bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular characterization of ancient algal mats from the McMurdo Dry Valleys, Antarctica
Authors: Antibus Doug E. , Leff Laura G. , Hall Brenda L. , Baeseman Jenny L. , Blackwood Christopher B. 
Published: November 2011

AbstractThe McMurdo Dry Valleys possess a cold and dry climate which favours biomolecular preservation, and present the possibility for preservation of biological materials over long timescales. We examined patterns of bacterial DNA abundance and diversity in algal mats from 8–26 539 years of age. Bacterial DNA abundance was inferred from extractable DNA quantity and quantitative polymerase chain reaction targeting the bacterial 16S rRNA gene. Because damage to bacterial DNA could limit its availability for polymerase chain reaction, the efficacy of DNA repair by a commercially available kit was also examined. Polymerase chain reaction amplicons of the bacterial 16S rRNA gene were obtained from seven of eight samples. Bulk DNA abundance and bacterial 16S rRNA gene copy number of template DNA declined with increasing sample age consistent with expectations of accumulation of DNA damage in ancient materials. Clone libraries revealed age related patterns of abundance for some bacterial phylogenetic groups. For example, Firmicutes and several other lineages were abundant in ancient samples, but Cyanobacteria were absent. This points to a biased persistence of bacterial lineages that change over time since photosynthesis was active.
Ultraviolet radiation tolerance of the Antarctic springtail,Gomphiocephalus hodgsoni
Authors: Hawes T.C. , Marshall C.J. , Wharton D.A. 
Published: November 2011

AbstractThis is the first study to examine the tolerance of Antarctic springtails (Collembola) to ultraviolet radiation (UV). Survival of extended attenuated exposure to sunlight was examined for both individuals and aggregations of the speciesGomphiocephalus hodgsoniCarpenter over a 10 day period. Both individuals and aggregations demonstrated significantly higher survival and moult rates from control treatments kept in the dark to those exposed to UV. A photo-inhibitive element to moulting is indicated that may function to protect post-ecdysial springtails when their emergent cuticles are more sensitive to the external environment. DNA damage was measured in springtails directly exposed to sunlight for 5 h on a clear sunny day. Significant differences were found between treated animals and controls kept in the dark. There was some reduction of damage 12 and 24 h after exposure, when springtails had been placed in the dark to recover. This indicates the up-regulation of DNA repair mechanisms, with the 12 h treatment in particular showing no significant difference with controls. In addition to providing a first look at UV tolerance in these soil arthropods, these findings recommend employing strict protocols for collections of sample material for subsequent biological analysis in order to minimize the interactive effects of photo-damage.
Ligand based virtual screening studies to design drug molecules for human PIN1 causing cardiovascular disease
Authors: Ramana C , Munikumar Manne , Umamaheswari Amineni 
Published: November 2011

AbstractPIN1 is a member of the cis/trans peptidyl-prolyl isomerase family which plays critical roles in cell-cycle regulation. Over expression of PIN1 in endothelial cells causes cardiovascular disease. The present study has focused on computational analysis to identify the potential inhibitors for PIN1. The human PIN1 crystal structure was retrieved from the protein data bank and prepared using protein preparation wizard of Maestro v9.2. Fourteen PIN1 inhibitors reported in recent literature were acquired and searched for structural analogs using Ligand.Info tool. 5675 PIN1 inhibitor analogs yielded were converted to 3D structures using LigPrep with constraints of ADME evaluation and toxicity assessments. The 3D ligand dataset was docked to PIN1 through docking protocol of Glide v5.7. Nine leads showing better binding affinity compared to fourteen published inhibitors were proposed as potential inhibitors of PIN1. The Lead 1 (2-(2-hydroxy-5-methoxy-pheny)-1h-benzoimidazole-5-carboxamidine) showed a docking score of -7.543 kcal/mol with strong hydrogen bond network with active site residues such as Arg-74, Tyr-92 and Glu-110 and good van der Waals interaction. Therefore, Lead 1 is proposed as a promising lead for developing potential drug molecules for cardiovascular disease therapy.
Cross sections and rate constants for OH + H2 reaction on three different potential energy surfaces for ro-vibrationally excited reagents
Authors: Bhattacharya Sayak , Panda Aditya N. , Meyer Hans-Dieter 
Published: November 2011

