bluuebunny/crossref_metadata_2025_split huggingface dataset:
A 5 year record of surface energy and mass balance from the ablation zone of Storbreen, Norway
Authors: Andreassen Liss M. , Van Den Broeke Michiel R. , Giesen Rianne H. , Oerlemans Johannes 
Published: July 2008

AbstractA 5 year record of data from an automatic weather station (AWS) operating in the ablation zone of Storbreen, Norway, has been used to calculate the local surface energy and mass balance. The AWS observations cover five mass-balance years with an unusually strong mass deficit on Storbreen. The average energy flux (Q) contributing to melt for the period 2001–06 is 113 W m−2. Of this, the net shortwave radiation flux is the dominant contributor (92 W m−2), followed by the sensible heat flux (20 W m−2) and the latent heat flux (9 W m−2). The net longwave radiation (–6 W m−2) and the subsurface heat flux (–2 W m−2) contribute negatively to the budget. Net radiation thus produces 76% of the melt, while the turbulent fluxes and the subsurface heat flux produce 24% of the total melt. The seasonal mean incoming shortwave radiation is remarkably constant between the years, whereas variations in temperature and reflected shortwave radiation (albedo) explain most of the interannual variation in melt. The modelled ablation compares well with the measured ablation from stake readings. The sensitivity of the energy-balance model was examined by varying the surface roughness length of momentum and the sensitivity of the calculated melt by perturbations of temperature, wind speed and relative humidity.
Characteristics and small-scale variability of GPR signals and their relation to snow accumulation in Greenland’s percolation zone
Authors: Dunse Thorben , Eisen Olaf , Helm Veit , Rack Wolfgang , Steinhage Daniel , Parry Victoria 
Published: July 2008

AbstractWe investigate snowpack properties at a site in west-central Greenland with ground-penetrating radar (GPR), supplemented by stratigraphic records from snow pits and shallow firn cores. GPR data were collected at a validation test site for CryoSat (T05 on the Expéditions Glaciologiques Internationales au Groenland (EGIG) line) over a 100 m × 100 m grid and along 1 km sections at frequencies of 500 and 800 MHz. Several internal reflection horizons (IRHs) down to a depth of 10 m were tracked. IRHs are usually related to ice-layer clusters in vertically bounded sequences that obtain their initial characteristics near the surface during the melt season. Warm conditions in the following melt season can change these characteristics by percolating meltwater. In cold conditions, smaller melt volumes at the surface can lead to faint IRHs. The absence of simple mechanisms for internal layer origin emphasizes the need for independent dating to reliably interpret remotely sensed radar data. Our GPR-derived depth of the 2003 summer surface of 1.48 m (measured in 2004) is confirmed by snow-pit observations. The distribution of IRH depths on a 1 km scale reveals a gradient of increasing accumulation to the northeast of about 5 cm w.e. km−1. We find that point measurements of accumulation in this area are representative only over several hundred metres, with uncertainties of about 15% of the spatial mean.
Use of MHC class II tetramers to investigate CD4+ T cell responses: Problems and solutions
Authors: Cecconi Virginia , Moro Monica , Del Mare Sara , Dellabona Paolo , Casorati Giulia 
Published: July 2008

AbstractMHC‐class I tetramers technology enabled the characterization of peptide‐specific T cells at the single cell level in a variety of studies. Several laboratories have also developed MHC‐class II multimers to characterize Ag‐specific CD4+ T cells. However, the generation and use of MHC‐class II multimers seems more problematic than that of MHC‐I multimers. We have generated HLA‐DR*1101 tetramers in a versatile empty form, which can be loaded after purification with peptides of interest. We discuss the impact of critical biological and structural parameters for the optimal staining of Ag‐specific CD4+ T cells using HLA‐DR*1101 tetramers, such as: (i) activation state of CD4+ T cells; (ii) membrane trafficking in the target CD4+ T cells; (iii) binding characteristics of the loaded CD4 epitope. Our data indicate that reorganization of TCR on the plasma membrane upon CD4+ T cell activation, as well as an homogenous binding frame of the CD4 epitopes to the soluble HLA‐DR monomer, are critical for a stable TCR/MHC‐class II tetramer interaction. These factors, together with the low frequencies and affinities of specific CD4+ T cells, explain the need for in vitro expansion or ex vivo enrichment of specific T cells for the optimal visualization with MHC‐class II tetramers. © 2008 International Society for Advancement of Cytometry
Optimization of yeast cell cycle analysis and morphological characterization by multispectral imaging flow cytometry
Authors: Calvert Meredith E. K. , Lannigan Joanne A. , Pemberton Lucy F. 
Published: July 2008

