1,186 research outputs found

    Multispace and Multilevel BDDC

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    BDDC method is the most advanced method from the Balancing family of iterative substructuring methods for the solution of large systems of linear algebraic equations arising from discretization of elliptic boundary value problems. In the case of many substructures, solving the coarse problem exactly becomes a bottleneck. Since the coarse problem in BDDC has the same structure as the original problem, it is straightforward to apply the BDDC method recursively to solve the coarse problem only approximately. In this paper, we formulate a new family of abstract Multispace BDDC methods and give condition number bounds from the abstract additive Schwarz preconditioning theory. The Multilevel BDDC is then treated as a special case of the Multispace BDDC and abstract multilevel condition number bounds are given. The abstract bounds yield polylogarithmic condition number bounds for an arbitrary fixed number of levels and scalar elliptic problems discretized by finite elements in two and three spatial dimensions. Numerical experiments confirm the theory.Comment: 26 pages, 3 figures, 2 tables, 20 references. Formal changes onl

    Behavioral Inhibition and Attentional Control in Adolescents: Robust Relationships with Anxiety and Depression

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    Behavioral inhibition (BI) has been associated with the development of internalizing disorders in children and adolescents. It has further been shown that attentional control (AC) is negatively associated with internalizing problems. The combination of high BI and low AC may particularly lead to elevated symptomatology of internalizing behavior. This study broadens existing knowledge by investigating the additive and interacting effects of BI and AC on the various DSM-IV based internalizing dimensions. A sample of non-clinical adolescents (N = 1806, age M = 13.6 years), completed the Behavioral Inhibition System/Behavioral Activation System Scales (BIS/BAS), the attentional control subscale of the Adult Temperament Questionnaire (ATQ) and the Revised Child Anxiety and Depression Scale (RCADS). As expected, BI was positively, and AC was negatively related to internalizing dimensions, with stronger associations of BI than of AC with anxiety symptoms, and a stronger association of AC than of BI with depressive symptoms. AC moderated the association between BI and all measured internalizing dimensions (i.e., symptoms of generalized anxiety disorder, social phobia, separation anxiety disorder, panic disorder, obsessive–compulsive disorder, and major depressive disorder). Since high AC may reduce the impact of high BI on the generation of internalizing symptoms, an intervention focused on changing AC may have potential for prevention and treatment of internalizing disorders

    Exploiting inflammation for therapeutic gain in pancreatic cancer

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    Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy associated with <5% 5-year survival, in which standard chemotherapeutics have limited benefit. The disease is associated with significant intra- and peritumoral inflammation and failure of protective immunosurveillance. Indeed, inflammatory signals are implicated in both tumour initiation and tumour progression. The major pathways regulating PDAC-associated inflammation are now being explored. Activation of leukocytes, and upregulation of cytokine and chemokine signalling pathways, both have been shown to modulate PDAC progression. Therefore, targeting inflammatory pathways may be of benefit as part of a multi-target approach to PDAC therapy. This review explores the pathways known to modulate inflammation at different stages of tumour development, drawing conclusions on their potential as therapeutic targets in PDAC

    Inverse relationship between oligoclonal expanded CD69- TTE and CD69+ TTE cells in bone marrow of multiple myeloma patients.

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    CD8+CD57+ terminal effector T (TTE) cells are a component of marrow-infiltrating lymphocytes and may contribute to the altered immune responses in multiple myeloma (MM) patients. We analyzed TTE cells in the bone marrow (BM) and peripheral blood (PB) of age-matched controls and patients with monoclonal gammopathy of undetermined significance (MGUS), smoldering MM (SMM), and newly diagnosed (ND) MM using flow cytometry, mass cytometry, and FlowSOM clustering. TTE cells are heterogeneous in all subjects, with BM containing both CD69- and CD69+ subsets, while only CD69- cells are found in PB. Within the BM-TTE compartment, CD69- and CD69+ cells are found in comparable proportions in controls, while CD69- cells are dominant in MGUS and SMM and predominantly either CD69- or CD69+ cells in NDMM. A positive relationship between CD69+TTE and CD69-TTE cells is observed in the BM of controls, lost in MGUS, and converted to an inverse relationship in NDMM. CD69-TTE cells include multiple oligoclonal expansions of T-cell receptor/Vβ families shared between BM and PB of NDMM. Oligoclonal expanded CD69-TTE cells from the PB include myeloma-reactive cells capable of killing autologous CD38hi plasma cells in vitro, involving degranulation and high expression of perforin and granzyme. In contrast to CD69-TTE cells, oligoclonal expansions are not evident within CD69+TTE cells, which possess low perforin and granzyme expression and high inhibitory checkpoint expression and resemble T resident memory cells. Both CD69-TTE and CD69+TTE cells from the BM of NDMM produce large amounts of the inflammatory cytokines interferon-γ and tumor necrosis factor α. The balance between CD69- and CD69+ cells within the BM-TTE compartment may regulate immune responses in NDMM and contribute to the clinical heterogeneity of the disease

