bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dissecting the THz spectrum of liquid water from first principles via correlations in time and space
Authors: Heyden Matthias , Sun Jian , Funkner Stefan , Mathias Gerald , Forbert Harald , Havenith Martina , Marx Dominik 
Published: June 2010

Solvation of molecules in water is at the heart of a myriad of molecular phenomena and of crucial importance to understanding such diverse issues as chemical reactivity or biomolecular function. Complementing well-established approaches, it has been shown that laser spectroscopy in the THz frequency domain offers new insights into hydration from small solutes to proteins. Upon introducing spatially-resolved analyses of the absorption cross section by simulations, the sensitivity of THz spectroscopy is traced back to characteristic distance-dependent modulations of absorption intensities for bulk water. The prominent peak at ≈200 cm
-1
is dominated by first-shell dynamics, whereas a concerted motion involving the second solvation shell contributes most significantly to the absorption at about 80 cm
-1
≈2.4 THz. The latter can be understood in terms of an umbrella-like motion of two hydrogen-bonded tetrahedra along the connecting hydrogen bond axis. Thus, a modification of the hydrogen bond network, e.g., due to the presence of a solute, is expected to affect vibrational motion and THz absorption intensity at least on a length scale that corresponds to two layers of solvating water molecules. This result provides a molecular mechanism explaining the experimentally determined sensitivity of absorption changes in the THz domain in terms of distinct, solute-induced dynamical properties in solvation shells of (bio)molecules—even in the absence of well-defined resonances.
Does it Matter? Primary Teacher Trainees' Subject Knowledge in Mathematics
Authors: Goulding Maria , Rowland Tim , Barber Patti 
Published: June 2010

AbstractThe mathematical subject knowledge of primary teacher trainees in England and Wales now has to be audited in line with government requirements for initial teacher training. This article examines how this knowledge has been conceptualised and presents the results of research in two institutions into the audited subject knowledge of primary teacher trainees and its relationship with classroom teaching. The research identified weaknesses in understanding, particularly in the syntactic elements of mathematics, and a link between insecure subject knowledge and poor planning and teaching. The dilemmas and policy issues which this focus on subject knowledge presents are discussed.
Identifying the Probable Timing and Setting of Respiratory Virus Infections
Authors: Lessler Justin , Brookmeyer Ron , Reich Nicholas G. , Nelson Kenrad E. , Cummings Derek A. T. , Perl Trish M. 
Published: June 2010

Objective.Show how detailed incubation period estimates can be used to identify and investigate potential healthcare-associated infections and dangerous diseases.Methods.We used the incubation period of 9 respiratory viruses to derive decision rules for distinguishing between community- and hospital-acquired infection. We developed a method, implemented in a simple spreadsheet, that can be used to investigate the exposure history of an individual patient and more specifically to identify the probable time and location of infection. Illustrative examples are used to explain and evaluate this technique.Results.If the risks of hospital and community infection are equal, 95% of patients who develop symptoms of adenovirus infection within 5 days of hospital admission will have been infected in the community, as will 95% of patients who develop symptoms within 3 days for human-coronavirus infection, 2.5 days for severe acute respiratory syndrome, 1 day for influenza A, 0.5 day for influenza B, 12 days for measles, 2 days for parainfluenza, 4 days for respiratory syncytial virus infection, and 1.5 days for rhinovirus infection. Sources of infection suggested by analysis of the symptom onset times of individual patients are consistent with those from detailed investigations.Conclusions.This work shows how a detailed understanding of the incubation period can be an effective tool for identifying the source of infection, ultimately ensuring patient safety.
Changing Indications for Upper Endoscopy in Children During a 20‐year Period
Authors: Franciosi James P , Fiorino Kristin , Ruchelli Eduardo , Shults Justine , Spergel Jonathan , Liacouras Chris A , Leonard Mary 
Published: June 2010

