Sampling Years Research Articles

Leveraging local wildlife surveys for robust occupancy trend estimation

Natural resource agencies are frequently tasked with monitoring populations of at-risk species to ensure management activities do not negatively affect the viability of wildlife populations. Typically, these monitoring efforts evaluate trends in a population’s abundance, occupancy, or geographic distribution. Often, surveys provide local information, but results are generally not incorporated into broad-scale monitoring efforts that focus on range-wide population changes due to their variable nature in both spatial extent and effort. We investigated whether aggregating these local (hereafter “variable”) surveys can generate enough statistical power to estimate broad-scale population trends using simulations of declining populations of fishers (Pekaniapennati) over a 10-year time horizon. Our simulations included three population sizes which we refer to as abundant, common, and rare (N0 = 700, 350, and 100 individuals, respectively) with each declining at a rapid and moderate pace (λ = 0.933, and 0.977, respectively). For each population, we simulated variable surveys using an occupancy framework to subsample the population with parameters that mimic combining multiple independent monitoring efforts which vary annually in location, and effort. Regardless of spatial consistency of annual sampling, there was minimal variation in statistical power under both high and low detection probability simulations. However, when sampling effort varied each year, statistical power was lower for most populations and sampling scenarios when compared to consistent sampling effort unless some baseline level of sampling effort was reliably achieved in all years. In many cases, adding low-level consistent baseline sampling to variable surveys resulted in statistical power close to that of consistent sampling efforts. Our results suggest statistical power is driven by annual consistency in the proportion of landscape sampled rather than spatial consistency in sampling locations. This result indicates that current variable surveys could be leveraged and combined to detect population declines for at-risk species at broad-scales if a baseline proportion of landscape is robustly sampled. The level of baseline sampling is highly dependent on population size and magnitudes of population change. In simulations with a common or abundant population experiencing a rapid decline, a baseline survey effort of at least 5% of the landscape in combination with variable surveys resulted in statistical power consistently above the standard threshold of 0.80 for occupancy monitoring. Leveraging existing local efforts to achieve high detection probability and baseline sampling would reduce financial and logistical burdens of broad-scale wildlife monitoring efforts.

Expected improvements in precision when integrating opportunistic close-kin mark-recapture data into fisheries stock assessments

Close-Kin Mark-Recapture (CKMR) sampling, by providing information on abundance and survival rates (and potentially other quantities), offers a promising new data source for fisheries stock assessments. Sample design in order to achieve a desired precision is somewhat straightforward in simple CKMR models; however when integrated within a full stock assessment model with many other data sources, the value of the data (in terms of a reduction in uncertainty of model estimates) is less clear. Herein I demonstrate, using self-test simulations, the expected improvements in precision and accuracy of derived quantities and estimated parameters within statistical catch-at-age models when opportunistic CKMR sampling is conducted and the data integrated within the assessment. By opportunistic CKMR sampling I mean to describe the genetic sampling of individuals that comprise the age composition data, such that increases in CKMR sampling would also increase the age composition samples (and vice versa). I examine the expected improvements across three life history types (cod-like, flatfish-like, and sardine-like) and different amounts of data available to the assessment, including the uncertainty and inclusion of an abundance index and the sample size and time series length of CKMR and age composition samples. Results suggest CKMR data can provide considerable improvements in accuracy and precision of spawning stock biomass at the end of the time series and parameters defining natural mortality and scale of the population, provided an adequate annual sample size is collected relative to the spawning abundance of the stock during the period of CKMR inference. The time-series length of CKMR data and uncertainty or inclusion of an abundance index played a much more moderate role in how much improvement CKMR data provided over models fit without CKMR. This result was likely a function of the model being privy to an effectively known catch time series and known steepness, allowing it to estimate stock scale and trend reasonably well without CKMR data given informative composition data. I recommend simulation analyses including stock assessments as estimation models be carried out for those considering routinely collecting and integrating CKMR data into fisheries stock assessments.

Detecting Perkinsus-like organisms and Perkinsus marinus (Myzozoa: Perkinsidae) within new bivalve hosts in the southeastern Gulf of California.

