273 research outputs found
Instrumentation and automation system defects detection
EN: This paper presents the methodology used for the automation of a mechatronic system, which will be used for information of teeth, the work was done using a microcontroller, which allows the reconfiguration of the system, the use of different ports communication and input-output ports, It was made a distance measuring system which allows the microcontroller to provide information about current position of each axis of the mechanism. Control routines are performed which allow manipulation mechanism on each axis independently of thus obtained independent control shaft which facilitates its positioning in any point of the working space of the mechanism to obtain about the theet. UK: У статті подано методику, що використовується для автоматизації механотронної системи, з метою отримання інформації про стан зубів. Автоматизована система включає мікроконтролер, що дозволяє її реконфігурацію і порти комунікації та уведення-виведення. Було розроблено систему вимірювання відстаней, яка дозволяє мікроконтролеру надавати інформацію про поточний стан кожної осі механізму. Розроблено програми управління, що забезпечують вільне переміщення механізму по кожній осі. Таким чином, програми забезпечують незалежне управління, що, в свою чергу, сприяє позиціонуванню механізму в будь-якій точці робочого простору для отримання інформації про стан зубів
Instrumentation and automation system defects detection
UK: У статті подано методику, що використовується для автоматизації механотронної
системи, з метою отримання інформації про стан зубів. Автоматизована система
включає мікроконтролер, що дозволяє її реконфігурацію і порти комунікації та уведеннявиведення.
Було розроблено систему вимірювання відстаней, яка дозволяє мікроконтролеру
надавати інформацію про поточний стан кожної осі механізму. Розроблено програми
управління, що забезпечують вільне переміщення механізму по кожній осі. Таким чином,
програми забезпечують незалежне управління, що, в свою чергу, сприяє позиціонуванню
механізму в будь-якій точці робочого простору для отримання інформації про стан зубів. EN:This paper presents the methodology used for the automation of a mechatronic system, which will be
used for information of teeth, the work was done using a microcontroller, which allows the reconfiguration
of the system, the use of different ports communication and input-output ports, It was made a distance
measuring system which allows the microcontroller to provide information about current position of each
axis of the mechanism. Control routines are performed which allow manipulation mechanism on each axis
independently of thus obtained independent control shaft which facilitates its positioning in any point of the
working space of the mechanism to obtain about the theet
The Mre11-Rad50-Nbs1 complex mediates activation of TopBP1 by ATM
The activation of ATR-ATRIP in response to double-stranded DNA breaks (DSBs) depends upon ATM in human cells and Xenopus egg extracts. One important aspect of this dependency involves regulation of TopBP1 by ATM. In Xenopus egg extracts, ATM associates with TopBP1 and thereupon phosphorylates it on S1131. This phosphorylation enhances the capacity of TopBP1 to activate the ATR-ATRIP complex. We show that TopBP1 also interacts with the Mre11-Rad50-Nbs1 (MRN) complex in egg extracts in a checkpoint-regulated manner. This interaction involves the Nbs1 subunit of the complex. ATM can no longer interact with TopBP1 in Nbs1-depleted egg extracts, which suggests that the MRN complex helps to bridge ATM and TopBP1 together. The association between TopBP1 and Nbs1 involves the first pair of BRCT repeats in TopBP1. In addition, the two tandem BRCT repeats of Nbs1 are required for this binding. Functional studies with mutated forms of TopBP1 and Nbs1 suggested that the BRCT-dependent association of these proteins is critical for a normal checkpoint response to DSBs. These findings suggest that the MRN complex is a crucial mediator in the process whereby ATM promotes the TopBP1-dependent activation of ATR-ATRIP in response to DSBs
Loop Quantum Cosmology: A Status Report
The goal of this article is to provide an overview of the current state of
the art in loop quantum cosmology for three sets of audiences: young
researchers interested in entering this area; the quantum gravity community in
general; and, cosmologists who wish to apply loop quantum cosmology to probe
modifications in the standard paradigm of the early universe. An effort has
been made to streamline the material so that, as described at the end of
section I, each of these communities can read only the sections they are most
interested in, without a loss of continuity.Comment: 138 pages, 15 figures. Invited Topical Review, To appear in Classical
and Quantum Gravity. Typos corrected, clarifications and references adde
Spintronics: Fundamentals and applications
Spintronics, or spin electronics, involves the study of active control and
manipulation of spin degrees of freedom in solid-state systems. This article
reviews the current status of this subject, including both recent advances and
well-established results. The primary focus is on the basic physical principles
underlying the generation of carrier spin polarization, spin dynamics, and
spin-polarized transport in semiconductors and metals. Spin transport differs
from charge transport in that spin is a nonconserved quantity in solids due to
spin-orbit and hyperfine coupling. The authors discuss in detail spin
decoherence mechanisms in metals and semiconductors. Various theories of spin
injection and spin-polarized transport are applied to hybrid structures
relevant to spin-based devices and fundamental studies of materials properties.
