372 research outputs found
Sensibilidade de plantas de eucalipto (Eucalyptus urograndis) à subdoses do herbicida dicamba
In view of the widespread increase in herbicide-resistant weeds, biotechnology companies have developed dicamba-tolerant soybean and cotton cultivars. This technology can, however, increase the risk of the product drifting to adjacent areas. This study was developed with the objective of the to evaluate the phytotoxicity and biometric variables of young eucalyptus plants exposed to subdoses of the herbicide dicamba. The experiment was carried out under field conditions in Rio Verde, state of Goiás, Brazil. The treatments were represented by the application of 0 (control), 7.5, 15, 30, 60, 120 or 240 g ae ha-1 of dicamba 45 days after the seedlings were planted in the field. In terms of phytotoxicity, the dicamba doses of 120 and 240 g ae ha-1 caused greater damage to the eucalyptus plants in all periods of evaluation. The predominant symptoms were epinasty, increased number of shoots and necrosis and senescence of young branches and leaves. The herbicide doses of 120 and 240 g ae ha-1 significantly compromised plant height and diameter, number of branches and dry mass of leaves and roots, interfering with the growth and development of the eucalyptus crop. The results indicate that the effect of subdoses of the herbicide dicamba can interfere with the proper development of young eucalyptus plants, which may cause losses in the initial planting phase and future losses for producers.Em decorrência do aumento generalizado de plantas daninhas com resistência a herbicidas, empresas de biotecnologia desenvolveram cultivares de soja e algodão tolerantes ao herbicida dicamba. Essa tecnologia pode, no entanto, aumentar o risco do produto ser deslocado para áreas adjacentes às aplicadas. Neste trabalho objetivou-se avaliar a fitotoxicidade e variáveis biométricas de plantas jovens de eucalipto tratadas com subdoses do herbicida dicamba. O experimento foi realizado em condições de campo em Rio Verde, Goiás, Brasil. Os tratamentos foram representados pela aplicação de 0 (testemunha), 7,5, 15, 30, 60, 120 ou 240 g ea ha-1 de dicamba aos 45 dias após o plantio das mudas no campo. Em termos de fitotoxicidade, as doses de dicamba de 120 e 240 g ea ha-1 causaram maiores danos às plantas de eucalipto em todos os períodos de avaliação. Os sintomas predominantes foram epinastia, aumento do número de brotações e necrose e senescência de ramos e folhas jovens. As doses de herbicidas de 120 e 240 g ea ha-1 comprometeram significativamente a altura e diâmetro das plantas, número de ramos e massa seca de folhas, caules e raízes, interferindo no crescimento e desenvolvimento da cultura do eucalipto. Os resultados indicam que o efeito de subdoses do herbicida dicamba pode interferir no bom desenvolvimento de plantas jovens de eucalipto, podendo causar prejuízos na fase inicial de plantio e prejuízos futuros para os produtores
A OFERTA DE CURSOS DO PROUNI E O MERCADO DE TRABALHO
Neste texto, analisamos a atual distribuição de bolsas do Prouni por curso de graduação, para identificar quais as principais áreas de conhecimento que são contempladas no mercado educacional superior por esse programa e em que medida ele se compatibiliza com a necessidade de incentivar a formação superior em áreas de conhecimento consideradas estratégicas, o que é declaradamente prioridade para o próprio governo que o elaborou. Argumentamos que a path dependence pode explicar por que a Lei n. 11.096/2005, que instituiu o Prouni, insere-se no modelo institucional histórico de expansão de oferta de cursos de educação superior vigente até hoje no Brasil, focado em instituições de ensino privadas e caracterizado pelo subinvestimento em carreiras estratégicas para o desenvolvimento nacional.In this article we examine the current breakdown of Prouni scholarships per kind of undergraduate course so as to identify the main fields of knowledge that are made available in the higher education market by Prouni and to which extent the program is compatible with the need to foster higher education in strategic fields of knowledge, which is an official priority of the government that designed the program. We argue that path dependence can contribute to explaining why Law No. 11.096/2005, which instituted Prouni, falls within the institutional framework that comprises the growth of higher education supply still existent today in Brazil. This model is focused on private institutions of higher education and is characterized by an underinvestment in fields of knowledge that are strategic for national development
Combining performance and estimated genetic diversity among soybean parents and F1 populations
