Ecological models derived from Optimal Foraging Theory have been used to understand the decision-making processes and optimization of artisanal fisheries. However, many studies do not consider the influence of fishing techniques or seasonality on foraging strategies. We analyzed the optimization strategies and decision-making processes of the fishers at a Brazilian reservoir. Data were collected through interviews and questionnaires involving 65 artisanal fishers, and daily catches were monitored in July/2015 and January/2016. Fishing techniques and seasonality influenced the fishers’ behavior. The fishery activities monitored here were partially or totally consistent with the predictions of the Central-Place Foraging model, but due to the complexity of these activities, other factors also influenced the decision-making of individual fishers. Furthermore, the adoption of strategies that involve “non-ideal” behaviors may be advantageous for the fishers in the context of their individual necessities. 相似文献
In this study, we detail the specificity of an aspartic peptidase from Rhizomucor miehei and evaluate the effects of this peptidase on clotting milk using the peptide sequence of k-casein (Abz-LSFMAIQ-EDDnp) and milk powder. Molecular mass of the peptidase was estimated at 37 kDa, and optimum activity was achieved at pH 5.5 and 55 °C. The peptidase was stable at pH values ranging from 3 to 5 and temperatures of up 45 °C for 60 min. Dramatic reductions in proteolytic activity were observed with exposure to sodium dodecyl sulfate, and aluminum and copper (II) chloride. Peptidase was inhibited by pepstatin A, and mass spectrometry analysis identified four peptide fragments (TWSISYGDGSSASGILAK, ASNGGGGEYIFGGYDSTK, GSLTTVPIDNSR, and GWWGITVDRA), similar to rhizopuspepsin. The analysis of catalytic specificity showed that the coagulant activity of the peptidase was higher than the proteolytic activity and that there was a preference for aromatic, basic, and nonpolar amino acids, particularly methionine, with specific cleavage of the peptide bond between phenylalanine and methionine. Thus, this peptidase may function as an important alternative enzyme in milk clotting during the preparation of cheese. 相似文献
Fungi constitute an invaluable natural resource for scientific research, owing to their diversity; they offer a promising alternative for bioprospecting, thus contributing to biotechnological advances. For a long time, extensive information has been exploited and fungal products have been tested as a source of natural compounds. In this context, enzyme production remains a field of interest, since it offers an efficient alternative to the hazardous processes of chemical transformations. Owing to their vast biodiversity and peculiar biochemical characteristics, two fungal categories, white-rot and anaerobic Neocallimastigomycota, have gathered considerable attention for biotechnological applications. These fungi are known for their ability to depolymerize complex molecular structures and are used in degradation of lignocellulosic biomass, improvement of animal feed digestibility, biogas and bioethanol production, and various other applications. However, there are only limited reports that describe proteolytic enzymes and esterases in these fungi and their synergistic action with lignocellulolytic enzymes on degradation of complex polymers. Thus, in this minireview, we focus on the importance of these organisms in enzyme technology, their bioprospecting, possibility of integration of their enzyme repertoire, and their prospects for future biotechnological innovation.
The vocalisations of wild common marmosets, Callithrix jacchus, were recorded to investigate whether call rate by individuals is affected by time of day, age, sex or dominance rank within
a group. We also investigated how vocalisation pitch was affected by age, focussing on a single common call, the trill call.
Adults vocalised more than juveniles or infants during the majority of daylight hours. Only the call rate of juveniles varied
significantly over the day. No differences were found between either sex or dominance rank with respect to rate of vocalisations.
The trill calls emitted by young wild common marmosets were of a higher pitch than those emitted by adults. We conclude that
the auditory communication of wild common marmosets is related to the age of the animals, both in terms of call rate and the
physical characteristics of their vocalisations. 相似文献
Ten zoanthamine-type alkaloids from two marine zoanthids belonging to the Zoanthus genus (Zoanthus nymphaeus and Zoanthus sp.) along with one semisynthetic derivative were evaluated for their antiplatelet activities on human platelet aggregation induced by several stimulating agents. 11-Hydroxyzoanthamine (11) and a synthetic derivative of norzoanthamine (16) showed strong inhibition against thrombin-, collagen- and arachidonic acid-induced aggregation, zoanthenol (15) displayed a selective inhibitory activity induced by collagen, while zoanthaminone (10) behaved as a potent aggregant agent. These evaluations allowed us to deduce several structure-activity relationships and suggest some mechanisms of action for this type of compounds. 相似文献
Habituation presents major challenges for the study of wild primates, particularly in areas where threats such as hunting pressure and increasing forest fragmentation exist. This study describes the use of ground camera trapping to investigate nonhabituated blonde capuchins. Capuchins are arboreal animals, but often use the ground when foraging. Thus, we hypothesized that a ground-baited camera trapping station would be an efficient method to document the presence of capuchins, and to collect information about aspects of their social behavior and ecology. We conducted 92 systematic trapping days over 15 months (from December 2010 to February 2011 and from August 2011 to July 2012). The capuchins visited the trapping stations 43 times. All visits occurred between 05:13h and 17:32h, and lasted 3 min-2:03 h. Sixty-five percent of the photographs included our target species. Groups contained up to 46 individuals and were multimale-multifemale. We recorded no monkeys at the trapping stations during August and November (2011) and January (2012). Infants were more likely to be carried than not. Infants were carried by both sexes; however, 96% of photographs showed females as carriers. Adult males always arrived first at the camera trapping stations, suggesting that males led the group’s movements. The ground-baited camera trapping stations proved effective for confirming the presence of the blonde capuchins in the study site and for documenting aspects of their social behavior. The technique could potentially be used to provide comparative data among populations of this and other primate species in areas where habituation is difficult or risky to the primates. 相似文献
Community-based conservation (CBC) projects represent one approach to biodiversity conservation when working with indigenous and local people. This method aims to achieve conservation and development goals simultaneously, however whether both types of goals can be met or whether competition between the two precludes success is an issue of much discussion. Conservation targets are one of the most important elements upon which a conservation project is built. We propose that one way to link biodiversity conservation with human development goals is to consider people’s needs and interests in the selection of the conservation target. Here, we present three categories of conservation targets that vary according to the origin of motivation that drives indigenous and local people to conserve the target. According to the type of target selected, the level of participation, integration of traditional ecological knowledge, level of external intervention and long-term sustainability will vary. We encourage conservation practitioners to understand the motivations that lead indigenous and local people to participate in conservation projects, and to develop and design CBC projects from these incentives. 相似文献