bluuebunny/crossref_metadata_2025_split huggingface dataset:
ASR FORUM: ENGAGING WITH AFRICAN INFORMAL ECONOMIES
Authors: Prag Ebbe 
Published: November 2013

Abstract:This article examines the impact of Chinese textile imports on the organization and politics of women’s textile trading networks in Benin. The incursion of cheap Chinese textiles into markets formerly dominated by imported European fabrics has shifted the balance of power between networks of traders in Benin’s textile market, reconfiguring relations between textile traders, state officials, and international companies. Focusing on political and economic dimensions of trading networks, the article reveals how global linkages transform local economic networks and how local actors structure networks for global economic partners. Far from bypassing state actors, this process is shown to incorporate state officials from above and from below, splintering established trading networks and weaving new ones from emerging configurations of traders, state officials, and global textile exporters.
THE GROTHENDIECK CONSTANT IS STRICTLY SMALLER THAN KRIVINE’S BOUND
Authors: BRAVERMAN MARK , MAKARYCHEV KONSTANTIN , MAKARYCHEV YURY , NAOR ASSAF 
Published: November 2013

AbstractThe (real) Grothendieck constant ${K}_{G} $ is the infimum over those $K\in (0, \infty )$ such that for every $m, n\in \mathbb{N} $ and every $m\times n$ real matrix $({a}_{ij} )$ we have $$\begin{eqnarray*}\displaystyle \max _{\{ x_{i}\} _{i= 1}^{m} , \{ {y}_{j} \} _{j= 1}^{n} \subseteq {S}^{n+ m- 1} }\sum _{i= 1}^{m} \sum _{j= 1}^{n} {a}_{ij} \langle {x}_{i} , {y}_{j} \rangle \leqslant K\max _{\{ \varepsilon _{i}\} _{i= 1}^{m} , \{ {\delta }_{j} \} _{j= 1}^{n} \subseteq \{ - 1, 1\} }\sum _{i= 1}^{m} \sum _{j= 1}^{n} {a}_{ij} {\varepsilon }_{i} {\delta }_{j} . &&\displaystyle\end{eqnarray*}$$ The classical Grothendieck inequality asserts the nonobvious fact that the above inequality does hold true for some $K\in (0, \infty )$ that is independent of $m, n$ and $({a}_{ij} )$. Since Grothendieck’s 1953 discovery of this powerful theorem, it has found numerous applications in a variety of areas, but, despite attracting a lot of attention, the exact value of the Grothendieck constant ${K}_{G} $ remains a mystery. The last progress on this problem was in 1977, when Krivine proved that ${K}_{G} \leqslant \pi / 2\log (1+ \sqrt{2} )$ and conjectured that his bound is optimal. Krivine’s conjecture has been restated repeatedly since 1977, resulting in focusing the subsequent research on the search for examples of matrices $({a}_{ij} )$ which exhibit (asymptotically, as $m, n\rightarrow \infty $) a lower bound on ${K}_{G} $ that matches Krivine’s bound. Here, we obtain an improved Grothendieck inequality that holds for all matrices $({a}_{ij} )$ and yields a bound ${K}_{G} \lt \pi / 2\log (1+ \sqrt{2} )- {\varepsilon }_{0} $ for some effective constant ${\varepsilon }_{0} \gt 0$. Other than disproving Krivine’s conjecture, and along the way also disproving an intermediate conjecture of König that was made in 2000 as a step towards Krivine’s conjecture, our main contribution is conceptual: despite dealing with a binary rounding problem, random two-dimensional projections, when combined with a careful partition of ${ \mathbb{R} }^{2} $ in order to round the projected vectors to values in $\{ - 1, 1\} $, perform better than the ubiquitous random hyperplane technique. By establishing the usefulness of higher-dimensional rounding schemes, this fact has consequences in approximation algorithms. Specifically, it yields the best known polynomial-time approximation algorithm for the Frieze–Kannan Cut Norm problem, a generic and well-studied optimization problem with many applications.
Steady one-dimensional nozzle flow solutions of liquid–gas mixtures
Authors: LeMartelot S. , Saurel R. , Le Métayer O. 
Published: November 2013

