bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pancreatic Duct Cells in Human Islet Cell Preparations Are a Source of Angiogenic Cytokines Interleukin-8 and Vascular Endothelial Growth Factor
Authors: Movahedi Babak , Gysemans Conny , Jacobs-Tulleneers-Thevissen Daniel , Mathieu Chantal , Pipeleers Daniel 
Published: May 2008

OBJECTIVE—Engraftment and function of human islet cell implants is considered to be dependent on their rapid and adequate revascularization. Studies with rodent islet grafts have shown that vascular endothelial growth factor (VEGF) expression by β-cells can promote this process. The present work examines whether human islet preparations produce VEGF as well as interleukin (IL)-8, another angiogenic protein, and assesses the role of contaminating duct cells in VEGF and IL-8–mediated angiogenesis.RESEARCH DESIGN AND METHODS—Human islet and pancreatic duct cell preparations are compared for their respective expression and production of VEGF and IL-8 during culture as well as following transplantation in nonobese diabetic (NOD)/scid mice. The associated angiogenic effects are measured in an in vitro aortic ring assay and in an in vivo chick embryo chorioallantoic membrane assay.RESULTS—Cultured pancreatic duct cells expressed 3- and 10-fold more VEGF and IL-8, respectively, than cultured human islet endocrine cells and released both proteins at angiogenic levels. The angiogenic effect of purified duct cells was higher than that of purified endocrine islet cells and was completely blocked by a combination of IL-8 and VEGF antibodies. Human duct cell implants under the kidney capsule of NOD/scid mice expressed higher levels of IL-8 and VEGF than human islet cell implants and induced circulating IL-8 and VEGF levels during the first day posttransplantation.CONCLUSIONS—Human duct cell–released IL-8 and VEGF may help revascularization of currently used human islet cell grafts. Further work should examine whether and when this effect can prevail over other inflammatory and immune influences of this cell type.
CD28/CD154 Blockade Prevents Autoimmune Diabetes by Inducing Nondeletional Tolerance After Effector T-Cell Inhibition and Regulatory T-Cell Expansion
Authors: Rigby Mark R. , Trexler Alison M. , Pearson Thomas C. , Larsen Christian P. 
Published: May 2008

OBJECTIVE—Blocking T-cell signaling is an effective means to prevent autoimmunity and allograft rejection in many animal models, yet the clinical translation of many of these approaches has not resulted in the success witnessed in experimental systems. Improved understanding of these approaches may assist in developing safe and effective means to treat disorders such as autoimmune diabetes.RESEARCH DESIGN AND METHODS—We studied the effect of anti-CD154 and CTLA4-Ig on diabetes development, and the requirements to induce tolerance in nod.scid mice after transfer of transgenic β-cell reactive BDC2.5.NOD T-cells.RESULTS—Nod.scid recipients of diabetogenic BDC2.5.NOD cells were protected indefinitely from diabetes by a short course of combined costimulation blockade, despite the continued diabetogenic potential of their T-cells. The presence of pathogenic T-cells in the absence of disease indicates peripheral immune tolerance. T-cell maturation occurred in protected recipients, yet costimulation blockade temporarily blunted early T-cell proliferation in draining pancreatic nodes. Tolerance required preexisting regulatory T-cells (Tregs), and protected recipients had greater numbers of Tregs than diabetic recipients. Diabetes protection was successful in the presence of homeostatic expansion and high T-cell precursor frequency, both obstacles to tolerance induction in other models of antigen-specific immunity.CONCLUSIONS—Immunotherapies that selectively suppress effector T-cells while permitting the development of natural regulatory mechanisms may have a unique role in establishing targeted long-standing immune protection and peripheral tolerance. Understanding the mechanism of these approaches may assist in the design and use of therapies for human conditions, such as type 1 diabetes.
Use of Internet Technology to Support Nutrition and Diabetes Self-Management Care
Authors: Powers Margaret A. , March Susan Burke , Evert Alison 
Published: May 2008

