Prediction of water temperature metrics using spatial modelling in the Eastern and Western Cape, South Africa

Key aspects of a river's temperature regime are described by magnitudes, timing and durations of thermal events, and frequencies of extreme exceedance events. To understand alterations to thermal regimes, it is necessary to describe thermal time series based on these statistics. Classification of sites based on their thermal metrics, and understanding of spatial patterns of these thermal statistics, provides a powerful approach for comparing study sites against reference sites. Water temperature regime dynamics should be viewed regionally, where regional divisions have an inherent underpinning by an understanding of natural thermal variability. The aim of this research was to link key water temperature metrics to readily-mapped environmental surrogates, and to produce spatial images of temperature metrics: 37 temperature metrics were derived for 12 months of sub-daily water temperatures at 90 sites in the Eastern Cape and Western Cape provinces, South Africa. These metrics were correlated with 16 environmental variables. Correlations enabled development of multiple regression models which facilitated mapping of temperature metrics over the study area. This approach has the potential to be applied at a national scale as more thermal time series are collected nationally. It is argued that the appropriateness of management decisions in rivers can be improved by including guidelines for thermal metrics at a regional scale. Such maps could facilitate incorporation of a temperature component into management guidelines for water resources

An empirical thermal history of the Earth's upper mantle

We have compiled petrological and geochemical data from 71 ophiolite suites and greenstone belts, which range in age from 15 to 3760 Ma. We have selected those rocks whose compositions indicate that they are either normal mid-ocean ridge basalts (MORBs) or hotspot-type MORBs. Then we used the data base to calculate the most primitive liquidus temperature for each rock suite. The results show that the liquidus temperature of the Phanerozoic ophiolites ranges from a low of 1212°C to a high of 1417°C. Using these data and two exponential curves bracketing the maximum and minimum temperatures versus time, we infer that the Phanerozoic suites had a mean liquidus temperature of 1272±7°C and a mean temperature range of 1218° to 1425°C. The liquidus temperatures of Archean MORBlike greenstones range from 1305° to 1576°C. Using these data and two exponential curves bracketing the maximum and minimum temperatures versus time, we infer that Archean melts at 2.8 Ga had a mean liquidus temperature of 1399±13°C and a temperature range from 1301° to 1533°C. Using two different methods, we show that the change in the mean liquidus temperature since the late Archean is from 96±13°C (from temperature ranges) to 127±20°C (from temperature means). When we convert these liquidus temperatures to potential temperature of the mantle, we find that the change in the mean upper mantle potential temperature since the late Archean is from 137±8°C (from temperature ranges) to 187±42°C (from temperature means). This change is less than that which was previously thought to have occurred. We compared the liquidus temperatures calculated from our data set with an independent data set from the modern day Pacific plate. The resulting histograms have the same shape and the same temperature range, showing that our method for calculating mantle temperatures from MORBlike rocks in ophiolite suites is valid. When our calculated liquidus temperatures for all time intervals are plotted in histograms, the resulting distributions are not bimodal, but skewed unimodal. That is, the distributions show a high-T tail which results from the presence of hotspot magmas in the data set. The Archean temperature distribution is also skewed unimodal, and the high-temperature Archean rocks, such as komatiites, plot in the hotspot area of the distribution. This strongly supports the contention that komatiites do not represent “normal” Archean mantle but rather were probably erupted by hotspots. Our data suggest that the relative proportion of hotspot magmas in oceanic lithosphere has remained nearly constant over geologic time

Rodents as receptor species at a tritium

New methods are being employed on the Department of Energy’s Savannah River Site to deal with the disposal of tritium, including the irrigation of a hardwood/pine forest with tritiated water from an intercepted contaminant plume to reduce concentrations of tritium outcropping into Fourmile Branch, a tributary of the Savannah River. The use of this system has proven to be an effective means of tritium disposal. To evaluate the impact of this activity on terrestrial biota, rodent species were captured on the tritium disposal site and a control site during two trapping seasons in order to assess tritium exposure resulting from the forest irrigation. Control site mice had background levels of tritium, 0.02 Bq/mL, with disposal site mice having significantly higher tritium concentrations, meanZ34.86 Bq/mL. Whole body tritium concentrations of the mice captured at the disposal site were positively correlated with tritium application and negatively correlated with precipitation at the site

