bluuebunny/crossref_metadata_2025_split huggingface dataset:
VARIETIES WHOSE TOLERANCES ARE HOMOMORPHIC IMAGES OF THEIR CONGRUENCES
Authors: CZÉDLI GÁBOR , KISS EMIL W. 
Published: August 2012

AbstractThe homomorphic image of a congruence is always a tolerance (relation) but, within a given variety, a tolerance is not necessarily obtained this way. By a Maltsev-like condition, we characterise varieties whose tolerances are homomorphic images of their congruences (TImC). As corollaries, we prove that the variety of semilattices, all varieties of lattices, and all varieties of unary algebras have TImC. We show that a congruencen-permutable variety has TImC if and only if it is congruence permutable, and construct an idempotent variety with a majority term that fails TImC.
Dak Roads, Dak Runners, and the Reordering of Communication Networks
Authors: Joshi Chitra 
Published: August 2012

SummaryWith the expansion of its territory in India in the first half of the nineteenth century, the British East India Company increasingly felt the need to widen postal networks and speed up communications. This essay looks at the crucial role of thedauriya(mail runner) in the development of postal networks by exploring the narratives around popular images of this “traditional” communication worker. Accounts of the lives of mail runners were interwoven with stories of their extraordinary physical strength and the dangers they negotiated along the way, their encounters with tigers, and their commitment to carry the imperial mail through rain and flood. Behind such narratives lay a history of regulations, a story of the making of a “modern” postal system. This entailed an effort to rationalize the system, calculating the speed of running, ensuring regularity, projecting estimated times of travel, and enforcing contracts. This essay aims to understand the logic of these changes, and the implications of these regulations.
Comparison of the population biology ofEpialtus bituberculatusfrom two rocky shores with distinct hydrodynamic patterns
Authors: Barros-Alves Samara de Paiva , Alves Douglas Fernandes Rodrigues , Cobo Valter José 
Published: August 2012

The population biology ofEpialtus bituberculatuswas compared between two different intertidal localities with differing levels of wave exposure. Sampling was conducted monthly between January and December, 2001 on seaweed banks ofSargassum cymosumin the intertidal zone of the rocky shores Grande (GR) (23°23′S–45°03′W) and Domingas Dias (DD) (23°29′S–45°08′W). Four hundred and twenty-eight crabs were captured at the GR site: 111 juvenile males, 106 adult males, 57 juvenile females, 17 adult females and 137 ovigerous females; while 455 specimens were obtained at the DD site: 76 juvenile males, 113 adult males, 37 juvenile females, 40 adult females and 189 ovigerous females. The population from GR showed a non-normal distribution and from DD a normal distribution. The sex-ratio (female/male) was 1:0.97 at GR (χ2 = 0.77,P = 0.084), whereas it was 1:1.41 at DD (χ2 = 13.03,P < 0.001). The largest individuals occurred at DD (U = 78249.0,P < 0.001). The estimated size at sexual maturity was 6.3 and 5.0 mm carapace width (CW) for males, and 5.4 and 5.2 mm CW for females, from GR and DD, respectively. The observed differences inE. bituberculatusbetween the studied localities might be explained by the different degrees of wave exposure between sites. However, other factors that might also explain the observed differences (e.g. temperature, salinity and food availability) cannot be discarded as relevant in influencing the population structure between sites herein studied.
The presence of HBV mRNA in the fertilized in vitro embryo of HBV patients confirms vertical transmission of HBV via the ovum
Authors: YE F. , JIN Y. , KONG Y. , SHI J. Z. , QIU H. T. , ZHANG X. , ZHANG S. L. , LIN S. M. 
Published: August 2012

SUMMARYThis study aimed to confirm that vertical transmission of hepatitis B virus (HBV) can occur via the infected ovum. Specimens studied were obtained from discarded test-tube embryos from mothers with chronic HBV infection who had received in vitro fertilization treatment. Single-cell reverse transcriptase–polymerase chain reaction was used to detect HBV mRNA in the embryos. HBV mRNA was detected in the cleavage embryos of patients with chronic HBV infection, with a detection rate of 13·2% (5/38). The level of serum HBV DNA was not related to the HBV mRNA positivity rates in embryos. In this study, HBV mRNA was detected in test-tube embryos from HBV-infected mothers who had received in vitro fertilization treatment. This confirms the theory of vertical transmission of HBV via the ovum, thereby providing an important theoretical basis for further study on the mechanism of HBV vertical transmission, influencing factors and blocking measures.
A clear view of the multifaceted dayside ionosphere of Mars
Authors: Withers Paul , Fallows Kathryn , Girazian Zachary , Matta Majd , Häusler Bernd , Hinson David , Tyler Len , Morgan David , Pätzold Martin , Peter Kerstin , Tellmann Silvia , Peralta Javier , Witasse Oliver 
Published: August 2012

