Fluctuating Topological Defects in 2D Liquids: Heterogeneous Motion and Noise

We measure the defect density as a function of time at different temperatures in simulations of a two dimensional system of interacting particles. Just above the solid to liquid transition temperature, the power spectrum of the defect fluctuations shows a 1/f signature, which crosses over to a white noise signature at higher temperatures. When 1/f noise is present, the 5-7 defects predominately form string like structures, and the particle trajectories show a 1D correlated motion that follows the defect strings. At higher temperatures this heterogeneous motion is lost. We demonstrate this heterogeneity both in systems interacting with a short ranged screened Coulomb interaction, as well as in systems with a long range logarithmic interaction between the particles.Comment: 4 pages, 5 postscript figure

Snowier Winters Extend Autumn Availability of High-quality Forage for Caribou in Arctic Alaska

Caribou (Rangifer tarandus) rely on the short Arctic growing season to restore body condition, support the demands of lactation, and prepare for the long arctic winter, making them susceptible to even small changes in forage availability or quality. Body condition in the summer and autumn is linked to winter survival rates and fecundity in cows, critical factors in the productivity of caribou populations. Climate change predictions of warmer and wetter northern winters suggest increased snowfall over Alaska’s North Slope, which has recently been verified between 1995 and 2017. However, a comprehensive analysis of how deeper snow will affect caribou forage quality is absent across Alaska. In this study, we quantify how snow depth alters the quality and seasonality of caribou forage using a long-term (24 yr) International Tundra Experiment snow depth manipulation to evaluate how winter climate change scenarios may affect tussock tundra systems in northern Alaska. Deeper snow in prior winters leads to increases in growing season leaf N and digestible protein (DP) in deciduous shrubs (and Betula spp.) and graminoids (Carex spp. and Eriophorum spp.), but not evergreen dwarf shrubs (Rhododendron spp. and Vaccinium spp.). Dry matter digestibility varied among species with small differences (\u3c5%) associated with snow depth. Most striking was the discovery that deeper snow in the prior winter increased the duration of DP levels above the minimum threshold for protein gain in caribou by as much as 25 d in Salix pulchra and 6–9 d in Betula nana and Carex bigelowii in late summer and early autumn. Consequently, deeper winter snow may provide an extended window of opportunity for foraging and the accumulation of lean body mass and fat reserves which promote winter survival and successful calving the following spring and potentially improve the productivity of caribou in northern Alaska

Short-Term Relapse Quantitation as a Fully Surrogate Endpoint for Long-Term Sustained Progression of Disability in RRMS Patients Treated with Natalizumab

Time to sustained worsening in the expanded disability status scale as the standard for evaluating the accumulation of disability has been used as a measure of clinical efficacy in many relapsing-remitting multiple sclerosis (RRMS) clinical trials. However, this measurement usually requires a large sample and long-term study to demonstrate the treatment effect. Annualized relapse rate or time to first relapse is also widely used as alternative measurements of clinical efficacy. A formal statistical validation of short-term relapse activity as a surrogate endpoint for long-term sustained progression of disability could potentially permit smaller, shorter, and less expensive clinical trials in RRMS. Four statistical validation/evaluation approaches consistently showed that relapse activity through one year of treatment serves as statistically valid surrogate endpoint for time to sustained progression of disability. The analysis demonstrates that long-term sustained progression of disability can be predicted by short-term relapse measures with 4 consistent validations of statistical approaches, including a formal statistical hypothesis test. This was demonstrated in a large phase III trial of natalizumab and showed that the beneficial clinical effect of natalizumab on sustained progression of disability at 2 years in patients with RRMS can be predicted by the total number of relapses at 1 year

