bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tropical mesopause: Is it always close to 100 km?
Authors: Venkat Ratnam M. , Patra A. K. , Krishna Murthy B. V. 
Published: March 2010

Global distribution of mesopause using observations of Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) aboard the Thermosphere‐Ionosphere‐Mesosphere Energetics and Dynamics satellite is studied with special emphasis on tropical latitudes. Temperature structure of the mesosphere and lower thermosphere over Gadanki (13.5°N, 79.2°E), a tropical latitude location in India, has been studied in detail. The mesopause altitude at Gadanki is observed to be in the range of 87–105 km with a mean of ∼98 km, and the temperature is in the range of 160–205 K with a mean of ∼170 K. A secondary temperature minimum is observed in the height region of 75–80 km with temperature in the range of 175–195 K. Although the mesopause temperature and altitude show pronounced short‐term variability, on a seasonal mean basis, the variation in these two parameters is rather small. There is no significant long‐term variation in mesopause altitude. The height of the secondary minimum, however, is found to show semiannual variation with a maximum in solstices and a minimum in equinoxes. Thus, the variabilities in the height and temperature of the mesopause and the secondary minimum reported here are different from the two‐level mesopause reported previously for middle and high latitudes. Another significant result that comes from the time series analysis of mesopause temperature is a decreasing trend with a rate of ∼0.72 ± 0.05 K/yr. Furthermore, the	long‐term mean profile of temperature does not show the secondary minimum, providing strong support that it could be due to shorter scale tides and gravity waves. The possible implications of the mesopause temperature structure on various physical processes occurring in the mesosphere and the lower thermosphere are discussed.
Site-specific recombination by φC31 integrase and other large serine recombinases
Authors: Smith Margaret C.M. , Brown William R.A. , McEwan Andrew R. , Rowley Paul A. 
Published: March 2010

Most temperate phages encode an integrase for integration and excision of the prophage. Integrases belong either to the λ Int family of tyrosine recombinases or to a subgroup of the serine recombinases, the large serine recombinases. Integration by purified serine integrases occurs efficiently in vitro in the presence of their cognate (~50 bp) phage and host attachment sites, attP and attB respectively. Serine integrases require an accessory protein, Xis, to promote excision, a reaction in which the products of the integration reaction, attL and attR, recombine to regenerate attP and attB. Unlike other directional recombinases, serine integrases are not controlled by proteins occupying accessory DNA-binding sites. Instead, it is thought that different integrase conformations, induced by binding to the DNA substrates, control protein–protein interactions, which in turn determine whether recombination proceeds. The present review brings together the evidence for this model derived from the studies on φC31 integrase, Bxb1 integrase and other related proteins.
Maintaining a sense of direction during long-range communication on DNA
Authors: Szczelkun Mark D. , Friedhoff Peter , Seidel Ralf 
Published: March 2010

Many biological processes rely on the interaction of proteins with multiple DNA sites separated by thousands of base pairs. These long-range communication events can be driven by both the thermal motions of proteins and DNA, and directional protein motions that are rectified by ATP hydrolysis. The present review describes conflicting experiments that have sought to explain how the ATP-dependent Type III restriction–modification enzymes can cut DNA with two sites in an inverted repeat, but not DNA with two sites in direct repeat. We suggest that an ATPase activity may not automatically indicate a DNA translocase, but can alternatively indicate a molecular switch that triggers communication by thermally driven DNA sliding. The generality of this mechanism to other ATP-dependent communication processes such as mismatch repair is also discussed.
Self-incompatibility in Papaver: identification of the pollen S-determinant PrpS
Authors: Poulter Natalie S. , Wheeler Michael J. , Bosch Maurice , Franklin-Tong Vernonica E. 
Published: March 2010

