Home About us Contact
|
Home About us Contact | ||
|
|
||
Greatest Influence (greatest + influence)
Selected AbstractsValidation of daily increment formation and the effects of different temperatures and feeding regimes on short-term otolith growth in Australian smelt Retropinna semoniECOLOGY OF FRESHWATER FISH, Issue 2 2008Z. Tonkin Abstract,,, To aid otolith interpretation of wild fish, we conducted a laboratory study using metalarval Australian smelt (Retropinna semoni) collected from the Murray River, to examine daily increment deposition and the effects of different temperatures and feeding regimes on otolith growth. Daily increment deposition was confirmed by comparing the number of increments from an oxytetracycline mark with the known number of days from marking. After holding fish at two temperature levels and three feeding rates, both food density and temperature were found to have a significant effect on otolith growth, with food density having the greatest influence. Overall trends in final lengths and condition of fish were well represented by recent otolith growth. The results of the experiment have implications for estimating growth histories and its relationship to various environmental conditions. [source] A physiologically based pharmacokinetic model for endosulfan in the male Sprague-Dawley ratsENVIRONMENTAL TOXICOLOGY, Issue 5 2006Melissa P. L. Chan Abstract Endosulfan, an organochlorine (OC) insecticide belonging to the cyclodiene group, is one of the most commonly used pesticides to control pests in vegetables, cotton, and fruits. To date, no physiologically based pharmacokinetic (PBPK) model has been located for endosulfan in animal species and humans. The estimation by a mathematical model is essential since information on humans can scarcely be obtained experimentally. The PBPK model was constructed based on the pharmacokinetic data of our experiment following single oral administration of 14C-Endosulfan to male Sprague-Dawley rats. The model was parameterized by using reference physiological parameter values and partition coefficients that were determined in the experiment and optimized by manual adjustment until the best visual fit of the simulations with the experimental data were observed. The model was verified by simulating the disposition of 14C-Endosulfan in vivo after single and multiple oral dosages and comparing simulated results with experimental results. The model was further verified by using experimental data retrieved from the literature. The present model could reasonably predict target tissue dosimetries in rats. Simulation with three-time repeated administration of 14C-Endosulfan and experimental data retrieved from the literature by the constructed model fitted fairly well with the experimental results; thus suggesting that the newly developed PBPK model was developed. Sensitivity analyses were used to determine those input parameters with the greatest influence on endosulfan tissue concentrations. © 2006 Wiley Periodicals, Inc. Environ Toxicol 21: 464,478, 2006. [source] Effects of soil improvement treatments on bacterial community structure and soil processes in an upland grassland soilFEMS MICROBIOLOGY ECOLOGY, Issue 1 2003Neil D. Gray Abstract Temporal temperature gradient electrophoresis (TTGE) analysis of 16S rRNA gene fragments amplified with primers selective for eubacteria and ,-proteobacterial ammonia-oxidising bacteria (AOB) was used to analyse changes in bacterial and AOB community profiles of an upland pasture following soil improvement treatments (addition of sewage sludge and/or lime). Community structure was compared with changes in activity assessed by laboratory measurements of basal respiration and ammonia oxidation potentials, and with measurements of treatment- and time-related changes in soil characteristics. The predominant bacterial populations had a high degree of similarity under all treatment regimens, which was most pronounced early in the growing season. Most of the differences that occurred between soil samples with time could be accounted for by spatial and temporal variation; however, analysis of variance and cluster analysis of similarities between 16S rDNA TTGE profiles indicated that soil improvement treatments exerted some effect on community structure. Lime application had the greatest influence. The impact of soil improvement treatments on autotrophic ammonia oxidation was significant and sustained, especially in soils which had received sewage sludge and lime treatments in combination. However, despite obvious changes in soil characteristics, e.g. pH and soil nitrogen, increasing heterogeneity in the AOB community structure over time obscured the treatment effects observed at the beginning of the experiment. Nevertheless, time series analysis of AOB TTGE profiles indicated that the AOB community in improved soils was more dynamic than in control soils where populations were found to be relatively stable. These observations suggest that the AOB populations exhibited a degree of functional redundancy. [source] Plant functional group identity influences short-term peatland ecosystem carbon flux: evidence from a plant removal experimentFUNCTIONAL ECOLOGY, Issue 2 2009Susan E. Ward Summary 1Northern hemisphere peatlands are globally important stores of organic soil carbon. We examined effects of plant functional group identity on short-term carbon (C) flux in an ombrotrophic peatland in northern England, UK, by selectively removing one of each of the three dominant plant functional groups (ericoid dwarf-shrubs, graminoids and bryophytes). Carbon dynamics were quantified by a combination of CO2 flux measurements and 13CO2 stable isotope pulse labelling approaches. 2Significant effects of plant functional group removals on CO2 fluxes and tracer 13C uptake and turnover were detected. Removal of ericoid dwarf-shrubs had the greatest influence on gross CO2 flux, increasing rates of respiration and photosynthesis by > 200% relative to the undisturbed control. After pulse labelling with 13CO2, we found that turnover of recent photosynthate, measured as respired 13CO2, was also greatest in the absence of dwarf-shrubs. 3Analysis of 13C tracer enrichment in leaf tissues from all plant removal treatments showed that the rate of fixation of 13CO2 and turnover of 13C labelled photosynthate in leaf tissue was greatest in graminoids and lowest in bryophytes. Furthermore, graminoid leaf 13C enrichment was greatest when growing in the absence of dwarf-shrubs, suggesting that the presence of dwarf-shrubs reduced the photosynthetic activity of graminoids. 