852 research outputs found
Breast-feeding and weaning practices in Venda, 1990
A stratified randOlll cluster survey, using a structured interview schedule, was performed to determine the prevalence, frequency and duration of breast-feeding alllong Venda mothers as well as the foods that Venda children commonly ate in their first 2 years of life. Nearly all children under 2 years old were being breast-fed and virtually all of these were fed on demand. Approximately 60% of infants under 3 months of age and virtually all others under 2 years old received supplementary foods daily. A further 30% ofinfants under the age of 3 months were given supplementary water daily. Forty per cent of infants under 3 months old and virtually all in the other age groups were given carbohydrates daily. Protein foods, vitamin mineral and high-energy sources were given less frequently. Only 12% in the 6 - 11-month age group and 21% in the 12 - 23-111onth age group received a balanced diet daily. A significant proportion of children in all age groups received only carbohydrates over and above breast-milk. Traditional xnixes were infrequently given. More research is needed to assess actual breast-milk production by mothers whose children are being fed supplelllentary foods. The effect of socio-economic status on weaning practices and that of weaning practices on nutritional status need to be investigated. Food supplelllentation and nutrition education progralllllles need to be intensified
Large scale flow effects, energy transfer, and self-similarity on turbulence
The effect of large scales on the statistics and dynamics of turbulent
fluctuations is studied using data from high resolution direct numerical
simulations. Three different kinds of forcing, and spatial resolutions ranging
from 256^3 to 1024^3, are being used. The study is carried out by investigating
the nonlinear triadic interactions in Fourier space, transfer functions,
structure functions, and probability density functions. Our results show that
the large scale flow plays an important role in the development and the
statistical properties of the small scale turbulence. The role of helicity is
also investigated. We discuss the link between these findings and
intermittency, deviations from universality, and possible origins of the
bottleneck effect. Finally, we briefly describe the consequences of our results
for the subgrid modeling of turbulent flows
Spin-polarized oxygen hole states in cation deficient La(1-x)CaxMnO(3+delta)
When holes are doped into a Mott-Hubbard type insulator, like lightly doped
manganites of the La(1-x)CaxMnO3 family, the cooperative Jahn-Teller
distortions and the appearance of orbital ordering require an arrangement of
Mn(3+)/Mn(4+) for the establishment of the insulating canted antiferromagnetic
(for x<=0.1), or of the insulating ferromagnetic (for 0.1<x<= 0.2) ground
state. In the present work we provide NMR evidence about a novel and at the
same time puzzling effect in La(1-x)CaxMnO(3+delta) systems with cation
deficience. We show that in the low Ca-doping regime, these systems exhibit a
very strong hyperfine field at certain La nuclear sites, which is not present
in the stoichiometric compounds. Comparison of our NMR results with recent
x-ray absorption data at the Mn K edge, suggests the formation of a
spin-polarized hole arrangement on the 2p oxygen orbitals as the origin of this
effect.Comment: 10 pages, 4 Figures, submitted to PR
Seesaw mechanism, baryon asymmetry and neutrinoless double beta decay
A simplified but very instructive analysis of the seesaw mechanism is here
performed. Assuming a nearly diagonal Dirac neutrino mass matrix, we study the
forms of the Majorana mass matrix of right-handed neutrinos, which reproduce
the effective mass matrix of left-handed neutrinos. As a further step, the
important effect of a non diagonal Dirac neutrino mass matrix is explored. The
corresponding implications for the baryogenesis via leptogenesis and for the
neutrinoless double beta decay are reviewed. We propose two distinct models
where the baryon asymmetry is enhanced.Comment: 21 pages, RevTex. Revise
Polymer Induced Bundling of F-actin and the Depletion Force
The inert polymer polyethylene glycol (PEG) induces a "bundling" phenomenon
in F-actin solutions when its concentration exceeds a critical onset value C_o.
Over a limited range of PEG molecular weight and ionic strength, C_o can be
expressed as a function of these two variables. The process is reversible, but
hysteresis is also observed in the dissolution of the bundles, with ionic
strength having a large influence. Additional actin filaments are able to join
previously formed bundles. Little, if any, polymer is associated with the
bundle structure.
Continuum estimates of the Asakura-Oosawa depletion force, Coulomb repulsion,
and van der Waals potential are combined for a partial explanation of the
bundling effect and hysteresis. Conjectures are presented concerning the
apparent limit in bundle size
The STOP-BANG questionnaire and the risk of perioperative respiratory complications in urgent surgery patients: A prospective, observational study
Introduction
The STOP-BANG (SB) questionnaire, a tool originally proposed for identifying patients at risk of obstructive sleep apnoea, may also identify patients at increased risk of perioperative complications (when > 3). Perioperative complications, including respiratory ones, are more frequent in emergency surgery. This study aimed at evaluating whether the SB is predictive of perioperative respiratory complications in urgent surgery.
Methods
Consecutive adult patients admitted for an urgent surgery under general anaesthesia were included. The STOP-BANG questionnaire was completed before anaesthesia. Perioperative respiratory complications were prospectively recorded during surgery and in the postoperative care unit (PACU).
Results
One hundred and eighty-nine patients were included (women 46%, median age 60 [43–78] years old) of which 104 (55%) were SB+. Diabetes mellitus and arrhythmia were more frequent in the SB+ patients than in SB-. The ASA class was higher in SB+ patients compared with SB-, but type and duration of surgery were statistically similar. The incidence of respiratory complications was higher in SB+ patients both during surgery (21% versus 6%, P < 0.002) and in the PACU (57% versus 34%, P = 0.0015). Furthermore, SB+ patients had a prolonged length of hospital stay (6 [3–12] versus 4 [2–7] days, P = 0.0002). In a multivariate analysis, the STOP-BANG score was independently associated with respiratory complications (OR [CI 95%] = 1.44 [1.03–2.03], P = 0.03).
Conclusions
An elevated STOP-BANG score (≥ 3) is associated with an increased risk of perioperative respiratory complications and with prolonged length of stay in urgent surgery patients
Human muscle-derived CLEC14A-positive cells regenerate muscle independent of PAX7
Skeletal muscle stem cells, called satellite cells and defined by the transcription factor PAX7, are responsible for postnatal muscle growth, homeostasis and regeneration. Attempts to utilize the regenerative potential of muscle stem cells for therapeutic purposes so far failed. We previously established the existence of human PAX7-positive cell colonies with high regenerative potential. We now identified PAX7-negative human muscle-derived cell colonies also positive for the myogenic markers desmin and MYF5. These include cells from a patient with a homozygous PAX7 c.86-1G > A mutation (PAX7null). Single cell and bulk transcriptome analysis show high intra- and inter-donor heterogeneity and reveal the endothelial cell marker CLEC14A to be highly expressed in PAX7null cells. All PAX7-negative cell populations, including PAX7null, form myofibers after transplantation into mice, and regenerate muscle after reinjury. Transplanted PAX7neg cells repopulate the satellite cell niche where they re-express PAX7, or, strikingly, CLEC14A. In conclusion, transplanted human cells do not depend on PAX7 for muscle regeneration
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