bluuebunny/crossref_metadata_2025_split huggingface dataset:
An analysis of the performance of UK medical graduates in the MRCOG Part 1 and Part 2 written examinations
Authors: Rushd S , Landau A B , Khan J A , Allgar V , Lindow S W 
Published: February 2012

Abstract

Background
There is a lack of evidence on whether graduates from different medical schools perform differently in postgraduate examinations.

Objective
To evaluate the variations in performance of UK medical graduates in Member of the Royal College of Obstetricians and Gynaecologists (MRCOG) examination.

Methods
A retrospective analysis of performance of 1335 doctors graduating in UK medical schools who entered the Part 1 MRCOG and 822 doctors taking the Part 2 MRCOG written examination for the first time between 1998 and 2008. The main outcome measures were to evaluate medical school effects, gender effects and academic performance effect.

Results
Graduates of UK medical schools performed differently in the Part 1 and Part 2 written MRCOG examination. The graduates of Oxford (pass rate 82.6%), Cambridge (75%), Bristol (59.3%) and Edinburgh (57.5%) performed significantly better and the graduates of Liverpool (26.8%), Southampton (21.8%) and Wales (18.2%) performed significantly worse than the remaining cohort in the Part 1 examination. The candidates of Newcastle (88.9%), Oxford (82.4%), Cambridge (81%) and Edinburgh (78.2%) performed significantly better and the graduates of Glasgow (49.2%) and Leicester (36.2%) have significantly underperformed compared with the remaining cohort in Part 2 written examination. There was no difference in the success rates of male (47.5%) and female (42.0%) candidates in the Part 1; however, female candidates had a significantly better success rate in the Part 2 written examination than male candidates (65.6% vs 52.9%).

Conclusion
These results show that there is variation in performance among the graduates from different medical schools in the Part 1 and Part 2 MRCOG written examination.
The impact of peer outreach on HIV knowledge and prevention behaviours of male sex workers in Mombasa, Kenya
Authors: Geibel Scott , King'ola Nzioki , Temmerman Marleen , Luchters Stanley 
Published: February 2012

IntroductionTargeting most at-risk populations is an essential component of HIV prevention strategies. Peer education programmes have been found to increase HIV knowledge, condom use and safer sex behaviours among female sex workers in Africa and men who have sex with men elsewhere. The authors aimed to evaluate the impact of a peer-driven intervention on male sex workers who sell sex to men in Mombasa, Kenya.MethodsUsing time-venue sampling, a baseline survey of 425 male sex workers was conducted in late 2006, after which, 40 peer educators were trained in HIV prevention, basic counselling skills and distribution of condoms and lubricants. A follow-up time-venue survey of 442 male sex workers was conducted in early 2008, and pre- and post-intervention changes were examined. The impact of peer educator exposure on HIV knowledge and condom use was analysed.ResultsPositive changes in HIV prevention behaviours were observed, including increases in consistent use of condoms with both male clients (35.9%–50.2%, p<0.001) and non-paying male partners (27.4%–39.5%, p=0.008). Exposure to peer educators (AOR=1.97, 95% CI 1.29 to 3.02) and ever having been counselled or tested for HIV (AOR=1.71, 95% CI 1.10 to 2.66) were associated with consistent condom use in multivariate analysis. Peer educator contact was also associated with improved HIV knowledge and use of water-based lubricants.ConclusionsPeer outreach programming reached highly stigmatised male sex workers in Mombasa, resulting in significant, but limited, improvements in HIV knowledge and prevention behaviours. Improved peer coverage and additional prevention initiatives are needed to sufficiently mitigate HIV transmission.
Effects of imidazolines on neurogenic contraction in isolated urinary bladder detrusor strips from rabbit
Authors: He Hong-Mei , Ren Lei-Ming , Tian He-Lin , Lu Hai-Gang , Zhao Ding 
Published: February 2012

