Tag: nevin manimala

Proc Natl Acad Sci U S A. 2023 Oct 17;120(42):e2306317120. doi: 10.1073/pnas.2306317120. Epub 2023 Oct 9.

ABSTRACT

Space weather, including solar storms, can impact Earth by disturbing the geomagnetic field. Despite the known dependence of birds and other animals on geomagnetic cues for successful seasonal migrations, the potential effects of space weather on organisms that use Earth’s magnetic field for navigation have received little study. We tested whether space weather geomagnetic disturbances are associated with disruptions to bird migration at a macroecological scale. We leveraged long-term radar data to characterize the nightly migration dynamics of the nocturnally migrating North American avifauna over 22 y. We then used concurrent magnetometer data to develop a local magnetic disturbance index associated with each radar station (ΔBmax), facilitating spatiotemporally explicit analyses of the relationship between migration and geomagnetic disturbance. After controlling for effects of atmospheric weather and spatiotemporal patterns, we found a 9 to 17% decrease in migration intensity in both spring and fall during severe space weather events. During fall migration, we also found evidence for decreases in effort flying against the wind, which may represent a depression of active navigation such that birds drift more with the wind during geomagnetic disturbances. Effort flying against the wind in the fall was most reduced under both overcast conditions and high geomagnetic disturbance, suggesting that a combination of obscured celestial cues and magnetic disturbance may disrupt navigation. Collectively, our results provide evidence for community-wide avifaunal responses to geomagnetic disturbances driven by space weather during nocturnal migration.

PMID:37812699 | DOI:10.1073/pnas.2306317120

Proc Natl Acad Sci U S A. 2023 Oct 17;120(42):e2307354120. doi: 10.1073/pnas.2307354120. Epub 2023 Oct 9.

ABSTRACT

Entrainment of dry air into clouds strongly influences cloud optical and precipitation properties and the response of clouds to aerosol perturbations. The response of cloud droplet size distributions to entrainment-mixing is examined in the Pi convection-cloud chamber that creates a turbulent, steady-state cloud. The experiments are conducted by injecting dry air with temperature (T_e) and flow rate (Q_e) through a flange in the top boundary, into the otherwise well-mixed cloud, to mimic the entrainment-mixing process. Due to the large-scale circulation, the downwind region is directly affected by entrained dry air, whereas the upwind region is representative of the background conditions. Droplet concentration (Cn) and liquid water content (L) decrease in the downwind region, but the difference in the mean diameter of droplets (D_m) is small. The shape of cloud droplet size distributions relative to the injection point is unchanged, to within statistical uncertainty, resulting in a signature of inhomogeneous mixing, as expected for droplet evaporation times small compared to mixing time scales. As T_e and Q_e of entrained air increase, however, Cn, L, and D_m of the whole cloud system decrease, resulting in a signature of homogeneous mixing. The apparent contradiction is understood as the cloud microphysical responses to entrainment and mixing differing on local and global scales: locally inhomogeneous and globally homogeneous. This implies that global versus local sampling of clouds can lead to seemingly contradictory results for mixing, which informs the long-standing debate about the microphysical response to entrainment and the parameterization of this process for coarse-resolution models.

PMID:37812695 | DOI:10.1073/pnas.2307354120

Angew Chem Int Ed Engl. 2023 Oct 9:e202313864. doi: 10.1002/anie.202313864. Online ahead of print.

ABSTRACT

Docking of alkali metal ions to water-soluble macrocyclic receptors generally reduces the affinity of guest molecules due to competitive binding. The idea that solvation water molecules could display a larger steric hindrance towards guest binding than cations has not been considered to date. We show that the docking of large cations to cucurbit[5]uril (CB5) unexpectedly increases (by a factor of 5-8) the binding of hydrophobic guests, methane and ethane. This is due to the removal of water molecules from the carbonyl portals of CB5 during cation binding, which frees up space for hydrophobe encapsulation. In contrast, smaller cations like sodium protrude deeply into the cavity of CB5 and cause the expected decrease in binding, such that the rational selection of alkali cations allows for a variation of up to a factor of 20 in binding of methane and ethane. The statistical analysis of crystallographic data shows that the cavity volume of CB5 can be enlarged by placing large alkali ions (Rb+ and Cs+) centro-symmetrically at the portals. The results reveal a hitherto elusive steric hindrance of solvation water molecules near receptor binding sites, which is pertinent for the design of supramolecular catalysts and the understanding of biological receptors.

