820 research outputs found
Random Networks Tossing Biased Coins
In statistical mechanical investigations on complex networks, it is useful to
employ random graphs ensembles as null models, to compare with experimental
realizations. Motivated by transcription networks, we present here a simple way
to generate an ensemble of random directed graphs with, asymptotically,
scale-free outdegree and compact indegree. Entries in each row of the adjacency
matrix are set to be zero or one according to the toss of a biased coin, with a
chosen probability distribution for the biases. This defines a quick and simple
algorithm, which yields good results already for graphs of size n ~ 100.
Perhaps more importantly, many of the relevant observables are accessible
analytically, improving upon previous estimates for similar graphs
Mean-field methods in evolutionary duplication-innovation-loss models for the genome-level repertoire of protein domains
We present a combined mean-field and simulation approach to different models
describing the dynamics of classes formed by elements that can appear,
disappear or copy themselves. These models, related to a paradigm
duplication-innovation model known as Chinese Restaurant Process, are devised
to reproduce the scaling behavior observed in the genome-wide repertoire of
protein domains of all known species. In view of these data, we discuss the
qualitative and quantitative differences of the alternative model formulations,
focusing in particular on the roles of element loss and of the specificity of
empirical domain classes.Comment: 10 Figures, 2 Table
Physical descriptions of the bacterial nucleoid at large scales, and their biological implications.
Recent experimental and theoretical approaches have attempted to quantify the physical organization (compaction and geometry) of the bacterial chromosome with its complement of proteins (the nucleoid). The genomic DNA exists in a complex and dynamic protein-rich state, which is highly organized at various length scales. This has implications for modulating (when not directly enabling) the core biological processes of replication, transcription and segregation. We overview the progress in this area, driven in the last few years by new scientific ideas and new interdisciplinary experimental techniques, ranging from high space- and time-resolution microscopy to high-throughput genomics employing sequencing to map different aspects of the nucleoid-related interactome. The aim of this review is to present the wide spectrum of experimental and theoretical findings coherently, from a physics viewpoint. In particular, we highlight the role that statistical and soft condensed matter physics play in describing this system of fundamental biological importance, specifically reviewing classic and more modern tools from the theory of polymers. We also discuss some attempts toward unifying interpretations of the current results, pointing to possible directions for future investigation
Efficacy and Safety of Daridorexant in Older and Younger Adults with Insomnia Disorder: A Secondary Analysis of a Randomised Placebo-Controlled Trial.
BACKGROUND AND OBJECTIVE
The dual orexin receptor antagonist daridorexant, studied in two phase III trials, dose-dependently improved objective and subjective sleep variables and daytime functioning in adults with insomnia. Because treatment of insomnia in older adults is challenging and has limited options, the purpose of the current analysis was to further analyse the phase III trial studying the higher doses of daridorexant, those that showed efficacy (daridorexant 50 mg, daridorexant 25 mg and placebo, nightly for 3 months), and compare the safety and efficacy of daridorexant in patients aged ≥ 65 ('older adults') to those aged < 65 years ('younger adults').
METHODS
Analyses by age (≥ 65 years, n = 364; < 65 years, n = 566) were performed on data from the randomised, double-blind, placebo-controlled Trial 1 in adult patients with insomnia (NCT03545191). Efficacy endpoints included a change from baseline at month 1 and month 3 in polysomnography-measured wake after sleep onset (WASO) and latency to persistent sleep (LPS), self-reported total sleep time (sTST) and daytime functioning assessed using the validated Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ). Safety endpoints included adverse events and the Visual Analog Scale for morning sleepiness.
RESULTS
At baseline, mean [standard deviation] WASO was numerically greater (110 [39] vs 92 [38] min) in older than younger adults, while LPS was comparable (~ 65 min). Mean baseline IDSIQ total and all domain scores were numerically lower (i.e. better) in older adults. Daridorexant caused similar reductions in WASO and LPS, and similar increases in sTST, from baseline, in both age groups; improvements were numerically greater with daridorexant 50 mg than 25 mg. At month 3, daridorexant 50 mg, compared with placebo, decreased WASO by a least-squares mean of 19.6 (95% confidence interval 9.7, 29.5) in older patients versus 17.4 min (10.7, 24.0) in younger patients and decreased LPS by a least-squares mean of 14.9 (7.5, 22.3) in older patients versus 9.7 min (3.7, 15.7) in younger patients. Daridorexant 50 mg increased sTST from baseline to month 3 by a least-squares mean of 59.9 (49.6, 70.3) in older patients versus 57.1 min (48.9, 65.3) in younger patients. Daridorexant 50 mg progressively improved IDSIQ total and domain scores from week 1 onwards similarly in both groups; daridorexant 25 mg improved IDSIQ scores, but only in younger adults. In both age groups, in comparison with placebo, the overall incidence of adverse events was comparable, and there were fewer falls on daridorexant. Daridorexant improved Visual Analog Scale morning sleepiness in both groups; daridorexant 50 mg increased the mean (standard deviation) Visual Analog Scale morning sleepiness score by 15.9 (20.7) in older adults and by 14.9 (18.7) in younger adults from baseline to month 3. In older adults, there was one case of sleep paralysis, and no cases of narcolepsy, cataplexy, or complex sleep behaviour.
CONCLUSIONS
In older patients with insomnia, as in younger patients, the efficacy of daridorexant is maximal on night-time and daytime variables at the higher dose of 50 mg. Older patients particularly require this dose to improve daytime functioning. Older patients are not at an increased risk of adverse events or residual effects the next morning after night-time administration of daridorexant, even at 50 mg. The dose of daridorexant does not need to be decreased for older patients.
