bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling occupancy of an imperilled stream fish at multiple scales while accounting for imperfect detection: implications for conservation
Authors: Dextrase Alan J. , Mandrak Nicholas E. , Schaefer James A. 
Published: April 2014

SummaryPredictive models of species distribution are useful tools to identify habitats of imperilled species for protection, inventory and restoration. Critical aspects of such models include the influence of scale, uncertainties associated with imperfect detection and spatial autocorrelation and transferability of model predictions.We addressed these issues in developing occupancy models of the imperilled eastern sand darter (Ammocrypta pellucida) based on surveys of the Grand and Thames Rivers, Ontario, Canada.Eastern sand darter detection probabilities were remarkably different between streams, but factors affecting site occupancy were similar. The proportion of sand and fine gravel was most important, but water clarity and biotic indices also received support in additive models. Accounting for spatial autocorrelation reduced the effect of important covariates.Occupancy was more closely related to substratum at the site level than factors at broader scales (reach and valley segment), further emphasising the substratum specificity of this species.Almost all of the top‐ranked site and reach occupancy models had good predictive performance based on assessments of transferability. These models indicate that three formerly occupied Ontario catchments have a high probability of supporting the species and deserve consideration for repatriation.Our methods demonstrate how a comprehensive approach to occupancy modelling can be used to help guide recovery efforts for imperilled species.
Have we been underestimating the effects of ocean acidification in zooplankton?
Authors: Cripps Gemma , Lindeque Penelope , Flynn Kevin J. 
Published: April 2014

AbstractUnderstanding how copepods may respond to ocean acidification (OA) is critical for risk assessments of ocean ecology and biogeochemistry. The perception that copepods are insensitive to OA is largely based on experiments with adult females. Their apparent resilience to increased carbon dioxide (pCO2) concentrations has supported the view that copepods are ‘winners’ under OA. Here, we show that this conclusion is not robust, that sensitivity across different life stages is significantly misrepresented by studies solely using adult females. Stage‐specific responses to pCO2 (385–6000 μatm) were studied across different life stages of a calanoid copepod, monitoring for lethal and sublethal responses. Mortality rates varied significantly across the different life stages, with nauplii showing the highest lethal effects; nauplii mortality rates increased threefold when pCO2 concentrations reached 1000 μatm (year 2100 scenario) with LC50 at 1084 μatm pCO2. In comparison, eggs, early copepodite stages, and adult males and females were not affected lethally until pCO2 concentrations ≥3000 μatm. Adverse effects on reproduction were found, with >35% decline in nauplii recruitment at 1000 μatm pCO2. This suppression of reproductive scope, coupled with the decreased survival of early stage progeny at this pCO2 concentration, has clear potential to damage population growth dynamics in this species. The disparity in responses seen across the different developmental stages emphasizes the need for a holistic life‐cycle approach to make species‐level projections to climate change. Significant misrepresentation and error propagation can develop from studies which attempt to project outcomes to future OA conditions solely based on single life history stage exposures.
Diversity of condensed tannin structures affects rumen in vitro methane production in sainfoin (Onobrychis viciifolia) accessions
Authors: Hatew B. , Hayot Carbonero C. , Stringano E. , Sales L. F. , Smith L. M. J. , Mueller‐Harvey I. , Hendriks W. H. , Pellikaan W. F. 
Published: April 2014

