1,345 research outputs found

    Netnography: Origins, Foundations, Evolution and Axiological and Methodological Developments and Trends

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    Netnography originated in ethnography and evolved following the advances in data transmission technology. The netnographic method is distinguished by its axiological orientation residing in recognition of online social experiences. The main method for data collection adopted by the netnographer is participant observation. One premise that must be observed is the necessary estrangement, which means that the researcher must be a layman as regards the object of study. In the field of administration, netnography emphasized the area of marketing and consumer behavior. The goal is to understand the consumer culture of online communities. One of its main challenges consists of how to conduct ethical research. The current article reviewed the available literature about the netnography method, bringing a brief explanation about its emergence and evolution, as well as its characteristics and application. The article also presents the advantages, challenges, and trends of this modern research method and also suggests topics for future research

    Colorectal Endoscopic Submucosal Dissection in a Western Center: Analysis of Outcomes and Safety Profile

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    Introduction: Endoscopic submucosal dissection (ESD) is a well-established endoscopic technique for the treatment of gastrointestinal lesions. Colorectal ESD outcomes are less reported in the Western literature, and Portuguese data are still very scarce. Our aim was to describe our experience on colorectal ESD regarding its outcomes and safety profile. Methods: We conducted a retrospective evaluation of recorded data on ESDs performed between 2015 and 2020. Only ESDs performed on epithelial neoplastic lesions were selected for further analysis. Results: Of a total of 167 colorectal ESDs, 153 were included. Technical success was achieved in 147 procedures (96%). The lesions were located in the colon (n = 24) and rectum (n = 123). The en bloc resection rate was 92% and 97%, the R0 resection rate was 83% and 82%, and the curative resection rate was 79% and 78% for the colon and the rectum, respectively. The need for a hybrid technique was the only risk factor for piecemeal or R1 resection. We report a perforation rate of 3.4% and a 4.1% rate of delayed bleeding; all the adverse events were manageable endoscopically, without the need of blood transfusions or surgery. Most of the lesions were laterally spreading tumours of the granular mixed type (70%), and 20% of the lesions were malignant (12% submucosal and 8% intramucosal cancer). Conclusion: Our series on colorectal ESD reports a very good efficacy and safety profile. This technique can be applied by endoscopists experienced in ESD

    SCARA Self Posture Recognition Using a Monocular Camera

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    Robotic manipulators rely on feedback obtained from rotary encoders for control purposes. This article introduces a vision-based feedback system that can be used in an agricultural context, where the shapes and sizes of fruits are uncertain. We aim to mimic a human, using vision and touch as manipulator control feedback. This work explores the use of a fish-eye lens camera to track a SCARA manipulator with coloured markers on its joints for the position estimation with the goal to reduce costs and increase reliability. The Kalman Filter and the Particle Filter are compared and evaluated in terms of accuracy and tracking abilities of the marker’s positions. The estimated image coordinates of the markers are converted to world coordinates using planar homography, as the SCARA manipulator has co-planar joints and the coloured markers share the same plane. Three laboratory experiments were conducted to evaluate the system’s performance in joint angle estimation of a manipulator. The obtained results are promising, for future cost effective agricultural robotic arms developments. Besides, this work presents solutions and future directions to increase the joint position estimation accuracy.info:eu-repo/semantics/publishedVersio

    Detecção e controle de Lasiodiplodia theobromae em sementes de graviola (Annona muricata L.).

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    bitstream/CNPAT-2010/11915/1/bd-27.pd

    Guardiões e guardiãs da agrobiodiversidade das regiões do Cariri, Curamataú e Seridó paraibano.

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    ref. 14455. Edição dos Resumos do VIII Congresso Brasileiro de Agroecologia, Porto Alegre, nov. 2013

    Chloroplastid pigment contents and chlorophyll a fluorescence in Amazonian tropical three species.

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    As plantas respondem a mudanças nas condições de luz e na disponibilidade hídrica em termos da quantidade e composição dos pigmentos cloroplastídicos, o que afeta as propriedades fotossintéticas e, conseqüentemente, o acúmulo de biomassa das espécies. Assim, a concentração de pigmentos cloroplastídicos e a fluorescência da clorofila a de três espécies arbóreas (Bertholletia excelsa, Carapa guianensis e Dipteryx odorata) da Amazônia foi investigada em folhas sombreadas e não-sombreadas da copa das árvores e em dois períodos distintos de precipitação (chuvoso e seco). As concentrações de pigmentos foram determinadas por espectrofotometria e as variáveis de fluorescência, por meio de um fluorômetro portátil. Os resultados indicaram que as espécies estudadas exibiram maiores concentrações de Chl a, Chl b e Chltotal no período chuvoso, em comparação com o período seco, em especial em folhas de sombra. As maiores concentrações de carotenóides foram observadas em B. excelsa, em comparação com as folhas de C. guianensis e D. odorata. Nas folhas de B. excelsa e D. odorata, não foram encontradas diferenças significativas em relação à fotoquímica do fotossistema II (Fv/Fm), entre os períodos chuvoso e seco. Conclui-se que as três espécies respondem de modo diferente à variação da luz e às condições distintas de precipitação quanto à captura de luz, aspecto que deveria ser considerado no manejo de plantios florestais