CLINICAL TRIAL REGISTRATION
ClinicalTrials.gov (NCT03545191) [first posted: 4 June, 4 2018], https://clinicaltrials.gov/ct2/show/NCT03545191
Single strain high-depth ngs reveals high rdna (Its-lsu) variability in the four prevalent pathogenic species of the genus candida
Ribosomal RNA in fungi is encoded by a series of genes and spacers included in a large operon present in 100 tandem repeats, normally in a single locus. The multigene nature of this locus was somehow masked by Sanger sequencing, which produces a single sequence reporting the prevalent nucleotide of each site. The introduction of next generation sequencing led to deeper knowledge of the individual sequences (reads) and therefore of the variants between the same DNA sequences located in different tandem repeats. In this framework, NGS sequencing of the rDNA region was used to elucidate the extent of intra-and inter-genomic variation at both the strain and species level. Specifically, the use of an innovative NGS technique allowed the high-throughput highdepth sequencing of the ITS1-LSU D1/D2 amplicons of 252 strains belonging to four opportunistic yeast species of the genus Candida. Results showed the presence of a large extent of variability among strains and species. These variants were differently distributed throughout the analyzed regions with a higher concentration within the Internally Transcribed Spacer (ITS) region, suggesting that concerted evolution was not able to totally homogenize these sequences. Both the internal variability and the SNPs between strain can be used for a deep typing of the strains and to study their ecology
Pontine stroke presenting as isolated facial nerve palsy mimicking Bell's palsy: a case report
<p>Abstract</p> <p>Introduction</p> <p>Isolated facial nerve palsy usually manifests as Bell's palsy. Lacunar infarct involving the lower pons is a rare cause of solitary infranuclear facial paralysis. The present unusual case is one in which the patient appeared to have Bell's palsy but turned out to have a pontine infarct.</p> <p>Case presentation</p> <p>A 47-year-old Asian Indian man with a medical history of hypertension presented to our institution with nausea, vomiting, generalized weakness, facial droop, and slurred speech of 14 hours' duration. His physical examination revealed that he was conscious, lethargic, and had mildly slurred speech. His blood pressure was 216/142 mmHg. His neurologic examination showed that he had loss of left-sided forehead creases, inability to close his left eye, left facial muscle weakness, rightward deviation of the angle of the mouth on smiling, and loss of the left nasolabial fold. Afferent corneal reflexes were present bilaterally. MRI of the head was initially read as negative for acute stroke. Bell's palsy appeared less likely because of the acuity of his presentation, encephalopathy-like imaging, and hypertension. The MRI was re-evaluated with a neurologist's assistance, which revealed a tiny 4 mm infarct involving the left dorsal aspect of the pons. The final diagnosis was isolated facial nerve palsy due to lacunar infarct of dorsal pons and hypertensive encephalopathy.</p> <p>Conclusion</p> <p>The facial nerve has a predominant motor component which supplies all muscles concerned with unilateral facial expression. Anatomic knowledge is crucial for clinical localization. Bell's palsy accounts for around 72% of facial palsies. Other causes such as tumors and pontine infarcts can also present as facial palsy. Isolated dorsal infarct presenting as isolated facial palsy is very rare. Our case emphasizes that isolated facial palsy should not always be attributed to Bell's palsy. It can be a presentation of a rare dorsal pontine infarct as observed in our patient.</p
Observation of Plasma Focusing of a 28.5 GeV Positron Beam
The observation of plasma focusing of a 28.5 GeV positron beam is reported.
The plasma was formed by ionizing a nitrogen jet only 3 mm thick. Simultaneous
focusing in both transverse dimensions was observed with effective focusing
strengths of order Tesla per micron. The minimum area of the beam spot was
reduced by a factor of 2.0 +/- 0.3 by the plasma. The longitudinal beam
envelope was measured and compared with numerical calculations
Cardiac point-of-care ultrasound in hospitalized coronavirus disease-2019 patients: findings and association with outcome
The role of dalbavancin for Gram positive infections in the COVID-19 era: state of the art and future perspectives
Development of an integrated environmental monitoring protocol for SARS-CoV-2 contamination. Applications at the IRCSS San Martino Polyclinic Hospital in Genoa, Italy
Scientific background: Environmental sampling of SARS-CoV-2 is a fundamental tool for evaluating the effectiveness of non-specific prophylaxis measures in counting their spread. The purpose of our work was to evaluate the effectiveness of the different sampling methods in the hospital setting to assess their correlation with the structural, functional, and operational situation of the monitored departments and to define the dynamics of the spread of the virus in indoor environments. Methods: The monitoring was carried out at the San Martino Polyclinic Hospital (Genoa, Italy) in the period from April 2020 to June 2021. The presence of viral RNA in the collected samples was evaluated by qPCR. The infection capacity of the sample collected was also evaluated by an in vitro challenge test on cells sensitive to SARS-CoV-2 infection. Results: The percentage of positivity with respect to the number of tests performed (sensitivity) were bubbler 50%, wipe test 17%, and challenge test 11%. Only 20% of the samples tested positive in the wipe test and 43% of the samples tested positive in the bubbler sampling were also positive in the challenge test. All the positivity obtained was detected at a distance of less than 2\u202fm and height of less than 1.5 from COVID-19 patient. Conclusions: Environmental contamination from SARS-CoV-2 detected at the San Martino Polyclinic Hospital is found lower than similar assessments performed in other hospitals both in Italy and abroad. Our study predicted that environmental monitoring of SARS-CoV-2 must be carried out in an integrated way by not using a single sampling method, as each individual test has a different biological significance and performance. However, the virus detected by wipe test is not a degraded viral fragment but an intact infecting virion, only in a modest percentage of cases
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