61 research outputs found

    Implementing the weakest failure detector for solving consensus

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    The concept of unreliable failure detector was introduced by Chandra and Toueg as a mechanism that provides information about process failures. This mechanism has been used to solve several agreement problems, such as the consensus problem. In this paper, algorithms that implement failure detectors in partially synchronous systems are presented. First two simple algorithms of the weakest class to solve the consensus problem, namely the Eventually Strong class (⋄S), are presented. While the first algorithm is wait-free, the second algorithm is f-resilient, where f is a known upper bound on the number of faulty processes. Both algorithms guarantee that, eventually, all the correct processes agree permanently on a common correct process, i.e. they also implement a failure detector of the class Omega (Ω). They are also shown to be optimal in terms of the number of communication links used forever. Additionally, a wait-free algorithm that implements a failure detector of the Eventually Perfect class (⋄P) is presented. This algorithm is shown to be optimal in terms of the number of bidirectional links used forever

    Trajectories of alcohol consumption during life and the risk of developing breast cancer

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    Background: Whether there are lifetime points of greater sensitivity to the deleterious effects of alcohol intake on the breasts remains inconclusive. Objective: To compare the influence of distinctive trajectories of alcohol consumption throughout a woman’s life on development of breast cancer (BC). Methods: 1278 confirmed invasive BC cases and matched (by age and residence) controls from the Epi-GEICAM study (Spain) were used. The novel group-based trajectory modelling was used to identify different alcohol consumption trajectories throughout women’s lifetime. Results: Four alcohol trajectories were identified. The first comprised women (45%) with low alcohol consumption (<5 g/day) throughout their life. The second included those (33%) who gradually moved from a low alcohol consumption in adolescence to a moderate in adulthood (5 to <15 g/day), never having a high consumption; and oppositely, women in the third trajectory (16%) moved from moderate consumption in adolescence, to a lower consumption in adulthood. Women in the fourth (6%) moved from a moderate alcohol consumption in adolescence to the highest consumption in adulthood (=15 g/day), never having a low alcohol consumption. Comparing with the first trajectory, the fourth doubled BC risk (OR 2.19; 95% CI 1.27, 3.77), followed by the third (OR 1.44; 0.96, 2.16) and ultimately by the second trajectory (OR 1.17; 0.86, 1.58). The magnitude of BC risk was greater in postmenopausal women, especially in those with underweight or normal weight. When alcohol consumption was independently examined at each life stage, =15 g/day of alcohol consumption in adolescence was strongly associated with BC risk followed by consumption in adulthood. Conclusions: The greater the alcohol consumption accumulated throughout life, the greater the risk of BC, especially in postmenopausal women. Alcohol consumption during adolescence may particularly influence BC risk. © 2021, The Author(s)

    Multiple myeloma and SARS-CoV-2 infection : clinical characteristics and prognostic factors of inpatient mortality

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    There is limited information on the characteristics, prognostic factors, and outcomes of patients with multiple myeloma (MM) hospitalized with COVID-19. This retrospective case series investigated 167 patients reported from 73 hospitals within the Spanish Myeloma Collaborative Group network in March and April, 2020. Outcomes were compared with 167 randomly selected, contemporary, age-/sex-matched noncancer patients with COVID-19 admitted at six participating hospitals. Among MM and noncancer patients, median age was 71 years, and 57% of patients were male; 75 and 77% of patients, respectively, had at least one comorbidity. COVID-19 clinical severity was moderate-severe in 77 and 89% of patients and critical in 8 and 4%, respectively. Supplemental oxygen was required by 47 and 55% of MM and noncancer patients, respectively, and 21%/9% vs 8%/6% required noninvasive/invasive ventilation. Inpatient mortality was 34 and 23% in MM and noncancer patients, respectively. Among MM patients, inpatient mortality was 41% in males, 42% in patients aged >65 years, 49% in patients with active/progressive MM at hospitalization, and 59% in patients with comorbid renal disease at hospitalization, which were independent prognostic factors on adjusted multivariate analysis. This case series demonstrates the increased risk and identifies predictors of inpatient mortality among MM patients hospitalized with COVID-19

    Domain Organization, Catalysis and Regulation of Eukaryotic Cystathionine Beta-Synthases

