576 research outputs found
Pleomorphic adenoma of the nasal septum : a case report
Polypoid nasal lesions are commonly encountered in clinical practice and all should be examined histologically. The authors report a case of pleomorphic adenoma arising in the nasal septum in salivary-type tissue. The interest of this case is both in the relative rarity of the condition, and also in its being the first such report in local practice.peer-reviewe
Papillitis as the prominent ocular sign in Acquired Immune Deficiency Syndrome (AIDS)
A 29-year old homosexual presented with clinical symptoms and an immunological picture of AIDS syndrome. Ocular involvement started in August 1986 with reduction of visual acuity in the right eye rapidly progressing to amaurosis. The most prominent ophthalmoscopical sign was of papillitis which had, in the beginning, the characteristics of an ischaemic optic neuropathy. Besides this, cotton-wool spots, retinal haemorrhages and limited areas of Cytomegalovirus (CMV) retinitis were found. Choroid was also involved with secondary CMV retinitis. On the other hand, sheathing of retinal vessels and Roth’s spots were absent. Although papilloedema, haemorrhages, cotton-wool exudates and CMV retinitis completely disappeared by October 1986, the general condition aggravated and the patient finally succumbed.peer-reviewe
Ocular manifestations in lepromatous and tuberculoid leprosy
Ocular manifestations of leprosy in 100 patients examined were reported on; -80% were suffering from the lepromatous type of the disease. The most frequent change was loss of eyebrows (40%) which was seen mainly in lepromatous patients. The sclera and cornea were rarely affected separately, but sclerokerato-iridocyclitis was found in 3%. On the other hand, the iris was involved rather more often -16% (atrophy of the iris -4, atrophy of the pupillary margin -3, miosis -1, posterior synechiae -6, keratic precipitates -1, and iris "pearls" -1). The iritis always had an insidious chronic evolution. The origin of the iritis is probably multifactorial: a) neuroparalytic due to involvement of the autonomic nerves supplying the iris muscles, primarily dilator; b) direct effect of Mycobacterium leprae on the iris tissue; and c) immune or auto-immune mechanisms. The posterior uvea was rarely affected (2%). No case of primary glaucoma was detected, but secondary glaucoma due to sclerokerato-iridocyclitis was found in 2 cases. Cataract seems to occur more frequently in leprosy patients (20%) than in the general population. The anterior segment was mostly affected (21%), and all these cases belonged to the lepromatous (16) or borderline lepromatous (5) type.peer-reviewe
Box 6. An initial analysis of the impact of inflation on collective bargaining in 2022
Artículo de revistaThis early-release box was published on 1 Apri
Expected, Unexpected, Good and Bad Uncertainty
By distinguishing between four general notions of uncertainty (good expected, bad-expected, good-unexpected, bad-unexpected) within a common and simple framework, we show that it is bad-unexpected uncertainty shocks that generate a negative reaction of macroeconomic variables (such as investment and consumption), and asset prices. Other notions of uncertainty might produce even positive responses in the macroeconomy. We also show that small uncertainty shocks might have larger impacts on economic activity and financial markets than bigger shocks between one to three years after its realization. We explore the time and magnitude of uncertainty shocks by means of a novel distributed lag nonlinear model. Our results help to elucidate the real and complex nature of uncertainty, which can be both a backward or forward-looking expected or unexpected event, with markedly different consequences for the economy. They have implications for policy making, asset pricing and risk management
Expected, unexpected, good and bad aggregate uncertainty
We study aggregate uncertainty and its linear and nonlinear impact on real and financial markets. By distinguishing between four general notions of aggregate uncertainty (good-expected, bad-expected, good-unexpected, bad-unexpected) within a simple, common framework, we show that it is bad-unexpected uncertainty shocks that generate a negative reaction of economic variables (such as investment and consumption) and asset prices. Our results help to elucidate the real, complex nature of uncertainty, which can be both a backward- or forward-looking expected or unexpected event, with markedly different consequences for the economy. We also document nonlinearities in the propagation of uncertainty to both real and financial markets, which calls for the close monitoring of the evolution of uncertainty so as to help mitigate the adverse effects of its occurrenc
Spillovers from the United States to Latin American and G7 stock markets: A VAR quantile analysis [WP]
We estimate multivariate quantile models to measure the responses of the six main Latin American (LA) stock markets to a shock in the United States (US) stock index. We compare the regional responses with those of seven developed markets. In general, we document weaker tailcodependences between the US and LA than those between the US and the mature markets. Our results suggest possible diversification strategies that could be exploited by investing in Latin America following a sizable shock to the US market. We also document asymmetrical responses to the shocks depending on the conditioning quantile at which they are calculated
Measuring Uncertainty in the Stock Market [WP]
We propose a daily index of time-varying stock market uncertainty. The index is constructed after first removing the common variations in the series, based on recent advances in the literature that emphasize the difference between risk (expected variation) and uncertainty (unexpected variation). To this end, we draw on data from 25 portfolios between 1926 and 2014, sorted by size and book-to-market value. This strategy considerably reduces information requirements and modeling design costs, compared to previous proposals. We compare our index with indicators of macrouncertainty and estimate the impact of an uncertainty shock on the dynamics of variables such as production, employment, consumption, stock market prices and interest rates. Our results show that, even when the estimates can be considered as a measure of stock market uncertainty (i.e., financial uncertainty), they perform very well as indicators of the uncertainty of the economy as a whole
Mortality and longevity risks in the United Kingdom: Dynamic factor models and copula-functions
We present a methodology to forecast mortality rates and estimate longevity and mortality risks. The methodology uses Generalized Dynamic Factor Models fitted over the differences of the log-mortality rates. We compare prediction performance with models previously proposed in the literature, such as the traditional Static Factor Model fitted over the level of log-mortality rates. We also construct risks measures by the means of vine-copula simulations, taking into account the dependence between the idiosyncratic components of the mortality rates.
The methodology is implemented to project the mortality rates of the United Kingdom, for which we consider a portfolio and study longevity and mortality risks
Daily Growth at Risk: financial or real drivers? The answer is not always the same
We estimate Growth-at-Risk (GaR) statistics for the US economy using daily regressors. We show that the relative importance, in terms of forecasting power, of financial and real variables is time varying. Indeed, the optimal forecasting weights of these types of variables were clearly different during the Global Financial Crisis and the recent Covid-19 crisis, which reflects the dissimilar nature of the two crises. We introduce the LASSO and the Elastic Net into the family of mixed data sampling models used to estimate GaR and show that these methods outperform past candidates explored in the literature. The role of the VXO and ADS indicators was found to be very relevant, especially in out-of-sample exercises and during crisis episodes. Overall, our results show that daily information for both real and financial variables is key for producing accurate point and tail risk nowcasts and forecasts of economic activity
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