Study of latencies in ThingSpeak

IoT platforms play an important role on modern measurement systems because they allow the ingestion and processing of huge amounts of data (big data). Given the increasing use of these platforms, it is important to characterize their performance and robustness in real application scenarios. The paper analyzes the ThingSpeak platform by measuring the latencies associated to data packets sent to cloud and replied back, and by checking the consistency of the returned data. Several experiments were done considering different ways to access the platform: REST API, MQTT API, and MQTT broker alone. For each experiment, the methodology is explained, results are presented, and conclusions are extracted. The REST and MQTT APIs have similar performances, with roundtrip times between 1 s and 3 s. The MQTT broker alone is more agile, with roundtrip times below 250 ms. In all cases, the up and down links are far from being symmetric, with the uplink delay showing higher variance than the downlink delay. The obtained results can serve as a reference for other IoT platforms and provide guidelines for application development.info:eu-repo/semantics/publishedVersio

Diagnóstico e tratamento da mastite.

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Bio-based synthesis of oxidation resistant copper nanowires using an aqueous plant extract

Copper nanowires have recently emerged as promising nanomaterials for transparent conducting electrodes applications, however, their production commonly involves the use of harmful reagents. In this study, we describe for the first time a simple and cost-effective bio-based synthesis of copper nanowires using an aqueous plant extract (Eucalyptus globulus) as the reducing/stabilizing agent and oleic acid and oleylamine as surfactants. Well-dispersed crystalline copper nanowires (λmáx = 584–613 nm) were obtained with average diameters in the nanometric range (44 and 145 nm) and lengths in the micrometric range (from 5 to dozens of micrometres) using extract concentrations between 10 and 50 mg mL−1. Moreover, the aspect ratio of these nanowires can be adjusted (from around 14–20 to 160–400) by changing the experimental conditions, namely the use of oleic acid. Phenolic compounds were found to have a key role in this bioreduction process allowing to obtain practically only nanowires (without other morphologies). Nevertheless, the use of oleic acid/oleylamine is essential to manipulate their size and aspect ratio. Most importantly, these bio-based copper nanowires were found to be resistant under storage in ethanol and when submitted to air exposure, both for 2 weeks, certainly due to the adsorption of antioxidant biomolecules (phenolic) at their surface, thus avoiding the use of other polymeric protective layers. The conductivity of the CuNWs was found to be 0.009 S cm−1. As a result, this study opens a new standpoint in this field, “closing the door” to the use of hazardous reagents and synthetic polymeric protective layers, on the production of stable copper nanowires with potential application as conductive materials.publishe

Optical Studies in Red/NIR Persistent Luminescent Cr‐Doped Zinc Gallogermanate (ZGGO:Cr)

Zn1+xGa2‐2xGexO4 (ZGGO:Cr)‐persistent phosphor, with a molar fraction, x, of x = 0.1, doped with a 0.5% molar of chromium, was synthesised via solid‐state reaction at 1350 °C for 36 h. X‐ray diffraction measurements and Raman spectroscopy evidence a single crystalline phase corresponding to the cubic spinel structure. Room temperature (RT) photoluminescence (PL) and afterglow decay profiles were investigated using above and below bandgap excitation. In both cases, persistent PL was observed for almost 8 h, mainly originating from a Cr3+ defect, the so‐called N2 optical centre. RT PL excitation and diffuse reflectance allow identification of the best pathways of Cr3+ red/NIR emission, as well as estimation of the ZGGO bandgap energy at 4.82 eV. An in‐depth investigation of the observed luminescence at 15 K and temperature‐dependent PL under site‐selective excitation reveals the spectral complexity of the presence of several optically active Cr3+ centres in the ZGGO host that emit in almost the same spectral region. Furthermore, the temperature dependence of the R‐lines’ intensity indicates the existence of thermal populating processes between the different optical centres. Such observations well account for a wide distribution of defect trap levels available for carrier capture/release, as measured by the persistent luminescence decay, from which the carriers are released preferentially to the N2 Cr3+‐related optical centre.publishersversionpublishe

Valor nutritivo do farelo de coco em ovinos: balanço energético e de nitrogênio.

Com o objetivo de avaliar o valor nutritivo do farelo de coco (Cocus nucifera) foi determinado o balanço energético e o balanço nitrogenado em borregos deslanados alojados em gaiolas metabólicas providas de separadores de fezes e urina recebendo feno de tifton-85 e níveis crescentes de farelo de coco nos níveis de zero, oito, 17 e 25% de farelo de coco com base na matéria natural, em um esquema inteiramente ao acaso com quatro tratamentos (nível de farelo de coco) e seis repetições (borregos) por tratamento perfazendo um total de 24 observações, empregando o método SNK a 5% de probabilidade para comparação das médias. Não houve efeito do nível de inclusão do farelo de coco sobre consumo e balanço de energia e sobre o consumo e balanço de nitrogênio, todos os níveis de inclusão dem farelo de coco tiveram balanço energético positivo no caso do balanço de nitrogênio todas as dietas tiveram balanço positivo com excessão da dieta com 25% de inclusão de farelo de coco. Concluiu-se que a inclusão de farelo de coco em até 25% teve efeito negativo sobre o consumo de energia, sem alcançar valores que prejudicariam o desempenho dos animais e que 25% de farelo de coco prejudicou o balanço protéico dos animais

