bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mammalian hybrid zones: a review
Authors: Shurtliff Quinn R. 
Published: December 2011

AbstractA hybrid zone is a region where interbreeding occurs between two or more genetically distinct populations. Recent studies have shown that mammalian hybrid zones occur in nature more frequently than previously thought.I summarize the history of research on mammalian hybrid zones, highlighting contributions that demonstrate genetic, behavioural and environmental mechanisms responsible for spatial distribution of genotypes, maintenance or elimination of reproductive barriers and evolutionary outcomes of hybridization.The role of hybridization in mammalian evolution, adaptation and diversification is demonstrated by the existence of hybrid swarms (e.g. caribou) and species genesis via homoploid hybridization (e.g. primates, bats).Mammalian hybrid zones are ideal settings in which to investigate genetic mechanisms that influence mate preferences as well as other questions regarding sexual selection. Many evolutionary processes and mechanisms associated with sexual selection have been well demonstrated in primate, rodent and seal hybrid zones by combining behavioural and genetic, and environmental techniques.Investigations of interbreeding chromosomal races of mouseMus musculusand shrewSorex araneusprovide insight into the role of chromosome rearrangements in the speciation process.The genomes of some mammals that hybridize in nature are fully sequenced, and rapid progress is being made towards understanding genetic underpinnings of phenotypes governing reproductive isolation. Future studies of mammalian hybrid zones will incorporate genomic techniques with increasing frequency and taxonomic representation. Such techniques may include examination of gene expression patterns using microarrays or large‐scale analysis of introgression using markers from multiple genetic systems (e.g. mitochondria, sex chromosomes).As methods improve, researchers will be better positioned to advise managers and policy makers about the potential outcomes of hybridization. This may be increasingly important as previously isolated forms come into contact as a result of global climate change.
Ecological aspects of plant selenium hyperaccumulation
Authors: El Mehdawi A. F. , Pilon‐Smits E. A. H. 
Published: December 2011

AbstractHyperaccumulators are plants that accumulate toxic elements to extraordinary levels. Selenium (Se) hyperaccumulators can contain 0.1–1.5% of their dry weight as Se, levels toxic to most other organisms. In this review we summarise what is known about the ecological functions and implications of Se (hyper)accumulation by plants. Selenium promotes hyperaccumulator growth and also offers a plant several ecological advantages through negative effects on Se‐sensitive partners. High tissue Se levels reduce herbivory and pathogen infection, and high‐Se litter deposition can inhibit neighbouring plants. There is no evidence for a cost of hyperaccumulation in terms of reproductive functions or pollinator visitation. Hyperaccumulators offer a niche for Se‐tolerant herbivores, pollinators, microbes and neighbouring plants. They may even facilitate these partners through Se enrichment: neighbouring plants with elevated Se levels enjoy enhanced growth and reduced herbivory. Through combined negative and positive effects on ecological partners, Se hyperaccumulators likely affect local plant, microbial and animal species composition and richness, favouring Se‐tolerant species at different trophic levels. By locally concentrating Se and altering its chemical form, Se hyperaccumulators likely play an important role in Se entry into, and Se cycling through, seleniferous ecosystems. These findings are of significance since they provide insight into the ecological reverberations of Se hyperaccumulation, and shed light on the possible selection pressures that have led to the evolution of this fascinating phenomenon. Better ecological insight will also help in the management of seleniferous areas and the agricultural production of Se‐rich crops for phytoremediation or biofortification.
Silicon supply modifies C:N:P stoichiometry and growth of Phragmites australis
Authors: Schaller J. , Brackhage C. , Gessner M. O. , Bäuker E. , Gert Dudel E. 
Published: December 2011