A systematic study of the reagent ro-vibrational excitations in H2 + OH reaction is presented on three different potential energy surfaces using the multiconfiguration time-dependent Hartree method. An exact form of the kinetic energy operator including Coriolis coupling has been used. Coupled channel results on WDSE surface for vibrational excitation of H2 produce very large cross sections in accordance with the previous approximate results. The rate constant obtained for H2(v = 1) at 300 K on the YZCL2 surface shows an excellent agreement with the most recent experimental result. Quantum dynamical results for ro-vibrational excitation of reagents obtained on the WSLFH surface show similar behavior to previous quasiclassical trajectory studies. The integral cross sections obtained for excited reagent rotations exhibit contrasting trends on the three surfaces. The effects are explained considering the different orientations of the transition state structure and the individual surface characteristics.
Enhanced microwave electromagnetic properties of Co0.4Fe0.6/Ce2O3 nanocomposites
Authors: Haibo Yi , Xinghua Li , Liang Qiao , Tao Wang , Fashen Li 
Published: November 2011

Abstract
Co0.4Fe0.6/Ce2O3 nanocomposites are fabricated by arc melting followed by ball milling. The CoFe nanocrystals are dispersed in cerium oxide. The complex permittivity, permeability and microwave absorbing properties of Co0.4Fe0.6/Ce2O3 powders/paraffin composites with orientation are studied. Lower permittivity and higher permeability of the oriented composites than those of the unoriented ones are clearly shown. A simulated microwave reflection result shows that the matching thickness and peak frequency are coincident with the quarter wavelength condition. For the oriented ones, the minimum RLm is reached with a matching thickness of about 2.49 mm at a corresponding frequency of 3.7 GHz. At this point, not only are the reflection waves out of phase by 180°, but also the input impedance of the absorber Z
in is equal to the impedance of air Z
0.
Modelling of keyhole dynamics and porosity formation considering the adaptive keyhole shape and three-phase coupling during deep-penetration laser welding
Authors: Zhao Haiyan , Niu Wenchong , Zhang Bin , Lei Yongping , Kodama Masaru , Ishide Takashi 
Published: November 2011

Abstract
The joint quality of deep-penetration laser beam welding is related to the keyhole behaviour, e.g. keyhole-induced porosities. In this paper, a model which considered the existence of three phases, including plasma gas, liquid metal and solid metal, was proposed to describe the keyhole phenomena of laser welding. The forces of interaction of fluid dynamics in the keyhole and molten pool were modelled using the CFD software, and an adaptive heat source model was proposed for the absorption of laser energy. The molten pool and keyhole phenomena of laser beam welding were simulated using the developed model, as well as the formation of keyhole-induced porosities. It was found that the keyhole depth self-fluctuates in continuous laser welding, and the bubbles formed from keyhole collapse and shrinkage are the cause of keyhole-induced porosity.
Direct Infusion Mass Spectrometry of Oxylipin-Containing Arabidopsis Membrane Lipids Reveals Varied Patterns in Different Stress Responses
Authors: Vu Hieu Sy , Tamura Pamela , Galeva Nadezhda A. , Chaturvedi Ratnesh , Roth Mary R. , Williams Todd D. , Wang Xuemin , Shah Jyoti , Welti Ruth 
Published: November 2011

Abstract
Direct infusion electrospray ionization triple quadrupole precursor scanning for three oxidized fatty acyl anions revealed 86 mass spectral peaks representing polar membrane lipids in extracts from Arabidopsis (Arabidopsis thaliana) infected with Pseudomonas syringae pv tomato DC3000 expressing AvrRpt2 (PstAvr). Quadrupole time-of-flight and Fourier transform ion cyclotron resonance mass spectrometry provided evidence for the presence of membrane lipids containing one or more oxidized acyl chains. The membrane lipids included molecular species of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, digalactosyldiacylglycerol, monogalactosyldiacylglycerol, and acylated monogalactosyldiacylglycerol. The oxidized chains were identified at the level of chemical formula and included C18H27O3 (abbreviated 18:4-O, to indicate four double bond equivalents and one oxygen beyond the carbonyl group), C18H29O3 (18:3-O), C18H31O3 (18:2-O), C18H29O4 (18:3-2O), C18H31O4 (18:2-2O), and C16H23O3 (16:4-O). Mass spectral signals from the polar oxidized lipid (ox-lipid) species were quantified in extracts of Arabidopsis leaves subjected to wounding, infection by PstAvr, infection by a virulent strain of P. syringae, and low temperature. Ox-lipids produced low amounts of mass spectral signal, 0.1% to 3.2% as much as obtained in typical direct infusion profiling of normal-chain membrane lipids of the same classes. Analysis of the oxidized membrane lipid species and normal-chain phosphatidic acids indicated that stress-induced ox-lipid composition differs from the basal ox-lipid composition. Additionally, different stresses result in the production of varied amounts, different timing, and different compositional patterns of stress-induced membrane lipids. These data form the basis for a working hypothesis that the stress-specific signatures of ox-lipids, like those of oxylipins, are indicative of their functions.
Nitrogen addition alters mineralization dynamics of 13C‐depleted leaf and twig litter and reduces leaching of older DOC from mineral soil
Authors: Hagedorn Frank , Kammer Adrian , Schmidt Michael W. I. , Goodale Christine L. 
Published: November 2011

