bluuebunny/crossref_metadata_2025_split huggingface dataset:
Career trajectories of nurses leaving the hospital sector in Ontario, Canada (1993–2004)
Authors: Alameddine Mohamad , Baumann Andrea , Laporte Audrey , O’Brien‐Pallas Linda , Levinton Carey , Onate Kanecy , Deber Raisa 
Published: March 2009

AbstractTitle. Career trajectories of nurses leaving the hospital sector in Ontario, Canada (1993–2004).Aim. This paper is a report of an analysis of the career trajectories of nurses 1 year after leaving hospitals.Background. Although hospitals are traditionally the largest employers of nurses, technological advances and budgetary constraints have resulted in many countries in relative shrinkage of the hospital sector and a shift of care (and jobs) into home/community settings. It has been often assumed that nurses displaced from hospitals will move to work in the other workplaces, especially the community sector.Method. Employment patterns were tracked by examining a longitudinal database of all 201,463 nurses registered with the College of Nurses Ontario (Canada) between 1993 and 2004. Focusing on the employment categories Active (Working in nursing), Eligible‐Seeking nursing employment or Dropout from the nursing labour market, year‐to‐year transition matrixes were generated by sector and sub‐sector of employment, nurse type, age group and work status.Findings. For every nurse practising nursing in any non‐hospital job or in the community a year after leaving hospitals, an average of 1·3 and four nurses, respectively, dropped out of Ontario’s labour market. The proportion of nurses leaving hospitals transitioning to the Dropout category ranged from 63·3% (1994–95) to 38·6% (2001–02). The proportion dropping out of Ontario’s market was higher for Registered Practical Nurses (compared to Registered Nurses), increased with age and decreased with degree of casualization in nurses’ jobs.Conclusion. Downsizing hospitals without attention to the potentially negative impact on the nursing workforce can lead to retention difficulties and adversely affects the overall supply of nurses.
Climate change and evolution of the New World pitviper genus Agkistrodon (Viperidae)
Authors: Douglas Michael E. , Douglas Marlis R. , Schuett Gordon W. , Porras Louis W. 
Published: March 2009

AbstractAim  We derived phylogenies, phylogeographies, and population demographies for two North American pitvipers, Agkistrodon contortrix (Linnaeus, 1766) and A. piscivorus (Lacépède, 1789) (Viperidae: Crotalinae), as a mechanism to evaluate the impact of rapid climatic change on these taxa.Location  Midwestern and eastern North America.Methods  We reconstructed maximum parsimony (MP) and maximum likelihood (ML) relationships based on 846 base pairs of mitochondrial DNA (mtDNA) ATPase 8 and ATPase 6 genes sequenced over 178 individuals. We quantified range expansions, demographic histories, divergence dates and potential size differences among clades since their last period of rapid expansion. We used the Shimodaira–Hasegawa (SH) test to compare our ML tree against three biogeographical hypotheses.Results  A significant SH test supported diversification of A. contortrix from northeastern Mexico into midwestern–eastern North America, where its trajectory was sundered by two vicariant events. The first (c. 5.1 Ma) segregated clades at 3.1% sequence divergence (SD) along a continental east–west moisture gradient. The second (c. 1.4 Ma) segregated clades at 2.4% SD along the Mississippi River, coincident with the formation of the modern Ohio River as a major meltwater tributary. A single glacial refugium was detected within the Apalachicola region of southeastern North America. Significant support was also found for a hypothesis of trans‐Gulf rafting by the common ancestor of A. piscivorus from eastern Mexico (possibly the Yucatan Peninsula) to northern Florida. There, a Mid–Late Pliocene marine transgression separated it at 4.8% SD from mainland North America. Significant range expansions followed compressive glacial effects in three (of four) A. contortrix clades and in two (of three) A. piscivorus clades, with the Florida A. piscivorus clade exhibiting significant distributional stasis.Main conclusions  Pliocene glaciations, rapidly developing western aridity, and Pleistocene glacial meltwaters seemingly led to the diversification of A. contortrix and A. piscivorus in North America. Both species were pushed southwards by Pleistocene climate change, with subsequent northward expansions uninhibited topographically. The subspecific taxonomy used for A. contortrix and A. piscivorus today, however, appear non‐representative. The monophyletic Florida subspecies of A. piscivorus may be a distinct species (at 4.8% SD), whereas two western subspecies of A. contortrix also appear to constitute a single distinct species, pending additional analyses. We conclude that both species of Agkistrodon can be used as suitable ectothermic models to gauge impacts of future climate change.
A history and review of school meal standards in the UK
Authors: Evans C. E. L. , Harper C. E. 
Published: March 2009

