bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rathke’s cleft cysts
Authors: Trifanescu Raluca , Ansorge Olaf , Wass John A. H. , Grossman Ashley B. , Karavitaki Niki 
Published: September 2011

SummaryRathke’s cleft cysts (RCCs) are benign, sellar and/or suprasellar lesions originating from the remnants of Rathke’s pouch. Although a common finding in routine autopsies (12–33% of normal pituitary glands), symptomatic cases are rare and comprise 5–15% of all surgically resected sellar lesions. Small, asymptomatic RCC do not require surgical intervention, and their natural history is not clear. In series of nonoperated presumed RCCs, 26–94% did not progress during follow‐up periods up to 9 years. In symptomatic ones, surgery is indicated, aiming to drain the cyst content and safely remove as much of the capsule as possible. Following surgical intervention, headaches and visual field defects improve or resolve in a significant number of patients (40–100% and 33–100%, respectively) and partial hypopituitarism recovers in 14–50%. Data on relapse rates published in the last 15 years are based on variable follow‐up periods and show wide variation (between 0% and 33%). The lowest relapse rates have been described in reports with relatively short mean observation periods (<3 years), whereas in those with longer follow‐up the relapse rates increase. Most of the relapses occur within 5–6 years, suggesting that follow‐up is required for at least 5 years after surgery. Risk factors for relapse include the presence of squamous metaplasia in the cyst wall, cyst size and the presence of inflammation. Long‐term sufficiently powered studies aiming to clarify the natural history of asymptomatic RCCs and of those relapsing postoperatively are required.
Subsurface geology of the Ariana region (Diapir Zone, northern Tunisia) by means of gravity analysis
Authors: Naouali B. Sarsar , Inoubli M.H. , Amiri A. , Chaqui A. , Hamdi I. 
Published: September 2011

ABSTRACTGravity data were used to investigate subsurface geology in the Ariana region from the Diapir Zone in Tunisia. Our study area is located in the north‐eastern part of the Maghrebides affected by the Alpine orogeny. Despite the smooth topography and the low density of the Quaternary series, integrated geological data and gravity responses (Bouguer anomaly and derivative mapping) help decipher the geological heterogeneities beneath the Quaternary overburden. The interpretation of the gravity data points to alignments of positive anomalies delineating two major orthogonal features that are thought to characterize the subsurface deep structures: 1) a lineament striking north‐west at the emplacement of an actual horst bordered by a buried fault‐system directed N140 and 2) a second counterpart striking north‐east, and is clearly expressed in the surface outcrops. These principal structural features were described as the result of a regional tectonic, compressive phase dating the Miocene. This phase was marked by reactivation and oblique‐slip displacements of regional faults; some of which (N070) are reverse and south‐east vergent. Further faulting enhanced the ascension of Triassic evaporites in diapir structures. This tectonic evolution may be integrated in the regional tectonic scheme of Alpine orogeny induced by a collision between African and European plates.
Potential field migration for rapid imaging of gravity gradiometry data
Authors: Zhdanov Michael S. , Liu Xiaojun , Wilson Glenn A. , Wan Le 
Published: September 2011

ABSTRACTThe geological interpretation of gravity gradiometry data is a very challenging problem. While maps of different gravity gradients may be correlated with geological structures present, maps alone cannot quantify 3D density distributions related to geological structures. 3D inversion represents the only practical tool for the quantitative interpretation of gravity gradiometry data. However, 3D inversion is a complicated and time‐consuming procedure that is very dependent on the a priori model and constraints used. To overcome these difficulties for the initial stages of an interpretation workflow, we introduce the concept of potential field migration, and demonstrate how it can be applied for rapid 3D imaging of entire gravity gradiometry surveys. This method is based on a direct integral transformation of the observed gravity gradients into a subsurface density distribution that can be used for interpretation or as an a priori model for subsequent 3D regularized inversion. For large‐scale surveys, we show how migration runs on the order of minutes compared to hours for 3D regularized inversion. Moreover, the results obtained from potential field migration are comparable to those obtained from regularized inversion with smooth stabilizers. We present a case study for the 3D imaging of FALCON airborne gravity gradiometry data from Broken Hill, Australia. We observe good agreement between results obtained from potential field migration and those generated by 3D regularized inversion.
Summer warming accelerates sub‐arctic peatland nitrogen cycling without changing enzyme pools or microbial community structure
Authors: T. Weedon James , A. Kowalchuk George , Aerts Rien , van Hal Jurgen , van Logtestijn Richard , Taş Neslihan , F. M. Röling Wilfred , M. van Bodegom Peter 
Published: September 2011

