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Search Results: 1 - 10 of 323428 matches for " Thomas J. Dean "
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Explaining First-Year Seedling Survival from Quality Distributions of Bare-Root Seedlings and Microsites in Industrial Plantations  [PDF]
Puskar N. Khanal, Thomas J. Dean, Scott D. Roberts, Donald L. Grebner, Thomas J. Straka
Open Journal of Forestry (OJF) , 2018, DOI: 10.4236/ojf.2018.83023
Abstract: First-year seedling survival impacts all subsequent management planning in plantation forestry. Descriptive statistics of first-year seedling survival data from the Louisiana Department of Agriculture and Forestry (LDAF) indicated that survival success reaches a plateau at between 79% - 85% under normal weather conditions. We provide an explanation for this plateau based on an analysis of seedling and microsite qualities involved in operational pine plantations by: 1) using a conceptual model demonstrating how variation in seedling quality and microsite quality interact to determine plantation survival, 2) presenting an example to characterize quality distributions of seedling and microsite qualities, and 3) comparing model outcomes based on measured distributions to realistic values of first-year survival. Simulation results indicated that consistent survival could result from random pairings of initial seedling and site quality distributions. LDAF data analysis indicated that 72% of seedlings were associated with the most frequent quality class that comprised seedlings with stem caliper between 3.2 to 4.7 mm and average stem height and volume of 25.75 cm and 3.43 cm3, respectively. Similarly, assessment of microsites at planting sites in Southeast Louisiana indicated that 48% of planted seedlings were associated with the most frequent microsite quality class which supported first-year height increment between 9 to 29 cm. Modelling of current operational practice indicated that using seedlings with larger caliper size would increase first year survival, but would result in higher establishment costs. The conceptual model could be modified to for use in other regions regardless of species types involved.
Health insurance, neighborhood income, and emergency department usage by Utah children 1996–1998
Anthony Suruda, Thomas J Burns, Stacey Knight, J Michael Dean
BMC Health Services Research , 2005, DOI: 10.1186/1472-6963-5-29
Abstract: Emergency department usage rates were calculated from 1996 through 1998 using Utah ED data for children with commercial health insurance, Medicaid, for uninsured children, and by income group estimating neighborhood household income from Zip code of residence. We analyzed usage following the July 1996 transition of Utah Medicaid to managed care.Children with Medicaid had approximately 50% greater ED utilization rates than children with commercial health insurance or uninsured children. The majority of usage for Medicaid and uninsured children was for non-traumatic conditions. Only 35% of total ED usage was for non-emergent or non-urgent conditions and this was related to both Medicaid and low household income. Children lacking health insurance were more likely to be discharged against medical advice (OR = 2.36, 95% C.I. 1.88–2.96). There was no reduction in Medicaid ED usage following the transition to managed care.Usage of ED services is related to both health insurance status and income. Children lacking health insurance and Medicaid children have excessive usage for conditions which could be treated in a primary care setting. That managed care does not reduce Medicaid ED usage is consistent with findings of other studies.The increase in utilization of emergency medical services in the U.S. and other developed countries in recent decades is related to availability of ambulatory medical services and to the provision of health insurance [1]. Acute injury [2], longevity [3], and health insurance coverage across an array of conditions [4] are related to the absolute and relative distribution of income in a society. In the United States it is estimated that from 40% to 60% of ED visits are for non-urgent conditions and that such usage is related to availability, social and economic factors, availability of other medical services, and consumer choice [5].The Emergency Medical Treatment and Active Labor Act of 1986 mandates that hospital emergency departments provide car
Population-based cohort study of outpatients with pneumonia: rationale, design and baseline characteristics
Dean T Eurich, Sumit R Majumdar, Thomas J Marriet
BMC Infectious Diseases , 2012, DOI: 10.1186/1471-2334-12-135
Abstract: From 2000–2002, all CAP patients presenting to 7 Emergency Departments in Edmonton, Alberta, Canada were prospectively enrolled in a population-based registry. Clinical data, including pneumonia severity index (PSI) were collected at time of presentation. Patients discharged to the community were then followed for up to 5?years through linkage to the provincial administrative databases. The current report provides the rationale and design for the cohort, as well as describes baseline characteristics and 30-day morbidity and mortality.The total sample included 3874 patients. After excluding patients who were hospitalized, died or returned to the Emergency Department the same day they were initially discharged (n?=?451; 12?%), and patients who could not be linked to provincial administrative databases (n?=?237; 6?%), the final cohort included 3186 patients treated according to a validated clinical management pathway and discharged back to the community. Mean age was 51 (SD?=?20) years, 53?% male; 4?% resided in a nursing home, 95?% were independently mobile, and 88?% had mild (PSI class I-III) pneumonia. Within 30-days, return to Emergency Department was common (25?%) as was hospitalization (8?%) and 1?% of patients had died.To our knowledge, this represents the largest clinically-detailed outpatient CAP cohort assembled to date and will add to our understanding of the determinants and outcomes in this under-researched patient population. The rich clinical data along with the long term health care utilization and mortality will allow for the identification of novel prognostic indicators. Given how under studied this population is, the findings should aid clinicians in the routine care of their outpatients with pneumonia and help define the next generation of research questions.
