THERMODYNAMIC ANALYSIS AND ECOLOGICAL EFFICIENCY OF A COMBINED CYCLE POWER PLANT

The purpose of this article is to through the analysis of the first law of thermodynamic for a combined cycle determines the ecological coefficient of the same. This system consists of two gas turbines, two heat recovery boilers and a steam turbine, having a total installed capacity of power generation of 500 MW. This plant will be installed in a small town located 180 km from São Paulo. This place was chosen based on technical aspects by present proximity to the pipeline and transmission line, water availability and other favorable environmental aspects of the project. The natural gas that will serve as the plant's fuel will come from the Field of Mexilhão, from the base of Caraguatatuba, and the water used for cooling will come from the Paraíba do Sul River

Fragmentation branching ratios of highly excited hydrocarbon molecules CnH and their cations CnH+ (n<4)

We have measured fragmentation branching ratios of neutral CnH and CnH+ cations produced in high velocity (4.5 a.u) collisions between incident CnH+ cations and helium atoms. Electron capture gives rise to excited neutral species CnH and electronic excitation to excited cations CnH+. Thanks to a dedicated set-up, based on coincident detection of all fragments, the dissociation of the neutral and cationic parents were recorded separately and in a complete way. For the fragmentation of CnH, the H-loss channel is found to be dominant, as already observed by other authors. By contrast, the H-loss and C-loss channels equally dominate the two-fragment break up of CnH+ species. For these cations, we provide the first fragmentation data (n > 2). Results are also discussed in the context of astrochemistry

Cell arrest and cell death in mammalian preimplantation development

The causes, modes, biological role and prospective significance of cell death in preimplantation development in humans and other mammals are still poorly understood. Early bovine embryos represent a very attractive experimental model for the investigation of this fundamental and important issue. To obtain reference data on the temporal and spatial occurrence of cell death in early bovine embryogenesis, three-dimensionally preserved embryos of different ages and stages of development up to hatched blastocysts were examined in toto by confocal laser scanning microscopy. In parallel, transcript abundance profiles for selected apoptosis-related genes were analyzed by real-time reverse transcriptase-polymerase chain reaction. Our study documents that in vitro as well as in vivo, the first four cleavage cycles are prone to a high failure rate including different types of permanent cell cycle arrest and subsequent non-apoptotic blastomere death. In vitro produced and in vivo derived blastocysts showed a significant incidence of cell death in the inner cell mass (ICM), but only in part with morphological features of apoptosis. Importantly, transcripts for CASP3, CASP9, CASP8 and FAS/FASLG were not detectable or found at very low abundances. In vitro and in vivo, errors and failures of the first and the next three cleavage divisions frequently cause immediate embryo death or lead to aberrant subsequent development, and are the main source of developmental heterogeneity. A substantial occurrence of cell death in the ICM even in fast developing blastocysts strongly suggests a regular developmentally controlled elimination of cells, while the nature and mechanisms of ICM cell death are unclear. Morphological findings as well as transcript levels measured for important apoptosis-related genes are in conflict with the view that classical caspase-mediated apoptosis is the major cause of cell death in early bovine development

Reverse Engineering Gene Networks with ANN: Variability in Network Inference Algorithms

Motivation :Reconstructing the topology of a gene regulatory network is one of the key tasks in systems biology. Despite of the wide variety of proposed methods, very little work has been dedicated to the assessment of their stability properties. Here we present a methodical comparison of the performance of a novel method (RegnANN) for gene network inference based on multilayer perceptrons with three reference algorithms (ARACNE, CLR, KELLER), focussing our analysis on the prediction variability induced by both the network intrinsic structure and the available data. Results: The extensive evaluation on both synthetic data and a selection of gene modules of "Escherichia coli" indicates that all the algorithms suffer of instability and variability issues with regards to the reconstruction of the topology of the network. This instability makes objectively very hard the task of establishing which method performs best. Nevertheless, RegnANN shows MCC scores that compare very favorably with all the other inference methods tested. Availability: The software for the RegnANN inference algorithm is distributed under GPL3 and it is available at the corresponding author home page (http://mpba.fbk.eu/grimaldi/regnann-supmat

Trinucleotide repeats in 202 families with ataxia: a small expanded (CAG)n allele at the SCA17 locus

