bluuebunny/crossref_metadata_2025_split huggingface dataset:
Environmental relationships with the interannual and seasonal variation of soil respiration in a cedar (Platycladus orientalis) plantation in northern China
Authors: Pang Zhuo , Yu Xinxiao , Zha Tianshan , Jia Guodong , Wu Hailong , Lv Xizhi , Li Yitao , Zhou Bin , Fan Minrui , Song Siming , Zhao Yang , Huang Zhiying , Deng Wenping , Wang Henian , Zhang Yi , Yang Zhige , Fan Dengxing 
Published: April 2012

The relationships between soil respiration and environmental factors determine the effect of warming soil on the carbon balance in temperate forest ecosystems and on changes in atmospheric CO2 concentrations. Here, we used 3 years of data regarding soil respiration rates (Rs), soil temperature (Ts), and soil volumetric water content (θ) from a 50-year-old mature cedar ( Platycladus orientalis L.) plantation at Jiufeng Mountain, Beijing, China, to demonstrate the seasonal and interannual variation of Rs dependence on Ts and θ throughout the period 2008–2010. We used the exponential model to calculate the temperature sensitivity indicator Q10 and we examined the annual and seasonal patterns of Rs and Q10. The Rs correlated with Ts annually (p < 0.05). The Rs–Ts exponential relationship was significant in the autumn and winter (p < 0.05), while the combined Ts and θ relationships with Rs were significant in the spring and summer (p < 0.001). The spring Rs anomalies caused by drought appeared to have carryover effects that translated to Rs anomalies in the following summer. Finally, the summer Rs, which was influenced by the coincident precipitation and θ anomalies, determined the magnitude of the annual total amount of soil respiration. This result has implications for how abiotic factors may drive shifts in seasonal patterns of soil respiration under a changing climate.
Long-distance swimming by polar bears (Ursus maritimus) of the southern Beaufort Sea during years of extensive open water
Authors: Pagano A.M. , Durner G.M. , Amstrup S.C. , Simac K.S. , York G.S. 
Published: April 2012

Polar bears ( Ursus maritimus Phipps, 1774) depend on sea ice for catching marine mammal prey. Recent sea-ice declines have been linked to reductions in body condition, survival, and population size. Reduced foraging opportunity is hypothesized to be the primary cause of sea-ice-linked declines, but the costs of travel through a deteriorated sea-ice environment also may be a factor. We used movement data from 52 adult female polar bears wearing Global Positioning System (GPS) collars, including some with dependent young, to document long-distance swimming (>50 km) by polar bears in the southern Beaufort and Chukchi seas. During 6 years (2004–2009), we identified 50 long-distance swims by 20 bears. Swim duration and distance ranged from 0.7 to 9.7 days (mean = 3.4 days) and 53.7 to 687.1 km (mean = 154.2 km), respectively. Frequency of swimming appeared to increase over the course of the study. We show that adult female polar bears and their cubs are capable of swimming long distances during periods when extensive areas of open water are present. However, long-distance swimming appears to have higher energetic demands than moving over sea ice. Our observations suggest long-distance swimming is a behavioral response to declining summer sea-ice conditions.
Individual Differences and Their Impact on the Safety and the Efficiency of Human-Wheelchair Systems
Authors: Jipp Meike 
Published: April 2012

Objective: The extent to which individual differences in fine motor abilities affect indoor safety and efficiency of human-wheelchair systems was examined. Background: To reduce the currently large number of indoor wheelchair accidents, assistance systems with a high level of automation were developed. It was proposed to adapt the wheelchair’s level of automation to the user’s ability to steer the device to avoid drawbacks of highly automated wheelchairs. The state of the art, however, lacks an empirical identification of those abilities. Method: A study with 23 participants is described. The participants drove through various sections of a course with a powered wheelchair. Repeatedly measured criteria were safety (numbers of collisions) and efficiency (times required for reaching goals). As covariates, the participants’ fine motor abilities were assessed. Results: A random coefficient modeling approach was conducted to analyze the data, which were available on two levels as course sections were nested within participants. The participants’ aiming, precision, and arm–hand speed contributed significantly to both criteria: Participants with lower fine motor abilities had more collisions and required more time for reaching goals. Conclusion: Adapting the wheelchair’s level of automation to these fine motor abilities can improve indoor safety and efficiency. In addition, the results highlight the need to further examine the impact of individual differences on the design of automation features for powered wheelchairs as well as other applications of automation. Application: The results facilitate the improvement of current wheelchair technology.
An optimal predictive control strategy for radiant floor district heating systems: Simulation and experimental study
Authors: Cho S Hwan , Hong Seong-ki , Li Song-chun , Zaheeruddin M 
Published: April 2012

