Structural MRI texture analysis for detecting Alzheimer's disease

Purpose:: Alzheimer’s disease (AD) has the highest worldwide prevalence of all neurodegenerative disorders, no cure, and low ratios of diagnosis accuracy at its early stage where treatments have some effect and can give some years of life quality to patients. This work aims to develop an automatic method to detect AD in 3 different stages, namely, control (CN), mild-cognitive impairment (MCI), and AD itself, using structural magnetic resonance imaging (sMRI). Methods:: A set of co-occurrence matrix and texture statistical measures (contrast, correlation, energy, homogeneity, entropy, variance, and standard deviation) were extracted from a two-level discrete wavelet transform decomposition of sMRI images. The discriminant capacity of the measures was analyzed and the most discriminant ones were selected to be used as features for feeding classical machine learning (cML) algorithms and a convolution neural network (CNN). Results:: The cML algorithms achieved the following classification accuracies: 93.3% for AD vs CN, 87.7% for AD vs MCI, 88.2% for CN vs MCI, and 75.3% for All vs All. The CNN achieved the following classification accuracies: 82.2% for AD vs CN, 75.4% for AD vs MCI, 83.8% for CN vs MCI, and 64% for All vs All. Conclusion:: In the evaluated cases, cML provided higher discrimination results than CNN. For the All vs All comparison, the proposedmethod surpasses by 4% the discrimination accuracy of the state-of-the-art methods that use structural MRI.info:eu-repo/semantics/publishedVersio

How footwear companies can use online CX to WOW customers

Purpose: E-commerce has become an essential and highly competitive channel for e-retailers, who have felt the need to invest in the experience delivered to customers. Therefore, it becomes necessary to unveil the online customer experience so that brands can improve their offerings. In this study, the authors proposed a model that explores customer experience on websites, namely, what concerns the use of the latest technological developments such as artificial intelligence, augmented reality and virtual reality. Design/methodology/approach: The study offers a model to explore and compare the online consumer experience in e-commerce websites, considering eight dimensions that cover recent technological advances. A multiple case study that evaluated companies in the footwear industry was used to assess the model's applicability. The case study methodology considered two distinct segments, the high-price and low-price segments. Findings: The data collected by the websites' examination enabled us to confirm part of the suggested propositions. However, propositions concerning new technologies were not proved. Opportunities for improvement were identified, especially for high-price segment companies, since the results showed that these companies provide a less pleasant consumer experience than those of the opposing segment. Originality/value: This study extends the scope of the online consumer experience by introducing more contemporary dimensions. Additionally, the model allows an evaluation and comparison of the knowledge delivered by several online retailers, using the Portuguese footwear industry as a reference.info:eu-repo/semantics/acceptedVersio

Absolute quantification of the host-to-parasite DNA ratio in Theileria parva-infected lymphocyte cell lines

Theileria parva is a tick-transmitted intracellular apicomplexan pathogen of cattle in sub-Saharan Africa that causes East Coast fever (ECF). ECF is an acute fatal disease that kills over one million cattle annually, imposing a tremendous burden on African small-holder cattle farmers. The pathology and level of T. parva infections in its wildlife host, African buffalo (Syncerus caffer), and in cattle are distinct. We have developed an absolute quantification method based on quantitative PCR (qPCR) in which recombinant plasmids containing single copy genes specific to the parasite (apical membrane antigen 1 gene, ama1) or the host (hypoxanthine phosphoribosyltransferase 1, hprt1) are used as the quantification reference standards. Our study shows that T. parva and bovine cells are present in similar numbers in T. parva-infected lymphocyte cell lines and that consequently, due to its much smaller genome size, T. parva DNA comprises between 0.9% and 3% of the total DNA samples extracted from these lines. This absolute quantification assay of parasite and host genome copy number in a sample provides a simple and reliable method of assessing T. parva load in infected bovine lymphocytes, and is accurate over a wide range of host-to-parasite DNA ratios. Knowledge of the proportion of target DNA in a sample, as enabled by this method, is essential for efficient high-throughput genome sequencing applications for a variety of intracellular pathogens. This assay will also be very useful in future studies of interactions of distinct host-T. parva stocks and to fully characterize the dynamics of ECF infection in the field

Degradation of ochratoxins A and B by lipases: a kinetic study unraveled by molecular modelling

Mycotoxins are toxic substances produced by fungi that are present in a variety of food commodities, being ochratoxin A (OTA) and B (OTB), a non-chlorinated OTA equivalent, examples of fungal toxins. These compounds differ in some chemical groups, promoting different levels of toxicity, being OTA the most common and hazardous for humans and animals. To reduce OTA exposure, many approaches for its degradation using microorganisms have been proposed in the last 20 years, both bacteria and fungi. However, the application of isolated enzymes seems to be one of the most promising strategies. Although there are some studies of OTA degradation using enzymes, they are few and produce unsatisfactory results, when compared to studies using living organisms. When considering simultaneous degradation studies of OTA and OTB, the available knowledge becomes even more limited. We investigated the potential of five isolated lipases to hydrolyze OTA and OTB into non-toxics chemicals. Amano lipase from Aspergillus niger (ANL) and porcine pancreatic lipase A (PPL) effectively degraded both substrates: OTA was totally degraded by ANL after 3 hours, and OTB by PPL after 9 hours. The impact of the chlorine group on the enzymatic hydrolysis of OTA was assessed using molecular dynamics. The analyses support the experimental findings that OTA has a greater affinity for PPL due to an interaction with chloride ions, impairing hydrolysis. To understand how the halogen affects the catalytic activity, the kinetic parameters were determined. These results demonstrate the applicability of these enzymes to detoxify co-occurring ochratoxins A and B in food matrices.This study was supported by the Portuguese Foundation for Science and Technology (FCT), under the scope of the strategic funding of UI/BD/152286/2021.info:eu-repo/semantics/publishedVersio

