292 research outputs found

    The impact of COVID-19 on destination visit intention and local food consumption

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    Purpose: This paper aims to investigate the relationships between motivation and intention to consume local food and between intention to consume local food and intention to visit the destination of that food's origin while examining the moderating effect of risk perception associated with coronavirus disease 2019 (COVID-19). Design/methodology/approach: Data were collected from two samples of potential Chinese tourists in the contexts of Italian and Thai food. Data obtained from 264 Chinese respondents for Italian food and 277 Chinese respondents for Thai food were analyzed. Partial least squares structural equation modeling was utilized to test the research model. Findings: The results indicate that, while motivational factors such as cultural experience, novelty and sensory appeal influence potential Chinese tourists' intention to consume Italian food, motivational factors such as cultural experience, health concern, novelty and sensory appeal influence tourists' intention to consume Thai food. The authors found that intention to consume local food positively influences tourists' intention to visit both destinations (Italy and Thailand). Moreover, tourists' risk perceptions of COVID-19 negatively moderate the effect of cultural experience and novelty on the intention to consume Italian food. Regarding the intention to consume Thai food, the authors found that tourists' risk perceptions have a diminishing effect on all motivational factors. Originality/value: This pioneering study examines the role of COVID-19-related risk perception on the relationships among motivation of local food consumption, intention of local food consumption and destination visit intention in the context of two destination countries. It reveals cross-country differences of the negative effect pertaining to the risk perceptions of COVID-19, which has important implications for international destination marketing

    FIR Filter Design by Convex Optimization Using Directed Iterative Rank Refinement Algorithm

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    The advances in convex optimization techniques have offered new formulations of design with improved control over the performance of FIR filters. By using lifting techniques, the design of a length-L FIR filter can be formulated as a convex semidefinite program (SDP) in terms of an L× L matrix that must be rank-1. Although this formulation provides means for introducing highly flexible design constraints on the magnitude and phase responses of the filter, convex solvers implementing interior point methods almost never provide a rank-1 solution matrix. To obtain a rank-1 solution, we propose a novel Directed Iterative Rank Refinement (DIRR) algorithm, where at each iteration a matrix is obtained by solving a convex optimization problem. The semidefinite cost function of that convex optimization problem favors a solution matrix whose dominant singular vector is on a direction determined in the previous iterations. Analytically it is shown that the DIRR iterations provide monotonic improvement, and the global optimum is a fixed point of the iterations. Over a set of design examples it is illustrated that the DIRR requires only a few iterations to converge to an approximately rank-1 solution matrix. The effectiveness of the proposed method and its flexibility are also demonstrated for the cases where in addition to the magnitude constraints, the constraints on the phase and group delay of filter are placed on the designed filter. © 2015 IEEE

    Mobility assemblages and lines of flight in women’s narratives of forced displacement

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    In this paper I take the notion of the mobility assemblage as a theoretical lens through which I consider entanglements between refugee and migrant women on the move, intense experiences of gendered labour, and affective encounters in crossing borders and following lines of flight. The analysis revolves around the life-story of a young refugee woman, who recounts her experiences of travelling to Greece. What emerges from her narrative is a whirl of lines of flight that deterritorialize her from patriarchal regimes, harsh border practices, labour exploitation and the pain of separation on a plane of remaking her present and re-imagining her future

    Inhibition of focal adhesion kinase with her-2 targeted antibody pertuzumab (Omnitarg®, 2C4) in breast cancer cells

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    Pertuzumab (Omnitarg®, 2C4) is a recombinant humanized monoclonal antibody targeted to extracellular region of HER-2. Previous results proved the inhibitory effect of Pertuzumab on the survival of breast cancer cells via MAPK and Akt pathway. Focal adhesion kinase (FAK) regulates multiple cellular processes including growth, differentiation, adhesion, motility and apoptosis. Here, we aimed to investigate the effects of Pertuzumab on ligand activated total FAK expression and phosphorylation in the HER-2 overexpressing BT-474 breast cancer cell line. Heregulin was used for ligand activation. We have found that FAK expression and phosphorylation were inhibited in with Pertuzumab in breast cancer cells

    Physicians’ Perspectives on the Diagnosis and Treatment of Chronic Nonbacterial Osteomyelitis

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    Background/Purpose. Understanding the practices of pediatric rheumatologists in diagnosing and treating chronic nonbacterial osteomyelitis (CNO) can provide important information to guide the development of consensus treatment plans. The objectives of this study were to determine physicians’ approaches to (1) diagnosing and monitoring CNO, (2) ordering a bone biopsy, and (3) making treatment decisions. Methods. A survey was distributed among members of the Childhood Arthritis and Rheumatology Research Alliance using a web-based questionnaire. Results. 121 of 277 (41%) attending physician members completed the survey. Plain radiographs (89%) were most commonly used followed by regional MRI (78%), bone scintigraphy (43%), and whole-body MRI (36%). The top three reasons for performing a biopsy were constitutional findings (66%), unifocal bone lesions (64%), and nocturnal bone pain (45%). Nearly all responders (95%) prescribed nonsteroidal anti-inflammatory drugs (NSAIDs) as initial therapy. For patients who failed NSAID treatment, methotrexate (67%), tumor necrosis factor inhibitors (65%), and bisphosphonates (46%) were the next most commonly used treatments. The presence of a spinal lesion increased the use of bisphosphonate treatment. Conclusion. The diagnostic approach and disease activity monitoring for CNO varied among surveyed physicians. Our survey findings provided important background for the development of consensus treatment plans for CNO

