bluuebunny/crossref_metadata_2025_split huggingface dataset:
Defining spatial and temporal patterns of phylogeographic structure in Madagascar’s iguanid lizards (genus Oplurus)
Authors: CHAN LAUREN M. , CHOI DEAN , RASELIMANANA ACHILLE P. , RAKOTONDRAVONY HERY A. , YODER ANNE D. 
Published: June 2012

AbstractUnderstanding the remarkably high species diversity and levels of endemism found among Madagascar’s flora and fauna has been the focus of many studies. One hypothesis that has received much attention proposes that Quaternary climate fluctuations spurred diversification. While spatial patterns of distribution and phylogenetic relationships can provide support for biogeographic predictions, temporal estimates of divergence are required to determine the fit of these geospatial patterns to climatic or biogeographic mechanisms. We use multilocus DNA sequence data to test whether divergence times among Malagasy iguanid lizards of the subfamily Oplurinae are compatible with a hypotheses of Pliocene–Pleistocene diversification. We estimate the oplurine species tree and associated divergence times under a relaxed‐clock model. In addition, we examine the phylogeographic structure and population divergence times within two sister species of Oplurus primarily distributed in the north‐west and south‐west of Madagascar (Oplurus cuvieri and Oplurus cyclurus, respectively). We find that divergence events among oplurine lineages occurred in the Oligocene and Miocene and are thus far older and incompatible with the hypothesis that recent climate fluctuations are related to current species diversity. However, the timing of intraspecific divergences and spatial patterns of population genetic structure within O. cuvieri and O. cyclurus suggest a role for both intrinsic barriers and recent climate fluctuations at population‐level divergences. Integrating information across spatial and temporal scales allows us to identify and better understand the mechanisms generating patterns diversity.
Elevated growth temperatures alter hydraulic characteristics in trembling aspen (Populus tremuloides) seedlings: implications for tree drought tolerance
Authors: WAY DANIELLE A. , DOMEC JEAN‐CHRISTOPHE , JACKSON ROBERT B. 
Published: June 2012

ABSTRACTAlthough climate change will alter both soil water availability and evaporative demand, our understanding of how future climate conditions will alter tree hydraulic architecture is limited. Here, we demonstrate that growth at elevated temperatures (ambient +5 °C) affects hydraulic traits in seedlings of the deciduous boreal tree species Populus tremuloides, with the strength of the effect varying with the plant organ studied. Temperature altered the partitioning of hydraulic resistance, with greater resistance attributed to stems and less to roots in warm‐grown seedlings (P < 0.02), and a 46% (but marginally significant, P = 0.08) increase in whole plant conductance at elevated temperature. Vulnerability to cavitation was greater in leaves grown at high than at ambient temperatures, but vulnerability in stems was similar between treatments. A soil–plant–atmosphere (SPA) model suggests that these coordinated changes in hydraulic physiology would lead to more frequent drought stress and reduced water‐use efficiency in aspen that develop at warmer temperatures. Tissue‐specific trade‐offs in hydraulic traits in response to high growth temperatures would be difficult to detect when relying solely on whole plant measurements, but may have large‐scale ecological implications for plant water use, carbon cycling and, possibly, plant drought survival.
The Arabidopsis thaliana DSB formation (AtDFO) gene is required for meiotic double‐strand break formation
Authors: Zhang Cheng , Song Yao , Cheng Zhi‐hao , Wang Ying‐xiang , Zhu Jun , Ma Hong , Xu Ling , Yang Zhong‐Nan 
Published: June 2012

SummaryDNA double‐strand break (DSB) formation is the initial event for meiotic recombination catalyzed by the conserved Spo11 protein. In Arabidopsis, several proteins have been reported to be involved in DSB formation. Here, we report an Arabidopsis DSB forming (DFO) gene in Arabidopsis that is involved in DSB formation. The dfo mutant exhibits reduced fertility, producing polyads with an abnormal number of microspores, unlike the tetrads in the wild type. The dfo meiocytes were defective in homologous chromosome synapsis and segregation. Genetic analysis revealed that the homologous recombination of Atdfo‐1 is severely affected in meiotic prophase I. DFO encodes a protein without any known conserved domain. There was no homologue identified outside the plant kingdom, indicating that AtDFO is a plant‐specific protein. AtMRE11 has been reported to be responsible for processing SPO11‐generated DSBs. The Atmre11 mutant displays chromosome fragmentation during meiosis. However, the Atdfo Atmre11 double mutant had no such chromosome fragmentation, indicating that AtDFO is required for DSB formation.
Interactions between pre‐ and post‐emergence weed harrowing in spring cereals
Authors: BRANDSÆTER L O , MANGERUD K , RASMUSSEN J 
Published: June 2012

