Tag: nevin manimala

Proc Natl Acad Sci U S A. 2023 Oct 17;120(42):e2307584120. doi: 10.1073/pnas.2307584120. Epub 2023 Oct 9.

ABSTRACT

As social animals, people are highly sensitive to the attention of others. Seeing someone else gaze at an object automatically draws one’s own attention to that object. Monitoring the attention of others aids in reconstructing their emotions, beliefs, and intentions and may play a crucial role in social alignment. Recently, however, it has been suggested that the human brain constructs a predictive model of other people’s attention that is far more involved than a moment-by-moment monitoring of gaze direction. The hypothesized model learns the statistical patterns in other people’s attention and extrapolates how attention is likely to move. Here, we tested the hypothesis of a predictive model of attention. Subjects saw movies of attention displayed as a bright spot shifting around a scene. Subjects were able to correctly distinguish natural attention sequences (based on eye tracking of prior participants) from altered sequences (e.g., played backward or in a scrambled order). Even when the attention spot moved around a blank background, subjects could distinguish natural from scrambled sequences, suggesting a sensitivity to the spatial-temporal statistics of attention. Subjects also showed an ability to recognize the attention patterns of different individuals. These results suggest that people possess a sophisticated model of the normal statistics of attention and can identify deviations from the model. Monitoring attention is therefore more than simply registering where someone else’s eyes are pointing. It involves predictive modeling, which may contribute to our remarkable social ability to predict the mind states and behavior of others.

PMID:37812722 | DOI:10.1073/pnas.2307584120

Proc Natl Acad Sci U S A. 2023 Oct 17;120(42):e2308496120. doi: 10.1073/pnas.2308496120. Epub 2023 Oct 9.

ABSTRACT

Human diseases involve metabolic alterations. Metabolomic profiles have served as a vital biomarker for the early identification of high-risk individuals and disease prevention. However, current approaches can only characterize individual key metabolites, without taking into account the reality that complex diseases are multifactorial, dynamic, heterogeneous, and interdependent. Here, we leverage a statistical physics model to combine all metabolites into bidirectional, signed, and weighted interaction networks and trace how the flow of information from one metabolite to the next causes changes in health state. Viewing a disease outcome as the consequence of complex interactions among its interconnected components (metabolites), we integrate concepts from ecosystem theory and evolutionary game theory to model how the health state-dependent alteration of a metabolite is shaped by its intrinsic properties and through extrinsic influences from its conspecifics. We code intrinsic contributions as nodes and extrinsic contributions as edges into quantitative networks and implement GLMY homology theory to analyze and interpret the topological change of health state from symbiosis to dysbiosis and vice versa. The application of this model to real data allows us to identify several hub metabolites and their interaction webs, which play a part in the formation of inflammatory bowel diseases. The findings by our model could provide important information on drug design to treat these diseases and beyond.

PMID:37812720 | DOI:10.1073/pnas.2308496120

Proc Natl Acad Sci U S A. 2023 Oct 17;120(42):e2307552120. doi: 10.1073/pnas.2307552120. Epub 2023 Oct 9.

ABSTRACT

There are empirical strategies for tuning the degree of strain localization in disordered solids, but they are system-specific and no theoretical framework explains their effectiveness or limitations. Here, we study three model disordered solids: a simulated atomic glass, an experimental granular packing, and a simulated polymer glass. We tune each system using a different strategy to exhibit two different degrees of strain localization. In tandem, we construct structuro-elastoplastic (StEP) models, which reduce descriptions of the systems to a few microscopic features that control strain localization, using a machine learning-based descriptor, softness, to represent the stability of the disordered local structure. The models are based on calculated correlations of softness and rearrangements. Without additional parameters, the models exhibit semiquantitative agreement with observed stress-strain curves and softness statistics for all systems studied. Moreover, the StEP models reveal that initial structure, the near-field effect of rearrangements on local structure, and rearrangement size, respectively, are responsible for the changes in ductility observed in the three systems. Thus, StEP models provide microscopic understanding of how strain localization depends on the interplay of structure, plasticity, and elasticity.

PMID:37812709 | DOI:10.1073/pnas.2307552120

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