Rare, Threatened and Endangered Vascular Plants in Oregon: An Interim Report

This report on rare, threatened and endangered vascular plants in Oregon is a basic document in the process of inventorying the state\u27s natural areas * Prerequisite to the orderly establishment of natural preserves for research and conservation in Oregon are (1) a classification of the ecological types, and (2) a listing of the special organisms, which should be represented in a comprehensive system of designated natural areas. The necessary ecological classification was published in the U.S. Forest Service Pacific Northwest Forest and Range Experiment Station document, Research Natural Area Needs in the Pacific Northwest, by Dyrness et al. (1975). This valuable reference also provided lists of vascular plants of special interest in each major physiographic province, based on early work by Chambers and Siddall. Under the direction of the Oregon Rare and Endangered Plant Species Taskforce, work has actively continued to expand and perfect the list of vascular plant species, to serve the needs of land management and natural area planning in Oregon, and of many other governmental and private activities. Studies of rare and endangered plants in Oregon have involved a unique coalition of professional and amateur botanists, who have systematically gathered data on the distribution, abundance, habitat, and ecological requirements of some 700 native species. Coordination and leadership have come from the Oregon Rare and Endangered Plant Species Taskforce, and specifically from the Taskforce chairman, Jean L. Siddall. The Natural Area Preserves Advisory Committee has long recognized the significance of this effort and has encouraged the Taskforce\u27s goal of assembling a list of rare, threatened and endangered plant species for the State of Oregon. In August,1979, it was decided to support the publication of an interim report, summarizing the present status of all the plants under review by the Taskforce. This list will serve as a working document for the many individuals and organizations, both public and private, needing information on the rare plants in Oregon. This list will be particularly useful to the Natural Heritage Advisory Council (replacing the Natural Area Preserves Advisory Committee) as it develops the Natural Heritage Plan required by Oregon statute. Ultimately, a detailed Oregon List of Rare, Threatened and Endangered Plants will be produced. This current interim report is a timely step toward this goal

A Glossary of Selected Telecommunications Terms

The following glossary provides short definitions and descriptions of selected telecommunications terminology, agencies, and organizations, as well as a listing of key laws and Federal Communications Commission regulations and decisions

A boundary exchange influence on deglacial neodymium isotope records from the deep western Indian Ocean

The use of neodymium (Nd) isotopes to reconstruct past water mass mixing relies upon the quasi-conservative behaviour of this tracer, whereas recent studies in the modern oceans have suggested that boundary exchange, involving the addition of Nd from ocean margin sediments, may be an important process in the Nd cycle. Here we suggest that the relative importance of water mass advection versus boundary exchange can be assessed where the deep western boundary current in the Indian Ocean flows past the Madagascan continental margin; a potential source of highly unradiogenic Nd. Foraminiferal coatings and bulk sediment reductive leachates are used to reconstruct bottom water Nd isotopic composition (εNd) in 8 Holocene age coretops, with excellent agreement between the two methods. These data record spatial variability of ∼4 εNd units along the flow path of Circumpolar Deep Water; εNd≈−8.8 in the deep southern inflow upstream of Madagascar, which evolves towards εNd≈−11.5 offshore northern Madagascar, whereas εNd≈−7.3 where deep water re-circulates in the eastern Mascarene Basin. This variability is attributed to boundary exchange and, together with measurements of detrital sediment εNd, an isotope mass balance suggests a deep water residence time for Nd of ≤400 yr along the Madagascan margin. Considering deglacial changes, a core in the deep inflow upstream of Madagascar records εNd changes that agree with previous reconstructions of the Circumpolar Deep Water composition in the Southern Ocean, consistent with a control by water mass advection and perhaps indicating a longer residence time for Nd in the open ocean away from local sediment inputs. In contrast, sites along the Madagascan margin record offset εNd values and reduced glacial–interglacial variability, underlining the importance of detecting boundary exchange before inferring water mass source changes from Nd isotope records. The extent of Madagascan boundary exchange appears to be unchanged between the Holocene and Late Glacial periods, while a consistent shift towards more radiogenic εNd values at all sites in the Late Glacial compared to the Holocene may represent a muted signal of a change in water mass source or composition

