bluuebunny/crossref_metadata_2025_split huggingface dataset:
Procalcitonin predicts mortality in HIV‐infected Ugandan adults with lower respiratory tract infections
Authors: Tokman Sofya , Barnett Christopher F. , Jarlsberg Leah G. , Taub Pam R. , den Boon Saskia , Davis J. Lucian , Cattamanchi Adithya , Worodria William , Maisel Alan , Huang Laurence ,   the International HIV‐Associated Opportunistic Pneumonias (IHOP) Study
Published: January 2014

AbstractBackground and objectiveIn low and middle‐income countries where HIV infection is prevalent, identifying patients at high risk of dying from lower respiratory tract infections is challenging and validated prognostic models are lacking. Serum procalcitonin may be a useful prognostic tool in these settings. We sought to determine if elevated serum procalcitonin is associated with increased in‐hospital mortality and to combine serum procalcitonin with available clinical characteristics to create a clinically useful prognostic model.MethodsWe conducted a prospective, nested case‐control study of 241 HIV‐infected adults admitted to Mulago Hospital in Kampala, Uganda with cough ≥2 weeks in duration. We collected demographic and clinical information, baseline serum for procalcitonin analysis, and followed patients to determine in‐hospital mortality.ResultsSerum procalcitonin was a strong and independent predictor of inpatient mortality (aOR = 7.69, p = 0.01, sensitivity = 93%, negative predictive value = 97%). Best subset multivariate analysis identified 3 variables that were combined into a prognostic model to risk stratify patients; these variables included respiratory rate ≥30 breaths/minute (aOR = 2.07, p = 0.11), oxygen saturation <90% (aOR = 3.07, p = 0.02), and serum procalcitonin >0.5 ng/ml (aOR = 7.69, p = 0.01). The predicted probability of inpatient mortality ranged from 1% when no variables were present, to 42% when all variables were present.ConclusionsElevated serum procalcitonin >0.5 ng/ml is an independent predictor of in‐hospital mortality. Elevated serum procalcitonin, tachypnea, and hypoxemia may be combined into a prognostic model to identify patients at high risk of dying in the hospital. This model may be used to estimate the probability of death and to guide triage and treatment decisions.
Use of IL3 and chromatin‐modifying reagents valproic acid and 5‐aza‐2′‐deoxycytidine to affect mobilized peripheral blood CD34+ cell fate decisions
Authors: Liu J. , Samuel K. , Turner M. L. , Gallagher R. C. J. 
Published: January 2014

Background and ObjectivesCulture of blood CD34+ cells with chromatin‐modifying agents can lead to an increase in marrow repopulating cells and in the case of valproic acid increased erythroid cell colony formation. We undertook research to help understand what effects these reagents have on mobilized peripheral blood (MPB) CD34+ cells.Materials and MethodsMobilized peripheral blood was obtained under informed consent and ethics committee approval from nine patients and allograft donors. Epigenetic modifiers valproic acid and 5‐aza‐2′‐deoxycytidine were used singly or in combination with each other and with IL3 when culturing mobilized peripheral blood CD34+ cells. Cultured cells were subsequently used in flow cytometry and colony‐forming unit assay experiments.ResultsAddition of IL3 to the in vitro cell growth medium improved the expansion and maintained the functionality of CD34+ cells. Valproic acid and IL3 also work synergistically to increase the numbers of CD34+/CD36+ double‐positive cells. We found that an apparent increase in red cell colony formation was a result of a decrease in white cell colonies, with no overall increase in red cell colonies when equivalent numbers of CD34+ cells are plated.ConclusionsMobilized peripheral blood CD34+ stem and progenitor cells are affected by chromatin‐modifying agents and IL3 giving higher numbers of CD34+/CD36+ double‐positive erythroid progenitors.
Frequency Analysis of Nonidentically Distributed Hydrometeorological Extremes Associated with Large-Scale Climate Variability Applied to South Korea
Authors: Lee Taesam , Jeong Changsam 
Published: January 2014