AbstractThe balance of primary production and decomposition in northern peatlands may shift due to climate change, with potential feedbacks to atmospheric CO2 concentrations. Nitrogen availability will modulate this shift, but little is known about the drivers of soil nitrogen dynamics in these environments. We used a long‐term (9 years) open top chamber (OTC) experiment in an ombrotrophic Sphagnum peat bog in sub‐arctic Sweden, to test for the interactive effects of spring warming, summer warming and winter snow addition on soil nitrogen fluxes, potential activities of nitrogen cycle enzymes, and soil microbial community composition. These simultaneous measurements allowed us to identify the level of organization at which climate change impacts are apparent, an important requirement for developing truly mechanistic understanding. Organic‐N pools and fluxes were an order of magnitude higher than inorganic‐N pools and fluxes. Summer warming approximately doubled fluxes of soil organic nitrogen and ammonia over the growing season. Such a large increase under 1 °C warming is unlikely to be due to kinetic effects, and we propose that it is linked to an observed seasonal decrease in microbial biomass, suggesting that N flux is driven by a substantial late‐season dieback of microbes. This change in N cycle dynamics was not reflected in any of the measured potential peptidase activities. Moreover, the soil microbial community structure was apparently stable across treatments, suggesting a non‐specific microbial dieback. Our results show that in these widespread peat bogs, where many plant species are capable of organic‐N uptake, organic soil N dynamics are quantitatively far more important than the commonly studied inorganic‐N dynamics. Understanding of climate change effects on organic soil N cycling in this system will be advanced by closer investigation of the seasonal dynamics of the microbial biomass and the input of substrates that maintain it.
Quantifying small‐scale deforestation and forest degradation in African woodlands using radar imagery
Authors: Ryan Casey M. , Hill Timothy , Woollen Emily , Ghee Claire , Mitchard Edward , Cassells Gemma , Grace John , Woodhouse Iain H. , Williams Mathew 
Published: September 2011

AbstractCarbon emissions from tropical land‐use change are a major uncertainty in the global carbon cycle. In African woodlands, small‐scale farming and the need for fuel are thought to be reducing vegetation carbon stocks, but quantification of these processes is hindered by the limitations of optical remote sensing and a lack of ground data. Here, we present a method for mapping vegetation carbon stocks and their changes over a 3‐year period in a > 1000 km2 region in central Mozambique at 0.06 ha resolution. L‐band synthetic aperture radar imagery and an inventory of 96 plots are combined using regression and bootstrapping to generate biomass maps with known uncertainties. The resultant maps have sufficient accuracy to be capable of detecting changes in forest carbon stocks of as little as 12 MgC ha−1 over 3 years with 95% confidence. This allows characterization of biomass loss from deforestation and forest degradation at a new level of detail. Total aboveground biomass in the study area was reduced by 6.9 ± 4.6% over 3 years: from 2.13 ± 0.12 TgC in 2007 to 1.98 ± 0.11 TgC in 2010, a loss of 0.15 ± 0.10 TgC. Degradation probably contributed 67% (96.9 ± 91.0 GgC) of the net loss of biomass, but is associated with high uncertainty. The detailed mapping of carbon stock changes quantifies the nature of small‐scale farming. New clearances were on average small (median 0.2 ha) and were often additions to already cleared land. Deforestation events reduced biomass from 33.5 to 11.9 MgC ha−1 on average. Contrary to expectations, we did not find evidence that clearances were targeted towards areas of high biomass. Our method is scalable and suitable for monitoring land cover change and vegetation carbon stocks in woodland ecosystems, and can support policy approaches towards reducing emissions from deforestation and degradation (REDD).
A rare Y chromosome constitutional rearrangement: a partial AZFb deletion and duplication within chromosome Yp in an infertile man with severe oligoasthenoteratozoospermia
Authors: Shi Y.‐C. , Cui Y.‐X. , Zhou Y.‐C. , Wei L. , Jiang H.‐T. , Xia X.‐Y. , Lu H.‐Y. , Wang H.‐Y. , Shang X.‐J. , Zhu W.‐M. , Li X.‐J. , Huang Y.‐F. 
Published: September 2011

