4,514 research outputs found
Kwashiorkor and Intellectual Development
Forty Cape Coloured children who had been hospitalized for kwashiorkor in infancy were compared with their siblings on an intelligence test battery at the 10th year of follow-up. No significant differences in intelligence test performance were noted. A significant discrepancy between the intelligence test score and the drawing score in late-onset cases may be due to affective factors. The groups were similar in terms of height, weight and head circumference. The differences between well nourished and poorly nourished groups found by previous investigators may be accounted for by the independent operation of non-nutritive variables in the social and emotional environment. The use of intrafamilial controls in the present study minimized these influences, as well as possible genetic factors in intellectual development.S. Afr. Med. J., 45, 1413 (1971
Kwashiorkor: A Prospective Ten-Year Follow-up Study
The physical status of 123 cases of kwashiorkor, followed up longitudinally for 10 years, was analysed. Their status was compared with that of 97 control siblings who had never suffered from kwashiorkor, but who had grown up under the same environmental conditions as the expatients. It was found that 10 years after the episode of kwashiorkor about half of the children had reached international growth standards in weight and height, thus demonstrating the capacity for complete physical recovery. No significant anthropometric or biochemical differences were found between ex-patients and control siblings at the 10-year follow-up examination. This is adequate proof that the episode of kwashiorkor per se cannot be held responsible for the growth retardation that occurred in some of the children. The children who were most severely retarded in weight and height on admission tended to remain the most severely retarded in growth after 10 years. The children who were the oldest on admission were more retarded in weight after 10 years than the children who were admitted at a younger age. Although these facts may imply that the severity and possibly the duration of the malnutrition episode adversely affected subsequent physical growth, a high current incidence of hypoalbuminaemia was found in both ex-patients and control siblings, indicating continuing malnutrition, the effects of which cannot be separated from possible deleterious effects of thil original malnutrition episode. Linear growth also correlated significantly with midparental height and a complex of adverse social circumstances.Failure to attain international growth standards in some of the children was therefore apparently due to a combination of factors and at present it is impossible to distinguish any single one of these as being more important than the others. Since about half of the children did reach adequate growth standards despite their poor living conditions, it is clearly worth while to treat every case of malnutrition. At the same time public health supervision and preventative social measures should be greatly increased to protect the child population throughout the growing period. S. Afr. Med. J., 45, 1427 (1971
Dynamic walking features and improved walking performance in multiple sclerosis patients treated with fampridine (4-aminopyridine)
Background: Impaired walking capacity is a frequent confinement in Multiple Sclerosis (MS). Patients are affected by limitations in coordination, walking speed and the distance they may cover. Also abnormal dynamic walking patterns have been reported, involving continuous deceleration over time. Fampridine (4-aminopyridine), a potassium channel blocker, may improve walking in MS. The objective of the current study was to comprehensively examine dynamic walking characteristics and improved walking capacity in MS patients treated with fampridine. Methods: A sample of N = 35 MS patients (EDSS median: 4) underwent an electronic walking examination prior to (Time 1), and during treatment with fampridine (Time 2). Patients walked back and forth a distance of 25 ft for a maximum period of 6 min (6-minute 25-foot-walk). Besides the total distance covered, average speed on the 25-foot distance and on turns was determined separately for each test minute, at Time 1 and Time 2. Results: Prior to fampridine administration, 27/35 patients (77 %) were able to complete the entire 6 min of walking, while following the administration, 34/35 patients (97 %) managed to walk for 6 min. In this context, walking distance considerably increased and treatment was associated with faster walking and turning across all six test minutes (range of effect sizes: partial eta squared = .34-.72). Importantly, previously reported deceleration across test minutes was consistently observable at Time 1 and Time 2. Discussion: Fampridine administration is associated with improved walking speed and endurance. Regardless of a treatment effect of fampridine, the previously identified, abnormal dynamic walking feature, i.e. the linear decline in walking speed, may represent a robust feature. Conclusions: The dynamic walking feature might hence be considered as a candidate for a new outcome measure in clinical studies involving interventions other than symptomatic treatment, such as immune-modulating medication. Trial registration: DRKS00009228 (German Clinical Trials Register). Date obtained: 25.08.2015
Two-neutron knockout from neutron-deficient Ar, S, and Si
Two-neutron knockout reactions from nuclei in the proximity of the proton
dripline have been studied using intermediate-energy beams of neutron-deficient
Ar, S, and Si. The inclusive cross sections, and also the
partial cross sections for the population of individual bound final states of
the Ar, S and Si knockout residues, have been determined
using the combination of particle and -ray spectroscopy. Similar to the
two-proton knockout mechanism on the neutron-rich side of the nuclear chart,
these two-neutron removal reactions from already neutron-deficient nuclei are
also shown to be consistent with a direct reaction mechanism.Comment: Phys. Rev. C, rapid communication, in pres
Similarities between structural distortions under pressure and chemical doping in superconducting BaFe2As2
The discovery of a new family of high Tc materials, the iron arsenides
(FeAs), has led to a resurgence of interest in superconductivity. Several
important traits of these materials are now apparent, for example, layers of
iron tetrahedrally coordinated by arsenic are crucial structural ingredients.
