detected between nutrient concentration and respiration rate in recently burned plots, suggesting a larger influence of nutrient limitation on regeneration as time since burn increases. These results reveal that the limiting factors governing soil activity shift after wildfires.

Development of an Advanced Respirometer for Experimental Studies of Benthic Rate Processes

NASA Astrophysics Data System (ADS)

Barry, J. P.; Buck, K. R.; Okuda, C.; Risi, M.; Parker, M.; Levesque, C.

2005-05-01

Rates of carbon remineralization and nutrient cycling by seafloor biotic assemblages are influenced by the availability of organic material, temperature, and oxygen availability, among other factors. The relative importance of various factors in controlling carbon cycling by the sediment community is poorly constrained, in part by technological limits on experiments that evaluate independently the effects of these factors. We have developed an advanced respiration chamber system capable of repeated rate measurements during a single deployment, with added capabilities for manipulating conditions within replicate chambers to test hypotheses concerning biogeochemical cycling by the benthos. The ROV-deployed respiration system has 12 syringes for tracer injection or sample withdrawal from 3 respiration chambers, pH, oxygen, and temperature sensors, stirring paddles, and a recirculation pump. The pump system is used to flush each chamber at preprogrammed intervals or oxygen tensions. Areas of investigation that are enabled by the system include the effects various factors on benthic oxygen consumptions (e.g. hypercapnia (elevated CO2), acidosis, ambient oxygen availability, temperature, organic carbon availability), rates of nutrient regeneration by the benthos in response to organic enrichments (labile and refractory organic carbon), time lags in carbon uptake and trophic pathways in responses to organic enrichment.

Diarrhoea in a large prospective cohort of European travellers to resource-limited destinations

PubMed Central

2010-01-01

Background Incidence rates of travellers' diarrhoea (TD) need to be updated and risk factors are insufficiently known. Methods Between July 2006 and January 2008 adult customers of our Centre for Travel Health travelling to a resource-limited country for the duration of 1 to 8 weeks were invited to participate in a prospective cohort study. They received one questionnaire pre-travel and a second one immediately post-travel. First two-week incidence rates were calculated for TD episodes and a risk assessment was made including demographic and travel-related variables, medical history and behavioural factors. Results Among the 3100 persons recruited, 2800 could be investigated, resulting in a participation rate of 89.2%. The first two-weeks incidence for classic TD was 26.2% (95%CI 24.5-27.8). The highest rates were found for Central Africa (29.6%, 95% CI 12.4-46.8), the Indian subcontinent (26.3%, 95%CI 2.3-30.2) and West Africa (21.5%, 95%CI 14.9-28.1). Median TD duration was 2 days (range 1-90). The majority treated TD with loperamide (57.6%), while a small proportion used probiotics (23.0%) and antibiotics (6.8%). Multiple logistic regression analysis on any TD to determine risk factors showed that a resolved diarrhoeal episode experienced in the 4 months pre-travel (OR 2.03, 95%CI 1.59-2.54), antidepressive comedication (OR 2.11, 95%CI 1.17-3.80), allergic asthma (OR 1.67, 95%CI 1.10-2.54), and reporting TD-independent fever (OR 6.56, 95%CI 3.06-14.04) were the most prominent risk factors of TD. Conclusions TD remains a frequent travel disease, but there is a decreasing trend in the incidence rate. Patients with a history of allergic asthma, pre-travel diarrhoea, or of TD-independent fever were more likely to develop TD while abroad. PMID:20684768

Metabolic rate does not calibrate the molecular clock

PubMed Central

Lanfear, Robert; Thomas, Jessica A.; Welch, John J.; Brey, Thomas; Bromham, Lindell

2007-01-01

Rates of molecular evolution vary widely among lineages, but the causes of this variation remain poorly understood. It has been suggested that mass-specific metabolic rate may be one of the key factors determining the rate of molecular evolution, and that it can be used to derive “corrected” molecular clocks. However, previous studies have been hampered by a paucity of mass-specific metabolic rate data and have been largely limited to vertebrate taxa. Using mass-specific metabolic rate measurements and DNA sequence data for >300 metazoan species for 12 different genes, we find no evidence that mass-specific metabolic rate drives substitution rates. The mechanistic basis of the metabolic rate hypothesis is discussed in light of these findings. PMID:17881572

Niche filling slows the diversification of Himalayan songbirds.

PubMed

Price, Trevor D; Hooper, Daniel M; Buchanan, Caitlyn D; Johansson, Ulf S; Tietze, D Thomas; Alström, Per; Olsson, Urban; Ghosh-Harihar, Mousumi; Ishtiaq, Farah; Gupta, Sandeep K; Martens, Jochen; Harr, Bettina; Singh, Pratap; Mohan, Dhananjai

2014-05-08

Speciation generally involves a three-step process--range expansion, range fragmentation and the development of reproductive isolation between spatially separated populations. Speciation relies on cycling through these three steps and each may limit the rate at which new species form. We estimate phylogenetic relationships among all Himalayan songbirds to ask whether the development of reproductive isolation and ecological competition, both factors that limit range expansions, set an ultimate limit on speciation. Based on a phylogeny for all 358 species distributed along the eastern elevational gradient, here we show that body size and shape differences evolved early in the radiation, with the elevational band occupied by a species evolving later. These results are consistent with competition for niche space limiting species accumulation. Even the elevation dimension seems to be approaching ecological saturation, because the closest relatives both inside the assemblage and elsewhere in the Himalayas are on average separated by more than five million years, which is longer than it generally takes for reproductive isolation to be completed; also, elevational distributions are well explained by resource availability, notably the abundance of arthropods, and not by differences in diversification rates in different elevational zones. Our results imply that speciation rate is ultimately set by niche filling (that is, ecological competition for resources), rather than by the rate of acquisition of reproductive isolation.

The desorptivity model of bulk soil-water evaporation

NASA Technical Reports Server (NTRS)

Clapp, R. B.

1983-01-01

Available models of bulk evaporation from a bare-surfaced soil are difficult to apply to field conditions where evaporation is complicated by two main factors: rate-limiting climatic conditions and redistribution of soil moisture following infiltration. Both factors are included in the "desorptivity model', wherein the evaporation rate during the second stage (the soil-limiting stage) of evaporation is related to the desorptivity parameter, A. Analytical approximations for A are presented. The approximations are independent of the surface soil moisture. However, calculations using the approximations indicate that both soil texture and soil moisture content at depth significantly affect A. Because the moisture content at depth decreases in time during redistribution, it follows that the A parameter also changes with time. Consequently, a method to calculate a representative value of A was developed. When applied to field data, the desorptivity model estimated cumulative evaporation well. The model is easy to calculate, but its usefulness is limited because it requires an independent estimate of the time of transition between the first and second stages of evaporation. The model shows that bulk evaporation after the transition to the second stage is largely independent of climatic conditions.

Hypoxia-inducible factor-targeting prodrug TOP3 combined with gemcitabine or TS-1 improves pancreatic cancer survival in an orthotopic model.

PubMed

Hoang, Ngoc Thi Hong; Kadonosono, Tetsuya; Kuchimaru, Takahiro; Kizaka-Kondoh, Shinae

2016-08-01

Pancreatic cancer is one of the most lethal digestive system cancers with a 5-year survival rate of 4-7%. Despite extensive efforts, recent chemotherapeutic regimens have provided only limited benefits to pancreatic cancer patients. Gemcitabine and TS-1, the current standard-of-care chemotherapeutic drugs for treatment of this severe cancer, have a low response rate. Hypoxia is one of the factors contributing to treatment resistance. Specifically, overexpression of hypoxia-inducible factor, a master transcriptional regulator of cell adaption to hypoxia, is strongly correlated with poor prognosis in many human cancers. TAT-ODD-procaspase-3 (TOP3) is a protein prodrug that is specifically processed and activated in hypoxia-inducible factor-active cells in cancers, leading to cell death. Here, we report combination therapies in which TOP3 was combined with gemcitabine or TS-1. As monotherapy, gemcitabine and TS-1 showed a limited effect on hypoxic and starved pancreatic cancer cells, whereas co-treatment with TOP3 successfully overcame this limitation in vitro. Furthermore, combination therapies of TOP3 with these drugs resulted in a significant improvement in survival of orthotopic pancreatic cancer models involving the human pancreatic cancer cell line SUIT-2. Overall, our study indicates that the combination of TOP3 with current chemotherapeutic drugs can significantly improve treatment outcome, offering a promising new therapeutic option for patients with pancreatic cancer. © 2016 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Photosynthetic induction and its diffusional, carboxylation and electron transport processes as affected by CO2 partial pressure, temperature, air humidity and blue irradiance.

PubMed

Kaiser, Elias; Kromdijk, Johannes; Harbinson, Jeremy; Heuvelink, Ep; Marcelis, Leo F M

2017-01-01

Plants depend on photosynthesis for growth. In nature, factors such as temperature, humidity, CO 2 partial pressure, and spectrum and intensity of irradiance often fluctuate. Whereas irradiance intensity is most influential and has been studied in detail, understanding of interactions with other factors is lacking. We tested how photosynthetic induction after dark-light transitions was affected by CO 2 partial pressure (20, 40, 80 Pa), leaf temperatures (15·5, 22·8, 30·5 °C), leaf-to-air vapour pressure deficits (VPD leaf-air ; 0·5, 0·8, 1·6, 2·3 kPa) and blue irradiance (0-20 %) in tomato leaves (Solanum lycopersicum). Rates of photosynthetic induction strongly increased with CO 2 partial pressure, due to increased apparent Rubisco activation rates and reduced diffusional limitations. High leaf temperature produced slightly higher induction rates, and increased intrinsic water use efficiency and diffusional limitation. High VPD leaf-air slowed down induction rates and apparent Rubisco activation and (at 2·3 kPa) induced damped stomatal oscillations. Blue irradiance had no effect. Slower apparent Rubisco activation in elevated VPD leaf-air may be explained by low leaf internal CO 2 partial pressure at the beginning of induction. The environmental factors CO 2 partial pressure, temperature and VPD leaf-air had significant impacts on rates of photosynthetic induction, as well as on underlying diffusional, carboxylation and electron transport processes. Furthermore, maximizing Rubisco activation rates would increase photosynthesis by at most 6-8 % in ambient CO 2 partial pressure (across temperatures and humidities), while maximizing rates of stomatal opening would increase photosynthesis by at most 1-3 %. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Autophagy: not good OR bad, but good AND bad.

PubMed

Altman, Brian J; Rathmell, Jeffrey C

2009-05-01

Autophagy is a well-established mechanism to degrade intracellular components and provide a nutrient source to promote survival of cells in metabolic distress. Such stress can be caused by a lack of available nutrients or by insufficient rates of nutrient uptake. Indeed, growth factor deprivation leads to internalization and degradation of nutrient transporters, leaving cells with limited means to access extracellular nutrients even when plentiful.This loss of growth factor signaling and extracellular nutrients ultimately leads to apoptosis, but also activates autophagy, which may degrade intracellular components and provide fuel for mitochondrial bioenergetics. The precise metabolic role of autophagy and how it intersects with the apoptotic pathways in growth factor withdrawal, however, has been uncertain. Our recent findings ingrowth factor-deprived hematopoietic cells show that autophagy can simultaneously contribute to cell metabolism and initiate a pathway to sensitize cells to apoptotic death. This pathway may promote tissue homeostasis by ensuring that only cells with high resistance to apoptosis may utilize autophagy as a survival mechanism when growth factors are limiting and nutrient uptake decreases.

Hyperkalemia and Hypokalemia in CKD: Prevalence, Risk Factors, and Clinical Outcomes.

PubMed

Gilligan, Sarah; Raphael, Kalani L

2017-09-01

Abnormalities of serum potassium are common in patients with CKD. Although hyperkalemia is a well-recognized complication of CKD, the prevalence rates of hyperkalemia (14%-20%) and hypokalemia (12%-18%) are similar. CKD severity, use of medications such as renin-angiotensin-aldosterone system inhibitors and diuretics, and dietary potassium intake are major determinants of serum potassium concentration in CKD. Demographic factors, acid-base status, blood glucose, and other comorbidities contribute as well. Both hyperkalemia and hypokalemia are associated with similarly increased risks of death, cardiovascular disease, and hospitalization. On the other hand, limited evidence suggests a link between hypokalemia, but not hyperkalemia, and progression of CKD. This article reviews the prevalence rates and risk factors for hyperkalemia and hypokalemia, and their associations with adverse outcomes in CKD. Published by Elsevier Inc.

Hantavirus Pulmonary Syndrome in Argentina, 1995–2008

PubMed Central

Bellomo, Carla M.; Cacace, María Luisa; Suárez, Paola; Bogni, Liliana; Padula, Paula J.

2010-01-01

We report a large case series of hantavirus pulmonary syndrome (HPS) in Argentina that was confirmed by laboratory restuls from 1995 through 2008. The geographic and temporal distribution of cases by age, sex, fatality rate, and risk factors for HPS was analyzed. A total of 710 cases were unequally distributed among 4 of the 5 Argentine regions. Different case-fatality rates were observed for each affected region, with a maximum rate of 40.5%. The male-to-female ratio for HPS case-patients was 3.7:1.0; the case-fatality rate was significantly higher for women. Agriculture-associated activities were most commonly reported as potential risk factors, especially among men of working age. Although HPS cases occurred predominantly in isolation, we identified 15 clusters in which strong relationships were observed between members, which suggests ongoing but limited person-to-person transmission. PMID:21122213

Fatigue life and crack growth prediction methodology

NASA Technical Reports Server (NTRS)

Newman, J. C., Jr.; Phillips, E. P.; Everett, R. A., Jr.

1993-01-01

The capabilities of a plasticity-induced crack-closure model and life-prediction code to predict fatigue crack growth and fatigue lives of metallic materials are reviewed. Crack-tip constraint factors, to account for three-dimensional effects, were selected to correlate large-crack growth rate data as a function of the effective-stress-intensity factor range (delta(K(sub eff))) under constant-amplitude loading. Some modifications to the delta(K(sub eff))-rate relations were needed in the near threshold regime to fit small-crack growth rate behavior and endurance limits. The model was then used to calculate small- and large-crack growth rates, and in some cases total fatigue lives, for several aluminum and titanium alloys under constant-amplitude, variable-amplitude, and spectrum loading. Fatigue lives were calculated using the crack growth relations and microstructural features like those that initiated cracks. Results from the tests and analyses agreed well.

Recent developments in computer modeling add ecological realism to landscape genetics

EPA Science Inventory

Background / Question / Methods A factor limiting the rate of progress in landscape genetics has been the shortage of spatial models capable of linking life history attributes such as dispersal behavior to complex dynamic landscape features. The recent development of new models...

Biomass of active microorganisms is not limited only by available carbon in the rhizosphere

NASA Astrophysics Data System (ADS)

Gilmullina, Aliia

2017-04-01

Microbial activity is generally limited by carbon (C) availability. The easily available substrate release by roots creates so called "hotspots" in the rhizosphere that drives microbial activity removing C limitation. We simulated a gradient of root exudates by glucose addition at different concentrations to stimulate the activation of microbial biomass (MB). Glucose was added at the rates lower than MB (5, 10, 25 and 50%) and at the rates similar or higher than MB (100, 150, 200, 250, 300 and 400%). During incubation CO2 efflux was measured by conductometry, the size of active MB and specific growth rate were estimated by substrate-induced growth response method. We tested a hypothesis that glucose addition exceeding 100% MB is able to activate major fraction of soil microbial community. Addition of glucose at concentrations higher than 5% decreased specific growth rate, demonstrating the shift of microbial community from r-strategy to K-strategy. The percentage of active MB grew up by the increase of glucose concentration. The treatment with glucose at 100% presented a dramatic shift in the activation of MB up to 14%. Contrary to our hypothesis, further increase in glucose rate caused moderate stimulation of active MB up to 22% of total MB. Furthermore, glucose addition above 200% did not increase the fraction of active biomass indicating glucose oversaturation and possible limitation by other nutrients. The results suggest that despite the fact that C is the most important limitation factor, limitless C supply is not able to activate MB up to 100%. Thus, if the rhizosphere is limited by nutrients, the fraction of active biomass remains at low level despite an excess of available C.

Defining the Status of RNA Polymerase at Promoters

PubMed Central

Core, Leighton J.; Waterfall, Joshua J.; Gilchrist, Daniel A.; Fargo, David C.; Kwak, Hojoong; Adelman, Karen; Lis, John T.

2012-01-01

Summary Recent genome-wide studies in metazoans have shown that RNA Polymerase II (Pol II) accumulates to high densities on many promoters at a rate-limited step in transcription. However, the status of this Pol II remains an area of debate. Here, we compare quantitative outputs of GRO-seq and ChIP-seq assays and demonstrate the majority of the Pol II on Drosophila promoters is transcriptionally-engaged - very little exists in a preinitiation or arrested complex. These promoter-proximal polymerases are inhibited from further elongation by detergent sensitive factors, and knockdown of negative elongation factor, NELF, reduces their levels. These results not only solidify that pausing occurs at most promoters, but demonstrate that it is the major rate-limiting step in early transcription at these promoters. Finally, the divergent elongation complexes seen at mammalian promoters are far less prevalent in Drosophila, and this specificity in orientation correlates with directional core promoter elements, which are abundant in Drosophila. PMID:23062713

Analogous nutrient limitations in unicellular diazotrophs and Prochlorococcus in the South Pacific Ocean.

PubMed

Moisander, Pia H; Zhang, Ruifeng; Boyle, Edward A; Hewson, Ian; Montoya, Joseph P; Zehr, Jonathan P

2012-04-01

Growth limitation of phytoplankton and unicellular nitrogen (N(2)) fixers (diazotrophs) were investigated in the oligotrophic Western South Pacific Ocean. Based on change in abundances of nifH or 23S rRNA gene copies during nutrient-enrichment experiments, the factors limiting net growth of the unicellular diazotrophs UCYN-A (Group A), Crocosphaera watsonii, γ-Proteobacterium 24774A11, and the non-diazotrophic picocyanobacterium Prochlorococcus, varied within the region. At the westernmost stations, numbers were enhanced by organic carbon added as simple sugars, a combination of iron and an organic chelator, or iron added with phosphate. At stations nearest the equator, the nutrient-limiting growth was not apparent. Maximum net growth rates for UCYN-A, C. watsonii and γ-24774A11 were 0.19, 0.61 and 0.52 d(-1), respectively, which are the first known empirical growth rates reported for the uncultivated UCYN-A and the γ-24774A11. The addition of N enhanced total phytoplankton biomass up to 5-fold, and the non-N(2)-fixing Synechococcus was among the groups that responded favorably to N addition. Nitrogen was the major nutrient-limiting phytoplankton biomass in the Western South Pacific Ocean, while availability of organic carbon or iron and organic chelator appear to limit abundances of unicellular diazotrophs. Lack of phytoplankton response to nutrient additions in the Pacific warm pool waters suggests diazotroph growth in this area is controlled by different factors than in the higher latitudes, which may partially explain previously observed variability in community composition in the region.

Finding the Perfect Match: Factors That Influence Family Medicine Residency Selection.

PubMed

Wright, Katherine M; Ryan, Elizabeth R; Gatta, John L; Anderson, Lauren; Clements, Deborah S

2016-04-01

Residency program selection is a significant experience for emerging physicians, yet there is limited information about how applicants narrow their list of potential programs. This study examines factors that influence residency program selection among medical students interested in family medicine at the time of application. Medical students with an expressed interest in family medicine were invited to participate in a 37-item, online survey. Students were asked to rate factors that may impact residency selection on a 6-point Likert scale in addition to three open-ended qualitative questions. Mean values were calculated for each survey item and were used to determine a rank order for selection criteria. Logistic regression analysis was performed to identify factors that predict a strong interest in urban, suburban, and rural residency programs. Logistic regression was also used to identify factors that predict a strong interest in academic health center-based residencies, community-based residencies, and community-based residencies with an academic affiliation. A total of 705 medical students from 32 states across the country completed the survey. Location, work/life balance, and program structure (curriculum, schedule) were rated the most important factors for residency selection. Logistic regression analysis was used to refine our understanding of how each factor relates to specific types of residencies. These findings have implications for how to best advise students in selecting a residency, as well as marketing residencies to the right candidates. Refining the recruitment process will ensure a better fit between applicants and potential programs. Limited recruitment resources may be better utilized by focusing on targeted dissemination strategies.

Incidence and risk factors for relapses in HIV-associated non-Hodgkin lymphoma as observed in the German HIV-related lymphoma cohort study.

PubMed

Schommers, Philipp; Gillor, Daniel; Hentrich, Marcus; Wyen, Christoph; Wolf, Timo; Oette, Mark; Zoufaly, Alexander; Wasmuth, Jan-Christian; Bogner, Johannes R; Müller, Markus; Esser, Stefan; Schleicher, Alisa; Jensen, Björn; Stoehr, Albrecht; Behrens, Georg; Schultze, Alexander; Siehl, Jan; Thoden, Jan; Taylor, Ninon; Hoffmann, Christian

2018-05-01

Outcome of HIV-infected patients with AIDS-related lymphomas has improved during recent years. However, data on incidence, risk factors, and outcome of relapses in AIDS-related lymphomas after achieving complete remission are still limited. This prospective observational multicenter study includes HIV-infected patients with biopsy- or cytology-proven malignant lymphomas since 2005. Data on HIV infection and lymphoma characteristics, treatment and outcome were recorded. For this analysis, AIDS-related lymphomas patients in complete remission were analyzed in terms of their relapse- free survival and potential risk factors for relapses. In total, 254 of 399 (63.7%) patients with AIDS-related lymphomas reached a complete remission with their first-line chemotherapy. After a median follow up of 4.6 years, 5-year overall survival of the 254 patients was 87.8% (Standard Error 3.1%). Twenty-nine patients relapsed (11.4%). Several factors were independently associated with a higher relapse rate, including an unclassifiable histology, a stage III or IV according to the Ann Arbor Staging System, no concomitant combined antiretroviral therapy during chemotherapy and R-CHOP-based compared to more intensive chemotherapy regimens in Burkitt lymphomas. In conclusion, complete remission and relapse rates observed in our study are similar to those reported in HIV-negative non-Hodgkin lymphomas. These data provide further evidence for the use of concomitant combined antiretroviral therapy during chemotherapy and a benefit from more intensive chemotherapy regimens in Burkitt lymphomas. Modifications to the chemotherapy regimen appear to have only a limited impact on relapse rate. Copyright © 2018 Ferrata Storti Foundation.

Investigation of High-Angle-of-Attack Maneuver-Limiting Factors. Part 1. Analysis and Simulation

DTIC Science & Technology

1980-12-01

useful, are not so satisfying or in- structive as the more positive identification of causal factors offered by the methods developed in Reference 5...same methods be applied to additional high-performance fighter aircraft having widely differing high AOA handling characteristics to see if further...predictions and the nonlinear model results were resolved. The second task involved development of methods , criteria, and an associated pilot rating scale, for

Self-rated health and standard risk factors for myocardial infarction: a cohort study.

PubMed

Waller, Göran; Janlert, Urban; Norberg, Margareta; Lundqvist, Robert; Forssén, Annika

2015-02-13

To investigate the relationship between self-rated health, adjusted for standard risk factors, and myocardial infarction. Population-based prospective cohort study. Enrolment took place between 1990 and 2004 in Västerbotten County, Sweden Every year, persons in the total population, aged 40, 50 or 60 were invited. Participation rate was 60%. The cohort consisted of 75 386 men and women. After exclusion for stroke or myocardial infarction before, or within 12 months after enrolment or death within 12 months after enrolment, 72 530 persons remained for analysis. Mean follow-up time was 13.2 years. Cox regression analysis was used to estimate HRs for the end point of first non-fatal or fatal myocardial infarction. HR were adjusted for age, sex, systolic blood pressure, total cholesterol, smoking, diabetes, body mass index, education, physical activity and self-rated health in the categories very good; pretty good; somewhat good; pretty poor or poor. In the cohort, 2062 persons were diagnosed with fatal or non-fatal myocardial infarction. Poor self-rated health adjusted for sex and age was associated with the outcome with HR 2.03 (95% CI 1.45 to 2.84). All categories of self-rated health worse than very good were statistically significant and showed a dose-response relationship. In a multivariable analysis with standard risk factors (not including physical activity and education) HR was attenuated to 1.61 (95% CI 1.13 to 2.31) for poor self-rated health. All categories of self-rated health remained statistically significant. We found no interaction between self-rated health and standard risk factors except for poor self-rated health and diabetes. This study supports the use of self-rated health as a standard risk factor among others for myocardial infarction. It remains to demonstrate whether self-rated health adds predictive value for myocardial infarction in combined algorithms with standard risk factors. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Microbial Fuel Cell Performance with a Pressurized Cathode Chamber

USDA-ARS?s Scientific Manuscript database

Microbial fuel cell (MFC) power densities are often constrained by the oxygen reduction reaction rate on the cathode electrode. One important factor for this is the normally low solubility of oxygen in the aqueous cathode solution creating mass transport limitations, which hinder oxygen reduction a...

14 CFR 23.221 - Spinning.

Code of Federal Regulations, 2011 CFR

2011-01-01

... limit maneuvering load factor must not be exceeded; (ii) No control forces or characteristic encountered... reversal of control effect and without exceeding the temporary control forces specified by § 23.143(c); and... spin. (4) There must be no characteristics during the spin (such as excessive rates of rotation or...

14 CFR 23.221 - Spinning.

Code of Federal Regulations, 2010 CFR

2010-01-01

... limit maneuvering load factor must not be exceeded; (ii) No control forces or characteristic encountered... reversal of control effect and without exceeding the temporary control forces specified by § 23.143(c); and... spin. (4) There must be no characteristics during the spin (such as excessive rates of rotation or...

14 CFR 23.221 - Spinning.

Code of Federal Regulations, 2012 CFR

2012-01-01

... limit maneuvering load factor must not be exceeded; (ii) No control forces or characteristic encountered... reversal of control effect and without exceeding the temporary control forces specified by § 23.143(c); and... spin. (4) There must be no characteristics during the spin (such as excessive rates of rotation or...

14 CFR 23.221 - Spinning.

Code of Federal Regulations, 2014 CFR

2014-01-01

... limit maneuvering load factor must not be exceeded; (ii) No control forces or characteristic encountered... reversal of control effect and without exceeding the temporary control forces specified by § 23.143(c); and... spin. (4) There must be no characteristics during the spin (such as excessive rates of rotation or...

14 CFR 23.221 - Spinning.

Code of Federal Regulations, 2013 CFR

2013-01-01

... limit maneuvering load factor must not be exceeded; (ii) No control forces or characteristic encountered... reversal of control effect and without exceeding the temporary control forces specified by § 23.143(c); and... spin. (4) There must be no characteristics during the spin (such as excessive rates of rotation or...

Debridement, antibiotics, irrigation, and retention (DAIR) of the prosthesis after hip hemiarthroplasty infections. Does it work?

PubMed

Kazimoglu, Cemal; Yalcin, Nadir; Onvural, Burak; Akcay, Serkan; Agus, Haluk

2015-08-01

Debridement, antibiotic, and implant retention (DAIR) is an attractive treatment modality after hip hemiarthroplasty (HA) infections. Data about the success of the procedure after acute onset infections is lacking. The aim of this study was to analyze the clinical outcome and associated risk factors. A multicenter, retrospective cohort study was designed, including 39 patients with acute onset prosthetic infection who had undergone debridement and irrigation with prosthesis retention. The primary outcome measure was infection eradication without prosthesis removal. We also analyzed how the success rate was influenced by the length of the interval between implantation of the prosthesis and the beginning of the treatment. The overall success rate was 41%. Sedimentation rate over 60 mm/h and the longer duration (2 weeks) after prosthesis implantation were found as factors negatively influencing the success rate. Our results indicated limited success to DAIR- treated patients with infected HA. The high failure rate of DAIR treatment after 2 weeks from the implantation should be taken into consideration.

[Risk factors for suicide attempt among college students at Central South University].

PubMed

Xu, Hui-lan; Xiao, Shui-yuan; Feng, Shan-shan; Chen, Xi-xi

2004-04-01

To understand the prevalence and risk factors for suicidal ideation among college students and to provide a scientific basis for promoting psychological health and suicide prevention. 623 college students at Central South University were selected using stratified cluster sampling and administered a suicide ideation questionnaire, a Symptom Check List (SCL-90), an Adolescent Self-Rating Life Events Check List (ASLEC), a Social Support Rating Scale (SSRS) and a questionnaire about background information. Multivariate logistic regression analysis was employed to identify risk factors for suicide ideation. One year prior to our investigation, 14.6% of respondents had suicide ideation, 2.5% had made a specific suicide plan, and 1.8% had made a suicide attempt. The main risk factors for suicide ideation were dissatisfaction with the selected major of study, limited social support, recent negative life events and depressive tendency. The prevalence of suicide ideation among these college students was high. Appropriate measures focusing on the risk factors identified in this study should be urgently developed to prevent suicides in college students.

Latinos and HIV/AIDS: Examining Factors Related to Disparity and Identifying Opportunities for Psychosocial Intervention Research

PubMed Central

Hendriksen, Ellen Setsuko; Collins, Erin Marie; Durán, Ron E.; Safren, Steven A.

2013-01-01

Latinos maintain an AIDS case rate more than 3 times higher than whites, a greater rate of progression to AIDS, and a higher rate of HIV/AIDS-related deaths. Three broad areas are reviewed related to these disparities: (1) relevant demographic, socioeconomic, and socio-cultural factors among Latinos; (2) drug abuse and mental health problems in Latinos relevant to HIV/AIDS outcomes; and (3) opportunities for psychosocial intervention. Latinos living with HIV are a rapidly growing group, are more severely impacted by HIV than whites, and confront unique challenges in coping with HIV/AIDS. A body of research suggests that depression, substance abuse, treatment adherence, health literacy, and access to healthcare may be fruitful targets for intervention research in this population. Though limited, the current literature suggests that psychosocial interventions that target these factors could help reduce HIV/AIDS disparities between Latinos and whites and could have important public health value. PMID:18498050

Estimation of the cure rate in Iranian breast cancer patients.

PubMed

Rahimzadeh, Mitra; Baghestani, Ahmad Reza; Gohari, Mahmood Reza; Pourhoseingholi, Mohamad Amin

2014-01-01

Although the Cox's proportional hazard model is the popular approach for survival analysis to investigate significant risk factors of cancer patient survival, it is not appropriate in the case of log-term disease free survival. Recently, cure rate models have been introduced to distinguish between clinical determinants of cure and variables associated with the time to event of interest. The aim of this study was to use a cure rate model to determine the clinical associated factors for cure rates of patients with breast cancer (BC). This prospective cohort study covered 305 patients with BC, admitted at Shahid Faiazbakhsh Hospital, Tehran, during 2006 to 2008 and followed until April 2012. Cases of patient death were confirmed by telephone contact. For data analysis, a non-mixed cure rate model with Poisson distribution and negative binomial distribution were employed. All analyses were carried out using a developed Macro in WinBugs. Deviance information criteria (DIC) were employed to find the best model. The overall 1-year, 3-year and 5-year relative survival rates were 97%, 89% and 74%. Metastasis and stage of BC were the significant factors, but age was significant only in negative binomial model. The DIC also showed that the negative binomial model had a better fit. This study indicated that, metastasis and stage of BC were identified as the clinical criteria for cure rates. There are limited studies on BC survival which employed these cure rate models to identify the clinical factors associated with cure. These models are better than Cox, in the case of long-term survival.

Limited socioeconomic opportunities and Latina teen childbearing: a qualitative study of family and structural factors affecting future expectations

PubMed Central

Minnis, Alexandra M.; Marchi, Kristen; Ralph, Lauren; Biggs, M. Antonia; Schwartz, Sarah; Arons, Abigail; Brindis, Claire D.; Braveman, Paula

2012-01-01

Background The decrease in adolescent birth rates in the United States has been slower among Latinas than among other ethnic/racial groups. Limited research has explored how socioeconomic opportunities influence childbearing among Latina adolescents. Methods We conducted in-depth interviews with 65 pregnant foreign- and U.S.-born Latina women (31 adolescents; 34 adults) in two California counties. We assessed perceived socioeconomic opportunities and examined how family, immigration and acculturation affected the relationships between socioeconomic opportunities and adolescent childbearing. Results Compared with women who delayed childbearing into adulthood, pregnant adolescents described having few resources for educational and career development and experiencing numerous socioeconomic and social barriers to achieving their goals. Socioeconomic instability and policies limiting access to education influenced childbearing for immigrant adolescents. In contrast, family disintegration tied to poverty figured prominently in U.S.-born adolescents’ childbearing. Conclusion Limited socioeconomic opportunities may play a large role in persistently high pregnancy rates among Latina adolescents. PMID:22678305

Fuel processing for PEM fuel cells: transport and kinetic issues of system design

NASA Astrophysics Data System (ADS)

Zalc, J. M.; Löffler, D. G.

In light of the distribution and storage issues associated with hydrogen, efficient on-board fuel processing will be a significant factor in the implementation of PEM fuel cells for automotive applications. Here, we apply basic chemical engineering principles to gain insight into the factors that limit performance in each component of a fuel processor. A system consisting of a plate reactor steam reformer, water-gas shift unit, and preferential oxidation reactor is used as a case study. It is found that for a steam reformer based on catalyst-coated foils, mass transfer from the bulk gas to the catalyst surface is the limiting process. The water-gas shift reactor is expected to be the largest component of the fuel processor and is limited by intrinsic catalyst activity, while a successful preferential oxidation unit depends on strict temperature control in order to minimize parasitic hydrogen oxidation. This stepwise approach of sequentially eliminating rate-limiting processes can be used to identify possible means of performance enhancement in a broad range of applications.

[Spanish drivers' beliefs about speed. Speeding is a major issue of road safety].

PubMed

Montoro González, Luis; Roca Ruiz, Javier; Lucas-Alba, Antonio

2010-11-01

Extending and updating our knowledge concerning drivers' motivational and cognitive processes is of essential importance if we are to apply policies with long-lasting effects. This study presents data from a representative national survey analyzing the Spanish drivers' beliefs about speed, the risks of speeding, the degree of violation of speed-limits and the reasons for speeding. Results indicate that Spanish drivers rate speeding as a serious offence, yet not among the most dangerous ones. All in all, they claim to comply mostly with the speed limits. However, some interesting violation patterns emerge: observance is lower for generic speed limits according to road type (vs. specific limits shown by certain road signs), and particularly in motorways (vs. single carriageways and urban areas). Risk perception and reasons for speeding emerge as the main factors predicting the levels of speed violations reported. Results suggest that any effective intervention strategy should consider such factors, namely the link between speed, road safety, and drivers' specific reasons for speeding.

Understanding the Low Photosynthetic Rates of Sun and Shade Coffee Leaves: Bridging the Gap on the Relative Roles of Hydraulic, Diffusive and Biochemical Constraints to Photosynthesis

PubMed Central

Martins, Samuel C. V.; Galmés, Jeroni; Cavatte, Paulo C.; Pereira, Lucas F.; Ventrella, Marília C.; DaMatta, Fábio M.

2014-01-01

It has long been held that the low photosynthetic rates (A) of coffee leaves are largely associated with diffusive constraints to photosynthesis. However, the relative limitations of the stomata and mesophyll to the overall diffusional constraints to photosynthesis, as well as the coordination of leaf hydraulics with photosynthetic limitations, remain to be fully elucidated in coffee. Whether the low actual A under ambient CO2 concentrations is associated with the kinetic properties of Rubisco and high (photo)respiration rates also remains elusive. Here, we provide a holistic analysis to understand the causes associated with low A by measuring a variety of key anatomical/hydraulic and photosynthetic traits in sun- and shade-grown coffee plants. We demonstrate that leaf hydraulic architecture imposes a major constraint on the maximisation of the photosynthetic gas exchange of coffee leaves. Regardless of the light treatments, A was mainly limited by stomatal factors followed by similar limitations associated with the mesophyll and biochemical constraints. No evidence of an inefficient Rubisco was found; rather, we propose that coffee Rubisco is well tuned for operating at low chloroplastic CO2 concentrations. Finally, we contend that large diffusive resistance should lead to large CO2 drawdown from the intercellular airspaces to the sites of carboxylation, thus favouring the occurrence of relatively high photorespiration rates, which ultimately leads to further limitations to A. PMID:24743509

[New social and economical issues in the assessment of Romanian population's health status].

PubMed

Duma, Odetta

2008-01-01

Health status is determined by a combination of biological, environmental (physical and socio-economic), behavioural/lifestyle and medical care factors. The social and economic factors include many influences over which an individual may have limited control, such as economic status or educational level. The most important measures of these factors are represented by: gross domestic product per capita, employment rate, unemployment rate, literacy rate, poverty line, and human development index. From this point of view, the following positive issues have been recorded in Romania: a low unemployment rate (6.1%) compared to European Union countries; a high literacy rate (97.3%), very close to the maximum of 100% reported by all developed countries; and a human development index of 0.805 (rank 60 in the international hierarchy), specific to a country with a high human development. Negative issues have been reported in case of the following indicators: the reported gross domestic product per capita expressed in PPP US$ was 8480, among the lowest in Europe, specific to a country with a medium income; population living with less than 2 US$ per day of 13% and living with less than 1 US$ per day 2.1%; the employment rate was 57.4%, but in female population only 51.3%, whereas in male population it was 63.9%.

Seizures and epilepsy in Alzheimer's disease.

PubMed

Friedman, Daniel; Honig, Lawrence S; Scarmeas, Nikolaos

2012-04-01

Many studies have shown that patients with Alzheimer's disease (AD) are at increased risk for developing seizures and epilepsy. However, reported prevalence and incidence of seizures and relationship of seizures to disease measures such as severity, outcome, and progression vary widely between studies. We performed a literature review of the available clinical and epidemiological data on the topic of seizures in patients with AD. We review seizure rates and types, risk factors for seizures, electroencephalogram (EEG) studies, and treatment responses. Finally, we consider limitations and methodological issues. There is considerable variability in the reported prevalence and incidence of seizures in patients with AD-with reported lifetime prevalence rates of 1.5-64%. More recent, prospective, and larger studies in general report lower rates. Some, but not all, studies have noted increased seizure risk with increasing dementia severity or with younger age of AD onset. Generalized convulsive seizures are the most commonly reported type, but often historical information is the only basis used to determine seizure type and the manifestation of seizures may be difficult to distinguish from other behaviors common in demented patients. EEG has infrequently been performed and reported. Data on treatment of seizures in AD are extremely limited. Similarly, the relationship between seizures and cognitive impairment in AD is unclear. We conclude that the literature on seizures and epilepsy in AD, including diagnosis, risk factors, and response to treatment suffers from methodological limitations and gaps. © 2011 Blackwell Publishing Ltd.

Evaluation of the optimal strategy for ex situ bioremediation of diesel oil-contaminated soil.

PubMed

Lin, Ta-Chen; Pan, Po-Tsen; Young, Chiu-Chung; Chang, Jo-Shu; Chang, Tsung-Chung; Cheng, Sheng-Shung

2011-11-01

Bioaugmentation and biostimulation have been widely applied in the remediation of oil contamination. However, ambiguous results have been reported. It is important to reveal the controlling factors on the field for optimal selection of remediation strategy. In this study, an integrated field landfarming technique was carried out to assess the relative effectiveness of five biological approaches on diesel degradation. The limiting factors during the degradation process were discussed. A total of five treatments were tested, including conventional landfarming, nutrient enhancement (NE), biosurfactant addition (BS), bioaugmentation (BA), and combination of bioaugmentation and biosurfactant addition (BAS). The consortium consisted of four diesel-degrading bacteria strains. Rhamnolipid was used as the biosurfactant. The diesel concentration, bacterial population, evolution of CO(2), and bacterial community in the soil were periodically measured. The best overall degradation efficiency was achieved by BAS treatment (90 ± 2%), followed by BA (86 ± 2%), NE (84 ± 3%), BS (78 ± 3%), and conventional landfarming (68 ± 3%). In the early stage, the total petroleum hydrocarbon was degraded 10 times faster than the degradation rates measured during the period from day 30 to 100. At the later stage, the degradation rates were similar among treatments. In the conventional landfarming, contaminated soil contained bacteria ready for diesel degradation. The availability of hydrocarbon was likely the limiting factor in the beginning of the degradation process. At the later stage, the degradation was likely limited by desorption and mass transfer of hydrocarbon in the soil matrix.

Diffusional conductance to CO2 is the key limitation to photosynthesis in salt-stressed leaves of rice (Oryza sativa).

PubMed

Wang, Xiaoxiao; Wang, Wencheng; Huang, Jianliang; Peng, Shaobing; Xiong, Dongliang

2018-05-01

Salinity significantly limits leaf photosynthesis but the factors causing the limitation in salt-stressed leaves remain unclear. In the present work, photosynthetic and biochemical traits were investigated in four rice genotypes under two NaCl concentration (0 and 150 mM) to assess the stomatal, mesophyll and biochemical contributions to reduced photosynthetic rate (A) in salt-stressed leaves. Our results indicated that salinity led to a decrease in A, leaf osmotic potential, electron transport rate and CO 2 concentrations in the chloroplasts (C c ) of rice leaves. Decreased A in salt-stressed leaves was mainly attributable to low C c , which was determined by stomatal and mesophyll conductance. The increased stomatal limitation was mainly related to the low leaf osmotic potential caused by soil salinity. However, the increased mesophyll limitation in salt-stressed leaves was related to both osmotic stress and ion stress. These findings highlight the importance of considering mesophyll conductance when developing salinity-tolerant rice cultivars. © 2017 Scandinavian Plant Physiology Society.

Developing a Comprehensive and Comparative Questionnaire for Measuring Personality in Chimpanzees Using a Simultaneous Top-Down/Bottom-Up Design

PubMed Central

Freeman, Hani D.; Brosnan, Sarah F.; Hopper, Lydia M.; Lambeth, Susan P.; Schapiro, Steven J.; Gosling, Samuel D.

2013-01-01

One effective method for measuring personality in primates is to use personality trait ratings to distill the experience of people familiar with the individual animals. Previous rating instruments were created using either top-down or bottom-up approaches. Top-down approaches, which essentially adapt instruments originally designed for use with another species, can unfortunately lead to the inclusion of traits irrelevant to chimpanzees or fail to include all relevant aspects of chimpanzee personality. Conversely, because bottom-up approaches derive traits specifically for chimpanzees, their unique items may impede comparisons with findings in other studies and other species. To address the limitations of each approach, we developed a new personality rating scale using a combined top-down/bottom-up design. Seventeen raters rated 99 chimpanzees on the new 41-item scale, with all but one item being rated reliably. Principal components analysis, using both varimax and direct oblimin rotations, identified six broad factors. Strong evidence was found for five of the factors (Reactivity/Undependability, Dominance, Openness, Extraversion, and Agreeableness). A sixth factor (Methodical) was offered provisionally until more data are collected. We validated the factors against behavioral data collected independently on the chimpanzees. The five factors demonstrated good evidence for convergent and predictive validity, thereby underscoring the robustness of the factors. Our combined top-down/ bottom-up approach provides the most extensive data to date to support the universal existence of these five personality factors in chimpanzees. This framework, which facilitates cross-species comparisons, can also play a vital role in understanding the evolution of personality and can assist with husbandry and welfare efforts. PMID:23733359

Risk factors for congenital diaphragmatic hernia in the Bogota birth defects surveillance and follow-up program, Colombia.

PubMed

García, Ana M; Machicado, S; Gracia, G; Zarante, I M

2016-03-01

The mortality rate for congenital diaphragmatic hernia (CDH) remains high and prevention efforts are limited by the lack of known risk factors. The aim of this study was to determine prevalence, risk factors, and neonatal results associated with CDH on a surveillance system hospital-based in Bogotá, Colombia. The data used in this study were obtained from The Bogota Birth Defects Surveillance and Follow-up Program (BBDSFP), between January 2001 and December 2013. With 386,419 births, there were 81 cases of CDH. A case-control methodology was conducted with 48 of the total cases of CDH and 192 controls for association analysis. The prevalence of CDH was 2.1 per 10,000 births. In the case-control analysis, risk factors found were maternal age ≥35 years (OR, 33.53; 95 % CI, 7.02-160.11), infants with CDH were more likely to be born before 37 weeks of gestation (OR, 5.57; 95 % CI, 2.05-15.14), to weigh less than 2500 g at birth (OR, 9.05; 95 % CI, 3.51-23.32), and be small for gestational age (OR, 5.72; 95 % CI, 2.18-14.99) with a high rate of death before hospital discharge in the CDH population (CDH: 38 % vs BBDSFP: <1 %; p < 0.001). The prevalence of CDH calculated was similar to the one reported in the literature. CDH is strongly associated with a high rate of death before hospital discharge and the risk factors found were maternal age ≥35 years, preterm birth, be small for gestational age, and have low weight at birth. These neonatal characteristics in developing countries would help to identify early CDH. Prevention efforts have been limited by the lack of known risk factors and established epidemiological profiles, especially in developing countries.

Evidence for a freezing tolerance-growth rate trade-off in the live oaks (Quercus series Virentes) across the tropical-temperate divide.

PubMed

Koehler, Kari; Center, Alyson; Cavender-Bares, Jeannine

2012-02-01

• It has long been hypothesized that species are limited to the north by minimum temperature and to the south by competition, resulting in a trade-off between freezing tolerance and growth rate. We investigated the extent to which the climatic origins of populations from four live oak species (Quercus series Virentes) were associated with freezing tolerance and growth rate, and whether species fitted a model of locally adapted populations, each with narrow climatic tolerances, or of broadly adapted populations with wide climatic tolerances. • Acorns from populations of four species across a tropical-temperate gradient were grown under common tropical and temperate conditions. Growth rate, seed mass, and leaf and stem freezing traits were compared with source minimum temperatures. • Maximum growth rates under tropical conditions were negatively correlated with freezing tolerance under temperate conditions. The minimum source temperature predicted the freezing tolerance of populations under temperate conditions. The tropical species Q. oleoides was differentiated from the three temperate species, and variation among species was greater than among populations. • The trade-off between freezing tolerance and growth rate supports the range limit hypothesis. Limited variation within species indicates that the distributions of species may be driven more strongly by broad climatic factors than by highly local conditions. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

Influence of external mass transfer limitation on apparent kinetic parameters of penicillin G acylase immobilized on nonporous ultrafine silica particles.

PubMed

Kheirolomoom, Azadeh; Khorasheh, Farhad; Fazelinia, Hossein

2002-01-01

Immobilization of enzymes on nonporous supports provides a suitable model for investigating the effect of external mass transfer limitation on the reaction rate in the absence of internal diffusional resistance. In this study, deacylation of penicillin G was investigated using penicillin acylase immobilized on ultrafine silica particles. Kinetic studies were performed within the low-substrate-concentration region, where the external mass transfer limitation becomes significant. To predict the apparent kinetic parameters and the overall effectiveness factor, knowledge of the external mass transfer coefficient, k(L)a, is necessary. Although various correlations exist for estimation of k(L)a, in this study, an optimization scheme was utilized to obtain this coefficient. Using the optimum values of k(L)a, the initial reaction rates were predicted and found to be in good agreement with the experimental data.

Determining water sensitive card spread factors for real world tank mixes

USDA-ARS?s Scientific Manuscript database

The use of water sensitive cards provides a quick and easy method to sample the coverage and deposition from spray applications. Typically, this measure is limited to percent coverage as measures of droplet size, and thus deposition rate, are highly influenced by the stain diameter resulting from t...

Stemming the Revolving Door: Teacher Retention and Attrition in Arctic Alaska Schools

ERIC Educational Resources Information Center

Kaden, Ute; Patterson, Philip P.; Healy, Joanne; Adams, Barbara L.

2016-01-01

Limited research is available concerning teacher retention and teacher attrition in Arctic Alaska. This paper reports survey research findings, which identify factors related to teacher retention and attrition in Alaskan Arctic Native communities. Teacher retention rates (2009-2013) vary widely over time showing no significant trends. Results…

Model for Improvement of Learning Using Topographic Mapping.

ERIC Educational Resources Information Center

Andrews, David B.

The paper develops a method for learning improvement which incorporates the learner in the development of the learning/instructional strategy. To this end, a rate limiting model using topographical brain mapping as an educational intervention is presented. It is suggested that such intervention programs focus on those factors which are…

43 CFR 426.6 - Leasing and full-cost pricing.

Code of Federal Regulations, 2011 CFR

2011-10-01

... payments due the United States. (6) In determining full-cost charges, the following factors will be...-cost entitlement for limited recipients that did not receive irrigation water on or prior to October 1... appropriate full-cost rate for irrigation water delivered to acreage that equals the amount of leased land...

43 CFR 426.6 - Leasing and full-cost pricing.

Code of Federal Regulations, 2012 CFR

2012-10-01

... payments due the United States. (6) In determining full-cost charges, the following factors will be...-cost entitlement for limited recipients that did not receive irrigation water on or prior to October 1... appropriate full-cost rate for irrigation water delivered to acreage that equals the amount of leased land...

43 CFR 426.6 - Leasing and full-cost pricing.

Code of Federal Regulations, 2013 CFR

2013-10-01

... payments due the United States. (6) In determining full-cost charges, the following factors will be...-cost entitlement for limited recipients that did not receive irrigation water on or prior to October 1... appropriate full-cost rate for irrigation water delivered to acreage that equals the amount of leased land...

43 CFR 426.6 - Leasing and full-cost pricing.

Code of Federal Regulations, 2014 CFR

2014-10-01

... payments due the United States. (6) In determining full-cost charges, the following factors will be...-cost entitlement for limited recipients that did not receive irrigation water on or prior to October 1... appropriate full-cost rate for irrigation water delivered to acreage that equals the amount of leased land...

Smoking rates and risk factors among youth in the Republic of the Marshall Islands: results of a school survey.

PubMed

Chen, Tai-Ho; Ou, Alan C; Haberle, Heather; Miller, Vincent P; Langidrik, Justina R; Palafox, Neal A

2004-09-01

Rapidly increasing tobacco use in developing countries will result in a large and increasing burden of tobacco-related illnesses as their populations age. The Republic of the Marshall Islands (RMI) is an island nation in the Pacific with a 1999 census population of 50,840, of whom more than fifty percent were under twenty years of age. There are limited data on the prevalence of smoking among youth in the RMI. A school survey of 3,294 RMI students in grades 5 through 12 was conducted in 2000. Urban and outer atoll schools were included in the sample. Demographic data and information on tobacco use and risk factors were collected. The overall smoking rate in this school sample was 10.6%. There were significantly higher smoking rates in the high school age group; the rate of smoking among 18 year olds was 33.5%. Smoking rates were higher among males compared to females (18.7% vs. 3.4%) and higher among outer atoll students compared to urban students (14.5% vs. 9.4%). The most prominent risk factors for smoking were: age, male gender, receiving or wearing tobacco-labeled equipment or clothing and willingness to participate in other high-risk behaviors. The survey provides an estimate of smoking rates among Marshallese school students and identifies and quantifies significant risk factors for smoking. This information can assist in guiding a comprehensive tobacco control strategy in the Republic of the Marshall Islands.

Limits to preference and the sensitivity of choice to rate and amount of food.

PubMed

Aparicio, Carlos F; Baum, William M; Hughes, Christine E; Pitts, Raymond C

2016-03-01

Studies of choice holding food-amount ratio constant while varying food-rate ratio within sessions showed that local changes in preference depend on relative amount of food. The present study investigated whether sensitivity of choice to food-rate ratio and sensitivity to food-amount ratio are independent of one another when food-rate ratios are varied across sessions and food-amount ratios are varied within sessions. Food deliveries for rats' presses on the left and right levers were scheduled according to three different food-rate ratios of 1:1, 9:1, and 1:9; each food-rate ratio lasted for 106 sessions and was arranged independently of seven food-amount ratios (7:1, 6:2, 5:3, 4:4, 3:5, 2:6, and 1:7 food pellets) occurring within sessions in random sequence. Each amount ratio lasted for 10 food deliveries and was separated from another by a 60-s blackout. Sensitivity to rate ratio was high (1.0) across food deliveries. Sensitivity to amount ratio was low when food rates were equal across alternatives, but was high when rate ratio and amount ratio opposed one another. When rate ratio and amount ratio went in the same direction, choice ratio reached an elevenfold limit which reduced sensitivity to approximately zero. We conclude that three factors affect sensitivity to amount: (1) the limit to preference, (2) the equal effect on preference of amounts greater than four pellets, and (3) the absence of differential effects of switches in amount in the equal-rates (1:1) condition. Taken together, these findings indicate that rate and amount only sometimes combine independently as additive variables to determine preference when amount ratios vary frequently within sessions. © 2016 Society for the Experimental Analysis of Behavior.

Effect of depletion rate on solution gas drive in shale

NASA Astrophysics Data System (ADS)

Zhang, Mingshan; Sang, Qian; Gong, Houjian; Li, Yajun; Dong, Mingzhe

2018-01-01

Solution gas drive process has been studied extensively in sand rocks and heavy oil reservoirs for a long time. Oil recovery is affected by several factors, such as depletion rate, initial GOR (gas oil ratio), oil viscosity, and temperature and so on. Before the solution gas drive tests, elastic drive without dissolved gas was carried out as a reference, which shows a limited oil recovery. Solution gas drive experiments were conducted in shale to study oil recovery with various depletion rates. Results show that oil recovery increases with the decrease of depletion rates because of the low permeability and desorption of methane.

Kidney transplantation--a 46-year experience from the Transplant Institute, Sahlgrenska University Hospital, Gothenburg, Sweden.

PubMed

Friman, S; Nordén, G; Lennerling, A; Fehrman-Ekholm, I; Felldin, M; Hansson, S; Rydberg, L; Holgersson, J; Rizell, M; Kvarnström, N; Gustafsson, B; Gäbel, M; Olausson, M; Mjörnstedt, L

2011-01-01

The limiting factor in organ transplantation is the availability of organs. Ongoing work to improve donation rates both at the public and the organizational level in donating hospitals is essential. We also think that encouragement of live donation is important, and the possibility of ABO incompatible transplantation has increased the number of LD transplantations. The one-year graft survival rate is excellent and focus has shifted towards achieving long-term results to reduce the attrition rate. There is also an increasing interest in studying and working to reduce comorbidities on a long-term basis and thus, improve survival rates and recipient quality of life.