By examining electron density profiles from the Mars Express Radio Science Experiment MaRS, we show that the vertical structure of the dayside ionosphere of Mars is more variable and more complex than previously thought. The top of the ionosphere can be below 250 km (25% occurrence rate) or above 650 km (1%); the topside ionosphere can be well‐described by a single scale height (10%) or two/three regions with distinct scale heights (25% or 10%), where those scale heights range between tens and hundreds of kilometers; the main layer of the ionosphere can have a sharply pointed (5%), flat‐topped (6%), or wavy (8%) shape, in contrast to its usual Chapman‐like shape; a broad increase in electron density is detected at 160–180 km (10%); a narrow increase in electron density is sometimes found in strongly‐magnetized regions; and an additional layer is present between the M1 and M2 layers (3%).
Statistical analysis of dipolarizations using spacecraft closely separated along Z in the near‐Earth magnetotail
Authors: Palin L. , Jacquey C. , Sauvaud J.‐A. , Lavraud B. , Budnik E. , Angelopoulos V. , Auster U. , McFadden J. P. , Larson D. 
Published: August 2012

The THEMIS mission includes three closely separated probes that provide the opportunity to analyze the small and meso‐scale dynamics of the cross‐tail current sheet in the near‐Earth magnetosphere (10 Re). In this study, we focus on dipolarization events which occurred when two of these satellites were: (1) separated only along the Z direction (i.e., at the same location in the XYGSM) plane, and: (2) on separate sides of the neutral sheet. Following these criteria, our search resulted in 25 dipolarization events. Most of them were not associated with global auroral substorm but were rather associated with arc intensification and magnetic perturbation observed from the ground only in limited local time sectors. Based on these, we demonstrate that dipolarizations systematically correspond to a thickening of the current sheet rather than any other phenomena (e.g., flapping). We also show that the current density in the sheet systematically decreases after onset. Most of the events show an increase of the Laplace force and of the magnetic tension after the dipolarization onset. This trend is however, sensitive to the coordinate system chosen (i.e., GSM or SM). We find that the total energy density (total pressure) increases after 70% of the dipolarization events. However, when excluding the Z‐component of the magnetic field (which is canceled by the dominant curvature terms) from the pressure, we find that the pressure decreases after 64% of events, and the remaining pressure increases occur closest to the neutral sheet. Five minutes averages are used 5 to 10 min before dipolarization and 10 to 15 min after dipolarization. We discuss the importance of both the spacecraft location relative to the neutral sheet and timescales chosen when calculating the pressure changes. These directly impact interpretations relative to dipolarization models.
Predictor selection for downscaling GCM data with LASSO
Authors: Hammami Dorra , Lee Tae Sam , Ouarda Taha B. M. J. , Lee Jonghyun 
Published: August 2012

Over the last 10 years, downscaling techniques, including both dynamical (i.e., the regional climate model) and statistical methods, have been widely developed to provide climate change information at a finer resolution than that provided by global climate models (GCMs). Because one of the major aims of downscaling techniques is to provide the most accurate information possible, data analysts have tried a number of approaches to improve predictor selection, which is one of the most important steps in downscaling techniques. Classical methods such as regression techniques, particularly stepwise regression (SWR), have been employed for downscaling. However, SWR presents some limits, such as deficiencies in dealing with collinearity problems, while also providing overly complex models. Thus, the least absolute shrinkage and selection operator (LASSO) technique, which is a penalized regression method, is presented as another alternative for predictor selection in downscaling GCM data. It may allow for more accurate and clear models that can properly deal with collinearity problems. Therefore, the objective of the current study is to compare the performances of a classical regression method (SWR) and the LASSO technique for predictor selection. A data set from 9 stations located in the southern region of Québec that includes 25 predictors measured over 29 years (from 1961 to 1990) is employed. The results indicate that, due to its computational advantages and its ease of implementation, the LASSO technique performs better than SWR and gives better results according to the determination coefficient and the RMSE as parameters for comparison.
Satellite observations of ship emission induced transitions from broken to closed cell marine stratocumulus over large areas
Authors: Goren Tom , Rosenfeld Daniel 
Published: August 2012

