1,609 research outputs found

    The results of an agricultural analysis of the ERTS-1 MSS data at the Johnson Space Center

    Get PDF
    The initial analysis of the ERTS-1 multispectral scanner (MSS) data at the Johnson Space Center (JSC), Houston, Texas is discussed. The primary data set utilized was the scene over Monterey Bay, California, on July 25, 1972, NASA ERTS ID No. 1002-18134. It was submitted to both computerized and image interpretative processing. An area in the San Joaquin Valley was submitted to an intensive evaluation of the ability of the data to (1) discriminate between crop types and (2) to provide a reasonably accurate area measurement of agricultural features of interest. The results indicate that the ERTS-1 MSS data is capable of providing the identifications and area extent of agricultural lands and field crop types

    Інтегро-диференціальні системи псевдопараболічного типу: апріорні оцінки та імпульсно-точкова керованість

    Get PDF
    Для вольтеррівського інтегро-диференціального оператора псевдопараболічного типу одержано апріорні оцінки у негативних нормах, теореми існування та єдиності узагальнених розв'язків відповідних крайових задач. Розглянуто питання імпульсно-точкової керованості систем, що описуються інтегро-диференціальними псевдопараболічними рівняннями.Для вольтерровского интегро-дифференциального оператора псевдопараболического типа получены априорные оценки в негативных нормах, теоремы существования и единственности обобщенных решений соответствующих граничных задач. Рассмотрен вопрос импульсно-точечной управляемости систем, описываемых интегро-дифференциальными псевдопараболическими уравнениями.For a pseudoparabolic Volterra integro-differential operator, the a priori estimates in negative norms and the unique generalized solvability theorems for the corresponding boundary value problems are obtained. The question of impulse-point controllability of systems governed by pseudoparabolic integro-differential equations is investigated

    SPLINE MODELS FOR ESTIMATING HEAT STRESS THRESHOLDS IN CATTLE

    Get PDF
    Studies of the relationship between animal body temperature and air temperature suggest body temperature is essentially unresponsive until a threshold is reached, then it responds dramatically to increasing air temperature. The goal is to estimate the threshold between the thermoneutral plateau and the beginning of the heat stress challenge. One approach is to fit a polynomial to estimate the knot position and use spline functions to perform linear least squares piecewise polynomial fitting. Another alternative is to use nonlinear regression to estimate the knot or an inflection point of a nonlinear function. In both approaches the cyclic nature of body temperature is ignored. This paper explores the use of nonlinear regression to estimate the knot position and handles the hysteresis effect resulting from the cyclic nature of body temperature. Models are fit to data collected from cattle in chambers subjected to semicontrolled sinusoidal air temperature at the University of Missouri-Columbia Animal Science department and a procedure for estimating the heat stress threshold is proposed

    Effects of Organic and Inorganic Fertilizers on Marigold Growth and Flowering

    Get PDF
    Two experiments were conducted to evaluate the growth and flowering responses of greenhouse-grown French marigold (Tagetes patula L. ‘Janie Deep Orange’) to two non-composted broiler chicken litter-based organic fertilizers, 4-2-2 and 3-3-3, and one commonly used synthetic controlled-release fertilizer, 14-14-14. In both experiments, fertilizer 4-2-2 was applied at four rates of 1%, 2%, 4%, and 6% (by volume); 3-3-3 was applied at four rates of 1.34%, 2.67%, 5.34%, and 8.0% (by volume); and 14-14-14 was applied at rates of 0.99, 1.98, 3.96, and 5.94 kg·m−3. In general, substrate containing different rates and types of fertilizers had a pH within the recommended range of 5.0 to 6.5. Electrical conductivity (EC) was similar among substrates containing different rates of 14-14-14; however, EC increased with increasing fertilizer rate for substrates containing 4-2-2 and 3-3-3. Substrate EC within each treatment was generally higher earlier in the experiment. For the fertilizer rates used in these two experiments, increasing 14-14-14 fertilizer rate increased plant growth and flowering performance. However, low to intermediate rates of 4-2-2 and 3-3-3 in general produced the highest plant growth index, shoot dry weight, number of flowers per plant, total flower dry weight, and root rating. Plants grown at high rates of 4-2-2 and 3-3-3 showed symptoms associated with excessive fertilization. Plant tissue nitrogen (N), phosphorus (P), and potassium (K) concentrations increased linearly or quadratically with increasing fertilizer rates for all three fertilizers. In general, plants receiving 4-2-2 and 3-3-3 had higher concentrations of N, P, and K than plants receiving 14-14-14. Results from this study indicated that broiler litter-based 4-2-2 and 3-3-3 have the potential to be used as organic fertilizer sources for container production of marigolds in greenhouses. However, growers need to be cautious with the rate applied. Because different crops may respond differently to these natural fertilizers, it is important for growers to test any new fertilizers before incorporating them into their production practices

    USING NONLINEAR FIXED AND MIXED MODELS TO STUDY ACCLIMATION TO HEAT STRESS IN CATTLE

    Get PDF
    Researchers studying acclimation of cattle to heat stress want to know if exposure to heat stress in controlled chambers will help cattle adjust to climatic conditions in the field. The four parameter nonlinear PET model is used to study the relationship between core body temperature and ambient temperature. This model works well when cattle are challenged by heat stress but the model is less useful for thermoneutral conditions. Both proc Nlin and Nlmixed are used to compare and contrast the field parameters between the controlled and the potentially acclimated group. Simulation studies were used to compare the effectiveness of proc Nlin versus proc Nlmixed. The results are helpful, not only for researchers who study acclimation, but also for those who study sensitivity, tolerance and robustness of cattle during heat stress

