Exploring the limits of crop productivity: A model to evaluate progress

The goal was to determine the limits of crop productivity when all environmental constraints were removed. Researchers define productivity as food output per unit of input. Researchers evaluated cultivars of wheat with reduced leaf size and number to decrease the leaf area index at high plant densities. These cultivars may also have an improved harvest index. Hydroponic studies indicate that 1 mM nitrate in solution is adequate to support maximum growth in these systems, provided iron nutrition is adequate. Wheat does not accumulate nitrate in leaves even when the solution nitrate concentration is 15 mM. Long-term photosynthetic efficiency (g mol (exp -1) of photons) and harvest index were not altered by photoperiod (16, 20, or 24 hours). Wheat does not need, nor benefit from, a diurnal dark period

The contribution of Rudyard Kipling to the short story

Thesis (M.A.)--Boston University PLEASE NOTE: page 82 appears to be missing from the thesis. Our determination is that this is the result of misnumbering by the author, and no substantive content is actually missing. If you are able to determine otherwise, please contact us

Three Challenges of Controlled Environment Research

A presentation given to show ways to grow plants in controlled research environments to more resemble plants found in the wild

Report on the Citizen\u27s Corps

This is a report by Daphne Bugbee, Chairman of the Citizen Corps, on the activities and purpose of the Citizen Corps.https://scholarworks.umt.edu/montanaconstitution/1440/thumbnail.jp

Control of Variable Watermilfoil in Bashan Lake, CT with 2,4-D: Monitoring of Lake and Well Water.

Variable watermilfoil (Myriophyllum heterophyllum Michx.) has recently become a problem in Bashan Lake, East Haddam, CT, USA. By 1998, approximately 4 ha of the 110 ha lake was covered with variable watermilfoil. In 1999, the milfoil was spot treated with Aquacide®, an 18% active ingredient of the sodium salt of 2,4-D [(2,4-dichlorophenoxy) acetic acid], applied at a rate of 114 kg/ha. Aquacide® was used because labeling regarding domestic water intakes and irrigation limitations prevented the use of Navigate® or AquaKleen®, a 19% active ingredient of the butoxyethyl ester of 2,4-D. Variable watermilfoil was partially controlled in shallow protected coves but little control occurred in deeper more exposed locations. 2,4-D levels in the treatment sites were lower than desired and offsite dilution was rapid. In 2000, the United States Environmental Protection Agency (USEPA) issued a special local need (SLN) registration to allow the use of Navigate ® or AquaKleen® in lakes with potable and irrigation water intakes. Navigate® was applied at a rate of 227 kg/ha to the same areas as treated in 1999. An additional 2 ha of variable watermilfoil was treated with Navigate® in 2001, and 0.4 ha was treated in mid-September. Dilution of the 2,4-D ester formulation to untreated areas was slower than with the salt formulation. Concentrations of 2,4-D exceeded 1000 μg/ L in several lake water samples in 2000 but not 2001. Nearly all of the treated variable watermilfoil was controlled in both years. The mid-September treatment appeared as effective as the spring and early summer treatments. Testing of homeowner wells in all 3 years found no detectable levels of 2,4-D.(PDF contains 8 pages.

Long-term beta-blocker therapy safe and effective in reducing cardiomyopathy in patients who actively abuse stimulant drugs

If anything was learned since Breaking Bad, it’s that the devastation due to the methamphetamine problem does not spare a single person. Similarly, cocaine abuse does not have benign effects on the heart. Methamphetamine and cocaine abuse are increasing worldwide including use among the younger population; making recognition of the cardiovascular risks more important than ever. If long-term BBT can decrease the incidence of stimulant-related cardiovascular complications commonly experienced in methamphetamine and cocaine users, then it may be possible to decrease unnecessary admissions to the hospital and ICU. Therefore, in patients who actively engage in stimulant drug abuse, how does long-term BBT, both selective and nonselective, affect cardiovascular outcomes compared to no BBT regarding prevention of stimulant-induced-cardiomyopathy

Toward an optimal spectral quality for plant growth and development: The importance of radiation capture

We have characterized the effects of individual wavelengths of light on single leaf photosynthesis but we do not yet fully understand the effects of multi-wavelength radiation sources on growth and whole-plant net assimilation. Studies with monochromatic light by Hoover, McCree and Inada nearly a half century ago indicated that blue and cyan photons are used less efficiently than orange and red photons. Contrary to these measurements, studies in whole plants have found that photosynthesis often increases with an increasing fraction of blue photons. Plant growth, however, typically decreases as the fraction of blue photons increases above 5 to 10%. The dichotomy of increasing photosynthesis and decreasing growth reflects an oversight of the critical role of radiation capture (light interception) in the growth of whole plants. Photosynthetic efficiency is measured as quantum yield: moles of carbon fixed per mole of photons absorbed. Increasing blue light often inhibits cell division, cell expansion, and thus reduces leaf area. The thicker leaves have higher photosynthetic rates per unit area, but reduced radiation capture. This blue-light-induced reduction in photon capture is usually the primary reason for reduced growth in spite of increased photosynthesis per unit leaf area. This distinction is critical when extrapolating from single leaves to plant communities

Faunal Analysis of the Licking Bison Site (39HN570): An Early Archaic Bison Kill Site from Harding County, South Dakota

The Licking Bison Site (39HN570) is located in Harding County, South Dakota and dates to 5570±30 14C yr BP (6406-6301 cal yr BP), during the Early Archaic period. The site was discovered in 1994 and excavated between 1995 and 2000 by the South Dakota State Archaeological Research Center (SARC). The Early Archaic corresponds with a period of warm and dry climatic conditions on the Northern Great Plains often referred to as the Altithermal. Archaeological sites from this time are relatively rare compared to both earlier and later periods. The Licking Bison Site is one of only two known bison kill sites from the Early Archaic of the region, and as such it has the potential to provide valuable information on prehistoric ways of life during the arid climatic conditions, as well as providing data about bison evolution. The faunal collection, housed at SARC, was analyzed to identify the species of bison, herd demographics (age, sex, MNI), and season of death. The excavated portion of the bonebed contained at least twenty-two individual bison killed and butchered by Early Archaic peoples in a single late fall kill event. The herd most likely consisted of predominately adult females, juveniles, and calves. Analysis of metacarpals shows at least four adult females and one adult male in the assemblage. The species of bison could not be identified due to a lack of well-preserved crania, but postcranial metrics suggest a possible slight trend towards Bison bison-sized individuals

Super Dwarf Wheat for Growth in Confined Spaces

USU-Perigee is a dwarf red spring wheat that is a hybrid of a high-yield early tall wheat (USU-Apogee) and a low-yield, extremely short wheat that has poor agronomic characteristics. USU-Perigee was selected for its extremely short height (.0.3 m) and high yield . characteristics that make it suitable for growth in confined spaces in controlled environments. Other desirable characteristics include rapid development and resistance to a leaf-tip necrosis, associated with calcium deficiency, that occurs in other wheat cultivars under rapid-growth conditions (particularly, continuous light). Heads emerge after only 21 days of growth in continuous light at a constant temperature of 25 C. In tests, USU-Perigee was found to outyield other full dwarf (defined as <0.4 m tall) wheat cultivars: The yield advantage at a constant temperature of 23 C was found to be about 30 percent. Originally intended as a candidate food crop to be grown aboard spacecraft on long missions, this cultivar could also be grown in terrestrial growth chambers and could be useful for plant-physiology and -pathology studies