Many flowering plants are hermaphrodite, posing the problem of self-fertilization and the subsequent loss of the genetic fitness of the offspring. To prevent this, many plants have developed a genetically controlled mechanism called self-incompatibility (SI). When the male and female S-determinants match, self (incompatible) pollen is recognized and rejected before fertilization can occur. In poppy (Papaver rhoeas), the pistil S-determinant (PrsS) is a small secreted protein that interacts with incompatible pollen, initiating a Ca2+-dependent signalling network. SI triggers several downstream events, including depolymerization of the cytoskeleton, phosphorylation of two soluble inorganic pyrophosphatases and an MAPK (mitogen-activated protein kinase). This culminates in PCD (programmed cell death) involving several caspase-like activities. The recent discovery of the Papaver pollen S-determinant PrpS marks a significant step forward in the understanding of the Papaver SI system. PrpS encodes a ~20 kDa predicted transmembrane protein which has no homology with known proteins. It is specifically expressed in pollen, linked to the pistil S-determinant, and displays the high polymorphism expected of an S-locus determinant. The present review focuses on the discovery and characterization of PrpS which strongly support the hypothesis that Papaver SI is triggered by the interaction of PrsS and PrpS.
Regulation of plant gene expression by alternative splicing
Authors: Simpson Craig G. , Manthri Sujatha , Raczynska Katarzyna Dorota , Kalyna Maria , Lewandowska Dominika , Kusenda Branislav , Maronova Monika , Szweykowska-Kulinska Zofia , Jarmolowski Artur , Barta Andrea , Brown John W.S. 
Published: March 2010

AS (alternative splicing) is a post-transcriptional process which regulates gene expression through increasing protein complexity and modulating mRNA transcript levels. Regulation of AS depends on interactions between trans-acting protein factors and cis-acting signals in the pre-mRNA (precursor mRNA) transcripts, termed ‘combinatorial’ control. Dynamic changes in AS patterns reflect changes in abundance, composition and activity of splicing factors in different cell types and in response to cellular or environmental cues. Whereas the SR protein family of splicing factors is well-studied in plants, relatively little is known about other factors influencing the regulation of AS or the consequences of AS on mRNA levels and protein function. To address fundamental questions on AS in plants, we are exploiting a high-resolution RT (reverse transcription)–PCR system to analyse multiple AS events simultaneously. In the present paper, we describe the current applications and development of the AS RT–PCR panel in investigating the roles of splicing factors, cap-binding proteins and nonsense-mediated decay proteins on AS, and examining the extent of AS in genes involved in the same developmental pathway or process.
Structure and function of an iterative polyketide synthase thioesterase domain catalyzing Claisen cyclization in aflatoxin biosynthesis
Authors: Korman Tyler Paz , Crawford Jason M. , Labonte Jason W. , Newman Adam G. , Wong Justin , Townsend Craig A. , Tsai Shiou-Chuan 
Published: March 2010

Polyketide natural products possess diverse architectures and biological functions and share a subset of biosynthetic steps with fatty acid synthesis. The final transformation catalyzed by both polyketide synthases (PKSs) and fatty acid synthases is most often carried out by a thioesterase (TE). The synthetic versatility of TE domains in fungal nonreducing, iterative PKSs (NR-PKSs) has been shown to extend to Claisen cyclase (CLC) chemistry by catalyzing C–C ring closure reactions as opposed to thioester hydrolysis or O–C/N–C macrocyclization observed in previously reported TE structures. Catalysis of C–C bond formation as a product release mechanism dramatically expands the synthetic potential of PKSs, but how this activity was acquired has remained a mystery. We report the biochemical and structural analyses of the TE/CLC domain in polyketide synthase A, the multidomain PKS central to the biosynthesis of aflatoxin B
1
, a potent environmental carcinogen. Mutagenesis experiments confirm the predicted identity of the catalytic triad and its role in catalyzing the final Claisen-type cyclization to the aflatoxin precursor, norsolorinic acid anthrone. The 1.7 Å crystal structure displays an α/β-hydrolase fold in the catalytic closed form with a distinct hydrophobic substrate-binding chamber. We propose that a key rotation of the substrate side chain coupled to a protein conformational change from the open to closed form spatially governs substrate positioning and C–C cyclization. The biochemical studies, the 1.7 Å crystal structure of the TE/CLC domain, and intermediate modeling afford the first mechanistic insights into this widely distributed C–C bond-forming class of TEs.
Comparison of 4 Different Types of Surgical Gloves Used for Preventing Blood
Contact
Authors: Wittmann Andreas , Kralj Nenad , Köver Jan , Gasthaus Klaus , Lerch Hartmut , Hofmann Friedrich 
Published: March 2010

Background.
Needlestick injuries are always associated with a risk of infection,
because these types of punctures may expose healthcare workers to a patient's
blood and/or body fluids.

