bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microhabitat use of the diamond darter
Authors: Welsh Stuart A. , Smith Dustin M. , Taylor Nate D. 
Published: May 2013

AbstractThe only known extant population of the diamond darter (Crystallaria cincotta) exists in the lower 37 km of Elk River, WV, USA. Our understanding of diamond darter habitat use was previously limited, because few individuals have been observed during sampling with conventional gears. We quantified microhabitat use of diamond darters based on measurements of water depth, water velocity and per cent substrate composition. Using spotlights at night‐time, we sampled 16 sites within the lower 133 km of Elk River and observed a total of 82 diamond darters at 10 of 11 sampling sites within the lower 37 km. Glides, located immediately upstream of riffles, were the primary habitats sampled for diamond darters, which included relatively shallow depths (<1 m), moderate‐to‐low water velocities (often < 0.5 m·s−1) and a smooth water surface. Microhabitat use (mean ± SE) of diamond darters was estimated for depth (0.47 ± 0.02 m), average velocity (0.27 ± 0.01 m·s−1) and bottom velocity (0.15 ± 0.01 m·s−1). Substrate used (mean ± SE) by diamond darters was predominantly sand intermixed with lesser amounts of gravel and cobble: % sand (52.1 ± 1.6), % small gravel (12.2 ± 0.78), % large gravel (14.2 ± 0.83), % cobble (19.8 ± 0.96) and % boulder (1.6 ± 0.36). Based on our microhabitat use data, conservation and management efforts for this species should consider preserving glide habitats within Elk River. Spotlighting, a successful sampling method for diamond darters, should be considered for study designs of population estimation and long‐term monitoring.
Hume's Unified Theory of Mental Representation
Authors: Schafer Karl 
Published: May 2013

AbstractOn its face, Hume's account of mental representation involves at least two elements. On the one hand, Hume often seems to write as though the representational properties of an idea are fixed solely by what it is a copy or image of. But, on the other, Hume's treatment of abstract ideas (and other similar cases) makes it clear that the representational properties of a Humean idea sometimes depend, not just on what it is copied from, but also on the manner in which the mind associates it with other ideas. Past interpretations of Hume have tended to focus on one of these elements of his account to the neglect of the other. But no interpretation of this sort is likely to capture the role that both copying and association play within Hume's discussion. In what follows, I argue that the most plausible way of understanding Hume's discussion involves attributing to him a unified account of mental representation in which both of these elements play a central role. I close by discussing the manner in which reading Hume in this way would alter our understanding of the relationship between Hume's thought and contemporary philosophy of mind.
Reduced activity of β‐glucosidase resulting from host‐guest interactions with dissolved fulvic acids as revealed by NMR spectroscopy
Authors: Mazzei P. , Piccolo A. 
Published: May 2013

SummaryInteractions between fulvic acids (FAs) and a β‐glucosidase (GLU) enzyme and consequent modifications of enzymatic activity were investigated at pH 5.0 and 7.2 by 1H nuclear magnetic resonance (NMR) spectroscopy. With increasing FA content, the enzyme proton signals were progressively broadened, while the relaxation (T1 and T2) and correlation (τc) times of GLU decreased and increased, respectively. Regardless of pH, these effects were greater for the hydroxy‐alkylic and aromatic protons of GLU, suggesting that the FA‐enzyme associations, which progressively limited GLU tumbling rate, resulted from weak interactions, such as H‐bonds and dispersive hydrophobic bonds. The catalytic activity of β‐D‐glucosidase, when in weakly bound complexes with FA, was studied by following the change of NMR signals of two different substrates, p‐nitrophenyl‐β‐D‐glucopyranoside (pNPG) and salicin, and their hydrolysis products. Spectral evidence suggests that enzyme activity was substantially reduced with increasing FA concentration and the rate reduction was more pronounced for salicin than for pNPG. The enzyme inhibition may be explained by either a partial cover of GLU active sites by fulvic molecules or modification of the enzyme conformational structure during formation of humic‐enzyme complexes. Our results indicate that even weak interactions of FA with GLU are sufficient to inhibit partially its catalytic activity, and that the environmental role of extracellular enzymes may be significantly reduced when coming into contact with organic matter in the soil.
Abnormal white matter correlates with neuropsychological impairment in children with localization‐related epilepsy
Authors: Widjaja Elysa , Skocic Jovanka , Go Cristina , Snead O. Carter , Mabbott Donald , Smith Mary Lou 
Published: May 2013

