bluuebunny/crossref_metadata_2025_split huggingface dataset:
Air Cooling of Variable Array of Heated Modules in a Vertical
Channel
Authors: Yadav Vipin , Kant Keshav 
Published: May 2007

Abstract
The effect of array size and substrate thermal conditions upon heat transfer characteristics of an array of heated modules subjected to buoyancy assisted convection cooling in air is investigated. The comparative analysis of numerical and experimental data for multimodular array of heated modules mounted on a printed circuit board (PCB) forming one of the walls of a vertical channel is presented. Numerical investigation involved turbulent flow analysis based on a realizable k−ε model. Experimental efforts involved development of a test rig and use of state-of-the-art data acquisition system for simulating the heat transfer phenomenon from the module surfaces under various test conditions. Moderate to high flow velocities in the channel and the heat flux values near those occurring in electronic cooling applications using air as coolant are considered. Initially, the data for mean Nusselt number occurring at various rows in the array under consideration are presented, and in order to validate the numerical model, variation pattern and deviation between numerical and experimental results are analyzed keeping the substrate (PCB) as the insulated surface. The same numerical model was extended to study the cases of varying substrate thermal conditions. An empirical relation is proposed for evaluating Nu under different substrate thermal conditions for array geometries considered and flow rates within the parametric ranges discussed.
Ecological Genomics of Marine Roseobacters
Authors: Moran M. A. , Belas R. , Schell M. A. , González J. M. , Sun F. , Sun S. , Binder B. J. , Edmonds J. , Ye W. , Orcutt B. , Howard E. C. , Meile C. , Palefsky W. , Goesmann A. , Ren Q. , Paulsen I. , Ulrich L. E. , Thompson L. S. , Saunders E. , Buchan A. 
Published: May 2007

ABSTRACT

Bacterioplankton of the marine
Roseobacter
clade have genomes that reflect a dynamic environment and diverse interactions with marine plankton. Comparative genome sequence analysis of three cultured representatives suggests that cellular requirements for nitrogen are largely provided by regenerated ammonium and organic compounds (polyamines, allophanate, and urea), while typical sources of carbon include amino acids, glyoxylate, and aromatic metabolites. An unexpectedly large number of genes are predicted to encode proteins involved in the production, degradation, and efflux of toxins and metabolites. A mechanism likely involved in cell-to-cell DNA or protein transfer was also discovered:
vir
-related genes encoding a type IV secretion system typical of bacterial pathogens. These suggest a potential for interacting with neighboring cells and impacting the routing of organic matter into the microbial loop. Genes shared among the three roseobacters and also common in nine draft
Roseobacter
genomes include those for carbon monoxide oxidation, dimethylsulfoniopropionate demethylation, and aromatic compound degradation. Genes shared with other cultured marine bacteria include those for utilizing sodium gradients, transport and metabolism of sulfate, and osmoregulation.
Physicians’ intent to comply with the American Medical Association’s guidelines on gifts from the pharmaceutical industry
Authors: Pinto Sharrel L , Lipowski Earlene , Segal Richard , Kimberlin Carole , Algina James 
Published: May 2007

Objective:To identify factors that predict physicians’ intent to comply with the American Medical Association’s (AMA’s) ethical guidelines on gifts from the pharmaceutical industry.Methods:A survey was designed and mailed in June 2004 to a random sample of 850 physicians in Florida, USA, excluding physicians with inactive licences, incomplete addresses, addresses in other states and pretest participants. Factor analysis extracted six factors: attitude towards following the guidelines, subjective norms (eg, peers, patients, etc), facilitating conditions (eg, knowledge of the guidelines, etc), profession-specific precedents (eg, institution’s policies, etc), individual-specific precedents (physicians’ own discretion, policies, etc) and intent. Multivariate regression modelling was conducted.Results:Surveys were received from 213 physicians representing all specialties, with a net response rate of 25.5%. 62% (n = 133) of respondents were aware of the guidelines; 50% (n = 107) had read them. 48% (n = 102) thought that following the guidelines would increase physicians’ credibility and professional image; 68% (n = 145) agreed that it was important to do so. Intent to comply was positively associated with attitude, subjective norms, facilitators and sponsorship of continuing medical education (CME) events, while individual-specific precedents had a negative relationship with intent to comply. Predictors of intent (R2 = 0.52, p <0) were attitude, subjective norms, the interaction term (attitude and subjective norms), sponsorship of CME events and individual-specific precedents.Conclusions:Physicians are more likely to follow the AMA guidelines if they have positive attitudes towards the guidelines, greater subjective norms, fewer expectations of CME sponsorship and fewer individual-specific precedents. Physicians believing that important individuals or organisations expect them to comply with the guidelines are more likely to express intent, despite having fewer beliefs that positive outcomes would result through compliance.
Leukaemia, brain tumours and exposure to extremely low frequency magnetic fields: cohort study of Swiss railway employees
Authors: Röösli Martin , Lörtscher Manfred , Egger Matthias , Pfluger Dominik , Schreier Nadja , Lörtscher Emanuel , Locher Peter , Spoerri Adrian , Minder Christoph 
Published: May 2007

