479 research outputs found

    The RCN in Transition, 1910-1985

    Get PDF

    Biochemical Analysis of Fossil and Living Plants

    Get PDF
    Lignin oxidation products from a variety of living and fossil plants were obtained using the alkaline cupric oxide method. The aldehydes and ketones obtained were separated by gas chromatography and gas chromatography/mass spectroscopy was used to verify the structures of the lignin oxidation products. Vanillin remained the major ligning oxidation product obtained from the lignin of gymnosperms. However small amounts of p-hydroxybenzaldehyde and syringic aldehyde were obtained from all the symnospermous ligning examined. Immature dicotyledons and the woodmeal of the monocotyledons examined gave varying emounts of p-hydroxybenzaldehyde when oxidized. No phydoxybenzaldehyde was detected from the lignin of the monoxotyledon fibres examined. Syringic aldehyde remained the major lignin oxidation product obtained from the angiosperms. All three types of lignin nuclei were obtained in small amounts from several lower plants including the mosses and liverworts. No correlation between the presence of syringic aldehyde and the occurrence of vessels was found. The suggestion that it is the fibres in plants which contribute to the presence of syringic aldehyde is made. All three types of lignin nuclei were observed from certain fossil wood, fossil compressions and coals. Syringic aldehyde remained as a lignin oxidation product in bituminous coals of 3OO million years old. Lignin derivatives can be used as supporting evidence for anatomical and morphological studies. However lignin derivatives cannot be used as characteristics for fossil compressions and coals because chemical changes which occur alter the original phenolic aldehyde ratios. Only speculations can be made

    Invasion: From the Armada to Hitler, 1588-1945

    Get PDF

    Immunological responses of Holstein-Friesian cattle to Staphylococcus aureus in vitro

    Get PDF
    The aim of this study was to develop and evaluate an in vitro proliferative response of peripheral blood mononuclear cells (PBM) isolated from Holstein-Friesian cattle, induced by formalin-killed Staphylococcus aureus, a major mastitis pathogen, as a potential indicator of resistance or susceptibility to mastitis. Different strains of S. aureus, isolated from cows with subclinical mastitis, and identified by restriction enzyme fragmentation pattern analysis, were shown to induce different levels of proliferation of PBM in vitro. One particular strain (strain A), induced the strongest proliferation response compared to the other strains tested and differences in the magnitude of the proliferative response, induced by S. aureus strain A, was noted among cows. Phenotypic analysis of PBM of cows, by flow cytometry, showed that normal proportions of cell sub-populations were present at the start of culture and that the proliferating cell population consisted mainly of T cells expressing CD4, CD8 or markers. Proliferation of PBM of cows, induced by Staphylococcal Enterotoxin B (SEB), showed that the peak day of proliferation occurred 72 to 96 hours earlier in the presence of SEB compared to in the presence of S. aureus strain A antigen.A statistically significant difference in the proliferative response induced by S. aureus strain A was seen in two progeny groups sired by two different commercial bulls, suggesting that genetic control of this response may be important in protection of the mammary glands against infection. The proliferative assay was, therefore, subsequently performed in bulls

    Effects of Phosphate Fertilizer Applications and Chemistry-Mineralogy of the Iron Oxide System on Phosphate Adsorption-Desorption by Stream Sediments : Final Report

    Get PDF
    (print) vii, 102 p. : ill., maps ; 28 cm.Item lacks publication date. Issue date supplied from WorldCat bibliographic recordDespite geologic, geomorphic, and land use differences, suspended sediments collected from the Muskingum River and its tributaries during spring flooding were remarkably uniform in mineralogy and size distribution. The greatest evidence of regional differences came from Moxahala Creek, which receives acid drainage from abandoned coal mines. As a result, Black Fork Creek, a tributary to Moxahala Creek, was chosen for detailed water quality and bottom sediment studies. Marked increases in dissolved SO4, Fe, and Al, and decreased. pH were observed in sections of the stream affected by acid mine drainage. In addition, a gelatinous yellow precipitate of iron was abundant in the bottom sediments below sources of pollution. This Fe-oxide or oxyhydroxide precipitate greatly increased surface area and reactivity of bottom sediments and added to the overall sediment load. A standard P adsorption procedure was proposed and the ability of four laboratories to produce consistent results over a wide range of soils was determined. Soil (0.5 or 1.0 g) was shaken in 0.01 mol L-1 CaCl2 at a soil: solution ratio of 1:25 in containers allowing a 50% head space for 24 hours at 24 to 26°C on an end-over-end shaker. Initial dissolved inorganic P concentrations of 0 to 323 u mol P L-1 (as KH2PO4 or NaH2PO4) were used and microbial activity inhibited by 20 g L-1 chloroform. Excellent agreement between the four laboratories was obtained for P adsorbed by the 12 soils studied, with a mean coefficient of variation over all P levels and soils of 0.91%. The laboratories also exhibited a high degree of replication of individual treatments with no laboratory showing a strong consistent bias across all soils and P levels in terms of P adsorption. Langmuir, Freundlich and Tempkin adsorption models were highly correlated with the adsorption data. Respective mean correlations for the 12 soils were 0.98, 0.97 and 0.95. The proposed method has the potential to produce consistent results which can be used to predict partitioning of dissolved inorganic P between solid and solution phases in the environment.Acknowledgements -- Abstract -- Chapter 1: Suspended Sediments of the Muskingum River Basin -- Chapter 2: Water and Bottom Sediment Quality in Streams Affected by Acid Coal Mine Drainage - a Study of the Black Fork Creek Watershed, Ohio -- Chapter 3: Interlaboratory Comparison of a Standardized Phosphorus Adsorption Procedur

