Cell cycle errors can lead to mutations, chromosomal instability, or death; thus, the precise control of cell cycle progression is essential for viability. The nutrient-sensing posttranslational ...modification, O-GlcNAc, regulates the cell cycle allowing one central control point directing progression of the cell cycle. O-GlcNAc is a single N-acetylglucosamine sugar modification to intracellular proteins that is dynamically added and removed by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. These enzymes act as a rheostat to fine-tune protein function in response to a plethora of stimuli from nutrients to hormones. O-GlcNAc modulates mitogenic growth signaling, senses nutrient flux through the hexosamine biosynthetic pathway, and coordinates with other nutrient-sensing enzymes to progress cells through Gap phase 1 (G1). At the G1/S transition, O-GlcNAc modulates checkpoint control, while in S Phase, O-GlcNAcylation coordinates the replication fork. DNA replication errors activate O-GlcNAcylation to control the function of the tumor-suppressor p53 at Gap Phase 2 (G2). Finally, in mitosis (M phase), O-GlcNAc controls M phase progression and the organization of the mitotic spindle and midbody. Critical for M phase control is the interplay between OGT and OGA with mitotic kinases. Importantly, disruptions in OGT and OGA activity induce M phase defects and aneuploidy. These data point to an essential role for the O-GlcNAc rheostat in regulating cell division. In this review, we highlight O-GlcNAc nutrient sensing regulating G1, O-GlcNAc control of DNA replication and repair, and finally, O-GlcNAc organization of mitotic progression and spindle dynamics.
Purpose: To assess the accuracy of answers provided by ChatGPT-3 when prompted with questions from the daily routine of radiologists and to evaluate the text response when ChatGPT-3 was prompted to ...provide references for a given answer. Methods: ChatGPT-3 (San Francisco, OpenAI) is an artificial intelligence chatbot based on a large language model (LLM) that has been designed to generate human-like text. A total of 88 questions were submitted to ChatGPT-3 using textual prompt. These 88 questions were equally dispersed across 8 subspecialty areas of radiology. The responses provided by ChatGPT-3 were assessed for correctness by cross-checking them with peer-reviewed, PubMed-listed references. In addition, the references provided by ChatGPT-3 were evaluated for authenticity. Results: A total of 59 of 88 responses (67%) to radiological questions were correct, while 29 responses (33%) had errors. Out of 343 references provided, only 124 references (36.2%) were available through internet search, while 219 references (63.8%) appeared to be generated by ChatGPT-3. When examining the 124 identified references, only 47 references (37.9%) were considered to provide enough background to correctly answer 24 questions (37.5%). Conclusion: In this pilot study, ChatGPT-3 provided correct responses to questions from the daily clinical routine of radiologists in only about two thirds, while the remainder of responses contained errors. The majority of provided references were not found and only a minority of the provided references contained the correct information to answer the question. Caution is advised when using ChatGPT-3 to retrieve radiological information.
Graphical Abstract
We determine the rate region of the quadratic Gaussian two-encoder source-coding problem. This rate region is achieved by a simple architecture that separates the analog and digital aspects of the ...compression. Furthermore, this architecture requires higher rates to send a Gaussian source than it does to send any other source with the same covariance. Our techniques can also be used to determine the sum-rate of some generalizations of this classical problem. Our approach involves coupling the problem to a quadratic Gaussian ldquoCEO problem.rdquo
The approximated identification of elemental composition of historic iron gall-inks is proposed based on results of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) ...measurements combined with a quick detection of iron (II) ions. Colorimetric response of test papers soaked with bathophenanthroline (BPhen) allows for detection of iron in the form of red-coloured complex of Fe(II) with BPhen. A co-migration of other elements (Cu, Zn, Pb, Al, K, Na, Mg) into indicators was confirmed by LA-ICP-MS measurements allowing for approximation of chemical diversity of handwritten documents in a totally non-invasive manner in respect to originals. The proposed analytical approach for in-direct studies of unique documents was tested on historic and model samples. The idea of approximation of elemental composition of the historic inks was found promising for purposes of conservation diagnosis towards estimation of corrosiveness of inks and eventual fingerprinting. It has been demonstrated that the presence of Fe as well as other elements (S, Cu and Mn) which are significant for recognition of ink corrosion can be detected in the used indicators extending the possibilities of examining valuable manuscripts in a way that is completely neutral for them.
Display omitted
•New concept of non-invasive approximation of chemical composition of historic inks.•Analytical re-cycling of indicators soaked with bathophenanthroline (BPhen) after their common use for conservation diagnosis.•Indirect estimation of elemental composition of original manuscripts based on sensitive LA-ICP-MS measurements.
The signs and symptoms of Zika virus infection are usually mild and self-limited. However, the disease has been linked to neurological complications such as Guillain-Barré syndrome and peripheral ...nerve involvement, and also to abortion and fetal deaths due to vertical transmission, resulting in various congenital malformations in newborns, including microcephaly. This review aimed to describe the o signs and symptoms that characterize the congenital Zika syndrome.
A systematic review was performed with a protocol and described according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The search strategy yielded 2,048 studies. After the exclusion of duplicates and application of inclusion criteria, 46 studies were included. The main signs and symptoms associated with the congenital Zika syndrome were microcephaly, parenchymal or cerebellar calcifications, ventriculomegaly, central nervous system hypoplasia or atrophy, arthrogryposis, ocular findings in the posterior and anterior segments, abnormal visual function and low birthweight for gestational age.