Moxonidine and clonidine, which are imidazoline compounds, are sympathetic modulators used as centrally acting antihypertensive drugs. Moxonidine, clonidine, and agmatine produce extensive effects in mammalian tissues via imidazoline recognition sites (or receptors) or α2-adrenoceptors. To investigate the effects of imidazolines on the function of the urinary bladder, we tested the effects of moxonidine, clonidine, and agmatine on the neurogenic contraction induced by electric field stimulation, and on the post-synaptic receptors in isolated urinary bladder detrusor strips from rabbit. Both moxonidine at 1.0–10.0 µmol/L and clonidine at 0.1–10.0 µmol/L inhibited electric-field-stimulation-induced contraction in a concentration-dependent manner, but not agmatine (10.0–1000.0 µmol/L). Both moxonidine and clonidine failed to affect carbachol or adenosine-triphosphate-induced contractions; however, 1000.0 µmol/L agmatine significantly increased these contractions. Our study indicates that (i) moxonidine and clonidine produce a concentration-dependent inhibition of the neurogenic contractile responses to electric field stimulation in isolated detrusor strips from male New Zealand rabbits; (ii) post-synaptic muscarinic receptor and purinergic receptor stimulation are not involved in the responses of moxinidine and clonidine in this study; (iii) the inhibitory effects of these agents are probably not mediated by presynaptic imidazoline receptors.
Inhibitory effect of ginsenoside-Rd on carrageenan-induced inflammation in rats
Authors: Wang Li , Zhang Yunxin , Wang Zhiping , Li Sijia , Min Guangning , Wang Lihua , Chen Jiajia , Cheng Junjun , Wu Yongjie 
Published: February 2012

A previous study reported that ginsenoside-Rd reduced the production of tumor necrosis factor-α by inhibiting nuclear factor-κB in lipopolysaccharide-activated N9 microglia in vitro. The aim of the present study was to confirm the anti-inflammatory effects and mechanisms of ginsenoside-Rd in animal experiments involving acute inflammation. The results indicated that ginsenoside-Rd at doses ranging from 12.5 to 50 mg/kg i.m. significantly inhibited the swelling of hind paws in rats for 1–6 h after the carrageenan injection. The levels of proinflammatory cytokines and proinflammatory mediators were markedly reduced by ginsenoside-Rd. Ginsenoside-Rd, when administered intramuscularly at 12.5, 25, and 50 mg/kg doses, showed signicant inhibition of carrageenan-induced production of interleukin-1β (6.91%, 45.75%, and 55.18%, respectively), tumor necrosis factor-α (37.99%, 56.39%, and 47.38%, respectively), prostaglandin E2 (22.92%, 30.12%, and 36.36%, respectively), and nitric oxide (28.27%, 44.53%, and 53.42%, respectively). In addition, ginsenoside-Rd (12.5, 25, and 50 mg/kg i.m.) effectively decreased the levels of nuclear factor-κB (6.77%, 20.28%, and 41.03%, respectively) and phosphorylation of IκBα (13.23%, 26.92%, and 41.80%, respectively) in the carrageenan-inflamed paw tissues. These results suggest that ginsenoside-Rd has significant anti-inflammatory effects in vivo, which might be due to its blocking of the nuclear factor-κB signaling pathway. Thus, it may be possible to develop ginsenoside-Rd as a useful agent for inflammatory diseases.
Dmp1 Physically Interacts with p53 and Positively Regulates p53′s Stability, Nuclear Localization, and Function
Authors: Frazier Donna P. , Kendig Robert D. , Kai Fumitake , Maglic Dejan , Sugiyama Takayuki , Morgan Rachel L. , Fry Elizabeth A. , Lagedrost Sarah J. , Sui Guangchao , Inoue Kazushi 
Published: February 2012

AbstractThe transcription factor Dmp1 is a Ras/HER2-activated haplo-insufficient tumor suppressor that activates the Arf/p53 pathway of cell-cycle arrest. Recent evidence suggests that Dmp1 may activate p53 independently of Arf in certain cell types. Here, we report findings supporting this concept with the definition of an Arf-independent function for Dmp1 in tumor suppression. We found that Dmp1 and p53 can interact directly in mammalian cells via the carboxyl-terminus of p53 and the DNA-binding domain of Dmp1. Expression of Dmp1 antagonized ubiquitination of p53 by Mdm2 and promoted nuclear localization of p53. Dmp1–p53 binding significantly increased the level of p53, independent of the DNA-binding activity of Dmp1. Mechanistically, p53 target genes were activated synergistically by the coexpression of Dmp1 and p53 in p53−/−;Arf−/− cells, and genotoxic responses of these genes were hampered more dramatically in Dmp1−/− and p53−/− cells than in Arf−/− cells. Together, our findings identify a robust new mechanism of p53 activation mediated by direct physical interaction between Dmp1 and p53. Cancer Res; 72(7); 1740–50. ©2012 AACR.
A Naive Bayesian Cloud-Detection Scheme Derived from CALIPSO and Applied within PATMOS-x
Authors: Heidinger Andrew K. , Evan Amato T. , Foster Michael J. , Walther Andi 
Published: February 2012

AbstractThe naive Bayesian methodology has been applied to the challenging problem of cloud detection with NOAA’s Advanced Very High Resolution Radiometer (AVHRR). An analysis of collocated NOAA-18/AVHRR and Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO)/Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) observations was used to automatically and globally derive the Bayesian classifiers. The resulting algorithm used six Bayesian classifiers computed separately for seven surface types. Relative to CALIPSO, the final results show a probability of correct detection of roughly 90% over water, deserts, and snow-free land; 82% over the Arctic; and below 80% over the Antarctic. This technique is applied within the NOAA Pathfinder Atmosphere’s Extended (PATMOS-x) climate dataset and the Clouds from AVHRR Extended (CLAVR-x) real-time product generation system. Comparisons of the PATMOS-x results with those from International Satellite Cloud Climatology Project (ISCCP) and Moderate Resolution Imaging Spectroradiometer (MODIS) indicate close agreement with zonal mean differences in cloud amount being less than 5% over most zones. Most areas of difference coincided with regions where the Bayesian cloud mask reported elevated uncertainties. The ability to report uncertainties is a critical component of this approach.
Seasonality of African Precipitation from 1996 to 2009
Authors: Liebmann Brant , Bladé Ileana , Kiladis George N. , Carvalho Leila M. V. , B. Senay Gabriel , Allured Dave , Leroux Stephanie , Funk Chris 
Published: February 2012

AbstractA precipitation climatology of Africa is documented using 12 years of satellite-derived daily data from the Global Precipitation Climatology Project (GPCP). The focus is on examining spatial variations in the annual cycle and describing characteristics of the wet season(s) using a consistent, objective, and well-tested methodology. Onset is defined as occurring when daily precipitation consistently exceeds its local annual daily average and ends when precipitation systematically drops below that value. Wet season length, rate, and total are then determined. Much of Africa is characterized by a single summer wet season, with a well-defined onset and end, during which most precipitation falls. Exceptions to the single wet season regime occur mostly near the equator, where two wet periods are usually separated by a period of relatively modest precipitation. Another particularly interesting region is the semiarid to arid eastern Horn of Africa, where there are two short wet seasons separated by nearly dry periods. Chiefly, the summer monsoon spreads poleward from near the equator in both hemispheres, although in southern Africa the wet season progresses northwestward from the southeast coast. Composites relative to onset are constructed for selected points in West Africa and in the eastern Horn of Africa. In each case, onset is often preceded by the arrival of an eastward-propagating precipitation disturbance. Comparisons are made with the satellite-based Tropical Rainfall Measuring Mission (TRMM) and gauge-based Famine Early Warning System (FEWS NET) datasets. GPCP estimates are generally higher than TRMM in the wettest parts of Africa, but the timing of the annual cycle and average onset dates are largely consistent.
Uncertainty and Intercalibration Analysis of H*Wind
Authors: DiNapoli Steven M. , Bourassa Mark A. , Powell Mark D. 
Published: February 2012

Abstract
The Hurricane Research Division (HRD) Real-time Hurricane Wind Analysis System (H*Wind) is a software application used by NOAA’s HRD to create a gridded tropical cyclone wind analysis based on a wide range of observations. These analyses are used in both forecasting and research applications. Although mean bias and RMS errors are listed, H*Wind lacks robust uncertainty information that considers the contributions of random observation errors, relative biases between observation types, temporal drift resulting from combining nonsimultaneous measurements into a single analysis, and smoothing and interpolation errors introduced by the H*Wind analysis. This investigation seeks to estimate the total contributions of these sources, and thereby provide an overall uncertainty estimate for the H*Wind product.
A series of statistical analyses show that in general, the total uncertainty in the H*Wind product in hurricanes is approximately 6% near the storm center, increasing to nearly 13% near the tropical storm force wind radius. The H*Wind analysis algorithm is found to introduce a positive bias to the wind speeds near the storm center, where the analyzed wind speeds are enhanced to match the highest observations. In addition, spectral analyses are performed to ensure that the filter wavelength of the final analysis product matches user specifications. With increased knowledge of bias and uncertainty sources and their effects, researchers will have a better understanding of the uncertainty in the H*Wind product and can then judge the suitability of H*Wind for various research applications.
A Unification of Ensemble Square Root Kalman Filters
Authors: Nerger Lars , Janjić Tijana , Schröter Jens , Hiller Wolfgang 
Published: February 2012

AbstractIn recent years, several ensemble-based Kalman filter algorithms have been developed that have been classified as ensemble square root Kalman filters. Parallel to this development, the singular “evolutive” interpolated Kalman (SEIK) filter has been introduced and applied in several studies. Some publications note that the SEIK filter is an ensemble Kalman filter or even an ensemble square root Kalman filter. This study examines the relation of the SEIK filter to ensemble square root filters in detail. It shows that the SEIK filter is indeed an ensemble square root Kalman filter. Furthermore, a variant of the SEIK filter, the error subspace transform Kalman filter (ESTKF), is presented that results in identical ensemble transformations to those of the ensemble transform Kalman filter (ETKF), while having a slightly lower computational cost. Numerical experiments are conducted to compare the performance of three filters (SEIK, ETKF, and ESTKF) using deterministic and random ensemble transformations. The results show better performance for the ETKF and ESTKF methods over the SEIK filter as long as this filter is not applied with a symmetric square root. The findings unify the separate developments that have been performed for the SEIK filter and the other ensemble square root Kalman filters.
Wintertime Extreme Precipitation Events along the Pacific Northwest Coast: Climatology and Synoptic Evolution
Authors: Warner Michael D. , Mass Clifford F. , Salathé Eric P. 
Published: February 2012

AbstractExtreme precipitation events impact the Pacific Northwest during winter months, causing flooding, landslides, extensive property damage, and loss of life. Outstanding questions about such events include whether there are a range of associated synoptic evolutions, whether such evolutions vary along the coast, and the associated rainfall duration and variability. To answer these questions, this study uses 60 years of National Climatic Data Center (NCDC) daily precipitation observations to identify the top 50 events in two-day precipitation at six coastal stations from northern California to northwest Washington. NCEP–NCAR reanalysis data were used to construct synoptic composite evolutions of these events for each coastal location. Most regional flooding events are associated with precipitation periods of 24 h or less, and two-day precipitation totals identify nearly all major events. Precipitation areas of major events are generally narrow, roughly 200 km in width, and most are associated with atmospheric rivers. Composite evolutions indicate negative anomalies in sea level pressure and upper-level height in the central Pacific, high pressure anomalies over the southwest United States, large positive 850-hPa temperature anomalies along the coast and offshore, and enhanced precipitable water and integrated water vapor fluxes over southwest to northeast swaths. A small subset of extreme precipitation events over the southern portion of the domain is associated with a very different synoptic evolution: a sharp trough in northwesterly flow and post-cold-frontal convection. High precipitable water values are more frequent during the summer, but are not associated with heavy precipitation due to upper-level ridging over the eastern Pacific and weak onshore flow that limit upward vertical velocities.
Lubricin Distribution in the Menisci and Labra of Human Osteoarthritic Joints
Authors: Zhang Dafang , Cheriyan Thomas , Martin Scott D. , Schmid Thomas M. , Spector Myron 
Published: February 2012