Aims:To investigate the relationship between extremely low frequency magnetic field (ELF-MF) exposure and mortality from leukaemia and brain tumour in a cohort of Swiss railway workers.Methods:20 141 Swiss railway employees with 464 129 person-years of follow-up between 1972 and 2002 were studied. Mortality rates for leukaemia and brain tumour of highly exposed train drivers (21 μT average annual exposure) were compared with medium and low exposed occupational groups (i.e. station masters with an average exposure of 1 μT). In addition, individual cumulative exposure was calculated from on-site measurements and modelling of past exposures.Results:The hazard ratio (HR) for leukaemia mortality of train drivers was 1.43 (95% CI 0.74 to 2.77) compared with station masters. For myeloid leukaemia the HR of train drivers was 4.74 (95% CI 1.04 to 21.60) and for Hodgkin’s disease 3.29 (95% CI 0.69 to 15.63). Lymphoid leukaemia, non-Hodgkin’s disease and brain tumour mortality were not associated with magnetic field exposure. Concordant results were obtained from analyses based on individual cumulative exposure.Conclusions:Some evidence of an exposure–response association was found for myeloid leukaemia and Hodgkin’s disease, but not for other haematopoietic and lymphatic malignancies and brain tumours.
Carnivore-specific stable isotope variables and variation in the foraging ecology of modern and ancient wolf populations: case studies from Isle Royale, Minnesota, and La Brea
Authors: Fox-Dobbs K. , Bump J.K. , Peterson R.O. , Fox D.L. , Koch P.L. 
Published: May 2007

We use carbon and nitrogen isotope data collected from two North American gray wolf ( Canis lupus L., 1758) populations (Isle Royale and northern Minnesota) to both calculate carnivore-specific isotopic variables and investigate wolf foraging ecology. The isotopic enrichments of13C and15N that occur between mammalian carnivores and their prey have not been well defined in modern populations. We use bone collagen from the Isle Royale National Park wolf, moose ( Alces alces (L., 1758)), and beaver ( Castor canadensis Kuhl, 1820) populations to determine trophic enrichment factors of 1.3‰ ± 0.6‰ for δ13C and 4.6‰ ± 0.7‰ for δ15N. We apply these carnivore-specific fractionation factors to a case study from the fossil record, and reconstruct the diets of late-Pleistocene dire wolves ( Canis dirus (Leidy, 1858)) from the La Brea tar pits. We use the Minnesota wolf tissue (collagen, hair, muscle) isotopic data to estimate carnivore population subsample sizes needed to replicate the mean values of the whole population within one standard deviation. Finally, we compare the Isle Royale and Minnesota collagen and hair isotopic data to published δ13C and δ15N values for North American gray wolf populations. We find that interpopulation differences in isotope variances provide insight into wolf foraging ecology.
Unusual fatty acid biomarkers reveal age- and sex-specific foraging in polar bears (Ursus maritimus)
Authors: Thiemann G.W. , Budge S.M. , Iverson S.J. , Stirling I. 
Published: May 2007

