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Atropelamentos de vertebrados silvestres no semiárido brasileiro: dinâmica temporal, hotspots e fatores ambientais

2026-07-20T00:00:00Z

Título: Atropelamentos de vertebrados silvestres no semiárido brasileiro: dinâmica temporal, hotspots e fatores ambientais Autor(es): Silva, João Gabriel Santos Abstract: The road network plays an important role in the movement of people and the transportation of goods between regions of the country. However, roads are responsible for a series of negative environmental impacts, such as wildlife roadkills. In general, these roadkills occur in clustered patterns along specific road segments, known as hotspots, and may be influenced by adjacent landscape characteristics and seasonal factors, such as precipitation. Therefore, the present study analyzed wild vertebrate roadkills along a 112-km stretch of the SE-230 highway, located in a Caatinga area in the state of Sergipe, northeast of Brazil, characterizing the affected fauna, its temporal dynamics, the spatial distribution of hotspots, and the influence of landscape and precipitation on these events. Monitoring was conducted biweekly between January and December 2025 by two observers traveling in a motorized vehicle at 50 km/h, during which information regarding specimen identification, date, and geographic coordinates was recorded. Circular analyses (Rayleigh and Mardia–Watson–Wheeler tests) were used to evaluate the temporal distribution of roadkills, while Ripley’s K 2D and 2D HotSpot Identification tests were applied to identify hotspots. In addition, logistic regression models were used to investigate the influence of landscape and precipitation. A total of 524 individuals belonging to 63 vertebrate species were recorded. Amphibia showed the highest number of records (37.79%), followed by Aves (24.62%), Mammalia (24.04%), and Reptilia (13.55%). Circular analyses indicated a non-uniform distribution of roadkills for amphibians, reptiles, and mammals, whereas birds showed a uniform distribution throughout the year, with differences in the temporal distribution of roadkills among vertebrate classes. The location of hotspots varied between dry and rainy months, showing low spatial similarity among taxonomic groups. Logistic regression models indicated that landscape variables influenced roadkills as urban areas and use mosaics. Furthermore, precipitation had a positive effect on amphibians and birds. The results demonstrate that vertebrate roadkills in the Caatinga exhibit temporal and spatial variation. Thus, this study contributes to expanding knowledge about the impacts of roads in semiarid regions and provides support for the implementation of mitigation measures aimed at wildlife conservation.

Determinantes ambientais da diversidade genética da fauna marinha brasileira: uma meta-análise

2026-07-24T00:00:00Z

Título: Determinantes ambientais da diversidade genética da fauna marinha brasileira: uma meta-análise Autor(es): Castro, Juliano Guerra de Abstract: Genetic diversity is a fundamental dimension of biodiversity, playing a key role in species evolution and in the resilience of populations to global climate change. This study aimed to conduct a systematic review of the scientific literature on population genetics of Brazilian shallow waters marine fauna and to synthesize its results using linear mixed models (LMMs) and meta-regressions, to evaluate the influence of environmental variables on genetic diversity. Studies were included if they measured, or allowed the measuring of, haplotype diversity (h) and nucleotide diversity (3,14) in at least three populations with five or more individuals of Brazilian marine species distributed along the coast and oceanic islands, based on mitochondrial molecular markers. The literature search was conducted in the Web of Science, Scopus, PubMed, and Periódicos CAPES databases on December 2, 2025, yielding 1,210 records, of which 63 were included, comprising 64 species and 375 populations. Data synthesis was performed using LMMs, including a spatial autocovariate as a fixed effect to consider the spatial dependence between populations. Results robustness to evolutionary dependence between species as assessed through phylogenetic models (pGLMMs). Model robustness to h and r precision was assessed through sensitivity analyses restricted to populations with 25 or more individuals. Risk of bias in the meta-regressions was evaluated using funnel plots, Egger’s test, Rosenthal’s Failsafe-N, and leave-one-out analyses. The LMMs revealed a weak but consistent positive effect of mean annual sea surface temperature (SST) on h (Estimate = 0.04; p = 0.001), whereas no robust effect was observed for 3,14. This pattern suggests that temperature primarily influences recent demographic events, with no evidence of detectable differences in mutation rates among environments. Meta-regressions conducted using Fisher’s Z-transformed correlation coefficients (Zr) for 40 species with four or more populations corroborated this result (Zr = 0.464; CI = 0.28–0.65; p < 0.0001). The effect was consistent across the most represented phyla and independent of the methodological approaches employed. Robustness analyses found no evidence of publication bias and supported consistency in the results. Limitations of this study include the exclusive use of mitochondrial markers, representing only a fraction of the genome, as well as taxonomic and geographic bias. Overall, the results reinforce that the phylogeographic patterns in Brazilian marine fauna genetic diversity emerge from the interaction between environmental variables, life history and evolutional processes. Therefore, more integrative conservation strategies, aided by high resolution genomic approaches, could highly benefit the understanding and preservation of Brazilian marine biodiversity.

