337 research outputs found
Involving local communities for effective citizen science: determining game species' reproductive status to assess hunting effects in tropical forests
1. Involving communities in sustainable wildlife management in tropical forests can ensure food security and livelihoods of millions of forest dwellers that depend on wild meat, but also safeguard hunted species. Mathematical models have been developed to assess hunting sustainability; but these require empirical information on reproductive parameters of the prey species, often challenging to obtain. 2. Here, we suggest that if local people can accurately identify the reproductive status of hunted animals in the field, these data could fill the existing knowledge gap regarding species’ life-history traits and enable better assessments of hunting impacts. 3. We first tested whether local people in 15 rural communities in three Amazonian sites could accurately diagnose, before and after training, the pregnancy status of hunted pacas (Cuniculus paca), which we use as our model. We then applied the results from these tests to correct reproductive status data of hunted specimens, voluntarily collected over 17 years (2002-2018) as part of a citizen science project in one of our study sites. We ran generalized additive models to contrast these corrected reproductive rates with those obtained from the direct analysis of genitalia by researchers, and with indices describing game extraction levels (catch-per-unit-effort, CPUE, and age structure of hunted individuals). 4. Before training, interviewees correctly diagnosed pregnancy in 72.5% of tests, but after training, interviewees accurately diagnosed pregnancy in 88.2% of tests, with high improvements especially for earlier pregnancy stages. Monthly pregnancy rates determined by hunters and by researchers were similar. Reported annual pregnancy Page 3 of 45 Confidential Review copy Journal of Applied Ecology 4 rates were negatively correlated with CPUE, and positively correlated with the percentage of immatures in the hunted population, in accordance to an expected densitydependent response to variations in hunting levels. 5. We showed that the voluntary diagnosis of game species’ reproductive status by local people is a feasible method to obtain accurate life-history parameters for hunted tropical species, and to assess hunting effects on game populations. Given that almost half of the protected areas in the world are co-managed by local people, our results confirm the potential of integrating local communities in citizen science initiatives to ensure faster, low-cost, and more accurate data collection for wildlife management
Asymmetric Dispersal and Colonization Success of Amazonian Plant-Ants Queens
The dispersal ability of queens is central to understanding ant life-history evolution, and plays a fundamental role in ant population and community dynamics, the maintenance of genetic diversity, and the spread of invasive ants. In tropical ecosystems, species from over 40 genera of ants establish colonies in the stems, hollow thorns, or leaf pouches of specialized plants. However, little is known about the relative dispersal ability of queens competing for access to the same host plants. We used empirical data and inverse modeling—a technique developed by plant ecologists to model seed dispersal—to quantify and compare the dispersal kernels of queens from three Amazonian ant species that compete for access to host-plants. We found that the modal colonization distance of queens varied 8-fold, with the generalist ant species (Crematogaster laevis) having a greater modal distance than two specialists (Pheidole minutula, Azteca sp.) that use the same host-plants. However, our results also suggest that queens of Azteca sp. have maximal distances that are four-sixteen times greater than those of its competitors. We found large differences between ant species in both the modal and maximal distance ant queens disperse to find vacant seedlings used to found new colonies. These differences could result from interspecific differences in queen body size, and hence wing musculature, or because queens differ in their ability to identify potential host plants while in flight. Our results provide support for one of the necessary conditions underlying several of the hypothesized mechanisms promoting coexistence in tropical plant-ants. They also suggest that for some ant species limited dispersal capability could pose a significant barrier to the rescue of populations in isolated forest fragments. Finally, we demonstrate that inverse models parameterized with field data are an excellent means of quantifying the dispersal of ant queens
Instrumento mensurador de adesão para hipertensos: contribuição da Teoria da Resposta ao Item
Urban wild meat consumption and trade in Central Amazonia