AbstractThis review details the history of school meals in the UK, from their origin in the mid‐19th Century, to the present day, and provides a summary of how each country has independently developed its own food and or nutrient‐based standards for school meals. The standards in place in the UK are amongst some of the most detailed and comprehensive in the world. Regular monitoring to ensure that these standards are being met and that schools are improving healthy eating is essential to their success. Of no lesser importance are assessments to determine whether changes to school meals are having an impact on the diets of school children. It is early days in terms of evaluation because food‐based standards have only recently been introduced and nutrient‐based standards are in the process of being developed and implemented. Studies in England provide some evidence that the re‐introduction of standards for school food is having a positive impact on both pupil’s food choices and the nutritional profile of school lunches. At present, there does not appear to be a pattern between current obesity levels and the types of school meals provided, although it is anticipated that, in the long term, these comprehensive standards may contribute to a less obesogenic environment.
Contribution of thickened drinks, food and enteral and parenteral fluids to fluid intake in hospitalised patients with dysphagia
Authors: Vivanti A. P. , Campbell K. L. , Suter M. S. , Hannan‐Jones M. T. , Hulcombe J. A. 
Published: March 2009

AbstractBackground:  Studies amongst older people with acute dysphagic stroke requiring thickened fluids have assessed fluid intakes from combinations of beverage, food, enteral and parenteral sources, but not all sources simultaneously. The present study aimed to comprehensively assess total water intake from food, beverages, enteral and parenteral sources amongst dysphagic adult in‐patients receiving thickened fluids.Methods:  Patients requiring thickened fluid following dysphagia diagnosis were recruited consecutively from a tertiary teaching hospital’s medical and neurosurgical wards. Fluid intake from food and beverages was assessed by wastage, direct observation and quantified from enteral and parenteral sources through clinical medical records.Results:  No patients achieved their calculated fluid requirements unless enteral or parenteral fluids were received. The mean daily fluid intake from food was greater than from beverages whether receiving diet alone (food: 807 ± 363 mL, food and beverages: 370 ± 179 mL; P < 0.001) or diet with enteral or parenteral fluid support (food: 455 ± 408 mL, food and beverages: 263 ± 232 mL; P < 0.001). Greater daily fluid intakes occurred when receiving enteral and parenteral fluid in addition to oral dietary intake, irrespective of age group, whether assistance was required, diagnosis and whether stage 3 or stage 2 thickened fluids were required (P < 0.05). After enteral and parenteral sources, food provided the most important contribution to daily fluid intakes.Conclusions:  The greatest contribution to oral fluid intake was from food, not beverages. Designing menus and food services that promote and encourage the enjoyment of fluid dense foods, in contrast to thickened beverages, may present an important way to improve fluid intakes of those with dysphagia. Supplemental enteral or parenteral fluid may be necessary to achieve minimum calculated fluid requirements.
Psychosocial factors underlying the mother’s decision to continue exclusive breastfeeding for 6 months: an elicitation study
Authors: Bai Y. K. , Middlestadt S. E. , Joanne Peng C.‐Y. , Fly A. D. 
Published: March 2009