We used fatty acid (FA) biomarkers in a novel approach to study the foraging habits of a top predator. We tested the hypothesis that non-methylene-interrupted FA (NMI FA), synthesized by benthic molluscs, are transferred via pinnipeds to polar bears ( Ursus maritimus Phipps, 1774) at the top of the arctic marine food web. Among eight species of marine mammals preyed upon by polar bears, NMI FA were prevalent only in benthic-feeding bearded seals ( Erignathus barbatus (Erxleben, 1777)) and Atlantic walruses ( Odobenus rosmarus rosmarus (L., 1758)). These two prey species differed in their relative proportions of NMI FA — 22:2Δ7,15 was almost exclusive to bearded seals, whereas 20:2Δ5,11 was most abundant in Atlantic walruses. Six different NMI FA were identified in polar bears. Trends in individual NMI FA showed that large, adult male polar bears were the primary predators of bearded seals and Atlantic walruses. These findings were confirmed through quantitative FA signature analysis (QFASA) using an entirely different set of FA. In addition to corroborating the accuracy of QFASA diet estimates, these results indicate that individual NMI FA can provide specific information on polar bear foraging and therefore provide insights into the bottom–up effects of environmental change in arctic ecosystems.
Portable Propane Micro-Tubular SOFC System Development
Authors: Finnerty Caine , Robinson Charles , Andrews Stanley , Du Yanhai , Cheekatamarla Praveen , DeWald Paul , Lu Yixin , Schwartz Timothy 
Published: May 2007

NanoDynamics Energy Inc. is developing a family of compact, integrated micro-tubular SOFC systems with high volumetric power density and multiple fuel options including methane, propane, diesel and JP8. The development program aims to bring to the market highly efficient, clean, and cost competitive fuel cell systems with outputs above 50We for portable power generation applications. Balance-of-plant (BoP), electronic controls, and power management systems have been identified and integrated with a partial oxidation reformer and SOFC stack.	A system test for the integrated process chain was performed with our proprietary cell and system technologies. The performance of a system developed using a micro-tubular SOFC stack is evaluated for different operating conditions. The results from these studies will be presented. System design, integration, and control methodologies are also discussed.
SOFC Based on Proton Conductors
Authors: Balachandran U. Balu , Lee Tae H. , Dorris Stephen E. 
Published: May 2007

We have fabricated a solid oxide fuel cell (SOFC) using BaCe0.8Y0.2Ox (BCY20) proton conductor as the electrolyte. An ≈10-μm-thick dense BCY film was prepared on a porous Ni/BCY cermet (i.e., ceramic/metal composite) substrate by a dip coating process. The gas-permeable Ni/BCY cermet substrate backed with nickel mesh was used as the anode, and a platinum paste backed with platinum mesh served as the cathode.	The current-voltage characteristics of the BCY-based SOFC were measured in the temperature range 450-800{degree sign}C using wet air on the cathode side and hydrogen on the anode side. The power density of the fuel cell was ≈90 and ≈1500 mW/cm2 at 450 and 800{degree sign}C, respectively.
Oxidation Behavior and Conductivity of UNS 430 Stainless Steel and Crofer 22 APU with Spinel Coatings
Authors: Wei Ping , Deng Xiaohua , Bateni M.Reza R. , Petric Anthony 
Published: May 2007

Coatings of Cu-Mn, Co-Mn, and Cu-Fe spinels were obtained on UNS 430 and Crofer 22 APU ferritic stainless steel by oxidation of electroplated metal coatings. The thickness of the spinel coatings was 20-30 um.	The average weight gain of Crofer 22 APU with Cu-Mn, Co-Mn, and Cu-Fe spinel coatings after 1400 hours oxidation at 750{degree sign}C was 0.00052 g/cm2, 0.00022 g/cm2, and 0.00027 g/cm2, whereas the average weight gain of UNS 430 stainless steel with Cu-Mn, Co-Mn, and Cu-Fe spinel coatings was respectively 0.0003 g/cm2, 0.0001 g/cm2, and 0.00021 g/cm2.	The area specific resistance of both Cu-Mn and Co-Mn spinel coated alloys was 0.003 Ω•cm2 after oxidation at 750åC for 1500 hours. Compared with an ASR of 0.189 Ω•cm2 for uncoated UNS 430, it is clear that the coatings can effectively provide a conductive path to the metallic substrate.
Planetary Wave Response to Surface Forcing and Instability in the Presence of Mean Flow and Topography
Authors: Killworth Peter D. , Blundell Jeffrey R. 
Published: May 2007