AbstractSainfoin is a non‐bloating temperate forage legume with a moderate‐to‐high condensed tannin (CT) content. This study investigated whether the diversity of sainfoin accessions in terms of CT structures and contents could be related to rumen in vitro gas and methane (CH4) production and fermentation characteristics. The aim was to identify promising accessions for future investigations. Accessions differed (P < 0·0001) in terms of total gas and CH4 productions. Fermentation kinetics (i.e. parameters describing the shape of the gas production curve and half‐time gas production) for CH4 production were influenced by accession (P ≤ 0·038), but not by PEG. Accession, PEG and time affected (P < 0·001) CH4 production, but accession and PEG interaction showed only a tendency (P = 0·08). Increase in CH4 due to PEG addition was not related to CT content. Further analysis of the relationships among multiple traits (nutritional composition, CT structure and CH4 production) using principal component analysis (PCA) based on optimally weighted variables revealed differences among accessions. The first two principal component axes, PC1 (57·6%) and PC2 (18·4%), explained 76·0% of the total variation among accessions. Loading of biplots derived from both PCAs made it possible to establish a relationship between the ratio of prodelphinidin:procyanidin (PD:PC) tannins and CH4 production in some accessions. The PD:PC ratio seems to be an important source of variation that is negatively related to CH4 production. These results suggested that sainfoin accessions collected from across the world exhibited substantial variation in terms of their effects on rumen in vitro CH4 production, revealing some promising accessions for future investigations.
An in vitro comparison of irrigation using photon‐initiated photoacoustic streaming, ultrasonic, sonic and needle techniques in removing calcium hydroxide
Authors: Arslan H. , Akcay M. , Capar I. D. , Saygili G. , Gok T. , Ertas H. 
Published: May 2014

AbstractAimTo evaluate the effect of various techniques including photon‐initiated photoacoustic streaming (PIPS), ultrasonic, sonic and needle irrigation on the removal of calcium hydroxide [Ca(OH)2] from artificial grooves created in root canals.MethodsThe root canals of 48 extracted single‐rooted teeth with straight canals were prepared using ProTaper rotary instruments up to size 40. After the specimens had been split longitudinally, a standardized groove was prepared in the apical part of one segment that was filled with Ca(OH)2 powder mixed with distilled water. Each tooth was reassembled and the apices closed with wax. The specimens were irrigated for 60 s with one of the following techniques: needle irrigation using 17% EDTA, PIPS with 17% EDTA, ultrasonic irrigation using 17% EDTA and sonic irrigation (EndoActivator) using 17% EDTA. The root segments were then disassembled, and the amount of remaining Ca(OH)2 evaluated under a stereomicroscope at 25× magnification. A pixel count of Ca(OH)2 remaining on the artificially created grooves was recorded as a percentage of the overall groove surface. The data were evaluated statistically using one‐way analysis of variance and the least significant difference post hoc tests at 95% confidence level (P = 0.05).ResultsPhoton‐initiated photoacoustic streaming was superior in removing Ca(OH)2 as compared to needle irrigation (P < 0.001), sonic irrigation (P < 0.001) and ultrasonic irrigation (P = 0.046).ConclusionPhoton‐initiated photoacoustic streaming provided complete removal of Ca(OH)2 from artificial grooves in straight root canals. Ultrasonic irrigation enhanced the Ca(OH)2 removal capacity of irrigating solution but did not provide complete removal from artificial grooves.
Development of a novel modified atmosphere container with a cycle‐time‐controlled perforation for enoki mushroom preservation
Authors: Kwon Min‐Ji , An Duck Soon , Lee Dong Sun 
Published: April 2014

SummaryA novel container system with a time‐controlled perforation device was designed to create a modified atmosphere (MA) beneficial for preserving 1.5 kg of enoki mushrooms at 10 °C. Periodic cycles of meeting and eclipse of the block‐arc‐shaped perforations on the rotor and the fixed container cover in the device provided the repeated time‐controlled opening/closing of the perforation to control the gas transfer. A mathematical model describing the container atmospheric change was used to determine an optimal design, which is specified with circular opening ratios of 7% for the rotor and 10% for the fixed cover for a 4‐h cycle. The design could create an MA of 1.8% O2 and 19.4% CO2 to preserve the quality in terms of weight loss, mushroom development, colour change, texture and overall appearance. The cycled time control of the perforation was found as an effective means to have MA condition keeping enoki mushrooms fresh.
Cognitive Performance after Stroke – The Framingham Heart Study
Authors: Weinstein Galit , Preis Sarah R. , Beiser Alexa S. , Au Rhoda , Kelly-Hayes Margaret , Kase Carlos S. , Wolf Philip A. , Seshadri Sudha 
Published: April 2014