SummaryPurposeThe white matter (WM) is considered critical for linking cortical processing networks necessary for cognition. The aim of this study was to assess diffusion tensor imaging (DTI) measures of regional WM in children with nonlesional localization‐related epilepsy in comparison to controls, and to determine the relation between lobar WM and neuropsychological performance.MethodsForty children with nonlesional localization‐related epilepsy and 25 healthy controls with no neurological or psychiatric disorders and normal magnetic resonance imaging (MRI) were recruited. All patients and controls underwent neuropsychological testing that evaluated intelligence, language, memory, executive function, and motor function, as well as DTI to assess regional WM measures of fractional anisotropy (FA) and mean diffusivity (MD). The regional FA and MD were compared between patients and controls, and correlated with neuropsychological function. The relations between regional FA and MD with age at seizure onset and duration of epilepsy were assessed.Key FindingsTwenty‐one patients had left‐sided and 19 patients had right‐sided epilepsy. There were no significant differences in seizure‐related variables including age at seizure onset, duration of epilepsy, seizure frequency, and number of antiepileptic medications, as well as no significant differences in neuropsychological function and DTI measures of white matter in left‐sided compared to right‐sided epilepsy. Therefore, all the patients with epilepsy were treated as one group. Patients with epilepsy performed significantly worse on intelligence (p < 0.001), language (p < 0.001), and executive function (p = 0.001) evaluation than controls. Patients had significantly reduced FA in left frontal (p = 0.015), right frontal (p = 0.004), left temporal (p = 0.039), right temporal (p = 0.003), right parietal (p = 0.014), and right occipital (p = 0.025) WM relative to controls. There were no significant regional WM differences (all p > 0.05) in MD between patients and controls. There was a significant positive correlation between right temporal FA with language (r = 0.535, p < 0.001) and executive function (r = 0.617, p < 0.001), as well as between body of corpus callosum FA with intelligence (r = 0.536, p < 0.001) and language (r = 0.529, p < 0.001) in patients. Left parietal MD was significantly correlated with language (r = −0.545, p < 0.001) in patients. FA of right temporal WM was significantly associated with age at seizure onset (t = 4.97, p < 0.001).SignificanceThere was widespread regional WM abnormality in children with nonlesional localization‐related epilepsy, which was associated with impaired neuropsychological function. The impairment in WM may reflect disruption in the connectivity for cortical processing networks, which is necessary for the development of cognition.
WiMAX traffic analysis and base stations classification in terms of LRD
Authors: Stolojescu‐Crisan Cristina , Isar Alexandru , Moga Sorin , Lenca Philippe 
Published: May 2013

AbstractThe goal of this paper is to highlight the particularities of Worldwide Interoperability for Microwave Access (WiMAX) traffic from a long‐range dependence perspective. The application presented in this paper consists in the estimation of the quality of base stations (BS) positioning in the architecture of a WiMAX network. Analysing the traffic of the considered WiMAX network, with an original data mining methodology based on long‐range dependence, we determine which BS have a correct position in the topology of the network and which BS have an incorrect position. These BS must be repositioned when the next session of the network maintenance will take place.
Visualization of evolving social networks using actor‐level and community‐level trajectories
Authors: Oliveira Márcia , Gama João 
Published: May 2013

AbstractVisualization of static social networks is a mature research field in information visualization. Conventional approaches rely on node‐link diagrams that provide a representation of the network topology by representing nodes as points and links between them as lines. However, the increasing availability of longitudinal network data has spurred interest in visualization techniques that go beyond the static node‐link representation of a network. In temporal settings, the focus is on the network dynamics at different levels of analysis (e.g. node, communities and whole network). Yet, the development of visualizations that are able to provide actionable insights into different types of changes occurring in the network and their impact on both the neighbourhood and the overall network structure is a challenging task. In such settings, traditional node‐link representations can prove to be limited (Yi et al., 2010). Alternative methods, such as matrix graph representations, fail in tasks involving path finding (Ghoniem et al., 2005). This work attempts to overcome these issues by proposing a methodology for tracking the evolution of dynamic social networks, at both the node‐level and the community‐level, based on the concept of temporal trajectory. We resort to three‐order tensors to represent evolving social networks, and we further decompose them using a Tucker3 model. The two most representative components of this model define the 2D space where the trajectories of social entities are projected. To illustrate the proposed methodology, we conduct a case study using a set of temporal self‐reported friendship networks.
The relative roles of contemporary and ancient processes in shaping genetic variation of a generalist fish in a catchment dominated by agriculture
Authors: Jordan Mark A. , Patel Deepal , Sanders Kathryn E. , Gillespie Robert B. 
Published: May 2013