Abstract
The local response of an ocean with slowly varying mean flow, stratification, and topography to two sources of disturbance is examined, concentrating on whether the resulting surface elevations are observable. The first is the ocean response to surface forcing (Ekman pumping or buoyancy forcing). For typical amplitudes of random forcing, while much of the ocean response is small (surface elevations less than 1 mm), there are sufficient near resonances (or pseudoresonances involving a critical layer) to produce elevations of 1 cm or more in much of the ocean. The second source is baroclinic instability. The fastest linear growth rate, as well as those for specific wavelengths, is computed globally. Almost all of the ocean is baroclinically unstable, and the most unstable waves are found to possess a small wavelength (often less than 10 km) with a disturbance concentrated near the surface: e-folding times O(20 days) are frequently found. However, the phase speed for the disturbances is almost everywhere slower westward than free planetary waves with mean flow and topography. Since the free waves propagate at speeds similar to observations, instability may be a good source of variability but is probably not responsible directly for observed wave propagation.
A Simple Model of Millennial Oscillations of the Thermohaline Circulation
Authors: Colin de Verdière A. 
Published: May 2007

Abstract
Stommel’s two-box model of thermohaline circulation is modified to include the possibility of convection. When reduced to a two-degrees-of-freedom dynamical system, the model exhibits the well-known multiple (thermal and haline) steady states as well as new convective thermal steady states. However, for some values of the control parameters (such as the freshwater flux) oscillations occur. Millennial period oscillatory regimes correspond to switches between the Stommel’s haline fixed point and the convective thermal state, both of which are unstable in a window of precipitation values. The transitions between steady and oscillatory regimes at the boundaries of the window are global bifurcations, which in some cases have an infinite period character. This character is due either to the proximity of the Stommel saddle node bifurcation or to the infinite time it takes for the convection to resume when the system is in the haline regime. The oscillations bear a close relationship to those of Welander’s flip–flop model. The physics of this class of millennial oscillations may be relevant to those observed in more complex OGCMs and may help to rationalize certain features of the millennial band oscillations that punctuate the last glacial period.
Coupled Interannual Rossby Waves in a Quasigeostrophic Ocean–Atmosphere Model
Authors: Farneti Riccardo 
Published: May 2007

Abstract
Rossby wave propagation is investigated in the framework of an idealized middle-latitude quasigeostrophic coupled ocean–atmosphere model. The Rossby waves are observed to propagate faster than both the classical linear theory (unperturbed solution) and the phase speed estimates when the effect of the zonal mean flow is added (perturbed solution). Moreover, using statistical eigentechniques, a clear coupled Rossby wave mode is identified between a baroclinic oceanic Rossby wave and an equivalent barotropic atmospheric wave. The spatial phase relationship of the coupled wave is similar to the one predicted by Goodman and Marshall, suggesting a positive ocean–atmosphere feedback. It is argued that oceanic Rossby waves can be efficiently coupled to the overlying atmosphere and that the atmospheric coupling is capable of adding an extra speedup to the wave; in fact, when the ocean is simply forced, the Rossby wave propagation speed approaches the perturbed solution.
Defective cytotoxic lymphocyte degranulation in syntaxin-11–deficient familial hemophagocytic lymphohistiocytosis 4 (FHL4) patients
Authors: Bryceson Yenan T. , Rudd Eva , Zheng Chengyun , Edner Josefine , Ma Daoxin , Wood Stephanie M. , Bechensteen Anne Grete , Boelens Jaap J. , Celkan Tiraje , Farah Roula A. , Hultenby Kjell , Winiarski Jacek , Roche Paul A. , Nordenskjöld Magnus , Henter Jan-Inge , Long Eric O. , Ljunggren Hans-Gustaf 
Published: May 2007

AbstractFamilial hemophagocytic lymphohistiocytosis (FHL) is typically an early onset, fatal disease characterized by a sepsislike illness with cytopenia, hepatosplenomegaly, and deficient lymphocyte cytotoxicity. Disease-causing mutations have been identified in genes encoding perforin (PRF1/FHL2), Munc13-4 (UNC13D/FHL3), and syntaxin-11 (STX11/FHL4). In contrast to mutations leading to loss of perforin and Munc13-4 function, it is unclear how syntaxin-11 loss-of-function mutations contribute to disease. We show here that freshly isolated, resting natural killer (NK) cells and CD8+ T cells express syntaxin-11. In infants, NK cells are the predominant perforin-containing cell type. NK cells from FHL4 patients fail to degranulate when encountering susceptible target cells. Unexpectedly, IL-2 stimulation partially restores degranulation and cytotoxicity by NK cells, which could explain the less severe disease progression observed in FHL4 patients, compared with FHL2 and FHL3 patients. Since the effector T-cell compartment is still immature in infants, our data suggest that the observed defect in NK-cell degranulation may contribute to the pathophysiology of FHL, that evaluation of NK-cell degranulation in suspected FHL patients may facilitate diagnosis, and that these new insights may offer novel therapeutic possibilities.
Identification of candidate regulatory sequences in mammalian 3' UTRs by statistical analysis of oligonucleotide distributions
Authors: Corà Davide , Di Cunto Ferdinando , Caselle Michele , Provero Paolo 
Published: May 2007

Abstract

Background
3' untranslated regions (3' UTRs) contain binding sites for many regulatory elements, and in particular for microRNAs (miRNAs). The importance of miRNA-mediated post-transcriptional regulation has become increasingly clear in the last few years.

