1,987 research outputs found
Heating and atom loss during upward ramps of Feshbach resonance levels in Bose-Einstein condensates
The production of pairs of fast atoms leads to a pronounced loss of atoms
during upward ramps of Feshbach resonance levels in dilute Bose-Einstein
condensates. We provide comparative studies on the formation of these bursts of
atoms containing the physical predictions of several theoretical approaches at
different levels of approximation. We show that despite their very different
description of the microscopic binary physics during the passage of a Feshbach
resonance, all approaches lead to virtually the same prediction on the total
loss of condensate atoms, provided that the ramp of the magnetic field strength
is purely linear. We give the reasons for this remarkable insensitivity of the
remnant condensate fraction to the microscopic physical processes and compare
the theoretical predictions with recent Feshbach resonance crossing experiments
on 23Na and 85Rb.Comment: 12 pages, 7 eps figures; final versio
Common aetiology for diverse language skills in 41/2-year-old twins
Multivariate genetic analysis was used to examine the genetic and environmental aetiology of the interrelationships of diverse linguistic skills. This study used data from a large sample of 4 1/2 year-old twins who were tested on measures assessing articulation, phonology, grammar, vocabulary, and verbal memory. Phenotypic analysis suggested two latent factors: articulation (2 measures) and general language (the remaining 7), and a genetic model incorporating these factors provided a good fit to the data. Almost all genetic and shared environmental influences on the 9 measures acted through the two latent factors. There was also substantial aetiological overlap between the two latent factors, with a genetic correlation of 0·64 and shared environment correlation of 1·00. We conclude that to a large extent, the same genetic and environmental factors underlie the development of individual differences in a wide range of linguistic skills
Antibodies to glycans dominate the host response to schistosome larvae and eggs: Is their role protective or subversive?
Multiple exposures of chimpanzees to the radiation-attenuated schistosome vaccine provoked a strong parasite-specific cellular and humoral immune response. Specific IgM and IgG were directed mainly against glycans on antigens released by cercariae; these were also cross-reactive with soluble antigens from larvae, adult worms, and eggs. Egg deposition was the major antigenic stimulus after challenge of vaccinated and control chimpanzees with normal parasites, eliciting strong antiglycan responses to egg secretions. Glycan epitopes recognized included LacdiNAc, fucosylated LacdiNAc, LewisX (weakly), and those on keyhole limpet hemocyanin. Antibodies to peptide epitopes became prominent only during the chronic phase of infection, as glycan-specific IgM and IgG decreased. Because of their intensity and cross-reactivity, the antiglycan responses resulting from infection could be a smoke screen to subvert the immune system away from more vulnerable larval peptide epitopes. Their occurrence in humans might explain the long time required for antischistosome immunity to build up after infection
Women with epilepsy have poorer knowledge and skills in child rearing than women without epilepsy
AbstractEpilepsy can negatively impact the child rearing ability of women because of the risk related to seizures, adverse effects of antiepileptic drugs and psychosocial factors.ObjectiveTo compare the child rearing knowledge (CRK) and practices (CRP) of women with epilepsy (WWE) with a matched group of women without epilepsy (WWoE).MethodologyThis study was carried out in the Kerala registry of epilepsy and pregnancy (KREP) at Sree Chitra Tirunal Institute for Medical Sciences and Technology in India. We prospectively recruited 100 WWE in first trimester of pregnancy from the KREP and 93 age, education and parity matched pregnant WWoE from the antenatal clinics of the Government medical college Thiruvananthapuram. Their child rearing knowledge (CRK) and practices (CRP) were evaluated with previously validated protocols. The CRK was assessed at the time of enrolment (first trimester of pregnancy) and the CRP was assessed when the baby was three to four months old.ResultsEighty-eight women each from WWE and WWoE had completed the study, over a period of three years. WWE and WWoE were comparable for age (25.56±4.66 and 25.69±4.49 years), pregnancy outcome and type of delivery. WWE had excess fetal