bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flaws in animal studies exploring statins and impact on meta‐analysis
Authors: Moja Lorenzo , Pecoraro Valentina , Ciccolallo Laura , Dall'Olmo Luigi , Virgili Gianni , Garattini Silvio 
Published: March 2014

AbstractBackgroundAnimal experiments should be appropriately designed, correctly analysed and transparently reported to increase their scientific validity and maximise the knowledge gained from each experiment. This systematic review of animal experiments investigating statins evaluates their quality of reporting and methodological aspects as well as their implications for the conduction of meta‐analyses.MethodsWe searched medline and embase for studies reporting research on statins in mice, rats and rabbits. We collected detailed information about the characteristics of studies, animals and experimental methods.ResultsWe retrieved 161 studies. A little over half did not report randomisation (55%) and most did not describe blinding (88%). All studies reported details on the experimental procedure, although many omitted information about animal gender, age or weight. Four percent did not report the number of animals used. None reported the sample size. Fixed‐ and random‐effects models gave different results (ratio of effect size increased by five folds). Heterogeneity was consistently substantial within animal models, for which accounting for covariates had minimal impact. Publication bias is highly suspected across studies.ConclusionsAlthough statins showed efficacy in animal models, preclinical studies highlighted fundamental problems in the way in which such research is conducted and reported. Results were often difficult to interpret and reproduce. Different meta‐analytic approaches were highly inconsistent: a reliable approach to estimate the true parameter was imperceptible. Policies that address these issues are required from investigators, editors and institutions that care about the quality standards and ethics of animal research.
Properties of 4 Hz stimulation‐induced parallel fiber–Purkinje cell presynaptic long‐term plasticity in mouse cerebellar cortex in vivo
Authors: Chu Chun‐Ping , Zhao Guo‐Yan , Jin Ri , Zhao Sheng‐Nan , Sun Lei , Qiu De‐Lai 
Published: March 2014

AbstractCerebellar parallel fiber–Purkinje cell (PF–PC) long‐term synaptic plasticity is important for the formation and stability of cerebellar neuronal circuits, and provides substrates for motor learning and memory. We previously reported both presynaptic long‐term potentiation (LTP) and long‐term depression (LTD) in cerebellar PF–PC synapses in vitro. However, the expression and mechanisms of cerebellar PF–PC synaptic plasticity in the cerebellar cortex in vivo are poorly understood. In the present study, we studied the properties of 4 Hz stimulation‐induced PF–PC presynaptic long‐term plasticity using in vivo the whole‐cell patch‐clamp recording technique and pharmacological methods in urethane‐anesthetised mice. Our results demonstrated that 4 Hz PF stimulation induced presynaptic LTD of PF–PC synaptic transmission in the intact cerebellar cortex in living mice. The PF–PC presynaptic LTD was attenuated by either the N‐methyl‐D‐aspartate receptor antagonist, D‐aminophosphonovaleric acid, or the group 1 metabotropic glutamate receptor antagonist, JNJ16259685, and was abolished by combined D‐aminophosphonovaleric acid and JNJ16259685, but enhanced by inhibition of nitric oxide synthase. Blockade of cannabinoid type 1 receptor activity abolished the PF–PC LTD and revealed a presynaptic PF–PC LTP. These data indicate that both endocannabinoids and nitric oxide synthase are involved in the 4 Hz stimulation‐induced PF–PC presynaptic plasticity, but the endocannabinoid‐dependent PF–PC presynaptic LTD masked the nitric oxide‐mediated PF–PC presynaptic LTP in the cerebellar cortex in urethane‐anesthetised mice.
Reduced levels of brain‐derived neurotrophic factor contribute to synaptic imbalance during the critical period of respiratory development in rats
Authors: Gao Xiu‐ping , Liu Qiuli , Nair Bindu , Wong‐Riley Margaret T. T. 
Published: March 2014

