RESUMO
Biomolecular condensates are membraneless organelle-like structures that can concentrate molecules and often form through liquid-liquid phase separation. Biomolecular condensate assembly is tightly regulated by developmental and environmental cues. Although research on biomolecular condensates has intensified in the past 10 years, our current understanding of the molecular mechanisms and components underlying their formation remains in its infancy, especially in plants. However, recent studies have shown that the formation of biomolecular condensates may be central to plant acclimation to stress conditions. Here, we describe the mechanism, regulation, and properties of stress-related condensates in plants, focusing on stress granules and processing bodies, 2 of the most well-characterized biomolecular condensates. In this regard, we showcase the proteomes of stress granules and processing bodies in an attempt to suggest methods for elucidating the composition and function of biomolecular condensates. Finally, we discuss how biomolecular condensates modulate stress responses and how they might be used as targets for biotechnological efforts to improve stress tolerance.
Assuntos
Condensados Biomoleculares , ProteomaRESUMO
INTRODUCTION: The Society for Vascular Surgery Threatened Limb Classification System ('WIfI') is used to predict risk of limb loss and identify peripheral artery disease in patients with foot ulcers or gangrene. We estimated the diagnostic sensitivity of multiple clinical and noninvasive arterial parameters to identify chronic limb-threatening ischemia (CLTI). METHODS: We performed a single-center review of 100 consecutive patients who underwent angiography for foot gangrene or ulcers. WIfI stages and grades were determined for each patient. Toe, ankle, and brachial pressure measurements were performed by registered vascular technologists. CLTI severity was characterized using Global Limb Anatomic Staging System (GLASS stages) and angiosomes. Medial artery calcification in the foot was quantified on foot radiographs. RESULTS: GLASS NA (not applicable), I, II, and III angiographic findings were seen in 21, 21, 23, and 35 patients, respectively. A toe-brachial index < 0.7 and minimum ipsilateral ankle-brachial index < 0.9 performed well in identifying GLASS II and III angiographic findings, with sensitivity rates 97.8% and 91.5%, respectively. The diagnostic accuracy rates of noninvasive measures peaked at 74.7% and 89.3% for identifying GLASS II/III and GLASS I+ angiographic findings, respectively. The presence of medial artery calcification significantly diminished the sensitivity of most noninvasive parameters. CONCLUSIONS: The use of alternative noninvasive arterial testing parameters improves sensitivity for detecting PAD. Abnormal noninvasive results should suggest the need for diagnostic angiography to further characterize arterial anatomy of the affected limb. Testing strategies with better accuracy are needed.
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Isquemia Crônica Crítica de Membro , Doença Arterial Periférica , Humanos , Gangrena/cirurgia , Isquemia/diagnóstico por imagem , Extremidade Inferior/irrigação sanguínea , Pé/irrigação sanguínea , Doença Arterial Periférica/diagnóstico por imagem , Salvamento de Membro/métodos , Estudos Retrospectivos , Resultado do Tratamento , Fatores de RiscoRESUMO
Legumes associate with Gram-negative soil bacteria called rhizobia, resulting in the formation of a nitrogen-fixing organ, the nodule. Nodules are an important sink for photosynthates for legumes, so these plants have developed a systemic regulation mechanism that controls their optimal number of nodules, the so-called autoregulation of nodulation (AON) pathway, to balance energy costs with the benefits of nitrogen fixation. In addition, soil nitrate inhibits nodulation in a dose-dependent manner, through systemic and local mechanisms. The CLE family of peptides and their receptors are key to tightly controlling these inhibitory responses. In the present study, a functional analysis revealed that PvFER1, PvRALF1, and PvRALF6 act as positive regulators of the nodule number in growth medium containing 0 mM of nitrate but as negative regulators in medium with 2 and 5 mM of nitrate. Furthermore, the effect on nodule number was found to be consistent with changes in the expression levels of genes associated with the AON pathway and with the nitrate-mediated regulation of nodulation (NRN). Collectively, these data suggest that PvFER1, PvRALF1, and PvRALF6 regulate the optimal number of nodules as a function of nitrate availability.