4We conclude that plant functional groups differentially influence the uptake and short-term flux of carbon in peatlands, suggesting that changes in the functional composition of vegetation resulting from global change have the potential to alter short-term patterns of carbon exchange in peatland. [source] Family-based association test for time-to-onset data with time-dependent differences between the hazard functionsGENETIC EPIDEMIOLOGY, Issue 2 2006Hongyu Jiang Abstract In genetic association studies, the differences between the hazard functions for the individual genotypes are often time-dependent. We address the non-proportional hazards data by using the weighted logrank approach by Fleming and Harrington [1981]:Commun Stat-Theor M 10:763,794. We introduce a weighted FBAT-Logrank whose weights are based on a non-parametric estimator for the genetic marker distribution function under the alternative hypothesis. We show that the computation of the marker distribution under the alternative does not bias the significance level of any subsequently computed FBAT-statistic. Hence, we use the estimated marker distribution to select the Fleming-Harrington weights so that the power of the weighted FBAT-Logrank test is maximized. In simulation studies and applications to an asthma study, we illustrate the practical relevance of the new methodology. In addition to power increases of 100% over the original FBAT-Logrank test, we also gain insight into the age at which a genotype exerts the greatest influence on disease risk. Genet. Epidemiol. 2006. © 2006 Wiley-Liss, Inc. [source] Perceptions of internal marketing and organizational commitment by nursesJOURNAL OF ADVANCED NURSING, Issue 1 2009Ching Sheng Chang Abstract Title.,Perceptions of internal marketing and organizational commitment by nurses. Aim., This paper is a report of a study to determine whether a favourable perception of internal marketing is associated with increased organizational commitment. Background., The role of nurses in healthcare treatment is expanding, and becoming more important as time progresses. Therefore, the primary concern of business of health care is to use internal marketing strategies effectively to enhance and develop nurses' organizational commitment and reduce turnover to promote competitive advantages for the organization. Methods., A cross-sectional design was used. Questionnaires were distributed in 2006 to a convenience sample of 450 Registered Nurses in two teaching hospitals in Taiwan, and 318 questionnaires were returned. Eighteen were excluded because of incomplete answers, which left 300 usable questionnaires (response rate 66·7%). Validity and reliability testing of the questionnaire proved satisfactory and Structural Equation Modeling was used to analyse the data. Results., A favourable perception of internal marketing was associated with increased organizational commitment. Communication management had the greatest influence on organizational commitment and external activity had the smallest impact. Conclusion., Hospital managers need to recognize the importance of internal marketing for staff retention and the survival of their organizations as competitive pressure increases. As a great deal of time and costs are involved in educating nurses, the best way to retain outstanding nurses and reduce turnover costs and personnel problems is for employers to understand the needs and expectations of their nursing staff. [source] Predicting the effects of perturbations on ecological communities: what can qualitative models offer?JOURNAL OF ANIMAL ECOLOGY, Issue 5 2005DAVE RAMSEY Summary 1Quantitative predictions of the effects of perturbations on communities of interacting species have often proved to be difficult. However, if precise predictions are not a requirement then qualitative models of community dynamics offer an alternative method for predicting species responses to perturbations. 2We used two qualitative modelling approaches to predict the effects of predator control on the fledging rate of an endangered New Zealand bird, the North Island kokako. The first approach was based on loop analysis and provided predictions on the probable direction of change in species abundances to single species perturbations. The second approach, ,fuzzy interaction webs', used fuzzy logic in the framework of a fuzzy cognitive map to provide predictions on the probable magnitude of change in species abundances to perturbations. 3Using both methods, we predicted the qualitative change in the equilibrium fledging rates of kokako under various regimes of single- and multispecies predator control (ship rats, brushtail possums and stoats). Single species control was insufficient to lift the fledging rate from ,low' to ,moderate'. However, simultaneous control of both ship rats and possums had the greatest influence on the fledging rates compared with any other combination as a result of the additional indirect effect of ship rat control on stoat abundance. 4We propose qualitative modelling of community dynamics as a method suitable for predicting the effects of perturbations in complex ecological communities that can encapsulate diverse sources of knowledge about food web interactions. We believe that these methods are a useful set of heuristic tools that can be used to propose testable hypotheses about ecosystem functioning that can complement existing statistical and quantitative modelling approaches. [source] Root defects following air polishingJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2003An in vitro study on the effects of working parameters Abstract Aim: Air-polishing devices (APDs) are highly effective in removing plaque and extrinsic staining. Their application on root surfaces, however, may result in clinically relevant substance removal, limiting the use in patients with periodontitis, where denuded root surfaces are frequently found. Therefore, the purpose of the study was to assess the influence of different working parameters on root damage and to identify those minimizing root damage. Material and methods: Defect depth and defect volume after instrumentation of roots with an APD (Dentsply Prophy-Jet®) using conventional NaHCO3 powder at instrumentation times of 5, 10 and 20 s, combinations of low, medium and high powder and water settings, distances of 2, 4 and 6 mm, and angulations of 45° and 90° were quantified laseroptically. A total of 297 roots were instrumented and parameter combinations were performed in triplicate. The influence of each working parameter on substance loss was determined by multiple regression analysis. Results: Time had the greatest influence on defect volume and depth (,-weights 0.6 and 0.57, respectively), when compared with powder setting (,-weights 0.49 and 0.3) and water setting (,-weights 0.28 and 0.3). Variations in distance affected defect depth (,-weight 0.44), but not volume (,-weight 0.04). No major differences were found at 45° and 90°. Various parameter combinations led to maximal defect depths of 473.5 ± 26.2 µm within 20 s. Conclusion: Root damage