Immigration and pension system in Portugal

The Portuguese Pension System is submitted to two risks. Over the period 2005-2050, a decrease of the workforce and an increase of old-age persons are eminent, which provide a doubling of the dependency rate. So, the system is not financially sustainable in the medium and long terms and it is expected that the system will enter in a growing deficit in 2015, when expenditures will overcome the revenues. Hence, the system is subject to a demographic risk (associated with the reduction of the fertility rates, the augmentation of the life expectancy and the increase of the dependency rate) and to a financial insolvency risk (motivated by the lack of equatorial correspondence between expenditures and revenues). Immigration could be a solution to the unsustainability of the pension systems. This paper examines the role of the immigration on resolving these two risks. We investigate, based on the European Economy (2006) projections about the impact of ageing on the public expenditure for the period 2005-50, the required immigrant flows that maintain the old-age dependency rate observed in 2004, and we calculate also the number of immigrants required to promote a null financial result for the Portuguese Pension System. We conclude that the number of immigrants that guarantees a null financial result is much lower than one that eliminates the demographic risk. Compared with the European Economy forecasts (2006), the number of immigrants required to guarantee the solvency of the Portuguese pension system is substantially higher and show an upward trend during the period under review contrary to the expected trend announced by that European entity.Portuguese Pension System, immigration, dependency rate, demographic risk, financial insolvency risk, ageing population

Programmed cell death (PCD): an essential process of cereal seed development and germination

The life cycle of cereal seeds can be divided into two phases, development and germination, separated by a quiescent period. Seed development and germination require the growth and differentiation of new tissues, but also the ordered disappearance of cells, which takes place by a process of programmed cell death (PCD). For this reason, cereal seeds have become excellent model systems for the study of developmental PCD in plants. At early stages of seed development, maternal tissues such as the nucellus, the pericarp and the nucellar projections undergo a progressive degeneration by PCD, which allows the remobilization of their cellular contents for nourishing new filial tissues such as the embryo and the endosperm. At a later stage, during seed maturation, the endosperm undergoes PCD, but these cells remain intact in the mature grain and their contents will not be remobilized until germination. Thus, the only tissues that remain alive when seed development is completed are the embryo axis, the scutellum and the aleurone layer. In germinating seeds, both the scutellum and the aleurone layer play essential roles in producing the hydrolytic enzymes for the mobilization of the storage compounds of the starchy endosperm, which serve to support early seedling growth. Once this function is completed, scutellum and aleurone cells undergo PCD; their contents being used to support the growth of the germinated embryo. PCD occurs with tightly controlled spatial-temporal patterns allowing coordinated fluxes of nutrients between the different seed tissues. In this review, we will summarize the current knowledge of the tissues undergoing PCD in developing and germinating cereal seeds, focussing on the biochemical features of the process. The effect of hormones and redox regulation on PCD control will be discussed

Short- and Long-Term Relations among Prices of the Mexican Crude Oil Blend, West Texas Intermediate, and Brent: Market Trend and Risk Premia, 2005-2016

This paper uses a Vector Error Correction Model (VECM) to obtain the decomposition in permanent and transient components of prices of the Mexican Crude Oil Blend, the West Texas Intermediate (WTI) oil, and the Brent oil of the North Sea. Moreover, Granger causality tests, impulse-response analysis, and variance decomposition are carried out.  The main findings are: 1) there are long-term relationships among these oil prices, 2) Brent oil mainly sets the market trend for the Mexican Crude Oil Blend, and 3) the yield-risk analysis shows that the Mexican crude oil blend offers the highest average yield and Brent provides the highest average risk premium. Keywords: Oil prices; econometric modeling, yield-risk analysis JEL Classifications: Q41, C51, G8

CYTOTOXIC EFFECT OF THE ETHANOLIC EXTRACT OF LOPHOCEREUS SCHOTTII: A MEXICAN MEDICINAL PLANT.

Lophocereus schottii is a Mexican cactus known as garambullo whose bark is used for the treatment of cancer, diabetes, ulcers, sores, stomach disorders and tuberculosis. The aim of this study was to evaluate the cytotoxic effect of the ethanolic extract of bark of L. Schottii. To assess these effects we established a flow of experiments in a model of BALB/c mice murine lymphoma. We value first survival of mice inoculated with 2 × 104 L5178Y murine lymphoma cells, orally treated with 10 mg/Kg of the extract for 10 consecutive days; the second assessment was to determine the influence of the immune system, we carry out studies of lymphoproliferation in mice with the same conditions of the previous study, only that the treatment was for 22 days before the completion cell cultures; the third study was to establish the cytotoxic effect of extract of L. schottii using different concentrations, by murine lymphoma cell cultures and splenocytes from healthy mice and finally we assessed the effect in vivo of extract of L. Schottii in a model of solid murine lymphoma inoculating 1 x 107 lymphoma cells in the gastrocnemius muscle observing the development of the tumor. We observed that oral treatment of 10 mg/kg of extract of L. schottii increased survival rate in treated mice; additionally, an intratumoral injection of 50 and 100 mg/kg in a solid murine lymphoma located in the gastrocnemius muscle, allowed a significantly slower tumor evolution. In vitro studies determined that extract inhibited 63% of lymphoma cell growth. With these evidences it is feasible to scientifically validate that ethanolic extract of L. schottii had an effect on L5178Y murine cells lymphoma and could have the same effect in human tumors

ANTI-GIARDIA ACTIVITY OF HEXANE EXTRACT OF CITRUS AURANTIFOLIA (CHRISTIM) SWINGLE AND SOME OF ITS CONSTITUENTS

Giardia lamblia is a parasite that causes giardiasis in humans and other mammals. The common treatment includes different classes of drugs, which were described to produce unpleasant side effects. Citrus aurantifolia, popularly known as lima, is a plant used in the traditional medicine to treat gastrointestinal symptoms. The aim of the present study was to evaluate the anti-Giardia activity of 10 pure compounds obtained from a hexanic extract of Mexican lime, on the basis of trophozoite growth inhibition. 4-hexen-3-one, citral and geraniol showed IC50 values of 34.2, 64.5 and 229.49 µg/ml in axenic cultures after 24 h of incubation, respectively. The obtained results lead us to propose that these compounds from C. aurantifolia have potential for use as therapeutic agents against giardiasis

More than smell - COVID-19 is associated with severe impairment of smell, taste, and chemesthesis

Recent anecdotal and scientific reports have provided evidence of a link between COVID-19 and chemosensory impairments, such as anosmia. However, these reports have downplayed or failed to distinguish potential effects on taste, ignored chemesthesis, and generally lacked quantitative measurements. Here, we report the development, implementation, and initial results of a multilingual, international questionnaire to assess self-reported quantity and quality of perception in 3 distinct chemosensory modalities (smell, taste, and chemesthesis) before and during COVID-19. In the first 11 days after questionnaire launch, 4039 participants (2913 women, 1118 men, and 8 others, aged 19-79) reported a COVID-19 diagnosis either via laboratory tests or clinical assessment. Importantly, smell, taste, and chemesthetic function were each significantly reduced compared to their status before the disease. Difference scores (maximum possible change ±100) revealed a mean reduction of smell (-79.7 ± 28.7, mean ± standard deviation), taste (-69.0 ± 32.6), and chemesthetic (-37.3 ± 36.2) function during COVID-19. Qualitative changes in olfactory ability (parosmia and phantosmia) were relatively rare and correlated with smell loss. Importantly, perceived nasal obstruction did not account for smell loss. Furthermore, chemosensory impairments were similar between participants in the laboratory test and clinical assessment groups. These results show that COVID-19-associated chemosensory impairment is not limited to smell but also affects taste and chemesthesis. The multimodal impact of COVID-19 and the lack of perceived nasal obstruction suggest that severe acute respiratory syndrome coronavirus strain 2 (SARS-CoV-2) infection may disrupt sensory-neural mechanisms. © 2020 The Author(s) 2020. Published by Oxford University Press. All rights reserved

Internet como fuente de información del alumno universitario

La âRed de redesâ revolucionó hace ya varias décadas la vida de todo estudiante universitario. Se ha convertido en una biblioteca mundial al alcance de un solo âclicâ. Sin embargo, eso no significa que sea de marcada fiabilidad y validez a la hora de utilizarlo como fuente de información para trabajos de educación superior. La mala calidad de la información unida a la facilidad de realizar el llamado ciberplagio, constituye un problema que todos los gobiernos deberían afrontar. Existen diversas formas de combatirlo y remediarlo, desde la utilización de enciclopedias de pago, más fiables y verídicas que las gratuitas, a la utilización de complejas aplicaciones informáticas reveladoras de plagio. | In just a few decades, the World Wide Web has revolutionized university studentsâ lives. The Internet has turned into a global library accessible at just the click of a mouse. However, this does not mean that all the information on the Web is trustworthy, nor does it make it a valid or reliable source for academic projects. The poor quality of much of the information, combined with the ease of committing cyber-plagiarism, is a problem that all governments need to confront. There are many ways of combating this problem, from the use of more credible sources, such as encyclopaedias requiring a subscription, to the use of complex applications that can detect cyber-plagiarism