61 research outputs found
Geographic variability in lidar predictions of forest stand structure in the Pacific Northwest
Estimation of the amount of carbon stored in forests is a key challenge for understanding the global carbon cycle, one which remote sensing is expected to help address. However, carbon storage in moderate to high biomass forests is difficult to estimate with conventional optical or radar sensors. Lidar (light detection and ranging) instruments measure the vertical structure of forests and thus hold great promise for remotely sensing the quantity and spatial organization of forest biomass. In this study, we compare the relationships between lidar measured canopy structure and coincident field measurements of forest stand structure at five locations in the Pacific Northwest of the U.S.A. with contrasting composition. Coefficient of determination values (r2) ranged between 41% and 96%. Correlations for two important variables, LAI (81%) and above ground biomass (92%), were noteworthy, as was the fact that neither variable showed an asymptotic response.
Of the 17 stand structure variables considered in this study, we were able to develop eight equations that were valid for all sites, including equations for two variables generally considered to be highly important (aboveground biomass and leaf area index). The other six equations that were valid for all sites were either related to height (which is most directly measured by lidar) or diameter at breast height (which should be closely related to height). Four additional equations (a total of 12) were applicable to all sites where either Douglas-fir (Pseudotsuga menziesii), western hemlock (Tsuga heterophylla) or Sitka spruce (Picea sitchensi) were dominant. Stand structure variables in sites dominated by true firs (Abies sp.) or ponderosa pine (Pinus ponderosa) had biases when predicted by these four additional equations. Productivity-related variables describing the edaphic, climatic and topographic environment of the sites where available for every regression, but only two of the 17 equations (maximum diameter at breast height, stem density) incorporated them. Given the wide range of these environmental conditions sampled, we conclude that the prediction of stand structure is largely independent of environmental conditions in this study area.
Most studies of lidar remote sensing for predicting stand structure have depended on intensive data collections within a relatively small study area. This study indicates that the relationships between many stand structure indices and lidar measured canopy structure have generality at the regional scale. This finding, if replicated in other regions, would suggest that mapping of stand structure using lidar may be accomplished by distributing field sites extensively over a region, thus reducing the overall inventory effort required
‘The Coaching Needs of High Performance Female Athletes within the Coach-Athlete Dyad’
Within the research literature there is little work that has examined how coaches (and coaching) can positively influence female athletes’ continued participation and development in performance sport. With this in mind, utilising a grounded theory approach, this study focused on what are the coaching preferences of female athletes within the elite coachathlete dyad. Through interviews with 27 current high performance female athletes, four major coaching needs were found. These were: to be supported as person as well a performer, coaching to be a joint endeavour, the need for positive communication and finally, recognition of the salience of gender within the coach-athlete dyad. The findings provide evidence that the relational expertise of coaches is at the forefront of these women’s coaching needs. This study also demonstrates that for the participants, the coach-athlete relationship is at the heart of improving athletic training and performance, and that gender is an important influence on this relationship. Furthermore, the research highlights the strength of using an interpretive-qualitative paradigmatic approach to athlete preferences through foregrounding the women’s voices and experiences
Resveratrol Targeting of Carcinogen-Induced Brain Endothelial Cell Inflammation Biomarkers MMP-9 and COX-2 is Sirt1-Independent
The occurrence of a functional relationship between the release of metalloproteinases (MMPs) and the expression of cyclooxygenase (COX)-2, two inducible pro-inflammatory biomarkers with important pro-angiogenic effects, has recently been inferred. While brain endothelial cells play an essential role as structural and functional components of the blood-brain barrier (BBB), increased BBB breakdown is thought to be linked to neuroinflammation. Chemopreventive mechanisms targeting both MMPs and COX-2 however remain poorly investigated. In this study, we evaluated the pharmacological targeting of Sirt1 by the diet-derived and antiinflammatory polyphenol resveratrol. Total RNA, cell lysates, and conditioned culture media from human brain microvascular endothelial cells (HBMEC) were analyzed using qRT-PCR, immunoblotting, and zymography respectively. Tissue scan microarray analysis of grade I–IV brain tumours cDNA revealed increased gene expression of Sirt-1 from grade I–III but surprisingly not in grade IV brain tumours. HBMEC were treated with a combination of resveratrol and phorbol 12-myristate 13-acetate (PMA), a carcinogen known to increase MMP-9 and COX-2 through NF-κB. We found that resveratrol efficiently reversed the PMA-induced MMP-9 secretion and COX-2 expression. Gene silencing of Sirt1, a critical modulator of angiogenesis and putative target of resveratrol, did not lead to significant reversal of MMP-9 and COX-2 inhibition. Decreased resveratrol inhibitory potential of carcinogen-induced IκB phosphorylation in siSirt1-transfected HBMEC was however observed. Our results suggest that resveratrol may prevent BBB disruption during neuroinflammation by inhibiting MMP-9 and COX-2 and act as a pharmacological NF-κB signal transduction inhibitor independent of Sirt1
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Overstory and shrub influences on seedling recruitment patterns in an old-growth ponderosa pine stand
Seedling recruitment in an old growth ponderosa pine (Pinus ponderosa) stand in central Oregon, USA, was studied to determine its relationship with overstorey trees and nearby shrubs, and to identify the spatial patterns resulting from these relationships. Results showed that the influence of adjacent vegetation was greatest among smaller size classes of regeneration. The strongest relationship between overstorey basal area, and germinant and seedling density was observed when calculated at a very local scale (5-m radius). Seedling and germinant densities were also adversely affected by adjacent saplings but were positively associated with shrubs. Spatial analysis revealed significant aggregation of germinants, seedlings and saplings, with the intensity of aggregation decreasing from smaller to larger size classes. These results suggest that regeneration is most sensitive to adjacent vegetation during the early stages, that the facilitative influence of shrubs diminishes relative to their competitive effect once regeneration reaches the sapling stage, and that the early aggregated condition of regeneration gradually transforms towards a more regular pattern as stand development progresses.Keyes et al "Overstory and shrub influences on seedling recruitment patterns in an old-growth ponderosa pine stand." Northwest Science. 2001; 75(3): 204-21
Carbon Storage in Coarse and Fine Fractions of Pacific Northwest Old‐Growth Forest Soils
Differences in Pharmacological Activities of the Antioxidant Flavonoid MonoHER in Humans and Mice Are Caused by Variations in Its Metabolic Profile
Increased cryosurvival of osteosarcoma cells using an amphipathic pH-responsive polymer for trehalose uptake
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