PMID:37812692 | DOI:10.1002/anie.202313864

PLoS Comput Biol. 2023 Oct 9;19(10):e1011520. doi: 10.1371/journal.pcbi.1011520. Online ahead of print.

ABSTRACT

Vector or host competence can be defined as the ability of an individual to become infected and subsequently transmit a pathogen. Assays to measure competence play a key part in the assessment of the factors affecting mosquito-borne virus transmission and of potential pathogen-blocking control tools for these viruses. For mosquitoes, competence for arboviruses can be measured experimentally and results are usually analysed using standard statistical approaches. Here we develop a mechanistic approach to studying within-mosquito virus dynamics that occur during vector competence experiments. We begin by developing a deterministic model of virus replication in the mosquito midgut and subsequent escape and replication in the hemocoel. We then extend this to a stochastic model to capture the between-individual variation observed in vector competence experiments. We show that the dose-response of the probability of mosquito midgut infection and variation in the dissemination rate can be explained by stochastic processes generated from a small founding population of virions, caused by a relatively low rate of virion infection of susceptible cells. We also show that comparing treatments or species in competence experiments by fitting mechanistic models could provide further insight into potential differences. Generally, our work adds to the growing body of literature emphasizing the importance of intrinsic stochasticity in biological systems.

PMID:37812643 | DOI:10.1371/journal.pcbi.1011520

PLoS Pathog. 2023 Oct 9;19(10):e1011722. doi: 10.1371/journal.ppat.1011722. Online ahead of print.

ABSTRACT

Sequential dengue virus (DENV) infections often generate neutralizing antibodies against all four DENV serotypes and sometimes, Zika virus. Characterizing cross-flavivirus broadly neutralizing antibody (bnAb) responses can inform countermeasures that avoid enhancement of infection associated with non-neutralizing antibodies. Here, we used single cell transcriptomics to mine the bnAb repertoire following repeated DENV infections. We identified several new bnAbs with comparable or superior breadth and potency to known bnAbs, and with distinct recognition determinants. Unlike all known flavivirus bnAbs, which are IgG1, one newly identified cross-flavivirus bnAb (F25.S02) was derived from IgA1. Both IgG1 and IgA1 versions of F25.S02 and known bnAbs displayed neutralizing activity, but only IgG1 enhanced infection in monocytes expressing IgG and IgA Fc receptors. Moreover, IgG-mediated enhancement of infection was inhibited by IgA1 versions of bnAbs. We demonstrate a role for IgA in flavivirus infection and immunity with implications for vaccine and therapeutic strategies.

PMID:37812640 | DOI:10.1371/journal.ppat.1011722

PLoS One. 2023 Oct 9;18(10):e0291665. doi: 10.1371/journal.pone.0291665. eCollection 2023.

ABSTRACT

INTRODUCTION: Dyslipidemia is a modifiable major risk factor for coronary heart disease. Although, the prevalence of dyslipidemia in high-income countries has been well documented, there is dearth of information about the dyslipidemia among working adults in sub-Saharan African countries including Ethiopia. Therefore, this study aimed to determine the magnitude of dyslipidemia and its associated factors among Haramaya University employees, in Eastern Ethiopia.

METHODS: A cross-sectional study was conducted among 1,200 university employees aged 20 to 60 years. Study participants were selected using a simple random sampling method. Data were collected face-to-face interview using a semi-structured questionnaire. Dyslipidemia was defined as unhealthy levels of one or more lipid profile such as high-density lipoprotein, low-density lipoprotein, triglycerides or total cholesterol. Data were entered into Epidata version 3.1 and analyzed using STATA version 16.1 software. Modified Poisson regression with robust variance was used to estimate adjusted prevalence ratios (APR) with its 95% confidence intervals. Statistical significance was declared at P-value < 0.05.

RESULTS: Of 1,164 participants, 59.6% participants had at least one lipid abnormality (i.e., 57.9% among men and 61.5% among women). Of which, 36.8% had high total cholesterol (TC), 21.6% had low high density lipoprotein cholesterol (HDL-c), 22.4% had high low density lipoprotein cholesterol (LDL-c), and 32.6% had high triglyceride (TG). We found that overweight/obesity, sedentary behavior, alcohol consumption, having hypertension and age 45 and above years were significant predictors of dyslipidemia. However, those who served fruit and vegetables more than five per day had significantly reduced prevalence ratio of dyslipidemia.