Brandsæter LO, Mangerud K & Rasmussen J (2012) Interactions between pre‐ and post‐emergence weed harrowing in spring cereals. Weed Research52, 338–347.SummaryPre‐ and post‐emergence weed harrowing were studied in spring cereals in different environments and with two types of harrows in Norway during 2004–2006. The objectives were to investigate interactions between pre‐ and post‐emergence weed harrowing and the importance of harrow type. We hypothesised that pre‐ and post‐emergence harrowing interact positively, that a combination gives more stable weed control effects than pre‐ and post‐emergence weed harrowing used alone, and that a harrow type with bent tines is more aggressive and suitable on hard‐packed soils than a harrow with strait tines. The results only supported the last of these hypotheses. Post‐emergence weed harrowing controlled a certain percentage of the present weeds, and this percentage was not dependent on pre‐emergence weed harrowing. On average, pre‐emergence harrowing reduced weed density by 26% and weed biomass by 22%, while the average effect of post‐emergence harrowing was 47% on weed density and 41% on weed biomass. The combined effect of pre‐ and post‐emergence weed harrowing was 61% on weed density and 54% on weed biomass. The combination did not give more stable weed control effects than pre‐ and post‐emergence weed harrowing used alone. Pre‐emergence harrowing increased the average crop yield by 6.2%, post‐emergence harrowing by 4.0% and the combined effect was 10%. Crop yield was mainly increased on hard‐packed soils. Weed and crop responses varied strongly among experiments, but the efficacy of pre‐ and post‐emergence weed harrowing was positively correlated across experiments. Weed species composition was of minor importance regarding weed control. The study indicates that one aggressive post‐emergence cultivation may be as good as one pre‐emergence and one less aggressive post‐emergence cultivation. However, little is known about the interactions between cultivation at different crop and weed growth stages.
Comparing Sex Steroid Levels During the Annual Cycles of Rainbow Trout (Oncorhynchus mykiss) Diploid Female (XX) and Triploid Female (XXX) Genotypic Sex
Authors: Espinosa E , Josa A , Gil L , Malo C , Mitjana O 
Published: June 2012

ContentsIn this study, the annual cycle of the gonadal steroids testosterone (T), 11‐ketotestosterone (11‐KT), 17β‐estradiol (E2) and 17α, 20β‐dihydroxy‐4‐pregnen‐3‐one (DHP) was determined using radioimmunoassay and then compared for two populations of rainbow trout, XX diploid females (n = 40) and XXX triploid females (n = 15). In females, E2 and DHP levels were found to be significantly related to body weight (r = 0.22513; p < 0.0001 and r = 0.15831; p >  0.001, respectively). In this group, E2 concentrations peaked in November (25.05 ng /ml), while maximum DHP levels, only measurable from October to April, were attained in February (64.14 ng /ml). No significant differences in hormone ranges related to egg output ability were observed. Finally, sex steroid concentrations were low in the triploid female XXX fish compared to the female XX population. Nevertheless, maximum T (33.85 ng /ml) and 11‐KT (32.35 ng /ml) levels were recorded in January, for XXX. The levels for these two hormones are relatively high and are also significantly associated (r = 0.8430; p < 0.0001). Diploid females showed significantly higher levels of E2 than triploids over the 12‐month study period. The female triploid fish produced the lowest steroid hormone levels, such that these would be the most suitable for human consumption.
Surgical risk in patients with cirrhosis
Authors: Nicoll Amanda 
Published: June 2012