AbstractSilicon is a non‐essential element for plant growth. Nevertheless, it affects plant stress resistance and in some plants, such as grasses, it may substitute carbon (C) compounds in cell walls, thereby influencing C allocation patterns and biomass production. How variation in silicon supply over a narrow range affects nitrogen (N) and phosphorus (P) uptake by plants has also been investigated in some detail. However, little is known about effects on the stoichiometric relationships between C, N and P when silicon supply varies over a broader range. Here, we assessed the effect of silicon on aboveground biomass production and C:N:P stoichiometry of common reed, Phragmites australis, in a pot experiment in which three widely differing levels of silicon were supplied. Scanning electron microscopy (SEM) showed that elevated silicon supply promoted silica deposition in the epidermis of Phragmites leaves. This resulted in altered N:P ratios, whereas C:N ratios changed only slightly. Plant growth was slightly (but not significantly) enhanced at intermediate silicon supply levels but significantly decreased at high levels. These findings point to the potential of silicon to impact plant growth and elemental stoichiometry and, by extension, to affect biogeochemical cycles in ecosystems dominated by Phragmites and other grasses and sedges.
Transaminase in rotavirus gastroenteritis
Authors: Kawashima Hisashi , Ishii Chiako , Ioi Hiroaki , Nishimata Shigeo , Kashiwagi Yasuyo , Takekuma Kouji 
Published: December 2011

AbstractBackground:  Children infected with rotavirus often show increased levels of transaminase, and symptoms are characterized by white stool, similar to biliary atresia. Rotavirus infections are also sporadically accompanied with convulsions, encephalopathy and Reye syndrome. The aim of the present study was therefore to investigate transaminase and interleukin (IL)‐6 levels in rotavirus infection, in order to better understand their clinical significance.Methods:  Results of liver function tests, mainly the elevation of transaminase and IL‐6 in rotavirus gastroenteritis with or without convulsions, were evaluated.Results:  Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were high in 23 of 26 samples (88.5%), and in three of 26 samples (11.5%), respectively. No significant differences in liver function tests could be found between the groups with or without convulsions. Three patients whose direct bilirubin levels were above the upper normal limit were all classified into the group without convulsions. Spearman's correlation coefficient was 0.89 between increasing AST levels and IL‐6 levels.Conclusion:  Rotavirus infection is occasionally accompanied with hepatitis, but only in a mild form, and does not correlate with neurological complications. High levels of transaminase might reflect high IL‐6.
The genetic signature of perineuronal oligodendrocytes reveals their unique phenotype
Authors: Szuchet Sara , Nielsen Joseph A. , Lovas Gabor , Domowicz Miriam S. , de Velasco Javier M. , Maric Dragan , Hudson Lynn D. 
Published: December 2011

AbstractOligodendrocytes – best known for assembling central nervous system myelin – can be categorized as precursors, myelin‐forming cells and non‐myelinating perineuronal cells. Perineuronal oligodendrocytes have been well characterized morphologically and ultrastructurally, but knowledge about their function remains scanty. It has been proposed that perineuronal oligodendrocytes support neurons and, following injury, transform into myelin‐synthesizing cells. Recent findings implicating perineuronal oligodendrocytes in cytoarchitectural abnormalities in the prefrontal cortex of schizophrenia and other psychiatric disorders shed new light on these cells. We have obtained the genetic signature of perineuronal oligodendrocytes by identifying gene expression differences between oligodendrocyte subpopulations using cell‐specific tags, microarray technology, quantitative time‐resolved polymerase chain reaction and bioinformatics tools. We show that perineuronal cells are the progeny of oligodendrocyte progenitors and, hence, are members of the oligodendrocyte lineage. Physiologically they exhibit a novel phenotype. Their expression of PDGFR‐αβ and its growth factor ligand PDGF‐CC sets them apart from members of their lineage as this receptor precludes their response to the same growth factors that act on myelinating cells. Their coordinate expression and context‐specific usage of transcription factors Olig2, Ascl1 and Pax6, together with the prominent presence of transcription factors Pea3, Lhx2 and Otx2 – not hitherto linked to the oligodendrocyte lineage – suggested a cell with features that blur the boundary between a neuron and a glial cell. But they also maintain a reservoir of untranslated transcripts encoding major myelin proteins presumably for a demyelinating episode. This first molecular characterization of perineuronal oligodendrocytes revealed the striking difference between the myelinating and non‐myelinating phenotypes.
Recovery of axonal myelination sheath and axonal caliber in the mouse corpus callosum following damage induced by N,N‐diethyldithiocarbamate
Authors: Utrera Juana , Romero Rafael , Verdaguer Ester , Junyent Fèlix , Auladell Carme 
Published: December 2011