Zika virus infection during pregnancy can cause a series of changes in the growth and development of children, while impacting the healthcare system due to the severity of cases. Our findings outline the disease profile in newborns and infants and may contribute to the development and updating of more specific clinical protocols.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
An Operational Approach to Information Leakage Issa, Ibrahim; Wagner, Aaron B.; Kamath, Sudeep
IEEE transactions on information theory,
2020-March, 2020-3-00, Letnik:
66, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Given two random variables <inline-formula> <tex-math notation="LaTeX">X </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">Y </tex-math></inline-formula>, an operational ...approach is undertaken to quantify the "leakage" of information from <inline-formula> <tex-math notation="LaTeX">X </tex-math></inline-formula> to <inline-formula> <tex-math notation="LaTeX">Y </tex-math></inline-formula>. The resulting measure <inline-formula> <tex-math notation="LaTeX">\mathcal {L}\left ({X \!\! \to \!\! Y}\right) </tex-math></inline-formula> is called maximal leakage , and is defined as the multiplicative increase, upon observing <inline-formula> <tex-math notation="LaTeX">Y </tex-math></inline-formula>, of the probability of correctly guessing a randomized function of <inline-formula> <tex-math notation="LaTeX">X </tex-math></inline-formula>, maximized over all such randomized functions. A closed-form expression for <inline-formula> <tex-math notation="LaTeX">\mathcal {L}\left ({X \!\! \to \!\! Y}\right) </tex-math></inline-formula> is given for discrete <inline-formula> <tex-math notation="LaTeX">X </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">Y </tex-math></inline-formula>, and it is subsequently generalized to handle a large class of random variables. The resulting properties are shown to be consistent with an axiomatic view of a leakage measure, and the definition is shown to be robust to variations in the setup. Moreover, a variant of the Shannon cipher system is studied, in which performance of an encryption scheme is measured using maximal leakage. A single-letter characterization of the optimal limit of (normalized) maximal leakage is derived and asymptotically-optimal encryption schemes are demonstrated. Furthermore, the sample complexity of estimating maximal leakage from data is characterized up to subpolynomial factors. Finally, the guessing framework used to define maximal leakage is used to give operational interpretations of commonly used leakage measures, such as Shannon capacity, maximal correlation, and local differential privacy.
No qualitative imaging feature currently predicts molecular alterations of pediatric low-grade gliomas with high sensitivity or specificity. The T2-FLAIR mismatch sign predicts
-mutated 1p19q ...noncodeleted adult gliomas with high specificity. We aimed to assess the significance of the T2-FLAIR mismatch sign in pediatric low-grade gliomas.
Pretreatment MR images acquired between January 2001 and August 2018 in pediatric patients with pediatric low-grade gliomas were retrospectively identified. Inclusion criteria were the following: 1) 0-18 years of age, 2) availability of molecular information in histopathologically confirmed cases, and 3) availability of preoperative brain MR imaging with non-motion-degraded T2-weighted and FLAIR sequences. Spinal cord tumors were excluded.
Three hundred forty-nine patients were included (187 boys; mean age, 8.7 SD, 4.8 years; range, 0.5-17.7 years).
-B-Raf proto-oncogene (
) fusion and
p.V600E mutation were the most common molecular markers (
= 148, 42%, and
= 73, 20.7%, respectively). The T2-FLAIR mismatch sign was present in 25 patients (7.2%). Of these, 9 were dysembryoplastic neuroepithelial tumors; 8, low-grade astrocytomas; 5, diffuse astrocytomas; 1, a pilocytic astrocytoma; 1, a glioneuronal tumor; and 1, an angiocentric glioma. None of the 25 T2-FLAIR mismatch pediatric low-grade gliomas were
p.V600E-mutated. Fourteen of 25 pediatric low-grade gliomas with the T2-FLAIR mismatch sign had rare molecular alterations, while the molecular subtype was unknown for 11 tumors.
The T2-FLAIR mismatch sign was not observed in the common molecular alterations,
p.V600E-mutated and
fused pediatric low-grade gliomas, while it was encountered in pediatric low-grade gliomas with rare pediatric molecular alterations.
Hydrogen-air mixtures are highly flammable. Hydrogen sensors are therefore of paramount importance for timely leak detection during handling. However, existing solutions do not meet the stringent ...performance targets set by stakeholders, while deactivation due to poisoning, for example by carbon monoxide, is a widely unsolved problem. Here we present a plasmonic metal-polymer hybrid nanomaterial concept, where the polymer coating reduces the apparent activation energy for hydrogen transport into and out of the plasmonic nanoparticles, while deactivation resistance is provided via a tailored tandem polymer membrane. In concert with an optimized volume-to-surface ratio of the signal transducer uniquely offered by nanoparticles, this enables subsecond sensor response times. Simultaneously, hydrogen sorption hysteresis is suppressed, sensor limit of detection is enhanced, and sensor operation in demanding chemical environments is enabled, without signs of long-term deactivation. In a wider perspective, our work suggests strategies for next-generation optical gas sensors with functionalities optimized by hybrid material engineering.
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