Search Results (184)

IPM (Integrated Pest Management) strategies present a good theoretical framework for sustainably controlling pest populations. In this paper, we propose a switched IPM model with predation-induced fear and seasonally birth in a pest population. Employing theories of impulsive differential equations, we gain evidence showing that the pest-eradication solution $(0,\overline{y\left(t\right)})$ of the investigated system is GAS. The investigated system is also proven to be persistent. Our results provide new methods for IPM strategies. Full article

The speckled smooth-hound Mustelus mento is an endemic coastal shark from the southeastern Pacific, currently listed as “Critically Endangered” due to intense fishing pressure and the absence of species-specific management across its distribution range. Between November 2021 and October 2023, 925 individuals were examined from artisanal landings in northern Chile to describe their reproductive biology and embryonic development characteristics. The total length ranged from 27.6–159.3 cm in females and 14.2–165.0 cm in males, with a sex ratio of 1:1.2, which was slightly biased towards females. The estimated size at 50% maturity was 53.6 cm for females and 48.7 cm for males, with 70.6% of females and 66.0% of males caught below these thresholds, indicating a predominance of immature individuals in landings. Nine gravid females (106–139 cm) contained 71 embryos, which were classified into five developmental stages (encapsulated ovum, early organogenesis, fin differentiation, pigmentation and growth, and pre-partum) based on their external morphology and yolk sac reduction. The litter size ranged from 4 to 12 embryos, and the estimated size at birth was 13–14 cm in length. Embryos were recorded only during the summer months, suggesting a seasonal reproductive cycle with parturition in the early autumn. The persistent yolk sac connection throughout development and the absence of placental structures confirm that M. mento exhibits aplacental viviparity. These results document the first population-level description of the reproductive biology of M. mento, redefine its reproductive mode, and provide baseline information essential for implementing species-specific management and conservation measures in Chilean waters. Full article

Background: Maternal vitamin D status during pregnancy has been hypothesized to influence offspring neurodevelopment; however, the evidence remains inconsistent. Methods: We studied 66 mother–child pairs from the KLOTHO cohort with serum 25-hydroxyvitamin D [25(OH)D] measurements at delivery (maternal and umbilical cord). At 10 years of age, neurodevelopment was assessed using standardized questionnaires, generating composite z-scores for cognitive (cognitive, communication, motor) and psychosocial (social–sentimental, special interests) domains. Multivariable models were adjusted for sex, maternal body mass index and education, and neonatal birth weight and gestational age. Results: Maternal 25(OH)D deficiency (<50 nmol/L) was not associated with cognitive composite scores (p = 0.77). The psychosocial composite scores showed a non-significant negative trend (p = 0.29). Neonatal deficiency showed no consistent association with cognition (p = 0.99) or psychosocial outcomes (p = 0.30). Exploratory partial correlations suggested a positive association between maternal 25(OH)D and psychosocial development (r = 0.60, p = 0.038, n = 12). Seasonal variation in maternal vitamin D was observed (autumn: 56.0 ± 24.6 vs. winter: 32.0 ± 18.3 nmol/L; p < 0.0001), but did not translate into differences in 10-year outcomes. Conclusions: In this cohort of 66 pairs, perinatal vitamin D status was not a determinant of global cognition at 10 years of age. A potential link with psychosocial development requires replication in larger longitudinal studies. Due to the limited sample size, all findings should be interpreted as exploratory. Full article

Background: Vitamin D (VD) plays a central role in calcium homeostasis during pregnancy and has been implicated in redox-related biological processes. While VD deficiency (VDD) has been consistently associated with adverse pregnancy outcomes, the relationships between VD insufficiency (VDI), maternal antioxidant-related biomarkers, and neonatal outcomes remain incompletely characterized, particularly during the third trimester. Objective: To determines the prevalence of VDI in third-trimester pregnant women and to examine its associations with antioxidant-related markers and selected neonatal outcomes. Methods: A cross-sectional study was conducted among pregnant women in the third trimester attending a tertiary referral hospital in Mexico City. Maternal serum 25-hydroxyvitamin D (25-OHD) concentrations were measured, along with a panel of redox-related markers, including 2,2-diphenyl-2-2picrylhydrazyl (DPPH) radical scavenging activity, reduced glutathione (GSH), glutathione S-transferase (GST), glutathione peroxidase (GPx), and oxygen radical absorbance capacity (ORAC). Neonatal anthropometric parameters were recorded at birth. Associations between maternal VD status, redox-related markers, environmental factors, and neonatal outcomes were evaluated using appropriate statistical analyses. Results: A high prevalence of VDI was observed in the study population. Maternal VDI was associated with lower activities of GSH, GST, and GPx. Passive exposure to tobacco smoke and season of sampling were also associated with lower VD concentrations. Neonates born to women with VDI had higher birth weight compared with those born to women with sufficient VD concentrations. Maternal serum 25-OHD concentrations correlated positively with selected antioxidant enzyme activities. Conclusions: In this cohort of third-trimester pregnant women, VDI co-occurred with environmental factors, differences in maternal redox-related markers, and selected neonatal outcomes. These findings support an associative framework in which suboptimal VD status during the third trimester is accompanied by variations in redox-related markers. Longitudinal and mechanistic studies are needed to clarify the temporal sequence and biological relevance of these associations. Full article

