321 research outputs found

    Shaping the organizational architecture for SME survival : a case of nascent small restaurants in Durban

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    This study explores how planning, leading and organising activities shaped the organisational architecture of the nascent small restaurants that survived the first five years of operating in Durban in South Africa. Twelve owners of nascent small restaurants in Durban were selected using purposive sampling and interviewed to gather data. Themes of how planning, leading and organizing shaped the components of the Mc Kinsey 7-S model in the restaurant were delineated using thematic analysis. The study reveal that the organisational architecture of the nascent restaurant relied on emergent and entrepreneurial planning in the creative use of staff and skills to exploit opportunities and contain disruptions to service. Engaging employees to model the desired values but also using them as an instrument to achieve specific goals depicted an ambidextrous style of leadership. Multiskilling of staff enhanced resilience to operational and customer changes while the empowerment of employees was undermined by trust deficit in the organisational architecture of the restaurant. Critical changes are imperative to re-align the organisational architecture of the restaurant and ensure that it enhances survival.http://www.ajhtl.comam2020Marketing Managemen

    Quasiparticle Interactions in Fractional Quantum Hall Systems: Justification of Different Hierarchy Schemes

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    The pseudopotentials describing the interactions of quasiparticles in fractional quantum Hall (FQH) states are studied. Rules for the identification of incompressible quantum fluid ground states are found, based upon the form of the pseudopotentials. States belonging to the Jain sequence nu=n/(1+2pn), where n and p are integers, appear to be the only incompressible states in the thermodynamic limit, although other FQH hierarchy states occur for finite size systems. This explains the success of the composite Fermion picture.Comment: RevTeX, 10 pages, 7 EPS figures, submitted fo Phys.Rev.

    How to increase and maintain high immunization coverage: Vaccination Demand Resilience (VDR) framework

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    Background: Resilience in vaccination demand is ever more critical as the COVID-19 pandemic has increased our understanding of the importance of vaccines on health and well-being. Yet timid demand for COVID-19 vaccines where available and reduced uptake of routine immunizations globally further raise the urgent need to build vaccination resilience. We demonstrate the complexity of vaccination demand and resilience in a framework where relevant dimensions are intertwined, fluid, and contextual. Methods: We developed the Vaccination Demand Resilience (VDR) framework based on a literature review on vaccination demand and expert consultation. The matrix framework builds on three main axes: 1) vaccination attitudes and beliefs; 2) vaccination seeking behavior; and 3) vaccination status. The matrix generated eight quadrants, which can help explain people's levels of vaccination demand and resilience. We selected four scenarios as examples to demonstrate different interventions that could move people across quadrants and build vaccination resilience. Results: Incongruence between individuals’ attitudes and beliefs, vaccination behavior, and vaccination status can arise. For example, an individual can be vaccinated due to mandates but reject vaccination benefits and otherwise avoid seeking vaccination. Such incongruence could be altered by interventions to build resilience in vaccination demand. These interventions include information, education and communication to change individuals' vaccination attitudes and beliefs, incentive programs and reminder-recalls to facilitate vaccination seeking, or by strengthening healthcare provider communications to reduce missed opportunities. Conclusions: Vaccination decision-making is complex. Individuals can be vaccinated without necessarily accepting the benefits of vaccination or seeking vaccination, threatening resilience in vaccination demand. The VDR framework can provide a useful lens for program managers and policy makers considering interventions and policies to improve vaccination resilience. This would help build and sustain confidence and demand for vaccinations, and help to continue to prevent disease, disability, and death from vaccine-preventable diseases

    T-bet controls intestinal mucosa immune responses via repression of type 2 innate lymphoid cell function

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    Innate lymphoid cells (ILCs) play an important role in regulating immune responses at mucosal surfaces. The transcription factor T-bet is crucial for the function of ILC1s and NCR+ ILC3s and constitutive deletion of T-bet prevents the development of these subsets. Lack of T-bet in the absence of an adaptive immune system causes microbiota-dependent colitis to occur due to aberrant ILC3 responses. Thus, T-bet expression in the innate immune system has been considered to dampen pathogenic immune responses. Here, we show that T-bet plays an unexpected role in negatively regulating innate type 2 responses, in the context of an otherwise intact immune system. Selective loss of T-bet in ILCs leads to the expansion and increased activity of ILC2s, which has a functionally important impact on mucosal immunity, including enhanced protection from Trichinella spiralis infection and inflammatory colitis. Mechanistically, we show that T-bet controls the intestinal ILC pool through regulation of IL-7 receptor signalling. These data demonstrate that T-bet expression in ILCs acts as the key transcriptional checkpoint in regulating pathogenic vs. protective mucosal immune responses, which has significant implications for the understanding of the pathogenesis of inflammatory bowel diseases and intestinal infections

    Mixed States of Composite Fermions Carrying Two and Four Vortices

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    There now exists preliminary experimental evidence for some fractions, such as ν\nu = 4/11 and 5/13, that do not belong to any of the sequences ν=n/(2pn±1)\nu=n/(2pn\pm 1), pp and nn being integers. We propose that these states are mixed states of composite fermions of different flavors, for example, composite fermions carrying two and four vortices. We also obtain an estimate of the lowest-excitation dispersion curve as well as the transport gap; the gaps for 4/11 are smaller than those for 1/3 by approximately a factor of 50.Comment: Accepted for PRB rapid communication (scheduled to appear in Nov 15, 2000 issue

    Negatively Charged Excitons and Photoluminescence in Asymmetric Quantum Well

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    We study photoluminescence (PL) of charged excitons (XX^-) in narrow asymmetric quantum wells in high magnetic fields B. The binding of all XX^- states strongly depends on the separation δ\delta of electron and hole layers. The most sensitive is the ``bright'' singlet, whose binding energy decreases quickly with increasing δ\delta even at relatively small B. As a result, the value of B at which the singlet--triplet crossing occurs in the XX^- spectrum also depends on δ\delta and decreases from 35 T in a symmetric 10 nm GaAs well to 16 T for δ=0.5\delta=0.5 nm. Since the critical values of δ\delta at which different XX^- states unbind are surprisingly small compared to the well width, the observation of strongly bound XX^- states in an experimental PL spectrum implies virtually no layer displacement in the sample. This casts doubt on the interpretation of PL spectra of heterojunctions in terms of XX^- recombination

    A functional IL1RL1 variant regulates corticosteroid-induced sST2 expression in ulcerative colitis

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    Indexación: Web of Science; Scopus.The ST2/IL33 signalling pathway has been associated with ulcerative colitis (UC). ST2, encoded by the IL1RL1 gene, is expressed as both a membrane-anchored receptor (ST2L) activated by IL33 and as a soluble receptor (sST2) with anti-inflammatory properties. In UC patients, sST2 is further increased by corticosteroid treatment; however, the glucocorticoid-mediated molecular regulation remains unknown. We therefore tested whether genetic variants in the IL1RL1 distal promoter are involved in UC and affect glucocorticoid-mediated ST2 expression. Serum ST2 levels and genetic variants in the IL1RL1 distal promoter were examined by ELISA and PCR sequencing in UC patients receiving corticosteroids. Glucocorticoid-mediated ST2 production was evaluated in intestinal mucosa cultures. Molecular regulation of glucocorticoid-mediated ST2 was assessed by RT-qPCR, ChIP assay and luciferase reporter assay. Dexamethasone effect on ST2 transcript expression was analyzed in leukocytes and related to IL1RL1 variants. Sequencing of a distal IL1RL1 promoter region demonstrated that SNPs rs6543115(C) and rs6543116(A) are associated with increased sST2 in UC patients on corticosteroids. Dexamethasone up-regulated sST2 transcription through interaction with the glucocorticoid-response element (GRE) carrying rs6543115(C) variant. Our data indicate that IL1RL1 SNPs rs6543115(C) confer susceptibility to UC and is contained in the GRE, which may modulate glucocorticoid-induced sST2 expression.https://www.nature.com/articles/s41598-017-10465-

    Multifunctional metal matrix composites with embedded printed electrical materials fabricated by Ultrasonic Additive Manufacturing

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    This work proposes a new method for the fabrication of Multifunctional Metal Matrix Composite (MMC) structures featuring embedded printed electrical materials through Ultrasonic Additive Manufacturing (UAM). Printed electrical circuitries combining conductive and insulating materials were directly embedded within the interlaminar region of UAM aluminium matrices to realise previously unachievable multifunctional composites. A specific surface flattening process was developed to eliminate the risk of short circuiting between the metal matrices and printed conductors, and simultaneously reduce the total thickness of the printed circuitry. This acted to improve the integrity of the UAM MMC’s and their resultant mechanical strength. The functionality of embedded printed circuitries was examined via four-point probe measurement. DualBeam Scanning Electron Microscopy (SEM) and Focused Ion Beam (FIB) milling were used to investigate the microstructures of conductive materials to characterize the effect of UAM embedding energy whilst peel testing was used to quantify mechanical strength of MMC structures in combination with optical microscopy. Through this process, fully functioning MMC structures featuring embedded insulating and conductive materials were realised whilst still maintaining high peel resistances of ca. 70 N and linear weld densities of ca. 90%
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