bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hybridization of Neotyphodium endophytes enhances competitive ability of the host grass
Authors: Saari S. , Faeth S. H. 
Published: April 2012

Summary
Associations with microbial symbionts may lead to niche differentiation of their host. Vertically transmitted Neotyphodium endophytes of grasses often hybridize in nature. Infection by these hybrid symbionts may result in different host–plant phenotypes from those caused as a result of infection by nonhybrid symbionts. Observations of wild Arizona fescue (Festuca arizonica) populations show that hybrid Neotyphodium‐infected (H+) grasses dominate in resource‐poor environments, whereas nonhybrid endophyte‐infected (NH+) grasses dominate in environments with more resources. We studied the hypothesis that hybridization of endophytes increases stress tolerance of the host.
To test whether hybridization of Neotyphodium affects performance and competitive abilities of the host depending on resources, we conducted a glasshouse experiment where competition, nutrients and watering were manipulated.
H+ plants had greater wet biomass than NH+ and endophyte‐free plants, when grown in competition, but only in low‐water and low‐nutrient treatments. By contrast, NH+ plants did not perform better than H+ or endophyte‐free plants regardless of the treatment combination.
Our results suggest that hybridization of symbiotic Neotyphodium endophytes may increase competitive potential of the host in stressful environments and that this hybridization may be underlying niche expansion of Arizona fescue in the environments with low resources.
The prevalence of maternal near miss: a systematic review
Authors: Tunçalp Ö , Hindin MJ , Souza JP , Chou D , Say L 
Published: April 2012

Please cite this paper as: Tunçalp Ö, Hindin MJ, Souza JP, Chou D, Say L. The prevalence of maternal near miss: a systematic review. BJOG 2012;119:653–661.Background  Severe maternal morbidity or ‘near miss’ is a promising indicator to improve quality of obstetric care.Objectives  To systematically review all available studies on ‘near miss’.Search strategy  Following a pre‐defined protocol, our review covered articles between January 2004 and December 2010. We used a combination of the following terms: near miss morbidity, severe maternal morbidity, severe acute maternal morbidity, obstetric near‐miss, maternal near miss, obstetric near miss, emergency hysterectomy, emergency obstetric hysterectomy, maternal complications, pregnancy complications, intensive care unit.Selection criteria  Nearly 4000 articles were screened by title and abstract, and 153 articles were retrieved for full text evaluation. There were no language restrictions.Data collection and analysis  Data extraction was performed using an instrument that included sections on study characteristics, quality of reporting, prevalence/incidence and the definition and identification criteria. Univariate analysis and meta‐analysis for sub‐groups were performed.Main results  A total of 82 studies from 46 countries were included. Criteria for identification of cases varied widely. Prevalence rates varied between 0.6 and 14.98% for disease‐specific criteria, between 0.04 and 4.54% for management‐based criteria and between 0.14 and 0.92% for organ‐based dysfunction based on Mantel criteria. The rates are higher in low‐income and middle‐income countries of Asia and Africa. Based on meta‐analysis, the estimate of near miss was 0.42% (95% CI 0.40–0.44%) for the Mantel (organ dysfunction) criteria and 0.039% (95% CI 0.037–0.042%) for emergency hysterectomy. Our meta‐regression results indicate that emergency hysterectomy rates have been increasing by about 8% per year.Authors’ conclusions  There is growing interest in the application of the maternal near‐miss concept as an adjunct to maternal mortality. However, in the literature published before 2011 there was still important variation in the criteria used to identify maternal near‐miss cases. The World Health Organization recently published criteria based on markers of management and of clinical and organ dysfunction which would enable systematic data collection on near miss and development of summary estimates. Comparing the rates over time and across regions, it is clear that different approaches are needed to lower the rates of near miss and that interventions must be developed with the local context in mind.
Depot medroxyprogesterone acetate and epithelial ovarian cancer: a multicentre case–control study
Authors: Wilailak S , Vipupinyo C , Suraseranivong V , Chotivanich K , Kietpeerakool C , Tanapat Y , Therasakvichya S , Hamontri S , Linasmita V , Bunyapipat S , Chindavijak S , Ittiwisavakul K , Khemapech N , Suekwattana P , Thanapprapasr D , Lumbiganon P 
Published: April 2012

