bluuebunny/crossref_metadata_2025_split huggingface dataset:
Concise Review: Defining Characteristics of Mammalian Spermatogenic Stem Cells
Authors: Griswold Michael D. , Oatley Jon M. 
Published: October 2012

AbstractThe enormous number of sperms produced daily and over the lifetime of mammals requires a stable source of stem cells that give rise to progenitor cells that proceed through spermatogenesis. Spermatogenic stem cells develop from primitive germ cells that occupy the developing gonad. A transplantation assay was developed for the spermatogenic stem cells, and it remains the only functional measure of authentic stem cells in the testis. Somatic cells comprise a “niche” environment that is essential for the maintenance of stem cell activity. Dividing progenitor cells have intercellular bridges and form syncytia with 2, 4, 8, or 16 cells. Fragmentation of these syncytia may allow some progenitor cells to occupy “niches” and function as stem cells, but this notion requires further investigation. Spermatogenic stem cells can be maintained in culture and are influenced by a number of growth factors. Thus far, the ultimate differentiation of cultured stem cells into functional gametes has not been demonstrated with any efficiency and reproducibility. The ability to maintain spermatogenic stem cells in culture and to induce differentiation into haploid cells and sperm could have many important implications for human medicine.
Demethylation of Epiregulin Gene by Histone Demethylase FBXL11 and BCL6 Corepressor Inhibits Osteo/dentinogenic Differentiation
Authors: Du Juan , Ma Yushi , Ma Ping , Wang Songlin , Fan Zhipeng 
Published: October 2012

Abstract
Mesenchymal stem cells (MSCs) are a reliable resource for tissue regeneration, but the molecular mechanism underlying directed differentiation remains unclear; this has restricted potential MSC applications. Histone methylation, controlled by histone methyltransferases and demethylases, may play a key role in MSC differentiation. Here, we investigated FBXL11, a histone demethylase, lysine (K)-specific demethylase 2A, which is evolutionarily conserved, ubiquitously expressed, and a member of the JmjC-domain-containing histone demethylase family. We tested whether FBXL11 could inhibit the osteo/dentinogenic differentiation potential in MSC cells with gain- and loss-of-function assays. We found that FBXL11 regulated osteo/dentinogenic differentiation in MSC cells. Furthermore, we found that the gene encoding the epidermal growth factor, Epiregulin (EREG), was a downstream target of FBXL11, and that EREG mediated FBXL11 regulation of MSC differentiation. Moreover, we found that the FBXL11 histone demethylase function was activated by associating with BCL6 corepressor, and this complex could repress EREG transcription by increasing histone K4/36 methylation in the EREG promoter. In conclusion, our results elucidated a new function for FBXL11 and EREG, explored the molecular mechanism underlying directed differentiation in MSC cells, and identified potential target genes for improving tissue regeneration techniques.
An algorithmic solution for computing circle intersection areas and its applications to wireless communications
Authors: Librino Federico , Levorato Marco , Zorzi Michele 
Published: October 2012

ABSTRACTA novel iterative algorithm for the efficient computation of the intersection areas of an arbitrary number of circles is presented. The algorithm, on the basis of a trellis structure, hinges on two geometric results, which allow the existence check and the computation of the area of the intersection regions generated by more than three circles by simple algebraic manipulations of the intersection areas of a smaller number of circles. The presented algorithm is a powerful tool for the performance analysis of wireless networks and finds many applications, ranging from sensor to cellular networks. As an example of practical application, an insightful study of the uplink outage probability in a wireless network with cooperative access points as a function of the transmission power and access point density is presented. Copyright © 2012 John Wiley & Sons, Ltd.
Near wake Reynolds‐averaged Navier–Stokes predictions of the wake behind the MEXICO rotor in axial and yawed flow conditions
Authors: Sørensen Niels N. , Bechmann A. , Réthoré P‐E. , Zahle F. 
Published: October 2012

ABSTRACTIn the present paper, Reynolds‐averaged Navier–Stokes predictions of the flow field around the MEXICO rotor in yawed conditions are compared with measurements. The paper illustrates the high degree of qualitative and quantitative agreement that can be obtained for this highly unsteady flow situation, by comparing measured and computed velocity profiles for all three Cartesian velocity components along four axial transects and several radial transects. Copyright © 2012 John Wiley & Sons, Ltd.
Short‐term extreme response analysis of a jacket supporting an offshore wind turbine
Authors: Saha Nilanjan , Gao Zhen , Moan Torgeir , Naess Arvid 
Published: October 2012