Pronounced non-Arrhenius behaviour of hydrogen-abstractions from toluene and derivatives by phthalimide-N-oxyl radicals: a theoretical study.

PubMed

Hermans, Ive; Jacobs, Pierre; Peeters, Jozef

2008-02-28

Abstraction of hydrogen atoms by pthalimide-N-oxyl radicals is an important step in the N-hydroxyphthalimide catalyzed autoxidation of hydrocarbons. In this contribution, the temperature dependency of this reaction is evaluated by a detailed transition state theory based kinetic analysis for the case of toluene. Tunneling was found to play a very important role, enhancing the rate constant by a factor of 20 at room temperature. As a result, tunneling, in combination with the existence of two distinct rotamers of the transition state, causes a pronounced temperature dependency of the pre-exponential frequency factor, and, as a consequence, marked curvature of the Arrhenius plot. This explains why earlier experimental studies over a limited temperature range around 300 K found formal Arrhenius activation energies and pre-factors that are 4 kcal mol(-1) and three orders of magnitude smaller than the actual energy barrier and the corresponding frequency factor, respectively. Also as a consequence of tunneling, substitution of a deuterium atom for a hydrogen atom causes a large decrease in the rate constant, in agreement with the measured kinetic isotope effects. The present theoretical analysis, complementary to the experimental rate coefficient data, allows for a reliable prediction of the rate coefficient at higher temperatures, relevant for actual autoxidation processes.

Incorporating Geochemical And Microbial Kinetics In Reactive Transport Models For Generation Of Acid Rock Drainage

NASA Astrophysics Data System (ADS)

Andre, B. J.; Rajaram, H.; Silverstein, J.

2010-12-01

Acid mine drainage, AMD, results from the oxidation of metal sulfide minerals (e.g. pyrite), producing ferrous iron and sulfuric acid. Acidophilic autotrophic bacteria such as Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans obtain energy by oxidizing ferrous iron back to ferric iron, using oxygen as the electron acceptor. Most existing models of AMD do not account for microbial kinetics or iron geochemistry rigorously. Instead they assume that oxygen limitation controls pyrite oxidation and thus focus on oxygen transport. These models have been successfully used for simulating conditions where oxygen availability is a limiting factor (e.g. source prevention by capping), but have not been shown to effectively model acid generation and effluent chemistry under a wider range of conditions. The key reactions, oxidation of pyrite and oxidation of ferrous iron, are both slow kinetic processes. Despite being extensively studied for the last thirty years, there is still not a consensus in the literature about the basic mechanisms, limiting factors or rate expressions for microbially enhanced oxidation of metal sulfides. An indirect leaching mechanism (chemical oxidation of pyrite by ferric iron to produce ferrous iron, with regeneration of ferric iron by microbial oxidation of ferrous iron) is used as the foundation of a conceptual model for microbially enhanced oxidation of pyrite. Using literature data, a rate expression for microbial consumption of ferrous iron is developed that accounts for oxygen, ferrous iron and pH limitation. Reaction rate expressions for oxidation of pyrite and chemical oxidation of ferrous iron are selected from the literature. A completely mixed stirred tank reactor (CSTR) model is implemented coupling the kinetic rate expressions, speciation calculations and flow. The model simulates generation of AMD and effluent chemistry that qualitatively agrees with column reactor and single rock experiments. A one dimensional reaction diffusion model at the scale of a single rock is developed incorporating the proposed kinetic rate expressions. Simulations of initiation, washout and AMD flows are discussed to gain a better understanding of the role of porosity, effective diffusivity and reactive surface area in generating AMD. Simulations indicate that flow boundary conditions control generation of acid rock drainage as porosity increases.

Linking FRRF Derived Photophysiology with Carbon-based Primary Productivity: Insights from Concepts of Cellular Energy Allocation

NASA Astrophysics Data System (ADS)

Schuback, N.; Schallenberg, C.; Duckham, C.; Flecken, M.; Maldonado, M. T.; Tortell, P. D.

2016-02-01

Active chlorophyll a fluorescence approaches, including fast repetition rate fluorometry (FRRF), have the potential to provide estimates of phytoplankton primary productivity at unprecedented spatial and temporal resolution. FRRF-derived productivity rates are based on estimates of charge separation in photosystem II (ETRRCII), which must be converted into ecologically relevant units of carbon fixation. Understanding sources of variability in the coupling of ETRRCII and carbon fixation provides important physiological insight into phytoplankton photosynthesis, and is critical for the application of FRRF as a primary productivity measurement tool. We present data from a series of experiments during which we simultaneously measured phytoplankton carbon fixation and ETRRCII in the iron-limited NE subarctic Pacific. Our results show significant variability of the derived conversion factor (Ve:C/nPSII), with highest values observed under conditions of excess excitation pressure at the level of photosystem II, caused by high light and/or low iron. Our results will be discussed in the context of metabolic plasticity, which evolved in phytoplankton to simultaneously maximize growth and provide photoprotection under fluctuating light and limiting nutrient availabilities. Because the derived conversion factor is associated with conditions of excess light, it correlates with the expression of non-photochemical quenching (NPQ) in the pigment antenna, also derived from FRRF measurements. Our results demonstrate a significant correlation between NPQ and the conversion factor Ve:C/nPSII, and the potential of this relationship to improve FRRF-based estimates of phytoplankton carbon fixation rates is discussed.

Female elk contacts are neither frequency nor density dependent

USGS Publications Warehouse

Cross, Paul C.; Creech, Tyler G.; Ebinger, Michael R.; Manlove, Kezia R.; Irvine, Kathryn M.; Henningsen, John C.; Rogerson, Jared D.; Scurlock, Brandon M.; Creely, Scott

2013-01-01

Identifying drivers of contact rates among individuals is critical to understanding disease dynamics and implementing targeted control measures. We studied the interaction patterns of 149 female elk (Cervus canadensis) distributed across five different regions of western Wyoming over three years, defining a contact as an approach within one body length (∼2 m). Using hierarchical models that account for correlations within individuals, pairs, and groups, we found that pairwise contact rates within a group declined by a factor of three as group sizes increased 33-fold. Per capita contact rates, however, increased with group size according to a power function, such that female elk contact rates fell in between the predictions of density- or frequency-dependent disease models. We found similar patterns for the duration of contacts. Our results suggest that larger elk groups are likely to play a disproportionate role in the disease dynamics of directly transmitted infections in elk. Supplemental feeding of elk had a limited impact on pairwise interaction rates and durations, but per capita rates were more than two times higher on feeding grounds. Our statistical approach decomposes the variation in contact rate into individual, dyadic, and environmental effects, and provides insight into factors that may be targeted by disease control programs. In particular, female elk contact patterns were driven more by environmental factors such as group size than by either individual or dyad effects.

Accuracy, calibration and clinical performance of the EuroSCORE: can we reduce the number of variables?

PubMed

Ranucci, Marco; Castelvecchio, Serenella; Menicanti, Lorenzo; Frigiola, Alessandro; Pelissero, Gabriele

2010-03-01

The European system for cardiac operative risk evaluation (EuroSCORE) is currently used in many institutions and is considered a reference tool in many countries. We hypothesised that too many variables were included in the EuroSCORE using limited patient series. We tested different models using a limited number of variables. A total of 11150 adult patients undergoing cardiac operations at our institution (2001-2007) were retrospectively analysed. The 17 risk factors composing the EuroSCORE were separately analysed and ranked for accuracy of prediction of hospital mortality. Seventeen models were created by progressively including one factor at a time. The models were compared for accuracy with a receiver operating characteristics (ROC) analysis and area under the curve (AUC) evaluation. Calibration was tested with Hosmer-Lemeshow statistics. Clinical performance was assessed by comparing the predicted with the observed mortality rates. The best accuracy (AUC 0.76) was obtained using a model including only age, left ventricular ejection fraction, serum creatinine, emergency operation and non-isolated coronary operation. The EuroSCORE AUC (0.75) was not significantly different. Calibration and clinical performance were better in the five-factor model than in the EuroSCORE. Only in high-risk patients were 12 factors needed to achieve a good performance. Including many factors in multivariable logistic models increases the risk for overfitting, multicollinearity and human error. A five-factor model offers the same level of accuracy but demonstrated better calibration and clinical performance. Models with a limited number of factors may work better than complex models when applied to a limited number of patients. Copyright (c) 2009 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Actin Depolymerizing Factor (ADF/Cofilin) Enhances the Rate of Filament Turnover: Implication in Actin-based Motility

PubMed Central

Carlier, Marie-France; Laurent, Valérie; Santolini, Jérôme; Melki, Ronald; Didry, Dominique; Xia, Gui-Xian; Hong, Yan; Chua, Nam-Hai; Pantaloni, Dominique

1997-01-01

Actin-binding proteins of the actin depolymerizing factor (ADF)/cofilin family are thought to control actin-based motile processes. ADF1 from Arabidopsis thaliana appears to be a good model that is functionally similar to other members of the family. The function of ADF in actin dynamics has been examined using a combination of physical–chemical methods and actin-based motility assays, under physiological ionic conditions and at pH 7.8. ADF binds the ADPbound forms of G- or F-actin with an affinity two orders of magnitude higher than the ATP- or ADP-Pi– bound forms. A major property of ADF is its ability to enhance the in vitro turnover rate (treadmilling) of actin filaments to a value comparable to that observed in vivo in motile lamellipodia. ADF increases the rate of propulsion of Listeria monocytogenes in highly diluted, ADF-limited platelet extracts and shortens the actin tails. These effects are mediated by the participation of ADF in actin filament assembly, which results in a change in the kinetic parameters at the two ends of the actin filament. The kinetic effects of ADF are end specific and cannot be accounted for by filament severing. The main functionally relevant effect is a 25-fold increase in the rate of actin dissociation from the pointed ends, while the rate of dissociation from the barbed ends is unchanged. This large increase in the rate-limiting step of the monomer-polymer cycle at steady state is responsible for the increase in the rate of actin-based motile processes. In conclusion, the function of ADF is not to sequester G-actin. ADF uses ATP hydrolysis in actin assembly to enhance filament dynamics. PMID:9087445

A portable circulating tumor cell capture microdevice

NASA Astrophysics Data System (ADS)

Datar, Ram H.

2009-03-01

Sensitive detection of earliest metastatic spread of tumors in a minimally invasive and user-friendly manner will revolutionize the clinical management of cancer patients. The current methodologies for circulating tumor cell (CTC) capture and identification have significant limitations including time, cost, limited capture efficiency and lack of standardization. We have developed and optimized a novel parylene membrane filter-based portable microdevice for size-based isolation of CTC from human peripheral blood. Following characterization with a model system to study the recovery rate and enrichment factor, a comparison of the microdevice with the commercially available system using blood from cancer patients demonstrated superior recovery rate and the promise of clinical utility of the microdevice. The development of the microdevice and its potential clinical applicability will be discussed.

Understanding limiting factors in thick electrode performance as applied to high energy density Li-ion batteries

DOE PAGES

Du, Zhijia; Wood, David L.; Daniel, Claus; ...

2017-02-09

We present that increasing electrode thickness, thus increasing the volume ratio of active materials, is one effective method to enable the development of high energy density Li-ion batteries. In this study, an energy density versus power density optimization of LiNi 0.8Co 0.15Al 0.05O 2 (NCA)/graphite cell stack was conducted via mathematical modeling. The energy density was found to have a maximum point versus electrode thickness (critical thickness) at given discharging C rates. The physics-based factors that limit the energy/power density of thick electrodes were found to be increased cell polarization and underutilization of active materials. The latter is affected bymore » Li-ion diffusion in active materials and Li-ion depletion in the electrolyte phase. Based on those findings, possible approaches were derived to surmount the limiting factors. Finally, the improvement of the energy–power relationship in an 18,650 cell was used to demonstrate how to optimize the thick electrode parameters in cell engineering.« less

Investigating risk factors and possible infectious aetiologies of mummified fetuses on a large piggery in Australia.

PubMed

Dron, N; Hernández-Jover, M; Doyle, R E; Holyoake, P K

2014-12-01

To investigate risk factors and potential infectious aetiologies of an increased mummification rate (>2%) identified over time on a 1200-sow farrow-to-finish farm in Australia. Association of potential non-infectious risk factors and the mummification rate was investigated using 15 years of breeding herd data (40,940 litters) and logistic regression analysis. Samples from a limited number of mummified fetuses were taken to identify potential infectious aetiologies (porcine parvovirus, Leptospira pomona, porcine circovirus type 2, Bungowannah virus and enterovirus). Logistic regression analysis suggested that the mummification rate was significantly associated with sow breed and parity, year and total born and stillborn piglets per litter. The mummification rate was lower (P < 0.001) in Landrace (3.4%) and Large White (2.6%) sows than in Duroc sows (4.9%). Gilts (2.9%) had a lower (P < 0.001) mummification rate than older sows. The mummification rate increased with total born litter size and decreased with the number of stillborn piglets (P < 0.001). A clustering effect within individual sows was identified, indicating that some sows with mummified fetuses in a litter were more likely to have repeated mummifications in subsequent litters. No infectious agents were identified in the samples taken. Results from this study suggest that the increased mummification rate identified over time on this farm is likely to be a non-infectious multifactorial problem predisposing the occurrence of mummification. Further research is required to better understand the pathophysiology of mummification and the role that different non-infectious factors play in the occurrence of mummified fetuses. © 2014 Australian Veterinary Association.

Volunteering, Driving Status and Mortality in US Retirees

PubMed Central

Lee, Sei J.; Steinman, Michael A.; Tan, Erwin J.

2011-01-01

OBJECTIVES: Volunteering is associated with lower mortality in the elderly. Driving is associated with health and well-being and driving cessation has been associated with decreased out-of-home activity levels including volunteering. We evaluated how accounting for driving status altered the relationship between volunteering and mortality in US retirees. DESIGN: Observational prospective cohort SETTING and PARTICIPANTS: Nationally representative sample of retirees over age 65 from the Health and Retirement Study in 2000 and 2002, followed to 2006 (n=6408). MEASUREMENTS: Participants self-reported their volunteering, driving status, age, gender and race/ethnicity, presence of chronic conditions, geriatrics syndromes, socioeconomic factors, functional limitations and psychosocial factors. Death by December 31, 2006 was the outcome. RESULTS: For drivers, the mortality rates between volunteers (9%) and non-volunteers (12%) were similar; for limited or non-drivers, the mortality rate for volunteers (15%) was markedly lower compared to non-volunteers (32%). Our adjusted results showed that for drivers, the volunteering-mortality Odds Ratio (OR) was 0.90 (95%CI: 0.66–1.22), whereas for limited or non-drivers, the OR was 0.62 (95%CI: 0.49–0.78), (interaction p=0.05). The impact of driving status was greater for rural participants, with greater differences between rural drivers versus rural limited or non-drivers (interaction p=0.02) compared to urban drivers versus urban limited or non-drivers (interaction p=0.81). CONCLUSION: The influence of volunteering in decreasing mortality seems to be stronger among rural retirees who are limited or non-drivers. This may be because rural or non-driving retirees are more likely to be socially isolated and thus receive more benefit from the increased social integration from volunteering. PMID:21314648

Statistical significance of combinatorial regulations

PubMed Central

Terada, Aika; Okada-Hatakeyama, Mariko; Tsuda, Koji; Sese, Jun

2013-01-01

More than three transcription factors often work together to enable cells to respond to various signals. The detection of combinatorial regulation by multiple transcription factors, however, is not only computationally nontrivial but also extremely unlikely because of multiple testing correction. The exponential growth in the number of tests forces us to set a strict limit on the maximum arity. Here, we propose an efficient branch-and-bound algorithm called the “limitless arity multiple-testing procedure” (LAMP) to count the exact number of testable combinations and calibrate the Bonferroni factor to the smallest possible value. LAMP lists significant combinations without any limit, whereas the family-wise error rate is rigorously controlled under the threshold. In the human breast cancer transcriptome, LAMP discovered statistically significant combinations of as many as eight binding motifs. This method may contribute to uncover pathways regulated in a coordinated fashion and find hidden associations in heterogeneous data. PMID:23882073

Complexities in barrier island response to sea level rise: Insights from numerical model experiments, North Carolina Outer Banks

USGS Publications Warehouse

Moore, Laura J.; List, Jeffrey H.; Williams, S. Jeffress; Stolper, David

2010-01-01

Using a morphological-behavior model to conduct sensitivity experiments, we investigate the sea level rise response of a complex coastal environment to changes in a variety of factors. Experiments reveal that substrate composition, followed in rank order by substrate slope, sea level rise rate, and sediment supply rate, are the most important factors in determining barrier island response to sea level rise. We find that geomorphic threshold crossing, defined as a change in state (e.g., from landward migrating to drowning) that is irreversible over decadal to millennial time scales, is most likely to occur in muddy coastal systems where the combination of substrate composition, depth-dependent limitations on shoreface response rates, and substrate erodibility may prevent sand from being liberated rapidly enough, or in sufficient quantity, to maintain a subaerial barrier. Analyses indicate that factors affecting sediment availability such as low substrate sand proportions and high sediment loss rates cause a barrier to migrate landward along a trajectory having a lower slope than average barrier island slope, thereby defining an “effective” barrier island slope. Other factors being equal, such barriers will tend to be smaller and associated with a more deeply incised shoreface, thereby requiring less migration per sea level rise increment to liberate sufficient sand to maintain subaerial exposure than larger, less incised barriers. As a result, the evolution of larger/less incised barriers is more likely to be limited by shoreface erosion rates or substrate erodibility making them more prone to disintegration related to increasing sea level rise rates than smaller/more incised barriers. Thus, the small/deeply incised North Carolina barriers are likely to persist in the near term (although their long-term fate is less certain because of the low substrate slopes that will soon be encountered). In aggregate, results point to the importance of system history (e.g., previous slopes, sediment budgets, etc.) in determining migration trajectories and therefore how a barrier island will respond to sea level rise. Although simple analytical calculations may predict barrier response in simplified coastal environments (e.g., constant slope, constant sea level rise rate, etc.), our model experiments demonstrate that morphological-behavior modeling is necessary to provide critical insights regarding changes that may occur in environments having complex geometries, especially when multiple parameters change simultaneously.

Increasing P limitation and viral infection impact lipid remodeling of the picophytoplankter Micromonas pusilla

NASA Astrophysics Data System (ADS)

Maat, Douwe S.; Bale, Nicole J.; Hopmans, Ellen C.; Sinninghe Damsté, Jaap S.; Schouten, Stefan; Brussaard, Corina P. D.

2016-03-01

The intact polar lipid (IPL) composition of phytoplankton is plastic and dependent on environmental factors. Previous studies have shown that phytoplankton under low phosphorus (P) availability substitutes phosphatidylglycerols (PGs) with sulfoquinovosyldiacylglycerols (SQDGs) and digalactosyldiacylglycerols (DGDGs). However, these studies focused merely on P depletion, while phytoplankton in the natural environment often experience P limitation whereby the strength depends on the supply rate of the limiting nutrient. Here we report on the IPL composition of axenic cultures of the picophotoeukaryote Micromonas pusilla under different degrees of P limitation, i.e., P-controlled chemostats at 97 and 32 % of the maximum growth rate, and P starvation (obtained by stopping P supply to these chemostats). P-controlled cultures were also grown at elevated partial carbon dioxide pressure (pCO2) to mimic a future scenario of strengthened vertical stratification in combination with ocean acidification. Additionally, we tested the influence of viral infection for this readily infected phytoplankton host species. Results show that both SQDG : PG and DGDG : PG ratios increased with enhanced P limitation. Lipid composition was, however, not affected by enhanced (750 vs. 370 µatm) pCO2. In the P-starved virally infected cells the increase in SQDG : PG and DGDG : PG ratios was lower, whereby the extent depended on the growth rate of the host cultures before infection. The lipid membrane of the virus MpV-08T itself lacked some IPLs (e.g., monogalactosyldiacylglycerols; MGDGs) in comparison with its host. This study demonstrates that, besides P concentration, also the P supply rate, viral infection and even the history of the P supply rate can affect phytoplankton lipid composition (i.e., the non-phospholipid : phospholipid ratio), with possible consequences for the nutritional quality of phytoplankton.

Phosphorus limitation during a phytoplankton spring bloom in the western Dutch Wadden Sea

NASA Astrophysics Data System (ADS)

Ly, Juliette; Philippart, Catharina J. M.; Kromkamp, Jacco C.

2014-04-01

Like many aquatic ecosystems, the western Dutch Wadden Sea has undergone eutrophication. Due to changes in management policy, nutrient loads, especially phosphorus decreased after the mid-80s. It is still under debate, however, whether nutrients or light is limiting phytoplankton production in the western Wadden Sea, as studies using monitoring data delivered sometimes opposite conclusions and outcomes were related to years, seasons and approaches used. Clearly, the monitoring data alone were not sufficient. We therefore examined the limiting factors for the phytoplankton spring bloom using different experimental approaches. During the spring bloom in April 2010, we investigated several nutrient regimes on natural phytoplankton assemblages at a long term monitoring site, the NIOZ-Jetty sampling (Marsdiep, The Netherlands). Four bioassays, lasting 6 days each, were performed in controlled conditions. From changes in phytoplankton biomass, chlorophyll-a (Chla), we could conclude that the phytoplankton in general was mainly P-limited during this period, whereas a Si-P-co-limitation was likely for the diatom populations, when present. These results were confirmed by changes in the photosynthetic efficiency (Fv/Fm), in the expression of alkaline phosphatase activity (APA) measured with the fluorescent probe ELF-97, and in the 13C stable isotope incorporation in particulate organic carbon (POC). During our bioassay experiments, we observed a highly dynamic phytoplankton community with regard to species composition and growth rates. The considerable differences in net population growth rates, occurring under more or less similar environmental incubation conditions, suggest that phytoplankton species composition and grazing activity by small grazers were important structuring factors for net growth during this period.

Adding insult to injury: intimate partner violence among women and men reporting activity limitations.

PubMed

Cohen, Marsha M; Forte, Tonia; Du Mont, Janice; Hyman, Ilene; Romans, Sarah

2006-08-01

Women with activity limitations (ALs) are at risk for Intimate partner violence (IPV). This study examined IPV in men versus women with ALs. Data from the Canadian 1999 General Social Survey compared physical, sexual, emotional, and financial IPV from a current/expartner in 5 years for men and women with ALs compared with those without ALs. Logistic regression examined sex differences in IPV among those with ALs, adjusting for sociodemographic factors. Rates of physical (11.9% versus 7.8%; p < 0.0001), sexual (3.5% versus 1.4%; p < 0.0001), emotional (27.1% versus 17.7%; p < 0.0001), and financial (7.5% versus 3.4%; p < 0.0001) IPV were greater in women with compared with without ALs. A similar pattern was seen for men, with greater rates of physical (9.2% versus 6.6%; p = 0.006), emotional (22.6% versus 18.2%; p = 0.002), and financial (2.6% versus 1.4%; p = 0.005) IPV in men with ALs than men without ALs. Risk factors for IPV included younger age, being divorced/separated or single, and having lower income and poorer health. Women with ALs were more likely than men to experience any IPV (29.1% versus 24.9%) and more severe and more incidents of IPV. In multivariable analysis, women were no longer at greater risk for "any IPV" after adjusting for sociodemographic variables (odds ratio = 1.09; 95% confidence interval, 0.88-1.36). This is the first study to document IPV rates in men with ALs. Women with ALs were more likely to be divorced/separated, living in poverty, and in poorer health than men with ALs. These factors accounted for sex differences in IPV rates.

An analysis of the value of spermicides in contraception.

PubMed

1979-11-01

Development of the so-called modern methods of contraception has somewhat eclipsed interest in traditional methods. However, spermicides are still important for many couples and their use appears to be increasing. A brief history of the use of and research into spermicidal contraceptives is presented. The limitations of spermicides are: the necessity for use at the time of intercourse, and their high failure rate. Estimates of the failure rates of spermicides have ranged from .3 pregnancies per 100 woman-years of use to nearly 40, depending on the product used and the population tested. Just as their use depends on various social factors, so does their failure rate. Characteristics of the user deterine failure rates. Motivation is important in lowering failure rates as is education, the intracouple relationship, and previous experience with spermicides. Method failure is also caused by defects in the product, either in the active ingredient of the spermicide or in the base carrier. The main advantage of spermicidal contraception is its safety. Limited research is currently being conducted on spermicides. Areas for improvement in existing spermicides and areas for possible innovation are mentioned.

Response rates for mailout survey-driven studies in patients waiting for thyroid surgery.

PubMed

Eskander, Antoine; Freeman, Jeremy; Rotstein, Lorne; Higgins, Kevin; Enepekides, Danny; Gilbert, Ralph; Brown, Dale; Gullane, Patrick; Irish, Jonathan; Sawka, Anna M; Goldstein, David P

2011-12-01

In the surgical literature, mailout survey studies are becoming more prevalent. The objective of this article is to summarize response rates in patients waiting for thyroid surgery and to document the methodology of mailout survey questionnaires. The results reported here are from a study assessing clinical and sociodemographic factors associated with high levels of anxiety while patients are waiting for thyroid surgery. The surveys used in this study include a sociodemographic patient opinion questionnaire, the Hospital Anxiety Depression Scale (HADS), the Illness Intrusiveness Ratings Scale (IIRS), the Perceived Stress Scale (PSS), and the Impact of Events Scale-Revised (IES-R). A modified Dillman tailored design approach was used. Assessment of nonresponders was performed. The methods used yielded a response rate of 54% with this patient population. Some differences were noted among responders and nonresponders. This response rate is comparable to but in the lower spectrum of that stated in the oncology literature likely owing to the increase in the length of the survey, number of sensitive questions, limitations in the number of mailouts, and limited familiarity with the surgeon requesting participation in research.

Advanced techniques for modeling avian nest survival

USGS Publications Warehouse

Dinsmore, S.J.; White, Gary C.; Knopf, F.L.

2002-01-01

Estimation of avian nest survival has traditionally involved simple measures of apparent nest survival or Mayfield constant-nest-survival models. However, these methods do not allow researchers to build models that rigorously assess the importance of a wide range of biological factors that affect nest survival. Models that incorporate greater detail, such as temporal variation in nest survival and covariates representative of individual nests represent a substantial improvement over traditional estimation methods. In an attempt to improve nest survival estimation procedures, we introduce the nest survival model now available in the program MARK and demonstrate its use on a nesting study of Mountain Plovers (Charadrius montanus Townsend) in Montana, USA. We modeled the daily survival of Mountain Plover nests as a function of the sex of the incubating adult, nest age, year, linear and quadratic time trends, and two weather covariates (maximum daily temperature and daily precipitation) during a six-year study (1995–2000). We found no evidence for yearly differences or an effect of maximum daily temperature on the daily nest survival of Mountain Plovers. Survival rates of nests tended by female and male plovers differed (female rate = 0.33; male rate = 0.49). The estimate of the additive effect for males on nest survival rate was 0.37 (95% confidence limits were 0.03, 0.71) on a logit scale. Daily survival rates of nests increased with nest age; the estimate of daily nest-age change in survival in the best model was 0.06 (95% confidence limits were 0.04, 0.09) on a logit scale. Daily precipitation decreased the probability that the nest would survive to the next day; the estimate of the additive effect of daily precipitation on the nest survival rate was −1.08 (95% confidence limits were −2.12, −0.13) on a logit scale. Our approach to modeling daily nest-survival rates allowed several biological factors of interest to be easily included in nest survival models and allowed us to generate more biologically meaningful estimates of nest survival.

Uncertainty analysis of multi-rate kinetics of uranium desorption from sediments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xiaoying; Liu, Chongxuan; Hu, Bill X.

2014-01-01

A multi-rate expression for uranyl [U(VI)] surface complexation reactions has been proposed to describe diffusion-limited U(VI) sorption/desorption in heterogeneous subsurface sediments. An important assumption in the rate expression is that its rate constants follow a certain type probability distribution. In this paper, a Bayes-based, Differential Evolution Markov Chain method was used to assess the distribution assumption and to analyze parameter and model structure uncertainties. U(VI) desorption from a contaminated sediment at the US Hanford 300 Area, Washington was used as an example for detail analysis. The results indicated that: 1) the rate constants in the multi-rate expression contain uneven uncertaintiesmore » with slower rate constants having relative larger uncertainties; 2) the lognormal distribution is an effective assumption for the rate constants in the multi-rate model to simualte U(VI) desorption; 3) however, long-term prediction and its uncertainty may be significantly biased by the lognormal assumption for the smaller rate constants; and 4) both parameter and model structure uncertainties can affect the extrapolation of the multi-rate model with a larger uncertainty from the model structure. The results provide important insights into the factors contributing to the uncertainties of the multi-rate expression commonly used to describe the diffusion or mixing-limited sorption/desorption of both organic and inorganic contaminants in subsurface sediments.« less

Case-mix adjustment and enabled reporting of the health care experiences of adults with disabilities.

PubMed

Palsbo, Susan E; Diao, Guoqing; Palsbo, Gregory A; Tang, Liansheng; Rosenberger, William F; Mastal, Margaret F

2010-09-01

To develop activity limitation clusters for case-mix adjustment of health care ratings and as a population profiler, and to develop a cognitively accessible report of statistically reliable quality and access measures comparing the health care experiences of adults with and without disabilities, within and across health delivery organizations. Observational study. Three California Medicaid health care organizations. Adults (N = 1086) of working age enrolled for at least 1 year in Medicaid because of disability. Not applicable. Principal components analysis created 4 clusters of activity limitations that we used to characterize case mix. We identified and calculated 28 quality measures using responses from a proposed enabled version of the Consumer Assessment of Healthcare Providers and Systems (CAHPS) survey. We calculated scores for overall care as the weighted mean of the case-mix adjusted ratings. Disability caused a greater bias on health plan ratings and specialist ratings than did demographic factors. Proxy respondents rated care the same as self-respondents. Telephone and mail administration were equivalent for service reports, but telephone respondents tended to offer more positive global ratings. Plan-level reliability estimates for new composites on shared decision making and advice on healthy living are .79 and .87, respectively. Plan-level reliability estimates for a new composite measure on family planning did not discriminate between health plans because respondents rated all health plans poorly. Approximately 125 respondents per site are necessary to detect group differences. Self-reported activity limitations incorporating standard questions from the American Community Survey can be used to create a disability case-mix index and to construct profiles of a population's activity limitations. The enabled comparative report, which we call the Assessment of Health Plans and Providers by People with Activity Limitations, is more cognitively accessible than typical CAHPS report templates for state Medicaid plans. The CAHPS Medicaid reporting tools may provide misleading ratings of health plan and physician quality by people with disabilities because the mean ratings do not account for systematic biases associated with disability. More testing on larger populations would help to quantify the strength of various reporting biases.

Self-reported health and functional limitations among older people in the Kassena-Nankana District, Ghana.

PubMed

Debpuur, Cornelius; Welaga, Paul; Wak, George; Hodgson, Abraham

2010-09-27

Ghana is experiencing significant increases in its ageing population, yet research on the health and quality of life of older people is limited. Lack of data on the health and well-being of older people in the country makes it difficult to monitor trends in the health status of adults and the impact of social policies on their health and welfare. Research on ageing is urgently required to provide essential data for policy formulation and programme implementation. To describe the health status and identify factors associated with self-rated health (SRH) among older adults in a rural community in northern Ghana. The data come from a survey on Adult Health and Ageing in the Kassena-Nankana District involving 4,584 people aged 50 and over. Survey participants answered questions pertaining to their health status, including self-rated overall health, perceptions of well-being and quality of life, and self-reported assessment of functioning on a range of different health domains. Socio-demographic information such as age, sex, marital status and education were obtained from a demographic surveillance database. The majority of older people rated their health status as good, with the oldest old reporting poorer health. Multivariate regression analysis showed that functional ability and sex are significant factors in SRH status. Adults with higher levels of functional limitations were much more likely to rate their health as being poorer compared with those having lower disabilities. Household wealth was significantly associated with SRH, with wealthier adults more likely to rate their health as good. The depreciation in health and daily functioning with increasing age is likely to increase people's demand for health care and other services as they grow older. There is a need for regular monitoring of the health status of older people to provide public health agencies with the data they need to assess, protect and promote the health and well-being of older people.

Self-reported health and functional limitations among older people in the Kassena-Nankana District, Ghana

PubMed Central

Debpuur, Cornelius; Welaga, Paul; Wak, George; Hodgson, Abraham

2010-01-01

Background Ghana is experiencing significant increases in its ageing population, yet research on the health and quality of life of older people is limited. Lack of data on the health and well-being of older people in the country makes it difficult to monitor trends in the health status of adults and the impact of social policies on their health and welfare. Research on ageing is urgently required to provide essential data for policy formulation and programme implementation. Objective To describe the health status and identify factors associated with self-rated health (SRH) among older adults in a rural community in northern Ghana. Methods The data come from a survey on Adult Health and Ageing in the Kassena-Nankana District involving 4,584 people aged 50 and over. Survey participants answered questions pertaining to their health status, including self-rated overall health, perceptions of well-being and quality of life, and self-reported assessment of functioning on a range of different health domains. Socio-demographic information such as age, sex, marital status and education were obtained from a demographic surveillance database. Results The majority of older people rated their health status as good, with the oldest old reporting poorer health. Multivariate regression analysis showed that functional ability and sex are significant factors in SRH status. Adults with higher levels of functional limitations were much more likely to rate their health as being poorer compared with those having lower disabilities. Household wealth was significantly associated with SRH, with wealthier adults more likely to rate their health as good. Conclusion The depreciation in health and daily functioning with increasing age is likely to increase people's demand for health care and other services as they grow older. There is a need for regular monitoring of the health status of older people to provide public health agencies with the data they need to assess, protect and promote the health and well-being of older people. PMID:20963186

A social change perspective on injury prevention in China.

PubMed

Ozanne-Smith, Joan; Li, Qingfeng

2018-05-05

China has undergone massive social change over the past four decades. Since national estimates became available in 1987, the overall fatal injury rate has decreased. This paper investigates targeted interventions and sociodemographic factors that may have contributed to fatal injury rate changes particularly for road traffic fatality (RTF), suicide and drowning. (1) To review the recent epidemiology of injury in China.(2)To investigate factors influencing trends in overall and specific cause injury mortality rates. Published injury mortality statistics and related literature were reviewed. Factors potentially influencing trends were investigated in the context of rapid development based on literature reviews of targeted interventions, macrolevel and microlevel contextual factors and changes specific to RTF, suicide and drowning. Overall estimated national injury mortality rates in China decreased between 1987 and 2015, despite a rapid rise in RTF. Suicide and drowning rates decreased significantly and falls displaced drowning among the leading causes. The higher female to male suicide ratio reversed. Differences were observed in frequencies and proportions of deaths by major cause by age group and over time. Economic and structural development and related social change in this period include: urbanisation, changes in demographics, life choices (eg, internal migration), education, poverty alleviation, health insurance and relevant regulations/legislation. These factors potentially explain much of the change in fatal injury rates in China. Data limitations persist. Increased investment in data and research would provide realistic opportunities for accelerated progress in implementing effective targeted interventions to further reduce China's injury burden. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Alarm Limits for Intraoperative Drug Infusions: A Report From the Multicenter Perioperative Outcomes Group.

PubMed

Berman, Mitchell F; Iyer, Nikhil; Freudzon, Leon; Wang, Shuang; Freundlich, Robert E; Housey, Michelle; Kheterpal, Sachin

2017-10-01

Continuous medication infusions are commonly used during surgical procedures. Alarm settings for infusion pumps are considered important for patient safety, but limits are not created in a standardized manner from actual usage data. We estimated 90th and 95th percentile infusion rates from a national database for potential use as upper limit alarm settings. We extracted infusion rate data from 17 major hospitals using intraoperative records provided by Multicenter Perioperative Outcomes Group for adult surgery between 2008 and 2014. Seven infusions were selected for study: propofol, remifentanil, dexmedetomidine, norepinephrine, phenylephrine, nitroglycerin, and esmolol. Each dosage entry for an infusion during a procedure was included. We estimated the 50th, 90th, and 95th percentile levels for each infusion across institutions, and performed quantile regression to examine factors that might affect the percentiles rates, such as use in general anesthesia versus sedation. The median 90th and 95th percentile infusion rates (with interquartile range) for propofol were 150 (140-150) and 170 (150-200) μg/kg/min. Quantile regression demonstrated higher 90th and 95th percentile rates during sedation for gastrointestinal endoscopy than for all surgical procedures performed under general anesthesia. For selected vasoactive medications, the corresponding median 90th and 95th percentile rates (with interquartile range) were norepinephrine 14.0 (9.8-18.1) and 18.3 (12.6-23.9) μg/min, and phenylephrine 60 (55-80) and 80 (75-100) μg/min. Alarm settings based on infusion rate percentile limits would be triggered at predictable rates; ie, the 95th percentile would be exceeded and an alarm sounded during 1 in 20 infusion rate entries. As a result, institutions could establish pump alarm settings consistent with desired alarm frequency using their own or externally validated usage data. Further study will be needed to determine the optimal percentile for infusion alarm settings.

Injury severity and disability in the selection of next level of care following acute medical treatment for traumatic brain injury.

PubMed

Malec, James F; Mandrekar, Jayawant N; Brown, Allen W; Moessner, Anne M

2009-01-01

To evaluate the association of demographic factors, post-traumatic amnesia (PTA) and a standardized measure of ability limitations with clinical decisions for Next Level of Care following acute hospital treatment for moderate-severe traumatic brain injury (TBI). A TBI Clinical Nurse specialist recorded PTA for 212 individuals and rated 159 on the Ability and Adjustment Indices of the Mayo-Portland Adaptability Inventory (MPAI-4) for comparison with clinical decisions. Multivariate logistic regression analyses revealed that independent ratings on the MPAI-4 Ability Index and PTA were associated with the clinical decision to admit to Inpatient Rehabilitation vs discharge to Home in 92.7% of the sample; ratings on the Ability Index alone were associated with this decision in 92.2% of cases. Age over 65 was the only variable associated with discharge to a Skilled Nursing Facility, correctly predicting this decision in 64% of cases. Use of a standardized measure of ability limitations appears feasible to provide supportive documentation and potentially improve the consistency of decision-making in recommending Inpatient Rehabilitation vs discharge to Home. Although age is a significant factor in the decision to discharge to a Skilled Nursing Facility, this decision appears complex and merits further study.

Dissemination of Health-Related Research among Scientists in Three Countries: Access to Resources and Current Practices

PubMed Central

2015-01-01

Objectives. In public health and clinical settings insufficient dissemination of evidence-based practices limits the reach of new discoveries to broad populations. This study aimed to describe characteristics of the dissemination process by researchers across three countries (Brazil, United Kingdom, and United States), explore how designing for dissemination practices has been used, and analyze factors associated with dissemination. Methods. A similar online survey was used to query researchers across the three countries; data were pooled to draw cross-country conclusions. Findings. This study identified similarities and differences between countries. Importance of dissemination to nonresearcher audiences was widely recognized as important; however, traditional academic venues were the main dissemination method. Several factors were associated with self-rated dissemination effort in the pooled sample, but these predictive factors (e.g., support and resources for dissemination) had low prevalence. Less than one-third of researchers rated their level of effort for dissemination as excellent. Respondents reported limited support and resources to make it easier for researchers who might want to disseminate their findings. Conclusion. Though intentions show the importance of dissemination, researchers across countries lack supports to increase dissemination efforts. Additional resources and training in designing for dissemination along with improved partnerships could help bridge the research-practice gap. PMID:26495287

Dissemination of health-related research among scientists in three countries: access to resources and current practices.

PubMed

Tabak, Rachel G; Reis, Rodrigo S; Wilson, Paul; Brownson, Ross C

2015-01-01

In public health and clinical settings insufficient dissemination of evidence-based practices limits the reach of new discoveries to broad populations. This study aimed to describe characteristics of the dissemination process by researchers across three countries (Brazil, United Kingdom, and United States), explore how designing for dissemination practices has been used, and analyze factors associated with dissemination. A similar online survey was used to query researchers across the three countries; data were pooled to draw cross-country conclusions. This study identified similarities and differences between countries. Importance of dissemination to nonresearcher audiences was widely recognized as important; however, traditional academic venues were the main dissemination method. Several factors were associated with self-rated dissemination effort in the pooled sample, but these predictive factors (e.g., support and resources for dissemination) had low prevalence. Less than one-third of researchers rated their level of effort for dissemination as excellent. Respondents reported limited support and resources to make it easier for researchers who might want to disseminate their findings. Though intentions show the importance of dissemination, researchers across countries lack supports to increase dissemination efforts. Additional resources and training in designing for dissemination along with improved partnerships could help bridge the research-practice gap.

Limited experience, high body mass index and previous urethral surgery are risk factors for failure in open urethroplasty due to penile strictures.

PubMed

Ekerhult, Teresa O; Lindqvist, Klas; Peeker, Ralph; Grenabo, Lars

2015-01-01

The aim of this study was to evaluate outcomes and possible risk factors for failure of open urethroplasty due to penile urethral strictures. A retrospective chart review was undertaken of 90 patients with penile stricture undergoing 109 open urethroplasties between 2000 and 2011. In 80 urethroplasties, a one-stage procedure was performed: 68 of these had a pediculated penile skin flap, nine had a free buccal mucosal graft and three had a free skin graft. A two-stage procedure using buccal mucosa was performed in 29 urethroplasties. Failure was defined as when further urethral instrumentation was needed. The mean age in the one-stage and two-stage groups were 50 and 54 years, respectively. The success rates in the corresponding groups were 65% and 72%, with follow-up times of 63 and 40 months, respectively. Multivariable analyses disclosed body mass index (BMI) and previous urethral surgery to be significant risk factors for failure in the one-stage group. Failure over time significantly decreased during the study period. Both one- and two-stage penile urethroplasty demonstrated success rates in line with previous reports. Limited experience, high BMI and previous urethral surgery appear to be associated with less favourable outcome.

Deriving in vivo biotransformation rate constants and metabolite parent concentration factor/stable metabolite factor from bioaccumulation and bioconcentration experiments: An illustration with worm accumulation data.

PubMed

Kuo, Dave Ta Fu; Chen, Ciara Chun

2016-12-01

Growing concern for the biological fate of organic contaminants and their metabolites and the urge to connect in vitro and in vivo toxicokinetics have prompted researchers to characterize the biotransformation behavior of organic contaminants in biota. The whole body biotransformation rate constant (k M ) is currently determined by the difference approach, which has significant methodological limitations. A new approach for determining k M from the kinetic observations of the parent contaminant and its intermediate metabolites is proposed. In this method, k M can be determined by fitting kinetic data of the parent contaminant and the metabolites to analytical equations that depict the bioaccumulation kinetics. The application of the proposed method is illustrated using worm bioaccumulation-biotransformation data collected from the literature. Furthermore, a metabolite parent concentration factor (MPCF) is also proposed to characterize the persistence of the metabolite in biota. Because both the proposed k M method and MPCF build on the existing theoretical framework for bioaccumulation, they can be readily incorporated into standard experimental bioaccumulation protocols or risk assessment procedures or frameworks. Possible limitations, implications, and future directions are elaborated. Environ Toxicol Chem 2016;35:2903-2909. © 2016 SETAC. © 2016 SETAC.

Particle bed reactor modeling

NASA Technical Reports Server (NTRS)

Sapyta, Joe; Reid, Hank; Walton, Lew

1993-01-01

The topics are presented in viewgraph form and include the following: particle bed reactor (PBR) core cross section; PBR bleed cycle; fuel and moderator flow paths; PBR modeling requirements; characteristics of PBR and nuclear thermal propulsion (NTP) modeling; challenges for PBR and NTP modeling; thermal hydraulic computer codes; capabilities for PBR/reactor application; thermal/hydralic codes; limitations; physical correlations; comparison of predicted friction factor and experimental data; frit pressure drop testing; cold frit mask factor; decay heat flow rate; startup transient simulation; and philosophy of systems modeling.

Measurements of the linear energy transfer spectra on the Mir orbital station and comparison with radiation transport models

NASA Technical Reports Server (NTRS)

Badhwar, G. D.; Konradi, A.; Atwell, W.; Golightly, M. J.; Cucinotta, F. A.; Wilson, J. W.; Petrov, V. M.; Tchernykh, I. V.; Shurshakov, V. A.; Lobakov, A. P.

1996-01-01

A tissue equivalent proportional counter designed to measure the linear energy transfer spectra (LET) in the range 0.2-1250 keV/micrometer was flown in the Kvant module on the Mir orbital station during September 1994. The spacecraft was in a 51.65 degrees inclination, elliptical (390 x 402 km) orbit. This is nearly the lower limit of its flight altitude. The total absorbed dose rate measured was 411.3 +/- 4.41 microGy/day with an average quality factor of 2.44. The galactic cosmic radiation (GCR) dose rate was 133.6 microGy/day with a quality factor of 3.35. The trapped radiation belt dose rate was 277.7 microGy/day with an average quality factor of 1.94. The peak rate through the South Atlantic Anomaly was approximately 12 microGy/min and nearly constant from one pass to another. A detailed comparison of the measured LET spectra has been made with radiation transport models. The GCR results are in good agreement with model calculations; however, this is not the case for radiation belt particles and again points to the need for improving the AP8 omni-directional trapped proton models.

Perforated peptic ulcer: how to improve outcome?

PubMed

Møller, Morten Hylander; Adamsen, Sven; Wøjdemann, Morten; Møller, Ann Merete

2009-01-01

Despite the introduction of histamine H2-receptor antagonists, proton-pump inhibitors and the discovery of Helicobacter pylori, both the incidence of emergency surgery for perforated peptic ulcer and the mortality rate for patients undergoing surgery for peptic ulcer perforation have increased. This increase has occurred despite improvements in perioperative treatment and monitoring. To improve the outcome of these patients, it is necessary to investigate the reasons behind this high mortality rate. In this review we evaluate the existing evidence in order to identify significant risk factors with an emphasis on risks that are preventable. A systematic review including randomized studies was carried out. There are a limited number of studies of patients with peptic ulcer perforation. Most of these studies are of low evident status. Only a few randomized, controlled trials have been published. The mortality rate and the extent of postoperative complications are fairly high but the reasons for this have not been thoroughly explained, even though a number of risk factors have been identified. Some of these risk factors can be explained by the septic state of the patient on admission. In order to improve the outcome of patients with peptic ulcer perforation, sepsis needs to be factored into the existing knowledge and treatment.

A Concept Mapping Study of Physicians' Perceptions of Factors Influencing Management and Control of Hypertension in Sub-Saharan Africa

PubMed Central

Iwelunmor, Juliet; Blackstone, Sarah; Gyamfi, Joyce; Airhihenbuwa, Collins; Plange-Rhule, Jacob; Tayo, Bamidele; Adanu, Richard; Ogedegbe, Gbenga

2015-01-01

Hypertension, once a rare problem in Sub-Saharan Africa (SSA), is predicted to be a major cause of death by 2020 with mortality rates as high as 75%. However, comprehensive knowledge of provider-level factors that influence optimal management is limited. The objective of the current study was to discover physicians' perceptions of factors influencing optimal management and control of hypertension in SSA. Twelve physicians attending the Cardiovascular Research Training (CaRT) Institute at the University of Ghana, College of Health Sciences, were invited to complete a concept mapping process that included brainstorming the factors influencing optimal management and control of hypertension in patients, sorting and organizing the factors into similar domains, and rating the importance and feasibility of efforts to address these factors. The highest ranked important and feasible factors include helping patients accept their condition and availability of adequate equipment to enable the provision of needed care. The findings suggest that patient self-efficacy and support, physician-related factors, policy factors, and economic factors are important aspects that must be addressed to achieve optimal hypertension management. Given the work demands identified by physicians, future research should investigate cost-effective strategies of shifting physician responsibilities to well-trained no-physician clinicians in order to improve hypertension management. PMID:26550488

On the Collisionless Asymmetric Magnetic Reconnection Rate

NASA Astrophysics Data System (ADS)

Liu, Yi-Hsin; Hesse, M.; Cassak, P. A.; Shay, M. A.; Wang, S.; Chen, L.-J.

2018-04-01

A prediction of the steady state reconnection electric field in asymmetric reconnection is obtained by maximizing the reconnection rate as a function of the opening angle made by the upstream magnetic field on the weak magnetic field (magnetosheath) side. The prediction is within a factor of 2 of the widely examined asymmetric reconnection model (Cassak & Shay, 2007, https://doi.org/10.1063/1.2795630) in the collisionless limit, and they scale the same over a wide parameter regime. The previous model had the effective aspect ratio of the diffusion region as a free parameter, which simulations and observations suggest is on the order of 0.1, but the present model has no free parameters. In conjunction with the symmetric case (Liu et al., 2017, https://doi.org/10.1103/PhysRevLett.118.085101), this work further suggests that this nearly universal number 0.1, essentially the normalized fast-reconnection rate, is a geometrical factor arising from maximizing the reconnection rate within magnetohydrodynamic-scale constraints.

Infiltration on mountain slopes: a comparison of three environments.

Treesearch

Carol P. Harden*; P. Delmas Scruggs

2003-01-01

Water is well established as a major driver of the geomorphic change that eventually reduces mountains to lower relief landscapes. Nonetheless, within the altitudinal limits of continuous vegetation in humid climates, water is also an essential factor in slope stability. In this paper, we present results from field experiments to determine infiltration rates at...

World Food Security and Insecurity, 1984-2000.

ERIC Educational Resources Information Center

Farrell, Kenneth R.

Effective economic demand, rather than resource constraints, will continue to be the dominant limiting factor in improving the security of world food supplies between now and the year 2000. The global demand for food will continue to grow but the rate of growth is declining in virtually all regions, easing the pressure on agricultural resources.…

78 FR 64913 - Certain New Pneumatic Off-the-Road Tires From the People's Republic of China: Initiation of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-30

.... (``Leo Rubber''), a separate-rate respondent in the original investigation. DATES: Effective: October 30... Uruguay Round Agreements Act (``URAA''), regarding the antidumping duty investigation on OTR Tires from... determination, the Department typically examines several factors including, but not limited to, changes in: (1...

Factors affecting pregnancy rates after ovum pick up-derived embryo transfer in lactating Holstein recipients under tropical conditions

USDA-ARS?s Scientific Manuscript database

High milk production, heat, physiological status and management impair reproduction in Holstein cows. The use of in vivo-produced embryos has been reported as an alternative to enhance pregnancy outcome in the tropics; however there are several limitations for its production, especially from variati...

Parental Characteristics and Resiliency in Identification Rates for Special Education

ERIC Educational Resources Information Center

Anderson, Jeffrey A.; Howland, Allison A.; McCoach, D. Betsy

2015-01-01

Even with increased risks, many children demonstrate resiliency and avoid being labeled for special education; however, research on risk and resilience has been problematic because of inadequate statistical models, limitations of available data, and the exclusion of key protective factors. This study used a national sample to examine the influence…

Linking thermal tolerances and biogeography: Mytilus edulis (L.) at its southern limit on the east coast of the United States.

PubMed

Jones, Sierra J; Mieszkowska, Nova; Wethey, David S

2009-08-01

Temperature is a major factor contributing to the latitudinal distribution of species. In the Northern Hemisphere, a species is likely to be living very close to its upper thermal tolerance limits at the southern limit of its biogeographic range. With global warming, this southern limit is expected to shift poleward. Moreover, intertidal ecosystems are expected to be especially strongly affected, mostly due to their large daily and seasonal variations in temperature and exposure. Hence, these are model systems in which to conduct experiments examining the ecological effects of climate change. In this study we determined the upper lethal thermal limits, for both air and water, of the blue mussel Mytilus edulis via laboratory experiments. Tolerances vary seasonally, with a difference between media of 0.7 degrees C in June and 4.8 degrees C in November, as well as a decrease with multiple exposures. Measured lethal limits were then compared to field measurements of environmental temperature and concurrent measurements of mortality rates. Field results indicate that mortality in the intertidal occurs at rates expected from laboratory responses to elevated temperature. Hindcasts, retrospective analyses of historical data, indicate that high rates of mortality have shifted 51 and 42 days earlier in Beaufort, North Carolina, and Oregon Inlet, North Carolina, respectively, between 1956 and 2007. The combined data suggest that the historical southern limit of M. edulis near Cape Hatteras, North Carolina, is indeed the result of intolerance to high temperature, and that this range edge is shifting poleward in a manner indicative of global warming.

Heat and mass transfer models to understand the drying mechanisms of a porous substrate.

PubMed

Songok, Joel; Bousfield, Douglas W; Gane, Patrick A C; Toivakka, Martti

2016-02-01

While drying of paper and paper coatings is expensive, with significant energy requirements, the rate controlling mechanisms are not currently fully understood. Two two-dimensional models are used as a first approximation to predict the heat transfer during hot air drying and to evaluate the role of various parameters on the drying rates of porous coatings. The models help determine the structural limiting factors during the drying process, while applying for the first time the recently known values of coating thermal diffusivity. The results indicate that the thermal conductivity of the coating structure is not the controlling factor, but the drying rate is rather determined by the thermal transfer process at the structure surface. This underlines the need for ensuring an efficient thermal transfer from hot air to coating surface during drying, before considering further measures to increase the thermal conductivity of porous coatings.

High cholesterol level is essential for myelin membrane growth.

PubMed

Saher, Gesine; Brügger, Britta; Lappe-Siefke, Corinna; Möbius, Wiebke; Tozawa, Ryu-ichi; Wehr, Michael C; Wieland, Felix; Ishibashi, Shun; Nave, Klaus-Armin

2005-04-01

Cholesterol in the mammalian brain is a risk factor for certain neurodegenerative diseases, raising the question of its normal function. In the mature brain, the highest cholesterol content is found in myelin. We therefore created mice that lack the ability to synthesize cholesterol in myelin-forming oligodendrocytes. Mutant oligodendrocytes survived, but CNS myelination was severely perturbed, and mutant mice showed ataxia and tremor. CNS myelination continued at a reduced rate for many months, and during this period, the cholesterol-deficient oligodendrocytes actively enriched cholesterol and assembled myelin with >70% of the cholesterol content of wild-type myelin. This shows that cholesterol is an indispensable component of myelin membranes and that cholesterol availability in oligodendrocytes is a rate-limiting factor for brain maturation.

