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The emergence of social robots in gerontology has introduced new playful and reassuring media into nursing homes and geriatric wards. Despite promising results, their complexity hinders their widespread adoption. The Intelligent Interactive Care System aims to remedy these limitations by offering interactive therapeutic workshops. This study evaluates residents' involvement in these workshops within an adapted activity and care center, revealing a high level of involvement and satisfaction.
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Robótica , Humanos , Idoso , Idoso de 80 Anos ou mais , Casas de Saúde , Masculino , Feminino , Melhoria de Qualidade , GeriatriaRESUMO
Cognitive performance slows down with increasing age. This includes cognitive processes that are essential for the performance of a motor act, such as the slowing down in response to an external stimulus. The objective of this study was to identify aging-associated functional changes in the brain networks that are involved in the transformation of external stimuli into motor action. To investigate this topic, we employed dynamic graphs based on phase-locking of Electroencephalography signals recorded from healthy younger and older subjects while performing a simple visually-cued finger-tapping task. The network analysis yielded specific age-related network structures varying in time in the low frequencies (2-7 Hz), which are closely connected to stimulus processing, movement initiation and execution in both age groups. The networks in older subjects, however, contained several additional, particularly interhemispheric, connections and showed an overall increased coupling density. Cluster analyses revealed reduced variability of the subnetworks in older subjects, particularly during movement preparation. In younger subjects, occipital, parietal, sensorimotor and central regions were-temporally arranged in this order-heavily involved in hub nodes. Whereas in older subjects, a hub in frontal regions preceded the noticeably delayed occurrence of sensorimotor hubs, indicating different neural information processing in older subjects. All observed changes in brain network organization, which are based on neural synchronization in the low frequencies, provide a possible neural mechanism underlying previous fMRI data, which report an overactivation, especially in the prefrontal and pre-motor areas, associated with a loss of hemispheric lateralization in older subjects.
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Envelhecimento/fisiologia , Córtex Cerebral/fisiologia , Conectoma , Eletroencefalografia , Atividade Motora/fisiologia , Rede Nervosa/fisiologia , Adulto , Fatores Etários , Idoso , Sincronização Cortical/fisiologia , Sinais (Psicologia) , Feminino , Dedos/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Percepção Visual/fisiologia , Adulto JovemRESUMO
Multiple sclerosis (MS) is an autoimmune disease that involves demyelination of axons in the central nervous system (CNS) and affects patients worldwide. It has been demonstrated that ligand-activated aryl hydrocarbon receptor (Ahr) ameliorates experimental autoimmune encephalomyelitis (EAE), a murine model of MS, by increasing CD4+FoxP3+ T cells. Recent evidence indicates that AT-rich interactive domain-containing protein 5a (Arid5a) is required for EAE pathogenesis by stabilizing Il6 and OX40 mRNAs. However, the differential modulation of Ahr and Arid5a in autoimmunity as a therapeutic strategy is unexplored. Herein, an in silico, in vitro and in vivo approach identified Flavipin (3,4,5-trihydroxy-6-methylphthalaldehyde) as an Ahr agonist that induces the expression of Ahr downstream genes in mouse CD4+ T cells and CD11b+ macrophages. Interestingly, Flavipin inhibited the stabilizing function of Arid5a and its counteracting effects on Regnase-1 on the 3' untranslated region (3'UTR) of target mRNAs. Furthermore, it inhibited the stabilizing function of Arid5a on Il23a 3'UTR, a newly identified target mRNA. In EAE, Flavipin ameliorated disease severity, with reduced CD4+IL-17+ T cells, IL-6 and TNF-α and increased CD4+FoxP3+ T cells. Moreover, EAE amelioration was concomitant with reduced CD4+OX40+ and CD4+CD45+ T cells in the CNS. RNA interference showed that the modulatory effects of Flavipin on pro- and anti-inflammatory mediators in CD4+ T cells and macrophages were Ahr- and/or Arid5a-dependent. In conclusion, our findings reveal differential modulation of Ahr and Arid5a as a new therapeutic strategy for MS.
