bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative Genetic Analysis of Thermal Dissipation in Arabidopsis
Authors: Jung Hou-Sung , Niyogi Krishna K. 
Published: April 2009

AbstractFeedback deexcitation is a photosynthetic regulatory mechanism that can protect plants from high light stress by harmlessly dissipating excess absorbed light energy as heat. To understand the genetic basis for intraspecies differences in thermal dissipation capacity, we investigated natural variation in Arabidopsis (Arabidopsis thaliana). We determined the variation in the amount of thermal dissipation by measuring nonphotochemical quenching (NPQ) of chlorophyll fluorescence in Arabidopsis accessions of diverse origins. Ll-1 and Sf-2 were selected as high NPQ Arabidopsis accessions, and Columbia-0 (Col-0) and Wassilewskija-2 were selected as relatively low NPQ accessions. In spite of significant differences in NPQ, previously identified NPQ factors were indistinguishable between the high and the low NPQ accessions. Intermediate levels of NPQ in Ll-1 × Col-0 F1 and Sf-2 × Col-0 F1 compared to NPQ levels in their parental lines and continuous distribution of NPQ in F2 indicated that the variation in NPQ is under the control of multiple nuclear factors. To identify genetic factors responsible for the NPQ variation, we developed a polymorphic molecular marker set for Sf-2 × Col-0 at approximately 10-centimorgan intervals. From quantitative trait locus (QTL) mapping with undistorted genotype data and NPQ measurements in an F2 mapping population, we identified two high NPQ QTLs, HQE1 (high qE 1, for high energy-dependent quenching 1) and HQE2, on chromosomes 1 and 2, and the phenotype of HQE2 was validated by analysis of near isogenic lines. Neither QTL maps to a gene that had been identified previously in extensive forward genetics screens using induced mutants, suggesting that quantitative genetics can be used to find new genes affecting thermal dissipation.
Near‐station topographic masses correction for high‐accuracy gravimetric prospecting
Authors: Schiavone D. , Capolongo D. , Loddo M. 
Published: April 2009

ABSTRACTThe expanding role of gravity prospecting in mineral and hydrocarbon exploration as well as seismic and volcanic risk studies will be related to its ability to provide high‐resolution anomalies. To achieve this goal it is necessary to consider the errors resulting from the topographic corrections, in particular near‐station effects. Such errors are relevant not only for severe topographies but also for relatively flat surfaces involving microgravity applications and large‐scale surveys.Indeed, the errors introduced by low‐resolution digital elevation models can be of the same order of magnitude as the anomalies of interest. This basic fact is demonstrated by tests on synthetic models. The results of this analysis are summarized in an intuitive graph that can be used to estimate what near‐station topographic resolution is necessary for a specific survey. For the Vulcano Island test site (in Southern Italy), we also compare results obtained using three different representations of the topographic surface with different horizontal resolutions and vertical precisions: one from existing photogrammetric data, the second from a digitized map and the third from a very high‐resolution laser scanning system. Among the three methods, laser scanning is shown to obtain the highest resolution topographic reconstructions in the shortest time. Some weaknesses of the laser scanning methodology are discussed and we suggest ways of overcoming them.
Climate warming effects on the Olea europaea–Bactrocera oleae system in Mediterranean islands: Sardinia as an example
Authors: PONTI LUIGI , COSSU Q. ANTONIO , GUTIERREZ ANDREW PAUL 
Published: April 2009

