Category: Statistics

J Aging Health. 2024 Aug 21:8982643241273298. doi: 10.1177/08982643241273298. Online ahead of print.

ABSTRACT

BACKGROUND: The well-known disablement process has been conceptualized as a series of transitions between progressive states of functional decline. We studied joint patterns of change within disablement states defined as walking speed, grip strength, and self-reported disability.

METHODS: 1702 participants aged 65 and over were included from the Longitudinal Aging Study Amsterdam, spanning seven waves over 20 years (1996-2016). Group-based multi-trajectory modeling yielded trajectory clusters (TCs) of different patterns of change, further characterized by baseline sociodemographic characteristics, physical and cognitive health, and survival rate.

RESULTS: Five TCs were identified, distinguished by increasing baseline age. Walking speed and disability showed generally concomitant trajectories. Women had poorer trajectories in grip strength than men, but not in walking speed and disability. Poor physical health distinguished especially the poorest, and cognitive impairment distinguished especially the one-before-poorest from the better TCs.

DISCUSSION: The findings suggest that the disablement states are not generally distinct or sequential.

PMID:39167684 | DOI:10.1177/08982643241273298

Sci Adv. 2024 Aug 23;10(34):eadl1079. doi: 10.1126/sciadv.adl1079. Epub 2024 Aug 21.

ABSTRACT

Peaty sediments in coastal wetlands play an important role in the sequestration of atmospheric carbon dioxide and its belowground storage. Sediment cores are used to quantify organic matter (OM) density, estimated by multiplying the bulk density of a core segment by its OM fraction. This method can be imprecise, as repeated samples often differ widely. Recent studies have shown that sediment bulk density and OM fraction are not independent but tightly related by a function called the ideal-mixing model. Thus, the bulk density of the sediment can be directly estimated from its OM fraction. Statistical theory and simulations demonstrate that the high variance in the product estimation of OM density is the result of error propagation in the product of two functionally related variables with independent errors. Estimating OM density in wetland sediments using the ideal-mixing model is more precise than the traditionally used product estimate, especially in highly organic sediments.

PMID:39167659 | DOI:10.1126/sciadv.adl1079

Sci Adv. 2024 Aug 23;10(34):eado9059. doi: 10.1126/sciadv.ado9059. Epub 2024 Aug 21.

ABSTRACT

Dynamic nuclear polarization (DNP) has revolutionized the field of nuclear magnetic resonance spectroscopy, expanding its reach and capabilities to investigate diverse materials, biomolecules, and complex dynamic processes. Bringing high-efficiency DNP to the nanometer scale would open exciting avenues for studying nanoscale nuclear spin ensembles, such as single biomolecules, virus particles, and condensed matter systems. Combining pulsed DNP with nanoscale force-detected magnetic resonance measurements, we demonstrated a 100-fold enhancement in the Boltzmann polarization of proton spins in nanoscale sugar droplets at 6 kelvin and 0.33 tesla. Crucially, this enhancement corresponds to a factor of 200 reduction in the averaging time compared to measurements that rely on the detection of statistical fluctuations in nanoscale nuclear spin ensembles. These results substantially advance the capabilities of force-detected magnetic resonance detection as a practical tool for nanoscale imaging.

PMID:39167648 | DOI:10.1126/sciadv.ado9059

Cornea. 2024 Aug 21. doi: 10.1097/ICO.0000000000003679. Online ahead of print.

ABSTRACT

PURPOSE: To analyze the corneal phenotypes of Japanese patients with myotonic dystrophy type 1 (DM1).

METHODS: We included patients with DM1 who were diagnosed with clinical neuromuscular symptoms by neurologists and CTG trinucleotide repeat (TNR) expansion of the (myotonic dystrophy protein kinase) DMPK gene. We analyzed the corneal phenotype using slit-lamp examination, specular microscopy, and anterior segment optical coherence tomography. We evaluated TNR expansion in the TCF4 gene of leukocyte-derived genomic DNA by fragment analysis using polymerase chain reaction and triplet-repeat primed polymerase chain reaction.

RESULTS: Nineteen eyes from 10 patients with DM1 (DM1 group) and 72 eyes from 37 healthy participants (control group) were analyzed. The average age was 49.3 ± 11.9 and 51.8 ± 12.9 years in the DM1 and control groups, respectively (P = 0.11). Slit-lamp examination demonstrated that 2 patients with DM1 had bilateral corneal guttae equivalent to modified Krachmer grade 1 of Fuchs endothelial corneal dystrophy. Dark areas on specular microscopy were observed in 4 of 19 eyes (21.1%) and 0 of 72 eyes (0%) in the DM1 and control groups, respectively, with statistically significant differences (P = 0.002). The average endothelial cell density in the DM1 group (3536 ± 722 cells/mm2) was significantly higher than that in the control group (3026 ± 412 cells/mm2) (P = 0.0006). TNR expansion in TCF4 was not detected in eyes with corneal guttae or in the dark areas in the DM1 group.