SummaryWe report a case of an infertile man with severe oligoasthenoteratozoospermia with a partial azoospermia factor b (AZFb) deletion and duplication region within chromosome Yp11.2. The hormonal profile was normal for serum concentrations of follicle‐stimulating hormone, luteinizing hormone, testosterone and oestradiol. The patient, who showed a 46,XY karyotype, had an approximate 2.4 Mb inherited duplication region in Yp11.2 and a de novo partial AZFb deletion, which spanned 5.25 Mb including eight protein coding genes and four non‐coding transcripts, but did not remove the RBMY gene family. Both proximal and distal breakpoints of the deletion were outside any palindromic region or inverted repeat sequence and intra‐chromosomal non‐allelic homologous recombination could not have been the deletion mechanism. The partial AZFb deletion in our case diminished sperm production, but did not completely extinguish spermatogenesis. Considering severe oligozoospermia, spermatozoa in the patient’s ejaculate were used for intracytoplasmic sperm injection, resulting in two twin pregnancies.
The caries‐preventive effect of xylitol/maltitol and erythritol/maltitol lozenges: results of a double‐blinded, cluster‐randomized clinical trial in an area of natural fluoridation
Authors: LENKKERI AIJA‐MAARIA HIETALA , PIENIHÄKKINEN KAISU , HURME SAIJA , ALANEN PENTTI 
Published: September 2011

International Journal of Paediatric Dentistry 2012; 22: 180–190Objective.  Xylitol studies suggest caries reductions in the order of 50%. Based on animal/microbial studies, erythritol potentially has caries‐preventive properties. However, clinical studies are required to confirm this.The aim of the study was to investigate the additional caries‐preventive effect of xylitol/maltitol and erythritol/maltitol lozenges delivered at school, relative to controls receiving comprehensive prevention, in a low‐caries prevalence population.Methods.  A 4‐year, cluster‐randomized, double‐blinded clinical trial. Five hundred and seventy‐nine 10‐year‐old consenting subjects from 21 schools were randomly assigned to one of five groups. Four groups used the lozenges on school days, in three teacher‐supervised sessions daily, over 1 or 2 years. The daily amount was 4.7 g/4.6 g for xylitol/maltitol and 4.5 g/4.2 g for erythritol/maltitol. The groups received free examinations and care in the public health centre. Four hundred and ninety‐six children were analysed. The main outcome measure was dentin caries increment based on a clinical examination at 4 years since the start. The groups were compared in relation to the increment using hierarchical logistic regression to adjust for potential clustering.Results.  Use of xylitol/maltitol or erythritol/maltitol lozenges did not result in caries reduction. A strong relationship between baseline caries prevalence and the 4‐year increment was observed (OR = 7.38; 95% CI: 3.78–14.41).Conclusions.  The results suggest that in relatively low‐caries conditions the school‐based use of xylitol/maltitol or erythritol/maltitol lozenges would not have additional caries‐preventive effect when compared with comprehensive prevention.
Depressive symptoms among Chinese nurses: prevalence and the associated factors
Authors: Gao Yu‐Qin , Pan Bo‐Chen , Sun Wei , Wu Hui , Wang Jia‐Na , Wang Lie 
Published: September 2011