AbstractPreviously, our electrophysiological studies revealed a transient imbalance between suppressed excitation and enhanced inhibition in hypoglossal motoneurons of rats on postnatal days (P) 12–13, a critical period when abrupt neurochemical, metabolic, ventilatory and physiological changes occur in the respiratory system. The mechanism underlying the imbalance is poorly understood. We hypothesised that the imbalance was contributed by a reduced expression of brain‐derived neurotrophic factor (BDNF), which normally enhances excitation and suppresses inhibition. We also hypothesised that exogenous BDNF would partially reverse this synaptic imbalance. Immunohistochemistry/single‐neuron optical densitometry, real‐time quantitative PCR (RT‐qPCR) and whole‐cell patch‐clamp recordings were done on hypoglossal motoneurons in brainstem slices of rats during the first three postnatal weeks. Our results indicated that: (1) the levels of BDNF and its high‐affinity tyrosine receptor kinase B (TrkB) receptor mRNAs and proteins were relatively high during the first 1–1.5 postnatal weeks, but dropped precipitously at P12–13 before rising again afterwards; (2) exogenous BDNF significantly increased the normally lowered frequency of spontaneous excitatory postsynaptic currents but decreased the normally heightened amplitude and frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) during the critical period; (3) exogenous BDNF also decreased the normally heightened frequency of miniature IPSCs at P12–13; and (4) the effect of exogenous BDNF was partially blocked by K252a, a TrkB receptor antagonist. Thus, our results are consistent with our hypothesis that BDNF and TrkB play an important role in the synaptic imbalance during the critical period. This may have significant implications for the mechanism underlying sudden infant death syndrome.
Rapid evolution of an introduced insect Ophraella communa LeSage in new environments: temporal changes and geographical differences in photoperiodic response
Authors: Tanaka Koichi , Murata Kouhei , Matsuura Asana 
Published: March 2014

AbstractThe accidentally introduced beetle Ophraella communa was first found in 1996 in Japan and has rapidly expanded its distribution range to include regions with substantially different climates. During this range expansion and subsequent establishment in new habitats, the life history traits of O. communa have changed depending on new habitat environmental conditions. In this study, we investigated the photoperiodic response of O. communa controlling its reproductive diapause, an important trait that adjusts the life cycle to local climate and phenology of host‐plants. We examined temporal changes and geographical differences in this trait. In the Tsukuba population of O. communa, the diapause incidence under conditions of 12 h light : 12 h dark (LD 12:12), 13:11 and 14:10 did not consistently increase or decrease during 2005–2012, although it fluctuated yearly. The diapause incidence in this period, however, was lower than that in 1999 reported previously and the critical day‐length inducing diapause was shortened by >1 h from 1999 to 2005. These results suggest that the photoperiodic response of O. communa shifted during this period. To examine geographical differences in this trait, we compared the Hirosaki, Morioka, Tsukuba and Koshi lines. The diapause incidence at LD 13:11 was significantly different between the O. communa lines: 86.5% in the Hirosaki line (collected in 2010) , 81.4% in Morioka (collected in 2010), 45.0% in Tsukuba (collected in 2011) and 7.1% in Koshi (collected in 2009), and was positively correlated with the latitude of the origin. These results suggest that this trait shifted, responding to the environmental conditions in the colonized regions.
Interpreting some experimental evidences of fatigue crack size effects through a kinked crack model
Authors: Spagnoli A. , Vantadori S. , Carpinteri A. 
Published: March 2014

AbstractThreshold condition and rate of fatigue crack growth in both short and long crack regime appear to be significantly affected by the degree of crack deflection. In the present paper, a theoretical model of a periodically kinked crack is proposed to describe the influence of the crack deflection degree on the fatigue behaviour. The kinking of the crack is due to a periodic self‐balanced microstress field having length scale d. By correlating the parameter d with a characteristic material length (e.g. average grain size in metals, maximum aggregate size in concrete), the present model is applied to interpret some experimental findings related to crack size effects in fatigue of materials. Well‐known experimental results concerning three different situations (fatigue threshold, fatigue short crack growth and fatigue crack growth in the Paris regime) are analysed.
Piscivory does not cause pansteatitis (yellow fat disease) in Oreochromis mossambicus from an African subtropical reservoir
Authors: Dabrowski J. , Hall G. , Lübcker N. , Oberholster P. J. , Phillips D. L. , Woodborne S. 
Published: March 2014

