106 research outputs found
Accumulation of chromium metastable atoms into an Optical Trap
We report the fast accumulation of a large number of metastable 52Cr atoms in
a mixed trap, formed by the superposition of a strongly confining optical trap
and a quadrupolar magnetic trap. The steady state is reached after about 400
ms, providing a cloud of more than one million metastable atoms at a
temperature of about 100 microK, with a peak density of 10^{18} atoms.m^{-3}.
We have optimized the loading procedure, and measured the light shift of the
5D4 state by analyzing how the trapped atoms respond to a parametric
excitation. We compare this result to a theoretical evaluation based on the
available spectroscopic data for chromium atoms.Comment: 7 pages, 5 Figure
Creating Ioffe-Pritchard micro-traps from permanent magnetic film with in-plane magnetization
We present designs for Ioffe-Pritchard type magnetic traps using planar
patterns of hard magnetic material. Two samples with different pattern designs
were produced by spark erosion of 40 m thick FePt foil. The pattern on the
first sample yields calculated axial and radial trap frequencies of 51 Hz and
6.8 kHz, respectively. For the second sample the calculated frequencies are 34
Hz and 11 kHz. The structures were used successfully as a magneto-optical trap
for Rb and loaded as a magnetic trap. A third design, based on
lithographically patterned 250 nm thick FePt film on a Si substrate, yields an
array of 19 traps with calculated axial and radial trap frequencies of 1.5 kHz
and 110 kHz, respectively.Comment: 8 pages, 5 figures Revised and accepted for EPJD, improved picture
MONITORING OXIDATIVE STRESS ACROSS WORSENING CHILD PUGH CLASS OF CIRRHOSIS
, , ) nmol/l} and a significant decrease in levels of , ) U/gm Hb}, , ) U/ gm , ) mmol/ gm Hb}. CONCLUSIONS: Oxidative stress is associated with the development and progression of cirrhosis
The BIOMEX experiment on-board the International Space Station: limits of life and detection of biomarkers after exposure to space- and to Mars-like conditions
To explore the limits of terrestrial life in space, we have to understand the effects of the space environment on unprotected biological and chemical material, and on the degradation of organic molecules or biomarkers. The exposure platform EXPOSE-R2 on the ISS offer a suitable facility for the exposure of samples of the astrobiological model lichen Circinaria gyrosa, included in the BIOMEX experiment (Biology and Mars Experiment, ESA). During 18 months (2014-2016), the lichens lived in a latent state at space and at simulated Mars-like conditions, to study Marsâ habitability and resistance to space conditions. After the return of the samples in June 2016, initial analysis showed rapid recovery of photosystem II (PSII) activity in the samples exposed exclusively to space vacuum and to Mars-like atmosphere. In contrast, the samples directly exposed to solar UV radiation showed a slow and a lower recovery, in reference to their observed original activity. This tendency was corroborated with the complementary morphological/ultrastructural and biomolecular analyses. Complementary, the biogeochemical variations have been examined with Raman spectroscopy to assess the possible degradation of cell surfaces and pigments which were in contact with terrestrial rocks, and Martian analogue regolith. Identification of the biomarker whewellite (calcium oxalate) and other organic compounds and mineral products of the biological activity of Circinaria gyrosa were detected by Raman Laser. These findings contribute to answer questions on the habitability of Mars, the likelihood of the Lithopanspermia Hypothesis, the capability to detect biomolecules exposed to an extraterrestrial environment by life-detection instruments and will be of relevance for planetary protection issues
Triangulations and Severi varieties
We consider the problem of constructing triangulations of projective planes
over Hurwitz algebras with minimal numbers of vertices. We observe that the
numbers of faces of each dimension must be equal to the dimensions of certain
representations of the automorphism groups of the corresponding Severi
varieties. We construct a complex involving these representations, which should
be considered as a geometric version of the (putative) triangulations
Edge-Graph Diameter Bounds for Convex Polytopes with Few Facets
We show that the edge graph of a 6-dimensional polytope with 12 facets has
diameter at most 6, thus verifying the d-step conjecture of Klee and Walkup in
the case of d=6. This implies that for all pairs (d,n) with n-d \leq 6 the
diameter of the edge graph of a d-polytope with n facets is bounded by 6, which