    Using metrics and sustainability considerations to evaluate the use of bio-based and non-renewable Brønsted acidic ionic liquids to catalyse Fischer esterification reactions

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    Background Ionic liquids have found uses in many applications, one of which is the joint solvation and catalysis of chemical transformations. Suitable Brønsted acidic ionic liquids can be formed by combining lactams with sulphonic acids. This work weighs up the relative benefits and disadvantages of applying these Brønsted acidic ionic liquid catalysts in esterifications through a series of comparisons using green chemistry metrics. Results A new bio-based ionic liquid was synthesised from N-methyl pyrrolidinone and p-cymenesulphonic acid, and tested as a catalyst in three Fischer esterifications under different conditions. An evaluation of the performance of this Brønsted acidic ionic liquid was made through the comparison to other ionic liquid catalysts as well as conventional homogeneous Brønsted acids. Conclusion Extending the argument to feedstock security as well as mass utilisation, ultimately in most instances traditional mineral acids appear to be the most sensible option for Brønsted acid esterification catalysts. Ester yields obtained from Brønsted acidic ionic liquid catalysed procedures were modest. This calls into question the diversity of research exploring esterification catalysis and the role of ionic liquids in esterifications

    Admission to acute care hospitals for adolescent substance abuse: a national descriptive analysis

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    BACKGROUND: Use of alcohol and illicit drugs by adolescents remains a problem in the U.S. Case identification and early treatment can occur within a broad variety of healthcare and non-healthcare settings, including acute care hospitals. The objective of this study is to describe the extent and nature of adolescent admissions to the acute inpatient setting for substance abuse (SA). We use the Agency for Healthcare Research and Quality (AHRQ) 2000 Healthcare Cost and Utilization Project Kids Inpatient Database (HCUP-KID) which includes over 2.5 million admissions for youth age 20 and under to 2,784 hospitals in 27 states in the year 2000. Specifically, this analysis estimates national number of admissions, mean total charges, and mean lengths of stay for adolescents between the ages of 12 and 17 admitted to an acute care hospital for the following diagnostic categories from the AHRQ's Clinical Classifications Software categories: "alcohol-related mental disorders" and "substance-related mental disorders". Frequency and percentage of total admissions were calculated for demographic variables of age, gender and income and for hospital characteristic variables of urban/rural designation and children's hospital designation. RESULTS: SA admissions represented 1.25 percent of adolescent admissions to acute care hospitals. Nearly 90 percent of the admission occurred in non-Children's hospitals. Most were for drug dependence (38%) or non-dependent use of alcohol or drugs (35%). Costs were highest for drug dependence admissions. Nearly half of admissions had comorbid mental health diagnoses. Higher rates of admission were seen in boys, in older adolescents, and in "self-pay" patients. Alcohol and drug rehabilitation/detoxification, alone or in combination with psychological and psychiatric evaluation and therapy, was documented for 38 percent of admissions. Over 50 percent of cases had no documentation of treatment specific to substance use behavior. CONCLUSION: General acute care hospitals have a significant and important opportunity to recognize, treat, and refer adolescents with substance abuse problems. These results suggest that inpatient facilities should develop and implement policies and processes to ensure that adolescent substance abusers admitted to their institutions receive appropriate care during the admission and appropriate referral to community care resources

    Galactic and Extragalactic Samples of Supernova Remnants: How They Are Identified and What They Tell Us

