bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ancient Trans-specific Polymorphism at Pheromone Receptor Genes in Basidiomycetes
Authors: Devier Benjamin , Aguileta Gabriela , Hood Michael E , Giraud Tatiana 
Published: November 2008

Abstract
In the majority of sexual organisms, reproduction occurs almost exclusively through the combination of distinct and alternate forms, called sexes or mating types. In some fungi, there can be dozens to hundreds of alternate alleles that determine compatible mating types. Such extensive polymorphism is expected to be maintained by balancing selection, and in extreme cases may give rise to trans-specific polymorphism. Here, we analyzed sequences of two pheromone receptors in the Microbotryum fungal species complex (Basidiomycota), which has only two alternate mating types. Several lines of evidence strongly suggest that the pheromone receptors are two allelic sequences acting to determine the alternate A1 and A2 mating types required for mating in Microbotryum. Phylogenetic trees of pheromone receptors in the Microbotryum species complex indicated a trans-specific polymorphism: the Microbotryum sequences from a given mating type were all more similar to the pheromone receptors of distantly related classes of fungi than to the alternate pheromone receptor in the Microbotryum species. A phylogenetic tree built using other known pheromone receptors from basidiomycetes showed that trans-specific polymorphism is widespread. The pheromone receptor alleles from Microbotryum appeared as the oldest, being at least 370 million years old. This represents the oldest known trans-specific polymorphism known in any organism so far, which may be due to the existence of sex chromosomes, obligate sexuality, mitochondrial inheritance linked to the mating type, and a highly selfing mating system in Microbotryum.
On Spo16 and the Coefficient of Coincidence
Authors: Stahl Franklin W , Foss Henriette M 
Published: November 2008

Abstract
spo16 mutants in yeast were reported to have reduced map lengths, a high frequency of nondisjunction in the first meiotic division, and essentially unchanged coefficients of coincidence. Were all crossing over in yeast subject to interference, such data would suggest that the “designation” of recombination events to become crossovers is separable from the “implementation” of that crossing over. In the presence of coexisting interference and noninterference phases of crossing over, however, lack of change in the coefficient of coincidence may show only that spo16 reduces crossing over in the two phases by a similar factor.
The Effect of Thickened-Feed Interventions on Gastroesophageal Reflux in Infants: Systematic Review and Meta-analysis of Randomized, Controlled Trials
Authors: Horvath Andrea , Dziechciarz Piotr , Szajewska Hania 
Published: November 2008

CONTEXT. Currently, thickened feeds are increasingly being used to treat infants with gastroesophageal reflux, driven in large part by the baby food industry. Previous meta-analyses have shown that although thickened formulas do not seem to reduce measurable reflux, they may reduce vomiting. However, because data are limited, there is still uncertainty regarding the use of thickening agents.
OBJECTIVE. Our goal was to systematically evaluate and update data from randomized, controlled trials on the efficacy and safety of thickened feeds for the treatment of gastroesophageal reflux in healthy infants.
METHODS. The Cochrane Library, Medline, Embase, and CINAHL databases and proceedings of the European and North American pediatric gastroenterology conferences (from 2000) were searched in May 2008; additional references were obtained from reviewed articles. Only randomized, controlled trials that evaluated thickened feeds used in infants for at least several days for the treatment of gastroesophageal reflux were considered for inclusion. Three reviewers independently performed data extraction by using standard data-extraction forms. Discrepancies between reviewers were resolved by discussion between all authors. Only the consensus data were entered.
RESULTS. Fourteen randomized, controlled trials with a parallel or crossover design, some with methodologic limitations, were included. Use of thickened formulas compared with standard formula significantly increased the percentage of infants with no regurgitation, slightly reduced the number of episodes of regurgitation and vomiting per day (assessed jointly or separately), and increased weight gain per day; it had no effect on the reflux index, number of acid gastroesophageal reflux episodes per hour, or number of reflux episodes lasting &gt;5 minutes but significantly reduced the duration of the longest reflux episode of pH &lt; 4. No definitive data showed that one particular thickening agent is more effective than another. No serious adverse effects were noted.
CONCLUSIONS. This meta-analysis shows that thickened food is only moderately effective in treating gastroesophageal reflux in healthy infants.
Recovery of Endogenous β-Cell Function in Nonhuman Primates After Chemical Diabetes Induction and Islet Transplantation
Authors: Bottino Rita , Criscimanna Angela , Casu Anna , He Jing , Van der Windt Dirk J. , Rudert William A. , Giordano Carla , Trucco Massimo 
Published: November 2008