AbstractBudding yeastSaccharoymyces cerevisiaeis a powerful model system for analyzing eukaryotic cell cycle regulation. Yeast cell cycle analysis is typically performed by visual analysis or flow cytometry, and both have limitations in the scope and accuracy of data obtained. This study demonstrates how multispectral imaging flow cytometry (MIFC) provides precise quantitation of cell cycle distribution and morphological phenotypes of yeast cells in flow. Cell cycle analysis of wild‐type yeast,nap1Δ, and yeast overexpressingNAP1, was performed visually, by flow cytometry and by MIFC. Quantitative morphological analysis employed measurements of cellular length, thickness, and aspect ratio in an algorithm to calculate a novel feature, bud length. MIFC demonstrated reliable quantification of the yeast cell cycle compared to morphological and flow cytometric analyses. By employing this technique, we observed both the G2/M delay and elongated buds previously described in thenap1Δstrain. Using MIFC, we demonstrate that overexpression ofNAP1causes elongated buds yet only a minor disruption in the cell cycle. The different effects ofNAP1expression level on cell cycle and morphology suggests that these phenotypes are independent. Unlike conventional yeast flow cytometry, MIFC generates complete cell cycle profiles and concurrently offers multiple parameters for morphological analysis. © 2008 International Society for Advancement of Cytometry
In vitro evaluation of the clastogenicity of fumagillin
Authors: Stevanovic Jevrosima , Stanimirovic Zoran , Radakovic Milena , Stojic Velibor 
Published: July 2008

AbstractFumagillin, an antibiotic compound produced by Aspergillus fumigatus, is effective against microsporidia and various Amoeba species, but is also toxic when administered systemically to mammals. Furthermore, a recent in vivo study by Stanimirovic Z et al. 2007: (Mutat Res 628:1–10) indicated genotoxic effects of fumagillin. The aim of the present study was to investigate and explain the clastogenic effects of fumagillin (in the form of fumagillin dicyclohexylamine salt) on human peripheral blood lymphocytes in vitro by sister‐chromatid exchanges (SCE), chromosome aberrations (CA), and micronucleus (MN) tests. The mitotic index (MI), proliferation index (PI), and nuclear division index (NDI) were calculated to evaluate the cytotoxic potential of fumagillin. Five concentrations of fumagillin (0.34, 0.68, 1.02, 3.07, and 9.20 μg/ml) were applied to lymphocyte cultures. All the tested concentrations of fumagillin increased the frequency of SCE per cell significantly (P < 0.001 or P < 0.01) compared with the negative control. A significant (P < 0.001) increase in frequency of structural CA was observed at the three highest concentrations in comparison with the negative control. In addition, the three highest test concentrations increased MN formation and decreased MI, PI, and NDI significantly compared with the negative control. The present results indicate that fumagillin is clastogenic and cytotoxic to cultured human lymphocytes. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Tissue‐specific metabolic activation and mutagenicity of 3‐nitrobenzanthrone in Muta™Mouse
Authors: Chen Guosheng , Gingerich John , Soper Lynda , Douglas George R. , White Paul A. 
Published: July 2008

Abstract3‐Nitrobenzanthrone (3‐NBA) is a mutagen and suspected human carcinogen detected in diesel exhaust, airborne particulate matter, and urban soil. We investigated the tissue specific mutagenicity of 3‐NBA at the lacZ locus of transgenic Muta™Mouse following acute single dose or 28‐day repeated‐dose oral administration. In the acute high dose (50 mg/kg) exposure, increased lacZ mutant frequency was observed in bone marrow and colonic epithelium, but not in liver and bladder. In the repeated‐dose study, a dose‐dependent increase in lacZ mutant frequency was observed in bone marrow and liver (2‐ and 4‐fold increase above control), but not in lung or intestinal epithelium. In addition, a concentration‐dependent increase in mutant frequency (8.5‐fold above control) was observed for Muta™Mouse FE1 lung epithelial cells exposed in vitro. 1‐Nitropyrene reductase, 3‐NBA reductase, and acetyltransferase activities were measured in a variety of Muta™Mouse specimens in an effort to link metabolic activation and mutagenicity. High 3‐NBA nitroreductase activities were observed in lung, liver, colon and bladder, and detectable N‐acetyltransferase activities were found in all tissues except bone marrow. The relatively high 3‐NBA nitroreductase activity in Muta™Mouse tissues, as compared with those in Salmonella TA98 and TA100, suggests that 3‐NBA is readily reduced and activated in vivo. High 3‐NBA nitroreductase levels in liver and colon are consistent with the elevated lacZ mutant frequency values, and previously noted inductions of hepatic DNA adducts. Despite an absence of induced lacZ mutations, the highest 3‐NBA reductase activity was detected in lung. Further studies are warranted, especially following inhalation or intratracheal exposures. Environ. Mol. Mutagen., 2008. Published 2008 Wiley‐Liss, Inc.
On the permissiveness of the abductive theory of method
Authors: Haig Brian D. 
Published: July 2008