AbstractRecent reviews indicate that N deposition increases soil organic matter (SOM) storage in forests but the undelying processes are poorly understood. Our aim was to quantify the impacts of increased N inputs on soil C fluxes such as C mineralization and leaching of dissolved organic carbon (DOC) from different litter materials and native SOM. We added 5.5 g N m−2 yr−1 as NH4NO3 over 1 year to two beech forest stands on calcareous soils in the Swiss Jura. We replaced the native litter layer with 13C‐depleted twigs and leaves (δ13C: −38.4 and −40.8‰) in late fall and measured N effects on litter‐ and SOM‐derived C fluxes. Nitrogen addition did not significantly affect annual C losses through mineralization, but altered the temporal dynamics in litter mineralization: increased N inputs stimulated initial mineralization during winter (leaves: +25%; twigs: +22%), but suppressed rates in the subsequent summer. The switch from a positive to a negative response occurred earlier and more strongly for leaves than for twigs (−21% vs. 0%). Nitrogen addition did not influence microbial respiration from the nonlabeled calcareous mineral soil below the litter which contrasts with recent meta‐analysis primarily based on acidic soils. Leaching of DOC from the litter layer was not affected by NH4NO3 additions, but DOC fluxes from the mineral soils at 5 and 10 cm depth were significantly reduced by 17%. The 13C tracking indicated that litter‐derived C contributed less than 15% of the DOC flux from the mineral soil, with N additions not affecting this fraction. Hence, the suppressed DOC fluxes from the mineral soil at higher N inputs can be attributed to reduced mobilization of nonlitter derived ‘older’ DOC. We relate this decline to an altered solute chemistry by NH4NO3 additions, an increased ionic strength and acidification resulting from nitrification, rather than to a change in microbial decomposition.
Ubiquitous games for learning (UbiqGames): Weatherlings, a worked example
Authors: Klopfer E. , Sheldon J. , Perry J. , Chen V. H.‐H. 
Published: November 2011

AbstractThis paper provides a rationale for a class of mobile, casual, and educational games, which we call UbiqGames. The study is motivated by the desire to understand how students use educational games in light of additional distractions on their devices, and how game design can make those games appealing, educationally useful, and practical. In particular, we explain the choices made to build an engaging and educational first example of this line of games, namely Weatherlings. Further, we report results from a pilot study with 20 students that suggest that students are engaged by the game and are interested in learning more about academic content topics, specifically weather and climate, after playing the game. Research should continue to determine whether Weatherlings specifically does increase learning in these areas, and more generally to determine whether any learning gains and similar results with regard to engagement can be replicated in other content areas following the general model for game design.
Cases, simulacra, and Semantic Web technologies
Authors: Carmichael P. , Tscholl M. 
Published: November 2011

Abstract‘Ensemble’ is an interdisciplinary research and development project exploring the potential role of emerging Semantic Web technologies in case‐based learning across learning environments in higher education. Empirical findings have challenged the claim that cases ‘bring reality into the classroom’ and that this, in turn, might provide the basis for an understanding of the role of Semantic Web technologies in case‐based learning environments. We describe how the work of authors including Baudrillard and Deleuze has provided an alternative framework for understanding the relationships between cases and the realities with which they are purportedly associated. We discuss how the idea of the ‘simulacrum’ has influenced our understanding of learning environments, has informed design and development practices, and has led to a shift in our understandings of the potential affordances of Semantic Web technologies in educational settings.
Asynchronous event‐based high speed vision for microparticle tracking
Authors: NI Z. , PACORET C. , BENOSMAN R. , IENG S. , RÉGNIER* S. 
Published: November 2011

