Spermatozoa Transcriptional Response and Alterations in PL Proteins Properties after Exposure of Mytilus galloprovincialis to Mercury

Mercury (Hg) is an environmental pollutant that impacts human and ecosystem health. In our previous works, we reported alterations in the properties of Mytilus galloprovincialis protamine-like (PL) proteins after 24 h of exposure to subtoxic doses of toxic metals such as copper and cadmium. The present work aims to assess the effects of 24 h of exposure to 1, 10, and 100 pM HgCl₂ on spermatozoa and PL proteins of Mytilus galloprovincialis. Inductively coupled plasma–mass spectrometry indicated accumulation of this metal in the gonads of exposed mussels. Further, RT-qPCR analyses showed altered expression levels of spermatozoa mt10 and hsp70 genes. In Mytilus galloprovincialis, PL proteins represent the major basic component of sperm chromatin. These proteins, following exposure of mussels to HgCl₂, appeared, by SDS-PAGE, partly as aggregates and showed a decreased DNA-binding capacity that rendered them unable to prevent DNA damage, in the presence of CuCl₂ and H₂O₂. These results demonstrate that even these doses of HgCl₂ exposure could affect the properties of PL proteins and result in adverse effects on the reproductive system of this organism. These analyses could be useful in developing rapid and efficient chromatin-based genotoxicity assays for pollution biomonitoring programs.     

Sarcopenia: Molecular Pathways and Potential Targets for Intervention

Aging is associated with sarcopenia. The loss of strength results in decreased muscle mass and motor function. This process accelerates the progressive muscle deterioration observed in older adults, favoring the presence of debilitating pathologies. In addition, sarcopenia leads to a decrease in quality of life, significantly affecting self-sufficiency. Altogether, these results in an increase in economic resources from the National Health Systems devoted to mitigating this problem in the elderly, particularly in developed countries. Different etiological determinants are involved in the progression of the disease, including: neurological factors, endocrine alterations, as well as nutritional and lifestyle changes related to the adoption of more sedentary habits. Molecular and cellular mechanisms have not been clearly characterized, resulting in the absence of an effective treatment for sarcopenia. Nevertheless, physical activity seems to be the sole strategy to delay sarcopenia and its symptoms. The present review intends to bring together the data explaining how physical activity modulates at a molecular and cellular level all factors that predispose or favor the progression of this deteriorating pathology.     

Public investment in transportation infrastructures and regional asymmetries in Portugal

The objective of this paper is to investigate the regional incidence of the effects of public investment in transportation infrastructures in Portugal. Our methodological approach consists of estimating vector autoregressive (VAR) models for the national economy as well as for each of the five administrative regions in the country. In the regional models, both public investment in transportation infrastructures in the region and public investment in transportation infrastructures elsewhere are considered, thereby taking into consideration the potential existence of regional spillovers. Empirical results suggest that although public investment in transportation infrastructures has been a powerful instrument to promote long-term growth, it does so in a way that is rather unbalanced across regions. We show that public investment in transportation infrastructures has markedly contributed to the concentration of economic activity in Lisbon, the largest region in the country, and therefore has contributed markedly to the macrocephaly of the country.

A response surface technique for fuzzy—random evaluations of local seismic hazard

Local soil amplification is one of the main phenomena contributing to local seismic hazard and consequently to local seismic risk. It is influenced both by randomness and by fuzziness. This paper offers a general fuzzy—random formulation, applicable to nonlinear soil amplification studies and hence to evaluations of local seismic hazard. The results obtainable by probabilistic analysis and also those arrived at using fuzzy analysis can be considered as consequences of particularizations of this formulation.

The treatment is rendered explicit by adapting the response surface technique to the problem, as this is advantageous in terms of computational economy.     

Geometric Parameterization Technique for Continuation Power Flow Based on Quadratic Curve

The electricity sector, especially in emerging countries, has experienced several transformations, mainly resulting from the increase of electricity demand. This encourages more investment in the generation sector and causes increasing concerns with the development and improvement of tools for static voltage stability analysis of electrical power systems. This paper presents a new geometric parameterization technique for continuation power flow (CPF) that works based on the addition of a parabola that passes through three points in the plane formed by the variables of total real power losses and loading factor. This technique eliminates the Jacobian matrix singularity at the maximum loading point, which allows obtaining the solution trajectory (P–V curve) without any need to change the parameter, which is a very common procedure in the currently available CPFs. Intending to define a simple and efficient step size control procedure, the total real power losses values are normalized by its base case value. The results obtained by applying the proposed technique to the IEEE-300 bus system and two real large systems of 638 and 787 buses show its effectiveness.