ABSTRACTWind turbines must be designed in such a way that they can survive in extreme environmental conditions. Therefore, it is important to accurately estimate the extreme design loads. This paper deals with a recently proposed method for obtaining short‐term extreme values for the dynamic responses of offshore fixed wind turbines. The 5 MW NREL wind turbine is mounted on a jacket structure (92 m high) at a water depth of 70 m at a northern offshore site in the North Sea. The hub height is 67 m above tower base or top of the jacket, i.e. 89 m above mean water level. The turbine response is numerically obtained by using the aerodynamic software HAWC2 and the hydrodynamic softwareUSFOS. Two critical responses are discussed, the base shear force and the bending moment at the bottom of the jacket. The extreme structural responses are considered for wave‐induced and wind‐induced loads for a 100 year return‐period harsh metocean condition with a 14.0 m significant wave height, a 16 s peak spectral period, a 50 m s − 1(10 min average) wind speed (at the hub) and a turbulence intensity of 0.1 for a parked wind turbine. After performing the 10 min nonlinear dynamic simulations, a recently proposed extrapolation method is used for obtaining the extreme values of those responses over a period of 3 h. The sensitivity of the extremes to sample size is also studied. The extreme value statistics are estimated from the empirical mean upcrossing rates. This method together with other frequently used methods (i.e. the Weibull tail method and the global maxima method) is compared with the 3 h extreme values obtained directly from the time‐domain simulations. Copyright © 2012 John Wiley & Sons, Ltd.
A spinner‐integrated wind lidar for enhanced wind turbine control
Authors: Mikkelsen T. , Angelou N. , Hansen K. , Sjöholm M. , Harris M. , Slinger C. , Hadley P. , Scullion R. , Ellis G. , Vives G. 
Published: October 2012

ABSTRACTA field test with a continuous wave wind lidar (ZephIR) installed in the rotating spinner of a wind turbine for unimpeded preview measurements of the upwind approaching wind conditions is described. The experimental setup with the wind lidar on the tip of the rotating spinner of a large 80 m rotor diameter, 59 m hub height 2.3 MW wind turbine (Vestas NM80), located at Tjæreborg Enge in western Denmark is presented. Preview wind data at two selected upwind measurement distances, acquired during two measurement periods of different wind speed and atmospheric stability conditions, are analyzed. The lidar‐measured speed, shear and direction of the wind field previewed in front of the turbine are compared with reference measurements from an adjacent met mast and also with the speed and direction measurements on top of the nacelle behind the rotor plane used by the wind turbine itself. Yaw alignment of the wind turbine based on the spinner lidar measurements is compared with wind direction measurements from both the nearby reference met mast and the turbine's own yaw alignment wind vane. Furthermore, the ability to detect vertical wind shear and vertical direction veer in the inflow, through the analysis of the spinner lidar data, is investigated. Finally, the potential for enhancing turbine control and performance based on wind lidar preview measurements in combination with feed‐forward enabled turbine controllers is discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Connections between chromatin signatures and splicing
Authors: Gómez Acuña Luciana I. , Fiszbein Ana , Alló Mariano , Schor Ignacio E. , Kornblihtt Alberto R. 
Published: October 2012

AbstractSplicing and alternative splicing are involved in the expression of most human genes, playing key roles in differentiation, cell cycle progression, and development. Misregulation of splicing is frequently associated to disease, which imposes a better understanding of the mechanisms underlying splicing regulation. Accumulated evidence suggests that multiple trans‐acting factors and cis‐regulatory elements act together to determine tissue‐specific splicing patterns. Besides, as splicing is often cotranscriptional, a complex picture emerges in which splicing regulation not only depends on the balance of splicing factor binding to their pre‐mRNA target sites but also on transcription‐associated features such as protein recruitment to the transcribing machinery and elongation kinetics. Adding more complexity to the splicing regulation network, recent evidence shows that chromatin structure is another layer of regulation that may act through various mechanisms. These span from regulation of RNA polymerase II elongation, which ultimately determines splicing decisions, to splicing factor recruitment by specific histone marks. Chromatin may not only be involved in alternative splicing regulation but in constitutive exon recognition as well. Moreover, splicing was found to be necessary for the proper ‘writing’ of particular chromatin signatures, giving further mechanistic support to functional interconnections between splicing, transcription and chromatin structure. These links between chromatin configuration and splicing raise the intriguing possibility of the existence of a memory for splicing patterns to be inherited through epigenetic modifications. WIREs RNA 2013, 4:77–91. doi: 10.1002/wrna.1142This article is categorized under:

