287 research outputs found

    PSM-DMO: power save mode and discontinuous BLE mesh operation

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    The Bluetooth Low Energy (BLE) mesh profile, standardized by the Bluetooth Special Interest Group (SIG), has an increasing interest in IoT solutions. However, the standard assumes that relay and friend nodes should be continuously scanning the channel awaiting any incoming transmissions. This could be very inefficient in terms of energy consumption, particularly in application scenarios where the backbone of the mesh network cannot be powered and traffic is infrequent. Hence, we present a novel strategy, named PSM-DMO, that minimizes the scan periods and thus, significantly reduces the overall energy consumption of the mesh network. PSM-DMO is defined as a new and optional feature for the currently published BLE mesh specifications, coexists with the standard operation, and is implemented without modifying the core of the specification. The proposal, that ensures the reliability of the mesh operation, can be used in BLE sensor networks that can tolerate a certain transmission delay. PSM-DMO replaces the continuous scan by a periodic but asynchronous polling process whereby the relay and sink nodes interrogate their neighbors about the existence of data to receive or to retransmit through the network. Nodes only go into scan mode during the period of time the mesh network will be involved in the transmission and dissemination. This period is estimated by the node which is the source of data, it is announced to its neighbors and it is propagated consecutively by all the relay nodes until the destination. PSM-DMO allows a theoretical reduction in the energy consumption of relay nodes up to 99.24 %

    On the use of sniffers for spectrum occupancy measurements of Bluetooth low energy primary channels

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    The methods usually employed to measure channel occupancy show limitations in the context of Bluetooth Low Energy (BLE) advertisements. We propose and analyze the use of BLE sniffers as light and portable low-cost spectrum occupancy meters to be used in scenarios where real time signal analyzers are not adequate. For the measurement technique to be successful, several low-level effects must be considered. The paper argues about on-air time, receiving blind times due to processing and intra system interference, buffer saturation and frequency anchoring. Hence, a compensation procedure based on collision rate estimation is proposed. Results with the refined method show that occupancies of 40% can be measured with an overestimation error whose percentile 95% is 5 percentage points. This is reduced to 1.9 points when the occupancy is 15%. The sniffers perform in real time and are shown to correctly track short term load variations. The strategy has been successfully used to characterize occupancy in highly variable and loaded scenarios such as subway platforms and a shopping mall. Values up to 25% have been observed, which implies a relevant packet error rate. Hence, the tool can be used to make agile audits and configure the parameters that control communication redundancy in new or existing networks

    Perceived discrimination and cancer screening behaviors in US Hispanics: the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study

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    Perceived discrimination has been associated with lower adherence to cancer screening guidelines. We examined whether perceived discrimination was associated with adherence to breast, cervical, colorectal, and prostate cancer screening guidelines in US Hispanic/Latino adults

    Performance analysis of fuzzy aggregation operations for combining classifiers for natural textures in images

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    One objective for classifying pixels belonging to specific textures in natural images is to achieve the best performance in classification as possible. We propose a new unsupervised hybrid classifier. The base classifiers for hybridization are the Fuzzy Clustering and the parametric Bayesian, both supervised and selected by their well-tested performance, as reported in the literature. During the training phase we estimate the parameters of each classifier. During the decision phase we apply fuzzy aggregation operators for making the hybridization. The design of the unsupervised classifier from supervised base classifiers and the automatic computation of the final decision with fuzzy aggregation operations, make the main contributions of this paper

    Pueblo sano pueblo feliz: promocionando salud en diferentes niveles educativos

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    El proyecto de extensión “Mas salud más vida: Promocionando salud en diferentes niveles educativos, pueblo sano pueblo feliz” tiene por finalidad prevenir y diagnosticar patologías bucomaxilo faciales, concientizar sobre enfermedades emergentes infecciosas, zoonoticas y toxicas debido a la interacción con sustancias alcohol, tabaco y fármacos, mediante acciones directas e indirectas cubrir a todos los grupos etarios en edad escolar, tutores, docentes y miembros de la sociedad, trabajando en conjunto con instituciones educativas rurales de San Luis del Palmar (Extensión Aulica N°121 4ta Sección Ramones -97km, Colegio Secundario para Adolescentes y Adultos 25 km, Escuela Primaria 812 25 km, Escuela Primaria 729 20 km), participan además ONG-Rotary Club de San Luis del Palmar, docentes y ayudantes alumnos de la Asignatura de Anatomía Patológica y Laboratorio de Aplicación Inmunohistoquimica de la Facultad de Medicina UNNE, el Servicio de Anatomía Patológica y Citología Hospital Pediátrico “Juan Pablo II" asociado a la FMUNNE a través de un equipo interdisciplinario médicos, odontólogos, veterinarios, docentes, alumnos, tutores y miembros de la comunidad acorde a la temática planteada