In Brief
The Internet can be a powerful support for diabetes nutrition and self-management care. It is prudent for health care professionals to learn how to maximize its use with their patient population. This article provides an overview of on how Internet websites can be used in diabetes care, provides evaluation criteria, and offers a review of selected sites.
Admissions Procedures at the University of Veterinary Medicine Vienna, Austria
Authors: Künzel Wolfgang , Breit Sabine M. 
Published: May 2008

Rationale for this study – The admission procedure implemented in fall 2005 in consequence of new laws passed in summer 2005 is described and evaluated. The general set-up, the underlying considerations, and the changes resulting from the establishment of this procedure are presented.Methodology – Admission variables and demographic information (sex, age, nationality) for 172 students who entered their first academic year at the University of Veterinary Medicine Vienna (VUW) and their academic performance measured according to their results in the three first-year examinations (successful versus unsuccessful) were assessed. Logistic regression was used to examine the relationship between predictor and outcome.Results – Regression analysis indicates that Austrian students were more likely to be unsuccessful than German students (R2= 0.366, p < 0.001). Previous school performance was the best predictor for success in the Austrian cohort (R2= 0.196; p < 0.001), whereas the personal interview scores provided the best predictor in the German cohort (R2= 0.122; p < 0.05).Conclusion – This study supports our existing selection practices relating to cognitive and non-cognitive skills. The number of strugglers may be reduced on the basis of an admissions procedure, but struggling may not be excluded by the existing selection practices, which do not assess a specific threshold but are related to a score-ranking system and a predefined number of available openings in the program.
Taxon combinations, parsimony analysis (PAUP*), and the taxonomy of the yellow‐tailed woolly monkey,Lagothrix flavicauda
Authors: Matthews Luke J. , Rosenberger Alfred L. 
Published: May 2008

AbstractThe classifications of primates, in general, and platyrrhine primates, in particular, have been greatly revised subsequent to the rationale for taxonomic decisions shifting from one rooted in the biological species concept to one rooted solely in phylogenetic affiliations. Given the phylogenetic justification provided for revised taxonomies, the scientific validity of taxonomic distinctions can be rightly judged by the robusticity of the phylogenetic results supporting them. In this study, we empirically investigated taxonomic‐sampling effects on a cladogram previously inferred from craniodental data for the woolly monkeys (Lagothrix). We conducted the study primarily through much greater sampling of species‐level taxa (OTUs) after improving some character codings and under a variety of outgroup choices. The results indicate that alternative selections of species subsets from within genera produce various tree topologies. These results stand even after adjusting the character set and considering the potential role of interobserver disagreement. We conclude that specific taxon combinations, in this case, generic or species pairings, of the primary study group has a biasing effect in parsimony analysis, and that the cladistic rationale for resurrecting theOreonaxgeneric distinction for the yellow‐tailed woolly monkey (Lagothrix flavicauda) is based on an artifact of idiosyncratic sampling within the study group below the genus level. Some recommendations to minimize the problem, which is prevalent in all cladistic analyses, are proposed. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
Study on the interaction between 2‐mercaptoethanol, dimercaprol and CdSe quantum dots
Authors: Dong Fei , Han Heyou , Liang Jiangong , Lu Donglian 
Published: May 2008

AbstractThe interactions between 2‐mercaptoethanol, dimercaprol and CdSe quantum dots (QDs) in organic media have been investigated by spectral methods. The results showed that the fluorescence (FL) emission of CdSe QDs gradually decreased, with a slight red‐shift, after adding thiols to CdSe QDs solutions. With the increase of the concentrations of thiols, the resonance light scattering (RLS) signal of CdSe QDs had been strongly enhanced in the wavelength range 300–500 nm, which was confirmed by the formation of larger CdSe QDs particles. The effect of thiols on the FL emission of CdSe QDs could be described by a Stern–Volmer‐type equation with the concentration ranges 1.0 × 10–6–7.5 × 10–4 mol/L for 2‐mercaptoethanol and 1.0 × 10–7–2.5 × 10–5 mol/L for dimercaprol. The possible mechanism of the interaction was proposed according to the results of UV‐vis absorption and micro‐Raman spectroscopy. The results indicated that FL quenching was mainly attributable to the exchange of the QDs surface molecules. Copyright © 2008 John Wiley & Sons, Ltd.
Cloning yeast actin cDNA leads to an investigative approach for the molecular biology laboratory
Authors: Black Michael W. , Tuan Alice , Jonasson Erin 
Published: May 2008