Assuntos
Phaseolus , Nodulação , Nodulação/genética , Nódulos Radiculares de Plantas/metabolismo , Phaseolus/genética , Phaseolus/metabolismo , Nitratos/farmacologia , Nitratos/metabolismo , Peptídeos/metabolismo , Simbiose , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMO
Genetic differentiation depends on ecological and evolutionary processes that operate at different spatial and temporal scales. While the geographical context is likely to determine large-scale genetic variation patterns, habitat disturbance events will probably influence small-scale genetic diversity and gene flow patterns. Therefore, the genetic diversity patterns that we observe today result from the combination of both processes, but they are rarely assessed simultaneously. We determined the population structure and genetic diversity of a hemiparasitic mistletoe (Tristerix corymbosus) from the temperate rainforests of southern Chile to determine the effects of geographical context and habitat disturbance at a regional scale and if it is affected by the abundance and occurrence of its seed disperser mutualist (the arboreal marsupial Dromiciops gliroides). We genotyped 359 individuals from 12 populations using single nucleotide polymorphisms, across three different geographical contexts and four disturbance conditions. We also used camera traps to estimate the abundance and occurrence of the seed disperser. Our results suggest that genetic differences among populations are related more to geographical context than to habitat disturbance. However, as disturbance increased, D. gliroides abundance and occurrence decreased, and mistletoe inbreeding index (FIS ) increased. We also found highly uneven gene flow among study sites. Despite the high levels of disturbance that these temperate rainforests are facing, our results suggest that mistletoe genetic differentiation at a regional scale was more influenced by historical events. However, habitat disturbance can indirectly affect mistletoe population genetic differentiation via the seed dispersal process, which may increase levels of inbreeding.
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Erva-de-Passarinho , Dispersão de Sementes , Ecossistema , Fluxo Gênico , Variação Genética/genética , Genética Populacional , Erva-de-Passarinho/genética , ÁrvoresRESUMO
OBJECTIVE: Chronic limb-threatening ischemia (CLTI) is associated with adverse limb outcomes and increased mortality. However, a small subset of the CLTI population will have no feasible conventional methods of revascularization. In such cases, venous arterialization (VA) could provide an alternative for limb salvage. The objective of the present study was to review the outcomes of VA at our institution. METHODS: We performed a single-institution review of 41 patients who had been followed up prospectively and had undergone either superficial or deep VA. The data collected included patient demographics, comorbidities, VA technique (endovascular vs hybrid), and WIfI (wound, ischemia, and foot infection) limb staging. Data were collected at 1-month, 6-month, and 1-year intervals and included the following outcomes: patency, wound healing, major adverse limb events, major amputation, and death. Descriptive statistics were used for analysis. RESULTS: The study group included 41 patients who had undergone successful open hybrid superficial or deep endovascular VA; 21 (51.2%) had undergone a purely endovascular procedure and 20 (48.8%), hybrid VA. The WIfI clinical stage was as follows: stage 4, 33 (80.5%); stage 3, 6 (14.6%); and stage 2, 1 (2.4%). Of the 41 patients, 24 (58.5%) had completed follow-up at 6 months and 16 (39%) at 1 year. At 1 year, the VA primary patency was 28.6% (95% confidence interval [CI], 0.15%-0.43%), primary assisted patency was 44.3% (95% CI, 0.27%-0.60%), and secondary patency was 67% (95% CI, 0.49%-0.80%). The complete wound healing rate was 2.7% (n = 1) at 1 month, 62.5% (n = 15) at 6 months, and 18.8% (n = 3) at 1 year. Overall wound healing at 1 year was 46.3% (n = 19). The number of major adverse limb events at 1 year was 15 (36.5%) and included 8 reinterventions (19.5%) and 7 major amputations (17%). The number of deaths was zero (0%) at 1 month and four (19%) at 6 months. Two deaths (9.5%) were attributed to COVID-19 (coronavirus disease 2019). No further deaths had occurred within 1 year. The limb salvage survival probability at 1 year was 81%. CONCLUSIONS: These findings suggest that for a select subset of CLTI patients presenting with a high WIfI clinical limb stage and no viable options for conventional open or endovascular arterial revascularization, superficial and deep VA are feasible options to achieve limb salvage.
