210 research outputs found
Constructing simply laced Lie algebras from extremal elements
For any finite graph Gamma and any field K of characteristic unequal to 2 we
construct an algebraic variety X over K whose K-points parameterise K-Lie
algebras generated by extremal elements, corresponding to the vertices of the
graph, with prescribed commutation relations, corresponding to the non-edges.
After that, we study the case where Gamma is a connected, simply laced Dynkin
diagram of finite or affine type. We prove that X is then an affine space, and
that all points in an open dense subset of X parameterise Lie algebras
isomorphic to a single fixed Lie algebra. If Gamma is of affine type, then this
fixed Lie algebra is the split finite-dimensional simple Lie algebra
corresponding to the associated finite-type Dynkin diagram. This gives a new
construction of these Lie algebras, in which they come together with
interesting degenerations, corresponding to points outside the open dense
subset. Our results may prove useful for recognising these Lie algebras.Comment: We made many corrections suggested by a referee, and extended our
results to positive characteristic greater than
Extremal Presentations for Classical Lie Algebras
The long-root elements in Lie algebras of Chevalley type have been well
studied and can be characterized as extremal elements, that is, elements
such that the image of (\ad x)^2 lies in the subspace spanned by . In this
paper, assuming an algebraically closed base field of characteristic not 2, we
find presentations of the Lie algebras of classical Chevalley type by means of
minimal sets of extremal generators. The relations are described by simple
graphs on the sets. For example, for the graph is a path of length ,
and for the graph is the triangle connected to a path of length .Comment: 26 pages, 6 figure
Pilots naar de vermindering van fijnstofemissie uit pluimveestallen: Granovi warmtewisselaar met absoluutfilter en recirculatie
To mitigate the concentrations of fine particulate matter in livestock farming areas, techniques are needed which reduce emissions from poultry barns. In this pilot study, measurements were carried out on the Granovi heat exchanger with absolute filter and recirculation, installed inside a broiler barn. In deviation from the measurement protocols, the so called “fine dust pilots” included one (instead of two) farm locations. The measurements show that the system reduces the emission of fine particulate matter (PM10) with 22%
Hemodynamic Changes, Plasma Catecholamine Responses, and Echocardiographically Detected Contractile Reserve During Two Different Dobutamine-Infusion Protocols
Hemodynamic changes, plasma catecholamine responses, and echocardiographically detected contractile reserve during two different dobutamine-infusion protocols
We studied hemodynamic changes, catecholamine responses, and the occurrence of improved wall thickening by echocardiography during two different dobutamine-infusion protocols. Forty-three patients were studied by using a stepwise incremental dobutamine dose-infusion protocol (10-40 μg/kg/min, 3-min intervals); a subgroup of 11 patients also underwent a continuous dobutamine-infusion protocol (10 μg/kg/min for 12 min) in random order. No patient used β-blockers. At 3-min intervals, blood pressure, heart rate, and plasma concentrations of dobutamine, epinephrine, and norepinephrine were measured. The echocardiographic improvement of wall thickening was analyzed only in paired protocols by visual assessment in left ventricular regions with normal wall motion at rest. The mean heart rate increased in the continuous and stepwise protocols from 73 to 99 and 74 to 132 beats/min. There was no significant change in blood pressure response between the two protocols. The mean plasma dobutamine concentrations during the continuous and stepwise protocols at 0, 3, 6, 9, and 12 min were 0/0; 31/38; 80/203; 106/448; and 120/692 ng/ml, respectively. In each patient, a response curve was constructed for the plasma dobutamine concentration versus heart rate. The heart rate increment and dobutamine concentration at which wall thickening was detected were similar with both protocols (14 ± 5 vs. 12 ± 7 beats/min) and (8) ± 40 vs. 92 ± 48 ng/ml; mean ± SD). Wall thickening was noted in two of 11 patients b
a critical review
The availability of wearable devices (WDs) to collect biometric information and their use during activities of daily living is significantly increasing in the general population. These small electronic devices, which record fitness and health-related outcomes, have been broadly utilized in industries such as medicine, healthcare, and fitness. Since they are simple to use and progressively cheaper, they have also been used for numerous research purposes. However, despite their increasing popularity, most of these WDs do not accurately measure the proclaimed outcomes. In fact, research is equivocal about whether they are valid and reliable methods to specifically evaluate physical activity and health-related outcomes in older adults, since they are mostly designed and produced considering younger subjects? physical and mental characteristics. Additionally, their constant evolution through continuous upgrades and redesigned versions, suggests the need for constant
up-to-date reviews and research. Accordingly, this article aims to scrutinize the state-of-the-art scientific evidence about the usefulness of WDs, specifically on older adults, to monitor physical activity and health-related outcomes. This critical review not only aims to inform older consumers but also aid researchers in study design when selecting physical activity and healthcare monitoring devices for elderly people.DB19-D819-F720 | Carlos Eduardo da Silva TeixeiraN/
Math saves the forest
Wireless sensor networks are decentralised networks consisting of sensors that can detect events and transmit data to neighbouring sensors. Ideally, this data is eventually gathered in a central base station. Wireless sensor networks have many possible applications. For example, they can be used to detect gas leaks in houses or fires in a forest.\ud
In this report, we study data gathering in wireless sensor networks with the objective of minimising the time to send event data to the base station. We focus on sensors with a limited cache and take into account both node and transmission failures. We present two cache strategies and analyse the performance of these strategies for specific networks. For the case without node failures we give the expected arrival time of event data at the base station for both a line and a 2D grid network. For the case with node failures we study the expected arrival time on two-dimensional networks through simulation, as well as the influence of the broadcast range
Prognostic value of discharge heart rate in acute heart failure patients: More relevant in atrial fibrillation?