AbstractBackground:  Despite numerous benefits of exclusive breastfeeding (EBF) for infants and mothers, a significant decrease in the EBF rate in the USA at six months compared to the rate at birth suggests that reasons for initiation and continuation of EBF may differ. The purpose of this qualitative study was to explore psychosocial factors underlying the continued EBF behaviour for six months, in order to identify salient belief structures according to the theory of planned behaviour.Methods:  Participants were recruited from central Indiana in the USA. They were asked to respond to an open‐ended questionnaire designed to elicit positive/negative consequences, approving/disapproving social referents, and easy/difficult circumstances in continuing EBF for six months. Responses were translated into behavioural, normative, and control beliefs of the theory.Results:  Findings suggest that respondents (1) value emotional and health benefits of continued EBF for six months; (2) feel the approval from family and friends but disapproval from the society; (3) view health professional’s position as positive and negative.Conclusions:  Breastfeeding educators can more likely improve the EBF duration by addressing these salient beliefs. Identified beliefs provide a basis for the development of a quantitative instrument to further study the EBF behaviour.
Gene flow of Acanthaster planci (L.) in relation to ocean currents revealed by microsatellite analysis
Authors: YASUDA NINA , NAGAI SATOSHI , HAMAGUCHI MASAMI , OKAJI KEN , GÉRARD KARIN , NADAOKA KAZUO 
Published: March 2009

AbstractPopulation outbreaks of the coral‐eating starfish, Acanthaster planci, are hypothesized to spread to many localities in the Indo‐Pacific Ocean through dispersal of planktonic larvae. To elucidate the gene flow of A. planci across the Indo‐Pacific in relation to ocean currents and to test the larval dispersal hypothesis, the genetic structure among 23 samples over the Indo‐Pacific was analysed using seven highly polymorphic microsatellite loci. The F‐statistics and genetic admixture analysis detected genetically distinct groups in accordance with ocean current systems, that is, the Southeast African group (Kenya and Mayotte), the Northwestern Pacific group (the Philippines and Japan), Palau, the North Central Pacific group (Majuro and Pohnpei), the Great Barrier Reef, Fiji, and French Polynesia, with a large genetic break between the Indian and Pacific Oceans. A pattern of significant isolation by distance was observed among all samples (P = 0.001, r = 0.88, n = 253, Mantel test), indicating restricted gene flow among the samples in accordance with geographical distances. The data also indicated strong gene flow within the Southeast African, Northwestern Pacific, and Great Barrier Reef groups. These results suggest that the western boundary currents have strong influence on gene flow of this species and may trigger secondary outbreaks.
Explaining educational inequalities in birthweight: the Generation R Study
Authors: Jansen Pauline W. , Tiemeier Henning , Looman Caspar W. N. , Jaddoe Vincent W. V. , Hofman Albert , Moll Henriëtte A. , Steegers Eric A. P. , Verhulst Frank C. , Mackenbach Johan P. , Raat Hein 
Published: March 2009

SummaryAlthough low socio‐economic status has consistently been associated with lower birthweight, little is known about the factors whereby socio‐economic disadvantage influences birthweight. We therefore examined explanatory mechanisms that may underlie the association between the educational level of pregnant women, as an indicator of socio‐economic status, and birthweight. The study was embedded within a population‐based cohort study in the Netherlands. Information on maternal education, offspring's birthweight and several determinants of birthweight was available for 3546 pregnant women of Dutch origin.Infants of the lowest educated women had a statistically significantly lower birthweight than infants of the highest educated women [difference adjusted for gender and gestational age: −123 g (95% CI −167, –79)]. Parity, age of the pregnant women, hypertension, parental height and parental birthweight, marital status, pregnancy planning, financial concerns, number of people in household, weight gain and smoking habits individually explained part of the differences in birthweight, while adjustment for working hours and body mass index resulted in increases in birthweight differences between the educational levels. After full adjustment, the difference in birthweight between lowest and highest education was reduced by 66%. Our study confirmed remarkable educational inequalities in birthweight, a large part of which was explained by pregnancy characteristics, anthropometrics, the psychosocial and material situation, and lifestyle‐related factors. Altering smoking habits may be an option to reduce educational differences in birthweight, as many lower‐educated women tend to continue smoking during pregnancy. In order to tackle inequalities in birthweight, it is important that interventions are accessible for pregnant women in lower socio‐economic strata.
Modelling the association of blood pressure during pregnancy with gestational age and body mass index
Authors: Thompson Mary Lou , Williams Michelle A. , Miller Raymond S. 
Published: March 2009

