bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is seed conditioning essential for Orobanche germination?
Authors: Plakhine Dina , Ziadna Hammam , Joel Daniel M 
Published: February 2009

AbstractBACKGROUND: Parasitic Orobanchaceae germinate only after receiving a chemical stimulus from roots of potential host plants. A preparatory phase of several days that follows seed imbibition, termed conditioning, is known to be required; thereafter the seeds can respond to germination stimulants. The aim of this study was to examine whether conditioning is essential for stimulant receptivity.RESULTS: Non‐conditioned seeds of both Orobanche cumana Wallr. and O. aegyptiaca Pers. [syn. Phelipanche aegyptiaca (Pers.) Pomel] were able to germinate in response to chemical stimulation by GR24 even without prior conditioning. Stimulated seeds reached maximal germination rates about 2 weeks after the onset of imbibition, no matter whether the seeds had or had not been conditioned before stimulation. Whereas the lag time between stimulation and germination response of non‐conditioned seeds was longer than for conditioned seeds, the total time between imbibition and germination was shorter for the non‐conditioned seeds. Unlike the above two species, O. crenata Forsk. was found to require conditioning prior to stimulation.CONCLUSIONS: Seeds of O. cumana and O. aegyptiaca are already receptive before conditioning. Thus, conditioning is not involved in stimulant receptivity. A hypothesis is put forward, suggesting that conditioning includes (a) a parasite‐specific early phase that allows the imbibed seeds to overcome the stress caused by failing to receive an immediate germination stimulus, and (b) a non‐specific later phase that is identical to the pregermination phase between seed imbibition and actual germination that is typical for all higher plants. Copyright © 2009 Society of Chemical Industry
Molecular genetics of race‐specific resistance of cowpea to Striga gesnerioides (Willd.)
Authors: Li Jianxiong , Lis Karolina E , Timko Michael P 
Published: February 2009

AbstractCowpea, Vigna unguiculata (L.) Walp., is an important warm‐season legume grown primarily in the semi‐arid tropics. The majority of cowpea is grown by subsistence farmers in West and Central sub‐Saharan Africa, where its grain and leaves are valued as human food and its stover is used for animal forage. Like all crop plants, cowpea is subject to yield losses resulting from a variety of biotic and abiotic stresses. Among the important biotic constraints to cowpea production is parasitism by the root hemiparasitic weeds Striga gesnerioides (Willd.) [witchweed] and Alectra vogelii (Benth.). At least seven races of S. gesnerioides have been identified within the cowpea‐growing regions of West Africa, based on host differential response and genetic diversity analysis. Several race‐specific resistance genes have been identified and located to one of two linkage groups (LG1 and LG6) of the current cowpea genetic map. Molecular markers associated with race‐specific resistance genes have been identified, and several sequence‐confirmed amplified regions (SCARs) have been developed for use in marker‐assisted selection and breeding strategies for rapid cowpea improvement. The mechanism of race‐specific resistance in the cowpea‐Striga interaction has also been examined, with several genes involved in phytohormone and general disease resistance signaling transduction observed to be differentially expressed in resistant and susceptible phenotypes. Results suggest that PR5 expression may be a useful marker of Striga infection, and that salicylic acid signaling appears to play a role in the cowpea–Striga interaction. Copyright © 2009 Society of Chemical Industry
Causes and recommended management of acute diarrhoea
Authors: Pasha Yasmin , Banks Matthew , Farthing Michael 
Published: February 2009

AbstractAlthough usually mild and self‐limiting, acute diarrhoea in some patients will require early medical intervention or even hospitalisation. In our Drug review, the authors discuss the aetiology and recommended management of acute diarrhoea, followed by a review of the prescription data and sources of further information. Copyright © 2009 Wiley Interface Ltd
Single‐scattering properties of aggregates of plates
Authors: Um Junshik , McFarquhar Greg M. 
Published: February 2009

