bluuebunny/crossref_metadata_2025_split huggingface dataset:
Training to maintain surgical skills during periods of robotic surgery inactivity
Authors: Guseila Loredana M. , Saranathan Archana , Jenison Eric L. , Gil Karen M. , Elias John J. 
Published: December 2013

AbstractBackgroundThe study was performed to establish a level of practice needed for newly‐trained residents to maintain robotic surgical skills during periods of robotic inactivity.MethodsTen surgical residents were trained to a standardized level of robotic surgery proficiency with inanimate models. At the end of two, four and six weeks, the residents practiced with the models for a total of one hour. Each resident performed a timed tissue closure task immediately after reaching the proficiency standards and twice in succession at eight weeks. Time to completion was compared between the three trials with a repeated measures ANOVA and a post‐hoc test.ResultsAverage time to complete the tissue closure task decreased by more than 25% over the period between reaching the proficiency standards and the trials at eight weeks, with the difference significant (P < 0.004).ConclusionsBiweekly practice for one hour was sufficient to maintain robotic surgical skills. Copyright © 2013 John Wiley & Sons, Ltd.
Putting the Cart Before the Horse: The Creation of Essences out of Processes in Science Education Research
Authors: LUNDEGÅRD IANN , HAMZA KARIM M. 
Published: December 2013

ABSTRACTThis article addresses the problem of treating generalizations of human activity as entities and structures that ultimately explain the activities from which they were initially drawn. This is problematic because it involves a circular reasoning leading to unwarranted claims explaining the originally studied activities of science teaching and learning. Unlike other fields within social science research, this problem has not been appreciated and discussed in the science education literature and the field thus needs to be reminded of it. A heuristic specifically developed for the purposes of this article is applied to two examples taken from a much‐cited research in the field. Through the examples it is argued that the practice of creating entities out of generalizations of science classroom activities leads to a number of unintended consequences. It is further argued that the stated purposes in the two example articles would actually have been better served by investigating the entire processes through which the activities develop, as well as how the activities may change through teaching. The article concludes that through the search for explanations caused by underlying entities, science education research runs a risk of alienating its results from the activities from which it initially wanted to meliorate.
Concise Review: The Plasticity of Stem Cell Niches: A General Property Behind Tissue Homeostasis and Repair
Authors: Rojas-Ríos Patricia , González-Reyes Acaimo 
Published: December 2013

AbstractStem cell activity is tightly regulated during development and in adult tissues through the combined action of local and systemic effectors. While stem cells and their microenvironments are capable of sustaining homeostasis in normal physiological circumstances, they also provide host tissues with a remarkable plasticity to respond to perturbations. Here, we review recent discoveries that shed light on the adaptive response of niches to systemic signals and aging, and on the ability of niches to modulate signaling upon local perturbations. These characteristics of stem cells and their niches give organs an essential advantage to deal with aging, injury or pathological conditions. Stem Cells 2014;32:852–859
Outcome of fetuses with short femur length detected at second‐trimester anomaly scan: a national survey
Authors: Mathiesen J. M. , Aksglaede L. , Skibsted L. , Petersen O. B. , Tabor A. ,   the Danish Fetal Medicine Study Group
Published: December 2013