Summary

Pansteatitis (yellow fat disease) is ubiquitous in the free‐ranging population of Oreochromis mossambicus from Loskop Reservoir (LR), South Africa. The disease is nutritionally mediated and associated with a diet high in polyunsaturated or rancid fats, frequently of fish origin. While piscivory has never been reported in dietary studies of O. mossambicus in their native range, their opportunistic and omnivorous feeding habits mean that piscivory cannot be ruled out as a cause of the disease.

The diet of O. mossambicus from LR (n = 91) was compared with a population from Flag Boshielo Reservoir (FBR; n = 81) located <100 km downstream, where no pansteatitis occurs. The stomach contents and stable isotope signatures (δ15N and δ13C) of fish and food sources were evaluated across four seasons. Isotope signatures were also compared over various time scales from historic samples and mortalities collected from LR.

There was no evidence of piscivorous feeding behaviour in fish from either location or from historic LR samples. The results of the stable isotope analysis in R mixing model and stomach contents analysis showed that the dinoflagellate, Ceratium hirundinella, was the dominant food source followed by zooplankton, detritus and Microcystis aeruginosa in LR. The diet of fish from FBR was less diverse than fish from LR and was dominated by sediment and detritus.

The distinguishing feature of the dietary comparison between reservoirs was the abundance of planktonic food items dominated by C. hirundinella in the diet of fish from LR. The lack of evidence for piscivory among O. mossambicus from LR suggests that the classic aetiology of pansteatitis does not apply. This highlights the need to further explore direct (environmental exposure to pollutants) and indirect (dietary exposure) links to pansteatitis. This study identified the major dietary constituents for O. mossambicus, which enables future research to focus on their nutritional and chemical composition.
Geographical variation in climatic sensitivity of intertidal mussel zonation
Authors: Mislan K. A. S. , Helmuth Brian , Wethey David S. 
Published: March 2014

AbstractAimTo identify geographic locations where lethal temperatures and upper zonation limits ofMytilus californianusbeds coincide and to determine the dominant climatic factor where lethal limits occur.LocationIntertidal shores along 1500 km of the west coast ofNorthAmerica.MethodsLethal temperatures forM. californianuswere determined using temperature‐controlled chambers in which both the magnitude and duration of exposure were manipulated. Field surveys of the shore level and solar exposure of upper zonation limits of mussel beds were conducted at 15 sites. Measurements from the lethal temperature studies and field surveys were used with a biophysical model of mussel body temperature to hindcastM. californianusmortality rates from 1997–2007.ResultsThe critical lethal high body temperature wasc. 38 °C. Hindcasts of mortality rates predicted that lethal temperatures occurred along the upper limits of the mussel bed at only two of the sites,SantaCruz andAlegria,CA,USA, and daily maximum air temperature during low tide was the variable that distinguished these sites.SantaCruz andAlegria were not adjacent to each other and not the most equatorward of the sites examined.Main conclusionsLocal upper zonation limits of the musselM. californianusare determined by lethal high body temperatures at two of 15 locations, which means that alternative environmental factors are determining local zonation at most of the study sites. Mussel body temperature is driven by many physical variables, but air temperature was higher atSantaCruz andAlegria than elsewhere making it the most likely factor driving the climatic sensitivity at local upper zonation limits. There was no significant evidence of local acclimation or local adaptation in this species. Some local zonation limits are more vulnerable to climate change than others, potentially causing the magnitude and timing of zonation shifts to differ even among closely situated sites.
A metamodelling approach to estimate global N2O emissions from agricultural soils
Authors: Perlman Joshua , Hijmans Robert J. , Horwath William R. 
Published: March 2014