    The Surprising Oceanography of the Gulf of Maine

    Get PDF
    The oceanography of the Gulf of Maine has changed in ways that have not been seen previously but that are likely to be more common in the future–changes like extreme rapid warming and declines in primary productivity. The changing oceanography has underpinned surprising losses in commercial stocks and endangered species. Because of the rapid rate of change, some have viewed the Gulf of Maine as a window into the ocean’s future, with the idea that lessons learned can be applied in places that have yet to experience similar rapid changes. We can examine the dynamics, origin, and implications of surprising oceanographic conditions–conditions that would have been considered unlikely based on recent prior experience. Based on a formal statistical definition of climate surprises, the frequency of oceanographic surprises in the Gulf of Maine is higher and has increased faster than what would be expected, even given underlying trends. Oceanographic surprises vary in character from one to the next and are often linked to larger scale shifting oceanography across the North Atlantic. The implications for ecological and human communities, industries, and conservation efforts imply a need for policies that consider adaptation to sudden events as well as long-term changes

    Overcoming the challenges and complexities of researching a vulnerable population within a palliative care context

    Get PDF
    While previous studies have investigated sleep issues in chronic illness and the effectiveness of Cognitive Behavioral Therapy for Insomnia (CBT-I), this has not been examined within palliative care. High rates of sleep difficulties have been found in patients receiving palliative care. We aimed to explore the practical feasibility of implementing CBT-I among palliative patients using techniques such as stimulus control therapy, progressive muscle relaxation and guided imagery/thought blocking. However, issues such as the intervention protocols being relatively labor intensive and time consuming for participants that were receiving palliative care, involving completion of daily diaries and quantitative outcome measures, led to high non-completion rates among participants. Consequently, a shift in methodology was required and a qualitative approach was adopted to explore participants’ experiences of sleep disturbance within palliative care. The aim was to gain an in-depth understanding of the specific issues and challenges within palliative care that impacted on sleep. Focus groups were conducted with patients, informal carers and hospice staff who all described how they experienced sleep difficulties. This provided a broader understanding of insomnia from multiple perspectives within palliative care. Furthermore, it helped inform how we will go about designing future studies in CBT-I in palliative care; having illuminated the appropriate adaptions required to current protocols. This case study will discuss the complexities and ethical issues we faced at each stage of the research process and how adopting both quantitative and qualitative approaches helped provide useful insights that will inform future research

    Spatial patterns of vegetation structure and structural diversity across edges between forested wetlands and upland forest in Atlantic Canada

    Get PDF
    Accepted versionForested wetlands are an integral but understudied part of heterogeneous landscapes in Atlantic Canada, although they are known to provide habitat for species at risk. Our objectives were to explore patterns of forest structure across edges between forested wetland and upland forest, to locate changes in vegetation structure and to assess multivariate relationships in vegetation structure. Our study sites were in temperate (Acadian) forested wetland landscapes. We sampled trees and recorded canopy cover every 20 m along 120-m-long transects. We estimated the cover of trees, saplings, shrubs in three height classes, Sphagnum, other bryophytes, lichens, graminoids, ferns, and forbs in contiguous 1 m Ă— 1 m quadrats. We calculated structural diversity using the Shannon index and used wavelet analysis to assess spatial patterns. We found few clear patterns except for lower tree structural diversity at the edge of forested wetlands. Structural diversity was not a reliable measure for distinguishing forested wetland from upland forest. Forested wetlands are an integral part of many forested landscapes in Atlantic Canada, but their detection and differentiation from surrounding ecosystems can be difficult. Policy should err on the side of caution when mapping forested wetlands and include them in wetland protection
    • …
    corecore