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The understanding of human mobility patterns in different transportation modes is an interdisciplinary research field with a direct impact in aspects as varied as urban planning, traffic optimization, sustainability, the reduction of operating costs as well as the mitigation of pollution in urban areas. In this paper, we study the global activity of users in bike-sharing systems operating in the cities of Chicago and New York. For this transportation mode, we explore the temporal and spatial characteristics of the mobility of cyclists. In particular, through the analysis of origin-destination matrices, we characterize the spatial structure of the displacements of users. We apply a mobility model for the global activity of the system that classifies the displacements between stations in local and non-local transitions. In local transitions, cyclists move in a region around each station whereas, in the non-local case, bike users travel with long-range displacements in a similar way to Lévy flights. We reproduce the spatial dynamics by using Monte Carlo simulations. The obtained results are similar to the observed in real data and reveal that the model implemented captures important characteristics of the global spatial dynamics in the systems analyzed. [ABSTRACT FROM AUTHOR]

Background and purpose: Zika virus (ZIKV) infection has been associated with an increased incidence of Guillain−Barré syndrome (GBS) but the relative frequency of acute inflammatory demyelinating polyradiculoneuropathy (AIDP) and axonal GBS subtypes is controversial. Methods: Twenty GBS patients diagnosed according to the Brighton criteria during the ZIKV outbreak in Cúcuta, Colombia, were evaluated clinically and electrophysiologically. The electrodiagnosis of GBS subtypes was made according to a recently described criteria set that demonstrated a high diagnostic accuracy on the basis of a single test. The electrophysiological features of 34 Italian AIDP patients were used as control. Results: All patients had symptoms compatible with ZIKV infection before the onset of GBS and ZIKV infection was laboratory confirmed through a plaque reduction neutralization test (PRNT90) in 100% of patients. The median time from onset of ZIKV infection symptoms to GBS was 5 days (interquartile range 1–6 days). Cranial nerve palsy was present in 85% of patients (facial palsy in 75%, bulbar nerve involvement in 60%), autonomic dysfunction in 85%, and 50% of patients required invasive mechanical ventilation. AIDP was diagnosed in 70% of patients. 40% of nerves of AIDP patients showed a prevalent distal demyelinating involvement but this pattern was not different from the Italian AIDP patients without ZIKV infection. Conclusions: Guillain−Barré syndrome associated with ZIKV infection in Cúcuta is characterized by a high frequency of cranial nerve involvement, autonomic dysfunction and requirement of mechanical ventilation indicating an aggressive and severe course. AIDP is the most frequent electrophysiological subtype. Demyelination is prevalent distally but this pattern is not specific for ZIKV infection. [ABSTRACT FROM AUTHOR]

