Outcomes of Distal Third Femur Fractures in Patients 18 Years and Older: A Pilot Study.

INTRODUCTION: The selection of the most optimal fixation method for fractures of the distal femur, whether intramedullary nail (NL), lateral locking plate (PL), or nail/plate (NP) is not always clear. This study retrospectively evaluates surgical patients with distal femur fractures and introduces a pilot study using cluster analysis to identify the most optimal fracture fixation method for a given fracture type. METHODS: This is a retrospective cohort study of patients 18 years and older with an isolated distal femur fracture who presented to our Level-1 trauma center between January 1, 2012, and December 31, 2022, and obtained NL, PL, or NP implants. Patients with polytrauma and those without at least six months of follow-up were excluded. A chart review was used to obtain demographics, fracture classification, fixation method, and postoperative complications. A cluster analysis was performed. The following factors were used to determine a successful outcome: ambulatory status pre-injury and 6-12 months postoperatively, infection, non-union, mortality, and implant failure. RESULTS: A total of 169 patients met inclusion criteria. No statistically significant association between the fracture classification and fixation type with overall outcome was found. However, patients treated with an NP (n = 14) had a success rate of 92.9% vs only a 68.1% success rate in those treated with a PL (n = 116) (p = 0.106). The most notable findings in the cluster analysis (15 total clusters) included transverse extraarticular fractures demonstrating 100% success if treated with NP (n = 6), 50% success with NL (n=2), and 78.57% success with PL fixation (n=14). NP constructs in complete articular fractures demonstrated success in 100% of patients (n = 5), whereas 77.78% of patients treated with NL (n = 9) and 61.36% of those treated with PL (n = 44). CONCLUSIONS: Plate fixation was the predominant fixation method used for distal third femur fractures regardless of fracture classification. However, NP constructs trended towards improved success rates, especially in complete intraarticular and transverse extraarticular fractures, suggesting the potential benefit of additional fixation with these fractures. Cluster analysis provided a heuristic way of creating patient profiles in patients with distal third femur fractures. However, a larger cohort study is needed to corroborate these findings to ultimately develop a clinical decision-making tool that also accounts for patient specific characteristics.

On the estimation of genome-average recombination rates.

The rate at which recombination events occur in a population is an indicator of its effective population size and the organism's reproduction mode. It determines the extent of linkage disequilibrium along the genome and, thereby, the efficacy of both purifying and positive selection. The population recombination rate can be inferred using models of genome evolution in populations. Classic methods based on the patterns of linkage-disequilibrium provide the most accurate estimates, providing large sample sizes are used and the demography of the population is properly accounted for. Here, the capacity of approaches based on the sequentially Markov coalescent (SMC) to infer the genome-average recombination rate from as little as a single diploid genome is examined. SMC approaches provide highly accurate estimates even in the presence of changing population sizes, providing that (1) within genome heterogeneity is accounted for and (2) classic maximum-likelihood optimization algorithms are employed to fit the model. SMC-based estimates proved sensitive to gene conversion, leading to an overestimation of the recombination rate if conversion events are frequent. Conversely, methods based on the correlation of heterozygosity succeed in disentangling the rate of crossing over from that of gene conversion events, but only when the population size is constant and the recombination landscape homogeneous. These results call for a convergence of these two methods to obtain accurate and comparable estimates of recombination rates between populations.

Cross-cousin marriage among Tsimane forager-horticulturalists during demographic transition and market integration.

Although still prevalent in many human societies, the practice of cousin marriage has precipitously declined in populations undergoing rapid demographic and socioeconomic change. However, it is still unclear whether changes in the structure of the marriage pool or changes in the fitness-relevant consequences of cousin marriage more strongly influence the frequency of cousin marriage. Here, we use genealogical data collected by the Tsimane Health and Life History Project to show that there is a small but measurable decline in the frequency of first cross-cousin marriage since the mid-twentieth century. Such changes are linked to concomitant changes in the pool of potential spouses in recent decades. We find only very modest differences in fitness-relevant demographic measures between first cousin and non-cousin marriages. These differences have been diminishing as the Tsimane have become more market integrated. The factors that influence preferences for cousin marriage appear to be less prevalent now than in the past, but cultural inertia might slow the pace of change in marriage norms. Overall, our findings suggest that cultural changes in marriage practices reflect underlying societal changes that shape the pool of potential spouses.

The World's consumption of free web-based Otolaryngology-Head and Neck Surgery educational resources: A global assessment of video usage trends.

Objectives: Online educational platforms with open access have seen a growing adoption in the field of medical education. However, the extent of their global usage is still unclear. To fill this knowledge gap, our objective is to examine the usage patterns of two renowned open-access resources in Otolaryngology. This includes identifying the most sought-after topics and understanding the demographics of their users. Methods: Retrospective study of web analytics data between 2016 and 2021 extracted from the Headmirror.com and Mayo Clinic Otolaryngology YouTube channel platforms analyzing demographic and education topic trends via descriptive, geospatial, time-series, t-tests, and ANOVA analyses. Results: Viewership spanned 124 countries in 7 different geographic regions, with 72 countries comprising low- to middle-income countries, mostly represented ages of 25-34 years old, came from high-income countries rather than low-income (p < .001), and used mobile phones followed by computers for device access. Video-educational material comprised of subspecialty topics on Rhinology and Sinus Surgery (25%) at the highest end and Facial Trauma (1%) at the lowest. Controlling for the age of the video content, the most-accessed videos comprised of subspecialty topics on Head and Neck Surgery at the highest end and Laryngology at the lowest with significant differentiation across topics of interest (p < .044). Conclusions: This assessment of web-analytics platforms from two widely used otolaryngology free, online-access materials showed increasing global usage trends with significant differentiating factors along viewership demographics, as well as sought-after subspecialty topics of interest. In turn, our results not only lay the groundwork for characterizing the global otolaryngology audience but also for future development of targeted educational materials and accessibility initiatives aimed at ameliorating global educational disparities in the field.

COVID-19 inequalities in England: a mathematical modelling study of transmission risk and clinical vulnerability by socioeconomic status.

BACKGROUND: The COVID-19 pandemic resulted in major inequalities in infection and disease burden between areas of varying socioeconomic deprivation in many countries, including England. Areas of higher deprivation tend to have a different population structure-generally younger-which can increase viral transmission due to higher contact rates in school-going children and working-age adults. Higher deprivation is also associated with a higher presence of chronic comorbidities, which were convincingly demonstrated to be risk factors for severe COVID-19 disease. These two major factors need to be combined to better understand and quantify their relative importance in the observed COVID-19 inequalities. METHODS: We used UK Census data on health status and demography stratified by decile of the Index of Multiple Deprivation (IMD), which is a measure of socioeconomic deprivation. We calculated epidemiological impact using an age-stratified COVID-19 transmission model, which incorporated different contact patterns and clinical health profiles by decile. To separate the contribution of each factor, we considered a scenario where the clinical health profile of all deciles was at the level of the least deprived. We also considered the effectiveness of school closures and vaccination of over 65-year-olds in each decile. RESULTS: In the modelled epidemics in urban areas, the most deprived decile experienced 9% more infections, 13% more clinical cases, and a 97% larger peak clinical size than the least deprived; we found similar inequalities in rural areas. Twenty-one per cent of clinical cases and 16% of deaths in England observed under the model assumptions would not occur if all deciles experienced the clinical health profile of the least deprived decile. We found that more deaths were prevented in more affluent areas during school closures and vaccination rollouts. CONCLUSIONS: This study demonstrates that both clinical and demographic factors synergise to generate health inequalities in COVID-19, that improving the clinical health profile of populations would increase health equity, and that some interventions can increase health inequalities.

Re-Examining the Link Between Premarital Sex and Divorce.

Premarital sex predicts divorce, but we do not know why. Scholars have attributed the relationship to factors such as differences in beliefs and values, but these explanations have not been tested. It is further unclear how this relationship changes by number of sexual partners, or differs by gender. We re-examine this relationship with event history models using data from the National Longitudinal Study of Adolescent to Adult Health. Models include measures of adolescent beliefs and values, religious background, and personal characteristics, as well as approximate number of premarital sexual partners in young adulthood. We find the relationship between premarital sex and divorce is highly significant and robust even when accounting for early-life factors. Compared to people with no premarital partners other than eventual spouses, those with nine or more partners exhibit the highest divorce risk, followed by those with one to eight partners. There is no evidence of gender differences.