A study was conducted to assess the energy performance of an optimal predictive control strategy for radiant floor district heating systems. A four-zone radiant floor heating system model was developed. The simulated performance of the optimal predictive control strategy was studied. The results showed 10% energy savings compared to a Proportional-Integral (PI) control strategy. Experiments were conducted in a laboratory radiant floor district heating system test facility. The description of the test facility, its operating conditions, and the results obtained are described. Experimental results further confirm the findings from the simulation study. Being simple and energy efficient, the optimal predictive control strategy is a good candidate control strategy for radiant floor district heating systems. Practical application: Energy efficiency is a major issue of interest in the design and operation of sustainable heating systems. The radiant floor district heating systems have been successfully installed and operated in many countries resulting in significant energy savings. The optimal predictive control strategy proposed in this study further enhances the potential for higher energy savings from the district heating systems. The optimal control strategy is simple to implement as it relies on the predicted outdoor air temperature and computes future temperature set-points for the boiler water temperature. A suitably tuned Proportional-Integral (PI) controller can be used to track the optimal set-point thus realizing potential energy savings. A programmable logic controller or a supervisory control system would be appropriate to implement the designed optimal control strategy. The local control can be realized by using industrial PI feedback controllers.
In Vivo Evidence for Tibial Plateau Slope as a Risk Factor for Anterior Cruciate Ligament Injury
Authors: Wordeman Samuel C. , Quatman Carmen E. , Kaeding Christopher C. , Hewett Timothy E. 
Published: April 2012

Background: In vivo studies reporting tibial plateau slope as a risk factor for anterior cruciate ligament (ACL) injury have been published with greatly increasing frequency. Purpose: To examine and summarize the in vivo evidence comparing tibial slope in ACL-injured and uninjured populations. Study Design: Systematic review and meta-analysis. Methods: We reviewed publications in Scopus, SPORTDiscus, CINAHL, and PubMed to identify all studies reporting a measure of tibial plateau slope between ACL-injured groups and controls. A meta-analysis was performed including calculation of effect size and 95% confidence interval as well as 95% confidence intervals for the mean values of the measurement in each study. Results: Fourteen studies met our inclusion/exclusion criteria. Five of 6 radiographic studies reporting medial tibial plateau slope (MTPS) demonstrated significant differences between controls and ACL-injured groups, while only 1 of 7 magnetic resonance imaging (MRI) studies reported significant differences between groups. Mean MTPS measurements and standard deviations reported for controls ranged from 2.9° ± 2.8° anterior to 9.5° ± 3° posterior. For ACL-injured patients, MTPS ranged from 1.8° ± 3.5° anterior to 12.1° ± 3.3° posterior. Lateral tibial plateau slope (LTPS) was reported to be significantly greater in ACL-injured groups in all 5 MRI-based studies reporting group comparisons. Mean values for LTPS in controls ranged from 0.3° ± 3.6° anterior slope to 9° ± 4° posterior slope. In ACL-injured groups, mean reported LTPS values ranged from 1.8° ± 3.2° to 11.5° ± 3.54° posterior slope. Conclusion: Despite high measures of reliability for the various methods reported in current studies, there is vast disagreement regarding the actual values of the slope that would be considered “at risk.” Reported tibial slope values for control groups vary greatly between studies. In many cases, the study-to-study differences in “normal” tibial slope exceed the difference between controls and ACL-injured patients. The clinical utility of imaging-based measurement methods for the determination of ACL injury risk requires more reliable techniques that demonstrate consistency between studies.
The Role of Age and Sex in Symptoms, Neurocognitive Performance, and Postural Stability in Athletes After Concussion
Authors: Covassin Tracey , Elbin R.J. , Harris William , Parker Tonya , Kontos Anthony 
Published: April 2012