Background Individuals with a high risk of stroke are also more prone to cognitive impairment perhaps because of concomitant vascular risk factors. In addition, clinical stroke increases the risk of subsequent dementia. Nevertheless, the relationship between clinical stroke and subsequent cognitive function in initially nondemented individuals remains less clear as most prior studies examined case series without controls. Aims To specify among nondemented individuals the cognitive domains affected by clinical stroke, independently of vascular risk factors and prestroke cognition. Methods One hundred thirty-two Framingham study participants (mean age = 77 ± 9 years, 54% women) with prospectively validated initial strokes, as well as age- and gender-matched controls, underwent identical cognitive evaluations ∼six-months after the stroke. Linear regression models were used to assess the differences in cognitive scores between stroke cases and controls adjusting for prestroke cognitive function as assessed by Mini-Mental State Examination scores, and with and without adjustment for vascular risk factors. Results Adjusting for prestroke cognition and vascular risk factors, persons with stroke had poorer cognitive function in the domains of immediate recall of logical and visual memories (β = −1·27 ± 0·60, P = 0·035; β = −1·03 ± 0·47, P = 0·028, respectively), verbal learning (paired associate test; β = −1·31 ± 0·57, P = 0·023), language (Boston naming test; β = −0·27 ± 0·08, P = 0·002), executive function (digit span backward; β = −0·53 ± 0·21, P = 0·015), and visuospatial and motor skills (block design; β = −3·02 ± 1·06, P = 0·005). Conclusions Clinical stroke is associated with subsequent poorer performance in multiple cognitive domains. This association cannot be entirely explained by the individual's cognitive function prior to stroke or by concomitant vascular risk factor levels.
Narrow tuning of an odorant receptor to plant volatiles in Spodoptera exigua (Hübner)
Authors: Liu Chengcheng , Liu Yang , Guo Mengbo , Cao Depan , Dong Shuanglin , Wang Guirong 
Published: April 2014

AbstractOlfaction plays an important role in insects in recognizing volatile compounds, which are used to find food and mates, as well as avoid danger, predators and pathogens. The key players in the detection of volatile compounds are olfactory receptor (OR) proteins, which are located within the dendritic membrane of sensory neurons and extend into the lymph of sensilla on insect antennae. In the present study, we identify an OR gene, named SexiOR3, which is expressed in adult antenna in both sexes, but with female bias, in the beet armyworm moth Spodoptera exigua. Further in situ hybridization analysis revealed that SexiOR3 was mainly located in short trichoid sensilla. In in vitro heterologous expression experiments, SexiOR3 was narrowly tuned to E‐β‐farnesene and several compounds of related structure, among 62 different compounds tested in this study. Furthermore, SexiOR3 responds to E‐β‐farnesene at a low concentration of 10−9 M, comparable to that of pheromone receptors (PRs) responding to the pheromones. This is a very interesting finding for a general OR, indicating that high specificity is a feature of at least one general OR and not only the PRs. The results suggest that the OR3 gene may play an important role in the moth olfactory system, and underpins important insect behaviour.
Usable Values of Nickel Ore and Nickel Concentrate Certified Reference Materials
Authors: Cheng Zhizhong , Liu Mei , Huang Hongku , Gu Tiexin , Yan Weidong , Wen Hongli 
Published: May 2014

The preparation and characterisation of three nickel ores and two nickel concentrate certified reference materials are described in this paper. The samples of nickel ore and nickel concentrate were collected from the Hongqiling nickel deposit in Jilin province. The raw materials were crushed and passed through a 2.0‐mm sieve. The rough samples were then ground for 48 hr in a high‐alumina ball mill to a final size of < 0.074 mm. Homogeneity of the samples was tested by X‐ray fluorescence spectrometry (WD‐XRF) and inductively coupled plasma‐atomic emission spectrometry (ICP‐AES). The relative standard deviations (RSD) of results on mass fraction measurements by WD‐XRF were < 1.0% m/m for eighteen components. F‐tests showed that all five samples were homogeneous. Nineteen laboratories contributed with measurement results (2127 in total) for the certification of mass fractions for twenty‐three elements and compounds. Twenty‐three components in the nickel ores and twenty components in the nickel concentrates were characterised as certified values, while the Ni mass fractions ranges from 0.1 to 9.02% m/m in these certified reference materials. These five samples were approved as national certified reference materials by the National Organisation of Reference Materials of China in 2012.
Distinct roles of age and abdominal visceral fat in reducing androgen receptor‐dependent negative feedback on LH secretion in healthy men
Authors: Takahashi P. Y. , Liu P. Y. , Veldhuis J. D. 
Published: April 2014

