A hypothetico-deductive approach to assessing the social function of chemical signalling in a non-territorial solitary carnivore

The function of chemical signalling in non-territorial solitary carnivores is still relatively unclear. Studies on territorial solitary and social carnivores have highlighted odour capability and utility, however the social function of chemical signalling in wild carnivore populations operating dominance hierarchy social systems has received little attention. We monitored scent marking and investigatory behaviour of wild brown bears Ursus arctos, to test multiple hypotheses relating to the social function of chemical signalling. Camera traps were stationed facing bear ‘marking trees’ to document behaviour by different age sex classes in different seasons. We found evidence to support the hypothesis that adult males utilise chemical signalling to communicate dominance to other males throughout the non-denning period. Adult females did not appear to utilise marking trees to advertise oestrous state during the breeding season. The function of marking by subadult bears is somewhat unclear, but may be related to the behaviour of adult males. Subadults investigated trees more often than they scent marked during the breeding season, which could be a result of an increased risk from adult males. Females with young showed an increase in marking and investigation of trees outside of the breeding season. We propose the hypothesis that females engage their dependent young with marking trees from a young age, at a relatively ‘safe’ time of year. Memory, experience, and learning at a young age, may all contribute towards odour capabilities in adult bears

Reduction in Predator Defense in the Presence of Neighbors in a Colonial Fish

Predation pressure has long been considered a leading explanation of colonies, where close neighbors may reduce predation via dilution, alarming or group predator attacks. Attacking predators may be costly in terms of energy and survival, leading to the question of how neighbors contribute to predator deterrence in relationship to each other. Two hypotheses explaining the relative efforts made by neighbors are byproduct-mutualism, which occurs when breeders inadvertently attack predators by defending their nests, and reciprocity, which occurs when breeders deliberately exchange predator defense efforts with neighbors. Most studies investigating group nest defense have been performed with birds. However, colonial fish may constitute a more practical model system for an experimental approach because of the greater ability of researchers to manipulate their environment. We investigated in the colonial fish, Neolamprologus caudopunctatus, whether prospecting pairs preferred to breed near conspecifics or solitarily, and how breeders invested in anti-predator defense in relation to neighbors. In a simple choice test, prospecting pairs selected breeding sites close to neighbors versus a solitary site. Predators were then sequentially presented to the newly established test pairs, the previously established stimulus pairs or in between the two pairs. Test pairs attacked the predator eight times more frequently when they were presented on their non-neighbor side compared to between the two breeding sites, where stimulus pairs maintained high attack rates. Thus, by joining an established pair, test pairs were able to reduce their anti-predator efforts near neighbors, at no apparent cost to the stimulus pairs. These findings are unlikely to be explained by reciprocity or byproduct-mutualism. Our results instead suggest a commensal relationship in which new pairs exploit the high anti-predator efforts of established pairs, which invest similarly with or without neighbors. Further studies are needed to determine the scope of commensalism as an anti-predator strategy in colonial animals

Perception of Male Caller Identity in Koalas (Phascolarctos cinereus): Acoustic Analysis and Playback Experiments

The ability to signal individual identity using vocal signals and distinguish between conspecifics based on vocal cues is important in several mammal species. Furthermore, it can be important for receivers to differentiate between callers in reproductive contexts. In this study, we used acoustic analyses to determine whether male koala bellows are individually distinctive and to investigate the relative importance of different acoustic features for coding individuality. We then used a habituation-discrimination paradigm to investigate whether koalas discriminate between the bellow vocalisations of different male callers. Our results show that male koala bellows are highly individualized, and indicate that cues related to vocal tract filtering contribute the most to vocal identity. In addition, we found that male and female koalas habituated to the bellows of a specific male showed a significant dishabituation when they were presented with bellows from a novel male. The significant reduction in behavioural response to a final rehabituation playback shows this was not a chance rebound in response levels. Our findings indicate that male koala bellows are highly individually distinctive and that the identity of male callers is functionally relevant to male and female koalas during the breeding season. We go on to discuss the biological relevance of signalling identity in this species' sexual communication and the potential practical implications of our findings for acoustic monitoring of male population levels

Benefits of a ball and chain: simple environmental enrichments improve welfare and reproductive success in farmed American mink (Neovison vison)

