16 research outputs found

    Rigidity and exotic models for the K-local stable homotopy category

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    Can the model structure of a stable model category be recovered from the triangulated structure of its homotopy category? This paper introduces a new positive example for this, namely the K-local stable homotopy at the prime 2. For odd primes, however, this is not true: we discuss a counterexample given by Jens Franke and show how such exotic models for the K-local stable homotopy category at odd primes can be detected

    Uniqueness of AA_\infty-structures and Hochschild cohomology

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    This paper investigates if a differential graded algebra can have more than one AA_\infty-structure extending the given differential graded algebra structure. We give a sufficient condition for uniqueness of such an AA_\infty-structure up to quasi-isomorphism using Hochschild cohomology. We then extend this condition to Sagave's notion of derived AA_\infty-algebras after introducing a notion of Hochschild cohomology that applies to this.Comment: The paper has been rearranged and the results are now formulated in terms of a filtration of the Hochschild cohomology groups. To appear in Algebraic and Geometric Topolog

    An extended set of PRDM1/BLIMP1 target genes links binding motif type to dynamic repression

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    The transcriptional repressor B lymphocyte-induced maturation protein-1 (BLIMP1) regulates gene expression and cell fate. The DNA motif bound by BLIMP1 in vitro overlaps with that of interferon regulatory factors (IRFs), which respond to inflammatory/immune signals. At such sites, BLIMP1 and IRFs can antagonistically regulate promoter activity. In vitro motif selection predicts that only a subset of BLIMP1 or IRF sites is subject to antagonistic regulation, but the extent to which antagonism occurs is unknown, since an unbiased assessment of BLIMP1 occupancy in vivo is lacking. To address this, we identified an extended set of promoters occupied by BLIMP1. Motif discovery and enrichment analysis demonstrate that multiple motif variants are required to capture BLIMP1 binding specificity. These are differentially associated with CpG content, leading to the observation that BLIMP1 DNA-binding is methylation sensitive. In occupied promoters, only a subset of BLIMP1 motifs overlap with IRF motifs. Conversely, a distinct subset of IRF motifs is not enriched amongst occupied promoters. Genes linked to occupied promoters containing overlapping BLIMP1/IRF motifs (e.g. AIM2, SP110, BTN3A3) are shown to constitute a dynamic target set which is preferentially activated by BLIMP1 knock-down. These data confirm and extend the competitive model of BLIMP1 and IRF interaction

    Shared attention for action selection and action monitoring in goal-directed reaching

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    Dual-task studies have shown higher sensitivity for stimuli presented at the targets of upcoming actions. We examined whether attention is directed to action targets for the purpose of action selection, or if attention is directed to these locations because they are expected to provide feedback about movement outcomes. In our experiment, endpoint accuracy feedback was spatially separated from the action targets to determine whether attention would be allocated to (a) the action targets, (b) the expected source of feedback, or (c) to both locations. Participants reached towards a location indicated by an arrow while identifying a discrimination target that could appear in any one of eight possible locations. Discrimination target accuracy was used as a measure of attention allocation. Participants were unable to see their hand during reaching and were provided with a small monetary reward for each accurate movement. Discrimination target accuracy was best at action targets but was also enhanced at the spatially separated feedback locations. Separating feedback from the reaching targets did not diminish discrimination accuracy at the movement targets but did result in delayed movement initiation and reduced reaching accuracy, relative to when feedback was presented at the reaching target. The results suggest attention is required for both action planning and monitoring movement outcomes. Dividing attention between these functions negatively impacts action performance

    Mycobacterium helveticum sp. nov., a novel slowly growing mycobacterial species associated with granulomatous lesions in adult swine

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    The occurrence of nontuberculous mycobacteria in different hosts and their implication as obligate or opportunistic pathogens remain mainly unclear. Mycobacteriosis in pigs is usually associated with members of the Mycobacterium avium complex and, in particular, infections with “Mycobacterium avium subsp. hominissuis”. Here we describe a novel slow growing mycobacterial species isolated from lymph nodes obtained from two sows housed in different Swiss farms. The animals presented chronic inappetence and/or mild diarrhea. Gross pathology revealed focal granulomatous caseous lymphadenopathy of the mesenteric lymph nodes. Complete genome sequencing of two isolates from the two sows was performed. The genomes comprised 5,76 Mb and an average nucleotide identity score of 99.97%. Phylogenetic, mycolic acid and matrix-assisted laser desorption ionization-time of flight mass spectrometry analyses revealed that the two isolates were not related to any previously described Mycobacterium species. Based on complete genome investigations, the closest related species is M. parmense, a slow growing scotochromogenic Mycobacterium first isolated from a cervical lymph node of a 3-year-old child. The name proposed for the new species is Mycobacterium helveticum sp. nov. and 16-83T (=DSM 109965T= BCCM/LMG 2457T) is the type strain