Results
We propose two complementary approaches to the statistical analysis of oligonucleotide frequencies in mammalian 3' UTRs aimed at the identification of candidate binding sites for regulatory elements. The first method is based on the identification of sets of genes characterized by evolutionarily conserved overrepresentation of an oligonucleotide. The second method is based on the identification of oligonucleotides showing statistically significant strand asymmetry in their distribution in 3' UTRs.

Conclusion
Both methods are able to identify many previously known binding sites located in 3'UTRs, and in particular seed regions of known miRNAs. Many new candidates are proposed for experimental verification.
Refining intra-protein contact prediction by graph analysis
Authors: Frenkel-Morgenstern Milana , Magid Rachel , Eyal Eran , Pietrokovski Shmuel 
Published: May 2007

Abstract

Background
Accurate prediction of intra-protein residue contacts from sequence information will allow the prediction of protein structures. Basic predictions of such specific contacts can be further refined by jointly analyzing predicted contacts, and by adding information on the relative positions of contacts in the protein primary sequence.

Results
We introduce a method for graph analysis refinement of intra-protein contacts, termed GARP. Our previously presented intra-contact prediction method by means of pair-to-pair substitution matrix (P2PConPred) was used to test the GARP method. In our approach, the top contact predictions obtained by a basic prediction method were used as edges to create a weighted graph. The edges were scored by a mutual clustering coefficient that identifies highly connected graph regions, and by the density of edges between the sequence regions of the edge nodes. A test set of 57 proteins with known structures was used to determine contacts. GARP improves the accuracy of the P2PConPred basic prediction method in whole proteins from 12% to 18%.

Conclusion
Using a simple approach we increased the contact prediction accuracy of a basic method by 1.5 times. Our graph approach is simple to implement, can be used with various basic prediction methods, and can provide input for further downstream analyses.
Differential development of neuronal physiological responsiveness in two human neural stem cell lines
Authors: Donato Roberta , Miljan Erik A , Hines Susan J , Aouabdi Sihem , Pollock Kenneth , Patel Sara , Edwards Frances A , Sinden John D 
Published: May 2007

Abstract

Background
Neural stem cells (NSCs) are powerful research tools for the design and discovery of new approaches to neurodegenerative disease. Overexpression of the myc family transcription factors in human primary cells from developing cortex and mesencephalon has produced two stable multipotential NSC lines (ReNcell VM and CX) that can be continuously expanded in monolayer culture.

Results
In the undifferentiated state, both ReNcell VM and CX are nestin positive and have resting membrane potentials of around -60 mV but do not display any voltage-activated conductances. As initially hypothesized, using standard methods (stdD) for differentiation, both cell lines can form neurons, astrocytes and oligodendrocytes according to immunohistological characteristics. However it became clear that this was not true for electrophysiological features which designate neurons, such as the firing of action potentials. We have thus developed a new differentiation protocol, designated 'pre-aggregation differentiation' (preD) which appears to favor development of electrophysiologically functional neurons and to lead to an increase in dopaminergic neurons in the ReNcell VM line. In contrast, the protocol used had little effect on the differentiation of ReNcell CX in which dopaminergic differentiation was not observed. Moreover, after a week of differentiation with the preD protocol, 100% of ReNcell VM featured TTX-sensitive Na+-channels and fired action potentials, compared to 25% after stdD. Currents via other voltage-gated channels did not appear to depend on the differentiation protocol. ReNcell CX did not display the same electrophysiological properties as the VM line, generating voltage-dependant K+ currents but no Na+ currents or action potentials under either stdD or preD differentiation.

Conclusion
These data demonstrate that overexpression of myc in NSCs can be used to generate electrophysiologically active neurons in culture. Development of a functional neuronal phenotype may be dependent on parameters of isolation and differentiation of the cell lines, indicating that not all human NSCs are functionally equivalent.