varies among combinations of working parameters. Using the APD with the assessed NaHCO3 powder, all parameter combinations led to substantial root damage. Thus, APDs using NaHCO3 may not be safely utilized on exposed root surfaces. Zusammenfassung Wurzeldefekte nach Pulverstrahlpolitur , Eine In-vitro-Untersuchung zur Auswirkung der Arbeitsparameter Hintergrund: Pulverstrahlgeräte sind sehr wirksam in der Entfernung von Plaque und externen Zahnverfärbungen. Die Bearbeitung von Wurzeloberflächen kann aber zu klinisch relevanten Hartsubstanzabträgen führen, die den Einsatz bei Parodontitispatienten einschränken, bei denen häufig entblößte Wurzeloberflächen gefunden werden. Zielsetzung: Untersuchung des Einflusses verschiedener Arbeitsparameter auf die Wurzeloberflächenschädigung mit dem Ziel diese zu reduzieren. Material und Methoden: Defekttiefe und ,volumen wurden nach Instrumentierung der Wurzeloberflächen mit einem Pulverstahlgerät (Dentsply Prophy-Jet®) bei Verwendung von konventionellem NaHCO3 -Pulver bei Bearbeitungszeiten von 5, 10 and 20 Sekunden, Kombinationen von niedrigen, mittleren und hohen Pulver- und Wassereinstellungen, Abständen von 2, 4 und 6 mm sowie Arbeitswinkeln von 45° und 90° laseroptisch quantifiziert. Insgesamt 297 Wurzeln extrahierter Zähne wurden bearbeitet und die Parameterkombinationen dreimal wiederholt. Der Einfluss der Arbeitsparameter auf den Substanzabtrag wurde für jeden Parameter mittels multipler Regressionsanalyse bestimmt. Ergebnisse: Zeit hatte den größten Einfluss auf Defektvolumen und -tiefe (ß-Gewichte 0,6 und 0,57) im Vergleich zur Pulver- (,-Gewichte 0,49 und 0,3) und Wassereinstellung (,-Gewichte 0,28 und 0,3). Veränderungen des Arbeitsabstandes beeinflussten die Defekttiefe (,-Gewicht 0,44), aber nicht das Volumen (,-Gewicht 0,04). Keine wesentlichen Unterschiede wurden zwischen den Arbeitswinkeln 45° und 90° gefunden. Die verschiedenen Parameterkombinationen führten zu maximalen Defekttiefen von 473,5±26,2 ,m innerhalb von 20 s. Schlussfolgerung: Der Substanzabtrag von Wurzeloberflächen unterscheidet sich für die verschiedenen Kombinationen der Arbeitsparameter. Bei Verwendung von Pulverstrahlgeräten mit dem untersuchten NaHCO3 -Pulver führten alle Kombinationen der Arbeitsparameter zu wesentlichen Substanzverlusten. Deshalb können Pulverstrahlgeräte mit NaHCO3 nicht sicher zur Reinigung freiliegender Wurzeloberflächen verwendet werden. Résumé Lésions radiculaires après aéro-polissage- une étude in vitro sur les effets des paramètres de travail. But de l'étude: Les aéro-polisseurs (APDs) sont très efficace pour l'élimination de la plaque et des colorations extrinsèques. Leur application sur les surfaces radiculaires, cependant, peut résulter en l'élimination cliniquement significative de substance ce qui limite leur utilisation chez les patients souffrant de parodontite, chez lesquels on observe fréquemment des dénudations radiculaires C'est pourquoi cette étude se propose de mettre en évidence l'influence des divers paramètres de travail sur les dommages radiculaires et d'identifier ceux qui limiteraient ces dommages. Matériels et Méthodes: La profondeur des lésions et le volume après instrumentation des racines avec un APD (Dentsply Prophy-Jet®) utilisant une poudre classique de NaHCO3 sur des durées d'utilisation de 5, 10 et 20 secondes, avec des combinaisons de réglages d'eau et de poudre bas, moyen et fort, à des distances de 2, 4 et 6 mm, et avec des angulations de 45° et 90° furent quantifiées par laser-optique. 297 racines furent instrumentées et les combinaisons de paramètres furent appliquées trois fois. L'influence de chaque paramètre de travail sur la perte de substance fut déterminée par analyse de régression multiple. Resultats: La durée avait la plus grande influence sur le volume des lésions et sur leurs profondeurs (,-poids 0.6 et 0.57 respectivement), lorsqu'on la comparait avec les réglages de poudre (,-poids 0.49 et 0.3) et d'eau (,-poids 0.28 et 0.3). Les variations de distance affectait les profondeurs des lésions (,-poids 0.44), mais pas le volume (,-poids 0.04). Aucune différence majeure ne put être trouvée entre les angulations. Les diverses combinaisons de paramètre entraînaient des profondeur de défaut maximales de 473.5±26.2 ,m en 20 s. Conclusion: les dommages radiculaires varient selon les combinaisons de paramétres de travail. Lors de l'utilisation de l'APD avec sa poudre de NaHCO3, toutes les combinaisons entraînaient des dommages radiculaires substantiels. Ainsi, les APDs à NaHCO3 ne peuvent pas être utilises en toute sécurité sur les surfaces radiculaires exposées. [source] Harm minimization strategies: opinions of health professionals in rural and remote AustraliaJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 5 2007G. M. Peterson BPharm (Hons) PhD MBA Summary Background and objective: There is some evidence that the problem of illicit drug use (IDU) is increasing in rural areas of Australia. Lack of access to harm minimization (HM) strategies is potentially exacerbated by a shortage of health care facilities and health care professionals in rural areas. This study was conducted to determine barriers to implementation, access to, and success of HM strategies, as seen by health professionals presently working in rural Australia. Methods: Four hundred rural pharmacists Australia-wide and 425 doctors in rural Victoria and Tasmania were sent postal surveys to assess their opinions on the level of IDU in their area, the types of drugs commonly used, the adequacy of HM strategies and facilities, and the barriers faced by doctors, pharmacists and clients. Results: The overall response rate was almost 50%. Slightly less than half of surveyed health professionals felt that IDU was increasing in their area, with heroin perceived to be the most prevalent drug used in all States except Tasmania and the Northern Territory. Both methadone prescribers and dispensers believed the methadone maintenance programmes were highly valuable to the community, but not without problems (e.g. risk of overdose). A lack of time or staff was the greatest influence on doctors not participating in the methadone programmes, whereas safety concerns were prominent with pharmacists. The majority of doctors felt HM facilities were inadequate, with needle-syringe exchange being the most frequently nominated HM strategy lacking. Conclusion: Despite best intentions, there are still problems with HM strategies in these areas. Improving the number and expertise of health professionals in rural areas, and providing adequate support for them, would address some of these problems. [source] INFLUENCE OF STARVATION, TEMPERATURE, AND pH ON CULTURABILITY OF ESCHERICHIA COLI O157:H7JOURNAL OF FOOD SAFETY, Issue 3 2000LIQIANG ZHAO ABSTRACT In farm and food processing environments Escherichia coli O157:H7 