bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intraseasonal and Seasonally Persisting Patterns of Indian Monsoon Rainfall
Authors: Krishnamurthy V. , Shukla J. 
Published: January 2007

AbstractThe space–time structure of the active and break periods of the Indian monsoon has been studied using 70-yr-long high-resolution gridded daily rainfall data over India. The analysis of lagged composites of rainfall anomalies based on an objective categorization of active and break phases shows that the active (break) cycle, with an average life of 16 days, starts with positive (negative) rainfall anomalies over the Western Ghats and eastern part of central India and intensifies and expands to a region covering central India and parts of north India during the peak phase, while negative (positive) anomalies cover the sub-Himalayan region and southeast India. During the final stage of the active (break) period, the positive (negative) rainfall anomalies move toward the foothills of the Himalayas while peninsular India is covered with opposite sign anomalies. The number of days on which lows and depressions are present in the region during active and break periods is consistent with the rainfall analysis. The number of depressions during the active phase is about 7 times that during the break phase.Using multichannel singular spectrum analysis of the daily rainfall anomalies, the seasonal monsoon rainfall is found to consist of two dominant intraseasonal oscillations with periods of 45 and 20 days and three seasonally persisting components. The 45- and 20-day oscillations are manifestations of the active and break periods but contribute very little to the seasonal mean rainfall. The seasonally persisting components with anomalies of the same sign, and covering all of India, have a very high interannual correlation with the total seasonal mean rainfall. These results support a conceptual model of the interannual variability of the monsoon rainfall consisting of seasonal mean components and a statistical average of the intraseasonal variations. The success in the prediction of seasonal mean rainfall depends on the relative strengths of the seasonally persisting components and intraseasonal oscillations.
The Frequency of Extreme Rain Events in Satellite Rain-Rate Estimates and an Atmospheric General Circulation Model
Authors: Wilcox Eric M. , Donner Leo J. 
Published: January 2007

Abstract
The frequency distributions of surface rain rate are evaluated in the Tropical Rainfall Measuring Mission (TRMM) and Special Sensor Microwave/Imager (SSM/I) satellite observations and the NOAA/GFDL global atmosphere model version 2 (AM2). Instantaneous satellite rain-rate observations averaged over the 2.5° latitude × 2° longitude model grid are shown to be representative of the half-hour rain rate from single time steps simulated by the model. Rain-rate events exceeding 10 mm h−1 are observed by satellites in most regions, with 1 mm h−1 events occurring more than two orders of magnitude more frequently than 10 mm h−1 events. A model simulation using the relaxed Arakawa–Schubert (RAS) formulation of cumulus convection exhibits a strong bias toward many more light rain events compared to the observations and far too few heavy rain events. A simulation using an alternative convection scheme, which includes an explicit representation of mesoscale circulations and an alternative formulation of the closure, exhibits, among other differences, an order of magnitude more tropical rain events above the 5 mm h−1 rate compared to the RAS simulation. This simulation demonstrates that global atmospheric models can be made to produce heavy rain events, in some cases even exceeding the observed frequency of such events. Additional simulations reveal that the frequency distribution of the surface rain rate in the GCM is shaped by a variety of components within the convection parameterization, including the closure, convective triggers, the spectrum of convective and mesoscale clouds, and other parameters whose physical basis is currently only understood to a limited extent. Furthermore, these components interact nonlinearly such that the sensitivity of the rain-rate distribution to the formulation of one component may depend on the formulation of the others. Two simulations using different convection parameterizations are performed using perturbed sea surface temperatures as a surrogate for greenhouse gas–forced climate warming. Changes in the frequency of rain events greater than 2 mm h−1 associated with changing the convection scheme in the model are greater than the changes in the frequency of heavy rain events associated with a 2-K warming using either model. Thus, uncertainty persists with respect to simulating intensity distributions for precipitation and projecting their future changes. Improving the representation of the frequency distribution of rain rates will rely on refinements in the formulation of cumulus closure and the other components of convection schemes, and greater certainty in predictions of future changes in both total rainfall and in rain-rate distributions will require additional refinements in those parameterizations that determine the cloud and water vapor feedbacks.
Trends in Block-Seasonal Extreme Rainfall over the Iberian Peninsula in the Second Half of the Twentieth Century
Authors: García JoséAgustín , Gallego María Cruz , Serrano Antonio , Vaquero JoséManuel 
Published: January 2007