ABSTRACTObjectiveTo assess the relationship between the finding of fetal femur diaphysis length (FL) below the 5th percentile at the second‐trimester scan and pregnancy outcome, in a population in which more than 90% of women attend first‐trimester screening.MethodsThis was a retrospective study of all Danish singleton pregnancies with a 17–22‐week anomaly scan between 1 January 2008 and 30 June 2011. Information on FL and gestational age (GA) at anomaly scan, on birth weight and GA at delivery and on chromosomal abnormalities was obtained from the Danish Fetal Medicine Database.ResultsShort FL was identified in 2718 (1.8%) of 147 766 fetuses and was present in 11 (16.2%) of the 68 fetuses affected by trisomy 21 (positive likelihood ratio (LR+) 8.8 (95% CI, 5.1–15.2)). Trisomy 13/18 and unbalanced autosomal structural abnormalities were also associated with a short FL in three (12.0%, LR+ 6.5 (95% CI, 2.3–18.9)) and eight (32.0%, LR+ 17.4 (95% CI, 9.8–30.9)) of the cases, respectively. The risk of a fetus having trisomy 21, trisomy 18, trisomy 13 or an unbalanced autosomal structural abnormality was 1 : 123 (95% CI, 79–192), given a short FL. Pregnancies with a fetus with short FL were more often affected by early preterm delivery (before 34 weeks) (5.6%; odds ratio (OR) = 4.2 (95% CI, 3.5–4.9)) and small‐for‐gestational‐age (SGA) infants (13.9%; OR = 4.3 (95% CI, 3.8–4.8)).ConclusionShort FL at the second‐trimester anomaly scan is associated with a significantly higher relative risk of chromosomal abnormalities, and a substantially higher absolute risk for SGA and early preterm delivery. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd
Replication enabled distributed cache invalidation method: replication enabled distributed cache management system for wireless mobile networks
Authors: Fawaz Kassem , Artail Abdalla , Al‐Khansa Rasha , Artail Hassan , Safa Haidar 
Published: December 2013

AbstractThis work proposes a replication scheme that is implemented on top of a previously proposed system for MANETs that cache submitted queries in special nodes, called query directories, and uses them to locate the data (responses) that are stored in the nodes that first request them, called caching nodes. The system, which was named distributed cache invalidation method (DCIM), includes client‐based mechanisms for keeping the cached data consistent with the data source. In this work, we extend DCIM to handle cache replicas inside the MANET. For this purpose, we utilize a push‐based approach within the MANET to propagate the server updates to replicas inside the network. The result is a hybrid approach that utilizes the benefits of pull approaches for client server communication and those of push approaches inside the network between the replicas. The approach is analyzed analytically, and the appropriate number of replicas is obtained, where it was concluded that full replication of the indices of data items at the query directory and two‐partial replication of the data items themselves makes most sense. Simulation results based on ns2 demonstrate the ability of the added replication scheme to lower delays and improve hit ration at the cost of mild increases in overhead traffic. Copyright © 2013 John Wiley & Sons, Ltd.
Towards Motivic Quantum Cohomology of M̄0,S
Authors: Manin Yuri I. , Smirnov Maxim 
Published: December 2013

AbstractWe explicitly calculate some Gromov–Witten correspondences determined by maps of labelled curves of genus 0 to the moduli spaces of labelled curves of genus 0. We consider these calculations as the first step towards studying the self-referential nature of motivic quantum cohomology.
Cayley Forms and Self-Dual Varieties
Authors: Catanese F. 
Published: December 2013

AbstractGeneralized Chow forms were introduced by Cayley for the case of 3-space; their zero set on the Grassmannian G(1, 3) is either the set Z of lines touching a given space curve (the case of an ‘honest’ Cayley form), or the set of lines tangent to a surface. Cayley gave some equations for F to be a generalized Cayley form, which should hold modulo the ideal generated by F and by the quadratic equation Q for G(1, 3). Our main result is that F is a Cayley form if and only if Z = G(1, 3) ∩ {F = 0} is equal to its dual variety. We also show that the variety of generalized Cayley forms is defined by quadratic equations, since there is a unique representative F0 + QF1 of F, with F0, F1 harmonic, such that the harmonic projection of the Cayley equation is identically 0. We also give new equations for honest Cayley forms, but show, with some calculations, that the variety of honest Cayley forms does not seem to be defined by quadratic and cubic equations.
Elliptic Fibrations on K3 Surfaces
Authors: Nikulin Viacheslav V. 
Published: December 2013