OBJECTIVE—To describe the ability of nonhuman primate endocrine pancreata to reestablish endogenous insulin production after chemical β-cell destruction.
RESEARCH DESIGN AND METHODS—Eleven monkeys (Macaca fascicularis) were rendered diabetic with streptozotocin. Eight diabetic monkeys received intraportal porcine islet transplantation.
RESULTS—Two monkeys transplanted after 75 days of type 1 diabetes showed recovery of endogenous C-peptide production a few weeks after transplantation, concomitant with graft failure. Histological analysis of the pancreas of these monkeys showed insulin-positive cells, single or in small aggregates, scattered in the pancreas and adjacent to ducts. Interestingly, numerous CK19+ cells costained with proinsulin and PDX-1 antibodies. Furthermore, the peculiar double phenotype glucagon-positive/GLUT2+ was observed. In these monkeys as well as in all others, the original islets showed no insulin staining.
CONCLUSIONS—Our data provide evidence that, in nonhuman primates, the pancreas can reestablish endogenous insulin production after chemical β-cell destruction. This seems to be a nongeneralizable event with only 2 out of 11 monkeys recovering β-cell function. In these two monkeys, younger age and islet graft behavior might have played a role in triggering endogenous β-cell recovery.
The common inhalation anesthetic isoflurane induces caspase activation and increases amyloid β‐protein level in vivo
Authors: Xie Zhongcong , Culley Deborah J. , Dong Yuanlin , Zhang Guohua , Zhang Bin , Moir Robert D. , Frosch Matthew P. , Crosby Gregory , Tanzi Rudolph E. 
Published: November 2008

AbstractObjectiveAn estimated 200 million patients worldwide have surgery each year. Anesthesia and surgery have been reported to facilitate emergence of Alzheimer's disease. The commonly used inhalation anesthetic isoflurane has previously been reported to induce apoptosis, and to increase levels and aggregation of Alzheimer's disease–associated amyloid β‐protein (Aβ) in cultured cells. However, the in vivo relevance has not been addressed.MethodsWe therefore set out to determine effects of isoflurane on caspase activation and levels of β‐site amyloid precursor protein–cleaving enzyme (BACE) and Aβ in naive mice, using Western blot, immunohistochemistry, and reverse transcriptase polymerase chain reaction.ResultsHere we show for the first time that a clinically relevant isoflurane anesthesia (1.4% isoflurane for 2 hours) leads to caspase activation and modest increases in levels of BACE 6 hours after anesthesia in mouse brain. Isoflurane anesthesia induces caspase activation, and increases levels of BACE and Aβ up to 24 hours after anesthesia. Isoflurane may increase BACE levels by reducing BACE degradation. Moreover, the Aβ aggregation inhibitor, clioquinol, was able to attenuate isoflurane‐induced caspase‐3 activation in vivo.InterpretationGiven that transient insults to brain may lead to long‐term brain damage, these findings suggest that isoflurane may promote Alzheimer's disease neuropathogenesis and, as such, have implications for use of isoflurane in humans, pending human study confirmation. Ann Neurol 2008
Erasure mechanisms of polarization holographic gratings in spirooxazine‐doped polymer films
Authors: Fu Shencheng , Hu Weilin , Xie Minggui , Liu Yichun , Duanmu Qingduo 
Published: November 2008

AbstractDynamic holographic recording under linear polarized writing beams at 632.8 nm was performed on two different new spirooxazine doped PMMA matrices assisted by UV light. Thermal rate constants of the two holographic storage medium were determined. It was found that diffraction efficiency and erasure dynamics of the holographic gratings in the two polymer films were dependent on the thermal stability and aggregation of spirooxazine molecules in PMMA matrices. During erasure of the holographic gratings, only in the polymer film with a lower thermal rate constant, a nearly instantaneous increase of diffraction efficiency was observed, resulting from the formation of a transient orientation grating. A theoretical description of the transient orientation grating, competing with isomerization gratings, agrees well with experimental results. The interaction between the chromophores and matrices was also discussed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Modeling gel effect in branched polymer systems: Free‐radical solution homopolymerization of vinyl acetate
Authors: Verros George D. , Achilias Dimitris S. 
Published: November 2008

