Determination of absorption length of CO2 and high power diode laser radiation for ordinary Portland cement and its influence on the depth of melting

The laser beam absorption lengths of CO2 and a high power diode laser (HPDL) radiation for concrete have been determined. By employing Beer-Lambert’s law the absorption lengths for concrete of CO2 and a HPDL radiation were 47022 m and 17715 m respectively. Indeed, this was borne out somewhat from a cross-sectional analysis of the melt region produced by both lasers which showed melting occurred to a greater depth when the CO2 laser was used

Evidence for universality in the initial planetesimal mass function

Planetesimals may form from the gravitational collapse of dense particle clumps initiated by the streaming instability. We use simulations of aerodynamically coupled gas-particle mixtures to investigate whether the properties of planetesimals formed in this way depend upon the sizes of the particles that participate in the instability. Based on three high resolution simulations that span a range of dimensionless stopping time $6 \times 10^{-3} \leq \tau \leq 2$ no statistically significant differences in the initial planetesimal mass function are found. The mass functions are fit by a power-law, ${\rm d}N / {\rm d}M_p \propto M_p^{-p}$, with $p=1.5-1.7$ and errors of $\Delta p \approx 0.1$. Comparing the particle density fields prior to collapse, we find that the high wavenumber power spectra are similarly indistinguishable, though the large-scale geometry of structures induced via the streaming instability is significantly different between all three cases. We interpret the results as evidence for a near-universal slope to the mass function, arising from the small-scale structure of streaming-induced turbulence.Comment: 7 pages, 4 figures, accepted to ApJ Letters after minor modifications, including two new figures and some new text that better clarify our result

Tadalafil in patients with chronic obstructive pulmonary disease:a randomised, double-blind, parallel-group, placebo-controlled trial

SummaryBackgroundPhosphodiesterase-5 (PDE5) inhibitors improve exercise capacity and quality of life in patients with idiopathic pulmonary arterial hypertension. However, whether such beneficial effects take place in selected populations with chronic obstructive pulmonary disease (COPD) remains uncertain. We aimed to assess the effects of tadalafil—a PDE5 inhibitor—on exercise capacity and quality of life in patients with COPD and mild pulmonary hypertension.MethodsWe did a randomised, double-blind, parallel-group, placebo-controlled trial at three centres in Scotland, UK, between Sept 1, 2010, and Sept 1, 2012. Patients with moderate to severe COPD were randomly assigned (1:1), via centralised randomisation with a computer-generated sequence and block sizes of four, to receive daily tadalafil 10 mg or placebo for 12 weeks. Patients, study investigators, outcome assessors, and those administering drugs were masked to group allocation. The primary endpoint was the mean placebo-corrected difference between the baseline and final 6 min walk distance after 12 weeks. We measured change in quality of life at baseline, 8 weeks, and 12 weeks, with standardised questionnaires. Analysis was per protocol and by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01197469.Findings120 patients were randomly assigned to receive tadalafil (n=60) or placebo (n=60), of whom 56 (93%) versus 57 (95%) completed the study. At 12 weeks the difference in 6 min walking distance between the tadalafil and placebo groups was 0·5 m (95% CI −11·6 to 12·5; p=0·937). We recorded no statistically significant changes in quality of life (between-group difference on the St George's Respiratory Questionnaire −2·64 [95% CI −6·43 to 1·15]; Research and Development version 1 short-form-36 4·08 [–1·35 to 9·52]; Minnesota Living with Heart Failure questionnaire −2·31 [–7·06 to 2·45]). 19 (32%) of 60 patients in the treatment group had dyspepsia; the severity of dyspepsia ranged from mild to severe, with four (21%) of 19 patients needing a proton-pump inhibitor. Five (8%) of 60 participants had dyspepsia in the placebo group. Headache was noted in 17 (28%) patients in the treatment group versus 5 (8%) in the placebo group, but was mild in all patients. Two (3%) patients in the treatment group had facial flushing, which resulted in one withdrawal. Other withdrawals within the tadalafil group happened after a transient ischaemic attack and two deaths (ruptured abdominal aortic aneurysm and pneumonia).InterpretationTadalafil does not improve exercise capacity or quality of life despite exerting pulmonary vasodilation.FundingChief Scientist Office for Scotland

LL601 Contamination and Its Impact on U.S. Rice Prices

LL601 is a genetically modified rice variety and unapproved for commercial use. Its presence was found in commercial shipments of U.S. rice in 2006. This article explores its impact on prices and volume marketed for both the United States and Thailand, the major export competitor. The results show a significantly adverse but short duration effect on the U.S. rice market and little to no effect on the Thai rice market.cointegration, error correction model, event study analysis, GM contamination, LibertyLink Rice 601, U.S. rice exports, Agribusiness, Agricultural and Food Policy, Crop Production/Industries, Food Consumption/Nutrition/Food Safety, International Relations/Trade, Research and Development/Tech Change/Emerging Technologies, C10, C32, Q11, A52,

Exploring tradeoffs in pleiotropy and redundancy using evolutionary computing

Evolutionary computation algorithms are increasingly being used to solve optimization problems as they have many advantages over traditional optimization algorithms. In this paper we use evolutionary computation to study the trade-off between pleiotropy and redundancy in a client-server based network. Pleiotropy is a term used to describe components that perform multiple tasks, while redundancy refers to multiple components performing one same task. Pleiotropy reduces cost but lacks robustness, while redundancy increases network reliability but is more costly, as together, pleiotropy and redundancy build flexibility and robustness into systems. Therefore it is desirable to have a network that contains a balance between pleiotropy and redundancy. We explore how factors such as link failure probability, repair rates, and the size of the network influence the design choices that we explore using genetic algorithms.Comment: 10 pages, 6 figure

Compound C inhibits nonsense-mediated RNA decay independently of AMPK

The nonsense mediated RNA decay (NMD) pathway safeguards the integrity of the transcriptome by targeting mRNAs with premature translation termination codons (PTCs) for degradation. It also regulates gene expression by degrading a large number of non-mutant RNAs (including mRNAs and noncoding RNAs) that bear NMD-inducing features. Consequently, NMD has been shown to influence development, cellular response to stress, and clinical outcome of many genetic diseases. Small molecules that can modulate NMD activity provide critical tools for understanding the mechanism and physiological functions of NMD, and they also offer potential means for treating certain genetic diseases and cancer. Therefore, there is an intense interest in identifying small-molecule NMD inhibitors or enhancers. It was previously reported that both inhibition of NMD and treatment with the AMPK-selective inhibitor Compound C (CC) induce autophagy in human cells, raising the possibility that CC may be capable of inhibiting NMD. Here we show that CC indeed has a NMD-inhibitory activity. Inhibition of NMD by CC is, however, independent of AMPK activity. As a competitive ATP analog, CC does not affect the kinase activity of SMG1, an essential NMD factor and the only known kinase in the NMD pathway. However, CC treatment down-regulates the protein levels of several NMD factors. The induction of autophagy by CC treatment is independent of ATF4, a NMD target that has been shown to promote autophagy in response to NMD inhibition. Our results reveal a new activity of CC as a NMD inhibitor, which has implications for its use in basic research and drug development

Application of the level-set method to the implicit solvation of nonpolar molecules

A level-set method is developed for numerically capturing the equilibrium solute-solvent interface that is defined by the recently proposed variational implicit solvent model (Dzubiella, Swanson, and McCammon, Phys. Rev. Lett. {\bf 104}, 527 (2006) and J. Chem.\Phys. {\bf 124}, 084905 (2006)). In the level-set method, a possible solute-solvent interface is represented by the zero level-set (i.e., the zero level surface) of a level-set function and is eventually evolved into the equilibrium solute-solvent interface. The evolution law is determined by minimization of a solvation free energy {\it functional} that couples both the interfacial energy and the van der Waals type solute-solvent interaction energy. The surface evolution is thus an energy minimizing process, and the equilibrium solute-solvent interface is an output of this process. The method is implemented and applied to the solvation of nonpolar molecules such as two xenon atoms, two parallel paraffin plates, helical alkane chains, and a single fullerene $C_{60}$. The level-set solutions show good agreement for the solvation energies when compared to available molecular dynamics simulations. In particular, the method captures solvent dewetting (nanobubble formation) and quantitatively describes the interaction in the strongly hydrophobic plate system