loss and postnatal seizures. The CRK was significantly lower for WWE (23.53±6.3) than for WWoE (26.08±5.3). The CRP was significantly lower for WWE (25.01±9.6) than for WWoE (28.14±7.1). WWE performed poorer in all domains of child rearing practices namely feeding, growth and development, cleaning and protection and infant stimulation. Poorer CRK was strongly associated with lower CRP while several demographic and economic characteristics were not relevant. WWE fared poorer in feeding and nursing their babies in spite of having the right knowledge in that domain. This may be due to several undisclosed concerns and social dynamics that need to be addressed while preparing any interventions
Solitons in Seiberg-Witten Theory and D-branes in the Derived Category
We analyze the "geometric engineering" limit of a type II string on a
suitable Calabi-Yau threefold to obtain an N=2 pure SU(2) gauge theory. The
derived category picture together with Pi-stability of B-branes beautifully
reproduces the known spectrum of BPS solitons in this case in a very explicit
way. Much of the analysis is particularly easy since it can be reduced to
questions about the derived category of CP1.Comment: 20 pages, LaTex2
Diencephalic syndrome in child with NF-1 and hypothalamic tumour
We describe a 20 month old boy with neuro-fibromatosis type 1 (NF-1) who presented with diencephalic syndrome due to a large hypothalamic tumour and developed massive necrosis after chemotherapy associated with severe encephalopathy.
We report this case because of rapid progression of presenting symptoms, the rare association with diencephalic syndrome in NF-1, chemotherapy induction of “tumour lysis” associated with encephalopathy, reduced toxicity and sustained improvement with vinblastine, the therapeutic benefit of tumour drainage signs of resolution of diencephalic syndrome and then restoration of visual movements and function associated with developmental recovery. The presentation of tumour in this case highlights the importance for parents and doctor to known and recognize the precocious symptoms, and justifies sharing these features as an indicator with parents and GP’s to justify early / urgent specialist review, particularly in the first two years of life. Early recognition could offer a reduced risk of brain injury
On the derived category of a regular toric scheme
Let X be a quasi-compact scheme, equipped with an open covering by affine
schemes. A quasi-coherent sheaf on X gives rise, by taking sections over the
covering sets, to a diagram of modules over the various coordinate rings. The
resulting "twisted" diagram of modules satisfies a certain gluing condition,
stating that the data is compatible with restriction to smaller open sets.
In case X is a regular toric scheme over an arbitrary commutative ring, we
prove that the unbounded derived category D(X) of quasi-coherent sheaves on X
can be obtained from a category of twisted diagrams which do not necessarily
satisfy any gluing condition by inverting maps which induce homology
isomorphisms on hyper-derived inverse limits. Moreover, we given an explicit
construction of a finite set of weak generators for the derived category.
For example, if X is projective n-space then D(X) is generated by n+1
successive twists of the structure sheaf; the present paper gives a new
homotopy-theoretic proof of this classical result.
The approach taken uses the language of model categories, and the machinery
of Bousfield-Hirschhorn colocalisation. The first step is to characterise
colocal objects; these turn out to be homotopy sheaves in the sense that chain
complexes over different open sets agree on intersections up to
quasi-isomorphism only. In a second step it is shown that the homotopy category
of homotopy sheaves is the derived category of X.Comment: 35 pages; diagrams need post script viewer or PDF v2: removed
"completeness" assumption, changed titl
Determination of the Elastic Constants of Thermally Modified Beech by Ultrasound and Static Tests Coupled with 3D Digital Image Correlation
Performance of Hamamatsu 64-anode photomultipliers for use with wavelength--shifting optical fibres
Hamamatsu R5900-00-M64 and R7600-00-M64 photomultiplier tubes will be used
with wavelength--shifting optical fibres to read out scintillator strips in the
MINOS near detector. We report on measurements of the gain, efficiency,
linearity, crosstalk, and dark noise of 232 of these PMTs, of which 219 met
MINOS requirements.Comment: 15 pages, 12 figures. Accepted by Nucl. Inst. Meth.
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