Autoimmune diseases (ADs) showcase the intricate balance between the immune system's protective functions and its potential for self-inflicted damage. These disorders arise from the immune system's erroneous targeting of the body's tissues, resulting in damage and disease. The ability of T cells to distinguish between self and non-self-antigens is pivotal to averting autoimmune reactions. Perturbations in this process contribute to AD development. Autoreactive T cells that elude thymic elimination are activated by mimics of self-antigens or are erroneously activated by self-antigens can trigger autoimmune responses. Various mechanisms, including molecular mimicry and bystander activation, contribute to AD initiation, with specific triggers and processes varying across the different ADs. In addition, the formation of neo-epitopes could also be implicated in the emergence of autoreactivity. The specificity of T cell responses centers on the antigen recognition sequences expressed by T cell receptors (TCRs), which recognize peptide fragments displayed by major histocompatibility complex (MHC) molecules. The assortment of TCR gene combinations yields a diverse array of T cell populations, each with distinct affinities for self and non-self antigens. However, new evidence challenges the traditional notion that clonal expansion solely steers the selection of higher-affinity T cells. Lower-affinity T cells also play a substantial role, prompting the "two-hit" hypothesis. High-affinity T cells incite initial responses, while their lower-affinity counterparts perpetuate autoimmunity. Precision treatments that target antigen-specific T cells hold promise for avoiding widespread immunosuppression. Nevertheless, detection of such antigen-specific T cells remains a challenge, and multiple technologies have been developed with different sensitivities while still harboring several drawbacks. In addition, elements such as human leukocyte antigen (HLA) haplotypes and validation through animal models are pivotal for advancing these strategies. In brief, this review delves into the intricate mechanisms contributing to ADs, accentuating the pivotal role(s) of antigen-specific T cells in steering immune responses and disease progression, as well as the novel strategies for the identification of antigen-specific cells and their possible future use in humans. Grasping the mechanisms behind ADs paves the way for targeted therapeutic interventions, potentially enhancing treatment choices while minimizing the risk of systemic immunosuppression., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The effect of the substitution of Ti by Zr on the crystal structure, microstructure, and first hydrogenation behavior of Ti 2-x Zr x CrV where X = 0.5, 1.0, 1.5, and 2.0 have been investigated. The samples were synthesized by arc-melting and characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. The hydrogenation capacity was measured using a home-made Sieverts apparatus. Pure-Ti 2 CrV crystallizes in a body-centered cubic structure (BCC). Substitution of Ti by Zr leads to the appearance of a secondary phase, namely a C15 Laves phase for the Ti-containing samples, and C15 Laves phase plus a Zr-rich phase for the X = 2.0 sample. The substitution of Ti by Zr increased the lattice parameters in both phases for all samples. Increasing Zr content made the first hydrogenation faster but reduced the hydrogen capacity., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Antimicrobial peptides (AMPs) are promising cationic and amphipathic molecules to fight antibiotic resistance. To search for novel AMPs, we applied a computational strategy to identify peptide sequences within the organisms' proteome, including in-house developed software and artificial intelligence tools. After analyzing 150.450 proteins from eight proteomes of bacteria, plants, a protist, and a nematode, nine peptides were selected and modified to increase their antimicrobial potential. The 18 resulting peptides were validated by bioassays with four pathogenic bacterial species, one yeast species, and two cancer cell-lines. Fourteen of the 18 tested peptides were antimicrobial, with minimum inhibitory concentrations (MICs) values under 10 µM against at least three bacterial species; seven were active against Candida albicans with MICs values under 10 µM; six had a therapeutic index above 20; two peptides were active against A549 cells, and eight were active against MCF-7 cells under 30 µM. This study's most active antimicrobial peptides damage the bacterial cell membrane, including grooves, dents, membrane wrinkling, cell destruction, and leakage of cytoplasmic material. The results confirm that the proposed approach, which uses bioinformatic tools and rational modifications, is highly efficient and allows the discovery, with high accuracy, of potent AMPs encrypted in proteins., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

In this work, the hydrogen storage behavior of Ti 2 CrV + X wt.% Zr 3 Fe, where X = 2, 4, 6, 8 and 10 was investigated. The synthesis of all samples was carried out through arc-melting, followed by comprehensive characterization using X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. The pure-Ti 2 CrV as-cast sample presented a single-phase microstructure. However, the addition of the Zr 3 Fe led to a remarkable transformation, resulting in the appearance of a Zr-rich secondary phase. It was found that the first hydrogenation is improved with the addition of at least 6 wt% of Zr 3 Fe, avoiding any preheating of the sample. These samples achieved their maximum capacity in approximately 10 min at room temperature. The maximum capacity recorded was 4.2 wt% H for the sample with X = 6 wt% Zr 3 Fe, while for X = 8 and 10 wt% Zr 3 Fe, the capacity recorded was 4.1 wt% and 4.0 wt%, respectively., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Background: Remote photoplethysmography (rPPG) is a technique developed to estimate heart rate using standard video cameras and ambient light. Due to the multiple sources of noise that deteriorate the quality of the signal, conventional filters such as the bandpass and wavelet-based filters are commonly used. However, after using conventional filters, some alterations remain, but interestingly an experienced eye can easily identify them., Results: We studied a long short-term memory (LSTM) network in the rPPG filtering task to identify these alterations using many-to-one and many-to-many approaches. We used three public databases in intra-dataset and cross-dataset scenarios, along with different protocols to analyze the performance of the method. We demonstrate how the network can be easily trained with a set of 90 signals totaling around 45 min. On the other hand, we show the stability of the LSTM performance with six state-of-the-art rPPG methods., Conclusions: This study demonstrates the superiority of the LSTM-based filter experimentally compared with conventional filters in an intra-dataset scenario. For example, we obtain on the VIPL database an MAE of 3.9 bpm, whereas conventional filtering improves performance on the same dataset from 10.3 bpm to 7.7 bpm. The cross-dataset approach presents a dependence in the network related to the average signal-to-noise ratio on the rPPG signals, where the closest signal-to-noise ratio values in the training and testing set the better. Moreover, it was demonstrated that a relatively small amount of data are sufficient to successfully train the network and outperform the results obtained by classical filters. More precisely, we have shown that about 45 min of rPPG signal could be sufficient to train an effective LSTM deep-filter., (© 2022. The Author(s).)