AbstractIn the frequency analyses of extreme hydrometeorological events, the restriction of statistical independence and identical distribution (iid) from year to year ensures that all observations are from the same population. In recent decades, the iid assumption for extreme events has been shown to be invalid in many cases because long-term climate variability resulting from phenomena such as the Pacific decadal variability and El Niño–Southern Oscillation may induce varying meteorological systems such as persistent wet years and dry years. Therefore, the objective of the current study is to propose a new parameter estimation method for probability distribution models to more accurately predict the magnitude of future extreme events when the iid assumption of probability distributions for large-scale climate variability is not adequate. The proposed parameter estimation is based on a metaheuristic approach and is derived from the objective function of the rth power probability-weighted sum of observations in increasing order. The combination of two distributions, gamma and generalized extreme value (GEV), was fitted to the GEV distribution in a simulation study. In addition, a case study examining the annual hourly maximum precipitation of all stations in South Korea was performed to evaluate the performance of the proposed approach. The results of the simulation study and case study indicate that the proposed metaheuristic parameter estimation method is an effective alternative for accurately selecting the rth power when the iid assumption of extreme hydrometeorological events is not valid for large-scale climate variability. The maximum likelihood estimate is more accurate with a low mixing probability, and the probability-weighted moment method is a moderately effective option.
Temporal Downscaling and Statistical Analysis of Rainfall across a Topographic Transect in Northwest Mexico
Authors: Mascaro Giuseppe , Vivoni Enrique R. , Gochis David J. , Watts Christopher J. , Rodriguez Julio C. 
Published: January 2014

AbstractIn this study a temporal statistical downscaling scheme of rainfall is calibrated using observations from 2007 to 2010 at eight sites located along a 14-km topographic transect of 784 m in elevation in northwest Mexico. For this purpose, the rainfall statistical properties over a wide range of temporal scales (3 months–1 min) for the summer (July–September) and winter (November–March) seasons are first analyzed. Rainfall accumulation is found not to be significantly correlated with elevation in either season, and a strong diurnal cycle is found to be present only in summer, peaking in the late afternoon. Winter rainfall events are highly correlated between individual stations across the transect even at short aggregation times (<30 min), and summer storms are more localized in space and time. Spectral and scale invariance analyses showed the presence of three (two) scaling regimes in summer (winter), which are associated with typical meteorological phenomena of the corresponding time scales (frontal systems and relatively isolated convective systems). These analyses formed the basis for calibrating a temporal downscaling model to disaggregate daily precipitation to hourly resolution in the summer season, based on scale invariance and multifractal theory. In this downscaling scheme, a modulation function was used to reproduce the time heterogeneity introduced by the diurnal cycle. The model showed adequate performances in reproducing the small-scale observed precipitation variability. Results of this work are useful for the interpretation of storm-generation mechanisms in the region, and for creating hourly rainfall time series from daily rainfall data, obtained from observations or simulated by climate, meteorological, or other statistical models.
The Origins of Late-Twentieth-Century Variations in the Large-Scale North Atlantic Circulation
Authors: Yeager Stephen , Danabasoglu Gokhan 
Published: January 2014

Abstract
Surface forcing perturbation experiments are examined to identify the key forcing elements associated with late-twentieth-century interannual-to-decadal Atlantic circulation variability as simulated in an ocean–sea ice hindcast configuration of the Community Earth System Model, version 1 (CESM1). Buoyancy forcing accounts for most of the decadal variability in both the Atlantic meridional overturning circulation (AMOC) and the subpolar gyre circulation, and the key drivers of these basin-scale circulation changes are found to be the turbulent buoyancy fluxes: evaporation as well as the latent and sensible heat fluxes. These three fluxes account for almost all of the decadal AMOC variability in the North Atlantic, even when applied only over the Labrador Sea region. Year-to-year changes in surface momentum forcing explain most of the interannual AMOC variability at all latitudes as well as most of the decadal variability south of the equator. The observed strengthening of Southern Ocean westerly winds accounts for much of the simulated AMOC variability between 30°S and the equator but very little of the recent AMOC change in the North Atlantic. Ultimately, the strengthening of the North Atlantic overturning circulation between the 1970s and 1990s, which contributed to a pronounced SST increase at subpolar latitudes, is explained almost entirely by trends in the atmospheric surface state over the Labrador Sea.
Seasonal Variations of Subtropical Precipitation Associated with the Southern Annular Mode
Authors: Hendon Harry H. , Lim Eun-Pa , Nguyen Hanh 
Published: January 2014