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    Cystathionine beta-synthase (CBS) is a key regulator of sulfur amino acid metabolism diverting homocysteine, a toxic intermediate of the methionine cycle, via the transsulfuration pathway to the biosynthesis of cysteine. Although the pathway itself is well conserved among eukaryotes, properties of eukaryotic CBS enzymes vary greatly. Here we present a side-by-side biochemical and biophysical comparison of human (hCBS), fruit fly (dCBS) and yeast (yCBS) enzymes. Preparation and characterization of the full-length and truncated enzymes, lacking the regulatory domains, suggested that eukaryotic CBS exists in one of at least two significantly different conformations impacting the enzyme’s catalytic activity, oligomeric status and regulation. Truncation of hCBS and yCBS, but not dCBS, resulted in enzyme activation and formation of dimers compared to native tetramers. The dCBS and yCBS are not regulated by the allosteric activator of hCBS, S-adenosylmethionine (AdoMet); however, they have significantly higher specific activities in the canonical as well as alternative reactions compared to hCBS. Unlike yCBS, the heme-containing dCBS and hCBS showed increased thermal stability and retention of the enzyme’s catalytic activity. The mass-spectrometry analysis and isothermal titration calorimetry showed clear presence and binding of AdoMet to yCBS and hCBS, but not dCBS. However, the role of AdoMet binding to yCBS remains unclear, unlike its role in hCBS. This study provides valuable information for understanding the complexity of the domain organization, catalytic specificity and regulation among eukaryotic CBS enzymes.This work was supported by Postdoctoral Fellowship 0920079G from the American Heart Association (to TM), by National Institutes of Health Grant HL065217, by American Heart Association Grant In-Aid 09GRNT2110159, by a grant from the Jerome Lejeune Foundation (all to JPK) and by a research contract RYC2009-04147 (to ALP). In addition, grant support (P11-CTS-07187, CSD2009-00088 and BIO2012-34937) to Dr. Jose M. Sanchez-Ruiz (University of Granada) and SGIker technical and human support (UPV/EHU, MICINN, GV/EJ, ESF) are gratefully acknowledged

    Substrate translocation involves specific lysine residues of the central channel of the conjugative coupling protein TrwB

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    Conjugative transfer of plasmid R388 requires the coupling protein TrwB for protein and DNA transport, but their molecular role in transport has not been deciphered. We investigated the role of residues protruding into the central channel of the TrwB hexamer by a mutational analysis. Mutations affecting lysine residues K275, K398, and K421, and residue S441, all facing the internal channel, affected transport of both DNA and the relaxase protein in vivo. The ATPase activity of the purified soluble variants was affected significantly in the presence of accessory protein TrwA or DNA, correlating with their behaviour in vivo. Alteration of residues located at the cytoplasmic or the inner membrane interface resulted in lower activity in vivo and in vitro, while variants affecting residues in the central region of the channel showed increased DNA and protein transfer efficiency and higher ATPase activity, especially in the absence of TrwA. In fact, these variants could catalyze DNA transfer in the absence of TrwA under conditions in which the wild-type system was transfer deficient. Our results suggest that protein and DNA molecules have the same molecular requirements for translocation by Type IV secretion systems, with residues at both ends of the TrwB channel controlling the opening?closing mechanism, while residues embedded in the channel would set the pace for substrate translocation (both protein and DNA) in concert with TrwA

    Menstrual and Reproductive Factors and Risk of Gastric and Colorectal Cancer in Spain

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    BACKGROUND: Sex hormones play a role in gastric cancer and colorectal cancer etiology, however, epidemiological evidence is inconsistent. This study examines the influence of menstrual and reproductive factors over the risk of both tumors. METHODS: In this case-control study 128 women with gastric cancer and 1293 controls, as well as 562 female and colorectal cancer cases and 1605 controls were recruited in 9 and 11 Spanish provinces, respectively. Population controls were frequency matched to cases by age and province. Demographic and reproductive data were directly surveyed by trained staff. The association with gastric, colon and rectal cancer was assessed using logistic and multinomial mixed regression models. RESULTS: Our results show an inverse association of age at first birth with gastric cancer risk (five-year trend: OR = 0.69; p-value = 0.006). Ever users of hormonal contraception presented a decreased risk of gastric (OR = 0.42; 95%CI = 0.26-0.69), colon (OR = 0.64; 95%CI = 0.48-0.86) and rectal cancer (OR = 0.61; 95%CI = 0.43-0.88). Postmenopausal women who used hormone replacement therapy showed a decreased risk of colon and rectal tumors. A significant interaction of educational level with parity and months of first child lactation was also observed. CONCLUSION: These findings suggest a protective role of exogenous hormones in gastric and colorectal cancer risk. The role of endogenous hormones remains unclear