CONCLUSIONS: Japanese patients with DM1 without TNR expansion in TCF4 have a mild phenotype equivalent to Fuchs endothelial corneal dystrophy. Endothelial cell density is higher in DM1 patients than in normal participants.

PMID:39167633 | DOI:10.1097/ICO.0000000000003679

Cornea. 2024 Aug 21. doi: 10.1097/ICO.0000000000003675. Online ahead of print.

ABSTRACT

PURPOSE: The purpose of this study was to evaluate the efficacy of temporary conjunctival flap with topical natamycin and oral voriconazole compared with medical treatment only in reducing the rate of perforation in high-risk fungal keratitis.

METHODS: Sixty-two eyes of 62 patients with severe fungal keratitis were examined; only 54 patients were enrolled and divided randomly into 2 groups. The first group received medical treatment only in the form of topical natamycin 5% together with oral voriconazole 200 mg, while the second group received the same medical treatment plus a temporary conjunctival flap that was removed after 2 weeks. Five patients were lost during the follow-up, and only 49 patients were statistically analyzed. All patients were examined frequently until reepithelialization or the development of perforation.

RESULTS: Fifteen perforations were reported, with a higher rate among the medical group (48%) compared with the conjunctival flap group (12.5%), with P value <0.05. A significant delay was noted in reepithelialization time in the medical group compared with the conjunctival flap group (mean time was 21.69 ± 5.41 and 15.36 ± 2.2 days, respectively), with P value = 0.001. Significant improvement in visual acuity was reported over time when comparing baseline versus 3-month visual acuity in the same group using paired t sample test (P value was 0.003 and <0.001 in the first and second group, respectively).

CONCLUSIONS: Temporary conjunctival flap is associated with a lower perforation rate compared with medical treatment only in severe fungal keratitis, which can provide a cheap and available alternative to therapeutic penetrating keratoplasty.

PMID:39167631 | DOI:10.1097/ICO.0000000000003675

PLoS Comput Biol. 2024 Aug 21;20(8):e1012342. doi: 10.1371/journal.pcbi.1012342. Online ahead of print.

ABSTRACT

Knowledge integration based on the relationship between structure and function of the neural substrate is one of the main targets of neuroinformatics and data-driven computational modeling. However, the multiplicity of data sources, the diversity of benchmarks, the mixing of observables of different natures, and the necessity of a long-term, systematic approach make such a task challenging. Here we present a first snapshot of a long-term integrative modeling program designed to address this issue in the domain of the visual system: a comprehensive spiking model of cat primary visual cortex. The presented model satisfies an extensive range of anatomical, statistical and functional constraints under a wide range of visual input statistics. In the presence of physiological levels of tonic stochastic bombardment by spontaneous thalamic activity, the modeled cortical reverberations self-generate a sparse asynchronous ongoing activity that quantitatively matches a range of experimentally measured statistics. When integrating feed-forward drive elicited by a high diversity of visual contexts, the simulated network produces a realistic, quantitatively accurate interplay between visually evoked excitatory and inhibitory conductances; contrast-invariant orientation-tuning width; center surround interactions; and stimulus-dependent changes in the precision of the neural code. This integrative model offers insights into how the studied properties interact, contributing to a better understanding of visual cortical dynamics. It provides a basis for future development towards a comprehensive model of low-level perception.

PMID:39167628 | DOI:10.1371/journal.pcbi.1012342

PLoS One. 2024 Aug 21;19(8):e0309074. doi: 10.1371/journal.pone.0309074. eCollection 2024.

ABSTRACT

Recently, it was recommended to omit tied observations before applying the two-sample Wilcoxon-Mann-Whitney test McGee M. et al. (2018). Using a simulation study, we argue for exact tests using all the data (including tied values) as a preferable approach. Exact tests, with tied observations included guarantee the type I error rate with a better exploitation of the significance level and a larger power than the corresponding tests after the omission of tied observations. The omission of ties can produce a considerable change in the shape of the sample, and so can violate underlying test assumptions. Thus, on both theoretical and practical grounds, the recommendation to omit tied values cannot be supported, relative to analysing the whole data set in the same way whether or not ties occur, preferably with an exact permutation test.

PMID:39167627 | DOI:10.1371/journal.pone.0309074

PLoS Negl Trop Dis. 2024 Aug 21;18(8):e0012378. doi: 10.1371/journal.pntd.0012378. eCollection 2024 Aug.

ABSTRACT

BACKGROUND: Snakebite envenoming (SBE) is a potentially life-threatening event that can lead to severe physical, mental, and economic hardships, particularly in under-resourced regions like sub-Saharan Africa. In Rwanda, there have been no epidemiological assessments of SBE to guide the Ministry of Health in its efforts to reduce the burden. This study had two main objectives: first, to estimate the incidence of snakebites across districts, and second, to describe formal versus informal healthcare seeking behaviors among snakebite victims in Eastern Province, Rwanda in 2020.

METHODOLOGY: This cross-sectional study utilized a cluster sampling approach, involving Community Health Workers (CHWs) who recorded snakebite cases across seven districts. The descriptive analysis considered sampling weights, and healthcare seeking behavior was assessed based on the type of care sought as the first point of treatment.

FINDINGS: The study surveyed 390,546 individuals across 763 villages and estimated a provincial annual incidence rate of 4.3 cases per 1,000 individuals. Incidence estimates ranged from 1.1 cases per 1,000 in Nyagatare to 9.1 cases per 1,000 individuals in Bugesera and Ngoma districts. Among the 2,545 cases recorded by CHWs, three resulted in deaths. Regarding healthcare-seeking behavior, 13% of snakebite victims (143 out of 1,098) initially consulted formal care providers (CHWs, health post/center, or hospital), while 87% sought informal care (family/friends, pharmacist, or traditional healer). Approximately half of the victims (583, 53.1%) reported severe symptoms. Unsafe practices included skin cutting/burning, tourniquet application, use of black stones, and venom extraction; only 24 cases (2.2%) received anti-venom.

CONCLUSIONS: This large-scale community-based assessment highlights variations in snakebite incidence between districts and confirms frequent involvement of traditional healers in management. Improving access to anti-venom and community education on the risks of ineffective practices, along with timely use of formal healthcare, are crucial. Collaboration between healthcare providers, traditional healers, community leaders, and policymakers is essential to implement targeted interventions for enhancing snakebite prevention and management strategies.

PMID:39167620 | DOI:10.1371/journal.pntd.0012378

PLoS One. 2024 Aug 21;19(8):e0305188. doi: 10.1371/journal.pone.0305188. eCollection 2024.

ABSTRACT

This paper examines the long-term and short-run causative relationship among environmental sustainability, energy efficiency, renewable energy and carbon emissions from all over sources (coal, oil and fossil fuels) and sector wise division (heat and power, transportation, residential, manufacturing and other sectors. The empirical evidence presented in this study is derived from a balanced panel dataset spanning the annual periods from 2000 to 2021. The dataset specifically focuses on a selection of BRI Countries. The Kao test demonstrates the presence of cointegration across variables such as carbon dioxide emissions, environmental suitability, energy efficiency and renewable energy. The Panel Pooled Mean Group-Autoregressive Distributed Lag (PMG-ARDL) model indicates a statistically significant positive association between the environmental sustainability and disaggregated CO2 emissions over a long-term period. The study found a positive relationship between disaggregated CO2 emissions and environmental sustainability and energy efficiency, with renewable energy sources reducing emissions. It suggests a need for a structural transition from an energy-intensive economy to a decarbonized one, with sectors like heat and power positively impacting sustainability. Implementing measures to reduce emissions is crucial for tackling climate change.

PMID:39167616 | DOI:10.1371/journal.pone.0305188

PLoS One. 2024 Aug 21;19(8):e0308105. doi: 10.1371/journal.pone.0308105. eCollection 2024.

ABSTRACT

Disparities in life expectancy between Black and White Americans increased substantially during the COVID-19 pandemic. During the same period, the US experienced the largest increase in homicide on record. Yet, little research has examined the contribution of homicide to Black-White disparities in longevity in recent years. Using mortality data and population estimates, we conduct a comprehensive decomposition of the drivers of Black-White inequality in life expectancy and lifespan variability between 2019 and 2021 among men. We find that homicide is one of the principal reasons why lifespans have become shorter for Black men than White men in recent years. In 2020 and 2021, homicide was the leading contributor to inequality in both life expectancy and lifespan variability between Black and White men, accounting for far more of the racial gap in longevity and variability than deaths from COVID-19. Addressing homicides should be at the forefront of any public health discussion aimed at promoting racial health equity.

PMID:39167593 | DOI:10.1371/journal.pone.0308105