Hasil untuk "Demography. Population. Vital events"

W. Morris, D. Doak

Stephanie A. Bennington, P. W. Dillingham, Lindsay Wickman et al.

Prediction of future population trajectories is vital in the management of threatened species but requires accurate estimates of demographic rates. One such parameter is fecundity, which is commonly expressed as the number of offspring produced per female per year. The endangered Hector's dolphin ( Cephalorhynchus hectori ) is Aotearoa New Zealand's only endemic cetacean and is threatened by bycatch from inshore trawl and gillnet fisheries. Here, we take advantage of 40 years of continued photo‐identification effort at Banks Peninsula to construct a Bayesian open‐population multi‐event capture–recapture model. We estimated fecundity for Hector's dolphins at 0.29 (95% credible interval [CI]: 0.22–0.39) which corresponds to an average calving frequency of one calf every 3.4 years (95% CI: 2.5–4.7 years). This new estimate is substantially lower and more precise than the previous estimate of fecundity for Hector's dolphins (e.g., 0.409, 95% CI: 0.267–0.635), but is based on a larger dataset, and aligns closely with estimates from other dolphin species. This updated estimate of fecundity indicates a lower capacity for population growth and reduced resilience to anthropogenic threats, including bycatch in fisheries.

Hamed Abdi, D. Sánchez-Molina, S. García-Vilana et al.

Traumatic brain injuries (TBIs) pose a significant health concern among the elderly population, influenced by age-related physiological changes and the prevalence of neurodegenerative diseases. Understanding the biomechanical dimensions of TBIs in this demographic is vital for developing effective preventive strategies and optimizing clinical management. This comprehensive review explores the intricate biomechanics of TBIs in the elderly, integrating medical and aging studies, experimental biomechanics of head tissues, and numerical simulations. Research reveals that global brain atrophy in normal aging occurs at annual rates of −0.2% to −0.5%. In contrast, neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and multiple sclerosis are associated with significantly higher rates of brain atrophy. These variations in atrophy rates underscore the importance of considering differing brain atrophy patterns when evaluating TBIs among the elderly. Experimental studies further demonstrate that age-related changes in the mechanical properties of critical head tissues increase vulnerability to head injuries. Numerical simulations provide insights into the biomechanical response of the aging brain to traumatic events, aiding in injury prediction and preventive strategy development tailored to the elderly. Biomechanical analysis is essential for understanding injury mechanisms and forms the basis for developing effective preventive strategies. By incorporating local atrophy and age-specific impact characteristics into biomechanical models, researchers can create targeted interventions to reduce the risk of head injuries in vulnerable populations. Future research should focus on refining these models and integrating clinical data to better predict outcomes and enhance preventive care. Advancements in this field promise to improve health outcomes and reduce injury risks for the aging population.

Elisabetta Canteri, Stuart C. Brown, E. Post et al.

Rangifer tarandus (caribou or reindeer) survived periods of abrupt climatic warming during the last deglaciation but are currently in global decline. Using process-explicit models of likely climate-human-Rangifer interactions and inferences of demographic change from radiocarbon-dated fossils and ancient DNA, we reconstruct and decipher 21,000 years of Rangifer population dynamics. These high-resolution population reconstructions pinpoint ecological characteristics and life-history traits that most likely enabled Rangifer to survive rapid warming events following the Last Glacial Maximum. Projecting these process-driven models into the future reveals that these attributes are unlikely to buffer Rangifer against wide-scale population declines from expected 21st Century climatic warming. Our findings highlight a need to boost investments in the management and conservation of Rangifer, particularly in North America, where projected losses are expected to exceed 80%. This will not only support the survival of the species and the vital services it renders in Arctic ecosystems, but also help sustain the socioeconomic, cultural, and emotional well-being of many Rangifer-dependent communities.