AbstractDuring the 2006 Tropical Warm Pool International Cloud Experiment (TWP‐ICE) sponsored by the Atmospheric Radiation Measurement programme, the Scaled Composites Proteus aircraft executed spiral profiles and flew horizontal legs through aging anvils, fresh anvils, and cirrus of unknown origin in the vicinity of Darwin, Australia. Pristine ice crystals including both plates and bullet rosettes, their aggregates, and unclassifiable ice crystals were observed by a Cloud Particle Imager. The widths of observed plates ranged between 80 µm and 200 µm. When a fresh dissipating anvil was observed on 2 February, aggregates of plates contributed 46.2% of the total area of measured ice crystals with maximum dimensions greater than 200 µm, while it was only 7.2% and 1.0% for 27 and 29 January, respectively, when aged cirrus was sampled. Because aggregates of plates have been observed to make large contributions to projected ice crystal area near convection during TWP‐ICE and other projects, their single‐scattering properties that have not been previously examined are investigated here.The dependence of the scattering phase function P11, asymmetry parameter g, and single‐scattering albedo ω0 on three parameters (the area ratio AR, normalized projected area An, and a newly defined aggregation index AI which varies between 0 and 1 with ice crystals with more compact shape having lower AI) defining the three‐dimensional shapes of aggregates of plates were calculated using a geometric ray‐tracing code at wavelengths λ of 0.55, 1.38 and 2.13 µm. The scattering properties depended on the crystal morphology with, for example, the g of an aggregate of plates with a high AI of 0.818 differing by + 6.89% (+6.44%; + 4.55%) from that with a lower AI of 0.378 at λ of 0.55 µm (1.38 µm; 2.13 µm), but by only + 0.29% (+0.25%; − 0.03%) from those of the component plates. The ω0 at absorbing λ increased with AI, 1 − AR, and An. Adding ray distortion to the aggregates caused a decrease in forward scattering and an increase in lateral and backward scattering, decreasing g, an effect that weakened with λ due to absorption. The aggregates of plates with low AI were more influenced by ray distortion compared to those with high AI. The dependence of scattering properties on crystal morphology noted here should be considered when computing bulk scattering properties of ice clouds to determine its importance for climate and remote‐sensing studies. Copyright © 2009 Royal Meteorological Society
Separation and characterization of clindamycin phosphate and related impurities in injection by liquid chromatography/electrospray ionization mass spectrometry
Authors: Wang Shao‐Min , Bu Shan‐Shan , Liu Hong‐Min , Li Hua‐Yu , Liu Wei , Wang Yu‐Dong 
Published: February 2009

AbstractA simple high‐performance liquid chromatography/electrospray ionization tandem mass spectrometric (HPLC/ESI‐MS/MS) method has been developed for the rapid identification of clindamycin phosphate and its degradation products or related impurities in clindamycin phosphate injection. Detection was performed by quadrupole time‐of‐flight mass spectrometry (Q‐TOFMS) via an ESI source in positive mode. Clindamycin phosphate and its related substances lincomycin, 7‐epilincomycin‐2‐phosphate, lincomycin‐2‐phosphate, clindamycin B, clindamycin B‐2‐phosphate, and clindamycin were identified simultaneously by HPLC/ESI‐MS/MS results. Based on the MS/MS spectra of their quasi‐molecular ions, the fragmentation pathways of clindamycin phosphate and its related substances were compared and proposed, which are specific and useful for the identification of the lincosamide antibiotics and related impurities. The method was rapid, sensitive and specific and can be used to identify clindamycin phosphate and its related impurities in clindamycin phosphate injection without control compounds. Copyright © 2009 John Wiley & Sons, Ltd.
Isotopomeric analysis of N2O dissolved in a river in the Tokyo metropolitan area
Authors: Toyoda Sakae , Iwai Hiroyuki , Koba Keisuke , Yoshida Naohiro 
Published: February 2009