    Henoch-Schönlein nephritis associated with streptococcal infection and persistent hypocomplementemia: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Henoch-Schönlein purpura is a systemic disease with frequent renal involvement, characterized by IgA mesangial deposits. Streptococcal infection can induce an abnormal IgA immune response like Henoch-Schönlein purpura, quite similar to typical acute post-infectious glomerulonephritis. Indeed, hypocomplementemia that is typical of acute glomerulonephritis has also been described in Henoch-Schönlein purpura.</p> <p>Case presentation</p> <p>We describe a 14-year-old Caucasian Spanish girl who developed urinary abnormalities and cutaneous purpura after streptococcal infection. Renal biopsy showed typical findings from Henoch-Schönlein purpura nephritis. In addition, she had low serum levels of complement (C4 fraction) that persisted during follow-up, in spite of her clinical evolution. She responded to treatment with enalapril and steroids.</p> <p>Conclusion</p> <p>The case described has, at least, three points of interest in Henoch-Schönlein purpura: 1) Initial presentation was preceded by streptococcal infection; 2) There was a persistence of low serum levels of complement; and 3) There was response to steroids and angiotensin-converting enzyme inhibitor in the presence of nephrotic syndrome. There are not many cases described in the literature with these characteristics. We conclude that Henoch-Schönlein purpura could appear after streptococcal infection in patients with abnormal complement levels, and that steroids and angiotensin-converting enzyme inhibitor could be successful treatment for the disease.</p

    The Ability to Generate Senescent Progeny as a Mechanism Underlying Breast Cancer Cell Heterogeneity

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    Background Breast cancer is a remarkably heterogeneous disease. Luminal, basal-like, "normal-like", and ERBB2+ subgroups were identified and were shown to have different prognoses. The mechanisms underlying this heterogeneity are poorly understood. In our study, we explored the role of cellular differentiation and senescence as a potential cause of heterogeneity. Methodology/Principal Findings A panel of breast cancer cell lines, isogenic clones, and breast tumors were used. Based on their ability to generate senescent progeny under low-density clonogenic conditions, we classified breast cancer cell lines as senescent cell progenitor (SCP) and immortal cell progenitor (ICP) subtypes. All SCP cell lines expressed estrogen receptor (ER). Loss of ER expression combined with the accumulation of p21Cip1 correlated with senescence in these cell lines. p21Cip1 knockdown, estrogen-mediated ER activation or ectopic ER overexpression protected cells against senescence. In contrast, tamoxifen triggered a robust senescence response. As ER expression has been linked to luminal differentiation, we compared the differentiation status of SCP and ICP cell lines using stem/progenitor, luminal, and myoepithelial markers. The SCP cells produced CD24+ or ER+ luminal-like and ASMA+ myoepithelial-like progeny, in addition to CD44+ stem/progenitor-like cells. In contrast, ICP cell lines acted as differentiation-defective stem/progenitor cells. Some ICP cell lines generated only CD44+/CD24-/ER-/ASMA- progenitor/stem-like cells, and others also produced CD24+/ER- luminal-like, but not ASMA+ myoepithelial-like cells. Furthermore, gene expression profiles clustered SCP cell lines with luminal A and "normal-like" tumors, and ICP cell lines with luminal B and basal-like tumors. The ICP cells displayed higher tumorigenicity in immunodeficient mice. Conclusions/Significance Luminal A and "normal-like" breast cancer cell lines were able to generate luminal-like and myoepithelial-like progeny undergoing senescence arrest. In contrast, luminal B/basal-like cell lines acted as stem/progenitor cells with defective differentiation capacities. Our findings suggest that the malignancy of breast tumors is directly correlated with stem/progenitor phenotypes and poor differentiation potential. © 2010 Mumcuoglu et al

    Role of Nitric Oxide in Shiga Toxin-2-Induced Premature Delivery of Dead Fetuses in Rats

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    Shiga toxin-producing Escherichia coli (STEC) infections could be one of the causes of fetal morbimortality in pregnant women. The main virulence factors of STEC are Shiga toxin type 1 and/or 2 (Stx1, Stx2). We previously reported that intraperitoneal (i.p.) injection of rats in the late stage of pregnancy with culture supernatant from recombinant E. coli expressing Stx2 and containing lipopolysaccharide (LPS) induces premature delivery of dead fetuses. It has been reported that LPS may combine with Stx2 to facilitate vascular injury, which may in turn lead to an overproduction of nitric oxide (NO). The aim of this study was to evaluate whether NO is involved in the effects of Stx2 on pregnancy. Pregnant rats were i.p. injected with culture supernatant from recombinant E. coli containing Stx2 and LPS (sStx2) on day 15 of gestation. In addition, some rats were injected with aminoguanidine (AG), an inducible isoform inhibitor of NO synthase (iNOS), 24 h before and 4 h after sStx2 injection. NO production was measured by NOS activity and iNOS expression by Western blot analysis. A significant increase in NO production and a high iNOS expression was observed in placental tissues from rats injected with sStx2 containing 0.7 ng and 2 ng Stx2/g body weight and killed 12 h after injection. AG caused a significant reduction of sStx2 effects on the feto-maternal unit, but did not prevent premature delivery. Placental tissues from rats treated with AG and sStx2 presented normal histology that was indistinguishable from the controls. Our results reveal that Stx2-induced placental damage and fetus mortality is mediated by an increase in NO production and that AG is able to completely reverse the Stx2 damages in placental tissues, but not to prevent premature delivery, thus suggesting other mechanisms not yet determined could be involved

    Novel Cell- and Tissue-Based Assays for Detecting Misfolded and Aggregated Protein Accumulation Within Aggresomes and Inclusion Bodies

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    Aggresomes and related inclusion bodies appear to serve as storage depots for misfolded and aggregated proteins within cells, which can potentially be degraded by the autophagy pathway. A homogenous fluorescence-based assay was devised to detect aggregated proteins inside aggresomes and inclusion bodies within an authentic cellular context. The assay employs a novel red fluorescent molecular rotor dye, which is essentially nonfluorescent until it binds to structural features associated with the aggregated protein cargo. Aggresomes and related structures were generated within cultured cells using various potent, cell permeable, proteasome inhibitors: MG-132, lactacystin, epoxomicin and bortezomib, and then selectively detected with the fluorescent probe. Employing the probe in combination with various fluorescein-labeled primary antibodies facilitated co-localization of key components of the autophagy system (ubiquitin, p62, and LC3) with aggregated protein cargo by fluorescence microscopy. Furthermore, cytoplasmic aggregates were highlighted in SK-N-SH human neuroblastoma cells incubated with exogenously supplied amyloid beta peptide 1–42. SMER28, a small molecule modulator of autophagy acting via an mTOR-independent mechanism, prevented the accumulation of amyloid beta peptide within these cells. The described assay allows assessment of the effects of protein aggregation directly in cells, without resorting to the use of non-physiological protein mutations or genetically engineered cell lines. With minor modification, the assay was also adapted to the analysis of frozen or formalin-fixed, paraffin-embedded tissue sections, with demonstration of co-localization of aggregated cargo with β-amyloid and tau proteins in brain tissue sections from Alzheimer’s disease patients

    Altered Neurocircuitry in the Dopamine Transporter Knockout Mouse Brain

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    The plasma membrane transporters for the monoamine neurotransmitters dopamine, serotonin, and norepinephrine modulate the dynamics of these monoamine neurotransmitters. Thus, activity of these transporters has significant consequences for monoamine activity throughout the brain and for a number of neurological and psychiatric disorders. Gene knockout (KO) mice that reduce or eliminate expression of each of these monoamine transporters have provided a wealth of new information about the function of these proteins at molecular, physiological and behavioral levels. In the present work we use the unique properties of magnetic resonance imaging (MRI) to probe the effects of altered dopaminergic dynamics on meso-scale neuronal circuitry and overall brain morphology, since changes at these levels of organization might help to account for some of the extensive pharmacological and behavioral differences observed in dopamine transporter (DAT) KO mice. Despite the smaller size of these animals, voxel-wise statistical comparison of high resolution structural MR images indicated little morphological change as a consequence of DAT KO. Likewise, proton magnetic resonance spectra recorded in the striatum indicated no significant changes in detectable metabolite concentrations between DAT KO and wild-type (WT) mice. In contrast, alterations in the circuitry from the prefrontal cortex to the mesocortical limbic system, an important brain component intimately tied to function of mesolimbic/mesocortical dopamine reward pathways, were revealed by manganese-enhanced MRI (MEMRI). Analysis of co-registered MEMRI images taken over the 26 hours after introduction of Mn^(2+) into the prefrontal cortex indicated that DAT KO mice have a truncated Mn^(2+) distribution within this circuitry with little accumulation beyond the thalamus or contralateral to the injection site. By contrast, WT littermates exhibit Mn^(2+) transport into more posterior midbrain nuclei and contralateral mesolimbic structures at 26 hr post-injection. Thus, DAT KO mice appear, at this level of anatomic resolution, to have preserved cortico-striatal-thalamic connectivity but diminished robustness of reward-modulating circuitry distal to the thalamus. This is in contradistinction to the state of this circuitry in serotonin transporter KO mice where we observed more robust connectivity in more posterior brain regions using methods identical to those employed here
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