Chaotic maps and flows: Exact Riemann-Siegel lookalike for spectral fluctuations

To treat the spectral statistics of quantum maps and flows that are fully chaotic classically, we use the rigorous Riemann-Siegel lookalike available for the spectral determinant of unitary time evolution operators $F$. Concentrating on dynamics without time reversal invariance we get the exact two-point correlator of the spectral density for finite dimension $N$ of the matrix representative of $F$, as phenomenologically given by random matrix theory. In the limit $N\to\infty$ the correlator of the Gaussian unitary ensemble is recovered. Previously conjectured cancellations of contributions of pseudo-orbits with periods beyond half the Heisenberg time are shown to be implied by the Riemann-Siegel lookalike

Semiclassical approach to discrete symmetries in quantum chaos

We use semiclassical methods to evaluate the spectral two-point correlation function of quantum chaotic systems with discrete geometrical symmetries. The energy spectra of these systems can be divided into subspectra that are associated to irreducible representations of the corresponding symmetry group. We show that for (spinless) time reversal invariant systems the statistics inside these subspectra depend on the type of irreducible representation. For real representations the spectral statistics agree with those of the Gaussian Orthogonal Ensemble (GOE) of Random Matrix Theory (RMT), whereas complex representations correspond to the Gaussian Unitary Ensemble (GUE). For systems without time reversal invariance all subspectra show GUE statistics. There are no correlations between non-degenerate subspectra. Our techniques generalize recent developments in the semiclassical approach to quantum chaos allowing one to obtain full agreement with the two-point correlation function predicted by RMT, including oscillatory contributions.Comment: 26 pages, 8 Figure

Pharmacological assessment of the contribution of the arterial baroreflex to sympathetic discharge patterns in healthy humans

To study how changes in baroreceptor afferent activity affect patterns of sympathetic neural activation, we manipulated arterial blood pressure with intravenous nitroprusside (NTP) and phenylephrine (PE) and measured action potential (AP) patterns with wavelet-based methodology. We hypothesized that 1) baroreflex unloading (NTP) would increase firing of low-threshold axons and recruitment of latent axons and 2) baroreflex loading (PE) would decrease firing of low-threshold axons. Heart rate (HR, ECG), arterial blood pressure (BP, brachial catheter), and muscle sympathetic nerve activity (MSNA, microneurography of peroneal nerve) were measured at baseline and during steady-state systemic, intravenous NTP (0.5-1.2 µg·kg -1 ·min -1 , n = 13) or PE (0.2-1.0 µg·kg -1 ·min -1 , n = 9) infusion. BP decreased and HR and integrated MSNA increased with NTP (P \u3c 0.01). AP incidence (326 ± 66 to 579 ± 129 APs/100 heartbeats) and AP content per integrated burst (8 ± 1 to 11 ± 2 APs/burst) increased with NTP (P \u3c 0.05). The firing probability of low-threshold axons increased with NTP, and recruitment of high-threshold axons was observed (22 ± 3 to 24 ± 3 max cluster number, 9 ± 1 to 11 ± 1 clusters/burst; P \u3c 0.05). BP increased and HR and integrated MSNA decreased with PE (P \u3c 0.05). PE decreased AP incidence (406 ± 128 to 166 ± 42 APs/100 heartbeats) and resulted in fewer unique clusters (15 ± 2 to 9 ± 1 max cluster number, P \u3c 0.05); components of an integrated burst (APs or clusters per burst) were not altered (P \u3e 0.05). These data support a hierarchical pattern of sympathetic neural activation during manipulation of baroreceptor afferent activity, with rate coding of active neurons playing the predominant role and recruitment/derecruitment of higher-threshold units occurring with steady-state hypotensive stress. NEW & NOTEWORTHY To study how changes in baroreceptor afferent activity affect patterns of sympathetic neural activation, we manipulated arterial blood pressure with intravenous nitroprusside and phenylephrine and measured sympathetic outflow with wavelet-based methodology. Baroreflex unloading increased sympathetic activity by increasing firing probability of low-threshold axons (rate coding) and recruiting new populations of high-threshold axons. Baroreflex loading decreased sympathetic activity by decreasing the firing probability of larger axons (derecruitment); however, the components of an integrated burst were unaffected

