Calibrated cryo-cell UV-LA-ICPMS elemental concentrations from the NGRIP ice core reveal abrupt, sub-annual variability in dust across the GI-21.2 interstadial period

Several abrupt shifts from periods of extreme cold (Greenland stadials, GS) to relatively warmer conditions (Greenland interstadials, GI) called Dansgaard–Oeschger events are recorded in the Greenland ice cores. Using cryo-cell UV-laser-ablation inductively coupled-plasma mass spectrometry (UV-LA-ICPMS), we analysed a 2.85 m NGRIP ice core section (2691.50–2688.65 m depth, age interval 84.86–85.09 ka b2k, thus covering  ∼  230 years) across the transitions of GI-21.2, a short-lived interstadial prior to interstadial GI-21.1. GI-21.2 is a  ∼  100-year long period with δ18O values 3–4 ‰ higher than the following  ∼  200 years of stadial conditions (GS-21.2), which precede the major GI-21.1 warming. We report concentrations of major elements indicative of dust and/or sea salt (Na, Fe, Al, Ca, Mg) at a spatial resolution of  ∼  200 µm, while maintaining detection limits in the low-ppb range, thereby achieving sub-annual time resolution even in deep NGRIP ice. We present an improved external calibration and quantification procedure using a set of five ice standards made from aqueous (international) standard solutions. Our results show that element concentrations decrease drastically (more than 10-fold) at the warming onset of GI-21.2 at the scale of a single year, followed by relatively low concentrations characterizing the interstadial part before gradually reaching again typical stadial values

Association of Academic Stress, Anxiety and Depression with Social-Demographic among Medical Students

Background: Medical education programmes aim at producing wholesome of competent and skilled graduates, research have shown that students experience stress which impacts on their health, academic performance and social functioning. This paper aims to determine the extent of academic stress, depression and anxiety among medical undergraduates and to explore the correlation between academic stressors, psychological stress and socio-demographic background among first year medical students at National University of Science and Technology.Method: This descriptive cross-sectional study was undertaken by first-year medical students in 2016 at NUST Division of Social Medical Sciences. A validated and standardised survey Depression Anxiety Stress Scale (DASS 42) questionnaire was used. Data was analysed by SPSS version 21.0.Results: Nineteen first-year midwifery students participated in the study. Males were 63.1% while females were 38.8%. Seventy-three per cent of the participants experienced stress during the programme, of which forty-nine percent were females. Female students showed severe stress of 6±1.15 as compared to their male counterparts who scored extremely severe stress of 3.81±1.53. Academic, health-related and psychosocial problems were the chief sources of stress.Conclusion: Stress impacts negatively on undergraduate students. Midwifery students need guidance, mentorship and educational integration support to identify and monitor their own well-being.  These measures should promote a balance in selection of positive strategies to overcome stress, managing workload and time effectively during study period

Occurrence and Removal of Persistent Organic Pollutants (POPs)

Since the revelation in the detection of the persistent organic pollutants (POPs) in industrial wastewater in the early 1990s, a notable progress has been achieved on the research and different removal applications or methods of this challenge at hand. This book chapter entails a decent understanding on the occurrence, effects, and amputation of POPs in the water sector in advancement of municipal performances of treating industrial wastewaters and environment at large. This current chapter also presents an overview of research associated to the amputation of persistent organic pollutants (POPs) from various water bodies, i.e., river sediments, sewage plants, industrial sludges, and wastewater. Also, discussing the relationships with actual pre-treatment and removal rates. Vital characteristics such as the wastewater matrix, location, sources of POPs, materials and modules, operational parameters and problems are presented with a clear focus on removal of these organic pollutant’s different sources (like, textile wastewater). The particular methods to the removal of POPs can be associated with the application of ultrafiltration, nanofiltration and reverse osmosis as advanced treatment stages are considered in correlation with the textile wastewater characteristics and removal efficiencies requirements. This gives significance to the amalgamation of physico-chemical and biological treatment with membrane processes which is likely to represent an efficient solution for the removal of POPs from textile wastewater. However, since membrane fouling and hydrophilicity are apparent in the execution of this process, this chapter also covers the effective strategies like fabrication of membrane with a suitable additive to counterattack these challenges, which are often used in membrane technological research. This chapter also proposes an updated understanding of fouling and improvement of membrane properties

Four Lentisphaerae family metagenome-assembled genomes from the South Atlantic ocean

DATA AVAILABILITY : The NCBI BioProject accession number is PRJNA748242, while the Whole Genome Shotgun project has been deposited at DDBJ/ENA/GenBank and the accession numbers are given in Table 1.We present four Lentisphaerae metagenome-assembled genomes (MAGs) from the South Atlantic Ocean. The medium-quality genomes, affiliated with the family of Lentisphaeraceae, ranged from 4.86 to 5.46 Mbp and harbored the genetic capacity to produce secondary metabolites. This resource provides a basis for investigating the functional attributes of this phylum.https://journals.asm.org/journal/mraam2023BiochemistryGeneticsMicrobiology and Plant Patholog