Antibody indexes in COVID-19 convalescent plasma donors: Unanswered questions

OBJECTIVE: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is characterized by high contagiousness, as well as variable clinical manifestations and immune responses. The antibody response to SARS-CoV-2 is directly related to viral clearance and the antibodies’ ability to neutralize the virus and confer long-term immunity. Nevertheless, the response can also be associated with disease severity and evolution. This study correlated the clinical characteristics of convalescent COVID-19 patients with immunoglobulin A (IgA) and IgG anti-SARS-CoV-2 antibodies. METHODS: This study included 51 COVID-19 health care professionals who were candidates for convalescent plasma donation from April to June 2020. The subjects had symptomatic COVID-19 with a polymerase chain reaction-confirmed diagnosis. We measured anti-SARS-CoV-2 IgA and IgG antibodies after symptom recovery, and the subjects were classified as having mild, moderate, or severe symptoms. RESULTS: Anti-SARS-CoV-2 antibodies were positive in most patients (90.2%). The antibody indexes for IgA and IgG did not differ significantly between patients presenting with mild or moderate symptoms. However, they were significantly higher in patients with severe symptoms. CONCLUSIONS: Our study showed an association between higher antibody indexes and severe COVID-19 cases, and several hypotheses regarding the association of the antibody dynamics and severity of the disease in SARSCoV-2 infection have been raised, although many questions remain unanswered

Habitat fragmentation and the future structure of tree assemblages in a fragmented Atlantic forest landscape

The biodiversity value of human-modified landscapes has become a central question in the tropical forest conservation biology, yet the degree to which plant populations and communities are restructured in response to environmental change remains unclear. Here, we address tree species density in a fragmented Atlantic forest landscape to test the hypothesis that tree assemblages inhabiting edge-dominated forest habitats approach typical conditions of early successional systems. Seedlings and adults from 141 tree species were sampled across 39 0.1-ha plots: 19 in small fragments (55 % of all tree species exhibiting higher densities in small fragments than in mature forest, particularly pioneers (>60 % of all species). Seedlings and adults of these proliferating species differed from species exhibiting population declines in terms of wood density and seed size, respectively. Additionally, pioneers were more abundant than shade-tolerant species, as were hardwood species in the case of seedlings. Tree species showing highest population increases consisted largely of long-lived, light-demanding canopy species bearing soft or hardwood and small-to-medium-sized seeds. Tree assemblage structure also differed in terms of forest habitats with small forest fragments supporting few rare species, whereas the most rapidly proliferating species were much more widespread and abundant in fragments. However, 60 % of all adult pioneer species recorded in small fragments were not recorded as seedlings in this habitat type, although both seedling and adult assemblages were dominated by pioneer species. Edge-dominated tree assemblages are likely to experience long-term shifts toward greater dominance of long-lived, pioneer canopy species

Glioblastoma entities express subtle differences in molecular composition and response to treatment

Glioblastoma (GBM) is a grade IV astrocytoma. GBM patients show resistance to chemotherapy such as temozolomide (TMZ), the gold standard treatment. In order to simulate the molecular mechanisms behind the different chemotherapeutic responses in GBM patients we compared the cellular heterogeneity and chemotherapeutic resistance mechanisms in different GBM cell lines. We isolated and characterized a human GBM cell line obtained from a GBM patient, named GBM11. We studied the GBM11 behaviour when treated with Tamoxifen (TMX) that, among other functions, is a protein kinase C (PKC) inhibitor, alone and in combination with TMZ in comparison with the responses of U87 and U118 human GBM cell lines. We evaluated the cell death, cell cycle arrest and cell proliferation, mainly through PKC expression, by flow cytometry and western blot analysis and, ultimately, cell migration capability and f-actin filament disorganization by fluorescence microscopy. We demonstrated that the constitutive activation of p-PKC seems to be one of the main metabolic implicated on GBM malignancy. Despite of its higher resistance, possibly due to the overexpression of P-glycoprotein and stem-like cell markers, GBM11 cells presented a subtle different chemotherapeutic response compared to U87 and U118 cells. The GBM11, U87, U118 cell lines show subtle molecular differences, which clearly indicate the characterization of GBM heterogeneity, one of the main reasons for tumor resistance. The adding of cellular heterogeneity in molecular behaviour constitutes a step closer in the understanding of resistant molecular mechanisms in GBM, and can circumvents the eventual impaired therapy