Brush Management/Water Yield Feasibility Study for Four Watersheds In Texas

The Soil and Water Assessment Tool (SWAT) model was used to simulate the effects of brush removal on water yield in four watersheds in Texas for 1960 through 1999. Methods used in this study were similar to methods used in a previous study (TAES, 2000) in which 8 watersheds were analyzed. Landsat 7 satellite imagery was used to classify land use, and the 1:24,000 scale digital elevation model (DEM) was used to delineate watershed boundaries and subbasins. SWAT was calibrated to measured stream gauge flow and reservoir storage. Brush removal was simulated by converting all heavy and moderate categories of brush (except oak) to open range (native grass). Simulated changes in water yield due to brush treatment varied by subbasin, with all subbasins showing increased water yield as a result of removing brush. Average annual water yield increases ranged from about 111,000 gallons per treated acre in the Fort Phantom Hill watershed to about 178,000 gallons per treated acre in the Palo Pinto watershed. Water yield increases per treated acre were similar to a previous study (COE, 2002), but higher than TAES (2000). As in previous studies, there was a strong, positive correlation between water yield increase and precipitation. BACKGROUND Increases in brush area and density may contribute to a decrease in water yield, possibly due to increased evapotranspiration (ET) on watersheds with brush as compared to those with grass (Thurow, 1998; Dugas et al., 1998). Previous modeling studies of watersheds in Texas (Upper Colorado River Authority, 1998; TAES, 2000) indicated that removing brush might result in a significant increase in water yield. During the 2000-2001 legislative session, the Texas Legislature appropriated funds to study the effects of brush removal on water yield in watersheds above Lake Arrowhead, Lake Brownwood, Lake Fort Phantom Hill, and Lake Palo Pinto (Figure 1-1). The hydrologi

Ecosystem and Wildlife Implications of Brush: Management System Designed to Improve Water Runoff and Percolation

With the settlement of Texas and establishment of ranchers to produce cattle, there was an effort to maximize beef production. This caused serious overgrazing. In addition, there was a reduced incidence of fires across the landscape to clear out brush. These factors led to deterioration of the grazing lands and provided an opportunity for invasive intrusion by brush and other species onto the land and riparian zones. There has been a large-scale conversion from grasslands and savannahs to wildlands over the last 150 years (Scholes and Archer, 1997). The overall impacts are significantly impaired uplands and reduced percolation and surface flow of water from rainfall which caused changes and loss in basic aquatic and terrestrial habitat. The State of Texas adopted a program to study and implement brush management systems across the state to improve the water availability in streams, rivers, reservoirs and aquifers, as well as to improve the rangelands. The feasibility studies have shown great promise for improving ranchland and improving the water situation. However, there is less known about the aquatic and wildlife species response implications of brush management. Certainly, there are opportunities for improving the viability of an ecosystem through brush management strategies and continuing management practices. The purpose of this study was to evaluate the changes in hydrology and biological diversity associated with brush management in two watersheds where significant data was already available. This study focused on assessing the aquatic and terrestrial species implications related to specified brush management strategies over time. This involved an integrated analysis including modeling of the landscape, assessing biological diversity and developing economic implications for the two watersheds (Twin Buttes and Edwards regions). Thus, this study is comprised of three parts: modeling of brush management strategies temporally, assessing biological diversity (aquatic and terrestrial) and estimating economic implications. This represents a complex analysis involving variable units and multiple disciplines. Previous feasibility studies of brush removal have been targeted at maximizing water runoff. This analysis is an extension that is designed to examine the implications of brush management under a more restrictive set of brush removal criteria that were chosen based upon wildlife considerations. To achieve the integration of hydrologic modeling, range ecology, and economic implications, there were three team meetings bringing together all components to review status and set priorities for the remainder of the work. In addition, scientists in the three basic groups of specialization interacted daily along with representatives of the Corps of Engineers to assure that each decision was reflected in other parts of the analyses. The major addition of this analysis to brush management feasibility studies being conducted as part of the Texas brush management plan is the consideration of wildlife and aquatic biota and assessing changes in biological diversity likely to result from alternative brush management scenarios