Can simple enrichments enhance caged mink welfare? Pilot data from 756 sub-adults spanning three colour-types (strains) identified potentially practical enrichments, and suggested beneficial effects on temperament and fur-chewing. Our main experiment started with 2032 Black mink on three farms: from each of 508 families, one juvenile male-female pair was enriched (E) with two balls and a hanging plastic chain or length of hose, while a second pair was left as a non-enriched (NE) control. At 8 months, more than half the subjects were killed for pelts, and 302 new females were recruited (half enriched: ‘late E’). Several signs of improved welfare or productivity emerged. Access to enrichment increased play in juveniles. E mink were calmer (less aggressive in temperament tests; quieter when handled; less fearful, if male), and less likely to fur-chew, although other stereotypic behaviours were not reduced. On one farm, E females had lower cortisol (inferred from faecal metabolites). E males tended to copulate for longer. E females also weaned more offspring: about 10% more juveniles per E female, primarily caused by reduced rates of barrenness (‘late E’ females also giving birth to bigger litters on one farm), effects that our data cautiously suggest were partly mediated by reduced inactivity and changes in temperament. Pelt quality seemed unaffected, but E animals had cleaner cages. In a subsidiary side-study using 368 mink of a second colour-type (‘Demis’), similar temperament effects emerged, and while E did not reduce fur-chewing or improve reproductive success in this colour-type, E animals were judged to have better pelts. Overall, simple enrichments were thus beneficial. These findings should encourage welfare improvements on fur farms (which house 60-70 million mink p.a.) and in breeding centres where endangered mustelids (e.g. black-footed ferrets) often reproduce poorly. They should also stimulate future research into more effective practical enrichments

miR-199a-5p Is Upregulated during Fibrogenic Response to Tissue Injury and Mediates TGFbeta-Induced Lung Fibroblast Activation by Targeting Caveolin-1

As miRNAs are associated with normal cellular processes, deregulation of miRNAs is thought to play a causative role in many complex diseases. Nevertheless, the precise contribution of miRNAs in fibrotic lung diseases, especially the idiopathic form (IPF), remains poorly understood. Given the poor response rate of IPF patients to current therapy, new insights into the pathogenic mechanisms controlling lung fibroblasts activation, the key cell type driving the fibrogenic process, are essential to develop new therapeutic strategies for this devastating disease. To identify miRNAs with potential roles in lung fibrogenesis, we performed a genome-wide assessment of miRNA expression in lungs from two different mouse strains known for their distinct susceptibility to develop lung fibrosis after bleomycin exposure. This led to the identification of miR-199a-5p as the best miRNA candidate associated with bleomycin response. Importantly, miR-199a-5p pulmonary expression was also significantly increased in IPF patients (94 IPF versus 83 controls). In particular, levels of miR-199a-5p were selectively increased in myofibroblasts from injured mouse lungs and fibroblastic foci, a histologic feature associated with IPF. Therefore, miR-199a-5p profibrotic effects were further investigated in cultured lung fibroblasts: miR-199a-5p expression was induced upon TGFβ exposure, and ectopic expression of miR-199a-5p was sufficient to promote the pathogenic activation of pulmonary fibroblasts including proliferation, migration, invasion, and differentiation into myofibroblasts. In addition, we demonstrated that miR-199a-5p is a key effector of TGFβ signaling in lung fibroblasts by regulating CAV1, a critical mediator of pulmonary fibrosis. Remarkably, aberrant expression of miR-199a-5p was also found in unilateral ureteral obstruction mouse model of kidney fibrosis, as well as in both bile duct ligation and CCl4-induced mouse models of liver fibrosis, suggesting that dysregulation of miR-199a-5p represents a general mechanism contributing to the fibrotic process. MiR-199a-5p thus behaves as a major regulator of tissue fibrosis with therapeutic potency to treat fibroproliferative diseases. © 2013 Lino Cardenas et al

Synthetic Mimic of Antimicrobial Peptide with Nonmembrane-Disrupting Antibacterial Properties

Proteolysis in dairy lactic acid bacteria has been studied in great detail by genetic, biochemical and ultrastructural methods. From these studies the picture emerges that the proteolytic systems of lactococci and lactobacilli are remarkably similar in their components and mode of action. The proteolytic system consists of an extracellularly located serine-proteinase, transport systems specific for di-tripeptides and oligopeptides (> 3 residues), and a multitude of intracellular peptidases. This review describes the properties and regulation of individual components as well as studies that have led to identification of their cellular localization. Targeted mutational techniques developed in recent years have made it possible to investigate the role of individual and combinations of enzymes in vivo. Based on these results as well as in vitro studies of the enzymes and transporters, a model for the proteolytic pathway is proposed. The main features are: (i) proteinases have a broad specificity and are capable of releasing a large number of different oligopeptides, of which a large fraction falls in the range of 4 to 8 amino acid residues; (ii) oligopeptide transport is the main route for nitrogen entry into the cell; (iii) all peptidases are located intracellularly and concerted action of peptidases is required for complete degradation of accumulated peptides.