AbstractIn this article, the author examines Romeijn's (2008) contention that the account of theory construction in the abductive theory of scientific method suffers from the problem of the underdetermination of theories by empirical evidence. Following Romeijn, the author focuses on the issue of underdetermination as it affects the method of exploratory factor analysis, the strategy of analogical modeling, and the theory of explanatory coherence. The author argues that in each case there are sufficient methodological resources available to researchers to use these methods to good effect. Additionally, he comments on the normative force of the abductive theory of method. © 2008 Wiley Periodicals, Inc. J Clin Psychol 64:1–9, 2008.
Application of fibrin glue in microvascular anastomoses: Comparative analysis with the conventional suture technique using a free flap model
Authors: Cho Alvaro B. , Júnior Rames Mattar 
Published: July 2008

AbstractBackground: Several studies have already reported the utilization of fibrin glue in microvascular anastomoses to minimize the number of sutures and to decrease the operative time. Despite the good results obtained in most of these experiments, its clinical application has not launched. The aim of this study was to clarify the controversies around the safeness of fibrin glue application in microvascular anastomoses, and also to demonstrate the potential benefits of fibrin glue application in a realistic free flap model. Methods: Twenty‐seven rabbits were used in this study. The experimental model consisted of a free groin flap transfer to the anterior cervical region. The flap's circulation was restored by means of an end‐to‐side anastomosis between the femoral and carotid arteries, and an end‐to‐end anastomosis between the femoral and external jugular veins. The animals were divided into two groups (n = 10) according to the anastomosis technique: Group I (conventional suture) and group II (fibrin glue). Results: The number of sutures required to complete the arterial and venous anastomoses was reduced in 39 and 37% in group II, respectively. Despite this reduction, the anastomoses maintained adequate patency rates and mechanical strength. Both arterial and venous anastomoses benefited from fibrin glue application, which made them easier and faster to perform. The flaps' ischemic time and the total operative time were also significantly shortened. Conclusions: In this study, the application of fibrin glue in microvascular anastomoses was safe and reliable. The risk‐benefit ratio of fibrin glue application in microvascular anastomoses is favorable for its use. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Two distinct tumor phenotypes isolated from glioblastomas show different MRS characteristics
Authors: Thorsen Frits , Jirak Daniel , Wang Jian , Sykova Eva , Bjerkvig Rolf , Enger Per Øyvind , van der Kogel Albert , Hajek Milan 
Published: July 2008

AbstractWe have developed a human brain tumor model in immunodeficient rats that gradually changes its phenotype by serial passages in vivo, from a highly infiltrative, non‐angiogenic one with numerous stem cell markers [low‐generation (LG) tumor] to a more typical glioblastoma one with extensive angiogenesis and necrosis [high‐generation (HG) tumor]. In this study we determined the metabolic properties of these two phenotypes, using 1H MRS. The LG tumors showed an intact blood–brain barrier and normal vascular morphology, as shown by MRI and Hoechst staining. In contrast, the HG tumors exhibited vascular leakage and necrosis. The animals with HG tumor had raised concentrations of choline and myo‐inositol, and decreased concentrations of glutamate and N‐acetylaspartate. In the LG tumor group, similar changes in metabolic concentrations were detected, although the alterations were more pronounced. The LG tumors also had higher concentrations of choline, taurine, and lactate. Subdividing the LG and HG tumors into large and small tumors revealed a significant increase in choline and decrease in glutamate as the LG tumors increased in size. Our results show that metabolic profiles produced by 1H MRS can be used to distinguish between two distinct glioblastoma phenotypes. More pronounced anaerobic metabolism was present in the LG stem‐cell‐like tumors, suggesting a more malignant phenotype. Copyright © 2008 John Wiley & Sons, Ltd.
Factors influencing diabetes self‐management in Chinese people with type 2 diabetes
Authors: Xu Yin , Toobert Deborah , Savage Christine , Pan Wei , Whitmer Kyra 
Published: July 2008