    ‘Ramata’: A New Dwarf Variegated Hedychium (Ornamental Ginger) Cultivar

    Get PDF
    Most Hedychium J. Koenig (Zingiberaceae) species have showy and fragrant flowers, which are used in leis and perfumery. Hedychium species are easy to grow and are mostly free of major diseases and pests. The essential oils of some species have been found to have insecticidal, antibacterial, and antifungal activities (Gopanraj et al., 2005; Jadhav et al., 2007; Medeiros et al., 2003). Hedychium plants prefer moist, fertile soil and are considered to be shade plants but will thrive in full sun if provided adequate moisture, and many species will grow and bloom throughout USDA zone 7 (Adams, 1999). Hedychium plants are suitable for landscape use, but their height (up to 2 m or more) generally limits their use as potted plants. Furthermore, Hedychium plants are well known for the diversity of their flower colors, but their green foliage is mostly uniform and lacks variegation. Only three variegated cultivars, Dr. Moy, Tahitian Flame, and Vanilla Ice, are commercially available. These three cultivars are related in that ‘Tahitian Flame’, a selection of Terra Nova Nurseries, Inc. (Canby, OR), occurred as a natural branch mutation of ‘Dr. Moy’ (Korlipara, 2009), and ‘Vanilla Ice’ is a sport of ‘Dr. Moy’ selected by Messenbrink’s Nursery of Nashville, NC. Developing new dwarf compact cultivars with novel foliar characteristics is a major objective of the Hedychium breeding program at the USDA-ARS Thad Cochran Southern Horticultural Laboratory (TCSHL) in Poplarville, MS. Reported here is Hedychium muluense R.M. Smith ‘Ramata’, a compact, dwarf (≈71 cm) cultivar with variegated leaves (Fig. 1A). Both dwarfism and variegation are highly desired but rare traits in Hedychium. This is the first report of both of these traits in one Hedychium cultivar

    CHARACTERIZING THERMAL HYSTERESIS IN BODY TEMPERATURE FOR A HEAT STRESSED STEER

    Get PDF
    Studies have shown that exposure of animals to a high ambient temperature environment poses serious threats to their health, performance and productivity. Above a certain threshold an animal\u27s body temperature (Tb) appears to be driven by the hot ambient temperature (Ta). For steers challenged by heat stress, the Tb-Ta relationship shows a dramatic increase in Tb per unit change of Ta and the dynamics of the Tb-Ta relationship follow a pattern which depends on whether Ta is increasing or decreasing. A delay becomes noticeable in a steer’s thermo-regulatory response to Ta when Ta is controlled to be sinusoidal in the steer’s heat stress chamber. In other words, Tb lags behind Ta. Consequently when plotted in a Tb-Ta phase diagram, a hysteresis effect appears in the form of a hysteresis loop, indicating the steer is thermally challenged. The hysteresis loop shows a rotated elliptical pattern which depends on the delay (or lag) between Tb and Ta. The angle of rotation of the hysteresis loop indicates the correlation (and lag) between Tb and Ta. The area of the elliptical hysteresis loop can be used to quantify the amount of heat stress during the period of thermal challenge. For example, results of a thermal challenge of 32±7oC applied to a Hereford steer showed, the delay is longer (4 hr lag) and ellipse is larger in an acute stage than in a chronic stage (3 hr lag). A greater delay (or lag) suggests more time is needed to dissipate the heat stress. This result suggests, steers in an acute stage require more energy to dissipate heat than steers in a chronic stage

    Impact of mobile phones and wireless devices use on children and adolescents´ mental health: a systematic review

    Get PDF
    Growing use of mobiles phones (MP) and other wireless devices (WD) has raised concerns about their possible effects on children and adolescents’ wellbeing. Understanding whether these technologies affect children and adolescents’ mental health in positive or detrimental ways has become more urgent following further increase in use since the COVID-19 outbreak. To review the empirical evidence on associations between use of MP/WD and mental health in children and adolescents. A systematic review of literature was carried out on Medline, Embase and PsycINFO for studies published prior to July 15th 2019, PROSPERO ID: CRD42019146750. 25 observational studies published between January 1st 2011 and 2019 were reviewed (ten were cohort studies, 15 were cross-sectional). Overall estimated participant mean age and proportion female were 14.6 years and 47%, respectively. Substantial between-study heterogeneity in design and measurement of MP/WD usage and mental health outcomes limited our ability to infer general conclusions. Observed effects differed depending on time and type of MP/WD usage. We found suggestive but limited evidence that greater use of MP/WD may be associated with poorer mental health in children and adolescents. Risk of bias was rated as ‘high’ for 16 studies, ‘moderate’ for five studies and ‘low’ for four studies. More high-quality longitudinal studies and mechanistic research are needed to clarify the role of sleep and of type of MP/WD use (e.g. social media) on mental health trajectories in children and adolescents
    corecore