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In non-salmonid fish, Aeromonas salmonicidacan cause local infections with severe skin ulcerations, known as atypical furunculosis. In this study, we present a systemic infection by a virulent A. salmonicidain European perch (Perca fluviatilis).This infection was diagnosed in a Swiss warm water recirculation aquaculture system. The isolate of A. salmonicida encodes a type three secretion system (TTSS) most likely located on a plasmid similar to pAsa5/pASvirA, which is known to specify one of the main virulence attributes of the species A. salmonicida. However, the genes specifying the TTSS of the perch isolate show a higher temperature tolerance than strains isolated from cold-water fish. The function of the TTSS in virulence was verified in a cytotoxicity test using bluegill fry and epithelioma papulosum cyprinid cells.
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Adaptação Biológica , Aeromonas salmonicida/fisiologia , Aeromonas salmonicida/patogenicidade , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Temperatura Alta , Percas , Animais , Furunculose , Genes Bacterianos , Infecções por Bactérias Gram-Negativas/microbiologia , Virulência/genéticaRESUMO
The Aphis gossypii Glover (Hemiptera: Aphididae) is one of the most serious pests worldwide, and imidacloprid has been widely used to control this insect pest. Just like other classes of insecticides, the resistance to imidacloprid has been found in A. gossypii. An amino acid mutation (R81T) in the nicotinic acetylcholine receptor (nAChR) beta1 subunit was detected in the imidacloprid-resistant A. gossypii collected from Langfang (LF) and Dezhou (DZ) cities. To estimate the R81T mutation frequency of A. gossypii field populations, a simple, rapid and accurate rtPASA (real-time PCR amplification of specific allele) protocol was developed. The performance of the rtPASA protocol was evaluated by comparing with the data generated by a cPASA (competitive PCR amplification of specific allele) method from 50 individual genotypes. The R81T allele frequencies of the LF population (34.7%±1.3%) and DZ population (45.2%±5.2%) estimated by the rtPASA protocol matched the frequencies (LF 38.1%, DZ 48.2%) deduced by the cPASA method in specimens. The results indicated that the rtPASA format was applicable for the detection of mutation associated with imidacloprid resistance and will allow rapid and efficient monitoring of A. gossypii resistance in field populations in a high throughput format.
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Afídeos/genética , Gossypium/parasitologia , Imidazóis/farmacologia , Resistência a Inseticidas , Inseticidas/farmacologia , Nitrocompostos/farmacologia , Doenças das Plantas/parasitologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Alelos , Sequência de Aminoácidos , Animais , Afídeos/efeitos dos fármacos , Afídeos/metabolismo , Sequência de Bases , Frequência do Gene , Gossypium/crescimento & desenvolvimento , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Dados de Sequência Molecular , Mutação , Neonicotinoides , Receptores Nicotínicos/genética , Receptores Nicotínicos/metabolismoRESUMO
The extensive application of flubendiamide has led to increasingly prominent development of resistance in diamondback moth, Plutella xylostella. Here we report that the moderate and high level resistance to flubendiamide was identified in a laboratory-selected and two field-collected strains of P. xylostella. The resistance ratios were tested in the lab-selected resistant strains (R), and two field strains (BY and ZC). Compared with the S strain, the R strain showed extended larval development time, decreased pupation rate, emergencing rate, and male adult longevity. The realized heritability (h(2)=0.135) implies the high risk of flubendiamide resistance development in P. xylostella. A Bi-PASA (bi-directional PCR amplification of specific allele)-based method was successfully developed to detect the point mutation (G4946E) potentially causing flubendiamide resistance in diamondback moth, in which different fragments 866 bp + 340 bp, 866 bp+568 bp, and 866 bp+568 bp+340 bp were presented in SS, RR and RS stains, respectively. The predominant genotype was 83.33% SS homozygote in the S strain, 80.77% RR homozygote in ZC population, and 73.08% RS heterozygote in BY population, respectively. Current results showed the significant correlation between the frequencies of the allele carrying G4946E mutation (51.92%, 55.77% and 90.38% for R, BY and ZC, respectively) and the resistance ratios (40.72, 24.24 and 1779.24-folds for R, BY and ZC, respectively) in the three strains/populations. In addition, the relative PxRyR mRNA transcript level in the R strain was 2.938 ± 0.53 folds as compared with the S strain (1.0-fold).