    Cómo poner puertas al campo : tres revisiones panorámicas sobre el uso de biomarcadores en prevención personalizada de enfermedades crónicas

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    Se incluye PDF de la presentación y vídeo del seminario.El seminario trata de dar respuesta a qué biomarcadores hay disponibles o en desarrollo para la prevención personalizada de enfermedades crónicas en la población general. Las revisiones realizadas resumen las principales características y conclusiones de la bibliografía sobre este tema. Abarca los tres principales grupos de enfermedades crónicas:11 tipos de cáncer, 9 enfermedades cardiovasculares y 7 enfermedades neurodegenerativas.N

    Memorias del Primer Congreso Ecuatoriano de Antropología. Volumen II

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    Este encuentro permitió visualizar los campos fundamentales en los que la antropología ecuatoriana ha incursionado y ha aportado como ciencia social. Se organizaron diez simposios que, de alguna manera, fueron un reflejo de las principales áreas de interés. Esa diversidad temática mostró que la antropología, a la vez que seguía preocupada por temáticas con larga trayectoria en el país como la arqueología, los estudios urbanos y rurales o la etnohistoria, también había incursionado en temáticas nuevas como son género, medio ambiente, identidad, entre otras

    Biomarker analysis of the ASPEN study comparing zanubrutinib with ibrutinib for patients with Waldenström macroglobulinemia

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    The phase 3 ASPEN trial (NCT03053440) compared Bruton tyrosine kinase inhibitors (BTKis), zanubrutinib and ibrutinib, in patients with Waldenström macroglobulinemia (WM). Post-hoc biomarker analysis was performed using next-generation sequencing on pretreatment bone marrow samples from 98 patients treated with zanubrutinib and 92 patients treated with ibrutinib with mutated (MUT) MYD88 and 20 patients with wild-type (WT) MYD88 treated with zanubrutinib. Of 329 mutations in 52 genes, mutations in CXCR4 (25.7%), TP53 (24.8%), ARID1A (15.7%), and TERT (9.0%) were most common. TP53MUT, ARID1AMUT, and TERTMUTwere associated with higher rates of CXCR4MUT(P < .05). Patients with CXCR4MUT(frameshift or nonsense [NS] mutations) had lower very good partial response (VGPR) and complete response rates (CR; 17.0% vs 37.2%, P = .020) and longer time to response (11.1 vs 8.4 months) than patients with CXCR4WTtreated with BTKis. CXCR4NSwas associated with inferior progression-free survival (PFS; hazard ratio [HR], 3.39; P = .017) in patients treated with ibrutinib but not in those treated with zanubrutinib (HR, 0.67; P = .598), but VGPR + CR rates were similar between treatment groups (14.3% vs 15.4%). Compared with ibrutinib, patients with CXCR4NStreated with zanubrutinib had a favorable major response rate (MRR; 85.7% vs 53.8%; P = .09) and PFS (HR, 0.30; P = .093). In patients with TP53MUT, significantly lower MRRs were observed for patients treated with ibrutinib (63.6% vs 85.7%; P = .04) but not for those treated with zanubrutinib (80.8% vs 81.9%; P = .978). In TP53MUT, compared with ibrutinib, patients treated with zanubrutinib had higher VGPR and CR (34.6% vs 13.6%; P < .05), numerically improved MRR (80.8% vs 63.6%; P = .11), and longer PFS (not reached vs 44.2 months; HR, 0.66; P = .37). Collectively, patients with WM with CXCR4MUTor TP53MUThad worse prognosis compared with patients with WT alleles, and zanubrutinib led to better clinical outcomes
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