AbstractGlobal warming will affect all species but in largely unknown ways, with certain regions such as the Mediterranean Basin and its major islands including Sardinia being particularly vulnerable to desertification. Olive (Olea europaea) is of eco‐social importance in the Mediterranean where it was domesticated. This drought‐resistant crop and its major pest, the olive fly (Bactrocera oleae), have tight biological links that make them a suitable model system for climate change studies in the Mediterranean. Here a physiologically based weather‐driven demographic model of olive and olive fly is used to analyze in detail this plant–pest system in Sardinia under observed weather (10 years of daily data from 48 locations), three climate warming scenarios (increases of 1, 2 and 3 °C in average daily temperature), and a 105‐year climate model scenario for the Alghero location (e.g. 1951–2055). grass gis is used to map model predictions of olive bloom dates and yield, total season‐long olive fly pupae, and percent fruit attacked by the fly. Island wide simulation data are summarized using multivariate regression. Model calibration with field bloom date data were performed to increase simulation accuracy of olive flowering predictions under climate change. As climate warms, the range of olive is predicted to expand to higher altitudes and consolidate elsewhere, especially in coastal areas. The range of olive fly will extend into previously unfavorable cold areas, but will contract in warm inland lowlands where temperatures approach its upper thermal limits. Consequently, many areas of current high risk are predicted to have decreased risk of fly damage with climate warming. Simulation using a 105‐year climate model scenario for Alghero, Sardinia predicts changes in the olive–olive fly system expected to occur if climate continued to warm at the low rate observed during in the past half century.
A study of the impact of information technology on firm performance: a flexible production function approach
Authors: Sircar Sumit , Choi Jung 
Published: April 2009

AbstractMost previous studies of the impact of information technology (IT) on firm performance have relied on the Cobb–Douglas production function, which makes unrealistic assumptions. These include assuming that (1) the scale elasticity, i.e. returns to scale, is constant throughout the entire output range; (2) the elasticity of substitution between inputs is one, whereas it can be anywhere from zero to infinity in practice; and (3) there are no complex interrelationships between inputs, i.e. no squared or product terms. The translog production function (used in two previous studies) does not make these assumptions and is therefore more accurate. However, the two previous studies found no significant difference between the two. This research has extended previous work on the impact of IT investments by providing more accurate results in some areas and new findings in others. IT's importance is shown to be much greater than previously thought. The translog function is used to demonstrate that the productivity paradox does not hold (i.e. both IT labor and capital indeed have a significant impact on firm revenues), but with considerably different results, i.e. the impact of IT is markedly more significant than that obtained from the Cobb–Douglas. Another interesting finding is that of scale elasticity. Our results show that this is less than 1, implying decreasing returns to scale of output. Finally, the substitutability between inputs was determined, which is not possible with the Cobb–Douglas. It was found that the partial elasticities of substitution for IT labor with IT capital and non‐IT labor were quite substantial.
The research questions and methodological adequacy of clinical studies of the voice and larynx published in Brazilian and international journals
Authors: Vieira Vanessa Pedrosa , De Biase Noemi , Peccin Maria Stella , Atallah Álvaro Nagib 
Published: April 2009

AbstractObjective  To evaluate the methodological adequacy of voice and laryngeal study designs published in speech‐language pathology and otorhinolaryngology journals indexed for the ISI Web of Knowledge® (ISI® Web) and the MEDLINE® database.Methods  A cross‐sectional study conducted at the Universidade Federal de São Paulo (Federal University of São Paulo). Two Brazilian speech‐language pathology and otorhinolaryngology journals (Pró‐Fono and Revista Brasileira de Otorrinolaringologia) and two international speech‐language pathology and otorhinolaryngology journals (Journal of Voice, Laryngoscope), all dated between 2000 and 2004, were hand‐searched by specialists. Subsequently, voice and larynx publications were separated, and a speech‐language pathologist and otorhinolaryngologist classified 374 articles from the four journals according to objective and study design.Results  The predominant objective contained in the articles was that of primary diagnostic evaluation (27%), and the most frequent study design was case series (33.7%). A mere 7.8% of the studies were designed adequately with respect to the stated objectives. There was no statistical difference in the methodological quality of studies indexed for the ISI® Web and the MEDLINE® database.Conclusion  The studies published in both national journals, indexed for the MEDLINE® database, and international journals, indexed for the ISI® Web, demonstrate weak methodology, with research poorly designed to meet the proposed objectives. There is much scientific work to be done in order to decrease uncertainty in the field analysed.
Effects of species and habitat positional errors on the performance and interpretation of species distribution models
Authors: Osborne Patrick E. , Leitão Pedro J. 
Published: April 2009