Age at first calving (AFC) and 305-day milk yield in the first lactation (MY) data of 18,545 Holstein-Friesian cows born between 2008 and 2018 in six herds were evaluated. The effects of some genetic and environmental factors, population genetic parameters, breeding value (BV), and phenotypic and genetic trends of AFC and MY traits were estimated. The GLM method (ANOVA Type III) and BLUP animal model were used for the estimations. One-way linear regression analysis was used for trend calculations. The adjusted overall mean value (±SE) of the AFC and MY traits was 25.19 ± 0.02 months and 10,287.14 ± 24.79 kg, respectively. The percentage proportion contribution of the different factors in the phenotype in the case of AFC was as follows: herd 94.41%, birth year of cow 3.26%, birth season of cow 1.39%, and sire 0.71%. For MY, the contribution was as follows: herd 89.17%, birth season of cow 5.38%, birth year of cow 4.09%, and sire 1.05%. The heritability of AFC and MY traits by two different models proved to be moderate (0.26 ± 0.02, 0.19 ± 0.01 and 0.30 ± 0.02, 0.34 ± 0.01, respectively). There were relatively small differences between the sires in the estimated BV for the traits AFC and MY. The phenotypic and genetic correlations between AFC and MY traits were weak (between −0.05 and −0.16). Based on the phenotypic trend calculation, AFC showed a decreasing direction (−0.12 months per year) and MY an increasing direction (+42.30 kg per year). However, the genetic trend was very slightly decreasing for AFC (−0.00 and −0.05 months per year) and slightly increasing for MY (+5.52 and +16.49 kg per year) over the period studied. Full article

Advocates for playful nature-based learning espouse the benefits of children’s self-directed play; however, past research has questioned whether this form of activity is beneficial to children of all ages, particularly the very young. In Australia, there are rapidly growing numbers of nature playgroups and bush kindergartens in which young children’s self-directed play-based learning is promoted. Bush kinders, as they are known in Australia, are a local adaptation of the European forest kindergarten approach, where three- and four-year-old children spend one day a week in outdoor contexts away from the kindergarten premises to learn and play. One further example of Australian nature-based approaches to Early Childhood Education and Care (ECEC) is the nature playgroup where forests, parklands, and beaches are used by parents to regularly meet so their children can socialise and play. Science learning is often prevalent in these nature playgroups where children observe the sky, ground, plants, and animals across changing seasons. The children can mix earth and water and move their bodies as they run, dance, and roll on the grass. Despite the popularity of nature-based ECEC approaches globally, Australian nature playgroups led by facilitators other than parents, aimed towards young children aged from birth to four, have only gained popularity in the past decade. This paper draws upon fieldwork informed by ethnographic methods and undertaken in 2024 at one nature playgroup. The observations of facilitators, parents, and children and the interactions between the researchers and the playgroup participants are described using vignettes to understand the experience of science learning during facilitated nature playgroup sessions. Through analysing research in ECEC nature-based science teaching and learning, we propose that facilitated playgroups are valuable for young children to interact with nature as an avenue to build science knowledge. Full article

Background: Respiratory syncytial virus (RSV) is a major contributor to severe Acute Respiratory Infections (ARI) in infants worldwide, leading to significant morbidity and mortality. The seasonal nature of RSV and other respiratory infections presents unique risks, especially for infants in low- and middle-income countries, such as Mexico, where comprehensive RSV surveillance is limited. This study aims to analyze respiratory infant mortality rates by month of birth across Mexico, with a focus on identifying high-risk periods and regional differences. Methods: National birth and mortality data from the Instituto Nacional de Estadística y Geografía were analyzed for all infants born between April 2014 and March 2020. Respiratory mortality rates (based on ICD-10 J and U codes) were calculated by month of birth and examined across eight geographical regions in Mexico. Mortality trends were analyzed using descriptive statistics to assess seasonal and regional variations. A correlation analysis was conducted between respiratory mortality and confirmed RSV hospitalization data to assess the temporal relationship between increased mortality and epidemic activity of this virus. Results: A total of 12,604,902 live births were recorded in Mexico during the study period, with 8805 infant deaths attributed to respiratory causes, resulting in a respiratory infant mortality rate of 0.7 deaths per 1000 births. Mortality rates exhibited strong seasonal patterns, with infants born between September and November at higher risk of respiratory death, peaking in October. The highest mortality rates were observed in the South region, while the lowest rates were in the Northeast. Conclusions: These findings highlight the importance of implementing preventive strategies in Mexico that are aligned with regional RSV seasonality. Timing preventive interventions with regional and seasonal mortality trends should enhance the cost-effectiveness and impact of RSV immunization programs, ultimately reducing infant mortality nationwide. Full article

