A computational study of order-disorder phenomena in Mg2TiO4 spinel (qandilite)

We have used a combination of classical and quantum-mechanical atomistic calculations, together with Monte Carlo simulations, to study order-disorder phenomena in the spinel mineral qandilite, Mg2TiO4. Using an interatomic potential model akin to those previously used for 2-3 spinels yielded a general increase in energy E as a function of inversion parameter x, and thus incorrectly predicted a normal-spinel ground state, whereas the E(x) behavior as modeled by density-functional theory exhibited a maximum at an intermediate degree of inversion and correctly predicted an inverse-spinel ground state. We therefore used the quantum-mechanical simulations to derive pair interaction parameters (for nearest-neighbor tetrahedral-tetrahedral, octahedral-octahedral, and tetrahedral-octahedral interactions) and chemical potential to use in Monte Carlo simulations of order-disorder in qandilite. The simulated cation distributions compared favorably with those obtained experimentally, although the long-range ordering transition to the tetragonal P4122 phase was not observed when using only nearest-neighbor interactions. However, this transition could be observed following the addition of two extra parameters to the model. The simulations were used to calculate the effect of short- and long-range cation order on the configurational entropy of qandilite as a function of temperature. The calculated entropy of the high-temperature cubic phase was in very good agreement with the experimental value recently determined, supporting the suggestion that there is considerable short-range order in qandilite

Canalization and Symmetry in Boolean Models for Genetic Regulatory Networks

Canalization of genetic regulatory networks has been argued to be favored by evolutionary processes due to the stability that it can confer to phenotype expression. We explore whether a significant amount of canalization and partial canalization can arise in purely random networks in the absence of evolutionary pressures. We use a mapping of the Boolean functions in the Kauffman N-K model for genetic regulatory networks onto a k-dimensional Ising hypercube to show that the functions can be divided into different classes strictly due to geometrical constraints. The classes can be counted and their properties determined using results from group theory and isomer chemistry. We demonstrate that partially canalized functions completely dominate all possible Boolean functions, particularly for higher k. This indicates that partial canalization is extremely common, even in randomly chosen networks, and has implications for how much information can be obtained in experiments on native state genetic regulatory networks.Comment: 14 pages, 4 figures; version to appear in J. Phys.

Establishing a meaningful human rights due diligence process for corporations : learning from experience of human rights impact assessment

The United Nations Special Representative of the Secretary-General on Business and Human Rights, Professor John Ruggie, has constructed a new international framework, which is set to become the cornerstone for all action on human rights and business at the international level. The principle of human rights due diligence (HRDD) is the central component of the corporate duty to respect human rights within that framework. This article argues that Ruggie's HRDD principle contains the majority of the core procedural elements that a reasonable human rights impact assessment (HRIA) process should incorporate. It is likely that the majority of corporations will adopt HRIA as a mechanism for meeting their due diligence responsibilities. However, in the context of the contentious debate around corporate human rights performance, the current state of the art in HRIA gives rise to concerns about the credibility and robustness of likely practice. Additional requirements are therefore essential if HRDD is to have a significant impact on corporate human rights performance – requirements in relation to transparency; external participation and verification; and independent monitoring and review

Gypsum-DL: an open-source program for preparing small-molecule libraries for structure-based virtual screening

Computational techniques such as structure-based virtual screening require carefully prepared 3D models of potential small-molecule ligands. Though powerful, existing commercial programs for virtual-library preparation have restrictive and/or expensive licenses. Freely available alternatives, though often effective, do not fully account for all possible ionization, tautomeric, and ring-conformational variants. We here present Gypsum-DL, a free, robust open-source program that addresses these challenges. As input, Gypsum-DL accepts virtual compound libraries in SMILES or flat SDF formats. For each molecule in the virtual library, it enumerates appropriate ionization, tautomeric, chiral, cis/trans isomeric, and ring-conformational forms. As output, Gypsum-DL produces an SDF file containing each molecular form, with 3D coordinates assigned. To demonstrate its utility, we processed 1558 molecules taken from the NCI Diversity Set VI and 56,608 molecules taken from a Distributed Drug Discovery (D3) combinatorial virtual library. We also used 4463 high-quality protein-ligand complexes from the PDBBind database to show that Gypsum-DL processing can improve virtual-screening pose prediction. Gypsum-DL is available free of charge under the terms of the Apache License, Version 2.0

