20 research outputs found
A Paleo-Arabic inscription on a route north of Ṭāʾif
This paper will produce a new edition of the Rīʿ al-Zallālah inscription, discussing in detail its paleographic features and content, and the ramifications it has on our understanding of the linguistic and religious milieu of the sixth–early seventh century Ḥigāz
Discovery of Self-Assembling -Conjugated Peptides by Active Learning-Directed Coarse-Grained Molecular Simulation
Electronically-active organic molecules have demonstrated great promise as
novel soft materials for energy harvesting and transport. Self-assembled
nanoaggregates formed from -conjugated oligopeptides composed of an
aromatic core flanked by oligopeptide wings offer emergent optoelectronic
properties within a water soluble and biocompatible substrate. Nanoaggregate
properties can be controlled by tuning core chemistry and peptide composition,
but the sequence-structure-function relations remain poorly characterized. In
this work, we employ coarse-grained molecular dynamics simulations within an
active learning protocol employing deep representational learning and Bayesian
optimization to efficiently identify molecules capable of assembling pseudo-1D
nanoaggregates with good stacking of the electronically-active -cores. We
consider the DXXX-OPV3-XXXD oligopeptide family, where D is an Asp residue and
OPV3 is an oligophenylene vinylene oligomer (1,4-distyrylbenzene), to identify
the top performing XXX tripeptides within all 20 = 8,000 possible
sequences. By direct simulation of only 2.3% of this space, we identify
molecules predicted to exhibit superior assembly relative to those reported in
prior work. Spectral clustering of the top candidates reveals new design rules
governing assembly. This work establishes new understanding of DXXX-OPV3-XXXD
assembly, identifies promising new candidates for experimental testing, and
presents a computational design platform that can be generically extended to
other peptide-based and peptide-like systems
Pre-existing autoimmunity is associated with increased severity of COVID-19: A retrospective cohort study using data from the National COVID Cohort Collaborative (N3C)
Identifying individuals with a higher risk of developing severe COVID-19 outcomes will inform targeted or more intensive clinical monitoring and management. To date, there is mixed evidence regarding the impact of pre-existing autoimmune disease (AID) diagnosis and/or immunosuppressant (IS) exposure on developing severe COVID-19 outcomes.A retrospective cohort of adults diagnosed with COVID-19 was created in the National COVID Cohort Collaborative enclave. Two outcomes, life-threatening disease, and hospitalization were evaluated by using logistic regression models with and without adjustment for demographics and comorbidities.Of the 2,453,799 adults diagnosed with COVID-19, 191,520 (7.81%) had a pre-existing AID diagnosis and 278,095 (11.33%) had a pre-existing IS exposure. Logistic regression models adjusted for demographics and comorbidities demonstrated that individuals with a pre-existing AID (OR = 1.13, 95% CI 1.09 - 1.17; P< 0.001), IS (OR= 1.27, 95% CI 1.24 - 1.30; P< 0.001), or both (OR = 1.35, 95% CI 1.29 - 1.40; P< 0.001) were more likely to have a life-threatening COVID-19 disease. These results were consistent when evaluating hospitalization. A sensitivity analysis evaluating specific IS revealed that TNF inhibitors were protective against life-threatening disease (OR = 0.80, 95% CI 0.66- 0.96; P=0.017) and hospitalization (OR = 0.80, 95% CI 0.73 - 0.89; P< 0.001).Patients with pre-existing AID, exposure to IS, or both are more likely to have a life-threatening disease or hospitalization. These patients may thus require tailored monitoring and preventative measures to minimize negative consequences of COVID-19
SSAGES : Software Suite for Advanced General Ensemble Simulations
Molecular simulation has emerged as an essential tool for modern-day research, but obtaining proper results and making reliable conclusions from simulations requires adequate sampling of the system under consideration. To this end, a variety of methods exist in the literature that can enhance sampling considerably, and increasingly sophisticated, effective algorithms continue to be developed at a rapid pace. Implementation of these techniques, however, can be challenging for experts and non-experts alike. There is a clear need for software that provides rapid, reliable, and easy access to a wide range of advanced sampling methods and that facilitates implementation of new techniques as they emerge. Here we present SSAGES, a publicly available Software Suite for Advanced General Ensemble Simulations designed to interface with multiple widely used molecular dynamics simulations packages. SSAGES allows facile application of a variety of enhanced sampling techniques—including adaptive biasing force, string methods, and forward flux sampling—that extract meaningful free energy and transition path data from all-atom and coarse-grained simulations. A noteworthy feature of SSAGES is a user-friendly framework that facilitates further development and implementation of new methods and collective variables. In this work, the use of SSAGES is illustrated in the context of simple representative applications involving distinct methods and different collective variables that are available in the current release of the suite. The code may be found at: https://github.com/MICCoM/SSAGES-public
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Daniel Alan Brubaker, Corrections in Early Qurʾānic Manuscripts
Daniel Alan Brubaker, Corrections in Early Qurʾānic Manuscripts: Twenty Examples (Lovettsville: Think and Tell Press, 2019), xxv + 102 pp. ISBN 978-1-949123-03-6. Price: $35 (paper)