The effects of working memory resource depletion and training on sensorimotor adaptation

PubMed Central

Anguera, Joaquin A.; Bernard, Jessica A.; Jaeggi, Susanne M.; Buschkuehl, Martin; Benson, Bryan L.; Jennett, Sarah; Humfleet, Jennifer; Reuter-Lorenz, Patricia; Jonides, John; Seidler, Rachael D.

2011-01-01

We have recently demonstrated that visuospatial working memory performance predicts the rate of motor skill learning, particularly during the early phase of visuomotor adaptation. Here, we follow up these correlational findings with direct manipulations of working memory resources to determine the impact on visuomotor adaptation, a form of motor learning. We conducted two separate experiments. In the first one, we used a resource depletion strategy to investigate whether the rate of early visuomotor adaptation would be negatively affected by fatigue of spatial working memory resources. In the second study, we employed a dual n-back task training paradigm that has been shown to result in transfer effects [1] over five weeks to determine whether training-related improvements would boost the rate of early visuomotor adaptation. The depletion of spatial working memory resources negatively affected the rate of early visuomotor adaptation. However, enhancing working memory capacity via training did not lead to improved rates of visuomotor adaptation, suggesting that working memory capacity may not be the factor limiting maximal rate of visuomotor adaptation in young adults. These findings are discussed from a resource limitation / capacity framework with respect to current views of motor learning. PMID:22155489

Climate Change Impacts on Waterborne Diseases: Moving Toward Designing Interventions.

PubMed

Levy, Karen; Smith, Shanon M; Carlton, Elizabeth J

2018-06-01

Climate change threatens progress achieved in global reductions of infectious disease rates over recent decades. This review summarizes literature on potential impacts of climate change on waterborne diseases, organized around a framework of questions that can be addressed depending on available data. A growing body of evidence suggests that climate change may alter the incidence of waterborne diseases, and diarrheal diseases in particular. Much of the existing work examines historical relationships between weather and diarrhea incidence, with a limited number of studies projecting future disease rates. Some studies take social and ecological factors into account in considerations of historical relationships, but few have done so in projecting future conditions. The field is at a point of transition, toward incorporating social and ecological factors into understanding the relationships between climatic factors and diarrheal diseases and using this information for future projections. The integration of these components helps identify vulnerable populations and prioritize adaptation strategies.

Which factors affect limitation of pronation/supination after forearm fractures in children? A prospective multicentre study.

PubMed

Colaris, Joost W; Allema, Jan Hein; Reijman, Max; de Vries, Mark R; Ulas Biter, L; Bloem, Rolf M; van de Ven, Cees P; Verhaar, Jan A N

2014-04-01

Both-bone forearm fractures in children frequently result in a limitation of pronation/supination, which hinders daily activities. The purpose of this prospective multicentre study was to investigate which clinical factors are related to the limitation of pronation/supination in children with a both-bone forearm fracture. In four Dutch hospitals, consecutive children (<16 years) who sustained a both-bone forearm fracture were included. Children were followed up for 6-9 months and data from questionnaires, physical examination and X-rays were collected. Univariate and multivariate logistic regression analyses were used to assess the relationship between limitation of pronation/supination (≥20°) and several clinical factors. A group of 410 children with both-bone forearm fractures were included, of which 10 children missed the final examination (follow-up rate of 97.6%). We found that a re-fracture (odds ratio (OR) 11.7, 95% confidence interval (CI) 1.2; 118.5), a fracture in the diaphysis (OR 3.3, 95% CI 1.4; 7.9) and less physiotherapy during follow-up (OR 0.90, 95% CI 0.82; 0.98) were independently associated with a limitation of pronation/supination of 20° or more. These findings imply that a re-fracture and a diaphyseal located fracture were associated independently of each other with a limitation of pronation/supination in children with a both-bone forearm fracture. Furthermore, in children with severe limitation extensive physiotherapy is associated with better functional outcome. Copyright © 2013 Elsevier Ltd. All rights reserved.

Hydrologic controls on nitrogen cycling processes and functional gene abundance in sediments of a groundwater flow-through lake

USGS Publications Warehouse

Stoliker, Deborah L.; Repert, Deborah A.; Smith, Richard L.; Song, Bongkeun; LeBlanc, Denis R.; McCobb, Timothy D.; Conaway, Christopher; Hyun, Sung Pil; Koh, Dong-Chan; Moon, Hee Sun; Kent, Douglas B.

2016-01-01

The fate and transport of inorganic nitrogen (N) is a critically important issue for human and aquatic ecosystem health because discharging N-contaminated groundwater can foul drinking water and cause algal blooms. Factors controlling N-processing were examined in sediments at three sites with contrasting hydrologic regimes at a lake on Cape Cod, MA. These factors included water chemistry, seepage rates and direction of groundwater flow, and the abundance and potential rates of activity of N-cycling microbial communities. Genes coding for denitrification, anaerobic ammonium oxidation (anammox), and nitrification were identified at all sites regardless of flow direction or groundwater dissolved oxygen concentrations. Flow direction was, however, a controlling factor in the potential for N-attenuation via denitrification in the sediments. Potential rates of denitrification varied from 6 to 4500 pmol N/g/h from the inflow to the outflow side of the lake, owing to fundamental differences in the supply of labile organic matter. The results of laboratory incubations suggested that when anoxia and limiting labile organic matter prevailed, the potential existed for concomitant anammox and denitrification. Where oxic lake water was downwelling, potential rates of nitrification at shallow depths were substantial (1640 pmol N/g/h). Rates of anammox, denitrification, and nitrification may be linked to rates of organic N-mineralization, serving to increase N-mobility and transport downgradient.

Hydrologic Controls on Nitrogen Cycling Processes and Functional Gene Abundance in Sediments of a Groundwater Flow-Through Lake.

PubMed

Stoliker, Deborah L; Repert, Deborah A; Smith, Richard L; Song, Bongkeun; LeBlanc, Denis R; McCobb, Timothy D; Conaway, Christopher H; Hyun, Sung Pil; Koh, Dong-Chan; Moon, Hee Sun; Kent, Douglas B

2016-04-05

The fate and transport of inorganic nitrogen (N) is a critically important issue for human and aquatic ecosystem health because discharging N-contaminated groundwater can foul drinking water and cause algal blooms. Factors controlling N-processing were examined in sediments at three sites with contrasting hydrologic regimes at a lake on Cape Cod, MA. These factors included water chemistry, seepage rates and direction of groundwater flow, and the abundance and potential rates of activity of N-cycling microbial communities. Genes coding for denitrification, anaerobic ammonium oxidation (anammox), and nitrification were identified at all sites regardless of flow direction or groundwater dissolved oxygen concentrations. Flow direction was, however, a controlling factor in the potential for N-attenuation via denitrification in the sediments. Potential rates of denitrification varied from 6 to 4500 pmol N/g/h from the inflow to the outflow side of the lake, owing to fundamental differences in the supply of labile organic matter. The results of laboratory incubations suggested that when anoxia and limiting labile organic matter prevailed, the potential existed for concomitant anammox and denitrification. Where oxic lake water was downwelling, potential rates of nitrification at shallow depths were substantial (1640 pmol N/g/h). Rates of anammox, denitrification, and nitrification may be linked to rates of organic N-mineralization, serving to increase N-mobility and transport downgradient.

Resource Supply Overrides Temperature as a Controlling Factor of Marine Phytoplankton Growth

PubMed Central

Marañón, Emilio; Cermeño, Pedro; Huete-Ortega, María; López-Sandoval, Daffne C.; Mouriño-Carballido, Beatriz; Rodríguez-Ramos, Tamara

2014-01-01

The universal temperature dependence of metabolic rates has been used to predict how ocean biology will respond to ocean warming. Determining the temperature sensitivity of phytoplankton metabolism and growth is of special importance because this group of organisms is responsible for nearly half of global primary production, sustains most marine food webs, and contributes to regulate the exchange of CO2 between the ocean and the atmosphere. Phytoplankton growth rates increase with temperature under optimal growth conditions in the laboratory, but it is unclear whether the same degree of temperature dependence exists in nature, where resources are often limiting. Here we use concurrent measurements of phytoplankton biomass and carbon fixation rates in polar, temperate and tropical regions to determine the role of temperature and resource supply in controlling the large-scale variability of in situ metabolic rates. We identify a biogeographic pattern in phytoplankton metabolic rates, which increase from the oligotrophic subtropical gyres to temperate regions and then coastal waters. Variability in phytoplankton growth is driven by changes in resource supply and appears to be independent of seawater temperature. The lack of temperature sensitivity of realized phytoplankton growth is consistent with the limited applicability of Arrhenius enzymatic kinetics when substrate concentrations are low. Our results suggest that, due to widespread resource limitation in the ocean, the direct effect of sea surface warming upon phytoplankton growth and productivity may be smaller than anticipated. PMID:24921945

The Association between State Policy Environments and Self-Rated Health Disparities for Sexual Minorities in the United States.

PubMed

Gonzales, Gilbert; Ehrenfeld, Jesse M

2018-06-01

A large body of research has documented disparities in health and access to care for lesbian, gay, and bisexual (LGB) people in the United States. Less research has examined how the level of legal protection afforded to LGB people (the state policy environment) affects health disparities for sexual minorities. This study used data on 14,687 sexual minority adults and 490,071 heterosexual adults from the 2014⁻2016 Behavioral Risk Factor Surveillance System to document differences in health. Unadjusted state-specific prevalence estimates and multivariable logistic regression models were used to compare poor/fair self-rated health by gender, sexual minority status, and state policy environments (comprehensive versus limited protections for LGB people). We found disparities in self-rated health between sexual minority adults and heterosexual adults in most states. On average, sexual minority men in states with limited protections and sexual minority women in states with either comprehensive or limited protections were more likely to report poor/fair self-rated health compared to their heterosexual counterparts. This study adds new findings on the association between state policy environments and self-rated health for sexual minorities and suggests differences in this relationship by gender. The associations and impacts of state-specific policies affecting LGB populations may vary by gender, as well as other intersectional identities.

Development of the Multiple Use Plug Hybrid for Nanosats (MUPHyN) miniature thruster

NASA Astrophysics Data System (ADS)

Eilers, Shannon

The Multiple Use Plug Hybrid for Nanosats (MUPHyN) prototype thruster incorporates solutions to several major challenges that have traditionally limited the deployment of chemical propulsion systems on small spacecraft. The MUPHyN thruster offers several features that are uniquely suited for small satellite applications. These features include 1) a non-explosive ignition system, 2) non-mechanical thrust vectoring using secondary fluid injection on an aerospike nozzle cooled with the oxidizer flow, 3) a non-toxic, chemically-stable combination of liquid and inert solid propellants, 4) a compact form factor enabled by the direct digital manufacture of the inert solid fuel grain. Hybrid rocket motors provide significant safety and reliability advantages over both solid composite and liquid propulsion systems; however, hybrid motors have found only limited use on operational vehicles due to 1) difficulty in modeling the fuel flow rate 2) poor volumetric efficiency and/or form factor 3) significantly lower fuel flow rates than solid rocket motors 4) difficulty in obtaining high combustion efficiencies. The features of the MUPHyN thruster are designed to offset and/or overcome these shortcomings. The MUPHyN motor design represents a convergence of technologies, including hybrid rocket regression rate modeling, aerospike secondary injection thrust vectoring, multiphase injector modeling, non-pyrotechnic ignition, and nitrous oxide regenerative cooling that address the traditional challenges that limit the use of hybrid rocket motors and aerospike nozzles. This synthesis of technologies is unique to the MUPHyN thruster design and no comparable work has been published in the open literature.

Response of the unicellular diazotrophic cyanobacterium Crocosphaera watsonii to iron limitation.

PubMed

Jacq, Violaine; Ridame, Céline; L'Helguen, Stéphane; Kaczmar, Fanny; Saliot, Alain

2014-01-01

Iron (Fe) is widely suspected as a key controlling factor of N2 fixation due to the high Fe content of nitrogenase and photosynthetic enzymes complex, and to its low concentrations in oceanic surface seawaters. The influence of Fe limitation on the recently discovered unicellular diazotrophic cyanobacteria (UCYN) is poorly understood despite their biogeochemical importance in the carbon and nitrogen cycles. To address this knowledge gap, we conducted culture experiments on Crocosphaera watsonii WH8501 growing under a range of dissolved Fe concentrations (from 3.3 to 403 nM). Overall, severe Fe limitation led to significant decreases in growth rate (2.6-fold), C, N and chlorophyll a contents per cell (up to 4.1-fold), N2 and CO2 fixation rates per cell (17- and 7-fold) as well as biovolume (2.2-fold). We highlighted a two phased response depending on the degree of limitation: (i) under a moderate Fe limitation, the biovolume of C. watsonii was strongly reduced, allowing the cells to keep sufficient energy to maintain an optimal growth, volume-normalized contents and N2 and CO2 fixation rates; (ii) with increasing Fe deprivation, biovolume remained unchanged but the entire cell metabolism was affected, as shown by a strong decrease in the growth rate, volume-normalized contents and N2 and CO2 fixation rates. The half-saturation constant for growth of C. watsonii with respect to Fe is twice as low as that of the filamentous Trichodesmium indicating a better adaptation of C. watsonii to poor Fe environments than filamentous diazotrophs. The physiological response of C. watsonii to Fe limitation was different from that previously shown on the UCYN Cyanothece sp, suggesting potential differences in Fe requirements and/or Fe acquisition within the UCYN community. These results contribute to a better understanding of how Fe bioavailability can control the activity of UCYN and explain the biogeography of diverse N2 fixers in ocean.

Job Accommodations Availability and Utilization Among People With Lupus: An Examination of Workplace Activity Limitations and Work Context Factors.

PubMed

Al Dhanhani, Ali M; Gignac, Monique A M; Beaton, Dorcas E; Su, Jiandong; Fortin, Paul R

2015-11-01

The aim of this study was to examine the availability of diverse job accommodations (or flexible working arrangements) and to describe their use among people with systemic lupus erythematosus (lupus), as well as to examine factors associated with the use of job accommodations. A mail survey was sent to adult lupus patients receiving care from a lupus clinic based in Toronto, Canada. The survey assessed demographic information, self-reported disease activity, work history, workplace activity limitations, job strain, and the availability and use of job accommodations. Standard multivariable linear regression analysis was used to examine factors associated with the use of job accommodations. We received 362 responses of 604 mailed surveys (60% response rate). Participants who were employed within the last 5 years, but who were not currently working, were less likely than currently employed participants to report having had job accommodations available to them at their last place of employment. The use of job accommodations was reported by 70% of currently employed respondents and by 72% of those not currently employed. The most common job accommodation used was sick leave days. Factors positively associated with the use of job accommodations among those who were employed included higher levels of education, being diagnosed with fibromyalgia, at least 1 episode of short-term work disability, not belonging to a union, greater workplace activity limitations, and greater job strain. The use of job accommodations among people with lupus is common. Work context factors, such as workplace activity limitations and job strain, are the main factors associated with the use of job accommodations. © 2015, American College of Rheumatology.

A Conceptual Framework for Barriers to the Recruitment and Retention of Rural CVD Participants in Behavior Intervention Trials.

PubMed

Young, Lufei; Montgomery, Melody; Barnason, Sue; Schmidt, Cindy; Do, Van

2015-08-01

Rural residents diagnosed with cardiovascular disease (CVD) or with CVD-related risks are underrepresented in behavioral intervention trials based on an extensive review of published studies. The low participation rate of rural residents weakens both the internal and external validity of published studies. Moreover, compared to urban residents, limited research exists to describe the unique barriers that limit the participation of rural residents in behavioral intervention trials. The purpose of this review is to identify a conceptual framework (CF) underpinning common barriers faced by rural CVD patients to enroll in behavioral intervention trials. We conducted a literature review using several electronic databases to obtain a representative sample of research articles, synthesized the evidence, and developed a CF to explain the barriers that may affect the research participation rate of rural residents with CVD or related risks. We found our evidence-based CF well explained the barriers for rural CVD patients to take part in behavioral intervention trials. Besides contextual factors (i.e. patient, community and research levels), other common factors impacting rural patients' intent to enroll are lack of awareness and understanding about behavioral trials, limited support from their healthcare providers and social circles, unfavorable attitudes, and the lack of opportunity to participating research. The findings demonstrate the evidence-based model consisting of interlinked multi-level factors may help our understanding of the barriers encountered by rural CVD patients participating interventions to promote behavioral change. The implication for researchers is that identifying and developing strategies to overcome the barriers precedes conducting studies in rural communities.

Assessing access to MRI of patients with magnetic resonance-conditional pacemaker and implantable cardioverter defibrillator systems: the Really ProMRI study design.

PubMed

Maglia, Giampiero; Curnis, Antonio; Brieda, Marco; Anaclerio, Matteo; Caccavo, Vincenzo; Bonfanti, Paolo; Melissano, Donato; Caravati, Fabrizio; Giovene, Lisa; Gargaro, Alessio

2015-10-01

Despite the fact that magnetic resonance (MR)-conditional pacemaker and lead systems have been introduced more than 5 years ago, it is still not clear whether they have actually facilitated the access of pacemaker patients to this important diagnostic tool. Factors limiting MR scans in daily practice in patients with MR-conditional cardiac implantable electronic device (CIED) systems may be related to organizational, cultural and sometimes legal aspects. The Really ProMRI registry is an ongoing survey designed to assess the annual rate of MR examinations in patients with MR-conditional implants, with either pacemakers or implantable cardioverter defibrillators, and to detect the main factors limiting MRI. The primary endpoint of the Really ProMRI registry is to assess the current access to MRI of patients with MR-conditional pacemaker or implantable cardioverter defibrillator systems during normal practice. Data in the literature reported a 17% annual incidence of medical conditions requiring MRI in CIED patients. The Really ProMRI registry has been designed to detect 4.5% absolute difference with an 80% statistical power, by recruiting 600 patients already implanted with MR-conditional CIED implant. Patients will be followed up for 1 year, during which they will be asked to refer any prescription, execution or denial of an MR examination by patient questionnaires and original source documents. The ongoing Really ProMRI registry will assess the actual rate of and factors limiting the access to MRI for patients with MR-conditional CIEDs.

Identification of growth phases and influencing factors in cultivations with AGE1.HN cells using set-based methods.

PubMed

Borchers, Steffen; Freund, Susann; Rath, Alexander; Streif, Stefan; Reichl, Udo; Findeisen, Rolf

2013-01-01

Production of bio-pharmaceuticals in cell culture, such as mammalian cells, is challenging. Mathematical models can provide support to the analysis, optimization, and the operation of production processes. In particular, unstructured models are suited for these purposes, since they can be tailored to particular process conditions. To this end, growth phases and the most relevant factors influencing cell growth and product formation have to be identified. Due to noisy and erroneous experimental data, unknown kinetic parameters, and the large number of combinations of influencing factors, currently there are only limited structured approaches to tackle these issues. We outline a structured set-based approach to identify different growth phases and the factors influencing cell growth and metabolism. To this end, measurement uncertainties are taken explicitly into account to bound the time-dependent specific growth rate based on the observed increase of the cell concentration. Based on the bounds on the specific growth rate, we can identify qualitatively different growth phases and (in-)validate hypotheses on the factors influencing cell growth and metabolism. We apply the approach to a mammalian suspension cell line (AGE1.HN). We show that growth in batch culture can be divided into two main growth phases. The initial phase is characterized by exponential growth dynamics, which can be described consistently by a relatively simple unstructured and segregated model. The subsequent phase is characterized by a decrease in the specific growth rate, which, as shown, results from substrate limitation and the pH of the medium. An extended model is provided which describes the observed dynamics of cell growth and main metabolites, and the corresponding kinetic parameters as well as their confidence intervals are estimated. The study is complemented by an uncertainty and outlier analysis. Overall, we demonstrate utility of set-based methods for analyzing cell growth and metabolism under conditions of uncertainty.

Identification of Growth Phases and Influencing Factors in Cultivations with AGE1.HN Cells Using Set-Based Methods

PubMed Central

Borchers, Steffen; Freund, Susann; Rath, Alexander; Streif, Stefan; Reichl, Udo; Findeisen, Rolf

2013-01-01

Production of bio-pharmaceuticals in cell culture, such as mammalian cells, is challenging. Mathematical models can provide support to the analysis, optimization, and the operation of production processes. In particular, unstructured models are suited for these purposes, since they can be tailored to particular process conditions. To this end, growth phases and the most relevant factors influencing cell growth and product formation have to be identified. Due to noisy and erroneous experimental data, unknown kinetic parameters, and the large number of combinations of influencing factors, currently there are only limited structured approaches to tackle these issues. We outline a structured set-based approach to identify different growth phases and the factors influencing cell growth and metabolism. To this end, measurement uncertainties are taken explicitly into account to bound the time-dependent specific growth rate based on the observed increase of the cell concentration. Based on the bounds on the specific growth rate, we can identify qualitatively different growth phases and (in-)validate hypotheses on the factors influencing cell growth and metabolism. We apply the approach to a mammalian suspension cell line (AGE1.HN). We show that growth in batch culture can be divided into two main growth phases. The initial phase is characterized by exponential growth dynamics, which can be described consistently by a relatively simple unstructured and segregated model. The subsequent phase is characterized by a decrease in the specific growth rate, which, as shown, results from substrate limitation and the pH of the medium. An extended model is provided which describes the observed dynamics of cell growth and main metabolites, and the corresponding kinetic parameters as well as their confidence intervals are estimated. The study is complemented by an uncertainty and outlier analysis. Overall, we demonstrate utility of set-based methods for analyzing cell growth and metabolism under conditions of uncertainty. PMID:23936299

The association of hospital prevention processes and patient risk factors with the risk of Clostridium difficile infection: a population-based cohort study.

PubMed

Daneman, N; Guttmann, A; Wang, X; Ma, X; Gibson, D; Stukel, T A

2015-07-01

Clostridium difficile is the most common cause of healthcare-acquired infection; the real-world impacts of some proposed C. difficile prevention processes are unknown. We conducted a population-based retrospective cohort study of all patients admitted to acute care hospitals between April 2011 and March 2012 in Ontario, Canada. Hospital prevention practices were determined by survey of infection control programmes; responses were linked to patient-level risk factors and C. difficile outcomes in Ontario administrative databases. Multivariable generalised estimating equation (GEE) regression models were used to assess the impact of selected understudied hospital prevention processes on the patient-level risk of C. difficile infection, accounting for patient risk factors, baseline C. difficile rates and structural hospital characteristics. C. difficile infections complicated 2341 of 653 896 admissions (3.6 per 1000 admissions). Implementation of the selected C. difficile prevention practices was variable across the 159 hospitals with isolation of all patients at onset of diarrhoea reported by 43 (27%), auditing of antibiotic stewardship compliance by 26 (16%), auditing of cleaning practices by 115 (72%), on-site diagnostic testing by 74 (47%), vancomycin as first-line treatment by 24 (15%) and reporting rates to senior leadership by 52 (33%). None of these processes were associated with a significantly reduced risk of C. difficile after adjustment for baseline C. difficile rates, structural hospital characteristics and patient-level factors. Patient-level factors were strongly associated with C. difficile risk, including age, comorbidities, non-elective and medical admissions. In the largest study to date, selected hospital prevention strategies were not associated with a statistically significant reduction in patients' risk of C. difficile infection. These prevention strategies have either limited effectiveness or were ineffectively implemented during the study period. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Cross-Country Individual Participant Analysis of 4.1 Million Singleton Births in 5 Countries with Very High Human Development Index Confirms Known Associations but Provides No Biologic Explanation for 2/3 of All Preterm Births

PubMed Central

Ferrero, David M.; Jacobsson, Bo; Di Renzo, Gian Carlo; Norman, Jane E.; Martin, James N.; D’Alton, Mary; Castelazo, Ernesto; Howson, Chris P.; Sengpiel, Verena; Bottai, Matteo; Mayo, Jonathan A.; Shaw, Gary M.; Verdenik, Ivan; Tul, Nataša; Velebil, Petr; Cairns-Smith, Sarah; Rushwan, Hamid; Arulkumaran, Sabaratnam; Howse, Jennifer L.; Simpson, Joe Leigh

2016-01-01

Background Preterm birth is the most common single cause of perinatal and infant mortality, affecting 15 million infants worldwide each year with global rates increasing. Understanding of risk factors remains poor, and preventive interventions have only limited benefit. Large differences exist in preterm birth rates across high income countries. We hypothesized that understanding the basis for these wide variations could lead to interventions that reduce preterm birth incidence in countries with high rates. We thus sought to assess the contributions of known risk factors for both spontaneous and provider-initiated preterm birth in selected high income countries, estimating also the potential impact of successful interventions due to advances in research, policy and public health, or clinical practice. Methods We analyzed individual patient-level data on 4.1 million singleton pregnancies from four countries with very high human development index (Czech Republic, New Zealand, Slovenia, Sweden) and one comparator U.S. state (California) to determine the specific contribution (adjusting for confounding effects) of 21 factors. Both individual and population-attributable preterm birth risks were determined, as were contributors to cross-country differences. We also assessed the ability to predict preterm birth given various sets of known risk factors. Findings Previous preterm birth and preeclampsia were the strongest individual risk factors of preterm birth in all datasets, with odds ratios of 4.6–6.0 and 2.8–5.7, respectively, for individual women having those characteristics. In contrast, on a population basis, nulliparity and male sex were the two risk factors with the highest impact on preterm birth rates, accounting for 25–50% and 11–16% of excess population attributable risk, respectively (p<0.001). The importance of nulliparity and male sex on population attributable risk was driven by high prevalence despite low odds ratios for individual women. More than 65% of the total aggregated risk of preterm birth within each country lacks a plausible biologic explanation, and 63% of difference between countries cannot be explained with known factors; thus, research is necessary to elucidate the underlying mechanisms of preterm birth and, hence, therapeutic intervention. Surprisingly, variation in prevalence of known risk factors accounted for less than 35% of the difference in preterm birth rates between countries. Known risk factors had an area under the curve of less than 0.7 in ROC analysis of preterm birth prediction within countries. These data suggest that other influences, as yet unidentified, are involved in preterm birth. Further research into biological mechanisms is warranted. Conclusions We have quantified the causes of variation in preterm birth rates among countries with very high human development index. The paucity of explicit and currently identified factors amenable to intervention illustrates the limited impact of changes possible through current clinical practice and policy interventions. Our research highlights the urgent need for research into underlying biological causes of preterm birth, which alone are likely to lead to innovative and efficacious interventions. PMID:27622562

Cross-Country Individual Participant Analysis of 4.1 Million Singleton Births in 5 Countries with Very High Human Development Index Confirms Known Associations but Provides No Biologic Explanation for 2/3 of All Preterm Births.

PubMed

Ferrero, David M; Larson, Jim; Jacobsson, Bo; Di Renzo, Gian Carlo; Norman, Jane E; Martin, James N; D'Alton, Mary; Castelazo, Ernesto; Howson, Chris P; Sengpiel, Verena; Bottai, Matteo; Mayo, Jonathan A; Shaw, Gary M; Verdenik, Ivan; Tul, Nataša; Velebil, Petr; Cairns-Smith, Sarah; Rushwan, Hamid; Arulkumaran, Sabaratnam; Howse, Jennifer L; Simpson, Joe Leigh

2016-01-01

Preterm birth is the most common single cause of perinatal and infant mortality, affecting 15 million infants worldwide each year with global rates increasing. Understanding of risk factors remains poor, and preventive interventions have only limited benefit. Large differences exist in preterm birth rates across high income countries. We hypothesized that understanding the basis for these wide variations could lead to interventions that reduce preterm birth incidence in countries with high rates. We thus sought to assess the contributions of known risk factors for both spontaneous and provider-initiated preterm birth in selected high income countries, estimating also the potential impact of successful interventions due to advances in research, policy and public health, or clinical practice. We analyzed individual patient-level data on 4.1 million singleton pregnancies from four countries with very high human development index (Czech Republic, New Zealand, Slovenia, Sweden) and one comparator U.S. state (California) to determine the specific contribution (adjusting for confounding effects) of 21 factors. Both individual and population-attributable preterm birth risks were determined, as were contributors to cross-country differences. We also assessed the ability to predict preterm birth given various sets of known risk factors. Previous preterm birth and preeclampsia were the strongest individual risk factors of preterm birth in all datasets, with odds ratios of 4.6-6.0 and 2.8-5.7, respectively, for individual women having those characteristics. In contrast, on a population basis, nulliparity and male sex were the two risk factors with the highest impact on preterm birth rates, accounting for 25-50% and 11-16% of excess population attributable risk, respectively (p<0.001). The importance of nulliparity and male sex on population attributable risk was driven by high prevalence despite low odds ratios for individual women. More than 65% of the total aggregated risk of preterm birth within each country lacks a plausible biologic explanation, and 63% of difference between countries cannot be explained with known factors; thus, research is necessary to elucidate the underlying mechanisms of preterm birth and, hence, therapeutic intervention. Surprisingly, variation in prevalence of known risk factors accounted for less than 35% of the difference in preterm birth rates between countries. Known risk factors had an area under the curve of less than 0.7 in ROC analysis of preterm birth prediction within countries. These data suggest that other influences, as yet unidentified, are involved in preterm birth. Further research into biological mechanisms is warranted. We have quantified the causes of variation in preterm birth rates among countries with very high human development index. The paucity of explicit and currently identified factors amenable to intervention illustrates the limited impact of changes possible through current clinical practice and policy interventions. Our research highlights the urgent need for research into underlying biological causes of preterm birth, which alone are likely to lead to innovative and efficacious interventions.

Selection of sampling rate for digital control of aircrafts

NASA Technical Reports Server (NTRS)

Katz, P.; Powell, J. D.

1974-01-01

The considerations in selecting the sample rates for digital control of aircrafts are identified and evaluated using the optimal discrete method. A high performance aircraft model which includes a bending mode and wind gusts was studied. The following factors which influence the selection of the sampling rates were identified: (1) the time and roughness response to control inputs; (2) the response to external disturbances; and (3) the sensitivity to variations of parameters. It was found that the time response to a control input and the response to external disturbances limit the selection of the sampling rate. The optimal discrete regulator, the steady state Kalman filter, and the mean response to external disturbances are calculated.

Dog bite and injury prevention—analysis, critical review, and research agenda

PubMed Central

Ozanne-Smith, J; Ashby, K; Stathakis, V

2001-01-01

Objectives—To analyze Australian dog bite injury data and make international comparisons; to review risk and protective factors relating to the dog, injured person, and environment; and to recommend action for prevention and research. Methods—Australian dog bite injury data, complemented by detailed Victorian and regional data from routine health records and vital statistics, were analyzed to determine incidence, severity, nature, circumstances, and trends. International comparison data were extracted from published reports. Risk and protective factor studies were selected for review from electronic and bibliographic searches where data were recent, sample sizes substantial, and bias limited. Results—The Australian dog bite death rate (0.004/100 000) is lower than both the United States (0.05–0.07/100 000) and Canadian rates (0.007/100 000). Victorian hospitalized trend rates were stable between 1987 and 1998, but there was a decline for children <5 years (p=0.019) corresponding with a reduction in dog ownership. Children 0–4 years have the highest rate of serious injury, particularly facial. Adults have longer hospitalizations, most frequently for upper extremity injury. Risk factors include: child, males, households with dogs, certain breeds, male dogs, home location, and leashed dog. Conclusions—Dog bite rates are high and it may therefore be assumed that current preventative interventions are inadequate. Responsible dog ownership, including separating young children from dogs, avoiding high risk dogs, neutering, regulatory enforcement, and standardized monitoring of bite rates are required. Controlled investigations of further risk and protective factors, and validated methods of breed identification, are needed. PMID:11770660

Acculturation and other risk factors of depressive disorders in individuals with Turkish migration backgrounds.

PubMed

Janssen-Kallenberg, Hanna; Schulz, Holger; Kluge, Ulrike; Strehle, Jens; Wittchen, Hans-Ulrich; Wolfradt, Uwe; Koch-Gromus, Uwe; Heinz, Andreas; Mösko, Mike; Dingoyan, Demet

2017-07-19

Acculturation is a long-term, multi-dimensional process occurring when subjects of different cultures stay in continuous contact. Previous studies have suggested that elevated rates of depression among different migrant groups might be due to patterns of acculturation and migration related risk factors. This paper focused on prevalence rates of depressive disorders and related risk factors among individuals with Turkish migration backgrounds. A population-based sample of 662 individuals with Turkish migration backgrounds were interviewed by bilingual interviewers using a standardised diagnostic interview for DSM-IV-TR and ICD-10 diagnoses (CIDI DIA-X Version 2.8). Associations between 12-month prevalence rates of depressive disorders with potential risk factors were assessed, including gender, age, socioeconomic status, acculturation status and migration status. 12-month prevalence rates of any depressive disorder were 29.0%, 14.4% of major depressive disorder (MDD) and 14.7% of dysthymia. Older age and low socioeconomic status were most consistently related to higher risks of depressive disorders. Acculturation status showed associations with subtypes of depressive disorder. Associations differed between men and women. Symptom severity of MDD was linked to gender, with females being more affected by severe symptoms. The prevalence of depressive disorders is high in individuals with Turkish migration backgrounds, which can be partly explained by older age, low socioeconomic status and acculturation pressures. Only a limited number of risk factors were assessed. Acculturation in particular is a complex process which might not be sufficiently represented by the applied measures. Further risk factors have to be identified in representative samples of this migrant group.

The Population Biology of Bacterial Plasmids: A PRIORI Conditions for the Existence of Conjugationally Transmitted Factors

PubMed Central

Stewart, Frank M.; Levin, Bruce R.

1977-01-01

A mathematical model for the population dynamics of conjugationally transmitted plasmids in bacterial populations is presented and its properties analyzed. Consideration is given to nonbacteriocinogenic factors that are incapable of incorporation into the chromosome of their host cells, and to bacterial populations maintained in either continuous (chemostat) or discrete (serial transfer) culture. The conditions for the establishment and maintenance of these infectious extrachromosomal elements and equilibrium frequencies of cells carrying them are presented for different values of the biological parameters: population growth functions, conjugational transfer and segregation rate constants. With these parameters in a biologically realistic range, the theory predicts a broad set of physical conditions, resource concentrations and dilution rates, where conjugationally transmitted plasmids can become established and where cells carrying them will maintain high frequencies in bacterial populations. This can occur even when plasmid-bearing cells are much less fit (i.e., have substantially lower growth rates) than cells free of these factors. The implications of these results and the reality and limitations of the model are discussed and the values of its parameters in natural populations speculated upon. PMID:17248761

Lilies at the limit: Variation in plant-pollinator interactions across an elevational range.

PubMed

Theobald, Elli J; Gabrielyan, Hrach; HilleRisLambers, Janneke

2016-02-01

Many studies assume climatic factors are paramount in determining species' distributions, however, biotic interactions may also play a role. For example, pollinators may limit species' ranges if floral abundance or floral attractiveness is reduced at range margins, thus causing lower pollinator visitation and reduced reproductive output. To test if pollinators influence the altitudinal distribution of Erythronium montanum (Liliaceae) at Mount Rainier National Park, we asked whether (1) seed production in this species relies on pollinators, (2) seed production and pollen limitation is greatest at range limits, and (3) pollinator visitation rates (either overall or by individual taxonomic groups) reflect patterns of seed production and pollen limitation. From this three-year study, we established that this plant does rely on pollinators for fruit set and we found that pollen limitation trended toward being higher at the upper range limit in some years, but not consistently year to year. Insect visitation rates did not mirror spatial patterns of pollen limitation, but annually variable pollinator composition suggested differential importance of some pollinator taxonomic groups (specifically, bumblebees may be better pollinators than syrphid flies). Overall, these results suggest that while pollinators are critical for the reproductive success of this high mountain wildflower, plant-pollinator interactions do not obviously drive the distribution of this species. Nonetheless, high spatio-temporal variability in range-wide plant-pollinator dynamics may complicate responses to climate change. © 2016 Botanical Society of America.

MPC and ALI: their basis and their comparison

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kennedy, W.E. Jr.; Watson, E.C.

Radiation protection regulations in the United States have evolved from the recommendations of the International Commission on Radiological Protection (ICRP) and the National Council on Radiation Protection and Measurements (NCRP). In 1959, the ICRP issued Publication 2 which contained specific recommendations on dose rate limits, permissible body burdens, metabolic data for radionuclides, and maximum permissible concentrations (MPC) in air or water. Over the next 20 years, new information became available concerning the effects of radiation, the uptake and retention of radionuclides, and the radioactive decay schemes of parent radionuclides. To include this newer information, the ICRP issued Publication 30 inmore » 1978 to supersede Publication 2. One of the secondary limits defined in Publication 30 is the annual limit of intake (ALI). Radionuclide specific ALI values are intended to replace MPC values in determining whether or not ambient air and water concentrations are sufficiently low to maintain the dose to workers within accepted dose rate limits. In this paper, we discuss the derivation of MPC and ALI values, compare inhalation committed dose equivalent factors derived from ICRP Publications 2 and 30, and discuss the practical implications of using either MPC or ALI in determining compliance with occupational exposure limits. 6 references.« less

Numerical Simulations of SCR DeNOx System for a 660MW coal-fired power station

NASA Astrophysics Data System (ADS)

Yongqiang, Deng; Zhongming, Mei; Yijun, Mao; Nianping, Liu; Guoming, Yin

2018-06-01

Aimed at the selective catalytic reduction (SCR) DeNOx system of a 660 MW coal-fired power station, which is limited by low denitrification efficiency, large ammonia consumption and over-high ammonia escape rate, numerical simulations were conducted by employing STAR-CCM+ (CFD tool). The simulations results revealed the problems existed in the SCR DeNOx system. Aimed at limitations of the target SCR DeNOx system, factors affecting the denitrification performance of SCR, including the structural parameters and ammonia injected by the ammonia nozzles, were optimized. Under the optimized operational conditions, the denitrification efficiency of the SCR system was enhanced, while the ammonia escape rate was reduced below 3ppm. This study serves as references for optimization and modification of SCR systems.

Key Factors in Development of Man-Made and Natural Ecosystems

NASA Astrophysics Data System (ADS)

Pechurkin, N. S.

1999-01-01

Key factors of ecosystem functioning are of the same nature for artificial and natural types. An hierarchical approach gives the opportunity for estimation of the quantitative behavior of both individual links and the system as a whole. At the organismic level we can use interactions of studied macroorganisms (man, animal, higher plant) with selected microorganisms as key indicating factors of the organisms immune status. The most informative factor for the population/community level is an age structure of populations and relationships of domination/elimination. The integrated key factors of the ecosystems level are productivity and rates of cycling of the limiting substances. The key factors approach is of great value for growth regulations and monitoring the state of any ecosystem, including the life support system (LSS)-type.

Assessment of printed patient-educational materials for chronic kidney disease

PubMed Central

Tuot, Delphine S; Davis, Elizabeth; Velasquez, Alexandra; Banerjee, Tanushree; Powe, Neil R

2013-01-01

Background Awareness of chronic kidney disease (CKD) is suboptimal among patients with CKD, perhaps due to poor readability of patient education materials (PEMs). We reviewed the suitability and readability of common PEMs that focused on 5 content areas: basics of CKD, risk factors for CKD development, risk factors for CKD progression, complications of CKD and self-management strategies to improve kidney health. Methods Three reviewers (nephrologist, primary care physician, patient) used the Suitability Assessment of Materials to rate PEMs on message content/stimulation of learning, typography, visuals and layout and determined literacy level. Mean ratings were calculated for each PEM by content area and overall (Superior=70–100; Adequate=40–69; Inadequate=<40). Linear regression was used to determine the impact of literacy level on mean rating. Results We reviewed 69 PEMs from 19 organizations, divided into 113 content area sections. Most (79%) PEM sections were “Adequate” (mean rating, 58.3%). Inclusion of patient-centered content and opportunities for patient interaction were associated with “Superior” ratings. Mean ratings (SD) were similar across content areas: basics of CKD, 58.9% [9.1]; risk factors for CKD development, 57.0% [12.3]; risk factors for CKD progression, 58.5% [12.0]; CKD complications, 62.3% [15.7] and self-management strategies, 62.2% [12.3]. ≤ 6th grade literacy level (vs >6th grade) was associated with an 11.7 point higher mean rating. Conclusion Most PEMs for kidney disease were adequate. Outstanding PEMs shared characteristics of patient centeredness, a low literacy level, and patient interaction. Providers should be aware of strengths and limitations of PEMs when educating their patients about CKD. PMID:23970127

Assessment of printed patient-educational materials for chronic kidney disease.

PubMed

Tuot, Delphine S; Davis, Elizabeth; Velasquez, Alexandra; Banerjee, Tanushree; Powe, Neil R

2013-01-01

Awareness of chronic kidney disease (CKD) is suboptimal among patients with CKD, perhaps due to poor readability of patient education materials (PEMs). We reviewed the suitability and readability of common PEMs that focused on 5 content areas: basics of CKD, risk factors for CKD development, risk factors for CKD progression, complications of CKD and self-management strategies to improve kidney health. Three reviewers (nephrologist, primary care physician, patient) used the Suitability Assessment of Materials to rate PEMs on message content/stimulation of learning, typography, visuals and layout and determined literacy level. Mean ratings were calculated for each PEM by content area and overall (superior = 70-100; adequate = 40-69; inadequate = <40). Linear regression was used to determine the impact of literacy level on mean rating. We reviewed 69 PEMs from 19 organizations, divided into 113 content area sections. Most (79%) PEM sections were 'adequate' (mean rating, 58.3%). Inclusion of patient-centered content and opportunities for patient interaction were associated with 'superior' ratings. Mean ratings (SD) were similar across content areas: basics of CKD, 58.9% (9.1); risk factors for CKD development, 57.0% (12.3); risk factors for CKD progression, 58.5% (12.0); CKD complications, 62.3% (15.7), and self-management strategies, 62.2% (12.3). ≤6th grade literacy level (vs. >6th grade) was associated with an 11.7 point higher mean rating. Most PEMs for kidney disease were adequate. Outstanding PEMs shared characteristics of patient centeredness, a low literacy level, and patient interaction. Providers should be aware of strengths and limitations of PEMs when educating their patients about CKD. Copyright © 2013 S. Karger AG, Basel.

Dynamic subcellular partitioning of the nucleolar transcription factor TIF-IA under ribotoxic stress.

PubMed

Szymański, Jedrzej; Mayer, Christine; Hoffmann-Rohrer, Urs; Kalla, Claudia; Grummt, Ingrid; Weiss, Matthias

2009-07-01

TIF-IA is a basal transcription factor of RNA polymerase I (Pol I) that is a major target of the JNK2 signaling pathway in response to ribotoxic stress. Using advanced fluorescence microscopy and kinetic modeling we elucidated the subcellular localization of TIF-IA and its exchange dynamics between the nucleolus, nucleoplasm and cytoplasm upon ribotoxic stress. In steady state, the majority of (GFP-tagged) TIF-IA was in the cytoplasm and the nucleus, a minor portion (7%) localizing to the nucleoli. We observed a rapid shuttling of GFP-TIF-IA between the different cellular compartments with a mean residence time of approximately 130 s in the nucleus and only approximately 30 s in the nucleoli. The import rate from the cytoplasm to the nucleus was approximately 3-fold larger than the export rate, suggesting an importin/exportin-mediated transport rather than a passive diffusion. Upon ribotoxic stress, GFP-TIF-IA was released from the nucleoli with a half-time of approximately 24 min. Oxidative stress and inhibition of protein synthesis led to a relocation of GFP-TIF-IA with slower kinetics while osmotic stress had no effect. The observed relocation was much slower than the nucleo-cytoplasmic and nucleus-nucleolus exchange rates of GFP-TIF-IA, indicating a time-limiting step upstream of the JNK2 pathway. In support of this, time-course experiments on the activity of JNK2 revealed the activation of the JNK kinase as the rate-limiting step.

Essentiality Is a Strong Determinant of Protein Rates of Evolution during Mutation Accumulation Experiments in Escherichia coli

PubMed Central

Alvarez-Ponce, David; Sabater-Muñoz, Beatriz; Toft, Christina; Ruiz-González, Mario X.; Fares, Mario A.

2016-01-01

Abstract The Neutral Theory of Molecular Evolution is considered the most powerful theory to understand the evolutionary behavior of proteins. One of the main predictions of this theory is that essential proteins should evolve slower than dispensable ones owing to increased selective constraints. Comparison of genomes of different species, however, has revealed only small differences between the rates of evolution of essential and nonessential proteins. In some analyses, these differences vanish once confounding factors are controlled for, whereas in other cases essentiality seems to have an independent, albeit small, effect. It has been argued that comparing relatively distant genomes may entail a number of limitations. For instance, many of the genes that are dispensable in controlled lab conditions may be essential in some of the conditions faced in nature. Moreover, essentiality can change during evolution, and rates of protein evolution are simultaneously shaped by a variety of factors, whose individual effects are difficult to isolate. Here, we conducted two parallel mutation accumulation experiments in Escherichia coli, during 5,500–5,750 generations, and compared the genomes at different points of the experiments. Our approach (a short-term experiment, under highly controlled conditions) enabled us to overcome many of the limitations of previous studies. We observed that essential proteins evolved substantially slower than nonessential ones during our experiments. Strikingly, rates of protein evolution were only moderately affected by expression level and protein length. PMID:27566759

Recent advances in lithotripsy technology and treatment strategies: A systematic review update

PubMed Central

Elmansy, H.E.; Lingeman, J.E.

2017-01-01

Introduction Shock wave lithotripsy (SWL) is a well – established treatment option for urolithiasis. The technology of SWL has undergone significant changes in an attempt to better optimize the results while reducing failure rates. There are some important limitations that restrict the use of SWL. In this review, we aim to place these advantages and limitations in perspective, assess the current role of SWL, and discuss recent advances in lithotripsy technology and treatment strategies. Methods A comprehensive review was conducted to identify studies reporting outcomes on ESWL. We searched for literature (PubMed, Embase, Medline) that focused on the physics of shock waves, theories of stone disintegration, and studies on optimising shock wave application. Relevant articles in English published since 1980 were selected for inclusion. Results Efficacy has been shown to vary between lithotripters. To maximize stone fragmentation and reduce failure rates, many factors can be optimized. Factors to consider in proper patient selection include skin – to – stone distance and stone size. Careful attention to the rate of shock wave administration, proper coupling of the treatment head to the patient have important influences on the success of lithotripsy. Conclusion Proper selection of patients who are expected to respond well to SWL, as well as attention to the technical aspects of the procedure are the keys to SWL success. Studies aiming to determine the mechanisms of shock wave action in stone breakage have begun to suggest new treatment strategies to improve success rates and safety. PMID:27890653

Ohm's Law, Batteries, and the Clean Energy Landscape

NASA Astrophysics Data System (ADS)

Balsara, Nitash

The need for creating safe electrolytes for lithium batteries is significant given the continued safety problems associated with current lithium-ion batteries. Nonflammable polymer electrolytes offer a possible solution but the rate of lithium ion transport is too low for practical applications. In this talk, I will discuss some of the fundamental factors that limit ion transport in polymers. Polymer electrolytes obey Ohm's Law, i.e. in the limit of small applied potentials, the current generated at steady state is proportional to the applied potential. Factors that determine the current generated will be determined using the continuum theory of Newman. Independent measurements of ion diffusion by pulsed-field gradient NMR will also be presented. The talk will end with a discussion of the possibility of commercializing all-solid batteries with polymer electrolytes.

A systematic review of the aetiology of tobacco disparities for sexual minorities

PubMed Central

Blosnich, John; Lee, Joseph G L; Horn, Kimberly

2013-01-01

Objective To conduct a systematic review of the literature examining risk factors/correlates of cigarette smoking among lesbian, gay and bisexual (ie, sexual minority) populations. Methods Sets of terms relevant to sexual minority populations and cigarette smoking were used in a simultaneous search of 10 databases through EBSCOhost. The search was limited to the peer-reviewed literature up to January 2011, using no geographic or language limits. For inclusion, the paper was required to: (1) have been written in English, (2) have sexual minorities (defined by either attraction, behaviour, or identity) included in the study population and (3) have examined some form of magnitude of association for risk factors/correlates of any definition of cigarette smoking. A total of 386 abstracts were reviewed independently, with 26 papers meeting all inclusion criteria. Abstracts were reviewed and coded independently by authors JB and JGLL using nine codes derived from the inclusion/exclusion criteria. Results Studies used various measures of sexual orientation and of smoking. Risk factors that could be considered unique to sexual minorities included internalised homophobia and reactions to disclosure of sexual orientation. Some studies also indicated common smoking risk factors experienced at higher rates among sexual minorities, including stress, depression, alcohol use and victimisation. Conclusions This review identified risks that were associated with sexual minority status and common to the general population but experienced at potentially higher rates by sexual minorities. Government and foundation funds should be directed towards research on the origins of this disparity. PMID:22170335

Heat strain, volume depletion and kidney function in California agricultural workers.

PubMed

Moyce, Sally; Mitchell, Diane; Armitage, Tracey; Tancredi, Daniel; Joseph, Jill; Schenker, Marc

2017-06-01

Agricultural work can expose workers to increased risk of heat strain and volume depletion due to repeated exposures to high ambient temperatures, arduous physical exertion and limited rehydration. These risk factors may result in acute kidney injury (AKI). We estimated AKI cumulative incidence in a convenience sample of 283 agricultural workers based on elevations of serum creatinine between preshift and postshift blood samples. Heat strain was assessed based on changes in core body temperature and heart rate. Volume depletion was assessed using changes in body mass over the work shift. Logistic regression models were used to estimate the associations of AKI with traditional risk factors (age, diabetes, hypertension and history of kidney disease) as well as with occupational risk factors (years in farm work, method of payment and farm task). 35 participants were characterised with incident AKI over the course of a work shift (12.3%). Workers who experienced heat strain had increased adjusted odds of AKI (1.34, 95% CI 1.04 to 1.74). Piece rate work was associated with 4.24 odds of AKI (95% CI 1.56 to 11.52). Females paid by the piece had 102.81 adjusted odds of AKI (95% CI 7.32 to 1443.20). Heat strain and piece rate work are associated with incident AKI after a single shift of agricultural work, though gender differences exist. Modifications to payment structures may help prevent AKI. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Rating of personality disorder features in popular movie characters.

PubMed

Hesse, Morten; Schliewe, Sanna; Thomsen, Rasmus R

2005-12-08

Tools for training professionals in rating personality disorders are few. We present one such tool: rating of fictional persons. However, before ratings of fictional persons can be useful, we need to know whether raters get the same results, when rating fictional characters. Psychology students at the University of Copenhagen (N = 8) rated four different movie characters from four movies based on three systems: Global rating scales representing each of the 10 personality disorders in the DSM-IV, a criterion list of all criteria for all DSM-IV personality disorders in random order, and the Ten Item Personality Inventory for rating the five-factor model. Agreement was estimated based on intraclass-correlation. Agreement for rating scales for personality disorders ranged from 0.04 to 0.54. For personality disorder features based on DSM-IV criteria, agreement ranged from 0.24 to 0.89, and agreement for the five-factor model ranged from 0.05 to 0.88. The largest multivariate effect was observed for criteria count followed by the TIPI, followed by rating scales. Raters experienced personality disorder criteria as the easiest, and global personality disorder scales as the most difficult, but with significant variation between movies. Psychology students with limited or no clinical experience can agree well on the personality traits of movie characters based on watching the movie. Rating movie characters may be a way to practice assessment of personality.

Rating of personality disorder features in popular movie characters

PubMed Central

Hesse, Morten; Schliewe, Sanna; Thomsen, Rasmus R

2005-01-01

Background Tools for training professionals in rating personality disorders are few. We present one such tool: rating of fictional persons. However, before ratings of fictional persons can be useful, we need to know whether raters get the same results, when rating fictional characters. Method Psychology students at the University of Copenhagen (N = 8) rated four different movie characters from four movies based on three systems: Global rating scales representing each of the 10 personality disorders in the DSM-IV, a criterion list of all criteria for all DSM-IV personality disorders in random order, and the Ten Item Personality Inventory for rating the five-factor model. Agreement was estimated based on intraclass-correlation. Results Agreement for rating scales for personality disorders ranged from 0.04 to 0.54. For personality disorder features based on DSM-IV criteria, agreement ranged from 0.24 to 0.89, and agreement for the five-factor model ranged from 0.05 to 0.88. The largest multivariate effect was observed for criteria count followed by the TIPI, followed by rating scales. Raters experienced personality disorder criteria as the easiest, and global personality disorder scales as the most difficult, but with significant variation between movies. Conclusion Psychology students with limited or no clinical experience can agree well on the personality traits of movie characters based on watching the movie. Rating movie characters may be a way to practice assessment of personality. PMID:16336663

Kinetic effects of toluene blending on the extinction limit of n-decane diffusion flames

DOE Office of Scientific and Technical Information (OSTI.GOV)

Won, Sang Hee; Sun, Wenting; Ju, Yiguang

The impact of toluene addition in n-decane on OH concentrations, maximum heat release rates, and extinction limits were studied experimentally and computationally by using counterflow diffusion flames with laser induced fluorescence imaging. Sensitivity analyses of kinetic path ways and species transport on flame extinction were also conducted. The results showed that the extinction strain rate of n-decane/toluene/nitrogen flames decreased significantly with an increase of toluene addition and depended linearly on the maximum OH concentration. It was revealed that the maximum OH concentration, which depends on the fuel H/C ratio, can be used as an index of the radical pool andmore » chemical heat release rate, since it plays a significant role on the heat production via the reaction with other species, such as CO, H{sub 2}, and HCO. Experimental results further demonstrated that toluene addition in n-decane dramatically reduced the peak OH concentration via H abstraction reactions and accelerated flame extinction via kinetic coupling between toluene and n-decane mechanisms. Comparisons between experiments and simulations revealed that the current toluene mechanism significantly over-predicts the radical destruction rate, leading to under-prediction of extinction limits and OH concentrations, especially caused by the uncertainty of the H abstraction reaction from toluene, which rate coefficient has a difference by a factor of 5 in the tested toluene models. In addition, sensitivity analysis of diffusive transport showed that in addition to n-decane and toluene, the transport of OH and H also considerably affects the extinction limit. A reduced linear correlation between the extinction limits of n-decane/toluene blended fuels and the H/C ratio as well as the mean fuel molecular weight was obtained. The results suggest that an explicit prediction of the extinction limits of aromatic and alkane blended fuels can be established by using H/C ratio (or radical index) and the mean fuel molecular weight which represent the rates of radical production and the fuel transport, respectively. (author)« less

Adult Support and Substance Use among Homeless Youths Who Attend High School

ERIC Educational Resources Information Center

Ferguson, Kristin M.; Xie, Bin

2012-01-01

Background: Despite high rates of substance use among homeless youths, little is known about the interaction of substance-use risk and protective factors. Further, limited research exists on substance use by school-attending homeless youths, as extant studies have relied on street- and shelter-based samples. Objective: The purpose of this study…

Gatekeepers or Facilitators: The Influence of Teacher Habitus on Students' Applications to Elite Universities

ERIC Educational Resources Information Center

Oliver, Caroline; Kettley, Nigel

2010-01-01

Low application rates of state school students to elite universities have been identified as a factor in their limited participation in elite universities. This article explores the role of teachers in state schools and colleges in guiding higher education (HE) choice. Drawing on qualitative research with teachers and students in six institutions,…

Moderating Effects of Mathematics Anxiety on the Effectiveness of Explicit Timing

ERIC Educational Resources Information Center

Grays, Sharnita D.; Rhymer, Katrina N.; Swartzmiller, Melissa D.

