492 research outputs found

    How reciprocity impacts ordering and phase separation in active nematics?

    Full text link
    Active nematics undergo spontaneous symmetry breaking and show phase separation instability. Within the prevailing notion that macroscopic properties depend only on symmetries and conservation laws, different microscopic models are used out of convenience. Here, we test this notion carefully by analyzing three different microscopic models of apolar active nematics. They share the same symmetry but differ in implementing reciprocal or non-reciprocal interactions, including a Vicsek-like implementation. We show how such subtle differences in microscopic realization determine if the ordering transition is continuous or first order. Despite the difference in the type of phase transition, all three models exhibit fluctuation-dominated phase separation and quasi-long-range order in the nematic phase.Comment: 8 pages, 8 figures; version accepted for publication in Soft Matte

    A prospective randomised, controlled clinical trial comparing medial and lateral entry pinning with lateral entry pinning for percutaneous fixation of displaced extension type supracondylar fractures of the humerus in children

    Get PDF
    <p>Abstract</p> <p>Objective</p> <p>To compare the efficacy of medial and lateral entry pinning with lateral entry pinning for percutaneous fixation of displaced (Gartland type II and type III) extension type supracondylar fractures of the humerus in children.</p> <p>Methods</p> <p>The study was a single center, prospective, randomized controlled clinical trial. Between October 2007 and September 2010, 160 patients who satisfy the inclusion and exclusion criterias were enrolled in the study, with 80 patients in each group. All the percutaneous pinning was done according to a uniform standardized technique. The patients were re-evaluated as outpatients at three weeks, six weeks and three months after the surgery. At three months follow-up visit, following informations were recorded as outcome measures: (i) Carrying angle (deg) (ii) passive range of elbow motion (deg) (iii) Flynn's criteria for grading, based on the loss of carrying angle and loss of total range of elbow motion. (iv) Baumann angle (deg) (v) Change in Baumann angle (deg) between the Intraoperative radiographs after the surgery and radiographs at three months follow-up visit (vi) loss of reduction grading, based on the change in the Baumann angle.</p> <p>Results</p> <p>There were no significant differences between the two groups with regard to base-line characteristics, withdrawals and complication rate. At three months follow-up visit, patients were evaluated by recording the various outcome measures. There were no significant differences between the two groups with regard to the various outcome measures such as carrying angle, passive range of elbow motion, Flynn grading, Baumann angle, change in the Baumann angle and loss of reduction grading.</p> <p>Conclusions</p> <p>If a uniform standardized operative technique is followed in each method, then the result of both the percutaneous fixation methods will be same in terms of safety and efficacy.</p

    Evaluating Product-Centric Continuous Improvements: Impact on Competitive Capabilities and Business Performance

    Get PDF
    Product-centric continuous improvements (CIs) are actions via which firms modify the design of a product after the start of its production and release into the market. Product-centric CIs are initiated to help build competitive capabilities and sustain competitive advantage throughout the product life cycle. This study complements the perspective pervasive in the extant literature that actions related to product-centric CIs can be disruptive to firms and be associated with negative performance consequences. It investigates a topic that is relatively much less researched, namely the upside potential of product-centric CIs. The empirical analysis is based on data collected from 144 plants in the United States representing process and discrete part manufacturing industries. Specifically, the study analyzes the impact of product-centric CIs on competitive capabilities and business performance. The results of the empirical analysis indicate the following: First, there exist two categories of product-centric CIs: (1) actions for quality improvement and (2) actions for cost reduction. Second, while there is a positive association between each type of CI and the intended competitive capability, there also is a trade-off—i.e., actions for quality improvement increase quality capability but reduce cost capability, and vice versa. Third, there is a strong linkage between business performance and quality capability, but not cost capability. All in all, the study presents empirical evidence that product-centric CIs have a significant impact on competitive capabilities related to quality and cost, and, in turn, have an impact on business performance. From the standpoint of practice, the study suggests that product-centric CIs should be managed to develop competitive capabilities and improve business performance

    Clinical and doppler monitoring of patients with Takayasu arteritis with ITAS 2010 and CDUS-K score respectively following medical intervention: a 12 months follow-up study

    Get PDF
    Background: The objective of the present study was to monitor the disease activity of Takayasu arteritis clinically by the Indian Takayasu Activity Score 2010 (ITAS) and ultra sonographically by Colour Doppler Ultrasound-Kolkata (CDUS-K) Score after 12months of treatment with methotrexate and steroid, and to find the correlation between these two scores.Methods: Around 25 Angiographically proven Takayasu arteritis patients were treated with Methotrexate (15mg weekly) and Steroids (1mg/kg/day for 6weeks and then tapered) for 12months. Wilcoxon matched pair signed rank test was done to assess the change in ITAS 2010 with treatment. A correlation study was done between ITAS 2010 and change in CDUS-K scores at the end of 12months.Results: By Wilcoxon’s matched pair signed rank test, a non-significant change of ITAS 2010 (p=0.066) was observed at the end of 12months, which means that the treatment helps to control the disease progression by preventing a significant increase in ITAS 2010. Strong correlation (correlation coefficient of 0.878, 95% CI = 0.602 to 1.000) was found between the ITAS 2010 and change in CDUS-K scores at 12months follow up.Conclusions: The combination of Methotrexate and steroids helps to control the disease progression in Takayasu arteritis. Colour doppler ultrasonography may serve as a reliable and safe surrogate disease activity measure at follow up, as it avoids the radioactivity exposure and invasiveness of angiography