Highly structured populations of copepods at risk to deep-sea mining: Integration of genomic data with demogenetic and biophysical modelling.

Copepoda is the most abundant taxon in deep-sea hydrothermal vents, where hard substrate is available. Despite the increasing interest in seafloor massive sulphides exploitation, there have been no population genomic studies conducted on vent meiofauna, which are known to contribute over 50% to metazoan biodiversity at vents. To bridge this knowledge gap, restriction-site-associated DNA sequencing, specifically 2b-RADseq, was used to retrieve thousands of genome-wide single-nucleotide polymorphisms (SNPs) from abundant populations of the vent-obligate copepod Stygiopontius lauensis from the Lau Basin. SNPs were used to investigate population structure, demographic histories and genotype-environment associations at a basin scale. Genetic analyses also helped to evaluate the suitability of tailored larval dispersal models and the parameterization of life-history traits that better fit the population patterns observed in the genomic dataset for the target organism. Highly structured populations were observed on both spatial and temporal scales, with divergence of populations between the north, mid, and south of the basin estimated to have occurred after the creation of the major transform fault dividing the Australian and the Niuafo'ou tectonic plate (350 kya), with relatively recent secondary contact events (<20 kya). Larval dispersal models were able to predict the high levels of structure and the highly asymmetric northward low-level gene flow observed in the genomic data. These results differ from most studies conducted on megafauna in the region, elucidating the need to incorporate smaller size when considering site prospecting for deep-sea exploitation of seafloor massive sulphides, and the creation of area-based management tools to protect areas at risk of local extinction, should mining occur.

Study protocol: improving response to malaria in the Amazon through identification of inter-community networks and human mobility in border regions of Ecuador, Peru and Brazil.

INTRODUCTION: Understanding human mobility's role in malaria transmission is critical to successful control and elimination. However, common approaches to measuring mobility are ill-equipped for remote regions such as the Amazon. This study develops a network survey to quantify the effect of community connectivity and mobility on malaria transmission. METHODS: We measure community connectivity across the study area using a respondent driven sampling design among key informants who are at least 18 years of age. 45 initial communities will be selected: 10 in Brazil, 10 in Ecuador and 25 in Peru. Participants will be recruited in each initial node and administered a survey to obtain data on each community's mobility patterns. Survey responses will be ranked and the 2-3 most connected communities will then be selected and surveyed. This process will be repeated for a third round of data collection. Community network matrices will be linked with each country's malaria surveillance system to test the effects of mobility on disease risk. ETHICS AND DISSEMINATION: This study protocol has been approved by the institutional review boards of Duke University (USA), Universidad San Francisco de Quito (Ecuador), Universidad Peruana Cayetano Heredia (Peru) and Universidade Federal Minas Gerais (Brazil). Results will be disseminated in communities by the end of the study.

Dementia Prevalence, Incidence and Mortality Trends Among US Adults Ages 72 and Older, 2011-2021.

BACKGROUND: U.S.-focused studies have reported decreasing dementia prevalence in recent decades, but have not yet focused on the implications of the COVID-19 pandemic for trends. METHODS: We use the 2011-2021 National Health and Aging Trends Study (N=48,065) to examine dementia prevalence, incidence and mortality trends among adults ages 72 and older, and the contribution to prevalence trends of changes in the distribution of characteristics of the older population ("compositional shifts") during the full and pre-pandemic periods. To minimize classification error, individuals must meet dementia criteria for two consecutive rounds. RESULTS: The prevalence of probable dementia declined from 11.9% in 2011 to 9.2% in 2019 and 8.2% in 2021 (3.1% average annual decline). Declines over the 2011-2021 period were concentrated among those ages 80-89 and non-Hispanic White individuals. Declines in dementia incidence were stronger for the 2011-2021 period than for the pre-pandemic period while mortality among those with dementia rose sharply with the onset of the COVID-19 pandemic. Shifts in the composition of the older population accounted for a smaller fraction of the decline over the full period (28%) than over the pre-pandemic period (45%). CONCLUSIONS: Declines in dementia prevalence continued into years marked by onset of the COVID-19 pandemic, along with declines in incidence and sharp increases in mortality among those with dementia. However, declines are no longer largely attributable to compositional changes in the older population. Continued tracking of dementia prevalence, incidence and mortality among those with and without dementia is needed to understand long-run consequences of the pandemic.