Documentation of the evolution of ship tracks during 42 h demonstrated that ship emissions are able to convert a marine stratocumulus regime of open cells into closed cells, along with significant negative radiative forcing. This was possible by examining continuous day and night geostationary satellite data that allowed for an uninterrupted documentation of the full life cycle of ship tracks. After nearly one day the ship tracks lost their linear appearance and expanded to cover large areas. These areas, when viewed out of sequence and context, would not be attributable to aerosol perturbations. A rejuvenation of previously dissipated ship tracks in the form of extensive closed cells was also observed. It is suggested that ship emissions may undergo photochemical reactions which nucleate new aerosols that, along with remaining ultrafine particles, grow to CCN that are activated hours later and close the open cells. The added radiative forcing from the closed cells that can be related to the ship tracks, which is mainly coming from the cloud cover effect, may exceed −100 Wm−2, depending on the season and latitude. This implies that anthropogenic aerosols that can be transported from continents through the boundary layer, or travel in the free troposphere and mix with the boundary layer from above, may explain the formation of large closed cells areas that are presently not recognized as originated by aerosol perturbations. The observations reported here pose a demanding test of the ability of cloud resolving models to replicate cloud‐aerosol interactions.
A new model for the spectral induced polarization signature of bacterial growth in porous media
Authors: Revil A. , Atekwana E. , Zhang C. , Jardani A. , Smith S. 
Published: August 2012

The complex conductivity of porous materials and colloidal suspensions comprises two components: an in‐phase conductivity associated with electromigration of the charge carriers and a quadrature conductivity associated with the reversible storage of the charges at some polarization length scales. We developed a quantitative model to investigate the frequency domain induced polarization response of suspensions of bacteria and bacteria growth in porous media. Induced polarization of bacteria (α polarization) is related to the properties of the electrical double layer of the bacteria. Surface conductivity and α polarization are due to the Stern layer of counterions occurring in a brush of polymers coating the surface of the bacteria. These phenomena can be related to their cation exchange capacity. The mobility of the counterions in this Stern layer is found to be very small (4.7 × 10−10 m2 s−1 V−1 at 25°C). This implies a very low relaxation frequency for the αpolarization of the bacteria cells (typically around 0.1–5 Hz), in agreement with experimental observations. This new model can be coupled to reactive transport modeling codes in which the evolution of bacterial populations are usually described by Monod kinetics. We show that the growth rate and endogenous decay coefficients of bacteria in a porous sand can be inferred nonintrusively from time‐lapse frequency domain induced polarization data.
Statin therapy and clinical outcomes in myocardial infarction patients complicated by acute heart failure: insights from the EPHESUS trial
Authors: Dobre Daniela , Rossignol Patrick , Murin Jan , Parkhomenko Alexander , Lamiral Zohra , Krum Henry , van Veldhuisen Dirk J. , Pitt Bertram , Zannad Faiez 
Published: August 2012

AimsSeveral clinical trials have shown that in patients with acute myocardial infarction (MI), statin therapy improves cardiovascular (CV) outcomes, but in these trials patients with acute heart failure (HF) were excluded or only a few were included. In patients with chronic HF, statin therapy does not reduce all‐cause or CV mortality. We aimed to assess the association between statin therapy and clinical outcomes in the setting of acute HF with systolic dysfunction complicating acute MI.Methods and resultsWe performed a post‐hoc analysis in 6632 patients included in the EPHESUS trial. The mean age of patients was 64 years and 71% were male. Overall, 47% of patients had a statin prescribed at baseline. Cox regression models and a secondary analysis using propensity score matching were fit to assess the association between statin prescription and clinical outcomes. During a mean follow‐up of 16 ± 7 months, all‐cause death occurred in 385 (12%) patients with and in 647 (18%) patients without a statin (P < 0.001). After extensive adjustment, the risk of all‐cause death was 20% lower in patients on statin [hazard ratio (HR) 0.80, 95% confidence interval (CI) 0.69–0.92, P = 0.001]. This positive association was mostly due to a lower risk of CV death (HR 0.76, 95% CI 0.65–0.88, P = 0.0002). In contrast, statin use was associated with a higher risk of non‐CV hospitalizations (HR 1.16, 95% CI 1.02–1.33, P = 0.02).ConclusionOur results suggest that patients with acute HF complicating acute MI may benefit from being on statin therapy. Prospective clinical trials are required to validate these findings.
The 40 m general purpose small-angle neutron scattering instrument at Oak Ridge National Laboratory
Authors: Wignall George D. , Littrell Kenneth C. , Heller William T. , Melnichenko Yuri B. , Bailey Kathy M. , Lynn Gary W. , Myles Dean A. , Urban Volker S. , Buchanan Michelle V. , Selby Douglas L. , Butler Paul D. 
Published: August 2012