Frenetic: A High-Level Language for OpenFlow Networks

Network administrators must configure network devices to simultaneously provide several interrelated services such as routing, load balancing, traffic monitoring, and access control. Unfortunately, most interfaces for programming networks are defined at the low level of abstraction supported by the underlying hardware, leading to complicated programs with subtle bugs. We present Frenetic, a high-level language for OpenFlow networks that enables writing programs in a declarative and compositional style, with a simple "program like you see every packet" abstraction. Building on ideas from functional programming, Frenetic offers a rich pattern algebra for classifying packets into traffic streams and a suite of operators for transforming streams. The run-time system efficiently manages the low-level details of (un)installing packet-processing rules in the switches. We describe the design of Frenetic, an implementation on top of OpenFlow, and experiments and example programs that validate our design choices.Office of Naval Research grant N00014-09-1-0770 "Networks Opposing Botnets

Low State, Phase-Resolved IR Spectroscopy of VV Puppis

We present phase-resolved low resolution $JHK$ and higher resolution $K$-band spectroscopy of the polar VV Pup. All observations were obtained when VV Pup was in a low accretion state having a K magnitude near 15. The low resolution observations reveal cyclotron emission in the $J$ band during some phases, consistent with an origin near the active 30.5 MG pole on the white dwarf. The secondary in VV Pup appears to be a normal M7V star and we find that the $H$ and $K$ band fluxes are entirely due to this star at all orbital phases during the low accretion state. We use our higher resolution Keck spectroscopy to produce the first $K$-band radial velocity curve for VV Pup. Our orbital solution yields $K_2$=414$\pm27$ km sec$^{-1}$ and leads to mass estimates of M$_1$=0.73$\pm$0.05 M$_{\odot}$ and M$_2$=0.10$\pm$0.02 M$_{\odot}$. We find that the mass accretion rates during the normal low states of the polars VV Pup, EF Eri, and EQ Cet are near 10$^{-13}$ M$_{\odot}$ yr$^{-1}$. The fact that \.M is not zero in low state polars indicates active secondary stars in these binary systems, including the sub-stellar donor star present in EF Eri.Comment: Accepted in Astronomical Journal 5 figure

Revealing natural relationships among arbuscular mycorrhizal fungi: culture line BEG47 represents Diversispora epigaea, not Glomus versiforme

Background: Understanding the mechanisms underlying biological phenomena, such as evolutionarily conservative trait inheritance, is predicated on knowledge of the natural relationships among organisms. However, despite their enormous ecological significance, many of the ubiquitous soil inhabiting and plant symbiotic arbuscular mycorrhizal fungi (AMF, phylum Glomeromycota) are incorrectly classified. Methodology/Principal Findings: Here, we focused on a frequently used model AMF registered as culture BEG47. This fungus is a descendent of the ex-type culture-lineage of Glomus epigaeum, which in 1983 was synonymised with Glomus versiforme. It has since then been used as ‘G. versiforme BEG47’. We show by morphological comparisons, based on type material, collected 1860–61, of G. versiforme and on type material and living ex-type cultures of G. epigaeum, that these two AMF species cannot be conspecific, and by molecular phylogenetics that BEG47 is a member of the genus Diversispora. Conclusions: This study highlights that experimental works published during the last >25 years on an AMF named ‘G. versiforme’ or ‘BEG47’ refer to D. epigaea, a species that is actually evolutionarily separated by hundreds of millions of years from all members of the genera in the Glomerales and thus from most other commonly used AMF ‘laboratory strains’. Detailed redescriptions substantiate the renaming of G. epigaeum (BEG47) as D. epigaea, positioning it systematically in the order Diversisporales, thus enabling an evolutionary understanding of genetical, physiological, and ecological traits, relative to those of other AMF. Diversispora epigaea is widely cultured as a laboratory strain of AMF, whereas G. versiforme appears not to have been cultured nor found in the field since its original description

d-Amino acid oxidase and serine racemase in human brain: normal distribution and altered expression in schizophrenia

