606 research outputs found

    Innovation in project management education - let’s get serious!

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    More educators use serious games (e.g., games where the primary objective is learning rather than enjoyment) to enhance learning due to benefits such as improved understanding and engagement. However, using serious games within project management education is not well understood. The aim of this research is to investigate project management serious games in higher education: i) determine the extent of gamification in PMI-accredited project management programs, and ii) survey university students about their experiences playing project management serious games. Two separate mixed-method studies reveal insights about serious games in higher education and where innovations may be leveraged. Traditional statistics were used to analyze quantitative data, and coding was used to analyze the qualitative data. The results from a global survey of ten PMI-accredited university programs suggest that serious games are embryonic but promising. A case study at one university reveals that students enjoy learning through games but caution against using games to formally assess students’ learning. The paper concludes with recommendations for further research and development

    Parameter estimation for strong phase transitions in supranuclear matter using gravitational-wave astronomy

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    At supranuclear densities, explored in the core of neutron stars, a strong phase transition from hadronic matter to more exotic forms of matter might be present. To test this hypothesis, binary neutron-star mergers offer a unique possibility to probe matter at densities that we can not create in any existing terrestrial experiment. In this work, we show that, if present, strong phase transitions can have a measurable imprint on the binary neutron-star coalescence and the emitted gravitational-wave signal. We construct a new parameterization of the supranuclear equation of state that allows us to test for the existence of a strong phase transition and extract its characteristic properties purely from the gravitational-wave signal of the inspiraling neutron stars. We test our approach using a Bayesian inference study simulating 600 signals with three different equations of state and find that for current gravitational-wave detector networks already twelve events might be sufficient to verify the presence of a strong phase transition. Finally, we use our methodology to analyze GW170817 and GW190425, but do not find any indication that a strong phase transition is present at densities probed during the inspiral.Comment: 17 pages, 11 figure

    Multimessenger constraints on the neutron-star equation of state and the Hubble constant

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    Observations of neutron-star mergers with distinct messengers, including gravitational waves and electromagnetic signals, can be used to study the behavior of matter denser than an atomic nucleus and to measure the expansion rate of the Universe as quantified by the Hubble constant. We performed a joint analysis of the gravitational-wave event GW170817 with its electromagnetic counterparts AT2017gfo and GRB170817A, and the gravitational-wave event GW190425, both originating from neutron-star mergers. We combined these with previous measurements of pulsars using X-ray and radio observations, and nuclear-theory computations using chiral effective field theory, to constrain the neutron-star equation of state. We found that the radius of a 1:4-solar mass neutron star is 11:75ĂŸ0:86_0:81 km at 90% confidence and the Hubble constant is 66:2ĂŸ4:4_4:2 at 1s uncertainty

    On the Nature of GW190814 and Its Impact on the Understanding of Supranuclear Matter

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    The observation of a compact object with a mass of 2.50-2.67Me on 2019 August 14, by the LIGO Scientific and Virgo collaborations (LVC) has the potential to improve our understanding of the supranuclear equation of state. While the gravitational-wave analysis of the LVC suggests that GW190814 likely was a binary black hole system, the secondary component could also have been the heaviest neutron star observed to date. We use our previously derived nuclear-physics-multimessenger astrophysics framework to address the nature of this object. Based on our findings, we determine GW190814 to be a binary black hole merger with a probability of >99.9%. Even if we weaken previously employed constraints on the maximum mass of neutron stars, the probability of a binary black hole origin is still ∌81%. Furthermore, we study the impact that this observation has on our understanding of the nuclear equation of state by analyzing the allowed region in the mass-radius diagram of neutron stars for both a binary black hole or neutron star-black hole scenario. We find that the unlikely scenario in which the secondary object was a neutron star requires rather stiff equations of state with a maximum speed of sound cs ≄0.6 times the speed of light, while the binary black hole scenario does not offer any new insight

    Probing Quarkyonic Matter in Neutron Stars with the Bayesian Nuclear-Physics Multi-Messenger Astrophysics Framework