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Benzamidas/farmacologia , Proteínas de Insetos/genética , Resistência a Inseticidas , Inseticidas/farmacologia , Mariposas/efeitos dos fármacos , Mutação de Sentido Incorreto , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Sulfonas/farmacologia , Alelos , Animais , Feminino , Proteínas de Insetos/metabolismo , Masculino , Mariposas/genética , Mariposas/metabolismo , Reação em Cadeia da Polimerase , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismoRESUMO
BACKGROUND: The house fly, Musca domestica, is a significant carrier of diseases that can impact public health. Repeated use of pyrethroid insecticides may act as a selection pressure for mutations and amino acid substitutions in the house fly voltage-sensitive sodium channel (VSSC), which ultimately confers resistance. The objectives of this study were to determine the presence of knockdown resistance (kdr) mutations using molecular tools and to set up a CDC bottle bioassay specific for house flies in the United Arab Emirates (UAE) to screen for deltamethrin resistance. METHODS: Adult flies were collected from 19 locations in Abu Dhabi, UAE, and DNA was extracted, followed by PCR amplification of specific alleles (PASA) and conventional PCR using several primers to amplify regions of the VSSC gene. Sanger sequencing was performed on PCR products. We also designed primers that detect four kdr mutations using complementary DNA (cDNA) in reverse transcriptase (RT)-PCR followed by Sanger sequencing. Additionally, a CDC bottle bioassay was set up for detecting deltamethrin resistance in adult house flies. RESULTS: In PASA, the primers successfully amplified the target bands (480, 280 and 200 bp). The kdr allele was found in flies collected from 18 of the 19 locations, at the highest and lowest prevalence of 46.9% and 9.4%, respectively. Resistant homozygous (RR) insects constituted 5.0% of the tested populations, and heterozygous (RS) insects accounted for 36.5%. The RR genotype was prevalent in house flies collected at 10 of 19 sampling locations. House fly populations were mostly in Hardy-Weinberg equilibrium, except in three locations. In addition to verifying the presence of the previously identified kdr mutation L1014F, in this study we detected two kdr mutations, L1014H and T929I, that have not previously been reported in the UAE. Also, for the first time in the UAE, a CDC bottle bioassay for deltamethrin resistance was used, which found that 60 min and 4.5 µg/ml were the diagnostic time and dose, respectively. Using this assay, we detected deltamethrin resistance in house flies from two of 16 locations, with a resistance level of 12.5%. CONCLUSIONS: Using DNA sequencing, we confirmed the presence of a known kdr mutation and uncovered two new kdr mutations in house flies from Abu Dhabi. Additionally, we detected deltamethrin resistance in these flies using a CDC bottle bioassay. Further research is recommended to comprehensively identify more kdr mutations in UAE house fly populations and assess their impacts on control strategies.
