Formation of a molecular Bose-Einstein condensate and an entangled atomic gas by Feshbach resonance

Processes of association in an atomic Bose-Einstein condensate, and dissociation of the resulting molecular condensate, due to Feshbach resonance in a time-dependent magnetic field, are analyzed incorporating non-mean-field quantum corrections and inelastic collisions. Calculations for the Na atomic condensate demonstrate that there exist optimal conditions under which about 80% of the atomic population can be converted to a relatively long-lived molecular condensate (with lifetimes of 10 ms and more). Entangled atoms in two-mode squeezed states (with noise reduction of about 30 dB) may also be formed by molecular dissociation. A gas of atoms in squeezed or entangled states can have applications in quantum computing, communications, and measurements.Comment: LaTeX, 5 pages with 4 figures, uses REVTeX

Evolutionary trends in RNA base selectivity within the RNase A superfamily

Altres ajuts: Fundació La Marató de TV3 (Marató 20180310)There is a growing interest in the pharmaceutical industry to design novel tailored drugs for RNA targeting. The vertebrate-specific RNase A superfamily is nowadays one of the best characterized family of enzymes and comprises proteins involved in host defense with specific cytotoxic and immune-modulatory properties. We observe within the family a structural variability at the substrate-binding site associated to a diversification of biological properties. In this work, we have analyzed the enzyme specificity at the secondary base binding site. Towards this end, we have performed a kinetic characterization of the canonical RNase types together with a molecular dynamic simulation of selected representative family members. The RNases' catalytic activity and binding interactions have been compared using UpA, UpG and UpI dinucleotides. Our results highlight an evolutionary trend from lower to higher order vertebrates towards an enhanced discrimination power of selectivity for adenine respect to guanine at the secondary base binding site (B2). Interestingly, the shift from guanine to adenine preference is achieved in all the studied family members by equivalent residues through distinct interaction modes. We can identify specific polar and charged side chains that selectively interact with donor or acceptor purine groups. Overall, we observe selective bidentate polar and electrostatic interactions: Asn to N1/N6 and N6/N7 adenine groups in mammals versus Glu/Asp and Arg to N1/N2, N1/O6 and O6/N7 guanine groups in non-mammals. In addition, kinetic and molecular dynamics comparative results on UpG versus UpI emphasize the main contribution of Glu/Asp interactions to N1/N2 group for guanine selectivity in lower order vertebrates. A close inspection at the B2 binding pocket also highlights the principal contribution of the protein β6 and L4 loop regions. Significant differences in the orientation and extension of the L4 loop could explain how the same residues can participate in alternative binding modes. The analysis suggests that within the RNase A superfamily an evolution pressure has taken place at the B2 secondary binding site to provide novel substrate-recognition patterns. We are confident that a better knowledge of the enzymes' nucleotide recognition pattern would contribute to identify their physiological substrate and eventually design applied therapies to modulate their biological functions

Exploring the links between secondary metabolites and leaf spectral reflectance in a diverse genus of Amazonian trees

Plant defense chemistry is often hypothesized to drive ecological and evolutionary success in diverse tropical forests, yet detailed characterizations of plant secondary metabolites in tropical plants are logistically challenging. Here, we explore a new integrative approach that combines visible-to-shortwave infrared (VSWIR) spectral reflectance data with detailed plant metabolomics data from 19 Protium (Burseraceae) tree species. Building on the discovery that different Protium species have unique chemistries yet share many secondary metabolites, we devised a method to test for associations between metabolites and VSWIR spectral data. Given species-level variation in metabolite abundance, we correlated the concentration of particular chemicals with the reflectance of the spectral bands in a wavelength band per secondary metabolite matrix. We included 45 metabolites that were shared by at least 5 Protium species and correlated their per-species foliar abundances against each one of 210 wavelength bands of field-measured VSWIR spectra. Finally, we tested whether classes of similar metabolites showed similar relationships with spectral patterns. We found that many secondary metabolites yielded strong correlations with VSWIR spectra of Protium. Furthermore, important Protium metabolite classes such as procyanidins (condensed tannins) and phytosterols were grouped together in a hierarchical clustering analysis (Ward’s algorithm), confirming similarity in their associations with plant spectral patterns. We also found a significant correlation in the phenolics content between juvenile and canopy trees of the same species, suggesting that species-level variation in defense chemistry is consistent across life stages and geographic distribution. We conclude that the integration of spectral and metabolic approaches could represent a powerful and economical method to characterize important aspects of tropical plant defense chemistry