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    The interior of neutron stars contains matter at the highest densities realized in our Universe. Interestingly, theoretical studies of dense matter, in combination with the existence of two solar mass neutron stars, indicate that the speed of sound csc_s has to increase to values well above the conformal limit (cs2∌1/3c_s^2\sim 1/3) before decreasing again at higher densities. The decrease could be explained by either a strong first-order phase transition or a cross-over transition from hadronic to quark matter. The latter scenario leads to a pronounced peak in the speed of sound reaching values above the conformal limit, naturally explaining the inferred behavior. In this work, we use the Nuclear-Physics Multi-Messenger Astrophysics framework \textsc{NMMA} to compare predictions of the quarkyonic matter model with astrophysical observations of neutron stars, with the goal of constraining model parameters. Assuming quarkyonic matter to be realized within neutron stars, we find that there can be a significant amount of quarks inside the core of neutron stars with masses in the two solar mass range, amounting to up to ∌0.13M⊙\sim 0.13M_\odot, contributing ∌5.9%\sim 5.9\% of the total mass. Furthermore, for the quarkyonic matter model investigated here, the radius of a 1.4M⊙1.4M_\odot neutron star would be 13.44−1.54+1.69(13.54−1.04+1.02)13.44^{+1.69}_{-1.54} (13.54^{+1.02}_{-1.04}) km, at 95%95\% credibility, without (with) the inclusion of AT2017gfo.Comment: 14 pages, 9 figure

    First crenarchaeal chitinase found in Sulfolobus tokodaii

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    This is the first description of a functional chitinase gene within the crenarchaeotes. Here we report of the heterologues expression of the ORF BAB65950 from Sulfolobus tokodaii in E. coli. The resulting protein degraded chitin and was hence classified as chitinase (EC 3.2.4.14). The protein characterization revealed a specific activity of 75 mU/mg using colloidal chitin as substrate. The optimal activity of the enzyme was measured at pH 2.5 and 70 °C, respectively. A dimeric enzyme configuration is proposed. According to amino acid sequence similarities chitinases are attributed to the two glycoside hydrolase families 18 and 19. The derived amino acid sequence of the S. tokodaii gene differed from sequences of these two glycoside hydrolase families. However, within a phylogenetic tree of protein sequences, the crenarchaeal sequence of S. tokodaii clustered in close proximity to members of the glycoside hydrolase family 18

    CD1b-restricted GEM T cell responses are modulated by Mycobacterium tuberculosis mycolic acid meromycolate chains

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    Tuberculosis, caused by Mycobacterium tuberculosis, remains a major human pandemic. Germline-encoded mycolyl lipid-reactive (GEM) T cells are donor-unrestricted and recognize CD1b-presented mycobacterial mycolates. However, the molecular requirements governing mycolate antigenicity for the GEM T cell receptor (TCR) remain poorly understood. Here, we demonstrate CD1b expression in tuberculosis granulomas and reveal a central role for meromycolate chains in influencing GEM-TCR activity. Meromycolate fine structure influences T cell responses in TB-exposed individuals, and meromycolate alterations modulate functional responses by GEM-TCRs. Computational simulations suggest that meromycolate chain dynamics regulate mycolate head group movement, thereby modulating GEM-TCR activity. Our findings have significant implications for the design of future vaccines that target GEM T cells

    Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial

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    Background: Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke. Methods: We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30–50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515. Findings: Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68–0·90), which indicated that albiglutide was superior to placebo (p<0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (<1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (<1%) deaths in the albiglutide group. Interpretation: In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes. Funding: GlaxoSmithKline

    The CMS Phase-1 pixel detector upgrade

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    The CMS detector at the CERN LHC features a silicon pixel detector as its innermost subdetector. The original CMS pixel detector has been replaced with an upgraded pixel system (CMS Phase-1 pixel detector) in the extended year-end technical stop of the LHC in 2016/2017. The upgraded CMS pixel detector is designed to cope with the higher instantaneous luminosities that have been achieved by the LHC after the upgrades to the accelerator during the first long shutdown in 2013–2014. Compared to the original pixel detector, the upgraded detector has a better tracking performance and lower mass with four barrel layers and three endcap disks on each side to provide hit coverage up to an absolute value of pseudorapidity of 2.5. This paper describes the design and construction of the CMS Phase-1 pixel detector as well as its performance from commissioning to early operation in collision data-taking.Peer reviewe
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