SummaryImproved understanding of the determinants of blood pressure (BP) changes during pregnancy is essential for decreasing the morbidity and mortality borne by women and their families worldwide. While most epidemiological studies consider associations based on categorical risk factor classifications, using measurements on a continuous scale has been advocated as a means of gaining richer insights into biological processes. We modelled the relationship during pregnancy of continuous systolic (S) and diastolic (D) BP distributions with gestational age and pre‐pregnancy body mass index (BMI) using fractional polynomials. We used information, including antenatal BP values abstracted from medical records, from a prospective cohort of 1733 women recruited before 20 weeks' gestation.The percentiles for SBP and DBP changed over pregnancy, with DBP percentiles decreasing initially, followed by an increase starting about mid‐second trimester. Modelling the joint impact of BMI and gestational age on mean BP indicated an increase in mean BP with increasing BMI that was attenuated at higher BMI levels, later in pregnancy. This attenuation persisted in a variety of sub‐analyses which explored the possibility that it was caused by confounding or by influential groupings of subjects. Estimated longitudinal percentiles that characterise the BP distribution across gestation may facilitate evaluation of BP during pregnancy. BP patterns observed over pregnancy and, in particular, the attenuation of BP increases at high BMI, late in pregnancy, can provide insights towards elucidating the mechanisms that drive BP changes during pregnancy.
Glutamate induces directed chemotaxis of microglia
Authors: Liu Guo Jun , Nagarajah Rajini , Banati Richard B. , Bennett Max R. 
Published: March 2009

AbstractMicroglia in the brain possess dynamic processes that continually sample the surrounding parenchyma and respond to local insults by rapidly converging on the site of an injury. One of the chemotaxic agents responsible for this response is ATP. Here we show that the transmitter glutamate is another such chemotaxic agent. Microglia exposed to glutamate increase their cell membrane ruffling and migrate to a source of glutamate in cell culture and in spinal cord slices. This chemotaxis is meditated by α‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid (AMPA) and metabotropic glutamate receptors on the microglia. Chemotaxis is dependent on redistribution of actin filaments in the cells and on tubulin following receptor activation. Thus glutamate, which is released at synapses as well as from damaged cells, can mediate rapid chemotaxic responses from microglial cells.
Recovery of motor and cognitive function after cerebellar lesions in a songbird – role of estrogens
Authors: Spence Rory D. , Zhen Yin , White Stephanie , Schlinger Barney A. , Day Lainy B. 
Published: March 2009

AbstractIn addition to its key role in complex motor function, the cerebellum is increasingly recognized to have a role in cognition. Songbirds are particularly good models for the investigation of motor and cognitive processes but little is known about the role of the songbird cerebellum in these processes. To explore cerebellar function in a songbird, we lesioned the cerebellum of adult female zebra finches and examined the effects on a spatial working memory task and on motor function during this task. There is evidence for steroid synthesis in the songbird brain and neurosteroids may have an impact on some forms of neural plasticity in adult songbirds. We therefore hypothesized that neurosteroids would affect motor and cognitive function after a cerebellar injury. We found that cerebellar lesions produced deficits in motor and cognitive aspects of a spatial task. In line with our prediction, birds in which estrogen synthesis was blocked had impaired performance in our spatial task compared with those that had estrogen synthesis blocked but estrogen replaced. There was no clear effect of estrogen replacement on motor function. We also found that lesions induced expression of the estrogen synthetic enzyme aromatase in reactive astrocytes and Bergmann glia around a cerebellar lesion. These data suggest that the cerebellum of songbirds mediates both motor and cognitive function and that estrogens may improve the recovery of cognitive aspects of cerebellar function after injury.
Links between resources, C metabolism and the major components of bacterioplankton community structure across a range of freshwater ecosystems
Authors: Comte Jérôme , Del Giorgio Paul A. 
Published: March 2009