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COVID-19 , Procedimentos Endovasculares , Doença Arterial Periférica , Amputação Cirúrgica , Isquemia Crônica Crítica de Membro , Procedimentos Endovasculares/efeitos adversos , Humanos , Isquemia/diagnóstico por imagem , Isquemia/cirurgia , Salvamento de Membro/efeitos adversos , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/cirurgia , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: The ability of SARS-CoV-2 to remain in asymptomatic individuals facilitates its dissemination and makes its control difficult. OBJECTIVE: To establish a cohort of asymptomatic individuals, change to the symptomatic status, and determine the most frequent clinical manifestations. METHODS: Between April 9 and August 9, 2020, molecular diagnosis of SARS-CoV-2 infection was confirmed in 154 asymptomatic people in contact with subjects diagnosed with COVID-19. Nasopharyngeal swabs were performed on these people in different hospitals in Córdoba, the Caribbean area of Colombia. The genes E, RdRp, and N were amplified with RT-qPCR. Based on the molecular results and the Cq values, the patients were subsequently followed up through telephone calls to verify their health conditions. RESULTS: Overall, of 154 asymptomatic individuals, 103 (66.9%) remained asymptomatic, and 51 (33.1%) changed to symptomatic. The most frequent clinical manifestations in young people were anosmia and arthralgia. Adults showed cough, ageusia, and odynophagia; in the elderly were epigastralgia, dyspnea, and headache. Mortality was 8%. CONCLUSIONS: A proportion of 33% of presymptomatic individuals was found, of which four of them died. This high rate could indicate a silent transmission, contributing significantly to the epidemic associated with SARS-CoV-2.
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COVID-19 , SARS-CoV-2 , Adolescente , Adulto , Idoso , COVID-19/diagnóstico , COVID-19/epidemiologia , Colômbia/epidemiologia , Tosse , Humanos , Saúde Pública , SARS-CoV-2/genéticaRESUMO
OBJECTIVE: Iatrogenic vascular injuries (IaVI's) appear to be increasing, with disparate prevalence across gender, race and ethnicity. We aim to assess the risk of IaVI's across these characteristics. METHODS: Using the Nationwide Inpatient Sample for the years 2008 to 2015, we identified rates of IaVI's among the top ten most frequently performed inpatient procedures in the United States. Joint point regression was employed to examine the trends in the rates of IaVI's. We also calculated the adjusted odds ratios for IaVI's using survey logistic regression. RESULTS: During the eight-year study period, a total of 29,877,180 procedures were performed (33.6% hip replacement, 14% knee arthroplasty, 11.2% cholecystectomy, 10.3% spinal fusion, 8.9% lysis of adhesions, 8% colorectal resection, 7.9% partial bone excision, 5% appendectomy, 0.6% percutaneous coronary angioplasty, 0.6% laminectomy). A total of 194,031 (0.65%) IaVI's were associated with these procedures. The incidence of IaVI's increased over time with an average annual percentage change (AAPC) of 4.2% (95% CI: 3.1, 5.4; P < 0.01). More females (105,747; 54.5%) than males (88,284; 45.5%) suffered IaVI's during their hospital admission (P < 0.01). Patients 70 years of age and older had the highest incidence of IaVI's (12,244,082; 34.3%; P ≤ 0.01). Among the ten index procedures, Non-Hispanic (NH) Whites underwent the highest proportion of procedures (14.1 procedures/100 hospitalizations; P < 0.01) and cholecystectomy was associated with the highest rate of IaVI's (19.4 per 1000 hospitalizations, P ≤ 0.01). Overall, patients from the lowest income quartile were least likely to suffer IaVI's (0.83 95% CI 0.79-0.88, P < 0.01) compared to the highest income quartile. All form of healthcare coverage increased the odds of IaVI's: Medicaid (1.07 95% CI 1.07-1.13, P < 0.01); Private insurance (1.35 95% CI 1.3-1.39, P < 0.01); Self-pay or no charge (1.45 95% CI 1.38-1.52, P < 0.01). IaVI's increased the odds of in-hospital mortality in all groups (1.25 95% CI 1.14-1.35, P < 0.01) and more pronounced in NH-Blacks (1.51 95% CI 1.15-1.99, P < 0.01). In the overall cohort, urban teaching hospitals observed the highest odds of in-hospital mortality (1.11 95% CI 1.07-1.15, P < 0.01). CONCLUSION: Between 2008 to 2015, IaVI's rates for the top ten most frequently performed inpatient procedures increased by 33.6% (4.2% annually; P < 0.01). The elderly, females, and Hispanics more frequently had hospitalizations complicated by IaVI's. Overall, IaVI's independently increased the adjusted odds of mortality by 25%. IaVI's were most fatal among Blacks, about 50% elevated risk of death compared to NH-Whites. These benchmarks will be critical to future efforts to reduce IaVI, and associated healthcare disparities.
