478 research outputs found

    An Implementation of Distance-Based Message Authentication for WSNs

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    Distance-Based Message Authentication (DBMA) provides an additional layer of access control and helps to defend against key compromise and denial-of-service attacks on constrained nodes. The distance between sender and receiver is measured securely. Messages sent from outside a defined physical distance can be rejected early, protecting vulnerable higher layers. We show our initial implementation using the Nanotron NA5TR1. We show how changing MAC addresses can avoid modification to ranging hardware

    Nivel de satisfacción de las madres y calidad de atención del profesional de enfermería en el consultorio de crecimiento y desarrollo del Centro de Salud Tacabamba, 2021

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    La investigación tuvo como objetivo determinar la relación entre el nivel de satisfacción de las madres y calidad de atención del profesional de Enfermería en el Consultorio de Crecimiento y Desarrollo del Centro de Salud Tacabamba, 2021. Fue un estudio descriptivo-correlacional y de corte transversal, con una muestra de 119 madres de niños menores de cinco años, para la recolección de información se utilizó dos instrumentos un cuestionario para satisfacción de Mellano C y otro para medir la calidad de atención de Chabeli y Chinchay, dichos instrumentos fueron validados por el autor obteniéndose valores confiables. Resultados: Las características sociodemográficas más frecuentes de las madres fueron: el 62,2% tienen entre 28 a 37 años, 42,8% con grado de instrucción secundaria, 79,8% de ocupación ama de casa, 54,6% procedencia urbana y 59,7% de estado civil conviviente. El 48,7% de madres refieren estar con un nivel de satisfacción alta con la atención que brinda el profesional de enfermería, mientras que, el 55% percibieron que la calidad de atención es mala. Al relacionar las variables se evidenció que el 55,8% de madres presentan un nivel de satisfacción alta y reciben regular calidad de atención. Se concluye que no existe relación significativa (P= 0,736) entre el nivel de satisfacción de las madres con la calidad de atención del profesional de Enfermería en el consultorio de Crecimiento y Desarrollo del Centro de Salud Tacabamba, 2021

    DHB-KEY: An Efficient Key Distribution Scheme for Wireless Sensor Networks

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    Real-world deployments of wireless sensor networks require secure communication. In many application cases it is sufficient to provide message authentication at the sink. To implement this requirement using symmetric ciphers, keys shared between each sensor node and the sink have to be established and kept fresh during network operation. This paper presents a key distribution scheme based on the well known Elliptic Curve Diffie-Hellman key exchange mechanism that allows us to fulfil the previously outlined requirements efficiently. The DHB-KEY scheme requires only the distribution of a single sink-initiated broadcast message to set individual keys on all sensor nodes. Thus, DHB-KEY has a low complexity and preserves scarce resources such as bandwidth and energy. In the paper we present a protocol specification based on the DHB-KEY scheme and its implementation for the well known TinyOS platform. A physical intrusion detection system in an office building is used to evaluate the protocol implementation. The evaluation shows that DHB-KEY is practical in real-world deployments

    Computational aberration correction of VIS-NIR multispectral imaging microscopy based on Fourier ptychography

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    Due to the chromatic dispersion properties inherent in all optical materials, even the best-designed multispectral objective will exhibit residual chromatic aberration. Here, we demonstrate a multispectral microscope with a computational scheme based on the Fourier ptychographic microscopy (FPM) to correct these effects in order to render undistorted, in-focus images. The microscope consists of 4 spectral channels ranging from 405 nm to 1552 nm. After the computational aberration correction, it can achieve isotropic resolution enhancement as verified with the Siemens star sample. We image a flip-chip to show the promise of our system to conduct fault detection on silicon chips. This computational approach provides a cost-efficient strategy for high quality multispectral imaging over a broad spectral range

    5G in the Wild:Performance of C-Band 5G-NR in Rural Low-Power Fixed Wireless Access

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    In this paper, we have evaluated the performance of one of the first community-led rural applications of standalone 5G for fixed wireless access on the n77 band in the UK. This was achieved through a full-stack holistic monitoring platform, evaluating the overall performance and quality of experience of connections in the network. Our results show that 5G n77 networks can provide sub-gigabit connectivity in line of sight applications in rural areas, even when accounting for the impact stemming from infrastructural constraints. We have evidenced that our platform has identified opportunities to improve performance and capacity