AbstractThis paper consists mainly of a review and applications of our old results relating to the title. We discuss how many elliptic fibrations and elliptic fibrations with infinite automorphism groups (or Mordell–Weil groups) an algebraic K3 surface over an algebraically closed field can have. As examples of applications of the same ideas, we also consider K3 surfaces with exotic structures: with a finite number of non-singular rational curves, with a finite number of Enriques involutions, and with naturally arithmetic automorphism groups.
Leuconostoc citreumMB1 as biocontrol agent ofListeria monocytogenesin milk
Authors: Pujato Silvina A , del L Quiberoni Andrea , Candioti Mario C , Reinheimer Jorge A , Guglielmotti Daniela M 
Published: December 2013

Cell-free supernatant fromLeuconostoc citreumMB1 revealed specific antilisterial activity. Preliminary studies demonstrated the proteinaceous, heat-stable, bacteriocin-like trait of the antimicrobial components present in the supernatant. Determination of the genes encoding bacteriocins by PCR and DNA sequencing led to amplification products highly homologous with leucocin A (found in diverseLeuconostocspecies) and UviB (found inLeuc. citreumKM20) sequences. Additionally, antimicrobial activity of cell-free supernatant fromLeuc. citreumMB1 was revealed by an inhibition halo of the SDS-PAGE gel subjected to a direct detection usingListeria monocytogenesas indicator strain. Different assays were carried out to assess the capacity ofLeuc.citreumMB1 to controlList. monocytogenesgrowth: (i) inactivation kinetics of the pathogen by antilisterial compounds present in concentrated cell-free supernatant fromLeuc. citreumMB1, (ii) evaluation of optimalLeuc. citreumMB1 initial concentration to obtain maximumList. monocytogenesATCC 15313 inhibition, and (iii) biocontrol ofList. monocytogenesATCC 15313 withLeuc. citreumMB1 during growth in milk at refrigeration temperature. According to our results, it is unquestionable that at least one bacteriocin is active inLeuc. citreumMB1, since important antilisterial activity was verified either in its cell-free supernatant or in co-culture experiments. Co-culture tests showed that ∼107 CFU/mlLeuc. citreumMB1 was the optimal initial concentration to obtain maximum pathogen inhibition. Moreover,Leuc. citreumMB1 was able to delayList. monocytogenesgrowth at refrigerated temperature.
Ultrasound effects on the assembly of casein micelles in reconstituted skim milk
Authors: Liu Zheng , Juliano Pablo , Williams Roderick PW , Niere Julie , Augustin Mary Ann 
Published: December 2013

Reconstituted skim milks (10 % w/w total solids, pH 6·7–8·0) were ultrasonicated (20, 400 or 1600 kHz at a specific energy input of 286 kJ/kg) at a bulk milk temperature of <30 °C. Application of ultrasound to milk at different pH altered the assembly of the casein micelle in milk, with greater effects at higher pH and lower frequency. Low frequency ultrasound caused greater disruption of casein micelles causing release of protein from the micellar to the serum phase than high frequency. The released protein re-associated to form aggregates of smaller size but with surface charge similar to the casein micelles in the original milk. Ultrasound may be used as a physical intervention to alter the size of the micelles and the partitioning of caseins between the micellar and serum phases in milk. The altered protein equilibria induced by ultrasound treatment may have potential for the development of milk with novel functionality.
Optimisation of medium composition for probiotic biomass production using response surface methodology
Authors: Anvari Masumeh , Khayati Gholam , Rostami Shora 
Published: December 2013

This study was aimed to optimise lactose, inulin and yeast extract concentration and also culture pH for maximising the growth of a probiotic bacterium,Bifidobacterium animalissubsp.lactisin apple juice and to assess the effects of these factors by using response surface methodology. A second-order central composite design was applied to evaluate the effects of these independent variables on growth of the microorganism. A polynomial regression model with cubic and quadratic terms was used for analysis of the experimental data. It was found that the effects involving inulin, yeast extract and pH on growth of the bacterium were significant, and the strongest effect was given by the yeast extract concentration. Estimated optimum conditions of the factors on the bacterial growth are as follows: lactose concentration=9·5 g/l; inulin concentration=38·5 mg/l; yeast extract concentration=9·6 g/l and initial pH=6·2.
Influence of Negative Stereotypes and Beliefs on Neuropsychological Test Performance in a Traumatic Brain Injury Population
Authors: Kit Karen A. , Mateer Catherine A. , Tuokko Holly A. , Spencer-Rodgers Julie 
Published: December 2013

