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The spotted fever group (SFG) rickettsiae, which are transmitted primarily by tick bite to rodents, dogs, wild animals, and persons, comprise a phylogenetically discrete clade of the family Rickettsiacae, encompassing [...]

The machine learning is different from other courses for its large span of mathematical knowledge, widely application of techniques, and fast updating of models.In traditional machine learning classes, due to the separation between review of mathematical knowledge and model explanation, boring content divorced from the reality, and the obsolete content of exam, undergraduates have difficulty in understanding machine learning models.Then they lack interest in learning and also consciousness of autonomous learning, which makes them difficult to solve practical problems with advanced machine learning technologies.Considering these facts, the teaching reform measures of machine learning course were proposed, in terms of teaching methods, content and exam.The teaching methods combined online learning and offline deduction to increase teacher-student interaction and connect key knowledge points.The teaching content introduced scientific stories and interesting challenges, which enriched the content and cultivates learning interest.The advanced machine learning technique-based practice exam was applied to enhance the capability of independent learning and explore advanced technologies.Consequently, the reform measures have been successfully applied in the machine learning teaching practice of Academician Binxing Fang undergraduate preparatory class of Guangzhou University, improving the teaching performance of machine learning course.

Mosquito-transmitted viruses represent substantial health burdens across the Americas. Despite the broad geographic ranges of Aedes spp. and Culex spp. mosquitoes, the endemicity of human arboviral diseases is incongruent with [...]

Background: Chagas disease or American trypanosomiasis, caused by Trypanosoma cruzi and vectored by triatomines, affects millions of people worldwide. In endemic countries including Mexico, infections in domestic animals, such as dogs, may affect the risk of human disease when they serve as a source of infection to vectors that subsequently infect humans. Materials and Methods: We conducted a cross-sectional study of 296 dogs from two cities near the northern and southern borders of Mexico: Reynosa, Tamaulipas, and Tuxtla Gutierrez, Chiapas. Infection was measured based on testing of blood using T. cruzi quantitative PCR (qPCR) and up to three antibody detection assays. The StatPak immunochromatographic assay was used to screen samples and the indirect fluorescent antibody (IFA) and multiplex microsphere immunoassay (MIA) tests were used as secondary tests on all samples that screened positive and a subset of negatives. Serologic positivity was defined based on reactivity on at least two independent tests. Results: Of the 280 samples tested for parasite DNA, two (0.7%) were positive, one of which (0.4%) was confirmed as T. cruzi discrete typing unit TcIV. Overall, 72 (24.3%) samples were reactive for T. cruzi antibodies via StatPak of which 8 were also positive using MIA and 2 were also positive using IFA (including one of the PCR-positive dogs). Overall, nine dogs (3.4%) met study criteria of positivity based on either/both serology or PCR tests. Positive dogs were found in both regions of Mexico; five (2.7%) from Reynosa and four (3.6%) from Tuxtla Gutierrez. We found no association between infection status and state of origin, sex, age group, breed group, neighborhood, and whether other pets lived in the home. Conclusion: Our results re-emphasize dogs' utility as sentinels for T. cruzi in Mexico and underscore the need for improved veterinary diagnostic tests and parasite surveillance at the household level in endemic countries. [ABSTRACT FROM AUTHOR]

The proportion of accident between right-turning truck and cyclist straight is smaller than other types of collision accidents. But it is far likely for cyclists to suffer severe injury when it happens. In this paper, we pay attention to the effects of four parameters (truck speed, collision angle, friction coefficient, and truck driver's reaction time) on the dynamic response process and the injury level of cyclist of the accident between right-turning truck and cyclist straight. We found that all the parameters have a great impact on those. Two types of dynamic response processes exist. In step one and step two, the injury values of cyclist were all below their threshold when the truck speed was less than 27 km/h. But when the truck speed is greater than or equal to 27 km/h, the injury value of the chest is higher than 60 g. Meanwhile, HIC and the resultant acceleration of the chest increase with truck speed. Most of the injury value of the crushed part exceeds the fixed value when step three happened. So, slowing down the truck speed and reducing the possibility of cyclist being crushed can improve the safety level of cyclists. [ABSTRACT FROM AUTHOR]