365 research outputs found
100K Pathogen Genome Project: 306 Listeria Draft Genome Sequences for Food Safety and Public Health.
Listeria monocytogenes is a food-associated bacterium that is responsible for food-related illnesses worldwide. This is the initial public release of 306 L. monocytogenes genome sequences as part of the 100K Pathogen Genome Project. These isolates represent global genomic diversity in L. monocytogenes
Limitations in quantum computing from resource constraints
Fault-tolerant quantum computation is the only known route to large-scale,
accurate quantum computers. Fault tolerance schemes prescribe how, by investing
more physical resources and scaling up the size (number of qubits and gates) of
the computer, we can keep the computational errors in check and carry out more
and more accurate calculations. Underlying all such schemes is the assumption
that the error per physical gate is independent of the size of the quantum
computer. This, unfortunately, is not reflective of current quantum computing
experiments. Here, we examine the general consequences on fault-tolerant
quantum computation when physical error rates grow as the computer grows. In
this case, fault tolerance schemes can no longer reduce computational error to
an arbitrarily small number, even if one starts below the so-called fault
tolerance noise threshold. Instead, there is a minimum attainable computational
error, beyond which further growth of the computer in an attempt to reduce the
error becomes counter-productive. We discuss simple, but rather generic,
situations where this arises. We explain how to deduce the maximum
computational accuracy for given resource constraints, or other sources of
scale-dependent noise. By inverting the logic, we provide experimenters with a
tool to finding the minimum resources required to run an algorithm with a given
computational accuracy. When combined with a full-stack quantum computing
model, this can provide the basis for energetic estimates of large-scale
quantum computers.Comment: 8 pages + Supplemental material; 6 figure
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Draft Genome Sequences of 1,183 Salmonella Strains from the 100K Pathogen Genome Project.
Salmonella is a common food-associated bacterium that has substantial impact on worldwide human health and the global economy. This is the public release of 1,183 Salmonella draft genome sequences as part of the 100K Pathogen Genome Project. These isolates represent global genomic diversity in the Salmonella genus
Where people shop is not associated with the nutrient quality of packaged foods for any racial-ethnic group in the United States
Background: In the literature, it has been suggested that there are race-ethnic disparities in what Americans eat. In addition, some studies have shown that residents of African American and low-income neighborhoods have less access to grocery stores and supermarkets, which tend to stock healthier foods. However, it is unclear whether differences in food shopping patterns contribute to the poorer nutrient profile of food purchases made by racial-ethnic minorities
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Structural studies of conformationally-restricted ligands binding to aspartic peptidases.
Static assessment of notched additively manufactured acrylonitrile butadiene styrene (ABS)
The present paper tackles the problem of performing the static assessment of notched additively manufactured (AM) acrylonitrile butadiene styrene (ABS) components. A large number of ABS specimens containing different notch profiles and sharpness were manufactured (flat on build plate) by varying the printing angles to simulate the stress concentration phenomena. These specimens were tested under tension and three-point bending to generate a large amount of experimental data. From the experimental results, it is evident that the AM ABS materials can simply be modelled as an elastic, brittle, homogenous and isotropic material. This simplification allowed the application of the Theory of Critical Distances (TCD) to become a viable static assessment tool for the AM ABS components. As a result, it was proven that the TCD is an accurate and valid static assessment tool for the AM ABS components with estimations mainly falling within an error interval of about ±20%. This result is certainly rewarding from an engineering application perspective as the TCD successfully enables engineers to assess the static strength of additively manufactured engineering components that contain intricate geometrical features accurately, rapidly, and economically
Fluoroquinolone and Other Antimicrobial Resistance in Invasive Pneumococci, Hong Kong, 1995–2001
Fluoroquinolone resistance among invasive pneumococci in Hong Kong was high and a result of clonal expansion and spread
Preconditioning of mesenchymal stromal cells with low-intensity ultrasound: influence on chondrogenesis and directed SOX9 signaling pathways
Background: Continuous low-intensity ultrasound (cLIUS) facilitates the chondrogenic differentiation of human mesenchymal stromal cells (MSCs) in the absence of exogenously added transforming growth factor-beta (TGFβ) by upregulating the expression of transcription factor SOX9, a master regulator of chondrogenesis. The present study evaluated the molecular events associated with the signaling pathways impacting SOX9 gene and protein expression under cLIUS.
Methods: Human bone marrow-derived MSCs were exposed to cLIUS stimulation at 14 kPa (5 MHz, 2.5 Vpp) for 5 min. The gene and protein expression of SOX9 was evaluated. The specificity of SOX9 upregulation under cLIUS was determined by treating the MSCs with small molecule inhibitors of select signaling molecules, followed by cLIUS treatment. Signaling events regulating SOX9 expression under cLIUS were analyzed by gene expression, immunofluorescence staining, and western blotting.
Results: cLIUS upregulated the gene expression of SOX9 and enhanced the nuclear localization of SOX9 protein when compared to non-cLIUS-stimulated control. cLIUS was noted to enhance the phosphorylation of the signaling molecule ERK1/2. Inhibition of MEK/ERK1/2 by PD98059 resulted in the effective abrogation of cLIUS-induced SOX9 expression, indicating that cLIUS-induced SOX9 upregulation was dependent on the phosphorylation of ERK1/2. Inhibition of integrin and TRPV4, the upstream cell-surface effectors of ERK1/2, did not inhibit the phosphorylation of ERK1/2 and therefore did not abrogate cLIUS-induced SOX9 expression, thereby suggesting the involvement of other mechanoreceptors. Consequently, the effect of cLIUS on the actin cytoskeleton, a mechanosensitive receptor regulating SOX9, was evaluated. Diffused and disrupted actin fibers observed in MSCs under cLIUS closely resembled actin disruption by treatment with cytoskeletal drug Y27632, which is known to increase the gene expression of SOX9. The upregulation of SOX9 under cLIUS was, therefore, related to cLIUS-induced actin reorganization. SOX9 upregulation induced by actin reorganization was also found to be dependent on the phosphorylation of ERK1/2.
Conclusions: Collectively, preconditioning of MSCs by cLIUS resulted in the nuclear localization of SOX9, phosphorylation of ERK1/2 and disruption of actin filaments, and the expression of SOX9 was dependent on the phosphorylation of ERK1/2 under cLIUS
The association between new generation oral contraceptive pill and the development of inflammatory bowel diseases
Background/AimsTo examine the association between use of oral contraceptive pills (OCPs) and the risk of developing inflammatory bowel diseases (IBD), in a modern cohort.MethodsA prospective nested case-control study across sites in the Asia-Pacific region was conducted; involving female IBD cases and asymptomatic controls. Subjects completed a questionnaire addressing questions related to OCP use. Primary outcome was the risk of development of IBD of those exposed to OCP versus non-exposure. Secondary outcomes were development of Crohn's disease (CD) versus ulcerative colitis (UC), and whether age of first use of OCP use may be associated with risk of IBD.ResultsThree hundred and forty-eight female IBD cases (41% CD, median age: 43 years) and 590 female age-matched controls were recruited. No significant association was found between OCP use and the risk of IBD (odds ratio [OR], 1.65; 95% confidence interval, 0.77–3.13; P=0.22), CD (OR, 1.55) or UC (OR, 1.01). The lack of association persisted when results were adjusted for age and smoking. IBD cases commenced OCP use at a younger age than controls (18 years vs. 20 years, P=0.049).ConclusionsIn this large cohort of subjects from the Asia-Pacific region, we found a modest but not significantly increased risk of developing IBD amongst OCP users
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