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Doença Iatrogênica/etnologia , Procedimentos Cirúrgicos Operatórios , Lesões do Sistema Vascular/etnologia , Lesões do Sistema Vascular/etiologia , Adulto , Idoso , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores Sexuais , Estados UnidosRESUMO
Metallothioneins (MTs) constitute a heterogeneous family of ubiquitous metal ion-binding proteins. In plants, MTs participate in the regulation of cell growth and proliferation, protection against heavy metal stress, oxidative stress responses, and responses to pathogen attack. Despite their wide variety of functions, the role of MTs in symbiotic associations, specifically nodule-fabacean symbiosis, is poorly understood. Here, we analyzed the role of the PvMT1A gene in Phaseolus vulgaris-Rhizobium tropici symbiosis using bioinformatics and reverse genetics approaches. Using in silico analysis, we identified six genes encoding MTs in P. vulgaris, which were clustered into three of the four classes described in plants. PvMT1A transcript levels were significantly higher in roots inoculated with R. tropici at 7 and 30 days post inoculation (dpi) than in non-inoculated roots. Functional analysis showed that downregulating PvMT1A by RNA interference (RNAi) reduced the number of infection events at 7 and 10 dpi and the number of nodules at 14 and 21 dpi. In addition, nodule development was negatively affected in PvMT1A:RNAi transgenic roots, and these nodules displayed a reduced nitrogen fixation rate at 21 dpi. These results strongly suggest that PvMT1A plays an important role in the infection process and nodule development in P. vulgaris during rhizobial symbiosis.
Assuntos
Metalotioneína/metabolismo , Phaseolus , Proteínas de Plantas/metabolismo , Rhizobium/crescimento & desenvolvimento , Nódulos Radiculares de Plantas , Simbiose , Phaseolus/metabolismo , Phaseolus/microbiologia , Nódulos Radiculares de Plantas/metabolismo , Nódulos Radiculares de Plantas/microbiologiaRESUMO
BACKGROUND: Tick-borne phenuivirus (TBPVs) comprise human and animal viruses that can cause a variety of clinical syndromes ranging from self-limiting febrile illness to fatal haemorrhagic fevers. OBJECTIVE: Detect Phlebovirus (Family Phenuiviridae) in ticks collected from domestic animals in Córdoba, Colombia. METHODS: We collected 2365 ticks from domestic animals in three municipalities of the Department of Cordoba, Colombia in 2016. Ticks were identified and pooled by species for RNA extraction. A nested real-time PCR with specific primers for Phlebovirus and a specific probe for Heartland virus (HRTV) formerly a Phlebovirus, now a Banyangvirus were performed. Also, a conventional nested PCR, with the same specific primers was used to detect other Phleboviruses, with positive reactions indicated by an amplified cDNA fragment of approximately 244 bp determined by gel electrophoresis. These bands were gel-purified and sequenced by the Sanger method. RESULTS: Using real-time RT-PCR, no positive results for HRTV were found. However, using conventional nested PCR 2.2% (5/229 pools) yielded a product of 244 bp. One positive sample was detected in a pool of Dermacentor nitens ticks collected from a horse, and the four remaining positive pools were from Rhipicephalus microplus collected from cattle. The five positive nucleotide sequences had identities of 93 to 96% compared to a section of the L-segment of Lihan Tick virus, a Phlebovirus originally detected in R. microplus ticks in China. The strongest identity (96-99%) was with Lihan Tick virus detected in R. microplus ticks from Brazil. CONCLUSIONS: This is the first report of viral detection in ticks in Colombia. We detected a Colombian strain of Lihan Tick virus. We recommend expanding the sampling area and carrying out more eco-epidemiological studies related to epidemiological surveillance of viruses on ticks in Colombia.
