On the Link between the Subseasonal Evolution of the North Atlantic Oscillation and East Asian Climate

We analyse the impact of the North Atlantic Oscillation (NAO) on the climate of East Asia at subseasonal time scales during both winter and summer. These teleconections have mainly been investigated at seasonal and longer time scales, while higher-frequency links are largely unexplored. The NAO is defined using extended empirical orthogonal functions on pentad-mean observations, which allows to elucidate the oscillation’s spatial and temporal evolution and clearly separate the development and decay phases. The downstream dynamical imprint and associated temperature and precipitation anomalies are quantified by means of a linear regression analysis. It is shown that the NAO generates a significant climate response over East Asia during both the dry and wet seasons, whose spatial pattern is highly dependent on the phase of the NAO’s life cycle. Temperature and precipitation anomalies develop concurrently with the NAO mature phase, and reach maximum amplitude 5–10 days later. These are shown to be systematically related to mid and high-latitude teleconnections across the Eurasian continent via eastward-propagating quasi-stationary Rossby waves instigated over the Atlantic and terminating in the northeastern Pacific. These findings underscore the importance of rapidly evolving dynamical processes in governing the NAO’s downstream impacts and teleconnections with East Asia.</p

Mutations underlying 3-Hydroxy-3-Methylglutaryl CoA Lyase deficiency in the Saudi population

BACKGROUND: 3-Hydroxy-3-Methylglutaric aciduria (3HMG, McKusick: 246450) is an autosomal recessive branched chain organic aciduria caused by deficiency of the enzyme 3-Hydroxy-3-Methylglutaryl CoA lyase (HL, HMGCL, EC 4.1.3.4). HL is encoded by HMGCL gene and many mutations have been reported. 3HMG is commonly observed in Saudi Arabia. METHODS: We utilized Whole Genome Amplification (WGA), PCR and direct sequencing to identify mutations underlying 3HMG in the Saudi population. Two patients from two unrelated families and thirty-four 3HMG positive dried blood spots (DBS) were included. RESULTS: We detected the common missense mutation R41Q in 89% of the tested alleles (64 alleles). 2 alleles carried the frame shift mutation F305fs (-2) and the last two alleles had a novel splice site donor IVS6+1G>A mutation which was confirmed by its absence in more than 100 chromosomes from the normal population. All mutations were present in a homozygous state, reflecting extensive consanguinity. The high frequency of R41Q is consistent with a founder effect. Together the three mutations described account for >94% of the pathogenic mutations underlying 3HMG in Saudi Arabia. CONCLUSION: Our study provides the most extensive genotype analysis on 3HMG patients from Saudi Arabia. Our findings have direct implications on rapid molecular diagnosis, prenatal and pre-implantation diagnosis and population based prevention programs directed towards 3HMG

Search for resonances in the mass distribution of jet pairs with one or two jets identified as <i>b</i> -jets in proton–proton collisions at √s = 13 TeV with the ATLAS detector

Searches for high-mass resonances in the dijet invariant mass spectrum with one or two jets identified as b -jets are performed using an integrated luminosity of 3.2 fb−1 of proton–proton collisions with a centre-of-mass energy of √s = 13 TeV recorded by the ATLAS detector at the Large Hadron Collider. No evidence of anomalous phenomena is observed in the data, which are used to exclude, at 95% credibility level, excited b* quarks with masses from 1.1 TeV to 2.1 TeV and leptophobic Z′ bosons with masses from 1.1 TeV to 1.5 TeV. Contributions of a Gaussian signal shape with effective cross sections ranging from approximately 0.4 to 0.001 pb are also excluded in the mass range 1.5–5.0 TeV

Search for resonances in diphoton events at √s = 13 TeV with the ATLAS detector

Searches for new resonances decaying into two photons in the ATLAS experiment at the CERN Large Hadron Collider are described. The analysis is based on proton-proton collision data corresponding to an integrated luminosity of 3.2 fb−1 at s√=13 TeV recorded in 2015. Two searches are performed, one targeted at a spin-2 particle of mass larger than 500 GeV, using Randall-Sundrum graviton states as a benchmark model, and one optimized for a spin-0 particle of mass larger than 200 GeV. Varying both the mass and the decay width, the most significant deviation from the background-only hypothesis is observed at a diphoton invariant mass around 750 GeV with local significances of 3.8 and 3.9 standard deviations in the searches optimized for a spin-2 and spin-0 particle, respectively. The global significances are estimated to be 2.1 standard deviations for both analyses. The consistency between the data collected at 13 TeV and 8 TeV is also evaluated. Limits on the production cross section times branching ratio to two photons for the two resonance types are reported

