975 research outputs found
Tecnologia de aplicação de agrotóxicos em cultivo protegido de tomate e pimentão.
Essa Circular Técnica tem como objetivos orientar produtores de tomate e pimentão quanto aos cuidados a serem adotados na aplicação de agrotóxicos nas culturas do tomate e do pimentão cultivados em ambiente protegido, auxiliar na escolha dos equipamentos de aplicação mais adequados e na realização de sua calibração, assim como orientar quanto às condições ambientais favoráveis para sua aplicação, sem colocar em risco a saúde do aplicador e dos consumidores. Além disso, visa orientar os olericultores a obter a máxima eficiência do agrotóxico, a fim de reduzir os custos com as aplicações.bitstream/item/130081/1/CT-144.pd
Penicillium crustosum as a potential OTA producer - new insights from whole - genome sequencing of strain MUM 16.125
Ochratoxin A (OTA) is a well-studied mycotoxin that poses severe health risks. OTA is mainly
produced by Aspergillus and Penicillium species associated with food spoilage and it is present
in a wide diversity of food and feed products. Recent studies have reported the presence of
OTA in food matrices where known OTA producers are not present1,2. For that reason, other
species such as P. crustosum are now being considered. A recent study using comparative
genomic analysis3 clarified the OTA biosynthetic gene cluster composition.
In order to gain insight into the secondary metabolism of P. crustosum, this study aimed to
sequence and explore the complete genome of strain MUM 16.125. This strain was isolated
from cheese rind sample contaminated with OTA in which no known OTA producers were
present1.
The genome assembly comprises 199 contigs with a total length of 30.95 Mb and contains
10975 predicted protein-coding genes. In total, 109 gene clusters potentially related with
secondary metabolism were identified, including putative gene clusters for penitrem, clavaric
acid or naphthopyrones biosynthesis. Nevertheless, no evidence of an OTA biosynthetic gene
cluster was found. A total of 83 complete and 49 partial protein sequences from published OTA
biosynthetic genes from 11 Aspergillus and 3 Penicillium species were queried against the
predicted P. crustosum proteins. Only 3 strong matches were found (to a short partial P.
verrucosum PKS and 2 P. thymicola chloroperoxidases) but matches to complete key genes
were absent.
Considering these findings, it appears that strain MUM 16.125 lacks the most common genetic
pathway to produce OTA, providing important information relevant to understand the role of P.
crustosum as putative OTA producer. Nevertheless, the additional secondary metabolism gene
clusters found (such as penitrem, clavaric acid or naphthopyrones) highlight the potential of
this strain for metabolite production, including other mycotoxins or compounds with antioxidant,
anticancer or antibiotic properties.This study was supported by the Portuguese Foundation for Science and Technology
(FCT) under the scope of the strategic funding of CEB (UID/BIO/04469/2019) and iBiMED (UIDB/04501/2020)
units; and by CANCYL (POCI-01-0145-FEDER-031849) and GenomePT (POCI-01-0145-FEDER-022184)
projectsinfo:eu-repo/semantics/publishedVersio
Codon-triplet context unveils unique features of the Candida albicans protein coding genome
<p>Abstract</p> <p>Background</p> <p>The evolutionary forces that determine the arrangement of synonymous codons within open reading frames and fine tune mRNA translation efficiency are not yet understood. In order to tackle this question we have carried out a large scale study of codon-triplet contexts in 11 fungal species to unravel associations or relationships between codons present at the ribosome A-, P- and E-sites during each decoding cycle.</p> <p>Results</p> <p>Our analysis unveiled high bias within the context of codon-triplets, in particular strong preference for triplets of identical codons. We have also identified a surprisingly large number of codon-triplet combinations that vanished from fungal ORFeomes. <it>Candida albicans </it>exacerbated these features, showed an unbalanced tRNA population for decoding its pool of codons and used near-cognate decoding for a large set of codons, suggesting that unique evolutionary forces shaped the evolution of its ORFeome.</p> <p>Conclusion</p> <p>We have developed bioinformatics tools for large-scale analysis of codon-triplet contexts. These algorithms identified codon-triplets context biases, allowed for large scale comparative codon-triplet analysis, and identified rules governing codon-triplet context. They could also detect alterations to the standard genetic code.</p
Species-Specific Codon Context Rules Unveil Non-Neutrality Effects of Synonymous Mutations
Codon pair usage (codon context) is a species specific gene primary structure feature whose evolutionary and functional roles are poorly understood. The data available show that codon-context has direct impact on both translation accuracy and efficiency, but one does not yet understand how it affects these two translation variables or whether context biases shape gene evolution.Here we study codon-context biases using a set of 72 orthologous highly conserved genes from bacteria, archaea, fungi and high eukaryotes to identify 7 distinct groups of codon context rules. We show that synonymous mutations, i.e., neutral mutations that occur in synonymous codons of codon-pairs, are selected to maintain context biases and that non-synonymous mutations, i.e., non-neutral mutations that alter protein amino acid sequences, are also under selective pressure to preserve codon-context biases.Since in vivo studies provide evidence for a role of codon context on decoding fidelity in E. coli and for decoding efficiency in mammalian cells, our data support the hypothesis that, like codon usage, codon context modulates the evolution of gene primary structure and fine tunes the structure of open reading frames for high genome translational fidelity and efficiency in the 3 domains of life
Avaliação do California Mastitis Test e da contagem de células somáticas para o diagnóstico da mastite subclínica caprina.