Assuntos
Phlebovirus/genética , Filogenia , Carrapatos/virologia , Animais , Animais Domésticos/parasitologia , Bovinos , Colômbia , Estudos Transversais , Dermacentor/virologia , Cães , Cavalos , Phlebovirus/classificação , Phlebovirus/isolamento & purificação , Estudos Prospectivos , Vírus de RNA/genética , Rhipicephalus/virologia , Análise de Sequência de DNARESUMO
BACKGROUND: Severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) is an emerging viral pandemic disease. In the last 6 months, SARS-CoV-2 has caused millions of reported cases and hundreds of thousands of deaths. As other world regions, South America has not contained the pandemic's advance since it lacks the hospital and economic capacities. Public health implications of transmission, while the asymptomatic/presymptomatic infection is a critical concern at the current pandemic. OBJECTIVE: Describe the socio-demographic, clinical, and viral features of a cohort of SARS-CoV-2 infected individuals from the Colombian Caribbean. METHODS: Six hundred eighty-six clinical samples of suspected SARS-CoV-2 infection cases and contacts individuals from several hospital centers in the department of Córdoba, Colombia, were received at our laboratory between April 9th and May 16th, 2020. RNA was extracted using lysis buffers and spin columns. The samples were tested for SARS-CoV-2 by reverse transcription real-time polymerase chain reaction (RT-qPCR) using commercially available multiplex real-time PCR assay for simultaneous detection of 3 target genes of SARS-CoV-2 (Allplex™, 2019-nCoV assay, Korea). Viral copies quantification was done using a standard curve constructed from seriated dilutions of a SARS-CoV-2 positive control. Statics descriptive methods were used. RESULTS: Thirty-five nasopharyngeal samples were positive for SARS-CoV-2 infection; the average age was 43 (range, 1-95 years). Seventeen of 35 (49%) of the patients showed symptoms. Most of them had a cough, fever, and odynophagia; three of the patients reported having arthralgia. Only two patients required hospitalization. None of the patients had known co-morbidities. RT-qPCR results show that two of the symptomatic patients had significantly higher RNA copies than the rest. Eighteen of 35 (51%) individuals were asymptomatic, and the average age was 30 (range, 6-61 years). Four asymptomatic individuals showed a higher copy than some symptomatic patients; nonetheless, the average of RNA copies 8.26 × 1010 was lower than the symptomatic. CONCLUSIONS: This study shows that asymptomatic patients may develop infections with a high number of RNA copies. Since a considerable percentage of infections may be asymptomatic/presymptomatic, enhanced testing approaches may be needed to detect these persons. Due the occurrence of a large proportion of infections being a result from transmission originated in asymptomatic/presymptomatic individuals, public health interventions in Colombia should be based on two steps: a massive molecular screening, and viral load quantification. Finally, a remarkable issue in our study is the average age of symptomatic and asymptomatic groups (43 and 30 respectively) which may be important because of the economic impact that has been caused by the coronavirus pandemic and may be probably the cause of the reduced lethality observed in the country and the department at the time of this study.
Assuntos
COVID-19/epidemiologia , COVID-19/etiologia , Adolescente , Adulto , Idoso de 80 Anos ou mais , COVID-19/transmissão , Região do Caribe/epidemiologia , Portador Sadio/epidemiologia , Criança , Pré-Escolar , Colômbia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , SARS-CoV-2/genética , Fatores Socioeconômicos , Carga Viral , Adulto JovemRESUMO
Vibrissae are an important tactile sense organ of many mammals, in particular rodents like rats and mice. For instance, these animals use them in order to detect different object features, e.g., object-distances and -shapes. In engineering, vibrissae have long been established as a natural paragon for developing tactile sensors. So far, having object shape scanning and reconstruction in mind, almost all mechanical vibrissa models are restricted to contact scenarios with a single discrete contact force. Here, we deal with the effect of multi-point contacts in a specific scanning scenario, where an artificial vibrissa is swept along partly concave object contours. The vibrissa is modeled as a cylindrical, one-sided clamped Euler-Bernoulli bending rod undergoing large deflections. The elasticae and the support reactions during scanning are theoretically calculated and measured in experiments, using a spring steel wire, attached to a force/torque-sensor. The experiments validate the simulation results and show that the assumption of a quasi-static scanning displacement is a satisfying approach. Beyond single- and two-point contacts, a distinction is made between tip and tangential contacts. It is shown that, in theory, these contact phases can be identified solely based on the support reactions, what is new in literature. In this way, multipoint contacts are reliably detected and filtered in order to discard incorrectly reconstructed contact points.
Assuntos
Modelos Biológicos , Tato/fisiologia , Algoritmos , Órgãos Artificiais , Simulação por ComputadorRESUMO
BACKGROUND: Flaviviruses are important pathogens for humans and animals (Dengue viruses, Yellow fever virus, Zika virus and West Nile virus). Culex flavivirus (CxFV) is an insect-specific virus of the genus Flavivirus, detected in a wide variety of mosquito species. OBJECTIVE: To detect Flavivirus in mosquitoes of a tropical region of the Colombian Caribbean. METHODS: In 2014, an entomological surveillance of arboviruses was conducted in the department of Cordoba area of the Caribbean, Colombia. A total of 8270 mosquitoes were captured as follow: Mansonia (n = 3271/39.5%), Culex (n = 2668/32.26%), Anopheles (n = 840/10.15%), Aedeomyia (n = 411/4.9%), Psorophora (n = 397/4.8%), Coquilletidia (n = 369/4.46%), Uranotaenia (n = 261/3.15%) and Aedes (n = 53/0.6%). All mosquito species were collected in dry tropical forest of the Caribbean area. Universal primers for NS5 gene (958 pb), RT-PCR for flavivirus and sequencing were used for molecular identification of viruses detected. RESULTS: Two pools belonging to Culex coronator were positive for flavivirus RNA sequence by RT-PCR. The sequences of the PCR amplicons, matched that of the Culex flaviviruses, CxFv COL PM_149 (GenBank: KR014201) and CxFv COL PM_212 (GenBank: KT307717). Phylogenetic analysis of the NS5 protein sequences of the Culex flaviviruses sequences with those of reference sequences available in GenBank indicated viruses of Genotype II, closely related to the Brazilian strain, BR_SJRP_01_ (GenBank: KT726939), from Culex sp. The alignment of Culex flavivirus sequences CxFv COL_ PM 212 and CxFv COL_ PM 149 with sequences of strains detected in different geographical regions grouped the strains in a Latin American clade reported in Brazil, Argentina and Mexico. CONCLUSIONS: The present work illustrated that CxFV was circulating among vectors of human pathogenic arboviruses in Colombia, but the impact of CxFV on other flaviviruses which are endemic in the study area still remains to be explored.