AbstractDisulfiram is an aldehyde dehydrogenase inhibitor used for the treatment of alcohol dependence and of cocaine addiction. It has been demonstrated that subchronic administration of disulfiram or N,N‐diethyldithiocarbamate (DEDTC), the main derivative of disulfiram, to rats can produce central–peripheral distal axonopathy. However, few data regarding the axonal effects of these compounds in the central nervous system exist. Our previous studies have revealed DEDTC‐induced axonal damage in the mouse brain during the course of postnatal development, together with alterations in axonal pathfinding and in the myelination process, with partial recovery during the post‐treatment period. In order to gather new data about how this axonal damage and recovery occurs in the central nervous system, we performed an ultrastructural analysis of the axons located in the corpus callosum from mice treated with DEDTC during postnatal development. The axonal caliber throughout the axonal area, the maximum axonal diameter, the maximum fiber diameter, and the axonal circularity, at different postnatal stages [from postnatal day (P)9 to P30], were analyzed. In addition, parameters related to the myelinization process (number of myelinated axons, sheath thickness, and the ratio of myelinated axons to total axons) were evaluated. A reduction in the average value of axonal caliber during treatment and a delay in the axonal myelination process were detected. Whereas early recovery of individual axons occurred after treatment (P22), complete recovery of myelinated axons occurred at late postnatal stages (P42). Therefore, chronic treatment with dithiocarbamates requires periods of rest to encourage the recovery of myelinated axons.
Glycaemic control and weight 7 years after Dose Adjustment For Normal Eating (DAFNE) structured education in Type 1 diabetes
Authors: Gunn D. , Mansell P. 
Published: December 2011

Diabet. Med. 29, 807–812 (2012)AbstractAims  The provision of structured education is increasingly prevalent in the management of Type 1 diabetes. There are little long‐term follow‐up data from such programmes. We have assessed HbA1c and weight over a 7‐year period following the Dose Adjustment For Normal Eating (DAFNE) structured education course.Methods  We obtained annual HbA1c and weight data in 111 patients who attended the initial series of DAFNE courses in our centre from June 2002 to end 2003 and in a matched group of 111 patients with Type 1 diabetes of similar age and duration of diabetes seen over the same period who had not undergone structured education.Results  With DAFNE structured education, the mean (± sd) HbA1c fell from 71 ± 12 mmol/mol (8.6 ± 1.1%) at baseline to 65 ± 12 mmol/mol (8.1 ± 1.1%) at year 1, with a subsequent rise to 67 ± 13 mmol/mol (8.3 ± 1.2%) at year 7 (P = 0.0048 vs. baseline). In the comparator group, the baseline HbA1c level was 70 ± 14 mmol/mol (8.5 ± 1.3%) and remained approximately constant during 7 years of follow‐up. Weight increased by 2.4 ± 6.0 and 2.8 ± 6.6 kg in the DAFNE and comparator group, respectively, during follow‐up (not significant).Conclusions  DAFNE structured education is associated with an improvement in glycaemic control at 1 year, and there remains a persistent and clinically relevant reduction in HbA1c of 3 mmol/mol (0.3%) after 7 years. The improvement in glycaemic control after DAFNE is achieved without excess weight gain.
Blood glucose testing and primary prevention of Type 2 diabetes—evaluation of the effect of evidence‐based patient information: a randomized controlled trial
Authors: Genz J. , Haastert B. , Müller H. , Verheyen F. , Cole D. , Rathmann W. , Nowotny B. , Roden M. , Giani G. , Mielck A. , Ohmann C. , Icks A. 
Published: December 2011