A Randomized Comparison of a Parker Endotracheal Tube and a Standard Tube Oriented 90° Counterclockwise  [PDF]
Wade A. Weigel, Thomas C. Dean
Open Journal of Anesthesiology (OJAnes) , 2012, DOI: 10.4236/ojanes.2012.25050
Abstract: Purpose: During oral fiberoptic intubation, advancement of an endotracheal tube (ETT) into the trachea is occasionally impeded by laryngeal structures. The curved flex tip Parker ETT has been shown to improve the likelihood of successful advancement as opposed to a standard ETT that is advanced in neutral orientation. However, a Parker tube has not been compared to a standard ETT oriented 90° counterclockwise from the neutral position. We hypothesize that fiber-optically-guided advancement of an ETT into the trachea will be more successful when using a Parker tube than a 90° counterclockwise-oriented standard ETT. Methods: This unblinded, randomized controlled trial compares the rate of successful advancement of a fiberoptically-guided endotracheal tube into the trachea. Two groups of randomly assigned patients with non-difficult airways are compared: a Parker flex-tip tube (Parker Group; n = 57) versus a standard ETT oriented 90° counterclockwise (Standard Group; n = 58). Our primary outcome is the first pass success rate of advanceing the ETT into the trachea. Results: First pass success occurred in 48 of 57 (84%) patients in the Parker Group vs. 39 of 58 (67%) of patients in the Standard Group (p = 0.0497). Conclusion: When advancing an ETT over an oral fiberoptic scope and into the trachea, a Parker curved flex tip ETT is statistically more likely to be placed successfully on the first pass than is a standard ETT oriented 90° counterclockwise.
Whole Farm Net Greenhouse Gas Abatement from Establishing Kikuyu-Based Perennial Pastures in South-Western Australia
Dean T. Thomas,Jonathan Sanderman,Sandra J. Eady,David G. Masters,Paul Sanford
Animals , 2012, DOI: 10.3390/ani2030316
Abstract: On-farm activities that reduce GHG emissions or sequester carbon from the atmosphere to compensate for anthropogenic emissions are currently being evaluated by the Australian Government as carbon offset opportunities. The aim of this study was to examine the implications of establishing and grazing Kikuyu pastures, integrated as part of a mixed Merino sheep and cropping system, as a carbon offset mechanism. For the assessment of changes in net greenhouse gas emissions, results from a combination of whole farm economic and livestock models were used (MIDAS and GrassGro). Net GHG emissions were determined by deducting increased emissions from introducing this practice change (increased methane and nitrous oxide emissions due to higher stocking rates) from the soil carbon sequestered from growing the Kikuyu pasture. Our results indicate that livestock systems using perennial pastures may have substantially lower net GHG emissions, and reduced GHG intensity of production, compared with annual plant-based production systems. Soil carbon accumulation by converting 45% of arable land within a farm enterprise to Kikuyu-based pasture was determined to be 0.80 t CO 2-e farm ha ?1 yr ?1 and increased GHG emissions (leakage) was 0.19 t CO 2-e farm ha ?1 yr ?1. The net benefit of this practice change was 0.61 t CO 2-e farm ha ?1 yr ?1 while the rate of soil carbon accumulation remains constant. The use of perennial pastures improved the efficiency of animal production almost eight fold when expressed as carbon dioxide equivalent emissions per unit of animal product. The strategy of using perennial pasture to improve production levels and store additional carbon in the soil demonstrates how livestock should be considered in farming systems as both sources and sinks for GHG abatement.