ABSTRACTObjectives:In parallel with the increase in pediatric esophagogastroduodenoscopy (EGD) procedures since the 1970s, the incidence of disorders that require EGD for diagnosis in children has increased. The aim of this study was to identify changes in subject characteristics and endoscopic procedures during a 20‐year interval in children undergoing EGD at a single center.Patients and Methods:All of the children undergoing first EGD with biopsy in 1985, 1995, or 2005 were identified. Details of the clinical presentation and EGD were abstracted from medical records in a random sample of subjects within each time point.Results:The number of first‐time EGDs rose dramatically from 107 in 1985 to 1294 in 2005. The proportion of subjects that were younger than 1 year of age varied significantly from 13% in 1985 to 23% in 1995 and 8% in 2005 (P < 0.001). The proportion of subjects with gastrointestinal (GI) bleeding declined from 34% to 5% during the 20‐year interval (P < 0.001), whereas the proportion with abdominal pain increased from 23% to 43% (P < 0.01). During the same interval, the proportion of subjects with complete EGD (biopsies from the esophagus, stomach, and duodenum) increased from 18% of EGDs in 1985 to 95% in 2005 (P < 0.001).Conclusions:This study of children undergoing first‐time EGDs with biopsy during a 20‐year interval demonstrated significant differences in subject characteristics and endoscopy practices. The inclusion of children with less severe clinical presentation and the collection of greater numbers of biopsies per procedure may contribute to the rising incidence rates of pediatric GI disorders.
Role of Small Bowel Follow‐through in Diagnosing Inflammation of the Terminal Ileum in Pediatric Patients
Authors: Stenerson Matthew , Vittinghoff Eric , Heyman Melvin B , Kim Grace E , Gupta Neera 
Published: June 2010

ABSTRACTBackground:The small bowel follow‐through (SBFT) is a noninvasive imaging modality for evaluating terminal ileum (TI) inflammation. The accuracy of this modality in pediatric patients is not well established.Patients and Methods:We retrospectively determined the sensitivity and specificity of SBFT for detecting TI inflammation diagnosed on histology in 93 pediatric patients studied in a single institution.Results:The mean age at the first study was 12.9 years (range 1.1–20.9 years). Forty‐five percent were girls. Twenty‐five patients (27%) had abnormal TIs on SBFT. Seventeen patients (18%) had TI inflammation diagnosed by biopsy. The sensitivity of SBFT was 59% and the specificity was 80% for detecting TI inflammation diagnosed on histology. Sensitivity and specificity did not change by demographic factors, final diagnoses, presenting symptoms, or laboratory parameters, reflecting the presence of intestinal inflammation.Conclusions:The sensitivity and specificity of SBFT in pediatric patients were poor and did not vary with demographic factors, final diagnoses, presenting symptoms, or laboratory parameters. Prospective longitudinal studies comparing various imaging modalities (SBFT, magnetic resonance enterography, and capsule endoscopy) are required to determine which is the most effective tool for evaluating pediatric patients for TI inflammation.
Anastomotic Strictures Following Esophageal Atresia Repair: A 20‐year Experience With Endoscopic Balloon Dilatation
Authors: Antoniou Dimitris , Soutis Michael , Christopoulos‐Geroulanos George 
Published: June 2010

ABSTRACTObjectives:The aim of the study was to evaluate the safety, effectiveness, and long‐term results of endoscopic balloon dilatation in children with anastomotic strictures following esophageal atresia (EA) repair.Patients and Methods:From January 1988 to January 2008, 59 patients were treated with balloon dilatation for anastomotic stricture following EA repair. Indication for dilatation was dysphagia of varying degree. Outcome parameters included the number of dilatations, response to dilatation, effectiveness, and complications. Response to dilatation was considered excellent when there was no need for any additional dilatation for recurrent dysphagia, satisfactory when up to 5 dilatations were required, and fair when >5 sessions were required. The treatment was considered effective when dysphagia was grade 0 or 1 for >12 months after the last dilatation session.Results:A total of 165 balloon dilatations were undertaken, with an average of 279 per patient (range 1–9). Age range at diagnosis was 1 to 36 months (mean 10.5). Response to dilatation was excellent in 21 cases (35.6%), satisfactory in 26 (44.1%), and fair in 12 (20.3%). The treatment was effective in 47 patients (79.7%) and ineffective in 12 (20.3%). The median follow‐up period was 19.5 months. Four patients underwent surgery; in 1 patient a retrievable stent was placed. No perforation occurred.Conclusions:Endoscopic balloon dilatation can be accomplished safely and effectively as a first‐line therapy for the management of anastomotic strictures following EA repair.
Structure determination of the minimal complex between Tfb5 and Tfb2, two subunits of the yeast transcription/DNA-repair factor TFIIH: a retrospective study
Authors: Kainov Denis E. , Cura Vincent , Vitorino Marc , Nierengarten Helène , Poussin Pierre , Kieffer Bruno , Cavarelli Jean , Poterszman Arnaud 
Published: June 2010