AbstractRiver water has been suggested as a potential source of nitrous oxide (N2O), which is a greenhouse gas that is accumulating rapidly in the troposphere and which is a precursor to stratospheric NOx that depletes ozone. Previous studies on freshwater N2O sources have specifically examined estuaries where sedimentary N2O production might be important and a few points near anthropogenic nitrogen sources such as agricultural or municipal wastewater areas. Here we present the first observation of a temporal and horizontal distribution of N2O and its isotopomers between the midstream and estuary of an urban river. Surface water was supersaturated (100–6800%) with N2O at all stations during the study period. The average or maximum saturation value was greater than described in most previous reports. High N2O concentrations were observed near sewage plants and the unique signature of isotopomer ratios implied direct N2O addition from the plants. The isotopomer ratios also suggested N2O production/consumption at the sediment‐water interface. Fluxes and isotopomer ratios of N2O, from the river to the atmosphere, estimated from our observations, indicated that the urban river is indeed a source of atmospheric N2O and that its production could be distinguished from other natural or anthropogenic sources using isotopomer ratios. Copyright © 2009 John Wiley & Sons, Ltd.
Rate limited stabilization: Sub‐optimal encoder–decoder schemes
Authors: Lopez Hurtado I. , Abdallah C. T. 
Published: February 2009

AbstractWe extend in this paper results from packet‐based control theory and present sufficient conditions on the rate of a packet network to guarantee asymptotic stabilizability of unstable discrete LTI systems with less inputs than states. We use a truncation‐based encoder/decoder scheme and two types of network control systems are considered in the absence of communication delays, then for one of the two types, the case of a constant time delay is discussed. For one of the network types, we also propose a zoom‐in‐type dynamic quantizer scheme with lower data rate but a more complex encoding scheme than the truncation‐based one. The new dynamic quantizer requires a lower data rate to achieve stabilization, and while it does not achieve the minimum data rate given by the Data Rate Theorem, it uses an encoding algorithm that is simpler than others reported in the literature. Copyright © 2009 John Wiley & Sons, Ltd.
Signal reconstruction in the presence of finite‐rate measurements: finite‐horizon control applications
Authors: Sarma Sridevi V. , Dahleh Munther A. 
Published: February 2009

AbstractIn this paper, we study finite‐length signal reconstruction over a finite‐rate noiseless channel. We allow the class of signals to belong to a bounded ellipsoid and derive a universal lower bound on a worst‐case reconstruction error. We then compute upper bounds on the error that arise from different coding schemes and under different causality assumptions. When the encoder and decoder are noncausal, we derive an upper bound that either achieves the universal lower bound or is comparable to it. When the decoder and encoder are both causal operators, we show that within a very broad class of causal coding schemes, memoryless coding prevails as optimal, imposing a hard limitation on reconstruction. Finally, we map our general reconstruction problem into two important control problems in which the plant and controller are local to each other, but are together driven by a remote reference signal that is transmitted through a finite‐rate noiseless channel. The first problem is to minimize a finite‐horizon weighted tracking error between the remote system output and a reference command. The second problem is to navigate the state of the remote system from a nonzero initial condition to as close to the origin as possible in finite‐time. Our analysis enables us to quantify the tradeoff between time horizon and performance accuracy, which is not well studied in the area of control with limited information as most works address infinite‐horizon control objectives (e.g. stability, disturbance rejection). Copyright © 2009 John Wiley & Sons, Ltd.
Systematically missing confounders in individual participant data meta‐analysis of observational cohort studies
Authors:   The Fibrinogen Studies Collaboration
Published: February 2009

AbstractOne difficulty in performing meta‐analyses of observational cohort studies is that the availability of confounders may vary between cohorts, so that some cohorts provide fully adjusted analyses while others only provide partially adjusted analyses. Commonly, analyses of the association between an exposure and disease either are restricted to cohorts with full confounder information, or use all cohorts but do not fully adjust for confounding. We propose using a bivariate random‐effects meta‐analysis model to use information from all available cohorts while still adjusting for all the potential confounders. Our method uses both the fully adjusted and the partially adjusted estimated effects in the cohorts with full confounder information, together with an estimate of their within‐cohort correlation. The method is applied to estimate the association between fibrinogen level and coronary heart disease incidence using data from 154 012 participants in 31 cohorts.†One hundred and ninety‐nine participants from the original 154 211 withdrew their consent and have been removed from this analysis. Copyright © 2009 John Wiley & Sons, Ltd.
Propensity score estimation with missing values using a multiple imputation missingness pattern (MIMP) approach
Authors: Qu Yongming , Lipkovich Ilya 
Published: February 2009