Background: Researchers have begun to focus on age and sex differences in concussion outcomes. Results suggest that younger athletes and female athletes may take longer to recover from a concussion. However, little is known about the interactive effects of age and sex on symptoms, neurocognitive testing (NCT), and postural stability. Hypothesis/Purpose: The purpose of the study was to examine sex and age differences in symptoms, NCT, and postural stability following concussion. We hypothesized that high school and female athletes would have worse symptoms, NCT, and postural stability than college and male athletes, respectively. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 296 concussed athletes from a multistate, 2-year study were enrolled in this study. Participants completed the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) and Post-Concussion Symptom Scale (PCSS) at baseline and again at 2, 7, and 14 days after concussion. Participants completed the Balance Error Scoring System (BESS) at 1, 2, and 3 days after concussion. Results: Female athletes performed worse than male athletes on visual memory (mean, 65.1% and 70.1%, respectively; P = .049) and reported more symptoms (mean, 14.4 and 10.1, respectively) after concussion ( P = .035). High school athletes performed worse than college athletes on verbal (mean, 78.8% and 82.7%, respectively; P = .001) and visual (mean, 65.8% and 69.4%, respectively; P = .01) memory. High school athletes were still impaired on verbal memory 7 days after concussion compared with collegiate athletes ( P = .001). High school male athletes scored worse on the BESS than college male athletes (mean, 18.8 and 13.0, respectively; P = .001). College female athletes scored worse on the BESS than high school female athletes (mean, 21.1 and 16.9, respectively; P = .001). Conclusion: The results of the current study supported age differences in memory and sex differences in memory and symptoms and an interaction between age and sex on postural stability after concussion that warrant consideration from clinicians and researchers when interpreting symptoms, specific components of NCT, and postural stability tests. Future research should develop and assess interventions tailored to age and sex differences and include younger (<14 years) participants.
Effects of Statin Monotherapy Versus Statin Plus Ezetimibe Combination on Serum Uric Acid Levels
Authors: Moutzouri Elisavet , Liberopoulos Evangelos N. , Florentin Matilda , Liamis George , Elisaf Moses S. 
Published: April 2012

Background: Uric acid is considered a risk factor for cardiovascular disease (CVD). The effect of statins and ezetimibe on serum uric acid levels has not been yet clarified. Objective: To compare the effect of simvastatin/ezetimibe 10/10 mg, simvastatin 40 mg, and rosuvastatin 10 mg daily on serum uric acid levels in patients with dyslipidemia. Methods: This was a prospective, randomized, open-label, blinded end point (PROBE) study. Following a 3-month dietary intervention, patients with hypercholesterolemia received simvastatin/ezetimibe 10/10 mg or simvastatin 40 mg or rosuvastatin 10 mg. Changes in serum levels of uric acid and fractional renal excretion of uric acid as well as changes in electrolyte and renal function parameters were assessed after 12 weeks of treatment. Results: One hundred fifty-three patients (56 male) were included. At week 12, a significant reduction in serum uric acid levels was seen in all treatment groups (simvastatin/ezetimibe 10/10 mg: −3.8%, simvastatin 40 mg: −5.7%, and rosuvastatin 10 mg: −3.8%; P < .05 compared with baseline; P = not significant [NS] for comparison between groups). Fractional excretion of uric acid nonsignificantly increased in all groups (simvastatin/ezetimibe 10/10 mg: +6.8%, simvastatin 40 mg: +6.8%, and rosuvastatin 10 mg: +5.9%). The reduction in serum uric acid levels correlated with the increase in fractional excretion of uric acid and baseline uric acid levels. Renal function parameters as well as serum levels and fractional excretions of electrolytes remained unchanged in all groups. Changes in serum lipids were similar across groups. Conclusion: Simvastatin/ezetimibe 10/10 mg, simvastatin 40 mg, and rosuvastatin 10 mg exhibit a similar uric acid–lowering effect.
Bcl-2, Bcl-xL, and Bcl-w are not equivalent targets of ABT-737 and navitoclax (ABT-263) in lymphoid and leukemic cells
Authors: Mérino Delphine , Khaw Seong L. , Glaser Stefan P. , Anderson Daniel J. , Belmont Lisa D. , Wong Chihunt , Yue Peng , Robati Mikara , Phipson Belinda , Fairlie Walter D. , Lee Erinna F. , Campbell Kirsteen J. , Vandenberg Cassandra J. , Cory Suzanne , Roberts Andrew W. , Ludlam Mary J. C. , Huang David C. S. , Bouillet Philippe 
Published: April 2012