BACKGROUND: Ten neurodegenerative disorders characterized by spinocerebellar ataxia (SCA) are known to be caused by trinucleotide repeat (TNR) expansions. However, in some instances the molecular diagnosis is considered indeterminate because of the overlap between normal and affected allele ranges. In addition, the mechanism that generates expanded alleles is not completely understood. OBJECTIVE: To examine the clinical and molecular characteristics of a large group of Portuguese and Brazilian families with ataxia to improve knowledge of the molecular diagnosis of SCA. PATIENTS AND METHODS: We have (1) assessed repeat sizes at all known TNR loci implicated in SCA; (2) determined frequency distributions of normal alleles and expansions; and (3) looked at genotype-phenotype correlations in 202 unrelated Portuguese and Brazilian patients with SCA. Molecular analysis of TNR expansions was performed using polymerase chain reaction amplification. RESULTS: Patients from 110 unrelated families with SCA showed TNR expansions at 1 of the loci studied. Dominantly transmitted cases had (CAG)(n) expansions at the Machado-Joseph disease gene (MJD1) (63%), at SCA2 (3%), the gene for dentatorubropallidoluysian atrophy (DRPLA) (2%), SCA6 (1%), or SCA7 (1%) loci, or (CTG)(n) expansions at the SCA8 (2%) gene, whereas (GAA)(n) expansions in the Freidreich ataxia gene (FRDA) were found in 64% of families with recessive ataxia. Isolated patients also had TNR expansions at the MJD1 (6%), SCA8 (6%), or FRDA (8%) genes; in addition, an expanded allele at the TATA-binding protein gene (TBP), with 43 CAGs, was present in a patient with ataxia and mental deterioration. Associations between frequencies of SCA2 and SCA6 and a frequency of large normal alleles were found in Portuguese and Brazilian individuals, respectively. Interestingly, no association between the frequencies of DRPLA and large normal alleles was found in the Portuguese group. CONCLUSIONS: Our results show that (1) a significant number of isolated cases of ataxia are due to TNR expansions; (2) expanded DRPLA alleles in Portuguese families may have evolved from an ancestral haplotype; and (3) small (CAG)(n) expansions at the TBP gene may cause SCA17

Neural circuits for the adaptive regulation of fear and extinction memory

The regulation of fear memories is critical for adaptive behaviors and dysregulation of these processes is implicated in trauma- and stress-related disorders. Treatments for these disorders include pharmacological interventions as well as exposure-based therapies, which rely upon extinction learning. Considerable attention has been directed toward elucidating the neural mechanisms underlying fear and extinction learning. In this review, we will discuss historic discoveries and emerging evidence on the neural mechanisms of the adaptive regulation of fear and extinction memories. We will focus on neural circuits regulating the acquisition and extinction of Pavlovian fear conditioning in rodent models, particularly the role of the medial prefrontal cortex and hippocampus in the contextual control of extinguished fear memories. We will also consider new work revealing an important role for the thalamic nucleus reuniens in the modulation of prefrontal-hippocampal interactions in extinction learning and memory. Finally, we will explore the effects of stress on this circuit and the clinical implications of these findings

Lower prevalence of congenital cytomegalovirus infection in Portugal: possible impact of COVID-19 lockdown?

Cytomegalovirus (CMV) is the most frequent cause of congenital infection all over the world. Its prevalence ranges from 0.2 to 2.2%. Transmission from children to their pregnant mothers is a well-known risk factor, particularly if they attend a childcare centre. This study aims to compare the prevalence of CMV congenital infection (CMV_CI) in Portugal (Lisbon) between two studies, performed respectively in 2019 and 2020. In the 2019 study, performed in two hospitals, we found a 0.67% CMV_CI prevalence, using a pool strategy previously tested with saliva samples. In the 2020 study, using the same pool approach in four hospitals (the previous and two additional), and based on 1277 samples, the prevalence was 0.078%.Conclusion: The close temporal coincidence with COVID-19 lockdown suggests that these measures may have had a significant impact on this reduction, although other explanations cannot be ruled-out. What is Known: • Cytomegalovirus is the leading cause of congenital infection. • Behavioural measures decrease cytomegalovirus seroconversion in pregnant women. What is New: • From 2019 to 2020 there was a significant reduction in the prevalence of congenital CMV infection.info:eu-repo/semantics/publishedVersio

Entanglement in supramolecular spin systems of two weakly coupled antiferromagnetic rings (purple-Cr7Ni)

International audienceWe characterize supramolecular magnetic structures, consisting of two weakly coupled antiferromagnetic rings, by low-temperature specific heat, susceptibility, magnetization and electron paramagnetic resonance measurements. Intra- and inter-ring interactions are modeled through a microscopic spin-Hamiltonian approach that reproduces all the experimental data quantitatively and legitimates the use of an effective two-qubit picture. Spin entanglement between the rings is experimentally demonstrated through magnetic susceptibility below 50 mK and theoretically quantified by the concurrence