Summary

Conversion of land for agriculture has led to the channelisation of headwater streams and reduced water quality. Resident fish populations are expected to be challenged under such conditions and may experience declines that lead to a loss of neutral genetic variation.

However, species‐specific responses to recent ecological changes in stream condition and/or range expansion following glacial retreat can also influence the pattern of genetic variation found within and among contemporary populations. To evaluate the relative roles of contemporary and ancient scenarios that are hypothesised to affect the genetics of populations in streams, we studied the creek chub (Semotilus atromaculatus), a common species that is tolerant of stream degradation.

We screened eight microsatellite loci on 308 individuals originating from ditches and streams surrounded by agricultural and forested land cover within the St. Joseph River catchment in north‐eastern Indiana and southern Michigan, U.S.A.

We found weak population structure associated with land cover and, in contrast to expectation, higher allelic richness in agricultural streams. Using Bayesian coalescent modelling, the strongest pattern found within the data set was evidence of a population decline throughout the catchment that most likely preceded stream channelisation and land conversion.

The results illustrate the complexity of using neutral genetic variation of populations to assay stream quality. Tolerant species may have increased gene flow in channelised streams that leads to an increase in genetic variation. Meanwhile, post‐glacial landscape change and subsequent colonisation of nascent freshwater streams appears to shape genetic variation regardless of contemporary land use.
Effects of ocean warming and acidification on survival, growth and skeletal development in the early benthic juvenile sea urchin (Heliocidaris erythrogramma)
Authors: Wolfe Kennedy , Dworjanyn Symon A. , Byrne Maria 
Published: May 2013

AbstractCo‐occurring ocean warming, acidification and reduced carbonate mineral saturation have significant impacts on marine biota, especially calcifying organisms. The effects of these stressors on development and calcification in newly metamorphosed juveniles (ca. 0.5 mm test diameter) of the intertidal sea urchin Heliocidaris erythrogramma, an ecologically important species in temperate Australia, were investigated in context with present and projected future conditions. Habitat temperature and pH/pCO2 were documented to place experiments in a biologically and ecologically relevant context. These parameters fluctuated diurnally up to 10 °C and 0.45 pH units. The juveniles were exposed to three temperature (21, 23 and 25 °C) and four pH (8.1, 7.8, 7.6 and 7.4) treatments in all combinations, representing ambient sea surface conditions (21 °C, pH 8.1; pCO2 397; ΩCa 4.7; ΩAr 3.1), near‐future projected change (+2–4 °C, −0.3–0.5 pH units; pCO2 400–1820; ΩCa 5.0–1.6; ΩAr 3.3–1.1), and extreme conditions experienced at low tide (+4 °C, −0.3–0.7 pH units; pCO2 2850–2967; ΩCa 1.1–1.0; ΩAr 0.7–0.6). The lowest pH treatment (pH 7.4) was used to assess tolerance levels. Juvenile survival and test growth were resilient to current and near‐future warming and acidification. Spine development, however, was negatively affected by near‐future increased temperature (+2–4 °C) and extreme acidification (pH 7.4), with a complex interaction between stressors. Near‐future warming was the more significant stressor. Spine tips were dissolved in the pH 7.4 treatments. Adaptation to fluctuating temperature‐pH conditions in the intertidal may convey resilience to juvenile H. erythrogramma to changing ocean conditions, however, ocean warming and acidification may shift baseline intertidal temperature and pH/pCO2 to levels that exceed tolerance limits.
Interleukin‐1β induces tumor necrosis factor‐α secretion from rat hepatocytes
Authors: Yoshigai Emi , Hara Takafumi , Inaba Hiroyuki , Hashimoto Iwao , Tanaka Yoshito , Kaibori Masaki , Kimura Tominori , Okumura Tadayoshi , Kwon A‐Hon , Nishizawa Mikio 
Published: May 2013

