478 research outputs found
High intensity tapping regime in a frustrated lattice gas model of granular compaction
In the frame of a well established lattice gas model for granular compaction,
we investigate the high intensity tapping regime where a pile expands
significantly during external excitation. We find that this model shows the
same general trends as more sophisticated models based on molecular dynamic
type simulations. In particular, a minimum in packing fraction as a function of
tapping strength is observed in the reversible branch of an annealed tapping
protocol.Comment: 5 pages, 4 figure
Identification of non-host resistance genes in wheat to barley yellow rust
Yellow rust, caused by Puccinia striiformis West., is an important foliar disease of wheat and barley throughout the world, and the development of resistant cultivars is the most economical and environmentally friendly method of control. Breeding for resistance to yellow rust has, for decades, been based on the use of race-specific resistance genes, which have shown to be short-lived. Non-host resistance has been studied as a possible source of durable resistance.
Two major genes, as well as an undetermined number of minor genes, for non-host resistance to the barley attacking form of yellow rust, P. striiformis f. sp. hordei, have been previously detected in the wheat cultivar ‘Lemhi’. The present study aimed at quantifying and mapping those genes using QTL (quantitative trait loci) mapping procedures. For that purpose, an F2 population of 114 individuals resulting from the cross of resistant ‘Lemhi’ with ‘Chinese 166’, a wheat cultivar susceptible to barley yellow rust, was used as the mapping population. QTL effects and significance were estimated by means of interval mapping and MQM mapping procedures.
A map for the F2 population was constructed which included 116 DNA markers (14 SSRs and 102 AFLPs). Two major QTLs have been mapped to chromosome arms 1DS (Psh1) and 2BL (Psh2), with significant LOD values. These two QTLs account for 76.7% of the phenotypic variance for resistance to barley yellow rust. Two other QTLs, with a minor effect, were mapped to chromosome arms 5AL (Psh3) and 6AL (Psh4), explaining 5.1% and 10.9% of the phenotypic variation, respectively. The QTL on 5A was derived from the susceptible variety, ‘Chinese 166’. In all cases the resistance towards P. striiformis f.sp. hordei was associated with a visual chlorosis/necrosis response typical of race-specific, host resistance
Percepção de professores sobre epilepsia
PURPOSE: To identify in a town of Brazil the knowledge, attitude and perception of epilepsy in teachers of elementary schools and to compare these before and after a training exercise. METHODS: Teachers of nine public schools of Barão Geraldo, Campinas, Brazil completed a questionnaire. Two researchers had meetings with teachers, presenting the Global Campaign Epilepsy out of the shadows, when the questionnaire was first completed by all attendees. Twenty teachers of these schools were motivated to attend a training course entitled Epilepsy and Health as part of their continuous education programme. Two years later the same questionnaire was again completed (post-test) by these 20 teachers. RESULTS: 100 teachers originally completed the questionnaire (97 women, mean age 42 years, 64 married). Forty-three percent of teachers said that they had enough knowledge regarding epilepsy and 20% said that they had poor knowledge about the condition. Regarding the IQ of children with epilepsy, 45% of teachers believed that they had average IQ, 18% above average, six percent under average and 29% did not know. Teachers believed that children with epilepsy have a higher possibility of acquiring mental disease in the future (51%); that epilepsy is a disease (68%); that epilepsy is contagious (1%); epilepsy is treatable (90%). After the course, the teachers beliefs seem to have improved. DISCUSSION: This work with elementary school teachers identified difficulties related to epilepsy which, if addressed, may help promote better quality of life of people with epilepsy in the community and help to decrease stigma attached to the condition. Better informed teachers are likely to have a more positive attitude and this will be passed to others. Educational campaigns about epilepsy amongst teachers should be encouraged as this may improve the management of epilepsy, by helping to develop a well informed and tolerant community.OBJETIVO: Identificar atitudes e percepção dos professores do ensino fundamental a respeito da epilepsia, antes e depois de um curso específico sobre o tema. MÉTODO: Participaram da pesquisa professores de nove escolas da rede pública do ensino fundamental de Barão Geraldo, distrito de Campinas, SP. Dois pesquisadores reuniram-se com os professores e apresentaram a Campanha Global Epilepsia fora das sombras, momento também em que os questionários foram aplicados. Vinte professores ficaram motivados para fazer o curso de extensão Temas transversais: epilepsia e saúde. Após este curso, os questionários foram re-aplicados. RESULTADOS: Foram aplicados 100 questionários em professores das nove escolas, sendo que: noventa e sete professores eram do sexo feminino, idade média de 42 (D.P. 22 a 63) e 64 estavam casados. Quarenta e três professores declararam possuir conhecimento sobre epilepsia abaixo da média e 20, disseram possuir um pobre conhecimento sobre a condição. No que diz respeito à idéias sobre epilepsia, os professores acham que: as crianças com epilepsia tem QI igual (45%), na média (18%), abaixo da média (6%) e não sabem opinar (29%); crianças com epilepsia têm maior chance de terem doença mental no futuro (51%); a epilepsia é uma doença (68%); a epilepsia é contagiosa (1%); a epilepsia é tratável (90%). Após o curso, crenças e mitos sobre epilepsia dos professores mostraram diferenças significativas. DISCUSSÃO: Idéias errôneas sobre epilepsia podem ser mudadas através de cursos educacionais sobre epilepsia. Este trabalho, realizado com professores do ensino fundamental, visou a identificação das dificuldades relacionadas à epilepsia para promover a redução do estigma. É importante que professores sejam melhor instruídos sobre a epilepsia para consequentemente, ter atitudes mais positivas em relação às crianças com epilepsia. Acreditamos que professores mais capacitados melhoram a maneira de lidar e de se relacionar com crianças com epilepsia, para a construção de uma comunidade bem informada e mais tolerante para lidar com as diferenças.283