Objective: Lubricin is the principal boundary lubricant on articular cartilage. We aimed to describe the distribution of lubricin in the other articulating structures in the human knee and hip—menisci and labra—and to relate this distribution to the degree of tissue degeneration. Methods: Eighteen menisci and 6 labra were obtained from patients with osteoarthritis undergoing total knee and total hip replacements, respectively. Macroscopically intact specimens were fixed in formalin and processed for H&E staining and immunohistochemical evaluation with an antilubricin monoclonal antibody. Results: Lubricin was found in all tissues as a discrete layer on the tissue surface, within the extracellular matrix, and intracellularly, indicating that it plays a role in the tribology of these tissues in human subjects, and can be synthesized by cells within the tissues. While none of the samples displayed macroscopic tears, approximately 40% of the surface of the menisci and 80% of the surface of the labra displayed microscopic fibrillations and slight fraying. There was no effect of the degenerative changes on the distribution of lubricin. Conclusions: Lubricin coats nearly the entirety of the surfaces of menisci and labra, including microfibrillations and tears, with possible implications towards the tribology of the tissues and healing of tissue damage.
Isolation and characterization of stromal progenitor cells from ascites of patients with epithelial ovarian adenocarcinoma
Authors: Ho Chih-Ming , Chang Shwu-Fen , Hsiao Chih-Chiang , Chien Tsai-Yen , Shih Daniel Tzu-Bi 
Published: February 2012

AbstractBackgroundAt least one-third of epithelial ovarian cancers are associated with the development of ascites containing heterogeneous cell populations, including tumor cells, inflammatory cells, and stromal elements. The components of ascites and their effects on the tumor cell microenvironment remain poorly understood. This study aimed to isolate and characterize stromal progenitor cells from the ascites of patients with epithelial ovarian adenocarcinoma (EOA).MethodsSeventeen ascitic fluid samples and 7 fresh tissue samples were collected from 16 patients with EOA. The ascites samples were then cultured in vitro in varying conditions. Flow cytometry and immunocytochemistry were used to isolate and characterize 2 cell populations with different morphologies (epithelial type and mesenchymal type) deriving from the ascites samples. The in vitro cell culture model was established using conditional culture medium.ResultsThe doubling times of the epithelial type and mesenchymal type cells were 36 h and 48 h, respectively, indicating faster growth of the epithelial type cells compared to the mesenchymal type cells. Cultured in vitro, these ascitic cells displayed the potential for self-renewal and long-term proliferation, and expressed the typical cancer stem/progenitor cell markers CD44high, CD24low, and AC133+. These cells also demonstrated high BMP-2, BMP4, TGF-β, Rex-1, and AC133 early gene expression, and expressed EGFR, integrin α2β1, CD146, and Flt-4, which are highly associated with tumorigenesis and metastasis. The epithelial type cells demonstrated higher cytokeratin 18 and E-cadherin expression than the mesenchymal type cells. The mesenchymal type cells, in contrast, demonstrated higher AC133, CD73, CD105, CD117, EGFR, integrin α2β1, and CD146 surface marker expression than the epithelial type cells.ConclusionThe established culture system provides an in vitro model for the selection of drugs that target cancer-associated stromal progenitor cells, and for the development of ovarian cancer treatments.
Distinct co-evolution patterns of genes associated to DNA polymerase III DnaE and PolC
Authors: Engelen Stefan , Vallenet David , Médigue Claudine , Danchin Antoine 
Published: February 2012

Abstract

Background
Bacterial genomes displaying a strong bias between the leading and the lagging strand of DNA replication encode two DNA polymerases III, DnaE and PolC, rather than a single one. Replication is a highly unsymmetrical process, and the presence of two polymerases is therefore not unexpected. Using comparative genomics, we explored whether other processes have evolved in parallel with each polymerase.

Results
Extending previous in silico heuristics for the analysis of gene co-evolution, we analyzed the function of genes clustering with dnaE and polC. Clusters were highly informative. DnaE co-evolves with the ribosome, the transcription machinery, the core of intermediary metabolism enzymes. It is also connected to the energy-saving enzyme necessary for RNA degradation, polynucleotide phosphorylase. Most of the proteins of this co-evolving set belong to the persistent set in bacterial proteomes, that is fairly ubiquitously distributed. In contrast, PolC co-evolves with RNA degradation enzymes that are present only in the A+T-rich Firmicutes clade, suggesting at least two origins for the degradosome.

Conclusion
DNA replication involves two machineries, DnaE and PolC. DnaE co-evolves with the core functions of bacterial life. In contrast PolC co-evolves with a set of RNA degradation enzymes that does not derive from the degradosome identified in gamma-Proteobacteria. This suggests that at least two independent RNA degradation pathways existed in the progenote community at the end of the RNA genome world.