The switch from hunting wild meat for home consumption to supplying more lucrative city marketsin Amazonia can adversely affect some game species. Despite this, information on the amounts of wild meateaten in Amazonian cities is still limited. We estimated wild meat consumption rates in 5 cities in the State ofAmazonas in Brazil through 1046 door-to-door household interviews conducted from 2004 to 2012. With thesedata, we modeled the relationship between wild meat use and a selection of socioeconomic indices. We thenscaled up our model to determine the amounts of wild meat likely to be consumed annually in the 62 urbancenters in central Amazonia. A total of 80.3% of all interviewees reported consuming wild meat during an averageof 29.3 (CI 11.6) days per year. Most wild meat was reported as bought in local markets (80.1%) or hunted by afamily member (14.9%). Twenty-one taxa were cited as consumed, mostly mammals (71.6%), followed by reptiles(23.2%) and then birds (5.2%). The declared frequency of wild meat consumption was positively correlated withthe proportion of rural population as well as with the per capita gross domestic product of the municipality(administrative divisions) where the cities were seated. We estimated that as much as 10,691 t of wild meat mightbe consumed annually in the 62 urban centers within central Amazonia, the equivalent of 6.49 kg per person peryear. In monetary terms, this amounts to US35.1 million overall, the latter figureis comparable to fish and timber production in the region. Given this magnitude of wild meat trade in centralAmazonia, it is fundamental to integrate this activity into the formal economy and actively develop policies thatallow the trade of more resilient taxa and restrict trade in species sensitive to hunting
L-Alanyl-Glutamine dipeptide pretreatment attenuates ischemia-reperfusion injury in rat testis
Subdominant/Cryptic CD8 T Cell Epitopes Contribute to Resistance against Experimental Infection with a Human Protozoan Parasite
During adaptive immune response, pathogen-specific CD8+ T cells recognize preferentially a small number of epitopes, a phenomenon known as immunodominance. Its biological implications during natural or vaccine-induced immune responses are still unclear. Earlier, we have shown that during experimental infection, the human intracellular pathogen Trypanosoma cruzi restricts the repertoire of CD8+ T cells generating strong immunodominance. We hypothesized that this phenomenon could be a mechanism used by the parasite to reduce the breath and magnitude of the immune response, favoring parasitism, and thus that artificially broadening the T cell repertoire could favor the host. Here, we confirmed our previous observation by showing that CD8+ T cells of H-2a infected mice recognized a single epitope of an immunodominant antigen of the trans-sialidase super-family. In sharp contrast, CD8+ T cells from mice immunized with recombinant genetic vaccines (plasmid DNA and adenovirus) expressing this same T. cruzi antigen recognized, in addition to the immunodominant epitope, two other subdominant epitopes. This unexpected observation allowed us to test the protective role of the immune response to subdominant epitopes. This was accomplished by genetic vaccination of mice with mutated genes that did not express a functional immunodominant epitope. We found that these mice developed immune responses directed solely to the subdominant/cryptic CD8 T cell epitopes and a significant degree of protective immunity against infection mediated by CD8+ T cells. We concluded that artificially broadening the T cell repertoire contributes to host resistance against infection, a finding that has implications for the host-parasite relationship and vaccine development
A PolÃtica Nacional de alimentação e Nutrição e seu diálogo com a PolÃtica Nacional de Segurança alimentar e Nutricional
2021 DORIS definition of remission in SLE: final recommendations from an international task force
OBJECTIVE: To achieve consensus on a definition of remission in SLE (DORIS). BACKGROUND: Remission is the stated goal for both patient and caregiver, but consensus on a definition of remission has been lacking. Previously, an international task force consisting of patient representatives and medical specialists published a framework for such a definition, without reaching a final recommendation. METHODS: Several systematic literature reviews were performed and specific research questions examined in suitably chosen data sets. The findings were discussed, reformulated as recommendations and voted on. RESULTS: Based on data from the literature and several SLE-specific data sets, a set of recommendations was endorsed. Ultimately, the DORIS Task Force recommended a single definition of remission in SLE, based on clinical systemic lupus erythematosus disease activitiy index (SLEDAI)=0, Evaluator's Global Assessment <0.5 (0-3), prednisolone 5 mg/day or less, and stable antimalarials, immunosuppressives, and biologics. CONCLUSION: The 2021 DORIS definition of remission in SLE is recommended for use in clinical care, education, and research including clinical trials and observational studies
- …