Feshbach resonances in the 6Li-40K Fermi-Fermi mixture: Elastic versus inelastic interactions

We present a detailed theoretical and experimental study of Feshbach resonances in the 6Li-40K mixture. Particular attention is given to the inelastic scattering properties, which have not been considered before. As an important example, we thoroughly investigate both elastic and inelastic scattering properties of a resonance that occurs near 155 G. Our theoretical predictions based on a coupled channels calculation are found in excellent agreement with the experimental results. We also present theoretical results on the molecular state that underlies the 155G resonance, in particular concerning its lifetime against spontaneous dissociation. We then present a survey of resonances in the system, fully characterizing the corresponding elastic and inelastic scattering properties. This provides the essential information to identify optimum resonances for applications relying on interaction control in this Fermi-Fermi mixture.Comment: Submitted to EPJD, EuroQUAM special issues "Cold Quantum Matter - Achievements and Prospects", v2 with updated calibration of magnetic field (+4mG correction) and updated figures 4 and

Transcriptomic analysis reveals an association of FCGBP with Parkinson’s disease

Transcriptomics in Parkinson’s disease (PD) offers new insights into the molecular mechanism of PD pathogenesis. Several pathways, such as inflammation and protein degradation, have been identified by differential gene expression analysis. Our aim was to identify gene expression differences underlying the disease etiology and the discovery of pre-symptomatic risk biomarkers for PD from a multicenter study in the context of the PROPAG-AGEING project. We performed RNA sequencing from 47 patients with de novo PD, 10 centenarians, and 65 healthy controls. Using identified differentially expressed genes, functional annotations were assigned using gene ontology to unveil significant enriched biological processes. The expression of 16 selected genes was validated using OpenArray® assays and samples from independent cohorts of 201 patients with advanced PD, 340 healthy siblings of PD patients, and 177 healthy controls. Differential gene expression analysis identified higher FCGBP expression in patients with de novo PD compared with healthy controls and compared with centenarians. Furthermore, FCGBP showed no differences in terms of population origin or aging process. The increased FCGBP expression was validated in patients with advanced PD and their siblings. Thus, we provided evidence for an upregulation of FCGBP mRNA levels not only in patients with PD but also in individuals at putative higher risk of PD, suggesting that it could be important in gut–brain PD interaction, mediating the connection between microbiota and intestinal inflammatory processes, as well as neuroinflammation and neurodegeneration

Serum heart-type fatty acid-binding protein and cerebrospinal fluid tau: Marker candidates for dementia with Lewy bodies

Background: The measurement of biomarkers in cerebrospinal fluid (CSF) has gained increasing acceptance in establishing the diagnosis of some neurodegenerative diseases. Heart-type fatty acid-binding protein (H-FABP) was recently discovered in CSF and serum of patients with neurodegenerative diseases. Objective: We investigated H-FABP in CSF and serum alone and in combination with CSF tau protein to evaluate these as potential biomarkers for the differentiation between dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). Methods: We established H-FABP and tau protein values in a set of 144 persons with DLB (n = 33), Parkinson disease with dementia (PDD; n = 25), AD (n = 35) and nonclemented neurological controls (NNC; n = 51). Additionally, serum H-FABP levels were analyzed in idiopathic Parkinson disease patients without evidence of cognitive decline (n = 45) using commercially available enzyme-linked immunosorbent assays. We calculated absolute values of HFABP and tau protein in CSF and serum and established relative ratios between the two to obtain the best possible match for the clinical working diagnosis. Results: Serum HFABP levels were elevated in DLB and PDD patients compared with NNC and AD subjects. To better discriminate between DLB and AD, we calculated the ratio of serum H-FABP to CSF tau protein levels. At the arbitrary chosen cutoff ratio >= 8 this quotient reached a sensitivity of 91% and a specificity of 66%. Conclusion: Our results suggest that the measurement of CSF tau protein, together with H-FABP quantification in serum and CSF, and the ratio of serum H-FABP to CSF tau protein represent marker candidates for the differentiation between AD and DLB. Copyright (c) 2007 S. Karger AG, Basel

Ultra-cold Polarized Fermi Gases

Recent experiments with ultra-cold atoms have demonstrated the possibility of realizing experimentally fermionic superfluids with imbalanced spin populations. We discuss how these developments have shed a new light on a half- century old open problem in condensed matter physics, and raised new interrogations of their own.Comment: 27 pages; 8 figures; Published in Report in Rep. Prog. Phys. 73 112401 (2010

Exploring an ultracold Fermi-Fermi mixture: Interspecies Feshbach resonances and scattering properties of 6Li and 40K

We report on the observation of Feshbach resonances in an ultracold mixture of two fermionic species, 6Li and 40K. The experimental data are interpreted using a simple asymptotic bound state model and full coupled channels calculations. This unambiguously assigns the observed resonances in terms of various s- and p-wave molecular states and fully characterizes the ground-state scattering properties in any combination of spin states.Comment: 4 pages, 4 figures, 1 tabl

Liberating Efimov physics from three dimensions

When two particles attract via a resonant short-range interaction, three particles always form an infinite tower of bound states characterized by a discrete scaling symmetry. It has been considered that this Efimov effect exists only in three dimensions. Here we review how the Efimov physics can be liberated from three dimensions by considering two-body and three-body interactions in mixed dimensions and four-body interaction in one dimension. In such new systems, intriguing phenomena appear, such as confinement-induced Efimov effect, Bose-Fermi crossover in Efimov spectrum, and formation of interlayer Efimov trimers. Some of them are observable in ultracold atom experiments and we believe that this study significantly broadens our horizons of universal Efimov physics.Comment: 17 pages, 5 figures, contribution to a special issue of Few-Body Systems devoted to Efimov Physic

Rare Variants in PLXNA4 and Parkinson's Disease.

Approximately 20% of individuals with Parkinson's disease (PD) report a positive family history. Yet, a large portion of causal and disease-modifying variants is still unknown. We used exome sequencing in two affected individuals from a family with late-onset familial PD followed by frequency assessment in 975 PD cases and 1014 ethnically-matched controls and linkage analysis to identify potentially causal variants. Based on the predicted penetrance and the frequencies, a variant in PLXNA4 proved to be the best candidate and PLXNA4 was screened for additional variants in 862 PD cases and 940 controls, revealing an excess of rare non-synonymous coding variants in PLXNA4 in individuals with PD. Although we cannot conclude that the variant in PLXNA4 is indeed the causative variant, these findings are interesting in the light of a surfacing role of axonal guidance mechanisms in neurodegenerative disorders but, at the same time, highlight the difficulties encountered in the study of rare variants identified by next-generation sequencing in diseases with autosomal dominant or complex patterns of inheritance

First comprehensive tool for screening pain in Parkinson's disease: the King's Parkinson's Disease Pain Questionnaire.

BACKGROUND AND PURPOSE: Pain is highly prevalent in Parkinson's disease (PD), impacting patients' ability, mood and quality of life. Detecting the presence of pain in its multiple modalities is necessary for adequate personalized management of PD. A 14-item, PD-specific, patient-based questionnaire (the King's Parkinson's Disease Pain Questionnaire, KPPQ) was designed corresponding to the rater-based KPP Scale (KPPS). The present multicentre study was aimed at testing the validity of this screening tool. METHODS: First, a comparison between the KPPQ scores of patients and matched controls was performed. Next, convergent validity, reproducibility (test-retest) and diagnostic performance of the questionnaire were analysed. RESULTS: Data from 300 patients and 150 controls are reported. PD patients declared significantly more pain symptoms than controls (3.96 ± 2.56 vs. 2.17 ± 1.39; P < 0.0001). The KPPQ convergent validity was high with KPPS total score (rS  = 0.80) but weak or moderate with other pain assessments. Test-retest reliability was satisfactory with kappa values ≥0.65 except for item 5, Dyskinetic pains (κ = 0.44), and the intraclass correlation coefficient (ICC) for the KPPQ total score was 0.98. After the scores of the KPPS were adapted for screening (0, no symptom; ≥1, symptom present), a good agreement was found between the KPPQ and the KPPS (ICC = 0.88). A strong correlation (rS  = 0.80) between the two instruments was found. The diagnostic parameters of the KPPQ were very satisfactory as a whole, with a global accuracy of 78.3%-98.3%. CONCLUSIONS: These results suggest that the KPPQ is a useful, reliable and valid screening instrument for pain in PD to advance patient-related outcomes

Overnight switch from ropinirole to transdermal rotigotine patch in patients with Parkinson disease

<p>Abstract</p> <p>Background</p> <p>A recent trial involving predominantly Caucasian subjects with Parkinson Disease (PD) showed switching overnight from an oral dopaminergic agonist to the rotigotine patch was well tolerated without loss of efficacy. However, no such data have been generated for Korean patients.</p> <p>Methods</p> <p>This open-label multicenter trial investigated PD patients whose symptoms were not satisfactorily controlled by ropinirole, at a total daily dose of 3 mg to 12 mg, taken as monotherapy or as an adjunct to levodopa. Switching treatment from oral ropinirole to transdermal rotigotine was carried out overnight, with a dosage ratio of 1.5:1. After a 28-day treatment period, the safety and tolerability of switching was evaluated. Due to the exploratory nature of this trial, the effects of rotigotine on motor and nonmotor symptoms of PD were analyzed in a descriptive manner.</p> <p>Results</p> <p>Of the 116 subjects who received at least one treatment, 99 (85%) completed the 28-day trial period. Dose adjustments were required for 11 subjects who completed the treatment period. A total of 76 treatment-emergent adverse events (AEs) occurred in 45 subjects. No subject experienced a serious AE. Thirteen subjects discontinued rotigotine prematurely due to AEs. Efficacy results suggested improvements in both motor and nonmotor symptoms and quality of life after switching. Fifty-two subjects (46%) agreed that they preferred using the patch over oral medications, while 31 (28%) disagreed.</p> <p>Conclusions</p> <p>Switching treatment overnight from oral ropinirole to transdermal rotigotine patch, using a dosage ratio of 1.5:1, was well tolerated in Korean patients with no loss of efficacy.</p> <p>Trial registration</p> <p>This trial is registered with the ClincalTrails.gov Registry (<a href="http://www.clinicaltrials.gov/ct2/show/NCT00593606">NCT00593606</a>).</p