Assuntos
Culicidae/virologia , Flavivirus/classificação , Mosquitos Vetores/virologia , Aedes/virologia , Animais , Anopheles/virologia , Região do Caribe , Colômbia , Feminino , Flavivirus/isolamento & purificação , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Masculino , Filogenia , Estudos Prospectivos , Clima Tropical , Proteínas não Estruturais Virais/genéticaRESUMO
In nature, there are several examples of sophisticated sensory systems to sense flows, e.g., the vibrissae of mammals. Seals can detect the flow of their prey, and rats are able to perceive the flow of surrounding air. The vibrissae are arranged around muzzle of an animal. A vibrissa consists of two major components: a shaft (infector) and a follicle-sinus complex (receptor), whereby the base of the shaft is supported by the follicle-sinus complex. The vibrissa shaft collects and transmits stimuli, e.g., flows, while the follicle-sinus complex transduces them for further processing. Beside detecting flows, the animals can also recognize the size of an object or determine the surface texture. Here, the combination of these functionalities in a single sensory system serves as paragon for artificial tactile sensors. The detection of flows becomes important regarding the measurement of flow characteristics, e.g., velocity, as well as the influence of the sensor during the scanning of objects. These aspects are closely related to each other, but, how can the characteristics of flow be represented by the signals at the base of a vibrissa shaft or by an artificial vibrissa-like sensor respectively? In this work, the structure of a natural vibrissa shaft is simplified to a slender, cylindrical/tapered elastic beam. The model is analyzed in simulation and experiment in order to identify the necessary observables to evaluate flows based on the quasi-static large deflection of the sensor shaft inside a steady, non-uniform, laminar, in-compressible flow.
RESUMO
Ornithodoros marinkellei was described from larvae collected on Pteronotus spp. bats in Colombia and Panama. More recently, this tick was reported in the Brazilian Amazon. Because some morphometric differences were observed between O. marinkellei larvae from Colombia and Brazil, it was proposed that further investigations were needed to assess whether the differences could be attributed to intra- or inter-specific polymorphism. Herein, we collected O. marinkellei specimens in the type locality of Colombia, in Brazil, and in a new locality in Nicaragua, expanding the distribution of the species to Nicaragua. Morphometric analysis of larvae and adults, corroborated by a principal component analysis (PCA), indicated that the Brazilian specimens were larger than specimens from Colombia and Nicaragua. Phylogenetic analysis inferred from the mitochondrial 16S rRNA gene showed ticks from Colombia and Nicaragua more genetically related than any of them with ticks from Brazil, although ticks from the three countries grouped in a clade sister to a major clade containing sequences of various Neotropical Ornithodoros species. We concluded that ticks identified as O. marinkellei from Colombia, Nicaragua, and Brazil represent the same taxon, and that the genetic and morphological differences between them are likely to have a geographical bias. We redescribed the nymph of O. marinkellei, which has a vestigial hypostome, probably incompatible with blood feeding. We also report human infestation by O. marinkellei adults. As all reports of O. marinkellei adults have been from hot caves (temperature > 35 °C), this abiotic condition could be a limiting factor for the occurrence of this tick species.