AbstractSurgery in the patient with cirrhosis is problematic, as encephalopathy, ascites, sepsis and bleeding are common in the postoperative period. Accurate preoperative assessment and planning, and careful postoperative management have the potential to reduce the frequency and severity of such complications, and reduce the length of hospital stay, but there is little literature evidence to prove this. Operative mortality and other risks correlate with the severity of the liver disease, co‐morbidities and the type of surgery. The Child‐Turcott‐Pugh (CTP) score or model for end‐stage liver disease (MELD) score may be used to determine the severity of the liver disease, but must also take into account recent changes in the patient's condition. Surgery that does not involve opening the peritoneum may have slightly better outcomes, as the risk of ascitic leak, sepsis and difficult fluid management are reduced. Mortality rates range from 10% in CTP‐A patients to 82% in CTP‐C patients. The presence of portal hypertension is an important negative predictor, especially in abdominal surgery, as refractory ascites may occur. Careful monitoring in the postoperative period and early intervention of complications are essential. Hepatic resections in cirrhosis are associated with other considerations such as leaving sufficient liver tissue to prevent liver failure, and are beyond the scope of this review.
Study of amino acids as nitrogen source in Chlamydomonas reinhardtii
Authors: Zuo Zhaojiang , Rong Qingqing , Chen Kai , Yang Lin , Chen Zhengzhen , Peng Keli , Zhu Yerong , Bai Yanling , Wang Yong 
Published: June 2012

SUMMARYAll five L‐amino acids tested (L‐serine, L‐lysine, L‐leucine, L‐cysteine and L‐arginine) were used by Chlamydomonas reinhardtii as sole nitrogen source. Among these, L‐Cys was special as it has not been reported before. While these amino acids could be used in the dark only in the presence of acetic acid, in conditions of light they could support the growth of C. reinhardtii without the supplementation of acetic acid. When cultured in the TAP‐N medium, the chlorophyll content was found to be lower in the dark, but higher in the light for the cells grown with L‐Arg than with other four amino acids. Exogenously supplied L‐Ser and L‐Lys did not accumulate in the cells, demonstrating that they were used by supplying ammonium to the cells from the activity of an extracellular deaminase. Further results showed that the induction of the extracellular deaminase activity required a period of nitrogen starvation, regardless of the medium containing acetic acid or not. Results also showed that the uptake of L‐Cys was similar to L‐Leu, most likely via passive diffusion. When L‐Cys and L‐Leu were supplied together to the nitrogen‐starved cells, the absorption of L‐Cys did not affect the uptake of L‐Leu.
How to manage unresponsiveness to misoprostol in failed second trimester pregnancy termination
Authors: Pongsatha Saipin , Tongsong Theera 
Published: June 2012

AbstractAim:  To present the experience of management of second trimester pregnancy termination by misoprostol after failure to abort within 48 h of its use.Material and Methods:  A retrospective, cohort descriptive study was carried out in the Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University Thailand between 1998 and 2010. All women at 14–28 weeks of gestation who failed to abort using misoprostol within 48 h were included. Management of failed pregnancy termination among these women is described here.Results:  Of a total of 680 women undergoing termination of pregnancy, 68 (10%) failed to abort. Mean maternal age was 28.71 years and mean gestational age was 19.91 weeks. Further management after failure included additional administration of misoprostol only (19.1%), modified condom balloon technique only (17.7%), modified condom balloon technique plus other methods (16.1%), while 47.1% needed only oxytocin as necessary. The mean interval between initiation of termination and delivery was 96.97 h.Conclusion:  Failure of pregnancy termination using misoprostol can be successfully managed by introducing additional misoprostol, modified condom balloon technique and oxytocin infusion. These methods should be considered before proceeding to hysterotomy.
Preventing maternal deaths due to acquired thrombotic thrombocytopenic purpura
Authors: Hunt Beverley J. , Thomas‐Dewing Rowena R. , Bramham Kate , Lucas Sebastian B. 
Published: June 2012