ART initiation among women newly diagnosed with HIV in a contraceptive trial in sub-Saharan Africa

Current guidelines recommend starting antiretroviral therapy (ART) as soon as possible after HIV diagnosis to reduce morbidity, mortality and onward HIV transmission. We examined factors influencing ART initiation by women who seroconverted during the Evidence for Contraceptive Options and HIV Outcomes (ECHO) Trial. ECHO, conducted between 2015 and 2018, enrolled HIV-negative, sexually active women, aged 16–35 years, from four African countries. Follow-up was 12–18 months, with quarterly HIV testing. Women with incident HIV infection received extensive counselling by trial staff and referral to local facilities for HIV care. Of 304 women with ≥90 days follow-up time since HIV diagnosis, 186(61.2%) initiated ART within 90 days, 69(22.7%) initiated after 90 days, and 49(16.1%) had not initiated by the end of the study. There were no statistically significant differences in characteristics among women who initiated ART ≤90 days versus those who did not. Frequent reasons for delayed or non-initiation of ART included not feeling ready to start ART and being newly diagnosed. In a large clinical trial, ART initiation was modest within 90 days of HIV diagnosis and grew to 84% with longer observation. Despite extensive counselling on the importance of early ART initiation, personal barriers delayed some women from starting ART.https://www.tandfonline.com/loi/caic20pm2021Medical Microbiolog

Antimicrobial and antioxidant properties of methanol extract, fractions and compounds from the stem bark of Entada abyssinica Stend ex A. Satabie

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to evaluate the antimicrobial and antioxidant activities of the methanol extract, fractions and isolated compounds from <it>Entada abyssinica </it>stem bark, plant used traditionally against gastrointestinal infections.</p> <p>Methods</p> <p>The methanol extract of <it>E. abyssinica </it>stem bark was pre-dissolved in a mixture of methanol and water, and then partitioned between <it>n</it>-hexane, ethyl acetate and <it>n</it>-butanol. The ethyl acetate portion was fractionated by column chromatography and the structures of isolated compounds elucidated by analysis of spectroscopic data and comparison with literature data. Antimicrobial activity was assayed by broth microdilution techniques on bacteria and yeasts. The antioxidant activity was determined by DPPH radical scavenging method.</p> <p>Results</p> <p>Four known compounds [(5<it>S</it>,6<it>R</it>,8a<it>R</it>)-5-(carboxymethyl)-3,4,4a,5,6,7,8,8a-octahydro-5,6,8a-trimethylnaphthalenecarboxylic acid (<b>1</b>), methyl 3,4,5-trihydroxybenzoate (<b>2</b>), benzene-1,2,3-triol (<b>3</b>) and 2,3-dihydroxypropyltriacontanoate (<b>4</b>)] were isolated. Compared to the methanol extract, fractionation increased the antibacterial activities of the <it>n</it>-hexane and ethyl acetate fractions, while the antifungal activities increased in ethyl acetate, <it>n</it>-butanol and aqueous residue fractions. The isolated compounds were generally more active on bacteria (9.7 to 156.2 μg/ml) than yeasts (78.1 to 312.5 μg/ml). Apart from compound <b>1</b>, the three others displayed DPPH^·scavenging activity (RSa), with RSa₅₀values of 1.45 and 1.60 μg/ml.</p> <p>Conclusion</p> <p>The results obtained from this study support the ethnomedicinal use of <it>E. abyssinica </it>in the treatment of gastrointestinal infections and the isolated compounds could be useful in the standardisation of antimicrobial phytomedicine from this plant.</p

Stress testing techniques and value-at-risk measures: A unified approach

Viene proposta una metodologia per costruire scenari coerenti per analisi distress testing nel controllo dei rischi finanziari. Il metodo, basato sull'approccio bayesiano di Black e Litterman per l'ottimizzazione del portafoglio, consente di anire informazione storica e implicita, pubblica e privata, in modo da tenere conto della struttura di dipendenza tra i mercati. Aggiustando i valori medi di ciascuno scenario ed il grado di precisione attribuito a ciascuno di essi siano in grado di generare un insieme di misure di perdita media o di massima perdita probabile, come il Value-at-Risk. In particolare, se lo scenario è molto preciso la perdita media e la massima perdita probabile tendono a convergere, mentre se il grado di confidenza nello scenario è molto basso la perdita media converge verso zero e la massima perdita probabile coincide con la nota misura di Value-at-Risk basata sull'informazione storica. L'analisi è applicabile anche a prodotti non lineari come le opzioni, per le quali mostriamo che l'aggiustamento della precisione degli scenari corrisponde all'analisi di sensitività rispetto a cambiamenti di volatilità. Infine, per posizioni complesse, come quelle che riguardano l'esposizione al rischio di credito, o posizioni di segno diverso su mercati diversi, suggeriamo un modello a “alberi” per la determinazione degli scenari rilevanti e l'identificazione delle fonti di rischio maggiori della posizione. Copyright Associazione per la Matematica Applicata alle Scienze Economiche e Sociali (AMASES) 1999