gao y.‐q., pan b.‐c., sun w., wu h., wang j.‐n. & wang l. (2011) Depressive symptoms among Chinese nurses: prevalence and the associated factors. Journal of Advanced Nursing 68(5), 1166–1175.AbstractAim.  This article is a report of exploration of depressive symptoms and the associated factors among Chinese nurses working at public city hospitals.Background.  Hospital nurses are known to work in psychologically and physically demanding work environment, which may lead to depressive symptoms. However, little research has been done to address this problem in Chinese nurses.Methods.  A cross‐sectional survey was carried out in seven randomly selected city hospitals of Liaoning Province, northeast of China in 2009. Depressive symptoms of the nurses were measured with the Chinese version of the Center for Epidemiologic Studies Depression Scale. Job Content Questionnaire and the effort‐reward imbalance, demographic features, life style and work conditions were measured as the related factors.Results.  A total of 1592 nurses participated in the study and the effective response rate was 79·5%. The prevalence of depressive symptoms among the nurses was 61·7% (n = 886), of whom 74·9% (n = 664) had mild depressive symptoms. Multivariate logistic regression analysis showed that lower job rank, higher over commitment, alcohol consumption, worse nurse–patient relationship and higher education background were positively associated with depressive symptoms, whereas supervisor support, taking regular meals, doing physical exercises, higher skill discretion and higher job satisfaction were negatively associated with depressive symptoms.Conclusion.  More than half of the Chinese nurses had depressive symptoms. As depressive symptoms may adversely affect quality of life and quality of care, consultation for the nurses with healthy life styles, work stress coping techniques and advice to administrator to improve social aspects of the work environment might be helpful to reduce the depressive symptoms in nurses.
Behavioural trade‐offs in response to external stimuli: time allocation of an Arctic ungulate during varying intensities of harassment by parasitic flies
Authors: Witter Leslie A. , Johnson Chris J. , Croft Bruno , Gunn Anne , Gillingham Michael P. 
Published: September 2011

Summary1. Macroparasites may be a major factor shaping animal behaviour. Tundra ecosystems inhabited by caribou and reindeer (Rangifer tarandus) are known for large concentrations of ectoparasites including mosquitoes (Culicidae) and black flies (Simuliidae), as well as endoparasitic oestrid flies (Oestridae).2. Increased intensity and duration of insect harassment because of climatic warming is hypothesized as a potential factor in recent declines ofRangiferacross the circumpolar north. Although there is a well‐observed relationship between insect harassment and caribou/reindeer behaviour, the influence of ecto‐ relative to endoparasitic species is unclear. Climatic changes may favour the activity patterns, distribution or abundance of certain insect species; thus, understanding differential effects on the behaviour ofRangiferis important.3. We recorded caribou behaviour using group scan and focal sampling methods, while simultaneously trapping insects and recording weather conditions on the postcalving/summer range of the Bathurst barren‐ground caribou herd in Northwest Territories and Nunavut, Canada, during 2007–2009.4. We developed statistical model sets representing hypotheses about the effects of insects, weather, habitat/location, and date/time on caribou behaviour. We used multinomial logistic regression models to explore factors affecting the relative dominance of behaviour types within groups of caribou and fractional multinomial logistic regression models to determine factors influencing time allocation by individual caribou. We examined changes in feeding intensity using fractional logistic regression.5. Relative dominance of insect avoidance behaviour within caribou groups and time allocation to insect avoidance by individual caribou increased when oestrid flies were present or black flies were active at moderate–high levels. Mosquito activity had relatively little effect on caribou behaviour. Time spent feeding was reduced by the greatest degree when all three insect types were present in combination. Feeding intensity was influenced to a greater extent by the accumulation of growing degree days over the course of the postcalving/summer season than by insect activity. Changes in Arctic systems that increase the activity/abundance of ecto‐ and endoparasites could have implications for the productivity ofRangiferpopulations.
Regional zooplankton biodiversity provides limited buffering of pond ecosystems against climate change
Authors: Thompson Patrick L. , Shurin Jonathan B. 
Published: September 2011

Summary1. Climate change and other human‐driven environmental perturbations are causing reductions in biodiversity and impacting the functioning of ecosystems on a global scale. Metacommunity theory suggests that ecosystem connectivity may reduce the magnitude of these impacts if the regional species pool contains functionally redundant species that differ in their environmental tolerances. Dispersal may increase the resistance of local ecosystems to environmental stress by providing regional species with traits adapted to novel conditions.2. We tested this theory by subjecting freshwater zooplankton communities in mesocosms that were either connected to or isolated from the larger regional species pool to a factorial manipulation of experimental warming and increased salinity.3. Compensation by regional taxa depended on the source of stress. Warming tolerant regional taxa partially compensated for reductions in heat sensitive local taxa but similar compensation did not occur under increased salinity.4. Dispersal‐mediated species invasions dampened the effects of warming on summer net ecosystem productivity. However, this buffering effect did not occur in the fall or for periphyton growth, the only other ecosystem function affected by the stress treatments.5. The results indicate that regional biodiversity can provide insurance in a dynamic environment but that the buffering capacity is limited to some ecosystem processes and sources of stress. Maintaining regional biodiversity and habitat connectivity may therefore provide some limited insurance for local ecosystems in changing environments, but is unable to impart resistance against all sources of environmental stress.
Migratory stopover in the long‐distance migrant silver‐haired bat,Lasionycteris noctivagans
Authors: McGuire Liam P. , Guglielmo Christopher G. , Mackenzie Stuart A. , Taylor Philip D. 
Published: September 2011