Abstract
In this study trends in extreme rainfall over the Iberian Peninsula at a daily scale in the second half of the twentieth century have been detected and analyzed. For this goal 35 stations evenly distributed over the region of study covering the period 1958–97 have been studied. Two different approaches have been used. The first one consists of the nonparametric Mann–Kendall test and the Sen method. The second approach is based on the statistical theory of extreme values, involving time-dependent parameters in order to be able to reflect possible temporal changes in the frequency distribution. Results from both methods agree, confirming the reliability of the analysis. Negative trends are found for the west and southwest of the Iberian Peninsula in spring and winter. In autumn a spatial dipolar pattern appears, but trends are not so evident.
The autoclavable semirigid thoracoscope: the way forward in pleural disease?
Authors: Munavvar M. , Khan M. A. I. , Edwards J. , Waqaruddin Z. , Mills J. 
Published: January 2007

Medical thoracoscopy is a valuable tool in the investigation and management of pleural disease. It has considerable advantages over conventional blind pleural biopsy and video-assisted thoracoscopic surgery. Despite this, the practice of this technique in the UK is limited. Most operators use the rigid thoracoscope, which may be an unfamiliar instrument to respiratory physicians. A semirigid thoracoscope is available but its use has not been possible in the UK as it requires sterilisation with ethylene oxide, which is not approved in this country. The present authors describe herein their experience with the first ever autoclavable semirigid thoracoscope.Medical thoracoscopy using the new instrument was performed in 56 patients between June 2004 and May 2006. All patients had been referred with a unilateral pleural effusion of unknown aetiology, where blind pleural aspiration had failed to yield an answer. Diagnostic samples were taken and talc poudrage performed where appropriate.The instrument was easy to handle and excellent views were obtained. Histologically adequate biopsy samples were obtained in 54 patients. The combination of clinical features, computed tomography findings and thoracoscopic biopsy enabled a definite diagnosis in 49 (90.7%) of these patients. There were no complications.The autoclavable semirigid thoracoscope has immense potential in the diagnosis and management of pleural disease. Its diagnostic yield in pleural disease is comparable to the conventional rigid thoracoscope. It is similar in design to the fibreoptic bronchoscope and respiratory physicians should be able to adapt to its use easily. It is also compatible with existing video processors and light sources available in most endoscopy suites. The fact that this instrument is autoclavable should open the field for its use in the UK as well as in other countries.
Safety and tolerability of bosentan in idiopathic pulmonary fibrosis: an open label study
Authors: Günther A. , Enke B. , Markart P. , Hammerl P. , Morr H. , Behr J. , Stähler G. , Seeger W. , Grimminger F. , Leconte I. , Roux S. , Ghofrani H-A. 
Published: January 2007

Idiopathic pulmonary fibrosis (IPF) is a fatal disease for which no effective treatment exists. In the present study, 12 IPF patients underwent analysis of gas exchange properties using the multiple inert gas elimination technique on day 1 before and after the administration of 125 mg bosentan, a dual endothelin antagonist. Following this, patients received chronic administration for 12 weeks (62.5 mgb.i.d.in week 1, 125 mgb.i.d.thereafter). The primary objective was to determine the effect of bosentan on gas exchange (day 1) and on oxygen saturation and minute ventilation (week 2).With one exception, where redistribution of total pulmonary blood flow from normal ventilation/perfusion (V′/Q′) areas (93% before, 72% after bosentan) to lowV′/Q′ areas (0% before, 22.2% after) was encountered, no patient showed any change in gas exchange (mean±sdshunt flow (% of cardiac output) 8.5±3.4% before, 6.1±2.3% after bosentan; day 1) or oxygen saturation and minute ventilation (week 2). Similarly, none of the secondary parameters was significantly changed either at week 2 or at the end of the study period (week 12). Five patients developed respiratory infections and two died because of pneumonia; this was judged as being unrelated to bosentan intake.In conclusion, bosentan administration does not seem to induce clinically relevant gas exchange abnormalities in idiopathic pulmonary fibrosis patients.
Glutathione S-transferase genotypes modify lung function decline in the general population: SAPALDIA cohort study
Authors: Imboden Medea , Downs Sara H , Senn Oliver , Matyas Gabor , Brändli Otto , Russi Erich W , Schindler Christian , Ackermann-Liebrich Ursula , Berger Wolfgang , Probst-Hensch Nicole M ,   the SAPALDIA Team
Published: January 2007

Abstract

Background
Understanding the environmental and genetic risk factors of accelerated lung function decline in the general population is a first step in a prevention strategy against the worldwide increasing respiratory pathology of chronic obstructive pulmonary disease (COPD). Deficiency in antioxidative and detoxifying Glutathione S-transferase (GST) gene has been associated with poorer lung function in children, smokers and patients with respiratory diseases. In the present study, we assessed whether low activity variants in GST genes are also associated with accelerated lung function decline in the general adult population.

Methods
We examined with multiple regression analysis the association of polymorphisms in GSTM1, GSTT1 and GSTP1 genes with annual decline in FEV1, FVC, and FEF25–75 during 11 years of follow-up in 4686 subjects of the prospective SAPALDIA cohort representative of the Swiss general population. Effect modification by smoking, gender, bronchial hyperresponisveness and age was studied.

Results
The associations of GST genotypes with FEV1, FVC, and FEF25–75 were comparable in direction, but most consistent for FEV1. GSTT1 homozygous gene deletion alone or in combination with GSTM1 homozygous gene deletion was associated with excess decline in FEV1 in men, but not women, irrespective of smoking status. The additional mean annual decline in FEV1 in men with GSTT1 and concurrent GSTM1 gene deletion was -8.3 ml/yr (95% confidence interval: -12.6 to -3.9) relative to men without these gene deletions. The GSTT1 effect on the FEV1 decline comparable to the observed difference in FEV1 decline between never and persistent smoking men. Effect modification by gender was statistically significant.

Conclusion
Our results suggest that genetic GSTT1 deficiency is a prevalent and strong determinant of accelerated lung function decline in the male general population.
Anterior anal sphincter repair can be of long term benefit: a 12-year case cohort from a single surgeon
Authors: Grey Benjamin R , Sheldon Rowena R , Telford Karen J , Kiff Edward S 
Published: January 2007

Abstract

Background
Early surgical results of anterior sphincter repair for faecal incontinence can be good, but in the longer term are often disappointing. This study aimed to determine the short and long term outcomes from anterior sphincter repair and identify factors predictive of long term success.

Methods
Patients who underwent anterior sphincter repair between 1989 and 2001 in one institution were identified. Postal questionnaires were sent to patients, which included validated scoring systems for symptom severity and quality of life assessments for faecal incontinence. Patient demographics and risk factors were recorded as were the results of anorectal physiology studies and endoanal ultrasound.

Results
Eighty-five patients underwent repair by one consultant. The length of follow up ranged from 1 to 12 years. Most patients (96%) had early symptom improvement postoperatively. Of the 47 patients assessed long term (≥ 5 years), 28 (60%) maintained this success. Significant improvements in quality of life were observed (P < 0.001). Neither patient, surgical nor anorectal physiology study parameters were predictive of outcome.

Conclusion
There were no predictive factors of outcome success and no changes in anal manometry identified, however anterior sphincter repair remains worthwhile. Changes in compliance of the anorectum may be responsible for symptom improvement.
Exploring the effects of telehealth on medical human resources supply: a qualitative case study in remote regions
Authors: Gagnon Marie-Pierre , Duplantie Julie , Fortin Jean-Paul , Landry Réjean 
Published: January 2007

Abstract
Background
The availability of medical human resource supply is a growing concern for rural and remote communities in many countries. In the last decade, various telehealth experiences in Canada have highlighted the potential impact of this technology on professional practice. The purpose of this study was to explore physicians' and managers' perceptions regarding the potential of telehealth to support recruitment and retention of physicians in remote and rural regions.