    Anxiety can significantly explain bolus perception in the context of hypotensive esophageal motility: Results of a large multicenter study in asymptomatic individuals

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    This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving'. © 2017 John Wiley & Sons, Inc. All rights reserved. This author accepted manuscript is made available following 12 month embargo from date of publication (May 2017) in accordance with the publisher’s archiving policyBackground Previous studies have not been able to correlate manometry findings with bolus perception. The aim of this study was to evaluate correlation of different variables, including traditional manometric variables (at diagnostic and extreme thresholds), esophageal shortening, bolus transit, automated impedance manometry (AIM) metrics and mood with bolus passage perception in a large cohort of asymptomatic individuals. Methods High resolution manometry (HRM) was performed in healthy individuals from nine centers. Perception was evaluated using a 5‐point Likert scale. Anxiety was evaluated using Hospitalized Anxiety and Depression scale (HAD). Subgroup analysis was also performed classifying studies into normal, hypotensive, vigorous, and obstructive patterns. Key Results One hundred fifteen studies were analyzed (69 using HRM and 46 using high resolution impedance manometry (HRIM); 3.5% swallows in 9.6% of volunteers were perceived. There was no correlation of any of the traditional HRM variables, esophageal shortening, AIM metrics nor bolus transit with perception scores. There was no HRM variable showing difference in perception when comparing normal vs extreme values (percentile 1 or 99). Anxiety but not depression was correlated with perception. Among hypotensive pattern, anxiety was a strong predictor of variance in perception (R2 up to .70). Conclusion and Inferences Bolus perception is less common than abnormal motility among healthy individuals. Neither esophageal motor function nor bolus dynamics evaluated with several techniques seems to explain differences in bolus perception. Different mechanisms seem to be relevant in different manometric patterns. Anxiety is a significant predictor of bolus perception in the context of hypotensive motility

    The Mexican consensus on non-cardiac chest pain

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    Introduction: Non-cardiac chest pain is defined as a clinical syndrome characterized by ret-rosternal pain similar to that of angina pectoris, but of non-cardiac origin and produced byesophageal, musculoskeletal, pulmonary, or psychiatric diseases. Aim: To present a consensus review based on evidence regarding the definition, epidemiology,pathophysiology, and diagnosis of non-cardiac chest pain, as well as the therapeutic options forthose patients. Methods Three general coordinators carried out a literature review of all articles published inEnglish and Spanish on the theme and formulated 38 initial statements, dividing them into 3 maincategories: 1) definitions, epidemiology, and pathophysiology, 2) diagnosis, and 3) treatment.The statements underwent 3 rounds of voting, utilizing the Delphi system. The final statementswere those that reached > 75% agreement, and they were rated utilizing the GRADE system. Results and conclusions The final consensus included 29 statements. All patients presentingwith chest pain should initially be evaluated by a cardiologist. The most common cause of non-cardiac chest pain is gastroesophageal reflux disease. If there are no alarm symptoms, the initialapproach should be a therapeutic trial with a proton pump inhibitor for 2-4 weeks. If dysphagiaor alarm symptoms are present, endoscopy is recommended. High-resolution manometry isthe best method for ruling out spastic motor disorders and achalasia and pH monitoring aidsin demonstrating abnormal esophageal acid exposure. Treatment should be directed at thepathophysiologic mechanism. It can include proton pump inhibitors, neuromodulators and/orsmooth muscle relaxants, psychologic intervention and/or cognitive therapy, and occasionallysurgery or endoscopic therapy