AimTumor necrosis factor‐α (TNF‐α) is a pleiotropic cytokine involved in various inflammatory diseases. The only production of TNF‐α in the liver is thought to be from hepatic macrophages known as Kupffer cells, predominantly in response to bacterial lipopolysaccharide (LPS).MethodsPrimary cultured rat hepatocytes were used to analyze TNF‐α expression in response to the pro‐inflammatory cytokine, interleukin‐1β (IL‐1β). Livers of rats subjected to LPS‐induced endotoxemia were analyzed.ResultsImmunocytochemistry and enzyme‐linked immunosorbent assays demonstrated that IL‐1β‐treated rat hepatocytes secreted TNF‐α, and RNA analyses indicated that TNF‐α mRNA was induced specifically by IL‐1β. Northern blot analysis showed that not only mRNA, but also a natural antisense transcript (asRNA), was transcribed from the rat Tnf gene in IL‐1β‐treated hepatocytes. TNF‐α was detected in the hepatocytes of LPS‐treated rats. Both TNF‐α mRNA and asRNA were expressed in the hepatocytes of LPS‐treated rats, human hepatocellular carcinoma and human monocyte/macrophage cells. To disrupt the interaction between TNF‐α asRNA and TNF‐α mRNA, sense oligonucleotides corresponding to TNF‐α mRNA were introduced into rat hepatocytes resulting in significantly increased levels of TNF‐α mRNA. One of these sense oligonucleotides increased a half‐life of TNF‐α mRNA, suggesting that the TNF‐α asRNA may reduce the stability of TNF‐α mRNA.ConclusionIL‐1β‐stimulated rat hepatocytes are a newly identified source of TNF‐α in the liver. TNF‐α mRNA and asRNA are expressed in rats and humans, and the TNF‐α asRNA reduces the stability of the TNF‐α mRNA. Hepatocytes and TNF‐α asRNA may be therapeutic targets to regulate levels of TNF‐α mRNA.
Comparison between fibroblasts and mesenchymal stem cells derived from dermal and adipose tissue
Authors: Brohem C. A. , de Carvalho C. M. , Radoski C. L. , Santi F. C. , Baptista M. C. , Swinka B. B. , de A. Urban C. , de Araujo L. R. R. , Graf R. M. , Feferman I. H. S. , Lorencini M. 
Published: May 2013

SynopsisObjectiveStem cells have the ability to renew themselves and differentiate into various cell types. For this reason, numerous research groups have been studying these cells for their therapeutic potential. Some of the therapies, however, are not producing the expected results because of contamination by other cell types, especially by fibroblasts. In the cosmetic industry, stem cells are used to test the efficacy of anti‐ageing and rejuvenation products. The purpose of this work was to gain a better understanding of the differences in phenotype, in gene expression associated with stem cells, in the pattern of cell surface proteins and in the differentiation capacity of adipose‐derived stem cells, of skin‐derived stem cells and of commercially available fibroblasts.MethodsIn this study, we compared fibroblasts with mesenchymal stem cells derived from bone marrow, skin (dermis) and adipose tissue, to assess the differentiation potential of fibroblasts. Dermal and adipose stem cells were isolated from aesthetic surgery patients, and fibroblasts were obtained from a commercial source. The following parameters were used in this study: immunophenotypic profile (positive: CD29, CD73, CD90 and CD105; negative: CD14, CD45 and HLA‐DR); differentiation into osteoblastic, chondrogenic and adipogenic cell types; and PCR array to analyse the gene expression of cells isolated from different culture passages.ResultsFibroblasts express the same cell immunophenotypic markers, as well as the genes that are known to be expressed in stem cells, and were shown to be expressed also in adipose and dermis stem cells. Fibroblasts are also able to differentiate into the three cell lineages mentioned above, that is, adipocytes, osteocytes and chondrocytes.ConclusionHuman dermal fibroblasts have a potential to adhere to plastic surfaces and differentiate into other cell types. However, for stem cells intended to be used in cosmetics, experiments conducted with contaminated fibroblasts may produce poor or even falsely negative results for the efficacy of the active ingredient or formulation and thus conceal their promising effects as anti‐ageing and skin rejuvenation products.
External cervical resorption: an analysis using cone beam and microfocus computed tomography and scanning electron microscopy
Authors: Gunst V. , Mavridou A. , Huybrechts B. , Van Gorp G. , Bergmans L. , Lambrechts P. 
Published: May 2013