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Dípteros , Moscas Domésticas , Inseticidas , Nitrilas , Piretrinas , Animais , Inseticidas/farmacologia , Emirados Árabes Unidos , Piretrinas/farmacologia , Moscas Domésticas/genética , Mutação , Resistência a Inseticidas/genéticaRESUMO
As a widely used feed additives, p-arsanilic acid (p-AsA) frequently detected in the environment poses serious threats to aquatic ecology and water security due to its potential in releasing more toxic inorganic arsenic. In this work, the efficiency of Fe(II)/sulfite, Fe(II)/PDS and Fe(II)/PMS systems in p-AsA degradation and simultaneous arsenic removal was comparatively investigated for the first time. Efficient p-AsA abatement was achieved in theses Fe-based systems, while notable discrepancy in total arsenic removal was observed under identical acidic condition. By using chemical probing method, quenching experiments, isotopically labeled water experiments, p-AsA degradation was ascribed to the combined contribution of high-valent Fe(IV) and SO4â¢-in these Fe(II)-based system. In particular, the relative contribution of Fe(IV) and SO4â¢- in the Fe(II)/sulfite system was highly dependent on the molar ratio of [Fe(II)] and [sulfite]. Negligible arsenic removal was observed in the Fe(II)/sulfite and Fe(II)/PDS systems, while â¼80% arsenic was removed in the Fe(II)/PMS system under identical acidic condition. This interesting phenomenon was due to that ferric precipitation only occurred in the Fe(II)/PMS system. As(V) was further removed via adsorption onto the iron precipitate or the formation of ferric arsenate-sulfate compounds, which was confirmed by particle diameter measurements, fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Through tuning solution pH, complete removal of total arsenic could achieve in all three systems. Among these three Fe-based technologies, the hybrid oxidation-coagulation Fe(II)/PMS system demonstrated potential superiority for arsenic immobilization by not requiring pH adjustment for coagulation and facilitating the in-situ generation of ferric arsenate-sulfate compounds with comparably low solubility levels like scorodite. These findings would deepen the understanding of these three Fe-based Fenton-like technologies for decontamination in water treatment.
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Arsênio , Poluentes Químicos da Água , Arsênio/química , Arseniatos/química , Ácido Arsanílico/química , Ferro/química , Compostos Férricos/química , Oxirredução , Sulfitos , Sulfatos , Óxidos de Enxofre , Compostos Ferrosos , Poluentes Químicos da Água/químicaRESUMO
The plasmid known as pAsa5 is present in Aeromonas salmonicida subsp. salmonicida, a fish pathogen. The pAsa5 plasmid carries genes that are essential for the bacterium's virulence. Recombination events are known to occur in pAsa5, resulting in the loss of certain segments or the acquisition of additional genetic elements. For example, the transposon carried by the large pAsa8 plasmid was found to be inserted into the pAsa5 plasmid in the SHY16-3432 strain, enabling the addition of antibiotic resistance genes to this plasmid, which does not normally possess any. In this study, we present the isolation of additional strains carrying pAsa8. Further analyses of these strains revealed that a fusion between pAsa5 and the complete version of pAsa8 is possible. The pAsa8 transposon insertion in pAsa5 seen in the SHY16-3432 strain appears to be an aberrant event compared to the fusion of the two full-length plasmids. A 22-nucleotide sequence, present in both plasmids, serves as the site for the fusion of the two plasmids. Moreover, it is possible to introduce pAsa8 through conjugation into naive strains of A. salmonicida subsp. salmonicida and once the plasmid is within a new strain, the fusion with pAsa5 is detectable. This study reveals a previously unexplored aspect of pAsa5 plasmid biology, highlighting an additional risk for the spread of antibiotic resistance genes in A. salmonicida subsp. salmonicida.
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Plasmids that carry antibiotic resistance genes occur frequently in Aeromonas salmonicida subsp. salmonicida, an aquatic pathogen with severe consequences in salmonid farming. Here, we describe a 67 kb plasmid found in the A. salmonicida subsp. salmonicida Strain SHY15-2939 from Quebec, Canada. This new plasmid, named pAsa-2939 and identified by high throughput sequencing, displays features never found before in this bacterial species. It contains a transposon related to the Tn21 family, but with an unusual organization. This transposon bears a catB3 gene (chloramphenicol resistance) that has not been detected yet in A. salmonicida subsp. salmonicida. The plasmid is transferable by conjugation into Aeromonas hydrophila, but not into Escherichia coli. Based on PCR analysis and genomic sequencing (Illumina and PacBio), we determined that the transposon is unstable in A. salmonicida subsp. salmonicida Strain SHY15-2939, but it is stable in A. hydrophila trans-conjugants, which explains the chloramphenicol resistance variability observed in SHY15-2939. These results suggest that this bacterium is likely not the most appropriate host for this plasmid. The presence of pAsa-2939 in A. salmonicida subsp. salmonicida also strengthens the reservoir role of this bacterium for antibiotic resistance genes, even those that resist antibiotics not used in aquaculture in Québec, such as chloramphenicol.