The N-methyl-d-aspartate receptor co-agonist d-serine is synthesized by serine racemase and degraded by d-amino acid oxidase. Both d-serine and its metabolizing enzymes are implicated in N-methyl-d-aspartate receptor hypofunction thought to occur in schizophrenia. We studied d-amino acid oxidase and serine racemase immunohistochemically in several brain regions and compared their immunoreactivity and their mRNA levels in the cerebellum and dorsolateral prefrontal cortex in schizophrenia. d-Amino acid oxidase immunoreactivity was abundant in glia, especially Bergmann glia, of the cerebellum, whereas in prefrontal cortex, hippocampus and substantia nigra, it was predominantly neuronal. Serine racemase was principally glial in all regions examined and demonstrated prominent white matter staining. In schizophrenia, d-amino acid oxidase mRNA was increased in the cerebellum, and as a trend for protein. Serine racemase was increased in schizophrenia in the dorsolateral prefrontal cortex but not in cerebellum, while serine racemase mRNA was unchanged in both regions. Administration of haloperidol to rats did not significantly affect serine racemase or d-amino acid oxidase levels. These findings establish the major cell types wherein serine racemase and d-amino acid oxidase are expressed in human brain and provide some support for aberrant d-serine metabolism in schizophrenia. However, they raise further questions as to the roles of d-amino acid oxidase and serine racemase in both physiological and pathophysiological processes in the brain

Mapping the Galactic Halo with blue horizontal branch stars from the 2dF quasar redshift survey

We use 666 blue horizontal branch (BHB) stars from the 2Qz redshift survey to map the Galactic halo in four dimensions (position, distance and velocity). We find that the halo extends to at least 100 kpc in Galactocentric distance, and obeys a single power-law density profile of index ~-2.5 in two different directions separated by 150 degrees on the sky. This suggests that the halo is spherical. Our map shows no large kinematically coherent structures (streams, clouds or plumes) and appears homogeneous. However, we find that at least 20% of the stars in the halo reside in substructures and that these substructures are dynamically young. The velocity dispersion profile of the halo appears to increase towards large radii while the stellar velocity distribution is non Gaussian beyond 60 kpc. We argue that the outer halo consists of a multitude of low luminosity overlapping tidal streams from recently accreted objects.Comment: Accepted for publication in the Astrophysical Journal Requires emulateapj to proces

Association of Genetic Variants in NUDT15 with Thiopurine-Induced Myelosuppression in Patients with Inflammatory Bowel Disease

