997 research outputs found

    Forest Conversion and Degradation in Papua New Guinea 1972-2002

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    Quantifying forest change in the tropics is important because of the role these forests play in the conservation of biodiversity and the global carbon cycle. One of the world's largest remaining areas of tropical forest is located in Papua New Guinea. Here we show that change in its extent and condition has occurred to a greater extent than previously recorded. We assessed deforestation and forest degradation in Papua New Guinea by comparing a land-cover map from 1972 with a land-cover map created from nationwide high-resolution satellite imagery recorded since 2002. In 2002 there were 28,251,967 ha of tropical rain forest. Between 1972 and 2002, a net 15 percent of Papua New Guinea's tropical forests were cleared and 8.8 percent were degraded through logging. The drivers of forest change have been concentrated within the accessible forest estate where a net 36 percent were degraded or deforested through both forestry and nonforestry processes. Since 1972, 13 percent of upper montane forests have also been lost. We estimate that over the period 1990–2002, overall rates of change generally increased and varied between 0.8 and 1.8 percent/yr, while rates in commercially accessible forest have been far higher—having varied between 1.1 and 3.4 percent/yr. These rates are far higher than those reported by the FAO over the same period. We conclude that rapid and substantial forest change has occurred in Papua New Guinea, with the major drivers being logging in the lowland forests and subsistence agriculture throughout the country with comparatively minor contributions from forest fires, plantation establishment, and mining

    EC86-1862 Nebraska Commercial Turfgrass Disease Control Guide For Profession Turfgrass Managers

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    This extension circular contains four-color photos to help professional turfgrass managers identify the different turfgrass diseases in Nebraska. Tables are included that describe the disease, the common name of fungicides, trade names, and descriptions of how to control these diseases

    EC86-1862 Nebraska Commercial Turfgrass Disease Control Guide For Profession Turfgrass Managers

    Get PDF
    This extension circular contains four-color photos to help professional turfgrass managers identify the different turfgrass diseases in Nebraska. Tables are included that describe the disease, the common name of fungicides, trade names, and descriptions of how to control these diseases

    James B Beard: The Father of Contemporary Turfgrass Science

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    James B Beard (24 Sept 1935 to 8 May 2018) can rightly be considered the “Father” of contemporary turfgrass science. During his career, he was known for setting a standard that provided the foundation for turfgrass science through his thorough approach to research, teaching, mentoring and communications. The books he published outlined a vision for an evolving scientific discipline. He trained and mentored \u3e45 domestic and international doctoral and master students and numerous post-doctoral trainees, who in turn continued to raise the quality of contemporary turfgrass science in the USA and internationally. He led the effort to change the name of Division C- 5 of the Crop Science Society of America (CSSA) from Turfgrass to Turfgrass Science, making C-5 an important and a vital part of the society. His subsequent rigorous education and mentoring of others continued to strengthen the division. He recognized the importance of quality, peer-reviewed science and the need for C-5 to be represented on the Crop Science Journal (CSJ) Editorial Board to expedite this goal. His leadership and encouragement led to the creation of a C-5 Technical Editor position on the CSJ Editorial Board in 2002. Beard provided the vision and worked with other leaders worldwide to develop the International Turfgrass Society (ITS) and the ITS Research Journal. The ITS and its leaders and members have been instrumental in enhancing turfgrass science internationally. Beard’s leadership, along with others in turfgrass academia and industry, resulted in the USGA Turfgrass and Environmental Research Program that provides a competitive grant-fund source for turfgrass research. Beard appreciated and vigorously studied history and contributions to turfgrass science by those who went before us. He leaves behind a legacy in science that deserves recognition and respect. It is our hope that this synopsis of Beard’s career accomplishments will inspire present and future turfgrass scientists to follow in his footsteps

    Extreme Differences in Forest Degradation in Borneo: Comparing Practices in Sarawak, Sabah, and Brunei