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The widespread occurrence of p-arsanilic acid (p-ASA) in natural environments poses big threats to the biosphere due to the generation of toxic inorganic arsenic (i.e., As(III) and As(V), especially As(III) with higher toxicity and mobility). Oxidation of p-ASA or As(III) to As(V) followed by precipitation of total arsenic using Fe-based advanced oxidation processes demonstrated to be a promising approach for the treatment of arsenic contamination. This study for the first time investigated the efficiency and inherent mechanism of p-ASA and As(III) oxidation by Fe(II)/peracetic acid (Fe(II)/PAA) and PAA processes. p-ASA was rapidly degraded by the Fe(II)/PAA process within 20 s at neutral to acidic pHs under different conditions, while it was insignificantly degraded by PAA oxidation alone. Lines of evidence suggested that hydroxyl radicals and organic radicals generated from the homolytic OO bond cleavage of PAA contributed to the degradation of p-ASA in the Fe(II)/PAA process. p-ASA was mainly oxidized to As (V), NH4+, and p-aminophenol by the Fe(II)/PAA process, wherein the aniline group and its para position were the most vulnerable sites. As(III) of concern was likely generated as an intermediate during p-ASA oxidation and it could be readily oxidized to As(V) by the Fe(II)/PAA process as well as PAA alone. The in-depth investigation demonstrated that PAA alone was effective in the oxidation of As(III) under varied conditions with a stoichiometric molar ratio of 1:1. Efficient removal (> 80%) of total arsenic during p-ASA oxidation by Fe(II)/PAA process or during As(III) oxidation by PAA process with additional Fe(III) in synthetic or real waters were observed, mainly due to the adsorptive interactions of amorphous ferric (oxy)hydroxide precipitates. This study systematically investigates the oxidation of p-ASA and As(III) by the Fe(II)/PAA and PAA processes, which is instructive for the future development of arsenic remediation technology.
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Arsênio , Arsenitos , Poluentes Químicos da Água , Compostos Férricos/química , Arsênio/química , Ácido Arsanílico/química , Ácido Peracético , Oxirredução , Compostos Ferrosos , Peróxido de HidrogênioRESUMO
Healthy aging is accompanied by multi-faceted changes. Especially within the brain, healthy aging exerts substantial impetus on core parts of cognitive and motivational networks. Rewards comprise basic needs, such as food, sleep, and social contact. Thus, a functionally intact reward system remains indispensable for elderly people to cope with everyday life and adapt to their changing environment. Research shows that reward system function is better preserved in the elderly than most cognitive functions. To investigate the compensatory mechanisms providing reward system stability in aging, we employed a well-established reward paradigm (Monetary Incentive Delay Task) in groups of young and old participants while undergoing EEG measurement. As a new approach, we applied EEG connectivity analyses to assess cortical reward-related network connectivity. At the behavioral level, our results confirm that the function of the reward system is preserved in old age. The mechanisms identified for maintaining reward system function in old age do not fit into previously described models of cognitive aging. Overall, older adults exhibit lower reward-related connectivity modulation, higher reliance on posterior and right-lateralized brain areas than younger adults, and connectivity modulation in the opposite direction than younger adults, with usually greater connectivity during non-reward compared to reward conditions. We believe that the reward system has unique compensatory mechanisms distinct from other cognitive functions, probably due to its etymologically very early origin. In summary, this study provides important new insights into cortical reward network connectivity in healthy aging.
