bluuebunny/crossref_metadata_2025_split huggingface dataset:
The relative importance of stabilizing mechanisms of coexistence
Authors: Yenni Glenda , Xiao Xiao 
Published: September 2009

Abstract
Background/Question/Methods
Stabilizing mechanisms of coexistence, by definition, cause a species to experience greater intraspecific competition than interspecific. This results in negative frequency-dependent growth rates for that species causing a negative relationship between its relative frequency in the community and its growth rate in the next year. The most crucial aspect of this negative relationship for persistence is that it enables a species to increase when rare. This has been empirically demonstrated for pairwise interactions. However, in species-rich communities, the effects of competition are not realistically pairwise. In cases where multiple species are competing for a resource, stabilizing mechanisms become increasingly important to ease the effects of that competition. Thus, for rare species, increasing the strength of stabilization may be essential to their persistence in the community, or their ability to invade. A mathematical model of negative frequency-dependent growth is used to explore how the strength of stabilization affects a species’ ability to persist in a community.

Results/Conclusions
Increasing the steepness of the negative frequency-dependent growth relationship for rare species significantly increases their mean time to extinction in this simulated community. Significantly, the desert rodent community at the Portal LTREB site shows this predicted pattern, in which rare species experience stronger negative frequency-dependant growth relationships than the dominant species. This pattern may be a characteristic of species-rich communities, and thus have implications for the ability of those communities to maintain stable structure despite change (climate change, invasive species, habitat loss).
Phenotypic Plasticity and the Invasiveness of Three Taraxacum Species
Authors: Luo Jing , Cardina John 
Published: September 2009

Abstract
Background/Question/Methods
Many factors have been found to be associated with the success of invasive species. Phenotypic plasticity, the ability of a plant genotype to respond to different environmental conditions by producing different phenotypes, is thought to play an important role plant invasions. In three major experiments, I tested the hypothesis that the invasive Taraxacum officinale (common dandelion) and its non-invasive congener T. laevigatum will exhibit different phenotypic plasticity in germination, growth, and reproduction. I also proposed that their responses to various environments could be used to assess the invasive behavior of a potential crop species: T. kok-saghyz.

Results/Conclusions
The results revealed complicated responses of the three species in various environments. The invasive T. officinale showed higher germination in high alternating temperature, and accumulated more biomass than the non-invasive T. laevigatum in favorable greenhouse conditions. Surprisingly, T. laevigatum germinated better than T. officinale in other stressful environments (dark, low water potential, long aging period), and also exhibited higher fecundity in favorable greenhouse conditions. In field experiments, however, the performance of T. officinale was overwhelmingly better than T. laevigatum, which suffered very high mortality and failed to survive for more than two growing seasons. These results suggest that T. officinale might benefit from its ability to grow, reproduce, and survive in various environments, while T. laevigatum relies on seed reproduction to maintain its population. With the exception of germination, the responses of T. kok-saghyz were more like T. officinale than T. laevigatum, which suggested that this species has some potential to behave as a weed.
Transmission of HIV-Associated Tuberculosis to Healthcare Workers
Authors: Perri Giovanni Di , Cadeo GianPietro , Castelli Francesco , Micciolo Rocco , Bassetti Sergio , Rubini Franco , Cazzadori Angelo , Marocco Stefania , Carlotto Antonio , Adami Teresa , Vento Sandro , Malena Marina , Carosi GianPiero , Concia Ercole , Bassetti Dante 
Published: September 2009