AbstractIn this work a comprehensive mathematical framework is developed for modeling gel effect in branched polymer systems with application in the solution polymerization of vinyl acetate. This model is based on sound principles such as the free‐volume theory for polymer chains diffusion. The model predictions for monomer conversion and number‐ and weight‐average molecular weights were found to be in good agreement with published data in the literature. Moreover, the joint molecular‐weight distribution–long chain branching distribution is calculated by direct numerical integration of a large system of nonlinear ordinary integral‐differential equations describing the mass conservation of macromolecular species in a batch reactor. This allows studying the effect of process conditions such as initiator and solvent concentration on the product quality. It is believed that this work might contribute to a more rational design of polymerization reactors. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
How reward, computer self‐efficacy, and perceived power security affect knowledge management systems success: An empirical investigation in high‐tech companies
Authors: Lai Jung‐Yu 
Published: November 2008

AbstractIn a highly competitive environment, high‐tech firms utilize capital‐intensive facilities, technology‐intensive products, and computer applications for gaining competitive advantages. It makes employees acquire more knowledge to perform more complex tasks. This has resulted in an increasing demand for organizations to implement knowledge management systems (KMS) for employees to steer organizational learning in the new era of knowledge‐based economy. However, prior empirical examinations on factors influencing KMS success are not sufficient, particularly in the high‐tech context. This study formulates and empirically tests a theoretical model to explain these factors and how they affect KMS success. Results from a sample of 141 employees selected from four high‐tech semiconductor manufacturing firms provide us a more comprehensive understanding about how benefits, self‐produced, and costs factors (i.e., reward, computer self‐efficacy, and perceived power security) affect KMS success. It can be seen that reward and perceived power security have both direct and indirect effects on user satisfaction and intention to use KMS through perceived usefulness and ease of use. Moreover, computer self‐efficacy influences user satisfaction and intention to use KMS through perceived usefulness and ease of use. Besides providing directions for development and testing of knowledge management theories, these findings will be valuable to practitioners.
Kosmos, Koralle und Kultur‐Milieu. Zur Bedeutung der populären Wissenschaftsvermittlung im späten Kaiserreich und in der Weimarer Republik
Authors: Schirrmacher Arne 
Published: November 2008

AbstractKosmos, Koralle and Cultural Milieu. On the Role of Popular Science Communication in the late Kaiserreich and Weimar Germany. This paper discusses the role of popular science communication for the ‘cultural milieu’ or more generally the ‘environment’ of scientists and science in Germany between c. 1900 and 1933 in the sense of Paul Forman. On the rich basis of diverse journals aiming at a differentiated public the discourse on atomic physics is sketched. Since the thesis of a general hostility towards atomic physics in particular and science in general cannot be accredited the question arises how widespread and in which sense a crisis of science was discussed in the Weimar years.
Knowledge‐guided laboratory evolution of protein thermolability
Authors: Reetz Manfred T. , Soni Pankaj , Fernández Layla 
Published: November 2008

AbstractIn rare but nevertheless important cases it is of practical interest to decrease the thermostability of an enzyme, that is, to increase thermolability in a controlled manner. In the present model study, this unconventional goal has been reached by applying directed evolution to the lipase from Pseudomonas aeruginosa (PAL). By utilizing the B‐factor iterative test (B‐FIT), previously developed to increase the thermostability of enzymes, it was possible to reduce the $T_{50}^{15} $ value from 71.6°C in the case of wild type (WT‐PAL) to 35.6°C (best mutant) without affecting the catalytic profile in terms of substrate acceptance or enantioselectivity at room temperature. Accordingly, saturation mutagenesis was performed at sites in PAL, which on the basis of its X‐ray structure, have the lowest B‐factors indicative of high rigidity. Focused mutations were introduced which can be expected to decrease rigidity, the ensuing increased flexibility leading to higher thermolability without changing the actual catalytic profile. Biotechnol. Bioeng. 2009;102: 1712–1717. © 2008 Wiley Periodicals, Inc.
Prokineticin receptor 2 expression identifies migrating neuroblasts and their subventricular zone transient‐amplifying progenitors in adult mice
Authors: Puverel Sandrine , Nakatani Hiroko , Parras Carlos , Soussi‐Yanicostas Nadia 
Published: November 2008