AbstractThe emergence of molecular tools in multiple disciplines has elevated the importance of undergraduate laboratory courses that train students in molecular biology techniques. Although it would also be desirable to provide students with opportunities to apply these techniques in an investigative manner, this is generally not possible in the classroom because of the preparation, expense, and logistics involved in independent student projects. The authors have designed a 10‐week lab series that mimics the research environment by tying separate fundamental lab techniques to a common goal: to build a plasmid with yeast actin cDNA cloned in a particular orientation. In the process of completing this goal, a problem arises in that students are unable to obtain the target plasmid and instead only recover the gene cloned in the opposite orientation. To address this problem, students identify four plausible hypotheses and work in teams to address them by designing and executing experiments. This project reinforces the utility and flexibility of techniques covered earlier in the class and serves to develop their skills in experimental design and analysis. As the project is focused on one problem, the diversity of experimental approaches is limited and may be prepared in advance with little additional expense in reagents or technical support.
Tonal interface to MacroMolecules (TIMMol)
Authors: Cordes Timothy J. , Carlson C. Britt , Forest Katrina T. 
Published: May 2008

AbstractWe developed the three‐dimensional visualization software, Tonal Interface to MacroMolecules or TIMMol, for studying atomic coordinates of protein structures. Key features include audio tones indicating x, y, z location, identification of the cursor location in one‐dimensional and three‐dimensional space, textual output that can be easily linked to speech or Braille output, and the ability to scroll along the main chain backbone of a protein structure. This program was initially designed for visually impaired users, and it already has shown its effectiveness in helping a blind researcher study X‐ray crystal structure data. Subsequently, TIMMol has been enhanced with a graphical display to act as a bridge to ease communication between sighted and visually impaired users as well as to serve users with spatial visualization difficulties. We performed a pilot study to assess the efficacy of the program in conveying three‐dimensional information about proteins with and without graphical output to a general scientific audience. Attitudes regarding using TIMMol were assessed using Rasmol, a common visualization package, for comparison. With the use of text and tones exclusively, a majority of users were able to identify specific secondary structure elements, three‐dimensional relationships among atoms, and atoms coordinating a ligand. In addition, a majority of users saw benefits in using TIMMol and would recommend it to those having difficulty with standard tools.
Climate‐based sensitivity of air quality to climate change scenarios for the southwestern United States
Authors: Wise Erika K. 
Published: May 2008

AbstractThe need to understand future trends in air quality is an issue that is frequently raised by air quality planners and managers. The potential for extreme events is of particular interest, but forecasts are difficult using traditional methods and further complicated by predictions of future climate change. This study aims to address this research need through a climate‐based sensitivity study of ground‐level ozone and particulate matter (PM) in the U.S. Southwest. Extreme value methods were used to examine ozone and PM in Tucson, Arizona, over the time period 1990–2001. A Statistical DownScaling Model (SDSM) was employed to build regression‐based models between gridded meteorological data and point time series of ozone and PM. Following model calibration and verification, future climate‐based ozone and PM scenarios were created for 2002–2050 and 2051–2099. Daily output of projected ozone and PM were then subjected to extreme value methods in order to estimate climate‐based changes in ozone and PM extremes over the next century. Results indicate that monthly mean and extreme ozone values are sensitive to predicted increases in temperature, particularly in the summer months. PM results are less certain but suggest that PM may be sensitive to changing moisture conditions. Copyright © 2008 Royal Meteorological Society
Radar‐guided interpolation of climatological precipitation data
Authors: DeGaetano Arthur T. , Wilks Daniel S. 
Published: May 2008

