886 research outputs found
A LINKED ANNUAL AND MONTHLY MODEL FOR FORECASTING ALFALFA HAY PRICES
This article develops a model to forecast monthly alfalfa hay prices before the first harvest. This is done by linking an annual model, which forecasts the initial May price, with a system of monthly equations that track the monthly seasonal price pattern, given the forecasted May price.Crop Production/Industries, Demand and Price Analysis,
Shaking Off the Rust: Unraveling the Depositional and Diagenetic History of Enigmatic Ferroan Dolostones in the Cambrian Bright Angel Formation, Tonto Group, Grand Canyon
Within the siliciclastic-sediment-dominated Bright Angel Formation (BAF) of the iconic Cambrian sedimentary strata (Tonto Group) in Grand Canyon National Park, Arizona, workers have identified and named prominent reddish-brown cliffs breaking up the generally slope-forming unit near, but separated from, its upper contact with the limestone-dominated Muav Formation, the Rusty Brown Dolostones (RBDs). Previous hypotheses suggest that the RBDs are chemically and physically altered tongues of the Muav Formation intercalated with the BAF at increasingly higher stratigraphic positions from west to east within the Canyon. A genetic association between the Muav Formation and the RBDs, as well as between the RBDs themselves, has yet to be established. Further, the paleoenvironment that these apparent couplets represent is poorly constrained. Understanding the formation and evolution of these deposits will fill a gap in our understanding that sits at a prominent transition in facies belts and thus depositional environments, elucidating processes that link two distinct belts of rock formed on the Cambrian Laurentian margin during a period of gradual sea level rise (termed the Sauk Transgression).
Here we use sedimentological observations and stratigraphic relationships to interpret the paleoenvironmental conditions that resulted in the deposition of the RBDs and provide a single more widely applicable definition of the member. We define the RBDs as sets of coupled repeating depositional cycles composed of subtidal marine shales, siltstones, and well-sorted fine-grained, glauconitic quartz arenites (sandstones). These packages transition upwards into iron enriched carbonates that span a genetic spectrum from apparently abiotic, to biotically-influenced, to biotically-mediated. These are interpreted as lagoonal to estuarine deposits influenced by tides, formed in a peritidal to shallow subtidal zone, and punctuated by storms that transition upsection into landward tongues of the Muav Formation developed during rising relative sea level. These sequences are subsequently overlain by BAF siliciclastic suites that advance seaward following the cessation of relative sea level rise. Sedimentological and geochemical analyses indicate a lack of subaerial exposure prior to burial and derivation of the ions necessary to transition these limestones into dolostones enriched in iron from the clay/mica mineral glauconite during shallow to intermediate burial alteration processes
Church of Christ 1964-1965 Radio Amateur Callbook Volume 4
https://digitalcommons.acu.edu/crs_books/1455/thumbnail.jp
Protection status, human disturbance, snow cover and trapping drive density of a declining wolverine population in the Canadian Rocky Mountains
Protected areas are important in species conservation, but high rates of human-caused mortality outside their borders and increasing popularity for recreation can negatively affect wildlife populations. We quantified wolverine (Gulo gulo) population trends from 2011 to 2020 in > 14,000 km2 protected and non-protected habitat in southwestern Canada. We conducted wolverine and multi-species surveys using non-invasive DNA and remote camera-based methods. We developed Bayesian integrated models combining spatial capture-recapture data of marked and unmarked individuals with occupancy data. Wolverine density and occupancy declined by 39%, with an annual population growth rate of 0.925. Density within protected areas was 3 times higher than outside and declined between 2011 (3.6 wolverines/1000 km2) and 2020 (2.1 wolverines/1000 km2). Wolverine density and detection probability increased with snow cover and decreased near development. Detection probability also decreased with human recreational activity. The annual harvest rate of ≥ 13% was above the maximum sustainable rate. We conclude that humans negatively affected the population through direct mortality, sub-lethal effects and habitat impacts. Our study exemplifies the need to monitor population trends for species at risk—within and between protected areas—as steep declines can occur unnoticed if key conservation concerns are not identified and addressed
Thermal/structural Tailoring of Engine Blades (T/STAEBL) User's Manual
The Thermal/Structural Tailoring of Engine Blades (T/STAEBL) system is a family of computer programs executed by a control program. The T/STAEBL system performs design optimizations of cooled, hollow turbine blades and vanes. This manual contains an overview of the system, fundamentals of the data block structure, and detailed descriptions of the inputs required by the optimizer. Additionally, the thermal analysis input requirements are described as well as the inputs required to perform a finite element blade vibrations analysis
