Impact of Mesh Tracks and Low-Ground-Pressure Vehicle Use on Blanket Peat Hydrology

No abstract available

The Sustainable Carbon Management of Moorlands: spatial distribution and accumulation of carbon on Dartmoor, southwest England

Peatlands are unique habitats that have absorbed large amounts of carbon dioxide and locked it away as carbon buried in peat for millennia. In the UK, blanket peatlands form one of the largest terrestrial stores of carbon (Milne and Brown, 1997). Recent research suggests that the carbon sequestering potential and carbon stores of UK blanket peatlands are at risk from changes in land use practices and climate. Although, to date, little research has considered blanket peatland at a landscape scale and a comprehensive understanding of land use and degradation impact upon carbon sequestration has not been gained. This thesis presents a study of Dartmoor, a blanket peatland in south west England vulnerable to climate change (Clark et al, 2010). A landscape scale carbon inventory, using a methodology designed for blanket peatlands is presented. Nearly 1000 peat depths and 30 cores were taken using stratified sampling across Dartmoor’s landscape. Functional relationships between peat depth, bulk density and carbon content and topographic parameters were found. In arc GIS 9.3 these were used to model landscape scale carbon, this estimates that Dartmoor contained 9.7 (-2.91 + 2.97) Mt of carbon, a value similar to that of the national inventory (Bradley et al, 2005). The thesis then considers the impact of drainage and degradation on carbon accumulation. Fifteen cores were dated from a drained, degraded site with a history of burning and control site using Spheroidal Carbonaceous Particles (SCPs) and radionuclide techniques. Previous studies have raised concern surrounding accuracy dating recent peats. Results indicate that although dating was largely successful, some discrepancies existed related to poor calibration of SCPs and mobility of radionuclides. To avoid error in dating, it was concluded that multiple dates should be used per core. With consideration of this, carbon accumulation was found to be active but significantly lower in the degraded site and unchanged in the drained site. Further analysis suggested that this outcome may vary with changing management and topographic situations. Future carbon accumulation at a landscape scale was calculated under different scenarios. This found degradation could potentially reduce carbon sequestration on Dartmoor by up to 32%. Economic valuation of accumulation values was used to demonstrate how this data could be used to inform management. This thesis provides an insight into the carbon storage and threats to Dartmoor, an under investigated, yet threatened blanket peatland environment. This helps broaden the spatialGreat Western Research with Duchy of Cornwall, Dartmoor National Park Authority, National Trust, Natural England and Seale-Hayne Education Trus

Does the Composition of Dissolved Organic Carbon (DOC) in Peatland Streams Reflect the DOC Leached from Vegetation, Litter and Soil?

No abstract available

Paleoecology of Columbian and Pygmy Mammoths in Southern Nevada and California: How Terminal Pleistocene Ecosystems Shaped Mammoths at the Individual, Population, and Community Level