AbstractObjective:A retrospective investigation was made to compare the occupational risk of tuberculosis in personnel assisting human immunodeficiency virus (HIV)-infected and uninfected subjects with active tuberculosis.Design:We retrospectively reviewed 6 years of hospital activity in 3 units where HIV-infected patients with tuberculosis are hospitalized and in 2 units where non-HIV-infected tuberculosis patients are hospitalized. The risk of occupational tuberculosis in healthcare workers who assisted HIV-infected and non-HIV-infected patients with tuberculosis was investigated.Participants:The risk of occupational tuberculosis in healthcare workers was studied by considering the numbers of potential source cases (hospitalized patients with tuberculosis) in the two conditions investigated (HIV-positive and HIV-negative). Both potential source cases and cases of tuberculosis in healthcare workers had to be microbiologically proven in order to be considered..Results:Seven cases of tuberculosis occurred in persons who cared for 85 HIV-infected subjects with tuberculosis, while only 2 cases occurred in staff members who took care of 1,079 HIV-negative tuberculosis patients over the same period (relative risk=44.4; 95% confidence interval = 8.5-438).Conclusions:Tuberculosis seems no longer to be a neglectable risk in healthcare workers assisting patients with HIV infection. Further study is urgently needed to see whether such unexpectedly high dissemination of tuberculosis also is demonstrable in the community.
Measles-Mumps-Rubella Immunization of Susceptible Hospital Employees During a Community Measles Outbreak Cost-Effectiveness and Protective Efficacy
Authors: Stover Beth H. , Adams Garrett , Kuebler Carol A. , Cost Karen M. , Rabalais Gerard P. 
Published: September 2009

AbstractObjective:To determine cost-effectiveness and protective efficacy of a program to identify and immunize susceptible hospital employees during a measles outbreak.Design:A cost analysis was made of blind measles-mumps-rubella (MMR) immunization versus directed MMR immunization based on 2,000 employees born after December 31, 1956. A directed MMR immunization program for susceptible employees was instituted. Actual costs of the program were calculated at the conclusion of the program.Setting:A medical center complex with more than 4,000 employees, two acute care community hospitals, and a tertiary care children's hospital.Results:A directed MMR immunization program was projected to he less expensive than blind immunization ($23,106 versus $70,720). MMR vaccine was administered to 169 of 188 susceptible employees. Actual cost of the directed MMR immunization program was $25,384.Conclusions:The directed MMR immunization program was cost-effective and prevented secondary cases among hospital employees during a community measles outbreak.
Conference on Prevention of Transmission of Bloodborne Pathogens in Surgery and Obstetrics
Authors: Bell David M. , Rhodes Robert S. 
Published: September 2009

Few issues in hospital infection control have evoked as much debate as the controversies regarding the risk and prevention of transmission of blood-borne pathogens to healthcare workers and patients during invasive procedures. To promote direct discussions among researchers and other interested participants from multiple disciplines affected by these issues, the American College of Surgeons and the Centers for Disease Control and Prevention cosponsored a Conference on Prevention of Transmission of Bloodborne Pathogens in Surgery and Obstetrics, February 13-15, 1994, in Atlanta, Georgia. The conference was attended by approximately 200 participants from nine countries, including surgeons from a variety of specialties, obstetricians, operating and delivery room personnel, anesthesiologists, hospital epidemiologists and infection control personnel, occupational health specialists, and public health professionals.Titles of plenary sessions included Risk of Occupational Transmission of Bloodborne Pathogens, Microbiologic Aspects (dealing with aerosols and disinfection and sterilization issues), Prevention of Injuries by Needles and Other Sharp Instruments, Hand Protection, Body and Facial Protection, Evaluation of New products on the Market, Postexposure Management, Are Universal Precautions Realistic, and Bloodborne Pathogen Transmission to Patients. Feedback from the attendees indicated that the conference achieved its goals and that future conferences on these issues would be welcome.
Healthcare Workers Risk of Contact With Body Fluids in a Hospital: The Effect of Complying With the Universal Precautions Policy
Authors: Kristensen Michael Seltz , Wernberg Niels Mogens , Anker-Moller Erling 
Published: September 2009