Funding Information: reported serving as a consultant for AbbVie UK; receiving honoraria from Falk and AbbVie UK; receiving grants from Crohn’s & Colitis UK and Tillott’s Pharmaceuticals; having a fellowship from the UK National Institute for Health Research; and receiving travel reimbursement from Merck Sharp & Dohme and Norgine. Dr Heap reported receiving travel reimbursement from AbbVie; and being a current employee of AbbVie and owning stock in the company. Dr Andersen reported receiving personal fees from Merck Sharp & Dohme and Janssen. Dr Ananthakrishnan reported receiving a grant from Pfizer; and receiving personal fees from Takeda. Dr Beaugerie reported receiving advisory board fees from Allergan, Janssen, and Pfizer; receiving a grant from Hospira; and receiving grants and honoraria from AbbVie, Merck Sharp & Dohme, Ferring, Takeda, and Tillott’s Pharmaceuticals. Dr Cummings reported receiving personal fees from AbbVie, Takeda, Biogen, Janssen, Merck Sharp & Dohme, Amgen, Hakim Pharmaceuticals, and Pfizer/Hospira; and receiving grants from Takeda, Biogen, AstraZeneca, and Pfizer/Hospira. Dr Halfvarson reported receiving personal fees from AbbVie, Hospira, Janssen, Medivir, Merck Sharp & Dohme, Pfizer, RenapharmaVifor, Takeda, Tillott’s Pharmaceuticals, Celgene, Sandoz, and Shire; and receiving grants from Janssen, Merck Sharp & Dohme, and Takeda. Dr Hart reported receiving advisory board fees from AbbVie, Atlantic, Bristol-Myers Squibb, Celltrion, Janssen, Merck Sharp & Dohme, Pfizer, Shire, and Takeda; receiving honoraria from Falk and Ferring; and receiving a grant from Takeda. Dr Irving reported receiving personal fees from Janssen, AbbVie, Takeda, Ferring, Pfizer, Lilly, Merck Sharp & Dohme, Samsung, and Sandoz; and receiving grants from Takeda and Merck Sharp & Dohme. Dr Lindsay reported receiving advisory board fees from Atlantic Health, AbbVie UK/global, Merck Sharp & Dohme, Shire UK, Vifor Pharma, Ferring International, Celltrion, Takeda, Napp, Pfizer, and Janssen; serving as a consultant for AbbVie UK/global, Takeda, and Pfizer; receiving grants from Shire UK, AbbVie UK/global, Warner Chilcott, Funding Information: Takeda, Hospira, Ferring International, and Merck Sharp & Dohme; receiving honoraria from Takeda, Cornerstones US, Tillott’s Pharmaceuticals, Napp, Shire International, Janssen, AbbVie, and Pfizer; and receiving travel reimbursement from AbbVie UK, Merck Sharp & Dohme, Warner Chilcott, Takeda, and Shire International. Dr McGovern reported receiving grants from the National Institutes of Health, Helmsley Charitable Trust, and Janssen; and serving as a consultant for Pfizer, Q Biologics, Cidara, Gilead, and Janssen. Dr Seksik reported receiving advisory board fees from Astellas; receiving honoraria from Takeda, AbbVie, and Ferring; and receiving grants from Merck Sharp & Dohme and Biocodex. Dr Sokol reported receiving grants from Biocodex, Danone, and BiomX; serving as a consultant for Enterome, Takeda, AbbVie, Roche, Amgen, Danone, BiomX, Ferring, Bristol-Myers Squibb, Astellas, Merck Sharp & Dohme, Novartis, Tillott’s Pharmaceuticals, and Biose; and being the co-founder of Nextbiotix. Dr Annese reported receiving advisory board fees from Takeda, AbbVie, and Medtronic; and receiving honoraria from Janssen, Takeda, AbbVie, and Medtronic. Dr Weersma reported receiving grants from Takeda, Ferring, and Tramedico; and receiving personal fees from AbbVie. Dr Goodhand reported receiving honoraria from Falk, AbbVie, and Shield Therapeutics. Dr Kennedy reported serving as a consultant for Falk; receiving honoraria from Falk, Allergan, Pharmacosmos, and Takeda; and being a deputy editor of Alimentary Pharmacology & Therapeutics. Dr Ahmad reported receiving unrestricted grants, advisory board fees, speaker honoraria, and support to attend international meetings from AbbVie, Merck Sharp & Dohme, Janssen, Takeda, Ferring, Tillott’s