AbstractAim  A key assumption in species distribution modelling is that both species and environmental data layers contain no positional errors, yet this will rarely be true. This study assesses the effect of introduced positional errors on the performance and interpretation of species distribution models.Location  Baixo Alentejo region of Portugal.Methods  Data on steppe bird occurrence were collected using a random stratified sampling design on a 1‐km2 pixel grid. Environmental data were sourced from satellite imagery and digital maps. Error was deliberately introduced into the species data as shifts in a random direction of 0–1, 2–3, 4–5 and 0–5 pixels. Whole habitat layers were shifted by 1 pixel to cause mis‐registration, and the cumulative effect of one to three shifted layers investigated. Distribution models were built for three species using three algorithms with three replicates. Test models were compared with controls without errors.Results  Positional errors in the species data led to a drop in model performance (larger errors having larger effects – typically up to 10% drop in area under the curve on average), although not enough for models to be rejected. Model interpretation was more severely affected with inconsistencies in the contributing variables. Errors in the habitat layers had similar although lesser effects.Main conclusions  Models with species positional errors are hard to detect, often statistically good, ecologically plausible and useful for prediction, but interpreting them is dangerous. Mis‐registered habitat layers produce smaller effects probably because shifting entire layers does not break down the correlation structure to the same extent as random shifts in individual species observations. Spatial autocorrelation in the habitat layers may protect against species positional errors to some extent but the relationship is complex and requires further work. The key recommendation must be that positional errors should be minimised through careful field design and data processing.
Rowing, the ultimate challenge to the human body – implications for physiological variables
Authors: Volianitis Stefanos , Secher Niels H. 
Published: April 2009

SummaryClinical diagnoses depend on a variety of physiological variables but the full range of these variables is seldom known. With the load placed on the human body during competitive rowing, the physiological range for several variables is illustrated. The extreme work produced during rowing is explained by the seated position and the associated ability to increase venous return and, thus, cardiac output. This review highlights experimental work on Olympic rowing that presents a unique challenge to the human capacities, including cerebral metabolism, to unprecedented limits, and provides a unique opportunity to reveal the extreme range of many physiological variables.
Almost Normal: Experiences of Adolescents With Implantable Cardioverter Defibrillators
Authors: Zeigler Vicki L. , Nelms Tommie 
Published: April 2009

PURPOSE. The purpose of this study was to describe the experiences of adolescents with implantable cardioverter defibrillators (ICDs).DESIGN AND METHODS. This qualitative study explored the lived experiences of 14 adolescents with ICDs using face‐to‐face, semistructured interviews.RESULTS. Six themes were identified: life interrupted; still the same, except; sometimes it's tough; it cuts both ways; unique joule; and living life regular.PRACTICE IMPLICATIONS. These findings suggest that nurses could make a significant impact on the lives of adolescents with ICDs by focusing their efforts away from viewing the adolescent through an illness lens and more toward a normalization lens.
COMPRESSING BEHAVIOR AND TEXTURE EVALUATION FOR POTATOES PRETREATED BY PULSED ELECTRIC FIELD
Authors: GRIMI NABIL , LEBOVKA NIKOLAÏ , VOROBIEV EUGENE , VAXELAIRE JEAN 
Published: April 2009