Objective.
To compare the efficacy of 4 different types of surgical gloves for
preventing exposure to blood as a result of needlestick injury.

Methods.
For simulation of needlestick injury, a circular sample of pork skin was
tightened onto a bracket, and a single finger from a medical glove was
stretched over the sample. First, a powder-free surgical glove with a gel
coating was used to test blood contact. Second, a glove with a patented
puncture indication system was used to test blood contact with a double-gloved
hand. Third, 2 powder-free latex medical gloves of the same size and hand were
combined for double gloving, again to test blood contact. Finally, we tested a
glove with an integrated disinfectant on the inside. The punctures were carried
out using diverse sharp surgical devices that were contaminated with
99Tc-marked blood. The amount of blood contact was
determined from the transmitted radioactivity.

Results.
For the powder-free surgical glove with a gel coating, a mean volume of
0.048 μL of blood (standard error of the mean [SEM], 0.077 μL.) was transferred
in punctures with an automated lancet at a depth of 2.4 mm through 1 layer of
latex. For the glove with an integrated disinfectant on the inside, the mean
volume of blood transferred was 0.030 μL (SEM, 0.0056 μL) with a single glove
and was 0.024 μL (SEM, 0.003 μL) with 2 gloves. For the glove with the patented
puncture indication system, a mean volume of 0.024 μL, (SEM, 0.003 μL) of blood
was transferred.

Conclusions.
Double gloving or the use of a glove with disinfectant can result in a
decrease in the volume of blood transferred. Therefore, the use of either of
these gloving systems could help to minimize the risk of bloodborne infections
for medical staff.
Continued adventures in open access: 2009 perspective
Authors: BIRD Claire 
Published: March 2010

ABSTRACTMany publishers have actively responded to the open access (OA) movement and have developed a variety of new models and policies as a result. Of those adopting OA models, the majority seek to cover costs through author‐side charges in the region of US$1,000–3,000. Optional or ‘hybrid’ OA models are increasingly commonplace, although most are experiencing uptake of below 10%, with some notable exceptions. Early evidence from these initiatives suggests that OA leads to an increase in online usage. Meanwhile numerous fully OA journals have launched, and a few subscription journals have made the transition to full OA. Several case studies indicate that fully OA models reliant upon author‐side charges are viable, depending on authors being able and willing to pay publication charges, and other influential factors including rejection rate. Most authors continue to rank other considerations, including speed of publication, quality of peer review, and impact factor, as more important than a journal's OA policies, although funder and university‐level mandates seem likely to have an increasing influence on an author's choice of where to publish. This article provides a number of case studies of gold OA journals – both hybrid and fully OA – with a particular focus on the sustainability of these models.
Effectiveness of cardiac resynchronization therapy in mild congestive heart failure: systematic review and meta‐analysis of randomized trials
Authors: Lubitz Steven A. , Leong‐Sit Peter , Fine Nowell , Kramer Daniel B. , Singh Jagmeet , Ellinor Patrick T. 
Published: March 2010