AbstractAimTo provide a three‐dimensional representation of external cervical resorption (ECR) with microscopy, stereo microscopy, cone beam computed tomography (CT), microfocus CT and scanning electron microscopy (SEM).SummaryExternal cervical resorption is an aggressive form of root resorption, leading to a loss of dental hard tissues. This is due to clastic action, activated by a damage of the covering cementum and stimulated probably by infection. Clinically, it is a challenging situation as it is characterized by a late symptomatology. This is due to the pericanalar protection from a resorption‐resistant sheet, composed of pre‐dentine and surrounding dentine. The clastic activity is often associated with an attempt to repair, seen by the formation of osteoid tissue.Key learning points

Cone beam CT is extremely useful in the diagnoses and treatment planning of ECR.

SEM analyses provide a better insight into the activity of osteoclasts.

The root canal is surrounded by a layer of dentine that is resistant to resorption.
Toward unification of exact and heuristic optimization methods
Authors: Hooker J. N. 
Published: May 2013

AbstractThis paper argues that many exact and heuristic methods have common structure that permits some degree of unification. It interprets solution algorithms as primal–dual methods in which the primal component searches over problem restrictions, and the dual component obtains bounds on the optimal value. In particular, the concept of an inference dual provides the basis for constraint‐directed search, which is a feature of many exact and heuristic methods. The motivations for unification are (a) to encourage the exchange of algorithmic techniques between exact and heuristic methods and (b) to design solution methods that transition gracefully from exact to heuristic modes as problem instances scale up.
Longevity costs of same‐sex interactions: first evidence from a parasitic wasp
Authors: Benelli Giovanni , Gennari Gabriele , Francini Alessandra , Canale Angelo 
Published: May 2013

AbstractCosts of sexual interactions play a key role in life‐history evolution. Although the costs of reproduction have been investigated in both sexes of many insects, the costs of same‐sex interactions have been examined in few species. In parasitic wasps, very little has been reported about the longevity costs of heterosexual interactions, and nothing is known about longevity costs of same‐sex interactions. In this study, the effects of heterosexual and homosexual activities on longevity were evaluated in Psyttalia concolor (Hymenoptera: Braconidae), a synovigenic koinobiont larval‐pupal endoparasitoid of tephritid flies. When compared with individually housed virgin wasps, male longevity was strongly reduced both in males kept with females, and in males kept with other males. When females were kept with males, their longevity was reduced compared with the virgin females and females kept with other females. Overall, the costs of male–female interactions were considerable in both sexes of P. concolor, while same‐sex activities were found to be costly only among males, suggesting that they may have implications for the evolution of the P. concolor mating system.
Relationship between environmental variables and surface activity of scorpions in the Arid Chaco ecoregion of Argentina
Authors: Nime Mónica F. , Casanoves Fernando , Vrech David E. , Mattoni Camilo I. 
Published: May 2013

AbstractMany environmental factors may influence the activity of scorpions in arid ecosystems. In this study, we examined the effects of such factors on scorpion activity at a mature and a secondary forest site in the Chancaní Reserve (Arid Chaco ecoregion in Córdoba, Argentina). Scorpions were collected using pitfall traps, and their nocturnal activity was observed by means of UV light during 14 nights. Temperature, air humidity, atmospheric pressure, and wind velocity were measured, and the percentage of visible moon was estimated. A total of 440 scorpions, representing seven species belonging to two families (Bothriuridae and Buthidae), were observed in the study area. Brachistosternus ferrugineus was the species most commonly observed using both methods. Mature and secondary forest shared slightly more than 50% of species. Surface activity of scorpions observed with the two methods differed significantly between the two areas. Surface activity of all scorpions and of B. ferrugineus were negatively related to the phase of the moon and positively related to air temperature. Physical factors thus have important effects on scorpion activity.