Please cite this paper as: Wilailak S, Vipupinyo C, Suraseranivong V, Chotivanich K, Kietpeerakool C, Tanapat Y, Therasakvichya S, Hamontri S, Linasmita V, Bunyapipat S, Chindavijak S, Ittiwisavakul K, Khemapech N, Suekwattana P, Thanapprapasr D, Lumbiganon P. Depot medroxyprogesterone acetate and epithelial ovarian cancer: a multicentre case–control study. BJOG 2012;119:672–677.Objective  To evaluate the effect of depot medroxyprogesterone acetate (DMPA) in protecting against epithelial ovarian cancer (EOC) and to evaluate factors associated with the risk of EOC.Design  A multicentre, case–control study.Setting  Twelve hospitals located across Thailand.Population  Three hundred and thirty patients with EOC (‘cases’) and 982 matched controls were recruited from the 12 hospitals. Cases were newly diagnosed patients with EOC, demonstrated pathologically. Controls were age‐matched patients admitted to different wards in the same hospital.Methods  Cases and controls were interviewed by trained interviewers using a standardised pre‐tested questionnaire. The factors associated with EOC were evaluated using univariate and multivariate analyses.Main outcome measures  The odds ratio (OR) and 95% confidence interval (95% CI) were calculated to assess the relationship between DMPA and EOC.Results  The use of DMPA was found to be associated with a 39% reduction in the risk of EOC with an OR of 0.61 and a 95% CI of 0.44–0.85 (P = 0.002). A significant risk reduction (83%) was observed when the duration of DMPA use was >3 years (OR 0.17; 95% CI 0.07–0.39; P < 0.001). Other factors associated with a reduced risk of EOC were the use of combined oral contraceptive pills and breastfeeding. A factor associated with an increased risk of EOC was a family history of gynaecological cancer.Conclusions  The results suggest that DMPA may have a protective effect against EOC. If this effect is real, then it represents an important non‐contraceptive benefit of DMPA.
Homocysteine and folate concentrations in early pregnancy and the risk of adverse pregnancy outcomes: the Generation R Study
Authors: Bergen NE , Jaddoe VWV , Timmermans S , Hofman A , Lindemans J , Russcher H , Raat H , Steegers‐Theunissen RPM , Steegers EAP 
Published: April 2012

Please cite this paper as: Bergen N, Jaddoe V, Timmermans S, Hofman A, Lindemans J, Russcher H, Raat H, Steegers‐Theunissen R, Steegers E. Homocysteine and folate concentrations in early pregnancy and the risk of adverse pregnancy outcomes: the Generation R Study. BJOG 2012;119:739–751.Objective  To investigate associations between early pregnancy homocysteine, folate and vitamin B12 concentrations and placental weight, birthweight and adverse pregnancy outcomes.Design  Population‐based birth cohort study.Setting  Rotterdam, the Netherlands.Population  Cohort of 5805 pregnant women.Methods  To analyse homocysteine, folate and vitamin B12 concentrations, blood was drawn in early pregnancy. These concentrations were divided into quintiles. Information on birth outcomes was retrieved from medical records. Multivariate regression analyses were used.Main outcome measures  Placental weight, birthweight, small for gestational age at birth (SGA) (<5th centile), prematurity and pre‐eclampsia.Results  High homocysteine concentrations (highest quintile) were associated with lower placental weight (difference 30 g; P < 0.001) and birthweight (difference 110 g; P < 0.001), and increased risk of SGA [odds ratio (OR) 1.7; P = 0.006] compared with lowest quintile (reference). Low folate concentrations (lowest quintile) were associated with lower placental weight (difference 26 g; P = 0.001) and birthweight (difference 125 g; P < 0.001), and increased risks of SGA (OR 1.9; P = 0.002), prematurity (OR 2.2; P = 0.002) and pre‐eclampsia (OR 2.1; P = 0.04) compared with highest quintile (reference). The risk of developing SGA and pre‐eclampsia was substantially higher in women who had higher homocysteine and lower folate concentrations. No associations were found with vitamin B12.Conclusions  Higher homocysteine and lower folate concentrations in early pregnancy are associated with lower placental weight and birthweight, and higher risk of adverse pregnancy outcomes. These findings suggest that high homocysteine and low folate concentrations in early pregnancy may adversely influence placentation and subsequently affect the success of pregnancy and birth outcomes.
Modelling invasive alien species distributions from digital biodiversity atlases. Model upscaling as a means of reconciling data at different scales
Authors: Marcer Arnald , Pino Joan , Pons Xavier , Brotons Lluís 
Published: April 2012