AbstractObjective:To test whether healthcare workers' knowledge of and compliance with the basic principle of the Universal Precautions policy (i.e., that all patients should be treated equally regarding contact with body fluids) influenced the rate of contact with patient blood.Design:Survey based on anonymous questionnaires.Setting:A 380-bed secondary and tertiary care hospital receiving emergency and elective patients.Participants:All employees having any contact with patients. Nine hundred one of 1,308 (69%) of the questionnaires were returned.Results:Twelve percent of the respondents (95% confidence interval [CI95] = 10.0%-14.4%) had experienced any contact with patient blood in the week preceding their answer. Physicians had the highest rate of contact with blood followed by nurses. In the five groups-physicians, nurses, laboratory technicians and phlebotomists, nursing aides, and student nurses-contact with blood was less frequent in the subgroup that did know and comply with the basic principle of the Universal Precautions policy, compared with the subgroup that did not. When adding the results for the 5 groups, contact with blood was experienced by 91 of 571 (15.9%, CI95=13%-19%) of the personnel who did not know and comply with Universal Precautions. The personnel who did know and comply with Universal Precautions had a significantly lower (9 of 111 [8.1%], p<.05, CI95 = 3.8%- 15%) rate of contact with blood.Conclusions:The healthcare workers who knew and complied with Universal Precautions had a significant lower rate of contact with patient blood than those who did not.
High‐Throughput Near‐Infrared Reflectance Spectroscopy for Predicting Quantitative and Qualitative Composition Phenotypes of Individual Maize Kernels
Authors: Spielbauer Gertraud , Armstrong Paul , Baier John W. , Allen William B. , Richardson Katina , Shen Bo , Settles A. Mark 
Published: September 2009

ABSTRACTNear‐infrared reflectance (NIR) spectroscopy can be used for fast and reliable prediction of organic compounds in complex biological samples. We used a recently developed NIR spectroscopy instrument to predict starch, protein, oil, and weight of individual maize (Zea mays) seeds. The starch, protein, and oil calibrations have reliability equal or better to bulk grain NIR analyzers. We also show that the instrument can differentiate quantitative and qualitative seed composition mutants from normal siblings without a specific calibration for the constituent affected. The analyzer does not require a specific kernel orientation to predict composition or to differentiate mutants. The instrument collects a seed weight and a spectrum in 4–6 sec and can collect NIR data alone at a 20‐fold faster rate. The spectra are acquired while the kernel falls through a glass tube illuminated with broad spectrum light. These results show significant improvements over prior single‐kernel NIR systems, making this instrument a practical tool to collect quantitative seed phenotypes at high throughput. This technology has multiple applications for studying the genetic and physiological influences on seed traits.
Miniature1-Encoded Cell Wall Invertase Is Essential for Assembly and Function of Wall-in-Growth in the Maize Endosperm Transfer Cell
Authors: Kang Byung-Ho , Xiong Yuqing , Williams Donna S. , Pozueta-Romero Diego , Chourey Prem S. 
Published: September 2009

AbstractThe miniature1 (mn1) seed phenotype in maize (Zea mays) is due to a loss-of-function mutation at the Mn1 locus that encodes a cell wall invertase (INCW2) that localizes exclusively to the basal endosperm transfer cells (BETCs) of developing seeds. A common feature of all transfer cells is the labyrinth-like wall-in-growth (WIG) that increases the plasma membrane area, thereby enhancing transport capacity in these cells. To better understand WIG formation and roles of INCW2 in the BETC development, we examined wild-type and mn1 mutant developing kernels by cryofixation and electron microscopy. In Mn1 seeds, WIGs developed uniformly in the BETC layer during 7 to 17 d after pollination, and the secretory/endocytic organelles proliferated in the BETCs. Mitochondria accumulated in the vicinity of WIGs, suggesting a functional link between them. In the mn1 BETCs, WIGs were stunted and their endoplasmic reticulum was swollen; Golgi density in the mutant BETCs was 51% of the Mn1 Golgi density. However, the polarized distribution of mitochondria was not affected. INCW2-specific immunogold particles were detected in WIGs, the endoplasmic reticulum, Golgi stacks, and the trans-Golgi network in the Mn1 BETCs, while immunogold particles were extremely rare in the mutant BETCs. Levels of WIG development in the empty pericarp4 mutant was heterogeneous among BETCs, and INCW2 immunogold particles were approximately four times more abundant in the larger WIGs than in the stunted WIGs. These results indicate that polarized secretion is activated during WIG formation and that INCW2 is required for normal development of WIGs to which INCW2 is localized.
A Nuclear Factor Regulates Abscisic Acid Responses in Arabidopsis
Authors: Kim Min Jung , Shin Ryoung , Schachtman Daniel P. 
Published: September 2009

