5,781 research outputs found
Super-spreading Events and Contribution to Transmission of MERS, SARS, and COVID-19
There is no clear definition for the term ‘super-spreader’ or ‘super-spreading event’. The World Health Organization refers to a super-spreader as a patient (or an event) that may transmit infection to a larger number of individuals than is usual by one individual (or event). In the severe acute respiratory syndrome (SARS) situation, a super-spreading event was defined as the transmission of SARS to at ≥8 contacts, and other authors defined this as individuals infecting an unusually large number of secondary cases [ 1 , 2 ]. A super-spreading event could merely be defined as an event in which one patient infects far more people than an average patient does, which is estimated by the basic reproduction number (R0)
Visible Light Communications for IoT services based on high-power LEDs in Industry 4.0
Proceeding of: IEEE Conference on Standards for Communications and Networking (CSCN 2022), 28-30 November 2022, Thessaloniki, GreeceIn the framework of Industry 4.0, visible light communications (VLC) are proposed for providing connectivity in those environments where radio-frequency (RF) transmission achieves a poor performance or it is even banned [1] . Specifically, VLC are potentially useful for providing Internet of Things (IoT) services while consuming a small portion of the transmission resources, considering a user-centric approach and subject to a low-cost implementation [2] . Recently, the European Commission warned about the need for employing low-cost and energy-efficient LEDs for future VLC systems to maintain the reduction in the energy consumption [3] . As a consequence, the VLC-IoT hardware implementations must consider commercial LEDs, which are subject to non-linearities, reduced and unknown bandwidth and other impairments for data transmission, while maintaining the energy efficiency for illumination purposes. In this work, a low-cost VLC-IoT implementation is presented based on commercial high-power LEDs. The proposed configuration is focused on providing connectivity in those environments where RF transmission is not efficient so that an external access point (AP) distributes the connectivity through a backhaul link that feeds the set of optical access points (APs).This work has received funding from the European Union Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie ETN TeamUp5G, grant agreement No. 813391, and from Spanish National Project IRENE-EARTH (PID2020-115323RB-C33) (MINECO/AEI/FEDER, UE). The work of Máximo Morales-Céspedes is also supported by the Juan de la Cierva Incorporación under Grant IJC2019-040317-I
Tangential Power Allocation NOMA scheme for Visible Light Communications
Proceeding of: IEEE Conference on Standards for Communications and Networking (CSCN 2022), 28-30 November 2022, Thessaloniki, GreeceNon-orthogonal multiple access (NOMA) has been proposed in both radio-frequency (RF) and visible light communications (VLC) to both improve the achievable rate and overcome the constrains in the number of users of orthogonal multiple access (OMA) schemes. Despite the advantages of NOMA, there still exist some issues that require more investigation such as power allocation schemes. This is issue is more remarkable in VLC due to the small and confined coverage footprint of each optical access point. In this poster, we propose a novel methodology denoted by tangential power allocation (TPA) for NOMA in VLC. Basically, the power allocation coefficients are calculated based on the tangential point on the NOMA rate region that is parallel to the OMA region. It is shown that TPA achieves greater performance in terms of achievable rate and fairness in comparison with conventional NOMA schemes.This work was funded by the European Union(EU) Horizon 2020 research and innovation program under the Marie Sklodowska-Curie ETN TeamUp5G, grant agreement No. 813391
Cerebrospinal fluid NCAM-1 concentration is associated with neurodevelopmental outcome in post-hemorrhagic hydrocephalus of prematurity
OBJECTIVE: Efforts directed at mitigating neurological disability in preterm infants with intraventricular hemorrhage (IVH) and post hemorrhagic hydrocephalus (PHH) are limited by a dearth of quantifiable metrics capable of predicting long-term outcome. The objective of this study was to examine the relationships between candidate cerebrospinal fluid (CSF) biomarkers of PHH and neurodevelopmental outcomes in infants undergoing neurosurgical treatment for PHH.
STUDY DESIGN: Preterm infants with PHH were enrolled across the Hydrocephalus Clinical Research Network. CSF samples were collected at the time of temporizing neurosurgical procedure (n = 98). Amyloid precursor protein (APP), L1CAM, NCAM-1, and total protein (TP) were compared in PHH versus control CSF. Fifty-four of these PHH subjects underwent Bayley Scales of Infant Development-III (Bayley-III) testing at 15-30 months corrected age. Controlling for false discovery rate (FDR) and adjusting for post-menstrual age (PMA) and IVH grade, Pearson\u27s partial correlation coefficients were used to examine relationships between CSF proteins and Bayley-III composite cognitive, language, and motor scores.
RESULTS: CSF APP, L1CAM, NCAM-1, and TP were elevated in PHH over control at temporizing surgery. CSF NCAM-1 was associated with Bayley-III motor score (R = -0.422, p = 0.007, FDR Q = 0.089), with modest relationships noted with cognition (R = -0.335, p = 0.030, FDR Q = 0.182) and language (R = -0.314, p = 0.048, FDR Q = 0.194) scores. No relationships were observed between CSF APP, L1CAM, or TP and Bayley-III scores. FOHR at the time of temporization did not correlate with Bayley-III scores, though trends were observed with Bayley-III motor (p = 0.0647 and R = -0.2912) and cognitive scores (p = 0.0506 and R = -0.2966).