CONCLUSIONS: The high prevalent dyslipidemia among university employees is an important public health problem. Hence, tailored interventions to reduce overweight/obesity, hypertension, alcohol consumption and low fruit and vegetable intake have paramount importance to tackle dyslipidemia particularly among older age.

PMID:37812638 | DOI:10.1371/journal.pone.0291665

PLoS One. 2023 Oct 9;18(10):e0290338. doi: 10.1371/journal.pone.0290338. eCollection 2023.

ABSTRACT

STUDY BACKGROUND: The use of dual protection methods among young women living with HIV (YWLHIV) aged 15-24 years in sub-Saharan Africa (SSA) is poorly researched despite the double risk of unintended pregnancy and HIV. Even more scanty is literature on the use of female-controlled dual protection methods. We propose to determine the female-controlled dual protection prevalence, and the predictors among YWLHIV in northern Uganda. The study will also explore the YWLHIV’s experiences and perceptions regarding the female-controlled dual protection methods.

MATERIALS AND METHODS: This study will employ a mixed-methods design. The study area will be Lira district and Lira city located in northern Uganda. The setting for recruitment of participants will be the public health facility-based anti-retroviral therapy (ART) clinics. These ART clinics serves a total of about 1,771 YWLHIV. A sample of 425 YWLHIV will be selected by stratified random sampling from the ART clinic registers. The three strata of interest will be the YWLHIV attending the ART clinic at referral hospitals, health centers level IV (primary healthcare centers), and health centers level III (dispensaries). The primary outcome will be the use of the female-controlled dual protection methods. The outcome will be measured by asking the YWLHIV ‘what methods under their control as YWLHIV do they use to protect against both unintended pregnancy and HIV during sexual intercourse with their male partners.’ The questionnaire also has measures for the unintended pregnancy, HIV status, and the potential predictors. Qualitative component of the study will be in-depth interviews of the participants about their experiences and perceptions regarding the female-controlled dual protection methods. Data collection was still ongoing at the time of first submission of this study protocol to the journal (14th March 2023). The Statistical Package for Social Sciences (SPSS) version 23.0 will be used for the statistical analyses. Descriptive statistics, bivariate and multivariate regression analyses will be used to establish the prevalence, associated factors and the predictors of the outcome respectively. The statistical significance level of 5% and 95% confidence interval will be considered. In-depth interviews will be manually analyzed using a thematic analysis approach for codes, themes, and categories.

PMID:37812632 | DOI:10.1371/journal.pone.0290338

PLoS One. 2023 Oct 9;18(10):e0292382. doi: 10.1371/journal.pone.0292382. eCollection 2023.

ABSTRACT

OBJECTIVE: To describe the surgical techniques of Caesarean delivery (CD) practiced by Ethiopian Obstetricians and Gynecologists.

METHODS: A descriptive survey study was conducted in Ethiopia from March 1, 2021 to April 30, 2021. Members of the Ethiopian Society of Obstetrician and Gynecologists were randomly selected and their Cesarean delivery surgical techniques were explored. Data were analyzed using IBM SPSS statistics 22. Simple descriptive analysis were employed and frequencies and percentage were calculated to present the data.

RESULTS: A total of 258 obstetricians and Gynecologists practicing in Ethiopia were approached with a response rate of 97.3% (251/258). Double layer closure of uterine incision (98.4%) and subcuticular closure of skin wound (96.4%) are practiced by most of the participants. There was a large difference in practice of blunt versus sharp fascia extension (43.3 vs 55.8%), cephalo-caudad versus lateral uterine incision extension (58 vs.39%), and closure versus non-closure of pelvic and parietal peritoneum (57.4 vs 42.6, and 39.8 versus 60.2%).

CONCLUSIONS: Blunt and sharp fascia extension, cephalo-caudad and lateral uterine incision extension, closure and non-closure of the pelvic and parietal peritoneum are practiced by similar numbers of Ethiopian Obstetricians and Gynecologists. This demonstrates a wide variation exists in the techniques of Cesarean Delivery across Ethiopia.

PMID:37812627 | DOI:10.1371/journal.pone.0292382

JMIR Public Health Surveill. 2023 Oct 9;9:e41862. doi: 10.2196/41862.