Azimuthal anisotropy in Au+Au collisions at sqrtsNN = 200 GeV

The results from the STAR Collaboration on directed flow (v_1), elliptic flow (v_2), and the fourth harmonic (v_4) in the anisotropic azimuthal distribution of particles from Au+Au collisions at sqrtsNN = 200 GeV are summarized and compared with results from other experiments and theoretical models. Results for identified particles are presented and fit with a Blast Wave model. Different anisotropic flow analysis methods are compared and nonflow effects are extracted from the data. For v_2, scaling with the number of constituent quarks and parton coalescence is discussed. For v_4, scaling with v_2^2 and quark coalescence is discussed.Comment: 26 pages. As accepted by Phys. Rev. C. Text rearranged, figures modified, but data the same. However, in Fig. 35 the hydro calculations are corrected in this version. The data tables are available at http://www.star.bnl.gov/central/publications/ by searching for "flow" and then this pape

Rapidity and Centrality Dependence of Proton and Anti-proton Production from Au+Au Collisions at sqrt(sNN) = 130GeV

We report on the rapidity and centrality dependence of proton and anti-proton transverse mass distributions from Au+Au collisions at sqrt(sNN) = 130GeV as measured by the STAR experiment at RHIC. Our results are from the rapidity and transverse momentum range of |y|<0.5 and 0.35 <p_t<1.00GeV/c. For both protons and anti-protons, transverse mass distributions become more convex from peripheral to central collisions demonstrating characteristics of collective expansion. The measured rapidity distributions and the mean transverse momenta versus rapidity are flat within |y|<0.5. Comparisons of our data with results from model calculations indicate that in order to obtain a consistent picture of the proton(anti-proton) yields and transverse mass distributions the possibility of pre-hadronic collective expansion may have to be taken into account.Comment: 4 pages, 3 figures, 1 table, submitted to PR

Minijet deformation and charge-independent angular correlations on momentum subspace (η,ϕ)(\eta,\phi) in Au-Au collisions at sNN\sqrt{s_{NN}} = 130 GeV

First measurements of charge-independent correlations on angular difference variables $\eta_1 - \eta_2$ (pseudorapidity) and $\phi_1 - \phi_2$ (azimuth) are presented for primary charged hadrons with transverse momentum $0.15 \leq p_t \leq 2$ GeV/$c$ and $|\eta| \leq 1.3$ from Au-Au collisions at $\sqrt{s_{NN}} = 130$ GeV. Strong charge-independent angular correlations are observed associated with jet-like structures and elliptic flow. The width of the jet-like peak on $\eta_1 - \eta_2$ increases by a factor 2.3 from peripheral to central collisions, suggesting strong coupling of semi-hard scattered partons to a longitudinally-expanding medium. New methods of jet analysis introduced here provide evidence for nonperturbative QCD medium effects in heavy ion collisions.Comment: 8 pages, 4 figure

CASTLEGUARD : anonymised data streams with guaranteed differential privacy

Data streams are commonly used by data controllers to outsource the processing of real-time data to third-party data processors. Data protection legislation and best practice in data management support the view that data controllers are responsible for providing a guarantee of privacy for user data contained within published data streams. Continuously Anonymising STreaming data via adaptive cLustEring (CASTLE) is an established method for anonymising data streams with a guarantee of k-anonymity. However, k-anonymity has been shown to be a weak privacy guarantee that has vulnerabilities in practical applications. In this paper we propose Continuously Anonymising STreaming data via adaptive cLustEring with GUAR-anteed Differential privacy (CASTLEGUARD), a data stream anonymisation algorithm that provides a reliable guarantee of k-anonymity, l-diversity and differential privacy to data subjects. We analyse CASTLEGUARD to show that, through safe k-anonymisation and β-sampling, the proposed approach satisfies differentially private k-anonymity. Further, we demonstrate the efficacy of the approach in the context of machine learning, presenting experimental analysis to demonstrate that it can be used to protect the individual privacy of users whilst maintaining the utility of a data stream

Hippocampal subfield volumes are nonspecifically reduced in premature‐born adults