Outcome analysis of upper and lower limb motor functions after anterior cervical discectomy and fusion for degenerative cervical disc disease

Background: Anterior cervical discectomy and fusion (ACDF) is the most commonly performed surgical procedure for symptomatic cervical disc disease. In this study, we analysed the upper and lower limb motor functions after ACDF for disc prolapse in patients with degenerative cervical disc disease. Methods: One hundred consecutive adult patients who underwent ACDF for single or two-level cervical disc prolapse during the study period (October 2015 to October 2017) were included in the study. Results: Preoperative motor deficits in limbs were noted in 73% (73/100) of the patients. Enhance recovery of motor deficits was noted in 72.6% (53/73) of these patients and persisting motor deficits in the remaining patients (20/73- 27.4%). Five patients (5/27- 18.5%) without any preoperative motor deficits developed motor deficits after ACDF. Detailed pre and postoperative (at the time of discharge) motor power (graded by MRC grade) in all 4 limbs (Shoulder abduction/adduction/flexion/extension, elbow flexion/extension, wrist flexion/extension, hip abduction/adduction/flexion/extension, knee flexion/extension, ankle flexion/extension) was recorded. Statistically significant improvement in motor power (as recorded at the time of discharge) was noted in all the tested muscle groups after ACDF. Conclusion: Early improvement in preoperative motor deficits can be expected in the majority of the patients with cervical PIVD following ACDF

Nonsingular FRW cosmology and nonlinear electrodynamics

The possibility to avoid the cosmic initial singularity as a consequence of nonlinear effects on the Maxwell eletromagnetic theory is discussed. For a flat FRW geometry we derive the general nonsingular solution supported by a magnetic field plus a cosmic fluid and a nonvanishing vacuum energy density. The nonsingular behavior of solutions with a time-dependent $\Lambda(t)$-term are also examined. As a general result, it is found that the functional dependence of $\Lambda(t)$ can uniquely be determined only if the magnetic field remains constant. All these models are examples of bouncing universes which may exhibit an inflationary dynamics driven by the nonlinear corrections of the magnetic field.Comment: 20 pages, 7 figure

External ventricular drainage for intraventricular hemorrhage

Background: Intervention to reduce intracranial pressure using External Ventricular Drain (EVD) is a common life saving measure in a neurosurgery intensive care unit(ICU). Objective: The present study was undertaken to assess the outcome of patients who underwent external ventricular drainage for intraventricular hemorrhage(IVH). Methods: The available data of the patients who underwent placement of external ventricular drain from February 2012 to May 2016 for intraventricular hemorrhage (IVH) at Narayana Medical College and Hospital, Nellore, was retrieved from the hospital case records and analyzed. Results: Total of 69 patients were included in this study. Mean age was 53.7 ±11.6 years. Clinical presentation included altered sensorium in 66 patients (96%), hemiparesis in 62 patients (90%) , vomiting in 40 patients (58%) and seizures in 9 patients (13%). Fifty two patients (75%) were known hypertensives and 10 patients (15%) were diabetic. Past history of smoking was recorded in 16(23%) patients and alcohol intake in 17 patients (25%). GCS at the time of admission was 3-8 (low) in 39 patients (57%), 9-12 in 23 patients(33%) and 13-15 in 7 patients (10%). At the time of admission, 60 patients ( 87%) had diastolic blood pressure more than 90 mmHg, 63 patients (91%) had systolic blood pressure more than 140 mmHg. Major site of hemorrhage was basal ganglia in 24 (35%), thalamus in 13 (19%), cerebellum in 5 (7%), brain stem in 3, frontal/temporal in 2 patients. SAH with IVH was noted in 12 patients (17%) and only IVH was noted in 10 patients (14%). Mean duration of external ventricular drainage was 4.6+1.7 days (Range 1-9 days). Mean hospital stay was 11.3±7.5 days and mean ICU stay was 8+5.4 days. Thirty eight patients (55%) died during hospital stay. At the time of discharge, poor out come (Glagow out come score 1-3) was noted in 52 patients (75%) and good out come (Glagow out come score-4,5) was noted in 17 patients. Among various parameters analyzed , poor GCS (3-8) at admission, history of smoking and alcohol intake were found to correlate significantly with poor outcome. None of the other factors like old age, site of bleed, pupillary asymmetry at admission, high blood pressure at admission, past history of hypertension and diabetes were found to correlate with poor outcome. Conclusions: Majority of the patients with intracranial hematomas with intraventricular extension presented in poor neurological condition (GCS= 3-8). Poor neurological condition at the time of admission, past history of smoking and alcohol intake were associated with poor outcome