can survive for days to months. In this study, we investigated the influence of starvation, pH (pH 4 or 7), temperature (4, 10 and 22C), and exposure to chlorine (50, 100, 150, 200 ppm) on culturability of E. coli O157:H7. The culturable cell population in PBS decreased to an undetectable level at 4C and 10C, but not at 22C during the experimental period. Cells suspended in PBS adjusted to pH 4 lost culturability more rapidly than at pH 7. Culturable cells were not detectable after exposure to chlorine, however, viable cell populations in the range of 1 , 2 log remained stable for 5 days. During loss of culturability two distinct morphological cell populations emerged; typical rod shaped and coccoid shaped cells. In this study, independent of exposure to chlorine, conditions of low temperature and low pH had the greatest influence on entry of E. coli O157:H7 into a VNC state. [source] Alternative Scenarios for Managing the Environmental Performance of a Service Sector CompanyJOURNAL OF INDUSTRIAL ECOLOGY, Issue 4 2006Seppo Junnila Summary This article presents a scenario analysis for a life-cycle model of service sector companies. The model is based on six case companies and it is applied to test the influence of 32 management scenarios. The scenarios simulate feasible options for environmental management measures in companies, and the life-cycle assessment method is used to model their relevance in terms of the total environmental impact of the company. The study found that the bulk of tested scenarios had only a minor influence on the total environmental impact of the company. Some individual management scenarios, though, turned out to have a major influence on the organization's environmental performance. The scenarios with greatest influence were those related to the procurement of electricity, building energy consumption, commuting vehicle mix, space usage efficiency, and refurbishment periods of the building. All of these management scenarios had an influence of more than 10% on the environmental impact of the model organization. [source] Gram-positive anaerobic bacilli in human periodontal diseaseJOURNAL OF PERIODONTAL RESEARCH, Issue 4 2004V. Booth Objective:, The uncertain taxonomy of oral anaerobic gram-positive bacilli and their generally slow growing nature has limited the understanding of their role in periodontal disease. The current objective was to design and use species-specific oligonucleotide probes to investigate the relationship of selected gram-positive anaerobic bacilli to periodontal disease. Methods:, Plaque and clinical measurements were collected from 40 patients with periodontitis and from 40 matched controls. Oligonucleotide probes were designed for Bulleidia extructa, Eubacterium nodatum, Mogibacterium timidum and Slackia exigua and used to probe nucleic acids extracted from the samples with a chemiluminescent detection method. Species were quantified as absent or present at low (approximately 103,104 cells), medium (approximately 104,105 cells) or high levels (approximately 105,106 cells). Results:,M. timidum and B. extructa were detected in only three and four samples, respectively. The level of both E. nodatum and S. exigua was significantly higher in deep than shallow pockets (Wilcoxon, p < 0.001). The level of E. nodatum, but not S. exigua, was higher in patients than matched controls (Mann,Whitney U, p < 0.03). Using an ordered logistic regression model, the probing depth of the sampled sites had the greatest influence on the level of both species and significant variations occurred between individuals. Bleeding also influenced the levels of both species, with supragingival plaque influencing S. exigua. Conclusion:, Both E. nodatum and S. exigua were associated with clinical indicators of periodontal disease. [source] Mechanism and structure,reactivity correlation in the homogeneous, unimolecular elimination kinetics of 2-substituted ethyl methylcarbonates in the gas phaseJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 11 2003Gabriel Chuchani Abstract The gas-phase elimination kinetics of 2-substituted ethyl methylcarbonates were determined in a static reaction system over the temperature range of 323,435°C and pressure range 28.5,242 Torr. The reactions are homogeneous, unimolecular and follow a first-order rate law. The kinetic and thermodynamic parameters are reported. The 2-substituents of the ethyl methylcarbonate (CH3OCOOCH2CH2Z, Z=substituent) give an approximate linear correlation when using the Taft,Topsom method, log(kZ/kH)=,(0.57±0.19),,+(1.34±0.49),R, (r=0.9256; SD=0.16) at 400°C. This result implies the elimination process to be sensitive to steric factors, while the electronic effect is unimportant. However, the resonance factor has the greatest influence for a favorable abstraction of the ,-hydrogen of the C,,H bond by the oxygen carbonyl. Because ,, is significant, a good correlation of the alkyl substituents of carbonates with Hancock's steric parameters was obtained: log(kR/kH) versus ESC for CH3OCOOCH2CH2R at 400°C, R=alkyl, ,=,0.17 (r=0.9993, SD=0.01). An approximate straight line was obtained on plotting these data with the reported Hancock's correlation of 2-alkyl ethylacetates. This result leads to evidence for the ,-hydrogen abstraction by the oxygen carbonyl and not by the alkoxy oxygen at the opposite side of the carbonate. The carbonate decompostion is best described in terms of a concerted six-membered cyclic transition state type of mechanism. Copyright © 2003 John Wiley & Sons, Ltd. [source] Habitat heterogeneity and its influence on benthic biodiversity in oxygen minimum zonesMARINE ECOLOGY, Issue 1 2010Andrew J. Gooday Abstract Oxygen minimum zones (OMZs; midwater regions with O2 concentrations <0.5 ml l,1) are mid-water features that intercept continental margins at bathyal depths (100,1000 m). They are particularly well developed in the Eastern Pacific Ocean, the Arabian Sea and the Bay of Bengal. Based on analyses of data from these regions, we consider (i) how benthic habitat heterogeneity is manifested within OMZs, (ii) which aspects of this heterogeneity exert the greatest influence on alpha and beta diversity within particular OMZs and (iii) how heterogeneity associated with OMZs influences regional (gamma) diversity on continental margins. Sources of sea-floor habitat heterogeneity within OMZs include bottom-water oxygen and sulphide gradients, substratum characteristics, bacterial mats, and variations in the organic matter content of the sediment and pH. On some margins, hard grounds, formed of phosphorites, carbonates or biotic substrata, represent distinct subhabitats colonized by encrusting faunas. Most of the heterogeneity associated with OMZs, however, is created by strong sea-floor oxygen gradients, reinforced by changes in sediment characteristics and organic