Effects of Cordyceps Mushroom Powder on Nursery Pig Performance

One hundred sixty crossbred pigs (Duroc × (York × Landrace)) weaned at 18.8 d of age and weighing an average of 13.1 lb were used in a 35-day growth trial to evaluate Cordyceps mushroom powder as potential alternative to carbadox in nursery pig diets. Pigs were divided by weight, sex, litter, and assigned to body weight (BW) blocks. Within BW blocks, sex ratios were constant in each pen. Each pen within a BW block was randomly assigned a dietary treatment. Growth performance was analyzed using BW, average daily gain (ADG), average daily feed intake (ADFI), and feed conversion as feed-to-gain (F:G). Pigs were blocked by weight with 5 or 6 pigs per pen and there were 6 pens per treatment. There were 5 diets used in the study: a negative diet or a positive control (carbadox, 50 g/ton); 300 or 600 ppm mushroom powder, and a step-down treatment (900, 900, 450, 300, and 150 ppm mushroom powder during weeks 1, 2, 3, 4, and 5, respectively). At various points of the study, pigs fed the 300 ppm and the step-down mushroom powder treatments tended to have improved (P \u3c 0.10) growth performance compared with those fed the negative control diet. During Phase 4 of the study, pigs fed carbadox had greater ADG (P \u3c 0.02) and improved feed efficiency (P \u3c 0.09) over pigs fed the negative control diet. However, overall data showed that there were no statistical differences among treatments (P \u3e 0.05). In summary, pigs fed 300 ppm mushroom powder or the step-down treatment showed comparable results to pigs fed carbadox. However, future research is needed under a greater disease pressure to show mushroom powder’s full potential as an alternative to antibiotics

Phase Transition in Liquid Drop Fragmentation

A liquid droplet is fragmented by a sudden pressurized-gas blow, and the resulting droplets, adhered to the window of a flatbed scanner, are counted and sized by computerized means. The use of a scanner plus image recognition software enables us to automatically count and size up to tens of thousands of tiny droplets with a smallest detectable volume of approximately 0.02 nl. Upon varying the gas pressure, a critical value is found where the size-distribution becomes a pure power-law, a fact that is indicative of a phase transition. Away from this transition, the resulting size distributions are well described by Fisher's model at coexistence. It is found that the sign of the surface correction term changes sign, and the apparent power-law exponent tau has a steep minimum, at criticality, as previously reported in Nuclear Multifragmentation studies [1,2]. We argue that the observed transition is not percolative, and introduce the concept of dominance in order to characterize it. The dominance probability is found to go to zero sharply at the transition. Simple arguments suggest that the correlation length exponent is nu=1/2. The sizes of the largest and average fragments, on the other hand, do not go to zero but behave in a way that appears to be consistent with recent predictions of Ashurst and Holian [3,4].Comment: 10 pages, 11 figures. LaTeX (revtex4) with psfig/epsfi

The Effects of Cordyceps Mushroom Powder and Purified Mushroom Beta-Glucan on Nursery Pig Performance

One hundred thirty-two gilts and barrows (18.2 d of age) weighing an average of 13.4 lb (Duroc × (York × Landrace)) were put on test for a 35-day growth trial to assess the effects of Cordyceps mushroom powder (MP) or purified mushroom beta-glucan (BG) as an antibiotic alternative in nursery diets. There were 6 diets, negative and positive controls (NC and PC), 150 and 300 ppm mushroom powder, and 150 and 300 ppm beta-glucan equivalents to the MP diets. Pigs were divided by weight, sex, litter, and assigned to 6 body weight (BW) blocks. Within BW blocks, sex ratios were constant in each pen. Pigs and feeders were weighed weekly to determine average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (F/G). During phase 1 (d 0 to 7), pigs fed the PC had increased ADG, ADFI, and d 7 BW (P \u3c 0.05) compared to pigs fed the NC. Beta-glucan and MP also increased ADFI in phase 1 (P \u3c 0.05) compared to the NC. During phase 2 (d 7 to 14), a health challenge (hemolytic Escherichia coli) went through half of the pigs with the other half challenged in phase 3 (d 14 to 21). This led to some erratic performance because of the pigs eating, but losing weight. In phase 4 there was a BG and MP interaction between source and dose. Pigs fed 300 level of MP had improved F/G, while those fed the 300 level of BG had poorer efficiency in phase 4 (P \u3c 0.07). Overall, there was an improvement (P \u3e 0.05) in F:G ratio in the PC when compared to the NC. There was also an interaction between source and dose for ADFI (P \u3c 0.05) between the BG and MP treatments. There was a significant improvement in F/G in MP and BG pigs compared to NC pigs (P \u3c 0.05). On day 35, there were no differences in final BW among treatments. A premarket weight was collected on all pigs at d 154 after weaning, and pigs fed the 300 BG from day 0 to 35 were 24.4 lb heavier than the NC (P \u3c 0.05) and 15.4 lb heavier than the PC (P \u3c 0.05)