Abstract
Seasonal variations of subtropical precipitation anomalies associated with the southern annular mode (SAM) are explored for the period 1979–2011. In all seasons, high-polarity SAM, which refers to a poleward-shifted eddy-driven westerly jet, results in increased precipitation in high latitudes and decreased precipitation in midlatitudes as a result of the concomitant poleward shift of the midlatitude storm track. In addition, during spring–autumn, high SAM also results in increased rainfall in the subtropics. This subtropical precipitation anomaly is absent during winter. This seasonal variation of the response of subtropical precipitation to the SAM is shown to be consistent with the seasonal variation of the eddy-induced divergent meridional circulation in the subtropics (strong in summer and weak in winter). The lack of an induced divergent meridional circulation in the subtropics during winter is attributed to the presence of the wintertime subtropical jet, which causes a broad latitudinal span of eddy momentum flux divergence due primarily to higher phase speed eddies breaking poleward of the subtropical jet and lower speed eddies not breaking until they reach the equatorward flank of the subtropical jet. During the other seasons, when the subtropical jet is less distinctive, the critical line for both high and low speed eddies is on the equatorward flank of the single jet and so breaking in the subtropics occurs over a narrow range of latitudes. The implications of these findings for the seasonality of future subtropical climate change, in which a shift to high SAM in all seasons is expected to be promoted, are discussed.
Telomerase functions beyond telomere maintenance in primary cutaneous T-cell lymphoma
Authors: Chevret Edith , Andrique Laetitia , Prochazkova-Carlotti Martina , Ferrer Jacky , Cappellen David , Laharanne Elodie , Idrissi Yamina , Boettiger Anna , Sahraoui Wafa , Ruiz Florian , Pham-Ledard Anne , Vergier Beatrice , Belloc Francis , Dubus Pierre , Beylot-Barry Marie , Merlio Jean-Philippe 
Published: January 2014

Key Points
Besides maintaining short telomeres, telomerase is required for cell proliferation and tumor growth in CTCL.
Prevalence of human papillomavirus infection in the oropharynx and urine among sexually active men: a comparative study of infection by papillomavirus and other organisms, including Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma spp., and Ureaplasma spp
Authors: Nakashima Kazufumi , Shigehara Kazuyoshi , Kawaguchi Shohei , Wakatsuki Akira , Kobori Yoshitomo , Nakashima Kazuyoshi , Ishii Yasunori , Shimamura Masayoshi , Sasagawa Toshiyuki , Kitagawa Yasuhide , Mizokami Atsushi , Namiki Mikio 
Published: January 2014

Abstract

Background
Oropharyngeal squamous cell carcinoma (OSCC) has shown a gradual increase in male predominance due to the increasing incidence of human papillomavirus (HPV)-associated OSCC. However, the mode of HPV transmission to the oral cavity is poorly understood, and little is known about the epidemiology of oral HPV infection in men. The prevalence rates of HPV, Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma spp., and Ureaplasma spp. were compared in the oropharynx (oral cavity) and urine of male Japanese patients attending a sexually transmitted disease clinic.

Methods
The study population consisted of 213 men aged 16 – 70 years old (mean: 34.4 years old). Oropharyngeal gargles and urine were collected, and sedimented cells were preserved in liquid-based cytology solution. After DNA extraction, β-globin and infectious organisms were analyzed by a PCR-based method. The HPV genotype was determined by HPV GenoArray test.