    Consenso mexicano sobre dolor torácico no cardiaco

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    Introducción: Dolor torácico no cardíaco (DTNC) se define como un síndrome clínico caracte-rizado por dolor retroesternal semejante a la angina de pecho, pero de origen no cardiaco ygenerado por enfermedades esofágicas, osteomusculares, pulmonares o psiquiátricas.Objetivo: Presentar una revisión consensuada basada en evidencias sobre definición, epidemio-logía, fisiopatología, diagnóstico y opciones terapéuticas para pacientes con DTNC.Métodos: Tres coordinadores generales realizaron una revisión bibliográfica de todas las publi-caciones en inglés y espa˜nol sobre el tema y elaboraron 38 enunciados iniciales divididosen tres categorías principales: 1) definiciones, epidemiología y fisiopatología; 2) diagnóstico,y 3) tratamiento. Los enunciados fueron votados (3 rondas) utilizando el sistema Delphi, y losque alcanzaron un acuerdo > 75% fueron considerados y calificados de acuerdo con el sistemaGRADE. Resultados y conclusiones: El consenso final incluyó 29 enunciados Todo paciente que debutacon dolor torácico debe ser inicialmente evaluado por un cardiólogo. La causa más común deDTNC es la enfermedad por reflujo gastroesofágico (ERGE). Como abordaje inicial, si no existensíntomas de alarma, se puede dar una prueba terapéutica con inhibidor de bomba de pro-tones (IBP) por 2-4 semanas. Si hay disfagia o síntomas de alarma, se recomienda hacer unaendoscopia. La manometría de alta resolución es el mejor método para descartar trastornosmotores espásticos y acalasia. La pHmetría ayuda a demostrar exposición esofágica anormal alácido. El tratamiento debe ser dirigido al mecanismo fisiopatológico, y puede incluir IBP, neu-romoduladores y/o relajantes de músculo liso, intervención psicológica y/o terapia cognitiva,y ocasionalmente cirugía o terapia endoscópica. ABSTRACT Introduction: Non-cardiac chest pain is defined as a clinical syndrome characterized by retros-ternal pain similar to that of angina pectoris, but of non-cardiac origin and produced byesophageal, musculoskeletal, pulmonary, or psychiatric diseases.Aim: To present a consensus review based on evidence regarding the definition, epidemiology,pathophysiology, and diagnosis of non-cardiac chest pain, as well as the therapeutic options forthose patients. Methods: Three general coordinators carried out a literature review of all articles published inEnglish and Spanish on the theme and formulated 38 initial statements, dividing them into 3 maincategories: (i) definitions, epidemiology, and pathophysiology; (ii) diagnosis, and (iii) treatment.The statements underwent 3 rounds of voting, utilizing the Delphi system. The final statementswere those that reached > 75% agreement, and they were rated utilizing the GRADE system.Results and conclusions: The final consensus included 29 statements. All patients presentingwith chest pain should initially be evaluated by a cardiologist. The most common cause ofnon-cardiac chest pain is gastroesophageal reflux disease. If there are no alarm symptoms, the initial approach should be a therapeutic trial with a proton pump inhibitor for 2-4 weeks. Ifdysphagia or alarm symptoms are present, endoscopy is recommended. High-resolution mano-metry is the best method for ruling out spastic motor disorders and achalasia and pH monitoringaids in demonstrating abnormal esophageal acid exposure. Treatment should be directed at thepathophysiologic mechanism. It can include proton pump inhibitors, neuromodulators and/orsmooth muscle relaxants, psychologic intervention and/or cognitive therapy, and occasionallysurgery or endoscopic therapy

    Effect of invader removal: pollinators stay but some native plants miss their new friend

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    Removal of invasive species often benefits biological diversity allowing ecosystems’ recovery. However, it is important to assess the functional roles that invaders may have established in their new areas to avoid unexpected results from species elimination. Invasive animal-pollinated plants may affect the plant–pollination interactions by changing pollinator availability and/or behaviour in the community. Thus, removal of an invasive plant may have important effects on pollinator community that may then be reflected positive or negatively on the reproductive success of native plants. The objective of this study was to assess the effect of removing Oxalis pescaprae, an invasive weed widely spread in the Mediterranean basin, on plant–pollinator interactions and on the reproductive success of co-flowering native plants. For this, a disturbed area in central Portugal, where this species is highly abundant, was selected. Visitation rates, natural pollen loads, pollen tube growth and natural fruit set of native plants were compared in the presence of O. pes-caprae and after manual removal of their flowers. Our results showed a highly resilient pollination network but also revealed some facilitative effects of O. pes-caprae on the reproductive success of co-flowering native plants. Reproductive success of the native plants seems to depend not only on the number and diversity of floral visitors, but also on their efficiency as pollinators. The information provided on the effects of invasive species on the sexual reproductive success of natives is essential for adequate management of invaded areas.This work is financed by FEDER funds through the COMPETE Program and by Portuguese Foundation for Science and Technology (FCT) funds in the ambit of the project PTDC/ BIA-BIC/110824/2009, by CRUP Acc¸o˜es Integradas Luso- Espanholas 2010 with the project E10/10, by MCI-Programa de Internacionalizacio´n de la I ? D (PT2009-0068) and by the Spanish DGICYT (CGL2009-10466), FEDER funds from the European Union, and the Xunta de Galicia (INCITE09- 3103009PR). FCT also supported the work of S. Castro (FCT/ BPD/41200/2007) and J. Costa (CB/C05/2009/209; PTDC/ BIA-BIC/110824/2009). The work of V. Ferrero was supported by the Fundacio´n Ramo´n Areces
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