Diabet. Med. 29, 1011–1020 (2012)AbstractAims  To compare the effect of our newly developed online evidence‐based patient information vs. standard patient information about sub‐threshold elevated blood glucose levels and primary prevention of diabetes on informed patient decision making.Methods  We invited visitors to the cooperating health insurance company, Techniker Krankenkasse, and the German Diabetes Center websites to take part in a web‐based randomized controlled trial. The population after randomization comprised 1120 individuals aged between 40 and 70 years without known diabetes, of whom 558 individuals were randomly assigned to the intervention group receiving evidence‐based patient information, and 562 individuals were randomly assigned to the control group receiving standard information from the Internet. The primary endpoint was acquired knowledge of elevated blood glucose level issues and the secondary outcomes were attitude to metabolic testing, intention to undergo metabolic testing, decisional conflict and satisfaction with the information.Results  Overall, knowledge of elevated glucose level issues and the intention to undergo metabolic testing were high in both groups. Participants who had received evidence‐based patient information, however, had significantly higher knowledge scores. The secondary outcomes in the evidence‐based patient information subgroup that completed the 2‐week follow‐up period yielded significantly lower intention to undergo metabolic testing, significantly more critical attitude towards metabolic testing and significantly higher decisional conflict than the control subgroup (n = 466). Satisfaction with the information was not significantly different between both groups.Conclusions  Evidence‐based patient information significantly increased knowledge about elevated glucose levels, but also increased decisional conflict and critical attitude to screening and treatment options. The intention to undergo metabolic screening decreased. Future studies are warranted to assess uptake of metabolic testing and satisfaction with this decision in a broader population of patients with unknown diabetes.
Toward an electrocortical biomarker of cognition for newborn infants
Authors: Isler Joseph R. , Tarullo Amanda R. , Grieve Philip G. , Housman Elizabeth , Kaku Michelle , Stark Raymond I. , Fifer William P. 
Published: December 2011

AbstractThe event‐related potential (ERP) effect of mismatch negativity (MMN) was the first electrophysiological probe to evaluate cognitive processing (change detection) in newborn infants. Initial studies of MMN predicted clinical utility for this measure in identification of infants at risk for developmental cognitive deficits. These predictions have not been realized. We hypothesized that in sleeping newborn infants, measures derived from wavelet assessment of power in the MMN paradigm would be more robust markers of the brain’s response to stimulus change than the ERP‐derived MMN. Consistent with this premise, we found increased power in response to unpredictable and infrequent tones compared to frequent tones. These increases were present at multiple locations on the scalp over a range of latencies and frequencies and occurred even in the absence of an ERP‐derived MMN. There were two predominant effects. First, theta band power was elevated at middle and late latencies (200 to 600 ms), suggesting that neocortical theta rhythms that subserve working memory in adults are present at birth. Second, late latency (500 ms) increased power to the unpredictable and infrequent tones was observed in the beta and gamma bands, suggesting that oscillations involved in adult cognition are also present in the neonate. These findings support the expectation that frequency dependent measures, such as wavelet power, will improve the prospects for a clinically useful test of cortical function early in the postnatal period.
Anatomical study of the pelvis in patients with adolescent idiopathic scoliosis
Authors: Qiu Xu‐Sheng , Zhang Jun‐Jie , Yang Shang‐Wen , Lv Feng , Wang Zhi‐Wei , Chiew Jonathan , Ma Wei‐Wei , Qiu Yong 
Published: December 2011