Results
β-Globin was positive in 100% and 97.7% of oral and urine samples, respectively. HPV detection rates were 18.8% and 22.1% in oral and urine samples, respectively, suggesting that the prevalence of HPV infection in the oral cavity was similar to that in the urinary tract. N. gonorrhoeae was more prevalent in oral (15.6%) than urine samples (9.1%), whereas C. trachomatis was detected more frequently in urine (15.9%) than oral samples (4.2%). The detection rates of M. genitalium, M. hominis, and Ureaplasma spp. were 5.2%, 10.3%, and 16.0% in oral samples, and 7.7%, 6.3%, and 19.2% in urine, respectively. There were no significant differences in the detection rates of Mycoplasma spp. and Ureaplasma spp. between anatomical locations. The distribution of HPV types were similar in oral and urine samples, and HPV16 was the most common type. The majority of men with HPV infection in both the oral cavity and urine had concordant oral and urinary HPV infection. The presence of urinary HPV infection was an independent risk factor of oral HPV infection, with an odds ratio of 3.39 (95% CI: 1.49 – 7.71), whereas oral gonococcal infection was inversely correlated with oral HPV infection (odds ratio: 0.096; 95% CI: 0.01 – 0.77).

Conclusions
Oral HPV infection commonly occurs in sexually active men, and is significantly correlated with urinary HPV infection.
Changes in cerebral oxygenation during early postnatal adaptation in newborns delivered by vacuum extraction measured by near-infrared spectroscopy
Authors: Karen Tanja , Wolf Martin , Nef Rahel , Haensse Daniel , Bucher Hans Ulrich , Schulz Gabriele , Fauchère Jean-Claude 
Published: January 2014

Abstract

Background
Newborns delivered by vacuum extraction quite often show clinical signs of a hemodynamic compromise, which is difficult to assess in terms of severity. The conventional means to measure the hemodynamic status are not sensitive enough to appreciate the severity of general, and more specifically of cerebral circulatory imbalance. The aim was to study cerebral tissue oxygenation during postnatal adaptation in these infants using near-infrared spectroscopy.

Methods
The tissue hemoglobin index (THI), tissue oxygenation index (TOI), arterial oxygen saturation (pre-ductal SaO2) and heart rate (HR) were recorded immediately after birth, and again after 12–24 hours of life in 15 newborns delivered by vacuum extraction due to fetal distress. A comparison with 19 healthy newborns delivered by elective cesarean section was performed.

Results
Newborns delivered by vacuum extraction had significantly higher THI 10 to 15 minutes after birth. TOI and HR were significantly higher in the first 5 min and SaO2 in the first 10 minutes but then did not differ from those after cesarean section.

Conclusion
Infants delivered by vacuum extraction following fetal distress show transient deviations in cerebral oxygenation and perfusion after birth which were not detectable after 24 hours.
High-order approximation algorithm using Gram-Schmidt QR transformations coupled with an iterative correction process for tracking frequency drift in OFDM systems
Authors: Yen Rainfield Y , Liu Hong-Yu , Yin Yung-Chang 
Published: January 2014

Abstract
To jointly track frequency drift (or fine frequency offset) and channel state variation for orthogonal frequency division multiplexing (OFDM) communications over mobile wireless channels, the maximum-likelihood (ML) estimation techniques are commonly adopted. A major difficulty arises from the highly nonlinear nature of the log-likelihood function which renders local extrema or multiple solutions. The use of mathematical approximation coupled with an adaptive iteration algorithm is a viable approach to ease problem solving. The approximation methods used in existing works are usually of the first-order level. In this work, we devise a high-order approximation algorithm to improve the tracking performance. As shall be seen, the problem amounts to finding the roots of an approximate high-degree polynomial equation derived from the log-likelihood function. To this end, we triangularize the companion matrix constructed from the high-degree polynomial using iterative Gram-Schmidt QR transformations, an eigenvalue problem in matrix computation, coupled with another iterative correction process to produce a frequency offset estimate to good accuracy. It is found that a high-order approximation algorithm formulated can achieve much better tracking performance in terms of estimation accuracy, tracking range, and error rate results than various other tracking algorithms appearing in the literature.
On combining multi-normalization and ancillary measures for the optimal score level fusion of fingerprint and voice biometrics
Authors: Mohammed Anzar Sharafudeen Thaha , Sathidevi Puthumangalathu Savithri 
Published: January 2014