AbstractExact compressible one-dimensional nozzle flow solutions at steady state are determined in various limit situations of two-phase liquid–gas mixtures. First, the exact solution for a pure liquid nozzle flow is determined in the context of fluids governed by the compressible Euler equations and the ‘stiffened gas’ equation of state. It is an extension of the well-known ideal-gas steady nozzle flow solution. Various two-phase flow models are then addressed, all corresponding to limit situations of partial equilibrium among the phases. The first limit situation corresponds to the two-phase flow model of Kapilaet al. (Phys. Fluids, vol. 13, 2001, pp. 3002–3024), where both phases evolve in mechanical equilibrium only. This model contains two entropies, two temperatures and non-conventional shock relations. The second one corresponds to a two-phase model where the phases evolve in both mechanical and thermal equilibrium. The last one corresponds to a model describing a liquid–vapour mixture in thermodynamic equilibrium. They all correspond to two-phase mixtures where the various relaxation effects are either stiff or absent. In all instances, the various flow regimes (subsonic, subsonic–supersonic, and supersonic with shock) are unambiguously determined, as well as various nozzle solution profiles.
Treatment with citalopram, but not with agomelatine, adversely affects sperm parameters: a case report and translational review
Authors: Elnazer Hesham Y. , Baldwin David S. 
Published: November 2013

BackgroundAdverse effects of antidepressant drug treatmenton sexual function are well documented but the effects of antidepressants on sperm production have not been researched extensively.MethodsA narrative of an interventional case report of sperm parameters in a 30-year-old Caucasian man with a diagnosis of mixed depressive and anxiety disorder, who underwent citalopram treatment, followed by agomelatine treatment. Clinical observations prompted a review of the pre-clinical and clinical literature on the effects of antidepressant administration or treatment on sperm production and parameters. Findings from the review are discussed to suggest potential underlying mechanisms.ResultsAbnormal sperm parameters were associated with treatment with the SSRI citalopram. There was an improvement in sperm concentration, motility, progressive motility and sperm morphology following its withdrawal. There was no similar association during subsequent treatment with agomelatine. The clinical observations reflect findings from animal studies, which indicate that antidepressants can have untoward effects on spermatogenesis.ConclusionsSSRI treatment can be associated with impaired semen quality. Potential underlying mechanisms include changes in sperm DNA integrity, activation of IDO and shifting tryptophan metabolism. Further studies of the effects of antidepressants on spermatogenesis might benefit from including investigation of changes in IDO activity during antidepressant administration.
Policy reform of emission taxes and environmental research and development incentives in an international Cournot model with product differentiation
Authors: Gautier Luis 
Published: November 2013

AbstractThis paper studies multilateral and unilateral policy reforms of environmental R&D subsidies and emission taxes in a two-country Cournot model with oligopolistic interdependence. The analysis indicates, inter alia, that there is a potential family of multilateral and unilateral policy reforms which can be set by pollution-intensive and pollution-moderate countries to reduce global emissions. In particular, the analysis suggests that a unilateral increase in the subsidy in the pollution-moderate country may reduce global emissions. The multilateral policy reform of the subsidy and tax in the pollution-intensive country can also reduce global emissions and increase welfare under certain conditions. The role of product differentiation in the context of policy reform is also examined.
Integrated sorting, concentration and real time PCR based detection system for sensitive detection of microorganisms
Authors: Nayak Monalisha , Singh Deepak , Singh Himanshu , Kant Rishi , Gupta Ankur , Pandey Shashank Shekhar , Mandal Swarnasri , Ramanathan Gurunath , Bhattacharya Shantanu 
Published: November 2013

