Anais da Academia Brasileira de Ciencias最新文献

Social engagement in environmental issues has significantly increased with the rise of social media, which plays a critical role in shaping public perception of climate change. This study examines the impact of the Intergovernmental Panel on Climate Change (IPCC) climate assessment reports on Twitter. A total of 897,562 English-language tweets related to the AR4, AR5, and AR6 reports were collected from 2006 to 2022. After preprocessing using Natural language processing (NLP) techniques, 583,493 tweets were analyzed through topic modeling based on Non-negative matrix factorization (NMF) and its nonlinear extension, linear-quadratic NMF (LQ-NMF). The results revealed notable shifts in public discourse before and after the reports' release, highlighting recurring topics such as climate risk, urgency for action, and greenhouse gas emissions. Additionally, sentiment analysis using the VADER method showed a decrease in neutral tweets and greater polarization in responses, especially regarding the AR6 report. These findings suggest that IPCC publications have generated measurable influence on social media and that the applied methods are effective tools for assessing public perception of climate communication.

This study evaluated industrial strategies to reduce the retention time of pork shank in a continuous freezing tunnel. The influence of the use of secondary packaging and the change in the supply method from horizontal to vertical in the freezing of pork shank was evaluated. This resulted in a reduction of 3.5 h in the retention time of the product to meet the critical freezing temperature of -18°C, and a 0.5% reduction in the percentage of reprocess. The temperature variation between the freezing levels was also evaluated, using the statistical process control tool. The temperature of the different freezing levels was monitored, and it was verified that the variations were caused by the defrosting process, due to mechanical problems in the ventilation system. With this work was possible to promote improvements in the freezing system to meet the critical temperature and to reduce the percentage of reprocessing of products.

Some probiotics bacterium such as Enterococcus faecium play an important role in the homeostasis of the gastrointestinal tract. It is therefore being a microorganism of interest in preventing the onset and progression of colorectal cancer (CRC). This study aimed to evaluate both the protective effect on colorectal carcinogenesis after the oral administration of Enterococcus faecium 137v - EF137v in an experimental model for CRC chemically induced by 1,2-dimethylhydrazine (DMH), and its hepatoprotective activity. Female Wistar rats were treated with DMH and received a dose of E. faecium at a concentration of 1010 CFU / ml, varying the consumption period per group. Biochemical, histopathological, histochemical, immunohistochemical analyzes for VEGF-A, IL-1β and TNF-α, morphometry and apoptosis were determined. The studyshowed that, after the administering of EF137v, the intestinal mucosa was preserved and an attenuated rate of apoptosis. Low glycogen levels were observed in the positive control group (G2) that received only DMH when compared to the others groups. Our findings suggest that EF137v has a preventive effect on preneoplasic lesion, reducing and/or inhibiting inflammation, in addition to which aberrant crypts form, and this especially contributes to preventing liver inflammation in na animal model.

We describe a large, three-dimensionally preserved pterosaur humerus from Bone Cabin Quarry in the Upper Jurassic Morrison Formation; one of the largest Jurassic pterosaur humeri on record. The tongue-shaped, relatively unconstricted deltopectoral crest suggests it belongs to a member of the clade Scaphognathinae, though humeri of scaphognathines remain poorly described in the literature. Bone Cabin Quarry has also produced the holotype rostrum of a scaphognathine pterosaur, Harpactognathus gentryii, which possesses a similar estimated wingspan of over two meters, so we tentatively refer the Bone Cabin Quarry humerus to this species. The three-dimensional preservation seen is very rare for "rhamphorhynchoid" elements, preserving features typically obscured or obliterated in other specimens. As a result, this humerus reveals potentially useful characters for rhamphorhynchids, particularly scaphognathines. This specimen is noteworthy for its prominent condyles and expanded distal end, which may have implications for functional morphology. The distal encd of the humerus bears a pneumatic foramen, representing the first known occurrence of pneumatization in the appendicular skeleton of non-monofenestratan pterosaurs. This pneumatization may be a function of size and convergent with pterodactyloids, but because most humeri lack well-preserved and visible distal ends, pneumatization in other known taxa of non-pterodactyloid pterosaurs cannot be explicitly ruled out.