ABSTRACT The objective of this study was to investigate the effects of pulsed electric field (PEF) treatment on compressing behavior and texture of potatoes. Textural data reveal that PEF treatment can cause enlargement of pressure for the same level of deformation. The fracture pressures Pc were approximately the same for both untreated and PEF‐treated specimens, Pc ≈ 4.5 ± 0.4 MPa. The maximal pressure Pm, at which the time of the pressure‐induced rupture of intact cells should be of the same order of magnitude as the time of fluid expression from damaged cells, was estimated as Pm ≈ 6 MPa. For a small pressure (P = 1 MPa) to obtain a similar deformation (ε = 0.15) requires pressing time t ≈ 3.5 h for untreated tissue and t ≈ 70 s for PEF‐treated tissue. Measured electrical conductivity was practically constant and exhibited no noticeable time dependence during constant pressure stage in untreated samples, while the conductivity of PEF‐treated specimens decreases in the course of pressing.PRACTICAL APPLICATIONSSolid–liquid expression is widely used in the food industry for the extraction of fruit and vegetables. Efficiency of this process can be increased by different pretreatment methods. Pulsed electric field (PEF) has been shown to be good for juice yield intensification and for improving the product quality in juice production. It is of great interest for process purposes to study texture proprieties of PEF‐treated and untreated tissues, because texture is one of the most important quality attributes of food products. This work also gives new information about the mechanism of the PEF‐induced damage and expression from tissues. The obtained results may be helpful for development of new engineering concepts based on PEF‐enhanced extraction at comparatively low pressures and moderate time of processing.
Low genetic diversity and high genetic differentiation in the critically endangeredOmphalogramma souliei(Primulaceae): implications for its conservation
Authors: HUANG Yuan , ZHANG Chang‐Qin , LI De‐Zhu 
Published: April 2009

AbstractOmphalogramma soulieiFranch. is an endangered perennial herb only distributed in alpine areas of SW China. ISSR markers were applied to determine the genetic variation and genetic structure of 60 individuals of three populations ofO. soulieiin NW Yunnan, China. The genetic diversity at the species level is low withP=42.5% (percentage of polymorphic bands) andHsp=0.1762 (total genetic diversity). However, a high level of genetic differentiation among populations was detected based on different measures (Nei's genetic diversity analysis:Gst=0.6038; AMOVA analysis:Fst=0.6797). Low level of genetic diversity within populations and significant genetic differentiation among populations might be due to the mixed mating system in which xenogamy predominated and autogamy played an assistant role inO. souliei.The genetic drift due to small population size and limited current gene flow also resulted in significant genetic differentiation. The assessment of genetic variation and differentiation of the endangered species provides important information for conservation on a genetic basis. Conservation strategies for this rare endemic species are proposed.
Outbreak of Hepatitis E Virus Infection in Darfur, Sudan: Effectiveness of Real-Time Reverse Transcription-PCR Analysis of Dried Blood Spots
Authors: Mérens Audrey , Guérin Philippe Jean , Guthmann Jean-Paul , Nicand Elisabeth 
Published: April 2009

ABSTRACT
Biological samples collected in refugee camps during an outbreak of hepatitis E were used to compare the accuracy of hepatitis E virus RNA amplification by real-time reverse transcription-PCR (RT-PCR) for sera and dried blood spots (concordance of 90.6%). Biological profiles (RT-PCR and serology) of asymptomatic individuals were also analyzed.
Adeno-Associated Virus Replication Induces a DNA Damage Response Coordinated by DNA-Dependent Protein Kinase
Authors: Schwartz Rachel A. , Carson Christian T. , Schuberth Christine , Weitzman Matthew D. 
Published: April 2009

ABSTRACTThe parvovirus adeno-associated virus (AAV) contains a small single-stranded DNA genome with inverted terminal repeats that form hairpin structures. In order to propagate, AAV relies on the cellular replication machinery together with functions supplied by coinfecting helper viruses such as adenovirus (Ad). Here, we examined the host cell response to AAV replication in the context of Ad or Ad helper proteins. We show that AAV and Ad coinfection activates a DNA damage response (DDR) that is distinct from that seen during Ad or AAV infection alone. The DDR was also triggered when AAV replicated in the presence of minimal Ad helper proteins. We detected autophosphorylation of the kinases ataxia telangiectasia mutated (ATM) and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and signaling to downstream targets SMC1, Chk1, Chk2, H2AX, and XRCC4 and multiple sites on RPA32. The Mre11 complex was not required for activation of the DDR to AAV infection. Additionally, we found that DNA-PKcs was the primary mediator of damage signaling in response to AAV replication. Immunofluorescence revealed that some activated damage proteins were found in a pan-nuclear pattern (phosphorylated ATM, SMC1, and H2AX), while others such as DNA-PK components (DNA-PKcs, Ku70, and Ku86) and RPA32 accumulated at AAV replication centers. Although expression of the large viral Rep proteins contributed to some damage signaling, we observed that the full response required replication of the AAV genome. Our results demonstrate that AAV replication in the presence of Ad helper functions elicits a unique damage response controlled by DNA-PK.
Early chromatin unfolding by RUNX1: a molecular explanation for differential requirements during specification versus maintenance of the hematopoietic gene expression program
Authors: Hoogenkamp Maarten , Lichtinger Monika , Krysinska Hanna , Lancrin Christophe , Clarke Deborah , Williamson Andrew , Mazzarella Luca , Ingram Richard , Jorgensen Helle , Fisher Amanda , Tenen Daniel G. , Kouskoff Valerie , Lacaud Georges , Bonifer Constanze 
Published: April 2009