RNA Processing > Splicing Mechanisms
RNA Processing > Splicing Regulation/Alternative Splicing
Effect of ghrelin on inflammatory response in lung contusion
Authors: Guven Berrak , Gokce Mertol , Saydam Ozkan , Can Murat , Bektas Sibel , Yurtlu Serhan 
Published: October 2012

AbstractThe purpose of this study was to investigate the effects of ghrelin on inflammatory response and tissue damage following trauma‐induced acute lung injury. Thirty male wistar albino rats (300–400 g) were randomly assigned into three groups: control group (n = 6), lung contusion plus saline (saline‐treated, n = 12), and lung contusion plus ghrelin (ghrelin‐treated, n = 12). Saline‐ or ghrelin‐treated traumatic rats were sacrificed at two time points (24 and 72 hours) after lung contusion. Blood was collected for the analysis of serum adenosine deaminase (ADA). Tissue transforming growth factor‐beta 1 (TGF‐β1) and matrix metalloproteinase‐2 (MMP‐2) levels were measured by enzyme‐linked immunosorbent assay and histopathological examination was performed on the lung tissue samples. Our results indicated that ghrelin significantly reduced morphologic damages. Serum ADA activities were significantly decreased after lung contusion and this decline started early with ghrelin treatment. TGF‐β1 and MMP‐2 levels in lung tissue were elevated at 72 hours after lung contusion and treatment with ghrelin significantly increased TGF‐β1 level and reduced MMP‐2 level. In conclusion, our study demonstrates that acute lung injury initiated proinflammatory responses and ghrelin administration showed an anti‐inflammatory effect in lung contusion.
Customer Order Flow, Intermediaries, and Discovery of the Equilibrium Risk-Free Rate
Authors: Menkveld Albert J. , Sarkar Asani , Wel Michel van der 
Published: October 2012

AbstractMacro announcements change the equilibrium risk-free rate. We find that Treasury prices reflect part of the impact instantaneously, but intermediaries rely on their customer order flow after the announcement to discover the full impact. This customer flow informativeness is strongest when analyst macro forecasts are most dispersed. The result holds for 30-year Treasury futures trading in both electronic and open-outcry markets. We further show that intermediaries benefit from privately recognizing informed customer flow, as their own-account trading profitability correlates with customer order access.
Are CFOs’ Trades More Informative Than CEOs’ Trades?
Authors: Wang Weimin , Shin Yong-Chul , Francis Bill B. 
Published: October 2012

AbstractWe investigate whether trades made by chief financial officers (CFOs) reveal more information about future stock returns than those by chief executive officers (CEOs). We find that CFOs earn statistically and economically higher abnormal returns following their purchases of company shares than CEOs. During 1992–2002, CFOs earned an average 12-month excess return that is 5% higher than that by CEOs. The superior performance by CFOs occurs notwithstanding controls for risk factors and persists even after their trades are publicly disclosed. Further analysis shows that CFO purchases are associated with more positive future earnings surprises than CEO purchases, suggesting that CFOs incorporate better information about future earnings.
Gastrointestinal nematodes of the lizardTropidurus hispidus(Squamata: Tropiduridae) from a semi-arid region of north-eastern Brazil
Authors: Anjos L.A. , Ávila R.W. , Ribeiro S.C. , Almeida W.O. , da Silva R.J. 
Published: October 2012