Background/Objectives: Prenatal environmental exposure may influence disease risk later in life. Previous studies suggest that season or month of birth affects susceptibility to various conditions, including type 2 diabetes. We aimed to evaluate whether birth timing is associated with gestational diabetes mellitus (GDM). Methods: We conducted a retrospective cohort study of 8744 pregnant women screened for GDM between August 2011 and March 2020, according to Italian Ministry of Health guidelines. Only women born and raised in Calabria were included. Logistic regression and Cosinor analysis were performed. Results: Birth distribution peaked in January (30.7%) and was lowest in October (22.3%). Being born in January was associated with higher GDM [OR 1.287 (1.090–1.520), p = 0.003], whereas October and June births were protective [OR 0.800 (0.672–0.954), p = 0.013, and OR 0.818 (0.682–0.980), p = 0.030, respectively]. Birth in cold months increased GDM risk [OR 1.196 (1.080–1.325), p < 0.001], while birth in warm months was protective [OR 0.834 (0.758–1.917), p < 0.001]. Cosinor analysis of fasting glucose at OGTT confirmed significant seasonal periodicity (p = 0.0053). Conclusions: Season and month of birth are associated with GDM risk, cold-month births predisposing and warm-month births protecting. These findings suggest that early-life seasonal factors, potentially including maternal hyperglycemia during pregnancy, may influence future GDM risk. Full article

Reproductive performance in rabbits is highly sensitive to seasonal environmental variation and management practices, while the proportion of variance attributable to additive genetics for litter-level traits is typically low. The objective of this study was to evaluate the effects of year and season on litter size at birth (BR), litter size at weaning (WR), and weaning rate (WT), and to estimate the heritability of these traits in a commercial rabbit farm. A total of 770 kindling events recorded between 2015 and 2021 were analyzed. The mixed model for BR included the fixed effects of year and season, and the random effects of sire and residual error. The model for WR included the same structure, with BR added as a covariate. Least-squares means for fixed effects were used for pairwise comparisons using Tukey’s test. Year and season effects were significant for BR (p < 0.005), and the year effect was also significant for WR (p < 0.021). Litter size at birth ranged from 7.80 (dry season) to 9.21 (year 2020), with higher means observed during the semi-dry (8.52) and humid (8.56) seasons compared to the dry season (7.80). Litter size at weaning varied between 4.65 and 5.81 kits depending on the year. Weaning rate showed interannual variation (56.1–68.2%), but seasonal differences did not reach statistical significance (p < 0.075). Heritability estimates from the sire variance component were low: 0.01 for BR, 0.04 for WR, and 0.05 for WT. These results indicate that phenotypic variation in prolificacy in this population was predominantly driven by interannual and seasonal environmental factors, as well as perinatal management practices, while the additive genetic contribution was marginal. Full article

Background: Evidence linking maternal vitamin D status with gestational hypertensive disorders and neonatal outcomes in Southern Europe remains limited. We evaluated maternal and cord 25-hydroxyvitamin D [25(OH)D] at birth in an urban Greek cohort and examined associations with gestational hypertension and preeclampsia. Methods: We conducted a cross-sectional study of 248 mother–infant dyads delivering at Tzaneio General Hospital of Piraeus, Greece. Eligible participants were of Greek origin or long-term residents (>10 years). Maternal venous and umbilical cord blood were obtained at birth and analyzed for serum 25(OH)D. Postpartum questionnaires captured sun exposure, supplement use, and selected lifestyle factors; clinical and obstetric data, including diagnoses of gestational hypertension and preeclampsia, were abstracted from medical records. We classified 25(OH)D as deficient (<20 ng/mL), insufficient (20–29 ng/mL), and, for risk-stratified analyses, treated values < 30 ng/mL as low. Results: Maternal 25(OH)D concentrations varied seasonally (winter 16.96 ± 9.60 ng/mL; summer 24.22 ± 12.57 ng/mL) and correlated with cord concentrations (r = 0.80). Most mothers (75–89%) had <30 ng/mL across seasons, and 73% of neonates were <20 ng/mL despite supplementation. Gestational hypertension occurred in 29/248 (11.7%) and preeclampsia in 15/248 (6.0%), with low maternal 25(OH)D common among affected women. Conclusions: In this cross-sectional study of an urban Mediterranean population, hypovitaminosis D was highly prevalent among mothers and neonates, with seasonal variation and clustering among hypertensive pregnancies. These findings support prenatal care strategies beyond fixed supplementation, incorporating season- and environment-sensitive dosing with screening and dietary counseling. Prospective studies are needed to clarify causality and refine supplementation targets. Full article