Towards a relevant set of state variables to describe static granular packings
We analyze, experimentally and numerically, the steady states, obtained by tapping, of a two-dimensional granular layer. Contrary to the usual assumption, we show that the reversible (steady state branch) of the
density-acceleration curve is nonmonotonous. Accordingly, steady states with the same mean volume can be reached by tapping the system with very different intensities. Simulations of dissipative frictional disks show that equal volume steady states have different values of the force moment tensor. Additionally, we find that steady states of equal stress can be obtained by changing the duration of the taps; however, these states present distinct mean volumes. These results confirm previous speculations that the volume and the force moment tensor are both needed to describe univocally equilibrium states in static granular assemblies
Relevance of system size to the steady-state properties of tapped granular systems
We investigate the steady-state packing fraction ϕ and force moment tensor Σ of quasi-two-dimensional granular columns subjected to tapping. Systems of different height h and width L are considered. We find that ϕ and Σ, which describe the macroscopic state of the system, are insensitive to L for L>50d (with d the grain diameter). However, results for granular columns of different heights cannot be conciliated. This suggests that comparison between results of different laboratories on this type of experiments can be done only for systems of same height. We show that a parameter ɛ=1+(Aω)^{2}/(2gh), with A and ω the amplitude and frequency of the tap and g the acceleration of gravity, can be defined to characterize the tap intensity. This parameter is based on the effective flight of the granular bed, which takes into account the h dependency. When ϕ is plotted as a function of ɛ, the data collapses for systems of different h. However, this parameter alone is unable to determine the steady state to be reached since different Σ can be observed for a given ɛ if different column heights are considered
The Presence of Flavonoids in Some Products and Fruits of the Genus Eugenia: An Integrative Review
ReviewThe Myrtaceae family, one of the most prominent botanical families, is represented in Brazil
with different fruit species, rich in bioactive compounds and gastronomically appreciated.
This study aimed to carry out an integrative review on the genus Eugenia, highlighting the
pitangueira (E. uniflora L.), cagaiteira (E. dysenterica), grumixameira (E. brasiliensis), pereira
(E. klotzschiana O. Berg), and uvaieira (E. pyriformis Cambess) and which flavonoids are
present in these fruits. Articles published between 2016 and 2021 were selected from the
following databases: Google Scholar, Periódicos CAPES, Scielo, and Science Direct.
According to each database, the descriptors used as a search strategy addressed the
popular and scientific names of the five selected species, associated or not with the term
“flavonoid,” according to each database. The results showed that quercetin was the main
flavonoid identified in the fruits, and the principal extraction method used was HPLC. Other
interesting compounds, such as catechin, epicatechin, rutin, myricetin, and kaempferol,
were also found. However, the amount and type of flavonoids detected varied according to
the applied methodology. Hence, these studies highlight the importance of species of the
genus Eugenia, which promotes beneficial health effects and possible applicability to the
food and pharmaceutical industryinfo:eu-repo/semantics/publishedVersio
Water deprivation and the double- depletion hypothesis: common neural mechanisms underlie thirst and salt appetite
Water deprivation-induced thirst is explained by the double-depletion hypothesis, which predicts that dehydration of the two major body fluid compartments, the extracellular and intracellular compartments, activates signals that combine centrally to induce water intake. However, sodium appetite is also elicited by water deprivation. In this brief review, we stress the importance of the water-depletion and partial extracellular fluid-repletion protocol which permits the distinction between sodium appetite and thirst. Consistent enhancement or a de novo production of sodium intake induced by deactivation of inhibitory nuclei (e.g., lateral parabrachial nucleus) or hormones (oxytocin, atrial natriuretic peptide), in water-deprived, extracellular-dehydrated or, contrary to tradition, intracellular-dehydrated rats, suggests that sodium appetite and thirst share more mechanisms than previously thought. Water deprivation has physiological and health effects in humans that might be related to the salt craving shown by our species
O extrativismo da fava d'anta (Dimorphandra mollis Benth.) na região do Norte de Minas Gerais
Past and present land use influences on tropical riparian zones: an isotopic assessment with implications for riparian forest width determination
Organophosphorus and carbamates residues in milk and feedstuff supplied to dairy cattle
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