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    Supernova remnants (SNRs) arise from the interaction between the ejecta of a supernova (SN) explosion and the surrounding circumstellar and interstellar medium. Some SNRs, mostly nearby SNRs, can be studied in great detail. However, to understand SNRs as a whole, large samples of SNRs must be assembled and studied. Here, we describe the radio, optical, and X-ray techniques which have been used to identify and characterize almost 300 Galactic SNRs and more than 1200 extragalactic SNRs. We then discuss which types of SNRs are being found and which are not. We examine the degree to which the luminosity functions, surface-brightness distributions and multi-wavelength comparisons of the samples can be interpreted to determine the class properties of SNRs and describe efforts to establish the type of SN explosion associated with a SNR. We conclude that in order to better understand the class properties of SNRs, it is more important to study (and obtain additional data on) the SNRs in galaxies with extant samples at multiple wavelength bands than it is to obtain samples of SNRs in other galaxiesComment: Final 2016 draft of a chapter in "Handbook of Supernovae" edited by Athem W. Alsabti and Paul Murdin. Final version available at https://doi.org/10.1007/978-3-319-20794-0_90-

    TRPA1 Contributes to the Acute Inflammatory Response and Mediates Carrageenan-Induced Paw Edema in the Mouse

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    Transient receptor potential ankyrin 1 (TRPA1) is an ion channel involved in thermosensation and nociception. TRPA1 is activated by exogenous irritants and also by oxidants formed in inflammatory reactions. However, our understanding of its role in inflammation is limited. Here, we tested the hypothesis that TRPA1 is involved in acute inflammatory edema. The TRPA1 agonist allyl isothiocyanate (AITC) induced inflammatory edema when injected intraplantarly to mice, mimicking the classical response to carrageenan. Interestingly, the TRPA1 antagonist HC-030031 and the cyclo-oxygenase (COX) inhibitor ibuprofen inhibited not only AITC but also carrageenan-induced edema. TRPA1-deficient mice displayed attenuated responses to carrageenan and AITC. Furthermore, AITC enhanced COX-2 expression in HEK293 cells transfected with human TRPA1, a response that was reversed by HC-030031. This study demonstrates a hitherto unknown role of TRPA1 in carrageenan-induced inflammatory edema. The results also strongly suggest that TRPA1 contributes, in a COX-dependent manner, to the development of acute inflammation

    Common Variants at 10 Genomic Loci Influence Hemoglobin A(1C) Levels via Glycemic and Nonglycemic Pathways

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    OBJECTIVE Glycated hemoglobin (HbA1c), used to monitor and diagnose diabetes, is influenced by average glycemia over a 2- to 3-month period. Genetic factors affecting expression, turnover, and abnormal glycation of hemoglobin could also be associated with increased levels of HbA1c. We aimed to identify such genetic factors and investigate the extent to which they influence diabetes classification based on HbA1c levels. RESEARCH DESIGN AND METHODS We studied associations with HbA1c in up to 46,368 nondiabetic adults of European descent from 23 genome-wide association studies (GWAS) and 8 cohorts with de novo genotyped single nucleotide polymorphisms (SNPs). We combined studies using inverse-variance meta-analysis and tested mediation by glycemia using conditional analyses. We estimated the global effect of HbA1c loci using a multilocus risk score, and used net reclassification to estimate genetic effects on diabetes screening. RESULTS Ten loci reached genome-wide significant association with HbA1c, including six new loci near FN3K (lead SNP/P value, rs1046896/P = 1.6 × 10−26), HFE (rs1800562/P = 2.6 × 10−20), TMPRSS6 (rs855791/P = 2.7 × 10−14), ANK1 (rs4737009/P = 6.1 × 10−12), SPTA1 (rs2779116/P = 2.8 × 10−9) and ATP11A/TUBGCP3 (rs7998202/P = 5.2 × 10−9), and four known HbA1c loci: HK1 (rs16926246/P = 3.1 × 10−54), MTNR1B (rs1387153/P = 4.0 × 10−11), GCK (rs1799884/P = 1.5 × 10−20) and G6PC2/ABCB11 (rs552976/P = 8.2 × 10−18). We show that associations with HbA1c are partly a function of hyperglycemia associated with 3 of the 10 loci (GCK, G6PC2 and MTNR1B). The seven nonglycemic loci accounted for a 0.19 (% HbA1c) difference between the extreme 10% tails of the risk score, and would reclassify ∼2% of a general white population screened for diabetes with HbA1c. CONCLUSIONS GWAS identified 10 genetic loci reproducibly associated with HbA1c. Six are novel and seven map to loci where rarer variants cause hereditary anemias and iron storage disorders. Common variants at these loci likely influence HbA1c levels via erythrocyte biology, and confer a small but detectable reclassification of diabetes diagnosis by HbA1c
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