Non-commutative deformations and quasi-coherent modules

We identify a class of "quasi-compact semi-separated" (qcss) twisted presheaves of algebras A for which well-behaved Grothendieck abelian categories of quasi-coherent modules Qch(A) are defined. This class is stable under algebraic deformation, giving rise to a 1-1 correspondence between algebraic deformations of A and abelian deformations of Qch(A). For a qcss presheaf A, we use the Gerstenhaber-Schack (GS) complex to explicitely parameterize the first order deformations. For a twisted presheaf A with central twists, we descibe an alternative category QPr(A) of quasi-coherent presheaves which is equivalent to Qch(A), leading to an alternative, equivalent association of abelian deformations to GS cocycles of qcss presheaves of commutative algebras. Our construction applies to the restriction O of the structure sheaf of a scheme X to a finite semi-separating open affine cover (for which we have an equivalence between Qch(O) and Qch(X)). Under a natural identification of Gerstenhaber-Schack cohomology of O and Hochschild cohomology of X, our construction is shown to be equivalent to Toda's construction in the smooth case

Book review: how to be a geek: essays on the culture of software by Matthew Fuller

In How to be a Geek: Essays on the Culture of Software, Matthew Fuller explores the bits and bytes that have reshaped our world through a collection of essays that examines the figure of the geek and software cultures. While the lack of cohesive thread and use of terminology means this collection is best suited to scholars already familiar with the field rather than newcomers, the book contains some useful and astute insights, writes Wendy Liu

Tetrahedrally coordinated carbonates in Earth's lower mantle

Carbonates are the main species that bring carbon deep into our planet through subduction. They are an important rock-forming mineral group, fundamentally distinct from silicates in Earth's crust in that carbon binds to three oxygen atoms, while silicon is bonded to four oxygens. Here, we present experimental evidence that under the sufficiently high pressures and high temperatures existing in the lower mantle, ferromagnesian carbonates transform to a phase with tetrahedrally coordinated carbons. Above 80 GPa, in situ synchrotron infrared experiments show the unequivocal spectroscopic signature of the high-pressure phase of (Mg,Fe)CO$_3$. Using ab-initio calculations, we assign the new IR signature to C-O bands associated with tetrahedrally coordinated carbon with asymmetric C-O bonds. Tetrahedrally coordinated carbonates are expected to exhibit substantially different reactivity than low pressure three-fold coordinated carbonates, as well as different chemical properties in the liquid state. Hence this may have significant implications on carbon reservoirs and fluxes and the global geodynamic carbon cycle

Influence of lipopolysaccharide on proinflammatory gene expression in human corneal, conjunctival and meibomian gland epithelial cells

PURPOSE: Lipopolysaccharide (LPS), a bacterial endotoxin, is known to stimulate leuokotriene B4 (LTB4) secretion by human corneal (HCECs), conjunctival (HConjECs) and meibomian gland (HMGECs) epithelial cells. We hypothesize that this LTB4 effect represents an overall induction of proinflammatory gene expression in these cells. Our objective was to test this hypothesis. METHODS: Immortalized HCECs, HConjECs and HMGECs were cultured in the presence or absence of LPS (15 μg/ml) and ligand binding protein (LBP; 150 ng/ml). Cells were then processed for RNA isolation and the analysis of gene expression by using Illumina BeadChips, background subtraction, cubic spline normalization and GeneSifter software. RESULTS: Our findings show that LPS induces a striking increase in proinflammatory gene expression in HCECs and HConjECs. These cellular reactions are associated with a significant up-regulation of genes associated with inflammatory and immune responses (e.g. IL-1β, IL-8, and tumor necrosis factor), including those related to chemokine and Toll-like receptor signaling pathways, cytokine-cytokine receptor interactions, and chemotaxis. In contrast, with the exception of Toll-like signaling and associated innate immunity pathways, almost no proinflammatory ontologies were upregulated by LPS in HMGECs. CONCLUSIONS: Our results support our hypothesis that LPS stimulates proinflammatory gene expression in HCECs and HConjECs. However, our findings also show that LPS does not elicit such proinflammatory responses in HMGECs

A Review of Practices and Technologies for Odor Control in Swine Production Facilities

The objective of this article is to provide a systematic review on practices and technologies for odor control in swine production facilities and to summarize available data on odor reduction effectiveness of promising technologies, as well as provide information on key parameters and associated costs. Odors from swine facilities comprise hundreds of chemicals, including volatile organic compounds (VOC), ammonia (NH₃), and hydrogen sulfide (H₂S). The medians of emission rates from swine houses in literature are 5 OU/s/pig for odor, and 0.4, 2.8, and 0.1 kg/yr/pig for VOC, NH₃, and H₂S respectively. The medians of emission rates from swine manure storage facilities in literature are 5 OU/s/m2 for odor, and 1.4, 2.1, and 0.2 kg/yr/pig for VOC, NH₃, and H₂S, respectively. Facility maintenance and management practices to reduce impact of odor are reviewed in regard to regular cleaning of facilities, ventilation, floor design, drainage and manure removal systems, frequent manure removal, manure storage, and odor separation distances. Approaches to control odor and air pollution can be classified into three categories: ration/diet modification, manure treatment, capture/treatment of emitted gases and enhanced dispersion. Each of these mitigation approaches includes several specific technologies, which are summarized in tables with an evaluation of overall cost and brief comments on advantages or limitations of each technology. Diet modification strategies have been shown to reduce NH₃ emissions effectively with low cost and should be considered as a best management practices, although their effectiveness in reducing odor is still uncertain. Permeable covers and biofilters seem to have great potential to be the most promising and cost effective technologies for manure storage facilities and swine houses respectively. However, both of the technologies need careful maintenance to perform effectively. Care must be taken to select technologies that are compatible with the management capabilities of the operation to prevent potential failure due to mismanagement

Clinical Applications of PD-L1 Bioassays for Cancer Immunotherapy

Programmed death ligand 1 (PD-L1) has emerged as a biomarker that can help to predict responses to immunotherapies targeted against PD-L1 and its receptor (PD-1). Companion tests for evaluating PD-L1 expression as a biomarker of response have been developed for many cancer immunotherapy agents. These assays use a variety of detection platforms at different levels (protein, mRNA), employ diverse biopsy and surgical samples, and have disparate positivity cutoff points and scoring systems, all of which complicate the standardization of clinical decision-making. This review summarizes the current understanding and ongoing investigations regarding PD-L1 expression as a potential biomarker for clinical outcomes of anti-PD-1/PD-L1 immunotherapy

Rigor, Relevance and Impact:The Tensions and Trade-Offs Between Research in the Lab and in the Wild

As an interdisciplinary field, CHI embraces multiple research methods, ranging from controlled lab experiments to field studies in homes and communities. While quantitative research in the lab emphasizes the scientific rigor of hypothesis testing; qualitative research in the wild focuses on the understanding of the context of technologies in use, and each type of research has a correspondingly different kind of impact. This panel invites researchers with varied backgrounds to talk about the tensions and trade-offs between research in the lab and in the wild, with respect to scientific rigor, real-world relevance and impact. The goal is to enhance mutual understanding among researchers with diverse goals, values and practices within the CHI community