SummaryTestosterone (T) impacts luteinizing hormone (LH) secretion through negative feedback via the androgen receptor (AR) in the hypothalamo‐pituitary system. An untested postulate is that increasing body mass index (BMI), abdominal visceral fat (AVF) or total abdominal fat (TAF) with ageing decreases LH secretion by heightening T negative feedback via AR. This hypothesis was tested in a prospective, randomized double‐blind cross‐over study of 19 healthy men comparing the effects of flutamide, a selective non‐steroidal AR antagonist and placebo administration on basal and pulsatile LH secretion as a function of age and obesity measures. To this end, serum levels of 2‐hydroxyflutamide (2‐OHF), a major active flutamide metabolite, were measured by mass spectrometry, and AVF/TAF quantified by abdominal computerized tomography. Statistical analysis showed that antiandrogen administration elevated 6‐h mean LH concentrations to 5.4 ± 1.3 IU/L compared with 3.3 ± 1.2 IU/L for placebo (p < 10−3), and total T by 35% (p < 10−4). The LH‐T concentration product doubled (p < 10−8). According to deconvolution analysis, flutamide exposure increased total LH secretion (p < 10−3) and pulsatile LH secretion (p = 0.0077), along with LH pulse frequency (p = 0.019). Despite feedback inhibition, the LH‐T product declined as a linear function of AVF (p = 0.021) and TAF (p = 0.017). This was explained by the fact that higher BMI was associated with lower 2‐OHF concentrations (R = −0.562, p = 0.012). In contrast, age was associated with less pulsatile LH secretion (R = −0.567, p = 0.011) even when LH responses were normalized to antiantrogen levels. In conclusion, increased AVF, TAF and BMI predict decreased LH and flutamide blood levels, whereas older age is marked by impaired stimulation of pulsatile LH secretion even when normalized for antiandrogen levels, suggesting different mechanisms of regulation by adiposity and age.
Conservation Agriculture – A Portuguese Case Study
Authors: Carvalho M. , Lourenço E. 
Published: May 2014

AbstractThis paper gives a glance about the conservation agriculture concept and the worldwide increase in agricultural area where this technique has been adopted. The main constraints to agricultural production in the Mediterranean region are discussed, highlighting the importance of conservation agriculture to mitigate them. Results of long‐term studies with this technique, in Portugal, showed an increase in organic matter, improvement of aggregates stability and continuity of biological porosity along the soil profile. These changes in soil properties are helping to overcome edaphic and climatic constrains under Mediterranean conditions. The saturated hydraulic conductivity is improved allowing a better drainage during wet winters, and together with higher soil cohesion, the transitability of the soil is enhanced, allowing a correct timing of field operations like nitrogen top dressing and herbicide application. Nitrogen‐use efficiency is improved either by the timing of application and by the improvement of soil organic matter content. Soil productivity is also enhanced and the overall energy‐use efficiency is double when soil organic matter content is raised from 1 to 2 % in the top 30 cm of the soil. Therefore, conservation agriculture is advantageous from the economic and environmental point of view contributing to the sustainability of rainfed agriculture.
Novel Synthesis of ZrB2 Powder Via Molten‐Salt‐Mediated Magnesiothermic Reduction
Authors: Zhang Shaowei , Khangkhamano Matthana , Zhang Haijun , Yeprem Hasibe Aygul 
Published: April 2014

Zirconium diboride (ZrB2) powder was synthesized at a low temperature via a molten‐salt‐mediated reduction route using ZrO2, Na2B4O7 and Mg powders as starting raw materials. By using appropriately excessive amounts of Mg and Na2B4O7 to compensate for their evaporation losses, ZrO2 could be completely converted into ZrB2 after 3 h at 1200°C. In addition, the formation of undesirable Mg3B2O6 could be effectively avoided. As‐prepared ZrB2 powders were phase pure, 300–400 nm in size and generally well dispersed. SEM images showed that to a large extent the reactively formed ZrB2 retained the morphology and size of the starting ZrO2. The salt melt formed from MgCl2 and Na2B4O7 at test temperatures is believed to be responsible for the reduced synthesis temperature and good dispersion of the final ZrB2 product powder.
Sintering Process and Microwave Dielectric Properties of Bi8TiO14 Ceramics
Authors: Joung Mi‐Ri , Jeong Byoung‐Jik , Kim Jin‐Seong , Woo Sung‐Ran , Park Hyun‐Min , Nahm Sahn 
Published: April 2014

