Broadband Tuning (170nm) of InGaAs Quantum Well Lasers

The wavelength tuning properties of strained InGaAs quantum well lasers using an external grating for feedback is reported. Tunable laser oscillation has been observed over a range of 170 nm, between 840 and 1010 nm, under pulsed current excitation. The optimal conditions for broadband tunability for the InGaAs lasers are different from GaAs lasers, which is attributed to a difference in spectral gain curves. Together with an optimised GaAs quantum well laser the entire region between 740 and 1010 nm is spanned

Ancestry-Dependent Enrichment of Deleterious Homozygotes in Runs of Homozygosity.

Runs of homozygosity (ROH) are important genomic features that manifest when an individual inherits two haplotypes that are identical by descent. Their length distributions are informative about population history, and their genomic locations are useful for mapping recessive loci contributing to both Mendelian and complex disease risk. We have previously shown that ROH, and especially long ROH that are likely the result of recent parental relatedness, are enriched for homozygous deleterious coding variation in a worldwide sample of outbred individuals. However, the distribution of ROH in admixed populations and their relationship to deleterious homozygous genotypes is understudied. Here we analyze whole-genome sequencing data from 1,441 unrelated individuals from self-identified African American, Puerto Rican, and Mexican American populations. These populations are three-way admixed between European, African, and Native American ancestries and provide an opportunity to study the distribution of deleterious alleles partitioned by local ancestry and ROH. We re-capitulate previous findings that long ROH are enriched for deleterious variation genome-wide. We then partition by local ancestry and show that deleterious homozygotes arise at a higher rate when ROH overlap African ancestry segments than when they overlap European or Native American ancestry segments of the genome. These results suggest that, while ROH on any haplotype background are associated with an inflation of deleterious homozygous variation, African haplotype backgrounds may play a particularly important role in the genetic architecture of complex diseases for admixed individuals, highlighting the need for further study of these populations

Therapy-based exercise from the perspective of adult patients: a qualitative systematic review conducted using an ethnographic approach

© The Author(s) 2019.Objectives: Many patients do not meet recommended levels of therapy-based exercise. This review aims to explore how adult patients view being prescribed therapy-based exercise, the information/education they are given and receive and if/how they independently practise and adhere. Design: A qualitative systematic review conducted using an ethnographic approach and in accordance with the PRISMA statement. Sources: PubMed, CINAHL, SCOPUS and EMBASE databases (01 January 2000–31 December 2018). Methods: Qualitative studies with a focus on engagement/adherence with therapy-based exercise were included. Data extraction and quality appraisal were undertaken by two reviewers. Results were discussed and data synthesized. Results: A total of 20,294 titles were screened, with data extracted from 39 full texts and data from 18 papers used to construct three themes. ‘The Guidance received’ suggests that the type of delivery desired to support and sustain engagement was context-dependent and individually situated. ‘The Therapist as teacher’ advocates that patients see independent therapy-based exercise as a shared activity and value caring, kind and professional qualities in their therapist. ‘The Person as learner’ proposes that when having to engage with and practise therapy-based exercise because of ill-health, patients often see themselves as new learners who experience fear and uncertainty about what to do. Patients may have unacknowledged ambivalences about learning that impact on engagement and persistence. Conclusion: The quality of the interaction between therapists and patients appears integral to patients engaging with, and sustaining practice of, rehabilitation programmes. Programmes need to be individualized, and health care professionals need to take patients’ previous experiences and ambivalences in motivation and empowerment into account.Peer reviewe

Out of equilibrium electronic transport properties of a misfit cobaltite thin film

We report on transport measurements in a thin film of the 2D misfit Cobaltite $Ca_{3}Co_{4}O_{9}$. Dc magnetoresistance measurements obey the modified variable range hopping law expected for a soft Coulomb gap. When the sample is cooled down, we observe large telegraphic-like fluctuations. At low temperature, these slow fluctuations have non Gaussian statistics, and are stable under a large magnetic field. These results suggest that the low temperature state is a glassy electronic state. Resistance relaxation and memory effects of pure magnetic origin are also observed, but without aging phenomena. This indicates that these magnetic effects are not glassy-like and are not directly coupled to the electronic part.Comment: accepted in Phys Rev B, Brief report