    Brachiaria brizantha cv. BRS Piatã forage yield under integrated crop-livestock-forestry systems in Brazil.

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    Integrated crop-livestock-forestry (ICLF) systems are increasingly considered for a diversified agricultural production in Brazil. In this study we analysed the forage yield [kg DM ha?1], of Brachiaria brizantha BRS cv. Piat?a for ICLF demonstration plots at the Brazilian Agricultural Research Corporation - EMBRAPA, located in Campo Grande-MS, Brazil. The analysed plots with four replicates corresponded to three production systems: Two integrated crop-livestock-forestry systems (ICLF1 and ICLF2) and an integrated crop-livestock system (ICL). The trees (Eucalyptus urograndis) in the ICLF systems were planted in single rows with 2m between tress and 14 or 22m between rows, resulting in 357 trees ha?1 (ICLF1) and 277 trees ha?1 (ICLF2), respectively. The crop component is soy-bean, planted every 4 years. Grass biomass was sampled monthly in a line of five sampling points at equal distance from each other between tree rows to represent the understory shading gradient. Animal feed intake was considered using the moving cages method. During the dry season (June - October) the forage yields between the different treatments didn?t differ significantly from each other (average 5.4 kg DM ha?1). In the rainy season (November - January) the ICLF system had the highest forage yield (ICLF 17.7 > ICL 6.6 kg DM ha?1). Most likely the main reason for these results is due to the management practice. In the dry season the ICLF systems had such a low stocking rate compared to the ICL system, that in the rainy season the ICLF systems were able to exceed the forage production of the ICL system. In the tree plots during the dry season the forage yields along the shading gradient didn?t differ significantly (average 5.3 kg DM ha?1). In the rainy season the points with higher shading (near the tree rows) had lower forage yields (9.9 and 11.8 kg DM ha?1, respectively) than the central points (16.1 kg DM ha?1). The microclimate within the tree plots has a great effect on the forage production. During the dry season the shading effect of the trees on the whole area is more evenly distributed resulting in similar forage yields along the shading gradient

    Impact of SM parameters and of the vacua of the Higgs potential in gravitational waves detection

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    In this work we discuss two different phases of a complex singlet extension of the Standard Model (SM) together with an extension that also includes new fermion fields, in particular, a Majoron model equipped with an inverse seesaw mechanism. All considered scenarios contain a global U(1)\mathrm{U}(1) symmetry and allow for first-order phase transitions while only two of them are strong enough to favour the detection of primordial gravitational waves (GWs) in planned experiments such as LISA. In particular, this is shown to be possible in the singlet extension with a non vanishing real VEV at zero temperature and also in the model with extra fermions. In the singlet extension with no additional fermions, the detection of GWs strongly depends on the U(1)\mathrm{U}(1) symmetry breaking pattern of the scalar potential at zero temperature. We study for the first time the impact of the precision in the determination of the SM parameters on the strength of the GWs spectrum. It turns out that the variation of the SM parameters such as the Higgs boson mass and top quark Yukawa coupling in their allowed experimental ranges has a notable impact on GWs detectability prospects.Comment: 28 pages, 13 figure

    Renal cell carcinoma with giant caval thrombus: multidisciplinary surgical approach

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    A nefrectomia radical associada a trombectomia da veia cava inferior constitui a única opção terapêutica passível de melhoria prognóstica dos carcinomas de células renais com trombos venosos major. Descrevemos o caso de um homem, 55 anos, com o diagnóstico de tumor renal com trombo intra-cávico de grandes dimensões. O doente foi alvo de uma abordagem multidisciplinar, tendo sido submetido a nefrectomia radical à direita, trombectomia e cavoplastia, com recurso ainda a bypass cardiopulmonar e circulação extra-corpórea. O pós-operatório não registou intercorrências. A análise histológica concluiu tratar-se de um carcinoma de células renais, variante células claras e trombo excisado na totalidade, sem invasão da parede venosa. Aos dois anos de pós-operatório o doente encontra-se sem evidência de recidiva tumoral nem foram descritos eventos de embolização pulmonar
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