ABSTRACT Studies about the combining ability and genetic diversity can provide information on the genetic resources contained in the working collection of germplasm. The objective of this study was to estimate the combining ability of ten soybean parents and their hybrids in the F1 generation using diallel analysis and genetic diversity analysis to evaluate the dissimilarity between parents and crosses. The experiment was carried out in a greenhouse, in a completely randomized design with five replications, during the 2019/2020 crop season, in the municipality of Rio Verde, State of Goiás, Brazil. Agronomic and physiological variables were evaluated. Data were subjected to analysis of variance. Diallel analysis was performed using the Griffing method 2. Analysis of genetic diversity was performed with the Mahalanobis generalized distance and the hierarchical average linkage clustering. Additive gene effects were predominant in the control of all variables analyzed in the F1 generation. The parents SYN 1163 RR and CG 7370 RR showed good complementarity for the variable grain yield. The thirty-five genotypes were separated into six groups, and the variable weight of one hundred seeds had the greatest contribution to genetic diversity
CRISPR-transient expression in soybean for simplified gRNA screening in planta
O objetivo deste trabalho foi desenvolver um método para criar e validar sistemas CRISPR-Cas e diferentes gRNAs em embriões de soja (Glycine max). Dois genes modelo foram usados para mutação simples com um gRNA ou deleção parcial do gene com dois guias. Os gRNAs foram inseridos nos vetores de transformação CRISPR por uma enzima de restrição do tipo IIS ou por subclonagem e inserção do promotor + gRNA2 no vetor de transformação final, com uso do método clássico de clonagem por enzimas de restrição. Os vetores foram construídos com sucesso para um e dois gRNAs. A transformação transiente de soja por Agrobacterium foi realizada para testar a qualidade dos gRNAs e do próprio sistema (cassete de expressão). Detectaram-se mutação simples e deleção gênica nos embriões transformados após o enriquecimento do DNA por digestão seguida de reação em cadeia da polimerase e sequenciamento, o que indica que o sistema CRISPR-Cas e os guias estavam funcionando. Este protocolo pode ser usado para acelerar as estratégias de edição de genoma baseadas em CRISPR, para transformação genética em soja.The objective of this work was to develop a method to create and validate CRISPR-Cas systems and different gRNAs in soybean (Glycine max) embryos. Two model genes were used for simple mutation with one gRNA or partial gene deletion with two guides. The gRNAs were inserted into the CRISPR transformation vectors by a type IIS restriction enzyme or by subcloning and inserting the promoter + gRNA2 in the final transformation vector using the classic restriction enzyme cloning method. The vectors were successfully constructed for one and two gRNAs. Agrobacterium-mediated transient transformation in soybean was carried out to test the quality of gRNAs and of the system itself (expression cassette). Simple mutation and gene deletion were detected in the embryos transformed after DNA enrichment by enzyme digestion followed by polymerase chain reaction and sequencing, which indicates that the CRISPR-Cas system and guides were working. This protocol can be used to accelerate CRISPR-based genome editing strategies for genetic transformation in soybean
Screening for Bioactive Metabolites in Leaves, Branches, and Roots of Mansoa hirsuta: : Phytochemical, Toxicological and Antioxidant Aspects
Acknowledgments The authors would like to thank the Research Support Foundation of the State of Maranhão (FAPEMA), Cactvs Instituto de Pagamentos SA and Cactvs Educa—Masters and Doctoral Scholarships, National Council for Scientific and Technological Development (CNPq), Federal University of Piauí (UFPI), and the Federal Institute of Piauí (IFPI). Funding This research was funded by FAPEMA, IFMA (23249.031946.2020-62) (23249.020554.2022-30), Cactvs Institution of Payments SA and of Cactvs Educa—Masters and Doctorate Scholarships and Cnpq 316647/2020-9.Peer reviewedPublisher PD
Estimation of specific VO2max for elderly in cycle ergometer
The aim of the present study was to develop and validate a specific estimation model of maximal oxygen consumption (VO2max) based on submaximal ventilatory indicators on a cycle ergometer test protocol in elderly men. We tested, using an incremental protocol, 181 healthy and non-athletes male volunteers, aged between 60 and 79 years old, randomly divided into two groups: group A, of estimation (n = 137), and group B, of validation (n = 44). The independent variables were: body mass in kg, second workload threshold (WT2) and heart rate at the second ventilatory threshold (VT2). The cross-validation method was used in group B, with group A serving as the basis for the model and the validation dataset. The results presented a multiple linear regression model for estimation of VO2max = 31.62 + 0.182 (WT2) – 0.302 (body mass) in mlO2/kg/min-1; adjusted R2 = 0.98 and SEE = 0.682 (mlO2/Kg/min-1). The construction of this specific model for healthy and non-athletes elderly men can demonstrate that it is possible to estimate VO2max with a minimum error (SEE < 1.00) from indicators of ventilatory thresholds obtained in an incremental submaximal test
The effects of acute and chronic sprint-interval training on cytokine responses are independent of prior caffeine intake