Abstract
Abscisic acid (ABA) is a plant hormone that regulates plant growth as well as stress responses. In this study, we identified and characterized a new Arabidopsis (Arabidopsis thaliana) protein, Nuclear Protein X1 (NPX1), which was up-regulated by stress and treatment with exogenous ABA. Stomatal closure, seed germination, and primary root growth are well-known ABA responses that were less sensitive to ABA in NPX1-overexpressing plants. NPX1-overexpressing plants were more drought sensitive, and the changes in response to drought were due to the altered guard cell sensitivity to ABA in transgenic plants and not to a lack of ABA production. The nuclear localization of NPX1 correlated with changes in the expression of genes involved in ABA biosynthesis and ABA signal transduction. To understand the function of NPX1, we searched for interacting proteins and found that an ABA-inducible NAC transcription factor, TIP, interacted with NPX1. Based on the whole plant phenotypes, we hypothesized that NPX1 acts as a transcriptional repressor, and this was demonstrated in yeast, where we showed that TIP was repressed by NPX1. Our results indicate that the previously unknown protein NPX1 acts as a negative regulator in plant response to changes in environmental conditions through the control of ABA-regulated gene expression. The characterization of this factor enhances our understanding of guard cell function and the mechanisms that plants use to modulate water loss from leaves under drought conditions.
Possible causes of decreasing migratory ungulate populations in an East African savannah after restrictions in their seasonal movements
Authors: Voeten Margje M. , Van De Vijver Claudius A.D.M. , Olff Han , Van Langevelde Frank 
Published: September 2009

AbstractIn many areas in Africa, seasonal movements of migratory ungulates are restricted and their population numbers decline, for example in the Tarangire region, Tanzania. Here, agriculture restricts migration of ungulates to their wet season ranges. We investigated whether low forage quality or supply are possible causes of population decline of wildebeest and zebra when access to these wet season ranges is restricted and migratory herds have to reside in the dry season range year‐round. We simulated grazing through a clipping experiment in the dry season range during the wet season. Clipping negatively affected forage supply and had a positive effect on forage quality by increasing proportions of live and leaf biomass as well as nutrient concentrations in the leaves. However, increase in forage quality in the dry season range due to grazing was not as such that requirements of wildebeest during the wet season, when females are lactating, could be met. We conclude that low forage quality in the dry season range during the wet season could cause the decrease in migratory ungulate populations in the Tarangire region. With this study, the necessity of protecting wet season ranges from expanding human activities to safeguard migratory systems is supported.
Pollution status of a tropical forest river using aquatic insects as indicators
Authors: Imoobe Tunde Ohiokhioya Thadeus , Ohiozebau Ehimai 
Published: September 2009

AbstractAquatic insects inhabiting Okhuo River, in a tropical forest near Benin City, Southern Nigerian, were studied between January and December 2006 to determine the taxa composition, diversity, EPT index, relative proportions of the various groups and hence the pollution level of the waterbody. Three stations were selected and sampled monthly using the kick sampling technique. A total of 3235 individual aquatic insects belonging to 24 taxa distributed among 23 genera in six orders were collected. The insect orders occurred in the following order of dominance: Ephemeroptera > Odonata > Coleoptera > Diptera > Plecoptera > Tricoptera. Based on the diverse composition of the community dominated by organisms intolerant of organic enrichment, and the high diversity and EPT index, water quality in Okhuo River is not significantly degraded. Community composition varies seasonally, with a trend toward a declining proportion during the rainy season and increasing proportions during the dry season. Aquatic insect composition in Okhuo River compares favourably with those in similar, relatively undisturbed forest streams and rivers in Nigeria, but the diversity and proportional distribution of taxa vary considerably between streams.
Umbilical cord blood processing using Prepacyte‐CB increases haematopoietic progenitor cell availability over conventional Hetastarch separation
Authors: Basford C. , Forraz N. , Habibollah S. , Hanger K. , McGuckin C. P. 
Published: September 2009