AbstractAimThere is a wealth of information on species occurrences in biodiversity data banks, albeit presence‐only, biased and scarce at fine resolutions. Moreover, fine‐resolution species maps are required in biodiversity conservation. New techniques for dealing with this kind of data have been reported to perform well. These fine‐resolution maps would be more robust if they could explain data at coarser resolutions at which species distributions are well represented. We present a new methodology for testing this hypothesis and apply it to invasive alien species (IAS).LocationCatalonia, Spain.MethodsWe used species presence records from the Biodiversity data bank of Catalonia to model the distribution of ten IAS which, according to some recent studies, achieve their maximum distribution in the study area. To overcome problems inherent with the data, we prepared different correction treatments: three for dealing with bias and five for autocorrelation. We used the MaxEnt algorithm to generate models at 1‐km resolution for each species and treatment. Acceptable models were upscaled to 10 km and validated against independent 10 km occurrence data.ResultsOf a total of 150 models, 20 gave acceptable results at 1‐km resolution and 12 passed the cross‐scale validation test. No apparent pattern emerged, which could serve as a guide on modelling. Only four species gave models that also explained the distribution at the coarser scale.Main conclusionsAlthough some techniques may apparently deliver good distribution maps for species with scarce and biased data, they need to be taken with caution. When good independent data at a coarser scale are available, cross‐scale validation can help to produce more reliable and robust maps. When no independent data are available for validation, however, new data gathering field surveys may be the only option if reliable fine‐scale resolution maps are needed.
Exercise intensity and muscle hypertrophy in blood flow–restricted limbs and non‐restricted muscles: a brief review
Authors: Abe Takashi , Loenneke Jeremy P. , Fahs Christopher A. , Rossow Lindy M. , Thiebaud Robert S. , Bemben Michael G. 
Published: April 2012

SummaryAlthough evidence for high‐intensity resistance training–induced muscle hypertrophy has accumulated over the last several decades, the basic concept of the training can be traced back to ancient Greece: Milo of Croton lifted a bull‐calf daily until it was fully grown, which would be known today as progressive overload. Now, in the 21st century, different types of training are being tested and studied, such as low‐intensity exercise combined with arterial as well as venous blood flow restriction (BFR) to/from the working muscles. Because BFR training requires the use of a cuff that is placed at the proximal ends of the arms and/or legs, the BFR is only applicable to limb muscles. Consequently, most previous BFR training studies have focused on the physiological adaptations of BFR limb muscles. Muscle adaptations in non‐BFR muscles of the hip and trunk are lesser known. Recent studies that have reported both limb and trunk muscle adaptations following BFR exercise training suggest that low‐intensity (20–30% of 1RM) resistance training combined with BFR elicits muscle hypertrophy in both BFR limb and non‐BFR muscles. However, the combination of leg muscle BFR with walk training elicits muscle hypertrophy only in the BFR leg muscles. In contrast to resistance exercise with BFR, the exercise intensity may be too low during BFR walk training to cause muscle hypertrophy in the non‐BFR gluteus maximus and other trunk muscles. Other mechanisms including hypoxia, local and systemic growth factors and muscle cell swelling may also potentially affect the hypertrophic response of non‐BFR muscles to BFR resistance exercise.
Cost‐efficient equitable water distribution in Algeria: a bicriteria fair division problem with network constraints
Authors: Udías Angel , Insua David Ríos , Cano Javier , Fellag Hocine 
Published: April 2012

AbstractWe deal with a complex water distribution problem through a bicriteria fair division model over time with network constraints: we aim at distributing water fairly in a cost‐efficient manner. The problem is illustrated for the region of Kabylia, Algeria. It involves the optimization of pump operational schedules as well as strategic planning issues. Complex rules establish energy tariffs depending on the time of day and the contractual issues of the pump facilities. We discuss the relevance and implementation of different solution concepts, showing various alternatives that improve upon current management procedures.
Insights into mechanisms of corticotropin‐releasing hormone receptor signal transduction
Authors: Grammatopoulos Dimitris K 
Published: April 2012

