Effects of local density dependence and temperature on the spatial synchrony of marine fish populations

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Effects of local density dependence and temperature on the spatial synchrony of marine fish populations

Disentangling the processes affecting spatial synchrony is challenging but essential to predict the effects of changing environmental conditions on populations. By studying spatial synchrony in density dynamics with and without accounting for the effects of temperature and density dependence, the authors show how temperature synchronizes while density dependence desynchronizes population dynamics.


Abstract

Disentangling empirically the many processes affecting spatial population synchrony is a challenge in population ecology. Two processes that could have major effects on the spatial synchrony of wild population dynamics are density dependence and variation in environmental conditions like temperature. Understanding these effects is crucial for predicting the effects of climate change on local and regional population dynamics. We quantified the direct contribution of local temperature and density dependence to spatial synchrony in the population dynamics of nine fish species inhabiting the Barents Sea. First, we estimated the degree to which the annual spatial autocorrelations in density are influenced by temperature. Second, we estimated and mapped the local effects of temperature and strength of density dependence on annual changes in density. Finally, we measured the relative effects of temperature and density dependence on the spatial synchrony in changes in density. Temperature influenced the annual spatial autocorrelation in density more in species with greater affinities to the benthos and to warmer waters. Temperature correlated positively with changes in density in the eastern Barents Sea for most species. Temperature had a weak synchronizing effect on density dynamics, while increasing strength of density dependence consistently desynchronised the dynamics. Quantifying the relative effects of different processes affecting population synchrony is important to better predict how population dynamics might change when environmental conditions change. Here, high degrees of spatial synchrony in the population dynamics remained unexplained by local temperature and density dependence, confirming the presence of additional synchronizing drivers, such as trophic interactions or harvesting.

Isolation and characterization of potential Lactobacillus acidophilus strains isolated from pig feces

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Abstract

The aim of this study was to isolate and characterize Lactic Acid Bacteria (LAB) from 16 feces samples of pig farm, and to evaluate the probiotic potential of these isolates as potential oral probiotic candidates. The selection process was based on the isolation, identification, and a series of experiments for the selection of appropriate candidates with beneficial properties. The results demonstrated that most of LAB showed relatively strong resistance to pH 2.5 and high bile salts (1%), and had good survival in simulated gastric and intestinal juice. 9 isolates displayed antimicrobial activities against Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa and Enterobacter sakazakii. Almost all isolates were sensitive to ampicillin, chloramphenicol, vancomycin and amoxicillin, and most of isolates exhibited resistance against tetracycline and vancomycin. The adhesion rates of LAB varied greatly. The results of the study suggested that the Lactobacillus acidophilus NCUA065001 have the important functional property of probiotic candidates to enhance gut integrity and could considered to be the potential antibiotic alternatives in the pig feed industry.

Experimental manipulation of perceived predation risk alters survival, cause of death, and demographic patterns in juvenile snowshoe hares

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Canadian Journal of Zoology, Ahead of Print.
Perceived predation risk alters prey behaviour and physiology, but few studies have examined downstream consequences on prey demography in wild populations. Perceived predation risk could alter adult reproductive performance via reduced investment in offspring quality and post-birth care. We manipulated perceived predation risk in snowshoe hare (Lepus americanus Erxleben, 1777) by exposing pregnant mothers to chases by a domestic dog (Canis familiaris Linnaeus, 1758). Litter size was comparable between risk-augmented and control groups, but treated females had more stillbirths and gave birth to leverets of lower body condition. Leverets from risk-augmented females had 88% higher 40-day mortality rate. Maternally preventable causes of death like starvation or predation by red squirrel (Tamiasciurus hudsonicus (Erxleben, 1777)) caused this difference, particularly during the nursing period. Risk-augmented mothers were always more active than controls, but the difference was greatest during the nursing period. We found that perceived predation risk reduces maternal productivity pre- and post-partum, implying downstream consequences to populations. Because our treatment ended before parturition, we can link offspring performance such as survival and behaviour specifically to maternal life-history trade-offs, which has not been shown in a wild mammal.

Statistical modelling to examine the impact of changes in crude oil and fertiliser prices on maize prices and future forecasts in India

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Statistical modelling to examine the impact of changes in crude oil and fertiliser prices on maize prices and future forecasts in India

This study examines the impact of crude oil and fertiliser price changes on maize crop prices in India using monthly time series data from May 2007 to September 2022. The best-fitted Autoregressive Integrated Moving Average model with the lowest Akaike's Information Criterion value is selected, and the Box–Ljung test is used to validate the prediction accuracy.


Abstract

This study examines the impact of crude oil and fertiliser price changes on maize crop prices in India using monthly time series data from May 2007 to September 2022. The best-fitted Autoregressive Integrated Moving Average model with the lowest Akaike's Information Criterion value is selected, and the Box–Ljung test is used to validate the prediction accuracy. Empirical results suggest that maize price is driven by crude oil and fertiliser prices since it has been found that maize prices are highly positively correlated with the prices of crude oil and fertiliser. Also, a strong correlation has been found between crude oil and fertiliser prices. The investigation for forecasting the next 15 months from November 2022 also revealed that maize prices showed no volatility because of a constant trend, but crude oil prices showed a declining trend, while di-ammonium phosphate prices showed an increasing trend over the period from November 2022 to February 2023. They then declined to June 2023 but again showed an increasing trend from July 2023 to January 2024 and achieved the highest price in December 2023. Because of a constant trend, urea prices showed no volatility over the 15 months. The estimates can aid the government in formulating policies to maintain agricultural crop production and control input price changes to meet the growing population's food demands.

Analysis of circRNA profiles and clinical value in Stevens‐Johnson syndrome and toxic epidermal necrolysis

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Abstract

Severe cutaneous adverse drug reactions, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), are challenging to be early diagnosed and evaluate their prognoses. This investigation aimed to analyse the expression profiles of SJS/TEN in peripheral blood mononuclear cells (PBMC) and assess the correlation between circular RNA (circRNA) and disease severity. Sixteen SJS/TEN patients and sixteen controls were enrolled and serum samples of both groups were obtained. CircRNA expression profiles in three SJS/TEN patients and three controls were detected by RNA sequencing and bioinformatic analyses were then performed. The differentially expressed circRNAs were verified by quantitative polymerase chain reaction (qPCR). Then, analysing the correlation of circRNAs with the toxic epidermal necrolysis-specific severity of illness score (SCORTEN) and the epidermal detachment area. A total of 134 circRNAs were differentially expressed in the PBMCs of SJS/TEN individuals, according to our results. The qPCR showed that three circRNAs (hsa_circ_0000711, hsa_circ_0083619 and hsa_circ_0005615) were down-regulated, and one circRNA (hsa_circ_0003028) was up-regulated, which were compatible with the sequencing findings. The concentration of hsa_circ_0083619 was closely associated with the SCORTEN scale (r = −0.581, p = 0.037) and the epidermal detachment area (r = −0.576, p = 0.039). The circRNA-miRNA-mRNA prediction network was used to construct the hsa_circ_0083619/miR-18a-5p/BCL2L10 axis. The hsa_circ_0083619 could serve as a disease severity indicator for SJS/TEN. Through bioinformatics analysis, we speculated that hsa_circ_0083619/miR-18a-5p/BCL2L10 axis might play a role in SJS/TEN pathogenesis.

Composite indexes of anthropometric failure in children under 5 years of age in Argentina: Comparative analysis among regions: 2019–2020

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Abstract

Objectives

Composite Index of Anthropometric Failure (CIAF) and Extended CIAF (ECIAF) allow for the identification of simultaneous presence of two or more types of malnutrition. The objective of this study was to analyze anthropometric failure in Argentinean children under 5 years old, taking into consideration regional and socioeconomic perspectives.

Materials and Methods

Data from the National Survey of Children and Adolescents MICS 2019–2020 were used, which included 5473 children under 5 years old of both sexes residing in the six regions of Argentina. CIAF and ECIAF excludes children not in anthropometric failure (group A) and was calculated from a percentage of children included in malnutrition categories B: wasting only; C: wasting and underweight; D: wasting, stunting, and underweight; E: stunting and underweight; F: stunting only; Y: underweight only; G: only weight excess; and H: stunting and weight excess. The data were analyzed according to region and wealth quintile.

Results

In children aged 0–2.99 years, CIAF was 12.5% and ECIAF was 27.7%, with boys being more affected. In children aged 3–4.99 years, the rates were 9.7% and 22.3%, respectively, with girls showing a higher prevalence. The highest ECIAF was recorded in the Patagonia region (31.3%), while the highest ECIAF was observed in the poorest quintile.

Discussion

The presence of double burden of malnutrition has been observed across all regions and household income levels. Additionally, overweight has shown a higher intensity in economically prosperous regions and households, while stunting has been more prevalent in economically disadvantaged areas.

Genetic parameters for health traits and their association with fertility and milk production in Chinese Holsteins

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Abstract

Herd health is one of the key problems influencing the efficiency of the dairy industry. Genetic selection, with a focus on animal health, is important for herd improvement. This study aimed to estimate genetic parameters for health traits and their correlations with fertility and milk production traits in dairy cattle. Based on records from 58,549 lactating cows calved between 2015 and 2021, a total of 24 health traits (six composite health traits and 18 independent health traits), four fertility traits and five milk production traits were analysed. First, linear and threshold animal models were used to estimate the variance components and heritabilities of the health traits. Second, a bivariate linear animal model was used to estimate genetic correlations among all 24 health traits. Finally, a bivariate linear animal model based on records from the first lactation was used to estimate the correlations between health traits and fertility or milk production traits. The results showed that all health traits had low heritabilities, ranging from 0.002 (0.001) to 0.048 (0.004) in the linear model and from <0.001 (0.021) to 0.226 (0.035) in the threshold model. Genetic correlations between health traits across categories were generally low, whereas the relatively high genetic correlations were found between health traits within the same category. In this study, only a few significant and moderate genetic correlations were observed between health traits and fertility or milk production traits. Clinical mastitis showed relatively moderate correlations with fertility traits, ranging from 0.277 (0.113) (interval from first to last insemination) to 0.401 (0.104) (calving interval). Moreover, there were moderate genetic correlations between hoof health and milk production traits. The results from the current study will support balanced dairy breeding to genetically improve disease resistance in dairy cows.

Growth performance, nutrient digestion, rumen fermentation and blood biochemistry in response to partially replacing cottonseed cake with sesame meal in a lamb feedlot diet

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Abstract

Recently, it is necessary to formulate high-quality, balanced and low-cost rations for ruminants from nontraditional sources. The present study conducted to investigate the impact of partially replacing corticated cottonseed (CS) cake with sesame meal (SM) in a lamb feedlot diet on growth performance, nutrient digestion, rumen fermentation and blood biochemistry. Fifteen growing lambs with an initial body weight of 27.4 ± 1.2 kg (6–7 months old) were randomly assigned into three equal groups (n = 5). Lambs in control group (CS) fed a basal diet, while 8% and 16% SM were used to replace an equal portion of corticated CS cake in the second (8SM) and third (16SM) groups respectively. Results showed that most parameters of growth performance and nutrient digestibility were significantly improved (p < 0.05) with the partial replacement of SM (8SM and/or 16SM). Regarding ruminal parameters, ruminal pH and total volatile fatty acids concentration increased (p < 0.05), while ammonia level and total protozoa count decreased with the partial replacement of SM. Moreover, blood parameters showed variant responses to SM partial replacement. Total protein increased, and glucose decreased significantly with 16SM, while cholesterol showed a significant decreasing with both SM replacement levels. SM may substitute CS cake in lamb diet without detrimental effects on performance, digestibility and ruminal fermentation.