The stagnation point von K\'arm\'an coefficient

On the basis of various DNS of turbulent channel flows the following picture is proposed. (i) At a height y from the y = 0 wall, the Taylor microscale \lambda is proportional to the average distance l_s between stagnation points of the fluctuating velocity field, i.e. \lambda(y) = B_1 l_s(y) with B_1 constant, for \delta_\nu << y \lesssim \delta. (ii) The number density n_s of stagnation points varies with height according to n_s = C_s y_+^{-1} / \delta_\nu^3 where C_s is constant in the range \delta_\nu << y \lesssim \delta. (iii) In that same range, the kinetic energy dissipation rate per unit mass, \epsilon = 2/3 E_+ u_\tau^3 / (\kappa_s y) where E_+ is the total kinetic energy per unit mass normalised by u_\tau^2 and \kappa_s = B_1^2 / C_s is the stagnation point von K\'arm\'an coefficient. (iv) In the limit of exceedingly large Re_\tau, large enough for the production to balance dissipation locally and for - ~ u_\tau^2 in the range \delta_\nu << y << \delta, dU_+/dy ~ 2/3 E_+/(\kappa_s y) in that same range. (v) The von K\'arm\'an coefficient \kappa is a meaningful and well-defined coefficient and the log-law holds only if E_+ is independent of y_+ and Re_\tau in that range, in which case \kappa ~ \kappa_s. The universality of \kappa_s = B_1^2 / C_s depends on the universality of the stagnation point structure of the turbulence via B_1 and C_s, which are conceivably not universal. (vi) DNS data of turbulent channel flows which include the highest currently available values of Re_\tau suggest E_+ ~ 2/3 B_4 y_+^{-2/15} and dU_+/dy_+ ~ B_4/(\kappa_s) y_+^{-1 - 2/15} with B_4 independent of y in \delta_\nu << y << \delta if the significant departure from - ~ u_\tau^2 is taken into account.Comment: 14 pages, 20 figures. This version of the article has been accepted for publication in PRE. Note though that the PRE paper format is differen

Murfreesboro Addresses

https://digitalcommons.acu.edu/crs_books/1086/thumbnail.jp

Effects of Antihypertensive Medications on Quality of Life in Elderly Hypertensive Women

The impact of antihypertensive medications on the quality of life of elderly hypertensive women has rarely been systematically evaluated in large clinical trials using drugs from the new generations of pharmaceutic preparations. We carried out a multicenter, randomized double-blind clinical trial with 309 hypertensive women aged 60 to 80 years to assess effects of atenolol, enalapril, and isradipine on measures of quality of life over a 22-week period. The patients had mild to moderate hypertension. Hydrochlorothiazide was added to treatment if monotherapy was inadequate in lowering blood pressure. At the conclusion of the trial the three drug groups did not differ in degree of reduction of diastolic blood pressure or in supplementation with hydrochlorothiazide. Over the 22-week trial, linear trend analysis showed no differences between the treatment groups in change from baseline on quality of life measures of well-being, physical status, emotional status, cognitive functioning, and social role participation. Regarding each of 33 physical side effects over the 22 weeks, we found no general difference between atenolol, enalapril, and isradipine groups on measures of change in distress over symptoms except for enalapril patients who worsened in distress over cough (P = .001) and atenolol patients who worsened in distress over dry mouth (P = .014). Centering on three medications that are relatively new additions to the armamentarium for blood pressure control, the findings underline the increasing opportunities for the physician to select drugs that can control blood pressure while maintaining the quality of life of elderly hypertensive women

