49 research outputs found
Cyber War, Cybered Conflict, and the Maritime Domain
Those who dismiss cyber war as mere hype or as driven by potential profits dismiss much too quickly growing evidence of the importance of cyber operations—to which the Navy may be uniquely qualified to adapt
G6PD deficiency alleles in a malaria-endemic region in the Western Brazilian Amazon.
BACKGROUND: Plasmodium vivax parasites are the predominant cause of malaria infections in the Brazilian Amazon. Infected individuals are treated with primaquine, which can induce haemolytic anaemia in glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals and may lead to severe and fatal complications. This X-linked disorder is distributed globally and is caused by allelic variants with a geographical distribution that closely reflects populations exposed historically to endemic malaria. In Brazil, few studies have reported the frequency of G6PD deficiency (G6PDd) present in malaria-endemic areas. This is particularly important, as G6PDd screening is not currently performed before primaquine treatment. The aim of this study was to determine the prevalence of G6PDd in the region of Alto do Juruá, in the Western Brazilian Amazon, an area characterized by a high prevalence of P. vivax infection. METHODS: Five-hundred and sixteen male volunteers were screened for G6PDd using the fluorescence spot test (Beutler test) and CareStart™ G6PD Biosensor system. Demographic and clinical-epidemiological data were acquired through an individual interview. To assess the genetic basis of G6PDd, 24 SNPs were genotyped using the Kompetitive Allele Specific PCR assay. RESULTS: Twenty-three (4.5%) individuals were G6PDd. No association was found between G6PDd and the number of malaria cases. An increased risk of reported haemolysis symptoms and blood transfusions was evident among the G6PDd individuals. Twenty-two individuals had the G6PDd A(-) variant and one the G6PD A(+) variant. The Mediterranean variant was not present. Apart from one polymorphism, almost all SNPs were monomorphic or with low frequencies (0-0.04%). No differences were detected among ethnic groups. CONCLUSIONS: The data indicates that ~1/23 males from the Alto do Juruá could be G6PD deficient and at risk of haemolytic anaemia if treated with primaquine. G6PD A(-) is the most frequent deficiency allele in this population. These results concur with reported G6PDd in other regions in Brazil. Routine G6PDd screening to personalize primaquine administration should be considered, particularly as complete treatment of patients with vivax malaria using chloroquine and primaquine, is crucial for malaria elimination
Ten Years In: Implementing Strategic Approaches to Cyberspace
This book represents a look beyond theories and analogies to examine the challenges of strategy implementation. In the essays that follow, practitioners who are building cyberspace forces at-scale join scholars who study power and force in this new domain to collectively offer a unique perspective on the evolution and future of cyber strategy and operations.https://digital-commons.usnwc.edu/usnwc-newport-papers/1044/thumbnail.jp
The SPARC Toroidal Field Model Coil Program
The SPARC Toroidal Field Model Coil (TFMC) Program was a three-year effort
between 2018 and 2021 that developed novel Rare Earth Yttrium Barium Copper
Oxide (REBCO) superconductor technologies and then successfully utilized these
technologies to design, build, and test a first-in-class, high-field (~20 T),
representative-scale (~3 m) superconducting toroidal field coil. With the
principal objective of demonstrating mature, large-scale, REBCO magnets, the
project was executed jointly by the MIT Plasma Science and Fusion Center (PSFC)
and Commonwealth Fusion Systems (CFS). The TFMC achieved its programmatic goal
of experimentally demonstrating a large-scale high-field REBCO magnet,
achieving 20.1 T peak field-on-conductor with 40.5 kA of terminal current, 815
kN/m of Lorentz loading on the REBCO stacks, and almost 1 GPa of mechanical
stress accommodated by the structural case. Fifteen internal demountable
pancake-to-pancake joints operated in the 0.5 to 2.0 nOhm range at 20 K and in
magnetic fields up to 12 T. The DC and AC electromagnetic performance of the
magnet, predicted by new advances in high-fidelity computational models, was
confirmed in two test campaigns while the massively parallel, single-pass,
pressure-vessel style coolant scheme capable of large heat removal was
validated. The REBCO current lead and feeder system was experimentally
qualified up to 50 kA, and the crycooler based cryogenic system provided 600 W
of cooling power at 20 K with mass flow rates up to 70 g/s at a maximum design
pressure of 20 bar-a for the test campaigns. Finally, the feasibility of using
passive, self-protection against a quench in a fusion-scale NI TF coil was
experimentally assessed with an intentional open-circuit quench at 31.5 kA
terminal current.Comment: 17 pages 9 figures, overview paper and the first of a six-part series
of papers covering the TFMC Progra
Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial
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
Reciprocal swimming at intermediate Reynolds number
In Stokes flow, Purcell's scallop theorem forbids objects with
time-reversible (reciprocal) swimming strokes from moving. In the presence of
inertia, this restriction is eased and reciprocally deforming bodies can swim.
A number of recent works have investigated dimer models that swim reciprocally
at intermediate Reynolds numbers Re ~ 1-1000. These show interesting results
(e.g. switches of the swim direction as a function of inertia) but the results
vary and seem to be case-specific. Here, we introduce a general model and
investigate the behaviour of an asymmetric spherical dimer of oscillating
length for small-amplitude motion at intermediate Re. In our analysis we make
the important distinction between particle and fluid inertia, both of which
need to be considered separately. We asymptotically expand the Navier-Stokes
equations in the small amplitude limit to obtain a system of linear PDEs. Using
a combination of numerical (Finite Element) and analytical (reciprocal theorem,
method of reflections) methods we solve the system to obtain the dimer's swim
speed and show that there are two mechanisms that give rise to motion: boundary
conditions (an effective slip velocity) and Reynolds stresses. Each mechanism
is driven by two classes of sphere-sphere interactions, between one sphere's
motion and 1) the oscillating background flow induced by the other's motion,
and 2) a geometric asymmetry induced by the other's presence. We can thus unify
and explain behaviours observed in other works. Our results show how sensitive,
counter-intuitive and rich motility is in the parameter space of finite inertia
of particles and fluid.Comment: 39 pages, 9 figures, in review at JF