AbstractThe extremely low limit of detection (LOD) posed by global food and water safety standards necessitates the need to perform a rapid process of integrated detection with high specificity, sensitivity and repeatability. The work reported in this article shows a microchip platform which carries out an ensemble of protocols which are otherwise carried in a molecular biology laboratory to achieve the global safety standards. The various steps in the microchip include pre-concentration of specific microorganisms from samples and a highly specific real time molecular identification utilizing a q-PCR process. The microchip process utilizes a high sensitivity antibody based recognition and an electric field mediated capture enabling an overall low LOD. The whole process of counting, sorting and molecular identification is performed in less than 4 hours for highly dilute samples.
Temporal Changes and Sexual Differences in Spatial Distribution of Burbot in Lake Erie
Authors: Stapanian Martin A. , Witzel Larry D. , Cook Andy 
Published: November 2013

AbstractWe used GIS mapping techniques to examine capture data for Burbot Lota lota from annual gill‐net surveys in Canadian waters of Lake Erie during late August and September 1994–2011. Adult males were captured over a larger area (3–17% for ≥20% maximum yearly catch [MYC]) than adult females. More males than females were caught in the gill nets in 14 of the 15 study years. Collectively, these results support a hypothesis of greater activity by adult males during summer, when Burbot are actively feeding. The area of capture contracted by more than 60% (for ≥20% MYC) for both sexes during the time period, which is consistent with the documented decrease of the Burbot population in the lake. The sex ratio (females: males) varied over the time series but declined steadily from 0.97 in 2001 to 0.59 in 2011. The overlap in the capture areas of adult males and females was scale dependent. The depth distribution at which adult Burbot were caught did not change over the time series, and there was no difference in the median depths (about 30 m) at which adult male and female Burbot were caught. The last results are consistent with the Burbot's reliance on coldwater habitats. Additional research is recommended, including telemetry to describe daily and seasonal movements and assessment of gender bias in active and passive capture gear.
Bioenergetics and Trophic Impacts of the Invasive Indo‐Pacific Lionfish
Authors: Cerino David , Overton Anthony S. , Rice James A. , Morris James A. 
Published: November 2013

AbstractIndo‐Pacific lionfish, the Red Lionfish Pterois volitans and the Devil Firefish P. miles, are nonnative marine fish that have invaded the western North Atlantic Ocean, Caribbean Sea, and Gulf of Mexico. Rapid population growth of this invasive predator threatens native fish communities. A bioenergetics model was developed for lionfish (i.e., both species) and then applied to estimate the potential impact of these predators on a reef fish community. We conducted a series of laboratory trials to evaluate consumption and respiration rates between 14°C and 32°C for lionfish weighing from 20 to 400 g. Water temperature greatly influenced consumption; mean daily consumption rates increased from 14°C to 29.7°C and declined at 32.5°C. Energy density of the prey was the most sensitive parameter in the model and estimates of food consumption corresponded with empirical and laboratory estimates. To realize population‐level impacts, we applied the bioenergetics model to a size‐structured virtual population of 393 lionfish/ha on a reef in the Bahamas. Model simulations estimated that this population would annually consume 929 kg of prey/ha when feeding at 60% of maximum consumption. This model provides the first comprehensive assessment of lionfish bioenergetics accounting for the effects of size and temperature on prey consumption and improves the capacity to evaluate the trophic impacts of lionfish in the Atlantic Ocean.
Assessing Effects of Stocked Trout on Nongame Fish Assemblages in Southern Appalachian Mountain Streams
Authors: Weaver Daniel M. , Kwak Thomas J. 
Published: November 2013