We examined the effect of acute and chronic sprint interval training (SIT), with or without prior caffeine intake, on levels of exercise-induced inflammatory plasma cytokines [interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α]. Twenty physically-active men ingested either a placebo (n = 10) or caffeine (n = 10) 1 h before each SIT session(13-s × 30-s sprint/15 s of rest) during six training sessions (2 weeks). The early (before, immediately after, and 45 min after the exercise) and late (24 and 48 h after the exercise) cytokine and creatine kinase (CK) responses were analyzed for the first and last training sessions. Plasma IL-6 and IL-10 peaked 45 min after the exercise, and then returned to basal values within 24 h (p \u3c 0.05) in both groups on both occasions (p \u3e 0.05). On both occasions, and for both groups, plasma TNF-α increased from rest to immediately after the exercise and then decreased at 45 min before reaching values at or below basal levels 48 h after the exercise (p \u3c 0.05). Serum CK increased from rest to 24 and 48 h post-exercise in the first training session (p \u3c 0.05), but did not alter in the last training session for the PLA group (p \u3e 0.05). Serum CK was unchanged in both the first and last training sessions for the CAF group (p \u3e 0.05). Two weeks of SIT induced a late decrease in the IL-6/IL-10 ratio (p \u3c 0.05) regardless of caffeine intake, suggesting an improved overall inflammatory status after training. In conclusion, a single session of SIT induces muscle damage that seems to be mitigated by caffeine intake. Two weeks of SIT improves the late SIT-induced muscle damage and inflammatory status, which seems to be independent of caffeine intake
Exercise twice-a-day potentiates markers of mitochondrial biogenesis in men
Endurance exercise begun with reduced muscle glycogen stores seems to potentiate skeletal muscle protein abundance and gene expression. However, it is unknown whether this greater signaling responses is due to performing two exercise sessions in close proximity-as a first exercise session is necessary to reduce the muscle glycogen stores. In the present study, we manipulated the recovery duration between a first muscle glycogen-depleting exercise and a second exercise session, such that the second exercise session started with reduced muscle glycogen in both approaches but was performed either 2 or 15 hours after the first exercise session (so-called twice-a-day and once-daily approaches, respectively). We found that exercise twice-a-day increased the nuclear abundance of transcription factor EB (TFEB) and nuclear factor of activated T cells (NFAT) and potentiated the transcription of peroxisome proliferator-activated receptor-ɣ coactivator 1-alpha (PGC-1α), peroxisome proliferator-activated receptor-alpha (PPARα), and peroxisome proliferator-activated receptor beta/delta (PPARβ/δ) genes, in comparison with the once-daily exercise. These results suggest that part of the elevated molecular signaling reported with previous train-low approaches might be attributed to performing two exercise sessions in close proximity. The twice-a-day approach might be an effective strategy to induce adaptations related to mitochondrial biogenesis and fat oxidation
Can carbohydrate mouth rinse improve performance during exercise? A systematic review
The purpose of this review was to identify studies that have investigated the effect of carbohydrate (CHO) mouth rinse on exercise performance, and to quantify the overall mean difference of this type of manipulation across the studies. The main mechanisms involving the potential benefit of CHO mouth rinse on performance was also explored. A systematic review was conducted in the following electronic databases: PubMed, SciELO, Science Direct, MEDLINE, and the Cochrane Library (Cochrane Central Register of Controlled Trials), without limit of searches. Eleven studies were classified as appropriate and their results were summarized and compared. In nine of them, CHO mouth rinse increased the performance (range from 1.50% to 11.59%) during moderate- to high-intensity exercise (~75% Wmax or 65% VO2max, ~1 h duration). A statistical analysis to quantify the individual and overall mean differences was performed in seven of the 11 eligible studies that reported power output (watts, W) as the main performance outcome. The overall mean difference was calculated using a random-effect model that accounts for true variation in effects occurring in each study, as well as random error within a single study. The overall effect of CHO mouth rinse on performance was significant (mean difference = 5.05 W, 95% CI 0.90 to 9.2 W, z = 2.39, p = 0.02) but there was a large heterogeneity between the studies (I2 = 52%). An activation of the oral receptors and consequently brain areas involved with reward (insula/operculum frontal, orbitofrontal cortex, and striatum) is suggested as a possible physiological mechanism responsible for the improved performance with CHO mouth rinse. However, this positive effect seems to be accentuated when muscle and liver glycogen stores are reduced, possibly due to a greater sensitivity of the oral receptors, and require further investigation. Differences in duration of fasting before the trial, duration of mouth rinse, type of activity, exercise protocols, and sample size may account for the large variability between the studies
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