2017-01-01

Explicit timing is an empirically validated intervention to increase problem completion rates by exposing individuals to a stopwatch and explicitly telling them of the time limit for the assignment. Though explicit timing has proven to be effective for groups of students, some students may not respond well to explicit timing based on factors such…

American Indian Women and Screening Mammography: Findings from a Qualitative Study in Oklahoma

ERIC Educational Resources Information Center

Tolma, Eleni; Batterton, Chasity; Hamm, Robert M.; Thompson, David; Engelman, Kimberly K.

2012-01-01

Background: Breast cancer is an important public health issue within the American Indian (AI) community in Oklahoma; however, there is limited information to explain the low screening mammography rates among AI women. Purpose: To identify the motivational factors affecting an AI woman's decision to obtain a mammogram. Methods: Through the use of…

Seasonal survival estimation for a long-distance migratory bird and the influence of winter precipitation

Treesearch

Sarah M. Rockwell; Joseph M. Wunderle; T. Scott Sillett; Carol I. Bocetti; David N. Ewert; Dave Currie; Jennifer D. White; Peter P. Marra

2017-01-01

Conservation of migratory animals requires information about seasonal survival rates. Identifying factors that limit populations, and the portions of the annual cycle in which they occur, are critical for recognizing and reducing potential threats. However, such data are lacking for virtually all migratory taxa. We investigated patterns and environmental correlates of...

A standardized approach for estimating the permeability of plastic films to soil fumigants under various field and environmental conditions

USDA-ARS?s Scientific Manuscript database

Minimizing atmospheric emissions of soil fumigants is critical for protecting human and environmental health. Covering the soil surface with a plastic tarp is a common approach to restrict fumigant emissions. The mass transfer of the fumigant vapors through the tarp is often the rate-limiting factor...

Assessing Children's Homework Performance: Development of Multi-Dimensional, Multi-Informant Rating Scales.

PubMed

Power, Thomas J; Dombrowski, Stefan C; Watkins, Marley W; Mautone, Jennifer A; Eagle, John W

2007-06-01

Efforts to develop interventions to improve homework performance have been impeded by limitations in the measurement of homework performance. This study was conducted to develop rating scales for assessing homework performance among students in elementary and middle school. Items on the scales were intended to assess student strengths as well as deficits in homework performance. The sample included 163 students attending two school districts in the Northeast. Parents completed the 36-item Homework Performance Questionnaire - Parent Scale (HPQ-PS). Teachers completed the 22-item teacher scale (HPQ-TS) for each student for whom the HPQ-PS had been completed. A common factor analysis with principal axis extraction and promax rotation was used to analyze the findings. The results of the factor analysis of the HPQ-PS revealed three salient and meaningful factors: student task orientation/efficiency, student competence, and teacher support. The factor analysis of the HPQ-TS uncovered two salient and substantive factors: student responsibility and student competence. The findings of this study suggest that the HPQ is a promising set of measures for assessing student homework functioning and contextual factors that may influence performance. Directions for future research are presented.

Assessing Children’s Homework Performance: Development of Multi-Dimensional, Multi-Informant Rating Scales

PubMed Central

Power, Thomas J.; Dombrowski, Stefan C.; Watkins, Marley W.; Mautone, Jennifer A.; Eagle, John W.

2007-01-01

Efforts to develop interventions to improve homework performance have been impeded by limitations in the measurement of homework performance. This study was conducted to develop rating scales for assessing homework performance among students in elementary and middle school. Items on the scales were intended to assess student strengths as well as deficits in homework performance. The sample included 163 students attending two school districts in the Northeast. Parents completed the 36-item Homework Performance Questionnaire – Parent Scale (HPQ-PS). Teachers completed the 22-item teacher scale (HPQ-TS) for each student for whom the HPQ-PS had been completed. A common factor analysis with principal axis extraction and promax rotation was used to analyze the findings. The results of the factor analysis of the HPQ-PS revealed three salient and meaningful factors: student task orientation/efficiency, student competence, and teacher support. The factor analysis of the HPQ-TS uncovered two salient and substantive factors: student responsibility and student competence. The findings of this study suggest that the HPQ is a promising set of measures for assessing student homework functioning and contextual factors that may influence performance. Directions for future research are presented. PMID:18516211

Self-Reported Functional Status among the Old-Old: A Comparison of Two Israeli Cohorts

PubMed Central

Litwin, Howard; Shrira, Amit; Shmotkin, Dov

2012-01-01

OBJECTIVES To examine differences in functional status among two successive cohorts. METHODS The study was a comparative analysis of Jewish respondents aged 75–94 from two nationwide random samples: the Cross-Sectional and Longitudinal Aging Study (1989–1992; N =1200) and the Survey of Health, Ageing, and Retirement in Europe (2005–2006; N =379). Self-reported functional limitation and disability were compared by means of logistic regressions and MANCOVA, controlling for age, gender, origin, education, marital status, income, self-rated health, and home care receipt. RESULTS Reported functional limitation decreased in the later cohort (SHARE-Israel), but ADL- and IADL-disability increased. Receipt of home care moderated these effects. ADL- and IADL-disability increased among home-care-receiving respondents in the later cohort whereas functional limitation decreased among respondents not in receipt of home care. DISCUSSION The findings suggest that different measures used to assess the disablement process capture different aspects, and that contextual factors influence how older people rate their own functional capacity. PMID:22422761

Readout concepts for the suppression of the slow component of BaF2 for the upgrade of the TAPS spectrometer at ELSA

NASA Astrophysics Data System (ADS)

Diehl, Stefan; Novotny, Rainer W.; Wohlfahrt, Benjamin; Beck, Reinhard

2015-02-01

For the measurement at extremely high interaction rates with fast scintillators, pile-up of consecutive events is a limiting factor. With a decay time of 600 ps of the fast crossluminescence component, Barium Fluoride (BaF2) is one of the fastest inorganic scintillators known today. However, the dominating slow component with a 3 orders of magnitude longer decay time of 630 ns limits the rate capability. To circumvent this limit, different approaches have been made in the past. The slow component can be suppressed for example by doping the crystals with rare earth ions like La3+. The paper will give an overview over the various concepts investigated in the past and present the suppression via optical band pass filters. This method has been chosen for the upgrade of the BaF2 crystals in the most forward region of the TAPS-spectrometer at ELSA in Bonn. It allows to reuse the existing crystals and to achieve a high degree of suppression of the slow component. The focus of the paper will be on the selection of the filters, the achievable rate capability and the energy resolution of the fast component.

Growing Rocks: Implications of Lithification for Microbial Communities and Nutrient Cycling

NASA Astrophysics Data System (ADS)

Corman, J. R.; Poret-Peterson, A. T.; Elser, J. J.

2014-12-01

Lithifying microbial communities ("microbialites") have left their signature on Earth's rock record for over 3.4 billion years and are regarded as important players in paleo-biogeochemical cycles. In this project, we study extant microbialites to understand the interactions between lithification and resource availability. All microbes need nutrients and energy for growth; indeed, nutrients are often a factor limiting microbial growth. We hypothesize that calcium carbonate deposition can sequester bioavailable phosphorus (P) and expect the growth of microbialites to be P-limited. To test our hypothesis, we first compared nutrient limitation in lithifying and non-lithifying microbial communities in Río Mesquites, Cuatro Ciénegas. Then, we experimentally manipulated calcification rates in the Río Mesquites microbialites. Our results suggest that lithifying microbialites are indeed P-limited, while non-lithifying, benthic microbial communities tend towards co-limitation by nitrogen (N) and P. Indeed, in microbialites, photosynthesis and aerobic respiration responded positively to P additions (P<0.05). Organic carbon (OC) additions caused shifts in bacterial community composition based on analysis of 16S rRNA genes. Unexpectedly, calcification rates increased with OC additions (P<0.05), but not with P additions, suggesting that sulfate reduction may be an important pathway for calcification. Experimental reductions in calcification rates caused changes to microbial biomass OC and P concentrations (P<0.01 and P<0.001, respectively), although shifts depended on whether calcification was decreased abiotically or biotically. These results show that resource availability does influence microbialite formation and that lithification may promote phosphorus limitation; however, further investigation is required to understand the mechanism by which the later occurs.

Factors associated with disability among middle-aged and older African American women with osteoarthritis.

PubMed

Walker, Janiece L; Harrison, Tracie C; Brown, Adama; Thorpe, Roland J; Szanton, Sarah L

2016-07-01

Middle-aged and older African American women experience disproportionate rates of functional limitations and disability from osteoarthritis (OA) compared to other racial ethnic groups; however, little is known about what factors contribute to this disparity within African American women. To examine factors associated with physical function and disability among African American women ages 50-80 with OA using the disablement process model. This descriptive study included 120 African American women with OA from the Southwestern region of the United States. Regression techniques were used to model the correlates of physical function and disability and to test a mediation model. BMI and pain severity were significantly related to functional limitations. Depressive symptoms mediated the relationship between racial discrimination and disability. Biological, intra-individual, and extra-individual factors are related to disablement outcomes in this sample of African American women, which is consistent with theory suggesting the need for treatment coupled with environmental modifications. This study can inform the development of future bio-behavioral interventions. Copyright © 2016 Elsevier Inc. All rights reserved.

Factors associated with declining under-five mortality rates from 2000 to 2013: an ecological analysis of 46 African countries.

PubMed

Kipp, Aaron M; Blevins, Meridith; Haley, Connie A; Mwinga, Kasonde; Habimana, Phanuel; Shepherd, Bryan E; Aliyu, Muktar H; Ketsela, Tigest; Vermund, Sten H

2016-01-08

Inadequate overall progress has been made towards the 4th Millennium Development Goal of reducing under-five mortality rates by two-thirds between 1990 and 2015. Progress has been variable across African countries. We examined health, economic and social factors potentially associated with reductions in under-five mortality (U5M) from 2000 to 2013. Ecological analysis using publicly available data from the 46 nations within the WHO African Region. We assessed the annual rate of change (ARC) of 70 different factors and their association with the annual rate of reduction (ARR) of U5M rates using robust linear regression models. Most factors improved over the study period for most countries, with the largest increases seen for economic or technological development and external financing factors. The median (IQR) U5M ARR was 3.6% (2.8 to 5.1%). Only 4 of 70 factors demonstrated a strong and significant association with U5M ARRs, adjusting for potential confounders. Higher ARRs were associated with more rapidly increasing coverage of seeking treatment for acute respiratory infection (β=0.22 (ie, a 1% increase in the ARC was associated with a 0.22% increase in ARR); 90% CI 0.09 to 0.35; p=0.01), increasing health expenditure relative to gross domestic product (β=0.26; 95% CI 0.11 to 0.41; p=0.02), increasing fertility rate (β=0.54; 95% CI 0.07 to 1.02; p=0.07) and decreasing maternal mortality ratio (β=-0.47; 95% CI -0.69 to -0.24; p<0.01). The majority of factors showed no association or raised validity concerns due to missing data from a large number of countries. Improvements in sociodemographic, maternal health and governance and financing factors were more likely associated with U5M ARR. These underscore the essential role of contextual factors facilitating child health interventions and services. Surveillance of these factors could help monitor which countries need additional support in reducing U5M. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Patterns and predictors of health service utilization in adolescents with pain: comparison between a community and a clinical pain sample.

PubMed

Toliver-Sokol, Marisol; Murray, Caitlin B; Wilson, Anna C; Lewandowski, Amy; Palermo, Tonya M

2011-07-01

There is limited research describing the patterns of healthcare utilization in adolescents with chronic pain. This study describes healthcare utilization in a clinical chronic pain sample, and compares the patterns of service use of this group to a community sample with intermittent pain complaints. We also investigated demographic and clinical factors that predicted healthcare visits and medication use in the clinical sample. Data on 117 adolescents (aged 12-18; n = 59 clinical pain sample, n = 58 community) were collected. Caregivers and adolescents reported on sociodemographics, medical visits, current medications, pain, activity limitations, and depression. As hypothesized, the clinical pain sample had higher rates of healthcare consultation on all types of medical visits (general, specialty care, complementary medicine, mental health, OT/PT), and higher medication use compared to the community sample. Regression analyses revealed that higher annual income, greater pain frequency, and higher levels of caregiver-reported activity limitations were associated with a greater number of healthcare visits for the total sample. Within the clinical pain sample, higher pain frequency and greater activity limitations (caregiver report) predicted more specialty care visits. Additionally, higher income and greater levels of depressive symptoms predicted a higher number of prescribed medications. This study contributes to the limited available data on health service and medication use in a clinical chronic pain sample versus a community sample of adolescents. We also identify clinical factors (pain frequency, parent-reported activity limitations, depressive symptoms) and demographic factors (gender, income) associated with healthcare utilization. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

What affects response rates in primary healthcare-based programmes? An analysis of individual and unit-related factors associated with increased odds of non-response based on HCV screening in the general population in Poland.

PubMed

Parda, Natalia; Stępień, Małgorzata; Zakrzewska, Karolina; Madaliński, Kazimierz; Kołakowska, Agnieszka; Godzik, Paulina; Rosińska, Magdalena

2016-12-07

Response rate in public health programmes may be a limiting factor. It is important to first consider their delivery and acceptability for the target. This study aimed at determining individual and unit-related factors associated with increased odds of non-response based on hepatitis C virus screening in primary healthcare. Primary healthcare units (PHCUs) were extracted from the Register of Health Care Centres. Each of the PHCUs was to enrol adult patients selected on a random basis. Data on the recruitment of PHCUs and patients were analysed. Multilevel modelling was applied to investigate individual and unit-related factors associated with non-response. Multilevel logistic model was developed with fixed effects and only a random intercept for the unit. Preliminary analysis included a random effect for unit and each of the individual or PHCU covariates separately. For each of the PHCU covariates, we applied a two-level model with individual covariates, unit random effect and a single fixed effect of this unit covariate. This study was conducted in primary care units in selected provinces in Poland. A total of 242 PHCUs and 24 480 adults were invited. Of them, 44 PHCUs and 20 939 patients agreed to participate. Both PHCUs and patients were randomly selected. Data on 44 PHCUs and 24 480 patients were analysed. PHCU-level factors and recruitment strategies were important predictors of non-response. Unit random effect was significant in all models. Larger and private units reported higher non-response rates, while for those with a history of running public health programmes the odds of non-response was lower. Proactive recruitment, more working hours devoted to the project and patient resulted in higher acceptance of the project. Higher number of personnel had no such effect. Prior to the implementation of public health programme, several factors that could hinder its execution should be addressed. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Influence of the formation- and passivation rate of boron-oxygen defects for mitigating carrier-induced degradation in silicon within a hydrogen-based model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hallam, Brett, E-mail: brett.hallam@unsw.edu.au; Abbott, Malcolm; Nampalli, Nitin

2016-02-14

A three-state model is used to explore the influence of defect formation- and passivation rates of carrier-induced degradation related to boron-oxygen complexes in boron-doped p-type silicon solar cells within a hydrogen-based model. The model highlights that the inability to effectively mitigate carrier-induced degradation at elevated temperatures in previous studies is due to the limited availability of defects for hydrogen passivation, rather than being limited by the defect passivation rate. An acceleration of the defect formation rate is also observed to increase both the effectiveness and speed of carrier-induced degradation mitigation, whereas increases in the passivation rate do not lead tomore » a substantial acceleration of the hydrogen passivation process. For high-throughput mitigation of such carrier-induced degradation on finished solar cell devices, two key factors were found to be required, high-injection conditions (such as by using high intensity illumination) to enable an acceleration of defect formation whilst simultaneously enabling a rapid passivation of the formed defects, and a high temperature to accelerate both defect formation and defect passivation whilst still ensuring an effective mitigation of carrier-induced degradation.« less

Injury Rates, Limited Duty Days, Medically Not Ready Rates, and Injury Risk Factors in an Army Chemical Brigade

DTIC Science & Technology

2015-09-01

7 7±0 0.6 Blister 1(ə%) -- -- -- -- Burn -- -- -- -- -- Concussion -- -- -- -- -- Other 40(6%) 31 2,297 74.1±87.0 191.4 Total 707(100%) 504...t      If you were asked to walk briskly up a slight incline of 100 yards (the length of a football field), what would your exertion...Please specify the sport causing the injury #1:  Football  Basketball  Soccer  Volleyball  Softball

Limitations to photosynthesis by proton motive force-induced photosystem II photodamage

PubMed Central

Davis, Geoffry A; Kanazawa, Atsuko; Schöttler, Mark Aurel; Kohzuma, Kaori; Froehlich, John E; Rutherford, A William; Satoh-Cruz, Mio; Minhas, Deepika; Tietz, Stefanie; Dhingra, Amit; Kramer, David M

2016-01-01

The thylakoid proton motive force (pmf) generated during photosynthesis is the essential driving force for ATP production; it is also a central regulator of light capture and electron transfer. We investigated the effects of elevated pmf on photosynthesis in a library of Arabidopsis thaliana mutants with altered rates of thylakoid lumen proton efflux, leading to a range of steady-state pmf extents. We observed the expected pmf-dependent alterations in photosynthetic regulation, but also strong effects on the rate of photosystem II (PSII) photodamage. Detailed analyses indicate this effect is related to an elevated electric field (Δψ) component of the pmf, rather than lumen acidification, which in vivo increased PSII charge recombination rates, producing singlet oxygen and subsequent photodamage. The effects are seen even in wild type plants, especially under fluctuating illumination, suggesting that Δψ-induced photodamage represents a previously unrecognized limiting factor for plant productivity under dynamic environmental conditions seen in the field. DOI: http://dx.doi.org/10.7554/eLife.16921.001 PMID:27697149

Limitations to photosynthesis by proton motive force-induced photosystem II photodamage

DOE PAGES

Davis, Geoffry A.; Kanazawa, Atsuko; Schöttler, Mark Aurel; ...

2016-10-04

The thylakoid proton motive force (pmf) generated during photosynthesis is the essential driving force for ATP production; it is also a central regulator of light capture and electron transfer. We investigated the effects of elevated pmf on photosynthesis in a library of Arabidopsis thaliana mutants with altered rates of thylakoid lumen proton efflux, leading to a range of steady-state pmf extents. We observed the expected pmf-dependent alterations in photosynthetic regulation, but also strong effects on the rate of photosystem II (PSII) photodamage. Detailed analyses indicate this effect is related to an elevated electric field (Δψ) component of the pmf, rathermore » than lumen acidification, which in vivo increased PSII charge recombination rates, producing singlet oxygen and subsequent photodamage. The effects are seen even in wild type plants, especially under fluctuating illumination, suggesting that Δψ-induced photodamage represents a previously unrecognized limiting factor for plant productivity under dynamic environmental conditions seen in the field.« less

Breaking the limitation of mode building time in an optoelectronic oscillator.

PubMed

Hao, Tengfei; Cen, Qizhuang; Dai, Yitang; Tang, Jian; Li, Wei; Yao, Jianping; Zhu, Ninghua; Li, Ming

2018-05-09

An optoelectronic oscillator (OEO) is a microwave photonic system with a positive feedback loop used to create microwave oscillation with ultra-low phase noise thanks to the employment of a high-quality-factor energy storage element, such as a fiber delay line. For many applications, a frequency-tunable microwave signal or waveform, such as a linearly chirped microwave waveform (LCMW), is also needed. Due to the long characteristic time constant required for building up stable oscillation at an oscillation mode, it is impossible to generate an LCMW with a large chirp rate using a conventional frequency-tunable OEO. In this study, we propose and demonstrate a new scheme to generate a large chirp-rate LCMW based on Fourier domain mode locking technique to break the limitation of mode building time in an OEO. An LCMW with a high chirp rate of 0.34 GHz/μs and a large time-bandwidth product of 166,650 is demonstrated.

Selecting Strategies to Reduce High-Risk Unsafe Work Behaviors Using the Safety Behavior Sampling Technique and Bayesian Network Analysis.

PubMed

Ghasemi, Fakhradin; Kalatpour, Omid; Moghimbeigi, Abbas; Mohammadfam, Iraj

2017-03-04

High-risk unsafe behaviors (HRUBs) have been known as the main cause of occupational accidents. Considering the financial and societal costs of accidents and the limitations of available resources, there is an urgent need for managing unsafe behaviors at workplaces. The aim of the present study was to find strategies for decreasing the rate of HRUBs using an integrated approach of safety behavior sampling technique and Bayesian networks analysis. A cross-sectional study. The Bayesian network was constructed using a focus group approach. The required data was collected using the safety behavior sampling, and the parameters of the network were estimated using Expectation-Maximization algorithm. Using sensitivity analysis and belief updating, it was determined that which factors had the highest influences on unsafe behavior. Based on BN analyses, safety training was the most important factor influencing employees' behavior at the workplace. High quality safety training courses can reduce the rate of HRUBs about 10%. Moreover, the rate of HRUBs increased by decreasing the age of employees. The rate of HRUBs was higher in the afternoon and last days of a week. Among the investigated variables, training was the most important factor affecting safety behavior of employees. By holding high quality safety training courses, companies would be able to reduce the rate of HRUBs significantly.

Suicide and occupation: further supportive evidence for their relevance.

PubMed

Nishimura, Mariko; Terao, Takeshi; Soeda, Shuji; Nakamura, Jun; Iwata, Noboru; Sakamoto, Kaoru

2004-01-01

In recent years, the relationship between occupation and suicide has been extensively investigated, but few definite conclusions regarding the nature of the relationship have been established. In the present study, this relationship was investigated by examining Japanese governmental statistics. First, correlations of suicide rate relative to industry categories were examined individually for primary industry (farmers, fishermen, and forest workers), secondary industry (construction workers, manufacture works, and miners), and tertiary industry (indoor workers) for all of the 47 prefectures of Japan. Second, in the industries that showed a significant correlation with suicide rate, the relationship to other factors was adjusted using possibly confounding factors. As a result, suicide rate was positively correlated with primary industry percentage, but not with secondary or tertiary industry percentages. Multiple regression analysis showed that suicide rate was positively associated with primary industry percentage with significant tendency while it was significantly and negatively associated with annual total sunshine. Limitations are that individual suicide rates according to occupational types were not available and direct correlations with the above variables could not be investigated. The present findings suggest a possibility that occupational factors associated with primary industry may be relevant to suicide, and that, additionally, annual total sunshine may affect suicide independently. Since workers with primary industry are likely to be exposed to sunshine than other workers, they may tend to be more affected by the decrease of annual total sunshine.

Factors influencing the delivery of abortion services in Ontario: a descriptive study.

PubMed

Ferris, L E; McMain-Klein, M; Iron, K

1998-01-01

Although Canadian women have had the right to obtain legal induced abortions for the past decade, access to the procedure is still limited and controversial in many areas. Chiefs of obstetrics and gynecology, chiefs of staff, directors of nursing and other health professionals at 163 general hospitals in Ontario, Canada, were asked to provide information on issues concerning the availability of abortion services of their facility. The hospital participation rate was 97% and the individual response rate was 75%. Nearly one-half (48%) of hospitals perform abortions. Approximately 36% of these hospitals do so up to a maximum gestational age of 12 weeks, 23% to a maximum of 13-16 weeks, 37% to a maximum of 17-20 weeks and 4% at greater than 20 weeks. Hospital factors, including resources and policies, did not significantly influence whether abortions are provided. However, these factors did affect the number performed, whether there were gestational limitations and the choice of procedure. About 13% of provider hospitals indicated that staff training contributes to the existence of gestational age limits, and 24% said that it directly influences procedure choice. Only 18% of hospitals reported that their physicians have received additional training outside of their medical school or medical residency education to learn abortion techniques or to gain new skills. Forty-five percent of hospitals that provide abortions had experienced harassment within the past two years, and 15% reported that this harassment has directly affected their staff members' willingness to provide abortions. Based upon the provision of obstetric care, many hospitals in Ontario that are capable of offering abortion services do not. Some of the reasons for this failure are related to the procedure itself, while others may be related to resource issues that affect the delivery of other medical services as well. Variation in the availability of abortions is due to a shortage of clinicians performing the procedure, and training directly influences gestational limits and procedural choices.

RF Safety Analysis of a Novel Ultra-wideband Fetal Monitoring System.

PubMed

Bushberg, Jerrold T; Tupin, J Paul

2017-05-01

The LifeWave Ultra-Wideband RF sensor (LWUWBS) is a monitoring solution for a variety of physiologic assessment applications, including maternal fetal monitoring in both the antepartum and intrapartum periods. The system uses extremely low power radio frequency (RF) ultra-wide band (UWB) signals to provide continuous fetal heart rate and contractions monitoring during labor and delivery. Even with the incorporation of three very conservative assumptions, (1) concentration of the RF energy in 1 cm, (2) minimal (2.5 cm) maternal tissue attenuation of fetal exposure, and (3) absence of normal thermoregulatory compensation, the maternal whole body spatial-averaged specific absorption rate (WBSAR) would be 34,000 times below the FCC public exposure limit of 0.08 W kg and, at 8 wk or more gestation, the peak spatial-averaged specific absorption rate (PSSAR) in the fetus would be more than 160 times below the localized exposure limit of 1.6 mW g. Even when using very conservative assumptions, an analysis of the LWUWBS's impact on tissue heating is a factor of 7 lower than what is allowed for fetal ultrasound and at least a factor of 650 compared to fetal MRI. The actual transmitted power levels of the LWUWBS are well below all Federal safety standards, and the potential for tissue heating is substantially lower than associated with current ultrasonic fetal monitors and MRI.

Impact of Release Rates on the Effectiveness of Augmentative Biological Control Agents

PubMed Central

Crowder, David W.

2007-01-01

To access the effect of augmentative biological control agents, 31 articles were reviewed that investigated the impact of release rates of 35 augmentative biological control agents on the control of 42 arthropod pests. In 64% of the cases, the release rate of the biological control agent did not significantly affect the density or mortality of the pest insect. Results where similar when parasitoidsor predators were utilized as the natural enemy. Within any order of natural enemy, there were more cases where release rates did not affect augmentative biological control than cases where release rates were significant. There were more cases in which release rates did not affect augmentative biological control when pests were from the orders Hemiptera, Acari, or Diptera, but not with pests from the order Lepidoptera. In most cases, there was an optimal release rate that produced effective control of a pest species. This was especially true when predators were used as a biological control agent. Increasing the release rate above the optimal rate did not improve control of the pest and thus would be economically detrimental. Lower release rates were of ten optimal when biological control was used in conjunction with insecticides. In many cases, the timing and method of biological control applications were more significant factors impacting the effectiveness of biological control than the release rate. Additional factors that may limit the relative impact of release rates include natural enemy fecundity, establishment rates, prey availability, dispersal, and cannibalism. PMID:20307240

Use of polynomial expressions to describe the bioconcentration of hydrophobic chemicals by fish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Connell, D.W.; Hawker, D.W.

1988-12-01

For the bioconcentration of hydrophobic chemicals by fish, relationships have been previously established between uptake rate constants (k1) and the octanol/water partition coefficient (Kow), and also between the clearance rate constant (k2) and Kow. These have been refined and extended on the basis of data for chlorinated hydrocarbons, and closely related compounds including polychlorinated dibenzodioxins, that covered a wider range of hydrophobicity (2.5 less than log Kow less than 9.5). This has allowed the development of new relationships between log Kow and various factors, including the bioconcentration factor (as log KB), equilibrium time (as log teq), and maximum biotic concentrationmore » (as log CB), which include extremely hydrophobic compounds previously not taken into account. The shape of the curves generated by these equations are in qualitative agreement with theoretical prediction and are described by polynomial expressions which are generally approximately linear over the more limited range of log Kow values used to develop previous relationships. The influences of factors such as hydrophobicity, aqueous solubility, molecular weight, lipid solubility, and also exposure time were considered. Decreasing lipid solubilities of extremely hydrophobic chemicals were found to result in increasing clearance rate constants, as well decreasing equilibrium times and bioconcentration factors.« less

Anti-Toxoplasma antibody prevalence, primary infection rate, and risk factors in a study of toxoplasmosis in 4,466 pregnant women in Japan.

PubMed

Sakikawa, Makiko; Noda, Shunichi; Hanaoka, Masachi; Nakayama, Hirotoshi; Hojo, Satoshi; Kakinoki, Shigeko; Nakata, Maki; Yasuda, Takashi; Ikenoue, Tsuyomu; Kojima, Toshiyuki

2012-03-01

Toxoplasmosis is a zoonosis caused by infection with Toxoplasma gondii and is prevalent worldwide under various climatic conditions. It is usually asymptomatic, but infection in pregnant women can pose serious health problems for the fetus. However, epidemiological information regarding toxoplasmosis in Japanese pregnant women is limited. This study aimed to determine the prevalence of anti-Toxoplasma antibodies, the primary infection rate, and the risk factors for toxoplasmosis in Japanese pregnant women. We measured anti-Toxoplasma antibody titers in 4,466 pregnant women over a period of 7.5 years and simultaneously conducted interviews to identify the risk factors for toxoplasmosis. The overall prevalence of anti-Toxoplasma antibodies was 10.3%, and it was significantly higher in women aged above 35 years. The rate of primary Toxoplasma infection during pregnancy was estimated to be 0.25%. A possibility of infection in the later stages of pregnancy was identified for those women who were not infected in the early stages. A history of raw meat intake was identified to be a risk factor related to toxoplasmosis. Therefore, to lower the risk of toxoplasmosis, pregnant women should refrain from eating raw and undercooked meat and maintain personal hygiene.

Relationships between pediatric asthma and socioeconomic/urban variables in Baltimore, Maryland

NASA Technical Reports Server (NTRS)

Kimes, Daniel; Ullah, Asad; Levine, Elissa; Nelson, Ross; Timmins, Sidey; Weiss, Sheila; Bollinger, Mary E.; Blaisdell, Carol

2004-01-01

Spatial relationships between clinical data for pediatric asthmatics (hospital and emergency department utilization rates), and socioeconomic and urban characteristics in Baltimore City were analyzed with the aim of identifying factors that contribute to increased asthma rates. Socioeconomic variables and urban characteristics derived from satellite data explained 95% of the spatial variation in hospital rates. The proportion of families headed by a single female was the most important variable accounting for 89% of the spatial variation. Evidence suggests that the high rates of hospital admissions and emergency department (ED) visits may partially be due to the difficulty of single parents with limited resources managing their child's asthma condition properly. This knowledge can be used for education towards mitigating ED and hospital events in Baltimore City.

Heavy smoking rate trends and related factors in Korean occupational groups: analysis of KNHANES 2007-2012 data.

PubMed

Kim, Bo-Guen; Pang, Do-Dam; Park, Young-Jun; Lee, Jong-In; Kim, Hyoung-Ryoul; Myong, Jun-Pyo; Jang, Tae-Won

2015-11-12

The present study was designed to investigate the smoking and heavy smoking trends and identify possible related factors among Korean male workers from 2007 to 2012 by occupational groups. The data were derived from the fourth (2007-2009) and fifth (2010-2012) waves of the Korean National Health and Nutrition Examination Survey (KNHANES). Occupational groups were categorised into three groups, which were non-manual, manual and service and sales groups. Age-adjusted prevalence rates of smoking and heavy smoking (>20 cigarettes/day) in men aged 25-64 years were calculated. Factors associated with heavy smoking were investigated using logistic regression analyses. Smoking rate in manual workers decreased gradually over time (p for trend <0.0001). Smoking rate was higher in manual than non-manual workers, but the difference reduced over time (p for trend <0.0001). Heavy smoking rate decreased from 2007 to 2012 (p for trend <0.0001). Heavy smoking rate was higher in manual than non-manual workers; however, this difference increased over time. Stress, depressive mood and long working hours (≥60 h/week) were associated with heavy smoking. Antismoking policy should focus on current and heavy smokers. Workplace antismoking programmes should consider working hours and stress, especially in manual workers. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Back and upper extremity disorders among enlisted U.S. Marines: burden and individual risk factors.

PubMed

Huang, G D; Feuerstein, M; Arroyo, F

2001-11-01

Although musculoskeletal disorders of the low back and upper extremities can affect military readiness, little is known about their extent and risk factors in the U.S. Marine Corps. Using the Defense Medical Epidemiology and Defense Medical Surveillance System databases, back and upper extremity diagnostic categories were among the top four sources of outpatient visits and duty limitation among enlisted Marines. Back disorders were also found to be the fifth most common cause for lost time. Subsequently, high-risk occupations were identified, age-related trends for clinic visit rates were determined, and rate ratios were computed for the top 15 low back and upper extremity diagnoses among enlisted Marines from 1997 through 1998. Occupational categories with the highest rates of musculoskeletal-related outpatient visits included image interpretation, auditing and accounting, disturbsing, surveillance/target acquisition, and aircraft launch equipment. Significantly increasing linear trends in rates across age groups were found for most diagnoses. For 1998, age-specific rate ratios indicated significantly higher rates for most low back and upper extremity disorders for females; lower rank (i.e., E1-E4) was also a risk, but for fewer diagnoses. The findings emphasize the need to identify modifiable (e.g., work-related, individual) risk factors and to develop focused primary and secondary prevention programs for musculoskeletal disorders in the Marine Corps. Subsequently, these efforts can assist in reducing associated effects, maximizing resource utilization, and enhancing operational readiness.

Challenges in using rater judgements in medical education.

PubMed

Albanese, M A

2000-08-01

Changes in the healthcare environment are putting increasing pressure on medical schools to make faculty accountable and to document the quality of the medical education they provide. Faculty's ratings of students' performances and students' ratings of faculty's teaching are important elements in these efforts to document educational quality. This article discusses selected research related to factors affecting raters' judgements, analyses how changes in the health care environment are influencing such judgements, offers some suggestions to moderate some of the effects and links these influences to the system that upholds professional standards. Ratings are known to have a positive bias (generosity error), provide limited discrimination and often fail to document serious deficits. The potential sources of these problems relate to the mechanics of the rating task, the system used to obtain ratings and factors affecting rater judgement. As managed care demands reduce the time faculty have for teaching, as system-wide disincentives to provide negative ratings proliferate and as social engineering challenges, such as the Americans with Disabilities Act, impose differential standards for students, the natural tendency to avoid giving negative ratings becomes even harder to resist. Ultimately, these forces compromise the capability of faculty to uphold the standards of the profession. The author calls for a national effort to stem the erosion of those standards.

HIV Testing and Diagnosis Rates in Kiev, Ukraine: April 2013-March 2014.

PubMed

Simmons, Ruth; Malyuta, Ruslan; Chentsova, Nelli; Medoeva, Antonia; Kruglov, Yuri; Yurchenko, Alexander; Copas, Andrew; Porter, Kholoud

2015-01-01

Data from Ukraine on risk factors for HIV acquisition are limited. We describe the characteristics of individuals testing for HIV in the main testing centres of the Ukrainian capital Kiev, including HIV risk factors, testing rates, and positivity rates. As part of a larger study to estimate HIV incidence within Kiev City, we included questions on possible risk factors for HIV acquisition and testing history to existing systems in 4 infectious disease clinics. Data were provided by the person requesting an HIV test using a handheld electronic tablet. All persons (≥16 yrs) presenting for an HIV test April 2013-March 2014 were included. Rates per 100,000 were calculated using region-specific denominators for Kiev. During the study period 6370 individuals tested for HIV, equivalent to a testing rate of 293.2 per 100,000. Of these, 467 (7.8%) were HIV-positive, with the highest proportion positive among 31-35 year olds (11.2%), males (9.4%), people who inject drugs (PWID) (17.9%) and men who have sex with men (MSM) (24.1%). Using published population size estimates of MSM, diagnosis rates for MSM ranged from 490.6 to 1548.3/100,000. A higher proportion of heterosexual women compared to heterosexual men reported contact with PWID, (16% vs. 4.7%) suggesting a bridging in risk between PWID and their sexual partners. Collection of HIV risk factor information in Kiev, essential for the purposes of developing effective HIV prevention and response tools, is feasible. The high percentage of MSM among those testing positive for HIV, may indicate a significant level of undisclosed sex between men in national figures.

HIV Testing and Diagnosis Rates in Kiev, Ukraine: April 2013 - March 2014

PubMed Central

Simmons, Ruth; Malyuta, Ruslan; Medoeva, Antonia; Kruglov, Yuri; Yurchenko, Alexander; Copas, Andrew; Porter, Kholoud

2015-01-01

Objective Data from Ukraine on risk factors for HIV acquisition are limited. We describe the characteristics of individuals testing for HIV in the main testing centres of the Ukrainian capital Kiev, including HIV risk factors, testing rates, and positivity rates. Methods As part of a larger study to estimate HIV incidence within Kiev City, we included questions on possible risk factors for HIV acquisition and testing history to existing systems in 4 infectious disease clinics. Data were provided by the person requesting an HIV test using a handheld electronic tablet. All persons (≥16yrs) presenting for an HIV test April 2013–March 2014 were included. Rates per 100,000 were calculated using region-specific denominators for Kiev. Results During the study period 6370 individuals tested for HIV, equivalent to a testing rate of 293.2 per 100,000. Of these, 467 (7.8%) were HIV-positive, with the highest proportion positive among 31–35 year olds (11.2%), males (9.4%), people who inject drugs (PWID) (17.9%) and men who have sex with men (MSM) (24.1%). Using published population size estimates of MSM, diagnosis rates for MSM ranged from 490.6to 1548.3/100,000. A higher proportion of heterosexual women compared to heterosexual men reported contact with PWID, (16% vs. 4.7%) suggesting a bridging in risk between PWID and their sexual partners. Conclusion Collection of HIV risk factor information in Kiev, essential for the purposes of developing effective HIV prevention and response tools, is feasible. The high percentage of MSM among those testing positive for HIV, may indicate a significant level of undisclosed sex between men in national figures. PMID:26322977

Survival and Associated Risk Factors for Mortality Among Infants with Critical Congenital Heart Disease in a Developing Country.

PubMed

Mat Bah, Mohd Nizam; Sapian, Mohd Hanafi; Jamil, Mohammad Tamim; Alias, Amelia; Zahari, Norazah

2018-05-14

Critical congenital heart disease (CCHD) is associated with significant morbidity and mortality. However, data on survival of CCHD and the risk factors associated with its mortality are limited. This study examined CCHD survival and the risk factors for CCHD mortality. Using a retrospective cohort study of infants born with CCHD from 2006 to 2015, survival over 10 years was estimated using Kaplan-Meier analysis, and the risk factors for mortality were analyzed using multivariate Cox proportional hazards regression. A total of 491 CCHD cases were included in the study, with an overall mortality rate of 34.8% (95% confidence interval [CI] 30.6-39.2). The intervention/surgical mortality rate was 9.8% ≤ 30 days and 11.5% > 30 days after surgery, and 17% died before surgery or intervention. The median age at death was 2.7 months [first quartile: 1 month, third quartile: 7.3 months]. The CCHD survival rate was 90.4% (95% CI 89-91.8%) at 1 month, 69.3% (95% CI 67.2-71.4%) at 1 year, 63.4% (95% CI 61.1-65.7%) at 5 years, and 61.4% (95% CI 58.9-63.9%) at 10 years. Weight of < 2 kg at diagnosis, associated syndromes, poor pre-operative condition, and non-duct-dependent CCHD were independent risk factors for poor survival, with hazard ratios of 2.61, 2.10, 2.22, and 1.70, respectively. CCHD is associated with a high mortality rate. Low weight, poor pre-operative condition, associated syndromes, and non-duct-dependent CCHD are significant risk factors affecting the survival of infants with CCHD.

Increased planned delivery contributes to declining rates of pregnancy hypertension in Australia: a population-based record linkage study.

PubMed

Roberts, Christine L; Algert, Charles S; Morris, Jonathan M; Ford, Jane B

2015-10-05

Since the 1990s, pregnancy hypertension rates have declined in some countries, but not all. Increasing rates of early planned delivery (before the due date) have been hypothesised as the reason for the decline. The aim of this study was to explore whether early planned delivery can partly explain the declining pregnancy hypertension rates in Australia. Population-based record linkage study utilising linked birth and hospital records. A cohort of 1,076,122 deliveries in New South Wales, Australia, 2001-2012. Pregnancy hypertension (including gestational hypertension, pre-eclampsia and eclampsia) was the main outcome; pre-eclampsia was a secondary outcome. From 2001 to 2012, pregnancy hypertension rates declined by 22%, from 9.9% to 7.7%, and pre-eclampsia by 27%, from 3.3% to 2.4% (trend p<0.0001). At the same time, planned deliveries increased: prelabour caesarean section by 43% (12.9-18.4%) and labour inductions by 10% (24.8-27.2%). Many maternal risk factors for pregnancy hypertension significantly increased (p<0.01) over the study period including nulliparity, age ≥35 years, diabetes, overweight and obesity, and use of assisted reproductive technologies; some risk factors decreased including multifetal pregnancies, age <20 years, autoimmune diseases and previous pregnancy hypertension. Given these changes in risk factors, the pregnancy hypertension rate was predicted to increase to 10.5%. Examination of annual gestational age distributions showed that pregnancy hypertension rates actually declined from 38 weeks gestation and were steepest from 41 weeks; at least 36% of the decrease could be attributed to planned deliveries. The risk factors for pregnancy hypertension were also risk factors for planned delivery. It appears that an unanticipated consequence of increasing early planned deliveries is a decline in the incidence of pregnancy hypertension. Women with risk factors for hypertension were relatively more likely to be selected for early delivery. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

A Population-Based Approach to Restore and Manage Ruppia Maritima (Wigeongrass) in the Highly Variable Everglades-Florida Bay Ecotone

NASA Astrophysics Data System (ADS)

Strazisar, T. M.; Koch, M.; Madden, C. J.

2016-02-01

Seagrasses and submerged aquatic vegetation (SAV) continue to decline globally from human-induced disturbance and habitat loss in estuarine and coastal ecosystems. The SAV Ruppia maritima historically created critical habitat at the Everglades-Florida Bay ecotone, but hydrological modifications and lower freshwater flows have resulted in significant declines in recent decades. We used a population-based approach to examine factors controlling Ruppia presence and abundance at the ecotone to expand the scientific base for management and restoration of SAV species in highly variable environments and examine factors required for Ruppia restoration in the Everglades. Life history transitions from seed through sexual reproduction were established under a range of field conditions critical to seagrass and SAV persistence, including salinity, temperature, light, sediment nutrients (P) and competitor SAV. We found multiple constraints to Ruppia life history development, including an ephemeral seed bank, low rates of successful germination and seedling survival and clonal reproduction limited by variable salinity, nutrients, light and competition with the macroalga Chara hornemannii. Because of low survival rates and limited clonal reproduction, Ruppia at the Evergaldes ecotone currently depends on high rates of viable seed production. However, development of large reproductive meadows requires high vegetative shoot densities. Thus, Everglades restoration should establish lower salinities to create higher seedling and adult survival and clonal reproduction to support successful sexual reproduction that can build up the seed bank for years when adult survival is limited. This population-based data from field experiments and surveys is being incorporated into a seagrass model to enable forecasting of population sustainability and evaluate Everglades restoration targets which includes restoring Ruppia to the southern Everglades-Florida Bay ecotone.

Factors That Influence the Practice of Elective Induction of Labor

PubMed Central

Moore, Jennifer; Low, Lisa Kane

2012-01-01

Elective induction of labor has been linked to increased rates of prematurity and rising rates of cesarean birth. The purpose of this investigation was to evaluate current trends in induction of labor scholarship focusing on evidence-based factors that influence the practice of elective induction. A key word search was conducted to identify studies on the practice of elective induction of labor. Analysis of the findings included clustering and identification of recurrent themes among the articles with 3 categories being identified. Under each category, the words/phrases were further clustered until a construct could be named. A total of 49 articles met inclusion criteria: 7 patient, 6 maternity care provider, and 4 organization factors emerged. Only 4 of the articles identified were evidence based. Patient factors were divided into preferences/convenience, communication, fear, pressure/influence, trust, external influences, and technology. Provider factors were then divided into practice preferences/convenience, lack of information, financial incentives, fear, patient desire/demand, and technology. Organization factors were divided into lack of enforcement/accountability, hospital culture, scheduling of staff, and market share issues. Currently, there is limited data-based information focused on factors that influence elective induction of labor. Despite patient and provider convenience/preferences being cited in the literature, the evidence does not support this practice. PMID:22843006

Factors that influence the practice of elective induction of labor: what does the evidence tell us?

PubMed

Moore, Jennifer; Low, Lisa Kane

2012-01-01

Elective induction of labor has been linked to increased rates of prematurity and rising rates of cesarean birth. The purpose of this investigation was to evaluate current trends in induction of labor scholarship focusing on evidence-based factors that influence the practice of elective induction. A key word search was conducted to identify studies on the practice of elective induction of labor. Analysis of the findings included clustering and identification of recurrent themes among the articles with 3 categories being identified. Under each category, the words/phrases were further clustered until a construct could be named. A total of 49 articles met inclusion criteria: 7 patient, 6 maternity care provider, and 4 organization factors emerged. Only 4 of the articles identified were evidence based. Patient factors were divided into preferences/convenience, communication, fear, pressure/influence, trust, external influences, and technology. Provider factors were then divided into practice preferences/convenience, lack of information, financial incentives, fear, patient desire/demand, and technology. Organization factors were divided into lack of enforcement/accountability, hospital culture, scheduling of staff, and market share issues. Currently, there is limited data-based information focused on factors that influence elective induction of labor. Despite patient and provider convenience/preferences being cited in the literature, the evidence does not support this practice.

Analysis of changes in relative elemental growth rate patterns in the elongation zone of Arabidopsis roots upon gravistimulation

NASA Technical Reports Server (NTRS)

Mullen, J. L.; Ishikawa, H.; Evans, M. L.

1998-01-01

Although Arabidopsis is an important system for studying root physiology, the localized growth patterns of its roots have not been well defined, particularly during tropic responses. In order to characterize growth rate profiles along the apex of primary roots of Arabidopsis thaliana (L.) Heynh (ecotype Columbia) we applied small charcoal particles to the root surface and analyzed their displacement during growth using an automated video digitizer system with custom software for tracking the markers. When growing vertically, the maximum elongation rate occurred 481 +/- 50 microns back from the extreme tip of the root (tip of root cap), and the elongation zone extended back to 912 +/- 137 microns. The distal elongation zone (DEZ) has previously been described as the apical region of the elongation zone in which the relative elemental growth rate (REGR) is < or = 30% of the peak rate in the central elongation zone. By this definition, our data indicate that the basal limit of the DEZ was located 248 +/- 30 microns from the root tip. However, after gravistimulation, the growth patterns of the root changed. Within the first hour of graviresponse, the basal limit of the DEZ and the position of peak REGR shifted apically on the upper flank of the root. This was due to a combination of increased growth in the DEZ and growth inhibition in the central elongation zone. On the lower flank, the basal limit of the DEZ shifted basipetally as the REGR decreased. These factors set up the gradient of growth rate across the root, which drives curvature.

Childhood obesity: a review of increased risk for physical and psychological comorbidities.

PubMed

Pulgarón, Elizabeth R

2013-01-01

Worldwide estimates of childhood overweight and obesity are as high as 43 million, and rates continue to increase each year. Researchers have taken interest in the childhood obesity epidemic and the impact of this condition across health domains. The consequences of childhood and adolescent obesity are extensive, including both medical and psychosocial comorbidities. The purpose of this review was to consolidate and highlight the recent literature on the comorbidities associated with childhood obesity, both nationally and internationally. PubMed and PsychINFO searches were conducted on childhood obesity and comorbidities. The initial search of the terms obesity and comorbidity yielded >5000 published articles. Limits were set to include studies on children and adolescents that were published in peer-reviewed journals from 2002 to 2012. These limits narrowed the search to 938. Review of those articles resulted in 79 that are included in this review. The major medical comorbidities associated with childhood obesity in the current literature are metabolic risk factors, asthma, and dental health issues. Major psychological comorbidities include internalizing and externalizing disorders, attention-deficit hyperactivity disorder, and sleep problems. The high prevalence rates of childhood obesity have resulted in extensive research in this area. Limitations to the current childhood obesity literature include differential definitions of weight status and cut-off levels for metabolic risk factors across studies. Additionally, some results are based on self-report of diagnoses rather than chart reviews or physician diagnosis. Even so, there is substantial support for metabolic risk factors, internalizing disorders, attention-deficit hyperactivity disorder, and decreased health-related quality of life as comorbidities to obesity in childhood. Additional investigations on other diseases and conditions that might be associated with childhood obesity are warranted and intervention research in this area is critical. Copyright © 2013 Elsevier HS Journals, Inc. All rights reserved.

Risk of revision surgery for adult idiopathic scoliosis: a survival analysis of 517 cases over 25 years.

PubMed

Riouallon, Guillaume; Bouyer, Benjamin; Wolff, Stéphane

2016-08-01

Little is known about the long-term status of patients operated for spine deformities. The aim of this study was to determine the survival of primary fusion in adult idiopathic scoliosis and identify the risk factors of revision surgery. Adult patients who underwent primary fusion for idiopathic scoliosis between 1983 and 2011 were included in a continuous monocentric retrospective series. Any additional surgery was registered for survival analysis. Survival and follow-up were estimated by the Kaplan-Meier method and an analysis was performed to identify the risk factors of revision surgery. This series included 447 women (86.5 %) and 70 men (13.5 %) reviewed after a mean follow-up of 7 years (range 0-26.4). Mean age was 44.4 years. Fusion was performed on a median 11 levels (range 3-15); revision rate was 13 % (CI 10-17), 18 % (CI 14-23) and 20 % (CI 16-26) at 5, 10 and 15 years, respectively. Revision surgery was associated with age, anterior release, length of fusion, the inferior limit of fusion, post-operative sagittal balance and junctional kyphosis. The length of fusion (HR 1.13 per vertebrae fused, p = 0.007) and the lower limit of fusion (HR 5.9, p < 0.001) remained independent predictors of revision surgery on multivariate analysis. This series evaluated the risk of revision surgery following spinal fusion for idiopathic scoliosis. Our results show that the risk seemed to increase linearly with a rate of nearly 20 % after 10 years. The length and lower limit of fusion are the main risk factors for revision surgery. Level IV (e.g. case series).

Injury rates and injury risk factors among U.S. Army wheel vehicle mechanics.

PubMed

Knapik, Joseph J; Jones, Sarah B; Darakjy, Salima; Hauret, Keith G; Bullock, Steven H; Sharp, Marilyn A; Jones, Bruce H

2007-09-01

This study describes injury rates, injury diagnoses, anatomical locations of injuries, limited duty days, and activities associated with injuries in a sample of Army mechanics. Medical records of 518 male and 43 female Army mechanics were screened for injuries during 1 year at a large U.S. Army installation. Weight, height, age, and ethnicity were also extracted from the medical records. Body mass index was calculated as weight/height2. Overall injury rates for men and women were 124 and 156 injuries/100 person-years, respectively, with a rate of 127 injuries/100 person-years for all soldiers combined. Women had higher overuse injury rates while men had higher traumatic injury rates. Limited duty days for men and women were 2,076 and 1,966 days/100 person-years, respectively. The lower back, knee, ankle, foot, and shoulder involved 61% of the injuries. Activities associated with injury included (in order of incidence) physical training, mechanical work, sports, airborne-related activities, road marching, garrison/home activities, and chronic conditions. Among the men, elevated injury risk was associated with higher body weight and higher body mass index. It may be possible to prevent many injuries by implementation of evidenced-based interventions currently available in the literature.

[Variation pattern and its affecting factors of three-dimensional landscape in urban residential community of Shenyang].

PubMed

Zhang, Pei-Feng; Hu, Yuan-Man; Xiong, Zai-Ping; Liu, Miao

2011-02-01

Based on the 1:10000 aerial photo in 1997 and the three QuickBird images in 2002, 2005, and 2008, and by using Barista software and GIS and RS techniques, the three-dimensional information of the residential community in Tiexi District of Shenyang was extracted, and the variation pattern of the three-dimensional landscape in the district during its reconstruction in 1997-2008 and related affecting factors were analyzed with the indices, ie. road density, greening rate, average building height, building height standard deviation, building coverage rate, floor area rate, building shape coefficient, population density, and per capita GDP. The results showed that in 1997-2008, the building area for industry decreased, that for commerce and other public affairs increased, and the area for residents, education, and medical cares basically remained stable. The building number, building coverage rate, and building shape coefficient decreased, while the floor area rate, average building height, height standard deviation, road density, and greening rate increased. Within the limited space of residential community, the containing capacity of population and economic activity increased, and the environment quality also improved to some extent. The variation degree of average building height increased, but the building energy consumption decreased. Population growth and economic development had positive correlations with floor area rate, road density, and greening rate, but negative correlation with building coverage rate.

Perforated peptic ulcer in southeastern Taiwan.

PubMed

Li, Chin-Hsien; Chang, Wen-Hsiung; Shih, Shou-Chuan; Lin, Shee-Chan; Bair, Ming-Jong

2010-09-01

No studies focus on the population with perforated peptic ulcer in southeastern Taiwan. The present study aimed to assess the differences between the different races and the risk factors related to mortality and morbidity in postoperative patients in southeastern Taiwan. The medical records of 237 patients were reviewed retrospectively. The following factors were analyzed: patient profiles, coexisting illnesses, diagnostic method, fever, preoperative shock, clinical data at emergency room, delay operation, site of perforation, operative method, positive ascites culture, species of microbes in ascites culture, postoperative complications, death and the length of hospital stay. Aborigines were significantly different from non-aborigines in the ratio of female cases and in the habits of alcohol drinking and betel nut chewing. There were also four significantly different variables between them: fever, hemoglobin value, site of perforation and operative method. Total postoperative complication rate was 41.3% and 39 patients (16.6%) died. In multivariate analysis, age > or = 65 years, lipase > upper normal limit and preoperative shock were independent predictors of mortality. Significant risk factors associated with morbidity were NSAIDs use, creatinine > 1.5 mg/dL and preoperative shock. Aborigines were different from non-aborigines in several categories. In southeastern Taiwan, NSAIDs use, creatinine > 1.5 mg/dL and preoperative shock were independent risk factors of morbidity, and age > or = 65 years, lipase > upper normal limit and preoperative shock were independent risk factors of mortality in postoperative perforated peptic ulcer. Lipase > upper normal limit is needed for further research on the influence on mortality.

Near-Limit Flamelet Phenomena in Buoyant Low Stretch Diffusion Flames Beneath a Solid Fuel

NASA Technical Reports Server (NTRS)

Olson, S. L.; Tien, J. S.

2000-01-01

A unique near-limit low stretch multidimensional stable flamelet phenomena has been observed for the first time which extends the material flammability limit beyond the one-dimensional low stretch flammability limit to lower burning rates and higher relative heat losses than is possible with uniform flame coverage. During low stretch experiments burning the underside of very large radii (greater than or = 75 cm stretch rate less than or = 3/s) cylindrical cast PMMA samples, multidimensional flamelets were observed, in contrast with a one-dimensional flame that was found to blanket the surface for smaller radii samples ( higher stretch rate). Flamelets were observed by decreasing the stretch rate or by increasing the conductive heat loss from the flame. Flamelets are defined as flames that cover only part of the burning sample at any given time, but persist for many minutes. Flamelet phenomena is viewed as the flame's method of enhancing oxygen flow to the flame, through oxygen transport into the edges of the flamelet. Flamelets form as heat losses (surface radiation and solid-phase conduction) become large relative to the weakened heat release of the low stretch flame. While heat loss rates remain fairly constant, the limiting factor in the heat release of the flame is hypothesized to be the oxygen transport to the flame in this low stretch (low convective) environment. Flamelet extinction is frequently caused by encroachment of an adjacent flamelet. Large-scale whole-body flamelet oscillations at 1.2 - 1.95 Hz are noted prior to extinction of a flamelet. This oscillation is believed to be due a repeated process of excess fuel leakage through the dark channels between the flamelets, fuel premixing with slow incoming oxidizer, and subsequent rapid flame spread and retreat of the flamelet through the premixed layer. The oscillation frequency is driven by gas-phase diffusive time scales.

HAMSTRING INJURY REHABILITATION AND PREVENTION OF REINJURY USING LENGTHENED STATE ECCENTRIC TRAINING: A NEW CONCEPT

PubMed Central

Tim, Tyler; McHugh, Malachy

2012-01-01

Back ground and Purpose: Hamstring injury is a common occurrence in sport and there has been limited success in reducing this rate of recurrence to date. Description of Topic with Related Evidence: High speed running requires eccentric strength when the hamstring muscles are in a lengthened state. The lengthened state occurs when the hip is in flexion and the lower leg moves into extension, thus lengthening the two joint hamstring muscle over both articulations upon which they act. There is evidence to suggest that athletes who have sustained a hamstring strain lack strength when the muscle is utilized during performance in a lengthened state. Purpose: To examine the risk factors contributing to such a high recurrence rate and propose a unique rehabilitation strategy addressing these factors in order to decrease the rate of reinjury. Discussion/Relation to Clinical Practice: Failing to increase an athlete's eccentric strength in a lengthened position after a hamstring injury may predispose an athlete to subsequent reinjury. Incorporating lengthened state eccentric training may help reduce the rate of reinjury. Level of Evidence: Level 5 PMID:22666648

Fatigue-Life Prediction Methodology Using Small-Crack Theory

NASA Technical Reports Server (NTRS)

Newmann, James C., Jr.; Phillips, Edward P.; Swain, M. H.

1997-01-01

This paper reviews the capabilities of a plasticity-induced crack-closure model to predict fatigue lives of metallic materials using 'small-crack theory' for various materials and loading conditions. Crack-tip constraint factors, to account for three-dimensional state-of-stress effects, were selected to correlate large-crack growth rate data as a function of the effective-stress-intensity factor range (delta K(eff)) under constant-amplitude loading. Some modifications to the delta k(eff)-rate relations were needed in the near-threshold regime to fit measured small-crack growth rate behavior and fatigue endurance limits. The model was then used to calculate small- and large-crack growth rates, and to predict total fatigue lives, for notched and un-notched specimens made of two aluminum alloys and a steel under constant-amplitude and spectrum loading. Fatigue lives were calculated using the crack-growth relations and microstructural features like those that initiated cracks for the aluminum alloys and steel for edge-notched specimens. An equivalent-initial-flaw-size concept was used to calculate fatigue lives in other cases. Results from the tests and analyses agreed well.

The (Un)Success of American Indian Gates Millennium Scholars within Institutions of Higher Education

ERIC Educational Resources Information Center

Youngbull, Natalie Rose

2017-01-01

There remains limited research on the gap between the participation and persistence to graduation rates for American Indian students in higher education. It is pertinent to explore the experiences of these students who did not persist to graduation to be able to gain a better understanding of the factors involved in this gap. The primary purpose…

The Impact of Primary Education on School-to-Work Transitions for Young People in Rural Bolivia

ERIC Educational Resources Information Center

Punch, Samantha

2004-01-01

As in many parts of the majority world, primary education in rural Bolivia is constrained by a range of factors: poor teaching quality, lack of resources, limited infrastructure, inadequate teaching materials, and low wages for teachers. Furthermore, high rates of absenteeism, drop-out, repetition, and failure can be exacerbated by children's work…

Markers of pregnancy: how early can we detect pregnancies in cattle using pregnancy-associated glycoproteins (PAGs) and microRNAs?

USDA-ARS?s Scientific Manuscript database

Pregnancy detection has evolved over the last few decades and the importance of early pregnancy detection is critical to minimize the amount of time a cow spends not pregnant or open. Embryonic mortality (EM) is generally considered to be the primary factor limiting pregnancy rates in cattle and occ...

Kinetics and clonality of immunological memory in humans.

PubMed

Beverley, Peter C L

2004-10-01

T-cell immunological memory consists largely of clones of proliferating lymphocytes maintained by antigenic stimulation and the survival and proliferative effects of cytokines. The duration of survival of memory clones in humans is determine by the Hayflick limit on the number of cell divisions, the rate of cycling of memory cells and factors that control erosion of telomeres, including mechanisms that control telomerase.

VizieR Online Data Catalog: Veritas family members Yarkovsky drift rates (Carruba+, 2017)

NASA Astrophysics Data System (ADS)

Carruba, V.; Vokrouhlicky, D.; Nesvorny, D.

2017-05-01

Data about 274 identified Veritas members, their absolute magnitude, proper a, e, sin(i), g, and s, Lyapunov exponent (multiplied by a factor 10+6), and estimated mean Yarkovsky drift speed, in AU/Myr (no such value is available for (1086) Nata itself, that because of its relative large size has very limited Yarkovsky mobility). (1 data file).

Extraterrestrial 3He as a tracer of marine sediment transport and accumulation

NASA Astrophysics Data System (ADS)

Marcantonio, Franco; Anderson, Robert F.; Stute, Martin; Kumar, Niraj; Schlosser, Peter; Mix, Alan

1996-10-01

THE deposition rate of deep-sea sediments, and their focused redeposition by deep-sea currents, can be evaluated from analyses of sedimentary 230Th with a temporal resolution limited only by bioturbation6,7,10,11. 230Th is produced uniformly throughout the ocean by radioactive decay of dissolved 234U and is removed sufficiently fast by sorption onto sinking particles to act as a 'constant-flux' tracer of sedimentation rates. But the half-life of 230Th (75 kyr) limits its use for this purpose to the past 200-250 kyr. Here we explore the use of extraterrestrial 3He from interplanetary dust particles1-4 (IDPs) as a constant-flux proxy that is free from this limitation. A comparison of 3He with 230Th in two cores from the equatorial Pacific Ocean indicates that the variability in the mean flux of IDPs over the past 200 kyr is less than 75%. But in contrast to this relatively constant rate of supply of 3He to the deep sea, the local burial rates of 3He and 230Th have varied by a factor of five over the past 450 and 200 kyr, respect-ively. We interpret this variability as reflecting sediment focusing, with a temporal pattern that suggests regular cycles of climate-driven reorganization of near-bottom currents in the deep Pacific Ocean.

DFT investigations of phosphotriesters hydrolysis in aqueous solution: a model for DNA single strand scission induced by N-nitrosoureas.

PubMed

Liu, Tingting; Zhao, Lijiao; Zhong, Rugang

2013-02-01

DNA phosphotriester adducts are common alkylation products of DNA phosphodiester moiety induced by N-nitrosoureas. The 2-hydroxyethyl phosphotriester was reported to hydrolyze more rapidly than other alkyl phosphotriesters both in neutral and in alkaline conditions, which can cause DNA single strand scission. In this work, DFT calculations have been employed to map out the four lowest activation free-energy profiles for neutral and alkaline hydrolysis of triethyl phosphate (TEP) and diethyl 2-hydroxyethyl phosphate (DEHEP). All the hydrolysis pathways were illuminated to be stepwise involving an acyclic or cyclic phosphorane intermediate for TEP or DEHEP, respectively. The rate-limiting step for all the hydrolysis reactions was found to be the formation of phosphorane intermediate, with the exception of DEHEP hydrolysis in alkaline conditions that the decomposition process turned out to be the rate-limiting step, owing to the extraordinary low formation barrier of cyclic phosphorane intermediate catalyzed by hydroxide. The rate-limiting barriers obtained for the four reactions are all consistent with the available experimental information concerning the corresponding hydrolysis reactions of phosphotriesters. Our calculations performed on the phosphate triesters hydrolysis predict that the lower formation barriers of cyclic phosphorane intermediates compared to its acyclic counter-part should be the dominant factor governing the hydrolysis rate enhancement of DEHEP relative to TEP both in neutral and in alkaline conditions.

Response of an algal assemblage to nutrient enrichment and shading in a Hawaiian stream

USGS Publications Warehouse

Stephens, S.H.; Brasher, A.M.D.; Smith, C.M.

2012-01-01

To investigate the effects of nitrate enrichment, phosphate enrichment, and light availability on benthic algae, nutrient-diffusing clay flowerpots were colonized with algae at two sites in a Hawaiian stream during spring and autumn 2002 using a randomized factorial design. The algal assemblage that developed under the experimental conditions was investigated by determining biomass (ash-free dry mass and chlorophyll a concentrations) and composition of the diatom assemblage. In situ pulse amplitude-modulated fluorometry was also used to model photosynthetic rate of the algal assemblage. Algal biomass and maximum photosynthetic rate were significantly higher at the unshaded site than at the shaded site. These parameters were higher at the unshaded site with either nitrate, or to a lesser degree, nitrate plus phosphate enrichment. Analysis of similarity of diatom assemblages showed significant differences between shaded and unshaded sites, as well as between spring and autumn experiments, but not between nutrient treatments. However, several individual species of diatoms responded significantly to nitrate enrichment. These results demonstrate that light availability (shaded vs. unshaded) is the primary limiting factor to algal growth in this stream, with nitrogen as a secondary limiting factor. ?? 2011 Springer Science+Business Media B.V.

Setting an Agenda to Address Intimate Partner Violence Among Young Men Who Have Sex With Men: A Conceptual Model and Review.

PubMed

Kubicek, Katrina

2016-10-18

Research investigating intimate partner violence (IPV) among sexual minorities is limited. The research that does exist has found that rates of IPV are similar to or higher than the rates found for heterosexual women, the most commonly studied population in this area. This limited research has resulted in a dearth of prevention/intervention programs targeted for these populations. While some may argue that existing IPV programs can be used for these populations, this review presents an argument for more targeted work with sexual minority populations, using young men who have sex with men (YMSM) as an example. Drawing on the framework of intersectionality, this article argues that the intersectionality of age, sexual identity, and gender combines to create a spectrum of unique factors that require specific attention. This framework allows for the identification of known correlates for IPV as well as factors that may be unique to YMSM or other sexual minority populations. The article presents a conceptual model that suggests new areas of research as well as a foundation for the topics and issues that should be addressed in an intervention. © The Author(s) 2016.

Health-Related Quality of Life Among Central Appalachian Residents in Mountaintop Mining Counties

PubMed Central

Hendryx, Michael

2011-01-01

Objectives. We examined the health-related quality of life of residents in mountaintop mining counties of Appalachia using the 2006 national Behavioral Risk Factor Surveillance System. Methods. Dependent variables included self-rated health; the number of poor physical, poor mental, and activity limitation days (in the past 30 days); and the Healthy Days Index. Independent variables included metropolitan status, primary care physician supply, and Behavioral Risk Factor Surveillance System behavioral and demographic variables. We compared dependent variables across 3 categories: mountaintop mining (yes or no), other coal mining (yes or no), and a referent nonmining group. We used SUDAAN MULTILOG and multiple linear regression models with post hoc least squares means to test mountaintop mining effects after adjusting for covariates. Results. Residents of mountaintop mining counties reported significantly more days of poor physical, mental, and activity limitation and poorer self-rated health (P < .01) compared with the other county groupings. Results were generally consistent in separate analyses by gender and age. Conclusions. Mountaintop mining areas are associated with the greatest reductions in health-related quality of life even when compared with counties with other forms of coal mining. PMID:21421943

Electric fence standards comport with human data and AC limits.

PubMed

Kroll, Mark W; Perkins, Peter E; Panescu, Dorin

2015-08-01

The ubiquitous electric fence is essential to modern agriculture and has saved lives by reducing the number of livestock automobile collisions. Modern safety standards such as IEC 60335-2-76 and UL 69 have played a role in this positive result. However, these standards are essentially based on energy and power (RMS current), which have limited direct relationship to cardiac effects. We compared these standards to bioelectrically more relevant units of charge and average current in view of recent work on VF (ventricular fibrillation) induction and to existing IEC AC current limits. There are 3 limits for normal (low) pulsing rate: IEC energy limit, IEC current limit, and UL current limit. We then calculated the delivered charge allowed for each pulse duration for these limits and then compared them to a charge-based safety model derived from published human ventricular-fibrillation induction data. Both the IEC and UL also allow for rapid pulsing for up to 3 minutes. We calculated maximum outputs for various pulse durations assuming pulsing at 10, 20, and 30 pulses per second. These were then compared to standard utility power safety (AC) limits via the conversion factor of 7.4 to convert average current to RMS current for VF risk. The outputs of TASER electrical weapons (typically < 100 μC and ~100 μs duration) were also compared. The IEC and UL electric fence energizer normal rate standards are conservative in comparison with actual human laboratory experiments. The IEC and UL electric fence energizer rapid-pulsing standards are consistent with accepted IEC AC current limits for commercially used pulse durations.

Inhalation injury in a burn unit: a retrospective review of prognostic factors

PubMed Central

Monteiro, D.; Silva, I.; Egipto, P.; Magalhães, A.; Filipe, R.; Silva, A.; Rodrigues, A.; Costa, J.

2017-01-01

Summary Inhalation injury (InI) is known to seriously affect the prognosis of burn patients, as it is strongly associated with high morbidity and mortality. Despite major advances in the treatment of burn patients in the past years, advances in the treatment of smoke InI have been somewhat limited; mortality reduction mostly results from improvements in critical care. It is difficult to separate the contribution of InI from other mechanisms that also affect respiratory tract and lungs. The aim of this study was to compare patients with and without InI and to identify prognostic factors among patients with smoke InI. Patients with InI displayed higher total body surface area (TBSA) burned, higher incidence of pneumonia and acute respiratory distress syndrome (ARDS), a higher rate of positive blood cultures and a significantly higher death rate. We could conclude that older age, higher TBSA, ARDS and pneumonia were independent predictive factors for mortality in our global study population. Older age and higher TBSA were the only independent factors found to be predictive of mortality in patients with InI. PMID:29021724

Inhalation injury in a burn unit: a retrospective review of prognostic factors.

PubMed

Monteiro, D; Silva, I; Egipto, P; Magalhães, A; Filipe, R; Silva, A; Rodrigues, A; Costa, J

2017-06-30

Inhalation injury (InI) is known to seriously affect the prognosis of burn patients, as it is strongly associated with high morbidity and mortality. Despite major advances in the treatment of burn patients in the past years, advances in the treatment of smoke InI have been somewhat limited; mortality reduction mostly results from improvements in critical care. It is difficult to separate the contribution of InI from other mechanisms that also affect respiratory tract and lungs. The aim of this study was to compare patients with and without InI and to identify prognostic factors among patients with smoke InI. Patients with InI displayed higher total body surface area (TBSA) burned, higher incidence of pneumonia and acute respiratory distress syndrome (ARDS), a higher rate of positive blood cultures and a significantly higher death rate. We could conclude that older age, higher TBSA, ARDS and pneumonia were independent predictive factors for mortality in our global study population. Older age and higher TBSA were the only independent factors found to be predictive of mortality in patients with InI.

An overview of racial disparities in preterm birth rates: caused by infection or inflammatory response?

PubMed Central

MENON, RAMKUMAR; DUNLOP, ANNE L.; KRAMER, MICHAEL R.; FORTUNATO, STEPHEN J.; HOGUE, CAROL J.

2017-01-01

Infection has been hypothesized to be one of the factors associated with spontaneous preterm birth (PTB) and with the racial disparity in rates of PTB between African American and Caucasian women. However, recent findings refute the generalizability of the role of infection and inflammation. African Americans have an increased incidence of PTB in the setting of intraamniotic infection, periodontal disease, and bacterial vaginosis compared to Caucasians. Herein we report variability in infection- and inflammation-related factors based on race/ethnicity. For African American women, an imbalance in the host proinflammatory response seems to contribute to infection-associated PTB, as evidenced by a greater presence of inflammatory mediators with limited or reduced presence of immune balancing factors. This may be attributed to differences in the genetic variants associated with PTB between African Americans and Caucasians. We argue that infection may not be a cause of racial disparity but in association with other risk factors such as stress, nutritional deficiency, and differences in genetic variations in PTB, pathways and their complex interactions may produce differential inflammatory responses that may contribute to racial disparity. PMID:21615712

A cross-national exploration of societal-level factors associated with child physical abuse and neglect.

PubMed

Klevens, Joanne; Ports, Katie A; Austin, Chelsea; Ludlow, Ivan J; Hurd, Jacqueline

2017-11-28

Children around the world experience violence at the hands of their caregivers at alarming rates. A recent review estimates that a minimum of 50% of children in Asia, Africa, and North America experienced severe physical violence by caregivers in the past year, with large variations between countries. Identifying modifiable country-level factors driving these geographic variations has great potential for achieving population-level reductions in rates of child maltreatment. This study builds on previous research by focusing on caregiver-reported physical abuse and neglect victimisation, examining 22 societal factors representing 11 different constructs among 42 countries from 5 continents at different stages of development. Our findings suggest that gender inequity may be important for both child physical abuse and neglect. Indicators of literacy and development may also be important for child neglect. Given the limitations of the correlational findings and measurement issues, it is critical to continue to investigate societal-level factors of child maltreatment so that interventions and prevention efforts can incorporate strategies that have the greatest potential for population-level impact.

The Benefits, Limitations, and Cost-Effectiveness of Advanced Technologies in the Management of Patients With Diabetes Mellitus

PubMed Central

Vigersky, Robert A.

2015-01-01

Background: Hypoglycemia mitigation is critical for appropriately managing patients with diabetes. Advanced technologies are becoming more prevalent in diabetes management, but their benefits have been primarily judged on the basis of hemoglobin A1c. A critical appraisal of the effectiveness and limitations of advanced technologies in reducing both A1c and hypoglycemia rates has not been previously performed. Methods: The cost of hypoglycemia was estimated using literature rates of hypoglycemia events resulting in hospitalizations. A literature search was conducted on the effect on A1c and hypoglycemia of advanced technologies. The cost-effectiveness of continuous subcutaneous insulin infusion (CSII) and real-time continuous glucose monitors (RT-CGM) was reviewed. Results: Severe hypoglycemia in insulin-using patients with diabetes costs $4.9-$12.7 billion. CSII reduces A1c in some but not all studies. CSII improves hypoglycemia in patients with high baseline rates. Bolus calculators improve A1c and improve the fear of hypoglycemia but not hypoglycemia rates. RT-CGM alone and when combined with CSII improve A1c with a neutral effect on hypoglycemia rates. Low-glucose threshold suspend systems reduce hypoglycemia with a neutral effect on A1c, and low-glucose predictive suspend systems reduce hypoglycemia with a small increase in plasma glucose levels. In short-term studies, artificial pancreas systems reduce both hypoglycemia rates and plasma glucose levels. CSII and RT-CGM are cost-effective technologies, but their wide adoption is limited by cost, psychosocial, and educational factors. Conclusions: Most currently available technologies improve A1c with a neutral or improved rate of hypoglycemia. Advanced technologies appear to be cost-effective in diabetes management, especially when including the underlying cost of hypoglycemia. PMID:25555391

Degradation of isobutanal at high loading rates in a compost biofilter.

PubMed

Sercu, Bram; Demeestere, Kristof; Baillieul, Hans; Van Langenhove, Herman; Verstraete, Willy

2005-08-01

Biofiltration has been increasingly used for cleaning waste gases, mostly containing low concentrations of odorous compounds. To expand the application area of this technology, the biofiltration of higher pollutant loading rates has to be investigated. This article focuses on the biodegradation of isobutanal (IBAL) in a compost biofilter (BF) at mass loading rates between 211 and 4123 g/m3/day (30-590 ppm(v)). At mass loading rates up to 785 g/m3/day, near 100% removal efficiencies could be obtained. However, after increasing the loading rate to 1500-1900 g/m3/ day, the degradation efficiency decreased to 62-98%. In addition, a pH decrease and production of isobutanol (IBOL) and isobutyric acid (IBAC) were observed. This is the first report showing that an aldehyde can act as electron donor as well as acceptor in a BF. To study the effects of pH, compost moisture content, and electron acceptor availability on the biofiltration of IBAL, IBOL, and IBAC, additional batch and continuous experiments were performed. A pH of 5.2 reduced the IBAL degradation rate and inhibited the IBOL degradation, although adaptation of the microorganisms to low pH was observed in the BFs. IBAC was not degraded in the batch experiments. High moisture content (51%) initially had no effect on the IBOL production, although it negatively affected the IBAL elimination increasingly during a 21-day time-course experiment. In batch experiments, the reduction of IBAL to IBOL did not decrease when the amount of available electron acceptors (oxygen or nitrate) was increased. The IBAL removal efficiency at higher loading rates was limited by a combination of nutrient limitation, pH decrease, and dehydration, and the importance of each limiting factor depended on the influent concentration.

Emergent relation between surface vapor conductance and relative humidity profiles yields evaporation rates from weather data

NASA Astrophysics Data System (ADS)

Salvucci, Guido D.; Gentine, Pierre

2013-04-01

The ability to predict terrestrial evapotranspiration (E) is limited by the complexity of rate-limiting pathways as water moves through the soil, vegetation (roots, xylem, stomata), canopy air space, and the atmospheric boundary layer. The impossibility of specifying the numerous parameters required to model this process in full spatial detail has necessitated spatially upscaled models that depend on effective parameters such as the surface vapor conductance (Csurf). Csurf accounts for the biophysical and hydrological effects on diffusion through the soil and vegetation substrate. This approach, however, requires either site-specific calibration of Csurf to measured E, or further parameterization based on metrics such as leaf area, senescence state, stomatal conductance, soil texture, soil moisture, and water table depth. Here, we show that this key, rate-limiting, parameter can be estimated from an emergent relationship between the diurnal cycle of the relative humidity profile and E. The relation is that the vertical variance of the relative humidity profile is less than would occur for increased or decreased evaporation rates, suggesting that land-atmosphere feedback processes minimize this variance. It is found to hold over a wide range of climate conditions (arid-humid) and limiting factors (soil moisture, leaf area, energy). With this relation, estimates of E and Csurf can be obtained globally from widely available meteorological measurements, many of which have been archived since the early 1900s. In conjunction with precipitation and stream flow, long-term E estimates provide insights and empirical constraints on projected accelerations of the hydrologic cycle.

Emergent relation between surface vapor conductance and relative humidity profiles yields evaporation rates from weather data.

PubMed

Salvucci, Guido D; Gentine, Pierre

2013-04-16

The ability to predict terrestrial evapotranspiration (E) is limited by the complexity of rate-limiting pathways as water moves through the soil, vegetation (roots, xylem, stomata), canopy air space, and the atmospheric boundary layer. The impossibility of specifying the numerous parameters required to model this process in full spatial detail has necessitated spatially upscaled models that depend on effective parameters such as the surface vapor conductance (C(surf)). C(surf) accounts for the biophysical and hydrological effects on diffusion through the soil and vegetation substrate. This approach, however, requires either site-specific calibration of C(surf) to measured E, or further parameterization based on metrics such as leaf area, senescence state, stomatal conductance, soil texture, soil moisture, and water table depth. Here, we show that this key, rate-limiting, parameter can be estimated from an emergent relationship between the diurnal cycle of the relative humidity profile and E. The relation is that the vertical variance of the relative humidity profile is less than would occur for increased or decreased evaporation rates, suggesting that land-atmosphere feedback processes minimize this variance. It is found to hold over a wide range of climate conditions (arid-humid) and limiting factors (soil moisture, leaf area, energy). With this relation, estimates of E and C(surf) can be obtained globally from widely available meteorological measurements, many of which have been archived since the early 1900s. In conjunction with precipitation and stream flow, long-term E estimates provide insights and empirical constraints on projected accelerations of the hydrologic cycle.

Examining the validity of the Homework Performance Questionnaire: Multi-informant assessment in elementary and middle school.

PubMed

Power, Thomas J; Watkins, Marley W; Mautone, Jennifer A; Walcott, Christy M; Coutts, Michael J; Sheridan, Susan M

2015-06-01

Methods for measuring homework performance have been limited primarily to parent reports of homework deficits. The Homework Performance Questionnaire (HPQ) was developed to assess the homework functioning of students in Grades 1 to 8 from the perspective of both teachers and parents. The purpose of this study was to examine the factorial validity of teacher and parent versions of this scale, and to evaluate gender and grade-level differences in factor scores. The HPQ was administered in 4 states from varying regions of the United States. The validation sample consisted of students (n = 511) for whom both parent and teacher ratings were obtained (52% female, mean of 9.5 years of age, 79% non-Hispanic, and 78% White). The cross-validation sample included 1,450 parent ratings and 166 teacher ratings with similar demographic characteristics. The results of confirmatory factor analyses demonstrated that the best-fitting model for teachers was a bifactor solution including a general factor and 2 orthogonal factors, referring to student self-regulation and competence. The best-fitting model for parents was also a bifactor solution, including a general factor and 3 orthogonal factors, referring to student self-regulation, student competence, and teacher support of homework. Gender differences were identified for the general and self-regulation factors of both versions. Overall, the findings provide strong support for the HPQ as a multi-informant, multidimensional measure of homework performance that has utility for the assessment of elementary and middle school students. (c) 2015 APA, all rights reserved).

Analyzing endocrine system conservation and evolution.

PubMed

Bonett, Ronald M

2016-08-01

Analyzing variation in rates of evolution can provide important insights into the factors that constrain trait evolution, as well as those that promote diversification. Metazoan endocrine systems exhibit apparent variation in evolutionary rates of their constituent components at multiple levels, yet relatively few studies have quantified these patterns and analyzed them in a phylogenetic context. This may be in part due to historical and current data limitations for many endocrine components and taxonomic groups. However, recent technological advancements such as high-throughput sequencing provide the opportunity to collect large-scale comparative data sets for even non-model species. Such ventures will produce a fertile data landscape for evolutionary analyses of nucleic acid and amino acid based endocrine components. Here I summarize evolutionary rate analyses that can be applied to categorical and continuous endocrine traits, and also those for nucleic acid and protein-based components. I emphasize analyses that could be used to test whether other variables (e.g., ecology, ontogenetic timing of expression, etc.) are related to patterns of rate variation and endocrine component diversification. The application of phylogenetic-based rate analyses to comparative endocrine data will greatly enhance our understanding of the factors that have shaped endocrine system evolution. Copyright © 2016 Elsevier Inc. All rights reserved.

Assessing doses to terrestrial wildlife at a radioactive waste disposal site: inter-comparison of modelling approaches.

PubMed

Johansen, M P; Barnett, C L; Beresford, N A; Brown, J E; Černe, M; Howard, B J; Kamboj, S; Keum, D-K; Smodiš, B; Twining, J R; Vandenhove, H; Vives i Batlle, J; Wood, M D; Yu, C

2012-06-15

Radiological doses to terrestrial wildlife were examined in this model inter-comparison study that emphasised factors causing variability in dose estimation. The study participants used varying modelling approaches and information sources to estimate dose rates and tissue concentrations for a range of biota types exposed to soil contamination at a shallow radionuclide waste burial site in Australia. Results indicated that the dominant factor causing variation in dose rate estimates (up to three orders of magnitude on mean total dose rates) was the soil-to-organism transfer of radionuclides that included variation in transfer parameter values as well as transfer calculation methods. Additional variation was associated with other modelling factors including: how participants conceptualised and modelled the exposure configurations (two orders of magnitude); which progeny to include with the parent radionuclide (typically less than one order of magnitude); and dose calculation parameters, including radiation weighting factors and dose conversion coefficients (typically less than one order of magnitude). Probabilistic approaches to model parameterisation were used to encompass and describe variable model parameters and outcomes. The study confirms the need for continued evaluation of the underlying mechanisms governing soil-to-organism transfer of radionuclides to improve estimation of dose rates to terrestrial wildlife. The exposure pathways and configurations available in most current codes are limited when considering instances where organisms access subsurface contamination through rooting, burrowing, or using different localised waste areas as part of their habitual routines. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

Work-related musculoskeletal disorders in physical therapists: a prospective cohort study with 1-year follow-up.

PubMed

Campo, Marc; Weiser, Sherri; Koenig, Karen L; Nordin, Margareta

2008-05-01

Work-related musculoskeletal disorders (WMSDs) have a significant impact on physical therapists, but few studies have addressed the issue. Research is needed to determine the scope of the problem and the effects of specific risk factors. The objectives of this study were: (1) to determine the 1-year incidence rate of WMSDs in physical therapists and (2) to determine the effects of specific risk factors. This was a prospective cohort study with 1-year follow-up. Subjects were randomly selected American Physical Therapy Association members (N=882). Exposure assessment included demographic data, physical risk factors, job strain, and specific physical therapy tasks. The primary outcome was WMSDs, with a severity rating of at least 4/10 and present at least once a month or lasting longer than a week. The response rate to the baseline questionnaire was 67%. Ninety-three percent of the subjects who responded to the baseline questionnaire responded to the follow-up questionnaire. The 1-year incidence rate of WMSDs was 20.7%. Factors that increased the risk for WMSDs included patient transfers, patient repositioning, bent or twisted postures, joint mobilization, soft tissue work, and job strain. The primary limitation of this study was the number of therapists who had a change in their job situation during the follow-up year. Work-related musculoskeletal disorders are prevalent in physical therapists. Physical therapy exposures, patient handling, and manual therapy, in particular, increase the risk for WMSDs.

Essentiality Is a Strong Determinant of Protein Rates of Evolution during Mutation Accumulation Experiments in Escherichia coli.

PubMed

Alvarez-Ponce, David; Sabater-Muñoz, Beatriz; Toft, Christina; Ruiz-González, Mario X; Fares, Mario A

2016-09-26

The Neutral Theory of Molecular Evolution is considered the most powerful theory to understand the evolutionary behavior of proteins. One of the main predictions of this theory is that essential proteins should evolve slower than dispensable ones owing to increased selective constraints. Comparison of genomes of different species, however, has revealed only small differences between the rates of evolution of essential and nonessential proteins. In some analyses, these differences vanish once confounding factors are controlled for, whereas in other cases essentiality seems to have an independent, albeit small, effect. It has been argued that comparing relatively distant genomes may entail a number of limitations. For instance, many of the genes that are dispensable in controlled lab conditions may be essential in some of the conditions faced in nature. Moreover, essentiality can change during evolution, and rates of protein evolution are simultaneously shaped by a variety of factors, whose individual effects are difficult to isolate. Here, we conducted two parallel mutation accumulation experiments in Escherichia coli, during 5,500-5,750 generations, and compared the genomes at different points of the experiments. Our approach (a short-term experiment, under highly controlled conditions) enabled us to overcome many of the limitations of previous studies. We observed that essential proteins evolved substantially slower than nonessential ones during our experiments. Strikingly, rates of protein evolution were only moderately affected by expression level and protein length. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Evaluating the Performance of Household Liquefied Petroleum Gas Cookstoves.

PubMed

Shen, Guofeng; Hays, Michael D; Smith, Kirk R; Williams, Craig; Faircloth, Jerroll W; Jetter, James J

2018-01-16

Liquefied petroleum gas (LPG) cookstoves are considered to be an important solution for mitigating household air pollution; however, their performance has rarely been evaluated. To fill the data and knowledge gaps in this important area, 89 laboratory tests were conducted to quantify efficiencies and pollutant emissions from five commercially available household LPG stoves under different burning conditions. The mean thermal efficiency (±standard deviation) for the tested LPG cookstoves was 51 ± 6%, meeting guidelines for the highest tier level (Tier 4) under the International Organization for Standardization, International Workshop Agreement 11. Emission factors of CO 2 , CO, THC, CH 4 , and NO x on the basis of useful energy delivered (MJ d ) were 142 ± 17, 0.77 ± 0.55, 130 ± 196, 5.6 ± 8.2, and 46 ± 9 mg/MJ d , respectively. Approximately 90% of the PM 2.5 data were below the detection limit, corresponding to an emission rate below 0.11 mg/min. For those data above the detection limit, the average emission factor was 2.4 ± 1.6 mg/MJ d , with a mean emission rate of 0.20 ± 0.16 mg/min. Under the specified gas pressure (2.8 kPa), but with the burner control set to minimum air flow rate, less complete combustion resulted in a visually yellow flame, and CO, PM 2.5 , EC, and BC emissions all increased. LPG cookstoves met guidelines for Tier 4 for both CO and PM 2.5 emissions and mostly met the World Health Organization Emission Rate Targets set to protect human health.

European birds adjust their flight initiation distance to road speed limits.

PubMed

Legagneux, Pierre; Ducatez, Simon

2013-10-23

Behavioural responses can help species persist in habitats modified by humans. Roads and traffic greatly affect animals' mortality not only through habitat structure modifications but also through direct mortality owing to collisions. Although species are known to differ in their sensitivity to the risk of collision, whether individuals can change their behaviour in response to this is still unknown. Here, we tested whether common European birds changed their flight initiation distances (FIDs) in response to vehicles according to road speed limit (a known factor affecting killing rates on roads) and vehicle speed. We found that FID increased with speed limit, although vehicle speed had no effect. This suggests that birds adjust their flight distance to speed limit, which may reduce collision risks and decrease mortality maximizing the time allocated to foraging behaviours. Mobility and territory size are likely to affect an individuals' ability to respond adaptively to local speed limits.

Centenarian Rates and Life Expectancy Related to the Death Rates of Multiple Sclerosis, Asthma, and Rheumatoid Arthritis and the Incidence of Type 1 Diabetes in Children.

PubMed

Lens-Pechakova, Lilia S

2016-02-01

The autoimmune diseases are among the 10 leading causes of death for women and the number two cause of chronic illness in America as well as a predisposing factor for cardiovascular diseases and cancer. Patients of some autoimmune diseases have shown a shorter life span and are a model of accelerated immunosenescence. Conversely, centenarians are used as a model of successful aging and have shown several immune parameters that are better preserved and lower levels of autoantibodies. The study reported here focused on clarifying the connection between longevity and some autoimmune and allergic diseases in 29 developed Organisation for Economic Co-operation and Development (OECD) countries, because multidisciplinary analyses of the accelerated or delayed aging data could show a distinct relationship pattern, help to identify common factors, and determine new important factors that contribute to longevity and healthy aging. The relationships between the mortality rates data of multiple sclerosis (MS), rheumatoid arthritis (RA), asthma, the incidence of type 1 diabetes (T1D) from one side and centenarian rates (two sets) as well as life expectancy data from the other side were assessed using regression models and Pearson correlation coefficients. The data obtained correspond to an inverse linear correlation with different degrees of linearity. This is the first observation of a clear tendency of diminishing centenarian rates or life expectancy in countries having higher death rates of asthma, MS, and RA and a higher incidence of T1D in children. The conclusion is that most probably there are common mechanistic pathways and factors affecting the above diseases and at the same time but in the opposite direction the processes of longevity. Further study, comparing genetic data, mechanistic pathways, and other factors connected to autoimmune diseases with those of longevity could clarify the processes involved, so as to promote longevity and limit the expansion of those diseases in the younger and older population.

A winter dinoflagellate bloom drives high rates of primary production in a Patagonian fjord ecosystem

NASA Astrophysics Data System (ADS)

Montero, P.; Pérez-Santos, I.; Daneri, G.; Gutiérrez, M. H.; Igor, G.; Seguel, R.; Purdie, D.; Crawford, D. W.

2017-12-01

A dense winter bloom of the dinoflagellate Heterocapsa triquetra was observed at a fixed station (44°35.3‧S; 72°43.6‧W) in the Puyuhuapi Fjord in Chilean Patagonia during July 2015. H. triquetra dominated the phytoplankton community in the surface waters between 2 and 15 m (13-58 × 109 cell m-2), with abundances some 3 to 15 times higher than the total abundance of the diatom assemblage, which was dominated by Skeletonema spp. The high abundance of dinoflagellates was reflected in high rates of gross primary production (GPP; 0.6-1.6 g C m-2 d-1) and chlorophyll-a concentration (Chl-a; 70-199.2 mg m-2) that are comparable to levels reported in spring diatom blooms in similar Patagonian fjords. We identify the main forcing factors behind a pulse of organic matter production during the non-productive winter season, and test the hypothesis that low irradiance levels are a key factor limiting phytoplankton blooms and subsequent productivity during winter. Principal Component Analysis (PCA) indicated that GPP rates were significantly correlated (r = -0.8, p < 0.05) with a decrease in salinity/temperature and the presence of the Heterocapsa bloom. The bloom occurred under low surface irradiance levels characteristic of austral winter and was accompanied by strong northern winds, associated with the passage of a low-pressure system, and a water column dominated by double diffusive layering. To our knowledge, this is the first report of a dense dinoflagellate bloom during deep austral winter in a Patagonian fjord, and our data challenge the paradigm of light limitation as a factor controlling phytoplankton blooms in this region in winter.

Predicting the Kinetics of Ice Recrystallization in Aqueous Sugar Solutions

PubMed Central

2018-01-01

The quality of stored frozen products such as foods and biomaterials generally degrades in time due to the growth of large ice crystals by recrystallization. While there is ample experimental evidence that recrystallization within such products (or model systems thereof) is often dominated by diffusion-limited Ostwald ripening, the application of Ostwald-ripening theories to predict measured recrystallization rates has only met with limited success. For a model system of polycrystalline ice within an aqueous solution of sugars, we here show recrystallization rates can be predicted on the basis of Ostwald ripening theory, provided (1) the theory accounts for the fact the solution can be nonideal, nondilute and of different density than the crystals, (2) the effect of ice-phase volume fraction on the diffusional flux of water between crystals is accurately described, and (3) all relevant material properties (involving binary Fick diffusion coefficients, the thermodynamic factor of the solution, and the surface energy of ice) are carefully estimated. To enable calculation of material properties, we derive an alternative formulation of Ostwald ripening in terms of the Maxwell–Stefan instead of the Fick approach to diffusion. First, this leads to a cancellation of the thermodynamic factor (a measure for the nonideality of a solution), which is a notoriously difficult property to obtain. Second, we show that Maxwell–Stefan diffusion coefficients can to a reasonable approximation be related to self-diffusion coefficients, which are relatively easy to measure or predict in comparison to Fick diffusion coefficients. Our approach is validated for a binary system of water and sucrose, for which we show predicted recrystallization rates of ice compare well to experimental results, with relative deviations of at most a factor of 2. PMID:29651228

An NMR-based quenched hydrogen exchange investigation of model amyloid fibrils formed by cold shock protein A.

PubMed

Alexandrescu, A T

2001-01-01

Acid-denatured cold shock protein A (CspA) self-assembles into polymers with properties typical of amyloid fibrils. In the present work, a quenched hydrogen exchange experiment was used to probe the interactions of CspA fibrils with solvent. Exchange was initiated by incubating suspensions of fibrils in D2O, and quenched by flash freezing. Following lyophilization, exchange-quenched samples were dissolved in 90% DMSO/10% D2O, giving DMSO-denatured monomers. Intrinsic exchange rates for denatured CspA in 90% DMSO/10% D2O (pH* 4.5) were sufficiently slow (approximately 1 x 10(-3) min-1) to enable quantification of NMR signal intensity decays due to H/D exchange in the fibrils. Hydrogen exchange rate constants for CspA fibrils were found to vary less than 3-fold from a mean value of 5 x 10(-5) min-1. The uniformity of rate constants suggests that exchange is in the EX1 limit, and that the mechanism of exchange involves a cooperative dissociation of CspA monomers from fibrils, concomitant with unfolding. Previous studies indicated that the highest protection factors in native CspA are approximately 10(3), and that protection factors for the acid-denatured monomer precursors of CspA fibrils are close to unity. Because exchange in is in the EX1 regime, it is only possible to place a lower limit of at least 10(5) on protection factors in CspA fibrils. The observation that all amide protons are protected from exchange indicates that the entire CspA polypeptide chain is structured in the fibrils.

Predicting the Kinetics of Ice Recrystallization in Aqueous Sugar Solutions.

PubMed

van Westen, Thijs; Groot, Robert D

2018-04-04

The quality of stored frozen products such as foods and biomaterials generally degrades in time due to the growth of large ice crystals by recrystallization. While there is ample experimental evidence that recrystallization within such products (or model systems thereof) is often dominated by diffusion-limited Ostwald ripening, the application of Ostwald-ripening theories to predict measured recrystallization rates has only met with limited success. For a model system of polycrystalline ice within an aqueous solution of sugars, we here show recrystallization rates can be predicted on the basis of Ostwald ripening theory, provided (1) the theory accounts for the fact the solution can be nonideal, nondilute and of different density than the crystals, (2) the effect of ice-phase volume fraction on the diffusional flux of water between crystals is accurately described, and (3) all relevant material properties (involving binary Fick diffusion coefficients, the thermodynamic factor of the solution, and the surface energy of ice) are carefully estimated. To enable calculation of material properties, we derive an alternative formulation of Ostwald ripening in terms of the Maxwell-Stefan instead of the Fick approach to diffusion. First, this leads to a cancellation of the thermodynamic factor (a measure for the nonideality of a solution), which is a notoriously difficult property to obtain. Second, we show that Maxwell-Stefan diffusion coefficients can to a reasonable approximation be related to self-diffusion coefficients, which are relatively easy to measure or predict in comparison to Fick diffusion coefficients. Our approach is validated for a binary system of water and sucrose, for which we show predicted recrystallization rates of ice compare well to experimental results, with relative deviations of at most a factor of 2.

Step Permeability on the Pt(111) Surface

NASA Astrophysics Data System (ADS)

Altman, Michael

2005-03-01

Surface morphology will be affected, or even dictated, by kinetic limitations that may be present during growth. Asymmetric step attachment is recognized to be an important and possibly common cause of morphological growth instabilities. However, the impact of this kinetic limitation on growth morphology may be hindered by other factors such as the rate limiting step and step permeability. This strongly motivates experimental measurements of these quantities in real systems. Using low energy electron microscopy, we have measured step flow velocities in growth on the Pt(111) surface. The dependence of step velocity upon adjacent terrace width clearly shows evidence of asymmetric step attachment and step permeability. Step velocity is modeled by solving the diffusion equation simultaneously on several adjacent terraces subject to boundary conditions at intervening steps that include asymmetric step attachment and step permeability. This analysis allows a quantitative evaluation of step permeability and the kinetic length, which characterizes the rate limiting step continuously between diffusion and attachment-detachment limited regimes. This work provides information that is greatly needed to set physical bounds on the parameters that are used in theoretical treatments of growth. The observation that steps are permeable even on a simple metal surface should also stimulate more experimental measurements and theoretical treatments of this effect.

Factors Affecting Nickel-oxide Electrode Capacity in Nickel-hydrogen Cells

NASA Technical Reports Server (NTRS)

Ritterman, P. F.

1984-01-01

The nickel-oxide electrode common to the nickel hydrogen and nickel cadmium cell is by design the limiting or capacity determining electrode on both charge and discharge. The useable discharge capacity from this electrode, and since it is the limiting electrode, the useable discharge capacity of the cell as well, can and is optimized by rate of charge, charge temperature and additives to electrode and electrolyte. Recent tests with nickel hydrogen cells and tests performed almost 25 years ago with nickel cadmium cells indicate an improvement of capacity as a result of using increased electrolyte concentration.

Modeling the Sustainability of a Ceramic Water Filter Intervention

PubMed Central

Mellor, Jonathan; Abebe, Lydia; Ehdaie, Beeta; Dillingham, Rebecca; Smith, James

2014-01-01

Ceramic water filters (CWFs) are a point-of-use water treatment technology that has shown promise in preventing early childhood diarrhea (ECD) in resource-limited settings. Despite this promise, some researchers have questioned their ability to reduce ECD incidences over the long term since most effectiveness trials conducted to date are less than one year in duration limiting their ability to assess long-term sustainability factors. Most trials also suffer from lack of blinding making them potentially biased. This study uses an agent-based model (ABM) to explore factors related to the long-term sustainability of CWFs in preventing ECD and was based on a three year longitudinal field study. Factors such as filter user compliance, microbial removal effectiveness, filter cleaning and compliance declines were explored. Modeled results indicate that broadly defined human behaviors like compliance and declining microbial effectiveness due to improper maintenance are primary drivers of the outcome metrics of household drinking water quality and ECD rates. The model predicts that a ceramic filter intervention can reduce ECD incidence amongst under two year old children by 41.3%. However, after three years, the average filter is almost entirely ineffective at reducing ECD incidence due to declining filter microbial removal effectiveness resulting from improper maintenance. The model predicts very low ECD rates are possible if compliance rates are 80-90%, filter log reduction efficiency is 3 or greater and there are minimal long-term compliance declines. Cleaning filters at least once every 4 months makes it more likely to achieve very low ECD rates as does the availability of replacement filters for purchase. These results help to understand the heterogeneity seen in previous intervention-control trials and reemphasize the need for researchers to accurately measure confounding variables and ensure that field trials are at least 2-3 years in duration. In summary, the CWF can be a highly effective tool in the fight against ECD, but every effort should be made by implementing agencies to ensure consistent use and maintenance. PMID:24355289

Influence of temperature, oxygen and salinity on the metabolism of the European sea bass

NASA Astrophysics Data System (ADS)

Claireaux, G.; Lagardère, J.-P.

1999-09-01

Standard (SMR) and routine (RMR) metabolic rates of groups (4 to 5 individuals) of European sea bass ( Dicentrarchus labrax) were measured at combinations of the following factors: temperature (10, 15, 20 and 25°C), oxygenation level (air saturation to 1.5 mg dm -3) and salinity (30, 20, 10 and 5‰). The influence of these environmental conditions on fish metabolic demand was then analysed through ANOVA. At 10, 15, 20 and 25°C, standard metabolic rates were 36, 65, 89, and 91 mg O 2 kg -1 h -1, respectively, while routine oxygen consumptions covered most of the metabolic range accessible. Osmoregulatory costs are linked to metabolic activity through ventilation. This relationship was highlighted by the observed interaction between environmental salinity and temperature. We were, however, unable to detect interactions between salinity and routine metabolic rate, or between salinity and oxygenation level. In order to delineate more precisely the restrictions imposed by water oxygenation on fish metabolic performance we determined the limiting oxygen concentration curves at each experimental temperature. We followed up by modelling the bass active metabolic rate (AMR) and metabolic scope (MS) as functions of both ambient temperature and oxygenation. These mathematical models allowed the characterisation of the controlling and limiting effects of water temperature and oxygen content on the metabolic capacity of the species. Thus, AMR at 10, 15 and 20°C were estimated at 65, 160 and 360 mg O 2 kg -1 h -1, respectively. However, at higher temperature (25°C) AMR dropped slightly (to 340 mg O 2 kg -1 h -1). Bass MS increased by a factor of 9 between 10 and 20°C, but diminished at higher temperatures. The present study contributes to our current understanding of the influences of environmental factors on the metabolism of sea bass and provides a bioenergetic basis for a study of how environmental constraints govern the spatial and temporal distribution pattern of this species.

Major Depressive Disorder and Dysthymia at the Intersection of Nativity and Racial-Ethnic Origins.

PubMed

Szaflarski, Magdalena; Cubbins, Lisa A; Bauldry, Shawn; Meganathan, Karthikeyan; Klepinger, Daniel H; Somoza, Eugene

2016-08-01

Immigrants often have lower rates of depression than US-natives, but longitudinal assessments across multiple racial-ethnic groups are limited. This study examined the rates of prevalent, acquired, and persisting major depression and dysthymia by nativity and racial-ethnic origin while considering levels of acculturation, stress, and social ties. Data from the National Epidemiologic Survey on Alcohol and Related Conditions were used to model prevalence and 3-year incidence/persistence of major depression and dysthymia (DSM-IV diagnoses) using logistic regression. Substantive factors were assessed using standardized measures. The rates of major depression were lower for most immigrants, but differences were noted by race-ethnicity and outcome. Furthermore, immigrants had higher prevalence but not incidence of dysthymia. The associations between substantive factors and outcomes were mixed. This study describes and begins to explain immigrant trajectories of major depression and dysthymia over a 3-year period. The continuing research challenges and future directions are discussed.

Neutron Thermal Cross Sections, Westcott Factors, Resonance Integrals, Maxwellian Averaged Cross Sections and Astrophysical Reaction Rates Calculated from the ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0, ROSFOND-2010, CENDL-3.1 and EAF-2010 Evaluated Data Libraries

NASA Astrophysics Data System (ADS)

Pritychenko, B.; Mughabghab, S. F.

2012-12-01

We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian-averaged cross sections and astrophysical reaction rates for 843 ENDF materials using data from the major evaluated nuclear libraries and European activation file. Extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate nuclear industry and neutron physics quantities, produce s-process Maxwellian-averaged cross sections and astrophysical reaction rates, systematically calculate uncertainties, and provide additional insights on currently available neutron-induced reaction data. Nuclear reaction calculations are discussed and new results are presented. Due to space limitations, the present paper contains only calculated Maxwellian-averaged cross sections and their uncertainties. The complete data sets for all results are published in the Brookhaven National Laboratory report.

Rate dependence of cell-to-cell variations of lithium-ion cells.

PubMed

An, Fuqiang; Chen, Lufan; Huang, Jun; Zhang, Jianbo; Li, Ping

2016-10-11

Lithium-ion cells are commonly used in a multicell configuration in power devices and electric vehicles, making the cell-to-cell variation (CtCV) a key factor to consider in system design and management. Previous studies on CtCV have two major limitations: the number of cells is usually less than one hundred, and the cells are usually commercial cells already subjected to cell-screenings. In this article, we first make a statistical analysis on the CtCV of 5473 fresh cells from an automotive battery manufacturer before the cell-screening process. Secondly, 198 cells are randomly selected from these 5473 cells and the rate dependence of the CtCV is examined, focusing on the correlations of capacity versus weight and capacity versus resistance, corresponding to thermodynamic and kinetic factors, respectively. The rate dependence of these two correlations is explained from a phenomenological model. Finally, eight cells from the 198 cells are further characterized with electrochemical impedance spectroscopy method to elucidate the kinetic origins of the CtCV.

Does size matter - What other factors are limiting the rate performance of Na3V2(PO4)3 cathode in sodium-ion batteries

NASA Astrophysics Data System (ADS)

Jiang, Xi; Zhang, Tianran; Lee, Jim Yang

2017-12-01

Na3V2(PO4)3 (NVP) is an extensively researched cathode material for the sodium-ion batteries (NIBs). Size reduction and nanocarbon coating are often used to improve its rate performance. These are strategies that have been proven highly effective for LiFePO4 (LFP), a phosphate-based cathode material which is nowadays popular with the lithium-ion batteries. Nanocarbon coating is undoubtedly useful since NVP encounters similar external electron transport barriers as LFP. The effect of size reduction, however, remains debatable since in theory, the 3D NASICON framework of NVP is more efficient for solid state ionic diffusion than is LFP. We have undertaken the measurements of the electrochemical performance of NVP particles of different sizes, electrode compositions, active material loadings and processing conditions, for the purpose of identifying the most significant factors which determine the rate performance of NVP as a NIB cathode material.

Female breast cancer in Vietnam: a comparison across Asian specific regions.