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Ma'pasa' Tedong is one of the ritual parts of Rambu Solo', a funeral ritual series in Toraja culture, Tana Toraja regency, South Sulawesi province, Indonesia. In this ethnicity, the ritual, Singgi' is communicated using a high level of Tominaa language. Therefore, this study aims to describe and explain the cultural attitudes of the Toraja ethnic recorded in Ma'pasa' Tedong discourse. This is qualitative research with the hermeneutic approach used to interpret and explain the meaning of Ma'pasa' Tedong discourses that reflect personal identity, social attitudes, and Toraja ethnic beliefs. Data were obtained by recording, interviewing two Tominaa inhabitants, and conducting a document study. The data were analyzed qualitatively by interpreting the meaning through the following stages (a) understanding the speech, (b) drawing, adjusting, and reflecting the results based on concrete actions by the Toraja ethnic group, and (c) interpreting the reflection results under its existence. The results showed that the Toraja ethnic group has self-awareness, tolerance, tenacity, honesty, discipline, and a tough personality. In addition, these personalities underlie politeness, tolerance, care, social, and cooperation in society. The unique and distinctive attitude of this ethnic group is reflected in their belief in carrying out the Rambu Solo' ritual. These findings were cultural documents with significant meaning for anyone interested in understanding the Toraja ethnic culture. Ma' pasa Tedong event contains relevant messages that aid in the community's development and reflect the Toraja ethnic group's culture. As a cultural heritage, its verses contain various ideas and values (meanings) useful for molding and shaping people's character.
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BACKGROUND: Sciatic nerve palsy is a serious complication after total hip arthroplasty (THA). This is the first study to report the relationship between the sciatic nerve and the acetabulum on magnetic resonance imaging (MRI) before THA. METHODS: 235 patients underwent 261 elective, primary THAs via the mini-incision posterolateral approach. We measured the horizontal distance (mm) and vertical distance (mm) from the posterior edge of the acetabulum to the sciatic nerve by T1-weighted imaging on an axial section of the centre of the femoral head. We defined the Dysplastic Group as having a posterior acetabular sector angle (PASA) <90° and the Non-dysplastic Group as having a PASA ⩾ 90°. We compared anatomical distances and angles between the 2 groups. RESULTS: The horizontal and vertical distances were (mean ± SD) 8.0 ± 9.2 mm and 14 ± 5.0 mm from the posterior edge of the acetabulum to the lateral edge of the sciatic nerve, respectively. The acetabular anteversion (AA), anterior acetabular sector angle (AASA), and PASA were (mean ± SD) 19 ± 6.7°, 49 ± 8.4°, and 87 ± 8.6°, respectively. The horizontal and vertical distances were positively correlated (p < 0.0001). AA and PASA were positively correlated with the horizontal distances (p < 0.0001) as well as with the vertical distances (p = 0.0017 and p = 0.0438, respectively). The horizontal and vertical distances were significantly shorter in the Dysplastic Group than in the Non-dysplastic Group (p < 0.0001 and p = 0.021, respectively). CONCLUSIONS: In cases of posterior acetabular dysplasia we have to be mindful of the course of the sciatic nerve.