Microsoft Word - 21410_0_art_file_1_1139507572.doc

Abstract This paper investigates the potential of various approaches for improving sweep in parts of the Daqing Oil Field that have been EOR targets. Possibilities included (1) gel treatments that are directed at channeling through fractures, (2) colloidal dispersion gels, (3) reduced polymer degradation, (4) more viscous polymer solutions, and (5) foams and other methods. Our studies indicated that the polymer flood should have provided excellent sweep throughout the vast majority of the patterns under consideration. However, since ASP flooding is being considered to increase recovery efficiency from the Daqing Oil Field, mobility control and sweep improvement will be especially important and challenging during implementation of any future ASP process. Fractures were present in a number of Daqing wells (both injectors and producers). Because the fractures were narrow far from the wellbore, severe channeling did not occur. On the contrary, fractures near the wellbore aided reservoir sweep. These near-wellbore fractures substantially increased the injectivity index during injection of polymer solutions and increased oil productivity index in the production wells. These observations may be valuable during implementation of future floods where very low-mobility chemical (i.e., ASP) banks must be injected to maintain mobility control. Several modes of polymer degradation were considered, with mechanical (shear) degradation being of most concern. Appropriate use of near-wellbore fractures may effectively mitigate mechanical degradation, as well as improving injectivity. Several new polymers show potential for cost-effective improvements at Daqing. Increased polymer concentration was also considered. A number of other approaches are (or have been) under investigation, including colloidal dispersion gels, foams, ASP foams, steam, microbes, and polymer solutions prepared with reduced salinity. Introduction Laboratory research began in the 1960s, investigating the potential of enhanced oil recovery (EOR) processes in the Daqing Oil Field. Use of polymer flooding was identified as a key method to improve areal and vertical sweep efficiency, as well as providing mobility control. 1 Consequently, the world&apos;s largest polymer flood was implemented at Daqing, beginning in 1996. 2,3 By 2004, 22.7% of total production from the Daqing Oil Field was attributed to polymer flooding. Polymer flooding should boost the ultimate recovery for the field to over 50% original oil in place (OOIP)-10% OOIP more than from waterflooding. Alkaline/surfactant/polymer flooding (ASP) has also experienced extensive laboratory testing in China. The ASP technique was gradually perfected for application at Daqing and has been pilot tested on a large scale. Although field tests of polymer and ASP flooding have been very successful at Daqing, concerns about sweep efficiency persist-particularly the possibility of channeling expensive chemical formulations through the reservoir. Therefore, the sweep efficiency at Daqing is receiving intense scrutiny, and possibilities for improvement are being considered. In this paper, we examine the nature of reservoir sweep in parts of the Daqing Oil Field that have been EOR targets. We investigate the potential of various approaches for improving sweep, including (1) gel treatments that are directed at channeling through fractures, (2) colloidal dispersion gels, (3) reduced polymer degradation, (4) more viscous polymer solutions, and (5) foams and other methods (e.g., thermal and microbial techniques). Our objective is to establish better options for improving sweep in the main producing zone in the future. Sweep Efficiency in the Daqing Oil Field Stratification. What is the nature of the sweep efficiency problem at Daqing? This study focused on the Eastern Berxi polymer flooding area of the Daqing field-specifically on 17 production wells and 8 injection wells. Layer PI, a principal target for EOR at Daqing, is composed of up to seven named &quot;zones.&quot; The gross pay for Layer PI varied between 18 and 33 SPE 9944

Prevalence of Chronic Hepatitis B Virus Infection in Sierra Leone, 1997-2022: A Systematic Review and Meta-Analysis.

Hepatitis B virus (HBV) infection is a major public health problem in Sierra Leone, yet reliable estimates of cases are lacking. This study aimed to provide an estimate of the national prevalence of chronic HBV infection in the general population and select groups in Sierra Leone. We used the electronic databases PubMed/MEDLINE, Embase, Scopus, ScienceDirect, Web of Science, Google Scholar, and African Journals Online to systematically review articles reporting hepatitis B infection surface antigen seroprevalence estimates in Sierra Leone during 1997-2022. We estimated pooled HBV seroprevalence rates and assessed potential sources of heterogeneity. Of 546 publications screened, 22 studies with a total sample size of 107,186 people were included in the systematic review and meta-analysis. The pooled prevalence of chronic HBV infection was 13.0% (95% CI, 10.0-16.0) (I2 = 99%; Pheterogeneity < 0.01). During the study period, the HBV prevalence rates were as follows: 17.9% (95% CI, 6.7-39.8) before 2015, 13.3% (95% CI, 10.4-16.9) during 2015-2019, and 10.7% (95% CI, 7.5-14.9) during 2020-2022. The use of the 2020-2022 HBV prevalence estimates corresponded to 870,000 cases of chronic HBV infection (uncertainty interval, 610,000-1,213,000), or approximately one in nine people. The highest HBV seroprevalence estimates were among adolescents aged 10-17 years (17.0%; 95% CI, 8.8-30.5), Ebola survivors (36.8%; 95% CI, 26.2-48.8), people living with HIV (15.9%; 95% CI, 10.6-23.0), and those in the Northern Province (19.0%; 95% CI, 6.4-44.7) and Southern Province (19.7%; 95% CI, 10.9-32.8) regions. These findings may help inform national HBV program implementation in Sierra Leone