matter content. For the Pakistan margin, combining these parameters revealed clear environmental and faunal differences between the OMZ core and the upper and lower boundary regions. In all Pacific and Arabian Sea OMZs examined, oxygen appears to be the master driver of alpha and beta diversity in all benthic faunal groups for which data exist, as well as macrofaunal assemblage composition, particularly in the OMZ core. However, other factors, notably organic matter quantity and quality and sediment characteristics, come into play as oxygen concentrations begin to rise. The influence of OMZs on meiofaunal, macrofaunal and megafaunal regional (gamma) diversity is difficult to assess. Hypoxia is associated with a reduction in species richness in all benthic faunal groups, but there is also evidence for endemism in OMZ settings. We conclude that, on balance, OMZs probably enhance regional diversity, particularly in taxa such as Foraminifera, which are more tolerant of hypoxia than others. Over evolutionary timescales, they may promote speciation by creating strong gradients in selective pressures and barriers to gene flow. [source] Exploring the barriers to exclusive breastfeeding in black and minority ethnic groups and young mothers in the UKMATERNAL & CHILD NUTRITION, Issue 3 2008Jenny Ingram Abstract UK health policy for many years has been to increase rates of breastfeeding because of the health benefits conferred on mothers and babies. World Health Organization recommends that babies should be breastfed exclusively for 6 months (without water or other fluids) and the National Institute for Health and Clinical Excellence promotes the provision of peer supporters or breastfeeding support groups to increase breastfeeding rates. This study aimed to explore the barriers to exclusive breastfeeding to 6 months with black and minority ethnic groups and with young mothers, and the strategies for overcoming these barriers, including peer support. Twenty-two mothers from Somali, Afro-Caribbean and South Asian communities or young mothers groups attended five focus groups. Transcripts were analysed using thematic and framework methods. There was enthusiasm for breastfeeding support groups, but with a wider remit to discuss other baby-related issues and provide general social support as well as support for breastfeeding. The Somali and South Asian women preferred the groups to be for their ethnic group, Afro-Caribbean women were keen that they should be open to all cultures and young mothers would like groups for their peers only. Encouraging mothers to breastfeed exclusively to 6 months should be promoted more and emphasized by health professionals when supporting women post-natally, and good support with breastfeeding management should be given to enable mothers to achieve this goal. Breastfeeding support groups may play a part in increasing breastfeeding continuation of breastfeeding, but for the groups studied this was not the greatest influence, with families and older women in the community having more influence in changing practice. [source] Factors affecting future choice of specialty among first-year medical students of the University of the West Indies, TrinidadMEDICAL EDUCATION, Issue 1 2007Nelleen S Baboolal Background, This study was conducted to determine factors that influence career choice among 1st-year medical students. Design And Methods, A cross-sectional survey of 170 1st-year medical students from the University of the West Indies, St Augustine Campus was undertaken with a questionnaire designed to assess their perceptions of careers in various specialties. Likert scales were used to quantify the reasons for their preferences. Results, The response rate was 136/170 (80%). The age of respondents ranged from 16 to 36 years, mean 20.45, SD 2.88. Of the generic factors students considered important in their choice of a specialty, students ranked the ability to help patients the highest (rating of 1.44), along with the diagnosis and treatment of disease second (rating of 1.49); 38 (27.9%) cited medicine, 26 (19.1%) surgery, 13 (9.6%) paediatrics, 10 (7.4%) family practice and 4 (2.9%) psychiatry as their chosen career. Students begin their medical training with the view that a career in psychiatry is less attractive than other specialties surveyed. The average attractiveness was estimated as surgery 1.64, medicine, 1.81, paediatrics 1.95 and psychiatry 2.57. The differences between the averages were highly significant (F = 57.6, P < 0.001). Conclusion, The findings suggest that although 1st-year medical students rank the diagnosis and treatment of disease and the ability to help patients as the greatest influence in choosing a specialty, internal medicine was the most popular chosen career, while the surgical specialties were identified as the most attractive. Medical students have serious reservations about psychiatry as a career choice. [source] Eco-evolutionary vs. habitat contributions to invasion in salmon: experimental evaluation in the wildMOLECULAR ECOLOGY, Issue 1 2008MICHAEL T. KINNISON Abstract Although trait evolution over contemporary timescales is well documented, its influence on ecological dynamics in the wild has received much less attention particularly compared to traditional ecological and environmental factors. For example, evolution over ecologically relevant timescales is expected in populations that colonize new habitats, where it should theoretically enhance fitness, associated vital rates of survival and reproduction, and population growth potential. Nonetheless, success of exotic species is much more commonly attributed to ecological aspects of habitat quality and ,escape from enemies' in the invaded range. Here, we consider contemporary evolution of vital rates in introduced Chinook salmon (Oncorhynchus tshawytscha) that quickly colonized New Zealand and diverged over c. 26 generations. By using experimental translocations, we partitioned the roles of evolution and habitat quality in modifying geographical patterns of vital rates. Variation in habitat quality within the new range had the greatest influence on broad geographical patterns of vital rates, but locally adapted salmon still exhibited more than double the vital rate performance, and hence fitness, of nonlocal counterparts. The scope of this fitness evolution far exceeds the scale of divergence in trait values for these populations, or even the expected fitness effects of particular traits. These results suggest that contemporary evolution can be an important part of the eco-evolutionary dynamics of invasions and highlight the need for studies of the emergent fitness and ecological consequences of such evolution, rather than just changes in trait values. [source] Socioeconomic and lifestyle determinants of body fat distribution in young working males