CONCLUSION: CSF NCAM-1 was associated with neurodevelopment in this multi-institutional PHH cohort. This is the first report relating a specific CSF protein, NCAM-1, to neurodevelopment in PHH. Future work will further investigate a possible role for NCAM-1 as a biomarker of PHH-associated neurological disability
Sinais clínicos associados a um caso de envenenamento iatrogênico de um equino com três dias de idade por um produto comercial baseado em terebintina
O objetivo deste estudo é relatar um caso de intoxicação iatrogênica por um produto comercial a base de terebentina em um potro de três días de idade e o sucesso do tratamento dessa condição. Um potro de três dias de idade foi apresentou um colapso cardiorrespiratório agudo, choque anafilático, desconforto respiratório grave, dispnéia e edema pulmonar. A história incluiu a administração prévia de um produto veterinário comercial (UNITIPAN). Ao exame clínico: temperatura: (39,9 °C), pulso: 135 bpm, respiração 51 bpm, membranas mucosas, congestionamento úmido, tempo de enchimento capilar: três segundos ou menos. O potro foi tratado com hidratação de emergência, duphalyte, anti-inflamatório esteroidal, sulfato de atropina e antibiótico. Após seis horas de tratamento, o potro foi estabilizado e os sinais vitais foram normalizados depois de oito horas do inicio do tratamento. O presente trabalho relata um caso de intoxicação iatrogênica por um produto à base de terebintina comercial em um potro de três dias de idade com rápido desenvolvimento de sinais de toxicidade aguda e uma resposta muito favorável ao tratamento sintomático.The aim of this study is to report a case of iatrogenic poisoning by a turpentine-based commercial product in a 3-day-old foal and the successful treatment of this condition. A 3-day-old male foal presented with acute cardio-respiratory collapse, anaphylactic shock, severe respiratory distress, dyspnea and pulmonary edema. The animal’s history included previous administration of a commercial veterinary product (UNITIPAN). Clinical examination revealed: temperature: (39.9 °C), pulse: 135 bpm, respiration: 51 bpm, mucous membranes: moist and congested, capillary refill time: 3 sec or less. The foal was treated with emergency hydration, duphalyte, steroidal anti-inflammatory, atropine sulphate and antibiotic. After 6 h of treatment, the foal was stabilized and vital signs were normalized 8 h after treatment start.El objetivo de este estudio es informar un caso de envenenamiento iatrogénico por un producto comercial basado en la trementina en un potro de 3 días y el tratamiento exitoso de esta afección. Se presentó un potro de 3 días de edad que mostraba colapso cardiorrespiratorio agudo, shock anafiláctico, dificultad respiratoria grave, disnea y edema pulmonar. La historia incluía la administración previa de un producto veterinario comercial (UNITIPAN). En el examen clínico: temperatura: (39.9 ° C), pulso: 135 lpm, respiración 51 lpm, membranas mucosas, congestión húmeda, tiempo de llenado capilar: tres segundos o menos. El potro fue tratado con hidratación de emergencia, duphalito, antiinflamatorio esteroideo, sulfato de atropina y antibiótico. Después de 6 horas de tratamiento, el potro se estabilizó y los signos vitales se normalizaron 8 después. En conclusión, informamos sobre un caso de intoxicación iatrogénica por un producto comercial a base de trementina en un potro de 3 días con un rápido desarrollo de signos de toxicidad aguda y una respuesta muy favorable al tratamiento sintomático
Clinical signs associated with a case of iatrogenic poisoning by a turpentine-based commercial product in a 3-day-old foal
The aim of this study is to report a case of iatrogenic poisoning by a turpentine-based commercial product in a 3-day-old foal and the successful treatment of this condition. A 3-day-old male foal presented with acute cardio-respiratory collapse, anaphylactic shock, severe respiratory distress, dyspnea and pulmonary edema. The animal’s history included previous administration of a commercial veterinary product (UNITIPAN). Clinical examination revealed: temperature: (39.9 °C), pulse: 135 bpm, respiration: 51 bpm, mucous membranes: moist and congested, capillary refill time: 3 sec or less. The foal was treated with emergency hydration, duphalyte, steroidal anti-inflammatory, atropine sulphate and antibiotic. After 6 h of treatment, the foal was stabilized and vital signs were normalized 8 h after treatment start
Enhancing structure relaxations for first-principles codes: an approximate Hessian approach
We present a method for improving the speed of geometry relaxation by using a
harmonic approximation for the interaction potential between nearest neighbor
atoms to construct an initial Hessian estimate. The model is quite robust, and
yields approximately a 30% or better reduction in the number of calculations
compared to an optimized diagonal initialization. Convergence with this
initializer approaches the speed of a converged BFGS Hessian, therefore it is
close to the best that can be achieved. Hessian preconditioning is discussed,
and it is found that a compromise between an average condition number and a
narrow distribution in eigenvalues produces the best optimization.Comment: 9 pages, 3 figures, added references, expanded optimization sectio