Abstract
The BH3-mimetic ABT-737 and an orally bioavailable compound of the same class, navitoclax (ABT-263), have shown promising antitumor efficacy in preclinical and early clinical studies. Although both drugs avidly bind Bcl-2, Bcl-xL, and Bcl-w in vitro, we find that Bcl-2 is the critical target in vivo, suggesting that patients with tumors overexpressing Bcl-2 will probably benefit. In human non-Hodgkin lymphomas, high expression of Bcl-2 but not Bcl-xL predicted sensitivity to ABT-263. Moreover, we show that increasing Bcl-2 sensitized normal and transformed lymphoid cells to ABT-737 by elevating proapoptotic Bim. In striking contrast, increasing Bcl-xL or Bcl-w conferred robust resistance to ABT-737, despite also increasing Bim. Cell-based protein redistribution assays unexpectedly revealed that ABT-737 disrupts Bcl-2/Bim complexes more readily than Bcl-xL/Bim or Bcl-w/Bim complexes. These results have profound implications for how BH3-mimetics induce apoptosis and how the use of these compounds can be optimized for treating lymphoid malignancies.
DNA-binding factor CTCF and long-range gene interactions in V(D)J recombination and oncogene activation
Authors: Ribeiro de Almeida Claudia , Stadhouders Ralph , Thongjuea Supat , Soler Eric , Hendriks Rudi W. 
Published: April 2012

Abstract
Regulation of V(D)J recombination events at immunoglobulin (Ig) and T-cell receptor loci in lymphoid cells is complex and achieved via changes in substrate accessibility. Various studies over the last year have identified the DNA-binding zinc-finger protein CCCTC-binding factor (CTCF) as a crucial regulator of long-range chromatin interactions. CTCF often controls specific interactions by preventing inappropriate communication between neighboring regulatory elements or independent chromatin domains. Although recent gene targeting experiments demonstrated that the presence of the CTCF protein is not required for the process of V(D)J recombination per se, CTCF turned out to be essential to control order, lineage specificity and to balance the Ig V gene repertoire. Moreover, CTCF was shown to restrict activity of κ enhancer elements to the Ig κ locus. In this review, we discuss CTCF function in the regulation of V(D)J recombination on the basis of established knowledge on CTCF-mediated chromatin loop domains in various other loci, including the imprinted H19-Igf2 locus as well as the complex β-globin, MHC class II and IFN-γ loci. Moreover, we discuss that loss of CTCF-mediated restriction of enhancer activity may well contribute to oncogenic activation, when in chromosomal translocations Ig enhancer elements and oncogenes appear in a novel genomic context.
Metabolic classification of microbial genomes using functional probes
Authors: Lee Chi-Ching , Lo Wei-Cheng , Lai Szu-Ming , Chen Yi-Ping Phoebe , Tang Chuan Yi , Lyu Ping-Chiang 
Published: April 2012

Abstract

Background
Microorganisms able to grow under artificial culture conditions comprise only a small proportion of the biosphere's total microbial community. Until recently, scientists have been unable to perform thorough analyses of difficult-to-culture microorganisms due to limitations in sequencing technology. As modern techniques have dramatically increased sequencing rates and rapidly expanded the number of sequenced genomes, in addition to traditional taxonomic classifications which focus on the evolutionary relationships of organisms, classifications of the genomes based on alternative points of view may help advance our understanding of the delicate relationships of organisms.

Results
We have developed a proteome-based method for classifying microbial species. This classification method uses a set of probes comprising short, highly conserved amino acid sequences. For each genome, in silico translation is performed to obtained its proteome, based on which a probe-set frequency pattern is generated. Then, the probe-set frequency patterns are used to cluster the proteomes/genomes.

Conclusions
Features of the proposed method include a high running speed in challenge of a large number of genomes, and high applicability for classifying organisms with incomplete genome sequences. Moreover, the probe-set clustering method is sensitive to the metabolic phenotypic similarities/differences among species and is thus supposed potential for the classification or differentiation of closely-related organisms.
In vitro study of uptake and synthesis of creatine and its precursors by cerebellar granule cells and astrocytes suggests some hypotheses on the physiopathology of the inherited disorders of creatine metabolism
Authors: Carducci Claudia , Carducci Carla , Santagata Silvia , Adriano Enrico , Artiola Cristiana , Thellung Stefano , Gatta Elena , Robello Mauro , Florio Tullio , Antonozzi Italo , Leuzzi Vincenzo , Balestrino Maurizio 
Published: April 2012

Abstract

Background
The discovery of the inherited disorders of creatine (Cr) synthesis and transport in the last few years disclosed the importance of blood Cr supply for the normal functioning of the brain. These putatively rare diseases share a common pathogenetic mechanism (the depletion of brain Cr) and similar phenotypes characterized by mental retardation, language disturbances, seizures and movement disorders. In the effort to improve our knowledge on the mechanisms regulating Cr pool inside the nervous tissue, Cr transport and synthesis and related gene transcripts were explored in primary cultures of rat cerebellar granule cells and astrocytes.

