A predictive control unit for a Low Power 10-bit 200kS/s SAR ADC with Adaptive Conversion Cycle oriented to Audio Applications

This document presents the implementation of a new predictive algorithm for a 10-bit analogto-digital converter based on the successive approximation register (SAR), technique. The predictive algorithm (PSAR), is designed to predict a specific number of consecutive bits depending on the difference between the analog input voltage (Vin) and the reference voltage (Vref), provided by the DAC used in the successive approximation conversion technique. The PSAR is able to predict from 3 bits to 8 bits in a single conversion cycle. The typical SAR conversion employs a comparison between Vin and Vref on the voltage domain. In the case of the proposed PSAR, the Vin and Vref are converted to a time pulse width proportional to the magnitude of the inputs and the comparison of both is made in the time domain. The time difference between these two pulses is compared and registered by a counter to determine the total number of consecutive bits to predict. The proposed PSAR requires 13 clock cycles to perform conversion if there are not more than 2 consecutive bits to predict. The PSAR reduce 21% of the average conversion time when an ascendant ramp with the 1024 possible input values is applied.ITESO, A. C

Diseño de dispositivos, circuitos y sistemas electrónicos

ITESO, A.C

Physicochemical and nutraceutical characterization of sirimbache fruit (Gaultheria glomerata (Cav.) Sleumer)

ABSTRACT The consumption of vegetables with the greatest nutraceutical potential, especially those with high levels of antioxidants such as anthocyanin and phenolic compounds, has become popular among health conscious consumers. The aim of this research was to determine the nutraceutical potential of sirimbache fruits (Gaultheria glomerata (Cav.) Sleumer). Characterization of the berries resulted in the following: 11.4 °Brix, 3.25 pH, 0.35% acidity, 83.74% moisture, 0.16% ash, monomeric anthocyanins (112.88 mg cyanidin 3-glucoside / 100 g of sample), total phenolic compounds (344.37 mg of gallic acid / 100 g of sample) and vitamin C (13.87 mg ascorbic acid/ 100 g of sample). These values indicate that sirimbache is a nutraceutical food of great interest. Therefore, the expansion of sirimbache to health conscious markets may be feasible. Such expansion is of great importance for rural agribusiness, as it could promote the development of new agroindustrial projects in the province of Celendin and other Andean areas of Peru

SepA Enhances Shigella Invasion of Epithelial Cells by Degrading Alpha-1 Antitrypsin and Producing a Neutrophil Chemoattractant

Shigella spp. are highly adapted pathogens that cause bacillary dysentery in human and nonhuman primates. An unusual feature of Shigella pathogenesis is that this organism invades the colonic epithelia from the basolateral pole. Therefore, it has evolved the ability to disrupt the intestinal epithelial barrier to reach the basolateral surface. We have shown previously that the secreted serine protease A (SepA), which belongs to the family of serine protease autotransporters of Enterobacteriaceae, is responsible for the initial destabilization of the intestinal epithelial barrier that facilitates Shigella invasion. However, the mechanisms used by SepA to regulate this process remain unknown. To investigate the protein targets cleaved by SepA in the intestinal epithelium, we incubated a sample of homogenized human colon with purified SepA or with a catalytically inactive mutant of this protease. We discovered that SepA targets an array of 18 different proteins, including alpha-1 antitrypsin (AAT), a major circulating serine proteinase inhibitor in humans. In contrast to other serine proteases, SepA cleaved AAT without forming an inhibiting complex, which resulted in the generation of a neutrophil chemoattractant. We demonstrated that the products of the AAT-SepA reaction induce a mild but significant increase in neutrophil transepithelial migration in vitro. Moreover, the presence of AAT during Shigella infection stimulated neutrophil migration and dramatically enhanced the number of bacteria invading the intestinal epithelium in a SepA-dependent manner. We conclude that by cleaving AAT, SepA releases a chemoattractant that promotes neutrophil migration, which in turn disrupts the intestinal epithelial barrier to enable Shigella invasion. IMPORTANCE Shigella is the second leading cause of diarrheal death globally. In this study, we identified the host protein targets of SepA, Shigella\u27s major protein secreted in culture. We demonstrated that by cleaving AAT, a serine protease inhibitor important to protect surrounding tissue at inflammatory sites, SepA releases a neutrophil chemoattractant that enhances Shigella invasion. Moreover, SepA degraded AAT without becoming inhibited by the cleaved product, and SepA catalytic activity was enhanced at higher concentrations of AAT. Activation of SepA by an excess of AAT may be physiologically relevant at the early stages of Shigella infection, when the amount of synthesized SepA is very low compared to the concentration of AAT in the intestinal lumen. This observation may also help to explain the adeptness of Shigella infectivity at low dose, despite the requirement of reaching the basolateral side to invade and colonize the colonic epithelium

Evaluation of functional and nutritional potential of a protein concentrate from Pleurotus ostreatus mushroom