Improvement of the Staggered Fermion Operators

We present a complete and detailed derivation of the finite lattice spacing corrections to staggered fermion matrix elements. Expanding upon arguments of Sharpe, we explicitly implement the Symanzik improvement program demonstrating the absence of order $a$ terms in the Symanzik improved action. We propose a general program to improve fermion operators to remove $O(a)$ corrections from their matrix elements, and demonstrate this program for the examples of matrix elements of fermion bilinears and $B_K$. We find the former does have $O(a)$ corrections while the latter does not.Comment: 16 pages, latex, 1 figur

Au/TiO2(110) interfacial reconstruction stability from ab initio

We determine the stability and properties of interfaces of low-index Au surfaces adhered to TiO2(110), using density functional theory energy density calculations. We consider Au(100) and Au(111) epitaxies on rutile TiO2(110) surface, as observed in experiments. For each epitaxy, we consider several different interfaces: Au(111)//TiO2(110) and Au(100)//TiO2(110), with and without bridging oxygen, Au(111) on 1x2 added-row TiO2(110) reconstruction, and Au(111) on a proposed 1x2 TiO reconstruction. The density functional theory energy density method computes the energy changes on each of the atoms while forming the interface, and evaluates the work of adhesion to determine the equilibrium interfacial structure.Comment: 20 pages, 11 figure

Niche-breadth of freshwater macrophytes occurring in tropical southern African rivers predicts species global latitudinal range

The study tested the hypothesis that measurement, using multivariate Principal Components Analy-sis (PCA), of the niche-breadth of river macrophyte species in southern tropical Africa, may predicttheir larger-scale biogeographical range. Two measures of niche-breadth were calculated for 44 riverinemacrophyte species, from 20 families commonly occurring in Zambia, using an approach based on PCAordination with 16 bio-physico-chemical input variables. These included altitude, stream order, streamflow, pH, conductivity and soluble reactive phosphate concentration (SRP). In the absence of additionalchemical water quality data for Zambian rivers, invertebrate-based measures of general water qualitywere also used. These were benthic macroinvertebrate Average Score per Taxon (ASPT), and individualabundance of nine macroinvertebrate families with differing water quality tolerance, indicated by theirSensitivity Weightings within the Zambian Invertebrate Scoring System (ZISS). Macrophyte large-scalelatitudinal range was derived from world geopositional records held by online databases, and additionalrecords held by the authors. The two niche-breadth metrics divided the species into narrow-niche andintermediate/broad-niche categories, showing significant variation (from one or both of correlation andANOVA test outcomes) in altitude, stream flow, conductivity, SRP, pH and ASPT, but not stream order.Macrophyte alpha-diversity (as a measure of number of individual niches co-existing per habitat) showedno significant relationship with individual species niche-breadth. Narrow-niche species included a higherproportion of Afrotropical endemics than did species with broader niche size. There were significant pre-dictive relationships between macrophyte niche-breadth and latitudinal range of the target species atglobal and Afrotropical scales, but not for the Neotropics.Fil: Kennedy, Michael. University Of Aberdeen; Reino UnidoFil: Lang, Pauline. University of Glasgow; Reino UnidoFil: Tapia Grimaldo, Julissa. University of Glasgow; Reino UnidoFil: Varandas Martins, Sara. University of Glasgow; Reino UnidoFil: Bruce, Alannah. University of Glasgow; Reino UnidoFil: Moore, Isabel. University of Glasgow; Reino UnidoFil: Taubert, Rebeca. University of Glasgow; Reino UnidoFil: Macleod-Nolan, Chantal. University of Glasgow; Reino UnidoFil: McWaters, Stephanie. University of Glasgow; Reino UnidoFil: Briggs, John. University of Glasgow; Reino UnidoFil: Lowe, Steve. University of Glasgow; Reino UnidoFil: Saili, Kochelani. University Of Zambia;Fil: SICHINGABULA, Henry. University Of Zambia;Fil: Dallas, Helen. Nelson Mandela Metropolitan University, Sudafrica; SudáfricaFil: Morrison, Sean. University of Glasgow; Reino UnidoFil: Franceschini, Maria Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Willems, Frank. The Kasanka Trust; ZambiaFil: Bottino, Flavia. Universidad Federal de San Carlos; BrasilFil: MURPHY Kevin. University of Glasgow; Reino Unid