PubMed

Trieu, Phuong Dung Yun; Mello-Thoms, Claudia; Brennan, Patrick C

2015-09-01

Breast cancer is one of the most commonly diagnosed malignancies and the leading cause of cancer death of women over the world. A large number of females with breast cancer in Vietnam and other Southeast Asian (SEA) countries present at an early age with more aggressive tumors compared with women in Australia. Despite experiencing a low incidence rate, the increasing incidence rate among SEA countries exceeds that of the Westernized world. Changes in reproductive factors, environmental exposures, and lifestyle are the possible causes of this trend. However, limited evidence shows that these factors are associated with breast cancer in the Vietnamese population. Breast cancer incidence rates within Vietnam are not uniform and appear to be dependent on geographic location. Findings from this review have important implications for breast cancer control and treatment in Vietnam. A good understanding of the morphology of the breast and the type and nature of breast cancers presenting in Vietnam is required to facilitate the introduction of an effective national breast screening program.

Rate dependence of cell-to-cell variations of lithium-ion cells

PubMed Central

An, Fuqiang; Chen, Lufan; Huang, Jun; Zhang, Jianbo; Li, Ping

2016-01-01

Lithium-ion cells are commonly used in a multicell configuration in power devices and electric vehicles, making the cell-to-cell variation (CtCV) a key factor to consider in system design and management. Previous studies on CtCV have two major limitations: the number of cells is usually less than one hundred, and the cells are usually commercial cells already subjected to cell-screenings. In this article, we first make a statistical analysis on the CtCV of 5473 fresh cells from an automotive battery manufacturer before the cell-screening process. Secondly, 198 cells are randomly selected from these 5473 cells and the rate dependence of the CtCV is examined, focusing on the correlations of capacity versus weight and capacity versus resistance, corresponding to thermodynamic and kinetic factors, respectively. The rate dependence of these two correlations is explained from a phenomenological model. Finally, eight cells from the 198 cells are further characterized with electrochemical impedance spectroscopy method to elucidate the kinetic origins of the CtCV. PMID:27725767

The Role of Cultural Factors on Dating Aggression and Delinquency Among Latino Youth.

PubMed

Cuevas, Carlos A; Sabina, Chiara; Fahlberg, Anjuli; Espinola, Maria

2018-02-01

There is limited research comparatively evaluating delinquency and dating aggression among Latino youth. This analysis examines the rates and cultural correlates associated with delinquency and dating aggression among Latino youth using data from the Dating Violence Among Latino Adolescents study. The study surveyed 1,525 Latino adolescents between the ages of 12 and 18 years about past-year dating aggression perpetration and delinquency. Dating aggression perpetration and delinquency rates and relative risk ratios are presented. Logistic regression analyses examined the role of cultural factors on the perpetration of dating aggression and delinquent behaviors. Results showed that cultural factors had differential influence on dating aggression versus delinquency. Specifically, victimization, acculturation, and familial support were associated with dating aggression whereas only victimization and familial support were associated with delinquency. The results provide guidance for intervention and prevention efforts with Latino youth, particularly on the need for cultural consideration and the supportive role family can play in addressing these behaviors.

Targeting MMP-13 in bronchial epithelial repair.

PubMed

Howell, Christopher; Smith, James R; Shute, Janis K

2018-06-20

Viral infection of the bronchial epithelium disrupts the barrier properties of the epithelium in healthy individuals and those with lung disease. Repair of the bronchial epithelium is dependent of the formation of a provisional fibrin matrix and migration of epithelial cells to cover denuded areas, followed by proliferation and differentiation. The objective was to test the hypothesis that poly I:C, a model of viral infection, limits epithelial repair through the stimulated release of matrix metalloproteinase-13 (MMP-13). Confluent layers of cultured normal human primary bronchial epithelial cells (NHBE) and SV-40 virus transformed 16HBE14o- bronchial epithelial cells were mechanically wounded, and video microscopy used to measure the rate of wound closure over 2 hours, in the absence and presence of poly I:C (1-20 μg/ml). MMP-13, tissue factor and endothelin release were measured by ELISA. The effect of inhibitors of MMP-13 activity and expression and a non-specific endothelin receptor antagonist, bosentan, on the rate of epithelial repair was investigated RESULTS: Poly I:C limited the rate of epithelial repair, and NHBE were significantly more sensitive to poly I:C effects than 16HBE14o- cells. NHBE, but not 16HBE14o-, released MMP-13 in response to poly I:C. Inhibitors of MMP-13 activity (WAY 170523) and expression (dimethyl fumarate) significantly enhanced the rate of repair. Bosentan enhanced the rate of bronchial epithelial repair by a mechanism that was independent of MMP-13. Bronchial epithelial repair is limited by endothelin and by MMP-13, a protease that degrades coagulation factors, such as fibrinogen, and matrix proteins essential for epithelial repair. Further studies with primary cells from patients are needed to confirm whether repurposing bosentan and inhibitors of MMP-13 expression or activity, for inhalation may be a useful therapeutic strategy in diseases where repeated cycles of epithelial injury and repair occur, such as asthma and COPD. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Gender differences in first-year dental students' motivation to attend dental school.

PubMed

Scarbecz, Mark; Ross, Judith A

2002-08-01

Women's role in the field of dentistry has historically been limited to the dental auxiliary fields, rather than that of D.D.S. or D.M.D. Today, women are nearly 38 percent of U.S. dental school students and 14 percent of active practitioners. The slow(er) influx of women into dentistry has been little studied by dental educators. During the 2000-01 academic year, we conducted a survey of first-year dental students at a sample of publicly funded U.S. dental schools. The purpose of the survey was to assess gender differences in motives for pursuing a dental career. The data show that male dental students rate self-employment and business-related motives as more important, while female dental students rate people-oriented motives more highly. Factor analysis revealed four distinct clusters of motives for pursuing a dental career: a financial motive, a business-oriented motive, a people-oriented or caring motive, and a flexibility motive. Women scored significantly higher than men on the caring factor, whereas the reverse was true on the business factor. Male and female students rated financial and flexibility motives equally. The implications of the results for attracting students to the profession of dentistry are discussed.

Physiology limits commercially viable photoautotrophic production of microalgal biofuels.

PubMed

Kenny, Philip; Flynn, Kevin J

2017-01-01

Algal biofuels have been offered as an alternative to fossil fuels, based on claims that microalgae can provide a highly productive source of compounds as feedstocks for sustainable transport fuels. Life cycle analyses identify algal productivity as a critical factor affecting commercial and environmental viability. Here, we use mechanistic modelling of the biological processes driving microalgal growth to explore optimal production scenarios in an industrial setting, enabling us to quantify limits to algal biofuels potential. We demonstrate how physiological and operational trade-offs combine to restrict the potential for solar-powered algal-biodiesel production in open ponds to a ceiling of ca. 8000 L ha -1 year -1 . For industrial-scale operations, practical considerations limit production to ca. 6000 L ha -1 year -1 . According to published economic models and life cycle analyses, such production rates cannot support long-term viable commercialisation of solar-powered cultivation of natural microalgae strains exclusively as feedstock for biofuels. The commercial viability of microalgal biofuels depends critically upon limitations in microalgal physiology (primarily in rates of C-fixation); we discuss the scope for addressing this bottleneck concluding that even deployment of genetically modified microalgae with radically enhanced characteristics would leave a very significant logistical if not financial burden.

Search for Gravitational Waves from Low Mass Compact Binary Coalescence in LIGO's Sixth Science Run and Virgo's Science Runs 2 and 3

NASA Technical Reports Server (NTRS)

Abadie, J.; Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M.; Accadia, T.; Acernese, F.; Adams, C.; Adhikari, R.; Affeldt, C.;

Search for gravitational waves from low mass compact binary coalescence in LIGO's sixth science run and Virgo's science runs 2 and 3

NASA Astrophysics Data System (ADS)

Abadie, J.; Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M.; Accadia, T.; Acernese, F.; Adams, C.; Adhikari, R.; Affeldt, C.; Agathos, M.; Ajith, P.; Allen, B.; Allen, G. S.; Amador Ceron, E.; Amariutei, D.; Amin, R. S.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Arain, M. A.; Araya, M. C.; Aston, S. M.; Astone, P.; Atkinson, D.; Aufmuth, P.; Aulbert, C.; Aylott, B. E.; Babak, S.; Baker, P.; Ballardin, G.; Ballmer, S.; Barker, D.; Barone, F.; Barr, B.; Barriga, P.; Barsotti, L.; Barsuglia, M.; Barton, M. A.; Bartos, I.; Bassiri, R.; Bastarrika, M.; Basti, A.; Batch, J.; Bauchrowitz, J.; Bauer, Th. S.; Bebronne, M.; Behnke, B.; Beker, M. G.; Bell, A. S.; Belletoile, A.; Belopolski, I.; Benacquista, M.; Berliner, J. M.; Bertolini, A.; Betzwieser, J.; Beveridge, N.; Beyersdorf, P. T.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Biswas, R.; Bitossi, M.; Bizouard, M. A.; Black, E.; Blackburn, J. K.; Blackburn, L.; Blair, D.; Bland, B.; Blom, M.; Bock, O.; Bodiya, T. P.; Bogan, C.; Bondarescu, R.; Bondu, F.; Bonelli, L.; Bonnand, R.; Bork, R.; Born, M.; Boschi, V.; Bose, S.; Bosi, L.; Bouhou, B.; Braccini, S.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Breyer, J.; Briant, T.; Bridges, D. O.; Brillet, A.; Brinkmann, M.; Brisson, V.; Britzger, M.; Brooks, A. F.; Brown, D. A.; Brummit, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Burguet–Castell, J.; Burmeister, O.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Calloni, E.; Camp, J. B.; Campsie, P.; Cannizzo, J.; Cannon, K.; Canuel, B.; Cao, J.; Capano, C. D.; Carbognani, F.; Caride, S.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C.; Cesarini, E.; Chaibi, O.; Chalermsongsak, T.; Chalkley, E.; Charlton, P.; Chassande-Mottin, E.; Chelkowski, S.; Chen, Y.; Chincarini, A.; Chiummo, A.; Cho, H.; Christensen, N.; Chua, S. S. Y.; Chung, C. T. Y.; Chung, S.; Ciani, G.; Clara, F.; Clark, D. E.; Clark, J.; Clayton, J. H.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colacino, C. N.; Colas, J.; Colla, A.; Colombini, M.; Conte, A.; Conte, R.; Cook, D.; Corbitt, T. R.; Cordier, M.; Cornish, N.; Corsi, A.; Costa, C. A.; Coughlin, M.; Coulon, J.-P.; Couvares, P.; Coward, D. M.; Coyne, D. C.; Creighton, J. D. E.; Creighton, T. D.; Cruise, A. M.; Cumming, A.; Cunningham, L.; Cuoco, E.; Cutler, R. M.; Dahl, K.; Danilishin, S. L.; Dannenberg, R.; D'Antonio, S.; Danzmann, K.; Dattilo, V.; Daudert, B.; Daveloza, H.; Davier, M.; Davies, G.; Daw, E. J.; Day, R.; Dayanga, T.; De Rosa, R.; DeBra, D.; Debreczeni, G.; Degallaix, J.; Del Pozzo, W.; del Prete, M.; Dent, T.; Dergachev, V.; DeRosa, R.; DeSalvo, R.; Dhurandhar, S.; Di Fiore, L.; Di Lieto, A.; Di Palma, I.; Di Paolo Emilio, M.; Di Virgilio, A.; Díaz, M.; Dietz, A.; DiGuglielmo, J.; Donovan, F.; Dooley, K. L.; Dorsher, S.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Dumas, J.-C.; Dwyer, S.; Eberle, T.; Edgar, M.; Edwards, M.; Effler, A.; Ehrens, P.; Endrőczi, G.; Engel, R.; Etzel, T.; Evans, K.; Evans, M.; Evans, T.; Factourovich, M.; Fafone, V.; Fairhurst, S.; Fan, Y.; Farr, B. F.; Farr, W.; Fazi, D.; Fehrmann, H.; Feldbaum, D.; Ferrante, I.; Fidecaro, F.; Finn, L. S.; Fiori, I.; Fisher, R. P.; Flaminio, R.; Flanigan, M.; Foley, S.; Forsi, E.; Forte, L. A.; Fotopoulos, N.; Fournier, J.-D.; Franc, J.; Frasca, S.; Frasconi, F.; Frede, M.; Frei, M.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Friedrich, D.; Fritschel, P.; Frolov, V. V.; Fulda, P. J.; Fyffe, M.; Galimberti, M.; Gammaitoni, L.; Ganija, M. R.; Garcia, J.; Garofoli, J. A.; Garufi, F.; Gáspár, M. E.; Gemme, G.; Geng, R.; Genin, E.; Gennai, A.; Gergely, L. Á.; Ghosh, S.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Giazotto, A.; Gill, C.; Goetz, E.; Goggin, L. M.; González, G.; Gorodetsky, M. L.; Goßler, S.; Gouaty, R.; Graef, C.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Gray, N.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Greverie, C.; Grosso, R.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guido, C.; Gupta, R.; Gustafson, E. K.; Gustafson, R.; Ha, T.; Hage, B.; Hallam, J. M.; Hammer, D.; Hammond, G.; Hanks, J.; Hanna, C.; Hanson, J.; Hardt, A.; Harms, J.; Harry, G. M.; Harry, I. W.; Harstad, E. D.; Hartman, M. T.; Haughian, K.; Hayama, K.; Hayau, J.-F.; Heefner, J.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hendry, M. A.; Heng, I. S.; Heptonstall, A. W.; Herrera, V.; Hewitson, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Holt, K.; Hong, T.; Hooper, S.; Hosken, D. J.; Hough, J.; Howell, E. J.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Ingram, D. R.; Inta, R.; Isogai, T.; Ivanov, A.; Izumi, K.; Jacobson, M.; Jang, H.; Jaranowski, P.; Johnson, W. W.; Jones, D. I.; Jones, G.; Jones, R.; Ju, L.; Kalmus, P.; Kalogera, V.; Kamaretsos, I.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Katsavounidis, E.; Katzman, W.; Kaufer, H.; Kawabe, K.; Kawamura, S.; Kawazoe, F.; Kells, W.; Keppel, D. G.; Keresztes, Z.; Khalaidovski, A.; Khalili, F. Y.; Khazanov, E. A.; Kim, B.; Kim, C.; Kim, D.; Kim, H.; Kim, K.; Kim, N.; Kim, Y.-M.; King, P. J.; Kinsey, M.; Kinzel, D. L.; Kissel, J. S.; Klimenko, S.; Kokeyama, K.; Kondrashov, V.; Kopparapu, R.; Koranda, S.; Korth, W. Z.; Kowalska, I.; Kozak, D.; Kringel, V.; Krishnamurthy, S.; Krishnan, B.; Królak, A.; Kuehn, G.; Kumar, R.; Kwee, P.; Lam, P. K.; Landry, M.; Lang, M.; Lantz, B.; Lastzka, N.; Lawrie, C.; Lazzarini, A.; Leaci, P.; Lee, C. H.; Lee, H. M.; Leindecker, N.; Leong, J. R.; Leonor, I.; Leroy, N.; Letendre, N.; Li, J.; Li, T. G. F.; Liguori, N.; Lindquist, P. E.; Lockerbie, N. A.; Lodhia, D.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Luan, J.; Lubinski, M.; Lück, H.; Lundgren, A. P.; Macdonald, E.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Mageswaran, M.; Mailand, K.; Majorana, E.; Maksimovic, I.; Man, N.; Mandel, I.; Mandic, V.; Mantovani, M.; Marandi, A.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markosyan, A.; Maros, E.; Marque, J.; Martelli, F.; Martin, I. W.; Martin, R. M.; Marx, J. N.; Mason, K.; Masserot, A.; Matichard, F.; Matone, L.; Matzner, R. A.; Mavalvala, N.; Mazzolo, G.; McCarthy, R.; McClelland, D. E.; McGuire, S. C.; McIntyre, G.; McIver, J.; McKechan, D. J. A.; Meadors, G. D.; Mehmet, M.; Meier, T.; Melatos, A.; Melissinos, A. C.; Mendell, G.; Menendez, D.; Mercer, R. A.; Meshkov, S.; Messenger, C.; Meyer, M. S.; Miao, H.; Michel, C.; Milano, L.; Miller, J.; Minenkov, Y.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Miyakawa, O.; Moe, B.; Moesta, P.; Mohan, M.; Mohanty, S. D.; Mohapatra, S. R. P.; Moraru, D.; Moreno, G.; Morgado, N.; Morgia, A.; Mori, T.; Mosca, S.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, C. L.; Mueller, G.; Mukherjee, S.; Mullavey, A.; Müller-Ebhardt, H.; Munch, J.; Murphy, D.; Murray, P. G.; Mytidis, A.; Nash, T.; Naticchioni, L.; Nawrodt, R.; Necula, V.; Nelson, J.; Newton, G.; Nishizawa, A.; Nocera, F.; Nolting, D.; Nuttall, L.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Oldenburg, R. G.; O'Reilly, B.; O'Shaughnessy, R.; Osthelder, C.; Ott, C. D.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Page, A.; Pagliaroli, G.; Palladino, L.; Palomba, C.; Pan, Y.; Pankow, C.; Paoletti, F.; Papa, M. A.; Parisi, M.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patel, P.; Pedraza, M.; Peiris, P.; Pekowsky, L.; Penn, S.; Peralta, C.; Perreca, A.; Persichetti, G.; Phelps, M.; Pickenpack, M.; Piergiovanni, F.; Pietka, M.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Pletsch, H. J.; Plissi, M. V.; Poggiani, R.; Pöld, J.; Postiglione, F.; Prato, M.; Predoi, V.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prodi, G. A.; Prokhorov, L.; Puncken, O.; Punturo, M.; Puppo, P.; Quetschke, V.; Raab, F. J.; Rabeling, D. S.; Rácz, I.; Radkins, H.; Raffai, P.; Rakhmanov, M.; Ramet, C. R.; Rankins, B.; Rapagnani, P.; Raymond, V.; Re, V.; Redwine, K.; Reed, C. M.; Reed, T.; Regimbau, T.; Reid, S.; Reitze, D. H.; Ricci, F.; Riesen, R.; Riles, K.; Robertson, N. A.; Robinet, F.; Robinson, C.; Robinson, E. L.; Rocchi, A.; Roddy, S.; Rodriguez, C.; Rodruck, M.; Rolland, L.; Rollins, J.; Romano, J. D.; Romano, R.; Romie, J. H.; Rosińska, D.; Röver, C.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Ryll, H.; Sainathan, P.; Sakosky, M.; Salemi, F.; Samblowski, A.; Sammut, L.; Sancho de la Jordana, L.; Sandberg, V.; Sankar, S.; Sannibale, V.; Santamaría, L.; Santiago-Prieto, I.; Santostasi, G.; Sassolas, B.; Sathyaprakash, B. S.; Sato, S.; Saulson, P. R.; Savage, R. L.; Schilling, R.; Schlamminger, S.; Schnabel, R.; Schofield, R. M. S.; Schulz, B.; Schutz, B. F.; Schwinberg, P.; Scott, J.; Scott, S. M.; Searle, A. C.; Seifert, F.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sergeev, A.; Shaddock, D. A.; Shaltev, M.; Shapiro, B.; Shawhan, P.; Shoemaker, D. H.; Sibley, A.; Siemens, X.; Sigg, D.; Singer, A.; Singer, L.; Sintes, A. M.; Skelton, G.; Slagmolen, B. J. J.; Slutsky, J.; Smith, J. R.; Smith, M. R.; Smith, N. D.; Smith, R. J. E.; Somiya, K.; Sorazu, B.; Soto, J.; Speirits, F. C.; Sperandio, L.; Stefszky, M.; Stein, A. J.; Steinert, E.; Steinlechner, J.; Steinlechner, S.; Steplewski, S.; Stochino, A.; Stone, R.; Strain, K. A.; Strigin, S.; Stroeer, A. S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sung, M.; Susmithan, S.; Sutton, P. J.; Swinkels, B.; Tacca, M.; Taffarello, L.; Talukder, D.; Tanner, D. B.; Tarabrin, S. P.; Taylor, J. R.; Taylor, R.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Thüring, A.; Titsler, C.; Tokmakov, K. V.; Toncelli, A.; Tonelli, M.; Torre, O.; Torres, C.; Torrie, C. I.; Tournefier, E.; Travasso, F.; Traylor, G.; Trias, M.; Tseng, K.; Tucker, E.; Ugolini, D.; Urbanek, K.; Vahlbruch, H.; Vajente, G.; Vallisneri, M.; van den Brand, J. F. J.; Van Den Broeck, C.; van der Putten, S.; van Veggel, A. A.; Vass, S.; Vasuth, M.; Vaulin, R.; Vavoulidis, M.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Veltkamp, C.; Verkindt, D.; Vetrano, F.; Viceré, A.; Villar, A. E.; Vinet, J.-Y.; Vitale, S.; Vitale, S.; Vocca, H.; Vorvick, C.; Vyatchanin, S. P.; Wade, A.; Waldman, S. J.; Wallace, L.; Wan, Y.; Wang, X.; Wang, Z.; Wanner, A.; Ward, R. L.; Was, M.; Wei, P.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Wen, S.; Wessels, P.; West, M.; Westphal, T.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; White, D.; Whiting, B. F.; Wilkinson, C.; Willems, P. A.; Williams, H. R.; Williams, L.; Willke, B.; Winkelmann, L.; Winkler, W.; Wipf, C. C.; Wiseman, A. G.; Wittel, H.; Woan, G.; Wooley, R.; Worden, J.; Yablon, J.; Yakushin, I.; Yamamoto, H.; Yamamoto, K.; Yang, H.; Yeaton-Massey, D.; Yoshida, S.; Yu, P.; Yvert, M.; Zadroźny, A.; Zanolin, M.; Zendri, J.-P.; Zhang, F.; Zhang, L.; Zhang, W.; Zhang, Z.; Zhao, C.; Zotov, N.; Zucker, M. E.; Zweizig, J.

2012-04-01

We report on a search for gravitational waves from coalescing compact binaries using LIGO and Virgo observations between July 7, 2009, and October 20, 2010. We searched for signals from binaries with total mass between 2 and 25M⊙; this includes binary neutron stars, binary black holes, and binaries consisting of a black hole and neutron star. The detectors were sensitive to systems up to 40 Mpc distant for binary neutron stars, and further for higher mass systems. No gravitational-wave signals were detected. We report upper limits on the rate of compact binary coalescence as a function of total mass, including the results from previous LIGO and Virgo observations. The cumulative 90% confidence rate upper limits of the binary coalescence of binary neutron star, neutron star-black hole, and binary black hole systems are 1.3×10-4, 3.1×10-5, and 6.4×10-6Mpc-3yr-1, respectively. These upper limits are up to a factor 1.4 lower than previously derived limits. We also report on results from a blind injection challenge.

Veterinarian's dilemma: a study of how Danish small animal practitioners handle financially limited clients.

PubMed

Kondrup, S V; Anhøj, K P; Rødsgaard-Rosenbeck, C; Lund, T B; Nissen, M H; Sandøe, P

2016-12-10

This study examined the extent to which Danish veterinary practices encounter financially limited clients and how different factors relating to the animal, the client and the veterinarian affect decisions to provide treatment for these clients. 300 small animal practices were invited to participate in an online survey. 195 participated, giving a response rate of 65 per cent. The results show that Danish small animal veterinary practices encounter clients with limited finances regularly: 33.8 per cent of them 3-4 times, 24.6 per cent 5-10 times and 19.5 per cent 1-2 times a month. Only around 9 per cent reported having a written practice policy on handling financially limited clients. Factors affecting decisions to treat include the severity and type of the animal's condition, the medical care needed and the client's expressed emotions. The propensity to treat is significantly higher in female veterinarians and in situations involving unborn animals. The overall conclusion is that small animal veterinary practices often provide treatment to clients who are not able to pay-far beyond what is legally required. This can be considered a major economic and psychological challenge for the practising veterinarians. British Veterinary Association.

Current practice of microsurgery by members of the American Society for Surgery of the Hand.

PubMed

Payatakes, Alexander H; Zagoreos, Nikolaos P; Fedorcik, Gregory G; Ruch, David S; Levin, L Scott

2007-04-01

First, to determine the percentage of members of the American Society for Surgery of the Hand (ASSH) that use microsurgical techniques as part of their surgery practice, and second, to identify factors limiting their use of these techniques. A 34-item, anonymous, Web-based survey was sent to all active ASSH members. Twelve items concerned demographics and 22 items addressed prior microsurgical training, current use of these techniques, factors currently limiting their use of these techniques, and potential methods to address these limiting factors. Responses were received from 561 of 1,238 of the ASSH members contacted (45% response rate). Most had residency training in orthopedics (N=460, 82%) or plastic surgery (N=79, 14%), followed by a hand fellowship in an orthopedic (N=363, 62%) or combined program (N=170, 30%). More than 54% (N=304) practiced privately, 33% (N=184) practiced in tertiary institutions, and the remainder practiced at regional centers. Of those responding, 505 (90%) stated that hand surgery constituted more than 50% of their practice, whereas for 527 (94%) respondents microsurgery comprised less than 25%. Most members (N=398, 71%) accepted emergency patients, of which 223 (56%) at a referral center. Three hundred sixteen respondents (56%) performed replantations, of whom 196 (62%) performed fewer than 5 per year. Four hundred fifteen respondents (74%) observed a decrease in replantation attempts over the past decade. This was attributed to refinement of indications (N=17, 83%), fewer patients with amputations (N=116, 28%), and declining reimbursement (N=344, 4%). Reasons for not personally performing replantations included busy elective schedules (N=125, 51%), inadequate confidence in performing replantations (N=96, 39%), and disappointment in results (N=56, 23%). Thirty percent (N=74) stated they would reconsider performing replantations if reimbursement was greater. Practice rates of examined microsurgical procedures ranged from 22% to 57%, although most had received microsurgical training. Despite rating their fellowship as excellent (N=393, 70%) or good (N=135, 24%), only 315 (56%) considered their present microsurgical skills to be above average. Many respondents believed that they would benefit from continuous training through continuing education courses. Educational, economic, and practical factors discourage the clinical application of microsurgical technique by hand surgeons. This unfavorable environment should be addressed by policy-making organizations and continuous surgical training. Other/Survey.

Development of Weld Metal Microstructures in Pulsed Laser Welding of Duplex Stainless Steel

NASA Astrophysics Data System (ADS)

Mirakhorli, F.; Malek Ghaini, F.; Torkamany, M. J.

2012-10-01

The microstructure of the weld metal of a duplex stainless steel made with Nd:YAG pulsed laser is investigated at different travel speeds and pulse frequencies. In terms of the solidification pattern, the weld microstructure is shown to be composed of two distinct zones. The presence of two competing heat transfer channels to the relatively cooler base metal and the relatively hotter previous weld spot is proposed to develop two zones. At high overlapping factors, an array of continuous axial grains at the weld centerline is formed. At low overlapping factors, in the zone of higher cooling rate, a higher percentage of ferrite is transformed to austenite. This is shown to be because with extreme cooling rates involved in pulsed laser welding with low overlapping, the ferrite-to-austenite transformation can be limited only to the grain boundaries.

Feasibility and Limitations of Vaccine Two-Dimensional Barcoding Using Mobile Devices.

PubMed

Bell, Cameron; Guerinet, Julien; Atkinson, Katherine M; Wilson, Kumanan

2016-06-23

Two-dimensional (2D) barcoding has the potential to enhance documentation of vaccine encounters at the point of care. However, this is currently limited to environments equipped with dedicated barcode scanners and compatible record systems. Mobile devices may present a cost-effective alternative to leverage 2D vaccine vial barcodes and improve vaccine product-specific information residing in digital health records. Mobile devices have the potential to capture product-specific information from 2D vaccine vial barcodes. We sought to examine the feasibility, performance, and potential limitations of scanning 2D barcodes on vaccine vials using 4 different mobile phones. A unique barcode scanning app was developed for Android and iOS operating systems. The impact of 4 variables on the scan success rate, data accuracy, and time to scan were examined: barcode size, curvature, fading, and ambient lighting conditions. Two experimenters performed 4 trials 10 times each, amounting to a total of 2160 barcode scan attempts. Of the 1832 successful scans performed in this evaluation, zero produced incorrect data. Five-millimeter barcodes were the slowest to scan, although only by 0.5 seconds on average. Barcodes with up to 50% fading had a 100% success rate, but success rate deteriorated beyond 60% fading. Curved barcodes took longer to scan compared with flat, but success rate deterioration was only observed at a vial diameter of 10 mm. Light conditions did not affect success rate or scan time between 500 lux and 20 lux. Conditions below 20 lux impeded the device's ability to scan successfully. Variability in scan time was observed across devices in all trials performed. 2D vaccine barcoding is possible using mobile devices and is successful under the majority of conditions examined. Manufacturers utilizing 2D barcodes should take into consideration the impact of factors that limit scan success rates. Future studies should evaluate the effect of mobile barcoding on workflow and vaccine administrator acceptance.

Limits of detection and decision. Part 4

NASA Astrophysics Data System (ADS)

Voigtman, E.

2008-02-01

Probability density functions (PDFs) have been derived for a number of commonly used limit of detection definitions, including several variants of the Relative Standard Deviation of the Background-Background Equivalent Concentration (RSDB-BEC) method, for a simple linear chemical measurement system (CMS) having homoscedastic, Gaussian measurement noise and using ordinary least squares (OLS) processing. All of these detection limit definitions serve as both decision and detection limits, thereby implicitly resulting in 50% rates of Type 2 errors. It has been demonstrated that these are closely related to Currie decision limits, if the coverage factor, k, is properly defined, and that all of the PDFs are scaled reciprocals of noncentral t variates. All of the detection limits have well-defined upper and lower limits, thereby resulting in finite moments and confidence limits, and the problem of estimating the noncentrality parameter has been addressed. As in Parts 1-3, extensive Monte Carlo simulations were performed and all the simulation results were found to be in excellent agreement with the derived theoretical expressions. Specific recommendations for harmonization of detection limit methodology have also been made.

An ergonomic approach to design hand tool for agricultural production.

PubMed

Khidiya, Mahendra Singh; Bhardwaj, Awadhesh

2012-01-01

Hand tool mechanisms designed to reduce the risk factors have rarely been studied. In this paper it is analyze trowel firstly designing in CATIA and then its Finite Element Analysis has been carried out by ABAQUS. The main emphasis is on finding stresses by using this software, then removing them by suitable mechanical working on tool & ergonomic change in the design of handle to make it more comfortable. Body part discomfort score and overall discomfort rating experienced by the subjects had also been estimated. During the muscular activity workers physiological responses i.e. energy expenditure rate, oxygen consumption rate and heart rate increases. This increase in physiological responses is related to the type, intensity and duration of work and thus sets limits to the performance of heavy work. In this paper oxygen consumption rate and heart rate was used for physiological cost estimation. These parameters were measured by Computerized Ambulatory Metabolic Measurement System K4b2.

High-Speed Videography Overview

NASA Astrophysics Data System (ADS)

Miller, C. E.

1989-02-01

The field of high-speed videography (HSV) has continued to mature in recent years, due to the introduction of a mixture of new technology and extensions of existing technology. Recent low frame-rate innovations have the potential to dramatically expand the areas of information gathering and motion analysis at all frame-rates. Progress at the 0 - rate is bringing the battle of film versus video to the field of still photography. The pressure to push intermediate frame rates higher continues, although the maximum achievable frame rate has remained stable for several years. Higher maximum recording rates appear technologically practical, but economic factors impose severe limitations to development. The application of diverse photographic techniques to video-based systems is under-exploited. The basics of HSV apply to other fields, such as machine vision and robotics. Present motion analysis systems continue to function mainly as an instant replay replacement for high-speed movie film cameras. The interrelationship among lighting, shuttering and spatial resolution is examined.

Effect of aeration rate, moisture content and composting period on availability of copper and lead during pig manure composting.

PubMed

Shen, Yujun; Zhao, Lixin; Meng, Haibo; Hou, Yueqing; Zhou, Haibin; Wang, Fei; Cheng, Hongsheng; Liu, Hongbin

2016-06-01

Pollution by heavy metals, such as copper and lead, has become a limiting factor for the land application of faecal manures, such as pig manure. This study was conducted to investigate the influence of composting process parameters, including aeration rate, moisture content and composting period, on the distribution of heavy metal species during composting, and to select an optimal parameter for copper and lead inactivation. Results showed that the distribution ratios of exchangeable fractions of copper and lead had a bigger decrease under conditions of aeration rate, 0.1 m(3) min(-1) m(-3), an initial moisture content of 65% and composting period of 50 days. Suboptimal composting process conditions could lead to increased availability of heavy metals. Statistical analysis indicated that the aeration rate was the main factor affecting copper and lead inactivation, while the effects of moisture content and composting period were not significant. The rates of reduction of copper-exchangeable fractions and lead-exchangeable fractions were positively correlated with increased pH. The optimal parameters for reducing heavy metal bioavailability during pig manure composting were aeration rate, 0.1 m(3) min(-1) m(-3), initial moisture content, 65%, and composting period, 20 days. © The Author(s) 2016.

The validity and internal structure of the Bipolar Depression Rating Scale: data from a clinical trial of N-acetylcysteine as adjunctive therapy in bipolar disorder.

PubMed

Berk, Michael; Dodd, Seetal; Dean, Olivia M; Kohlmann, Kristy; Berk, Lesley; Malhi, Gin S

2010-10-01

Berk M, Dodd S, Dean OM, Kohlmann K, Berk L, Malhi GS. The validity and internal structure of the Bipolar Depression Rating Scale: data from a clinical trial of N-acetylcysteine as adjunctive therapy in bipolar disorder. The phenomenology of unipolar and bipolar disorders differ in a number of ways, such as the presence of mixed states and atypical features. Conventional depression rating instruments are designed to capture the characteristics of unipolar depression and have limitations in capturing the breadth of bipolar disorder. The Bipolar Depression Rating Scale (BDRS) was administered together with the Montgomery Asberg Rating Scale (MADRS) and Young Mania Rating Scale (YMRS) in a double-blind randomised placebo-controlled clinical trial of N-acetyl cysteine for bipolar disorder (N = 75). A factor analysis showed a two-factor solution: depression and mixed symptom clusters. The BDRS has strong internal consistency (Cronbach's alpha = 0.917), the depression cluster showed robust correlation with the MADRS (r = 0.865) and the mixed subscale correlated with the YMRS (r = 0.750). The BDRS has good internal validity and inter-rater reliability and is sensitive to change in the context of a clinical trial.

Ecophysiology of Nais elinguis (Oligochaeta) in a brackish-water lagoon

NASA Astrophysics Data System (ADS)

Little, Colin

1984-02-01

Population densities of Nais elinguis Müller were determined in Swanpool, a brackish-water lagoon at Falmouth, Cornwall, U.K., over a four-year period. High densities were found only from January to May, usually with a peak in March. Significant negative correlations were shown between population density and both salinity and temperature. In laboratory tests, feeding rates remained unchanged from freshwater to 20‰ salinity (S), but declined above this salinity. Nais elinguis was shown to be a good osmoregulator, remaining hyperosmotic below 7‰ S, and hypo-osmotic above this. Feeding rate showed a Q 10 of approximately 2 from 1 to 25°C, but above this the rate declined. Feeding rate was unaffected between pH 6 and 11. Increased salinity to (10‰ S) did not influence the effect of temperature on feeding rate. This high salinity did reduce feeding rate at a pH of 10 and above. It is concluded that the physical and chemical variables considered are unlikely to be direct causal factors limiting populations of N. elinguis in Swanpool. The influence of food supply, competition, predation and changes in reproductive mode are discussed as possible controlling factors. It is shown that the population decline of N. elinguis in early summer usually coincides with the rise of populations of chironomid larvae.

Study of Synthetic Vision Systems (SVS) and Velocity-vector Based Command Augmentation System (V-CAS) on Pilot Performance

NASA Technical Reports Server (NTRS)

Liu, Dahai; Goodrich, Ken; Peak, Bob

2006-01-01

This study investigated the effects of synthetic vision system (SVS) concepts and advanced flight controls on single pilot performance (SPP). Specifically, we evaluated the benefits and interactions of two levels of terrain portrayal, guidance symbology, and control-system response type on SPP in the context of lower-landing minima (LLM) approaches. Performance measures consisted of flight technical error (FTE) and pilot perceived workload. In this study, pilot rating, control type, and guidance symbology were not found to significantly affect FTE or workload. It is likely that transfer from prior experience, limited scope of the evaluation task, specific implementation limitations, and limited sample size were major factors in obtaining these results.

Resident Perceptions of the Impact of Work Hour Limitations

PubMed Central

Beck, David C.; Stewart, Anita L.; Garbutt, Jane M.

2007-01-01

BACKGROUND Mandatory work hour limitations for residents began in July 2003. There has been little evaluation of the impact of the new limitations on Internal Medicine residency training. OBJECTIVE To assess Internal Medicine residents’ perceptions of the impact of work hour limitations on clinical experiences, patient care, resident education, and well-being, and their compliance with the limitations. DESIGN AND PARTICIPANTS Cross-sectional survey administered to Internal Medicine residents at 1 large U.S. teaching hospital. MEASUREMENTS Resident perceptions using 5-point Likert scales, and self-reported compliance. Exploratory factor analysis was used to identify underlying domains and develop scales. RESULTS The survey response rate was 85%. Five domains were identified by factor analysis: 1) clinical experience, 2) patient care and safety, 3) communication, 4) satisfaction with training, and 5) work–rest balance. Residents perceived work hour limitations to have a negative impact on clinical experience (mean scale score 1.84, 1 = negative, 5 = positive), patient care and safety (2.64), and communication domains (1.98). Effects on satisfaction (3.12) and work–rest balance domains (2.95) were more positive. Senior residents perceived more negative effects of work hour limitations than interns. Compliance was difficult; 94% interns and 70% residents reported violating work hour limits. Patient care and teaching duties were the main reasons for work hour violations. CONCLUSIONS This study suggests that the current work hour limitations may be having unintended negative consequences on residency training. Ongoing monitoring to evaluate the impact of program changes as a result of work hour regulation is crucial to improving residency training. PMID:17468888

Environmental and societal influences acting on cardiovascular risk factors and disease at a population level: a review

PubMed Central

Chow, Clara Kayei; Lock, Karen; Teo, Koon; Subramanian, SV; McKee, Martin; Yusuf, Salim

2009-01-01

It has long been known that cardiovascular disease (CVD) rates vary considerably among populations, across space and through time. It is now apparent that most of the attributable risk for myocardial infarction ‘within’ populations from across the world can be ascribed to the varying levels of a limited number of risk factors among individuals in a population. Individual risk factors (e.g. blood pressure) can be modified with resulting health gains. Yet, the persistence of large international variations in cardiovascular risk factors and resulting CVD incidence and mortality indicates that there are additional factors that apply to ‘populations’ that are important to understand as part of a comprehensive approach to CVD control. This article reviews the evidence on why certain populations are more at risk than others. PMID:19261658

Environmental and societal influences acting on cardiovascular risk factors and disease at a population level: a review.

PubMed

Chow, Clara Kayei; Lock, Karen; Teo, Koon; Subramanian, S V; McKee, Martin; Yusuf, Salim

2009-12-01

It has long been known that cardiovascular disease (CVD) rates vary considerably among populations, across space and through time. It is now apparent that most of the attributable risk for myocardial infarction 'within' populations from across the world can be ascribed to the varying levels of a limited number of risk factors among individuals in a population. Individual risk factors (e.g. blood pressure) can be modified with resulting health gains. Yet, the persistence of large international variations in cardiovascular risk factors and resulting CVD incidence and mortality indicates that there are additional factors that apply to 'populations' that are important to understand as part of a comprehensive approach to CVD control. This article reviews the evidence on why certain populations are more at risk than others.

Factorial structure of the locomotor disability scale in a sample of adults with mobility impairments in Bangladesh.

PubMed

Mahmud, Ilias; Clarke, Lynda; Nahar, Nazmun; Ploubidis, George B

2018-05-02

Disability does not only depend on individuals' health conditions but also the contextual factors in which individuals live. Therefore, disability measurement scales need to be developed or adapted to the context. Bangladesh lacks any locally developed or validated scales to measure disabilities in adults with mobility impairment. We developed a new Locomotor Disability Scale (LDS) in a previous qualitative study. The present study developed a shorter version of the scale and explored its factorial structure. We administered the LDS to 316 adults with mobility impairments, selected from outpatient and community-based settings of a rehabilitation centre in Bangladesh. We did exploratory factor analysis (EFA) to determine a shorter version of the LDS and explore its factorial structure. We retained 19 items from the original LDS following evaluation of response rate, floor/ceiling effects, inter-item correlations, and factor loadings in EFA. The Eigenvalues greater than one rule and the Scree test suggested a two-factor model of measuring locomotor disability (LD) in adults with mobility impairment. These two factors are 'mobility activity limitations' and 'functional activity limitations'. We named the higher order factor as 'locomotor disability'. This two-factor model explained over 68% of the total variance among the LD indicators. The reproduced correlation matrix indicated a good model fit with 14% non-redundant residuals with absolute values > 0.05. However, the Chi-square test indicated poor model fit (p < .001). The Bartlett's test of Sphericity confirmed patterned relationships amongst the LD indicators (p < .001). The Kaiser-Meyer-Olkin Measure (KMO) of sampling adequacy was .94 and the individual diagonal elements in the anti-correlation matrix were > .91. Among the retained 19 items, there was no correlation coefficient > .9 or a large number of correlation coefficients < .3. The communalities were high: between .495 and .882 with a mean of 0.684. As an evidence of convergent validity, we had all loadings above .5, except one. As an evidence of discriminant validity, we had no strong (> .3) cross loadings and the correlation between the two factors was .657. The 'mobility activity limitations' and 'functional activity limitations' sub-scales demonstrated excellent internal consistency (Cronbach's alpha were .954 and .937, respectively). The 19-item LDS was found to be a reliable and valid scale to measure the latent constructs mobility activity limitations and functional activity limitations among adults with mobility impairments in outpatient and community-based settings in Bangladesh.

The burden of respiratory syncytial virus (RSV) associated acute lower respiratory infections in children with Down syndrome: A systematic review and meta-analysis.

PubMed

Chan, Markus; Park, John J; Shi, Ting; Martinón-Torres, Federico; Bont, Louis; Nair, Harish

2017-12-01

Acute lower respiratory tract infections (ALRIs) caused by respiratory syncytial virus (RSV) are a leading cause of hospitalization in infants. Numerous risk factors have been identified in the aetiology of severe RSV-associated ALRI necessitating hospitalisation, including prematurity and congenital heart disease. Down syndrome (DS), a common genetic disorder associated with congenital and dysmorphic features, has recently been identified as an independent risk factor for RSV-associated ALRI requiring hospitalisation; however, the disease burden of RSV-associated ALRI in this population has not yet been established. Similarly, the impact of DS as an independent risk factor has not yet been quantified. We aimed therefore to estimate the incidence of admissions in children with DS, and by comparing this with unaffected children, to quantify the risk of DS independent of other risk factors. A systematic review of the existing literature published between 1995 and March 1, 2017 was performed to quantify the incidence of hospitalisation due to RSV-associated ALRI in children with DS. Meta-analyses were performed on extracted data using STATA statistical software, and hospitalisation rates for children with and without DS under the age of 2 were calculated. 5 articles were ultimately deemed eligible for analyses. Analyses were limited to children under the age of 2 years. We calculated the hospitalisation rate for children with DS in this age group to be 117.6 per 1000 child-years (95% CI 67.4-205.2), vs a rate of 15.2 per 1000 child-years (95% CI 8.3-27.6) in unaffected children. This indicates DS contributes to a 6.8 (95% CI 5.5-8.4) fold increase in the relative risk of hospitalisation for RSV-associated ALRI. Though limited by a small number of articles, this review found sufficient evidence to conclude DS was a significant independent risk factor for the development of severe RSV-associated ALRI requiring hospitalisation. Further studies are needed to define the impact of DS in conjunction with other comorbidities on the risk of severe RSV infection. Determining benefits of immunoprophylaxis or future vaccines against RSV in this at-risk population is warranted.

Characterization of the radiation environment at the UNLV accelerator facility during operation of the Varian M6 linac

NASA Astrophysics Data System (ADS)

Hodges, M.; Barzilov, A.; Chen, Y.; Lowe, D.

2016-10-01

The bremsstrahlung photon flux from the UNLV particle accelerator (Varian M6 model) was determined using MCNP5 code for 3 MeV and 6 MeV incident electrons. Human biological equivalent dose rates due to accelerator operation were evaluated using the photon flux with the flux-to-dose conversion factors. Dose rates were computed for the accelerator facility for M6 linac use under different operating conditions. The results showed that the use of collimators and linac internal shielding significantly reduced the dose rates throughout the facility. It was shown that the walls of the facility, in addition to the earthen berm enveloping the building, provide equivalent shielding to reduce dose rates outside to below the 2 mrem/h limit.

Cultivation of animal cells in a reticulated vitreous carbon foam.

PubMed

Kent, B L; Mutharasan, R

1992-02-01

A reticulated vitreous carbon foam (RVCF) was used as a surface to cultivate a model anchorage-dependent animal cell line, 3T6 (mouse embryo fibroblast). This fixed-surface bioreactor provided a low-shear, chemically-inert, and reusable environment for cell growth. An external medium recirculation loop allowed aeration, nutrient monitoring, and medium replacement without disturbing the cells. Optimal flow rates for the attachment and growth phases were determined. Growth rates comparable to static (T-flask and petri dish) cultures and agitated microcarrier cultures were achieved with appropriately high medium recirculation rates. Metabolic parameters were shown to be useful indicators of cell mass, although specific glucose consumption rates were considerably higher for cultures in the RVCF reactor. Oxygen supply was shown to be the most likely limiting factor for scaleup.

Electronic consent channels: preserving patient privacy without handcuffing researchers.

PubMed

Shelton, Robert H

2011-02-09

Advances in health information technology and electronic medical records have the tremendous potential to accelerate translational and clinical research. However, privacy concerns threaten to be a rate-limiting factor. By recognizing and responding to patient privacy concerns, policy-makers, researchers, and information technology leaders have the opportunity to transform trial recruitment and make it safer to electronically locate and convey sensitive health information.

Enforced Sparse Non-Negative Matrix Factorization

DTIC Science & Technology

2016-01-23

documents to find interesting pieces of information. With limited resources, analysts often employ automated text - mining tools that highlight common...represented as an undirected bipartite graph. It has become a common method for generating topic models of text data because it is known to produce good results...model and the convergence rate of the underlying algorithm. I. Introduction A common analyst challenge is searching through large quantities of text

[Lessons from 10 years of the Advanced Glaucoma Intervention Study (AGIS)].

PubMed

Dietlein, T S

2005-03-01

The 10-year results of the AGIS have revealed different outcomes of therapeutic strategies depending on ethnic factors, but also different success rates of trabeculectomy depending on age, preoperative intraocular pressure, and presence of diabetes or postoperative complications. Conclusions from the study may be limited by the fact that medical options and surgical strategies in glaucoma treatment have obviously changed during the last decade.

Energy Expenditure During Extravehicular Activity Through Apollo

NASA Technical Reports Server (NTRS)

Paul, Heather L.

2011-01-01

Monitoring crew health during manned space missions has always been an important factor to ensure that the astronauts can complete the missions successfully and within safe physiological limits. The necessity of real-time metabolic rate monitoring during extravehicular activities (EVAs) came into question during the Gemini missions, when the energy expenditure required to complete EVA tasks exceeded the life support capabilities for cooling and humidity control and crewmembers (CMs) ended the EVAs fatigued and overworked. This paper discusses the importance of real-time monitoring of metabolic rate during EVA, and provides a historical look at energy expenditure during EVA through the Apollo program.

Neodymium glass laser with a phase conjugate mirror producing 220 J pulses at 0.02 Hz repetition rate.

PubMed

Kuzmin, A A; Khazanov, E A; Kulagin, O V; Shaykin, A A

2014-08-25

For pumping multipetawatt Ti:sapphire laser facilities we developed a compact repetitively pulsed laser based on neodymium phosphate glass with pulse energy of 220 J, pulse repetition rate of 0.02 Hz, beam diameter of 43 mm, aperture fill factor of 0.8, and FWHM pulse duration of 30 ns. The phase distortions of laser radiation were compensated by optical phase conjugation via stimulated Brillouin scattering. The depolarization was reduced to 0.4% using linear compensation methods. The beam quality was 2.5 x diffraction limit (150 µrad).

Fall-related injuries among initially 75- and 80-year old people during a 10-year follow-up.

PubMed

Saari, Päivi; Heikkinen, Eino; Sakari-Rantala, Ritva; Rantanen, Taina

2007-01-01

The aim of this study was to investigate the occurrence, type, scene and seasonal variation of fall related injuries, and the impact of socio-economic factors, mobility limitation, and the most common diseases on the risk of injurious falls over a 10-year follow-up. Elderly residents of Jyväskylä, Finland, aged initially 75 and 80 years, took part in the study in 1989-1990. The health and functional capacity assessments were carried out at the baseline. Injurious falls were monitored over a 10-year period. The rate of injurious falls per thousand person-years was 188 among women and 78 among men. Of all fall-related diagnoses, head injuries comprised 32%, upper limb injuries 27% and hip injuries 19%. Majority of injurious falls took place indoors and no seasonal variation in fall occurrence was observed. Recurring falls were more likely to take place in institutions. Osteoarthritis increased the risk of injurious falls but no effect was observed for coronary heart diseases or mobility limitation. All in all, intrinsic factors, such as chronic diseases and mobility limitation had only minor effect on risk of injurious falls among older people. The current results suggest that preventive interventions for injurious falls among older people should pay attention to the risk factors present indoors.

Military Service, Deployments, and Exposures in Relation to Amyotrophic Lateral Sclerosis Etiology and Survival

PubMed Central

Beard, John D.; Kamel, Freya

2015-01-01

Rates of amyotrophic lateral sclerosis (ALS) have been reported to be higher among US military veterans, who currently number more than 21 million, but the causal factor(s) has not been identified. We conducted a review to examine the weight of evidence for associations between military service, deployments, and exposures and ALS etiology and survival. Thirty articles or abstracts published through 2013 were reviewed. Although the current evidence suggests a positive association with ALS etiology, it is too limited to draw firm conclusions regarding associations between military service and ALS etiology or survival. Some evidence suggests that deployment to the 1990–1991 Persian Gulf War may be associated with ALS etiology, but there is currently no strong evidence that any particular military exposure is associated with ALS etiology. Future studies should address the limitations of previous ones, such as reliance on mortality as a surrogate for incidence, a dearth of survival analyses, lack of clinical data, low statistical power, and limited exposure assessment. The Genes and Environmental Exposures in Veterans with Amyotrophic Lateral Sclerosis (GENEVA) Study is one such study, but additional research is needed to determine whether military-related factors are associated with ALS and to assess potential prevention strategies. PMID:25365170

Role of Nuclear Factor Erythroid 2-Related Factor 2 in Diabetic Nephropathy

PubMed Central

Min, Xu; Xu, Xiaohong

2017-01-01

Diabetic nephropathy (DN) is manifested as increased urinary protein level, decreased glomerular filtration rate, and final renal dysfunction. DN is the leading cause of end-stage renal disease worldwide and causes a huge societal healthcare burden. Since satisfied treatments are still limited, exploring new strategies for the treatment of this disease is urgently needed. Oxidative stress takes part in the initiation and development of DN. In addition, nuclear factor erythroid 2-related factor 2 (Nrf2) plays a key role in the cellular response to oxidative stress. Thus, activation of Nrf2 seems to be a new choice for the treatment of DN. In current review, we discussed and summarized the therapeutic effects of Nrf2 activation on DN from both basic and clinical studies. PMID:28512642

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stephen Seong Lee

Fuel flow to individual burners is complicated and difficult to determine on coal fired boilers, since coal solids were transported in a gas suspension that is governed by the complex physics of two-phase flow. The objectives of the project were the measurements of suspended coal solids-flows in the simulated test conditions. Various extractive methods were performed manually and can give only a snapshot result of fuel distribution. In order to measure particle diameter & velocity, laser based phase-Doppler particle analyzer (PDPA) and particle image velocimetry (PIV) were carefully applied. Statistical methods were used to analyze particle characteristics to see whichmore » factors have significant effect. The transparent duct model was carefully designed and fabricated for the laser-based-instrumentation of solids-flow monitoring (LISM). The experiments were conducted with two different kinds of particles with four different particle diameters. The particle types were organic particles and saw dust particles with the diameter range of 75-150 micron, 150-250 micron, 250-355 micron and 355-425 micron. The densities of the particles were measured to see how the densities affected the test results. Also the experiment was conducted with humid particles and fog particles. To generate humid particles, the humidifier was used. A pipe was connected to the humidifier to lead the particle flow to the intersection of the laser beam. The test results of the particle diameter indicated that, the mean diameter of humid particles was between 6.1703 microns and 6.6947 microns when the humid particle flow was low. When the humid particle flow was high, the mean diameter was between 6.6728 microns and 7.1872 microns. The test results of the particle mean velocity indicated that the mean velocity was between 1.3394 m/sec and 1.4556 m/sec at low humid particle flow. When the humid particle flow was high, the mean velocity was between 1.5694 m/sec and 1.7856 m/sec. The Air Flow Module, TQ AF 17 and shell ondina oil were used to generate fog particles. After the oil was heated inside the fog generator, the blower was used to generate the fog. The fog flew along the pipe to the intersection of the laser beam. The mean diameter of the fog particles was 5.765 microns. Compared with the humid particle diameter, we observed that the mean diameter of the fog particles was smaller than the humid particles. The test results of particle mean velocity was about 3.76 m/sec. Compared with the mean velocity of the humid particles, we can observed the mean velocity of fog particles were greater than humid particles. The experiments were conducted with four different kinds of particles with five different particle diameters. The particle types were organic particles, coal particles, potato particles and wheat particles with the diameter range of 63-75 micron, less than 150 micron, 150-250 micron, 250-355 micron and 355-425 micron. To control the flow rate, the control gate of the particle dispensing hopper was adjusted to 1/16 open rate, 1/8 open rate and 1/4 open rate. The captured image range was 0 cm to 5 cm from the control gate, 5 cm to 10 cm from the control gate and 10 cm to 15 cm from the control gate. Some of these experiments were conducted under both open environment conditions and closed environment conditions. Thus these experiments had a total of five parameters which were type of particles, diameter of particles, flow rate, observation range, and environment conditions. The coal particles (diameter between 63 and 75 microns) tested under the closed environment condition had three factors that were considered as the affecting factors. They were open rate, observation range, and environment conditions. In this experiment, the interaction of open rate and observation range had a significant effect on the lower limit. On the upper limit, the open rate and environment conditions had a significant effect. In addition, the interaction of open rate and environment conditions had a significant effect. The coal particles tested (diameter between 63 and 75 microns) under open environment, two factors were that considered as the affecting factors. They were the open rate and observation ranges. In this experiment, there was no significant effect on the lower limit. On the upper limit, the observation range had a significant effect. In addition, the interaction of open rate and observation range had a significant effect for the source of variation with 95% of confidence based on analysis of variance (ANOVA) results.« less

FEV1 decline in patients with chronic obstructive pulmonary disease associated with biomass exposure.

PubMed

Ramírez-Venegas, Alejandra; Sansores, Raul H; Quintana-Carrillo, Roger H; Velázquez-Uncal, Monica; Hernandez-Zenteno, Rafael J; Sánchez-Romero, Candelaria; Velazquez-Montero, Alejandra; Flores-Trujillo, Fernando

2014-11-01

Biomass exposure is an important risk factor for chronic obstructive pulmonary disease (COPD). However, the time-course behavior of FEV1 in subjects exposed to biomass is unknown. We undertook this study to determine the FEV1 rate decline in subjects exposed to biomass. Pulmonary function was assessed every year in a Mexican cohort of patients with COPD associated with biomass or tobacco during a 15-year follow-up period. The mean rate of decline was significantly lower for the biomass exposure COPD group (BE-COPD) than for the tobacco smoke COPD group (TS-COPD) (23 vs. 42 ml, respectively; P < 0.01). Of the TS-COPD group, 11% were rapid decliners, whereas only one rapid decliner was found in the BE-COPD group; 69 and 21% of smokers versus 17 and 83% of the BE-COPD group were slow decliners and sustainers, respectively. A higher FEV1 both as % predicted and milliliters was a predictive factor for decline for BE-COPD and TS-COPD, whereas reversibility to bronchodilator was a predictive factor for both groups when adjusted by FEV1% predicted and only for the TS-COPD group when adjusted by milliliters. In the biomass exposure COPD group the rate of FEV1 decline is slower and shows a more homogeneous rate of decline over time in comparison with smokers. The rapid rate of FEV1 decline is a rare feature of biomass-induced airflow limitation.

Size-dependent survivorship in the web-building spiderAgelena limbata.

PubMed

Tanaka, Koichi

1992-07-01

Stage-specific mortality rates and mortality factors for the web-building spiderAgelena limbata, which is suggested to be food-limited, were studied, and the relationship between body size of spiders and survivorship for instar 3 to adults was examined. The mortality rate of the egg sac stage including eggs, deutova (prenymphal stage), and overwintering instar 1 nymphs was low. The low mortality of this stage was partly due to maternal care that reduced the mortality caused by predation and/or abiotic factors. From emergence of instar 1 nymphs from egg sacs to reproduction, the stagespecific mortality rates were almost constant, 32-47%, and the time-specific mortality rates were also constant. These results suggest a Deevey (1947) type II survivorship curve inA. limbata, in contrast to other reports on the wandering or burrowing spiders which suggested type III curves. Important mortality factors for nymphs and adults were parasitism by an ichneumonid wasp and predation by spiders. There were great variations in body size (carapace width) ofA. limbata in the field. Smaller individuals survived at a lower rate to the next stage than larger individuals. This tendency was clearer for the population living under poorer prey availability.A. limbata was unlikely to starve to death in the field because every stage ofA. limbata could survive starvation for a long time in the laboratory, 22-65 days on average. I suggest that the size-dependent survivorship of this spider is associated with vulnerability of smaller individuals to parasitism and predation.

The hazard of spatial disorientation during helicopter flight using night vision devices.

PubMed

Braithwaite, M G; Douglass, P K; Durnford, S J; Lucas, G

1998-11-01

Night Vision Devices (NVDs) provide an enormous advantage to the operational effectiveness of military helicopter flying by permitting flight throughout the night. However, compared with daytime flight, many of the depth perception and orientational cues are severely degraded. These degraded cues predispose aviators to spatial disorientation (SD), which is a serious drawback of these devices. As part of an overall analysis of Army helicopter accidents to assess the impact of SD on military flying, we scrutinized the class A-C mishap reports involving night-aided flight from 1987 to 1995. The accidents were classified according to the role of SD by three independent assessors, with the SD group further analyzed to determine associated factors and possible countermeasures. Almost 43% of all SD-related accidents in this series occurred during flight using NVDs, whereas only 13% of non-SD accidents involved NVDs. An examination of the SD accident rates per 100,000 flying hours revealed a significant difference between the rate for day flying and the rate for flight using NVDs (mean rate for daytime flight = 1.66, mean rate for NVD flight = 9.00, p < 0.001). The most important factors associated with these accidents were related to equipment limitations, distraction from the task, and training or procedural inadequacies. SD remains an important source of attrition of Army aircraft. The more than fivefold increase in risk associated with NVD flight is of serious concern. The associated factors and suggested countermeasures should be urgently addressed.

Contribution of manipulable and non-manipulable environmental factors to trapping efficiency of invasive sea lamprey

USGS Publications Warehouse

Dawson, Heather A.; Bravener, Gale; Beaulaurier, Joshua; Johnson, Nicholas S.; Twohey, Michael; McLaughlin, Robert L.; Brenden, Travis O.

2017-01-01

We identified aspects of the trapping process that afforded opportunities for improving trap efficiency of invasive sea lamprey (Petromyzon marinus) in a Great Lake's tributary. Capturing a sea lamprey requires it to encounter the trap, enter, and be retained until removed. Probabilities of these events depend on the interplay between sea lamprey behavior, environmental conditions, and trap design. We first tested how strongly seasonal patterns in daily trap catches (a measure of trapping success) were related to nightly rates of trap encounter, entry, and retention (outcomes of sea lamprey behavior). We then tested the degree to which variation in rates of trap encounter, entry, and retention were related to environmental features that control agents can manipulate (attractant pheromone addition, discharge) and features agents cannot manipulate (water temperature, season), but could be used as indicators for when to increase trapping effort. Daily trap catch was most strongly associated with rate of encounter. Relative and absolute measures of predictive strength for environmental factors that managers could potentially manipulate were low, suggesting that opportunities to improve trapping success by manipulating factors that affect rates of encounter, entry, and retention are limited. According to results at this trap, more sea lamprey would be captured by increasing trapping effort early in the season when sea lamprey encounter rates with traps are high. The approach used in this study could be applied to trapping of other invasive or valued species.

Economic considerations in the use of inhaled anesthetic agents.

PubMed

Golembiewski, Julie

2010-04-15

To describe the components of and factors contributing to the costs of inhaled anesthesia, basis for quantifying and comparing these costs, and practical strategies for performing pharmacoeconomic analyses and reducing the costs of inhaled anesthetic agents. Inhaled anesthesia can be costly, and some of the variable costs, including fresh gas flow rates and vaporizer settings, are potential targets for cost savings. The use of a low fresh gas flow rate maximizes rebreathing of exhaled anesthetic gas and is less costly than a high flow rate, but it provides less control of the level of anesthesia. The minimum alveolar concentration (MAC) hour is a measure that can be used to compare the cost of inhaled anesthetic agents at various fresh gas flow rates. Anesthesia records provide a sense of patterns of inhaled anesthetic agent use, but the amount of detail can be limited. Cost savings have resulted from efforts to reduce the direct costs of inhaled anesthetic agents, but reductions in indirect costs through shortened times to patient recovery and discharge following the judicious use of these agents are more difficult to demonstrate. The patient case mix, fresh gas flow rates typically used during inhaled anesthesia, availability and location of vaporizers, and anesthesia care provider preferences and practices should be taken into consideration in pharmacoeconomic evaluations and recommendations for controlling the costs of inhaled anesthesia. Understanding factors that contribute to the costs of inhaled anesthesia and considering those factors in pharmacoeconomic analyses and recommendations for use of these agents can result in cost savings.

Reduced effectiveness of escitalopram in the forced swimming test is associated with increased serotonin clearance rate in food restricted rats

PubMed Central

France, CP; Li, J-X; Owens, WA; Koek, W; Toney, GM; Daws, LC

2012-01-01

Efficacy of antidepressant drugs is often limited. One of the limiting factors may be diet. This study shows that the effect of escitalopram in the forced swimming test is diminished in rats by food restriction that decreased body weight by 8%. The primary target for escitalopram is the serotonin (5-HT) transporter. Using high-speed chronoamperometry to measure 5-HT clearance in vivo in rats fed the same food restricted diet, the rate of 5-HT clearance from extracellular fluid in brain was dramatically increased. Increased 5-HT transporter function under conditions of dietary restriction might contribute to the decreased effect of escitalopram. These results suggest that diet plays an integral role in determining efficacy of antidepressant drugs, and might well generalize to other psychoactive drugs that impinge upon the 5-HT transporter. PMID:19419596

Alcohol use among Arab Americans: what is the prevalence?

PubMed

Arfken, Cynthia L; Arnetz, Bengt B; Fakhouri, Monty; Ventimiglia, Matthew J; Jamil, Hikmet

2011-08-01

Information is limited on alcohol use among Arab Americans. The purpose of this study was to describe and analyze the alcohol use pattern among Arab Americans by reviewing existing surveys using an acculturation model. Secondary data analysis. Nationally, English-speaking immigrant Arab Americans reported lower rates of lifetime alcohol use (50.8%), past month use (26.4%) and binge drinking (10%) than the White majority group. In a state survey, self-identified English-speaking Arab Americans were less likely to report past month use (45.6%) than the White majority group but reported similar rate of binge drinking (17.0%). Locally, lifetime drinking was reported by 46.2% of the immigrants but only 13.4% of refugees fleeing war. Few databases are available to estimate alcohol use pattern among Arab Americans; the limited data suggest a drinking pattern consistent with acculturation. However, the potential influence of other factors is unknown and needs to be investigated.

Alcohol Use Among Arab Americans: What is the Prevalence?

PubMed Central

Arfken, Cynthia L.; Arnetz, Bengt B.; Fakhouri, Monty; Ventimiglia, Matthew J.; Jamil, Hikmet

2014-01-01

Information is limited on alcohol use among Arab Americans. The purpose of this study was to describe and analyze the alcohol use pattern among Arab Americans by reviewing existing surveys using an acculturation model. Secondary data analysis. Nationally, English-speaking immigrant Arab Americans reported lower rates of lifetime alcohol use (50.8%), past month use (26.4%) and binge drinking (10%) than the White majority group. In a state survey, self-identified English-speaking Arab Americans were less likely to report past month use (45.6%) than the White majority group but reported similar rate of binge drinking (17.0%). Locally, lifetime drinking was reported by 46.2% of the immigrants but only 13.4% of refugees fleeing war. Few databases are available to estimate alcohol use pattern among Arab Americans; the limited data suggest a drinking pattern consistent with acculturation. However, the potential influence of other factors is unknown and needs to be investigated. PMID:21279687

Suicidality in Body Dysmorphic Disorder

PubMed Central

Phillips, Katharine A.

2008-01-01

Suicidal ideation, suicide attempts, and completed suicide appear common in individuals with body dysmorphic disorder (BDD). Available evidence indicates that approximately 80% of individuals with BDD experience lifetime suicidal ideation and 24% to 28% have attempted suicide. Although data on completed suicide are limited and preliminary, the suicide rate appears markedly high. These findings underscore the importance of recognizing and effectively treating BDD. However, BDD is underrecognized in clinical settings even though it is relatively common and often presents to psychiatrists and other mental health practitioners, dermatologists, surgeons, and other physicians. This article reviews available evidence on suicidality in BDD and discusses how to recognize and diagnose this often secret disorder. Efficacious treatments for BDD, ie, serotonin reuptake inhibitors (SRIs) and cognitive-behavioral therapy, are also discussed. Although data are limited, it appears that SRIs often diminish suicidality in these patients. Additional research is greatly needed on suicidality rates, characteristics, correlates, risk factors, treatment, and prevention of suicidality in BDD. PMID:18449358

Parameters and kinetics of olive mill wastewater dephenolization by immobilized Rhodotorula glutinis cells.

PubMed

Bozkoyunlu, Gaye; Takaç, Serpil

2014-01-01

Olive mill wastewater (OMW) with total phenol (TP) concentration range of 300-1200 mg/L was treated with alginate-immobilized Rhodotorula glutinis cells in batch system. The effects of pellet properties (diameter, alginate concentration and cell loading (CL)) and operational parameters (initial TP concentration, agitation rate and reusability of pellets) on dephenolization of OMW were studied. Up to 87% dephenolization was obtained after 120 h biodegradations. The utilization number of pellets increased with the addition of calcium ions into the biodegradation medium. The overall effectiveness factors calculated for different conditions showed that diffusional limitations arising from pellet size and pellet composition could be neglected. Mass transfer limitations appeared to be more effective at high substrate concentrations and low agitation rates. The parameters of logistic model for growth kinetics of R. glutinis in OMW were estimated at different initial phenol concentrations of OMW by curve-fitting of experimental data with the model.

Factoring stream turbulence into global assessments of nitrogen pollution.

PubMed

Grant, Stanley B; Azizian, Morvarid; Cook, Perran; Boano, Fulvio; Rippy, Megan A

2018-03-16

The discharge of excess nitrogen to streams and rivers poses an existential threat to both humans and ecosystems. A seminal study of headwater streams across the United States concluded that in-stream removal of nitrate is controlled primarily by stream chemistry and biology. Reanalysis of these data reveals that stream turbulence (in particular, turbulent mass transfer across the concentration boundary layer) imposes a previously unrecognized upper limit on the rate at which nitrate is removed from streams. The upper limit closely approximates measured nitrate removal rates in streams with low concentrations of this pollutant, a discovery that should inform stream restoration designs and efforts to assess the effects of nitrogen pollution on receiving water quality and the global nitrogen cycle. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Drug coated balloon in peripheral artery disease.

PubMed

Shanmugasundaram, Madhan; Murugapandian, Sangeetha; Truong, Huu Tam; Lotun, Kapildeo; Banerjee, Subhash

2018-04-21

Peripheral artery disease (PAD) is highly prevalent but is often underdiagnosed and undertreated. Lower extremity PAD can often be life style limiting. Revascularization in carefully selected lower extremity PAD patients improves symptoms and functional status. Surgical revascularization used to be the only available strategy, but in the recent years, endovascular strategies have gained popularity due to faster recovery times with low morbidity and mortality rates. Endovascular procedures have increased significantly in the United States in the past few years. That being said, higher restenosis rates and low long-term patency rates have been the limiting factors for this strategy. Drug eluting stents have been introduced to help with lowering restenosis, however lower extremity PAD involves long segment where the outcomes of stents are suboptimal. Also, the disease often crosses joint line that makes it less ideal for the stents. Drug coated balloons (DCB) have been introduced to improve patency rates following endovascular intervention for lower extremity PAD. They have gained popularity among endovascular specialists due to its ease of use and the concept of "leave nothing behind". This is a review of scientific evidence supporting DCB use in PAD. Published by Elsevier Inc.

CO2 and vitamin B12 interactions determine bioactive trace metal requirements of a subarctic Pacific diatom.

PubMed

King, Andrew L; Sañudo-Wilhelmy, Sergio A; Leblanc, Karine; Hutchins, David A; Fu, Feixue

2011-08-01

Phytoplankton growth can be limited by numerous inorganic nutrients and organic growth factors. Using the subarctic diatom Attheya sp. in culture studies, we examined how the availability of vitamin B(12) and carbon dioxide partial pressure (pCO(2)) influences growth rate, primary productivity, cellular iron (Fe), cobalt (Co), zinc (Zn) and cadmium (Cd) quotas, and the net use efficiencies (NUEs) of these bioactive trace metals (mol C fixed per mol cellular trace metal per day). Under B(12)-replete conditions, cells grown at high pCO(2) had lower Fe, Zn and Cd quotas, and used those trace metals more efficiently in comparison with cells grown at low pCO(2). At high pCO(2), B(12)-limited cells had ~50% lower specific growth and carbon fixation rates, and used Fe ~15-fold less efficiently, and Zn and Cd ~3-fold less efficiently, in comparison with B(12)-replete cells. The observed higher Fe, Zn and Cd NUE under high pCO(2)/B(12)-replete conditions are consistent with predicted downregulation of carbon-concentrating mechanisms. Co quotas of B(12)-replete cells were ∼5- to 14-fold higher in comparison with B(12)-limited cells, suggesting that >80% of cellular Co of B(12)-limited cells was likely from B(12). Our results demonstrate that CO(2) and vitamin B(12) interactively influence growth, carbon fixation, trace metal requirements and trace metal NUE of this diatom. This suggests the need to consider complex feedback interactions between multiple environmental factors for this biogeochemically critical group of phytoplankton in the last glacial maximum as well as the current and future changing ocean.

Controlled ecological life support system - biological problems

NASA Technical Reports Server (NTRS)

Moore, B., III (Editor); Macelroy, R. D. (Editor)

1982-01-01

The general processes and controls associated with two distinct experimental paradigms are examined. Specific areas for research related to biotic production (food production) and biotic decomposition (waste management) are explored. The workshop discussions were directed toward Elemental cycles and the biological factors that affect the transformations of nutrients into food, of food material into waste, and of waste into nutrients were discussed. To focus on biological issues, the discussion assumed that (1) food production would be by biological means (thus excluding chemical synthesis), (2) energy would not be a limiting factor, and (3) engineering capacity for composition and leak rate would be adequate.

Factors associated with poor satisfaction with treatment and trial discontinuation in chronic schizophrenia.

PubMed

Schoemaker, Joep H; Vingerhoets, Ad J J M; Emsley, Robin A

2018-06-05

IntroductionDespite consistently high discontinuation rates due to withdrawal of consent (WOC) and insufficient therapeutic effect (ITE) in schizophrenia trials, insight into the underlying factors contributing to poor satisfaction with treatment and dropout is limited. A better understanding of these factors could help to improve trial design and completion rates. Using data from 1,136 trial participants with schizophrenia or schizoaffective disorder, we explored associations between predictor variables with (1) dropout due to WOC and ITE and (2) satisfaction with treatment among patients and investigators by means of hierarchic multiple regression analyses. ITE was associated with poor clinical improvement, poor investigator satisfaction with treatment, and poor patient insight into their own disease, whereas WOC only showed a meaningful association with poor patient satisfaction with treatment. Investigator satisfaction with treatment appeared most strongly associated with Positive and Negative Syndrome Scale (PANSS) positive factor endpoint scores, whereas patient satisfaction with treatment was best predicted by the endpoint score on the PANSS emotional distress factor. The occurrence of severe side effects showed no meaningful association to satisfaction with treatment among investigators and patients, and neither did a patient's experienced psychopathology, nor their self-rating of functional impairment. Whereas trial discontinuation due to ITE is associated with poor treatment effectiveness, a patient's decision to withdraw from an antipsychotic trial remains unpredictable and may occur even when the investigator observes a global clinical improvement and is satisfied with the treatment.

Influence of postmortem time on the outcome of blood cultures among cadaveric tissue donors.

PubMed

Saegeman, V; Verhaegen, J; Lismont, D; Verduyckt, B; De Rijdt, T; Ectors, N

2009-02-01

Tissue banks provide tissues of human cadaver donors for transplantation. The maximal time limit for tissue retrieval has been set at 24 h postmortem. This study aimed at evaluating the evidence for this limit from a microbiological point of view. The delay of growth in postmortem blood cultures, the identification of the species isolated and clinical/environmental factors were investigated among 100 potential tissue donors. No significant difference was found in the rate of donors with grown blood cultures within (25/65=38%) compared with after (24/65=37%) 24 h of death. Coagulase-negative staphylococci and gastro-intestinal microorganisms were isolated within and after 24 h of death. Two factors--antimicrobial therapy and "delay before body cooling"--were significantly inversely related with donors' blood culture results. From a microbiological point of view, there is no evidence for avoiding tissue retrieval among donors after 24 h of death.

Effect of water hardness and dissolved-solid concentration on hatching success and egg size in bighead carp

USGS Publications Warehouse

Chapman, Duane C.; Deters, Joseph E.

2009-01-01

Bighead carp Hypophthalmichthys nobilis is an Asian species that has been introduced to the United States and is regarded as a highly undesirable invader. Soft water has been said to cause the bursting of Asian carp eggs and thus has been suggested as a factor that would limit the spread of this species. To evaluate this, we subjected fertilized eggs of bighead carp to waters with a wide range of hardness and dissolved-solid concentrations. Hatching rate and egg size were not significantly affected by the different water qualities. These results, combined with the low hardness (28–84 mg/L) of the Yangtze River (the primary natal habitat of Hypophthalmichthys spp.), suggest that managers and those performing risk assessments for the establishment of Hypophthalmichthys spp. should be cautious about treating low hardness and dissolved-solid concentrations as limiting factors.

What You Don't Know: Improving Family Health History Knowledge among Multigenerational Families of Mexican Origin.

PubMed

Goergen, Andrea F; Ashida, Sato; Skapinsky, Kaley; de Heer, Hendrik D; Wilkinson, Anna V; Koehly, Laura M

2016-01-01

This study investigated diabetes and heart disease family health history (FHH) knowledge and changes after providing personalized disease risk feedback. A total of 497 adults from 162 families of Mexican origin were randomized by household to conditions based on feedback recipient and content. Each provided personal and relatives' diabetes and heart disease diagnoses and received feedback materials following baseline assessment. Multivariate models were fitted to identify factors associated with the rate of 'don't know' FHH responses. At baseline, US nativity was associated with a higher 'don't know' response rate (p = 0.002). Though confounded by country of birth, younger age showed a trend toward higher 'don't know' response rates. Overall, average 'don't know' response rates dropped from 20 to 15% following receipt of feedback (p < 0.001). An intervention effect was noted, as 'don't know' response rates decreased more in households where one family member (vs. all) received supplementary risk assessments (without behavioral recommendations; p = 0.011). Limited FHH knowledge was noted among those born in the US and younger participants, representing a key population to reach with intervention efforts. The intervention effect suggests that 'less is more', indicating the potential for too much information to limit health education program effectiveness. © 2016 S. Karger AG, Basel.

Reaction mechanism for the aqueous-phase mineral carbonation of heat-activated serpentine at low temperatures and pressures in flue gas conditions.

PubMed

Pasquier, Louis-César; Mercier, Guy; Blais, Jean-François; Cecchi, Emmanuelle; Kentish, Sandra

2014-05-06

Mineral carbonation is known as one of the safest ways to sequester CO2. Nevertheless, the slow kinetics and low carbonation rates constitute a major barrier for any possible industrial application. To date, no studies have focused on reacting serpentinite with a relatively low partial pressure of CO2 (pCO2) close to flue gas conditions. In this work, finely ground and heat-treated serpentinite [Mg3Si2O5(OH)4] extracted from mining residues was reacted with a 18.2 vol % CO2 gas stream at moderate global pressures to investigate the effect on CO2 solubility and Mg leaching. Serpentinite dissolution rates were also measured to define the rate-limiting step. Successive batches of gas were contacted with the same serpentinite to identify surface-limiting factors using scanning electron microscopy (SEM) analysis. Investigation of the serpentinite carbonation reaction mechanisms under conditions close to a direct flue gas treatment showed that increased dissolution rates could be achieved relative to prior work, with an average Mg dissolution rate of 3.55 × 10(-11) mol cm(-2) s(-1). This study provides another perspective of the feasibility of applying a mineral carbonation process to reduce industrial greenhouse gas (GHG) emissions from large emission sources.

Using occupancy modeling and logistic regression to assess the distribution of shrimp species in lowland streams, Costa Rica: Does regional groundwater create favorable habitat?

USGS Publications Warehouse

Snyder, Marcia; Freeman, Mary C.; Purucker, S. Thomas; Pringle, Catherine M.

2016-01-01

Freshwater shrimps are an important biotic component of tropical ecosystems. However, they can have a low probability of detection when abundances are low. We sampled 3 of the most common freshwater shrimp species, Macrobrachium olfersii, Macrobrachium carcinus, and Macrobrachium heterochirus, and used occupancy modeling and logistic regression models to improve our limited knowledge of distribution of these cryptic species by investigating both local- and landscape-scale effects at La Selva Biological Station in Costa Rica. Local-scale factors included substrate type and stream size, and landscape-scale factors included presence or absence of regional groundwater inputs. Capture rates for 2 of the sampled species (M. olfersii and M. carcinus) were sufficient to compare the fit of occupancy models. Occupancy models did not converge for M. heterochirus, but M. heterochirus had high enough occupancy rates that logistic regression could be used to model the relationship between occupancy rates and predictors. The best-supported models for M. olfersii and M. carcinus included conductivity, discharge, and substrate parameters. Stream size was positively correlated with occupancy rates of all 3 species. High stream conductivity, which reflects the quantity of regional groundwater input into the stream, was positively correlated with M. olfersii occupancy rates. Boulder substrates increased occupancy rate of M. carcinus and decreased the detection probability of M. olfersii. Our models suggest that shrimp distribution is driven by factors that function at local (substrate and discharge) and landscape (conductivity) scales.

Optimal exploitation of spatially distributed trophic resources and population stability

USGS Publications Warehouse

Basset, A.; Fedele, M.; DeAngelis, D.L.

2002-01-01

The relationships between optimal foraging of individuals and population stability are addressed by testing, with a spatially explicit model, the effect of patch departure behaviour on individual energetics and population stability. A factorial experimental design was used to analyse the relevance of the behavioural factor in relation to three factors that are known to affect individual energetics; i.e. resource growth rate (RGR), assimilation efficiency (AE), and body size of individuals. The factorial combination of these factors produced 432 cases, and 1000 replicate simulations were run for each case. Net energy intake rates of the modelled consumers increased with increasing RGR, consumer AE, and consumer body size, as expected. Moreover, through their patch departure behaviour, by selecting the resource level at which they departed from the patch, individuals managed to substantially increase their net energy intake rates. Population stability was also affected by the behavioural factors and by the other factors, but with highly non-linear responses. Whenever resources were limiting for the consumers because of low RGR, large individual body size or low AE, population density at the equilibrium was directly related to the patch departure behaviour; on the other hand, optimal patch departure behaviour, which maximised the net energy intake at the individual level, had a negative influence on population stability whenever resource availability was high for the consumers. The consumer growth rate (r) and numerical dynamics, as well as the spatial and temporal fluctuations of resource density, which were the proximate causes of population stability or instability, were affected by the behavioural factor as strongly or even more strongly than by the others factors considered here. Therefore, patch departure behaviour can act as a feedback control of individual energetics, allowing consumers to optimise a potential trade-off between short-term individual fitness and long-term population stability. ?? 2002 Elsevier Science B.V. All rights reserved.

14 CFR 27.337 - Limit maneuvering load factor.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Limit maneuvering load factor. 27.337... Limit maneuvering load factor. The rotorcraft must be designed for— (a) A limit maneuvering load factor... load factor not less than 2.0 and any negative limit maneuvering load factor of not less than −0.5 for...

14 CFR 29.337 - Limit maneuvering load factor.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Limit maneuvering load factor. 29.337... Limit maneuvering load factor. The rotorcraft must be designed for— (a) A limit maneuvering load factor... load factor not less than 2.0 and any negative limit maneuvering load factor of not less than −0.5 for...

Λb→p ℓ-ν¯ ℓ and Λb→Λcℓ-ν¯ ℓ form factors from lattice QCD with relativistic heavy quarks

NASA Astrophysics Data System (ADS)

Detmold, William; Lehner, Christoph; Meinel, Stefan

2015-08-01

Measurements of the Λb→p ℓ-ν¯ ℓ and Λb→Λcℓ-ν¯ ℓ decay rates can be used to determine the magnitudes of the Cabibbo-Kobayashi-Maskawa matrix elements Vu b and Vc b, provided that the relevant hadronic form factors are known. Here we present a precise calculation of these form factors using lattice QCD with 2 +1 flavors of dynamical domain-wall fermions. The b and c quarks are implemented with relativistic heavy-quark actions, allowing us to work directly at the physical heavy-quark masses. The lattice computation is performed for six different pion masses and two different lattice spacings, using gauge-field configurations generated by the RBC and UKQCD Collaborations. The b →u and b →c currents are renormalized with a mostly nonperturbative method. We extrapolate the form factor results to the physical pion mass and the continuum limit, parametrizing the q2 dependence using z expansions. The form factors are presented in such a way as to enable the correlated propagation of both statistical and systematic uncertainties into derived quantities such as differential decay rates and asymmetries. Using these form factors, we present predictions for the Λb→p ℓ-ν¯ℓ and Λb→Λc ℓ-ν¯ℓ differential and integrated decay rates. Combined with experimental data, our results enable determinations of |Vu b|, |Vc b|, and |Vu b/Vc b| with theory uncertainties of 4.4%, 2.2%, and 4.9%, respectively.

The Type of Payment and Working Conditions.

PubMed

Rhee, Kyung Yong; Kim, Young Sun; Cho, Yoon Ho

2015-12-01

The type of payment is one of the important factors that has an effect on the health of employees, as a basic working condition. In the conventional research field of occupational safety and health, only the physical, chemical, biological, and ergonomic factors are treated as the main hazardous factors. Managerial factors and basic working conditions such as working hours and the type of payment are neglected. This paper aimed to investigate the association of the type of payment and the exposure to the various hazardous factors as an heuristic study. The third Korean Working Conditions Survey (KWCS) by the Occupational Safety and Health Research Institute in 2011 was used for this study. Among the total sample of 50,032 economically active persons, 34,788 employees were considered for analysis. This study examined the relation between the three types of payment such as basic fixed salary and wage, piece rate, and extra payment for bad and dangerous working conditions and exposure to hazardous factors like vibration, noise, temperature, chemical contact, and working at very high speeds. Multivariate regression analysis was used to measure the effect of the type of payment on working hours exposed to hazards. The result showed that the proportion of employees with a basic fixed salary was 94.5%, the proportion with piece rates was 38.6%, and the proportion who received extra payment for hazardous working conditions was 11.7%. The piece rate was associated with exposure to working with tight deadlines and stressful jobs. This study had some limitations because KWCS was a cross-sectional survey.

Stability and Bifurcation Analysis of a Three-Species Food Chain Model with Fear

NASA Astrophysics Data System (ADS)

Panday, Pijush; Pal, Nikhil; Samanta, Sudip; Chattopadhyay, Joydev

In the present paper, we investigate the impact of fear in a tri-trophic food chain model. We propose a three-species food chain model, where the growth rate of middle predator is reduced due to the cost of fear of top predator, and the growth rate of prey is suppressed due to the cost of fear of middle predator. Mathematical properties such as equilibrium analysis, stability analysis, bifurcation analysis and persistence have been investigated. We also describe the global stability analysis of the equilibrium points. Our numerical simulations reveal that cost of fear in basal prey may exhibit bistability by producing unstable limit cycles, however, fear in middle predator can replace unstable limit cycles by a stable limit cycle or a stable interior equilibrium. We observe that fear can stabilize the system from chaos to stable focus through the period-halving phenomenon. We conclude that chaotic dynamics can be controlled by the fear factors. We apply basic tools of nonlinear dynamics such as Poincaré section and maximum Lyapunov exponent to identify the chaotic behavior of the system.

Iodine distribution in the environment as a limiting factor for roe deer antler development.

PubMed

Lehoczki, Róbert; Erdélyi, Károly; Sonkoly, Krisztina; Szemethy, László; Csányi, Sándor

2011-02-01

The iodine-containing hormones produced by the thyroid gland play a role in the complex neuro-hormonal regulation of antler development. The proper function of the thyroid depends on the adequate iodine supply of the organism, which is directly related to the iodine content of food and drinking water. The purpose of this study was to explore the connection between the iodine content of the water base, which has a strong correlation with the iodine concentration of environmental components available to animals, and the antler weight of roe deer (Capreolus capreolus) shot in Hungarian hunting areas. Using a general linear model, controlling for the collective effects of other environmental factors (deer population density, harvest rate, land use, and soil fertility information), the iodine content of the water base explained 51.4% of the total variance of antler weights. The results suggest that antler weights increase with increasing iodine concentration regardless of other factors; thus, the environmental iodine distribution can be a limiting factor suppressing roe deer performance assessed here as antler weight. Further experimental studies of controlled iodine uptake are needed to define the exact physiological iodine requirements of roe deer bucks.

Subjective wellbeing, suicide and socioeconomic factors: an ecological analysis in Hong Kong.

PubMed

Hsu, C-Y; Chang, S-S; Yip, P S F

2018-04-10

There has recently been an increased interest in mental health indicators for the monitoring of population wellbeing, which is among the targets of Sustainable Development Goals adopted by the United Nations. Levels of subjective wellbeing and suicide rates have been proposed as indicators of population mental health, but prior research is limited. Data on individual happiness and life satisfaction were sourced from a population-based survey in Hong Kong (2011). Suicide data were extracted from Coroner's Court files (2005-2013). Area characteristic variables included local poverty rate and four factors derived from a factor analysis of 21 variables extracted from the 2011 census. The associations between mean happiness and life satisfaction scores and suicide rates were assessed using Pearson correlation coefficient at two area levels: 18 districts and 30 quantiles of large street blocks (LSBs; n = 1620). LSB is a small area unit with a higher level of within-unit homogeneity compared with districts. Partial correlations were used to control for area characteristics. Happiness and life satisfaction demonstrated weak inverse associations with suicide rate at the district level (r = -0.32 and -0.36, respectively) but very strong associations at the LSB quantile level (r = -0.83 and -0.84, respectively). There were generally very weak or weak negative correlations across sex/age groups at the district level but generally moderate to strong correlations at the LSB quantile level. The associations were markedly attenuated or became null after controlling for area characteristics. Subjective wellbeing is strongly associated with suicide at a small area level; socioeconomic factors can largely explain this association. Socioeconomic factors could play an important role in determining the wellbeing of the population, and this could inform policies aimed at enhancing population wellbeing.

Rates and risk factors of injury in CrossFitTM: a prospective cohort study.

PubMed

Moran, Sebastian; Booker, Harry; Staines, Jacob; Williams, Sean

2017-09-01

CrossFitTM is a strength and conditioning program that has gained widespread popularity since its inception approximately 15 years ago. However, at present little is known about the level of injury risk associated with this form of training. Movement competency, assessed using the Functional Movement ScreenTM (FMS), has been identified as a risk factor for injury in numerous athletic populations, but its role in CrossFit participants is currently unclear. The aim of this study was to evaluate the level of injury risk associated with CrossFit training, and examine the influence of a number of potential risk factors (including movement competency). A cohort of 117 CrossFit participants were followed prospectively for 12 weeks. Participants' characteristics, previous injury history and training experience were recorded at baseline, and an FMS assessment was conducted. The overall injury incidence rate was 2.10 per 1000 training hours (90% confidence limits: 1.32-3.33). A multivariate Poisson regression model identified males (rate ratio [RR]: 4.44 ×/÷ 3.30, very likely harmful) and those with previous injuries (RR: 2.35 ×/÷ 2.37, likely harmful) as having a higher injury risk. Inferences relating to FMS variables were unclear in the multivariate model, although number of asymmetries was a clear risk factor in a univariate model (RR per two additional asymmetries: 2.62 ×/÷ 1.53, likely harmful). The injury incidence rate associated with CrossFit training was low, and comparable to other forms of recreational fitness activities. Previous injury and gender were identified as risk factors for injury, whilst the role of movement competency in this setting warrants further investigation.

The Validation of Macro and Micro Observations of Parent–Child Dynamics Using the Relationship Affect Coding System in Early Childhood

PubMed Central

Mun, Chung Jung; Tein, Jenn-Yun; Kim, Hanjoe; Shaw, Daniel S.; Gardner, Frances; Wilson, Melvin N.; Peterson, Jenene

2018-01-01

This study examined the validity of micro social observations and macro ratings of parent–child interaction in early to middle childhood. Seven hundred and thirty-one families representing multiple ethnic groups were recruited and screened as at risk in the context of Women, Infant, and Children (WIC) Nutritional Supplement service settings. Families were randomly assigned to the Family Checkup (FCU) intervention or the control condition at age 2 and videotaped in structured interactions in the home at ages 2, 3, 4, and 5. Parent–child interaction videotapes were microcoded using the Relationship Affect Coding System (RACS) that captures the duration of two mutual dyadic states: positive engagement and coercion. Macro ratings of parenting skills were collected after coding the videotapes to assess parent use of positive behavior support and limit setting skills (or lack thereof). Confirmatory factor analyses revealed that the measurement model of macro ratings of limit setting and positive behavior support was not supported by the data, and thus, were excluded from further analyses. However, there was moderate stability in the families’ micro social dynamics across early childhood and it showed significant improvements as a function of random assignment to the FCU. Moreover, parent–child dynamics were predictive of chronic behavior problems as rated by parents in middle childhood, but not emotional problems. We conclude with a discussion of the validity of the RACS and on methodological advantages of micro social coding over the statistical limitations of macro rating observations. Future directions are discussed for observation research in prevention science. PMID:27620623

The Validation of Macro and Micro Observations of Parent-Child Dynamics Using the Relationship Affect Coding System in Early Childhood.

PubMed

Dishion, Thomas J; Mun, Chung Jung; Tein, Jenn-Yun; Kim, Hanjoe; Shaw, Daniel S; Gardner, Frances; Wilson, Melvin N; Peterson, Jenene

2017-04-01

This study examined the validity of micro social observations and macro ratings of parent-child interaction in early to middle childhood. Seven hundred and thirty-one families representing multiple ethnic groups were recruited and screened as at risk in the context of Women, Infant, and Children (WIC) Nutritional Supplement service settings. Families were randomly assigned to the Family Checkup (FCU) intervention or the control condition at age 2 and videotaped in structured interactions in the home at ages 2, 3, 4, and 5. Parent-child interaction videotapes were micro-coded using the Relationship Affect Coding System (RACS) that captures the duration of two mutual dyadic states: positive engagement and coercion. Macro ratings of parenting skills were collected after coding the videotapes to assess parent use of positive behavior support and limit setting skills (or lack thereof). Confirmatory factor analyses revealed that the measurement model of macro ratings of limit setting and positive behavior support was not supported by the data, and thus, were excluded from further analyses. However, there was moderate stability in the families' micro social dynamics across early childhood and it showed significant improvements as a function of random assignment to the FCU. Moreover, parent-child dynamics were predictive of chronic behavior problems as rated by parents in middle childhood, but not emotional problems. We conclude with a discussion of the validity of the RACS and on methodological advantages of micro social coding over the statistical limitations of macro rating observations. Future directions are discussed for observation research in prevention science.

Precession relaxation of viscoelastic oblate rotators

NASA Astrophysics Data System (ADS)

Frouard, Julien; Efroimsky, Michael

2018-01-01

Perturbations of all sorts destabilize the rotation of a small body and leave it in a non-principal spin state. In such a state, the body experiences alternating stresses generated by the inertial forces. This yields nutation relaxation, i.e. evolution of the spin towards the principal rotation about the maximal-inertia axis. Knowledge of the time-scales needed to damp the nutation is crucial in studies of small bodies' dynamics. In the literature hitherto, nutation relaxation has always been described with aid of an empirical quality factor Q introduced to parametrize the energy dissipation rate. Among the drawbacks of this approach was its inability to describe the dependence of the relaxation rate upon the current nutation angle. This inability stemmed from our lack of knowledge of the quality factor's dependence on the forcing frequency. In this article, we derive our description of nutation damping directly from the rheological law obeyed by the material. This renders us the nutation damping rate as a function of the current nutation angle, as well as of the shape and the rheological parameters of the body. In contradistinction from the approach based on an empirical Q factor, our development gives a zero damping rate in the spherical-shape limit. Our method is generic and applicable to any shape and to any linear rheological law. However, to simplify the developments, here we consider a dynamically oblate rotator with a Maxwell rheology.

Genetic and familial environmental effects on suicide attempts: a study of Danish adoptees and their biological and adoptive siblings.

PubMed

Petersen, Liselotte; Sørensen, Thorkild I A; Kragh Andersen, Per; Mortensen, Preben Bo; Hawton, Keith

2014-02-01

Genetic factors have been found to influence the risk of suicide. It is less clear if this also applies to attempted suicide. We have investigated genetic and familial environmental factors by studying the occurrence of suicide attempts in biological and adoptive siblings of adoptees who attempted suicide compared to siblings of adoptees with no suicide attempts. We used a random sample of 1933 adoptees from the Danish Adoption Register, a register of non-familial adoptions of Danish children, i.e. the adoptive parents are biologically unrelated to the adoptee. Analyses were conducted on incidence rates of attempted suicide in biological and adoptive siblings given occurrence of attempted suicide in the adoptees while also taking into account psychiatric disorders. Information about suicidal attempt and history of psychiatric disorder was based on hospital admissions. The rate of attempted suicide in full siblings of adoptees who attempted suicide before age 60 years was higher than in full siblings of adoptees who had not attempted suicide (incidence rate ratios (IRR)=3.45; 95% confidence interval [CI]=0.94-12.7). After adjustment for history of psychiatric admission of siblings the increased rate was statistically significant (IRR=3.88; 95% CI-1.42-10.6). Information on attempted suicide and psychiatric history was limited to that which involved hospitalisation. Genetic factors influence risk of suicide attempts. © 2013 Published by Elsevier B.V.

Trends in ethnic disparities in stroke incidence in Auckland, New Zealand, during 1981 to 2003.

PubMed

Carter, Kristie; Anderson, Craig; Hacket, Maree; Feigin, Valery; Barber, P Alan; Broad, Joanna B; Bonita, Ruth

2006-01-01

Although geographical variations in stroke rates are well documented, limited data exist on temporal trends in ethnic-specific stroke incidence. We assessed trends in ethnic-specific stroke rates using standard diagnostic criteria and community-wide surveillance procedures in Auckland, New Zealand (NZ) in 1981 to 1982, 1991 to 1992, and 2002 to 2003. Indirect and direct methods were used to adjust first-ever (incident) and total (attack) rates for changes in the structure of the population and reported with 95% CIs. Ethnicity was self-defined and categorized as "NZ/European," "Maori," "Pacific peoples," and "Asian and other." Stroke attack (19%; 95% CI, 11% to 26%) and incidence rates (19%; 95% CI, 12% to 24%) declined significantly in NZ/Europeans from 1981 to 1982 to 2002 to 2003. These rates remained high or increased in other ethnic groups, particularly for Pacific peoples in whom stroke attack rates increased by 66% (95% CI; 11% to 225%) over the periods. Some favorable downward trends in vascular risk factors, such as cigarette smoking, were counterbalanced by increasing age, body mass index, and diabetes in certain ethnic groups. Divergent trends in ethnic-specific stroke incidence and attack rates, and of associated risk factors, have occurred in Auckland over recent decades. The findings provide mixed views as to the future burden of stroke in populations undergoing similar lifestyle and structural changes.

Weathering as the limiting factor of denudation in the Western escarpment of the Andes

NASA Astrophysics Data System (ADS)

Abbühl, L. M.; Schlunegger, F.; Kracht, O.; Ramseyer, K.; Rieke-Zapp, D.; Aldahan, A.; von Blanckenburg, F.

2009-04-01

A crucial issue in process geomorphology is the search for the scale and the extent to which precipitation, and climate in general, influences the nature and the rates of sediment transfer (weathering, erosion, sediment transport and deposition). We present an analysis of the possible interplay between precipitation, weathering and denudation rates for the western Andean slope between the Cordillera and the Pacific coast. It is based on morphometric studies and quantitative 10Be denudation rate estimates of three transverse river systems (Piura at 5°S, Pisco at 13°S, and Lluta at 18°S) draining the Western escarpment of the Peruvian and North Chilean Andes. The systems originate at elevations >3000 m above sea level, cover an area between 3000 and 10'000 km2 and discharge into the Pacific Ocean. The precipitation rate pattern implies a hyperarid climate at the coast, and semi-arid to semi-humid conditions in the Cordillera where the streams rise. There, climatic conditions are generally controlled by the easterlies that deliver moisture from the Atlantic Ocean via the low level Andean jet. The precipitation rate pattern of the Cordillera shows a North-South decreasing trend, from ca. 1000 mm/yr in Northern Peru to 150 mm/yr in Northern Chile. In these higher regions of the drainage basins, hillslopes are convex with nearly constant curvatures and are mantled by a >1 m thick regolith cover. In addition, hillslope erosion is limited to the regolith-bedrock interface. We interpret these geomorphic features to indicate weathering-controlled sediment discharge. In the lower river segments, beyond tectonic knickzones, regular precipitation is almost absent. For the case of the Piura river in Northern Peru, precipitation in this segment occurs in relation to highly episodic El Niño events related to the westerlies. This results in a supply-limited sediment discharge, leading to predominance of channelized processes on the hillslopes, a spare regolith cover and an additional river profile knickzone in the transition zone between the easterlies and the westerlies. Analysis of 10Be in quartz of river-born sand and of bedrock reveals that denudation correlates positively with the present-day rainfall pattern related to the easterlies. Denudation rates in the headwaters range from 0.14 mm/year in Northern Peru down to 0.05 mm/yr in Northern Chile (Kober et al., 2007). In addition, 10Be-based denudation rates reveal a decreasing trend from the Cordillera to the Pacific coast that positively correlates with the decreasing precipitation rate, irrespective of the nature of the bedrock. Interestingly, the 10Be analysis conducted in the Piura system reveals no influence of the episodic precipitation in relation to El Niño on the sediment production rates. In summary, the pattern of denudation rates together with morphometric observations and quantitative denudation rate estimates strongly hints at weathering being the driving but also limiting factor of denudation. Accordingly, in the western Peruvian Andes, sediment production and export are most probably controlled by the pattern and rate of precipitation. Kober, F., Ivy-Ochs, S., Schlunegger, F., Baur, H., Kubik, P. W., and Wieler, R. (2007). Denudation rates and a topography-driven rainfall threshold in northern Chile: Multiple cosmogenic nuclide data and sediment yield budgets. Geomorphology 83, 97-120.

Geographic and ethnic disparities in osteoporotic fractures.

PubMed

Cauley, Jane A; Chalhoub, Didier; Kassem, Ahmed M; Fuleihan, Ghada El-Hajj

2014-06-01

Osteoporotic fractures are a major worldwide epidemic. Here, we review global variability, ethnic differences and secular changes in osteoporotic fractures. Worldwide, age-standardized incidence rates of hip fracture vary >200-fold in women and >140-fold in men when comparing the country in which incidence rates are the highest with that in which they are the lowest. Median age-standardized rates are highest in North America and Europe, followed by Asia, Middle East, Oceania, Latin America and Africa. Globally, rates of hip fracture are greater in women than in men, with an average ratio of ∼2:1. The incidence of radiographic vertebral fractures is much higher than that of hip fractures, whereas the incidence rates of clinical vertebral fractures mirror hip fracture rates in most countries. Methodological challenges of defining and ascertaining vertebral fractures limit the interpretation of these data. Secular declines in hip fracture rates have been reported in populations from North America, Europe and Oceania. These declines are especially notable in women, suggesting that reproductive factors might contribute to this reduction. By contrast, hip fracture rates are increasing in parts of Asia and Latin America. Global indicators of health, education and socioeconomic status are positively correlated with fracture rates suggesting that lifestyles in developed countries might contribute to hip fracture. Improvements in fracture assessment, in particular for nonhip fractures, and identification of factors that contribute to this variability might substantially influence our understanding of osteoporotic fracture aetiology and provide new avenues for prevention.

Nintedanib: evidence for its therapeutic potential in idiopathic pulmonary fibrosis

PubMed Central

Inomata, Minoru; Nishioka, Yasuhiko; Azuma, Arata

2015-01-01

Idiopathic pulmonary fibrosis (IPF) is a progressive disease with poor prognosis. The molecular mechanisms involved in the progression of IPF are not fully understood; however, the platelet-derived growth factor (PDGF)/PDGF receptor pathway is thought to play a critical role in fibrogenesis of the lungs. Other growth factors, including fibroblast growth factor and vascular endothelial growth factor, are also thought to contribute to the pathogenesis of pulmonary fibrosis. Nintedanib is an inhibitor of multiple tyrosine kinases, including receptors for PDGF, fibroblast growth factor, and vascular endothelial growth factor. In the Phase II TOMORROW trial, treatment with 150 mg of nintedanib twice daily showed a trend to slow the decline in lung function and significantly decrease acute exacerbations in patients with IPF, while showing an acceptable safety profile. The Phase III INPULSIS trials demonstrated a significant decrease in the annual rate of decline in forced vital capacity in IPF patients treated with 150 mg nintedanib twice daily. In the INPULSIS-2 trial, the time to the first acute exacerbation significantly increased in IPF patients who were treated with 150 mg of nintedanib twice daily. Pirfenidone, another antifibrotic drug, was shown to limit the decline in pulmonary function in patients with IPF in the ASCEND trial. Combination therapy with nintedanib and pirfenidone is anticipated, although further evaluation of its long-term safety is needed. There is limited evidence for the safety of the combination therapy although a Phase II trial conducted in Japan demonstrated that combination therapy with nintedanib and pirfenidone was tolerable for 1 month. Available antifibrotic agents (ie, pirfenidone and N-acetylcysteine) have limited efficacy as single therapies for IPF; therefore, further study of combination therapy with antifibrotic agents is needed. PMID:26346347

Development Of A Multivariate Prognostic Model For Pain And Activity Limitation In People With Low Back Disorders Receiving Physiotherapy.

PubMed

Ford, Jon J; Richards BPhysio, Matt C; Surkitt BPhysio, Luke D; Chan BPhysio, Alexander Yp; Slater, Sarah L; Taylor, Nicholas F; Hahne, Andrew J

2018-05-28

To identify predictors for back pain, leg pain and activity limitation in patients with early persistent low back disorders. Prospective inception cohort study; Setting: primary care private physiotherapy clinics in Melbourne, Australia. 300 adults aged 18-65 years with low back and/or referred leg pain of ≥6-weeks and ≤6-months duration. Not applicable. Numerical rating scales for back pain and leg pain as well as the Oswestry Disability Scale. Prognostic factors included sociodemographics, treatment related factors, subjective/physical examination, subgrouping factors and standardized questionnaires. Univariate analysis followed by generalized estimating equations were used to develop a multivariate prognostic model for back pain, leg pain and activity limitation. Fifty-eight prognostic factors progressed to the multivariate stage where 15 showed significant (p<0.05) associations with at least one of the three outcomes. There were five indicators of positive outcome (two types of low back disorder subgroups, paresthesia below waist, walking as an easing factor and low transversus abdominis tone) and 10 indicators of negative outcome (both parents born overseas, deep leg symptoms, longer sick leave duration, high multifidus tone, clinically determined inflammation, higher back and leg pain severity, lower lifting capacity, lower work capacity and higher pain drawing percentage coverage). The preliminary model identifying predictors of low back disorders explained up to 37% of the variance in outcome. This study evaluated a comprehensive range of prognostic factors reflective of both the biomedical and psychosocial domains of low back disorders. The preliminary multivariate model requires further validation before being considered for clinical use. Copyright © 2018. Published by Elsevier Inc.

The Potential for Low-Temperature Abiotic Hydrogen Generation and a Hydrogen-Driven Deep Biosphere

PubMed Central

Huang, Shanshan; Thorseth, Ingunn H.

2011-01-01

Abstract The release and oxidation of ferrous iron during aqueous alteration of the mineral olivine is known to reduce aqueous solutions to such extent that molecular hydrogen, H2, forms. H2 is an efficient energy carrier and is considered basal to the deep subsurface biosphere. Knowledge of the potential for H2 generation is therefore vital to understanding the deep biosphere on Earth and on extraterrestrial bodies. Here, we provide a review of factors that may reduce the potential for H2 generation with a focus on systems in the core temperature region for thermophilic to hyperthermophilic microbial life. We show that aqueous sulfate may inhibit the formation of H2, whereas redox-sensitive compounds of carbon and nitrogen are unlikely to have significant effect at low temperatures. In addition, we suggest that the rate of H2 generation is proportional to the dissolution rate of olivine and, hence, limited by factors such as reactive surface areas and the access of water to fresh surfaces. We furthermore suggest that the availability of water and pore/fracture space are the most important factors that limit the generation of H2. Our study implies that, because of large heat flows, abundant olivine-bearing rocks, large thermodynamic gradients, and reduced atmospheres, young Earth and Mars probably offered abundant systems where microbial life could possibly have emerged. Key Words: Serpentinization—Olivine—Hydrogen—Deep biosphere—Water—Mars. Astrobiology 11, 711–724. PMID:21923409

Influence of specific muscle training on pain, activity limitation and kinesiophobia in women with back pain post-partum--a 'single-subject research design'.

PubMed

Gustafsson, Johanna; Nilsson-Wikmar, Lena

2008-03-01

Many women suffer from back pain and experience activity limitation post-partum. To our knowledge the physiological factors and physiotherapy related to back pain post-partum have received limited evaluation and the effectiveness of specific physiotherapeutic approaches to exercise should be tested. In addition, there has been limited research on kinesiophobia in women with back pain post-partum. The purpose of the current study was to test the influence of specific trunk muscle training on pain, activity limitation and kinesiophobia in 10 subjects with back pain post-partum. The treatment consisted of specific deep muscle training of the transversus abdominus and multifidus muscles. Pain was rated based on the visual analogue scale (VAS) and pain drawings. Activity limitation was recorded using the Disability Rating Index. Kinesiophobia was evaluated using the Swedish version of the Tampa Scale for Kinesiophobia. An A-B-A single-subject research design was used and a number of measurements were obtained during each phase. The analysis consisted of a visual inspection and a two standard deviation band test (2-SD). The visual analysis showed a trend towards reduced pain and activity limitation for all 10 subjects. The 2-SD test showed mixed results among all subjects. In addition, all subjects reported kinesiophobia before and after treatment. Individual specific deep muscle training of the transversus abdominus and multifidus muscles reduced pain and activity limitation in women with back pain post-partum. Further research is needed to determine more precisely how kinesiophobia affects women with back pain post-partum.