Pharmaceuticals, Ferring, Pfizer, Napp, Celltrion, and Hospira. No other disclosures were reported. Funding Information: Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, California), Alistair McNair, PhD (Queen Elizabeth Hospital, London, UK), Anita Modi, MD (Luton and Dunstable University Hospital, Luton, UK), Kevin Monahan, PhD (West Middlesex University Hospital, Middlesex, UK), Alex Moran, MD (Northern Devon Healthcare Trust, Barnstaple, UK), Mary-Anne Morris, MD (Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, UK), Marianne Mortimore, MBBS (Mater Research Institute, University of Queensland, South Brisbane, Australia), Craig Mowat, MD (Ninewells Hospital, NHS Tayside, Dundee, UK), Rafeeq Muhammed, MD (Birmingham Children's Hospital, Birmingham, UK), Charles D. R. Murray, PhD (Royal Free Hospital, Royal Free London NHS Foundation Trust, London, UK), Hanlie Olivier (IBD Pharmacogenetics Group, University of Exeter, Exeter, UK), Timothy R. Orchard, DM (Imperial College Healthcare NHS Trust, London, UK), Simon Panter, MD (South Tyneside District Hospital, South Tyneside, UK), Vinod Patel, MBBS (Tameside and Glossop Integrated Care NHS Foundation Trust, Ashton-under-Lyne, UK), Rosemary Phillips, MD (Princess Alexandra Hospital, Essex, UK), Neeraj Prasad, MSc (Wrightington Hospital, Wrightington, UK), Cathryn Preston, MBChB (Bradford Royal Infirmary, Bradford, UK), Graham Radford-Smith, PhD (Royal Brisbane and Women’s Hospital, Brisbane, Australia), Praveen Rajasekhar, MD (Northumbria NHS Trust, Tyne and Wear, UK), Dipak Roy, PhD (Tameside and Glossop Integrated Care NHS Foundation Trust, Ashton-under-Lyne, UK), Rebecca Saich, PhD (Basingstoke and North Hampshire Hospital, Basingstoke, UK), Jack Satsangi, PhD (Western General Hospital, NHS Lothian, Edinburgh, UK), Stefan Schreiber, PhD (Kiel University, Kiel, Germany), Sandip Sen, MD (Royal Stoke University Hospital, Stoke-on-Trent, UK), Neil Shah, MD (Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK), Richard Shenderay, MBBS (Airedale NHS Foundation Trust, Keighley, UK), Acuth Shenoy, MD (Colchester Hospital University NHS Foundation Trust, Colchester, UK), James Shutt, DM (Dorset County Hospital NHS Foundation Trust, Dorchester, UK), Mark Silverberg, PhD (Mount Sinai Hospital, Toronto, Ontario, Canada), Alison Simmons, PhD (Oxford University Hospitals, Oxford, UK), Jonathan Simmons, DM (Royal Berkshire Hospital, Royal Berkshire NHS Foundation Trust, Reading, UK), Salil Singh, PhD (Bolton NHS Foundation Trust, Bolton, UK), Malcolm Smith, MBChB (Aberdeen Royal Infirmary, Aberdeen, UK), Mark Smith, MD (Shrewsbury and Telford Hospital NHS Trust, Shrewsbury, UK), Melissa Smith, MB (Royal Sussex County Hospital, Brighton, UK), Jonathon A. Snook, DPhil (Poole Hospital NHS Foundation Trust, Poole, UK), Sunil Sonwalker, MD (Calderdale Royal Hospital, Halifax, UK), Christine R. Stevens, PhD (Broad Institute, Harvard University, Cambridge, Massachusetts), Giacomo Sturniolo, PhD (Univerita di Padova, Padova, Italy), Sreedhar Subramanian, MD (Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool, UK), Amanda Thomas, MBBS (Department of Gastroenterology, Royal Devon and Exeter Hospital NHS Foundation Trust, Exeter, UK), Mark Tighe, BM (Poole Hospital NHS Foundation Trust, Poole, UK), Franco Torrente, MD (Department of Gastroenterology, Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK), Mark Tremelling, MD (Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, UK), Epameinondas Tsianos, PhD (University Hospital of Ioannina, Ioannina, Greece), Deven Vani, MD (Mid Yorkshire Hospitals NHS Trust, Wakefield, UK), Alissa Walsh, MBBS (St Vincent’s Hospital, Sydney, Australia), Gillian Watermeyer, MBChB (Groote Schuur Hospital, Cape Town, South Africa), David Watts, MBChB (Forth Valley Royal Hospital, Larbert, UK), Gill Watts, MD (Wythenshawe Hospital, South Manchester, UK), Sean Weaver, PhD (Royal Bournemouth General Hospital, Bournemouth, UK), Emma