AbstractFisheries managers are faced with the challenge of balancing the management of recreational fisheries with that of conserving native species and preserving ecological integrity. The negative effects that nonnative trout species exert on native trout are well documented and include alteration of competitive interactions, habitat use, and production. However, the effects that nonnative trout may exert on nongame fish assemblages are poorly understood. Our objectives were to quantify the effects of trout stocking on native nongame fish assemblages intensively on one newly stocked river, the North Toe River, North Carolina, and extensively on other southern Appalachian Mountain streams that are annually stocked with trout. In the intensive study, we adopted a before–after, control–impact (BACI) experimental design to detect short‐term effects on the nongame fish assemblage and found no significant differences in fish density, species richness, species diversity, or fish microhabitat use associated with trout stocking. We observed differences in fish microhabitat use between years, however, which suggests there is a response to environmental changes, such as the flow regime, which influence available habitat. In the extensive study, we sampled paired stocked and unstocked stream reaches to detect long‐term effects from trout stocking; however, we detected no differences in nongame fish density, species richness, species diversity, or population size structure between paired sites. Our results revealed high inherent system variation caused by natural and anthropogenic factors that appear to overwhelm any acute or chronic effect of stocked trout. Furthermore, hatchery‐reared trout may be poor competitors in a natural setting and exert a minimal or undetectable impact on native fish assemblages in these streams. These findings provide quantitative results necessary to assist agencies in strategic planning and decision making associated with trout fisheries, stream management, and conservation of native fishes.
Depths and Thermal Habitat Used by Large versus Small Northern Pike in Three Minnesota Lakes
Authors: Pierce Rodney B. , Carlson Andrew J. , Carlson Bruce M. , Hudson Dallas , Staples David F. 
Published: November 2013

AbstractWe monitored depths and temperatures used by large (>71‐cm) versus small Northern Pike Esox lucius in three north‐central Minnesota lakes with either acoustic telemetry or archival tags. Individual Northern Pike demonstrated flexibility in depths used within a season and between years. The fish had some tolerance for low levels of dissolved oxygen (<3 mg/L), but depth selection was generally constrained by low dissolved oxygen in summer and winter. The fish more fully exploited all available depths during winter and thermal turnover periods. During July and August, large Northern Pike tended to follow the thermocline into cooler water as upper water layers warmed. Selection ratios indicated that large Northern Pike preferred water temperatures of 16–21°C during August when temperatures up to 28°C were available. In two lakes providing dense overhead cover from water lilies in shallow water, small Northern Pike used warmer, shallower water compared with large fish during summer. In a third lake providing no such cover, small fish were more often in deeper, cooler water. For small Northern Pike, temperature seemed to be a secondary habitat consideration behind the presence of shallow vegetated cover. This study provided detailed temperature selection information that will be useful when considering temperature as an ecological resource for different sizes of Northern Pike.
Combining optimization and machine learning techniques for genome-wide prediction of human cell cycle-regulated genes
Authors: De Santis Marianna , Rinaldi Francesco , Falcone Emmanuela , Lucidi Stefano , Piaggio Giulia , Gurtner Aymone , Farina Lorenzo 
Published: November 2013

Abstract
Motivation: The identification of cell cycle-regulated genes through the cyclicity of messenger RNAs in genome-wide studies is a difficult task due to the presence of internal and external noise in microarray data. Moreover, the analysis is also complicated by the loss of synchrony occurring in cell cycle experiments, which often results in additional background noise.
Results: To overcome these problems, here we propose the LEON (LEarning and OptimizatioN) algorithm, able to characterize the ‘cyclicity degree’ of a gene expression time profile using a two-step cascade procedure. The first step identifies a potentially cyclic behavior by means of a Support Vector Machine trained with a reliable set of positive and negative examples. The second step selects those genes having peak timing consistency along two cell cycles by means of a non-linear optimization technique using radial basis functions. To prove the effectiveness of our combined approach, we use recently published human fibroblasts cell cycle data and, performing in vivo experiments, we demonstrate that our computational strategy is able not only to confirm well-known cell cycle-regulated genes, but also to predict not yet identified ones.
Availability and implementation: All scripts for implementation can be obtained on request.
Contact: lorenzo.farina@uniroma1.it or gurtner@ifo.it
Supplementary information: Supplementary data are available at Bioinformatics online.
A lithium depletion boundary age of 21 Myr for the Beta Pictoris moving group
Authors: Binks A. S. , Jeffries R. D. 
Published: November 2013

