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Optimal gridding and degridding in radio interferometry imaging
In radio interferometry imaging, the gridding procedure of convolving
visibilities with a chosen gridding function is necessary to transform
visibility values into uniformly sampled grid points. We propose here a
parameterised family of "least-misfit gridding functions" which minimise an
upper bound on the difference between the DFT and FFT dirty images for a given
gridding support width and image cropping ratio. When compared with the widely
used spheroidal function with similar parameters, these provide more than 100
times better alias suppression and RMS misfit reduction over the usable dirty
map. We discuss how appropriate parameter selection and tabulation of these
functions allow for a balance between accuracy, computational cost and storage
size. Although it is possible to reduce the errors introduced in the gridding
or degridding process to the level of machine precision, accuracy comparable to
that achieved by CASA requires only a lookup table with 300 entries and a
support width of 3, allowing for a greatly reduced computation cost for a given
performance
THE IMPORTANCE OF LOOP REGION RESIDUES 40-46 IN HUMAN DIHYDROFOLATE-REDUCTASE AS REVEALED BY SITE-DIRECTED MUTAGENESIS
Salt content of instant noodles in Malaysia: a cross-sectional study
Objective To determine the salt content in instant noodles sold in Malaysia. Study design A cross-sectional survey was done involving 707 different flavours and packaging of instant noodles sold in six hypermarkets and retailer chains in Malaysia and the corresponding brand's official websites in 2017. Methods The salt content (gram per serving and per 100 g) was collected from the product packaging and corresponding brand's official website. Results Of the 707 different packaging and flavours of instant noodles, only 62.1% (n=439) provided the salt content in their food label. The mean (±SD) salt per 100 g of instant noodles was 4.3±1.5 g and is nearly four times higher than the salt content of food classified in Malaysia as a high salt content (>1.2 g salt per 100 g). The salt content for instant noodle per packaging ranged from 0.7 to 8.5 g. 61.7% of the instant noodles exceeded the Pacific Salt Reduction Target, 11.8% exceeded the WHO recommended daily salt intake of <5.0 per day and 5.50% exceeded Malaysia Salt Action Target. 98% of instant noodles will be considered as high salt food according to the Malaysia Guidelines. The probability of the instant noodles without mixed flavour (n=324) exceeding the Pacific Salt Reduction Target was tested on univariate and multivariate analysis. Instant noodles with soup, Tom Yam flavour, pork flavour and other flavours were found to be predictors of instant noodles with the tendency to exceed Pacific Salt Reduction Target when compared with instant noodles without mixed flavours (p<0.05). Conclusion Only 62% of instant noodles displayed the salt content on their food label. Salt content in instant noodles is very high, with 90% exceeding the daily salt intake recommended by WHO. Prompt action from regulatory and health authorities is needed to reduce the salt content in instant noodles. © Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ
ROLE OF LYSINE-54 IN DETERMINING COFACTOR SPECIFICITY AND BINDING IN HUMAN DIHYDROFOLATE-REDUCTASE
The actin-myosin regulatory MRCK kinases: regulation, biological functions and associations with human cancer
The contractile actin-myosin cytoskeleton provides much of the force required for numerous cellular activities such as motility, adhesion, cytokinesis and changes in morphology. Key elements that respond to various signal pathways are the myosin II regulatory light chains (MLC), which participate in actin-myosin contraction by modulating the ATPase activity and consequent contractile force generation mediated by myosin heavy chain heads. Considerable effort has focussed on the role of MLC kinases, and yet the contributions of the myotonic dystrophy-related Cdc42-binding kinases (MRCK) proteins in MLC phosphorylation and cytoskeleton regulation have not been well characterized. In contrast to the closely related ROCK1 and ROCK2 kinases that are regulated by the RhoA and RhoC GTPases, there is relatively little information about the CDC42-regulated MRCKα, MRCKβ and MRCKγ members of the AGC (PKA, PKG and PKC) kinase family. As well as differences in upstream activation pathways, MRCK and ROCK kinases apparently differ in the way that they spatially regulate MLC phosphorylation, which ultimately affects their influence on the organization and dynamics of the actin-myosin cytoskeleton. In this review, we will summarize the MRCK protein structures, expression patterns, small molecule inhibitors, biological functions and associations with human diseases such as cancer
Gold nanoparticles improve metabolic profile of mice fed a high-fat diet