Theoretical Insights into Vinyl Derivatives Adsorption on a Cu(100) Surface

This document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry C, © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/abs/10.1021/acs.jpcc.8b06142Here, we present a thorough theoretical study of the adsorption of acrolein (ACO), acrylonitrile (ACN), and acrylamide (ACA) on Cu(100) surface. For this purpose, we have used the density functional theory, imposing periodic boundary conditions to have a correct description of the electronic band structure of the metal and including dispersion forces through two different schemes: the D2 method of Grimme and the vdW-DF. We have found several adsorption geometries. In all of them, the vinyl group together with the amide (in ACA), ciano (in ACN), and carbonyl (in ACO) groups, is highly involved. The highest adsorption energy is found for acrylamide, followed by acrolein and the lowest for acrylonitrile (depending on the level of theory employed ∼1.2, 1.0, and 0.9 eV, respectively). We show that a strong coupling between the π electronic system (both occupied and virtual orbitals) and the electronic levels of the metal is mainly responsible of the chemisorption. As a consequence, electronic density is transferred from the surface to the molecule, whose carbon atoms acquire a partial sp3 hybridization. Lone-pair orbitals of the cyano, amide, and carbonyl groups also play a role in the interaction. The simulations and following analysis allow to disentangle the nature of the interaction, which can be explained on the basis of a simple chemical picture: donation from the occupied lone pair and π orbitals of the molecule to the surface and backdonation from the surface to the π∗ orbital of the molecule (π-backbonding)This work was partially supported by the project CTQ2016-76061-P of the Spanish Ministerio de Economı́a y Competitividad (MINECO). F.A.G. acknowledges the FPI grant associated with the project CTQ2013-43698-P (MINECO). Financial support from the MINECO through the “Marı́a de Maeztu” Program for Units of Excellence in R&D (MDM-2014-0377) is also acknowledge

1994 turfgrass research report

Moss control on bentgrass greens evaluation / Jill Taylor -- Preemergent spotted spurge broadleaf weed control evaluation / William Pound and Renee Stewart -- Finale/Roundup herbicide demonstration evaluation / William Pound and Renee Stewart -- Turflon solvent evaluation / William Pound and Renee Stewart -- General turfgrass broadleaf weed control evaluation / William Pound and Renee Stewart -- Postemergence herbicide efficacy on crabgrass / John Street and Renee Stewart -- Preemergence herbicide efficacy on crabgrass / John Street, Jill Taylor and Renee Stewart -- Leaf spot control study / Joe Rimelspach, Karl Danneberger and Jill Taylor -- Dollar spot control study / Karl Danneberger, Joe Rimelspach and Jill Taylor -- Brown patch control study / Karl Danneberger, Joe Rimelspach and Jill Taylor -- Anthracnose control study / Karl Danneberger, Joe Rimelspach and Jill Taylor -- Summer patch control study / Joe Rimelspach, Karl Danneberger and Jill Taylor -- Yellow tuft control study / Karl Danneberger, Joe Rimelspach and Jill Taylor -- Red thread control study, Columbus / Joe Rimelspach, Karl Danneberger and Jill Taylor -- Red thread control study, Delaware / Joe Rimelspach, Bobby Joyner, Joe Green and Jerry Sullivan -- Susceptibility of bentgrass cultivars to Fore+ Aliette combinations / Karl Danneberger and Jill Taylor -- Suppression of turf diseases with biocontrol agent fortified compost-amended topdressings / Marcella Grebus, Carol Musselman, Joe Rimelspach and Harry Hoitink -- Evaluation of fungicides for resistance to dollar spot (Sclerotinia homoecmpa) on creeping bentgrass / Joe Rimelspach, Jill Taylor and Karl Danneberger -- Application of an insect growth regulator and insecticide on baits for control of ant mounds in turfgrass / David Shetlar, Harry Niemczyk and Kevin Power -- Application of insecticides for control of black turfgrass ataenius larvae in turfgrass / David Shetlar, Harry Niemczyk and Kevin Power -- Evaluation of biorationals and biologicals for control of black cutworm (Agrotis ipsilon Hufnagel) and sod webworm (Pyralidae, Crambinae) larvae in bentgrass, 1994 / David Shetlar, Harry Niemczyk and Kevin Power -- Evaluation of pyrethroids and other insecticides for control of black cutworm (Agrotis ipsilon Hufnagel) and sod webworm (Pyralidae, Crambinae) larvae in bentgrass, 1994 / David Shetlar, Harry Niemczyk and Kevin Power -- Surface and subsurface applied insecticides for control of white grubs in turfgrass / David Shetlar, Harry Niemczyk and Kevin Power -- Influence of application time on the efficacy of insect growth regulators for control of white grubs in turfgrass / David Shetlar, Harry Niemczyk and Kevin Power -- Subsurface placement of controlled release chlorpyrifos granules for extended control of Japanese beetle larvae in turfgrass: third report / Harry Niemczyk and David Shetlar -- Evaluation of Turplex 3 % EC for control of black cutworm larvae on the greens of Shadow Creek Golf Course, N. Las Vegas, Nevada / Harry Niemczyk -- Nitrogen Source and Rate effect on Kentucky bluegrass / John Street and Renee Stewart -- Polymer-coated nitrogen source effect on Kentucky bluegrass / John Street and Renee Stewart -- Evaluation of turfgrass species and cultivars for shade / Jill Taylor -- Regional low input sustainable turf study / Jill Taylor -- 1990 NTEP perennial ryegrass test / Jill Taylor -- 1994 NTEP perennial ryegrass test / Jill Taylor -- 1993 NTEP bentgrass test (fairway/tee) / Jill Taylor -- 1993 NTEP fineleaf fescue test / Jill Taylor -- Bermudagrass management study / John Street and Jill Taylor -- Duration of rolling as measured by ball roll / Karl Danneberger, Jill Taylor and Jobin Morrow -- Golf ball roll as influenced by soft spike and traditional metal spike golf shoes / Karl Danneberger and Jobin Morrow -- Primo/Banner interaction study / Bill Pound, Renee Stewart and Joe Rimelspach -- Primo growth regulator evaluation on creeping bentgrass / William Pound and Renee Stewart -- Restriction of arbitrary amplification fragments of Poa annua L. / Patty Sweeney and Karl Danneberge

Characterization of subsurface media from locations up- and down-gradient of a uranium-contaminated aquifer.

