Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|$\eta$|<0.8) and transverse momentum range 0.2< $p_{\rm T}$< 5.0 GeV/$c$. The elliptic flow signal v$_2$, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 $\pm$ 0.002 (stat) $\pm$ 0.004 (syst) in the 40-50% centrality class. The differential elliptic flow v$_2(p_{\rm T})$ reaches a maximum of 0.2 near $p_{\rm T}$ = 3 GeV/$c$. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/389

Higher harmonic anisotropic flow measurements of charged particles in Pb-Pb collisions at 2.76 TeV

We report on the first measurement of the triangular $v_3$, quadrangular $v_4$, and pentagonal $v_5$ charged particle flow in Pb-Pb collisions at 2.76 TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow $v_2$ and $v_3$ have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients.Comment: 10 pages, 4 figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/387

Measurement of D+- and D0 production in deep inelastic scattering using a lifetime tag at HERA

The production of D-+/-- and D-0-mesons has been measured with the ZEUS detector at HERA using an integrated luminosity of 133.6 pb(-1). The measurements cover the kinematic range 5 < Q(2) < 1000 GeV2, 0.02 < y < 0.7, 1.5 < p(T)(D) < 15 GeV and |eta(D)| < 1.6. Combinatorial background to the D-meson signals is reduced by using the ZEUS microvertex detector to reconstruct displaced secondary vertices. Production cross sections are compared with the predictions of next-to-leading-order QCD, which is found to describe the data well. Measurements are extrapolated to the full kinematic phase space in order to obtain the open-charm contribution, F-2(c (c) over bar), to the proton structure function, F-2

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Riesgo cardiovascular en estudiantes de medicina del municipio Puerto Padre de Las Tunas

Introduction: cardiovascular diseases are the first cause of death in Cuba; as a result, the identification of cardiovascular risks from early ages allows the implementation of health promotion and prevention strategies to reduce their impact in the futureObjective: to identify the cardiovascular risk in medical students in Puerto Padre Municipality, Las Tunas province.Methods: an observational, descriptive and cross-sectional study was conducted. The target group included 545 medical students, 237 of whom were selected by means of a simple random sample. The body mass index and waist-hip ratio were studied. Descriptive statistics was applied.Results: the predominant age group was 18-21 years old (50,2 %). The 51,47 % of the students presented a high waist-hip ratio, 54,02 % a high abdominal circumference, 52,74 % a high body mass index, and in all groups 35,44 % presented blood pressure figures lower than 120/80 mmHg; 39 % had a cardiovascular risk.Conclusions: low percentages of cardiovascular risk were identified in medical students from Puerto Padre Municipality, Las Tunas province, determined by high values of waist-hip index, body mass index and abdominal circumference.Introducción: las enfermedades cardiovasculares constituyen la primera causa de mortalidad en Cuba; por lo cual la identificación de riesgos cardiovasculares desde edades tempranas permite implementar estrategias de promoción y prevención de salud para disminuir su impacto en el futuroObjetivo: identificar el riesgo cardiovascular en estudiantes de medicina del municipio Puerto Padre de Las Tunas.Método: se realizó un estudio observacional, descriptivo y transversal. El universo estuvo constituido por 545 estudiantes de medicina, seleccionándose 237 mediante un muestreo aleatorio simple. Se estudió el índice de masa corporal, la circunferencia abdominal y la índice cintura cadera. Se empleó estadística descriptiva.Resultados: se encontró predominio del grupo etario de 18 a 21 años (50,2 %). El 51,47 % de los estudiantes presentó un índice cintura-cadera alto, el 54,02 % una circunferencia abdominal alta, el 52,74 % un índice de masa corporal alta, así como en todos los grupos el 35,44 % presentó cifras de tensión arterial inferiores a 120/80 mmHg. El 39 % presentó riesgo cardiovascular.Conclusiones: se identificaron bajos porcientos de riesgo cardiovascular en los estudiantes de medicina del municipio Puerto Padre de Las Tunas, determinado por altos valores los índice cintura-cadera, índice de masa corporal y circunferencia abdominal

Day-night differences in hydroacoustic estimates of fish abundance and distribution in Lake Laojianghe, China

Hydroacoustic surveys were performed in an oxbow lake (Lake Laojianghe, China) along the Yangtze River. The study took place during the day and night in October 2012 using the Simrad EY60 split beam echo sounder. A clear day-night difference in fish densities was observed in selected transect areas. The mean density estimate at night was three times higher than during the day, while at night densities were similar in the two adjacent areas. Significantly positive relationships were found between fish density and average depth for the night and daytime transects, however, the regression slope for the daytime density estimates was much smaller than for the surveys at night. Small fish dominated the acoustic size structure during both day and night, but were more accessible at night. The average biomass estimate from the daytime transects was nearly 60% lower than those from the corresponding night transects. These results indicate that an entire lake estimate of a fish population may be severely biased if fish tend to aggregate temporarily in the bottom or littoral zone or display diurnal behaviour. The conclusion is that acoustic sampling in Lake Laojianghe is best done at night. Diel differences in the lake should be further investigated by carrying out additional day-night comparison experiments and also by using control catches.Hydroacoustic surveys were performed in an oxbow lake (Lake Laojianghe, China) along the Yangtze River. The study took place during the day and night in October 2012 using the Simrad EY60 split beam echo sounder. A clear day-night difference in fish densities was observed in selected transect areas. The mean density estimate at night was three times higher than during the day, while at night densities were similar in the two adjacent areas. Significantly positive relationships were found between fish density and average depth for the night and daytime transects, however, the regression slope for the daytime density estimates was much smaller than for the surveys at night. Small fish dominated the acoustic size structure during both day and night, but were more accessible at night. The average biomass estimate from the daytime transects was nearly 60% lower than those from the corresponding night transects. These results indicate that an entire lake estimate of a fish population may be severely biased if fish tend to aggregate temporarily in the bottom or littoral zone or display diurnal behaviour. The conclusion is that acoustic sampling in Lake Laojianghe is best done at night. Diel differences in the lake should be further investigated by carrying out additional day-night comparison experiments and also by using control catches