A series of upgrades have been undertaken at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, including the installation of a supercritical hydrogen moderator (T≃ 20 K), which has boosted the flux of long-wavelength neutrons by over two orders of magnitude. In order to take advantage of the new capabilities, a 40 m-long small-angle neutron scattering (SANS) instrument has been constructed, which utilizes a mechanical velocity selector, pinhole collimation and a high-count-rate (>105 Hz) large-area (1 m2) two-dimensional position-sensitive detector. The incident wavelength (λ), resolution (Δλ/λ), incident collimation and sample-to-detector distance are independently variable under computer control. The detector can be moved up to 45 cm off-axis to increase the overallQrange [<0.001 <Q= (4π/λ)sinθ < 1 Å−1, where 2θ is the angle of scatter]. The design and characteristics of this instrument are described, along with examples of scattering data to illustrate the performance.
Efficacy and Safety of Standard‐Dose Versus Half‐Dose Tirofiban in Patients with Non‐ST Elevation Acute Coronary Syndromes Undergoing Early Percutaneous Coronary Intervention
Authors: Li Wei , Fu Xianghua , Xue Haiwei , Wang Yanbo , Wang Xuechao , Zhao Yujun , Geng Wei , Yang Zengxin , Gu Xinshun , Hao Guozhen , Jiang Yunfa , Fan Weize , Wu Weili , Li Shiqiang 
Published: August 2012

SummaryIntroductionTo explore the optimal dosage of tirofiban associated with double benefits of efficacy and safety in patients with non‐ST elevation acute coronary syndromes (NSTE‐ACS) undergoing early percutaneous coronary intervention (PCI).AimsA total of 163 patients were included in this study (78 in SD group versus 85 in HD group). In SD (HD) group, tirofiban was administered intravenously with a bolus dose of 10 (5) μg/kg within 3 min and followed by continuous intravenous infusion of 0.15 (0.075) μg/kg/min for 48 h. Within 24 h on admission, patients underwent CAG or CAG+PCI. The angiographic results (initial TIMI, final TIMI/CTFC/TMPG) were evaluated. Platelet aggregation rate (PAR) was measured before and 2, 24, 48 h after bolus tirofiban. MACEs were evaluated at 7‐day, 30‐day, and 6‐month follow‐up. Bleeding was observed at 7 days.ResultsThe proportions of TIMI grade 3 seemed higher in SD group before and after PCI followed by a better myocardial perfusion, but not statistically different (P = 0.26/0.08). PAR was lower in SD group than that in HD group at 2 h after bolus tirofiban (P = 0.03). MACEs were not statistically different at 7, 30 day, and 6 month in two groups. The incidence of minor bleeding was significantly lower in HD group than that in SD group (8.2% vs. 20.5%, P = 0.04). The risk of bleeding would increase under the conditions of decreased PAR, increased dose of tirofiban and decreased CCr.ConclusionHalf‐dose tirofiban was not inferior to standard‐dose in efficacy, what is more, half‐dose tirofiban showed a better safety characteristic of lower bleeding risk. Therefore, half‐dose tirofiban is recommended to patients with NSTE‐ACS undergoing early PCI.
Use of multiple linear regression and logistic regression models to investigate changes in birthweight for term singleton infants in Scotland
Authors: Bonellie Sandra R 
Published: August 2012