The processing of sediment to accurately characterize the spatially-resolved depth profiles of geophysical and geochemical properties along with signatures of microbial density and activity remains a challenge especially in complex contaminated areas. This study processed cores from two sediment boreholes from background and contaminated core sediments and surrounding groundwater. Fresh core sediments were compared by depth to capture the changes in sediment structure, sediment minerals, biomass, and pore water geochemistry in terms of major and trace elements including pollutants, cations, anions, and organic acids. Soil porewater samples were matched to groundwater level, flow rate, and preferential flows and compared to homogenized groundwater-only samples from neighboring monitoring wells. Groundwater analysis of nearby wells only revealed high sulfate and nitrate concentrations while the same analysis using sediment pore water samples with depth was able to suggest areas high in sulfate- and nitrate-reducing bacteria based on their decreased concentration and production of reduced by-products that could not be seen in the groundwater samples. Positive correlations among porewater content, total organic carbon, trace metals and clay minerals revealed a more complicated relationship among contaminant, sediment texture, groundwater table, and biomass. The fluctuating capillary interface had high concentrations of Fe and Mn-oxides combined with trace elements including U, Th, Sr, Ba, Cu, and Co. This suggests the mobility of potentially hazardous elements, sediment structure, and biogeochemical factors are all linked together to impact microbial communities, emphasizing that solid interfaces play an important role in determining the abundance of bacteria in the sediments

Molecular crowding defines a common origin for the Warburg effect in proliferating cells and the lactate threshold in muscle physiology

Aerobic glycolysis is a seemingly wasteful mode of ATP production that is seen both in rapidly proliferating mammalian cells and highly active contracting muscles, but whether there is a common origin for its presence in these widely different systems is unknown. To study this issue, here we develop a model of human central metabolism that incorporates a solvent capacity constraint of metabolic enzymes and mitochondria, accounting for their occupied volume densities, while assuming glucose and/or fatty acid utilization. The model demonstrates that activation of aerobic glycolysis is favored above a threshold metabolic rate in both rapidly proliferating cells and heavily contracting muscles, because it provides higher ATP yield per volume density than mitochondrial oxidative phosphorylation. In the case of muscle physiology, the model also predicts that before the lactate switch, fatty acid oxidation increases, reaches a maximum, and then decreases to zero with concomitant increase in glucose utilization, in agreement with the empirical evidence. These results are further corroborated by a larger scale model, including biosynthesis of major cell biomass components. The larger scale model also predicts that in proliferating cells the lactate switch is accompanied by activation of glutaminolysis, another distinctive feature of the Warburg effect. In conclusion, intracellular molecular crowding is a fundamental constraint for cell metabolism in both rapidly proliferating- and non-proliferating cells with high metabolic demand. Addition of this constraint to metabolic flux balance models can explain several observations of mammalian cell metabolism under steady state conditions

Aerobic capacity, activity levels and daily energy expenditure in male and female adolescents of the kenyan nandi sub-group

The relative importance of genetic and socio-cultural influences contributing to the success of east Africans in endurance athletics remains unknown in part because the pre-training phenotype of this population remains incompletely assessed. Here cardiopulmonary fitness, physical activity levels, distance travelled to school and daily energy expenditure in 15 habitually active male (13.9±1.6 years) and 15 habitually active female (13.9±1.2) adolescents from a rural Nandi primary school are assessed. Aerobic capacity ([Formula: see text]) was evaluated during two maximal discontinuous incremental exercise tests; physical activity using accelerometry combined with a global positioning system; and energy expenditure using the doubly labelled water method. The [Formula: see text] of the male and female adolescents were 73.9±5.7 ml(.) kg(-1.) min(-1) and 61.5±6.3 ml(.) kg(-1.) min(-1), respectively. Total time spent in sedentary, light, moderate and vigorous physical activities per day was 406±63 min (50% of total monitored time), 244±56 min (30%), 75±18 min (9%) and 82±30 min (10%). Average total daily distance travelled to and from school was 7.5±3.0 km (0.8-13.4 km). Mean daily energy expenditure, activity-induced energy expenditure and physical activity level was 12.2±3.4 MJ(.) day(-1), 5.4±3.0 MJ(.) day(-1) and 2.2±0.6. 70.6% of the variation in [Formula: see text] was explained by sex (partial R(2) = 54.7%) and body mass index (partial R(2) = 15.9%). Energy expenditure and physical activity variables did not predict variation in [Formula: see text] once sex had been accounted for. The highly active and energy-demanding lifestyle of rural Kenyan adolescents may account for their exceptional aerobic fitness and collectively prime them for later training and athletic success