proves the Hirsch conjecture for all n-d \leq 6. We show this result by showing
this bound for a more general structure -- so-called matroid polytopes -- by
reduction to a small number of satisfiability problems.Comment: 9 pages; update shortcut constraint discussio
Health promoting settings in primary health care - "hÀlsotorg": an implementation analysis
Background
Sweden, like many other western countries, faces increasing rates of lifestyle
related diseases and corresponding rise in costs for health care. To meet these
challenges, a number of efforts have been introduced at different societal
levels. One such effort is "HĂ€lsotorg" (HS). HS is a new health promotion
setting that emerged in collaboration between the Swedish County Councils and
Apoteket AB, a state-owned pharmacy company. HS's overall aim was to improve
population health and facilitate inhabitants' responsibility for self-care. A
new National Public Health Policy, introduced in 2008, emphasizes more focus on
individual's needs and responsibility as well as strong need for county
councils to provide supportive environment for individual-centred health
services and increased health literacy among the population. In light of this
policy, there is a need to examine existing settings that can provide
supportive environment for individuals at community level. The aim of this
study was to explore HS's policy implementation at local level and analyse HS's
activities, in order to provide a deeper understanding of HS's potential as a
health promoting setting.
Methods
Materials included a survey and key documents related to the development and
nature of HS on local and national levels. A policy analysis inspired by Walt
and Gilson was used in data analysis. In addition, an analysis using the
principles of health promotion in relation to HS policy process and activities
was also carried out.
Results
The analysis illuminated strengths and weaknesses in the policy process, its
actors, contextual factors and activities. The health communication approach in
the analysed documents contained health promoting intentions but the health
promoting approach corresponding to a health promoting setting was neither
apparent nor shared among the stakeholders. This influenced the interpretation
and implementation of HS negatively.
Conclusions
The analysis indicates that HS has potential to be a valuable health promotion
setting for both population and individuals, given the strong intentions for a
health and empowerment building approach that is expressed in the documents.
However, for a more sustainable implementation of HS, there is need for an in-
depth understanding of the health promotion approach among HS stakeholders
Planck Intermediate Results II: Comparison of SunyaevâZeldovich measurements from Planck and from the Arcminute Microkelvin Imager for 11 galaxy clusters
A comparison is presented of SunyaevâZeldovich measurements for 11 galaxy clusters as obtained by Planck and by the ground-based interferom- eter, the Arcminute Microkelvin Imager. Assuming a universal spherically-symmetric Generalised Navarro, Frenk & White (GNFW) model for the cluster gas pressure profile, we jointly constrain the integrated Compton-Y parameter (Y500) and the scale radius (Ξ500) of each cluster. Our resulting constraints in the Y500 â Ξ500 2D parameter space derived from the two instruments overlap significantly for eight of the clusters, although, overall, there is a tendency for AMI to find the SunyaevâZeldovich signal to be smaller in angular size and fainter than Planck. Significant discrepancies exist for the three remaining clusters in the sample, namely A1413, A1914, and the newly-discovered Planck cluster PLCKESZ G139.59+24.18. The robustness of the analysis of both the Planck and AMI data is demonstrated through the use of detailed simulations, which also discount confusion from residual point (radio) sources and from diffuse astrophysical foregrounds as possible explanations for the discrepancies found. For a subset of our cluster sample, we have investigated the dependence of our results on the assumed pressure profile by repeating the analysis adopting the best-fitting GNFW profile shape which best matches X-ray observations. Adopting the best-fitting profile shape from the X-ray data does not, in general, resolve the discrepancies found in this subset of five clusters. Though based on a small sample, our results suggest that the adopted GNFW model may not be sufficiently flexible to describe clusters universally
Planck intermediate results I : Further validation of new Planck clusters with XMM-Newton
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