Vários estudos têm confirmado diferenças fisiológicas entre a glândula mamária caprina e a bovina, demonstrando que devem ser realizadas adaptações para caprinos, determinando escores que melhor reflitam o verdadeiro estado sanitário da glândula mamária nesta espécie. O objetivo deste estudo foi correlacionar os resultados do Califórnia Mastitis Test (CMT), da contagem de células somáticas (CCS) e do exame bacteriológico do leite de caprinos e comparar com os padrões existentes na literatura. Foram utilizadas 23 fêmeas da raça Saanen pertencentes a Embrapa Caprinos e realizados exame clínico dos animais e teste da caneca telada, sendo que nenhum animal apresentava sintomas de mastite clínica. Posteriormente realizou-se o CMT, a coleta de leite para a contagem de células somáticas e exame Microbiológico. Para a análise estatística foi utilizado o programa Assistat 7.5. Não foi observada diferença estatística significativa entre os escores 3+ e 2+ ou entre os escores 1+, traços e 0 do CMT, quando correlacionado com o exame microbiológico. A reação 3+ foi estatisticamente diferente (p<0,01) das reações 1+, traços e 0. Considerando o valor de 1120 x 103 céls/mL como o limite máximo de células no leite caprino, foi demonstrada diferença altamente significativa (p<0,001) entre as amostras microbiologicamente positivas e negativas. Quanto à correlação entre a CCS e o CMT, foi constatada diferença significativa (p<0,05) somente entre os escores 0 e 3+ do CMT
Reduced tillage, but not organic matter input, increased nematode diversity and food web stability in European long‐term field experiments
Soil nematode communities and food web indices can inform about the complexity, nutrient flows and decomposition pathways of soil food webs, reflecting soil quality. Relative abundance of nematode feeding and life‐history groups are used for calculating food web indices, i.e., maturity index (MI), enrichment index (EI), structure index (SI) and channel index (CI). Molecular methods to study nematode communities potentially offer advantages compared to traditional methods in terms of resolution, throughput, cost and time. In spite of such advantages, molecular data have not often been adopted so far to assess the effects of soil management on nematode communities and to calculate these food web indices. Here, we used high‐throughput amplicon sequencing to investigate the effects of tillage (conventional vs. reduced) and organic matter addition (low vs. high) on nematode communities and food web indices in 10 European long‐term field experiments and we assessed the relationship between nematode communities and soil parameters. We found that nematode communities were more strongly affected by tillage than by organic matter addition. Compared to conventional tillage, reduced tillage increased nematode diversity (23% higher Shannon diversity index), nematode community stability (12% higher MI), structure (24% higher SI), and the fungal decomposition channel (59% higher CI), and also the number of herbivorous nematodes (70% higher). Total and labile organic carbon, available K and microbial parameters explained nematode community structure. Our findings show that nematode communities are sensitive indicators of soil quality and that molecular profiling of nematode communities has the potential to reveal the effects of soil management on soil quality
Characterization of titanium welded joints by the orbital gas tungsten arc welding process for aerospace application
In this work, three welding programs for orbital gas tungsten arc welding (GTAW), previously developed, were used, using pulsed current and increasing speed (#A), constant current (#B) and pulsed current and decreasing current (#C). One of these should be used for the propulsion system of the Satellite CBERS (China – Brazil Earth Resources Satellite). Welded joints using tubes of commercially pure titanium were obtained with these procedures, which were characterized by means of mechanical and metallographic tests. The obtained results showed that the three welding procedures produce welded joints free of defects and with adequate shape. Although small differences on mechanical properties and on microstructure have been observed, the three welding programs attained compatible results with international standards used in the aerospace segment. The welding program #B, due to the reduced heat input used, was considered to obtain slightly advantage over the others
COPD: can genetic Background inform about disease heterogeneity?
People with COPD vary substantially on their pulmonary (e.g., airway obstruction) and extra-pulmonary (e.g., symptoms, functional status) manifestations. The aim of this study was to relate this high heterogeneity to the patient’s genetic Background, namely focusing on polymorphisms associated with COPD and COPD-associated phenotypes and features.
Summary statistics for COPD and COPD-associated phenotypes and features (emphysema, FEV1, FEV1/FVC, smoking, BMI, asthma, airway responsiveness, coronary heart disease, blood pressure, pulmonary artery enlargement, resting heart rate and resting oxygen saturation) were obtained from GWAS Catalog (https://www.ebi.ac.uk/gwas/ accessed in August 2021). A local COPD cohort was genotyped using Global Screening Arrays (GSA-Illumina) and polygenic risk scores were calculated per phenotype/feature. A cluster analysis was then carried out to determine how patients would group according to their assessed genetic risks.
The study currently includes 255 participants with COPD (68 [61, 74] years old; 79.61% male; FEV1/FVC 53.02 [41.24, 61.94]). Our preliminary results show that people cluster into 3 main groups based on their genetic risk for emphysema, followed by COPD, whilst their clinical characteristics remained similar among groups. Future work is currently being conducted to further explore these clusters and perform their validation.
This work was funded by FEDER funds through COMPETE 2020, Operational Programme for Competitiveness and Internationalization (POCI-01-0145-FEDER-028806), CENTRO 2020 (CENTRO-01-0246-FEDER-000018; CENTRO-08-5864-FSE-000039) and by Fundação para a Ciência e a Tecnologia (UI/BD/151337/2021). The iBiMED is supported by FCT funds under UIDP/04501/2020.publishe
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