SummaryThis paper presents a new high speed vision system using an asynchronous address‐event representation camera. Within this framework, an asynchronous event‐based real‐time Hough circle transform is developed to track microspheres. The technology presented in this paper allows for a robust real‐time event‐based multiobject position detection at a frequency of several kHz with a low computational cost. Brownian motion is also detected within this context with both high speed and precision. The carried‐out work is adapted to the automated or remote‐operated microrobotic systems fulfilling their need of an extremely fast vision feedback. It is also a very promising solution to the micro physical phenomena analysis and particularly for the micro/nanoscale force measurement.
Tomato plants overexpressing cryptochrome 2 reveal altered expression of energy and stress‐related gene products in response to diurnal cues
Authors: LOPEZ LOREDANA , CARBONE FABRIZIO , BIANCO LINDA , GIULIANO GIOVANNI , FACELLA PAOLO , PERROTTA GAETANO 
Published: November 2011

ABSTRACTIn order to sense and respond to the fluctuating light conditions, higher plants possess several families of photoreceptors, such as phytochromes (PHYs), cryptochromes (CRYs) and phototropins. CRYs are responsible for photomorphogenesis and play a role in circadian, developmental and adaptive growth regulation of plants. In tomato (Solanum lycopersicum), CRY2 controls vegetative development, flowering time, fruit antioxidant content as well as the diurnal transcription of several other photoreceptor genes. We applied large‐scale molecular approaches to identify altered transcripts and proteins in tomato wild‐type (WT) versus a CRY2 overexpressing transgenic genotype, under a diurnal rhythm. Our results showed that tomato CRY2 profoundly affects both gene and protein expression in response to daily light cycle. Particularly altered molecular pathways are related to biotic/abiotic stress, photosynthesis, including components of the light and dark reactions and of starch and sucrose biosynthesis, as well as to secondary metabolism, such as phenylpropanoid, phenolic and flavonoid/anthocyanin biosynthesis pathways. One of the most interesting results is the coordinated up‐regulation, in the transgenic genotype, of a consistent number of transcripts and proteins involved in photorespiration and photosynthesis. It is conceivable that light modulates the energetic metabolism of tomato through a fine CRY2‐mediated transcriptional control.
Acroangiodermatitis in a lower leg amputee related to suction socket use
Authors: Armenores Paul , James Craig L , Weightman Warren , Huilgol Shyamala C 
Published: November 2011

ABSTRACTAcroangiodermatitis is a rare condition with numerous causes typically presenting as purple macules on the lower extremities. Although benign, it can mimic the presentation of more serious underlying conditions such as Kaposi's sarcoma. We present a case of acroangiodermatitis in the stump of an amputee related to suction socket use in order to raise awareness of an unusual setting for this vascular proliferation.
Predictive factors of solid food intake in patients with malignant gastric outlet obstruction receiving self‐expandable metallic stents for palliation
Authors: Sasaki Takashi , Isayama Hiroyuki , Nakai Yousuke , Togawa Osamu , Kogure Hirofumi , Kawakubo Kazumichi , Mizuno Suguru , Yashima Yoko , Ito Yukiko , Yamamoto Natsuyo , Sasahira Naoki , Hirano Kenji , Tsujino Takeshi , Toda Nobuo , Tada Minoru , Omata Masao , Koike Kazuhiko 
Published: November 2011