from Cracow, PolandAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 1 2008Agnieszka Suder The aim of the study was to determine the degree of explanation of the central adiposity variation, presented by waist circumference (WC), waist-hip ratio (WHR), and the sum of the three trunk skinfold thicknesses (subscapular, abdominal, suprailiac) (TTS) through the socioeconomic status (SES) and lifestyle. The material included cross-sectional population-based research of 259 healthy working males aged 20,30 from the city of Cracow, Poland. Objective anthropometric measurements, the results of motor fitness tests, and social and lifestyle data from a questionnaire were analyzed. The independent variables were: age, SES (the birthplace, place of residence until the age of 14, social class, educational level, and the type of work done), and lifestyle elements (smoking habits, dietary habits, family obesity resemblance, sport activity in the past, leisure time physical activity (LTPA), and the level of motor fitness). Three separate full models were created using stepwise straightforward regression with WC, WHR, and TTS as dependent variables. The highest autonomous influence on WC was ascribed to age, level of motor fitness, and family obesity resemblance. Variation in WHR was explained by age, level of motor fitness, upper-middle class, LTPA, and village as the birthplace. Level of motor fitness, place of residence until the age of 14 (city), age, smoking fewer than 20 cigarettes a day, and family obesity resemblance had greatest influence on TTS. The findings indicated the importance, besides age, of lifestyle elements connected with motor fitness and LTPA in determining body fat distribution in young working males. Am. J. Hum. Biol., 2008. © 2007 Wiley-Liss, Inc. [source] Presidential-Congressional Budget Agreement, 1949,1995POLITICS & POLICY, Issue 3 2001Steven A. Shull In this paper, presidential-congressional budget agreement, measured as the percentage of presidential budget requests appropriated by Congress, is explained. Budget agreement reflects a pivotal point in the struggle between the president and the Congress to enact their respective preferences since funding brings such preferences to life. In order to explain budget agreement, the existing tandem institutions approach to studying presidential-congressional relations is expanded by positing a multiple perspective encompassing a three environment model: executive, legislative and exogenous environments. Three variables tap each institutional environment, comprised of the executive and the legislative, and two variables are included in the exogenous environment. Findings reflect that a multiple perspectives approach better captures the complexities of presidential-congressional relations than a strictly institutional approach. The institutional resources available to both the president and Congress contribute little, but the exogenous environment has the greatest influence on budget agreement. Differences in explanation are observed when budget agreement is divided by domestic and foreign policy. [source] Exchange, affiliation, and protective interventions in semifree-ranging brown capuchin monkeys (Cebus apella)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 8 2006Renata G. Ferreira Abstract The "social intelligence" hypothesis proposes that intelligence evolved as a consequence of the need for behavioral maneuvering to deal with the complexities of social life. As a result, coalitions have received considerable attention. Here we present the patterns of coalitionary behavior observed in a semifree-ranging group of Cebus apella and explore the effects of kinship, spatial proximity, and rank. In contrast to descriptions of Old World monkeys and to some descriptions of capuchins, kinship did not influence the pattern of coalitionary behavior, although individuals tended to help those that remained in close proximity. Rank had the greatest influence on coalitions: those that interfered in conflicts (often the alpha) were higher ranking than both contestants and supported the most subordinate (younger) interactant. However, rank did not influence the coalitionary support when conflicts involved only adults. We found no evidence that individuals were making use of triadic knowledge, and most of the coalitions can best be described as protective interventions involving immatures. The overall low rate of coalitions may be due to a period of social stability. Am. J. Primatol. 68:765,776, 2006. © 2006 Wiley-Liss, Inc. [source] Arid Recovery , A comparison of reptile and small mammal populations inside and outside a large rabbit, cat and fox-proof exclosure in arid South AustraliaAUSTRAL ECOLOGY, Issue 2 2009KATHERINE ELIZABETH MOSEBY Abstract Australian arid zone mammal species within the Critical Weight Range (CWR) of 35 g,5.5 kg have suffered disproportionately in the global epidemic of contemporary faunal extinctions. CWR extinctions have been attributed largely to the effects of introduced or invasive mammals; however, the impact of these threatening processes on smaller mammals and reptiles is less clear. The change in small mammal and reptile assemblages after the removal of rabbits, cats and foxes was studied over a 6-year period in a landscape-scale exclosure in the Australian arid zone. Rodents, particularly Notomys alexis and Pseudomys bolami, increased to 15 times higher inside the feral-proof Arid Recovery Reserve compared with outside sites, where rabbits, cats and foxes were still present. Predation by cats was thought to exert the greatest influence on rodent numbers owing to the maintenance of the disparity in rodent responses through dry years and the differences in dietary preferences between rabbits and P. bolami. The presence of introduced Mus domesticus or medium-sized re-introduced mammal species did not significantly affect resident small mammal or reptile abundance. Abundance of most dasyurids and small lizards did not change significantly after the removal of feral animals although reductions in gecko populations inside the reserve may be attributable to second order trophic interactions or subtle changes in vegetation structure and cover. This study suggests that populations of rodent species in northern South Australia below the CWR may also be significantly affected by introduced cats, foxes and/or rabbits and that a taxa specific model of Australian mammal decline may be more accurate than one based on body weight. [source] Responses of ant communities to experimental fire regimes on rangelands in the Victoria River District of the Northern TerritoryAUSTRAL ECOLOGY, Issue 2 2003BENJAMIN D. HOFFMANN Abstract Fire is a significant feature of Australia's savannas. Its use is being encouraged for cattle rangeland management, but there is little knowledge of the