The formation of a homogeneous Bi8TiO14 phase was successfully achieved in a specimen calcined at 600°C. However, a Bi4Ti3O12 secondary phase also developed in specimens calcined at temperatures higher than 600°C, probably because of Bi2O3 evaporation. For specimens sintered above 800°C, a small amount of the Bi8TiO14 phase melted during sintering, with the liquid phase contributing to the densification of the specimens; however, Bi4Ti3O12 and Bi12TiO20 secondary phases were still formed in these specimens. The microwave dielectric properties of the Bi8TiO14 phase were considerably affected by variations in the microstructure of the specimens. When the sintering temperature exceeded 825°C, the amount of secondary phases increased, and this decreased the density and Q×f values of the specimens. Bi8TiO14 ceramics sintered at 825°C exhibited promising microwave dielectric properties, with εr = 47.4, Q×f = 5370 GHz, and τf = −16.01 ppm/°C.
Thermal Expansion of Ln6WO12 (Ln = Y,Ho,Er,Yb) and Ln2WO6 (Ln = Gd,Dy,Ho) – an In Situ Synchrotron X‐ray Diffraction Study
Authors: Apostolov Zlatomir D. , Sarin Pankaj , Hughes Robert W. , Kriven Waltraud M. 
Published: April 2014

The thermal expansion (TE) behavior of cubic and rhombohedral Ln6WO12 (Ln = Y, Ho, Er, Yb) and monoclinic Ln2WO6 (Ln = Gd, Dy, Ho) was investigated by synchrotron X‐ray diffraction from room temperature to approximately 1500°C. The volumetric and lattice parameter expansions were measured for all compositions in both systems, and the respective expansion coefficients were derived and fitted over the observed temperature range with a second‐order polynomial. The relative TE evolution along the unit cell edges in each phase was described from a crystallographic perspective, with the reasons for TE dynamics explained in terms of the fundamental constituent units of the structure. Analysis of the TE ellipsoid of the monoclinic Ln2WO6 revealed a continuous change in both its shape and orientation, with the latter effect strongly manifested in the (010) plane. A noticeable reversal of the relative expansion rates between a, and b and c lattice parameters was attributed to the rotation of the ellipsoid cross section in this plane, bringing the larger of the two eigenvectors closer to a, while the smaller one to c. Investigating the structural dynamics of the constituent layers in Ln2WO6 suggested that the bridging role of the Ln polyhedron centered on the only general position in the unit cell may be the reason for the rotating TE ellipsoid.
A 576‐Year Weber River Streamflow Reconstruction from Tree Rings for Water Resource Risk Assessment in the Wasatch Front, Utah
Authors: Bekker Matthew F. , Justin DeRose R. , Buckley Brendan M. , Kjelgren Roger K. , Gill Nathan S. 
Published: April 2014

AbstractWe present a 576‐year tree‐ring‐based reconstruction of streamflow for northern Utah's Weber River that exhibits considerable interannual and decadal‐scale variability. While the 20th Century instrumental period includes several extreme individual dry years, it was the century with the fewest such years of the entire reconstruction. Extended droughts were more severe in duration, magnitude, and intensity prior to the instrumental record, including the most protracted drought of the record, which spanned 16 years from 1703 to 1718. Extreme wet years and periods are also a regular feature of the reconstruction. A strong early 17th Century pluvial exceeds the early 20th Century pluvial in magnitude, duration, and intensity, and dwarfs the 1980s wet period that caused significant flooding along the Wasatch Front. The long‐term hydroclimatology of northern Utah is marked by considerable uncertainty; hence, our reconstruction provides water managers with a more complete record of water resource variability for assessment of the risk of droughts and floods for one of the largest and most rapidly growing population centers in the Intermountain West.