AbstractAimModelling complex environmental and ecological processes over large geographic areas is challenging, particularly when basic research and model development for such processes has historically been at the local scale. Moving from local toward global analysis brings up numerous issues related to data processing, aggregation, tradeoffs between model quality and data quality, and prioritization of data collection and/or compilation efforts. We studied these issues in the context of modelling emissions of N2O (a potent greenhouse gas) from agricultural soils.LocationGlobal.MethodsWe developed metamodels of the DeNitrification–DeComposition (DNDC) model, a mechanistic model that simulates greenhouse gas emissions from agricultural soils, to estimate global N2O emissions from maize and wheat fields. We ran DNDC for a diverse sample of global climate and soil types, and fitted the model output as a function of (sometimes simplified) model input variables, using the random forest machine learning algorithm. We used the metamodels to estimate global N2O emissions from maize and wheat at a very high spatial resolution (c. 1 km2) and examined the effects of different approaches of using soil data as well as the effects of spatial aggregation of soil and climate data.ResultsThe average coefficient of determination (R2) between holdout data (DNDC output not used to construct the metamodel) and metamodel predictions was 0.97 for maize and 0.91 for wheat. The metamodels were sensitive to soil properties, particularly to soil organic carbon content. Global emission estimates with the metamodel were highly sensitive to the spatial aggregation and other forms of generalization of soil data, but much less so to aggregation of climate data.Main conclusionsUsing a simplified metamodel with data of high spatial resolution could produce results that are more accurate than those obtained with a full mechanistic model and lower‐resolution data.
Determinants of species abundance for eastern North American trees
Authors: Xing Dingliang , Swenson Nathan G. , Weiser Michael D. , Hao Zhanqing 
Published: March 2014

AbstractAimWe aimed to quantify the relative contributions of trait‐based selection and the flow of individuals across space created by differences in species abundance, i.e. mass effects, in determining local‐scale species relative abundance (SRA) at 0.07 ha, 1° grid cell and subregion grains.LocationThe eastern USA.MethodsWe coupled a maximum entropy model (MaxEnt) with nine species‐specific plant traits and a continental‐scale forest inventory dataset to perform our analyses. Mass effects were estimated using the next grain size up as the metacommunity (or the eastern USA at the subregion grain, and also at the 1° grid cell grain in a fourth analysis). Permutation tests were conducted to test the significance of trait constraints. The Kullback–Leibler divergence index was used to decompose the information content in each assemblage SRA.ResultsTrait constraints were significant in predicting community structures at coarse scales, but were largely not significant at fine or medium scales. At the 0.07 ha grain little of the variation in local SRA can be explained by either trait constraints or a regional SRA. At the 1° grain c. 61% of the variation could be accounted for by a regional SRA represented by subregions. At the subregion grain c. 74% of the variation could be accounted for by trait constraints and the SRA of the entire study area.Main conclusionsOur results suggest that the relative importance of community assembly processes is scale dependent. Estimated mass effects predominated at small spatial scales where environmental gradients were weak. Trait‐based selection was hard to detect at small scales and was strongest at large scales where environmental gradients are stronger. The fact that, at all scales, mass effects accounted for more variation in assemblage SRA than trait‐based selection in our analyses suggests that regional processes are important in determining community structures more locally.
Semi‐Arid Aquifer Responses to Forest Restoration Treatments and Climate Change
Authors: Wyatt Clinton J.W. , O'Donnell Frances C. , Springer Abraham E. 
Published: March 2014

AbstractThe purpose of this study was to develop an interpretive groundwater‐flow model to assess the impacts that planned forest restoration treatments and anticipated climate change will have on large regional, deep (>400 m), semi‐arid aquifers. Simulations were conducted to examine how tree basal area reductions impact groundwater recharge from historic conditions to 2099. Novel spatial analyses were conducted to determine areas and rates of potential increases in groundwater recharge. Changes in recharge were applied to the model by identifying zones of basal area reduction from planned forest restoration treatments and applying recharge‐change factors to these zones. Over a 10‐year period of forest restoration treatment, a 2.8% increase in recharge to one adjacent groundwater basin (the Verde Valley sub‐basin) was estimated, compared to conditions that existed from 2000 to 2005. However, this increase in recharge was assumed to quickly decline after treatment due to regrowth of vegetation and forest underbrush and their associated increased evapotranspiration. Furthermore, simulated increases in groundwater recharge were masked by decreases in water levels, stream baseflow, and groundwater storage resulting from surface water diversions and groundwater pumping. These results indicate that there is an imbalance between water supply and demand in this regional, semi‐arid aquifer. Current water management practices may not be sustainable into the far future and comprehensive action should be taken to minimize this water budget imbalance.
Degree of conversion of resin‐based materials cured with dual‐peak or single‐peak LED light‐curing units
Authors: Lucey Siobhan M. , Santini Ario , Roebuck Elizabeth M. 
Published: March 2014