Fatigue in Women with Fibromyalgia: A Gene-Physical Activity Interaction Study

Fatigue is a cardinal symptom in fibromyalgia. Fatigue is assumed to be the result of genetic susceptibility and environmental factors. We aimed at examining the role of genetic susceptibility for fatigue in southern Spanish women with fibromyalgia, by looking at single nucleotide polymorphisms in 34 fibromyalgia candidate-genes, at the interactions between genes, and at the gene-physical activity interactions. We extracted DNA from saliva of 276 fibromyalgia women to analyze gene-polymorphisms. Accelerometers registered physical activity and sedentary behavior. Fatigue was assessed with the Multidimensional Fatigue Inventory. Based on the Bonferroni's and False Discovery Rate values, we found that the genotype of the rs4453709 polymorphism (sodium channel protein type 9 subunit alpha, SCN9A, gene) was related to reduced motivation (AT carriers showed the highest reduced motivation) and reduced activity (AA carriers showed the lowest reduced activity). Carriers of the heterozygous genotype of the rs1801133 (methylene tetrahydrofolate reductase, MTHFR, gene) or rs4597545 (SCN9A gene) polymorphisms who were physically active reported lower scores on fatigue compared to their inactive counterparts. Highly sedentary carriers of the homozygous genotype of the rs7607967 polymorphism (AA/GG genotype; SCN9A gene) presented more reduced activity (a dimension of fatigue) than those with lower levels of sedentary behavior. Collectively, findings from the present study suggest that the contribution of genetics and gene-physical activity interaction to fatigue in fibromyalgia is modest

Measurement of the View the tt production cross-section using eμ events with b-tagged jets in pp collisions at √s = 13 TeV with the ATLAS detector

This paper describes a measurement of the inclusive top quark pair production cross-section (σtt¯) with a data sample of 3.2 fb−1 of proton–proton collisions at a centre-of-mass energy of √s = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron–muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously σtt¯ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: σtt¯ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented

Measurement of the branching ratio Γ(Λb⁰ → ψ(2S)Λ0)/Γ(Λb⁰ → J/ψΛ0) with the ATLAS detector

An observation of the $\Lambda_b^0 \rightarrow \psi(2S) \Lambda^0$ decay and a comparison of its branching fraction with that of the $\Lambda_b^0 \rightarrow J/\psi \Lambda^0$ decay has been made with the ATLAS detector in proton--proton collisions at $\sqrt{s}=8\,$TeV at the LHC using an integrated luminosity of $20.6\,$fb$^{-1}$. The $J/\psi$ and $\psi(2S)$ mesons are reconstructed in their decays to a muon pair, while the $\Lambda^0\rightarrow p\pi^-$ decay is exploited for the $\Lambda^0$ baryon reconstruction. The $\Lambda_b^0$ baryons are reconstructed with transverse momentum $p_{\rm T}>10\,$GeV and pseudorapidity $|\eta|<2.1$. The measured branching ratio of the $\Lambda_b^0 \rightarrow \psi(2S) \Lambda^0$ and $\Lambda_b^0 \rightarrow J/\psi \Lambda^0$ decays is $\Gamma(\Lambda_b^0 \rightarrow \psi(2S)\Lambda^0)/\Gamma(\Lambda_b^0 \rightarrow J/\psi\Lambda^0) = 0.501\pm 0.033 ({\rm stat})\pm 0.019({\rm syst})$, lower than the expectation from the covariant quark model.Comment: 12 pages plus author list (28 pages total), 5 figures, 1 table, published on Physics Letters B 751 (2015) 63-80. All figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/BPHY-2013-08

Search for dark matter produced in association with a hadronically decaying vector boson in pp collisions at sqrt (s) = 13 TeV with the ATLAS detector

A search is presented for dark matter produced in association with a hadronically decaying W or Z boson using 3.2 fb−1 of pp collisions at View the MathML sources=13 TeV recorded by the ATLAS detector at the Large Hadron Collider. Events with a hadronic jet compatible with a W or Z boson and with large missing transverse momentum are analysed. The data are consistent with the Standard Model predictions and are interpreted in terms of both an effective field theory and a simplified model containing dark matter