Aim.  To illustrate the use of regression and logistic regression models to investigate changes over time in size of babies particularly in relation to social deprivation, age of the mother and smoking.Background.  Mean birthweight has been found to be increasing in many countries in recent years, but there are still a group of babies who are born with low birthweights.Design.  Population‐based retrospective cohort study.Method.  Multiple linear regression and logistic regression models are used to analyse data on term ‘singleton births’ from Scottish hospitals between 1994–2003.Results.  Mothers who smoke are shown to give birth to lighter babies on average, a difference of approximately 0·57 Standard deviations lower (95% confidence interval. 0·55–0·58) when adjusted for sex and parity. These mothers are also more likely to have babies that are low birthweight (odds ratio 3·46, 95% confidence interval 3·30–3·63) compared with non‐smokers. Low birthweight is 30% more likely where the mother lives in the most deprived areas compared with the least deprived, (odds ratio 1·30, 95% confidence interval 1·21–1·40).Conclusions.  Smoking during pregnancy is shown to have a detrimental effect on the size of infants at birth. This effect explains some, though not all, of the observed socioeconomic birthweight. It also explains much of the observed birthweight differences by the age of the mother.Relevance to clinical practice.  Identifying mothers at greater risk of having a low birthweight baby as important implications for the care and advice this group receives.
Abrupt early Eocene global climatic change as a control of carbonate facies and diagenesis: a new record of the Palaeocene–Eocene Thermal Maximum in the Umm er Radhuma Formation, Saudi Arabia and Kuwait
Authors: Pollitt David A. , Anthonissen Erik , Saller Arthur H. , BouDagher‐Fadel Marcelle K. , Dickson J. A. D. 
Published: August 2012

Terra Nova, 24, 487–498, 2012AbstractRecords of the Palaeocene–Eocene Thermal Maximum (PETM) and associated Carbon Isotope Excursion (CIE) are relatively rare in shallow‐ marine carbonates when compared with those from other regimes, and it remains unclear exactly what effect this global climatic event had upon the widespread epeiric carbonate platforms of the Palaeogene. In this study, we demonstrate that the Umm er Radhuma Formation in the Wafra field, Kuwait and Saudi Arabia, shows a carbon isotope profile consistent with the CIE that can be correlated globally and further, that global climate change during and subsequent to the PETM exerted a fundamental control on primary depositional facies and subsequent diagenesis. The Palaeocene–Eocene Thermal Maximum was a brief hyper‐thermal event marking the onset of sustained high global temperatures during the Early Eocene. This warm period increased aridity in epeiric carbonate platform interiors of what is now the Middle East, affecting composition of depositional facies and the precipitation of early dolomite. This is demonstrated through the use of new data from the Umm er Radhuma Formation, Wafra field, Partitioned Zone, Saudi Arabia and Kuwait. Biostratigraphy and carbon isotope profiles have been used to constrain the position of the PETM and Carbon Isotope Excursion; a distinct ∼2–3‰ negative spike. The observed excursion is demonstrated to correlate globally and provides age dating of this regionally important succession. Core and thin‐section data show marked restriction of facies across the PETM, evidence of increasing aridity reflected in proportion of evaporite precipitates and a stratigraphically restricted non‐mimetic dolomite coeval to the CIE that is interpreted to relate to a change in the rate of dolomite precipitation. This work provides an example of how a global environmental event is manifest in depositional and early diagenetic changes in marine carbonates.
Non‐invasive imaging of living kidney donors: intraindividual comparison of multislice computed tomography angiography with magnetic resonance angiography
Authors: Liefeldt Lutz , Klüner Claudia , Glander Petra , Giessing Markus , Budde Klemens , Taupitz Matthias , Rogalla Patrik , Kroencke Thomas J. 
Published: August 2012

AbstractBackgroundEvaluation of vascular variants is crucial for donor assessment prior to living kidney transplantation. Both contrast‐enhanced (CE) magnetic resonance angiography (MRA) and multislice computed tomography (MSCT) are currently used for imaging living kidney donors. Aim of this study was the comparison of the accuracy of MSCT angiography and CE‐MRA for the assessment of renal vascular anatomy.MethodsProspective study at a university transplant center including 65 potential living kidney donors. Pre‐operative imaging by MSCT angiography and CE‐MRA was correlated with the findings of laparoscopic donor nephrectomy in 48 donors.Results
MSCT detected significantly more patients and more kidneys with accessory arteries than CE‐MRA (p < 0.05). MSCT and CE‐MRA performed similarly in identifying venous and ureteral abnormalities. The overall sensitivity, specificity, and accuracy for identifying accessory arteries were 85%/97%/94% for MSCT and 54%/97%/85% for CE‐MRA. The sensitivity, specificity, and accuracy for the identification of supernumerary veins were 67%/95%/92% for MSCT and 67%/98%/94% for CE‐MRA, respectively.ConclusionWe found MSCT angiography to be more sensitive and accurate than CE‐MRA in the detection of supernumerary arteries prior to living donor nephrectomy.