79 research outputs found
Sugarcane Straw Blanket Management Effects on Plant Growth, Development, and Yield in Southeastern Brazil
In Brazilian sugarcane (Saccharum spp.) production systems, the practice of moving harvesting residue from row to inter-row positions (i.e., raking) has increased in response to producer concerns over the potential negative effects of sugarcane straw on crop establishment and stalk yield. Despite increasing adoption among sugarcane farmers, the impacts of straw raking practices on plant growth and yield remain unclear. A 2-yr experiment that included both dry and wet seasons was conducted at two sites in southeastern Brazil to evaluate straw management strategy effects on plant tillering, phytomass accumulation, plant nutritional status, and stalk yield. The experiments were established at the Bom Retiro mill and the Univalem mill. Experimental treatments included raking straw to inter-rows (raked), total straw removal (bare soil), and no straw removal (straw cover). Raked and bare soil treatments improved plant tillering but did not influence final plant population. Straw management had a slight effect on phytomass accumulation. Reduction of phytomass yield was observed from the first to the second ratoon during both seasons at both sites. At Bom Retiro, phytomass yield decreased 37% for stands established during the dry season and 19% for stands established during the wet season. At Univalem, phytomass yield decreased 20% for stands established during the dry season and 30% for stands established during the wet season. Retaining straw in the field (regardless of treatment) increased leaf tissue P content but not stalk yield. Raking straw from row to interrow positions at these locations in southeastern Brazil had no benefit on sugarcane yield but may result in soil compaction and higher production costs over time
Residual Stresses and Cracking in Dental Restorations due to Resin Contraction Considering In-Depth Young\u27s Modulus Variation
A pandemia de COVID-19 e seu efeito na estrutura do Brief-COPE
This study aimed to investigate the dimensional structure of Brief-COPE during the COVID-19 pandemic. Six hundred and sixty-six adults from all regions of Brazil, mostly women (77 %), aged between 18 and 79 years old (M = 36.70; SD = 13.12), took part in this research. They answered sociodemographic questions and the Brief-COPE. Descriptive and confirmatory factor analyzes were performed. The first order dimensional structure was confirmed with the 14 original factors. The second order structure did not converge, and a new second order structure was proposed based on the correlation indexes among the first order factors. The proposed new model presented adequate indexes of adjustment to the data. Such results suggest that the pandemic may have changed the way participants perceive and relate coping strategies.El presente estudio tuvo como objetivo investigar la estructura dimensional de Brief-COPE durante la pandemia de COVID-19. Seiscientos sesenta y seis adultos de todas las regiones de Brasil participaron en esta investigación, en su mayoría mujeres (77 %), con edades entre 18 y 79 años (M = 36.70; DE = 13.12). Los participantes respondieron preguntas sociodemográficas y el Brief-COPE. Se realizaron análisis descriptivos y análisis factoriales confirmatorios. Se confirmó la estructura dimensional de primer orden, con 14 factores. La estructura de segundo orden no convergió y se propuso una nueva estructura de segundo orden basada en la correlación entre los factores de primer orden. El nuevo modelo propuesto presentó índices adecuados de ajuste a los datos. Estos resultados sugieren que la pandemia puede haber cambiado la forma en que los participantes perciben y relacionan las estrategias de afrontamiento.O presente estudo teve como objetivo investigar a estrutura dimensional do Brief-COPE durante a pandemia de COVID-19. Participaram desta pesquisa 666 adultos de todas as regiões do Brasil, majoritariamente mulheres (77 %), com idade entre 18 e 79 anos (M = 36,70; DP = 13,12). Estes responderam perguntas sociodemográficas e o Brief-COPE. Foram realizadas análises descritivas e Análises Fatoriais Confirmatórias. A estrutura dimensional de primeira ordem foi confirmada, com 14 fatores. A estrutura de segunda ordem não convergiu, sendo proposta uma nova estrutura de segunda ordem tomando como base a correlação entre os fatores de primeira ordem. O novo modelo proposto apresentou índices adequados de ajuste aos dados. Tais resultados sugerem que a pandemia pode ter alterado a forma como os participantes percebem e relacionam as estratégias de enfrentamento
Macaronesia Acts as a Museum of Genetic Diversity of Relict Ferns: The Case of Diplazium caudatum (Athyriaceae)
Macaronesia has been considered a refuge region of the formerly widespread subtropical
lauroid flora that lived in Southern Europe during the Tertiary. The study of relict angiosperms
has shown that Macaronesian relict taxa preserve genetic variation and revealed general patterns
of colonization and dispersal. However, information on the conservation of genetic diversity and
range dynamics rapidly diminishes when referring to pteridophytes, despite their dominance of the
herbaceous stratum in the European tropical palaeoflora. Here we aim to elucidate the pattern of
genetic diversity and phylogeography of Diplazium caudatum, a hypothesized species of the Tertiary
Palaeotropical flora and currently with its populations restricted across Macaronesia and disjunctly in
the Sierras de Algeciras (Andalusia, southern Iberian Peninsula). We analysed 12 populations across
the species range using eight microsatellite loci, sequences of a region of plastid DNA, and carry out
species-distribution modelling analyses. Our dating results confirm the Tertiary origin of this species.
The Macaronesian archipelagos served as a refuge during at least the Quaternary glacial cycles, where
populations of D. caudatum preserved higher levels of genetic variation than mainland populations.
