134 research outputs found
SPH simulations of Shakura-Sunyaev instability at intermediate accretion rates
We show that a standard Shakura-Sunyaev accretion disc around a black hole
with an accretion rate lower than the critical Eddington limit does show the
instability in the radiation pressure dominated zone. We obtain this result
performing time-dependent simulations of accretion disks for a set of values of
the viscosity parameter and accretion rate. In particular we always find the
occurrence of the collapse of the disc: the instability develops always towards
a collapsed gas pressure dominated disc and not towards the expansion. This
result is valid for all initial configurations we tested. We find significant
convective heat flux that increases the instability development time, but is
not strong enough to inhibit the disc collapse. A physical explanation of the
lack of the expansion phase is proposed considering the role of the radial heat
advection. Our finding is relevant since it excludes the formation of the hot
comptonizing corona -often suggested to be present- around the central object
by the mechanism of the Shakura-Sunyaev instability. We also show that, in the
parameters range we simulated, accretion disks are crossed by significant
amplitude acoustic waves.Comment: 8 pages, 12 Postscript figures, uses natbib.sty, accepted for
publication in MNRA
Malt in Combination with Lactobacillus rhamnosus Increases Concentrations of Butyric Acid in the Distal Colon and Serum in Rats Compared with Other Barley Products but Decreases Viable Counts of Cecal Bifidobacteria123
Several substances, including glutamine and propionic acid but in particular butyric acid, have been proposed to be important for colonic health. β-Glucans lead to the formation of comparatively high amounts of butyric acid, and germinated barley foodstuff obtained from brewer’s spent grain (BSG), containing high amounts of β-glucans and glutamine, has been reported to reduce the inflammatory response in the colon of patients with ulcerative colitis. The present study examines how 3 barley products, whole grain barley, malt, and BSG, affect SCFA in the hindgut and serum of rats and whether the addition of Lactobacillus rhamnosus 271 to each of these diets would have further effects. Amino acids in plasma and the cecal composition of the microbiota were also analyzed. The butyric acid concentration in the distal colon and serum was higher in the malt groups than in the other groups as was the serum concentration of propionic acid. The concentrations of propionic and butyric acids were higher in the cecum and serum of rats given L. rhamnosus than in those not given this strain. The proportion of plasma glutamine and the cecal number of bifidobacteria were lower in the malt groups than in the other groups. L. rhamnosus decreased the number of cecal bifidobacteria, whereas plasma glutamine was unaffected. We conclude that malt together with L. rhamnosus 271 had greater effects on propionic and butyric acid concentrations in rats than the other barley products. This is interesting when developing food with effects on colonic health
Social anxiety symptoms in young children:Investigating the interplay of theory of mind and expressions of shyness
Children’s early onset of social anxiety may be associated with their social understanding, and their ability to express emotions adaptively. We examined whether social anxiety in 48-month-old children (N = 110; 54 boys) was related to: a) a lower level of theory of mind (ToM); b) a lower proclivity to express shyness in a positive way (adaptive); and c) a higher tendency to express shyness in a negative way (non-adaptive). In addition, we investigated to what extent children’s level of social anxiety was predicted by the interaction between ToM and expressions of shyness. Children’s positive and negative expressions of shyness were observed during a performance task. ToM was measured with a validated battery, and social anxiety was assessed using both parents’ reports on questionnaires. Socially anxious children had a lower level of ToM, and displayed more negative and less positive shy expressions. However, children with a lower level of ToM who expressed more positive shyness were less socially anxious. Additional results show that children who displayed shyness only in a negative manner were more socially anxious than children who expressed shyness only in a positive way and children who did not display any shyness. Moreover, children who displayed both positive and negative expressions of shyness were more socially anxious than children who displayed shyness only in a positive way. These findings highlight the importance of ToM development and socio-emotional strategies, and their interaction, on the early development of social anxiety
Pigeonpea nutrition and its improvement
Pigeonpea (Cajanus cajan [L.] Millsp.), known by several
vernacular and names such as red gram, tuar, Angola
pea. yellow dhal and oil dhal, is one of the major grain legume crops of
the tropics and sub-tropics. It is a crop of small holder dryland
fmmers because it can grow well under subsistence level of agriculture
and provides nutritive food, fodder, and fuel wood. It also improves soil
by fixing atmospheric nitrogen. India by far is the largest pigeonpea producer
it is consumed as decorticated split peas, popularly called as
'dhaL' In other countries, its consumption as whole dty and green
vegetable is popular. Its foliage is used as fodder and milling by-products
[onn an excellent feed for domestic animals. Pigeonpea seeds contain
about 20-22% protein and appreciable amounts of essential amino.acids
and minerals. DehuHing and boiling treatments of seeds get rid of the
most antinutritional factors as tannins and enzyme inhibitors. Seed
storage causes considerable losses in the quality of this legume. The seed
protein of pigeonpea has been successfully enhanced by breeding from
20-22% to 28-30%. Such lines also agronomically performed well and
have acceptable and color. The high-protein lines were found nutritionally superior to the cultivars because they would provide more
quantities of utilizable protein and sulfur-containing amino acids
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