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Distribuição Animal , Ecossistema , Interações Hospedeiro-Parasita , Ornithodoros/anatomia & histologia , Ornithodoros/fisiologia , Infestações por Carrapato/parasitologia , Animais , Brasil , Colômbia , Feminino , Humanos , Larva/anatomia & histologia , Larva/classificação , Larva/genética , Larva/fisiologia , Masculino , Nicarágua , Ninfa/anatomia & histologia , Ninfa/classificação , Ninfa/genética , Ninfa/fisiologia , Ornithodoros/classificação , Ornithodoros/genética , Filogenia , RNA Ribossômico 16S/análiseRESUMO
Damage to the CNS can cause a differential spatio-temporal release of multiple factors, such as nucleotides, ATP and UTP. The latter interact with neuronal and glial nucleotide receptors. The P2Y2 nucleotide receptor (P2Y2R) has gained prominence as a modulator of gliotic responses after CNS injury. Still, the molecular mechanisms underlying these responses in glia are not fully understood. Membrane-raft microdomains, such as caveolae, and their constituent caveolins, modulate receptor signaling in astrocytes; yet, their role in P2Y2R signaling has not been adequately explored. Hence, this study evaluated the role of caveolin-1 (Cav-1) in modulating P2Y2R subcellular distribution and signaling in human 1321N1 astrocytoma cells. Recombinant hP2Y2R expressed in 1321N1 cells and Cav-1 were found to co-fractionate in light-density membrane-raft fractions, co-localize via confocal microscopy, and co-immunoprecipitate. Raft localization was dependent on ATP stimulation and Cav-1 expression. This hP2Y2R/Cav-1 distribution and interaction was confirmed with various cell model systems differing in the expression of both P2Y2R and Cav-1, and shRNA knockdown of Cav-1 expression. Furthermore, shRNA knockdown of Cav-1 expression decreased nucleotide-induced increases in the intracellular Ca(2+) concentration in 1321N1 and C6 glioma cells without altering TRAP-6 and carbachol Ca(2+) responses. In addition, Cav-1 shRNA knockdown also decreased AKT phosphorylation and altered the kinetics of ERK1/2 activation in 1321N1 cells. Our findings strongly suggest that P2Y2R interaction with Cav-1 in membrane-raft caveolae of 1321N1 cells modulates receptor coupling to its downstream signaling machinery. Thus, P2Y2R/Cav-1 interactions represent a novel target for controlling P2Y2R function after CNS injury.
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Cavéolas/metabolismo , Caveolina 1/metabolismo , Receptores Purinérgicos P2Y2/metabolismo , Transdução de Sinais , Trifosfato de Adenosina/farmacologia , Astrocitoma/genética , Astrocitoma/metabolismo , Astrocitoma/patologia , Cálcio/metabolismo , Cavéolas/efeitos dos fármacos , Caveolina 1/genética , Linhagem Celular Tumoral , Células HEK293 , Humanos , Immunoblotting , Microscopia Confocal , Fosforilação , Ligação Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNARESUMO
Population aging and increasing pressure on health systems are two issues that demand solutions. Involving and empowering citizens as active managers of their health represents a desirable shift from the current culture mainly focused on treatment of disease, to one also focused on continuous health management and well-being. Current developments in technological areas such as the Internet of Things (IoT), lead to new technological solutions that can aid this shift in the healthcare sector. This study presents the design, development, implementation and evaluation of a platform called Common Recognition and Identification Platform (CRIP), a part of the CareStore project, which aims at supporting caregivers and citizens to manage health routines in a seamless way. Specifically, the CRIP offers sensor-based support for seamless identification of users and health devices. A set of initial requirements was defined with a focus on usability limitations and current sensor technologies. The CRIP was designed and implemented using several technologies that enable seamless integration and interaction of sensors and people, namely Near Field Communication and fingerprint biometrics for identification and authentication, Bluetooth for communication with health devices and web services for wider integration with other platforms. Two CRIP prototypes were implemented and evaluated in laboratory during a period of eight months. The evaluations consisted of identifying users and devices, as well as seamlessly configure and acquire vital data from the last. Also, the entire Carestore platform was deployed in a nursing home where its usability was evaluated with caregivers. The evaluations helped assess that seamless identification of users and seamless configuration and communication with health devices is feasible and can help enable the IoT on healthcare applications. Therefore, the CRIP and similar platforms could be transformed into a valuable enabling technology for secure and reliable IoT deployments on the healthcare sector.