Wesley, MBBS (Musgrove Park Hospital, Taunton and Somerset NHS Hospitals, Taunton, UK), Anne Willmott, MBChB (Leicester Royal Infirmary-Paediatric, Leicester, UK), Karen Yearsley, BM (Nevill Hall Hospital, Abergavenny, UK), Veena Zambar, MBBS (Leeds General Infirmary, Leeds, UK), and Sebastian Zeissig, MD (University Medical Center Schleswig-Hostein, Kiel, Germany). These individuals identified and recruited patient s to the study and provided comments on a draft of the manuscript. Funding Information: Adverse Events Consortium funded the sample collection and genotyping at the Broad Institute. The UK National Institute for Health Research provided research nurse support to facilitate recruitment at all UK research sites. Crohn’s & Colitis UK and forCrohns provided funding support and publicized this study to their members. The Exeter National Institute for Health Research Clinical Research Facility provided DNA storage and management. Institutional strategic support award WT097835MF from Wellcome Trust supported the management of the study. Samples from Cedars-Sinai were collected and processed through the MIRIAD biobank that was funded by grant P01DK046763 from the National Institutes of Health. Publisher Copyright: © 2019 American Medical Association. All rights reserved.IMPORTANCE Use of thiopurines may be limited by myelosuppression. TPMT pharmacogenetic testing identifies only 25% of at-risk patients of European ancestry. Among patients of East Asian ancestry, NUDT15 variants are associated with thiopurine-induced myelosuppression (TIM). OBJECTIVE To identify genetic variants associated with TIM among patients of European ancestry with inflammatory bowel disease (IBD). DESIGN, SETTING, AND PARTICIPANTS Case-control study of 491 patients affected by TIM and 679 thiopurine-tolerant unaffected patients who were recruited from 89 international sites between March 2012 and November 2015. Genome-wide association studies (GWAS) and exome-wide association studies (EWAS) were conducted in patients of European ancestry. The replication cohort comprised 73 patients affected by TIM and 840 thiopurine-tolerant unaffected patients. EXPOSURES Genetic variants associated with TIM. MAIN OUTCOMES AND MEASURES Thiopurine-induced myelosuppression, defined as a decline in absolute white blood cell count to 2.5 x 10(9)/L or less or a decline in absolute neutrophil cell count to 1.0 x 10(9)/L or less leading to a dose reduction or drug withdrawal. RESULTS Among 1077 patients (398 affected and 679 unaffected; median age at IBD diagnosis, 31.0 years [interquartile range, 21.2 to 44.1 years]; 540 [50%] women; 602 [56%] diagnosed as having Crohn disease), 919 (311 affected and 608 unaffected) were included in the GWAS analysis and 961 (328 affected and 633 unaffected) in the EWAS analysis. The GWAS analysis confirmed association of TPMT (chromosome 6, rs11969064) with TIM (30.5% [95/311] affected vs 16.4% [100/608] unaffected patients; odds ratio [OR], 2.3 [95% CI, 1.7 to 3.1], P = 5.2 x 10(-9)). The EWAS analysis demonstrated an association with an in-frame deletion in NUDT15 (chromosome 13, rs746071566) and TIM (5.8% [19/328] affected vs 0.2% [1/633] unaffected patients; OR, 38.2 [95% CI, 5.1 to 286.1], P = 1.3 x 10(-8)), which was replicated in a different cohort (2.7% [2/73] affected vs 0.2% [2/840] unaffected patients; OR, 11.8 [95% CI, 1.6 to 85.0], P = .03). Carriage of any of 3 coding NUDT15 variants was associated with an increased risk (OR, 27.3 [95% CI, 9.3 to 116.7], P = 1.1 x 10(-7)) of TIM, independent of TPMT genotype and thiopurine dose. CONCLUSIONS AND RELEVANCE Among patients of European ancestry with IBD, variants in NUDT15 were associated with increased risk of TIM. These findings suggest that NUDT15 genotyping may be considered prior to initiation of thiopurine therapy; however, further study including additional validation in independent cohorts is required.Peer reviewe