Oxidative stress-induced mitochondrial failure and vasoactive substances as key initiators of pathology favor the reclassification of Alzheimer Disease as a vasocognopathy
La enfermedad de Alzheimer y el accidente cerebrovascular son dos causas que conducen a la demencia relativa a la edad. El aumento de la evidencia apoya la idea de que la hipoperfusión crónica es sobre todo responsable de la patogénesis que es la base de ambos procesos de la enfermedad. La hipoperfusión se asocia al desequilibrio oxidativo, en gran parte debido a las especies reactivas del oxígeno, que se asocian a otros desórdenes degenerativos relativos a la edad. Evidencia reciente indica que un estímulo crónico de lesión induce la hipoperfusión vista en la microcirculación de las regiones vulnerables del cerebro. Esto conduce a la falta de energía, manifestada por daño a la ultraestructura mitocondrial. Los trastornos mitocondriales conducen a la formación de una gran cantidad de mitocondrias “hipoxicas” electrón-densas y causan la sobreproducción de deleciones en el ADN mitocondrial (mtADN), debidas muy probablemente a la ruptura de la doble hélice. Además, estas anormalidades mitocondriales coexisten con la actividad redox incrementada, peroxidación lipídica y la oxidación del ARN, que son características bien establecidas de la patología de Alzheimer, antes de la aparición de los depósitos del b-amiloide.
En la enfermedad de Alzheimer, el estrés oxidativo ocurre dentro de los varios compartimientos celulares y dentro de ciertos tipos de células más que en otros, a saber el endotelio vascular, que se asocia a daño aterosclerótico, así como en las neuronas piramidales y glia. Es interesante que estas células vulnerables demuestran deleciones del mtADN y marcadores de estrés oxidativo solamente en las regiones que están cercanamente relacionadas a los vasos dañados. Esta evidencia sugiere fuertemente que la hipoperfusión crónica induce la acumulación de los productos del estrés oxidativo. Además, las lesiones de la pared vascular del cerebro se correlacionan linealmente con el grado de daño celular neuronal y glial. Por lo tanto, concluimos que la hipoperfusión crónica es un iniciador clave del estrés oxidativo en varias células parénquimales del cerebro, y las mitocondrias parecen ser blancos primarios para el daño de cerebro en la enfermedad de Alzheimer. En este trabajo, delineamos el papel de la acumulación continua de los productos del estrés oxidativo, tales como una abundancia de productos de óxido nítrico (vía la sobreexpresión de NO sintasa inducible y/o neuronal (iNOS y nNOS respectivamente) y de acumulación del peroxinitrito, como factores secundarios pero acelerantes que comprometen la barrera hematoencefálica. Si éste resulta ser el caso, las intervenciones farmacológicas que apuntan a la hipoperfusion crónica pudieran mejorar las características dominantes de la demencia neurodegenerativa
Direct Connection of Supercapacitor-Battery Hybrid Storage System to the Grid-tied Photovoltaic System
IEEE Penetration rate of grid-connected photovoltaic (PV) generation to the existing utility grid is rapidly increasing over the years. Since the power generated from PV systems fluctuate according to the weather condition, e.g., cloud passing, this can significantly disturb the stability of a weak utility grid. The integration of energy storage devices and its ramp-rate control technique are required to reduce the impact of PV systems output fluctuations and augment the stability of the utility grid. In this paper, ramp-rate control is applied to the direct connection of energy storage devices in PV generation system configuration. The direct connection of supercapacitors string and battery combination scheme is proposed to reduce the number of power converters so that the efficiency of the system is increased. In this work, the PV system output is controlled by directly control the energy storage system (ESS) to limit the changing rate of PV output to desired ramp-rate value. Hence, reducing the battery charge/discharge cycles and extending the expected lifetime of the ESS. The performance of the proposed direct connection scheme of ESS and its ramp-rate control strategy is verified using a 1-kW PV system prototype
UOLO - automatic object detection and segmentation in biomedical images
We propose UOLO, a novel framework for the simultaneous detection and
segmentation of structures of interest in medical images. UOLO consists of an
object segmentation module which intermediate abstract representations are
processed and used as input for object detection. The resulting system is
optimized simultaneously for detecting a class of objects and segmenting an
optionally different class of structures. UOLO is trained on a set of bounding
boxes enclosing the objects to detect, as well as pixel-wise segmentation
information, when available. A new loss function is devised, taking into
account whether a reference segmentation is accessible for each training image,
in order to suitably backpropagate the error. We validate UOLO on the task of
simultaneous optic disc (OD) detection, fovea detection, and OD segmentation
from retinal images, achieving state-of-the-art performance on public datasets.Comment: Publised on DLMIA 2018. Licensed under the Creative Commons
CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0
- …