63 research outputs found
Evaluating currency crises: A multivariate Markov regime switching approach
This paper provides an empirical framework to analyse the nature of currency crises byextending earlier work of Jeanne and Masson (2000) who suggest that a currency crisismodel with multiple equilibria can be estimated using Markov regime switching (MRS)models. However, Jeanne and Masson (2000) assume that the transition probabilitiesacross equilibria are constant and independent of fundamentals. Thus, currency crisis isdriven by a sunspot unrelated to fundamentals. This paper further contributes to theliterature by suggesting a multivariate MRS model to analyse the nature of currencycrises. In the new set up, one can test for the impact of the unobserved dynamics offundamentals on the probability of devaluation. Empirical evidence shows thatexpectations about fundamentals, which are reflected by their unobserved state variables,not only affect the probability of devaluation but also can be used to forecast a currencycrisis one period ahead
Quantitative expression of osteopontin in nasal mucosa of patients with allergic rhinitis: effects of pollen exposure and nasal glucocorticoid treatment
<p>Abstract</p> <p>Background</p> <p>Osteopontin (OPN) is a multifunctional cytokine that has been primarily investigated in Th1 diseases. Recently, it has also been implicated in Th2-mediated allergic diseases, such as asthma. The expression of OPN in allergic rhinitis (AR) is currently unknown, as is the effect of intranasal glucocorticosteroids (GCs) on that expression.</p> <p>Methods</p> <p>Subjects with AR were randomised to receive treatment with fluticasone propionate (FP) (n = 12) or a placebo (n = 16) over the grass pollen season and nasal biopsies were taken prior to, and during the season. OPN expression in the nasal mucosa was examined with immunohistochemistry. Healthy non-AR controls (n = 5) were used as a comparator.</p> <p>Results</p> <p>OPN expression was detected in epithelial cells, subepithelial infiltrating/inflammatory cells and cells lining the vessels and glands of all subjects. Comparison of the pre- and peak-pollen season biopsy sections in placebo treated patients revealed no increase in OPN expression during the grass pollen season (5.7% vs 6.4%). Treatment with a local glucocorticosteroid did not alter the expression of OPN during pollen exposure (6.2% vs 6.7%).</p> <p>Conclusion</p> <p>OPN has been increasingly associated with the pathogenesis of various Th2-mediated diseases. However, our finding that the OPN expression in the nasal mucosa of AR patients is not significantly affected by allergen exposure and is comparable to that of the healthy controls, suggests that intracellular OPN is not directly involved in the pathogenesis of allergic rhinitis.</p
Expansion of CD4+CD25+ and CD25- T-Bet, GATA-3, Foxp3 and RORγt Cells in Allergic Inflammation, Local Lung Distribution and Chemokine Gene Expression
Allergic asthma is associated with airway eosinophilia, which is regulated by
different T-effector cells. T cells express transcription factors T-bet, GATA-3,
RORγt and Foxp3, representing Th1, Th2, Th17 and Treg cells respectively. No
study has directly determined the relative presence of each of these T cell
subsets concomitantly in a model of allergic airway inflammation. In this study
we determined the degree of expansion of these T cell subsets, in the lungs of
allergen challenged mice. Cell proliferation was determined by incorporation of
5-bromo-2′-deoxyuridine (BrdU) together with 7-aminoactnomycin (7-AAD).
The immunohistochemical localisation of T cells in the lung microenvironments
was also quantified. Local expression of cytokines, chemokines and receptor
genes was measured using real-time RT-PCR array analysis in tissue sections
isolated by laser microdissection and pressure catapulting technology. Allergen
exposure increased the numbers of T-bet+,
GATA-3+, RORγt+ and
Foxp3+ cells in CD4+CD25+
and CD4+CD25- T cells, with the greatest expansion of
GATA-3+ cells. The majority of
CD4+CD25+ T-bet+,
GATA-3+, RORγt+ and
Foxp3+ cells had incorporated BrdU and underwent
proliferation during allergen exposure. Allergen exposure led to the
accumulation of T-bet+, GATA-3+ and
Foxp3+ cells in peribronchial and alveolar tissue,
GATA-3+ and Foxp3+ cells in perivascular
tissue, and RORγt+ cells in alveolar tissue. A total of 28
cytokines, chemokines and receptor genes were altered more than 3 fold upon
allergen exposure, with expression of half of the genes claimed in all three
microenvironments. Our study shows that allergen exposure affects all T effector
cells in lung, with a dominant of Th2 cells, but with different local cell
distribution, probably due to a distinguished local inflammatory milieu
Is diet partly responsible for differences in COVID-19 death rates between and within countries?