Tfb5 interacts with the Tfb2 subunit of the general transcription factor TFIIH to ensure efficient nucleotide-excision repair in eukaryotes. The crystal structure of the complex between Tfb5 and the C-terminal region of Tfb2 (Tfb2C) fromSaccharomyces cerevisiaehas recently been reported. Here, the structure-determination process is described as a case study. Although crystals were obtained readily, it was not possible to determine experimental phases from a first crystal form (Tfb2412–513–Tfb52–72) that diffracted to 2.6 Å resolution. Shortening of the Tfb2C from its N-terminus was decisive and modified the crystal packing, leading to a second crystal form (Tfb2435–513–Tfb52–72). These crystals diffracted to 1.7 Å resolution with excellent mosaicity and allowed structure determination by conventional approaches using heavy atoms. The refined structure from the second crystal form was used to solve the structure of the first crystal form by molecular replacement. Comparison of the two structures revealed that the N-terminal region of Tfb2C and (to a lesser extent) the C-terminal region of Tfb5 contributed to the crystal packing. A detailed analysis illustrates how variation in domain boundaries influences crystal packing and quality.
Ficus racemosa is pollinated by a single population of a single agaonid wasp species in continental South‐East Asia
Authors: KOBMOO N. , HOSSAERT‐MCKEY M. , RASPLUS J. Y. , KJELLBERG F. 
Published: June 2010

AbstractHigh specificity in the Ficus‐agaonid wasp mutualism has lead to the assumption of a mostly ‘one‐to‐one’ relationship, albeit with some exceptions. This view has been challenged by new molecular data in recent years, but surprisingly little is known about local and spatial genetic structuring of agaonid wasp populations. Using microsatellite markers, we analysed genetic structuring of Ceratosolen fusciceps, the fig wasp pollinating Ficus racemosa, a fig tree species widely distributed from India to Australia. In sampling stretching from the south of China to the south of Thailand we found evidence for only a single pollinating wasp species in continental South‐East Asian mainland. We found no evidence for the co‐occurrence of cryptic species within our subcontinent sampling zone. We observed no spatial genetic structure within sites and only limited structuring over the whole sampling zone, suggesting that F. racemosa is pollinated by a single population of a single agaonid wasp species all over continental South‐East Asia. An additional sample of wasps collected on F. racemosa in Australia showed clear‐cut genetic differentiation from the Asian continent, suggesting allopatric divergence into subspecies or species. We propose that the frequent local co‐occurrence of sister species found in the literature mainly stems from contact zones between biogeographic regions, and that a single pollinator species over wide areas might be the more common situation everywhere else.
Macrogeographic population structuring in the cosmopolitan agricultural pest Bactrocera cucurbitae (Diptera: Tephritidae)
Authors: VIRGILIO M. , DELATTE H. , BACKELJAU T. , DE MEYER M. 
Published: June 2010