AbstractPatients with diabetes must incorporate a complicated regimen of self‐management into their daily lives (e.g., taking medication, diet, exercise). Diabetes self‐management (DSM) is the cornerstone for controlling diabetes and preventing diabetic complications. The purpose of this study was to test a model describing the effects of individual and environmental factors on DSM in a sample of patients with diabetes in Beijing, China. Survey data were gathered from a convenience sample of 201 Chinese adults with type 2 diabetes during outpatient visits. Data were analyzed using structural equation modeling. Model fit indices indicated a good fit to the data. In the final model, belief in treatment effectiveness and diabetes self‐efficacy were proximate factors affecting DSM. Knowledge, social support, and provider–patient communication affected self‐management indirectly via beliefs and self‐efficacy. The findings provide a theoretical basis to direct the development of interventions for improving DSM in Chinese individuals with diabetes. © 2008 Wiley Periodicals, Inc. Res Nurs Health 31:613–625, 2008
Trends in the clinical characteristics of the U.S. cystic fibrosis patient population from 1995 to 2005
Authors: VanDevanter Donald R. , Rasouliyan Lawrence , Murphy Thomas M. , Morgan Wayne J. , Ren Clement L. , Konstan Michael W. , Wagener Jeffrey S. 
Published: July 2008

AbstractRationaleRespiratory signs and symptoms (cough, sputum production, or crackles) are considered bellwethers of underlying cystic fibrosis (CF) lung disease. If respiratory signs and symptoms predict future lung function loss, then improvements in population lung function over the past decade should have been paralleled by a decrease in the prevalence of these variables in the same population. Additionally, changes in these variables over the past decade may provide insight into the improving health of the CF population.MethodsCross‐sectional data from the Epidemiologic Study of Cystic Fibrosis for each year between 1995 and 2005 were analyzed to characterize changes in pulmonary function and respiratory signs and symptoms over time. Patients were separated into five age groups: <6, 6–12, 13–17, 18–24, and ≥25 years.ResultsSerial cross‐sectional analyses of an average of 13,381 patients per year indicated that mean pulmonary function for the CF population improved and the percent of patients reporting cough or sputum production or having crackles or wheeze at their clinic visit decreased over the study period. Observed changes in pulmonary function were not consistently mirrored by changes in symptoms, which differed as a function of the variable studied and the age group.ConclusionsReductions in respiratory signs and symptoms have paralleled improvements in pulmonary function. Both the absolute and relative magnitude of changes in prevalence for cough, sputum production, crackles, and wheeze differed among age groups and among variables. These results suggest the possibility that differences in respiratory signs and symptoms may arise from different underlying pathologies and may be influenced differently by therapeutic interventions. Pediatr Pulmonol. 2008; 43:739–744. © 2008 Wiley‐Liss, Inc.
Rapid pulmonary delivery of inhaled tobramycin for Pseudomonas infection in cystic fibrosis: A pilot project
Authors: Coates Allan L , Green Maria , Leung Kitty , Chan Jeffrey , Ribeiro Nancy , Louca Emily , Ratjen Felix , Charron Martin , Tservistas Markus , Keller Manfred 
Published: July 2008

AbstractBackgroundPatients with cystic fibrosis spend as much 30 min a day inhaling tobramycin. Could a new rapid system deposit the equivalent amount of tobramycin faster?MethodsSix healthy adult males inhaled 5 ml (300 mg) of tobramycin from a breath enhanced nebulizer and either 125 mg (n = 3) or 150 mg (n = 3) from a vibrating membrane system with a large or small aerosol mixing chamber respectively. A radiolabel was added to the solution and shown to “track” with the tobramycin. Imaging was done with a dual headed gamma camera. Because the radiolabel will be cleared by mucociliary action during administration, algorithms were developed to allow the comparison of a slower system to a faster one.ResultsBoth formulations were well tolerated. The lung deposition was 16.6 ± 3.2% (mean ± SD) of the charge dose delivered in 10.9 ± 1.0 min for the breath enhanced nebulizer versus 32.0 ± 5.1% delivered in 2.5 ± 0.4 min from the vibrating membrane system. The absolute pulmonary delivery of tobramycin was 49.9 ± 9.6 versus 43.9 ± 4.8 mg for the two systems respectively, differences that were statistically significant (pair t‐test) but unlikely to be clinically significant. There was a similar deposition of tobramycin for the 125 and 150 mg dose.ConclusionsIt is possible to deliver an equivalent amount of tobramycin in a shorter period of time with the new vibrating membrane system and a more concentrated formulation. These data will allow the design of a comparison in patients with CF. Pediatr Pulmonol. 2008; 43:753–759. © 2008 Wiley‐Liss, Inc.
Stable isotopes may provide evidence for starvation in reptiles
Authors: McCue Marshall D. , Pollock Erik D. 
Published: July 2008