AbstractStanding posterior–anterior (PA) radiographs from our clinical practice show that the concave and convex ilia are not always symmetrical in patients with adolescent idiopathic scoliosis (AIS). Transverse pelvic rotation may explain this observation, or pelvic asymmetry may be responsible. The present study investigated pelvic symmetry by examining the volume and linear measurements of the two hipbones in patients with AIS. Forty‐two female patients with AIS were recruited for the study. Standing PA radiographs (covering the thoracic and lumbar spinal regions and the entire pelvis), CT scans and 3D reconstructions of the pelvis were obtained for all subjects. The concave/convex ratio of the inferior ilium at the sacroiliac joint medially (SI) and the anterior superior iliac spine laterally (ASIS) were measured on PA radiographs. Hipbone volumes and several distortion and abduction parameters were measured by post‐processing software. The concave/convex ratio of SI–ASIS on PA radiographs was 0.97, which was significantly < 1 (P < 0.001). The concave and convex hipbone volumes were comparable in patients with AIS. The hipbone volumes were 257.3 ± 43.5 cm3 and 256.9 ± 42.6 cm3 at the concave and convex sides, respectively (P > 0.05). Furthermore, all distortion and abduction parameters were comparable between the convex and concave sides. Therefore, the present study showed that there was no pelvic asymmetry in patients with AIS, although the concave/convex ratio of SI–ASIS on PA radiographs was significantly < 1. The clinical phenomenon of asymmetrical concave and convex ilia in patients with AIS in preoperative standing PA radiographs may be caused by transverse pelvic rotation, but it is not due to developmental asymmetry or distortion of the pelvis.
Isolating neural components of threat bias in pediatric anxiety
Authors: Britton Jennifer C. , Bar‐Haim Yair , Carver Frederick W. , Holroyd Tom , Norcross Maxine A. , Detloff Allison , Leibenluft Ellen , Ernst Monique , Pine Daniel S. 
Published: December 2011

Background:  Attention biases toward threat are often detected in individuals with anxiety disorders. Threat biases can be measured experimentally through dot‐probe paradigms, in which individuals detect a probe following a stimulus pair including a threat. On these tasks, individuals with anxiety tend to detect probes that occur in a location previously occupied by a threat (i.e., congruent) faster than when opposite threats (i.e., incongruent). In pediatric anxiety disorders, dot‐probe paradigms detect abnormal attention biases toward threat and abnormal ventrolateral prefrontal cortex (vlPFC) function. However, it remains unclear if this aberrant vlPFC activation occurs while subjects process threats (e.g., angry faces) or, alternatively, while they process and respond to probes. This magnetoencephalography (MEG) study was designed to answer this question.Methods:  Adolescents with either generalized anxiety disorder (GAD, n = 17) or no psychiatric diagnosis (n = 25) performed a dot‐probe task involving angry and neutral faces while MEG data were collected. Synthetic Aperture Magnetometry (SAM) beamformer technique was used to determine whether there were group differences in power ratios while subjects processed threats (i.e., angry vs. neutral faces) or when subjects responded to incongruent versus. congruent probes.Results:  Group differences in vlPFC activation during the response period emerged with a 1–30 Hz frequency band. No group differences in vlPFC activation were detected in response to angry‐face cues.Conclusions:  In the dot‐probe task, anxiety‐related perturbations in vlPFC activation reflect abnormal attention control when responding to behaviorally relevant probes, but not to angry faces. Given that motor responses to these probes are used to calculate threat bias, this study provides insight into the pathophysiology reflected in this commonly used marker of anxiety. In addition, this finding may inform the development of novel anxiety‐disorder treatments targeting the vlPFC to enhance attention control to task‐relevant demands.
Price assessments by consumers: influence of purchase context and price structure
Authors: Rosa Diaz Isabel Maria 
Published: December 2011

AbstractAmong the numerous factors that influence decisions on prices, consumer behaviour has special significance. This paper reviews and analyses relevant studies conducted during the last few decades. On the basis of our analysis, four categories of factors that determine consumer behaviour have been identified. Additionally, we have developed an experimental research design to analyse the influence that the following factors have on price perception: price structure (i.e. price level, order of presentation and price differences), purchase context (i.e. reason for purchase or product use) and demographic characteristics (i.e. gender). Results reveal a significant influence of these variables on consumer behaviour.