Abstract
Optical spectroscopy is used to confirm membership for eight low-mass candidates in the young Beta Pic moving group (BPMG) via their radial velocities, chromospheric activity and kinematic parallaxes. We searched for the presence of the Li i 6708 Å resonance feature and combined the results with literature measurements of other BPMG members to find the age-dependent lithium depletion boundary (LDB) – the luminosity at which Li remains unburned in a coeval group. The LDB age of the BPMG is 21 ± 4 Myr and insensitive to the choice of low-mass evolutionary models. This age is more precise, likely to be more accurate, and much older than that commonly assumed for the BPMG. As a result, substellar and planetary companions of BPMG members will be more massive than previously thought.
DNA secondary structures are associated with recombination in majorPlasmodium falciparumvariable surface antigen gene families
Authors: Sander Adam F. , Lavstsen Thomas , Rask Thomas S. , Lisby Michael , Salanti Ali , Fordyce Sarah L. , Jespersen Jakob S. , Carter Richard , Deitsch Kirk W. , Theander Thor G. , Pedersen Anders Gorm , Arnot David E. 
Published: November 2013

AbstractMany bacterial, viral and parasitic pathogens undergo antigenic variation to counter host immune defense mechanisms. In Plasmodium falciparum, the most lethal of human malaria parasites, switching of var gene expression results in alternating expression of the adhesion proteins of the Plasmodium falciparum-erythrocyte membrane protein 1 class on the infected erythrocyte surface. Recombination clearly generates var diversity, but the nature and control of the genetic exchanges involved remain unclear. By experimental and bioinformatic identification of recombination events and genome-wide recombination hotspots in var genes, we show that during the parasite’s sexual stages, ectopic recombination between isogenous var paralogs occurs near low folding free energy DNA 50-mers and that these sequences are heavily concentrated at the boundaries of regions encoding individual Plasmodium falciparum-erythrocyte membrane protein 1 structural domains. The recombinogenic potential of these 50-mers is not parasite-specific because these sequences also induce recombination when transferred to the yeast Saccharomyces cerevisiae. Genetic cross data suggest that DNA secondary structures (DSS) act as inducers of recombination during DNA replication in P. falciparum sexual stages, and that these DSS-regulated genetic exchanges generate functional and diverse P. falciparum adhesion antigens. DSS-induced recombination may represent a common mechanism for optimizing the evolvability of virulence gene families in pathogens.
Effect of Catechol-o-methyltransferase-gene (COMT) Variants on Experimental and Acute Postoperative Pain in 1,000 Women undergoing Surgery for Breast Cancer
Authors: Kambur Oleg , Kaunisto Mari A. , Tikkanen Emmi , Leal Suzanne M. , Ripatti Samuli , Kalso Eija A. 
Published: November 2013

Abstract

Background:
Catechol-O-methyltransferase (COMT) metabolizes catecholamines in different tissues. Polymorphisms in COMT gene can attenuate COMT activity and increase sensitivity to pain. Human studies exploring the effect of COMT polymorphisms on pain sensitivity have mostly included small, heterogeneous samples and have ignored several important single nucleotide polymorphisms (SNPs). This study examines the effect of COMT polymorphisms on experimental and postoperative pain phenotypes in a large ethnically homogeneous female patient cohort.

Methods:
Intensity of cold (+2-4°C) and heat (+48°C) pain and tolerance to cold pain were assessed in 1,000 patients scheduled for breast cancer surgery. Acute postoperative pain and oxycodone requirements were recorded. Twenty-two COMT SNPs were genotyped and their association with six pain phenotypes analyzed with linear regression.

Results:
There was no association between any of the tested pain phenotypes and SNP rs4680. The strongest association signals were seen between rs165774 and heat pain intensity as well as rs887200 and cold pain intensity. In both cases, minor allele carriers reported less pain. Neither of these results remained significant after strict multiple testing corrections. When analyzed further, the effect of rs887200 was, however, shown to be significant and consistent throughout the cold pressure test. No evidence of association between the SNPs and postoperative oxycodone consumption was found.

Conclusions:
SNPs rs887200 and rs165774 located in the untranslated regions of the gene had the strongest effects on pain sensitivity. Their effect on pain is described here for the first time. These results should be confirmed in further studies and the potential functional mechanisms of the variants studied.