1,185 research outputs found
An experiment to detect gravity at sub-mm scale with high-Q mechanical oscillators
Silicon double paddle oscillators are well suited for the detection of weak
forces because of their high Q factor (about 10^5 at room temperature). We
describe an experiment aimed at the detection of gravitational forces between
masses at sub-mm distance using such an oscillator. Gravitational excitation is
produced by a rotating aluminium disk with platinum segments. The force
sensitivity of this apparatus is about 10 fN at room temperature for 1000 s
averaging time at room temperature. The current limitations to detection of the
gravitational force are mentioned.Comment: 19 pages, to appear in Proceedings of the Tenth Marcel Grossmann
Meeting on General Relativity, edited by M. Novello, S. Perez-Bergliaffa and
R. Ruffini, World Scientific. Revision: portable format and revised figure
Collisional stability of a three-component degenerate Fermi gas
We report on the creation of a degenerate Fermi gas consisting of a balanced
mixture of atoms in three different hyperfine states of Li. This new system
consists of three distinguishable Fermions with different and tunable
interparticle scattering lengths , and . We are able
to prepare samples containing atoms in each state at a
temperature of about nK, which corresponds to . We
investigated the collisional stability of the gas for magnetic fields between 0
and 600 G and found a prominent loss feature at 130 G. From lifetime
measurements we determined three-body loss coefficients, which vary over nearly
three orders of magnitude
Quick X-ray microtomography using a laser-driven betatron source
Laser-driven X-ray sources are an emerging alternative to conventional X-ray
tubes and synchrotron sources. We present results on microtomographic X-ray
imaging of a cancellous human bone sample using synchrotron-like betatron
radiation. The source is driven by a 100-TW-class titanium-sapphire laser
system and delivers over X-ray photons per second. Compared to earlier
studies, the acquisition time for an entire tomographic dataset has been
reduced by more than an order of magnitude. Additionally, the reconstruction
quality benefits from the use of statistical iterative reconstruction
techniques. Depending on the desired resolution, tomographies are thereby
acquired within minutes, which is an important milestone towards real-life
applications of laser-plasma X-ray sources
LMOD3 gene variant in familial periodic hypersomnolence.
INTRODUCTION
Kleine-Levin syndrome (KLS) is a rare and debilitating disorder presenting with periodic hypersomnolence, cognitive, psychiatric and behavioral disturbances. In the absence of biomarkers it can be difficult to diagnose. Rare LMOD3 variants in a family and in seven sporadic cases with KLS have been described. Here we report a patient and her family with an unclassified, familial, periodic central disorder of hypersomnolence (CDH) in whom the presence of a LMOD3 gene variant was assessed.
CASE DESCRIPTION
The female patient presented since early adulthood with recurrent episodes of hypersomnolence. Over more than 20 years of follow-up the diagnoses of idiopathic hypersomnia, KLS and hypersomnia associated with a psychiatric condition were made. The family history is positive for periodic hypersomnolence and psychiatric conditions. The patient, her symptomatic mother and her asymptomatic sister carried a Proline for Histidine substitution at codon 552 of the LMOD3-gene. This variant was previously reported in two sporadic KLS patients and its frequency in the general population is below 0.02%.
DISCUSSION
We report the association of periodic hypersomnia with a polymorphism of the LMOD3-gene in a patient with atypical KLS and a positive family history. Further research is needed to assess the pathological and predictive value of LMOD3 variants in KLS
Fermionization of two distinguishable fermions
In this work we study a system of two distinguishable fermions in a 1D
harmonic potential. This system has the exceptional property that there is an
analytic solution for arbitrary values of the interparticle interaction. We
tune the interaction strength via a magnetic offset field and compare the
measured properties of the system to the theoretical prediction. At the point
where the interaction strength diverges, the energy and square of the wave
function for two distinguishable particles are the same as for a system of two
identical fermions. This is referred to as fermionization. We have observed
this phenomenon by directly comparing two distinguishable fermions with
diverging interaction strength with two identical fermions in the same
potential. We observe good agreement between experiment and theory. By adding
one or more particles our system can be used as a quantum simulator for more
complex few-body systems where no theoretical solution is available
Implementing the Massachusetts Child Trauma Project (MCTP) to Improve Services for Children with Complex Trauma in Child Welfare: Phase I Needs and Readiness Assessment
MCTP seeks to improve placement stability and outcomes for children with complex trauma in the care of the Massachusetts Department of Children and Families (DCF) by creating a sustainable capacity for providing evidence-based trauma interventions within provider agencies, and trauma-informed practices within DCF
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