832 research outputs found
Hematopoietic progenitor cell content of vertebral body marrow used for combined solid organ and bone marrow transplantation
While cadaveric vertebral bodies (VB) have long been proposed as a suitable source of bone marrow (BM) for transplantation (BMT), they have rarely been used for this purpose. We have infused VB BM immediately following whole organ (WO) transplantation to augment donor cell chimerism. We quantified the hematopoietic progenitor cell (HPC) content of VB BM as well as BM obtained from the iliac crests (IC) of normal allogeneic donors (ALLO) and from patients with malignancy undergoing autologous marrow harvest (AUTO). Patients undergoing WO/BM transplantation also had AUTO BM harvested in the event that subsequent lymphohematopoietic reconstitution was required. Twenty-four VB BM, 24 IC BM-ALLO, 31 IC AUTO, and 24 IC WO-AUTO were harvested. VB BM was tested 12 to 72 hr after procurement and infused after completion of WO grafting. IC BM was tested and then used or cryopreserved immediately. HPC were quantified by clonal assay measuring CFU-GM, BFU-E, and CFU-GEMM, and by flow cytometry for CD34+ progenitor cells. On an average, 9 VB were processed during each harvest, and despite an extended processing time the number of viable nucleated cells obtained was significantly higher than that from IC. Furthermore, by HPC content, VB BM was equivalent to IC BM, which is routinely used for BMT. We conclude that VB BM is a clinically valuable source of BM for allogeneic transplantation. © 1995 by Williams & Wilkins
Protecting biodiversity and economic returns in resource rich tropical forests
In pursuit of socioeconomic development, many countries are expanding oil and mineral extraction into tropical forests. These activities seed access to remote, biologically rich areas, thereby endangering global biodiversity. Here we demonstrate that conservation solutions that effectively balance the protection of biodiversity and economic revenues are possible in biologically valuable regions. Using spatial data on oil profits and predicted species and ecosystem extents, we optimise the protection of 741 terrestrial species and 20 ecosystems of the Ecuadorian Amazon, across a range of opportunity costs (i.e. sacrifices of extractive profit). For such an optimisation, giving up 5% of a year's oil profits (US 1.7 billion), and uses only marginally less land, to achieve equivalent levels of ecological protection. Applying spatial statistics to remotely sensed, historic deforestation data, we further focus the optimisation to areas most threatened by imminent forest loss. We identify Emergency Conservation Targets: areas that are essential to a costâeffective conservation reserve network and at imminent risk of destruction, thus requiring urgent and effective protection. Governments should employ the methods presented here when considering extractive led development options, to responsibly manage the associated ecologicalâeconomic tradeâoffs and protect natural capital
The Stress Transmission Universality Classes of Periodic Granular Arrays
The transmission of stress is analysed for static periodic arrays of rigid
grains, with perfect and zero friction. For minimal coordination number (which
is sensitive to friction, sphericity and dimensionality), the stress
distribution is soluble without reference to the corresponding displacement
fields. In non-degenerate cases, the constitutive equations are found to be
simple linear in the stress components. The corresponding coefficients depend
crucially upon geometrical disorder of the grain contacts.Comment: 7 pages, 1 figur
Moment-based parameter estimation in binomial random intersection graph models
Binomial random intersection graphs can be used as parsimonious statistical
models of large and sparse networks, with one parameter for the average degree
and another for transitivity, the tendency of neighbours of a node to be
connected. This paper discusses the estimation of these parameters from a
single observed instance of the graph, using moment estimators based on
observed degrees and frequencies of 2-stars and triangles. The observed data
set is assumed to be a subgraph induced by a set of nodes sampled from
the full set of nodes. We prove the consistency of the proposed estimators
by showing that the relative estimation error is small with high probability
for . As a byproduct, our analysis confirms that the
empirical transitivity coefficient of the graph is with high probability close
to the theoretical clustering coefficient of the model.Comment: 15 pages, 6 figure
Pilot study of a social network intervention for heroin users in opiate substitution treatment: study protocol for a randomized controlled trial
Background: Research indicates that 3% of people receiving opiate substitution treatment (OST) in the UK manage to achieve abstinence from all prescribed and illicit drugs within 3 years of commencing treatment, and there is concern that treatment services have become skilled at engaging people but not at helping them to enter a stage of recovery and drug abstinence. The National Treatment Agency for Substance Misuse recommends the involvement of families and wider social networks in supporting drug users' psychological treatment, and this pilot randomized controlled trial aims to evaluate the impact of a social network-focused intervention for patients receiving OST.Methods and design: In this two-site, early phase, randomized controlled trial, a total of 120 patients receiving OST will be recruited and randomized to receive one of three treatments: 1) Brief Social Behavior and Network Therapy (B-SBNT), 2) Personal Goal Setting (PGS) or 3) treatment as usual. Randomization will take place following baseline assessment. Participants allocated to receive B-SBNT or PGS will continue to receive the same treatment that is routinely provided by drug treatment services, plus four additional sessions of either intervention. Outcomes will be assessed at baseline, 3 and 12 months. The primary outcome will be assessment of illicit heroin use, measured by both urinary analysis and self-report. Secondary outcomes involve assessment of dependence, psychological symptoms, social satisfaction, motivation to change, quality of life and therapeutic engagement. Family members (n = 120) of patients involved in the trial will also be assessed to measure the level of symptoms, coping and the impact of the addiction problem on the family member at baseline, 3 and 12 months.Discussion: This study will provide experimental data regarding the feasibility and efficacy of implementing a social network intervention within routine drug treatment services in the UK National Health Service. The study will explore the impact of the intervention on both patients receiving drug treatment and their family members.Trial registration: Trial Registration Number: ISRCTN22608399. ISRCTN22608399 registration: 27/04/2012. Date of first randomisation: 14/08/2012. © 2013 Day et al.; licensee BioMed Central Ltd
Not fitting in and getting out : psychological type and congregational satisfaction among Anglican churchgoers in England
Listening to the motivations reported by individuals for ceasing church attendance and becoming church leavers, Francis and Richter identified high on the list the sense of "not fitting in". Drawing on psychological type theory, several recent studies have documented the way in which some psychological types are over-represented in church congregations and other psychological types are under-represented. Bringing these two observations together, the present study tested the hypothesis that church congregations have created type-alike communities within which individuals displaying the opposite type preferences are more likely to feel marginalised and to display lower levels of satisfaction with the congregations they attend. Data were provided by 1867 churchgoers who completed a measure of psychological type, together with measures of frequency of attendance and congregational satisfaction. These data confirmed that congregations were weighted towards preferences for introversion, sensing, feeling and judging, and that individuals displaying the opposite preferences (especially intuition, thinking and perceiving) recorded lower levels of congregational satisfaction. The implications of these findings are discussed for promoting congregational retention by enhancing awareness of psychological type preferences among those who attend
Xenotransplantation of hematopoietic cells resistant to HIV as a potential treatment for patients with AIDS
Adsorption hysteresis and capillary condensation in disordered porous solids: a density functional study
We present a theoretical study of capillary condensation of fluids adsorbed
in mesoporous disordered media. Combining mean-field density functional theory
with a coarse-grained description in terms of a lattice-gas model allows us to
investigate both the out-of-equilibrium (hysteresis) and the equilibrium
behavior. We show that the main features of capillary condensation in
disordered solids result from the appearance of a complex free-energy landscape
with a large number of metastable states. We detail the numerical procedures
for finding these states, and the presence or absence of transitions in the
thermodynamic limit is determined by careful finite-size studies.Comment: 30 pages, 18 figures. To appear in J. Phys.: Condens. Matte
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