AbstractBackground:  Currently the most frequently used method for umbilical cord blood separation in many hospitals across the UK and the rest of the world, where small‐to‐medium amounts of samples are processed, is Hetastarch, a mechanical, starch‐based method, which causes red cell agglutination by rouleaux formation.Aim:  In this study, a novel method (Prepa‐Cyte‐CB), in comparison with Hetastarch as part of an FDA‐approved clinical study, was evaluated.Materials and Methods:  Validation of data included recovery of nucleated and CD34+ cells, red blood cell reduction, colony forming unit potential, flow cytometric analysis and sterility tests.Results:  PrepaCyte‐CB, in comparison with Hetastarch offers fast, reliable separation with improved recovery of nucleated cells, 72.03% (±8.48 SD) compared to 58.09% (±20.06 SD), and CD34+ haematopoietic progenitor cells, 76% (±19.54 SD) compared to 64.19% (±29.77 SD). PrepaCyte‐CB was also 12‐fold more efficient in removing red blood cells and haemoglobin (P < 0.001) than Hetastarch.Conclusions:  These results show that PrepaCyte‐CB offers superior separation of UCB when compared to Hetastarch.
Physiological skin conditions of preterm and term neonates
Authors: Afsar F. S. 
Published: September 2009

Summary
Skin problems in children during the first few weeks of life can raise concern, even for experienced neonatologists and paediatric dermatologists. The skin of preterm and term newborn babies has distinct differences from juvenile and adult skin. An understanding of the nature of neonatal skin, the physiological and nonphysiological skin conditions of preterm and term neonates, and skin care are essential in paediatric practice. This article discusses the nature of the neonatal skin and its physiological phenomena.
A physiologically relevant atherogenic diet causes severe endothelial dysfunction within 4 weeks in rabbit
Authors: Rai Sudarshan , Hare David L. , Zulli Anthony 
Published: September 2009

SummaryA physiological atherogenic human diet consists of 0.1% cholesterol, fat, as well as high levels of methionine, which is the precursor to homocysteine. The pathological effects of a diet enriched with physiologically high levels of cholesterol, methionine and fat over a short period on the aorta are unknown. In this regard, we sought to determine the effects of a 0.1% cholesterol diet in combination with a 1% methionine over a 4‐week period on endothelial function and artery pathology and the expression of endothelial nitric oxide synthase as well as nitrosative stress by nitrotyrosine (NT), oxidative stress by heat shock protein 70 (HSP70) and endoplasmic reticulum stress by glucose regulated protein 78 (GRP78). Rabbits were fed for 4 weeks a diet supplemented with 1% methionine + 0.1% cholesterol + 5% peanut oil (MC). The endothelial function of the abdominal aorta was examined using organ bath techniques, atherosclerosis determined in each artery by microscopy and eNOS, NT, GRP78 and HSP70 by standard immunohistochemistry. Endothelium dependent relaxation in response to acetylcholine significantly decreased by 63% at 1 μM acetylcholine (P < 0.001) compared with control arteries. There was no evidence of atherosclerosis formation in any artery studied, however, eNOS, NT and GRP78 was clearly present in all arteries studied but HSP70 was not easily detectable. Severe endothelial dysfunction is present in the abdominal aorta of rabbits within 4 weeks of physiological dietary manipulation, possibly due to NT formation and endoplasmic reticulum stress. This model could be used to study the early onset of endothelial dysfunction prior to the initiation of atherosclerosis.
A test procedure to characterise the heating performance of domestic microwave ovens
Authors: Swain Mark Jeffery , Spinassou Adrien , Swain Maria Veronica Lyra 
Published: September 2009

SummaryA test procedure has been developed and used to characterise the performance of domestic microwave ovens in relation to the heating of chilled ready meals. The procedure uses reproducible test loads, which simulate the heating and weight loss characteristics of a chilled ready meal under consumer use. The temperature distribution after heating from 5 °C to a defined minimum temperature of 70 °C is measured in the food simulant using a purpose designed multipoint thermocouple ‘hedgehog’ probe. The temperature, weight loss and heating time data from the test are entered into a spreadsheet analysis program, which provides a simple oven performance ‘score’ and/or comprehensive heating performance data.