AbstractPrevious studies have attempted to correlate stable isotope signatures of tissues with the nutritional condition of birds, mammals, fishes, and invertebrates. Unfortunately, very little is known about the relationship between food limitation and the isotopic composition of reptiles. We examined the effects that starvation has on δ13C and δ15N signatures in the tissues (excreta, carcass, scales, and claws) of six, distantly related squamate reptiles (gaboon vipers, Bitis gabonica; ball pythons, Python regius; ratsnakes, Elaphe obsoleta; boa constrictors, Boa constrictor; western diamondback rattlesnakes, Crotalus atrox, and savannah monitor lizards, Varanus exanthematicus). Analyses revealed that the isotopic composition of reptile carcasses did not change significantly in response to bouts of starvation lasting up to 168 days. In contrast, the isotopic signatures of reptile excreta became significantly enriched in 15N and depleted in 13C during starvation. The isotopic signatures of reptile scales and lizard claws were less indicative of starvation time than those of excreta. We discuss the physiological mechanisms that might be responsible for the starvation‐induced changes in 13C and 15N signatures in the excreta, and present a mixing model to describe the shift in excreted nitrogen source pools (i.e. from a labile source pool to a nonlabile source pool) that apparently occurs during starvation in these animals. The results of this study suggest that naturally occurring stable isotopes might ultimately have some utility for characterizing nitrogen and carbon stress among free‐living reptiles. Copyright © 2008 John Wiley & Sons, Ltd.
A secure two‐factor authentication scheme for single sign‐on services
Authors: Brasee Kaleb , Makki S. Kami , Zeadally Sherali 
Published: July 2008

AbstractWe present a novel single sign‐on (SSO) scheme known as secure distributed SSO (SeDSSO). SeDSSO provides secure fault‐tolerant authentication using threshold key encryption with a distributed authentication service. The authentication service consists of n total authentication servers utilizing a (t, n) threshold encryption scheme, where t distinct server‐signed messages are required to generate a message signed by the service. SeDSSO provides secure portable identities by defining a two‐factor identity that uses both a username/password and a unique USB device. The combination of a distributed authentication service and two‐factor identities allows SeDSSO to securely authenticate users in any environment. Copyright © 2008 John Wiley & Sons, Ltd.
Encounter frequencies between GPS‐collared wolves (Canis lupus) and moose (Alces alces) in a Scandinavian wolf territory
Authors: Eriksen Ane , Wabakken Petter , Zimmermann Barbara , Andreassen Harry P. , Arnemo Jon M. , Gundersen Hege , Milner Jos M. , Liberg Olof , Linnell John , Pedersen Hans C. , Sand Håkan , Solberg Erling J. , Storaas Torstein 
Published: July 2008

AbstractOver 6,000 GPS fixes from two wolves (Canis lupus) and 30,000 GPS fixes from five moose (Alces alces) in a wolf territory in southern Scandinavia were used to assess the static and dynamic interactions between predator and prey individuals. Our results showed that wolves were closer to some of the moose when inside their home ranges than expected if they had moved independently of each other, and we also found a higher number of close encounters (<500 m) than expected. This suggests that the wolves were actively seeking the individual moose within their territory. Furthermore, the wolves showed a preference for moving on gravel forest roads, which may be used as convenient travel routes when patrolling the territory and seeking areas where the moose are. However, due to the particularly large size of the wolf territory combined with relatively high moose densities, the wolves generally spent a very small proportion of their time inside the home range of each individual moose, and the frequency of encounters between the wolves and any particular moose was very low. We suggest that the high moose:wolf ratio in this large Scandinavian wolf territory compared to that typically occurring in North America, results in a relatively low encounter frequency and a low predation risk for individual moose, as the predation pressure is spread over a high number of prey individuals.