Summary1. Some bat species make long‐distance latitudinal migrations between summer and winter grounds, but because of their elusive nature, few aspects of their biology are well understood. The need for migratory stopover sites to rest and refuel, such as used by birds, has been repeatedly suggested, but not previously tested empirically in bats.2. We studied migrating silver‐haired bats (Lasionycteris noctivagans) at Long Point, ON, Canada. We used digital radio‐transmitters to track 30 bats using an array of five towers that effectively covered the entire region (c.20 × 40 km). We measured stopover duration and departure direction, and documented movement patterns, foraging activity and roost sites. We measured body composition on arrival using quantitative magnetic resonance and simulated long‐distance migration using observed body composition to predict migration range and rate.3. Migration occurred in two waves (late August and mid‐September). Most bats stayed 1–2 days, although two remained >2 weeks. One third of the bats foraged while at the site, many foraging opportunistically on nights when rain precluded continued migration. Bats roosted in a variety of tree species and manmade structures in natural and developed areas. Half of the bats departed across Lake Erie (minimum crossing distancec.38 km) while half departed along the shoreline.4. Simulations predicted a migration rate ofc.250–275 km per day and suggest that all but one of the bats in our study carried sufficient fuel stores to reach the putative wintering area (estimated distance 1500 km) without further refuelling.5. Our results suggest that migrating bats stopover for sanctuary or short‐term rest as opposed to extended rest and refuelling as in many songbirds. Daily torpor could reduce energy costs when not in flight, minimizing the need for extended stopovers and allowing bats to potentially complete their migration at a fraction of the time and energy cost of similar sized birds.
Elevational variation in regional vegetation responses to late‐glacial climate changes in the Carpathians
Authors: Feurdean Angelica , Tămaş Tudor , Tanţău Ioan , Fărcaş Sorina 
Published: September 2011

AbstractAim  We used fossil records to explore patterns of change in vegetation composition, turnover and diversity along an elevational gradient during the late‐glacial to early Holocene, and to locate the elevations most sensitive to past climate changes.Location  Romania.Methods  Changes in the late‐glacial vegetation communities were inferred from seven published pollen records distributed within the main vegetation belts of the Romanian Carpathians, at elevations from 275 to 1840 m. Principal components analysis, detrended canonical correspondence analysis (DCCA) and rarefaction analysis were undertaken on these data.Results  DCCA indicates that compositional change is strongest (SD 1.2, c. 70%) at the late‐glacial/Holocene transition (c. 11,500 cal. yr bp), but significant shifts also occur at c. 14,700, c. 13,800 and c. 12,700 cal. yr bp (SD 0.4–0.8, 25–50%). Palynological turnover is greater for mid‐elevation records (730–1100 m) than at low and high elevations. Intervals of greater palynological richness occur between c. 13,800 and 12,500 cal. yr bp and after 11,500 cal. yr bp, and intervals of lower richness occur before c. 14,000 cal. yr bp and between c. 12,900 and 11,500 cal. yr bp.Main conclusions  Variations in species composition during repeated climate changes of the late‐glacial suggest that community composition at a given time was not only a result of the environmental conditions of that period, but also the legacy of previous cumulative recruitment and extirpation events. Turnover estimates suggest that mid‐elevations have been the most sensitive to climate change during the late‐glacial and early Holocene. Palynological richness estimates show a less clear elevational pattern and no evidence for a greater sensitivity of this measure of biodiversity at high elevations to past climate change. However, results may have been affected by taxa with high pollen productivity and distance dispersability. Our finding concurs with other palaeoecological and local‐scale modelling studies in suggesting that small populations have survived in favourable microhabitats embedded within larger unsuitable areas during the late‐glacial, features not captured by broad‐scale model predictions.