AbstractThe impact of stereotype threat and self-efficacy beliefs on neuropsychological test performance in a clinical traumatic brain injury (TBI) population was investigated. A total of 42 individuals with mild-to-moderate TBI and 42 (age-, gender-, educationally matched) healthy adults were recruited. The study consisted of a 2 (Type of injury: control, TBI) × 2 (Threat Condition: reduced threat, heightened threat) between-participants design. The purpose of the reduced threat condition was to reduce negative stereotyped beliefs regarding cognitive effects of TBI and to emphasize personal control over cognition. The heightened threat condition consisted of an opposing view. Main effects included greater anxiety, motivation, and dejection but reduced memory self-efficacy for head-injured-groups, compared to control groups. On neuropsychological testing, the TBI-heightened-threat-group displayed lower scores onInitial Encoding(initial recall) and trended toward displaying lower scores onAttention(working memory) compared to the TBI-reduced-threat-group. No effect was found for Delayed Recall measures. Memory self-efficacy mediated the relation between threat condition and neuropsychological performance, indicating a potential mechanism for the threat effect. The findings highlight the impact of stereotype threat and self-referent beliefs on neuropsychological test performance in a clinical TBI population. (JINS, 2013,20, 1–11)
Microbial population and functional dynamics associated with surface potential and carbon metabolism
Authors: Ishii Shun’ichi , Suzuki Shino , Norden-Krichmar Trina M , Phan Tony , Wanger Greg , Nealson Kenneth H , Sekiguchi Yuji , Gorby Yuri A , Bretschger Orianna 
Published: December 2013

Abstract
Microbial extracellular electron transfer (EET) to solid surfaces is an important reaction for metal reduction occurring in various anoxic environments. However, it is challenging to accurately characterize EET-active microbial communities and each member’s contribution to EET reactions because of changes in composition and concentrations of electron donors and solid-phase acceptors. Here, we used bioelectrochemical systems to systematically evaluate the synergistic effects of carbon source and surface redox potential on EET-active microbial community development, metabolic networks and overall electron transfer rates. The results indicate that faster biocatalytic rates were observed under electropositive electrode surface potential conditions, and under fatty acid-fed conditions. Temporal 16S rRNA-based microbial community analyses showed that Geobacter phylotypes were highly diverse and apparently dependent on surface potentials. The well-known electrogenic microbes affiliated with the Geobacter metallireducens clade were associated with lower surface potentials and less current generation, whereas Geobacter subsurface clades 1 and 2 were associated with higher surface potentials and greater current generation. An association was also observed between specific fermentative phylotypes and Geobacter phylotypes at specific surface potentials. When sugars were present, Tolumonas and Aeromonas phylotypes were preferentially associated with lower surface potentials, whereas Lactococcus phylotypes were found to be closely associated with Geobacter subsurface clades 1 and 2 phylotypes under higher surface potential conditions. Collectively, these results suggest that surface potentials provide a strong selective pressure, at the species and strain level, for both solid surface respirators and fermentative microbes throughout the EET-active community development.
Tunable single-photon frequency conversion in a Sagnac interferometer
Authors: Yan Wei-Bin , Huang Jin-Feng , Fan Heng 
Published: December 2013

AbstractQuantum information carriers like photons might be manipulated, stored and transmitted in different quantum systems. It is important to integrate those systems efficiently. The capability of converting photons from one wavelength to another wavelength is a key requirement for combining the photons in telecommunications band for quantum transmission and the photons in near-visible band for quantum storage. Here, we investigate the tunable single-photon frequency conversion in the five-level emitter-Sagnac interferometer system. We show that the efficient single-photon conversion can be achieved in this scheme, at the same time, the frequencies of the input and output photons can be tuned in a large scale by controlling the frequencies and Rabi frequencies of the external driving fields. The realization of this scheme may lead to the efficient combination of quantum storage system with the quantum communication system.
Real‐time freeway sideswipe crash prediction by support vector machine
Authors: Qu Xu , Wang Wei , Wang Wenfu , Liu Pan 
Published: December 2013