© 2018 The Author(s). Background: Obesity is a high risk for multiple metabolic disorders due to excessive influx of energy, glucose and lipid, often from a western based diet. Low-grade inflammation plays a key role in the progression of such metabolic disorders. The anti-inflammatory property of gold compounds has been used in treating rheumatoid arthritis in the clinic. Previously we found that pure gold nanoparticles (AuNPs, 21 nm) also possess anti-inflammatory effects on the retroperitoneal fat tissue following intraperitoneal injection, by downregulating tumor necrosis factor (TNF) α. However, whether such an effect can change the risk of metabolic disorders in the obese has not been well studied. The study employed C57BL/6 mice fed a pellet high fat diet (HFD, 43% as fat) that were treated daily with AuNPs [low (HFD-LAu) or high (HFD-HAu) dose] via intraperitoneal injection for 9 weeks. In the in vitro study, RAW264.7 macrophages and 3T3-L1 adipocytes were cultured with low and high concentrations of AuNPs alone or together. Results: The HFD-fed mice showed a significant increase in fat mass, glucose intolerance, dyslipidemia, and liver steatosis. The HFD-LAu group showed an 8% reduction in body weight, ameliorated hyperlipidemia, and normal glucose tolerance; while the HFD-HAu group had a 5% reduction in body weight with significant improvement in their glucose intolerance and hyperlipidemia. The underlying mechanism may be attributed to a reduction in adipose and hepatic local proinflammatory cytokine production, e.g. TNFα. In vitro studies of co-cultured murine RAW264.7 macrophage and 3T3-L1 adipocytes supported this proposed mechanism. Conclusion: AuNPs demonstrate a promising profile for potential management of obesity related glucose and lipid disorders and are useful as a research tool for the study of biological mechanisms
Strategically Equivalent Contests
Using a two-player Tullock-type contest, we show that intuitively and structurally different contests can be strategically equivalent. Strategically equivalent contests generate the same best response functions and, as a result, the same equilibrium efforts. However, strategically equivalent contests may yield different equilibrium payoffs. We propose a simple two-step procedure to identify strategically equivalent contests. Using this procedure, we identify contests that are strategically equivalent to the original Tullock contest, and provide new examples of strategically equivalent contests. Finally, we discuss possible contest design applications and avenues for future theoretical and empirical research
Challenges in perioperative fluid management and anticoagulant therapy in a woman with cardio-pulmonary-renal disease diagnosed with preinvasive breast carcinoma
An elderly woman with preinvasive breast cancer, atrial fibrillation, coronary artery-pulmonary artery fistula, pulmonary hypertension and Stage 4 diabetic nephropathy underwent a mastectomy and sentinel lymph node biopsy. Managing her perioperative fluid balance and anticoagulation treatment were challenging. Having a malignancy, atrial fibrillation plus underhydration will increase her risk of hypercoagulation. However, fluid overload will lead to pulmonary oedema which will decrease her oxygenation further in pulmonary hypertension. Cessation of anticoagulation also increased the risk of hypercoagulation. Anticoagulant therapy increases the risk of a perioperative wound haematoma, which may require another general anaesthesia for identification and arrest of the bleeding source and haematoma evacuation. A haematoma will also increase the risk of surgical site infection; especially as a diabetic. Her anticoagulant therapy (rivoroxaban) was stopped four days preoperatively. Her ejection fraction was 50%, with Grade II diastolic dysfunction and TAPSE 0.6 cm. Her CHA2DS2-VASc Score was 5. Perioperatively, intraarterial cannulation was connected to the FloTrac™ sensor and EV1000™ monitor. Her fluid management was monitored using goal directed (GD) fluid therapy. The patient underwent surgery successfully and her anticoagulant therapy was recommenced 14 days postoperatively
[Accepted Manuscript] Narratives of Promise, Narratives of Caution: A Review of the Literature on Social Impact Bonds
Social Impact Bonds (SIBs) are a new mechanism for delivering public services. This article reviews the emerging SIB literature in high-income settings. It identifies three distinct narratives: a public sector reform narrative; a financial sector reform narrative; and a cautionary narrative. These are analyzed relative to three themes: public versus private values; outcomes contracting; and risk allocation. The first two narratives are complementary and offer a ‘win-win’ portrayal of SIBs. The third narrative challenges this dominant commentary by highlighting potential risks. There is limited empirical evidence on active SIBs to support these narratives. SIBs may have the potential to align public and private interests while improving outcomes for people affected by entrenched social problems, but this is yet to be established and appears less probable than the third more cautionary narrative. More empirical research is needed to consider the potential risks, drawbacks, benefits and alternatives of SIBs in different settings
Can a falling tree make a noise in two forests at the same time?
It is a commonplace to claim that quantum mechanics supports the old idea
that a tree falling in a forest makes no sound unless there is a listener
present. In fact, this conclusion is far from obvious. Furthermore, if a
tunnelling particle is observed in the barrier region, it collapses to a state
in which it is no longer tunnelling. Does this imply that while tunnelling, the
particle can not have any physical effects? I argue that this is not the case,
and moreover, speculate that it may be possible for a particle to have effects
on two spacelike separate apparatuses simultaneously. I discuss the measurable
consequences of such a feat, and speculate about possible statistical tests
which could distinguish this view of quantum mechanics from a ``corpuscular''
one. Brief remarks are made about an experiment underway at Toronto to
investigate these issues.Comment: 9 pp, Latex, 3 figs, to appear in Proc. Obsc. Unr. Conf.; Fig 2
postscript repaired on 26.10.9
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