Reduced global hippocampus volumes have been demonstrated in premature‐born individuals, from newborns to adults; however, it is unknown whether hippocampus subfield (HCSF) volumes are differentially affected by premature birth and how relevant they are for cognitive performance. To address these questions, we investigated magnetic resonance imaging (MRI)‐derived HCSF volumes in very premature‐born adults, and related them with general cognitive performance in adulthood. We assessed 103 very premature‐born (gestational age [GA] <32 weeks and/or birth weight <1,500 g) and 109 term‐born individuals with cognitive testing and structural MRI at 26 years of age. HCSFs were automatically segmented based on three‐dimensional T1‐ and T2‐weighted sequences and studied both individually and grouped into three functional units, namely hippocampus proper (HP), subicular complex (SC), and dentate gyrus (DG). Cognitive performance was measured using the Wechsler‐Adult‐Intelligence‐Scale (full‐scale intelligence quotient [FS‐IQ]) at 26 years. We observed bilateral volume reductions for almost all HCSF volumes in premature‐born adults and associations with GA and neonatal treatment intensity but not birth weight. Left‐sided HP, SC, and DG volumes were associated with adult FS‐IQ. Furthermore, left DG volume was a mediator of the association between GA and adult FS‐IQ in premature‐born individuals. Results demonstrate nonspecifically reduced HCSF volumes in premature‐born adults; but specific associations with cognitive outcome highlight the importance of the left DG. Data suggest that specific interventions toward hippocampus function might be promising to lower adverse cognitive effects of prematurity

Delta- phi Delta- eta Correlations in Central Au+Au Collisions at sqrt{s_{NN}} = 200 Gev

We report charged-particle pair correlation analyses in the space of Delta -phi (azimuth) and Delta -eta (pseudo-rapidity), for central Au + Au collisions at sqrt{s_{NN}} = 200 GeV in the STAR detector. The analysis involves unlike-sign charge pairs and like-sign charge pairs, which are transformed into charge-dependent (CD) signals and charge-independent (CI) signals. We present detailed parameterizations of the data. A model featuring dense gluonic hot spots as first proposed by van Hove predicts that the observables under investigation would have sensitivity to such a substructure should it occur, and the model also motivates selection of transverse momenta in the range 0.8 < p_t < 2.0$ GeV/c. Both CD and CI correlations of high statistical significance are observed and possible interpretations are discussed.Comment: 18 pages, 8 figures, 2 tables submitted- Revised version Accepted-in press Phys. Rev.

Incident energy dependence of p(t) correlations at relativistic energies

Journals published by the American Physical Society can be found at http://publish.aps.org/We present results for two-particle transverse momentum correlations, , as a function of event centrality for Au+Au collisions at root SNN = 20, 62, 130, and 200 GeV at the BNL Relativistic Heavy Ion Collider. We observe correlations decreasing with centrality that are similar at all four incident energies. The correlations multiplied by the multiplicity density increase with incident energy, and the centrality dependence may show evidence of processes such as thermalization, jet production, or the saturation of transverse flow. The square root of the correlations divided by the event-wise average transverse momentum per event shows little or no beam energy dependence and generally agrees with previous measurements made at the CERN Super Proton Synchrotron

K(892)(*) resonance production in Au+Au and p+p collisions at root s(NN)=200 GeV

Journals published by the American Physical Society can be found at http://publish.aps.org/The short-lived K(892)* resonance provides an efficient tool to probe properties of the hot and dense medium produced in relativistic heavy-ion collisions. We report measurements of K* in root s(NN)=200 GeV Au+Au and p+p collisions reconstructed via its hadronic decay channels K(892)*(0)-> K pi and K(892)*(+/-)-> K(S)(0)pi(+/-) using the STAR detector at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. The K*(0) mass has been studied as a function of p(T) in minimum bias p+p and central Au+Au collisions. The K(*) p(T) spectra for minimum bias p+p interactions and for Au+Au collisions in different centralities are presented. The K*/K yield ratios for all centralities in Au+Au collisions are found to be significantly lower than the ratio in minimum bias p+p collisions, indicating the importance of hadronic interactions between chemical and kinetic freeze-outs. A significant nonzero K*(0) elliptic flow (v(2)) is observed in Au+Au collisions and is compared to the K(S)(0) and Lambda v(2). The nuclear modification factor of K* at intermediate p(T) is similar to that of K(S)(0) but different from Lambda. This establishes a baryon-meson effect over a mass effect in the particle production at intermediate p(T) (2 < p(T)<= 4 GeV/c)