Abstract
In this paper, we have considered the utility of multi-normalization and ancillary measures, for the optimal score level fusion of fingerprint and voice biometrics. An efficient matching score preprocessing technique based on multi-normalization is employed for improving the performance of the multimodal system, under various noise conditions. Ancillary measures derived from the feature space and the score space are used in addition to the matching score vectors, for weighing the modalities, based on their relative degradation. Reliability (dispersion) and the separability (inter-/intra-class distance and d-prime statistics) measures under various noise conditions are estimated from the individual modalities, during the training/validation stage. The ‘best integration weights’ are then computed by algebraically combining these measures using the weighted sum rule. The computed integration weights are then optimized against the recognition accuracy using techniques such as grid search, genetic algorithm and particle swarm optimization. The experimental results show that, the proposed biometric solution leads to considerable improvement in the recognition performance even under low signal-to-noise ratio (SNR) conditions and reduces the false acceptance rate (FAR) and false rejection rate (FRR), making the system useful for security as well as forensic applications.
Inconsistencies between alcohol screening results based on AUDIT-C scores and reported drinking on the AUDIT-C questions: prevalence in two US national samples
Authors: Delaney Kate E , Lee Amy K , Lapham Gwen T , Rubinsky Anna D , Chavez Laura J , Bradley Katharine A 
Published: January 2014

AbstractBackgroundThe AUDIT-C is an extensively validated screen for unhealthy alcohol use (i.e. drinking above recommended limits or alcohol use disorder), which consists of three questions about alcohol consumption. AUDIT-C scores ≥4 points for men and ≥3 for women are considered positive screens based on US validation studies that compared the AUDIT-C to “gold standard” measures of unhealthy alcohol use from independent, detailed interviews. However, results of screening—positive or negative based on AUDIT-C scores—can be inconsistent withreported drinkingon the AUDIT-C questions. For example, individuals can screen positive based on the AUDIT-Cscorewhile reporting drinking below US recommended limits on the same AUDIT-C. Alternatively, they can screen negative based on the AUDIT-Cscorewhile reporting drinking above US recommended limits. Such inconsistencies could complicate interpretation of screening results, but it is unclear how often they occur in practice.MethodsThis study used AUDIT-C data from respondents who reported past-year drinking on one of two national US surveys: a general population survey (N = 26,610) and a Veterans Health Administration (VA) outpatient survey (N = 467,416). Gender-stratified analyses estimated the prevalence of AUDIT-C screen results—positive or negative screens based on the AUDIT-C score—that were inconsistent withreported drinking(above or below US recommended limits) on the same AUDIT-C.ResultsAmong men who reported drinking, 13.8% and 21.1% of US general population and VA samples, respectively, had screening results based on AUDIT-C scores (positive or negative) that were inconsistent with reported drinking on the AUDIT-C questions (above or below US recommended limits). Among women who reported drinking, 18.3% and 20.7% of US general population and VA samples, respectively, had screening results that were inconsistent with reported drinking.LimitationsThis study did not include an independent interview gold standard for unhealthy alcohol use and therefore cannot address how often observed inconsistencies represent false positive or negative screens.ConclusionsUp to 21% of people who drink alcohol had alcohol screening results based on the AUDIT-C score that were inconsistent with reported drinking on the same AUDIT-C. This needs to be addressed when training clinicians to use the AUDIT-C.