SummaryWe explored the patterns in bacterioplankton community metabolism (BCM) and four components of community structure [composition (BCC), metabolic capacities (MC), physiological structure (PS) and single‐cell characteristics (SCC)], between lakes, rivers and marshes within a watershed in Québec, to assess the connections that exist between them and with the main resources (organic matter, nutrients). Habitat types were well segregated by both resources and BCM and their corresponding dissimilarity matrices were significantly correlated, suggesting that BCM tracks resource conditions in a consistent manner across ecosystem types. MC also segregated the various habitats and was correlated to BCM but less so to resources, whereas BCC at times resulted in a clear separation of habitats, but was rarely correlated to resources and never to BCM, suggesting a higher degree of ecosystem specificity at this particular level. Finally, there was no clear separation of habitats in terms of PS and SCC, and none covaried with resources or BCM. The habitat patterns based on these different components of structure were rarely correlated to each other, indicating weak deterministic connections between them. MC appears to mediate the link between resources and BCM more directly and consistently across systems; BCC appears to be more influenced by ecosystem‐specific factors that weaken its overall connection to both resources and BCM, whereas PS and SCC show no discernible patterns. Our results thus suggest that the bottom‐up regulation of BCM by resources is mediated by complex shifts within components of community structure that can be directional, ecosystem‐specific or apparently random, which combined nevertheless result in a systematic overall response to resources in terms of C metabolism.
RETRACTED: The Escherichia coli ycbQRST operon encodes fimbriae with laminin‐binding and epithelial cell adherence properties in Shiga‐toxigenic E. coli O157:H7
Authors: Samadder Partha , Xicohtencatl‐Cortes Juan , Saldaña Zeus , Jordan Dianna , Tarr Phillip I. , Kaper James B. , Girón Jorge A. 
Published: March 2009

SummaryThe human pathogen Shiga‐toxigenic Escherichia coli (STEC) O157:H7 contains a ycbQRST fimbrial‐like operon, which shares significant homology to the family of F17 fimbrial biogenesis genes f17ADCG found in enterotoxigenic E. coli. We report that growth of STEC O157:H7 strain EDL933 in minimal Minca medium at 37°C and during adherence to epithelial cells led to the production of fine peritrichous fimbriae, which were found to be composed of a major subunit of 18 kDa whose N‐terminal amino acid sequence matched the predicted protein product of the ycbQ gene; and showed significant homology to the F17a‐A fimbrin. Similar to the F17 fimbriae, the purified STEC fimbriae and the recombinant YcbQ protein fused to a His peptide tag bound laminin, but not fibronectin or collagen. Thus, we propose the name E. coli YcbQ laminin‐binding fimbriae (ELF) to designate the fimbriae encoded by the ycbQRST operon. The role of ELF as an adherence factor of STEC to cultured epithelial cells was investigated. We provide compelling evidence demonstrating that ELF contributes to adherence of STEC to human intestinal epithelial cells and to cow and pig gut tissue in vitro. Deletion in the fimbrin subunit gene elfA (or ycbQ) in STEC strain EDL933 led to an isogenic strain, which showed significant reduction (60%) in adherence to HEp‐2 cells in comparison with the parental strain. In addition, antibodies against the purified ELF also partially blocked adherence of two STEC O157:H7 strains. These observations suggest that ELF functions as an accessory adherence factor that, along with other known redundant adhesins, contributes to the overall adhesive properties of STEC O157:H7 providing these organisms with ecological advantages to survive in different hosts and in the environment.