AimsCardiac resynchronization therapy (CRT) improves echocardiographic parameters, symptoms, hospitalizations, and mortality in patients with New York Heart Association (NYHA) Class III or IV symptoms with left ventricular systolic dysfunction, sinus rhythm, and a prolonged QRS duration. The effectiveness of CRT in patients with mild heart failure symptoms has not been systematically reviewed.Methods and resultsRandomized controlled trials of CRT in patients with NYHA Class I or II heart failure were identified from MEDLINE and EMBASE. The effects of CRT on left ventricular remodelling at 1 year were systematically reviewed, and the effects of CRT on clinical outcomes at 1 year were meta‐analysed. Two studies met the pre‐specified search criteria, with a total of 2430 patients (REVERSE n = 610 and MADIT‐CRT n = 1820). CRT was associated with a reduction in heart failure events in both trials [combined OR 0.57, 95% confidence interval (CI) 0.46–0.70], but not mortality (combined OR 0.96, 95% CI 0.67–1.36). The effect of CRT on the combined endpoint of heart failure events or death favoured CRT (OR 0.63, 95% CI 0.51–0.77). CRT was also associated with improvement in left ventricular remodelling parameters in both studies, including a greater increase in left ventricular ejection fraction in the CRT group than in the control group, at 1 year after randomization. Serious adverse events were rare with CRT.ConclusionCRT reduces heart failure events in patients with mild heart failure symptoms, left ventricular dysfunction, sinus rhythm, and prolonged QRS duration.
Severe Dysphagia in Children With Eosinophilic Esophagitis and Esophageal Stricture: An Indication for Balloon Dilation?
Authors: Robles‐Medranda Carlos , Villard Florence , le Gall Catherine , Lukashok Hannah , Rivet Christine , Bouvier Raymonde , Dumortier Jerome , Lachaux Alain 
Published: March 2010

ABSTRACTBackground:Esophageal stricture is one of the most severe complications in eosinophilic esophagitis (EoE). Clinical practice is based on limited data and some treatments are still considered controversial. We report on our experience in the treatment of severe dysphagia and esophageal strictures in EoE, especially using balloon dilation, showing the clinical practice in our pediatric population.Patients and Methods:This was a single‐center retrospective study between December 2002 to November 2007, identifying all of the pediatric patients with severe dysphagia in the context of EoE. Demographic data and the results of various treatment regimens were reviewed.Results:Severe dysphagia was identified in 13 cases (77% male, mean age 12.8 ± 4.4 years). Endoscopic findings were mucosal edema (62%), long segment strictures, esophagitis, and off‐white appearance in 31%. Histologically, >20 eosinophils per high‐power field were present in all of the patients. Medical treatment consisted of proton pump inhibitor PPI (77%), montelukast (31%), local corticosteroids (54%), systemic corticosteroids (8%), elemental diet (15%), and food elimination diet (61%). A combined therapeutic approach was performed in all of the cases, due to clinical relapse or no response to monotherapy. Good response was obtained clinically in 70%, endoscopically in 62%, and histologically in 75%. Relapses were observed in 46% of the cases. Balloon dilation was necessary in 31% of the cases (mean dilation sessions 3.3 ± 0.95), being effective in 100% of patients, without complications.Conclusions:In our pediatric series, combined medical (corticosteroids, elemental diet, and food elimination diet) and endoscopic approach (repeated balloon dilation) were effective and safe in patients with severe EoE and esophageal stricture.
Quality of Life in Children Managed for Extrahepatic Portal Venous Obstruction
Authors: Krishna Y Radha , Yachha Surender Kumar , Srivastava Anshu , Negi Deepa , Lal Richa , Poddar Ujjal 
Published: March 2010