Methods
Cr uptake and synthesis were explored in vitro by incubating monotypic primary cultures of rat type I astrocytes and cerebellar granule cells with: a) D3-Creatine (D3Cr) and D3Cr plus β-guanidinopropionate (GPA, an inhibitor of Cr transporter), and b) labelled precursors of Guanidinoacetate (GAA) and Cr (Arginine, Arg; Glycine, Gly). Intracellular D3Cr and labelled GAA and Cr were assessed by ESI-MS/MS. Creatine transporter (CT1), L-arginine:glycine amidinotransferase (AGAT), and S-adenosylmethionine:guanidinoacetate N-methyltransferase (GAMT) gene expression was assessed in the same cells by real time PCR.

Results
D3Cr signal was extremely high in cells incubated with this isotope (labelled/unlabelled Cr ratio reached about 10 and 122, respectively in cerebellar granule cells and astrocytes) and was reduced by GPA. Labelled Arg and Gly were taken up by the cells and incorporated in GAA, whose concentration paralleled that of these precursors both in the extracellular medium and inside the cells (astrocytes). In contrast, the increase of labelled Cr was relatively much more limited since labelled Cr after precursors' supplementation did not exceed 2,7% (cerebellar granule cells) and 21% (astrocytes) of unlabelled Cr. Finally, AGAT, GAMT and SLC6A8 were expressed in both kind of cells.

Conclusions
Our results confirm that both neurons and astrocytes have the capability to synthesize and uptake Cr, and suggest that at least in vitro intracellular Cr can increase to a much greater extent through uptake than through de novo synthesis. Our results are compatible with the clinical observations that when the Cr transporter is defective, intracellular Cr is absent despite the brain should be able to synthesize it. Further research is needed to fully understand to what extent our results reflect the in vivo situation.
Distinct muscarinic acetylcholine receptor subtypes mediate pre- and postsynaptic effects in rat neocortex
Authors: Gigout Sylvain , Jones Gareth A , Wierschke Stephan , Davies Ceri H , Watson Jeannette M , Deisz Rudolf A 
Published: April 2012

Abstract

Background
Cholinergic transmission has been implicated in learning, memory and cognition. However, the cellular effects induced by muscarinic acetylcholine receptors (mAChRs) activation are poorly understood in the neocortex. We investigated the effects of the cholinergic agonist carbachol (CCh) and various agonists and antagonists on neuronal activity in rat neocortical slices using intracellular (sharp microelectrode) and field potential recordings.

Results
CCh increased neuronal firing but reduced synaptic transmission. The increase of neuronal firing was antagonized by pirenzepine (M1/M4 mAChRs antagonist) but not by AF-DX 116 (M2/M4 mAChRs antagonist). Pirenzepine reversed the depressant effect of CCh on excitatory postsynaptic potential (EPSP) but had marginal effects when applied before CCh. AF-DX 116 antagonized the depression of EPSP when applied before or during CCh. CCh also decreased the paired-pulse inhibition of field potentials and the inhibitory conductances mediated by GABAA and GABAB receptors. The depression of paired-pulse inhibition was antagonized or prevented by AF-DX 116 or atropine but only marginally by pirenzepine. The inhibitory conductances were unaltered by xanomeline (M1/M4 mAChRs agonist), yet the CCh-induced depression was antagonized by AF-DX 116. Linopirdine, a selective M-current blocker, mimicked the effect of CCh on neuronal firing. However, linopirdine had no effect on the amplitude of EPSP or on the paired-pulse inhibition, indicating that M-current is involved in the increase of neuronal excitability but neither in the depression of EPSP nor paired-pulse inhibition.

Conclusions
These data indicate that the three effects are mediated by different mAChRs, the increase in firing being mediated by M1 mAChR, decrease of inhibition by M2 mAChR and depression of excitatory transmission by M4 mAChR. The depression of EPSP and increase of neuronal firing might enhance the signal-to-noise ratio, whereas the concomitant depression of inhibition would facilitate long-term potentiation. Thus, this triade of effects may represent a “neuronal correlate” of attention and learning.