Quadruped Robot Control: An Approach Using Body Planar Motion Control, Legs Impedance Control and Bézier Curves.

In robotics, the ability of quadruped robots to perform tasks in industrial, mining, and disaster environments has already been demonstrated. To ensure the safe execution of tasks by the robot, meticulous planning of its foot placements and precise leg control are crucial. Traditional motion planning and control methods for quadruped robots often rely on complex models of both the robot itself and its surrounding environment. Establishing these models can be challenging due to their nonlinear nature, often entailing significant computational resources. However, a more simplified approach exists that focuses on the kinematic model of the robot's floating base for motion planning. This streamlined method is easier to implement but also adaptable to simpler hardware configurations. Moreover, integrating impedance control into the leg movements proves advantageous, particularly when traversing uneven terrain. This article presents a novel approach in which a quadruped robot employs impedance control for each leg. It utilizes sixth-degree Bézier curves to generate reference trajectories derived from leg velocities within a planar kinematic model for body control. This scheme effectively guides the robot along predefined paths. The proposed control strategy is implemented using the Robot Operating System (ROS) and is validated through simulations and physical experiments on the Go1 robot. The results of these tests demonstrate the effectiveness of the control strategy, enabling the robot to track reference trajectories while showing stable walking and trotting gaits.

Drug design and repurposing with DockThor-VS web server focusing on SARS-CoV-2 therapeutic targets and their non-synonym variants.

The COVID-19 caused by the SARS-CoV-2 virus was declared a pandemic disease in March 2020 by the World Health Organization (WHO). Structure-Based Drug Design strategies based on docking methodologies have been widely used for both new drug development and drug repurposing to find effective treatments against this disease. In this work, we present the developments implemented in the DockThor-VS web server to provide a virtual screening (VS) platform with curated structures of potential therapeutic targets from SARS-CoV-2 incorporating genetic information regarding relevant non-synonymous variations. The web server facilitates repurposing VS experiments providing curated libraries of currently available drugs on the market. At present, DockThor-VS provides ready-for-docking 3D structures for wild type and selected mutations for Nsp3 (papain-like, PLpro domain), Nsp5 (Mpro, 3CLpro), Nsp12 (RdRp), Nsp15 (NendoU), N protein, and Spike. We performed VS experiments of FDA-approved drugs considering the therapeutic targets available at the web server to assess the impact of considering different structures and mutations to identify possible new treatments of SARS-CoV-2 infections. The DockThor-VS is freely available at www.dockthor.lncc.br .

Resposta da co-inoculação de bactérias promotoras de crescimento em plantas e Bradyrhizobium sp. em caupi / Co-inoculation response of growth promoting bacterias in plants and Bradyrhizobium sp. in cowpea

Para a região árida e semi-árida do Nordeste brasileiro, o cultivo do caupi (Vigna unguiculata [L.] Walp.) vem se destacando por ser uma cultura adaptável as condições da região. Devido à capacidade do caupi de, em simbiose com o rizóbio, realizar a FBN, a co-inoculação rizóbio e bactérias promotoras de crescimento em plantas (BPCP's) poderá optimizar a fixação do N2 atmosférico dependendo da combinação e compatibilidade das estirpes envolvidas. O objetivo do trabalho foi avaliar a resposta da co-inoculação de BPCP's e Bradyrhizobium sp. como alternativa para optimizar a performance simbiótica e o desenvolvimento do caupi em condições de casa-de-vegetação. O experimento foi instalado em casa de vegetação, utilizando como substrato areia lavada e autoclavada em vasos de Leonard. Os tratamentos foram: 22 estirpes de BPCP's comparadas com a estirpe padrão (BR 3267), no caupi cv. "IPA 206". A colheita foi efetuada aos 35 dias após o plantio (DAP) e foram avaliados as seguintes variáveis: altura de planta (AP) aos 15, 25 e 35 dias, comprimento da raiz (CR), matéria seca da parte aérea (MSPA), matéria seca da raiz (MSR), matéria seca do nódulo (MSN), nodulação específica (NE) e nitrogênio acumulado na parte aérea (Nac). Os resultados mostram que a cultura do caupi respondeu significativamente a inoculação de estirpes de Bacillus, Brevibacillus e Paenibacillus co-inoculados com a estirpe de Bradyrhizobium sp. (BR 3267). A interação dos micro-organismos estudados não influenciou as variáveis, nodulação específica e matéria seca dos nódulos no caupi cv. IPA 206. A estirpe de Paenibacillus graminis (MC 04.21) co-inoculada com Bradyrhizobium sp. (BR 3267) foi superior em relação às demais estirpes avaliadas na produção de nitrogênio acumulado na matéria seca da parte aérea, proporcionando uma melhor performance simbiótica.