R. Cai, Shuang Gu, Boxuan Zhang et al.

Heat-stress resilience is vital for poultry in tropical/subtropical regions where high temperatures impair productivity. Ake chickens, as the only naked-neck chicken breed in China, exhibit robust resistance to heat stress, but this breed lacks clarity in its genetic origins. This study utilized the next-generation sequencing data from 22 chicken breeds to conduct phylogenetic and population analyses. Gene flow analysis revealed a gene migration event from Iranian naked-neck chickens and Indian local breeds to Ake chickens, and population separation estimates suggested that the naked-neck gene was introduced to China around 500–600 years ago. NJ-tree, PCA, and population structure analyses showed that Ake chickens cluster with Yunnan native breeds, which diverged only 100–200 years ago. A selective sweep in the candidate region on chromosome 3 (97.0–97.37 Mb) showed elevated genetic differentiation (FST) and reduced nucleotide diversity (π) compared to the genome-wide average, indicating rapid fixation of the trait under natural/artificial selection. Demographic reconstruction indicated that the current effective size of Ake chickens is stable at 2000–3000 individuals. These findings deepen our understanding of Ake chicken evolution and provide valuable insights for conservation and the development of heat-stress-resistant poultry breeds.

Jialu Pi, J. Farina, C. Chao et al.

Mitigating population drift is vital for developing robust AI models for clinical use. While current methodologies focus on reducing demographic bias in disease predictions, they overlook the significant impact of chronic comorbidities. Addressing these complexities is essential to enhance predictive accuracy and reliability across diverse patient demographics, ultimately improving healthcare outcomes. We propose a causal reasoning framework to address selection bias in opportunistic screening for 1-year composite MACE risk using chest X-ray images. Training in high-risk primarily Caucasian patients (43% MACE event), the model was evaluated in a lower-risk emergency department setting (12.8% MACE event) and a relatively lower-risk external Asian patient population (23.81% MACE event) to assess selection bias effects. We bench-marked our approach against a high-performance disease classification model, a propensity score matching strategy, and a debiasing model for unknown biases. The causal+confounder framework achieved an AUC of 0.75 and 0.7 on Shift data and Shift external, outperforming baselines, and a comparable AUC of 0.7 on internal data despite penalties for confounders. It minimized disparities in confounding factors and surpassed traditional and state-of-the-art debiasing methods. Experimental data show that integrating causal reasoning and confounder adjustments in AI models enhances their effectiveness. This approach shows promise for creating fair and robust clinical decision support systems that account for population shifts, ultimately improving the reliability and ethical integrity of AI-driven clinical decision-making.

Quoc Thinh Vo, David Han

This technical report outlines our approach to Task 3A of the Detection and Classification of Acoustic Scenes and Events (DCASE) 2024, focusing on Sound Event Localization and Detection (SELD). SELD provides valuable insights by estimating sound event localization and detection, aiding in various machine cognition tasks such as environmental inference, navigation, and other sound localization-related applications. This year's challenge evaluates models using either audio-only (Track A) or audiovisual (Track B) inputs on annotated recordings of real sound scenes. A notable change this year is the introduction of distance estimation, with evaluation metrics adjusted accordingly for a comprehensive assessment. Our submission is for Task A of the Challenge, which focuses on the audio-only track. Our approach utilizes log-mel spectrograms, intensity vectors, and employs multiple data augmentations. We proposed an EINV2-based [1] network architecture, achieving improved results: an F-score of 40.2%, Angular Error (DOA) of 17.7 degrees, and Relative Distance Error (RDE) of 0.32 on the test set of the Development Dataset [2 ,3].

Marron McConnell, William F. Fagan

Population cycles are important components of many natural systems. Most studied in short-lived and small-bodied species, cycles frequently appear to be driven by density-dependent feedbacks. However, compelling evidence of cycles -- often more qualitative than quantitative -- also exists in large mammals. Among ungulates, both density-dependent vital rates and 'cohort effects' (lasting impacts of birth conditions on fecundity and survival) exist, but the implications of such feedbacks for oscillatory population dynamics have not been explored. Here, we present a synthetic model of ungulate population dynamics, parameterized for barren-ground caribou (Rangifer tarandus groenlandicus) and motivated by extensive Indigenous knowledge suggesting decades-long fluctuations in abundance. Caribou herds are theorized to be subject to both cohort effects and density dependence, and we linked these endogenous factors with environmental stochasticity to understand cycling. Using wavelet analysis, we characterized periodic phenomena and performed sensitivity analyses to clarify the drivers and characteristics of population cycles. We found that cohort effects, predominantly those impacting survival, can produce long-period oscillatory behavior across a wide range of environments and demographic structures. Our modeling framework is generalizable to other long-lived, large-bodied species with complex demography, and collectively, these efforts broaden the scope of inquiry into proximal drivers of population cycling.

Eduardo Esteves, Piere Rodriguez, Eduardo Vital

Degenerations of linear series on smooth projective varieties approaching multicomponent varieties $X$ give rise to certain quiver representations in the category of linear series over $X$, which yield rational maps from $X$ to the corresponding quiver Grassmannians of codimension 1 subspaces. We describe these quiver Grassmannians for the case of the simplest quiver, arising when $X$ has only two components. We prove that they are reduced, local complete intersections whose components are rational of the same dimension. Also, we show that they are limits of projective spaces when they do arise from degenerations, and thus are special fibers of certain Mustafin varieties. Finally, we address a Riemann--Roch question for these quiver representations.

Margherita Moretti, K. Korhonen, Alyson A. van Raalte et al.

Widowhood is a disruptive life event, and in aging societies, increased numbers of individuals are potentially exposed to it. Yet, we lack a comprehensive understanding of the demography of widowhood. Using total population data with information on marital and cohabiting unions, discrete-time event-history analysis, and incidence-based multistate life tables, we analyze lifetime risk of widowhood, mean age at becoming widowed, widowhood expectancy, and variation in years spent widowed, and also document gender and educational differences in these metrics over the last three decades in Finland. Our results show that, over time, individuals are less likely to experience widowhood, and when they do, it occurs at older ages. Compared with men, women have higher widowhood risk and widowhood expectancy (duration) and a lower mean age at widowhood. Widowhood expectancy for women declined from 8 to 6 years between 1988 and 2018, whereas for men it stagnated at around 2 years. Low-educated women faced more widowhood years than the highly educated, while the opposite held for men. In showing decreased risks, delayed onset, and shorter widowhood expectancy, particularly among women, our results suggest that the current older population may experience reduced exposure to the psychosocial and financial challenges of widowhood, with potentially reduced caregiving burden on families and the state.

V. J, P. Gophi, E. T P

Introduction: Patients undergoing non-cardiac surgeries face a measurable risk of cardiovascular events, making preoperative risk assessment vital. This study aimed to assess the level of peri-operative cardiovascular risk and its association with socio-demographic and clinical variables among patients undergoing non-cardiac surgeries. Methods: A cross-sectional analytical study was conducted among 92 patients with comorbidities undergoing non cardiac surgery selected using convenience sampling at Surgery OPD, JIPMER. The data was collected using the AUB-HAS2 Cardiovascular Risk Index which is a structured questionnaire. Results: Descriptive and inferential statistics like likelihood ration test was used. Mean AUB-HAS2 score was 1.12 ± 1.06. Majority (71.7%) had low, 20.7% intermediate, and 7.6% had high cardiovascular risk. Significant associations were found between cardiovascular risk and regular physical activity (p=0.001) and presence of co-morbidities (p=0.002). No significant association was found with socio demographic variables. Discussion: Compared with global data, this population showed a predominance of low cardiovascular risk. However, even within this category, individuals with comorbidities and low activity levels showed increased risk. The findings reinforce the necessity of clinical-based, not demographic-based, assessments. Most patients had low perioperative risk; however, attention is warranted for those with comorbidities and sedentary lifestyles.

Xuesong Wang, Caisheng Wang

Power system resilience is vital to modern society, as outages caused by extreme weather can severely disrupt communities. Existing statistical and simulation-based methods for resilience quantification are either retrospective or rely on simplified physical models, limiting their applicability. This paper proposes a deep learning-based framework that integrates historical outage and weather data to predict event-level resilience, measured using the resilience trapezoid method. The trained model is then applied to a benchmark weather dataset to estimate regional resilience, with optional socioeconomic and demographic factors incorporated as weighting terms when policymakers wish to emphasize the needs of specific population groups. The effectiveness of the framework is first validated on simulated outage records, showing strong agreement between predicted and simulated resilience values. It is then applied to real historical outage data to assess the resilience of actual power systems. Beyond evaluation, the results can guide targeted investments in distributed energy resources to improve resilience in vulnerable regions.

F. Grippo, L. Frova, M. Pappagallo et al.

In countries with high life expectancy, a growing share of the population is living with several diseases, a situation referred to as multi-morbidity. In addition to health data, cause-of-death data, based on the information reported on death certificates, can help monitor and characterize this situation. This requires going beyond the underlying cause of death and accounting for all causes on the death certificates which may have played various roles in the morbid process, depending on how they relate to each other. Apart from the underlying cause, the cause-of death data available in vital registration systems do not differentiate all other causes. We developed an algorithm based on the WHO rules that assigns a “role” to each entry on the death certificate. We distinguish between the following roles: originating (o), when the condition has initiated a sequence of events leading directly to death; precipitating (p), when it was caused by an originating condition or one of its consequences; associated (a), when it contributed to death but was not part of the direct sequence leading to death; ill-defined (i), i.e., conditions such as symptoms or signs or poorly informative causes. We applied this algorithm to all death records in four countries (Italy, France, Spain and the US) in 2017. The average number of originating causes is similar in the four countries. The proportion of death certificates with more than one originating cause—a situation typical of multi-morbidity—ranges from 10% in the US to 18% in Spain. All ages combined, the proportion of deaths with at least one associated cause is higher in Italy (41%) and in the US (42%) than in France (29%) and in Spain (27%). It is especially high in the US at all adult ages. Variations in the average number of causes between the four countries are mainly due to precipitating and ill-defined causes. The output of our algorithm sheds light on cross-country differences in the average number of causes on death certificates. It also opens the door for improvements in the methods used for multiple cause-of-death analysis.

Liang Zhu, Ming‐Zhu Yuan, David W. Armitage et al.

Insect populations in temperate climates can show seasonal differences in demographic rates. Extreme high‐temperature events (EHTs) are increasing in frequency across all seasons. These may, in turn, disrupt insects' season‐specific demographic strategies. However, whether insect populations respond to EHTs in a season‐specific fashion is not known, but may be critical for forecasting their responses to climate change. We conducted a series of common garden experiments measuring the inherent vital rates of spring, summer, and autumn cohorts of a global nonmigratory pest, the oriental fruit moth (Grapholita molesta), under constant mild temperatures, EHT exposures at different life stages, and short‐term heat hardening followed by EHT exposure at different life stages. We simultaneously conducted a 4‐year survey of G. molesta in orchards to link our experimental results to observed population dynamics in the field. We encountered intrinsic variation in vital rates and reproductive traits among seasonal cohorts, such that summer cohorts had higher intrinsic population growth rates but smaller eggs than spring and autumn cohorts. Moreover, these responses varied among the life stages to which the EHT was applied. Pre‐acclimation via heat hardening did not strongly affect these results but did slightly increase growth rates when applied to late‐stage larvae. These results were qualitatively recovered in natural population time series, with moderate EHTs enhancing population growth in the spring and reducing it in autumn. Our results underscore the importance of climatic seasonality in shaping season‐specific thermal responses to EHTs among ectotherms. Season‐specific EHT responses can potentially enhance growth of weak spring cohorts and depress the growth of autumn cohorts failing in dormancy, thereby contributing to insects' annual population persistence. Our study helps clarify how a deeper understanding of season and life‐stage‐specific heat responses can enable a more informed forecasting and management of multivoltine insect populations under climate change. Read the free Plain Language Summary for this article on the Journal blog.

Ulrich Pfister, G. Fertig

Abstract The article provides an overview of the historical organization of data collection on vital events and population in German territories during the pre-statistical era and briefly presents about a dozen related datasets. Data can be divided into the two categories of aggregate data on population and vital rates at the national, regional and community levels, and of nominative data at individual and household levels. The latter type of data is typically available only for individual communities or parishes. We illustrate the use of the datasets in published studies and point to directions for future research. The most important recent development concerns the increasing availability of indexed church records and online village genealogies, which offer a vast and little exploited potential for analysing the demographic patterns that prevailed prior to the onset of the demographic transition.

Angelita Alves de Carvalho, Gabriela Marise Bonifácio

This study aims to estimate and analyze four selected indicators of contradictions in female fertility preferences, which are called mismatches. Therefore, we seek to analyze the responses to the questions that women are asked regarding their ideal number of children, their current number of children, their future fertility intentions, and their use of contraceptive methods. Data from demographic and reproductive health surveys from fourteen countries in Latin America between 2006 and 2017 were used. An estimated occurrence of mismatches of 11 % was observed for the countries studied, and cases in which women were classified with a negative discrepancy and said that they do not want more children in the future prevailed. It can be inferred that despite the existence of several inconsistencies, the responses of Latin American women to questions about their fertility preferences are robust and very predictive.

Seyedeh Somayyeh Mousavi, Yuting Guo, Abeed Sarker et al.

Hypertension is a global health concern with an increasing prevalence, underscoring the need for effective monitoring and analysis of blood pressure (BP) dynamics. We analyzed a substantial BP dataset comprising 75,636,128 records from 2,054,462 unique patients collected between 2000 and 2022 at Emory Healthcare in Georgia, USA, representing a demographically diverse population. We examined and compared population-wide statistics of bivariate changes in systolic BP (SBP) and diastolic BP (DBP) across sex, age, and race/ethnicity. The analysis revealed that males have higher BP levels than females and exhibit a distinct BP profile with age. Notably, average SBP consistently rises with age, whereas average DBP peaks in the forties age group. Among the ethnic groups studied, Blacks have marginally higher BPs and a greater standard deviation. We also discovered a significant correlation between SBP and DBP at the population level, a phenomenon not previously researched. These results emphasize the importance of demography-specific BP analysis for clinical diagnosis and provide valuable insights for developing personalized, demography-specific healthcare interventions.

Oleksii Havryliuk

This paper describes and analyses the geography and factors of the neighbourhood satisfaction of the residents of a former post-WWII Soviet closed city in Ukraine – the post-Soviet city of Dnipro (population ca. one million). It is based on a questionnaire survey (n=1248) among adult (18+) inhabitants in Dnipro conducted in early 2018. The results show that the current inner-urban pattern is characterised by semi-peripheralised neighbourhood satisfaction, which is a consequence of the significant influence of (among other factors): infrastructure availability in the neighbourhood, the social and natural environmental in the neighbourhood, and the set of Soviet-legacy factors (the “Soviet” factor). Surprisingly, the highest level of neighbourhood satisfaction in the city of Dnipro is observed in one of the peripheral neighbourhoods (with predominant detached housing), in which the residents’ evaluation of their residential neighbourhood follows the proximity effect.

Shamel Fahmi, Victor Barasuol, Domingo Esteban et al.

This work is on vision-based planning strategies for legged robots that separate locomotion planning into foothold selection and pose adaptation. Current pose adaptation strategies optimize the robot's body pose relative to given footholds. If these footholds are not reached, the robot may end up in a state with no reachable safe footholds. Therefore, we present a Vision-Based Terrain-Aware Locomotion (ViTAL) strategy that consists of novel pose adaptation and foothold selection algorithms. ViTAL introduces a different paradigm in pose adaptation that does not optimize the body pose relative to given footholds, but the body pose that maximizes the chances of the legs in reaching safe footholds. ViTAL plans footholds and poses based on skills that characterize the robot's capabilities and its terrain-awareness. We use the 90 kg HyQ and 140 kg HyQReal quadruped robots to validate ViTAL, and show that they are able to climb various obstacles including stairs, gaps, and rough terrains at different speeds and gaits. We compare ViTAL with a baseline strategy that selects the robot pose based on given selected footholds, and show that ViTAL outperforms the baseline.

V. Vilasini, Mischa P. Woods

Extended Wigner's Friend Scenarios (EWFSs) go beyond the standard usage of quantum theory, where agents are treated classically, and instead model agents as unitary evolving quantum systems. This has been the subject of several no-go results: Frauchiger and Renner (FR) suggested that quantum agents reasoning using quantum theory will arrive at logical paradoxes, while other results highlight challenges for having an objective notion of measurement events and for causal reasoning in EWFSs. This raises the question: Is it possible to reliably make and test scientific predictions, and consistently reason about the world when applying quantum theory universally without assuming that observed measurement outcomes are absolute? We give a positive answer by developing a general quantum circuit framework for EWFSs. We formalise the concept of Heisenberg cuts by mapping them to distinct channels in a quantum circuit, and prove that FR-type paradoxes can be fully resolved by making explicit the conditioning on the quantum channels that are used in the reasoning process. We provide concrete rules by which quantum agents can reason and make predictions in a logically and causally consistent manner. Our framework describes all perspectives and predictions of an EWFS within a single, well-defined causal structure, although it allows events to be fundamentally subjective. Moreover, we show that an objective notion of measurement events nevertheless emerges in real-world experiments. This demonstrates the possibility of a relational yet operational framework overcoming challenges to scientific reasoning in EWFSs without modifying the Born rule, quantum unitarity, or the axioms of classical logic and probability theory. This enables analysis of different EWFS arguments and provides a platform to consistently extend quantum information methods and studies to Wigner's Friend Scenarios.