This research aims to propose a machine learning approach to classify dropout outcomes among students in Statistics undergraduate programs in Brazil, identifying the most important factors associated with this phenomenon. This study uses microdata from the National Institute for Educational Studies and Research Anísio Teixeira (INEP) Higher Education Census to analyze the experiences of 10,387 undergraduate students who began their bachelor's degrees between 2009 and 2014 in Brazil and were monitored until the end of 2017. Approximately 65% of these students dropped out, highlighting the critical dropout challenge in Brazilian Statistics programs. The outcome of interest is the student's final status in the census data, either completion or dropout. Logistic regression, random forest , and support vector machine algorithms were fitted in the learning stage. For each algorithm, the best model was evaluated on test data. Results indicate that the logistic regression model outperforms the others, achieving an accuracy of 86.1% and offering greater interpretability compared to the other models. The study reveals that the duration of enrollment is a key predictor of dropout likelihood. Moreover, receiving social support and participating in complementary activities are significant factors in reducing dropout rates.

Despite recent scientific advances, biodiversity remains underestimated and faces gaps, including the Wallacean gap, referring to the lack of knowledge about geographical distribution and limited understanding of taxa. The Amazon, as a center of endemism, requires more research, hindered by limited resources and access. Despite increased studies on the Cyperaceae family, significant research gaps remain in the Brazilian Amazon. This study identified gaps in Cyperaceae distribution that occur in Brazil in the Brazilian Amazon, analyzing the efficiency of Protected Areas in preserving its diversity. Data revealed 850 species and 223,779 occurrences; after updates, 324 species remained, totaling 5.741 records, with 74.1% belonging to Rhynchospora (n=1.436), Cyperus (n=1.272), Scleria (n=822), Eleocharis (n=439), and Calyptrocarya (n=285). Collections are unevenly distributed, with notable gaps in Pará and Amazonas, concentrated near urban centers. Analyses show most Protected Areas fail to encompass Cyperaceae biodiversity. Investments in research and access to remote regions are key to reducing gaps. Understanding why Amazonian Protected Areas are under-sampled is crucial.

Pterosaurs had a unique morphology among flying vertebrates, and therefore, a direct comparison with living vertebrates regarding their terrestrial locomotion is impossible. In this study, we used the athletic capability indexes to infer aspects of the terrestrial proficiency of pterosaurs. We estimated the body mass, bending strength, and stylopodial axial strength indexes of 25 specimens of non-pterodactyloid and pterodactyloid pterosaurs. We used linear regression models to investigate the relationships between the indexes of athletic capability and the two stylopodia, and the indexes of athletic capability and the body mass of pterosaurs. We also compared the values of the index with those of other extinct and living animals. The results show higher values of the indexes of athletic capability for the humerus than the femur, indicating a higher relative strength of the forelimbs compared to the hindlimbs for bending and axial compression forces. We also detected a negative relationship between both indexes of athletic capability and body mass. Comparing the pterosaur athletic capability with other quadruped vertebrates indicates they had a good proficiency for terrestrial locomotion, even for plesiomorphic forms previously thought to have limited terrestrial locomotion. Even so, pteranodontoids are found to exhibit lower femoral ACI if compared to similar-sized pterodactyloids, notably azhdarchoids and dsungaripterids.

Promoting sustainable development depends on addressing the challenges generated by climate change. The nature of these complex and interconnected challenges requires knowledge generation and the strengthening of interdisciplinary research networks. Research developed by the National Institute for Science and Technology for Climate Change Phase 2 (INCT-MC2) project, with its six thematic lines (or subcomponents) and three integrative (crosscutting) topics, provides a deep understanding of the interactions between the different aspects of climate change and sustainable development. Emphasis is placed on the impacts on water, energy, food security, health, ecosystems, and disaster risk reduction under urban development. These core topics are transversally integrated by climate modeling, economics, education, and communication research. The article analyzes the contribution of the INCT-MC2 scientific production and knowledge towards a better understanding of climate change and its impacts on various strategic sectors in Brazil. The results of the INCT-MC2 go along with the Sustainable Development Goals. Our analysis is based on a conceptual model that argues that the economy and society depend on the biosphere and ecosystem services and that their integrity is fundamental for global sustainability.