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Daniela Meneses-Santos,1 Daniella do Carmo Buonfiglio,2 Rodrigo Antonio Peliciari-Garcia,3 Angela Maria Ramos-Lobo,2 Divanízia do Nascimento Souza,1 Angelo Rafael Carpinelli,2 Carla Roberta de Oliveira Carvalho,2 Rogério Antônio Laurato Sertie,2 Sandra Andreotti,2 Fabio Bessa Lima,2 Solange Castro Afeche,4 Emerson Ticona Fioretto,1 José Cipolla-Neto,2 Anderson Carlos Marçal1 1Department of Morphology, Center of Biological Sciences and Health, Federal University of Sergipe, São Cristóvão, Brazil; 2Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil; 3Morphophysiology & Pathology Sector, Department of Biological Sciences, Federal University of São Paulo, São Paulo, Brazil; 4Laboratory of Pharmacology, Butanta Institute, São Paulo, Brazil Background: Melatonin is a neuroendocrine hormone that regulates many functions involving energy metabolism and behavior in mammals throughout the light/dark cycle. It is considered an output signal of the central circadian clock, located in the suprachiasmatic nucleus of the hypothalamus. Melatonin synthesis can be influenced by other hormones, such as insulin and glucocorticoids in pathological conditions or during stress. Furthermore, glucocorticoids appear to modulate circadian clock genes in peripheral tissues and are associated with the onset of metabolic diseases. In the pineal gland, the modulation of melatonin synthesis by clock genes has already been demonstrated. However, few studies have shown the effects of glucocorticoids on clock genes expression in the pineal gland. Results: We verified that rats treated with dexamethasone (2 mg/kg body weight, intraperitoneal) for 10 consecutive days, showed hyperglycemia and pronounced hyperinsulinemia during the dark phase. Insulin sensitivity, glucose tolerance, melatonin synthesis, and enzymatic activity of arylalkylamine N-acetyltransferase, the key enzyme of melatonin synthesis, were reduced. Furthermore, we observed an increase in the expression of Bmal1, Per1, Per2, Cry1, and Cry2 in pineal glands of rats treated with dexamethasone. Conclusion: These results show that chronic treatment with dexamethasone can modulate both melatonin synthesis and circadian clock expression during the dark phase. Keywords: clock genes, glucocorticoids, pineal gland, nocturnal insulinemia, glycemia profile, AANAT activity

When dealing with large marine species, individual photographic identification plays a very important part in capture-mark-recapture studies. The success of this method is determined by the consistent correct identification of individuals, but as the number of images in the database increases, the task becomes increasingly time-consuming, affecting the accuracy of the matches. Although a few software packages are available, universally applied methods remain problematic in long-term studies, suggesting the need for species-specific software. This study presents new image recognition software tested on white sharks’ dorsal fins and is based on a dynamic time warping algorithm. The software is specifically designed to improve the matching success of individuals, to standardise the data collection and to increase the overall accuracy when managing a large capture-mark-recapture database. [ABSTRACT FROM AUTHOR]

Abstract: Following a shark attack, local governments often rapidly respond by implementing indiscriminate shark culls. These culls have been demonstrated to have substantial localized and adverse effects on a variety of marine organisms, and therefore there is an increasing need for an eco‐friendly alternative that maximizes both beachgoer and marine organismal safety. In response to such culls, the novel magnetic barrier technology, the Sharksafe Barrier was developed and rigorously tested on a variety of sharks implicated in shark attacks (e.g. bull sharks – Carcharhinus leucas and white sharks – Carcharodon carcharias). Although these studies exhibited promise in shark swim pattern manipulation and C. leucas exclusion, research was lacking in assessing if the technology could serve as an alternative to shark nets, or more specifically, if it could exclude motivated C. carcharias from bait. Using a 13 m × 13 m square exclusion zone, this study aimed to test the C. carcharias exclusion capabilities of the Sharksafe Barrier while additionally assessing the long‐term structural integrity of the system. After 34 trials and approximately 255 hours of total video collected over two years, data illustrate that all interacting C. carcharias were successfully excluded from the baited Sharksafe Barrier region, whereas teleosts and other small elasmobranch species were not. In addition, the long‐term deployment potential of this barrier system held promise owing to its ability to withstand harsh environmental conditions. Therefore, with the successful exclusion of a second large shark species, C. carcharias, from a baited region, continued long‐term research and implementation of this system at other locations should be considered to assess its viability and overall success as a bather and shark protection system. [ABSTRACT FROM AUTHOR]

Background: Anthelmintic resistance in ruminants is a widespread problem that has a severe impact on productivity and animal welfare. The helminth Haemonchus contortus is generally considered the most important parasite in small ruminants due to its high pathogenicity and the widespread occurrence of anthelmintic resistance in it. Although the molecular mechanisms associated with resistance against the anthelmintics benzimidazoles (BZs) and levamisole are relatively well understood, the resistance mechanisms against the widely used anthelmintic macrocyclic lactones (MLs) ivermectin (IVM) and moxidectin (MOX) remain poorly understood. Detoxifying enzymes and xenobiotic transporters have been frequently proposed to play a role in ML resistance in multiple organisms, including nematodes., Methods: The reference genome of H. contortus was screened for cytochrome P450 genes (cyp genes) by using the Basic Local Alignment Search Tool, and maximum-likelihood phylogenetic analysis was used to assign the sequences to gene families. Fourth-stage larvae of the susceptible (McMaster) and the ML-resistant (Berlin-selected) H. contortus isolates were generated in vitro and compared regarding basal expression levels of cyp genes and ATP-binding cassette (ABC) transporters by using RNA sequencing. The resistant isolate was further incubated with 100 nM IVM or MOX for 3, 6 and 12 h, and the effects of incubation time and drugs were evaluated., Results: Twenty-five cyp genes were identified in the H. contortus genome and assigned to 13 different families. The ML-resistant isolate showed significantly higher and lower constitutive expression of 13 and four cyp genes, respectively. Out of the 50 ABC transporter genes, only six showed significantly higher expression in the ML-resistant isolate, while 12 showed lower expression. The fold changes were in general low (range 0.44-5.16). Only pgp-13 showed significant downregulation in response to IVM (0.77 fold change at 6 h, 0.96 fold change at 12 h) and MOX (0.84 fold change at 12 h). In contrast, mrp-5 was significantly, albeit minimally, upregulated in the presence of IVM, but not MOX, after 12 h (1.02 fold change)., Conclusions: Despite little observable ML-inducible gene expression in the isolate examined here, some of the changes in the baseline expression levels might well contribute to ML resistance in the context of additional changes in a multigenic resistance model. However, neither cyp genes nor the ABC transporters appear to be the main drivers that can explain the high levels of resistance observed in the resistant isolate examined here., Competing Interests: Declarations. Ethics approval and consent to participate: All animal experiments were carried out in accordance with European directive 2010/63/EU and German law (Tierschutzgesetz), and were approved by the responsible local authorities (LAGeSo Berlin) under reference number L0088/10. No consent for publication was required for this study. Consent for publications: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)