Our data suggest the disappearance of the species in the continent and the subsequent recolonization
from Macaronesia. The results of the AMOVA analysis and the indices of clonal diversity and
linkage disequilibrium suggest that D. caudatum is a species in which inter-gametophytic outcrossing
predominates, and that in the Andalusian populations there was a shift in mating system toward
increased inbreeding and/or clonality. The model that best explains the genetic diversity distribution
pattern observed in Macaronesia is, the initial and recurrent colonization between islands and
archipelagos and the relatively recent diversification of restricted area lineages, probably due to the
decrease of favorable habitats and competition with lineages previously established. This study
extends to ferns the concept of Macaronesia archipelagos as refugia for genetic variation
Global mismatches in aboveground and belowground biodiversity
Human activities are accelerating global biodiversity change and have resulted in severely threatened ecosystem services. A large proportion of terrestrial biodiversity is harbored by soil, but soil biodiversity has been omitted from many global biodiversity assessments and conservation actions, and understanding of global patterns of soil biodiversity remains limited. In particular, the extent to which hotspots and coldspots of aboveground and soil biodiversity overlap is not clear. We examined global patterns of these overlaps by mapping indices of aboveground (mammals, birds, amphibians, vascular plants) and soil (bacteria, fungi, macrofauna) biodiversity that we created using previously published data on species richness. Areas of mismatch between aboveground and soil biodiversity covered 27% of Earth's terrestrial surface. The temperate broadleaf and mixed forests biome had the highest proportion of grid cells with high aboveground biodiversity but low soil biodiversity, whereas the boreal and tundra biomes had intermediate soil biodiversity but low aboveground biodiversity. While more data on soil biodiversity are needed, both to cover geographic gaps and to include additional taxa, our results suggest that protecting aboveground biodiversity may not sufficiently reduce threats to soil biodiversity. Given the functional importance of soil biodiversity and the role of soils in human well-being, soil biodiversity should be considered further in policy agendas and conservation actions by adapting management practices to sustain soil biodiversity and considering soil biodiversity when designing protected areas.Peer reviewe
The COVID-19 pandemic and its effect on the Brief-COPE structure
This study aimed to investigate the dimensional structure of Brief-COPE during the COVID-19 pandemic. Six hundred and sixty-six adults from all regions of Brazil, mostly women (77%), aged between 18 and 79 years old (M= 36.70; SD= 13.12), took part in this research. They answered sociodemographic questions and the Brief-COPE. Descriptive and confirmatory factor analyzes were performed. The first order dimensional structure was confirmed with the 14 original factors. The second order structure did not converge, and a new second order structure was proposed based on the correlation indexes among the first order factors. The proposed new model presented adequate indexes of adjustment to the data. Such results suggest that the pandemic may have changed the way participants perceive and relate coping strategies
Quantification and tissue localization of selenium in rice (Oryza sativa l., poaceae) grains: A perspective of agronomic biofortification
grant number 101-030671In worldwide production, rice is the second-most-grown crop. It is considered a staple food for many populations and, if naturally enriched in Se, has a huge potential to reduce nutrient deficiencies in foodstuff for human consumption. This study aimed to develop an agronomic itinerary for Se biofortification of Oryza sativa L. (Poaceae) and assess potential physicochemical deviations. Trials were implemented in rice paddy field with known soil and water characteristics and two genotypes resulting from genetic breeding (OP1505 and OP1509) were selected for evaluation. Plants were sprayed at booting, anthesis and milky grain phases with two different foliar fertilizers (sodium selenate and sodium selenite) at different concentrations (25, 50, 75 and 100 g Se·ha−1). After grain harvesting, the application of selenate showed 4.9–7.1 fold increases, whereas selenite increased 5.9–8.4-fold in OP1509 and OP1505, respectively. In brown grain, it was found that in the highest treatment selenate or selenite triggered much higher Se accumulation in OP1505 relatively to OP1509, and that no relevant variation was found with selenate or selenite spraying in each genotype. Total protein increased exponentially in OP1505 genotype when selenite was applied, and higher dosage of Se also increased grain weight and total protein content. It was concluded that, through agronomic biofortification, rice grain can be enriched with Se without impairing its quality, thus highlighting its value in general for the industry and consumers with special needs.publishersversionpublishe
Decreased renal function in overweight and obese prepubertal children
BACKGROUND: Obesity is a potentially modifiable risk factor for the development and progression of kidney disease, both in adults and children. We aim to study the association of obesity and renal function in children, by comparing estimated glomerular filtration rate (eGFR) in nonoverweight and overweight/obese children. Secondarily, we aim to evaluate the accuracy of equations on eGFR estimation when compared to 24-h urinary creatinine clearance (CrCl).
METHODS: Cross-sectional study of 313 children aged 8-9 y, followed in the birth cohort Generation XXI (Portugal). Creatinine and cystatin C, GFR estimated by several formulas and CrCl were compared in 163 nonoverweight and 150 overweight/obese, according to World Health Organization growth reference.
RESULTS: Overweight/obese children had significantly lower eGFR, estimated by all methods, except for CrCl and revised Schwartz formula. Despite all children having renal function in the normal range, eGFR decreased significantly with BMI z-score (differences ranging from -4.3 to -1.1 ml/min/1.73 m(2) per standard deviation of BMI). The Zappitelli combined formula presented the closest performance to CrCl, with higher correlation coefficients and higher accuracy values.
CONCLUSION: Young prepubertal children with overweight/obesity already present significantly lower GFR estimations that likely represent some degree of renal impairment associated with the complex deleterious effects of adiposity
Prevalence of abnormal electrocardiographic findings in a Brazilian cohort of young football players : b-pro foot ECG pilot study
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