ABSTRACT

BACKGROUND: There is limited evidence regarding the adverse impact of particulate matters (PMs) on multiple body systems from both epidemiological and mechanistic studies. The association between size-fractionated PMs and mortality risk, as well as the burden of a whole spectrum of causes of death, remains poorly characterized.

OBJECTIVE: We aimed to examine the wide range of susceptible diseases affected by different sizes of PMs. We also assessed the association between PMs with an aerodynamic diameter less than 1 µm (PM₁), 2.5 µm (PM_2.5), and 10 µm (PM₁₀) and deaths from 36 causes in Guangzhou, China.

METHODS: Daily data were obtained on cause-specific mortality, PMs, and meteorology from 2014 to 2016. A time-stratified case-crossover approach was applied to estimate the risk and burden of cause-specific mortality attributable to PMs after adjusting for potential confounding variables, such as long-term trend and seasonality, relative humidity, temperature, air pressure, and public holidays. Stratification analyses were further conducted to explore the potential modification effects of season and demographic characteristics (eg, gender and age). We also assessed the reduction in mortality achieved by meeting the new air quality guidelines set by the World Health Organization (WHO).

RESULTS: Positive and monotonic associations were generally observed between PMs and mortality. For every 10 μg/m³ increase in 4-day moving average concentrations of PM₁, PM_2.5, and PM₁₀, the risk of all-cause mortality increased by 2.00% (95% CI 1.08%-2.92%), 1.54% (95% CI 0.93%-2.16%), and 1.38% (95% CI 0.95%-1.82%), respectively. Significant effects of size-fractionated PMs were observed for deaths attributed to nonaccidental causes, cardiovascular disease, respiratory disease, neoplasms, chronic rheumatic heart diseases, hypertensive diseases, cerebrovascular diseases, stroke, influenza, and pneumonia. If daily concentrations of PM₁, PM_2.5, and PM₁₀ reached the WHO target levels of 10, 15, and 45 μg/m³, 7921 (95% empirical CI [eCI] 4454-11,206), 8303 (95% eCI 5063-11,248), and 8326 (95% eCI 5980-10690) deaths could be prevented, respectively. The effect estimates of PMs were relatively higher during hot months, among female individuals, and among those aged 85 years and older, although the differences between subgroups were not statistically significant.

CONCLUSIONS: We observed positive and monotonical exposure-response curves between PMs and deaths from several diseases. The effect of PM₁ was stronger on mortality than that of PM_2.5 and PM₁₀. A substantial number of premature deaths could be preventable by adhering to the WHO’s new guidelines for PMs. Our findings highlight the importance of a size-based strategy in controlling PMs and managing their health impact.

PMID:37812487 | DOI:10.2196/41862

Clin Exp Rheumatol. 2023 Oct 5. doi: 10.55563/clinexprheumatol/st5fl0. Online ahead of print.

ABSTRACT

OBJECTIVES: To evaluate adherence to medication in patients with systemic autoimmune diseases (SAD), comparing pregnant and non-pregnant women.

METHODS: 200 patients with SAD were consecutively enrolled, 100 pregnant and 100 non-pregnant women. Each patient completed the 8-item Morisky Medication Adherence Scale (MMAS-8), one copy for hydroxychloroquine (HCQ) and one for other treatments for rheumatic disease, and Hospital Anxiety and Depression Scale (HADS).

RESULTS: No significant differences were found in ongoing therapies between pregnant and non-pregnant women. 148 patients (74.0%) were taking HCQ and 160 (80.0%) other therapies for rheumatic disease. The mean MMAS-8 score was >6 in all groups indicating a good adherence, on average. The rate of patients with good medication adherence was higher in pregnant patients (73.9% vs. 63.3% and 76.5% vs. 64.5%, for HCQ and other therapies, respectively) although this difference was not statistically significant. Eight patients had very poor medical adherence, and all were non-pregnant women. Anxiety (15% of patients) was associated to low medication adherence for drugs other than HCQ (p=0.02), while depression (4% of patients) did not seem to have an impact on adherence.

CONCLUSIONS: In our cohort we recorded a good adherence to prescribed medication, although adequate adherence was not achieved in about 30% of patients, confirming that non-adherence is an important issue in SAD. It is difficult to define a profile of patients at risk of poor adherence, but it appears important to implement communication and adherence monitoring strategies since strict monitoring also during pregnancy could improve medical adherence.

PMID:37812486 | DOI:10.55563/clinexprheumatol/st5fl0