Aim:  As for self‐expandable metallic stents (SEMS) for malignant gastric outlet obstruction (GOO), some predictive factors of stent patency have been reported, although re‐canalization of GOO by SEMS does not necessarily lead to favorable food intake. Therefore, we analyzed the predictive factors of oral food intake following SEMS placement.Methods:  A total of 97 consecutive patients in whom SEMS were placed for malignant GOO in five hospitals were included in this retrospective study. Clinical outcomes and predictive factors influencing solid food intake were analyzed.Results:  The technical and clinical success rates were 97.9% and 87.6%, respectively. The mean gastric outlet obstruction scoring system (GOOSS) improved from 0.39 to 2.24 after SEMS placement (P < 0.01). The median eating period was 2.1 months (95% CI, 1.1–3.0 months), and the median survival time was 3.1 months (95% CI, 2.0–4.2 months). A Karnofsky performance status of ≤50 (odds ratio, 3.65; 95% CI, 1.17–13.1; P = 0.03) and ascites (odds ratio, 3.28; 95% CI, 1.23–9.05; P = 0.02) were identified as statistically significant independent poor predictive factors of solid food intake.Conclusion:  SEMS is an effective treatment for patients with malignant GOO. Ascites and a poor performance status were poor predictive factors of solid food intake.
Outlet obstruction after sling surgery
Authors: Tse Vincent , Chan Lewis 
Published: November 2011

What's known on the subject? and What does the study add?This article provides a current update on the risk factors, clinical features, and diagnosis on obstruction after female stress incontinence surgery using the mid‐urethral synthetic sling. Particular attention has been paid to identify the patient at risk for developing voiding difficulty post‐sling surgery, as well as the utility of urodynamics and various imaging modalities, especially translabial ultrasound, in the diagnostic process.Urethral obstruction is not an uncommon complication after sling surgery for female stress urinary incontinence (SUI). This paper focuses on this complication in the context of the mid‐urethral synthetic sling, which is now the predominate surgical option used by many surgeons in the treatment of female SUI. The epidemiology and risk factors predisposing to sling obstruction is reviewed, followed by a description of clinical features used in supporting the diagnosis. The use of urodynamics in conjunction with translabial ultrasound as a novel approach to assess the position of the sling and its relation to the urethra is explained. This is particularly important in the understanding of why the sling obstructs from an anatomical standpoint. The paper concludes with a brief overview on treatment options.
Urethral diverticula in females
Authors: Foley Charlotte L. , Greenwell Tamsin J. , Gardiner Robert A. 
Published: November 2011

What's known on the subject? and What does the study add?This is a review of urethral diverticula in females. In addition to modes of presentation, differential diagnosis, complications and surgical management, the increasingly recognised value of computerised axial imaging, especially with MRI, is highlighted.Urethral diverticula are rare but under‐diagnosed entities that may cause a variety of urinary and pelvic symptoms in women. They are best demonstrated by magnetic resonance imaging and micturating cysto‐urethrography prior to transvaginal surgical excision. Although unlikely, the possibility of malignant transformation should not be forgotten.
Threshold Value: How Binding Thresholds Affect the Outcome of a Negotiation
Authors: THORON SYLVIE 
Published: November 2011

AbstractThe objective of this paper is to give the prospective outcome or “prospect” of a negotiation when the players’ value can only be realized if a certain threshold is reached. A threshold is usually defined as a certain total level of contribution. Here, I define a threshold in a cooperative game by the players who are necessary to reach it. It can take different forms such as a certain number of players, or certain coalitions of players. An important example is the minimum participation constraint in international environmental agreements. A value is proposed, which is defined for a given game and a given threshold. The threshold players may bear a commitment cost which decreases the benefit they can obtain from the negotiation.
Farsighted Stability for Roommate Markets
Authors: KLAUS BETTINA , KLIJN FLIP , WALZL MARKUS 
Published: November 2011

AbstractWe study farsighted stability for roommate markets. We show that a matching for a roommate market indirectly dominates another matching if and only if no blocking pair of the former is matched in the latter (Proposition 1). Using this characterization of indirect dominance, we investigate von Neumann–Morgenstern farsightedly stable sets. We show that a singleton is von Neumann–Morgenstern farsightedly stable if and only if the matching is stable (Theorem 1). We also present a roommate market without a von Neumann–Morgenstern farsightedly stable set (Example 1) and a roommate market with a nonsingleton von Neumann–Morgenstern farsightedly stable set (Example 2).
Public Expenditures, Taxes, Federal Transfers, and Endogenous Growth
Authors: GONG LIUTANG , ZOU HENG‐FU 
Published: November 2011

AbstractThis paper extends the Barro (1990) model with single aggregate government spending and one flat income tax to include public expenditures and taxes by multiple levels of government. It derives the rate of endogenous growth and, with both simulations and special examples, examines how that rate changes with respect to federal income tax, local taxes, and federal transfers. It also discusses the growth and welfare‐maximizing choices of taxes and federal transfers.