Toward the Development of Ethical Guidelines for Family Preservation
Family preservation workers need a standard set of ethical guidelines to assist them in providing their service in a proper manner. This paper describes how ethical codes have been developed for the traditional mental health care disciplines and why such codes are not sufficient for the type of work done in family preservation. The paper further provides examples of the types of ethical dilemmas family preservation workers encounter as well as suggestions for workers, supervisors, and agencies in dealing with such dilemmas
NASA Flight Planning Branch Space Shuttle Lessons Learned
Planning products and procedures that allowed the mission Flight Control Teams and the Astronaut crews to plan, train and fly every Space Shuttle mission were developed by the Flight Planning Branch at the NASA Johnson Space Center in Houston, Texas. As the Space Shuttle Program came to a close, lessons learned were collected from each phase of the successful execution of these Space Shuttle missions. Specific examples of how roles and responsibilities of console positions that develop the crew and vehicle attitude timelines have been analyzed and will be discussed. Additionally, the relationships and procedural hurdles experienced through international collaboration have molded operations. These facets will be explored and related to current and future operations with the International Space Station and future vehicles. Along with these important aspects, the evolution of technology and continual improvement of data transfer tools between the Space Shuttle and ground team has also defined specific lessons used in improving the control team s effectiveness. Methodologies to communicate and transmit messages, images, and files from the Mission Control Center to the Orbiter evolved over several years. These lessons were vital in shaping the effectiveness of safe and successful mission planning and have been applied to current mission planning work in addition to being incorporated into future space flight planning. The critical lessons from all aspects of previous plan, train, and fly phases of Space Shuttle flight missions are not only documented in this paper, but are also discussed regarding how they pertain to changes in process and consideration for future space flight planning
Review of the analysis of 234Th in small volume (2–4 L) seawater samples: Improvements and recommendations
The short-lived radionuclide 234Th is widely used to study particle scavenging and transport from the upper ocean to deeper waters. This manuscript optimizes, reviews and validates the collection, processing and analyses of total 234Th in seawater and suggests areas of further improvements. The standard 234Th protocol method consists of scavenging 234Th from seawater via a MnO2 precipitate, beta counting, and using chemical recoveries determined by adding 230Th. The revised protocol decreases sample volumes to 2 L, shortens wait times between steps, and simplifies the chemical recovery process, expanding the ability to more rapidly and safely apply the 234Th method
Florivory Shapes both Leaf and Floral Interactions
Florivory, or the consumption of flowers, is a ubiquitous interaction that can reduce plant reproduction directly by damaging reproductive tissues and indirectly by deterring pollinators. However, we know surprisingly little about how florivory alters plant traits or the larger community of species interactions. Although leaf damage is known to affect floral traits and interactions in many systems, the consequences of floral damage for leaf traits and interactions are unknown. We manipulated floral damage in Impatiens capensisand measured effects on floral attractive traits and secondary chemicals, leaf secondary chemicals, floral interactions, leaf herbivory, and plant reproduction. We also examined relationships between early season floral traits and floral interactions, to explore which traits structure floral interactions. Moderate but not high florivory significantly increased relative selfed reproduction, leading to a shift in mating system away from outcrossing. Florivory increased leaf secondary compounds and decreased leaf herbivory, although mechanisms other than leaf chemistry may be responsible for some of the reduced leaf damage. Florivory altered four of seven measured interactions, including increased subsequent florivory and reduced flower spiders, although only leaf damage effects were significant after correcting for multiple tests. Pretreatment concentrations of floral anthocyanins and condensed tannins were associated with reduced levels of many floral antagonisms, including florivory, nectar larceny, and flower spider abundance, suggesting these traits play a role in floral resistance. Overall, our results indicate a broad range of community and potential evolutionary consequences of florivory through structuring subsequent floral interactions, altering leaf secondary chemicals, and shaping leaf herbivory
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