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Artroplastia de Quadril , Osteoartrite do Quadril , Acetábulo/diagnóstico por imagem , Acetábulo/cirurgia , Artroplastia de Quadril/efeitos adversos , Humanos , Imageamento por Ressonância Magnética , Osteoartrite do Quadril/diagnóstico por imagem , Osteoartrite do Quadril/cirurgia , Estudos Retrospectivos , Nervo IsquiáticoRESUMO
Genetic variations in the host TLRs genes play an important role in susceptibility and/or resistance to visceral leishmaniasis by altering the host-pathogen interaction. In this study, we investigated the association between polymorphisms of TLR4 (Asp299Gly, Thr399Ile) and TLR-9 (T-1237C), with susceptibility to visceral leishmaniasis. A bi-directional PCR amplification of specific alleles technique was used to characterize the distribution of TLR4 (Asp299Gly and Thr399Ile) and TLR9 (T-1237C) polymorphisms. A total of 60 samples were randomly selected from confirmed visceral leishmaniasis patients and 24 endemic healthy volunteers. The samples were genotyped and allele frequencies were determined. We observed that TLR4 Asp299Gly and Thr399Ile genotypes were more frequent in visceral leishmaniasis patients (10% and 15% respectively) compared to controls (4.2% and 8.3% respectively). However, the differences were not significant in TLR4 Asp299Gly and Thr399Ile alleles and genotypes. In the case of TLR9, we observed the frequency of T1237C genotype was higher in visceral leishmaniasis patients (43.3%) than in healthy controls (33.3%). Statistically significant differences were observed in TLR9 T1237C alleles and genotypes. We concluded that TLR9 T1237C, but not TLR4, gene polymorphisms can be regarded as contributors to visceral leishmaniasis susceptibility among the Indian population of Bihar state.
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Genótipo , Leishmania donovani/fisiologia , Leishmaniose Visceral/imunologia , Grupos Populacionais , Receptor 4 Toll-Like/metabolismo , Receptor Toll-Like 9/metabolismo , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Índia , Leishmaniose Visceral/genética , Doenças Negligenciadas , Polimorfismo Genético , Receptor 4 Toll-Like/genética , Receptor Toll-Like 9/genéticaRESUMO
Neural dedifferentiation refers to an age-related phenomenon whereby brain functions that are localized to specific, distinct, and differentiated brain areas in young adults become less so as people reach more advanced age. Older adults tend to exhibit greater spread of cortical activation on fMRI during cognitive processing compared to younger adults, with evidence that this occurs during visuoperceptual processing. Some age-related functional changes are considered compensatory, but whether dedifferentiation is compensatory is not clearly understood. The current study assessed dedifferentiation and visual discrimination performance during simultaneous match-to-sample tasks from the Visual Assessment Battery (VAB) among 40 healthy middle-aged and older adults using fMRI. Task-relevant regions of interest (ROIs) were created in the dorsal stream for discrimination of spatial location, the ventral stream for shape, and an area encompassing V5 for velocity. Dedifferentiation, or less specificity in functional activation, was associated with greater discrimination accuracy and more years of education. Secondary analyses showed that reduced functional activation in task-relevant ROIs was associated with faster discrimination speed. Age was unassociated with functional activation. Results suggest that dedifferentiation is compensatory. Lack of age effects suggest that other factors beyond age, such as cognitive or brain reserve, may better predict performance when considering cognitive skills that are relatively stable as adults age, such as visual discrimination.
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Electroencephalography (EEG) studies investigating visuo-spatial working memory (vWM) in aging typically adopt an event-related potential (ERP) analysis approach that has shed light on the age-related changes during item retention and retrieval. However, this approach does not fully enable a detailed description of the time course of the neural dynamics related to aging. The most frequent age-related changes in brain activity have been described by two influential models of neurocognitive aging, the Hemispheric Asymmetry Reduction in Older Adults (HAROLD) and the Posterior-Anterior Shift in Aging (PASA). These models posit that older adults tend to recruit additional brain areas (bilateral as predicted by HAROLD and anterior as predicted by PASA) when performing several cognitive tasks. We tested younger (N = 36) and older adults (N = 35) in a typical vWM task (delayed match-to-sample) where participants have to retain items and then compare them to a sample. Through a data-driven whole scalp EEG analysis we aimed at characterizing the temporal dynamics of the age-related activations predicted by the two models, both across and within different stages of stimulus processing. Behaviorally, younger outperformed older adults. The EEG analysis showed that older adults engaged supplementary bilateral posterior and frontal sites when processing different levels of memory load, in line with both HAROLD and PASA-like activations. Interestingly, these age-related supplementary activations dynamically developed over time. Indeed, they varied across different stages of stimulus processing, with HAROLD-like modulations being mainly present during item retention, and PASA-like activity during both retention and retrieval. Overall, the present results suggest that age-related neural changes are not a phenomenon indiscriminately present throughout all levels of cognitive processing.