Aims: The prognostic impact of heart rate (HR) in acute heart failure (AHF) patients is not well known especially in atrial fibrillation (AF) patients. The aim of the study was to evaluate the impact of admission HR, discharge HR, HR difference (admission-discharge) in AHF patients with sinus rhythm (SR) or AF on long- term outcomes. Methods: We included 1398 patients consecutively admitted with AHF between October 2013 and December 2014 from a national multicentre, prospective registry. Logistic regression models were used to estimate the association between admission HR, discharge HR and HR difference and one- year all-cause mortality and HF readmission. Results: The mean age of the study population was 72+/-12years. Of these, 594 (42.4%) were female, 655 (77.8%) were hypertensive and 655 (46.8%) had diabetes. Among all included patients, 745 (53.2%) had sinus rhythm and 653 (46.7%) had atrial fibrillation. Only discharge HR was associated with one year all-cause mortality (Relative risk (RR)=1.182, confidence interval (CI) 95% 1.024-1.366, p=0.022) in SR. In AF patients discharge HR was associated with one year all cause mortality (RR=1.276, CI 95% 1.115-1.459, p</=0.001). We did not observe a prognostic effect of admission HR or HRD on long-term outcomes in both groups. This relationship is not dependent on left ventricular ejection fraction. Conclusions: In AHF patients lower discharge HR, neither the admission nor the difference, is associated with better long-term outcomes especially in AF patients
RELATIONSHIP BETWEEN REDNESS INDEX OF SOIL AND CARBON STOCK OF AERIAL BIOMASS IN CERRADO VEGETATION
A varia\ue7\ue3o da cor do solo \ue9 uma resposta relacionada
principalmente a sua composi\ue7\ue3o f\uedsica, qu\uedmica,
biol\uf3gica e mineral\uf3gica. O sistema de cores de Munsell
\ue9 baseado na cor de forma objetiva, em que, atrav\ue9s dela
\ue9 poss\uedvel avaliar diversos fatores do solo, como a
presen\ue7a de \uf3xidos de ferro, granulometria e material
org\ue2nico. O objetivo do trabalho foi realizar uma
rela\ue7\ue3o e identifica\ue7\ue3o entre o \uedndice de
avermelhamento (IAV) com o estoque de carbono presente na parte
a\ue9rea da vegeta\ue7\ue3o de Cerrado. O trabalho foi realizado
em sete munic\uedpios do Oeste Baiano, em \ue1reas nativas de
Cerrado, nas fitofisionomias: Floresta de Galeria, Cerrad\ue3o,
Cerrado stricto sensu e Campo Sujo. A determina\ue7\ue3o da cor foi
efetuada no campo em amostras de solo \ufamido, empregando-se a
caderneta de Munsell. A partir da avalia\ue7\ue3o da matiz, valor e
croma, foi calculado o \uedndice de avermelhamento (IAV). A
estimativa do estoque de carbono acima do solo foi realizada a partir
dos compartimentos: tronco e galhos, tanto das \ue1rvores vivas
quanto \ue1rvores mortas, atrav\ue9s de uma equa\ue7\ue3o
alom\ue9trica desenvolvida para o Cerrado. O \uedndice de
avermelhamento da cor do solo na camada de 0,00 a 0,20 m possui uma
rela\ue7\ue3o diretamente proporcional e significativa com o
estoque de carbono da biomassa a\ue9rea da vegeta\ue7\ue3o de
Cerrado, podendo ser extrapolado o c\ue1lculo do estoque de carbono
(EC) pelo valor do \uedndice de avermelhamento (IAV) do solo pela
equa\ue7\ue3o [EC = 0,4936 \ub7 IAV + 4,2286 (-1,5%)]. A
praticidade pela coleta dos dados de IAV, atrav\ue9s da carta de
Munsell e a confiabilidade do ajuste, dado pelo erro residual menor do
que 5%, faz com que esta rela\ue7\ue3o possa ser utilizada para
fins acad\ueamicos e coorporativos em estima\ue7\ue3o dos
estoques de carbono para aplica\ue7\ue3o em manejos florestais e
ambientais. A varia\ue7\ue3o de EC entre as fitofisionomias
estudadas faz-se, principalmente, pela distinta densidade de
indiv\uedduos arb\uf3reos por hectare. A varia\ue7\ue3o do IAV
nas \ue1reas estudadas \ue9 devido \ue0 mat\ue9ria
org\ue2nica acumulada na superf\uedcie do solo, ao conte\ufado
mineral e \ue0 capacidade de drenagem, segundo infer\ueancias da
literatura, refletindo assim nas distintas cores do solo nas
fitofisionomias estudadas.The color variety of soil is response of its physical, chemical,
biological and mineralogical composition. The Munsell color system is
based on an objective color evaluation in which it is possible to
evaluate different color soil factors such as the presence of iron
oxides, particle size, and accumulated organic material. The objective
of this study was to identify the relation between the redness index
(IAV) of soil and the amount of carbon content present in the aerial
part of Cerrado vegetation. The study was conducted in seven cities in
western Bahia state, in native areas of Cerrado. The determination o
soil color was made in the field, with moist soil samples, using the
Munsell color chart. From the evaluation of hue, value and chroma, the
redness index (IAV) was calculated. The estimation of carbon stock
above ground was carried out from: trunk and branches, both living and
dead trees by the allometric equation developed in Cerrado areas. The
redness index of soil, from the layer 0.00 to 0.20 m, has a significant
and directly proportional relationship with the carbon stock of above
ground biomass of Cerrado vegetation. This may be extrapolated to
calculate the carbon stock (EC) by the redness index (IAV) of soil by
the equation [EC = 0.4936 \ub7 IAV + 4.2286 (-1.5%)]. The
practicality of sampling of data by IAV with Munsell chart, and the
reliability of data fit by results of residual error less than 5%, make
that this relationship may be used for academic and corporative in
carbon stocks estimation for use in forest and environmental
management. The EC variation between the studied physiognomies is
mainly by distinct density of tree individuals per hectare. The
variation of IAV in studied areas is due to the accumulated organic
matter on the soil surface, the mineral content and drainage capacity,
according to inferences of literature, and this reflecting the
different colors of soil in the studied phytophysiognomies
ANATOMICAL COMPARISON OF POPULAR BRACATINGA ( Mimosa scabrella Bentham) VARIETIES OF WOOD
Esta pesquisa objetivou comparar anatomicamente a madeira das
variedades populares de bracatinga ( Mimosa scabrella Bentham):
bracatinga-branca, bracatinga-vermelha e bracatinga-argentina. Para a
realiza\ue7\ue3o deste trabalho, foram coletadas \ue1rvores com
idades entre 6 e 7 anos, provenientes de \ue1reas pertencentes \ue0
Embrapa Florestas, localizadas no munic\uedpio de Colombo-PR, Brasil
cujo material bot\ue2nico coletado foi identificado e descrito. Foram
obtidas amostras de madeira com casca para a caracteriza\ue7\ue3o.
As an\ue1lises evidenciaram que n\ue3o h\ue1 diferen\ue7as
estat\uedsticas entre os elementos anat\uf4micos do lenho da
bracatingabranca e da bracatinga-vermelha, indicando que as
diferencia\ue7\uf5es que tais plantas recebem por causa da a cor da
madeira n\ue3o est\ue3o presentes no aspecto anat\uf4mico. As
duas variedades populares, tamb\ue9m conhecidas como
bracatinga-comum, diferiram estatisticamente entre si com
rela\ue7\ue3o \ue0 bracatinga-argentina, quanto ao di\ue3metro
tangencial dos poros, quantidade de poros/mm2, comprimento dos
elementos vasculares, di\ue2metro das c\ue9lulas
par\ueanquimo-axiais, largura dos raios unisseriados e
multisseriados. Os resultados podem ser considerados um importante
aux\uedlio na distin\ue7\ue3o das variedades populares de
bracatinga-comum e bracatingaargentina em variedades bot\ue2nicas.The main objective of this research was to compare anatomical wood
characteristics of the popular varieties of Mimosa scabrella Bentham
known as bracatinga-branca, bracatinga-vermelha and
bracatingaargentina. The material used in this work was collected from
6 to 7 years old trees of the popular varieties from areas located in
Colombo municipality, State of Paran\ue1, owned by Embrapa Florestas.
Botanic for anatomical characterization of wood material was identified
and described. Results did not show differences of anatomical
characteristics between the bracatinga-branca and bracatinga-vermelha.
The bracatingabranca and bracatinga-vermelha showed statistically
differences in relation to bracatinga-argentina to average values in
pores tangential diameter, pores quantity per square mm, vessel
elements individual length, axial parenchyma cells diameter,
unisseriate and multisseriate rays width. In conclusion, the
observations contribute to a better understanding of the differences
showed by the popular varieties
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