Bovine tuberculosis (bTB) is mainly caused by Mycobacterium bovis, which affects cattle, leading to significant economic losses. In Chile, the vaccination with the M. bovis Bacillus Calmette-Guérin (BCG) strain has been implemented in dairy herds with high prevalence of bTB. This study evaluated non-specific protection associated with BCG on the detection of pathogen-associated genes (nsp5, stx1, stx2, invA, IS1081) and mortality related to diarrhea and pneumonia in calves. A total of 186 calves from a commercial dairy farm were enrolled and grouped as vaccinated (n = 96) and non-vaccinated (n = 90). The BCG Russia strain (2–5 × 10⁵ UFC) was inoculated subcutaneously within the first 30 days after birth. Animals were monitored through fecal sampling at 3 and 6 months of age for molecular detection of gene sequences. A logistic regression analysis showed differences in detection rates of the stx1 sequence at 3 months, with a higher risk for the non-vaccinated individuals (OR 2.91, CI 1.42–5.94, p = 0.03) and for those born in the cold season (OR 9.55, CI 2.02–45.11, p = 0.004). A Kaplan–Meier survival analysis showed a significant difference in deaths in vaccinated calves compared with non-vaccinated animals (p = 0.018), suggesting that BCG confers non-specific protection during the first 3 months after birth, in field conditions. Full article

Numerous factors, including genetic, environmental, and nutritional, are involved in testicular development and spermatogenesis. However, little is known about the effects of seasonal factors on pre-sexual maturity testicular development in Hu rams, which are famous for their high fertility and year-round estrus onset. This study explored the effect of the birth season on testicular development and spermatogenesis in Hu sheep. Thirty-six 6-month-old male lambs born in summer (n = 18) and winter (n = 18) were selected for analysis. Results showed that summer-born lambs exhibited significantly higher cauda sperm density (102.65 ± 9.56 vs. 16.86 ± 2.02 × 10⁷/g), antioxidant indices such as superoxide dismutase (SOD: 6.29 ± 1.01 vs. 4.09 ± 0.25 U/mgprot), and higher expression levels of glutathione peroxidase 3 (GPX3), glutathione peroxidase 4 (GPX4), and copper/zinc superoxide dismutase (Cu/Zn-SOD) than winter-born lambs. Conversely, the malondialdehyde content (1.08 ± 0.32 vs. 2.13 ± 0.34 nmol/mgprot) was significantly lower in the summer-born group (p < 0.05) than in the winter-born group. A total of 44 differential oxylipins and 326 differentially expressed genes (DEGs) were screened by ultra-performance liquid chromatography–tandem mass spectrometry and transcriptomics, respectively. An integrated analysis of oxylipins and transcriptomics revealed that these differential molecules were enriched in metabolic pathways. Notably, downregulated DEGs (e.g., UAP1L1 and NAT8L) were significantly correlated with upregulated differential oxylipins (e.g., epoxyeicosatrienoic acids and dihydroxyeicosatrienoic acids). These results indicate that compared to the winter-born group, the testicular tissues of summer-born rams showed stronger testicular antioxidant capacity and lower lipid peroxidation at the sexual maturity stage, which contributes to spermatogenesis. Full article

Neopterin is a well-characterized marker of cell-mediated immunity. Here, we used neopterin as a biomarker to identify the cellular immunity status of breeding giant pandas throughout gestation. Urine samples were collected from captive adult female giant pandas that had entered estrus and were either naturally bred and/or artificially inseminated (AI) during the breeding seasons at the Chengdu Research Base of Giant Panda Breeding. This study was divided into two parts. In the first part, we examined the urinary neopterin and progesterone (Pg) profiles during pregnancy in parturient and nonparturient individuals. From the day of mating to the Pg peak, there was no correlation between neopterin and Pg in both parturient individuals (n = 3) and nonparturient individuals (n = 3). During the period when the Pg dropped from its peak to approximately 100 ng/mg Cr, the changes in neopterin and Pg showed a negative correlation in parturient individuals, while there was no correlation between the changes in neopterin and Pg in nonparturient individuals. Subsequently, urine samples were categorized into four phases based on the reproductive status of giant pandas: (1) Estrus phase (Es); (2) Primary Pg increase phase (S1), during which Pg levels rise from the day of mating to 100 ng/mg Cr; (3) Secondary Pg increase phase (S2), during which Pg levels rise from 100 ng/mg Cr (inclusive) to their peak value; and (4) Post-peak Pg decline phase (S3), during which Pg levels decrease from their peak (inclusive) until they drop to approximately 200 ng/mg Cr. Analysis revealed that differences between parturient and nonparturient females emerged in the S3 phase. Compared to nonparturient individuals, neopterin concentrations showed sustained elevation in parturient pandas during the S3 phase. The second part of the study, building on the findings of the first part, specifically focused on analyzing the urine samples of giant pandas during the S2 and S3 phases. Statistical analysis of an expanded sample of individuals (including those from the first part) revealed a significant difference in the neopterin mean S3/S2 ratio between the parturient group (mean S3/S2 = 1.71 ± 0.12; n = 14) and the nonparturient group (mean S3/S2 = 0.85 ± 0.04; n = 17). Correspondingly, parturient individuals gave birth 5 to 16 days after the end of the S3 phase (this time corresponds to the point when Pg levels decrease to approximately 200 ng/mg Cr). The results revealed the validity and applicability of using the neopterin mean S3/S2 ratio (1.71 ± 0.12) for diagnosing successful pregnancy in mated female giant pandas. Full article

The phenomenon of counterurbanization, understood as the migration of urban residents to rural areas beyond the suburbanization zone, includes both permanent relocation to the countryside and seasonal migration. The aim of the study is to identify the relationship between newcomers or people temporarily staying in rural areas and their permanent residents, with particular emphasis on the impact of the former group on the local community. The research was conducted in 2023 in 18 villages from different regions of Poland. It was assumed that the villages studied were located outside the zones of strong influence of large urban centers, including outside metropolitan areas. Surveys and in-depth interviews were conducted aimed at both permanent residents of the villages living there from birth and newcomers. The group of newcomers was divided into two categories—new residents who settled in the village in the last few years and owners of second homes who stay in the village temporarily. It can be generally stated that the newcomers from the city, when organizing their life in the countryside, are more active and more frequently initiate contact with the permanent residents than this takes place in the opposite direction. The purpose of the contact is to acquire information, useful for settling down or maintaining the estate, as well as for daily functioning in the countryside. The interactions between the representatives of the two groups considered are usually short-lived and momentary, and they take place usually in the central square of the village, in the street, or in a shop. Conversations concern daily life in the village and private matters. Encounters at home or in other places, which might be conducive to deeper exchange of knowledge and experiences and which might establish conditions for undertaking joint initiatives, are much rarer. Full article

The low profitability of small-scale dual-purpose (milk–meat) farming has caused the decline of Tsurcana sheep, making hormonal reproductive optimization essential to sustain Tsurcana sheep farming. We aimed to identify an effective protocol for out-of-season estrous induction in Tsurcana micro-farms. Five protocols were tested in multiparous ewes under free-range conditions (n = 100; 20/group): T1—prostaglandin F₂α (PGF₂α) on day 9/gonadotropin-releasing hormone (GnRH) on day 12; T2—PGF₂α on day 9/pregnant mare serum gonadotropin (PMSG) on day 11; T3—PGF₂α + PMSG on day 9/GnRH on day 12; T4—PGF₂α on day 12/PMSG on day 13; T5—PMSG on day 13. The fluorogestone acetate (FGA) sponges were removed on day 9 (T1–T3), day 12 (T4), or day 13 (T5). The estrous responses (70–100%) mainly occurred 36–48 h post-sponge removal, with no differences between protocols or time points. The sponge losses (≤10%) were similar among groups. The occurrence of vaginitis differed significantly between the groups (p = 0.008) and was restricted to the long-duration treatments (T4 and T5; ≤10%). Singleton births predominated, the twinning rate was modest (highest in T1–T3), and no multiple births occurred. The lambing, singleton, twinning, and prolificacy rates, as well as birth weights, showed no significant differences between the groups. The estrous responses correlated strongly with the pregnancy, lambing, and singleton rates (Kendall’s τ = 0.82, p < 0.05). Cost analysis identified T1 as the most efficient protocol. Short-duration sponge retention combined with PGF₂α and GnRH (T1) provides the optimal reproductive results for sustainable Tsurcana micro-farming. Full article