Advances in precocity research of the Chinese mitten crab Eriocheir sinensis

Precocity has been observed in fishes and crustaceans. However, mechanisms underlying precocity have not been well documented in crustaceans and are thought to be influenced by both genetic and environmental factors. Also, precocity is generally considered to have negative effects on crustaceans. The Chinese mitten crab Eriocheir sinensis, a catadromous species endemic to China, is a high valued commodity and in the recent past is being extensively cultured to meet the growing demand by the restaurant trade. The mitten crab is an ideal candidate for precocity studies because of their large size, distinct secondary sex characters, wide distribution and abundant availability from commercial farms. In this article, progress in several aspects of precocity of E. sinensis is reviewed, including the phenomena of precocity and its effect, identification of precocious crabs, factors related to precocity (temperature, salinity, light, nutrition, stocking density, and germplasm), relationships between precocity and neuro-endocrine system, steroid hormones or hepatopancreas, prevention and control methods of precocity. In addition, possible future directions for the study of precocity are suggested

Reproductive biology of Chinese minnow Hemiculterella sauvagei Warpachowski, 1888 in the Chishui River, China

This study describes the reproductive biology of the Chinese minnow Hemiculterella sauvagei. The length-weight relationship, sex ratio, spawning season, size at first maturity, and fecundity were analyzed based on 685 specimens collected from the Chishui River between July 2011 and July 2012. The relationship between standard length (SL) and body weight (BW) were estimated as BW=2.14x10(-4)xSL(2.801) (R-2=0.839; N=413; P&lt;0.05) for females and BW=1.31 x10(-4)xSL(3.001) (R-2=0.868; N=272; P&lt;0.05) for males. The female to male sex ratio, 1.52:1, differed significantly from a 1:1 ratio. Females predominated in standard lengths &gt;12cm. Analyses of the monthly variation in the gonadosomatic index (GSI), the monthly proportions of macroscopic gonadal maturity, and the size distribution of oocytes consistently suggested a prolonged spawning season of H.sauvagei from March to August, with a peak from April to May. Logistic curves describing the relationship between proportion of maturity (P-r) at each length interval and standard length were estimated as P-r=1/(1+e(26.867-0.306SL)) (R-2=0.999; N=413; P&lt;0.05) for females and P-r=1/(1+e(10.522-0.142SL)) (R-2=0.999; N=272; P&lt;0.05) for males. Size at first maturity was estimated as 7.4cm for males and 8.8cm SL for females. Absolute fecundity varied from 563 to 5052, with a mean of 2413 +/- 874 oocytes per ovary. The relative fecundity was estimated to be 41-299, with a mean of 171 +/- 55 oocytes per ovary. The present study provides useful information for fishery management and resources conservation.This study describes the reproductive biology of the Chinese minnow Hemiculterella sauvagei. The length-weight relationship, sex ratio, spawning season, size at first maturity, and fecundity were analyzed based on 685 specimens collected from the Chishui River between July 2011 and July 2012. The relationship between standard length (SL) and body weight (BW) were estimated as BW=2.14x10(-4)xSL(2.801) (R-2=0.839; N=413; P12cm. Analyses of the monthly variation in the gonadosomatic index (GSI), the monthly proportions of macroscopic gonadal maturity, and the size distribution of oocytes consistently suggested a prolonged spawning season of H.sauvagei from March to August, with a peak from April to May. Logistic curves describing the relationship between proportion of maturity (P-r) at each length interval and standard length were estimated as P-r=1/(1+e(26.867-0.306SL)) (R-2=0.999; N=413; P<0.05) for females and P-r=1/(1+e(10.522-0.142SL)) (R-2=0.999; N=272; P<0.05) for males. Size at first maturity was estimated as 7.4cm for males and 8.8cm SL for females. Absolute fecundity varied from 563 to 5052, with a mean of 2413 +/- 874 oocytes per ovary. The relative fecundity was estimated to be 41-299, with a mean of 171 +/- 55 oocytes per ovary. The present study provides useful information for fishery management and resources conservation

Composition and length-weight relationships of fish species in Lake Erhai, southwestern China

Length-weight relationships (LWRs) are described for 23 fish species (five indigenous species and 18 exotic species) in Lake Erhai, a plateau deep lake located in southwestern China. Four different types of fishing gear were used in order to include all possible length ranges from 2009 to 2012. Results show that the exponent b ranged from 2.72 to 3.79. The length of the growth inflection point between juveniles and females of Pseudorasbora parva and Micropercops swinhonis coincides with the length at which 50% of the females are sexually mature, respectively. The LWRs of P. parva and M. swinhonis are affected by sexual dimorphism, and Hemiculter leucisculus shows significant differences between juveniles and females. In addition, the first LWR records for nine species are provided in this study.Length-weight relationships (LWRs) are described for 23 fish species (five indigenous species and 18 exotic species) in Lake Erhai, a plateau deep lake located in southwestern China. Four different types of fishing gear were used in order to include all possible length ranges from 2009 to 2012. Results show that the exponent b ranged from 2.72 to 3.79. The length of the growth inflection point between juveniles and females of Pseudorasbora parva and Micropercops swinhonis coincides with the length at which 50% of the females are sexually mature, respectively. The LWRs of P. parva and M. swinhonis are affected by sexual dimorphism, and Hemiculter leucisculus shows significant differences between juveniles and females. In addition, the first LWR records for nine species are provided in this study