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Genomic islands (Aeromonas salmonicida genomic islands, AsaGEIs) are found worldwide in many isolates of Aeromonas salmonicida subsp. salmonicida, a fish pathogen. To date, five variants of AsaGEI (1a, 1b, 2a, 2b and 2c) have been described. Here, we investigate a sixth AsaGEI, which was identified in France between 2016 and 2019 in 20 A. salmonicida subsp. salmonicida isolates recovered from sick salmon all at the same location. This new AsaGEI shares the same insertion site in the chromosome as the other AsaGEI2s as they all have a homologous integrase gene. This new AsaGEI was thus named AsaGEI2d, and has five unique genes compared to the other AsaGEIs. The isolates carrying AsaGEI2d also bear the plasmid pAsa7, which was initially found in an isolate from Switzerland. This plasmid provides resistance to chloramphenicol thanks to a cat gene. This study reveals more about the diversity of the AsaGEIs.
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Aeromonas/genética , Ilhas Genômicas , Plasmídeos , Aeromonas/classificação , Aeromonas/efeitos dos fármacos , Aeromonas/isolamento & purificação , Animais , Antibacterianos/farmacologia , Resistência ao Cloranfenicol/genética , Doenças dos Peixes/microbiologia , França , Genoma Bacteriano/genética , Ilhas Genômicas/genética , Integrases/genética , Testes de Sensibilidade Microbiana , Fases de Leitura Aberta , Filogenia , Plasmídeos/genética , SalmãoRESUMO
The type three secretion system (TTSS) locus of Aeromonas salmonicida subsp. salmonicida, located on the plasmid pAsa5, is known to be lost when the bacterium is grown at temperatures of 25 °C. The loss of the locus is due to the recombination of the insertion sequences flanking the TTSS region. However, the mechanism involved in this recombination is still elusive. Here, we analyzed 22 A. salmonicida subsp. salmonicida strains that had already lost their TTSS locus, and we systematically explored another 47 strains for their susceptibility to lose the same locus when grown at 25 °C. It appeared that strains from Europe were more prone to lose their TTSS locus compared to Canadian strains. More specifically, it was not possible to induce TTSS loss in Canadian strains that have AsaGEI2a, a genomic island, and prophage 3, or in Canadian strains without a genomic island. A comparative genomic approach revealed an almost perfect correlation between the presence of a cluster of genes, not yet characterized, and the susceptibility of various groups of strains to lose their locus. This cluster of genes encodes putative proteins with DNA binding capacity and phage proteins. This discovery creates new opportunities in the study of pAsa5 thermosensitivity.
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Organic arsenicals are important environment pollutants due to wide use in livestock and toxicity of degradation products. In this work we report about the efficient photodegradation of the p-arsanilic acid (p-ASA) and its decomposition products in the Fe(III)-oxalate assisted approach under nature-relevant conditions. At neutral pH under near-visible UV irradiation the Fe(III) oxalate complexes generate the primary oxidizing intermediate, OH radical (the quantum yield of ÏOH â¼ 0.06), which rapidly reacts with p-ASA with high rate constant, (8.6 ± 0.5) × 109 M-1s-1. Subsequent radical reactions result in the complete photooxidation of both p-ASA and basic aromatic photoproducts with the predominant formation of inorganic arsenic species, mainly As(V), under optimal conditions. Comparing with the direct UV photolysis, the presented Fe(III)-oxalate mediated degradation of p-ASA has several advantages: higher efficiency at low p-ASA concentration and complete degradation of organic arsenic by-products without use of short-wavelength UV radiation. The obtained results illustrate that the Fe(III)-oxalate complexes are promising natural photosensitizers for the removal of arsenic pollutants from contaminated waters.