AbstractThe adult subventricular zone (SVZ) contains progenitors cells, which continually give rise to new neurons that migrate along the rostral migratory stream (RMS) to the olfactory bulbs (OB). Prokineticin receptor 2 (ProKR2) is a G‐protein‐coupled receptor that plays an essential role in this migration process. However, the identity of the prokr2‐expressing cells has not yet been clearly established. Here, we have characterized in detail the identity of the prokr2‐expressing cells in the SVZ/RMS/OB pathway in adult mice. In the SVZ, accumulation of prokr2 transcripts was detected in almost all migrating neuroblasts or type A cells as well as in a large population of their precursors, the rapidly dividing type C cells. Moreover, we observed that, in dissociated SVZ cells from Mash1::GFP postnatal mice, ProKR2 protein is also present in type C and type A cells. We found that, along the RMS and in the OB, prokr2 expression was restricted to migrating type A cells and was absent in astrocytes. Finally, we observed a highly marked decrease of prokr2 expression in Mash1−/− mutant mice, suggesting that this transcription factor directly or indirectly regulates prokr2 expression. Although the expression of ProKR2 in migrating type A cells is in good agreement with the essential role played by this receptor during this migration process, its expression in a large population of their progenitors suggests an additional function for ProKR2, providing novel insights into the role of ProKR2/ProK2 signalling in adult neurogenesis. J. Comp. Neurol. 512:232–242, 2009. © 2008 Wiley‐Liss, Inc.
Projection of reconstructed single purkinje cell axons in relation to the cortical and nuclear aldolase C compartments of the rat cerebellum
Authors: Sugihara Izumi , Fujita Hirofumi , Na Jie , Quy Pham Nguyen , Li Bing‐Yang , Ikeda Daisuke 
Published: November 2008

AbstractAlthough the overall topography of the cerebellar corticonuclear projection formed by Purkinje cell (PC) axons has been described, only a few studies have dealt with the organization of this projection at the level of individual PC axons. Thus, we reconstructed 65 single PC axons that were labeled with biotinylated dextran amine in the rat. We then analyzed the relationship between the projections of these PCs and the compartmentalization of the cerebellar cortex and nuclei based on the topography of olivocerebellar projection and aldolase C expression in PCs. After giving rise to short local recurrent collaterals near the soma, a PC axon formed a terminal arbor in a specific small area in the cerebellar nuclei (CN). The terminal arbors of vermal PCs were spread more widely than those of hemispheric PCs and sometimes extended to extracerebellar targets. PCs located in any of the aldolase C‐positive (Groups I and II) and ‐negative (Groups III and IV) stripes consistently projected to the caudoventral and rostrodorsal parts of the CN, respectively, precisely in accordance with the compartmentalization of the cortex and nuclei. Mediolateral segregation and rostrocaudal convergence were seen between projections of separate PCs in a single aldolase C compartment. The results revealed a tight link between the projection patterns of individual PC axons, the topography of the olivocerebellar pathway, and the aldolase C expression pattern. Their overall correspondence seems to reflect a basic aspect of cerebellar organization, although some area‐dependent variation in the relationship of these three entities was also present. J. Comp. Neurol. 512:282–304, 2009. © 2008 Wiley‐Liss, Inc.
Multimodal architectonic subdivision of the rostral part (area F5) of the macaque ventral premotor cortex
Authors: Belmalih Abdelouahed , Borra Elena , Contini Massimo , Gerbella Marzio , Rozzi Stefano , Luppino Giuseppe 
Published: November 2008