ABSTRACTObjectives:There are no studies on health‐related quality of life (HRQOL) in children with extrahepatic portal venous obstruction (EHPVO). The present study evaluated the QOL in children with EHPVO, prevariceal and postvariceal esophageal variceal eradication, and postsurgery in comparison with healthy controls.Methods:Children with EHPVO and variceal bleeding were divided into 3 groups: group A, before variceal eradication (n = 50); group B, after variceal eradication (n = 50); and group C, after surgery (n = 12). Group D comprised healthy children (n = 50). Clinical details and investigations were recorded. The Pediatric Quality of Life Inventory parent‐proxy HRQOL questionnaire was used for assessment of QOL.Results:Compared with controls, patients with EHPVO in groups A, B, and C had lower median QOL scores in physical, emotional, social, and school functioning health domains. Esophageal variceal eradication had no significant effect on QOL (median total QOL score pre‐ and postvariceal eradication of 87.5 vs 86.3). Increasing size of spleen (mild 92.5, moderate 88.2, and severe 76.2; P < 0.001), presence of hypersplenism (90 vs 73.7, P = 0.001), and growth retardation (90 vs 82.5, P = 0.04) caused significant reduction of the total QOL score. On multivariate regression analysis, splenic size and growth retardation were found to be independent predictors that affect the QOL. After surgery, a trend toward improvement in physical, psychosocial, and total QOL scores was present, but it was not significant.Conclusions:Children with EHPVO have a poor QOL that is not affected by variceal eradication. Splenomegaly and growth retardation significantly affect the HRQOL. A trend toward improvement of QOL scores is observed in the postsurgery group.
From tears to words: the development of language to express pain in young children with everyday minor illnesses and injuries
Authors: Franck L. , Noble G. , Liossi C. 
Published: March 2010

AbstractBackground  Little is known about the development of language to express pain in the young or how children and parents verbally communicate when young children have everyday minor illnesses and injuries.Methods  UK parents of children between the ages of 1 and 6 were invited to complete an Internet survey on children's pain language during everyday situations of minor illness or injury.Results  Of the 1716 parents completing the survey, 45% reported their child had at least one word to express pain by 17 months of age, increasing to 81% by 23 months of age. Children used different words based on their age and in the contexts of minor illnesses and injuries, with words for expressing pain related to illness emerging slightly later. Children's language was purposeful in describing causes of pain and requesting specific forms of assistance from parents even in the very youngest age groups. Parents' communicated with their children primarily to gain further information about the source and nature of pain and to direct children's behaviour.Conclusions  Children rapidly develop an extensive vocabulary to describe pain between 12 and 30 months of age, with words for pain from injury emerging first and reflecting the development of normal speech acquisition. The differences in verbal expressions in the context of minor illnesses and injuries suggest that children make a cognitive distinction between the origins and sensory aspects of pain. These findings can help parents, childcare and healthcare professionals to appreciate the early communication capabilities of young children and to engage in more effective pain assessment and management for young children.
The origin of herbicide‐resistant Chenopodium album: analysis of genetic variation and population structure
Authors: APER J , DE RIEK J , MECHANT E , DE CAUWER B , BULCKE R , REHEUL D 
Published: March 2010

Aper J, De Riek J, Mechant E, De Cauwer B, Bulcke R & Reheul D (2010). The origin of herbicide‐resistant Chenopodium album: analysis of genetic variation and population structure. Weed Research50, 235–244.Summary Chenopodium album is a predominantly self‐fertilising weed species common in temperate regions of the world that has developed resistance to photosystem II inhibitors. The genetic variation and population structure of eight populations from North West Europe were investigated using 416 amplified fragment length polymorphism (AFLP) markers. The populations were checked for their level of herbicide resistance by pot experiments and the investigated plants were genotyped for the Ser264 to Gly mutation by cleaved amplified polymorphic sequence. Five populations were sampled in sugar beet, one population from a maize monoculture served as a triazine‐resistant reference and the two other populations were susceptible reference populations. Nei’s gene diversity within populations for the whole dataset was low (0.073), whereas, the differentiation among populations was significant (ΦST = 0.26, amova, P < 0.001). There was no correlation between geographical and genetic distance of population pairs. The allelic richness (estimated by ‘band richness’ and percentage of polymorphic loci) was lowest in the two populations with a complete set of herbicide‐resistant plants and in one population with a mixture of herbicide‐resistant and ‐susceptible plants, giving evidence for a historical bottleneck. However, the loss in genetic variation was not that large, indicating that herbicide‐resistant populations may maintain their adaptive capacity. Furthermore, this study shows that different techniques can be used to extract information from AFLP markers for the investigation of the genetic background of weed populations. Knowledge about the origin and spread of herbicide‐resistant weed populations may give opportunities to manage the resistance problem, with its associated ecological and economic consequences.