    Clinically inapparent right heart dysfunction is associated with reduced myofilament force development in coronary artery disease

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    Background Right ventricular dysfunction after CABG is associated with poor peri- and postoperative outcomes. We aimed to identify clinical and experimental predictors for preoperative inapparent right ventricular dysfunction and therefore hypothesized that reduced myofilament force development as well as altered levels of biomarkers might predict inapparent right ventricular dysfunction. Methods From 08/2016 to 02/2018, 218 patients scheduled for CABG were divided into two groups (TAPSE ≥ 20 mm, n = 178; TAPSE < 20 mm, n = 40). Baseline serum samples for biomarkers (Galectin, TGFß1, N Acyl-SDMA, Arginine, ADMA and Pentraxin-3), clinical laboratory and transthoracic echocardiographic parameters were evaluated. To examine the myocardial apparatus of the right ventricle intraoperative right auricular tissue was harvested for stepwise skinned fiber force measurements. Results Patients with TAPSE < 20 mm had a higher incidence of DM (55 vs. 34%, p = 0.018), preoperative AFib (43 vs. 16%, p < 0.001), reduced GFR (67 ± 18 vs. 77 ± 24 ml/min/1.73 m2^2, p = 0.013), larger LA area (22 ± 6 vs. 20 ± 5 cm2^2, p = 0.005) and reduced LVEF (50 vs. 55%, p = 0.008). Furthermore, higher serum ADMA (0.70 ± 0.13 vs. 0.65 ± 0.15 µmol/l, p = 0.046) and higher serum Pentraxin-3 levels (3371 ± 1068 vs. 2681 ± 1353 pg/dl, p = 0.004) were observed in these patients. Skinned fiber force measurements showed significant lower values at almost every step of calcium concentration (pCa 4.52 to pCa 5.5, p < 0.01 and pCa 5.75–6.0, p < 0.05). Multivariable analysis revealed DM (OR 2.53, CI 1.12–5.73, Euro Score II (OR 1.34, CI 1.02–1.78), preoperative AF (OR 4.86, CI 2.06–11.47), GFR (OR 7.72, CI 1.87–31.96), albumin (OR 1.56, CI 0.52–2.60), Pentraxin-3 (OR 19.68, CI 14.13–25.24), depressed LVEF (OR 8.61, CI 6.37–10.86), lower force values: (pCa 5.4; OR 2.34, CI 0.40–4.29 and pCa 5.2; OR 2.00, CI 0.39–3.60) as predictors for clinical inapparent right heart dysfunction. Conclusions These preliminary data showed that inapparent right heart dysfunction in CAD is already associated with reduced force development of the contractile apparatus

    Absence of Association between Cyclin D1 (CCND1) G870A Polymorphism and Age of Onset in Hereditary Nonpolyposis Colorectal Cancer

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    Abstract CCND1 encodes cyclin D1, which plays an important role in the G 1 to S phase transition of the cell cycle. A common polymorphism (c.G870A) increases alternate splicing. Hereditary nonpolyposis colorectal cancer (HNPCC) is caused by mutations in mismatch repair (MMR) genes, mainly MSH2 and MLH1, and shows a wide range in the age of its onset (AO), suggesting the existence of other modifying genetic factors. To date, two studies have investigated the association between CCND1 G/A variation and AO in HNPCC with contradictory results in 86 and 146 MMR mutation carriers, respectively. To clarify the role of the CCND1 G/A variation in HNPCC, we performed a study in 406 individuals carrying exclusively clear cut pathogenic mutations in MSH2 or MLH1. We did not observe a significant difference in genotype frequencies of affected and unaffected mutation carriers and healthy controls. A significant association between CCND1 genotypes and AO was found neither in the global comparison (log-rank, P = 0.2981; Wilcoxon, P = 0.2567) nor in a multivariate Cox regression analysis (hazard ratios 1.111, 95%CI 0.950 -1.299, P = 0.188 and 1.090, 95%CI 0.868 -1.369, P = 0.459 for the additive and dominant effect, respectively). We conclude, that the CCND1 G870A sequence variation is not a genetic modifier of the phenotype of HNPCC
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