Reactivity of neodymium carriers in deep sea sediments: Implications for boundary exchange and paleoceanography

The dissolved neodymium (Nd) isotopic distribution in the deep oceans is determined by continental weathering inputs, water mass advection, and boundary exchange between particulate and dissolved fractions. Reconstructions of past Nd isotopic variability may therefore provide evidence on temporal changes in continental weathering inputs and/or ocean circulation patterns over a range of timescales. However, such an approach is limited by uncertainty in the mechanisms and importance of the boundary exchange process, and the challenge in reliably recovering past seawater Nd isotopic composition (εNd) from deep sea sediments. This study addresses these questions by investigating the processes involved in particulate–solution interactions and their impact on Nd isotopes. A better understanding of boundary exchange also has wider implications for the oceanic cycling and budgets of other particle-reactive elements. Sequential acid-reductive leaching experiments at pH ∼2–5 on deep sea sediments from the western Indian Ocean enable us to investigate natural boundary exchange processes over a timescale appropriate to laboratory experiments. We provide evidence that both the dissolution of solid phases and exchange processes influence the εNd of leachates, which suggests that both processes may contribute to boundary exchange. We use major element and rare earth element (REE) data to investigate the pools of Nd that are accessed and demonstrate that sediment leachate εNd values cannot always be explained by admixture between an authigenic component and the bulk detrital component. For example, in core WIND 24B, acid-reductive leaching generates εNd values between −11 and −6 as a function of solution/solid ratios and leaching times, whereas the authigenic components have εNd ≈ −11 and the bulk detrital component has εNd ≈ −15. We infer that leaching in the Mascarene Basin accesses authigenic components and a minor radiogenic volcanic component that is more reactive than Madagascan-derived clays. The preferential mobilisation of such a minor component demonstrates that the Nd released by boundary exchange could often have a significantly different εNd composition than the bulk detrital sediment. These experiments further demonstrate certain limitations on the use of acid-reductive leaching to extract the εNd composition of the authigenic fraction of bulk deep sea sediments. For example, the detrital component may contain a reactive fraction which is also acid-extractible, while the incongruent nature of this dissolution suggests that it is often inappropriate to use the bulk detrital sediment elemental chemistry and/or εNd composition when assessing possible detrital contamination of leachates. Based on the highly systematic controls observed, and evidence from REE patterns on the phases extracted, we suggest two approaches that lead to the most reliable extraction of the authigenic εNd component and good agreement with foraminiferal-based approaches; either (i) leaching of sediments without a prior decarbonation step, or (ii) the use of short leaching times and low solution/solid ratios throughout

Electron transport components of the parasitic protozoon Giardia lamblia

AbstractThe energy metabolism of the intestinal parasite, Giardia lamblia, involves the iron-sulphur protein, pyruvate:ferredoxin oxidoreductase. Cell fractionation studies showed that this enzyme is associated with the membranes. NADH and NADPH dehydrogenases were found in both the membrane and cytosolic fractions. EPR spectroscopic studies showed the presence of iron-sulphur clusters in the membrane fraction and in the cytosolic fraction, non-sedimentable at 6 × 106g · min. An acidic, soluble protein fraction was separated from the cytosol. It had an EPR spectrum in the reduced state, characteristic of the 2[4Fe-4S] type of ferredoxin, with g-factors at 2.04, 1.93 and l .89. and the midpoint redox potential was estimated to be −360 mV. This species is probably a ferredoxin, like those of anaerobic bacteria such as Closlridium and Desiilfovihrio spp. and also that of Entamoeba histolytica. The protein was readily and irreversibly oxidized to give [3Fe 4S] clusters

Biopsychosocial management of chronic low back pain patients with psychological assessment and management tools