The fortunes and misfortunes of social life across the life course: A new era of research from field, laboratory and comparative studies.

Social gradients in health and aging have been reported in studies across many human populations, and - as the papers included in this special collection highlight - also occur across species. This paper serves as a general introduction to the special collection of Neuroscience and Biobehavioral Reviews entitled "Social dimensions of health and aging: population studies, preclinical research, and comparative research using animal models". Authors of the fourteen reviews are primarily members of a National Institute of Aging-supported High Priority Research Network on "Animal Models for the Social Dimensions of Health and Aging". The collection is introduced by a foreword, commentaries, and opinion pieces by leading experts in related fields. The fourteen reviews are divided into four sections: Section 1: Biodemography and life course studies; Section 2: Social behavior and healthy aging in nonhuman primates; Section 3: Social factors, stress, and hallmarks of aging; Section 4: Neuroscience and social behavior.

Health and demographic indicators of selected districts of India: An impact of Swasthya Rakshan Programme (SRP).

Swasthya Rakshan Programme (SRP) provides health care services through Ayurveda, an initiative of the Government of India that aims to survey and create alertness of essential health appliances to ameliorate society from its grassroots level. The present study aimed to survey the prevailing health standards of residents in certain districts of India and to record the prevalence of diseases among them according to their living conditions, food habits, lifestyle, education, occupation and other socio-economic status. Data was collected through a community-based cross-sectional survey conducted from April 2018 to March 2019 in 22 Districts of 19 states in India. A stratified multi-stage sampling design was adopted for the survey. Documentation of demographic profile, food habits, lifestyle, hygiene status, and existing health conditions was assessed. A pre-designed semi-structured questionnaire was used for the collection of the data. Before initiating the programme, written consent was obtained. In this study, from 162 selected villages/colonies/areas, a total of 562,913 population and 81,651 households were surveyed. Sixty-nine thousand three hundred nineteen patients were cared for various ailments through health camps. The study found that the most prevalent disease in the concerned population was 'Sandhivata' (Osteo-arthritis), that is, 43.0%, followed by 'Dourbalya' (Debility), that is, 11.7%. The study includes insightful analyses of comprehensive demographic and health indicators classified by various socio-economic categories. The collected data regarding the prevalence of diseases with their sociodemographic correlations may provide a better understanding of the locality and thus may help in all future health endeavours.

Changes in transfusion-transmissible infection prevalence and demographics among US blood donors during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic impacted the US blood supply. We compared blood donor demography and infectious disease prevalence before and during the pandemic using a large multicenter database. METHODS: Data were categorized as "Before COVID-19" (March 2018-February 2020) or "During COVID-19" (March 2020-February 2022). Donor demographics, donation frequency, and infectious marker prevalence of HIV, HBV, and HCV were compared for the two time periods. The odds of a donor testing positive for these infections among the two time periods were calculated using multivariable logistic regression. RESULTS: Our study assessed a total of 26,672,213 donations including 13,430,380 before and 13,241,833 during COVID-19. There were significantly more donations from donors who were female, aged 40 and older, white, and repeat, during COVID-19. Donation frequency comparison quantified the increase in donations from donors who were white, female, older, and repeat during the pandemic. The prevalence of HIV and HCV decreased significantly during COVID-19 compared to before, but not for HBV. For HIV, the adjusted odds of infection during the pandemic did not differ but for HBV, the odds were significantly more likely during the pandemic and were significantly lower for HCV. DISCUSSION: Demographics and infectious disease marker prevalence changed during the COVID-19 pandemic in the United States. Prevalence of each infection in the donor population will continue to be monitored to determine if changes were specific to the pandemic period.

The anthropogenic imprint on temperate and boreal forest demography and carbon turnover.

Aim: The sweeping transformation of the biosphere by humans over the last millennia leaves only limited windows into its natural state. Much of the forests that dominated temperate and southern boreal regions have been lost and those that remain typically bear a strong imprint of forestry activities and past land-use change, which have changed forest age structure and composition. Here, we ask how would the dynamics, structure and function of temperate and boreal forests differ in the absence of forestry and the legacies of land-use change? Location: Global. Time Period: 2001-2014, integrating over the legacy of disturbance events from 1875 to 2014. Major Taxa Studied: Trees. Methods: We constructed an empirical model of natural disturbance probability as a function of community traits and climate, based on observed disturbance rate and form across 77 protected forest landscapes distributed across three continents. Coupling this within a dynamic vegetation model simulating forest composition and structure, we generated estimates of stand-replacing disturbance return intervals in the absence of forestry for northern hemisphere temperate and boreal forests. We then applied this model to calculate forest stand age structure and carbon turnover rates. Results: Comparison with observed disturbance rates revealed human activities to have almost halved the median return interval of stand-replacing disturbances across temperate forest, with more moderate changes in the boreal region. The resulting forests are typically much younger, especially in northern Europe and south-eastern North America, resulting in a 32% reduction in vegetation carbon turnover time across temperate forests and a 7% reduction for boreal forests. Conclusions: The current northern hemisphere temperate forest age structure is dramatically out of equilibrium with its natural disturbance regimes. Shifts towards more nature-based approaches to forest policy and management should more explicitly consider the current disturbance surplus, as it substantially impacts carbon dynamics and litter (including deadwood) stocks.

Grandmother effects over the Finnish demographic transition.

Demographic transitions are defining events for human societies, marking shifts from natural mortality and fertility rates to the low rates seen in industrialised populations. These transitions can affect trait evolution through altering the direction and strength of selection when variance in fertility and mortality decline. One key feature of human evolution is the evolution of extended post-reproductive life through indirect fitness benefits from grandmothering. Although studies in pre- and post-transition societies have documented beneficial grandmother presence, it remains unknown whether these associations changed before, during, or after the transition. Here, we use genealogical data from eighteenth- to twientieth-century Finland to show grandmother-associated changes of two measures of evolutionary fitness (grandchild survival and birth rate) over the transition. We find that grandmothers had greater opportunity to help as the transition progressed, but their effect on grandchild survival declined alongside general mortality rates, implying that selection on lifespan from grandmothering declined too. Whilst grandmother presence was still associated with reduced birth intervals and hence more grandchildren born post-transition, the nature of this relationship changed greatly. This suggests that although potential for intergenerational interactions increased over the demographic transition, the (hypothesised) evolutionary importance of these interactions declined, which reduced selection for extended post-reproductive lifespan.

Untwisting healthcare access disparities: A comprehensive analysis of demographic, socio-economic and racial disparities impacting patient outcomes in myocardial infarction patients.

INTRODUCTION: Myocardial infarction (MI) is one of the most life-threatening pathologies characterized by sudden cardiac death and is among the leading causes of mortality in the developed world. AIMS: This study investigates the demographic, socio-economic, and healthcare access disparities in the US among patients with myocardial infarction (MI). METHODOLOGY: This was a retrospective original research study conducted using the BRFSS (Behavioural risk factor surveillance system) database of CDC (Centers for disease control and prevention).Data was extracted from the BRFSS on 3rd January 2024 to identify patients with MI in the year 2021 and multivariate models were used to assess the relationship between factors such as age, gender, income levels, and education in patients with myocardial infarction. RESULTS: Individuals in the age group of 65 years or older constituted the highest percentage of MI cases at 66.33% (OR, 16.66; 95% CI, 10.27-27.02; p-value <0.0001).Males showed a higher prevalence of MI, accounting for 61.19% of cases, and females demonstrated lower susceptibility (OR, 0.46; 95% CI, 0.43-0.50; p-value <0.0001).High school graduates (Grade 12 or GED) exhibited the highest incidence at 32.08% (OR, 1.44; 95% CI, 0.81-2.56; p-value 0.2084). Retirees accounted for the highest incidence at 56.06%, with significantly increased odds compared to those employed for wages (OR, 1.93; 95% CI, 1.71-2.19; p-value <0.0001).The analysis of income levels indicated the highest MI incidence in the $25,000 <= Income < $35,000 group (17.31% of cases). CONCLUSIONS: Additional research is necessary to further disentangle the interaction between MI and factors such as age, gender, education level, race, employment status, and income level, and as the findings of this study suggest, retired individuals and individuals from lower-income groups indicate a disparity in access to timely treatment regarding MI. Thus, the determination of such discrepancies needs to be addressed regarding how such factors affect access to timely healthcare, especially in matters of widely prevalent diseases such as MI.

Mitogenomics reveals extremely low genetic diversity in the endangered Jilin clawed salamander: Implications for its conservation.

The Jilin clawed salamander (Onychodactylus zhangyapingi) is an endemic, endangered, and level-two protected amphibian species of China. In the context of serious threats to amphibians worldwide, conservation studies of this endangered species are urgently needed. In this study, mitogenomic conservation genetics and species distribution modeling analyses were performed for O. zhangyapingi. Sixty-three samples were collected from nine different locations, and the complete mitochondrial genome was sequenced. Population genetic analyses revealed that O. zhangyapingi exhibits only one genetic structure with extremely low nucleotide diversity. Late Pleistocene climate cooling may have led to a reduction in effective population size and extremely low mitogenomic nucleotide diversity in this salamander, and the subsequent temperature increase (~20 kya to present) provided the opportunity for rapid population growth. The continuous highly suitable region for O. zhangyapingi is only approximately 3000 km2 on the southeastern boundary of Jilin Province, China. Fortunately, there are three large forested national nature reserves within the distribution of O. zhangyapingi that can effectively protect endangered species. Our findings suggest that O. zhangyapingi is a vulnerable species with a narrow distribution and extremely low genetic diversity, and we should pay more attention to the conservation management of this species.

Situational and Victim Correlates of Increased Case Fatality Rates in Los Angeles Shootings, 2005-2021.

The gun assault case fatality rate measures the fraction of shooting victims who die from their wounds. Considerable debate has surrounded whether gun assault case fatality rates have changed over time and what factors may be involved. We use crime event data from Los Angeles to examine the victim and situational correlates of gun assault case fatality rates over time. We estimated log binomial regression models for the probability of death in each year from 2005 to 2021, conditioned on situational and victim characteristics of the crime. Case fatality rates increased by around 1.3% per year between 2005 and 2021 from around 15.9 to 19.7%. Baseline case fatality rates differed systematically by most situational and victim but followed similar temporal trends. Only victim age significantly covaried with the temporal trend in case fatality rates. An individual shot in Los Angeles in 2021 was 23.7% more likely to die than the equivalent victim in 2005. The steady increase in case fatality rates suggests that there were around 394 excess fatalities over what would have occurred if case fatality rates remained at the 2005 level. Increases in the average age of victims over time may contribute to the general temporal trend. We hypothesize that older victims are more likely to be shot indoors where lethal close-range wounds are more likely.

Temporal challenges in detecting balancing selection from population genomic data.

The role of balancing selection in maintaining genetic variation remains an open question in population genetics. Recent years have seen numerous studies identifying candidate loci potentially experiencing balancing selection, most predominantly in human populations. There are however numerous alternative evolutionary processes that may leave similar patterns of variation, thereby potentially confounding inference, and the expected signatures of balancing selection additionally change in a temporal fashion. Here we use forward-in-time simulations to quantify expected statistical power to detect balancing selection using both site frequency spectrum (SFS)- and linkage disequilibrium (LD)-based methods under a variety of evolutionarily realistic null models. We find that whilst SFS-based methods have little power immediately after a balanced mutation begins segregating, power increases with time since the introduction of the balanced allele. Conversely, LD-based methods have considerable power whilst the allele is young, and power dissipates rapidly as the time since introduction increases. Taken together, this suggests that SFS-based methods are most effective at detecting long-term balancing selection (>25N generations since the introduction of the balanced allele) whilst LD-based methods are effective over much shorter timescales (<1N generations), thereby leaving a large time frame over which current methods have little power to detect the action of balancing selection. Finally, we investigate the extent to which alternative evolutionary processes may mimic these patterns, and demonstrate the need for caution in attempting to distinguish the signatures of balancing selection from those of both neutral processes (e.g., population structure and admixture) as well as of alternative selective processes (e.g., partial selective sweeps).