Speed limiter integrated fatigue analyzer (SLIFA) for speed and fatigue control on diesel engine truck and bus

NASA Astrophysics Data System (ADS)

Wahyudi, Haris; Pranoto, Hadi; Leman, A. M.; Sebayang, Darwin; Baba, I.

2017-09-01

Every second, the number of road traffic deaths is increased globally with millions more sustaining severe injuries and living with long-term adverse health consequences. Jakarta alone in year 2015 had recorded 556 people died due to road accidents, approximately reached 6.231 road accident cases. The identified major contributory factors of such unfortunate events are both driver fatigue and over speeding habit especially related to the driving of truck and bus. This paper presents the idea on how to control the electronic system from input fuel system of injection pump and the combustion chamber engine will control the valve solenoid in injection pump which can lock and fuel will stop for moment, and speed limit can be success, by using sensor heart rate we can input reduce speed limit when fatigue detection driver. Integration process this tool can be relevant when Speed Limiter Integrated Fatigue Analyser (SLIFA) trial in the diesel engine for truck and bus, the result of this research Speed Limiter Integrated Fatigue Analyser (SLIFA) able to control speed of diesel engine for truck and bus almost 30km/h, 60km/h, and until 70 km/h. The installation of the sensor heart rate as the input speed limit SLIFA would work when the driver is detected to be in the fatigue condition. We make Speed Limiter Integrated Fatigue Analyser (SLIFA) for control and monitoring system for diesel engine in truck and bus. Speed Limiter Integrated Fatigue Analyser (SLIFA) system can save the historical of the speed record, fatigue, rpm, and body temperature of the driver.

The Rate of Core Collapse Supernovae to Redshift 2.5 from the CANDELS and CLASH Supernova Surveys

NASA Astrophysics Data System (ADS)

Strolger, Louis-Gregory; Dahlen, Tomas; Rodney, Steven A.; Graur, Or; Riess, Adam G.; McCully, Curtis; Ravindranath, Swara; Mobasher, Bahram; Shahady, A. Kristin

2015-11-01

The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey and Cluster Lensing And Supernova survey with Hubble multi-cycle treasury programs with the Hubble Space Telescope (HST) have provided new opportunities to probe the rate of core-collapse supernovae (CCSNe) at high redshift, now extending to z≈ 2.5. Here we use a sample of approximately 44 CCSNe to determine volumetric rates, RCC, in six redshift bins in the range 0.1\\lt z\\lt 2.5. Together with rates from our previous HST program, and rates from the literature, we trace a more complete history of {R}{CC}(z), with {R}{CC}=0.72+/- 0.06 yr-1 Mpc-3 10-4{h}703 at z\\lt 0.08, and increasing to {3.7}-1.6+3.1 yr-1 Mpc-3 10-4{h}703 to z≈ 2.0. The statistical precision in each bin is several factors better than than the systematic error, with significant contributions from host extinction, and average peak absolute magnitudes of the assumed luminosity functions for CCSN types. Assuming negligible time delays from stellar formation to explosion, we find these composite CCSN rates to be in excellent agreement with cosmic star formation rate density (SFRs) derived largely from dust-corrected rest-frame UV emission, with a scaling factor of k=0.0091+/- 0.0017 {M}⊙ -1, and inconsistent (to \\gt 95% confidence) with SFRs from IR luminous galaxies, or with SFR models that include simple evolution in the initial mass function over time. This scaling factor is expected if the fraction of the IMF contributing to CCSN progenitors is in the 8-50 M⊙ range. It is not supportive, however, of an upper mass limit for progenitors at \\lt 20 {M}⊙ .

Recruitment limitation of long-lived conifers: implications for climate change responses.

PubMed

Kroiss, Steve J; Hillerslambers, Janneke

2015-05-01

Seed availability and suitable microsites for germination are likely to severely constrain the responses of plant species to climate change, especially at and beyond range edges. For example, range shifts may be slow if seed availability is low at range edges due to low parent-tree abundance or reduced fecundity. Even when seeds are available, climatic and biotic factors may further limit the availability of suitable microsites for recruitment. Unfortunately, the importance of seed and microsite limitation during range shifts remains unknown, since few studies have examined both factors simultaneously, particularly across species' ranges. To address this issue, we assessed seed availability and the factors influencing germination for six conifer species across a large environmental gradient encompassing their elevational ranges. Specifically, we assessed (1) how parent-tree abundance influences annual seed availability; (2) how seed limitation varies across species' ranges; (3) how climatic and biotic factors affect germination; and (4) how seed and suitable microsite availability covary annually within and among species. We found that seed availability declined toward species' upper range edges for most species, primarily due to low parent-tree abundance rather than declining fecundity. Range expansions are thus likely to be lagged with respect to climate change, as long generation times preclude rapid increases in tree density. Negative impacts of canopy cover on germination rates suggest range shifts will further be slowed by competition with existing vegetation. Moreover, years of high seed production were generally correlated among species, but not correlated with the availability of suitable microsites, implying that seedling competition and the interaction between seed and microsite limitation will further constrain recruitment. However, the nature of microsite limitation varied strongly between treeline and low-elevation species due to differing responses to snowpack duration and. competition, suggesting that treeline species may be quicker to shift their ranges in response to warming than low-elevation species. In all, our results demonstrate that seed and microsite limitation will likely result in lagged responses to climate change but with differences among species leading to complex range shift dynamics.

Monte Carlo Modeling of Sodium in Mercury's Exosphere During the First Two MESSENGER Flybys

NASA Technical Reports Server (NTRS)

Burger, Matthew H.; Killen, Rosemary M.; Vervack, Ronald J., Jr.; Bradley, E. Todd; McClintock, William E.; Sarantos, Menelaos; Benna, Mehdi; Mouawad, Nelly

2010-01-01

We present a Monte Carlo model of the distribution of neutral sodium in Mercury's exosphere and tail using data from the Mercury Atmospheric and Surface Composition Spectrometer (MASCS) on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft during the first two flybys of the planet in January and September 2008. We show that the dominant source mechanism for ejecting sodium from the surface is photon-stimulated desorption (PSD) and that the desorption rate is limited by the diffusion rate of sodium from the interior of grains in the regolith to the topmost few monolayers where PSD is effective. In the absence of ion precipitation, we find that the sodium source rate is limited to approximately 10(exp 6) - 10(exp 7) per square centimeter per second, depending on the sticking efficiency of exospheric sodium that returns to the surface. The diffusion rate must be at least a factor of 5 higher in regions of ion precipitation to explain the MASCS observations during the second MESSENGER f1yby. We estimate that impact vaporization of micrometeoroids may provide up to 15% of the total sodium source rate in the regions observed. Although sputtering by precipitating ions was found not to be a significant source of sodium during the MESSENGER flybys, ion precipitation is responsible for increasing the source rate at high latitudes through ion-enhanced diffusion.

Improvements in an in vivo neutron activation analysis (NAA) method for the measurement of fluorine in human bone.

PubMed

Mostafaei, F; McNeill, F E; Chettle, D R; Prestwich, W V

2013-10-01

We previously published a method for the in vivo measurement of bone fluoride using neutron activation analysis (NAA) and demonstrated the utility of the technique in a pilot study of environmentally exposed people. The method involved activation of the hand in an irradiation cavity at the McMaster University Accelerator Laboratory and acquisition of the resultant γ-ray signals in a '4π' NaI(Tl) detector array of nine detectors. In this paper we describe a series of improvements to the method. This was investigated via measurement of hand simulating phantoms doped with varying levels of fluorine and fixed amounts of sodium, chlorine and calcium. Four improvements to the technique were tested since our first publication. The previously published detection limit for phantom measurements using this system was 0.66 mg F/g Ca. The accelerator irradiation and detection facilities were relocated to a new section of the laboratory and one more detector was added to the detection system. This was found to reduce the detection limit (possibly because of better detection shielding and additional detector) to 0.59 mg F/g Ca, a factor of 1.12. A new set of phantoms was developed and in this work we show that they improved the minimum detectable limit for fluoride in phantoms irradiated using neutrons produced by 2.15 MeV protons on lithium by a factor of 1.55. We compared the detection limits previously obtained using a summed signal from the nine detectors with the detection limit obtained by acquiring the spectra in anticoincidence mode for reduction of the disturbing signal from chlorine in bone. This was found to improve the ratio of the detection of fluorine to chlorine (an interfering signal) by a factor of 2.8 and the resultant minimum detection limit was found to be reduced by a factor of 1.2. We studied the effects of changing the timing of γ-ray acquisition. Our previously published data used a series of three 10 s acquisitions followed by a 300 s count. Changing the acquisition to a series of six 5 s acquisitions was found to further improve the detection limit by a factor of 1.4. We also present data showing that if the neutron dose is delivered to the phantom in a shorter time period, i.e. the dose rate is increased and irradiation shortened then the detection limit can be reduced by a further factor of 1.35.The overall improvement in detection limit by employing all of these changes was found to be a factor of 3.9. The technique now has an in phantom detection limit of 0.17 mg F/g Ca compared to a previous detection limit of 0.66 mg F/g Ca. The system can now be tested on human volunteers to see if individuals with diagnosed fluorosis can be distinguished from the general Canadian population using this technique.

Investigation of Near Shannon Limit Coding Schemes

NASA Technical Reports Server (NTRS)

Kwatra, S. C.; Kim, J.; Mo, Fan

1999-01-01

Turbo codes can deliver performance that is very close to the Shannon limit. This report investigates algorithms for convolutional turbo codes and block turbo codes. Both coding schemes can achieve performance near Shannon limit. The performance of the schemes is obtained using computer simulations. There are three sections in this report. First section is the introduction. The fundamental knowledge about coding, block coding and convolutional coding is discussed. In the second section, the basic concepts of convolutional turbo codes are introduced and the performance of turbo codes, especially high rate turbo codes, is provided from the simulation results. After introducing all the parameters that help turbo codes achieve such a good performance, it is concluded that output weight distribution should be the main consideration in designing turbo codes. Based on the output weight distribution, the performance bounds for turbo codes are given. Then, the relationships between the output weight distribution and the factors like generator polynomial, interleaver and puncturing pattern are examined. The criterion for the best selection of system components is provided. The puncturing pattern algorithm is discussed in detail. Different puncturing patterns are compared for each high rate. For most of the high rate codes, the puncturing pattern does not show any significant effect on the code performance if pseudo - random interleaver is used in the system. For some special rate codes with poor performance, an alternative puncturing algorithm is designed which restores their performance close to the Shannon limit. Finally, in section three, for iterative decoding of block codes, the method of building trellis for block codes, the structure of the iterative decoding system and the calculation of extrinsic values are discussed.

Hydrolytic stability of biomolecules at high temperatures and its implication for life at 250 °C

NASA Astrophysics Data System (ADS)

White, Robert H.

1984-08-01

The upper temperature at which a living system can exist is limited by the hydrolytic breakdown rate of its chemical constituents. The peptide bonds of proteins, the phosphodiester and N-glycosyl bonds in RNA and DNA, and the pyrophosphate and N-glycosyl bonds in nucleotides such as ATP and NAD are among the more important bonds that will undergo hydrolysis. The decomposition of biomolecules via non-hydrolytic pathways such as decarboxylations and dehydrations may also be critical factors in determining this upper temperature limit. Baross and Deming1 recently reported `black smoker' bacteria, which they isolated from deep-sea hydrothermal vents, growing at 250 °C. Here I have attempted to establish the rates for the hydrolysis and/or decomposition of critical biomolecules to determine their ability to exist at this temperature. My results clearly indicate that if these organisms exist, and if their metabolic reactions occur in an aqueous environment, they could not survive at this temperature if they were composed of biomolecules such as proteins and nucleic acids, due to the very rapid rate of decomposition of such molecules.

A transversal pilot study of oropharyngeal carriage of Kingella kingae in healthy children younger than 6 months.

PubMed

Spyropoulou, Vasiliki; Brändle, Gabriel; Maggio, Albane Bertha Rosa; Anderson Della Llana, Rebecca; Cherkaoui, Abdessalam; Renzi, Gesuele; Schrenzel, Jacques; Manzano, Sergio; Ceroni, Dimitri

2017-12-01

The aim of this pilot study was to investigate the extent of oropharyngeal Kingella kingae carriage during the first 6 months of life. We conducted a monocentric transversal pilot study on healthy children younger than 6 months in order to define the oropharyngeal carriage rate. Participants were recruited between December 2013 and September 2015 among children without symptoms or signs of invasive infections. We demonstrated an oropharyngeal carriage rate of 0.67% in children younger than 6 months. Due to the really low carriage rate, it was not possible to draw statistically significant conclusion about any other characteristic of our population. The present study suggests that the oropharyngeal carriage of Kingella kingae among a Swiss population of healthy infants younger than 6 months is exceptional. The scarcity of colonization and disease in the early months of life suggests thus that defense against mucosal carriage and invasive infection is above all provided by vertically acquired immunity. Limited exposure of the neonates due to limited social contacts may also represent another factor avoiding neonates' mucosal Kingella kingae carriage.

Increased Toxicity of Karenia brevis during Phosphate Limited Growth: Ecological and Evolutionary Implications

PubMed Central

Hardison, Donnie Ransom; Sunda, William G.; Shea, Damian; Litaker, Richard Wayne

2013-01-01

Karenia brevis is the dominant toxic red tide algal species in the Gulf of Mexico. It produces potent neurotoxins (brevetoxins [PbTxs]), which negatively impact human and animal health, local economies, and ecosystem function. Field measurements have shown that cellular brevetoxin contents vary from 1–68 pg/cell but the source of this variability is uncertain. Increases in cellular toxicity caused by nutrient-limitation and inter-strain differences have been observed in many algal species. This study examined the effect of P-limitation of growth rate on cellular toxin concentrations in five Karenia brevis strains from different geographic locations. Phosphorous was selected because of evidence for regional P-limitation of algal growth in the Gulf of Mexico. Depending on the isolate, P-limited cells had 2.3- to 7.3-fold higher PbTx per cell than P-replete cells. The percent of cellular carbon associated with brevetoxins (%C-PbTx) was ∼ 0.7 to 2.1% in P-replete cells, but increased to 1.6–5% under P-limitation. Because PbTxs are potent anti-grazing compounds, this increased investment in PbTxs should enhance cellular survival during periods of nutrient-limited growth. The %C-PbTx was inversely related to the specific growth rate in both the nutrient-replete and P-limited cultures of all strains. This inverse relationship is consistent with an evolutionary tradeoff between carbon investment in PbTxs and other grazing defenses, and C investment in growth and reproduction. In aquatic environments where nutrient supply and grazing pressure often vary on different temporal and spatial scales, this tradeoff would be selectively advantageous as it would result in increased net population growth rates. The variation in PbTx/cell values observed in this study can account for the range of values observed in the field, including the highest values, which are not observed under N-limitation. These results suggest P-limitation is an important factor regulating cellular toxicity and adverse impacts during at least some K. brevis blooms. PMID:23554901

Optical design considerations when imaging the fundus with an adaptive optics correction

NASA Astrophysics Data System (ADS)

Wang, Weiwei; Campbell, Melanie C. W.; Kisilak, Marsha L.; Boyd, Shelley R.

2008-06-01

Adaptive Optics (AO) technology has been used in confocal scanning laser ophthalmoscopes (CSLO) which are analogous to confocal scanning laser microscopes (CSLM) with advantages of real-time imaging, increased image contrast, a resistance to image degradation by scattered light, and improved optical sectioning. With AO, the instrumenteye system can have low enough aberrations for the optical quality to be limited primarily by diffraction. Diffraction-limited, high resolution imaging would be beneficial in the understanding and early detection of eye diseases such as diabetic retinopathy. However, to maintain diffraction-limited imaging, sufficient pixel sampling over the field of view is required, resulting in the need for increased data acquisition rates for larger fields. Imaging over smaller fields may be a disadvantage with clinical subjects because of fixation instability and the need to examine larger areas of the retina. Reduction in field size also reduces the amount of light sampled per pixel, increasing photon noise. For these reasons, we considered an instrument design with a larger field of view. When choosing scanners to be used in an AOCSLO, the ideal frame rate should be above the flicker fusion rate for the human observer and would also allow user control of targets projected onto the retina. In our AOCSLO design, we have studied the tradeoffs between field size, frame rate and factors affecting resolution. We will outline optical approaches to overcome some of these tradeoffs and still allow detection of the earliest changes in the fundus in diabetic retinopathy.

Does phosphate enhance the natural attenuation of crude oil in groundwater under defined redox conditions?

PubMed

Ponsin, Violaine; Mouloubou, Olsen Raïnness; Prudent, Pascale; Höhener, Patrick

2014-11-15

After a crude oil spill caused by a broken pipeline in 2009 to a gravel aquifer in southern France, degradation processes under various redox conditions progressively established, but at rates that predict a long life-time of the source under natural attenuation after partial source removal. In this study, we aimed at identifying the rate-limiting factors for each redox condition, with special emphasis on phosphate as limiting nutrient. The study was conducted in laboratory microcosms assembled with material collected on site: sediments, water from monitoring wells, oil and microbial sludge. Redox conditions were promoted by adding electron acceptors (either oxygen, nitrate, limonite (FeO(OH)), cryptomelane (K(Mn(4+),Mn(2+))8O16), or sulfate). For each condition, the role of phosphate was studied by repeated additions for up to 290days. The results showed a very strong stimulation of aerobic and denitrifying rates of oil degradation by phosphate, provided that oxygen and nitrate were repeatedly supplied. Phosphate caused also a marked stimulation of methanogenic degradation, and a relatively small stimulation of metal reduction. These anaerobic processes started only after marked lag phases, and phosphate shortened the lag phase for methanogenic degradation. Degradation of aromatic and aliphatic hydrocarbons with less than 8 carbons, including benzene, was confirmed even under unstimulated conditions. It is concluded that degradation rates at the site are limited by both, availability of electron acceptors and availability of phosphate needed for promoting microbial growth. Copyright © 2014 Elsevier B.V. All rights reserved.

14 CFR 23.337 - Limit maneuvering load factors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Limit maneuvering load factors. 23.337... Flight Loads § 23.337 Limit maneuvering load factors. (a) The positive limit maneuvering load factor n... airplanes; or (3) 6.0 for acrobatic category airplanes. (b) The negative limit maneuvering load factor may...

Identifying factors for optimal development of health-related websites: a delphi study among experts and potential future users.

PubMed

Schneider, Francine; van Osch, Liesbeth; de Vries, Hein

2012-02-14

The Internet has become a popular medium for offering tailored and targeted health promotion programs to the general public. However, suboptimal levels of program use in the target population limit the public health impact of these programs. Optimizing program development is considered as one of the main processes to increase usage rates. To distinguish factors potentially related to optimal development of health-related websites by involving both experts and potential users. By considering and incorporating the opinions of experts and potential users in the development process, involvement in the program is expected to increase, consequently resulting in increased appreciation, lower levels of attrition, and higher levels of sustained use. We conducted a systematic three-round Delphi study through the Internet. Both national and international experts (from the fields of health promotion, health psychology, e-communication, and technical Web design) and potential users were invited via email to participate. During this study an extensive list of factors potentially related to optimal development of health-related websites was identified, by focusing on factors related to layout, general and risk information provision, questionnaire use, additional services, and ease of use. Furthermore, we assessed the extent to which experts and potential users agreed on the importance of these factors. Differences as well as similarities among experts and potentials users were deduced. In total, 20 of 62 contacted experts participated in the first round (32% response rate); 60 of 200 contacted experts (30% response rate) and 210 potential users (95% response rate) completed the second-round questionnaire, and 32 of 60 contacted experts completed the third round (53% response rate). Results revealed important factors consented upon by experts and potential users (eg, ease of use, clear structure, and detailed health information provision), as well as differences regarding important factors consented upon by experts (eg, visual aids, self-monitoring tool, and iterative health feedback) or by potential users only (eg, bread crumb navigation and prevention of receiving spam). This study is an important first step in determining the agreed-upon factors that should be taken into account when developing online health promotion programs. The public health impact of these programs will be improved by optimizing the development process in line with these factors.

What drives interaction strengths in complex food webs? A test with feeding rates of a generalist stream predator.

PubMed

Preston, Daniel L; Henderson, Jeremy S; Falke, Landon P; Segui, Leah M; Layden, Tamara J; Novak, Mark

2018-05-08

Describing the mechanisms that drive variation in species interaction strengths is central to understanding, predicting, and managing community dynamics. Multiple factors have been linked to trophic interaction strength variation, including species densities, species traits, and abiotic factors. Yet most empirical tests of the relative roles of multiple mechanisms that drive variation have been limited to simplified experiments that may diverge from the dynamics of natural food webs. Here, we used a field-based observational approach to quantify the roles of prey density, predator density, predator-prey body-mass ratios, prey identity, and abiotic factors in driving variation in feeding rates of reticulate sculpin (Cottus perplexus). We combined data on over 6,000 predator-prey observations with prey identification time functions to estimate 289 prey-specific feeding rates at nine stream sites in Oregon. Feeding rates on 57 prey types showed an approximately log-normal distribution, with few strong and many weak interactions. Model selection indicated that prey density, followed by prey identity, were the two most important predictors of prey-specific sculpin feeding rates. Feeding rates showed a positive relationship with prey taxon densities that was inconsistent with predator saturation predicted by current functional response models. Feeding rates also exhibited four orders-of-magnitude in variation across prey taxonomic orders, with the lowest feeding rates observed on prey with significant anti-predator defenses. Body-mass ratios were the third most important predictor variable, showing a hump-shaped relationship with the highest feeding rates at intermediate ratios. Sculpin density was negatively correlated with feeding rates, consistent with the presence of intraspecific predator interference. Our results highlight how multiple co-occurring drivers shape trophic interactions in nature and underscore ways in which simplified experiments or reliance on scaling laws alone may lead to biased inferences about the structure and dynamics of species-rich food webs. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Physiotherapy, rehabilitation and sports in countries with limited replacement coagulation factor supply.

PubMed

Buzzard, B M

2007-09-01

It is well documented that physiotherapy and rehabilitation benefit people with haemophilia by strengthening the key muscle groups and protecting joints from the adverse effects of repeated haemorrhages. Rehabilitation, in conjunction with the availability of replacement coagulation factor products, has revolutionized approaches to the management of patients with haemophilia in developed countries and has led to a substantial decrease in both the morbidity and mortality rates among the haemophilic population. Modern treatment approaches have also enabled persons with haemophilia to participate in sporting activities along with their peers; however, these improvements in care have not been achieved in developing nations, where health-care resources and facilities are scarce and the supply of coagulation factor products is limited. This article attempts to address the following questions about the management of haemophilic patients in developing countries: Can physiotherapy, rehabilitation and sports prevent disabilities and preserve independence? Is participation in sports activities possible in developing countries? Do countries differ with regard to guidelines for participation in sports? Should we be encouraging participation in sports or allowing patients with haemophilia to do as they choose?

Musculoskeletal pain and limitations in work ability in Swedish marines: a cross-sectional survey of prevalence and associated factors

PubMed Central

Monnier, Andreas; Larsson, Helena; Djupsjöbacka, Mats; Brodin, Lars-Åke; Äng, Björn O

2015-01-01

Objectives To estimate the prevalence of self-rated musculoskeletal pain and pain limiting work ability in Swedish Armed Forces (SAF) marines, and to study factors potentially associated with pain limiting work ability for the most prevalent pain regions reported. Design Population-based, cross-sectional survey. Participants There were 272 SAF marines from the main marine battalion in Sweden included in the study. Outcomes Self-assessed musculoskeletal pain and pain limiting the marines' work ability within a 6-month period, as obtained from structured questionnaires. The association of individual, health and work-related factors with musculoskeletal pain limiting work ability was systematically regressed with multiple logistic models, estimating OR and 95% CI. Results Musculoskeletal pain and pain limiting work ability were most common in the back, at 46% and 20%, and lower extremities at 51% and 29%, respectively. Physical training ≤1 day/week (OR 5.3, 95% CI 1.7 to 16.8); body height ≤1.80 m (OR 5.0, 95% CI 1.6 to 15.1) and ≥1.86 m (OR 4.4, 95% CI 1.4 to 14.1); computer work 1/4 of the working day (OR 3.2, 95% CI 1.0 to 10.0) and ≥1/2 (OR 3.3, 95% CI 1.1 to 10.1) of the working day were independently associated with back pain limiting work ability. None of the studied variables emerged significantly associated with such pain for the lower extremities. Conclusions Our findings show that musculoskeletal pain and resultant limitations in work ability are common in SAF marines. Low frequency of physical training emerged independently associated with back pain limiting work ability. This suggests that marines performing physical training 1 day per week or less are suitable candidates for further medical evaluation and secondary preventive actions. While also associated, body height and computer work need further exploration as underlying mechanisms for back pain limiting work ability. Further prospective studies are necessary to clarify the direction of causality. PMID:26443649

The epidemiological characteristics of depressive symptoms in the left-behind children and adolescents of Chongqing in China.

PubMed

Wang, Lifei; Feng, Zhengzhi; Yang, Guoyu; Yang, Yaling; Dai, Qin; Hu, Chaobing; Liu, Keyu; Guang, Yu; Zhang, Rui; Xia, Fan; Zhao, Mengxue

2015-05-15

To assess the prevalence rate of depressive symptoms in left-behind participants aged 7-17 years and to explore the associated socio-demographic and communication factors. Participants were 4857 left-behind children and adolescents in Chongqing. They were screened for depressive symptoms using a 27-item Children׳s Depression Inventory (CDI) and social-demographic variables were evaluated with a structured scale. Uncorrected Pearson chi-square test and logistic regression were applied to analyzing the data. The total prevalence rate of depressive symptoms was 24.8%. Significant difference was found in the prevalence rate of depressive symptoms among groups of different income, grade, age, left-behind subtypes, and different frequency, ways and topics of parent-child communication. We found that the risk factors for depression were absence of parents, low frequency of parent-child communication, and communication by letter or about sensitive topics. The grade group 2-3 and age group 16-17 were at a higher risk of depression than all other grade and age subgroups. The protective factors for depression were high-income, high frequency of parent-child communication, communication by telephone or about such topic as learning experience, school life, and feelings. Self-report bias and cross-sectional nature of the sampling are major limitations of this study. The prevalence rate of depressive symptoms among left-behind children and adolescents in Chongqing is much higher than previously reported prevalence in other regions of China. The risk and protective factors for depression among left-behind children and adolescents are worthy of public attention. Copyright © 2015. Published by Elsevier B.V.

Method validation for the determination of ochratoxin A in green and soluble coffee by immunoaffinity column cleanup and liquid chromatography.

PubMed

Diaz, G J; Ariza, D; Perilla, N S

2004-06-01

A method was validated for the determination of ochratoxin A (OTA) in soluble and green coffee. Performance parameters evaluated included selectivity, accuracy, intermediate precision, linearity, limit of detection, limit of quantitation, and ruggedness. The method was found to be selective for OTA in both matrices tested. Recovery rates from soluble coffee samples ranged from 73.5 to 91.2%, and from green coffee samples from 68.7 to 84.5%. The intermediate precision (RSDr) was between 9.1 and 9.4% for soluble coffee and between 14.3 and 15.5% for green coffee analysis. The linearity of the standard calibration curve (r(2)) was <0.999 for OTA levels of 1.0-20.0 μg/kg in coffee samples. The limit of detection was determined to be 0.01 ng of OTA on column, while the limit of quantitation was found to be 0.03 ng on column. The limit of quantitation is equivalent to 0.6 μg/kg in soluble coffee samples and 0.3 μg/kg in green coffee samples. The results of the ruggedness trial showed two factors are critical for soluble coffee analysis: the extraction method, and the flow rate of the mobile phase. For green coffee analysis two critical factors detected were the extraction method and the storage temperature of the immunoaffinity column.Five samples of soluble coffee and 42 of green coffee were analysed using the validated method. All soluble coffee samples contained OTA at levels that ranged from 8.4 to 13.9 μg/kg. Six of the 42 green coffee samples analysed (14.3%) contained OTA at levels ranging from 0.9 to 19.4 μg/kg. The validated method can be used to monitor OTA levels in Colombian coffee for export or for local consumption.

Metabolic rates of giant pandas inform conservation strategies.

PubMed

Fei, Yuxiang; Hou, Rong; Spotila, James R; Paladino, Frank V; Qi, Dunwu; Zhang, Zhihe

2016-06-06

The giant panda is an icon of conservation and survived a large-scale bamboo die off in the 1980s in China. Captive breeding programs have produced a large population in zoos and efforts continue to reintroduce those animals into the wild. However, we lack sufficient knowledge of their physiological ecology to determine requirements for survival now and in the face of climate change. We measured resting and active metabolic rates of giant pandas in order to determine if current bamboo resources were sufficient for adding additional animals to populations in natural reserves. Resting metabolic rates were somewhat below average for a panda sized mammal and active metabolic rates were in the normal range. Pandas do not have exceptionally low metabolic rates. Nevertheless, there is enough bamboo in natural reserves to support both natural populations and large numbers of reintroduced pandas. Bamboo will not be the limiting factor in successful reintroduction.

Nondimensional scaling of magnetorheological rotary shear mode devices using the Mason number

NASA Astrophysics Data System (ADS)

Becnel, Andrew C.; Sherman, Stephen; Hu, Wei; Wereley, Norman M.

2015-04-01

Magnetorheological fluids (MRFs) exhibit rapidly adjustable viscosity in the presence of a magnetic field, and are increasingly used in adaptive shock absorbers for high speed impacts, corresponding to high fluid shear rates. However, the MRF properties are typically measured at very low (γ ˙<1000 s-1) shear rates due to limited commercial rheometer capabilities. A custom high shear rate (γ ˙>10,000 s-1) Searle cell magnetorheometer, along with a full scale rotary-vane magnetorheological energy absorber (γ ˙>25,000 s-1) are employed to analyze MRF property scaling across shear rates using a nondimensional Mason number to generate an MRF master curve. Incorporating a Reynolds temperature correction factor, data from both experiments is shown to collapse to a single master curve, supporting the use of Mason number to correlate low- and high-shear rate characterization data.

Metabolic rates of giant pandas inform conservation strategies

NASA Astrophysics Data System (ADS)

Fei, Yuxiang; Hou, Rong; Spotila, James R.; Paladino, Frank V.; Qi, Dunwu; Zhang, Zhihe

2016-06-01

The giant panda is an icon of conservation and survived a large-scale bamboo die off in the 1980s in China. Captive breeding programs have produced a large population in zoos and efforts continue to reintroduce those animals into the wild. However, we lack sufficient knowledge of their physiological ecology to determine requirements for survival now and in the face of climate change. We measured resting and active metabolic rates of giant pandas in order to determine if current bamboo resources were sufficient for adding additional animals to populations in natural reserves. Resting metabolic rates were somewhat below average for a panda sized mammal and active metabolic rates were in the normal range. Pandas do not have exceptionally low metabolic rates. Nevertheless, there is enough bamboo in natural reserves to support both natural populations and large numbers of reintroduced pandas. Bamboo will not be the limiting factor in successful reintroduction.

Metabolic rates of giant pandas inform conservation strategies

PubMed Central

Fei, Yuxiang; Hou, Rong; Spotila, James R.; Paladino, Frank V.; Qi, Dunwu; Zhang, Zhihe

2016-01-01

The giant panda is an icon of conservation and survived a large-scale bamboo die off in the 1980s in China. Captive breeding programs have produced a large population in zoos and efforts continue to reintroduce those animals into the wild. However, we lack sufficient knowledge of their physiological ecology to determine requirements for survival now and in the face of climate change. We measured resting and active metabolic rates of giant pandas in order to determine if current bamboo resources were sufficient for adding additional animals to populations in natural reserves. Resting metabolic rates were somewhat below average for a panda sized mammal and active metabolic rates were in the normal range. Pandas do not have exceptionally low metabolic rates. Nevertheless, there is enough bamboo in natural reserves to support both natural populations and large numbers of reintroduced pandas. Bamboo will not be the limiting factor in successful reintroduction. PMID:27264109

The study on the outsourcing of Taiwan's hospitals: a questionnaire survey research

PubMed Central

Hsiao, Chih-Tung; Pai, Jar-Yuan; Chiu, Hero

2009-01-01

Background The aim of this study was to assess the outsourcing situation in Taiwanese hospitals and compares the differences in hospital ownership and in accreditation levels. Methods This research combined two kinds of methods: a questionnaire survey and the in-depth interview to two CEOs of the sample hospitals. One hospital is not-for-profit, while the other is a public hospital and the research samples are from the hospital data from Taiwan's 2005 to 2007 Department of Health qualifying lists of hospital accreditation. The returned questionnaires were analyzed with STATISTICA® 7.1 version software. Results The results for non-medical items showed medical waste and common trash both have the highest rate (94.6 percent) of being outsourced. The gift store (75 percent) and linen (73 percent) follow close behind, while the lowest rate of outsourcing is in utility maintenance (13.5 percent). For medical items, the highest rate of outsourcing is in the ambulance units (51.4 percent), while the hemodialysis center follows close behind with a rate of 50 percent. For departments of nutrition, pharmacy, and nursing however, the outsourcing rate is lower than 3 percent. This shows that Taiwan's hospitals are still conservative in their willingness to outsource for medical items. The results of the satisfaction paired t-test show that the non-medical items have a higher score than the medical items. The factor analysis showed the three significant factors in of non medical items' outsourcing are "performance", "finance", and "human resource". For medical items, the two factors are "operation" and satisfaction". To further exam the factor validity and reliability of the satisfaction model, a confirmative factor analysis (CFA) was conducted using structure equation modeling (SEM) method and found the model fitting well. Conclusion Hospitals, especially for public hospitals, can get benefits from outsourcing to revive the full-time-equivalent and human resource limitation. PMID:19435526

The study on the outsourcing of Taiwan's hospitals: a questionnaire survey research.

PubMed

Hsiao, Chih-Tung; Pai, Jar-Yuan; Chiu, Hero

2009-05-13

The aim of this study was to assess the outsourcing situation in Taiwanese hospitals and compares the differences in hospital ownership and in accreditation levels. This research combined two kinds of methods: a questionnaire survey and the in-depth interview to two CEOs of the sample hospitals. One hospital is not-for-profit, while the other is a public hospital and the research samples are from the hospital data from Taiwan's 2005 to 2007 Department of Health qualifying lists of hospital accreditation. The returned questionnaires were analyzed with STATISTICA 7.1 version software. The results for non-medical items showed medical waste and common trash both have the highest rate (94.6 percent) of being outsourced. The gift store (75 percent) and linen (73 percent) follow close behind, while the lowest rate of outsourcing is in utility maintenance (13.5 percent). For medical items, the highest rate of outsourcing is in the ambulance units (51.4 percent), while the hemodialysis center follows close behind with a rate of 50 percent. For departments of nutrition, pharmacy, and nursing however, the outsourcing rate is lower than 3 percent. This shows that Taiwan's hospitals are still conservative in their willingness to outsource for medical items. The results of the satisfaction paired t-test show that the non-medical items have a higher score than the medical items. The factor analysis showed the three significant factors in of non medical items' outsourcing are "performance", "finance", and "human resource". For medical items, the two factors are "operation" and satisfaction". To further exam the factor validity and reliability of the satisfaction model, a confirmative factor analysis (CFA) was conducted using structure equation modeling (SEM) method and found the model fitting well. Hospitals, especially for public hospitals, can get benefits from outsourcing to revive the full-time-equivalent and human resource limitation.

Radiotherapy in the treatment of solitary plasmacytoma.

PubMed

Jyothirmayi, R; Gangadharan, V P; Nair, M K; Rajan, B

1997-05-01

Solitary plasmacytoma of bone (SPB) and extramedullary plasmacytoma (EMP) are rare. High local control rates are reported with radiotherapy, although the optimal dose and extent of radiotherapy portals remains controversial. Between 1983 and 1993, 30 patients with solitary plasmacytoma were seen at the Regional Cancer Centre, Trivandrum, India. 23 patients had SPB and seven EMP. The mean age was 52 years and the male to female ratio 3.2:1. Diagnosis of SPB was confirmed by biopsy in 16 patients and tumour excision in seven. 20 patients received megavoltage radiotherapy to the bone lesion with limited margins, and one received chemotherapy. Two patients who underwent complete tumour excision received no further treatment. All seven patients with EMP received megavoltage radiotherapy, four following biopsy and three after tumour excision. Local control was achieved in all patients with SPB. Nine progressed to multiple myeloma and one developed a solitary plasmacytoma in another bone. Six patients with EMP achieved local control. Three later progressed to multiple myeloma and one had local relapse. Median time to relapse was 28 months in SPB and 30 months in EMP. 5-year overall survival rates were 82% and 57% for patients with SPB and EMP, respectively. The corresponding progression free survival rates were 55% and 50%, respectively. Age, sex, site of tumour, serum M protein and haemoglobin levels did not significantly influence progression free survival. The extent of surgery, radiotherapy dose or time to relapse were not significant prognostic factors. Radiotherapy appears to be an effective modality of treatment of solitary plasmacytoma. No dose-response relationship is observed, and high local control rates are achieved with limited portals. Progression to multiple myeloma is the commonest pattern of failure, although no prognostic factors for progression are identified. The role of chemotherapy in preventing disease progression needs further evaluation.

The learning curve to achieve satisfactory completion rates in upper GI endoscopy: an analysis of a national training database.

PubMed

Ward, S T; Hancox, A; Mohammed, M A; Ismail, T; Griffiths, E A; Valori, R; Dunckley, P

2017-06-01

The aim of this study was to determine the number of OGDs (oesophago-gastro-duodenoscopies) trainees need to perform to acquire competency in terms of successful unassisted completion to the second part of the duodenum 95% of the time. OGD data were retrieved from the trainee e-portfolio developed by the Joint Advisory Group on GI Endoscopy (JAG) in the UK. All trainees were included unless they were known to have a baseline experience of >20 procedures or had submitted data for <20 procedures. The primary outcome measure was OGD completion, defined as passage of the endoscope to the second part of the duodenum without physical assistance. The number of OGDs required to achieve a 95% completion rate was calculated by the moving average method and learning curve cumulative summation (LC-Cusum) analysis. To determine which factors were independently associated with OGD completion, a mixed effects logistic regression model was constructed with OGD completion as the outcome variable. Data were analysed for 1255 trainees over 288 centres, representing 243 555 OGDs. By moving average method, trainees attained a 95% completion rate at 187 procedures. By LC-Cusum analysis, after 200 procedures, >90% trainees had attained a 95% completion rate. Total number of OGDs performed, trainee age and experience in lower GI endoscopy were factors independently associated with OGD completion. There are limited published data on the OGD learning curve. This is the largest study to date analysing the learning curve for competency acquisition. The JAG competency requirement for 200 procedures appears appropriate. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

New South Wales annual vaccine-preventable disease report, 2013.

PubMed

Rosewell, Alexander; Spokes, Paula; Gilmour, Robin

2015-01-01

To describe the epidemiology of selected vaccine-preventable diseases in New South Wales, Australia for 2013. Data from the New South Wales Notifiable Conditions Information Management System were analysed by local health district of residence, age, Aboriginality, vaccination status and organism. Risk factor and vaccination status data were collected by public health units. Pertussis notification rates in infants were low, and no infant pertussis deaths were reported. Despite a high number of imported measles cases, there was limited secondary transmission. The invasive meningococcal disease notification rate declined, and disease due to serogroup C remained low and stable. Vaccine-preventable diseases were relatively well controlled in New South Wales in 2013, with declining or stable notification rates in most diseases compared with the previous year.

Evaluation of the DSM-5 severity ratings for anorexia nervosa in a clinical sample.

PubMed

Dakanalis, Antonios; Alix Timko, C; Colmegna, Fabrizia; Riva, Giuseppe; Clerici, Massimo

2018-04-01

We examined the validity and utility of the DSM-5 severity ratings for anorexia nervosa (AN) in a clinical (treatment-seeking) sample (N = 273; 95.6% women). Participants classified with mild, moderate, severe, and extreme severity of AN based on their measured body mass index, differed significantly from each other in eating disorder features, putative maintenance factors, and illness-specific functional impairment (medium effect sizes). However, they were statistically indistinguishable in psychiatric-disorder comorbidity and distress, demographics, and age-of-AN onset. The implications of our findings, providing limited support for the DSM-5 severity ratings for AN, and directions for future research are outlined. Copyright © 2018 Elsevier B.V. All rights reserved.

Scan-rate and vacuum pressure dependence of the nucleation and growth dynamics in a spin-crossover single crystal: the role of latent heat.

PubMed

Ridier, Karl; Rat, Sylvain; Salmon, Lionel; Nicolazzi, William; Molnár, Gábor; Bousseksou, Azzedine

2018-04-04

Using optical microscopy we studied the vacuum pressure dependence (0.1-1000 mbar) of the nucleation and growth dynamics of the thermally induced first-order spin transition in a single crystal of the spin-crossover compound [Fe(HB(tz)3)2] (tz = 1,2,4-triazol-1-yl). A crossover between a quasi-static hysteresis regime and a temperature-scan-rate-dependent kinetic regime is evidenced around 5 mbar due to the change of the heat exchange coupling between the crystal and its external environment. Remarkably, the absorption/dissipation rate of latent heat was identified as the key factor limiting the switching speed of the crystal.

Using the Tax System to Promote Physical Activity: Critical Analysis of Canadian Initiatives

PubMed Central

Larre, Tamara; Sauder, JoAnne

2011-01-01

In Canada, tax incentives have been recently introduced to promote physical activity and reduce rates of obesity. The most prominent of these is the federal government's Children's Fitness Tax Credit, which came into effect in 2007. We critically assess the potential benefits and limitations of using tax measures to promote physical activity. Careful design could make these measures more effective, but any tax-based measures have inherent limitations, and the costs of such programs are substantial. Therefore, it is important to consider whether public funds are better spent on other strategies that could instead provide direct public funding to address environmental and systemic factors. PMID:21680912

Using the tax system to promote physical activity: critical analysis of Canadian initiatives.

PubMed

von Tigerstrom, Barbara; Larre, Tamara; Sauder, Joanne

2011-08-01

In Canada, tax incentives have been recently introduced to promote physical activity and reduce rates of obesity. The most prominent of these is the federal government's Children's Fitness Tax Credit, which came into effect in 2007. We critically assess the potential benefits and limitations of using tax measures to promote physical activity. Careful design could make these measures more effective, but any tax-based measures have inherent limitations, and the costs of such programs are substantial. Therefore, it is important to consider whether public funds are better spent on other strategies that could instead provide direct public funding to address environmental and systemic factors.

Landslides and rock fall processes in the proglacial area of the Gepatsch glacier, Tyrol, Austria - Quantitative assessment of controlling factors and process rates

NASA Astrophysics Data System (ADS)

Vehling, Lucas; Rohn, Joachim; Moser, Michael

2013-04-01

Due to the rapid deglaciation since 1850, lithological structures and topoclimatic factors, mass movements like rock fall, landslides and complex processes are important contributing factors to sediment transport and modification of the earth's surface in the steep, high mountain catchment of the Gepatsch reservoir. Contemporary geotechnical processes, mass movement deposits, their source areas, and controlling factors like material properties and relief parameters are mapped in the field, on Orthofotos and on digital elevation models. The results are presented in an Arc-Gis based geotechnical map. All mapped mass movements are stored in an Arc-Gis geodatabase and can be queried regarding properties, volume and controlling factors, so that statistical analyses can be conducted. The assessment of rock wall retreat rates is carried out by three different methods in multiple locations, which differ in altitude, exposition, lithology and deglaciation time: Firstly, rock fall processes and rates are investigated in detail on five rock fall collector nets with an overall size of 750 m2. Rock fall particles are gathered, weighed and grain size distribution is detected by sieving and measuring the diameter of the particles to distinct between rock fall processes and magnitudes. Rock wall erosion processes like joint formation and expansions are measured with high temporal resolution by electrical crack meters, together with rock- and air temperature. Secondly, in cooperation with the other working groups in the PROSA project, rock fall volumes are determined with multitemporal terrestrial laserscanning from several locations. Lately, already triggered rock falls are accounted by mapping the volume of the deposit and calculating of the bedrock source area. The deposition time span is fixed by consideration of the late Holocene lateral moraines and analysing historical aerial photographs, so that longer term rock wall retreat rates can be calculated. In order to limit homogenous bedrock sections for calculating specific rock wall retreat rates and to extrapolate the local determinated rock wall retreat rates to larger scale, bedrock areas will be divided into units of similar morphodynamic intensities which will be therefore classified by a rock mass strength (RMS) system. The RMS-System contains lithological and topoclimatic factors but also takes the measured rock wall retreat rates into account.

Recruitment strategies should not be randomly selected: empirically improving recruitment success and diversity in developmental psychology research

PubMed Central

Sugden, Nicole A.; Moulson, Margaret C.

2015-01-01

Psychological and developmental research have been critiqued for the lack of diversity of research samples. Because differences in culture, race, and ethnicity can influence participant behavior, limited diversity limits the generalizability of the findings. These differences may also impact how participants behave in response to recruitment attempts, which suggests that recruitment itself may be leveraged to increase sample diversity. The goal of the current study was to determine what factors, within a recruitment interaction, could be leveraged to increase success and diversity when recruiting families with children for developmental research. Study 1 found three factors influenced success: (1) recruitment was more successful when other potential participants were also interested (i.e., recruiters were busy), (2) recruiters of particular races were more successful than recruiters of other races, and (3) differences in success were related to what the recruiter said to engage the potential participant (i.e., the script). The latter two factors interacted, suggesting some recruiters were using less optimal scripts. To improve success rates, study 2 randomly assigned scripts to recruiters and encouraged them to recruit more vigorously during busy periods. Study 2 found that two factors influenced success: (1) some scripts were more successful than others and (2) we were more successful at recruiting non-White potential participants than White participants. These two interacted, with some scripts being more successful with White and other scripts being more successful with non-White families. This intervention significantly increased recruitment success rate by 8.1% and the overall number of families recruited by 15.3%. These findings reveal that empirically evaluating and tailoring recruitment efforts based on the most successful strategies is effective in boosting diversity through increased participation of children from non-White families. PMID:25972829

Public knowledge and beliefs about depression among urban and rural Chinese in Malaysia.

PubMed

Loo, Phik-Wern; Furnham, Adrian

2012-09-01

The study compared knowledge and beliefs about depression among urban and rural Chinese in a Malaysian sample. A total of 409 participants were asked to identify cases of depression varying in intensity from two vignettes and rate their beliefs regarding a list of possible causes and treatments for depression. The urban Chinese were more likely to identify depression as the problem in the vignette. Beliefs about causes of depression were factored into five components, whereas beliefs about treatment for depression factored into four components. The results indicated that the causes most strongly endorsed were stress and pressure, and standard treatments rated the highest as treatments for depression. Overall, depression literacy was moderate for Chinese Malaysians. The results are discussed in relation to Chinese cultural beliefs about depression. Limitations of this preliminary study were acknowledged. Copyright © 2012 Elsevier B.V. All rights reserved.

Factors affecting recruitment and participation of bereaved parents and siblings in grief research.

PubMed

Akard, Terrah Foster; Gilmer, Mary Jo; Miller, Katy; Steele, Amii Corbisiero; Hancock, Kelly; Barrera, Maru; Compas, Bruce; Davies, Betty; Dietrich, Mary S; Fairclough, Diane L; Hogan, Nancy S; Vannatta, Kathryn; Gerhardt, Cynthia A

2014-04-01

This study examined participation factors in a study of families ( N  = 84) within 1 year of a child's cancer-related death. Specific aims were to examine associations between: (a) recruitment variables (number of phone calls made to eligible families, number of calls answered by eligible families) and participation rates (study agreement and refusal) and (b) characteristics of deceased children (gender, age, length of illness, time since death) and participation rates. Characteristics of deceased children did not differ between participating and non-participating families. Researchers made significantly fewer calls to participating versus refusing families. Participating families most often agreed during the first successful call connection, and more calls did not mean more recruitment success. Thus, it is reasonable to limit the number of calls made to bereaved families. Despite recruitment challenges, many bereaved parents and siblings are willing and interested to participate in grief research.

Elastic interactions between single microcrack and single osteon microstructure of human femur cortical bone

NASA Astrophysics Data System (ADS)

Mansor, N. N.; Daud, R.; Basaruddin, K. S.; Mat, F.; Bajuri, Y.; Ariffin, A. K.

2017-09-01

Inmultiscale Haversian system of cortical bone fracture, a homogenous bone modeling consideration is limited to only one Young modulus was significant for each cortex without having any constituents in that bone. A two dimension model of human femur cortical bone is presented by considering the anatomical positions of four cortices, e.g anterior, posterior, medial and lateral. The Haversian system is modeled under tensile loading by considering the interstitial matrix, osteon and cement line mechanical properties. The interaction between single microcrack and single osteon is evaluated using linear elastic fracture mechanics theory, and was determined using of stress intensity factor, strain energy release rate, and the critical stress intensity factor and critical strain energy release rate parameter. The results indicate that the medial cortex has the highest SIFs while the lowest was posterior cortex. The Young modulus of material was greatly influence the fracture parameters. More stiff the material, the SIF was reduced.

Sociocultural Influences on Arab Women's Participation in Breast Cancer Screening in Qatar.

PubMed

Hwang, Jasmine J; Donnelly, Tam T; Ewashen, Carol; McKiel, Elaine; Raffin, Shelley; Kinch, Janice

2017-04-01

Breast cancer, the most common cancer among Arab women in Qatar, significantly affects the morbidity and mortality of Arab women largely because of low participation rates in breast cancer screening. We used a critical ethnographic approach to uncover and describe factors that influence Arab women's breast cancer screening practices. We conducted semistructured interviews with 15 health care practitioners in Qatar. Through thematic analysis of the data, we found three major factors influencing breast cancer screening practices: (a) beliefs, attitudes, and practices regarding women's bodies, health, and illness; (b) religious beliefs and a culturally sensitive health care structure; and (c) culturally specific gender relations and roles. Arab women's health practices cannot be understood in isolation from the sociocultural environment. The problem of low rates of breast cancer screening practices and supportive interventions must be addressed within the context and not be limited to the individual.

Mathematical modeling of hydrolysate diffusion and utilization in cellulolytic biofilms of the extreme thermophile Caldicellulosiruptor obsidiansis.

PubMed

Wang, Zhi-Wu; Hamilton-Brehm, Scott D; Lochner, Adriane; Elkins, James G; Morrell-Falvey, Jennifer L

2011-02-01

In this study, a hydrolysate diffusion and utilization model was developed to examine factors influencing cellulolytic biofilm morphology. Model simulations using Caldicellulosiruptor obsidiansis revealed that the cellulolytic biofilm needs to generate more hydrolysate than it consumes to establish a higher than bulk solution intra-biofilm substrate concentration to support its growth. This produces a hydrolysate surplus that diffuses through the thin biofilm structure into the bulk solution, which gives rise to a uniform growth rate and hence the homogeneous morphology of the cellulolytic biofilm. Model predictions were tested against experimental data from a cellulose-fermenting bioreactor and the results were consistent with the model prediction and indicated that only a small fraction (10-12%) of the soluble hydrolysis products are utilized by the biofilm. The factors determining the rate-limiting step of cellulolytic biofilm growth are also analyzed and discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Energy transfer and kinetics in mechanochemistry.

PubMed

Chen, Zhiliang; Lu, Shengyong; Mao, Qiongjing; Buekens, Alfons; Wang, Yuting; Yan, Jianhua

2017-11-01

Mechanochemistry (MC) exerts extraordinary degradation and decomposition effects on many chlorinated, brominated, and even fluorinated persistent organic pollutants (POPs). However, its application is still limited by inadequate study of its reaction kinetic aspects. In the present work, the ball motion and energy transfer in planetary ball mill are investigated in some detail. Almost all milling parameters are summarised in a single factor-total effective impact energy. Furthermore, the MC kinetic between calcium oxide/Al and hexachlorobenzene is well established and modelled. The results indicate that total effective impact energy and reagent ratio are the two factors sufficient for describing the MC degradation degree of POPs. The reaction rate constant only depends on the chemical properties of reactants, so it could be used as an important index to appraise the quality of MC additives. This model successfully predicts the reaction rate for different operating conditions, indicating that it could be suitably applied for conducting MC reactions in other reactors.

Calibration factors for the SNOOPY NP-100 neutron dosimeter

NASA Astrophysics Data System (ADS)

Moscu, D. F.; McNeill, F. E.; Chase, J.

2007-10-01

Within CANDU nuclear power facilities, only a small fraction of workers are exposed to neutron radiation. For these individuals, roughly 4.5% of the total radiation equivalent dose is the result of exposure to neutrons. When this figure is considered across all workers receiving external exposure of any kind, only 0.25% of the total radiation equivalent dose is the result of exposure to neutrons. At many facilities, the NP-100 neutron dosimeter, manufactured by Canberra Industries Incorporated, is employed in both direct and indirect dosimetry methods. Also known as "SNOOPY", these detectors undergo calibration, which results in a calibration factor relating the neutron count rate to the ambient dose equivalent rate, using a standard Am-Be neutron source. Using measurements presented in a technical note, readings from the dosimeter for six different neutron fields in six source-detector orientations were used, to determine a calibration factor for each of these sources. The calibration factor depends on the neutron energy spectrum and the radiation weighting factor to link neutron fluence to equivalent dose. Although the neutron energy spectra measured in the CANDU workplace are quite different than that of the Am-Be calibration source, the calibration factor remains constant - within acceptable limits - regardless of the neutron source used in the calibration; for the specified calibration orientation and current radiation weighting factors. However, changing the value of the radiation weighting factors would result in changes to the calibration factor. In the event of changes to the radiation weighting factors, it will be necessary to assess whether a change to the calibration process or resulting calibration factor is warranted.