Acompanhamento de pacientes submetidos à cirurgia bariátrica : aspectos laboratoriais nos períodos pré e pós-operatório

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Farmácia, Florianópolis, 2017A obesidade é uma doença crônica e endócrino-metabólica caracterizada pelo acúmulo excessivo de triacilgliceróis no tecido adiposo, capaz de ser revertida ou amenizada através de intervenção cirúrgica. Epidemiologicamente têm sido descritas associações entre o excesso de peso, resistência à insulina e processo inflamatório crônico. Além disso, nas últimas décadas o sistema complemento foi associado a doenças metabólicas e cardiovasculares e intimamente relacionado com a obesidade e resistência à insulina. Sendo assim, a melhora do estado metabólico e a remissão da inflamação em pacientes obesos submetidos à cirurgia bariátrica foram avaliadas, bem como a associação dos fatores 3 e 4 (C3 e C4) do sistema complemento com a sensibilidade à insulina e a perda de peso após a cirurgia bariátrica. Para isso, a presença de comorbidades e as concentrações séricas de leptina, adiponectina, resistina e grelina foram avaliados em pacientes obesos mórbidos antes, 1, 3 e 6 meses após a cirurgia bariátrica. Também foram medidas as concentrações de IL-1ß, IL-6, TNF-a, proteína amiloide sérica A (SAA), proteína quimiotática de monócitos 1 (MCP-1), C3, C4, glicose, insulina, colesterol total, triacilglicerol, LDL- colesterol, HDL-colesterol e foi realizado o cálculo do modelo de avaliação da homeostase da resistência à insulina (HOMA-IR) durante o seguimento da cirurgia, bem como em comparação com um grupo de indivíduos não-obesos. Como resultado, observou-se uma redução significativa de peso acompanhada de melhora do perfil lipídico, da sensibilidade à insulina e das comorbidades. Ainda, houve diminuição de leptina e aumento de adiponectina no período pós-cirúrgico. IL-1ß, IL-6, TNF-a, MCP-1 e SAA não mostraram diferença no acompanhamento da cirurgia, porém SAA correlacionou-se com o IMC e apresentou-se muito mais alto no grupo de pacientes obesos. Além disso, C3 e C4 foram significativamente maiores em indivíduos obesos quando comparados aos indivíduos não-obesos e C3 e C4 foram positivamente correlacionados com HOMA-IR e as concentrações de C3 foram significativamente diminuídas após a cirurgia. Com base nesses resultados, a cirurgia bariátrica mostrou melhorar o estado metabólico melhorando as comorbidades associadas à obesidade e os biomarcadores de adiposidade leptina e adiponectina, mas não os demais hormônios e citocinas inflamatórias e C3 e C4 foram fortemente associados à sensibilidade à insulina.Abstract: Obesity is a chronic and endocrine-metabolic disease characterized by triacylglycerol accumulation in the adipose tissue, which can be reversed or improved through surgical intervention. Epidemiologically, associations between overweight, insulin resistance and chronic inflammatory process have been described. Furthermore, in the last decades the complement system was associated with metabolic and cardiovascular diseases and related to obesity and insulin resistance. Thus, metabolic status improvement and inflammation remission in obese patients undergoing bariatric surgery were evaluated, as well as the association of complement system factors 3 and 4 (C3 and C4) with insulin sensitivity and weight loss after bariatric surgery. For this, comorbidities and leptin, adiponectin, resistin and ghrelin serum concentrations were evaluated in morbidly obese patients before, 1, 3 and 6 months after bariatric surgery. IL-1ß, IL-6, TNF-a, serum amyloid A protein (SAA), monocyte chemotactic protein 1 (MCP-1), C3, C4, glucose, insulin, total cholesterol, triacylglycerol, LDL-cholesterol, HDL-cholesterol concentrations and the calculation of the homeostasis model of insulin resistance (HOMA-IR) were performed during the surgery follow-up, as well in a group of non-obese individuals. As a result, significant weight loss followed by improvement in lipid profile, insulin sensitivity and comorbidities were observed. Still, there was a decrease in leptin and an increase in adiponectin in the postoperative period. IL-1ß, IL-6, TNF-a, MCP-1 and SAA showed no difference after surgery, but SAA correlated with BMI and was much higher in obese patients. In addition, both C3 and C4 were significantly higher in obese individuals when compared to lean individuals and positively correlated with HOMA-IR. C3 concentrations were significantly decreased after surgery. Based on these results, bariatric surgery has been shown to improve metabolic status by improving obesity-associated comorbidities and adiposity biomarkers leptin and adiponectin but not the other hormones and inflammatory cytokines and C3 and C4 were strongly associated with insulin sensitivity