The purpose of this dissertation research is to examine the paleoecology of the Columbian mammoth (Mammuthus columbi) and the pygmy mammoth (M. exilis) on the individual, population, and community level, emphasizing factors internal to their ecosystem that may have contributed to their extinction. I focus specifically on mammoths from Southern Nevada and Southern California to add regional data to the complex and evolving study of North American mammoth paleoecology. Chapter 2 documents the permitted excavation of a partial mammoth (Mammuthus sp.) between 2016-2018 from late Pleistocene groundwater-discharge deposits near Fairbanks Spring in the Amargosa Valley, Nevada. A preliminary radiocarbon date from an in situ mollusk shell indicates a calibrated age of 25,580 – 25,149 cal BP, indicating the mammoth remains are of Last Glacial Maximum age. Recovered elements from the mammoth include the proximal portions of two articulated tusks within the (incisive bones) alveoli of the skull, skull bones that were disarticulated from the tusks prior to burial, a partial right scapula, the atlas, axis, and several other partial cervical vertebrae. The sedimentology and stratigraphy of the Fairbanks Spring mammoth site suggests a depositional environment along the margins of a perennial, marl-producing marsh with seasonally dry edges and seasonal influence from spring channels or ephemeral washes. Chapter 3 examines mammoth paleoecology at the population level, using mortality profile data to test the top-down trophic control hypothesis for Pleistocene extinction. For this study, a set of standard tooth measurement and identification standards for this analysis were compiled after extensive literature review. Fifty-eight Columbian mammoth molariform teeth were selected from the Gilcrease Cauldron Spring Paleontological Site (GCSPS), Las Vegas Formation, NV, to determine the ages of the animals in African elephant equivalent years for the purpose of constructing an age (a.k.a. mortality) profile. A Recalibrated radiocarbon dates of a subset of these teeth range from 14,336-20,567 rcy BP, around the onset of deglaciation. Ripple and Van Valkenburgh (2010) proposed that top-down trophic control of Pleistocene megaherbivore populations was a precursor to extinction and might have been secondarily enabled by predation pressure from Clovis hunters. Data generated from my study support this hypothesis. My results suggest that mammoth population sizes in the Las Vegas Valley during the Terminal Pleistocene were controlled from the top of the ecological pyramid down and were likely below carrying capacity. This trophic relationship may have made them vulnerable to extinction by an external catalyst. Mortality profiles from this study do not suggest that the GCSPS mammoth assemblage experienced lethal drought-stress or resource unavailability. Results from my study and others are consistent with top-down trophic controls on proboscideans surrounding the Last Glacial Maximum that may have made them susceptible to extinction at the end of the Pleistocene. Chapter 4 takes a similar approach to Chapter 3, constructing mortality profiles for the assemblage of Columbian mammoth teeth from Rancho La Brea (RLB), CA. This study was an opportunity to supplement RLB mammoth mortality profile data with paleoecological studies of Pleistocene large carnivores from RLB to test the top-down trophic control hypothesis by Ripple and Van Valkenburgh (2010). Thirty-eight fossil mammoth molariform teeth were selected from La Brea Tar Pits and Museum for this study to determine the tooth assignment and percentage of wear. I observed selective mortality within the mature-adult age class, with a background “Type A” pattern in other age classes. This pattern could be reflective of mortality during the warmest months of the year and warmer overall years between 40,000-14,000 cal BP. In particular, this mortality was likely additive, considering presumably healthy, mature adults became mired within the asphalt, but not likely contributing to population instability. This mortality pattern could also be a result of sex-selective mortality of mature adult males due to either entrapment or intraspecific male combat. My data, corroborated by other studies, do not suggest mammoth population instability or decline at RLB due to resource stress during the interval of 40,000-14,000 cal BP, allowing me to refute the alternative hypothesis of bottom-up control. Although I cannot support the top-down trophic control hypothesis directly with this dataset, data from numerous studies of large carnivores at RLB paint a picture of a diverse and competitive predator guild during the late Pleistocene. Chapter 5 examines mammoth paleoecology at the community level on the Northern Channel Islands of California. It has been suggested that body size played an important role in the behavioral isolation of M. columbi and M. exilis on the Northern Channel Islands of California; however this hypothesis has not previously been tested. Additionally, Channel Islands mammoth tooth morphological variation prompts questions about the timing, cause, and number of speciation events within this insular mammoth lineage. In this study, I test a hypothesis that body size played a role in niche partitioning between Channel Islands mammoth taxa. All teeth sampled for this study from the Natural History Museum of Los Angeles County were originally identified as M. exilis; however, several are within the size ranges observed for M. columbi. It is unclear if these teeth morphologically all belong to the same species, M. exilis. I used bulk (n=6) and serial (n=2) stable carbon and oxygen isotope data to interpret the ecological niche of this subset of Channel Islands mammoths. The δ13Csc values of tooth enamel from bulk sampling and mean serial sample values ranged from -13.07‰ to -6.8‰, VPDB (σ = 1.92). The calculated δ18OVSMOW values of tooth enamel ranged from 26.29‰ to 28.13‰, VSMOW (σ = 0.64). The calculated δ13Cdiet values of all the mammoth teeth sampled, excluding LPS2, suggest they ate a C3-dominated mixed feeder diet. The δ13Csc values from LPS2 were outliers within this assemblage of teeth, suggesting a mixed feeder diet with a higher concentration of C4 plants than the other sampled teeth in this study. The stable carbon isotope data from this study are consistent with reconstructed plant communities from the Channel Islands during the Pleistocene, and Channel Islands mammoths likely ate a much more C3-dominated diet than mammoths on mainland North America. The range of calculated drinking water δ18OWater values from this assemblage of teeth are unusually high (2.63‰ to 4.54‰, VSMOW), compared to the modern δ18O value for precipitation in Santa Barbara County, CA (-6‰, VSMOW) (Kendall and Coplen, 2001), which I interpret to reflect a dependence on surface waters sourced from condensed fog. During the Pleistocene, fewer fog events could have led to a corresponding decrease in conifer canopy cover on Santarosae, which in turn could have led to lower rates of fog drip, so the limited fog that Santarosae experienced would not be condensed and captured into surface waters as efficiently. In this way, Channel Islands mammoths may have needed to decrease their dependency on fog-sourced surface waters. Considering phylogenetic relationships, morphological variation, and gene flow within the continental North American Mammuthus metapopulation (See overview in Widga et al., 2017), it is likely that M. columbi and M. exilis of the Northern Channel Islands were not genetically or behaviorally isolated. Specifically, from this dataset, there does not seem to be any significant relationship between tooth size and inferred dietary niche