Methods
A case study in Eastern Quebec was performed to explore this complex phenomenon. The analytical framework was based on two literature reviews and a Delphi study. Data were collected from semi-structured interviews with 41 physicians and 22 managers. Transcripts were produced and interview content was coded independently by two judges and validated by an expert panel.

Results
Interviews have highlighted the potential impact of telehealth on several factors influencing the recruitment and retention of physicians in rural and remote regions. The potential effects of telehealth on physicians' choice of practice location could be seen at the professional, organizational, educational and individual levels. For instance, telehealth could improve work satisfaction by allowing a regional on-call duty system and a better follow-up of patients. However, there are also certain limits related to telehealth, such as the fear that it would eventually replace all continuing medical education activities and onsite specialists in remoteregions.

Conclusion
Telehealth is likely to have an impact on several factors related to medical workforce supply in remote and rural regions. However, the expected benefits will materialize if and only if this technology is properly integrated into organizations as a support to professional practice.
Zebularine reactivates silenced E-cadherin but unlike 5-Azacytidine does not induce switching from latent to lytic Epstein-Barr virus infection in Burkitt's lymphoma Akata cells
Authors: Rao Sieta P , Rechsteiner Markus P , Berger Christoph , Sigrist Jürg A , Nadal David , Bernasconi Michele 
Published: January 2007

Abstract
Epigenetic silencing of regulatory genes by aberrant methylation contributes to tumorigenesis. DNA methyltransferase inhibitors (DNMTI) represent promising new drugs for anti-cancer therapies. The DNMTI 5-Azacytidine is effective against myelodysplastic syndrome, but induces switching of latent to lytic Epstein-Barr virus (EBV) in vitro and results in EBV DNA demethylation with the potential of induction of lytic EBV in vivo. This is of considerable concern given that recurrent lytic EBV has been linked with an increased incidence of EBV-associated lymphomas. Based on the distinct properties of action we hypothesized that the newer DNMTI Zebularine might differ from 5-Azacytidine in its potential to induce switching from latent to lytic EBV. Here we show that both 5-Azacytidine and Zebularine are able to induce expression of E-cadherin, a cellular gene frequently silenced by hypermethylation in cancers, and thus demonstrate that both DNMTI are active in our experimental setting consisting of EBV-harboring Burkitt's lymphoma Akata cells. Quantification of mRNA expression of EBV genes revealed that 5-Azacytidine induces switching from latent to lytic EBV and, in addition, that the immediate-early lytic infection progresses to early and late lytic infection. Furthermore, 5-Azacytidine induced upregulation of the latent EBV genes LMP2A, LMP2B, and EBNA2 in a similar fashion as observed following switching of latent to lytic EBV upon cross-linking of the B-cell receptor. In striking contrast, Zebularine did not exhibit any effect neither on lytic nor on latent EBV gene expression. Thus, Zebularine might be safer than 5-Azacytidine for the treatment of cancers in EBV carriers and could also be applied against EBV-harboring tumors, since it does not induce switching from latent to lytic EBV which may result in secondary EBV-associated malignancies.
Importance of A-loop complementarity with tRNAHis anticodon for continued selection of tRNAHis as the HIV reverse transcription primer
Authors: Ni Na , Xu Wenqin , Morrow Casey D 
Published: January 2007

Abstract

Background
Human immunodeficiency virus (HIV-1) preferentially selects tRNALys,3 as the primer for reverse transcription. HIV-1 can be forced to select alternative tRNAs through mutation in the primer-binding site (PBS) and a region upstream of the PBS designated as the A-loop. Alteration of the PBS and A-loop to be complementary to the 3' terminal nucleotides and anticodon of tRNAHis results in HIV-1 that can stably utilize this tRNA for replication.