Kinetic Limit for Wave Propagation in a Random Medium

We study crystal dynamics in the harmonic approximation. The atomic masses are weakly disordered, in the sense that their deviation from uniformity is of order epsilon^(1/2). The dispersion relation is assumed to be a Morse function and to suppress crossed recollisions. We then prove that in the limit epsilon to 0 the disorder averaged Wigner function on the kinetic scale, time and space of order epsilon^(-1), is governed by a linear Boltzmann equation.Comment: 71 pages, 3 figure

Heparin suppresses mesangial cell proliferation and matrix expansion in experimental mesangioproliferative glomerulonephritis

Heparin suppresses mesangial cell proliferation and matrix expansion in experimental mesangioproliferative glomerulonephritis. Proliferation and extracellular matrix (ECM) overproduction by glomerular mesangial cells characterizes many types of glomerulonephritis and often precedes the development of glomerulosclerosis. Heparin is a potent inhibitor of mesangial cell growth in vitro. We examined whether standard heparin can inhibit mesangial cell proliferation in vivo in the mesangioproliferative anti-Thy 1.1 nephritis. Untreated control rats were compared to rats infused with heparin either early (day -2 to 1) or late (day 2 to 5) after induction of anti-Thy 1.1 nephritis. The results show that heparin treatment significantly reduced mesangial cell proliferation regardless of when it was initiated. Heparin (either early or late treatment) also reduced mesangial basic fibroblast growth factor (bFGF) expression and platelet-derived growth factor (PDGF) receptor up-regulation as reflected by immunostaining, whereas PDGF B-chain expression was reduced only by late heparin treatment. Furthermore, heparin treatment markedly inhibited the mesangial matrix expansion for a variety of ECM proteins, including laminin, type I and IV collagen, fibronectin and entactin. Heparin did not affect the initial mesangiolysis, glomerular macrophage influx, deposition of anti-Thy 1.1 IgG or fibrinogen, or the glomerular platelet influx. These results suggest that heparin, via its antiproliferative rather than anticoagulant effect, can inhibit mesangial cell proliferation, overexpression of polypeptide growth factors, and ECM protein overproduction in vivo. The beneficial effect of heparin can be demonstrated even if treatment is initiated after the development of nephritis. By virtue of these properties, heparin may be an effective agent in the treatment of human mesangioproliferative disease and in the prevention of glomerulosclerosis

Synthesis, Characterization and Biological Activity of Dimethyltin Dicarboxylates Containing Germanium

A series of diorganotin dicarboxylates of the general formula (CH3)2Sn(OCOCHR3CHR2GeR1)2 where R1=(C6H5)3, (P-CH3C6H4)3, N(CH2CH2O)3, R2=C6H5, H, CH3, P-CH3OC6H4, P-ClC6H4, P-CH3C6H4, R3=CH3 and H, have been synthesized by the reaction of dimethyltin oxide with germanium substituted propionic acid in 1:2 molar ratio in toluene. The H2O formed was removed azeotropically using a Dean and Stark apparatus. All the compounds have been characterized by IR, multinuclear (1H, 13C, 119Sn) NMR, mass and Mössbauer spectroscopies. All compounds were found to have potential activity against bacteria

Double quantum dot with tunable coupling in an enhancement-mode silicon metal-oxide semiconductor device with lateral geometry

We present transport measurements of a tunable silicon metal-oxide-semiconductor double quantum dot device with lateral geometry. Experimentally extracted gate-to-dot capacitances show that the device is largely symmetric under the gate voltages applied. Intriguingly, these gate voltages themselves are not symmetric. Comparison with numerical simulations indicates that the applied gate voltages serve to offset an intrinsic asymmetry in the physical device. We also show a transition from a large single dot to two well isolated coupled dots, where the central gate of the device is used to controllably tune the interdot coupling.Comment: 4 pages, 3 figures, to be published in Applied Physics Letter