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    The Malaysian states of Sabah and Sarawak are global hotspots of forest loss and degradation due to timber and oil palm industries; however, the rates and patterns of change have remained poorly measured by conventional field or satellite approaches. Using 30 m resolution optical imagery acquired since 1990, forest cover and logging roads were mapped throughout Malaysian Borneo and Brunei using the Carnegie Landsat Analysis System. We uncovered ∼364,000 km of roads constructed through the forests of this region. We estimated that in 2009 there were at most 45,400 km(2) of intact forest ecosystems in Malaysian Borneo and Brunei. Critically, we found that nearly 80% of the land surface of Sabah and Sarawak was impacted by previously undocumented, high-impact logging or clearing operations from 1990 to 2009. This contrasted strongly with neighbouring Brunei, where 54% of the land area remained covered by unlogged forest. Overall, only 8% and 3% of land area in Sabah and Sarawak, respectively, was covered by intact forests under designated protected areas. Our assessment shows that very few forest ecosystems remain intact in Sabah or Sarawak, but that Brunei, by largely excluding industrial logging from its borders, has been comparatively successful in protecting its forests.CLASlite is made possible by the Gordon and Betty Moore Foundation, the John D. and Catherine T. MacArthur Foundation, and the Grantham Foundation for the Protection of the Environment. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Measurement of cardiorespiratory fitness in children from two commonly used field tests after accounting for body fatness and maturity

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    Body fat and maturation both influence cardiorespiratory fitness, however few studies have taken these variables into account when using field tests to predict children's fitness levels. The purpose of this study was to determine the relationship between two field tests of cardiorespiratory fitness (20 m Maximal Multistage Shuttle Run [20-MST], 550 m distance run [550-m]) and direct measurement of VO2max after adjustment for body fatness and maturity levels. Fifty-three participants (25 boys, 28 girls, age 10.6 ± 1.2 y, mean ± SD) had their body fat levels estimated using bioelectrical impedance (16.6% ± 6.0% and 20.0% ± 5.8% for boys and girls, respectively). Participants performed in random order, the 20-MST and 550-m run followed by a progressive treadmill test to exhaustion during which gas exchange measures were taken. Pearson correlation coefficient analysis revealed that the participants' performance in the 20-MST and 550-m run were highly correlated to VO2 max obtained during the treadmill test to exhaustion (r = 0.70 and 0.59 for 20-MST and 550-m run, respectively). Adjusting for body fatness and maturity levels in a multivariate regression analysis increased the associations between the field tests and VO2max (r = 0.73 for 20-MST and 0.65 for 550-m). We may conclude that both the 20-MST and the 550-m distance run are valid field tests of cardiorespiratory fitness in New Zealand 8-13 year old children and incorporating body fatness and maturity levels explains an additional 5-7% of the variance. © Editorial Committee of Journal of Human Kinetics

    Accumulation of Microbial Biomass within Particulate Organic Matter of Aging Golf Greens

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    Microbial biomass (MB) is a key variable controlling soil organic matter dynamics in soil. Currently, there is little information on the amount and significance of MB in highly managed golf greens. Our objective was to determine the amount and distribution of MB within soil structural components of golf greens and its relationship to the location of organic substrates. During 1996, 47 greens were sampled from 12 golf courses within Nebraska (USA). Microbial biomass, determined as extractable lipid phosphate on field-moist soils, increased linearly with age of green (Y = 19.39 + 3.54x; r2 = 0.87, P = 0.001). In 1997 and 1999, selected greens were resampled and separated into mineral fraction (MF) and particulate organic matter (POM) fraction using a sodium metatungstate (NMT; r = 2.3 g cm-3). Then, POM was separated into light (L-POM) and heavy (H-POM) fractions using NMT (r = 2.0 g cm-3). Amount of MB of whole soil and POM was linearly related to green age (r2 = 0.76 and 0.68, respectively). Amount of MB in MF was not related to green age. The portion of total soil MB associated with POM increased significantly from 25.6% for an 8-yr-old green to 77.8% for a 28-yr-old green. Carbon in fulvic acid and humic acid increased with green age from 0.5 to 1.7 and 0.6 to 2.6 g kg-1 soil, respectively. As humus is a relatively stable form of soil organic matter, we hypothesized that humus accumulation within POM renders both POM and associated MB more resistant to degradation; thus, they accumulate