Perkinsus marinus, a parasite myzozoa native from the Atlantic Ocean, has spread across various bivalve species in the Pacific Ocean. In the Gulf of California, clams like Larkinia grandis and Leukoma grata have become a secondary fishery, experiencing demand. During annual sampling (August 2017 - July 2018, n = 30/month), the Ray's fluid thioglycollate medium (RFTM) revealed presumptive hypnospores of Perkinsus sp. in L. grandis, with a low parasite prevalence (4.16%) and density (≤ 3.14 hypnospores g-1 tissue). From summer 2020 to summer 2021, P. marinus was seasonally identified in L. grata via staining and PCR tests, showing mean prevalence and density of 48.33% and 48 hypnospores g-1 tissue, respectively. The infection level was light in both clams. This parasite's presence in these new hosts within the southeastern Gulf of California confirms its ability to expand into non-native places, signaling a need for intervention strategies in managing and transporting mollusk species within the region.

Downstream effects of the pandemic? Spatiotemporal trends of quaternary ammonium compounds in suspended particulate matter of German rivers

During the SARS-CoV-2 pandemic, the preventive use of antimicrobials such as quaternary ammonium compounds (QACs) surged worldwide. As cationic and surface-active biocides, QACs are only partly removed during wastewater treatment and may cause adverse ecological effects in the downstream environment. To understand the environmental consequences of increased disinfectant use during the pandemic, we investigated spatiotemporal QAC concentration trends in the suspended particulate matter (SPM) of three diverse German rivers. Covering pooled annual SPM samples from 2006–2021 and monthly samples from 2018–2021 collected by the German Environmental Specimen Bank, 31 QACs were quantified by high performance liquid chromatography–mass spectrometry. ∑QAC concentrations in annual samples differed by more than tenfold between rivers in the order Saar (average 6.7 µg/g) > Rhine (0.9 µg/g) > Mulde (0.3 µg/g). The strongest potential pandemic imprint was however observed in the Mulde (+67 %) and Rhine (+22 %). Besides pandemic dynamics, also seasonal variation and mineral content of SPM tentatively affected QAC concentrations. Exceedance of predicted no-effect concentrations for sediment suggest ecotoxicological risks for long-chained QACs already before the pandemic. Our study thus highlights the importance of monitoring the environmental effects of antimicrobial use during pandemics and calls for an urgent minimization of non-essential applications.

Poppers, the Politics of Exemption and the Characteristics of Poppers Users in the annual English Festival Study, 2014–23

Abstract This paper explores the relationship between socio-demographic characteristics, self-reported alkyl nitrite (‘poppers’) use and sexual behaviours against a backdrop of UK policy change and ambiguity surrounding legal status. In 2024, the Advisory Council on the Misuse of Drugs recommended a unique, government-initiated, legal exemption from the Psychoactive Substances Act 2016 for poppers, because of its use by gay and bisexual men to reduce the risk of injury during anal sexual intercourse. Data from the annual convenience sample English Festival Study 2014–23 (n = 11,566) were used for Bayesian regression analyses of self-reported poppers use in three-time frames: lifetime, past year and past month use. Gay men were significantly more likely to report poppers use and particularly those reporting past-year participation in anal sex. Providing a critical analysis of recent trends in UK drug policy, the authors highlight how differential discrimination occurs within drug control where targeted exemption meets the politics of protected characteristics in UK law. This paper argues that poppers, therefore, provide a unique example in UK drug policy of how an apparent liberalization of legislative control could bolster the overarching drug prohibition regime while maintaining the appearance of rationality and fairness.

451 Establishing producer research sites for the development of beef and bison climate-smart agriculture

Abstract Greenhouse gas (GHG) emissions and livestock production are topics that are increasingly intertwined. While livestock production is frequently presented as harmful to the environment, this perception fails to consider the carbon sequestration that takes place in livestock grazing systems and the role that grazing ruminants have in maintaining healthy grassland ecosystems. Grazing lands, which are often unsuited to row crop agriculture, are estimated to account for 25% of the global soil sequestration potential for soil carbon storage. Grazing livestock producers are often overlooked in the GHG reduction conversation, despite over 70% of beef GHG emissions being attributed to the cow-calf sector, which is primarily grazing. Furthermore, there is a relative lack of data surrounding the implementation of climate-smart agriculture practices on grazing operations and a lack of cost-effective methods to measure carbon/GHG sinks and sources on these landscapes. The potential climate benefits are considerable, with nearly 940 million acres of rangelands in the U.S. supporting forage-based livestock production. South Dakota State University recently received funding to support a large-scale climate-smart project focused on grazing beef and bison. For this project, we are utilizing the Cottonwood Field Station that has over 80 yr of historical grazing data, along with six grazing beef and bison ranching operations in the Northern Great Plains. The work on these ranches will focus on measuring and monitoring the impacts of climate-smart NRCS land practices, including cover crops, improved pasture and range seedings, prescribed grazing, and prescribed burning. A significant focus will be extensive, annual soil sampling across these operations to continuously monitor changes in soil organic carbon, bulk density, texture, pH, and soil microbiome community profiles. Each operation will have GreenFeed methane pasture units deployed for 5 yr to monitor changes in beef cattle and bison methane emissions in response to climate-smart practice adoption. We are also assessing biodiversity pre and post climate-smart practice adoption, as biodiversity improvements may be one of the most overlooked and yet most important responses to climate-smart land practice implementation. Over the duration of this project, a large-scale, comprehensive data collection will be achieved and used to refine GHG and carbon sequestration estimates associated with range livestock systems. Data resulting from this project will be used to inform research protocols and prediction models, fill knowledge gaps, and shape science-based discussions and marketing strategies for climate-smart agricultural commodities.

Progress Toward Achieving National HIV/AIDS Strategy Goals for Quality of Life Among Persons Aged ≥50 Years with Diagnosed HIV - Medical Monitoring Project, United States, 2017-2023.

Ensuring good quality of life (QoL) among persons with diagnosed HIV (PWH) is a priority of the National HIV/AIDS Strategy (NHAS), which established 2025 goals for improving QoL. Goals are monitored through five indicators: self-rated health, unmet needs for mental health services, unemployment, hunger or food insecurity, and unstable housing or homelessness. Among the growing population of PWH aged ≥50 years, progress toward these goals has not been assessed. Data collected during the 2017-2022 cycles of the Medical Monitoring Project, an annual complex sample survey of U.S. adults with diagnosed HIV, assessed progress toward NHAS 2025 QoL goals among PWH aged ≥50 years, overall and by age group. The recent estimated annual percentage change from baseline (2017 or 2018) to 2022 was calculated for each indicator. Among PWH aged ≥50 years, the 2025 goal of 95% PWH with good or better self-rated health is 46.2% higher than the 2022 estimate. The 2025 goals of a 50% reduction in the other indicators range from 26.3% to 56.3% lower than the 2022 estimates. Decreasing hunger or food insecurity by 50% among PWH aged ≥65 was the only goal met by 2022. If recent trends continue, other NHAS QoL 2025 goals are unlikely to be met. Multisectoral strategies to improve access to housing, employment, food, and mental health will be needed to meet NHAS 2025 goals for QoL among older PWH.

Insomnia and unhealthy alcohol use in a National Sample of Women Veterans 50 years and older enrolled in the Veterans Health Administration

In this study, we examined rates of insomnia and co-occurring unhealthy alcohol use in a national sample of women Veterans age 50 years and older. We further explored associations between sociodemographic measures, insomnia-related clinical characteristics, and unhealthy alcohol use, and analyzed whether women with insomnia were more likely to report unhealthy alcohol use. Study aims were evaluated using national Veterans Health Administration (VA) electronic health records data from VA’s Corporate Data Warehouse. Data were extracted for women Veterans ≥50 years old with ≥1 VA primary care visit in each study year (2018: 3/11/18–3/10/19; 2020: 3/11/20–3/10/21; 2022: 3/11/22–3/10/23). Cases of insomnia were identified via diagnostic codes and prescription medications for insomnia. Unhealthy alcohol use was identified via Alcohol Use Disorders Identification Test-Consumption screening scores indicating unhealthy alcohol use. Annual sample sizes ranged from 240,420–302,047. Over the study timeframe, insomnia rates (diagnosis or medication) among women ≥50 years old ranged from 18.11–19.29%; co-occurring insomnia and unhealthy alcohol use rates ranged from 2.02–2.52%. Insomnia and unhealthy alcohol use rates were highest among women aged 50–59 years old. Depression and physical health comorbidities were consistently associated with insomnia; associations by race and ethnicity were less consistent. Compared to women without insomnia, women Veterans with either concurrent or unremitting insomnia were more likely to endorse unhealthy alcohol use. Findings signal a potential need for assessment and preventative efforts aimed at addressing insomnia and unhealthy alcohol use among women Veterans.

Costs of Health Registries: An Exploration for Health Services Research.

Health registries are an established methodology in health services research. Regarded as cheap bidder for observation studies in earlier times, many registries now benefit from an appropriate funding. However, reference figures for costs of registries in health services research are missing. Based on literature data as well as figures from a German funding initiative, the relationship between costs per newly recruited case and the annual sample size was analyzed. One can assume that a standard multicenter registry in health services research with 1,000 new patients each year will be appropriately financed with 1.1 to 2.2 million Euro in a period of five years. So smaller the sample size, so higher the costs for a newly recruited patient. The cost model of health registries should be further elaborated taking into account specifics of individual registries and differences in the level of case money.

Micro-costing of genetic diagnostics in acute leukemia in Sweden: from standard-of-care to whole-genome sequencing

Aims and background Whole-genome sequencing (WGS) is increasingly applied in clinical practice and expected to replace standard-of-care (SoC) genetic diagnostics in hematological malignancies. This study aims to assess and compare the fully burdened cost (‘micro-costing’) per patient for Swedish laboratories using WGS and SoC, respectively, in pediatric and adult patients with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Methods The resource use and cost details associated with SoC, e.g. chromosome banding analysis, fluorescent in situ hybridization, and targeted sequencing analysis, were collected via activity-based costing methods from four diagnostic laboratories. For WGS, corresponding data was collected from two of the centers. A simulation-based scenario model was developed for analyzing the WGS cost based on different annual sample throughput to evaluate economy of scale. Results The average SoC total cost per patient was €2,465 for pediatric AML and €2,201 for pediatric ALL, while in adults, the corresponding cost was €2,458 for AML and €1,207 for ALL. The average WGS cost (90x tumor/30x normal; sequenced on the Illumina NovaSeq 6000 platform) was estimated to €3,472 based on an annual throughput of 2,500 analyses, however, with an annual volume of 7,500 analyses the average cost would decrease by 23% to €2,671. Conclusion In summary, WGS is currently more costly than SoC, however the cost can be reduced by utilizing laboratories with higher throughput and by the expected decline in cost of reagents. Our data provides guidance to decision-makers for the resource allocation needed when implementing WGS in diagnostics of hematological malignancies.

Blood cytokines as potential predictors of the development of SARS-CoV-2 associated pneumonia in patients with stage II ESSENTIAL hypertension

The search for predictors of the severe course of COVID-19 was relevant both during the pandemic and at the present time. The aim of the study was to analyze the relationship of cytokine levels in patients with EН before SARS-CoV-2 infection with the incidence of coronavirus pneumonia. Materials and methods. From the database of 290 patients with stage II EAG who have been under observation for 8–12 years with annual blood sampling to determine cytokine levels, COVID-19 survivors were selected (mild without pneumonia and moderate to severe, pneumonia CT 1–2, CT-3). Anamnestic levels of IL-1β, IL-1α, IL-1ra, IL-18, IL-18 BP, IL-37, IL-6, sIL-6r, M-CSF, VEGF-A, IL-34 and HMGB1) in the blood serum of patients with stage II EH were analyzed (method ELISA). The analysis of the obtained results was carried out using Stat Soft Statistica 13.5. Results and discussion. Patients with EH and COVID-19 with pneumonia (CT I-II) after SARS-CoV-2 infection 2–6 months before the infectious disease had significantly higher serum levels: IL-1α (p 0.05) and a decrease in IL-37 (p 0.001). During multivariate correlation analysis, a statistically independent relationship between an increase in the incidence of viral pneumonia in patients with stage II EН was confirmed only for IL-37 with a blood level of less than 60.2 pg/ml (regression coefficient — 2.21, standard error — 0.28, t criterion — 6.12, relative risk — 2.52, criterion Walda — 7.92, p = 0.006). When studying circadian rhythms of cytokine content in blood serum in patients of the analyzed groups, calculating the strength of correlations of anamnestic evening IL-37 levels in patients with stage II EР at 19.00–20.00 with the frequency of pneumonia against the background of SARS-CoV-2 infection, it has greater specificity and sensitivity (specificity — 0.75, sensitivity — 0.82) than morning concentrations. Considering that data on circadian rhythms were obtained in a limited number of patients, further monitoring is necessary, which is carried out by our scientific group. It should be noted that patients with essential hypertension are pathogenetically heterogeneous, including in terms of cytokine regulation. The study of this area will make it possible to personalize cytokine phenotypes of the disease and develop new methods for calculating the prognosis of both cardiovascular complications and features of the course of infectious diseases.

Does powerlessness motivate men and women to endorse sexism?

AbstractPeople who feel powerless are motivated to gain power, which may include men endorsing hostile sexism to affirm societal power or women endorsing benevolent sexism to affirm power in relationships. We used four waves of an annual longitudinal panel sample (N = 58,405) to test whether within‐person changes in powerlessness predicted subsequent changes in men's hostile sexism and women's benevolent sexism. Results from a random intercept cross‐lagged panel model indicated that men who generally felt more powerless tended to endorse hostile sexism, but within‐person tests did not provide directional evidence linking men's powerlessness with hostile sexism. By contrast, women who generally felt more powerless endorsed benevolent sexism more strongly, and small within‐person lagged effects indicated that upward deviations in women's powerlessness in 1 year predicted stronger endorsement of benevolent sexism the following year. These results provide novel evidence that powerlessness motivates women's benevolent sexism and their toleration of gender inequalities.

Transcriptome analysis of cynomolgus macaques throughout their lifespan reveals age-related immune patterns

Despite the different perspectives by diverse research sectors spanning several decades, aging research remains uncharted territory for human beings. Therefore, we investigated the transcriptomic characteristics of eight male healthy cynomolgus macaques, and the annual sampling was designed with two individuals in four age groups. As a laboratory animal, the macaques were meticulously shielded from all environmental factors except aging. The results showed recent findings of certain immune response and the age-associated network of primate immunity. Three important aging patterns were identified and each gene clusters represented a different immune response. The increased expression pattern was predominantly associated with innate immune cells, such as Neutrophils and NK cells, causing chronic inflammation with aging whereas the other two decreased patterns were associated with adaptive immunity, especially “B cell activation” affecting antibody diversity of aging. Furthermore, the hub gene network of the patterns reflected transcriptomic age and correlated with human illness status, aiding in future human disease prediction. Our macaque transcriptome profiling results offer systematic insights into the age-related immunological features of primates.

About the fertility of pink salmon Iturup Island

The purpose of the work is to present data for the last 15 years and analyze the fecundity of pink salmon at the present stage of its natural and hatchery reproduction on the island Iturup.The research material was based on the results of biological analysis of pink salmon breeders running to spawn in the basins of Prostor and Kurilsky bays (Iturup Island, Sakhalin region) in July-September 2008–2022. Methods used: standard methods of biological analysis, descriptive statistics methods.Results: it was established that over the past 15 years there has been a trend towards a decrease in the weight of female pink salmon. The value of absolute fecundity during this period varied from 289 to 3568 oocytes, and on average, with one exception, ranged from 1277 to 1640 oocytes. Fecundity was positively but weakly correlated with the length and weight of females within each of the annual samples, and the reliability of this relationship was achieved due to the volume of the samples. The relationship between the fecundity and weight was stronger than that between the fecundity and the length of fish. Average fecundity values were closely correlated with the average weight of females, and, therefore, as in the case of fish weight, in the period from 2008 to 2022 there was a trend toward a decrease in average fecundity values.Practical significance: we studied the fertility of female pink salmon from the only large commercial stock in Russia, formed through natural and hatchery reproduction.

Key determinants of soil labile nitrogen changes under climate change in the Arctic: A meta-analysis of the responses of soil labile nitrogen pools to experimental warming and snow addition

The Arctic terrestrial ecosystems are undergoing rapid climate change, causing shifts in the dynamics of soil nitrogen (N), a pivotal but relatively underexplored component. To understand the impacts of climate change on soil labile N pools, we performed meta- and decision-tree analyses of 391 observations from 38 peer-reviewed publications across the Arctic, focusing on experimental warming and snow addition. Soil dissolved organic nitrogen (DON), ammonium (NH4+), and nitrate (NO3-) pools under experimental warming exhibited overall standard mean differences (SMDs) ranging from −0.08 to 0.02, with no significance (P > 0.05); however, specific conditions led to significant changes. The key determinants of soil labile N responses to warming were experimental duration and mean annual summer temperature for DON; annual precipitation, soil moisture, and sampling timing for NH4+; and soil layer for NO3-. Snow addition significantly increased all labile N pools (overall SMD = 0.23–0.36; P < 0.05), influenced by factors such as sampling timing and vegetation type for DON; experimental duration and soil moisture for NH4+; and soil pH for NO3-. By consolidating and reprocessing datasets, we not only showed the overall responses of soil labile N pools to climate manipulation experiments in Arctic tundra ecosystems but also identified key determinants for changes in soil N pools among environmental and experimental variables. Our findings demonstrate that warming and snow-cover changes significantly affect soil labile N pools, highlighting how the unique environmental characteristics of different sites influence terrestrial N cycling and underscoring the complexity of Arctic N dynamics under climate change.

National Trends in Emergency Department Visits for Suicide Attempts and Intentional Self-Harm.

This study estimated national annual trends and characteristics of emergency department visits for suicide attempts and intentional self-harm in the United States from 2011 to 2020. Data were from the National Hospital Ambulatory Medical Care Survey, an annual cross-sectional national sample survey of emergency departments. Visits for suicide attempts and intentional self-harm were identified using discharge diagnosis codes (ICD-9-CM for 2011-2015; ICD-10-CM for 2016-2020) or reason-for-visit codes. The annual proportion of emergency department visits for suicide attempts and intentional self-harm was estimated. The weighted number of emergency department visits for suicide attempts and intentional self-harm increased from 1.43 million, or 0.6% of total emergency department visits, in 2011-2012 to 5.37 million, or 2.1% of total emergency department visits in 2019-2020 (average annual percent change, 19.5%, 95% CI=16.9, 22.2). Visits per capita increased from 261 to 871 visits per 100,000 persons (average annual percent change, 18.8%, 95% CI=17.6, 20.0). The increase in visits was widely distributed across sociodemographic groups. While suicide attempt and intentional self-harm visits were most common among adolescents, adults age 65 or older demonstrated the largest increase (average annual percent change, 30.2%, 95% CI=28.5, 32.0). Drug-related diagnoses were the most common co-occurring diagnosis among suicide attempt and intentional self-harm visits. Despite the rise in emergency department visits for suicide attempts and intentional self-harm, less than 16% included an evaluation by a mental health professional. A significant national increase in emergency department visits for suicide attempts and intentional self-harm occurred from 2011 to 2020, as a proportion of total emergency department visits and as visits per capita. These trends underscore an urgent need to improve the continuum of mental health care for individuals with suicidal symptoms.

Source, Migration Pathways, and Atmospheric Release of Geologic Methane Associated With the Complex Permafrost Regimes of the Outer Mackenzie River Delta, Northwest Territories, Canada

AbstractSources and fluxes of methane to the atmosphere from permafrost are significant but poorly constrained in global climate models. We present data collected from the variable permafrost setting of the outer Mackenzie River Delta, including observations of aquatic methane seepage, core determinations of in situ methane occurrence and seep gas isotope geochemistry. The sources and locations of in situ geologic methane occurrence and aquatic and atmospheric gas release appear to be controlled by the regional geology and permafrost conditions. Where permafrost is &gt;250 m thick, thermogenic gas deposits at depth are isolated by laterally continuous, low permeability ice‐bearing sediments with few through‐going thawed taliks. Thus, the observed in situ methane and aquatic gas seepage appears to be dominated by microbial methane. In contrast, where permafrost is &lt;80 m thick, taliks are more likely to be through‐going, providing permeable conduits from depth and migration pathways for both thermogenic and biogenic gas. Continuous annual fluid sampling of two lakes and a river channel documents aquatic methane flux from microbial sources, more deeply buried thermogenic sources, and mixtures of both. Using estimates of in situ methane concentration from deep core samples and observations of in situ free gas occurrences, we conclude that the reservoir of in situ geologic methane within ice bonded permafrost is substantial and that this methane is presently migrating with ongoing atmospheric release. It is our assessment that the permafrost setting, and processes described are sensitive to future climate change as the permafrost warms.

Research on Annual Runoff Prediction Model Based on Adaptive Particle Swarm Optimization–Long Short-Term Memory with Coupled Variational Mode Decomposition and Spectral Clustering Reconstruction

Accurate medium- and long-term runoff prediction models play crucial guiding roles in regional water resources planning and management. However, due to the significant variation in and limited amount of annual runoff sequence samples, it is difficult for the conventional machine learning models to capture its features, resulting in inadequate prediction accuracy. In response to the difficulties in leveraging the advantages of machine learning models and limited prediction accuracy in annual runoff forecasting, firstly, the variational mode decomposition (VMD) method is adopted to decompose the annual runoff series into multiple intrinsic mode function (IMF) components and residual sequences, and the spectral clustering (SC) algorithm is applied to classify and reconstruct each IMF. Secondly, an annual runoff prediction model based on the adaptive particle swarm optimization–long short-term memory network (APSO-LSTM) model is constructed. Finally, with the basis of the APSO-LSTM model, the decomposed and clustered IMFs are predicted separately, and the predicted results are integrated to obtain the ultimate annual runoff forecast results. By decomposing and clustering the annual runoff series, the non-stationarity and complexity of the series have been reduced effectively, and the endpoint effect of modal decomposition has been effectively suppressed. Ultimately, the expected improvement in the prediction accuracy of the annual runoff series based on machine learning models is achieved. Four hydrological stations along the upper reaches of the Fen River in Shanxi Province, China, are studied utilizing the method proposed in this paper, and the results are compared with those obtained from other methods. The results show that the method proposed in this article is significantly superior to other methods. Compared with the APSO-LSTM model and the APSO-LSTM model based on processed annual runoff sequences by single VMD or Wavelet Packet Decomposition (WPD), the method proposed in this paper reduces the RMSE by 40.95–80.28%, 25.26–57.04%, and 15.49–40.14%, and the MAE by 24.46–80.53%, 16.50–59.30%, and 16.58–41.80%, in annual runoff prediction, respectively. The research has important reference significance for annual runoff prediction and hydrological prediction in areas with data scarcity.

Removing bovine leukemia virus–infected animals with high proviral load leads to lower within-herd prevalence and new case reduction

Bovine leukosis is prevalent in the North American dairy industry and its effect on animal health and production is widely documented. However, not all bovine leukemia virus (BLV) infected animals transmit the virus equally. Animals with high BLV proviral loads (HPL) are associated with higher transmission risks and therefore, their removal may reduce transmission and eventually within-herd prevalence. We aimed to evaluate the impact of selectively removing HPL cows on the within-herd BLV prevalence and incidence rate of BLV infection in 10 dairy herds. Annual blood and/or milk samples were collected from adult cows over 3 years. Positivity with BLV were determined by ELISA tests and proviral loads in blood of BLV-positive animals were estimated with BLV SS1 quantitative PCR assays. Herd managers were encouraged to consider the proviral load when making culling decisions and implement BLV control practices. High proviral load cows had the highest relative risk of removal indicating the farmers prioritized HPL cows for culling. The within-herd BLV prevalence decreased significantly in 4 herds whereas BLV incidence rate decreased in 9 herds. Over the 3 years, the proviral load demonstrated a relatively stable level, suggesting a single proviral load test in an adult cow may suffice to make culling decisions.

Successful Control of Mycobacterium avium Subspecies paratuberculosis Infection in a Dairy Herd within a Decade-A Case Study.

This longitudinal case study provides an in-detail report of the process towards the elimination of Mycobacterium avium subsp. paratuberculosis (MAP) from a closed 450-head commercial dairy herd. In parallel, two diagnostic approaches were applied to all cows in annual intervals during 2012-2022: detection of MAP in individual faecal samples by bacteriological cultivation on solid medium and detection of MAP-specific antibodies by ELISA. For each annual sampling, the kappa coefficients for test agreement and the survival rates of MAP-positive and MAP-negative cows were calculated. Applying a multivariable linear regression model revealed a significantly lower fat-corrected 305-day milk yield for MAP-positive cows. The true prevalence of MAP shedders reduced from 24.2% in 2012 to 0.4% in 2019 and during 2020-2022, no MAP shedder was identified. Test agreement was generally low and bacteriological cultivation showed positive results earlier than the ELISA. In the first years of control, the survival of MAP shedders was longer than in the final stage. In conclusion, the elimination of MAP from a dairy herd might be feasible within a decade. Changes in the test agreement must be considered. Timely removal of MAP shedders, hygienic calf rearing, and colostrum supply are key for successful control.