AbstractIn order to identify the cause of maternal deaths due to thrombotic thrombocytopenic purpura (TTP) and identify future preventative measures we retrospectively reviewed all maternal deaths due to TTP in London from 2003 to 2008 that were confirmed on post‐mortem examination. There were three maternal deaths due to sudden cardiac arrest within 1, 5 and 2 days of presentation, respectively. Post‐mortem findings revealed they all died with intramyocardial microvascular thrombosis, the thrombi being characteristically platelet rich (CD61+, fibrin−). Platelet thrombi in the coronary microvasculature are the cause of early sudden death in TTP in pregnancy. If TTP cannot be excluded in the differential diagnosis of thrombotic microangiopathies of pregnancy, then plasmapheresis should be instituted as a medical emergency. ADAMTS‐13 levels are helpful in making the diagnosis, but results should not be awaited before instituting plasmapheresis.
Thrombophilia investigation in Pakistani women with recurrent pregnancy loss
Authors: Hossain Nazli , Shamsi Tahir , Khan Nazeer , Naz Arshi 
Published: June 2012

AbstractAim:  The aim of the study was to identify thrombophilic defects in women with a history of recurrent miscarriage.Methods:  This was a case‐control study in which the cases were women who had undergone spontaneous recurrent pregnancy losses and the controls were women in matched reproductive age groups without any history of miscarriage or pregnancy loss. Both groups of women were identified from our department's high‐risk and gynecological outpatient clinics. A total of 52 women with recurrent pregnancy losses and 268 controls were tested for protein C, protein S, factor V Leiden (FVL), antithrombin and anticardiolipin (immunoglobulin M and G) antibodies, and the odds ratio and P‐values were calculated.Results:  The mean age was 28.0 ± 4.4 years in the cases and 32.0 ± 8.0 years in the controls. The mean number of abortions among women with recurrent losses was 3.40 ± 1.23. The mean parity was 1.04 ± 1.23 (range 1–6), and 3.27 ± 2.51 among controls. Among women with recurrent pregnancy loss, 22 (42%) had first trimester losses, 19 (36%) had second trimester losses, and 11 (21%) women had both first and second trimester losses. Protein C deficiency was identified in three out of 52 cases and 18 out of 268 controls (P‐value 0.49), protein S deficiency in two cases and 12 controls (P‐value 0.35), factor V Leiden mutation in 10 cases and 27 controls (P = 0.059), antithrombin in one case and 41 controls (P = 0.009), and anticardiolipin antibodies in one case and nine controls (P = 0.49).Conclusion:  No significant association between inherited thrombophilia and recurrent pregnancy loss in Pakistani women was found.
Hand hygiene compliance and irritant dermatitis: a juxtaposition of healthcare issues
Authors: Visscher M. O. , Randall Wickett R. 
Published: June 2012

SynopsisReduction and prevention of health care‐associated infections is a worldwide priority with emphasis on increasing hand hygiene compliance. Repetitive exposure to hand hygiene products and procedures is a significant factor in the development of occupational irritant hand dermatitis. Compliance has been difficult to achieve often due to skin irritation. The introduction of alcohol hand rubs has positively influenced compliance but rates remain lower than required. Genetic and environmental factors to the frequency and severity of irritant contact dermatitis have been identified. Because of the skin's role in innate immunity, maintenance of epidermal integrity is a key strategy for reducing health care‐associated infections. In this review, we examine the interdependence of the two issues and the challenges of simultaneously accomplishing both goals. We emphasize research conducted among healthcare workers in their clinical settings. The factors that influence skin integrity and the challenges in meeting both goals simultaneously are explored. Cosmetic scientists have played key roles in the development of improved skin care products, and the issues present an excellent opportunity for them to provide potentially life‐saving contributions to health care.
7,8‐dihydroxyflavone rescues spatial memory and synaptic plasticity in cognitively impaired aged rats
Authors: Zeng Yan , Lv Feng , Li Long , Yu Hui , Dong Min , Fu Qinghai 
Published: June 2012