AbstractPropensity scores have been used widely as a bias reduction method to estimate the treatment effect in nonrandomized studies. Since many covariates are generally included in the model for estimating the propensity scores, the proportion of subjects with at least one missing covariate could be large. While many methods have been proposed for propensity score‐based estimation in the presence of missing covariates, little has been published comparing the performance of these methods. In this article we propose a novel method called multiple imputation missingness pattern (MIMP) and compare it with the naive estimator (ignoring propensity score) and three commonly used methods of handling missing covariates in propensity score‐based estimation (separate estimation of propensity scores within each pattern of missing data, multiple imputation and discarding missing data) under different mechanisms of missing data and degree of correlation among covariates. Simulation shows that all adjusted estimators are much less biased than the naive estimator. Under certain conditions MIMP provides benefits (smaller bias and mean‐squared error) compared with existing alternatives. Copyright © 2009 John Wiley & Sons, Ltd.
A comparative study on e‐learning technologies and products: from the East to the West
Authors: Liu Yanping , Wang Hong 
Published: February 2009

AbstractAmong the many technologies that support knowledge management, electronic learning or e‐learning has become as popular as business intelligence. Along with the rapid development of modern communications and information technology and the increasing demand for building and maintaining business continuity capabilities, e‐learning has emerged into a viable solution for continuous, on‐demand training and organizational learning. It becomes critical for organizations to design and develop an effective e‐learning system by using well‐researched theories and technologies that fit their organizational environment. As we discovered in our study, a successful e‐learning system is supported by many critical success factors (CSFs), and technology is the key factor among the CSFs. We also conducted a comparative study on e‐learning theories, technologies and products from the perspectives of both western practitioners and Chinese counterparts. Due to the rapid economic development in China and its fast adoption of communications and information technology, the ways Chinese practitioners are developing e‐learning theories, technologies and products have inevitably become a focal point in the world of information technology. Through the analysis of the current e‐learning technologies and products, we outline the trends of developing e‐learning systems and emphasize the importance of proper theories in guiding e‐learning systems development. Copyright © 2009 John Wiley & Sons, Ltd.
Erratum to ‘empirical approximation for Lα production cross sections’[X‐ray Spectrumetry 37, 188–192, 2008]
Authors: Šmith Ž. , Tancek A. 
Published: February 2009

AbstractThe original article to which this Erratum refers was published in X‐ray Spectrumetry, 37, 188–192, 2008
Omission of Nasogastric Tube Application in Postoperative Care of Esophagectomy
Authors: Daryaei Parviz , Vaghef Davari Farzad , Mir Mohammadreza , Harirchi Iraj , Salmasian Hojjat 
Published: February 2009

AbstractIntroductionSurgeons routinely use nasogastric (NG) tubes in most esophageal resection surgeries. Considering the numerous complications caused by using the tube and the uncertainty about its usefulness and the scarcity of studies conducted on the subject, particularly in patients with esophageal cancer, the necessity of using the tube in these types of cases is investigated in the present study.MethodsIn this clinical trial, patients with esophageal cancer were randomized into groups with NG tube and without NG tube after surgery; the latter were prescribed Metoclopramide, as well. The variables recorded for each patient included the first day of gas passage, defecation and bowel sounds (BSs) auscultation, as well as the duration of postoperative hospitalization, nausea and vomiting, abdominal distension, pulmonary complications, wound complications, anastomosis leak, and the need for placing/replacing the NG tube.ResultsThe incidence of anastomosis leak was significantly higher in the NG‐tube group (6 vs. 0; P = 0.016). Other complications were not different in the two groups. The mean time of gas passage, defecation, BS auscultation, and the duration of postoperative hospitalization did not have meaningful differences in the two groups. The need for placing/replacing the NG tube was the same for both groups.ConclusionsThe routine application of NG tubes after surgery is not recommended for all patients. We suggest that NG tubes should be used according to the specific problems of each patient.
Video‐Assisted Minimally Invasive Parathyroidectomy: Benefits and Long‐Term Results
Authors: Lombardi Celestino P. , Raffaelli Marco , Traini Emanuela , De Crea Carmela , Corsello Salvatore M. , Bellantone Rocco 
Published: February 2009