    Nonsymbiotic hemoglobins in rice are synthesized during germination and in differentiating cell types

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    Nonsymbiotic hemoglobins (ns-Hbs) previously have been found in monocots and dicots; however, very little is known about the tissue and cell type localization as well as the physiological function(s) of these oxygen-binding proteins. We report the immunodetection and immunolocalization of ns-Hbs in rice (Oryza sativa L.) by Western blotting and in situ confocal laser scanning techniques. Ns-Hbs were detected in soluble extracts of different tissues from the developing rice seedling by immunoblotting. Levels of ns-Hbs increased in the germinating seed for the first six days following imbibition and remained relatively constant thereafter. In contrast, ns-Hb levels decreased during leaf maturation. Roots and mesocotyls contained detectable, but low levels of ns-Hbs. Split-seed experiments revealed that ns-Hbs are synthesized de novo during seed germination and are expressed in the absence of any signal originating from the embryo. Immunolocalization of ns-Hbs by con- focal microscopy indicated the presence of ns-Hbs primarily in differentiated and differentiating cell types of the developing seedling, such as the aleurone, scutellum, root cap cells, sclerenchyma, and tracheary elements. To our knowledge, this is the first report of the specific cellular localization of these proteins during seedling development

    Approximate probabilistic verification of hybrid systems

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    Hybrid systems whose mode dynamics are governed by non-linear ordinary differential equations (ODEs) are often a natural model for biological processes. However such models are difficult to analyze. To address this, we develop a probabilistic analysis method by approximating the mode transitions as stochastic events. We assume that the probability of making a mode transition is proportional to the measure of the set of pairs of time points and value states at which the mode transition is enabled. To ensure a sound mathematical basis, we impose a natural continuity property on the non-linear ODEs. We also assume that the states of the system are observed at discrete time points but that the mode transitions may take place at any time between two successive discrete time points. This leads to a discrete time Markov chain as a probabilistic approximation of the hybrid system. We then show that for BLTL (bounded linear time temporal logic) specifications the hybrid system meets a specification iff its Markov chain approximation meets the same specification with probability 11. Based on this, we formulate a sequential hypothesis testing procedure for verifying -approximately- that the Markov chain meets a BLTL specification with high probability. Our case studies on cardiac cell dynamics and the circadian rhythm indicate that our scheme can be applied in a number of realistic settings

    Nonsymbiotic hemoglobins in rice are synthesized during germination and in differentiating cell types

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    Nonsymbiotic hemoglobins (ns-Hbs) previously have been found in monocots and dicots; however, very little is known about the tissue and cell type localization as well as the physiological function(s) of these oxygen-binding proteins. We report the immunodetection and immunolocalization of ns-Hbs in rice (Oryza sativa L.) by Western blotting and in situ confocal laser scanning techniques. Ns-Hbs were detected in soluble extracts of different tissues from the developing rice seedling by immunoblotting. Levels of ns-Hbs increased in the germinating seed for the first six days following imbibition and remained relatively constant thereafter. In contrast, ns-Hb levels decreased during leaf maturation. Roots and mesocotyls contained detectable, but low levels of ns-Hbs. Split-seed experiments revealed that ns-Hbs are synthesized de novo during seed germination and are expressed in the absence of any signal originating from the embryo. Immunolocalization of ns-Hbs by con- focal microscopy indicated the presence of ns-Hbs primarily in differentiated and differentiating cell types of the developing seedling, such as the aleurone, scutellum, root cap cells, sclerenchyma, and tracheary elements. To our knowledge, this is the first report of the specific cellular localization of these proteins during seedling development
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