550 research outputs found
Pinyon-juniper fire regime: Natural range of variability
In this study, we used a variety of methods to quantify and describe historical patterns of fire and forest structure in two pinyon-juniper ecosystems of the Southwest. Sites were located on the Kaibab National Forest in Arizona, south of Grand Canyon National Park (Tusayan), and on the Carson National Forest in New Mexico, north of Espanola (Canjilon). Methodological approaches included analysis of fire scars, contemporary forest structure, fire evidence, modern fire records, and forest reconstruction. GIS surface maps, constructed using inverse distance weighted interpolation, were used to assess spatial patterns of fire and forest structure. Results indicated distinct fire histories and recent forest changes at the two sites. At Tusayan, surface fires burned historically at frequencies of 7.2-7.4 years (Weibull median probability) in canyons and draws dominated by ponderosa pine. On uplands dominated by pinyon-juniper communities, longer point fire intervals suggested fires occurred at a mean frequency of 41.6 years. Point intervals stratified by species indicated longer return periods for Utah juniper than pinyon or ponderosa pine. Fire evidence in the form of charred tree structures was ubiquitous at the site and there was no clear relationship between stand age and fire evidence. Live, old trees (300 yr) were prevalent and averaged 26 trees per hectare (TPH). Stands were all ages up to 400 yr and patch sizes were generally small (30 ha). Reconstructions showed a moderate overall increase (39(percent)) in stand density since the late 19th century. Ponderosa pine increases were responsible for the majority of recent structural changes although pinyon density also had apparently increased. We found no evidence of extensive stand replacing fire over the last 400 years at Tusayan and concluded that the historical pattern has been one of frequent surface fires in ponderosa pine communities and small severe fires on pinyon-juniper uplands. At Canjilon, fire scar analysis showed longer mean fire intervals (81.1 yr), suggesting that infrequent crown fires or severe surface fires were an important component of the historical regime. Like Tusayan, charred structures were found across the Canjilon site, although they appeared to be more abundant at lower elevations where stands ages were younger. Few live old trees (300 yr) were found at the site (4.2 TPH). The site dominated by stands in the 200-250-yr and 250-300-yr age classes. Mean patch sizes for stands of these age classes were 24 and 79 ha, respectively. Reconstructions showed relatively greater increases in tree density (61(percent)) with Rocky Mountain juniper and pinyon pine both showing positive changes since the late 19th century. Evidence of stand replacing fire was seen along the eastern edge of the study site and young trees appeared to be encroaching into previously open areas, particularly around big sagebrush meadows. Woodland treatments that may parallel historical patterns of fire and forest structure at these sites include targeted tree thinning and/or use of prescribed fire to create canopy openings of various sizes
Participants’ perceptions of “C.H.A.M.P. families”: A parent-focused intervention targeting paediatric overweight and obesity
Background: Recently, our team implemented a 13-week group-based intervention for parents of children with obesity (“C.H.A.M.P. Families”). The primary objective of this study was to explore, qualitatively, parents’ perspectives of their experiences in and influence of C.H.A.M.P. Families, as well as their recommendations for future paediatric obesity treatment interventions. Methods: Twelve parents (seven mothers, five fathers/step-fathers) representing seven children (four girls, three boys) with obesity participated in one of two focus groups following the intervention. Focus groups were audio recorded and transcribed verbatim and data were analyzed using inductive thematic analysis. Results: Findings showed that parents perceived their participation in C.H.A.M.P. Families to be a positive experience. Participants highlighted several positive health-related outcomes for children, families, and parents. Parents also underscored the importance and positive impact of the group environment, specific educational content, and additional program components such as free child-minding. Recommendations for future interventions were also provided, including greater child involvement and more practical strategies. Finally, parents identified several barriers including socioenvironmental issues, time constraints, and parenting challenges. Conclusions: Researchers developing family-based childhood obesity interventions should consider the balance of parent and child involvement, as well as emphasize group dynamics strategies and positive family communication
C.H.A.M.P. Families : Description and Theoretical Foundations of a Paediatric Overweight and Obesity Intervention Targeting Parents-A Single-Centre Non-Randomised Feasibility Study.