Results
In the current study, we have investigated the effect that mutations within the A-loop have on the stability of HIV-1 with a PBS complementary to tRNAHis. For these studies, we have altered the A-loop to be complementary to tRNAMet, tRNAGln, tRNAIle, tRNAThr and tRNASer. All substitutions of the A-loops with the PBS complementary to tRNAHis resulted in a reduction of infectious virus obtained following transfection of proviral genomes in the 293T cells. Virus replication in SupT1 cells was also impaired as a result of the alteration of the A-loop. Viruses with the A-loop complementary to tRNALys,3 and tRNASer reverted to utilize tRNALys,3 following in vitro replication. In contrast, viruses with the A-loop complementary to the other tRNAs remained stable and continued to use tRNAHis. RNA modeling of the stem-loop structure revealed that nucleotides were displayed on the loop region that could potentially interact with the anticodon of tRNAHis. To further explore the effects of the A-loop mutations on virus replication, the A-loops complementary to tRNASer or tRNAHis were cloned into the wild type genome with the PBS complementary to tRNALys,3. Transfection of proviral genomes which contained the wild type PBS and A-loops complementary to tRNASer or tRNAHis into 293 T cells did not impact on the production of viruses as measured by p24 antigen ELISA. However, viruses with the A-loop complementary to tRNAHis had greatly reduced infectivity and replicated poorly in SupT1 compared to the wild type or viruses with the A-loop complementary to tRNASer.

Conclusion
These studies demonstrate that complementarity of A-loop region with the anticodon of tRNAHis has a pronounced effect on the capacity of HIV-1 to utilize tRNAHis as the primer for reverse transcription. Complementarity between A-loop and anticodon of the tRNA then is important for the selection of the tRNA primer used for reverse transcription.
Mutations in the TΨC Loop of E. coli tRNALys,3 Have Varied Effects on In Trans Complementation of HIV-1 Replication
Authors: Yu Wanfeng , McCulley Anna , Morrow Casey D 
Published: January 2007

Abstract

Background
Human immunodeficiency virus (HIV-1) exclusively selects and utilizes tRNALys,3 as the primer for initiation of reverse transcription. Several elements within the TΨC stem loop of tRNALys,3 are postulated to be important for selection and use in reverse transcription. The post-transcriptional modification at nucleotide 58 could play a role during plus-strand synthesis to stop reverse transcriptase from re-copying the tRNA primer. Nucleotides 53 and 54 within the TΨC stem loop of the tRNA have been shown to be important to form the complex between tRNA and the HIV-1 viral genome during initiation of reverse transcription.

Results
To further delineate the features of the TΨC stem loop of tRNALys,3 in reverse transcription, we have developed a complementation system in which E. coli tRNALys,3 is provided in trans to an HIV-1 genome in which the PBS is complementary to this tRNA. Successful selection and use of E. coli tRNALys,3 results in the production of infectious virus. We have used this single round infectious system to ascertain the effects that different mutants in the TΨC stem loop of tRNALys,3 have on complementation. Mutants were designed within the TΨC loop (nucleotide 58) and within the stem and loop of the TΨC loop (nucleotides 53 and 54). Analysis of the expression of E. coli tRNALys,3 mutants revealed differences in the capacity for aminoacylation, which is an indication of intracellular stability of the tRNA. Alteration of nucleotide 58 from A to U (A58U), T54G and TG5453CC all resulted in tRNALys,3 that was aminoacylated when expressed in cells, while a T54C mutation resulted in a tRNALys,3 that was not aminoacylated. Both the A58U and T54G mutated tRNALys,3 complemented HIV-1 replication similar to wild type E. coli tRNALys,3. In contrast, the TG5453CC tRNALys,3 mutant did not complement replication.

Conclusion
The results demonstrate that post-transcriptional modification of nucleotide 58 in tRNALys,3 is not essential for HIV-1 reverse transcription. In contrast, nucleotides 53 and 54 of tRNALys,3 are important for aminoacylation and selection and use of the tRNALys,3 in reverse transcription.