Correction: Volume: 10 Issue: 1 Article Number: 44 DOI: 10.1186/s13601-020-00351-w Published: OCT 26 2020Reported COVID-19 deaths in Germany are relatively low as compared to many European countries. Among the several explanations proposed, an early and large testing of the population was put forward. Most current debates on COVID-19 focus on the differences among countries, but little attention has been given to regional differences and diet. The low-death rate European countries (e.g. Austria, Baltic States, Czech Republic, Finland, Norway, Poland, Slovakia) have used different quarantine and/or confinement times and methods and none have performed as many early tests as Germany. Among other factors that may be significant are the dietary habits. It seems that some foods largely used in these countries may reduce angiotensin-converting enzyme activity or are anti-oxidants. Among the many possible areas of research, it might be important to understand diet and angiotensin-converting enzyme-2 (ACE2) levels in populations with different COVID-19 death rates since dietary interventions may be of great benefit.Peer reviewe
Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19
Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe
Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies
There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity
Applications of Genetic Programming to Finance and Economics: Past, Present, Future
While the origins of Genetic Programming (GP) stretch back over fifty years, the field of GP was invigorated by John Koza’s popularisation of the methodology in the 1990s. A particular feature of the GP literature since then has been a strong interest in the application of GP to real-world problem domains. One application domain which has attracted significant attention is that of finance and economics, with several hundred papers from this subfield being listed in the Genetic Programming Bibliography. In this article we outline why finance and economics has been a popular application area for GP and briefly indicate the wide span of this work. However, despite this research effort there is relatively scant evidence of the usage of GP by the mainstream finance community in academia or industry. We speculate why this may be the case, describe what is needed to make this research more relevant from a finance perspective, and suggest some future directions for the application of GP in finance and economics
Assessment of satisfaction with different dry powder inhalation devices in Greek patients with COPD and asthma: the ANASA study
Eleftherios Zervas, Konstantinos Samitas, Mina Gaga 7th Respiratory Department and Asthma Center, Athens Chest Hospital “Sotiria”, Athens, Greece Background: Poor adherence to inhaled therapy is common in patients with asthma and COPD. An inhaler selection based on patients’ preference could be beneficial to adherence and treatment effectiveness. Properly designed questionnaires can assess patients’ satisfaction with their medication devices. The aim of this study was to estimate, using the Feeling of Satisfaction with Inhaler (FSI-10) questionnaire, the ease of use and satisfaction of patients regarding three different marketed dry powder inhalers (DPIs): Diskus® (DK), Elpenhaler® (EH), and Turbuhaler® (TH). The FSI-10 is a self-completed questionnaire to assess patients’ opinions regarding ease of use, portability, and usability of devices, irrespective of the drug used.Patients and methods: We performed a 4-week, open, noninterventional, multicenter, parallel clinical study in 560 asthmatic and 561 COPD patients. During the first visit, patients were classified into three groups according to the DPI they were already using. Patients were regularly receiving their treatments (Seretide DK, Rolenium EH, and Symbicort TH) and agreed to complete the FSI-10 questionnaire in the second visit.Results: A total of 517 COPD and 523 asthma patients completed the study. All DPIs tested received satisfactory results, while the EH obtained consistently higher scores in the FSI-10 in both COPD and asthma patients (44.7 and 44.1 vs 41.5 and 43 for TH, 40.8 and 41.4 for DK, P<0.001 and P<0.01, respectively). TH was rated better than DK by asthma patients. Patients suffering with severe COPD tended to express higher feeling of satisfaction than those with moderate or mild disease, irrespective of the device used.Conclusion: All DPIs tested were highly acceptable by asthma and COPD patients of different ages; nevertheless, EH received significantly higher ratings in most of the questionnaire domains. COPD patients in advanced stages of the disease generally expressed higher level of satisfaction with their devices.Keywords: asthma, COPD, dry powder inhaler, patient satisfaction, FSI-10 questionnair
Evaluating currency crises: A multivariate markov regime switching approach*
This paper provides an empirical framework to analyse the nature of currency crises by extending earlier work of Jeanne and Masson (2000; Journal of International Economics, Vol. 50, pp. 327-350). Jeanne and Masson suggest a Markov regime switching models to analyse models of currency crises with multiple equilibria. This paper further contributes to the literature by suggesting a multivariate Markov regime switching model. In the new set-up, one can test for the impact of the unobserved dynamics of fundamentals on the probability of devaluation. © 2012 Blackwell Publishing Ltd and The University of Manchester
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