Wetland resource evaluation and the NRA's role in its conservation. Classification of British wetlands

This is the Wetland resource evaluation and the NRA's role in its conservation: Classification of British wetlands report produced by the National Rivers Authority in 1995. This R&D document provides a clear classification for wetlands in England and Wales. The classification incorporates many of the existing ideas on the subject but avoids some of the problems associated with other classifications. A two-layered 'hydrotopographical' classification is proposed. The first layer identifies situation-types, i.e. the position the wetland occupies in the landscape, with special emphasis upon the principal sources of water. The second layer identifies hydrotopographical elements, i.e. units with distinctive water supply and, sometimes, distinctive topography in response to this. This system is seen as an independent, basic, classification upon which it is possible to superimpose additional, independent classifications based on other features (e.g. base-status, fertility, vegetation, management etc.). Some proposals for such additional classifications are provided

Wetland resource evaluation and the NRA's role in its conservation. 1. Resource assessment

This is the Wetland resource evaluation and the NRA's role in its conservation: Resource assessment report produced by the National Rivers Authority in 1995. This R&D document provides a strategy for the assessment of the wetland resource of England and Wales. As a first step the report defines wetlands in their UK context. The following working definition is suggested: Wetland is land that has (or had until modified) a water level predominantly at, near, or up to 1.5 m above the ground surface for sufficient time during the year to allow hydrological processes to be a major influence on the soils and biota. These processes may be expressed in certain features, such as characteristic soils and vegetation. The report also summarises a hydrotopographical classification of wetlands. The report then develops a strategy for the establishment of a wetland resource Inventory based on a geographical information system (GIS) as a means of storing and manipulating site data from across England and Wales

The results of subintimal angioplasty in a district general hospital

AbstractObjectives and Design: we report a prospective study to determine if subintimal angioplasty can be performed in non-teaching centres and to establish its learning curve. Materials and Methods: subintimal angioplasty was performed on 50 limbs in 46 patients (34 male) with a median age of 72 years (range 45–93 years). Indication was critical limb ischaemia (27 limbs) or intermittent claudication (23 limbs). Occlusions were located in the superficial femoral artery in 44 limbs, popliteal artery in 4 limbs and the peroneal artery in two limbs. At a median of 7.9 months patients had colour duplex imaging of the vessels that underwent angioplasty to assess vessel patency. Results: primary technical success was achieved in 39 cases (78%). Primary technical success was greater in the second group of 25 consecutive limbs to undergo angioplasty at 92% (23 cases) compared with the first 25 consecutive limbs at 64% (16 cases). At 6 months the overall vessel patency rate on duplex imaging was 57%, improving to 64% in the group having a primarily successful procedure. The equivalent rate of symptomatic improvement was 59 and 66% respectively. Complications occurred in five procedures, most were minor, but a single fatality was directly attributable to the procedure. Conclusion: subintimal angioplasty can reasonably be performed outside major teaching institutions. There is a short learning curve associated with the procedure

Preliminary design for Arctic atmospheric radiative transfer experiments

If current plans are realized, within the next few years, an extraordinary set of coordinated research efforts focusing on energy flows in the Arctic will be implemented. All are motivated by the prospect of global climate change. SHEBA (Surface Energy Budget of the Arctic Ocean), led by the National Science Foundation (NSF) and the Office of Naval Research (ONR), involves instrumenting an ice camp in the perennial Arctic ice pack, and taking data for 12--18 months. The ARM (Atmospheric Radiation Measurement) North Slope of Alaska and Adjacent Arctic Ocean (NSA/AAO) Cloud and Radiation Testbed (CART) focuses on atmospheric radiative transport, especially in the presence of clouds. The NSA/AAO CART involves instrumenting a sizeable area on the North Slope of Alaska and adjacent waters in the vicinity of Barrow, and acquiring data over a period of about 10 years. FIRE (First ISCCP [International Satellite Cloud Climatology Program] Regional Experiment) Phase 3 is a program led by the National Aeronautics and Space Administration (NASA) which focuses on Arctic clouds, and which is coordinated with SHEBA and ARM. FIRE has historically emphasized data from airborne and satellite platforms. All three program anticipate initiating Arctic data acquisition during spring, 1997. In light of his historic opportunity, the authors discuss a strawman atmospheric radiative transfer experimental plan that identifies which features of the radiative transport models they think should be tested, what experimental data are required for each type of test, the platforms and instrumentation necessary to acquire those data, and in general terms, how the experiments could be conducted. Aspects of the plan are applicable to all three programs

Short note on improved integration of mechanical testing in predictive wear models

In this work, a new global increment nano-fretting wear model based on the effective indenter concept has been used and the results were compared with experimental data. A series of DLC coatings with varied mechanical properties was deposited using industrial scale PECVD system and characterised on a low-drift nanomechanical test platform (NanoTest Vantage). 4500. cycle nano-scale fretting measurements have been performed in order to examine the tribological properties of the coatings. A physical analysis of the nanoindentation test enabled the true coating Young's Modulus (E) and the coating yield strength (Y) to be determined. In comparison to the hardness (H) this is the basis for a more generic understanding of the mechanical coating behaviour. This allowed a direct examination of the influence of the variation of Y/. E in the coatings on the observed nano-fretting wear, with the coating with highest Y/. E showing significantly improved resistance to nano-fretting wear. A preliminary evaluation of the stress field evolution during the test and the extraction of wear and fretting parameters provides the opportunity to discuss the effects possibly being dominant within the nano-scale tribo-tests