Limiar glicêmico durante teste muscular inspiratório incremental em indivíduos saudáveis e com doença pulmonar obstrutiva crônica

2026-07-29T00:00:00Z

Título: Limiar glicêmico durante teste muscular inspiratório incremental em indivíduos saudáveis e com doença pulmonar obstrutiva crônica Autor(es): Silva, Wasly Santana Abstract: Introduction: The glycemic threshold (GT) during the incremental inspiratory muscle test (IIMT) has been proposed by our research group as a tool for inspiratory muscle functional assessment and individualized inspiratory muscle training (IMT) prescription. However, its agreement with the first lactate threshold (LT1) and its applicability in individuals with chronic obstructive pulmonary disease (COPD) have not yet been investigated. Objectives: To evaluate the agreement between GT and LT1 during the IIMT in healthy individuals and to investigate the determination of GT in individuals with COPD, as well as its associations with clinical and functional variables. Methods: Two studies were conducted using the IIMT. In the first study, healthy individuals performed the IIMT with simultaneous determination of GT, LT1, and the second lactate threshold (LT2). In the second study, individuals with COPD performed the IIMT for GT determination and analysis of its association with rating of perceived exertion, dyspnea, functional capacity, and cardiovascular autonomic balance. The incremental protocol started at 10% of the S-Index, with progressive workload increments until the point of exhaustion (PE). Results: In the first study, GT showed good agreement with LT1. LT1 and GT occurred at 22±8.3% and 26±13.2% of the S-Index, respectively, whereas LT2 and PE were identified at 44±10.1% and 60±14.1% of the S-Index. Bland–Altman analysis demonstrated low bias between methods for relative workload (−3.84±10.44% of the S-Index) and no proportional bias (p=0.06; R²=0.25). In the second study, GT was identified at 25±11.6% of the S-Index and showed a strong correlation with rating of perceived exertion during the IIMT (r=0.84; p<0.01). In addition, PE and ΔGT–PE were correlated with cardiovascular autonomic balance (LF/HF: r=−0.83 and r=−0.71; p<0.01), whereas ΔGT–PE was also correlated with dyspnea assessed by the modified Medical Research Council (mMRC) scale (r=−0.68; p=0.01) and Borg dyspnea at the end of the six-minute walk test (r=−0.83; p<0.01). Conclusion: GT is an identifiable physiological marker during the IIMT, showing agreement with LT1 in healthy individuals and association with important clinical and functional variables in individuals with COPD. These findings support its potential as a tool for inspiratory muscle functional assessment and individualized IMT prescription.

Avaliação dos perfis comportamentais e inflamatórios em modelos murinos de obesidade: influência do sexo e do tempo de exposição

2026-07-21T00:00:00Z

Título: Avaliação dos perfis comportamentais e inflamatórios em modelos murinos de obesidade: influência do sexo e do tempo de exposição Autor(es): Freitas, Camila Evelyn Perete de Abstract: Advances in the study of the Developmental Origins of Health and Disease (DOHaD) suggest that insults occurring during early developmental stages can trigger significant physiological changes in adulthood, rendering the individual more susceptible to developing conditions such as obesity. In this context, "neonatal overnutrition" is a known factor associated with various metabolic and inflammatory alterations similar to those observed in obesity. It is also known that the persistence of obesity-related inflammatory changes negatively affects neural metabolism and synaptic transmission, leading to behavioral alterations. Thus, this study compared the effects of obesity induced by different murine models on metabolism and behavioral responses in both sexes. Male and female Swiss mice were assigned to control (CTRL) groups or to obesity-induction groups using either litter reduction (SL) or a high-fat diet (HFD). Body mass was monitored weekly after weaning. This monitoring lasted 10 weeks for both experimental groups, extending to 21 weeks for a subgroup of SL animals. Following an acclimatization period, a battery of three behavioral tests (defensive, social interaction, and cognitive) was conducted, followed by an analysis of locomotor activity in an open-field test. To evaluate the influence of time on the progression of the inflammatory response in LR animals, cytokine concentrations and the expression of genes associated with macrophage polarization were analyzed in various tissues at two different time points. Results showed a progressive increase in body mass and adiposity in both models at the 10-week and 21-week marks, with higher food intake observed only in male LR mice. Regarding behavior, female SL mice and both male and female HFD mice exhibited reduced active defense responses. Alterations in social affiliation and social memory were found, and age-dependent cognitive deficits were observed in SL animals of both sexes. Regarding inflammation, male RN mice exhibited an early inflammatory profile—characterized by increased TNF-α concentrations in adipose tissue and the liver, as well as the expression of genes associated with M1 macrophage polarization in the liver—as early as 10 weeks of age. In contrast, female SL mice displayed a delayed and limited inflammatory profile, with increased IL-1β levels observed only in the spleen. These results establish a significant sexual dimorphism by demonstrating that, in both models, obesity manifested as distinct metabolic and behavioral phenotypes in males and females. Furthermore, in SL animals, the progression over time played a significant role in the development of the metabolic and behavioral outcomes observed in both sexes.