Childhood obesity represents a significant global health challenge, and treatment interventions are needed. The purpose of this paper is to describe the components and theoretical model that was used in the development and implementation of a unique parent-focussed paediatric overweight/obesity intervention. C.H.A.M.P. Families was a single-centre, prospective intervention offered to parents of children aged between 6⁻14 years with a body mass index (BMI) ≥85th percentile for age and sex. The intervention included: (1) eight group-based (parent-only) education sessions over 13-weeks; (2) eight home-based activities; and (3) two group-based (family) follow-up support sessions. The first section of the manuscript contains a detailed description of each intervention component, as well as an overview of ongoing feasibility analyses. The theoretical portion details the use of evidence-based group dynamics principles and motivational interviewing techniques within the context of a broader social cognitive theory foundation. This paper provides researchers with practical examples of how theoretical constructs and evidence-based strategies can be applied in the development and implementation of parent-focussed paediatric obesity interventions. Given the need for transparent reporting of intervention designs and theoretical foundations, this paper also adds to the areas of implementation science and knowledge translation research
Human CLEC9A antibodies deliver Wilms' tumor 1 (WT1) antigen to CD141+ dendritic cells to activate naïve and memory WT1‐specific CD8+ T cells
Objectives
Vaccines that prime Wilms' tumor 1 (WT1)‐specific CD8+ T cells are attractive cancer immunotherapies. However, immunogenicity and clinical response rates may be enhanced by delivering WT1 to CD141+ dendritic cells (DCs). The C‐type lectin‐like receptor CLEC9A is expressed exclusively by CD141+ DCs and regulates CD8+ T‐cell responses. We developed a new vaccine comprising a human anti‐CLEC9A antibody fused to WT1 and investigated its capacity to target human CD141+ DCs and activate naïve and memory WT1‐specific CD8+ T cells.
Methods
WT1 was genetically fused to antibodies specific for human CLEC9A, DEC‐205 or β‐galactosidase (untargeted control). Activation of WT1‐specific CD8+ T‐cell lines following cross‐presentation by CD141+ DCs was quantified by IFNγ ELISPOT. Humanised mice reconstituted with human immune cell subsets, including a repertoire of naïve WT1‐specific CD8+ T cells, were used to investigate naïve WT1‐specific CD8+ T‐cell priming.
Results
The CLEC9A‐WT1 vaccine promoted cross‐presentation of WT1 epitopes to CD8+ T cells and mediated priming of naïve CD8+ T cells more effectively than the DEC‐205‐WT1 and untargeted control‐WT1 vaccines.
Conclusions
Delivery of WT1 to CD141+ DCs via CLEC9A stimulates CD8+ T cells more potently than either untargeted delivery or widespread delivery to all Ag‐presenting cells via DEC‐205, suggesting that cross‐presentation by CD141+ DCs is sufficient for effective CD8+ T‐cell priming in humans. The CLEC9A‐WT1 vaccine is a promising candidate immunotherapy for malignancies that express WT1
Topological spin memory of antiferromagnetically coupled skyrmion pairs in Co/Gd/Pt multilayers
Antiferromagnetically (AFM) coupled skyrmions offer potential advantages for spintronic devices, including reduced dipolar fields that may enable smaller skyrmion sizes and a reduction of the skyrmion Hall effect. However, the topological stability of AFM-coupled skyrmions subjected to dramatic spin deformation through low-temperature cycling has not been investigated. Here we report the discovery of a topological spin memory effect for AFM-coupled skyrmion pairs in [Co/Gd/Pt]10 multilayered films. Photoemission electron microscopy imaging shows that bubble skyrmions in the multilayer that are stable at room temperature evolve into complex in-plane spin textures as the temperature is lowered and reform completely when the sample is warmed back up. Simulations demonstrate that Dzyaloshinskii-Moriya interactions play a key role in this spin memory effect, and furthermore reveal that the topological charge is preserved throughout the dramatic spin texture rearrangement and recovery. These results highlight a key aspect of topological protection—the preservation of the topological properties under continuous deformation—and also provide a promising avenue for information encryption and recovery
Single Molecule Imaging Reveals Differences in Microtubule Track Selection Between Kinesin Motors
Molecular motors differentially recognize and move cargo along discrete microtubule subpopulations in cells, resulting in preferential transport and targeting of subcellular cargoes
Comparing Two CBM Maze Selection Tools: Considering Scoring and Interpretive Metrics for Universal Screening
Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan
This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good
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