BackgroundThere is a lack of data on polymerization of resin‐based materials (RBMs) used in paediatric dentistry, using dual‐peak light‐emitting diode (LED) light‐curing units (LCUs).ObjectiveTo evaluate the degree of conversion (DC) of RBMs cured with dual‐peak or single‐peak LED LCUs.MethodsSamples of Vit‐l‐escence (Ultradent) and Herculite XRV Ultra (Kerr) and fissure sealants Delton Clear and Delton Opaque (Dentsply) were prepared (n = 3 per group) and cured with either one of two dual‐peak LCUs (bluephase® G2; Ivoclar Vivadent or Valo; Ultradent) or a single‐peak (bluephase®; Ivoclar Vivadent). High‐performance liquid chromatography and nuclear magnetic resonance spectroscopy were used to confirm the presence or absence of initiators other than camphorquinone. The DC was determined using micro‐Raman spectroscopy. Data were analysed using general linear model anova; α = 0.05.ResultsWith Herculite XRV Ultra, the single‐peak LCU gave higher DC values than either of the two dual‐peak LCUs (P < 0.05). Both fissure sealants showed higher DC compared with the two RBMs (P < 0.05); the DC at the bottom of the clear sealant was greater than the opaque sealant, (P < 0.05). 2,4,6‐trimethylbenzoyldiphenylphosphine oxide (Lucirin® TPO) was found only in Vit‐l‐escence.ConclusionsDual‐peak LED LCUs may not be best suited for curing non‐Lucirin® TPO‐containing materials. A clear sealant showed a better cure throughout the material and may be more appropriate than opaque versions in deep fissures.
Classes of oppositional‐defiant behavior: concurrent and predictive validity
Authors: Althoff Robert R. , Kuny‐Slock Ana V. , Verhulst Frank C. , Hudziak James J. , van der Ende Jan 
Published: March 2014

BackgroundOppositional defiant disorder (ODD) has components of both irritability and defiance. It remains unclear whether children with variation in these domains have different adult outcomes. This study examined the concurrent and predictive validity of classes of oppositional defiant behavior.MethodsLatent class analysis was performed on the oppositional defiant problems scale of the Child Behavior Checklist in two samples, one in the US (the Achenbach Normative Sample, N = 2029) and one in the Netherlands (the Zuid‐Holland Study, N = 2076). A third sample of American children (The Vermont Family Study, N = 399) was examined to determine concurrent validity with DSM diagnoses. Predictive validity over 14 years was assessed using the Zuid‐Holland Study.ResultsFour classes of oppositional defiant problems were consistent in the two latent class analyses: No Symptoms, All Symptoms, Irritable, and Defiant. Individuals in the No Symptoms Class were rarely diagnosed concurrently with ODD or any future disorder. Individuals in the All Symptoms Class had an increased frequency of concurrent childhood diagnosis of ODD and of violence in adulthood. Subjects in the Irritable Class had low concurrent diagnosis of ODD, but increased odds of adult mood disorders. Individuals in the Defiant Class had low concurrent diagnosis of ODD, but had increased odds of violence as adults.ConclusionsOnly children in the All Symptoms class were likely to have a concurrent diagnosis of ODD. Although not diagnosed with ODD, children in the Irritable Class were more likely to have adult mood disorders and children in the Defiant Class were more likely to engage in violent behavior.