AbstractThe tropidurid lizardTropidurus hispidushas a wide distribution in South America. However, knowledge about its helminth fauna is patchy and has been reported for only a few localities along its range of distribution. This study presents data on helminth fauna composition and parameters of infection for a population ofT. hispidusfrom an area within the Brazilian Caatinga biome (semi-arid physiognomy). We found five nematode species within the gastrointestinal tract of lizards:Parapharyngodonsceleratus(Pharyngodonidae);Physalopteralutzi,PhysalopteraretusaandPhysalopteroidesvenancioi(Physalopteridae); andStrongylurisoscari(Heterakidae). The overall prevalence was 84.2% and the mean intensity of infection was 8.5 ± 1.1. The body size of adult male lizards influenced positively the intensity of infection. The infracommunities of nematodes presented an intermediate aggregated distribution (discrepancy index;D= 0.519) and a depauperate nematode fauna. The presence of generalist parasite species has contributed to an increase in the overall richness of the component community. This sampled host population presented the highest prevalence of parasites compared with other studies onT. hispidus, but their relatively low richness can be related to the disturbed environment of the study area.
Molecular characterization of Portuguese populations of the pinewood nematodeBursaphelenchus xylophilususing cytochromeband cellulase genes
Authors: Valadas V. , Laranjo M. , Mota M. , Oliveira S. 
Published: October 2012

AbstractBursaphelenchus xylophilusis the causal agent of pine wilt disease and a worldwide pest with high economic impact. Since its first diagnosis in Portugal in 1999, it has been subjected to quarantine measures with impact on forest health and ecosystem stability, significantly affecting international trade of wood products. The disease was detected in the north and centre of continental Portugal and, since 2008, the whole country has been considered an affected area. Recently, it was detected in Madeira Island. In order to avoid new outbreaks, it has become of major importance to understand the patterns of spread, introduction points and to characterize the new populations from continental Portugal and Madeira Island. Mitochondrial cytochromeb(cytb) and parasitic cellulase gene sequences were used to evaluate the genetic relationships among isolates that could indicate possible origins of the new outbreaks. Portuguese isolates were compared with isolates from USA, China, Japan and South Korea, in order to investigate possible infection pathways and disease spread patterns in Portugal. Phylogenetic trees based on both genes show that Portuguese isolates group with Asian isolates. Isolates from USA are in a separate position in both gene trees. However, the phylogenetic tree based on the cellulase gene sequences shows higher differentiation among Portuguese isolates than that ofcytb.These results agree with those previously obtained using inter-simple sequence repeats (ISSR). This was the first study to usecytband cellulase genes to characterize pinewood nematode (PWN) populations. This study suggests that cellulase is a better marker thancytbto study genetic diversity inB. xylophilus.
Image-guided sinus surgery: practical and financial experiences from a UK centre 2001–2009
Authors: Masterson L , Agalato E , Pearson C 
Published: October 2012

AbstractBackground:Image guidance surgery is an emerging technology that may allow more efficient treatment of sinus disease. This retrospective study examines National Health Service and military patients who underwent procedures using image guidance surgery during the period 2001–2009.Methods:Medical records were reviewed in terms of indications for surgery, incidence of major complications and need for revision following image guidance surgery. An attempt was also made to determine the cost-effectiveness of purchasing this navigational system.Results:A total of 132 patients underwent 147 procedures using image guidance surgery over the 8-year period. The indications for surgery ranged from severe nasal polyposis and chronic rhinosinusitis to malignant tumours in the paranasal sinus and skull base region. Average length of follow up was 17.6 months. Four patients had a major complication. Fourteen patients underwent revision surgery. The cost of providing an image guidance surgery service was estimated to be £110,000–120,000 during the study period. The economic model for the subgroup of nineteen military patients (with non-polypoid chronic rhinosinusitis) suggests that use of this technology will reduce overall costs by approximately £70,000 when compared with conventional sinus surgery.Conclusion:This study provides some evidence that image-guided sinus surgery is cost effective, safe and may decrease surgical revision rates.
Bryoria rigida, a new Asian lichen species from the Himalayan region
Authors: JØRGENSEN Per M. , MYLLYS Leena , VELMALA Saara , WANG Li-Song 
Published: October 2012