AbstractWe used a cyto‐, myelo‐, and chemoarchitectonic (distribution of SMI‐32 and calbindin immunoreactivity) approach to assess whether the rostral histochemical area F5 of the ventral premotor cortex (PMv) comprises architectonically distinct areas, possibly corresponding to functionally different fields. Three areas were identified, occupying different parts of F5. One area, designated as “convexity” F5 (F5c), extends on the postarcuate convexity cortex adjacent to the inferior arcuate sulcus and is characterized, cytoarchitectonically, by a poorly laminated appearance, resulting from an overall cell population rather homogeneous in size and density. The other two areas, designated as “posterior” and “anterior” F5 (F5p and F5a, respectively), lie within the postarcuate bank at different anteroposterior levels. Major cytoarchitectonic features of F5p are a layer III relatively homogeneous in cell size and density, a cell‐dense layer Va, and the presence of relatively large pyramids in layer Vb. Major cytoarchitectonic features of F5a are the presence of relatively large pyramids in lowest layer III and a prominent, homogenous layer V. Furthermore, our results showed that F5c and F5p border caudally with a caudal PMv area corresponding to histochemical area F4, providing additional evidence for a general subdivision of the macaque PMv into a caudal and a rostral part, corresponding to F4 and to the F5 complex, respectively. The present data, together with other functional and connectional data, suggest that the three rostral PMv areas F5p, F5a, and F5c correspond to distinct cortical entities, possibly involved in different aspects of motor control and cognitive motor functions. J. Comp. Neurol. 512:183–217, 2009. © 2008 Wiley‐Liss, Inc.
Single‐cell‐based image analysis of high‐throughput cell array screens for quantification of viral infection
Authors: Matula Petr , Kumar Anil , Wörz Ilka , Erfle Holger , Bartenschlager Ralf , Eils Roland , Rohr Karl 
Published: November 2008

AbstractThe identification of eukaryotic genes involved in virus entry and replication is important for understanding viral infection. Our goal is to develop a siRNA‐based screening system using cell arrays and high‐throughput (HT) fluorescence microscopy. A central issue is efficient, robust, and automated single‐cell‐based analysis of massive image datasets. We have developed an image analysis approach that comprises (i) a novel, gradient‐based thresholding scheme for cell nuclei segmentation which does not require subsequent postprocessing steps for separation of clustered nuclei, (ii) quantification of the virus signal in the neighborhood of cell nuclei, (iii) localization of regions with transfected cells by combining model‐based circle fitting and grid fitting, (iv) cell classification as infected or noninfected, and (v) image quality control (e.g., identification of out‐of‐focus images). We compared the results of our nucleus segmentation approach with a previously developed scheme of adaptive thresholding with subsequent separation of nuclear clusters. Our approach, which does not require a postprocessing step for the separation of nuclear clusters, correctly segmented 97.1% of the nuclei, whereas the previous scheme achieved 95.8%. Using our algorithm for the detection of out‐of‐focus images, we obtained a high discrimination power of 99.4%. Our overall approach has been applied to more than 55,000 images of cells infected by either hepatitis C or dengue virus. Reduced infection rates were correctly detected in positive siRNA controls, as well as for siRNAs targeting, for example, cellular genes involved in viral infection. Our image analysis approach allows for the automatic and accurate determination of changes in viral infection based on high‐throughput single‐cell‐based siRNA cell array imaging experiments. © 2008 International Society for Advancement of Cytometry
Additional molecular support for the new chordate phylogeny
Authors: Delsuc Frédéric , Tsagkogeorga Georgia , Lartillot Nicolas , Philippe Hervé 
Published: November 2008

AbstractRecent phylogenomic analyses have suggested tunicates instead of cephalochordates as the closest living relatives of vertebrates. In direct contradiction with the long accepted view of Euchordates, this new phylogenetic hypothesis for chordate evolution has been the object of some skepticism. We assembled an expanded phylogenomic dataset focused on deuterostomes. Maximum‐likelihood using standard models and Bayesian phylogenetic analyses using the CAT site‐heterogeneous mixture model of amino‐acid replacement both provided unequivocal support for the sister‐group relationship between tunicates and vertebrates (Olfactores). Chordates were recovered as monophyletic with cephalochordates as the most basal lineage. These results were robust to both gene sampling and missing data. New analyses of ribosomal rRNA also recovered Olfactores when compositional bias was alleviated. Despitethe inclusion of 25 taxa representing all major lineages, the monophyly of deuterostomes remained poorly supported. The implications of these phylogenetic results for interpreting chordate evolution are discussed in light of recent advances from evolutionary developmental biology and genomics. genesis 46:592–604, 2008. © 2008 Wiley‐Liss, Inc.