    Eye of the tiger sign in neurodegeneration with brain iron accumulation: a case report

    Get PDF
    Neurodegeneration with brain iron accumulation (NBIA) is a rare autosomal recessive disorder characterized by abnormal accumulation of ferritin in globus pallidus of brain. Magnetic resonance imaging (MRI) of brain demonstrates a characteristic ‘eye-of-the-tiger’ sign. We describe a case of NBIA in a child with classical clinical and MRI of brain features

    Discussion on a possible neutrino detector located in India

    Get PDF
    We have identified some important and worthwhile physics opportunitites with a possible neutrino detector located in India. Particular emphasis is placed on the geographical advantage with a stress on the complimentary aspects with respect to other neutrino detectors already in operation.Comment: 9 pages; arXiv copy of published proceedings contributio

    Autophagy in the eye:from physiology to pathophysology

    Get PDF
    Autophagy is a catabolic self-degradative pathway that promotes the degradation and recycling of intracellular material through the lysosomal compartment. Although first believed to function in conditions of nutritional stress, autophagy is emerging as a critical cellular pathway, involved in a variety of physiological and pathophysiological processes. Autophagy dysregulation is associated with an increasing number of diseases, including ocular diseases. On one hand, mutations in autophagy-related genes have been linked to cataracts, glaucoma, and corneal dystrophy; on the other hand, alterations in autophagy and lysosomal pathways are a common finding in essentially all diseases of the eye. Moreover, LC3-associated phagocytosis, a form of non-canonical autophagy, is critical in promoting visual cycle function. This review collects the latest understanding of autophagy in the context of the eye. We will review and discuss the respective roles of autophagy in the physiology and/or pathophysiology of each of the ocular tissues, its diurnal/circadian variation, as well as its involvement in diseases of the eye

    Physics Potential of the ICAL detector at the India-based Neutrino Observatory (INO)

    Get PDF
    The upcoming 50 kt magnetized iron calorimeter (ICAL) detector at the India-based Neutrino Observatory (INO) is designed to study the atmospheric neutrinos and antineutrinos separately over a wide range of energies and path lengths. The primary focus of this experiment is to explore the Earth matter effects by observing the energy and zenith angle dependence of the atmospheric neutrinos in the multi-GeV range. This study will be crucial to address some of the outstanding issues in neutrino oscillation physics, including the fundamental issue of neutrino mass hierarchy. In this document, we present the physics potential of the detector as obtained from realistic detector simulations. We describe the simulation framework, the neutrino interactions in the detector, and the expected response of the detector to particles traversing it. The ICAL detector can determine the energy and direction of the muons to a high precision, and in addition, its sensitivity to multi-GeV hadrons increases its physics reach substantially. Its charge identification capability, and hence its ability to distinguish neutrinos from antineutrinos, makes it an efficient detector for determining the neutrino mass hierarchy. In this report, we outline the analyses carried out for the determination of neutrino mass hierarchy and precision measurements of atmospheric neutrino mixing parameters at ICAL, and give the expected physics reach of the detector with 10 years of runtime. We also explore the potential of ICAL for probing new physics scenarios like CPT violation and the presence of magnetic monopoles.Comment: 139 pages, Physics White Paper of the ICAL (INO) Collaboration, Contents identical with the version published in Pramana - J. Physic

    Loss of NRF-2 and PGC-1α genes leads to retinal pigment epithelium damage resembling dry age-related macular degeneration

    Get PDF
    Age-related macular degeneration (AMD) is a multi-factorial disease that is the leading cause of irreversible and severe vision loss in the developed countries. It has been suggested that the pathogenesis of dry AMD involves impaired protein degradation in retinal pigment epithelial cells (RPE). RPE cells are constantly exposed to oxidative stress that may lead to the accumulation of damaged cellular proteins, DNA and lipids and evoke tissue deterioration during the aging process. The ubiquitin-proteasome pathway and the lysosomal/autophagosomal pathway are the two major proteolytic systems in eukaryotic cells. NRF-2 (nuclear factor-erythroid 2-related factor-2) and PGC-1 alpha (peroxisome proliferator-activated receptor gamma coactivator-1 alpha) are master transcription factors in the regulation of cellular detoxification. We investigated the role of NRF-2 and PGC-1 alpha in the regulation of RPE cell structure and function by using global double knockout (dKO) mice. The NRF-2/PGC-1 alpha dKO mice exhibited significant age-dependent RPE degeneration, accumulation of the oxidative stress marker, 4-HNE (4-hydroxynonenal), the endoplasmic reticulum stress markers GRP78 (glucose-regulated protein 78) and ATF4 (activating transcription factor 4), and damaged mitochondria. Moreover, levels of protein ubiquitination and autophagy markers p62/SQSTM1 (sequestosome 1), Beclin-1 and LC3B (microtubule associated protein 1 light chain 3 beta) were significantly increased together with the Iba-1 (ionized calcium binding adaptor molecule 1) mononuclear phagocyte marker and an enlargement of RPE size. These histopathological changes of RPE were accompanied by photoreceptor dysmorphology and vision loss as revealed by electroretinography. Consequently, these novel findings suggest that the NRF-2/PGC-1 alpha dKO mouse is a valuable model for investigating the role of proteasomal and autophagy clearance in the RPE and in the development of dry AMD.Peer reviewe
    corecore