During evolution, mammals have developed remarkably similar molecular mechanisms to respond to external challenges and maintain survival. Critical regulators of these mechanisms are the family of ‘stress’‐peptides that consists of the corticotropin‐releasing hormone (CRH) and urocortins (Ucns). These neuropeptides ‘fine‐tune’ integration of an intricate series of physiological responses involving the autonomic, endocrine, immune, cardiovascular and reproductive systems, which induce a spectrum of behavioural and homeostatic changes. CRH and Ucns exert their actions by activating two types of CRH receptors (CRH‐R), CRH‐R1 and CRH‐R2, which belong to the class‐B1 family of GPCRs. The CRH‐Rs exhibit signalling promiscuity facilitated by their ability to couple to multiple G‐proteins and regulate diverse intracellular networks that involve intracellular effectors such as cAMP and an array of PKs in an agonist and tissue‐specific manner, a property that allows them to exert unique roles in the integration of homeostatic mechanisms. We only now begin to unravel the plethora of CRH‐R biological actions and the transcriptional and post‐translational mechanisms such as alternative mRNA splicing or phosphorylation‐mediated desensitization developed to tightly control CRH‐Rs biological activity and regulate their physiological actions. This review summarizes the current understanding of CRH‐R signalling complexity and regulatory mechanisms that underpin cellular responses to CRH and Ucns.LINKED ARTICLES This article is part of a themed section on Secretin Family (Class B) G Protein‐Coupled Receptors. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.166.issue‐1
Targeting a family B GPCR/RAMP receptor complex: CGRP receptor antagonists and migraine
Authors: Moore Eric L , Salvatore Christopher A 
Published: April 2012

The clinical effectiveness of antagonizing the calcitonin gene‐related peptide (CGRP) receptor for relief of migraine pain has been clearly demonstrated, but the road to the development of these small molecule antagonists has been daunting. The key hurdle that needed to be overcome was the CGRP receptor itself. The vast majority of the current antagonists recognize similar epitopes on the calcitonin receptor‐like receptor (CLR) and receptor activity‐modifying protein 1 (RAMP1). RAMP1 is a relatively small, single, transmembrane‐spanning protein and along with the G‐protein‐coupled receptor CLR comprise a functional CGRP receptor. The tri‐helical extracellular domain of RAMP1 plays a key role in the high affinity binding of CGRP receptor antagonists and drives their species‐selective pharmacology. Over the years, a significant amount of mutagenesis data has been generated to identify specific amino acids or regions within CLR and RAMP1 that are critical to antagonist binding and has directed attention to the CLR/RAMP1 extracellular domain (ECD) complex. Recently, the crystal structure of the CGRP receptor ECD has been elucidated and not only reinforces the early mutagenesis data, but provides critical insight into the molecular mechanism of CGRP receptor antagonism. This review will highlight the drug design hurdles that must be overcome to meet the desired potency, selectivity and pharmacokinetic profile while retaining drug‐like properties. Although the development of these antagonists has proved challenging, blocking the CGRP receptor may one day represent a new way to manage migraine and offer hope to migraine sufferers.LINKED ARTICLES This article is part of a themed section on Secretin Family (Class B) G Protein‐Coupled Receptors. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.166.issue‐1
Cannabinoid CB1 receptors mediate the effects of corticotropin‐releasing factor on the reinstatement of cocaine seeking and expression of cocaine‐induced behavioural sensitization
Authors: Kupferschmidt DA , Klas PG , Erb S 
Published: April 2012

BACKGROUND AND PURPOSEThe endocannabinoid and corticotropin‐releasing factor (CRF) systems have been implicated in several long‐lasting behavioural effects of prior cocaine experience. The present experiments were designed to probe functional interactions between endocannabinoids and CRF by testing the role of cannabinoid CB1 receptors in cocaine‐related behaviours induced or mediated by CRF.EXPERIMENTAL APPROACHIn Experiment 1, rats trained to self‐administer cocaine were pretreated with the CB1 receptor antagonist, AM251 (0, 10, 100 or 200 µg, i.c.v.), before tests for reinstatement in response to CRF (0, 0.5 µg, i.c.v.), intermittent footshock stress (0, 0.9 mA) or cocaine (0, 10 mg·kg−1, i.p.). In Experiment 2, rats pre‐exposed to cocaine (15–30 mg·kg−1, i.p.) or saline for 7 days were pretreated with AM251 (0, 10 or 100 µg, i.c.v.) before tests for locomotion in response to CRF (0.5 µg, i.c.v.), cocaine (15 mg·kg−1, i.p.) or saline (i.c.v.).KEY RESULTSPretreatment with AM251 selectively interfered with CRF‐, but not footshock‐ or cocaine‐induced reinstatement. AM251 blocked the expression of behavioural sensitization induced by challenge injections of both CRF and cocaine.CONCLUSIONS AND IMPLICATIONSThese findings reveal a mediating role for CB1 receptor transmission in the effects of CRF on cocaine‐related behaviours.
Quality Assessment Of Geometric Façade Models Reconstructed From TLS Data
Authors: Landes Tania , Boulaassal Hakim , Grussenmeyer Pierre 
Published: April 2012

AbstractTerrestrial laser scanner (TLS) data plays an important role in 3D modelling of urban scenes. Much research is carried out in the fields of pre‐processing, segmentation and geometric reconstruction of laser data of building faÇades. However, the quality of 3D models obtained from this data is rarely assessed. This paper proposes a qualitative and quantitative assessment approach to evaluate the quality of 3D models of faÇades constructed with TLS data. Only segmentation and reconstruction operations are considered in this paper, because they cover the main steps in the 3D modelling process. Since every processing step produces an intermediate result, each one must be analysed and compared with an appropriate reference model. A new approach has been conceived to evaluate the precision of the segmentation results. It is based on the calculation of Boolean operators enabling the comparison of planar clusters produced by the segmentation. To evaluate the vector models resulting from the reconstruction step, a method based on quality indices is proposed. It is adapted not only for precision but also for accuracy calculations. The results show that the quality assessment approach is coherent and, moreover, easy to apply.
Numerical Optimization Studies of Cardiovascular–Rotary Blood Pump Interaction
Authors: Lim Einly , Dokos Socrates , Salamonsen Robert F. , Rosenfeldt Franklin L. , Ayre Peter J. , Lovell Nigel H. 
Published: April 2012

AbstractA heart–pump interaction model has been developed based on animal experimental measurements obtained with a rotary blood pump in situ. Five canine experiments were performed to investigate the interaction between the cardiovascular system and the implantable rotary blood pump over a wide range of operating conditions, including variations in cardiac contractility and heart rate, systemic vascular resistance (SVR), and total blood volume (Vtotal). It was observed in our experiments that SVR decreased with increasing mean pump speed under the healthy condition, but was relatively constant during the speed ramp study under reduced cardiac contractility conditions. Furthermore, we also found a significant increase in pulmonary vascular resistance with increasing mean pump speed and decreasing total blood volume, despite a relatively constant SVR. Least squares parameter estimation methods were utilized to fit a subset of model parameters in order to achieve better agreement with the experimental data and to evaluate the robustness and validity of the model under various operating conditions. The fitted model produced reasonable agreement with the experimental measurements, both in terms of mean values and steady‐state waveforms. In addition, all the optimized parameters were within physiological limits.
Improvement of Morphology and Luminescence Properties of Powellite Type Red Phosphors CaGd1−xNbMoO8: xEu3+ Synthesized via Citrate Gel Route
Authors: Thomas Mariyam , Prabhakar Rao Padala , Mahesh Sundaresan Pillai Kamalam , Reshmi Vijaya Ravindran , Linda Francis Thekkudan , Koshy Peter 
Published: April 2012

Powellite type molybdate‐based red phosphors CaGd1−xNbMoO8: xEu3+ (x = 0.05, 0.1, 0.15, 0.20, 0.25, and 0.30) were synthesized by a solid‐state reaction (SSR) route, and a citrate gel (CG) route. The crystalline structure, morphology, absorbance, and luminescent properties of these phosphors were characterized using powder X‐ray diffraction, scanning electron microscopy, UV visible absorption spectroscopy, and photoluminescence spectroscopy. The solid solution formation of the phosphor effectively takes place at a lower temperature by the CG route than the SSR route. Particle morphology of the phosphors prepared by the CG route reveals that they are less agglomerated, more spherical, and homogenous in nature with uniform particle size. Investigations on photoluminescence properties show that these phosphors emit strong red light (614 nm) under both near UV (395 nm), and blue (465 nm) excitations. The morphological variation of the developed phosphors with respect to synthesis method and heat treatment played an important role in their luminescence enhancement. The red phosphors prepared via CG route were characterized by enhanced and sharper red emission with longer life time compared to that of phosphors synthesized via SSR route. The CIE color coordinates of the developed red phosphors are (0.65, 0.34) that are closer to NTSC standard red phosphor. Thus, these phosphors could be a promising red candidate for the phosphor converted white light emitting diode applications.