AbstractMolecular studies have revealed the presence of yet another species in the Bryoria bicolor complex in China, which confirms that the mountains of SE Asia to be an evolutionary centre for Bryoria sect. Divaricatae. The new species B. rigida is formally described. It is characterized by a stiff and coarse thallus, which contains fumarprotocetraric acid and often protocetraric acid as the main substances. A key to the divaricate species of Bryoria in the Himalayan region is provided.
Redefining the deviance objective for generalised linear models
Authors: Lovick A. C. , Lee P. K. W. 
Published: October 2012

AbstractThis paper defines the ‘Case Deleted’ Deviance - a new objective function for evaluating Generalised Linear Models, and applies this to a number of practical examples in the pricing of general insurance. The paper details practical approximations to enable the efficient calculation of the objective, and derives modifications to the standard Generalised Linear Modelling algorithm to allow the derivation of scaled parameters from this measure to reduce potential over fitting to historical data. These scaled parameters improve the predictiveness of the model when applied to previously unseen data points, the most likely being related to future business written. The potential for over fitting has increased due to number of factors now used, particularly in pricing personal lines business and the advent of price comparison sites which has increased the penalties of mis-estimation. New material in this paper has been included in a UK patent application No. 1020091.3.
Can differences in physical activity by socio-economic status in European adolescents be explained by differences in psychosocial correlates? A mediation analysis within the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study
Authors: De Cocker Katrien , Artero Enrique G , De Henauw Stefaan , Dietrich Sabine , Gottrand Frédéric , Béghin Laurent , Hagströmer Maria , Sjöström Michael , Plada Maria , Manios Yannis , Mauro Beatrice , Molnár Dénes , Moreno Luis A , Ottevaere Charlene , Valtueña Jara , Maes Lea , De Bourdeaudhuij Ilse 
Published: October 2012

AbstractObjectiveSocio-economic status (SES) has been positively associated with physical activity (PA) levels in adolescents. In order to tackle these social inequalities, information is needed about the underlying mechanisms of this association. The present study aimed to investigate the potential mediating role of psychosocial correlates of PA on the relationship between SES and PA in European adolescents.DesignCross-sectional study testing the mediating role of psychosocial correlates in the SES–PA association using the product-of-coefficients test of MacKinnon.SettingTen European cities in nine different countries, the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study.SubjectsAdolescents (n 2780) aged 12·5–17·49 years self-reported on PA (moderate-to-vigorous intensity PA and total PA), SES indicators (education of the mother and Family Affluence Scale) and psychosocial correlates of PA (stage of change, attitudes, awareness, modelling, social support, self-efficacy, benefits, barriers and environmental correlates).ResultsSES (Family Affluence Scale) was significantly associated with moderate-to-vigorous intensity PA. According to single-mediator models, this association was significantly mediated by stage of change (t = 3·6, P ≤ 0·001), awareness (t = 2·7, 0·001 < P ≤ 0·01), modelling (t = 4·8, P ≤ 0·001), self-efficacy (t = 2·5, 0·01<P ≤ 0·05), barriers (t = 2·7, 0·001 < P ≤ 0·01) and environmental (t = 3·0, 0·001 < P ≤ 0·01) correlates of PA. The multiple-mediators model showed that the mediating role of the combination of these psychosocial correlates was also significant (t = 6·2, P ≤ 0·001).ConclusionsAdolescents with low family wealth scored lower on stage of change, awareness, modelling, self-efficacy and environmental correlates of PA, and higher on PA barriers, which in turn resulted in lower levels of moderate-to-vigorous PA. Future interventions should target these individual and environmental constructs in order to tackle and intervene on social inequalities in PA among adolescents.
Schopenhauer, Kant and Compassion
Authors: Guyer Paul 
Published: October 2012

AbstractSchopenhauer presents his moral philosophy as diametrically opposed to that of Kant: for him, pure practical reason is an illusion and morality can arise only from the feeling of compassion, while for Kant it cannot be based on such a feeling and can be based only on pure practical reason. But the difference is not as great as Schopenhauer makes it seem, because for him compassion is supposed to arise from metaphysical insight into the unity of all being, thus from pure if theoretical reason, while for Kant pure practical reason works only by effecting a feeling of respect (in the ‘Critical’ works) or by cultivating, i.e. affecting, natural dispositions to moral feeling (in the ‘post-Critical’ works). I argue that Kant's is the more realistic theory on this point.