It is also now well established that the parent non-superconducting phases are
itinerant magnets, and that superconductivity can be induced by either chemical
substitution or application of pressure, in sharp contrast to the cuprate
family of materials. The structure and properties of chemically substituted
samples are known to be intimately linked, however, remarkably little is known
about this relationship when high pressure is used to induce superconductivity
in undoped compounds. Here we show that the key structural features in
BaFe2As2, namely suppression of the tetragonal to orthorhombic phase transition
and reduction in the As-Fe-As bond angle and Fe-Fe distance, show the same
behavior under pressure as found in chemically substituted samples. Using
experimentally derived structural data, we show that the electronic structure
evolves similarly in both cases. These results suggest that modification of the
Fermi surface by structural distortions is more important than charge doping
for inducing superconductivity in BaFe2As2
Following autophagy step by step
Autophagy is an evolutionarily conserved lysosomal degradation route for soluble components of the cytosol and organelles. There is great interest in identifying compounds that modulate autophagy because they may have applications in the treatment of major diseases including cancer and neurodegenerative disease. Hundeshagen and colleagues describe this month in BMC Biology a screening assay based on flow cytometry that makes it possible to track distinct steps in the autophagic process and thereby identify novel modulators of autophagy
Olfactory and solitary chemosensory cells: two different chemosensory systems in the nasal cavity of the American alligator, Alligator mississippiensis
<p>Abstract</p> <p>Background</p> <p>The nasal cavity of all vertebrates houses multiple chemosensors, either innervated by the Ist (olfactory) or the Vth (trigeminal) cranial nerve. Various types of receptor cells are present, either segregated in different compartments (e.g. in rodents) or mingled in one epithelium (e.g. fish). In addition, solitary chemosensory cells have been reported for several species. Alligators which seek their prey both above and under water have only one nasal compartment. Information about their olfactory epithelium is limited. Since alligators seem to detect both volatile and water-soluble odour cues, I tested whether different sensory cell types are present in the olfactory epithelium.</p> <p>Results</p> <p>Electron microscopy and immunocytochemistry were used to examine the sensory epithelium of the nasal cavity of the American alligator. Almost the entire nasal cavity is lined with olfactory (sensory) epithelium. Two types of olfactory sensory neurons are present. Both types bear cilia as well as microvilli at their apical endings and express the typical markers for olfactory neurons. The density of these olfactory neurons varies along the nasal cavity. In addition, solitary chemosensory cells innervated by trigeminal nerve fibres, are intermingled with olfactory sensory neurons. Solitary chemosensory cells express components of the PLC-transduction cascade found in solitary chemosensory cells in rodents.</p> <p>Conclusion</p> <p>The nasal cavity of the American alligator contains two different chemosensory systems incorporated in the same sensory epithelium: the olfactory system proper and solitary chemosensory cells. The olfactory system contains two morphological distinct types of ciliated olfactory receptor neurons.</p
Extending colonic mucosal microbiome analysis - Assessment of colonic lavage as a proxy for endoscopic colonic biopsies
This study was supported through GI Research funds and MRC Grant Ref: MR/M00533X/1 to GH.Peer reviewedPublisher PD
Generalized Uncertainty Principle, Modified Dispersion Relation and Barrier penetration by a Dirac particle
We have studied the energy band structure of a Dirac particle in presence of
a generalised uncertainty principle (GUP). We start from defining a modified
momentum operator and derive corresponding modified dispersion relation (MDR)
and GUP. Apart from the forbidden band within the range , being the
mass of the particle, we find the existence of additional forbidden bands at
the both ends of the spectrum. Such band structure forbids a Dirac particle to
penetrate a potential step of sufficient height (, being Planck
energy). This is also true for massless particle. Unlike the relativistic case,
a massless particle also can reflect from a barrier of sufficient height.
Finally we discuss about the Klein's paradox in presence of the GUP.Comment: 10 pages, 7 figures, LaTe
Composite Fermion Metals from Dyon Black Holes and S-Duality
We propose that string theory in the background of dyon black holes in
four-dimensional anti-de Sitter spacetime is holographic dual to conformally
invariant composite Dirac fermion metal. By utilizing S-duality map, we show
that thermodynamic and transport properties of the black hole match with those
of composite fermion metal, exhibiting Fermi liquid-like. Built upon
Dirac-Schwinger-Zwanziger quantization condition, we argue that turning on
magnetic charges to electric black hole along the orbit of Gamma(2) subgroup of
SL(2,Z) is equivalent to attaching even unit of statistical flux quanta to
constituent fermions. Being at metallic point, the statistical magnetic flux is
interlocked to the background magnetic field. We find supporting evidences for
proposed holographic duality from study of internal energy of black hole and
probe bulk fermion motion in black hole background. They show good agreement
with ground-state energy of composite fermion metal in Thomas-Fermi
approximation and cyclotron motion of a constituent or composite fermion
excitation near Fermi-point.Comment: 30 pages, v2. 1 figure added, minor typos corrected; v3. revised
version to be published in JHE
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