    The modulation of topoisomerase I-mediated DNA cleavage and the induction of DNA–topoisomerase I crosslinks by crotonaldehyde-derived DNA adducts

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    Crotonaldehyde is a representative α,β-unsaturated aldehyde endowed of mutagenic and carcinogenic properties related to its propensity to react with DNA. Cyclic crotonaldehyde-derived deoxyguanosine (CrA-PdG) adducts can undergo ring opening in duplex DNA to yield a highly reactive aldehydic moiety. Here, we demonstrate that site-specifically modified DNA oligonucleotides containing a single CrA-PdG adduct can form crosslinks with topoisomerase I (Top1), both directly and indirectly. Direct covalent complex formation between the CrA-PdG adduct and Top1 is detectable after reduction with sodium cyanoborohydride, which is consistent with the formation of a Schiff base between Top1 and the ring open aldehyde form of the adduct. In addition, we show that the CrA-PdG adduct alters the cleavage and religation activities of Top1. It suppresses Top1 cleavage complexes at the adduct site and induces both reversible and irreversible cleavage complexes adjacent to the CrA-PdG adduct. The formation of stable DNA–Top1 crosslinks and the induction of Top1 cleavage complexes by CrA-PdG are mutually exclusive. Lastly, we found that crotonaldehyde induces the formation of DNA–Top1 complexes in mammalian cells, which suggests a potential relationship between formation of DNA–Top1 crosslinks and the mutagenic and carcinogenic properties of crotonaldehyde

    Computational aberration correction of VIS-NIR multispectral imaging microscopy based on Fourier ptychography

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    Due to the chromatic dispersion properties inherent in all optical materials, even the best-designed multispectral objective will exhibit residual chromatic aberration. Here, we demonstrate a multispectral microscope with a computational scheme based on the Fourier ptychographic microscopy (FPM) to correct these effects in order to render undistorted, in-focus images. The microscope consists of 4 spectral channels ranging from 405 nm to 1552 nm. After the computational aberration correction, it can achieve isotropic resolution enhancement as verified with the Siemens star sample. We image a flip-chip to show the promise of our system to conduct fault detection on silicon chips. This computational approach provides a cost-efficient strategy for high quality multispectral imaging over a broad spectral range

    Combined exome and whole-genome sequencing identifies mutations in ARMC4 as a cause of primary ciliary dyskinesia with defects in the outer dynein arm

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    Primary ciliary dyskinesia (PCD) is a rare, genetically heterogeneous ciliopathy disorder affecting cilia and sperm motility. A range of ultrastructural defects of the axoneme underlie the disease, which is characterised by chronic respiratory symptoms and obstructive lung disease, infertility and body axis laterality defects. We applied a next-generation sequencing approach to identify the gene responsible for this phenotype in two consanguineous families

    Does pleural fluid appearance really matter? The relationship between fluid appearance and cytology, cell counts, and chemical laboratory measurements in pleural effusions of patients with cancer

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    <p>Abstract</p> <p>Background</p> <p>Previous reports have suggested that the appearance of pleural effusions (i.e., the presence or absence of blood) might help to establish the etiology of the effusions. This study explores the relationship between pleural fluid appearance and the results of chemical and cytological analyses in a group of patients with recurrent symptomatic pleural effusions and a diagnosis of cancer.</p> <p>Methods</p> <p>Medical records were reviewed from all 390 patients who were diagnosed with cancer, who underwent thoracentesis before placement of an intrapleural catheter (IPC) between April 2000 and January 2006. Adequate information for data analysis was available in 365 patients. The appearance of their pleural fluid was obtained from procedure notes dictated by the pulmonologists who had performed the thoracenteses. The patients were separated into 2 groups based on fluid appearance: non-bloody and bloody. Group differences in cytology interpretation were compared by using the chi square test. Cellular counts, chemical laboratory results, and survival after index procedure were compared by using the student's t test.</p> <p>Results</p> <p>Pleural fluid cytology was positive on 82.5% of the non-bloody effusions and on 82.4% of the bloody ones. The number of red blood cells (220.5 × 10<sup>3</sup>/μL vs. 12.3 × 10<sup>3</sup>/μL) and LDH values (1914 IU/dl vs. 863 IU/dl) were statistically higher in bloody pleural effusions.</p> <p>Conclusion</p> <p>The presence or absence of blood in pleural effusions cannot predict their etiology in patients with cancer and recurrent symptomatic pleural effusions.</p
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