Assuntos
Algoritmos , Atenção à Saúde , Internet , Telemedicina/instrumentaçãoRESUMO
BACKGROUND: Pedometers are considered desirable devices for monitoring physical activity. Two population groups of interest include patients having undergone surgery in the lower extremities or who are otherwise weakened through disease, medical treatment, or surgery procedures, as well as the slow walking senior population. For these population groups, pedometers must be able to perform reliably and accurately at slow walking speeds. The objectives of this study were to evaluate the step count accuracy of three commercially available pedometers, the Yamax (Tokyo, Japan) Digi-Walker(®) SW-200 (YM), the Omron (Kyoto, Japan) HJ-720 (OM), and the Fitbit (San Francisco, CA) Zip (FB), at slow walking speeds, specifically at 1, 2, and 3 km/h, and to raise awareness of the necessity of focusing research on step-counting devices and algorithms for slow walking populations. MATERIALS AND METHODS: Fourteen participants 29.93 ±4.93 years of age were requested to walk on a treadmill at the three specified speeds, in four trials of 100 steps each. The devices were worn by the participants on the waist belt. The pedometer counts were recorded, and the error percentage was calculated. RESULTS: The error rate of all three evaluated pedometers decreased with the increase of speed: at 1 km/h the error rates varied from 87.11% (YM) to 95.98% (FB), at 2 km/h the error rates varied from 17.27% (FB) to 46.46% (YM), and at 3 km/h the error rates varied from 22.46% (YM) to a slight overcount of 0.70% (FB). CONCLUSIONS: It was observed that all the evaluated devices have high error rates at 1 km/h and mixed error rates at 2 km/h, and at 3 km/h the error rates are the smallest of the three assessed speeds, with the OM and the FB having a slight overcount. These results show that research on pedometers' software and hardware should focus more on accurate step detection at slow walking speeds.
Assuntos
Actigrafia/instrumentação , Actigrafia/normas , Velocidade de Caminhada , Adulto , Teste de Esforço , Feminino , Humanos , MasculinoRESUMO
Chronic limb threatening ischemia (CLTI) poses a significant treatment challenge for vascular surgeons, interventionalists, podiatrists, and associated medical specialists. The evidence for what constitutes appropriate care is rapidly evolving and new treatment options are in constant development. This review examines the current guidelines for CLTI care, as well as reported outcomes for multiple care strategies in this patient population, including revascularization and medical optimization. We performed a literature review of the PubMed database, reviewing articles that reported outcomes for CLTI care between 2000 and 2023, and described these outcomes as they relate to the current state of CLTI treatment. Significant data are still forthcoming regarding CLTI care, but widespread adoption of appropriate CLTI care is essential for the treatment of this vulnerable population.
Assuntos
Isquemia Crônica Crítica de Membro , Humanos , Resultado do Tratamento , Fatores de Risco , Isquemia Crônica Crítica de Membro/terapia , Procedimentos Cirúrgicos Vasculares/normas , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Doença Arterial Periférica/terapia , Doença Arterial Periférica/diagnóstico , Doença Arterial Periférica/fisiopatologia , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/normas , Medicina Baseada em Evidências/normas , Guias de Prática Clínica como Assunto , Isquemia/terapia , Isquemia/diagnóstico , Isquemia/fisiopatologia , Salvamento de Membro , Doença CrônicaRESUMO
BACKGROUND: Evidence shows that motivational practices focused on utility, importance, and autonomy shape university students' motivational orientation toward learning. On the other hand, the relationship between these variables and motivational orientation toward learning is not linear and requires models that describe their behavior over time. METHOD: In this study, mathematical modeling based on system dynamics methodology is used to simulate in health students the temporal dynamics of the motivational orientation toward learning based on the behavior of these variables in different scenarios. RESULTS: The results indicate that a) Mastery is sensitive to changes in frequency when importance and autonomy practices are performed; b) the development of Mastery is critical in the first three semesters of academic life, but its loss is hardly recoverable even when practices are incorporated in subsequent semesters; c) Utility-focused motivational practices have no significant effect on the development of learning-oriented motivation. CONCLUSION: These findings have significant practical implications for higher education. Understanding the critical role of Mastery in the early stages of academic life and the limited potential for recovery if lost can help raise awareness of the importance of early implementation of motivational practices focused on relevance and autonomy.
Assuntos
Aprendizagem , Motivação , Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Estudantes de Ciências da Saúde/psicologia , Autonomia Pessoal , Modelos TeóricosRESUMO
Stress granules (SGs) are conserved cytoplasmic biomolecular condensates mainly formed by proteins and RNA molecules assembled by liquid-liquid phase separation. Isolation of SGs components has been a major challenge in the field due to the dynamic and transient nature of stress granule shells. Here, we describe the methodology for the isolation and visualization of SGs proteins from Arabidopsis thaliana plants using a scaffold component as the target. The protocol consists of the first immunoprecipitation of GFP-tagged scaffold protein, followed by an on-beads enzymatic digestion and previous mass spectrometry identification. Finally, the localization of selected SGs candidates is visualized in Nicotiana benthamiana mesophyll protoplasts.