Edible mushrooms used as a protein-rich food may be an attractive alternative to conventional protein sources, while promoting its valorization. This work aimed to obtain a protein concentrate from a Pleurotus ostreatus mushroom flour, its characterization, and nutritional and functional properties evaluation. Methodologies applied for extraction and precipitation of protein were optimized - pH 4 and 12, respectively; and flour-solvent ratio of 1:20 w/v. The protein density was increased by 78 %. P. ostreatus flour and concentrate were characterized by proximal composition. The content of total phenolic compounds in the protein concentrate decreased, leading to a positive effect on protein digestibility, while the DPPH radical scavenging activity was not significantly affected. Peptides with molecular weights from 12 to 35 kDa, with possible bioactivity, were identified by electrophoresis. Protein digestibility assessed by in vitro gastrointestinal digestion showed a 4.2-fold higher hydrolysis degree in the protein concentrate than the flour.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE–01–0145–FEDER-000004) funded by the European Regional Development Fund under the scope of Norte 2020–Programa Operacional Regional do Norte and the Project ColOsH PTDC/BTM–SAL/30071/2017 (POCI–01–0145–FEDER–030071). The authors also acknowledge the grant for a postgraduate scholarship (CVU number 922722) provided by National Council of Science and Technology (CONACYT) Mexico.info:eu-repo/semantics/publishedVersio

The Carnegie Supernova Project: The Low-Redshift Survey

Supernovae are essential to understanding the chemical evolution of the Universe. Type Ia supernovae also provide the most powerful observational tool currently available for studying the expansion history of the Universe and the nature of dark energy. Our basic knowledge of supernovae comes from the study of their photometric and spectroscopic properties. However, the presently available data sets of optical and near-infrared light curves of supernovae are rather small and/or heterogeneous, and employ photometric systems that are poorly characterized. Similarly, there are relatively few supernovae whose spectral evolution has been well sampled, both in wavelength and phase, with precise spectrophotometric observations. The low-redshift portion of the Carnegie Supernova Project (CSP) seeks to remedy this situation by providing photometry and spectrophotometry of a large sample of supernovae taken on telescope/filter/detector systems that are well understood and well characterized. During a five-year program which began in September 2004, we expect to obtain high-precision u'g'r'i'BVYJHKs light curves and optical spectrophotometry for about 250 supernovae of all types. In this paper we provide a detailed description of the CSP survey observing and data reduction methodology. In addition, we present preliminary photometry and spectra obtained for a few representative supernovae during the first observing campaign.Comment: 45 pages, 13 figures, 3 tables, accepted by PAS

Cognitive complaints in older adults at risk for Alzheimer's disease are associated with altered resting-state networks

INTRODUCTION: Pathophysiological changes that accompany early clinical symptoms in prodromal Alzheimer's disease (AD) may have a disruptive influence on brain networks. We investigated resting-state functional magnetic resonance imaging (rsfMRI), combined with brain connectomics, to assess changes in whole-brain functional connectivity (FC) in relation to neurocognitive variables. METHODS: Participants included 58 older adults who underwent rsfMRI. Individual FC matrices were computed based on a 278-region parcellation. FastICA decomposition was performed on a matrix combining all subjects' FC. Each FC pattern was then used as a response in a multilinear regression model including neurocognitive variables associated with AD (cognitive complaint index [CCI] scores from self and informant, an episodic memory score, and an executive function score). RESULTS: Three connectivity independent component analysis (connICA) components (RSN, VIS, and FP-DMN FC patterns) associated with neurocognitive variables were identified based on prespecified criteria. RSN-pattern, characterized by increased FC within all resting-state networks, was negatively associated with self CCI. VIS-pattern, characterized by an increase in visual resting-state network, was negatively associated with CCI self or informant scores. FP-DMN-pattern, characterized by an increased interaction of frontoparietal and default mode networks (DMN), was positively associated with verbal episodic memory. DISCUSSION: Specific patterns of FC were differently associated with neurocognitive variables thought to change early in the course of AD. An integrative connectomics approach relating cognition to changes in FC may help identify preclinical and early prodromal stages of AD and help elucidate the complex relationship between subjective and objective indices of cognitive decline and differences in brain functional organization

Chapter 5: Food Security

The current food system (production, transport, processing, packaging, storage, retail, consumption, loss and waste) feeds the great majority of world population and supports the livelihoods of over 1 billion people. Since 1961, food supply per capita has increased more than 30%, accompanied by greater use of nitrogen fertilisers (increase of about 800%) and water resources for irrigation (increase of more than 100%). However, an estimated 821 million people are currently undernourished, 151 million children under five are stunted, 613 million women and girls aged 15 to 49 suffer from iron deficiency, and 2 billion adults are overweight or obese. The food system is under pressure from non-climate stressors (e.g., population and income growth, demand for animal-sourced products), and from climate change. These climate and non-climate stresses are impacting the four pillars of food security (availability, access, utilisation, and stability)