Experimental work is reviewed with the emphasis on projected applications, in
which external electric and magnetic fields and illumination by light will be
used to control spin and charge dynamics to create new functionalities not
feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes
from the published versio
Homozygous variants in the HEXB and MBOAT7 genes underlie neurological diseases in consanguineous families
Neurological disorders are a common cause of morbidity and mortality within Pakistani populations. It is one of the most important challenges in healthcare, with significant life-long socio-economic burden.This article is freely available via Open Access. Click on the Publisher URL to access the full-text
Single-cell Atlas of common variable immunodeficiency shows germinal center-associated epigenetic dysregulation in B-cell responses
Common variable immunodeficiency (CVID), the most prevalent symptomatic primary immunodeficiency, displays impaired terminal B-cell differentiation and defective antibody responses. Incomplete genetic penetrance and ample phenotypic expressivity in CVID suggest the participation of additional pathogenic mechanisms. Monozygotic (MZ) twins discordant for CVID are uniquely valuable for studying the contribution of epigenetics to the disease. Here, we generate a single-cell epigenomics and transcriptomics census of naïve-to-memory B cell differentiation in a CVID-discordant MZ twin pair. Our analysis identifies DNA methylation, chromatin accessibility and transcriptional defects in memory B-cells mirroring defective cell-cell communication upon activation. These findings are validated in a cohort of CVID patients and healthy donors. Our findings provide a comprehensive multi-omics map of alterations in naïve-to-memory B-cell transition in CVID and indicate links between the epigenome and immune cell cross-talk. Our resource, publicly available at the Human Cell Atlas, gives insight into future diagnosis and treatments of CVID patients
Tumor surveillance by circulating microRNAs: a hypothesis
A growing body of experimental evidence supports the diagnostic relevance of circulating microRNAs in various diseases including cancer. The biological relevance of circulating microRNAs is, however, largely unknown, particularly in healthy individuals. Here, we propose a hypothesis based on the relative abundance of microRNAs with predominant tumor suppressor activity in the blood of healthy individuals. According to our hypothesis, certain sets of circulating microRNAs might function as a tumor surveillance mechanism exerting continuous inhibition on tumor formation. The microRNA-mediated tumor surveillance might complement cancer immune surveillance
A Benchmark of Parametric Methods for Horizontal Transfers Detection
Horizontal gene transfer (HGT) has appeared to be of importance for prokaryotic species evolution. As a consequence numerous parametric methods, using only the information embedded in the genomes, have been designed to detect HGTs. Numerous reports of incongruencies in results of the different methods applied to the same genomes were published. The use of artificial genomes in which all HGT parameters are controlled allows testing different methods in the same conditions. The results of this benchmark concerning 16 representative parametric methods showed a great variety of efficiencies. Some methods work very poorly whatever the type of HGTs and some depend on the conditions or on the metrics used. The best methods in terms of total errors were those using tetranucleotides as criterion for the window methods or those using codon usage for gene based methods and the Kullback-Leibler divergence metric. Window methods are very sensitive but less specific and detect badly lone isolated gene. On the other hand gene based methods are often very specific but lack of sensitivity. We propose using two methods in combination to get the best of each category, a gene based one for specificity and a window based one for sensitivity
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