AbstractBackgroundIn recent years several endoscopic and video‐assisted techniques for parathyroidectomy have been described. The role of these techniques, with respect to time‐honored conventional surgery, has been largely debated. This paper was designed to review the evidence, and make the recommendations, for the video‐assisted/endoscopic approach to parathyroidectomy.MethodsA database search was conducted in PubMed from which abstracts were screened matching our definition. Publications were further assessed and assigned their respective level of evidence. Additional data were obtained on the basis of our personal experience.ResultsThirty‐eight mainly retrospective studies have been published. Only four small, prospective, randomized trials, providing level II evidence, and one retrospective case‐control comparative study, providing level IV evidence, have been found. Minimally invasive video‐assisted parathyroidectomy (MIVAP) has emerged as one of the leading techniques. To date several randomized studies have shown that MIVAP is an efficacious and feasible procedure with the same complications rate as conventional surgery. Moreover, MIVAP seems to have significant advantages in terms of cosmetic result, postoperative pain and recovery, and patient satisfaction.ConclusionsFrom an evidence‐based point of view, MIVAP should be considered a valid and validated option for the treatment of sporadic primary hyperparathyroidism sustained by a well‐localized, single adenoma. Its role for the treatment of multiglandular diseases (familial hyperparathyroidism, secondary hyperparathyroidism) needs to be better clarified.
Mortality Impact of Hypothermia After Cavitary Explorations in Trauma
Authors: Inaba Kenji , Teixeira Pedro G. R. , Rhee Peter , Brown Carlos , Salim Ali , DuBose Joseph , Chan Linda S. , Demetriades Demetrios 
Published: February 2009

AbstractBackgroundAdmission hypothermia (core temperature ≤ 35°C) is an independent risk factor for mortality after trauma. The predictive value of perioperative core temperatures during acute trauma surgery, however, although widely employed as a criterion for initiating damage control, is unknown. We hypothesized that for trauma patients undergoing laparotomy or thoracotomy, early postoperative hypothermia is a predictor of mortality.MethodsAfter institutional review board (IRB) approval, all critically ill trauma patients undergoing cavitary surgery (laparotomy or thoracotomy) at a level 1 trauma center from 01/1998 to 07/2006 were identified from the trauma registry. Immediate postoperative core temperature (Tc) was used to classify patients as hypothermic (Tc ≤ 35°C) or normothermic (Tc > 35°C). The profoundly hypothermic subgroup of patients with a Tc < 33°C was also analyzed.ResultsDuring the study period, 2,489 patients required cavitary surgery, 1,252 of whom (50%) were admitted to the intensive care unit (ICU). On arrival in the ICU 15% of the patients had a Tc ≤ 35°C and were more likely to be ≥ 55 years old (12% versus 7%; p = 0.04); in addition, they were hypotensive on admission (25% versus 13%; p < 0.001), had a lower admission Glasgow Coma Score (GCS; 11 ± 5 versus 14 ± 3; p < 0.001), a higher Injury Severity Score (ISS; 29 ± 15 versus 22 ± 12; p < 0.001), higher head and chest Abbreviated Injury Scale (AIS), and greater intraoperative blood loss (2.6 ± 2.4 l versus 1.7 ± 1.8 l; p < 0.001). When compared to patients who were normothermic at the end of their operation, hypothermic patients had a significantly higher mortality (35% versus 8%; p < 0.001). With decreasing Tc, there was a stepwise increase in mortality. Compared to patients with a Tc > 35°C, the relative risk of death for patients with a Tc between 35°C and 33°C was 4.0, and that for patients with a Tc ≤ 33°C it was 7.1. After adjusting for multiple differences between groups, postoperative hypothermia remained an independent predictor of mortality (adjusted odds ratio [OR] 3.2; 95% confidence interval [CI] 1.9–5.3; p < 0.001).ConclusionsPostoperative hypothermia is common in critically injured patients requiring cavitary surgery and is an independent predictor of mortality. The impact of measures to maintain or restore normothermia in the operating room warrants further investigation.