ecological effects of prescribed fire regimes on native biodiversity. The responses of ant communities to five experimental fire regimes over 2 years are reported from the Victoria River District in the semi-arid tropics of northern Australia. The experiment was stratified at two levels: soil type (red and black) and fire treatment (unburnt; burnt twice in successive years in early (May) or late (October) dry season and unburnt thereafter; and burnt twice, 3 years apart, in early or late dry season). Ants were sampled twice in April, corresponding with the end of the 1997 and 1998 wet seasons. Ant species richness was not responsive to fire treatment, but reduced with time since fire on black soil. Total ant abundance also reduced with time since fire on the black soil, with significant different abundances in burnt versus unburnt plots in the 1998 sample. Soil type and sampling time had the greatest influence on ant community composition in multivariate analysis than did fire regime, although there were moderate gradients of time since fire with the black soil plots. The abundance of 19 species were significantly different between fire regimes in ANOVA, 13 on red soil and six on black soil. The abundance of eight species (four each on red and black soil) changed significantly with time since fire, with seven promoted by burning. Ant functional group profiles changed little with fire. Total ant abundance and richness had significant relationships with key pasture species and vegetative variables. The responses of ants largely recapitulated those of plants, birds and reptiles on the same plots. It is envisaged that ants will have an important role to play in the sustainable management of Australia's rangelands aiding the off-reserve conservation of biodiversity. [source] Effects of Season and Successional Stage on Leaf Area Index and Spectral Vegetation Indices in Three Mesoamerican Tropical Dry Forests,BIOTROPICA, Issue 4 2005Margaret E. R. Kalacska ABSTRACT We compared plant area index (PAI) and canopy openness for different successional stages in three tropical dry forest sites: Chamela, Mexico; Santa Rosa, Costa Rica; and Palo Verde, Costa Rica, in the wet and dry seasons. We also compared leaf area index (LAI) for the Costa Rican sites during the wet and dry seasons. In addition, we examined differences in canopy structure to ascertain the most influential factors on PAI/LAI. Subsequently, we explored relationships between spectral vegetation indices derived from Landsat 7 ETM+ satellite imagery and PAI/LAI to create maps of PAI/LAI for the wet season for the three sites. Specific forest structure characteristics with the greatest influence on PAI/LAI varied among the sites and were linked to climatic differences. The differences in PAI/LAI and canopy openness among the sites were explained by both the past land-use history and forest management practices. For all sites, the best-fit regression model between the spectral vegetation indices and PAI/LAI was a Lorentzian Cumulative Function. Overall, this study aimed to further research linkages between PAI/LAI and remotely sensed data while exploring unique challenges posed by this ecosystem. RESUMEN En este estudio comparamos el índice de área de plantas PAI, el índice de área foliar (LAI), y la apertura de dosel para diferentes etapas sucesionales en tres sitios del bosque seco tropical: Chamela, México; Santa Rosa, Costa Rica y Palo Verde, Costa Rica en la estación lluviosa y seca. Además, examinamos las diferencias en la estructura de dosel para indagar los factores que más influyen en el PAI/LAI. En forma adicional, exploramos las relaciones entre los índices espectrales de vegetación derivados de imágenes satelitales Landsat 7 ETM+ y el PAI/LAI para así crear mapas de PAI/LAI de la estación lluviosa para los tres sitios. En este estudio encontramos que las características específicas de la estructura del bosque con mayor influencia en PAI/LAI varían entre sitios y las mismas están asociadas a diferencias climáticas. Las diferencias en el PAI/LAI y la apertura del dosel entre los sitios son explicadas tanto por el historial de uso del suelo y asi como las prácticas de manejo del bosque. Para todos los sitios el mejor modelo de regresión entre los índices espectrales de vegetación y el PAI/LAI es la función Cumulativa Lorentziana. En general, este estudio tiene como objetivo estudiar más a fondo las relaciones entre el PAI/LAI y los datos colectados de manera remota, mientras se exploran otros retos particulares que plantea este ecosistema. [source] Environmental strategy and low waste operations: exploring complementaritiesBUSINESS STRATEGY AND THE ENVIRONMENT, Issue 2 2010Dayna Simpson Abstract Organizations require guidance on the most effective functional areas in which to invest in order to improve and sustain environmental performance. As managerial practices progress from concerns with compliance towards practices seeking competitive advantage, more theory is needed regarding the manner in which corporate strategy and operational practices influence environmental performance. This research considers the potential for previously under-researched complementarities between strategy and operations and the bridging role of environmentally specific practices such as the use of environmental experts as determinants of environmental performance. Using a sample of manufacturing firms, this study explores the relative contribution to environmental performance of strategic intentions, core operational practices such as data and quality management and environmentally specific practices that link strategy to operations. The most significant influence on environmental performance was found to be environmental expertise , which creates a bridge between strategy and operations , and information-intensive practices such as quality and data management. Strategic intentions or core operational practices in isolation were not considered sufficient support to successfully maintain or improve environmental performance. This research provides a contribution to our understanding of interactions between those functions that have the greatest influence on environmental performance management in manufacturing firms. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment. [source] Weight loss predicts mortality after recurrent oral cavity and oropharyngeal carcinomas,CANCER, Issue 3 2002Thao V. Nguyen B.S.E. Abstract BACKGROUND The prognosis of patients with recurrent tumors of the head and neck generally is considered poor. Better prediction of outcomes can help physicians counsel patients about the merits of additional treatment. The TNM system, which was created for patients with primary tumors, may not provide optimal information. Anatomic staging systems traditionally have ignored symptom-based variables, such as weight loss, despite their known prognostic value. The objectives of this study were 1) to measure the prognostic impact of weight loss, 2) to evaluate the prognostic value of the TNM staging system, and 3) to create a practical staging system capable of predicting survival after patients develop recurrent tumors of the oral cavity and oropharynx. METHODS A retrospective chart review was used to identify an inception cohort of patients seeking treatment for recurrent, persistent, and second primary tumors of the oral cavity and oropharynx at the University of Washington. The primary outcome variable was 1-year survival. RESULTS The 1-year survival rate for the cohort (n = 97 patients) was 38%, with a median survival of 0.7 years. Multivariate analysis (Cox regression) identified weight loss, previous radiation to the head and neck, and TNM stage of the recurrent tumor as factors that had a substantial impact on mortality. A second multivariate technique called conjunctive consolidation was used to determine the relative quantitative impact of each variable on survival and to develop a clinical staging system. Weight loss and previous radiation had the greatest influence, and the use of just these two variables resulted in a three-tiered staging system with 1-year survival rates of 62% (16 of 26 patients), 44% (18 of 41 patients), and 10% (3 of 30 patients). In contrast, the TNM staging system produced survival rates of 60% (patients with Stage I disease), 67% (patients with Stage II disease), 32% (patients with Stage III disease), and 32% (patients with Stage IV disease). CONCLUSIONS The authors found substantial variation in survival after patients developed recurrent tumors of the oral cavity and oropharynx. Two readily available clinical variables,weight loss and previous radiation,were combined to create a clinically practical staging scheme with more prognostic power than the TNM staging system. Until molecular markers can reliably used be to predict outcomes, greater attention needs to be given to the utility of simple, inexpensive, and surprisingly powerful clinical variables. Cancer 2002;95:553,62. © 2002 American Cancer Society. DOI 10.1002/cncr.10711 [source] Emergency treatment of chemical and thermal eye burnsACTA OPHTHALMOLOGICA, Issue 1 2002Ralf Kuckelkorn ABSTRACT. Chemical and thermal eye burns account for a small but significant fraction of ocular trauma. The speed at which initial irrigation of the eye begins, has the greatest influence on the prognosis and outcome of eye burns. Water is commonly recommended as an irrigation fluid. However, water is hypotonic to the corneal stroma. The osmolarity gradient causes an increased water influx into the cornea and the invasion of the corrosive substance into deeper corneal structures. We therefore recommend higher osmolarities for the initial rinsing to mobilize water and the dissolved corrosives out of the burnt tissue. Universal systems such as amphoteric solutions, which have an unspecific binding with bases and acids, provide a convenient solution for emergency neutralisation. Both conservative anti-inflammatory therapy and early surgical intervention are important to reduce the inflammatory response of the burnt tissue. In most severe eye burns, tenonplasty re-establishes the conjunctival surface and limbal vascularity and prevents anterior segment necrosis. [source] The Time to Talk: The Influence of the Timing of Adult,Child Talk on Children's Event MemoryCHILD DEVELOPMENT, Issue 3 2004Fiona McGuigan To investigate the influence of the nature and timing of adult,child talk on event recall, this study engaged 63 three-year-olds and 65 five-year-olds in a staged event and interviewed them 2 weeks later. Children were assigned to 1 of 4 conditions: elaborative pre-, during-, and post-talk, and empty talk (during the event). Children in the elaborative, relative to the empty, talk conditions made fewer errors. Furthermore, post-talk had the greatest influence on correct recall, although for the 5-year-olds, during-talk was also facilitative. Recall was enhanced to a greater extent by the child's contribution to the talk, relative to that of the adult. The findings contribute to an understanding of the mechanisms by which adult,child conversations influence recall. [source] Length of stay and procedure utilization are the major determinants of hospital charges for heart failureCLINICAL CARDIOLOGY, Issue 1 2001Edward F. Philbin M.D.Facc Abstract Background: Most of the 10 billion dollars spent annually on heart failure (HF) management in this country is attributed to hospital charges. There are widespread efforts to decrease the costs of treating this disorder, both by preventing hospital admissions and reducing lengths of stay (LOS). Methods: Administrative information on all 1995 New York State hospital discharges assigned ICD-9-CM codes indicative of HF in the principal diagnosis position were obtained. Bivariate and multivariate statistical analyses were utilized to determine those patient- and hospital-specific characteristics which had the greatest influence on hospital charges. Results: In all, 43,157 patients were identified. Mean hospital charges were $11,507 ± 15,995 and mean hospital LOS was 9.6 ± 14.5 days. With multivariate analyses, the most significant independent predictors of higher hospital charges were longer LOS, admission to a teaching hospital, treatment in an intensive care unit, and the utilization of cardiac surgery, permanent pacemakers, and mechanical ventilation. Age, gender, race, comorbidity score, and medical insurance, as well as treatment by a cardiologist and death during the index hospitalization were not among the most significant predictors. Conclusions: We conclude that LOS and procedure utilization are the major determinants of hospital charges for an acute episode of inpatient HF care. Reducing LOS and other initiatives to restructure hospital-based HF care may reduce total health care costs for HF. [source] The Influence of Ivan Turgenev's Sportsman's Sketches on the Stories of Detlev von LiliencronORBIS LITERARUM, Issue 2 2001Barbara Burns Although Detlev von Liliencron (1844,1909) cited the Russian writer Ivan Turgenev (1818,1883) as one of the greatest influences on his literary work, the exact nature of the connection between them has not been investigated. The article examines aspects of Turgenev's early work A Sportsman's Sketches which made a particular impression on Liliencron and which, it is argued, served as a model for the development of scenes and characters in Liliencron's own prose. The similarities and differences in the two writers' world-views and creative scope are considered, and the significance of Turgenev's impact on the formative period of Liliencron's artistic career is evaluated. [source] | ||||||||||||||||||||||