AbstractA refined approach for interpolating daily precipitation accumulations is presented, which combines radar‐based information to characterize the spatial distribution and gross accumulation of precipitation with observed daily rain‐gauge data to adjust for spatially varying errors in the radar estimates. Considering the rain gauge observations to be true values at each measurement location, daily radar errors are calculated at these points. These errors are then interpolated back to the radar grid, providing a spatially varying daily adjustment that can be applied across the radar domain. In contrast to similar techniques that are employed at hourly intervals to adjust radar‐rainfall estimates operationally, this refined approach is intended to provide high‐spatial‐resolution precipitation data for climatological purposes, such as drought and environmental monitoring, retrospective impact analyses, and (when time series of sufficient length become available) assessment of temporal precipitation variations at high‐spatial‐resolution.Compared to the Multisensor Precipitation Estimators (MPEs) used operationally, the refined method yields lower cross‐validated interpolation errors regardless of season or daily precipitation amount. Comparisons between cross‐validated radar estimates aggregated to monthly totals with operational (non‐cross‐validated) Parameter‐elevation Regressions on Independent Slopes Model (PRISM) precipitation estimates are also favourable. The new method provides a radar‐based alternative to similar climatologies based on the spatial interpolation of gauge data alone (e.g. PRISM). Copyright © 2008 Royal Meteorological Society
Dynamically and statistically downscaled seasonal temperature and precipitation hindcast ensembles for the southeastern USA
Authors: Schoof J. T. , Shin D. W. , Cocke S. , LaRow T. E. , Lim Y.‐K. , O'Brien J. J. 
Published: May 2008

AbstractWe present results from a 15‐year 10‐member warm season (March–September) hindcast ensemble of maximum and minimum surface air temperatures and precipitation in southeast USA. The hindcasts are derived from the Florida State University/Center for Ocean‐Atmospheric Prediction Studies Global Spectral Model (FSU/COAPS GSM) and downscaled using both the FSU/COAPS Nested Regional Spectral Model (NRSM) and a statistical downscaling method based on stochastic weather generator techniques. We additionally consider statistical bias correction of the dynamical model output. Basic descriptive statistics indicate that the bias‐corrected and statistically downscaled data reduce the FSU/COAPS GSM bias considerably in terms of basic climatology. Statistics describing the daily precipitation process are improved by both downscaling techniques relative to the bias‐corrected GSM. Improvement in monthly and seasonal hindcasts relative to FSU/COAPS GSM is spatially and temporally varying. Precipitation hindcasts are generally less skillful than those for temperature, although useful precipitation predictability exists at many locations. Hindcast improvements due to downscaling are greatest over peninsular Florida. The smallest root mean square errors (RMSE) for temperature hindcasts are found in the southern part of the study region during the spring months of March, April and May (MAM) for maximum surface air temperature, and in the summer, June, July and August (JJA), for minimum surface air temperature. Overall, there is no indication that either downscaling method has a direct advantage over the other. Copyright © 2008 Royal Meteorological Society
Potential for diffuse parenchymal lung disease after exposures at World Trade Center Disaster site
Authors: Szeinuk Jaime , Padilla María , de la Hoz Rafael E. 
Published: May 2008