This study presents the applications of a pattern classifier named support vector machine (SVM) in predicting freeway sideswipe crash potential. Historical loop detector data for sideswipe crashes and corresponding non‐crash cases were collected from Interstate‐894 in the Milwaukee, Wisconsin, USA. Two sets of significant explanatory features were aggregated from the collected detector data to capture the prevailing traffic state and variances between adjacent lanes. Then, three SVMs with different nonlinear kernel function were formulated with the significant features as inputs. To comparatively evaluate the performance of SVM models against other commonly applied crash potential predictors, the multi‐layer perceptron (MLP) artificial neural network models were also developed to predict sideswipe crash potential. The results showed that SVM models offers similar overall accuracy as the premier MLP model, but SVMs achieved better sideswipe crash identification at higher false alarm rates. The research also investigated the potential of using the SVM model for evaluating the impacts of traffic factors on sideswipe crash. Sensitivity analysis conducted on the trained SVM models successfully identified the variables’ impact on sideswipe crash. These results affirmed the superior performance of SVM technique in crash potential prediction analysis.
Automated fit of high-dimensional potential energy surfaces using cluster analysis and interpolation over descriptors of chemical environment
Authors: Fournier René , Orel Slava 
Published: December 2013

We present a method for fitting high-dimensional potential energy surfaces that is almost fully automated, can be applied to systems with various chemical compositions, and involves no particular choice of function form. We tested it on four systems: Ag20, Sn6Pb6, Si10, and Li8. The cost for energy evaluation is smaller than the cost of a density functional theory (DFT) energy evaluation by a factor of 1500 for Li8, and 60 000 for Ag20. We achieved intermediate accuracy (errors of 0.4 to 0.8 eV on atomization energies, or, 1% to 3% on cohesive energies) with rather small datasets (between 240 and 1400 configurations). We demonstrate that this accuracy is sufficient to correctly screen the configurations with lowest DFT energy, making this function potentially very useful in a hybrid global optimization strategy. We show that, as expected, the accuracy of the function improves with an increase in the size of the fitting dataset.
Impact of laser power density on tribological properties of Pulsed Laser Deposited DLC films
Authors: Gayathri S. , Kumar N. , Krishnan R. , AmirthaPandian S. , Ravindran T. R. , Dash S. , Tyagi A. K. , Sridharan M. 
Published: December 2013

Fabrication of wear resistant and low friction carbon films on the engineered substrates is considered as a challenging task for expanding the applications of diamond-like carbon (DLC) films. In this paper, pulsed laser deposition (PLD) technique is used to deposit DLC films on two different types of technologically important class of substrates such as silicon and AISI 304 stainless steel. Laser power density is one of the important parameter used to tailor the fraction of sp2 bonded amorphous carbon (a-C) and tetrahedral amorphous carbon (ta-C) made by sp3 domain in the DLC film. The I(D)/I(G) ratio decreases with the increasing laser power density which is associated with decrease in fraction of a-C/ta-C ratio. The fraction of these chemical components is quantitatively analyzed by EELS which is well supported to the data obtained from the Raman spectroscopy. Tribological properties of the DLC are associated with chemical structure of the film. However, the super low value of friction coefficient 0.003 is obtained when the film is predominantly constituted by a-C and sp2 fraction which is embedded within the clusters of ta-C. Such a particular film with super low friction coefficient is measured while it was deposited on steel at low laser power density of 2 GW/cm2. The super low friction mechanism is explained by low sliding resistance of a-C/sp2 and ta-C clusters. Combination of excellent physical and mechanical properties of wear resistance and super low friction coefficient of DLC films is desirable for engineering applications. Moreover, the high friction coefficient of DLC films deposited at 9GW/cm2 is related to widening of the intergrain distance caused by transformation from sp2 to sp3 hybridized structure.