AbstractAt the cellular level, development progresses through successive regulatory states, each characterized by their specific gene expression profile. However, the molecular mechanisms regulating first the priming and then maintenance of gene expression within one developmental pathway are essentially unknown. The hematopoietic system represents a powerful experimental model to address these questions and here we have focused on a regulatory circuit playing a central role in myelopoiesis: the transcription factor PU.1, its target gene colony-stimulating-factor 1 receptor (Csf1r), and key upstream regulators such as RUNX1. We find that during ontogeny, chromatin unfolding precedes the establishment of active histone marks and the formation of stable transcription factor complexes at the Pu.1 locus and we show that chromatin remodeling is mediated by the transient binding of RUNX1 to Pu.1 cis-elements. By contrast, chromatin reorganization of Csf1r requires prior expression of PU.1 together with RUNX1 binding. Once the full hematopoietic program is established, stable transcription factor complexes and active chromatin can be maintained without RUNX1. Our experiments therefore demonstrate how individual transcription factors function in a differentiation stage–specific manner to differentially affect the initiation versus maintenance of a developmental program.
The transcriptional cascade associated with creatine kinase down-regulation and mitochondrial biogenesis in mice sarcoma
Authors: Bera Soumen , Ray Manju 
Published: April 2009

AbstractThe tissue-specific expressions of creatine kinase (CK) isoforms are regulated by the coordinated action of various transcription factors. The myogenic differentiation factor D (MyoD) family of proteins and the myocyte-specific enhancer binding factor 2 family of transcription factors are important in regulating the muscle-specific expression of cytosolic muscle-type CK (MCK) and mitochondrial CKs. As reported in some related studies, TNF-α mediated degradation of MyoD and myogenin mRNA may lead to severe muscle wasting and cachexia, which is characterized by a low transcript level of MCK and myosin heavy chain proteins. In our previous study, we reported on a complete loss of total CK activity and expression when sarcoma was induced in mouse skeletal muscle (Patra et al. FEBS J. 275 (2008) 3236–3247). This study aimed at investigating the transcriptional cascade of CK down-regulation in carcinogen-induced sarcoma in mouse muscle. Both CK deficiency and enhanced nitric oxide synthase (NOS) were known to augment mitochondrial biogenesis, so we also explored the activation of the transcriptional cascade of mitochondrial biogenesis in this cancer. We observed the activation of the TNF-α-mediated nitric oxide production pathway with NFκB activation and concomitant degradation of MyoD and myogenin mRNA. Exploration of mitochondrial biogenesis revealed high cytochrome c oxidase activity and mitochondrial DNA content in sarcoma. The PGC-related co-activator seems to have a major role in regulating mitochondrial biogenesis by upregulating nuclear respiratory factors and mitochondrial transcription factor A. From the above findings, it can be concluded that severe muscle degeneration leads to CK down-regulation in sarcoma, and that the stimulation of mitochondrial biogenesis indicated a scenario representing both CK deficiency and NOS overexpression on the one hand, and altered bioenergetic profiling on the other.