The volume of evidence questioning the efficacy of traditional treatment methods for chronic low back pain sufferers is equalled only by that condoning a more biopsychosocial approach to assessment and treatment. Unfortunately literature on this subject is often academic and does little to offer practical advice to clinicians on how they can apply psychosocial principles to practice. This paper briefly explores the reasons behind the increasing number of chronic back pain patients, reviews the psychological models relevant to understanding this client group, and offers basic practical advice on psychosocial assessment and treatment methods

Dynamic oscillatory signatures of central neuropathic pain in spinal cord injury

Central Neuropathic Pain (CNP) is believed to be accompanied by increased activation of the sensory and motor cortices. Our knowledge on this interaction is based mainly on fMRI studies, but there is little direct evidence on how these changes manifest in terms of dynamic neuronal activity. This study reports on the presence of transient EEG based measures of brain activity during motor imagery in spinal cord injured patients with CNP. We analyse dynamic EEG responses during imaginary movements of arms and legs in 3 groups of 10 volunteers each, comprising able-bodied people, paraplegic patients with CNP (lower abdomen and legs) and paraplegic patients without CNP. Paraplegic patients with CNP had increased event-related desynchronisation in the theta, alpha and beta bands (16-24 Hz) during imagination of movement of both non-painful (arms) and painful limbs (legs). Compared to patients with CNP, paraplegics with no pain showed a much reduced power in relaxed state and reduced event-related desynchronisation during imagination of movement. Understanding these complex dynamic, frequency-specific activations in CNP in the absence of nociceptive stimuli could inform the design of interventional therapies for patients suffering from CNP and possibly further understanding of the mechanisms involved

Denudation of the continental shelf between Britain and France at the glacial-interglacial timescale

The erosional morphology preserved at the sea bed in the eastern English Channel dominantly records denudation of the continental shelf by fluvial processes over multiple glacial-interglacial sea-level cycles rather than by catastrophic flooding through the Straits of Dover during the mid-Quaternary. Here, through the integration of multibeam bathymetry and shallow sub-bottom 2D seismic reflection profiles calibrated with vibrocore records, the first stratigraphic model of erosion and deposition on the eastern English Channel continental shelf is presented. Published Optical Stimulated Luminescence (OSL) and C ages were used to chronometrically constrain the stratigraphy and allow correlation of the continental shelf record with major climatic/sea-level periods. Five major erosion surfaces overlain by discrete sediment packages have been identified. The continental shelf in the eastern English Channel preserves a record of processes operating from Marine Isotope Stage (MIS) 6 to MIS 1. Planar and channelised erosion surfaces were formed by fluvial incision during lowstands or relative sea-level fall. The depth and lateral extent of incision was partly conditioned by underlying geology (rock type and tectonic structure), climatic conditions and changes in water and sediment discharge coupled to ice sheet dynamics and the drainage configuration of major rivers in Northwest Europe. Evidence for major erosion during or prior to MIS 6 is preserved. Fluvial sediments of MIS 2 age were identified within the Northern Palaeovalley, providing insights into the scale of erosion by normal fluvial regimes. Seismic and sedimentary facies indicate that deposition predominantly occurred during transgression when accommodation was created in palaeovalleys to allow discrete sediment bodies to form. Sediment reworking over multiple sea-level cycles (Saalian-Eemian-early Weichselian) by fluvial, coastal and marine processes created a multi-lateral, multi-storey succession of palaeovalley-fills that are preserved as a strath terrace. The data presented here reveal a composite erosional and depositional record that has undergone a high degree of reworking over multiple sea-level cycles leading to the preferential preservation of sediments associated with the most recent glacial-interglacial period

Cellular therapies for treating pain associated with spinal cord injury

Spinal cord injury leads to immense disability and loss of quality of life in human with no satisfactory clinical cure. Cell-based or cell-related therapies have emerged as promising therapeutic potentials both in regeneration of spinal cord and mitigation of neuropathic pain due to spinal cord injury. This article reviews the various options and their latest developments with an update on their therapeutic potentials and clinical trialing