Establishment and mitotic stability of an extra-chromosomal mammalian replicon
Isa M Stehle, Jan Postberg, Sina Rupprecht, Thomas Cremer, Dean A Jackson, Hans J Lipps
BMC Cell Biology , 2007, DOI: 10.1186/1471-2121-8-33
Abstract: The autonomous replicon replicates in all eukaryotic cells and is stably maintained in the absence of selection but, as other extra-chromosomal replicons, its establishment is very inefficient. We now show that following establishment the vector is stably associated with nuclear compartments involved in gene expression and chromosomal domains that replicate at the onset of S-phase. While the vector stays autonomous, its association with these compartments ensures the efficiency of replication and mitotic segregation in proliferating cells.Using this novel minimal model system we demonstrate that relevant functions of the eukaryotic nucleus are strongly influenced by higher nuclear architecture. Furthermore our findings have relevance for the rational design of episomal vectors to be used for genetic modification of cells: in order to improve such constructs with respect to efficiency elements have to be identified which ensure that such constructs reach regions of the nucleus favorable for replication and transcription.Basic functions of the eukaryotic nucleus, like transcription and replication, are regulated in a hierarchic fashion and it is assumed that epigenetic factors influence the precision and efficiency of these processes [1]. Epigenetic regulators operate at many levels such as post-translational modifications of histone proteins that define a histone code [2], the 3D architecture and dynamic properties of chromatin domains and chromosome territories [3], and the interaction of chromatin with nuclear compartments that form dedicated sites of nuclear function [1,4]. The regulatory potential that results from the combination of these features is clearly complex, and as a result it is extremely challenging to define how each feature might influence chromatin function. One approach to address this problem is to locally uncouple the different epigenetic features.Here we describe how this can be achieved using the autonomously replicating vector pEPI (Figure 1A
Study protocol: Addressing evidence and context to facilitate transfer and uptake of consultation recording use in oncology: A knowledge translation implementation study
Thomas F Hack, J Dean Ruether, Lorna M Weir, Debjani Grenier, Lesley F Degner
Implementation Science , 2011, DOI: 10.1186/1748-5908-6-20
Abstract: Sixteen oncologists from cancer centres in three Canadian cities will participate in this three-phase study. The preimplementation phase will be used to identify and address those factors that are fundamental to facilitating the smooth adoption and delivery of the intervention during the implementation phase. During the implementation phase, breast and prostate cancer patients will receive a recording of their initial oncology consultation to take home. Patient interviews will be conducted in the days following the consultation to gather feedback on the benefits of the intervention. Patients will complete the Digital Recording Use Semi-Structured Interview (DRUSSI) and be invited to participate in focus groups in which their experiences with the consultation recording will be explored. Oncologists will receive a summary letter detailing the benefits voiced by their patients. The postimplementation phase includes a conceptual framework development meeting and a seven-point dissemination strategy.Consultation recording has been used in oncology, family medicine, and other medicine specialties, and despite affirming evidence and probable applications to a large number of diseases and a variety of clinical contexts, clinical adoption of this intervention has been slow. The proposed study findings will advance our conceptual knowledge of the ways to enhance uptake of consultation recordings in oncology.The time from diagnosis through to completion of therapy is challenging for newly diagnosed cancer patients. Patients have a substantial need for information, decision aids, and psychosocial support. One intervention that has proved promising in addressing these needs is providing a recording of the initial consultation [1-16]. Consultation recordings allow for memories to be refreshed, for the learning of information not recalled from the initial consultation, for a clearer understanding of one's cancer treatment [6-8], for greater confidence that critical aspects of the
Sources of light-absorbing aerosol in arctic snow and their seasonal variation
Dean A. Hegg, Stephen G. Warren, Thomas C. Grenfell, Sarah J Doherty,Antony D. Clarke
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2010,
Abstract: Two data sets consisting of measurements of light absorbing aerosols (LAA) in arctic snow together with suites of other corresponding chemical constituents are presented; the first from Siberia, Greenland and near the North Pole obtained in 2008, and the second from the Canadian arctic obtained in 2009. A preliminary differentiation of the LAA into black carbon (BC) and non-BC LAA is done. Source attribution of the light absorbing aerosols was done using a positive matrix factorization (PMF) model. Four sources were found for each data set (crop and grass burning, boreal biomass burning, pollution and marine). For both data sets, the crops and grass biomass burning was the main source of both LAA species, suggesting the non-BC LAA was brown carbon. Depth profiles at most of the sites allowed assessment of the seasonal variation in the source strengths. The biomass burning sources dominated in the spring but pollution played a more significant (though rarely dominant) role in the fall, winter and, for Greenland, summer. The PMF analysis is consistent with trajectory analysis and satellite fire maps.
Neutron matter on the lattice with pionless effective field theory
Dean Lee,Thomas Schaefer
Physics , 2004, DOI: 10.1103/PhysRevC.72.024006
Abstract: We study neutron matter by combining pionless effective field theory with non-perturbative lattice methods. The neutron contact interaction is determined by zero temperature scattering data. We simulate neutron matter on the lattice at temperatures 4 and 8 MeV and densities below one-fifth normal nuclear matter density. Our results at different lattice spacings agree with one another and match bubble chain calculations at low densities. The equation of state of pure neutron matter obtained from our simulations agrees quantitatively with variational calculations based on realistic potentials.
Cold dilute neutron matter on the lattice I: Lattice virial coefficients and large scattering lengths
Dean Lee,Thomas Schaefer
Physics , 2005, DOI: 10.1103/PhysRevC.73.015201
Abstract: We study cold dilute neutron matter on the lattice using an effective field theory. We work in the unitary limit in which the scattering length is much larger than the interparticle spacing. In this paper we focus on the equation of state at temperatures above the Fermi temperature and compare lattice simulations to the virial expansion on the lattice and in the continuum. We find that in the unitary limit lattice discretization errors in the second virial coefficient are significantly enhanced. As a consequence the equation of state does not show the universal scaling behavior expected in the unitary limit. We suggest that scaling can be improved by tuning the second virial coefficient rather than the scattering length.
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