Transnational banking supervision and resilience: the SSM case

In this letter we assess the impact of adopting a transnational supervisor on the resilience of large and complex banks, exploring the establishment of the Single Supervisory Mechanism (SSM) in 2014. Using a differences-in-differences approach, we compare the performance of SSM banks vis-à-vis other banks with a similar size and complexity. Our results suggest that the adoption of a transnational supervisor can improve the resilience of large and complex banks, particularly for those operating in countries with larger banking sectors, higher market concentration and higher supervisory discretion.info:eu-repo/semantics/publishedVersio

Signature of adaptive evolution in olfactory receptor genes in Cory's Shearwater supports molecular basis for smell in procellariiform seabirds

Olfactory receptors (ORs), encoded by the largest vertebrate multigene family, enable the detection of thousands of unique odorants in the environment and consequently play a critical role in species survival. Here, we advance our knowledge of OR gene evolution in procellariiform seabirds, an avian group which relies on the sense of olfaction for critical ecological functions. We built a cosmid library of Cory's Shearwater (Calonectris borealis) genomic DNA, a model species for the study of olfaction-based navigation, and sequence OR gene-positive cosmid clones with a combination of sequencing technologies. We identified 220 OR open reading frames, 20 of which are full length, intact OR genes, and found a large ratio of partial and pseudogenes to intact OR genes (2:1), suggestive of a dynamic mode of evolution. Phylogenetic analyses revealed that while a few genes cluster with those of other sauropsid species in a γ (gamma) clade that predates the divergence of different avian lineages, most genes belong to an avian-specific γ-c clade, within which sequences cluster by species, suggesting frequent duplication and/or gene conversion events. We identified evidence of positive selection on full length γ-c clade genes. These patterns are consistent with a key role of adaptation in the functional diversification of olfactory receptor genes in a bird lineage that relies extensively on olfaction.info:eu-repo/semantics/publishedVersio

Intron gain and loss in segmentally duplicated genes in rice

BACKGROUND: Introns are under less selection pressure than exons, and consequently, intronic sequences have a higher rate of gain and loss than exons. In a number of plant species, a large portion of the genome has been segmentally duplicated, giving rise to a large set of duplicated genes. The recent completion of the rice genome in which segmental duplication has been documented has allowed us to investigate intron evolution within rice, a diploid monocotyledonous species. RESULTS: Analysis of segmental duplication in rice revealed that 159 Mb of the 371 Mb genome and 21,570 of the 43,719 non-transposable element-related genes were contained within a duplicated region. In these duplicated regions, 3,101 collinear paired genes were present. Using this set of segmentally duplicated genes, we investigated intron evolution from full-length cDNA-supported non-transposable element-related gene models of rice. Using gene pairs that have an ortholog in the dicotyledonous model species Arabidopsis thaliana, we identified more intron loss (49 introns within 35 gene pairs) than intron gain (5 introns within 5 gene pairs) following segmental duplication. We were unable to demonstrate preferential intron loss at the 3' end of genes as previously reported in mammalian genomes. However, we did find that the four nucleotides of exons that flank lost introns had less frequently used 4-mers. CONCLUSION: We observed that intron evolution within rice following segmental duplication is largely dominated by intron loss. In two of the five cases of intron gain within segmentally duplicated genes, the gained sequences were similar to transposable elements

Análise da sequência do movimento de levantar/sentar, em indivíduos pós AVE: Estudo da relação da activação dos músculos vasto medial oblíquo e vasto lateral

O objectivo deste estudo foi comparar o rácio dos músculos Vasto Medial Oblíquo (VMO) e Vasto Lateral (VL), na sequência de movimento de levantar e sentar, em indivíduos sem patologia e em indivíduos com Acidente Vascular Encefálico (AVE). Pretendeu-se também verificar a sequência de activação de alguns músculos do membro inferior na sequência de movimento de levantar. Verificou-se existir diferenças significativas para afirmar que, no movimento de levantar, indivíduos com sequelas de AVE apresentam menor rácio VMO/VL no membro predominantemente atingido em relação aos indivíduos sem patologia. Diferentes sequências de activação muscular durante o movimento de levantar foram observadas.The purpose of this study was to compare the ratio of the Vastus medialis oblique (VMO) and vastus lateralis (VL), in sit-to-stand movement in subjects without pathology and in individuals with stroke. The article tries to verify the sequence of activation of some muscles of the lower limb during standing up. There are significant differences to argue that, in standing up movement, subjects with sequelae of stroke have a lower ratio VMO / VL in predominantly affected limb compared to subjects without pathology. Different sequences of muscle activation during standing up movement were observed