AbstractObjective: The diffuse parenchymal lung diseases (DPLDs) are a heterogeneous group of disorders that result from damage to the lung parenchyma. While the cause of most DPLDs remains unknown, extensive epidemiological and experimental evidence has linked exposure to environmental toxins to the pathogenesis of some of those diseases. The purpose of this review is to examine the potential relation between exposure to toxins released from the World Trade Center (WTC) collapse on September 11th, 2001 and the development of DPLD based on published evidence up to date.Methods: We examine such evidence from two points of view, (1) exposure, and (2) histopathogenesis. Exposure: Analyses of WTC‐dust and particle size demonstrate that some portion of the dust was composed of particles small enough to penetrate deep into the lungs, reaching distal airways and alveoli. The presence of such particles has been confirmed in studies of induced sputum and bronchoalveolar lavage in WTC‐exposed firefighters. Histopathogenesis: In vitro and animal experiments and patient evidence suggest that WTC dust is capable of inducing a pulmonary interstitial inflammatory response.Results: To date, there have been limited clinical reports documenting the development of diffuse parenchymal responses following exposure to WTC dust. No single common pathologic response has been described. The one common denominator in the reports is that the individuals who developed disease were heavily exposed either during the disaster or during the initial 2‐to‐3 days following the disaster.Conclusion: DLPDs are probably associated with heavy or extended exposure to the toxins released at the WTC disaster site. Coupled with the historical experience with exposures to occupational toxins this mandates continued long‐term clinical observation of this cohort. Mt Sinai J Med 75:101–107, 2008 © 2008 Mount Sinai School of Medicine
Free radical copolymerization of 2,2,2‐trifluoroethyl α‐fluoroacrylate and tert‐butyl α‐trifluoromethylacrylate: Thermal and optical properties of the copolymers
Authors: Cracowski Jean‐Marc , Montembault Véronique , Hardy Isabelle , Bosc Dominique , Améduri Bruno , Fontaine Laurent 
Published: May 2008

AbstractThe radical copolymerization of 2,2,2‐trifluoroethyl α‐fluoroacrylate (FATRIFE) with tert‐butyl α‐trifluoromethylacrylate (MAF‐TBE) initiated by tert‐butyl 2,2‐dimethylperoxypropanoate was investigated in acetonitrile solution. A series of poly(FATRIFE‐co‐MAF‐TBE) copolymers were synthesized with MAF‐TBE compositions, determined by 19F NMR, ranging from 12 to 44 mol %. MAF‐TBE incorporation was less than 50 mol % as this monomer underwent no radical homopolymerization. The obtained copolymers exhibited number‐average molecular weights and polydispersity indexes ranging from 1.5 × 104 to 9.6 × 104 g/mol and from 1.5 to 3.1, respectively. The reactivity ratios were determined by the Kelen‐Tüdos method (rFATRIFE = 1.71 ± 0.01 and rMAF‐TBE = 0 at 74 °C) leading to random copolymers and alternating copolymers when the MAF‐TBE molar ratio in copolymer is close to 50 mol %. Thermal and optical properties of the resulting polymers were examined. Glass transition temperatures of copolymers were varying from 89 to 108 °C. Modifying the compositions of these copolymers allowed a precise control over the refractive index measured at 633, 1320, and 1550 nm. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4383–4391, 2008
Representations of nature of science in high school chemistry textbooks over the past four decades
Authors: Abd‐El‐Khalick Fouad , Waters Mindy , Le An‐Phong 
Published: May 2008

AbstractThis study assessed the representations of nature of science (NOS) in high school chemistry textbooks and the extent to which these representations have changed during the past four decades. Analyses focused on the empirical, tentative, inferential, creative, theory‐driven, and social NOS, in addition to the myth of “The Scientific Method,” the nature of scientific theories and laws, and the social and cultural embeddedness of science. A total of 14 textbooks, including five “series” spanning one to four decades, were analyzed. The textbooks commanded significant market shares in the United States and were widely used in some of the most populace states. Relevant textbook sections were scored on each of the target NOS aspects on a scale ranging from −3 to +3, which reflected the accuracy, completeness, and manner (explicit versus implicit) in which these aspects were addressed. The textbooks fared poorly in their representations of NOS. Additionally, with a few exceptions, textbook scores either did not change or decreased over the past four decades. These trends are incommensurate with the discourse in national and international science education reform documents, which has witnessed an increasing emphasis on the centrality of NOS to scientific literacy and pre‐college science education during the same time period. Assessment and evaluation strategies, and policies need to be targeted if substantial and desired changes in the ways NOS is addressed in science textbooks are to be effected. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 835–855, 2008