Does the Composition of Dissolved Organic Carbon (DOC) in Peatland Streams Reflect the DOC Leached from Vegetation, Litter and Soil?

No abstract available

How do nurse practitioners work in primary health care settings? A scoping review

© 2017 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 12 month embargo from date of publication (June 2017) in accordance with the publisher’s archiving policyObjectives This scoping review explores the work of nurse practitioners in primary health care settings in developed countries and critiques their contribution to improved health outcomes. Design A scoping review design was employed and included development of a research question, identification of potentially relevant studies, selection of relevant studies, charting data, collating, summarising and reporting findings. An additional step was added to evaluate the methodological rigor of each study. Data Data sources included literature identified by a search of electronic databases conducted in September 2015 (CINAHL, Informit, Web of Science, Scopus and Medline) and repeated in July 2016. Additional studies were located through hand searching and authors’ knowledge of other relevant studies. Results 74 articles from eight countries were identified, with the majority emanating from the United States of America. Nurse practitioners working in communities provided care mostly in primary care centres (n = 42), but also in community centres (n = 6), outpatient departments (n = 6), homes (n = 5), schools (n = 3), child abuse clinics (n = 1), via communication technologies (n = 6), and through combined face-to-face and communication technologies (n = 5). The scope of nurse practitioner work varied on a continuum from being targeted towards a specific disease process or managing individual health and wellbeing needs in a holistic manner. Enhanced skills included co-ordination, collaboration, education, counselling, connecting clients with services and advocacy. Measures used to evaluate outcomes varied widely from physiological data (n = 25), hospital admissions (n = 10), use of health services (n = 15), self-reported health (n = 13), behavioural change (n = 14), patient satisfaction (n = 17), cost savings (n = 3) and mortality/morbidity (n = 5). Conclusions The majority of nurse practitioners working in community settings did so within a selective model of primary health care with some examples of nurse practitioners contributing to comprehensive models of primary health care. Nurse practitioners predominantly worked with populations defined by an illness with structured protocols for curative and rehabilitative care. Nurse practitioner work that also incorporated promotive activities targeted improving social determinants of health for people rendered vulnerable due to ethnicity, Aboriginal identity, socioeconomic disadvantage, remote location, gender and aging. Interventions were at individual and community levels with outcomes including increased access to care, cost savings and salutogenic characteristics of empowerment for social change

Collaboration and contestation in further and higher education partnerships in England: a Bourdieusian field analysis

Internationally, ‘College for All’ policies are creating new forms of vocational higher education (HE), and shifting relationships between HE and further education (FE) institutions. In this paper, we consider the way in which this is being implemented in England, drawing on a detailed qualitative case study of a regional HE–FE partnership to widen participation. We focus on the complex mix of collaboration and contestation that arose within it, and how these affected socially differentiated groups of students following high- and low-status routes through its provision. We outline Bourdieu’s concept of ‘field’ as a framework for our analysis and interpretation, including its theoretical ambiguities regarding the definition and scale of fields. Through hermeneutic dialogue between data and theory, we tentatively suggest that such partnerships represent bridges between HE and FE. These bridges are strong between higher-status institutions, but highly contested between lower-status institutions competing closely for distinction. We conclude that the trajectories and outcomes for socially disadvantaged students require attention and collective action to address the inequalities they face, and that our theoretical approach may have wider international relevance beyond the English case

Early inflammatory cytokine expression in cerebrospinal fluid of patients with spontaneous intraventricular hemorrhage

We investigated cerebrospinal fluid (CSF) expression of inflammatory cytokines and their relationship with spontaneous intracerebral and intraventricular hemorrhage (ICH, IVH) and perihematomal edema (PHE) volumes in patients with acute IVH. Twenty-eight adults with IVH requiring external ventricular drainage for obstructive hydrocephalus had cerebrospinal fluid (CSF) collected for up to 10 days and had levels of interleukin-1α (IL-1α), IL-1β, IL-6, IL-8, IL-10, tumor necrosis factor-α (TNFα), and C-C motif chemokine ligand CCL2 measured using enzyme-linked immunosorbent assay. Median [IQR] ICH and IVH volumes at baseline (T0) were 19.8 [5.8–48.8] and 14.3 [5.3–38] mL respectively. Mean levels of IL-1β, IL-6, IL-10, TNF-α, and CCL2 peaked early compared to day 9–10 (p < 0.05) and decreased across subsequent time periods. Levels of IL-1β, IL-6, IL-8, IL-10, and CCL2 had positive correlations with IVH volume at days 3–8 whereas positive correlations with ICH volume occurred earlier at day 1–2. Significant correlations were found with PHE volume for IL-6, IL-10 and CCL2 at day 1–2 and with relative PHE at days 7–8 or 9–10 for IL-1β, IL-6, IL-8, and IL-10. Time trends of CSF cytokines support experimental data suggesting association of cerebral inflammatory responses with ICH/IVH severity. Pro-inflammatory markers are potential targets for injury reduction

Chronic widespread pain after motor vehicle collision typically occurs through immediate development and nonrecovery: results of an emergency department-based cohort study

Motor vehicle collision (MVC) can trigger chronic widespread pain (CWP) development in vulnerable individuals. Whether such CWP typically develops via the evolution of pain from regional to widespread or via the early development of widespread pain with non-recovery is currently unknown. We evaluated the trajectory of CWP development (American College of Rheumatology criteria) among 948 European-American individuals who presented to the emergency department (ED) for care in the early aftermath of MVC. Pain extent was assessed in the ED and 6 weeks, 6 months, and 1 year after MVC on 100%, 91%, 89%, and 91% of participants, respectively. Individuals who reported prior CWP at the time of ED evaluation (n = 53) were excluded. Trajectory modeling identified a two-group solution as optimal, with the Bayes Factor value (138) indicating strong model selection. Linear solution plots supported a non-recovery model. While the number of body regions with pain in the non-CWP group steadily declined, the number of body regions with pain in the CWP trajectory group (192/895, 22%) remained relatively constant over time. These data support the hypothesis that individuals who develop CWP after MVC develop widespread pain in the early aftermath of MVC which does not remit