AbstractThe macrogeographic population structure of the agricultural pest Bactrocera cucurbitae (Diptera: Tephritidae) was investigated in order to identify the geographic origin of the species and reconstruct its range expansion. Individuals of B. cucurbitae were collected from 25 worldwide‐distributed localities (n = 570) and genotyped at 13 microsatellite loci. The Bayesian clustering reveals that B. cucurbitae can be subdivided into five main groups corresponding to populations from (i) the African continent, (ii) La Réunion, (iii) Central Asia, (iv) East Asia and (v) Hawaii. The proportions of inter‐regional assignments and the higher values of genetic diversity in populations from Pakistan, India and Bangladesh suggest that B. cucurbitae originated in Central Asia and expanded its range to East Asia and Hawaii on one hand and to Africa and the islands of the Indian Ocean on the other. A number of outliers (10–19 specimens according to different clustering algorithms) show high levels of admixture (Q > 0.70) with populations from different regions and reveal complex patterns of inter‐regional gene flow. Anthropogenic transport is the most plausible promoter of this large‐scale dispersal. The introduction of individuals from geographically distant sources did not have a relevant role in the most recent African invasions, which originated from the expansion of local populations. These results could provide a useful background to better evaluate invasion risks and establish priorities for the management of this cosmopolitan agricultural pest.
Structure‐function analysis of npr1 alleles in Arabidopsis reveals a role for its paralogs in the perception of salicylic acid
Authors: CANET JUAN VICENTE , DOBÓN ALBOR , ROIG ALEJANDRA , TORNERO PABLO 
Published: June 2010

ABSTRACTSalicylic acid (SA) is necessary for plant defence against some pathogens, whereas NPR1 is necessary for SA perception. Plant defence can be induced to an extreme by several applications of benzothiadiazole (BTH), an analogue of SA. Thus, plants that do not perceive BTH grow unaffected, whereas wild‐type plants grow stunted. This feature allows us to screen for mutants in Arabidopsis thaliana that show insensitivity to BTH in a high‐throughput fashion. Most of the mutants are npr1 alleles, with similar phenotypes in plant weight and pathogen growth. The mutations are clustered in the carboxyl‐terminal part of the protein, and no obvious null alleles were recovered. These facts have prompted a search for knockouts in the NPR1 gene. Two of these KO alleles identified are null and have an intermediate phenotype. All the evidence presented lead us to propose a redundancy in SA perception, with the paralogs of NPR1 taking part in this signalling. We show that the mutations recovered in the screening genetically interact with the paralogs preventing their function in SA signalling.
Can the progressive increase of C4 bundle sheath leakiness at low PFD be explained by incomplete suppression of photorespiration?
Authors: KROMDIJK JOHANNES , GRIFFITHS HOWARD , SCHEPERS HANS E. 
Published: June 2010

ABSTRACTThe ability to concentrate CO2 around Rubisco allows C4 crops to suppress photorespiration. However, as phosphoenolpyruvate regeneration requires ATP, the energetic efficiency of the C4 pathway at low photosynthetic flux densities (PFD) becomes a balancing act between primary fixation and concentration of CO2 in mesophyll (M) cells, and CO2 reduction in bundle sheath (BS) cells. At low PFD, retro‐diffusion of CO2 from BS cells, relative to the rate of bicarbonate fixation in M cells (termed leakiness φ), is known to increase. This paper investigates whether this increase in ϕ could be explained by incomplete inhibition of photorespiration.The PFD response of φ was measured at various O2 partial pressures in young Zea mays plants grown at 250 (LL) and 750 µmol m−2 s−1 PFD (HL). φ increased at low PFD and was positively correlated with O2 partial pressure. Low PFD during growth caused BS conductance and interveinal distance to be lower in the LL plants, compared to the HL plants, which correlated with lower φ. Model analysis showed that incomplete inhibition of photorespiration, especially in the HL plants, and an increase in the relative contribution of mitochondrial respiration at low PFD could explain the observed increases in φ.
Continuous glucose monitoring by intravenous microdialysis
Authors: ROOYACKERS O. , BLIXT C. , MATTSSON P. , WERNERMAN J. 
Published: June 2010

Background: The conflicting results from studies over tight glucose control in intensive care unit (ICU) patients ask for a continuous on‐line real‐time glucose monitoring in future. Here, intravenous microdialysis was tested in ICU patients and healthy volunteers. Primary aims were technical feasibility and accuracy.Methods: A microdialysis catheter was inserted into a peripheral vein. ICU patients (n=10) were studied for up to 5 days. Healthy volunteers (n=6) were studied on one occasion. Recordings were monitored during 70 min each 24‐h period to allow for an estimate of variability over time. Microdialysis glucose and lactate were compared with plasma glucose and whole blood lactate. Results are presented as medians (quartiles) of the differences between microdialysis and plasma concentrations over each of the 70‐min recording periods.Results: Out of the included ICU patients, no exclusions or early terminations were due to failure of the microdialysis catheter. The concordance was highly variable. The difference of medians over the recording periods differed by −34% (−40, −16) in patients and −22% (−31, −15) for the volunteers. In contrast, the overall variability within the individual measurement periods was low.Conclusion: Technical feasibility was good, but the accuracy was not sufficient and the variability between the recording periods was high without calibrations. The non‐availability of suitable peripheral veins was a problem in many patients screened but not included in the study. Intravenous microdialysis to obtain continuous on‐line real‐time glucose monitoring is technically feasible, but accuracy needs to be improved.
DROUGHT STRESS: Physiological Basis for Genotypic Variation in Tolerance to and Recovery from Pre‐flowering Drought in Peanut
Authors: Puangbut D. , Jogloy S. , Toomsan B. , Vorasoot N. , Akkasaeng C. , Kesmala T. , Rachaputi R. C. N. , Wright G. C. , Patanothai A. 
Published: June 2010

AbstractDrought during the pre‐flowering stage can increase yield of peanut. There is limited information on genotypic variation for tolerance to and recovery from pre‐flowering drought (PFD) and more importantly the physiological traits underlying genotypic variation. The objectives of this study were to determine the effects of moisture stress during the pre‐flowering phase on pod yield and to understand some of the physiological responses underlying genotypic variation in response to and recovery from PFD. A glasshouse and field experiments were conducted at Khon Kaen University, Thailand. The glasshouse experiment was a randomized complete block design consisting of two watering regimes, i.e. fully‐irrigated control and 1/3 available soil water from emergence to 40 days after emergence followed by adequate water supply, and 12 peanut genotypes. The field experiment was a split‐plot design with two watering regimes as main‐plots, and 12 peanut genotypes as sub‐plots. Measurements of N2 fixation, leaf area (LA) were made in both experiments. In addition, root growth was measured in the glasshouse experiment. Imposition of PFD followed by recovery resulted in an average increase in yield of 24 % (range from 10 % to 57 %) and 12 % (range from 2 % to 51 %) in the field and glasshouse experiments, respectively. Significant genotypic variation for N2 fixation, LA and root growth was also observed after recovery. The study revealed that recovery growth following release of PFD had a stronger influence on final yield than tolerance to water deficits during the PFD. A combination of N2 fixation, LA and root growth accounted for a major portion of the genotypic variation in yield (r = 0.68–0.93) suggesting that these traits could be used as selection criteria for identifying genotypes with rapid recovery from PFD. A combined analysis of glasshouse and field experiments showed that LA and N2 fixation during the recovery had low genotype × environment interaction indicating potential for using these traits for selecting genotypes in peanut improvement programs.
SHORT COMMUNICATION: Effect of Salt Stress on Peruvian Germplasm of Chenopodium quinoa Willd.: A Promising Crop
Authors: Gómez‐Pando L. R. , Álvarez‐Castro R. , Eguiluz‐de la Barra A. 
Published: June 2010

AbstractSoil salinity is a major problem in today’s agriculture. Quinoa has become an important crop because it exhibits high levels of salinity tolerance. In addition, its seeds contain an excellent balance of carbohydrates, lipids, amino acids and proteins for human nutrition. The quinoa germplasm includes almost 2500 accessions, some of which have been tested under salt stress. Here, we report the effect of NaCl on the germination of 182 previously untested accessions. When seeds were irrigated with saline water at 30 dS m−1 EC, the stress appeared to be too high: all accessions showed less than 60 % germination. In contrast, irrigation with 25 dS m−1 EC saline water allowed over 60 % germination in 15 accessions. These latter accessions’ agricultural traits were then evaluated. The overall coefficients of variation indicated that quinoa genotype and salt treatment dramatically influence root dry mass per plant, but do not noticeably affect the length of the plant’s life cycle. Unexpectedly, salt treatment resulted in increased plant height, leaf dry mass and grain yield. Using Euclidean distance for the simultaneous selection of these five agricultural traits, accessions 100, 136, 127 and 105 proved to be the best performing genotypes under salt stress.