In the arid and semi-arid northeastern Brazil, the cultivation of cowpea has stood out for being an adaptable culture conditions in the region. Because of the ability of cowpea, in symbiosis with rhizobia carry out the FBN, the co-inoculation Rhizobium and growth promoting bacteria in plants can optimize the fixation of atmospheric N2 depending on the combination and compatibility of the strains involved. The objective of this study was to evaluate the response of the inoculation BPCP's and Bradyrhizobium sp. as an alternative to optimize performance and development of symbiotic cowpea under conditions of green-house. The experiment was conducted in a greenhouse, using as substrate washed and sterilized sand in Leonard jars. The treatments were: 22 strains BPCP's compared with the strain (BR 3267), on cowpea cv. IPA 206. At harvest 35 days after planting (DAP) and the following variables were evaluated: plant height (AP) 15, 25 and 35 days, root length (CR), shoot dry matter (MSPA), root dry matter (MSR), nodule dry matter (MSN), specific nodulation (NE) and nitrogen accumulated in shoots (Nac). The results show that the culture of cowpea responded significantly to inoculation of strains of Bacillus, Brevibacillus and Paenibacillus co-inoculated with the strain of Bradyrhizobium sp. (BR 3267). The interaction of microorganisms studied non-influenced the variables specific nodulation and dry matter of nodules in cowpea cv. IPA 206. The strain of Paenibacillus graminis (MC 04/21) coinoculated with Bradyrhizobium sp. (BR 3267) was higher compared to other strains tested in the production of nitrogen accumulated in shoot dry matter, providing a better performance symbiotic.

Amplification of the cap20 pathogenicity gene and genetic characterization using different markers molecular in Colletotrichum gloeosporioides isolates

Studies were performed to analyze the genetic characterization using RFLP-ITS and Intron (primer EI1) markers and the amplification of the cap20 pathogenicity gene by PCR in Colletotrichum gloeosporioides isolates of different hosts plant. The genetic variability was accessed using RFLP-ITS and Intron markers and grouping by UPGMA method. Primers to cap20 gene were constructed using selected sequences of the GenBank (National Center of Biotechnology Information, http://www.ncbi.nlm.nih.gov) with the Primer 3 program. The dendrograms analysis showed that the RFLP-ITS marker was more informative to separate the Colletotrichum sp, and that primer EI1 demonstrated greater genetic diversity. The amplification of the DNA of the Colletotrichum isolates to the cap20 gene with primers P1 and P2 indicated that this gene could present variations into C. gloeosporioides related with the host, and also that it was present in other Colletotrichum sp.

Estudos foram realizados para analisar a caracterização genética usando marcadores de RFLP-ITS e ISSP e a amplicação do gene de patogenicidade cap20 por PCR em isolados de Colletotrichum gloeosporioides de diferentes hospedeiros. Primers para o gene cap20 foram construídos a partir de seqüências selecionadas do GenBank (National Center of Biotechnology Information, http://www.ncbi.nlm.nih.gov) com o programa Primer 3. A análise dos dendrogramas revelou que o marcador RFLP-ITS foi mais informativo em separar as espécies de Colletotrichum, e que o primer EI1 evidenciou maior diversidade genética. A amplificação do DNA dos isolados de Colletotrichum para o gene cap20 com os primers P1 e P2 indicou que este gene pode apresentar variações dentro de C. gloeosporioides relacionada ao hospedeiro, e que também está presente em outras espécies de Colletotrichum.