J. Neurochem. (2012) 122, 800–811.Abstract7,8‐dihydroxyflavone (7,8‐DHF) has recently been identified as a potential TrkB agonist that crosses the blood–brain barrier after i.p. administration. We previously demonstrated that 7,8‐DHF in vitro rescues long‐term synaptic plasticity in the hippocampus of aged rats. This study assessed the rescue effect of 7,8‐DHF in vivo on aging‐related cognitive impairment in rats, and further determined whether the effect of 7,8‐DHF is age dependent. Aged rats at 22 and 30 months of age were pretested for spatial memory in Morris water maze. The aged‐impaired rats were retested twice during 7,8‐DHF or vehicle treatment, which started 3 weeks after the completion of the pretest. In the 22‐month‐old rats, daily i.p. administration of 7,8‐DHF for 2 weeks improved spatial memory. The improvement in behavioral tests was associated with increases in synapse formation and facilitation of synaptic plasticity in the hippocampus, as well as the activation of several proteins crucial to synaptic plasticity and memory. A more extended treatment paradigm with 7,8‐DHF was required to achieve a significant memory improvement in the severely impaired 30‐month‐old rats. Moreover, 7,8‐DHF moderately facilitated the synaptic plasticity, modified the density but not number of spines in the hippocampus of the oldest rats. Taken together, our results suggest that 7,8‐DHF can act in vivo to counteract aging‐induced declines in spatial memory and synaptic plasticity and morphological changes of hippocampal neurons. The effect of 7,8‐DHF is more pronounced in relatively younger impaired rats than in those of more advanced age. These findings demonstrate the reversal of age‐dependent memory impairment by in vivo 7,8‐DHF application and support the benefit of early treatment for cognitive aging.
Back‐loading: A Potential Side Effect of Employing Digital Design Tools in New Product Development
Authors: Fixson Sebastian K. , Marion Tucker J. 
Published: June 2012

Over the past 20 years, the use of digital design tools such as Computer‐Aided‐Design (CAD) has increased dramatically. Today, almost no product development project is conducted without the use of CAD models. Major advantages typically ascribed to using CAD include better solutions through broader exploration of the solution space as well as faster and less expensive projects through faster and earlier iterations. This latter effect, the shifting of simulation and testing traditionally accomplished with the help of physical prototypes late in the process—a slow and expensive activity—to doing similar activities with virtual prototypes faster and earlier in the process, has been identified as a key aspect of front‐loading, an activity shift promising to enable superior product development (PD) performance.Given CAD's recent pervasive use, the research questions for this paper became “how has CAD use actually changed the way in which product development is conducted, and through which mechanisms and pathways can CAD impact PD performance, especially with respect to the idea of front‐loading?” This paper addresses these questions by studying in a longitudinal comparison in detail two similar product development projects, one conducted in 2001, the other in 2009. The projects were carefully selected to isolate the substantially higher levels of CAD use of the second project while controlling for most other input factors that influence project performance.The project with substantially higher use of CAD exhibited significant improvements in prototyping costs but only marginal changes in project time and project engineering labor cost relative to the project with lower CAD use. In‐depth intra‐project analysis on the phase level reveals that the use of CAD affected how the product development was executed, with both positive and negative consequences. In addition to, and separate from positive aspects of front‐loading, unintended consequences in the form of back‐loading work are also observed. Back‐loading can occur in two places in the product development process: First, the availability of CAD systems can cause an early jump into detail design, effectively shortcutting concept development. Second, the ability to relatively quickly conduct small changes virtually to the design can erode process discipline; late changes are made simply because they are possible. Both of these effects back‐load work in the opposite direction of the positive front‐loading. The theoretical implications of our observations are discussed, and a simple framework to convert our findings into managerial advice is proposed.
Influence of Magnetic Field Annealing on Magnetic Behaviors of La0.6Sr0.4MnO3 Particles
Authors: Zi Zhenfa , Liu Qiangchun , Cheng Yulan , Dai Jianming , Sun Yuping 
Published: June 2012

La0.6Sr0.4MnO3 particles were prepared using the sol‐gel method with an external magnetic field (Hext = 4 kOe) and without an external magnetic field. Structural and magnetic properties were systematically investigated. X‐ray powder diffraction results show that both samples are single‐phase. The results of field‐emission scanning electronic microscopy show that the mean particle size of the sample synthesized under Hext = 4 kOe are slightly larger than that of the sample without an external magnetic field. The enhanced magnetic properties are attributed to the less disordered defects induced by an external magnetic field.