Mitochondrial proteomics: analysis of a whole mitochondrial extract with two-dimensional electrophoresis

Mitochondria are complex organelles, and their proteomics analysis requires a combination of techniques. The emphasis in this chapter is made first on mitochondria preparation from cultured mammalian cells, then on the separation of the mitochondrial proteins with two-dimensional electrophoresis (2DE), showing some adjustment over the classical techniques to improve resolution of the mitochondrial proteins. This covers both the protein solubilization, the electrophoretic part per se, and the protein detection on the gels, which makes the interface with the protein identification part relying on mass spectrometry

Evaluating the Interactive Effects of Cordyceps Mushroom Powder and Carbadox to Pharmacological Copper and Zinc for Nursery Pigs

The objective of this study was to evaluate the independent and additive effects of Cordyceps mushroom powder (MP) and carbadox to pharmacological levels of copper and zinc in nursery pig diets. Two hundred and ten crossbred weanling pigs (Duroc × (York × Landrace)) average of 19 d of age and 12.8 lb were used in a 33-day growth trial. Pigs were allotted by weight, sex, ancestry, and assigned to body weight (BW) blocks. Within BW blocks, sex ratios were constant in each pen. Pen was the experimental unit, and growth performance was analyzed using BW, average daily gain (ADG), average daily feed intake (ADFI), and feed-to-gain ratio (F:G). There were 7 pigs/pen and 6 pens/treatment. Treatments were: 1) a negative control diet (NC); 2) positive control (PC; carbadox, 50 g/ton); 3) NC+ 300 ppm Cordyceps mushroom powder (NC+MP); 4) PC + 300 ppm mushroom powder (PC+MP); 5) supplemental copper sulfate (125 ppm) and zinc oxide (3000 ppm d 0 to 7, 2000 ppm d 7 to 35), CuZn. Dietary treatments were fed in a four-phase feeding program (d 0 to 7, d 7 to 14, d 14 to 21, and d 21 to 33). Pigs fed the PC, PC+MP, and CuZn diets had increased BW (P \u3c 0.05), ADG (P \u3c 0.05), and ADFI (P \u3c 0.10) over those fed the NC at the end of phases 1, 2, and 3, with no main effect of MP treatment. During phase 4, pigs fed MP, PC, and CuZn diets all had increased ADG (P \u3c 0.05; 0.95, 1.05, 1.00, 1.11, 1.07 lb/d, diet 1–5, respectively) and ADFI (P \u3c 0.05) over the NC fed pigs. Overall, d 0 to 33, pigs fed PC diets and CuZn had increased ADG (P \u3c 0.05) and ADFI (P \u3c 0.05), with pigs fed MP tending to have increased ADFI (P \u3c 0.08) over NC-fed pigs. Plasma TNF-α concentrations at d 14 postweaning showed a trend for a carbadox main effect, as well as a mushroom by carbadox interaction (P \u3c 0.10) for plasma TNF-α, with the 300 ppm MP having the numerically highest value, while the combination of carbadox and 300 ppm MP had the lowest concentration of TNF-α. Feeding nursery pigs pharmacological levels of Cu+Zn and carbadox have economical value to increase nursery pig performance, while MP may increase pig ADFI and final BW through potentially complementary modes of action to carbadox

Adaptive Control for Haptics with Time-Delay

Abstract-This paper presents an adaptive haptic control for a one degree-of-freedom surgical device. The control addresses the problem of hitting a solid object too hard in the presence of time delay. The proposed control runs in the inner-loop, with no time delay, and follows commanded forces from the outer loop. A Lyapunov-stable backstepping-with-tuning-functions design provides a way to ensure smooth forces are applied that guarantee stability in the presence of unmodeled environmental stiffness. The method naturally becomes a velocity-tracking system when no forces are measured, without need for a switching control law. Experiments using a Phantom hand controller interacting with simulated environment show that collision forces are substantially reduced. The overshoot during a puncture, when moving from a stiff environment to free space, is not worse than with other designs