Background and Purpose: Zika virus (ZIKV) infection has been associated with an increased incidence of Guillain-Barré syndrome (GBS) but the relative frequency of acute inflammatory demyelinating polyradiculoneuropathy (AIDP) and axonal GBS subtypes is controversial., Methods: Twenty GBS patients diagnosed according to the Brighton criteria during the ZIKV outbreak in Cúcuta, Colombia, were evaluated clinically and electrophysiologically. The electrodiagnosis of GBS subtypes was made according to a recently described criteria set that demonstrated a high diagnostic accuracy on the basis of a single test. The electrophysiological features of 34 Italian AIDP patients were used as control., Results: All patients had symptoms compatible with ZIKV infection before the onset of GBS and ZIKV infection was laboratory confirmed through a plaque reduction neutralization test (PRNT 90 ) in 100% of patients. The median time from onset of ZIKV infection symptoms to GBS was 5 days (interquartile range 1-6 days). Cranial nerve palsy was present in 85% of patients (facial palsy in 75%, bulbar nerve involvement in 60%), autonomic dysfunction in 85%, and 50% of patients required invasive mechanical ventilation. AIDP was diagnosed in 70% of patients. 40% of nerves of AIDP patients showed a prevalent distal demyelinating involvement but this pattern was not different from the Italian AIDP patients without ZIKV infection., Conclusions: Guillain-Barré syndrome associated with ZIKV infection in Cúcuta is characterized by a high frequency of cranial nerve involvement, autonomic dysfunction and requirement of mechanical ventilation indicating an aggressive and severe course. AIDP is the most frequent electrophysiological subtype. Demyelination is prevalent distally but this pattern is not specific for ZIKV infection., (© 2017 EAN.)

VRK2 is a novel Ser-Thr kinase whose VRK2A isoform is located in the endoplasmic reticulum and mitochondrial membranes. We have studied the potential role that VRK2A has in the regulation of mitochondrial-mediated apoptosis. VRK2A can regulate the intrinsic apoptotic pathway in two different ways. The VRK2A protein directly interacts with Bcl-xL, but not with Bcl-2, Bax, Bad, PUMA or Binp-3L. VRK2A does not compete with Bax for interaction with Bcl-xL, and these proteins can form a complex that reduces apoptosis. Thus, high VRK2 levels confer protection against apoptosis. In addition, VRK2 knockdown results in an increased expression of BAX gene expression that is mediated by its proximal promoter, thus VRK2A behaves as a negative regulator of BAX. Low levels of VRK2A causes an increase in mitochondrial Bax protein level, leading to an increase in the release of cytochrome C and caspase activation, detected by PARP processing. VRK2A loss results in an increase in cell death that can be detected by an increase in annexinV+ cells. Low levels of VRK2A increase cell sensitivity to induction of apoptosis by chemotherapeutic drugs like camptothecin or doxorubicin. We conclude that VRK2A protein is a novel modulator of apoptosis.

The adw4 subtype of hepatitis B virus (HBV) belongs to a unique genomic group (genotype F) representing the original HBV strains from the New World. Data regarding the prevalence of this subtype among HBV carriers in South America are, however, scarce, and those concerning HBV genotype F are based on only a few samples from Latin America. In this study, serum samples were obtained from 141 hepatitis B surface antigen (HBsAg) carriers from Amerindians and urban populations from Venezuela. The HBsAg subtype was identified with monoclonal antibodies in 105 samples, and the HBV genotype was identified by reverse-phase hybridization with DNA fragments in 58 samples. The adw4 subtype was highly prevalent in the population studied (75%); among the Amerindians, the prevalence was 97%. The adw2 subtype was also present (10%), while other subtypes (ayw3 and ayw4) were only occasionally found. The HBV subtype was associated with the expected genotype in most cases (80%), and thus genotype F was highly prevalent. Sequencing of viral strains that gave genotypes unpredicted by the HBsAg subtyping confirmed seven of them as belonging to not previously described genotype-subtype associations: namely, adw2 and ayw4 within genotype F.