Using confirmatory factor analysis to evaluate construct validity of the Brief Pain Inventory (BPI)

Context: The Brief Pain Inventory (BPI) is a frequently used instrument designed to assess the patient-reported outcome of pain. The majority of factor analytic studies have found a two-factor (i.e., pain intensity and pain interference) structure for this instrument; however, because the BPI was developed with an a priori hypothesis of the relationship among its items, it follows that construct validity investigations should use confirmatory factor analysis (CFA). Objectives: The purpose of this work was to establish the construct validity of the BPI using a CFA framework and demonstrate factorial invariance using a range of demographic variables. Methods: A retrospective CFA was completed in a sample of individuals diagnosed with HIV/AIDS and cancer (n = 364; 63% male; age 21-92 years, M = 51.80). A baseline one-factor model was compared against two-factor and three-factor models (i.e., pain intensity, activity interference, and affective interference) that were developed based on the hypothetical design of the instrument. Results: Fit indices for the three-factor model were statistically superior when compared with the one-factor model and marginally better when compared with the two-factor model. This three-factor structure was found to be invariant across disease, age, and ethnicity groups. Conclusion: The results of this study provide evidence to support a three-factor representation of the BPI, and the originally hypothesized two-factor structure. Such findings will begin to provide clinical trialists, pharmaceutical sponsors, and regulators with confidence in the psychometric properties of this instrument when considering its inclusion in clinical research

The First Magnetic Fields

We review current ideas on the origin of galactic and extragalactic magnetic fields. We begin by summarizing observations of magnetic fields at cosmological redshifts and on cosmological scales. These observations translate into constraints on the strength and scale magnetic fields must have during the early stages of galaxy formation in order to seed the galactic dynamo. We examine mechanisms for the generation of magnetic fields that operate prior during inflation and during subsequent phase transitions such as electroweak symmetry breaking and the quark-hadron phase transition. The implications of strong primordial magnetic fields for the reionization epoch as well as the first generation of stars is discussed in detail. The exotic, early-Universe mechanisms are contrasted with astrophysical processes that generate fields after recombination. For example, a Biermann-type battery can operate in a proto-galaxy during the early stages of structure formation. Moreover, magnetic fields in either an early generation of stars or active galactic nuclei can be dispersed into the intergalactic medium.Comment: Accepted for publication in Space Science Reviews. Pdf can be also downloaded from http://canopus.cnu.ac.kr/ryu/cosmic-mag1.pd

Heavy Quarks and Heavy Quarkonia as Tests of Thermalization

We present here a brief summary of new results on heavy quarks and heavy quarkonia from the PHENIX experiment as presented at the "Quark Gluon Plasma Thermalization" Workshop in Vienna, Austria in August 2005, directly following the International Quark Matter Conference in Hungary.Comment: 8 pages, 5 figures, Quark Gluon Plasma Thermalization Workshop (Vienna August 2005) Proceeding

Single Electrons from Heavy Flavor Decays in p+p Collisions at sqrt(s) = 200 GeV

The invariant differential cross section for inclusive electron production in p+p collisions at sqrt(s) = 200 GeV has been measured by the PHENIX experiment at the Relativistic Heavy Ion Collider over the transverse momentum range $0.4 <= p_T <= 5.0 GeV/c at midrapidity (eta <= 0.35). The contribution to the inclusive electron spectrum from semileptonic decays of hadrons carrying heavy flavor, i.e. charm quarks or, at high p_T, bottom quarks, is determined via three independent methods. The resulting electron spectrum from heavy flavor decays is compared to recent leading and next-to-leading order perturbative QCD calculations. The total cross section of charm quark-antiquark pair production is determined as sigma_(c c^bar) = 0.92 +/- 0.15 (stat.) +- 0.54 (sys.) mb.Comment: 329 authors, 6 pages text, 3 figures. Submitted to Phys. Rev. Lett. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Nuclear Modification of Electron Spectra and Implications for Heavy Quark Energy Loss in Au+Au Collisions at sqrt(s_NN)=200 GeV

The PHENIX experiment has measured mid-rapidity transverse momentum spectra (0.4 < p_T < 5.0 GeV/c) of electrons as a function of centrality in Au+Au collisions at sqrt(s_NN)=200 GeV. Contributions from photon conversions and from light hadron decays, mainly Dalitz decays of pi^0 and eta mesons, were removed. The resulting non-photonic electron spectra are primarily due to the semi-leptonic decays of hadrons carrying heavy quarks. Nuclear modification factors were determined by comparison to non-photonic electrons in p+p collisions. A significant suppression of electrons at high p_T is observed in central Au+Au collisions, indicating substantial energy loss of heavy quarks.Comment: 330 authors, 6 pages text, 3 figures. Submitted to Phys. Rev. Lett. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm