Age structure and spatial pattern of old-growth ponderosa pine in Pringle Falls Experimental Forest, central Oregon

The dynamics of stands In old-growth ponderosa pine (Pinus ponderosa) forests on the eastern flank of the central Oregon Cascades are Investigated. Age structure and spatial pattern of ponderosa pine within the Pringle Falls Experimental Forest Research Natural Area coupled with the fire history of the area aid In Interpreting stand development. Two 1.0-ha permanent reference stands were established in the Pinus ponderosa/Purshia tridentata-Ceanothus velutinus/Stipa occidentalis comunity type. Age data were taken from 294 Pinus ponderosa and 223 Pinus contorta >10 cm dbh, and 98 Pinus ponderosa and 57 Pinus contorta <10 cm dbh. Spatial dispersion of trees within identifiable age cohorts was tested using Morisit&s Index. The historical development of both stands since 1500 is examined using a chronosequence of the location of stems of known ages. Associations using chi-square tests are examined for the identified cohorts of both species. Both reference stands are composed of three identifiable age cohorts. Comparison of the age data with a fire history of the Pringle Falls Experimental Forest indicates that periods of increased fire activity correspond to periods of decreased survivorship in both stands. Regeneration of Pinus ponderosa and Pinus contorta on both stands since the turn of the century, in the absence of fire, indicates that successful regeneration within these stands is not as dependent on fire-prepared mineral seedbed as is regeneration in pine stands in the Southwest. Trees on both stands in all three cohorts occur in clumps ranging from 25-3500 m2. Distribution within the clumps is aggregated as well, with small, usually even-aged clusters of trees being a common component of the larger aggregations. Two scales of pattern are identified in both stands. High mortality during periods of increased fire activity produce long-term temporal and coarse-grained spatial patterns of the broad age cohorts. Fine-grained spatial and shorter temporal patterns result from contemporaneous reproduction in small areas. Chi-square associations indicate that the spatial and temporal patterns of the older cohorts have been maintained in the stands for the last 250 years. Fire exclusion has caused a deterioration in both types of patterns. A fire regime that includes frequent (7-20 years) low-Intensity burns must be introduced to these stands if the desired goal is to maintain patterns characteristic of the primeval forest. Furthermore, rare fires that are either larger or hotter must be periodically included in the fire regime if coarse-grained spatial and long-term temporal patterns are to be maintained

Making Plant-Support Structures From Waste Plant Fiber

Environmentally benign, biodegradable structures for supporting growing plants can be made in a process based on recycling of such waste plant fiber materials as wheat straw or of such derivative materials as paper and cardboard. Examples of structures that can be made in this way include plant plugs, pots, planter-lining mats, plant fences, and root and shoot barriers. No chemical binders are used in the process. First, the plant material is chopped into smaller particles. The particles are leached with water or steam to remove material that can inhibit plant growth, yielding a fibrous slurry. If the desired structures are plugs or sheets, then the slurry is formed into the desired shapes in a pulp molding subprocess. If the desired structures are root and shoot barriers, pots, or fences, then the slurry is compression-molded to the desired shapes in a heated press. The processed materials in these structures have properties similar to those of commercial pressboard, but unlike pressboard, these materials contain no additives. These structures have been found to withstand one growth cycle, even when we

Solid Freeform Fabrication of Transparent Fused Quartz using a Filament Fed Process

Glass is a critical material for many scientific and engineering applications including optics, communications, electronics, and hermetic seals. Despite this technological relevance, there has been minimal research toward Additive Manufacturing (AM) of glass, particularly optically transparent glass. Additive Manufacturing of transparent glass offers potential advantages for lower processing costs for small production volumes, increased design freedom, and the ability to locally vary the optical properties of the part. Compared to common soda lime glass, fused quartz is better for AM since it has lower thermal expansion and higher index homogeneity. This paper presents a study of additive manufacturing of transparent fused quartz by a filament fed process. A CW CO2 laser (10.6 µm) is used to melt glass filaments layer by layer. The laser couples to phononic modes in the glass and is well absorbed. The beam and melt pool are stationary while the work piece is scanned using a standard lab motion system. Representative parts are built to explore the effects of variable laser power on the properties of printed fused quartz. During printing the incandescent emission from the melt pool is measured using a spectrometer. This permits process monitoring and identifies potential chemical changes in the glass during printing. After deposition, the printed parts are polished and the transmission measured to calculate the absorption/scattering coefficient. Finally, a low-order thermal analysis is presented and correlated to experimental results, including an energy balance and finite volume analysis using Fluent. These results suggest that optical quality fused quartz parts with low absorption and high index of refraction uniformity may be printed using the filament-fed process

Clinical Characteristics of Children with Autism Spectrum Disorder and Co-Occurring Epilepsy

Objectives: To estimate the prevalence of epilepsy in children with Autism Spectrum Disorder (ASD) and to determine the demographic and clinical characteristics of children with ASD and epilepsy in a large patient population. Methods: Cross-sectional study using four samples of children with ASD for a total of 5,815 participants with ASD. The prevalence of epilepsy was estimated from a population-based sample. Children with and without epilepsy were compared on demographic and clinical characteristics. Multivariate logistic regression was used to examine the association between demographic and clinical characteristics and epilepsy. Results: The average prevalence of epilepsy in children with ASD 2–17 years was 12.5%; among children aged 13 years and older, 26% had epilepsy. Epilepsy was associated with older age, lower cognitive ability, poorer adaptive and language functioning, a history of developmental regression and more severe ASD symptoms. The association between epilepsy and the majority of these characteristics appears to be driven by the lower IQ of participants with epilepsy. In a multivariate regression model, only age and cognitive ability were independently associated with epilepsy. Children age 10 or older had 2.35 times the odds of being diagnosed with epilepsy (p<.001) and for a one standard deviation increase in IQ, the odds of having epilepsy decreased by 47% (p<.001). Conclusion: This is among the largest studies to date of patients with ASD and co-occurring epilepsy. Based on a representative sample of children with ASD, the average prevalence of epilepsy is approximately 12% and reaches 26% by adolescence. Independent associations were found between epilepsy and older age and lower cognitive ability. Other risk factors, such as poor language and developmental regression, are not associated with epilepsy after controlling for IQ. These findings can help guide prognosis and alert clinicians to patients with ASD who are at increased risk for epilepsy

Age-Induced Changes in Anti-Tumor Immunity Alter the Tumor Immune Infiltrate and Impact Response to Immuno-Oncology Treatments

INTRODUCTION: Immuno-oncology (IO) research relies heavily on murine syngeneic tumor models. However, whilst the average age for a cancer diagnosis is 60 years or older, for practical purposes the majority of preclinical studies are conducted in young mice, despite the fact that ageing has been shown to have a significant impact on the immune response. METHODS: Using aged (60-72 weeks old) mice bearing CT26 tumors, we investigated the impact of ageing on tumor growth as well as the immune composition of the tumor and peripheral lymphoid organs. RESULTS: We found many differences in the immune cell composition of both the tumor and tumor-draining lymph node between aged and young mice, such as a reduction in the naïve T cell population and a decreased intratumoral CD8/Treg ratio in aged animals. We hypothesized that these differences may contribute to impaired anti-cancer immune responses in aged mice and therefore assessed the anti-tumor efficacy of different IO therapies in aged mice, including both co-stimulation (using an anti-OX40 antibody) and immune checkpoint blockade (using anti-PD-L1 and anti-CTLA-4 antibodies). Whilst aged mice retained the capacity to generate anti-tumor immune responses, these were significantly attenuated when compared to the responses observed in young mice. DISCUSSION: These differences highlight the importance of age-related immunological changes in assessing and refining the translational insights gained from preclinical mouse models

Cryoprecipitate transfusion in trauma patients attenuates hyperfibrinolysis and restores normal clot structure and stability : Results from a laboratory sub-study of the FEISTY trial

Acknowledgements We acknowledge the Aberdeen Microscopy and Histology Core Facility and thank Judith de Vries for her guidance in analysing the confocal images. We thank Megan Simpson for measuring PAI-1 and uPA antigen levels in the fibrinogen preparations. We thank all of the FEISTY research staff who collected and processed the patient samples. Funding This work was supported by research grants from CSL Behring and Tenovus Scotland.Peer reviewedPublisher PD

Bostonia: 1998-1999, no. 1, 3-4

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs