3,316 research outputs found
Absorption of Phosphorus by Foliage of Malus Robusta
Five different phosphorus slats were applied to the foliage of Malus robusta trees growing in the greenhouse. The radioactive isotope of phosphorus (P32) was used as a tracer in studying the absorption and translocation of the foliarly applied phosphorus.
Observations were made on the translocation of phosphorus by taking radioactive counts on fifteen-sixteenths inch leave discs at weekly intervals. At the end of the experiment, samples from the old and new leaves and stems and from the roots were analyzed and counted to determine the total P2O5 in the sample. The percent P2O5 which cam from foliar application was determined from the radioactive counts per minute obtained from the samples.
The results show conclusively that water soluble phosphorus applied as a foliar spray to foliage and small branches of apple trees can be absorbed and translocated to other parts of the trees. Under conditions of this experiment di-ammonium phosphate was absorbed and translocated in larger amounts than any of the other phosphorus salts used.
The phosphorus applied as a foliar spray was absorbed and translocated to the roots in more than double the quantity that was translocated to foliage in the unsprayed area on the same tree. Translocation of phosphorus was greater to young leaves in the unsprayed area than to older leaves in the same area
Explaining the Nazi Vote: The Findings and Limits of Ecological Analysis
http://deepblue.lib.umich.edu/bitstream/2027.42/50909/1/134.pd
Method of treating fescue toxicosis with domperidone
A novel method for using domperidone, a dopamine receptor antagonist, for treating fescue toxicosis in animals is provided. Fescue toxicosis is caused by animals grazing on endophyte-infected fescue grass. Treatment of the animal with various dosages of domperidone results in effective management of the toxin. The domperidone treatments do not cause any substantial adverse behavioral or neurological side effects in the animal. Domperidone is a more effective treatment for fescue toxicosis than previously-known agents such a metoclopramide and sulpiride
Spontaneous Mutations Decrease Sensitivity of Gene Expression to Random Environmental Variation in Caenorhabditis elegans
Biological phenotypes are described as “canalized” if they are robust to minor variation of environment and/or genetic background. The existence of a robust phenotype logically implies that some underlying mechanism must be variable, in the sense of “able to vary”, in order to compensate for variation in the environment and/or genetic effects. Several lines of evidence lead to the conclusion that deleterious mutations predictably render morphological, developmental, and life-history traits more sensitive to small random environmental perturbations - that is, mutations de-canalize the phenotype. and the common (unmutated) ancestor. There was significantly less environmental variance in the MA lines than in the ancestor, both among replicates of the same gene and among genes.Deleterious mutations consistently decrease the within-line component of variance in transcript abundance, which is straightforwardly interpreted as reducing the sensitivity of gene expression to small random variation in the environment. This finding is consistent with the idea that underlying variability in gene expression might be mechanistically responsible for phenotypic robustness
Physicians\u27 use of the personal digital assistant (PDA) in clinical decision making
Purpose: This study examined how frequently attending physicians and physicians in training used personal digital assistants (PDAs) for patient care and explored physicians\u27 perceptions of the impact of PDA use on several areas of clinical decision making. Setting/Subjects: The 108 participants included 59 attending physicians and 49 physicians in training from teaching hospitals in Tennessee, Florida, Alabama, Kentucky, and Pennsylvania. Methodology: Respondents completed a questionnaire designed to explore PDA use in a clinical setting. Results: Eighty-seven percent of the respondents reported PDA use for patient encounters. Fifty-five percent of respondents reported frequent use, and 32% reported occasional use of a PDA for patient care. Of the frequent PDA users, 85% said PDA use had influenced their overall clinical decision making and 73% mentioned treatment alterations specifically. Approximately 60% of the participants reporting occasional PDA use indicated that the PDA had influenced their overall clinical decision making, while 54% specifically mentioned a change to their patient\u27s treatment plan. Discussion/Conclusion: Attending physicians and physicians in training who used a PDA during patient encounters perceived that even occasional PDA use had an impact on their clinical decision making and treatment choices. Health sciences librarians are perfectly positioned to provide PDA training and assistance not only to physicians who are frequent PDA users, but also to those who are occasional users
Structural Stability and Renormalization Group for Propagating Fronts
A solution to a given equation is structurally stable if it suffers only an
infinitesimal change when the equation (not the solution) is perturbed
infinitesimally. We have found that structural stability can be used as a
velocity selection principle for propagating fronts. We give examples, using
numerical and renormalization group methods.Comment: 14 pages, uiucmac.tex, no figure
A Year in Space for the CubeSat Multispectral Observing System: CUMULOS
CUMULOS is a three-camera system flying as a secondary payload on the Integrated Solar Array and Reflectarray Antenna (ISARA) mission with the goals of researching the use of uncooled commercial infrared cameras for Earth remote sensing and demonstrating unique nighttime remote sensing capabilities. Three separate cameras comprise the CUMULOS payload: 1) a visible (VIS) Si CMOS camera, 2) a shortwave infrared (SWIR) InGaAs camera, and 3) a longwave infrared (LWIR) vanadium oxide microbolometer. This paper reviews on-orbit operations during the past year, in-space calibration observations and techniques, and Earth remote sensing highlights from the first year of space operations. CUMULOS operations commenced on 8 June 2018 following the successful completion of the primary ISARA mission. Some of the unique contributions from the CUMULOS payloads include: 1) demonstrating the use of bright stars for on-orbit radiometric calibration of CubeSat payloads, 2) acquisition of science-quality nighttime lights data at 130-m resolution, and 3) operating the first simple Earth observing infrared payloads successfully flown on a CubeSat. Sample remote sensing results include images of: cities at night, ship lights (including fishing vessels), oil industry gas flares, serious wildfires, volcanic activity, and daytime and nighttime clouds. The CUMULOS VIS camera has measured calibrated nightlights imagery of major cities such as Los Angeles, Singapore, Shanghai, Tokyo, Kuwait City, Abu Dhabi, Jeddah, Istanbul, and London at more than 5x the resolution of VIIRS. The utility of these data for measuring light pollution, and mapping urban growth and infrastructure development at higher resolution than VIIRS is being studied, with an emphasis placed on Los Angeles. The Carr , Camp and Woolsey fires from the 2018 California fire season were imaged with all three cameras and results highlight the excellent wildfire imaging performance that can be achieved by small sensors. The SWIR camera has exhibited extreme sensitivity to flare and fire hotspots, and was even capable of detecting airglow-illuminated nighttime cloud structures by taking advantage of the strong OH emissions within its 0.9-1.7 micron bandpass. The LWIR microbolometer has proven successful at providing cloud context imagery for our nightlights mapping experiments, can detect very large fires and the brightest flare hotspots, and can also image terrain temperature variation and urban heat islands at 300-m resolution. CUMULOS capabilities show the potential of CubeSats and small sensors to perform several VIIRS-like nighttime mission areas in which wide area coverage can be traded for greater resolution over a smaller field of view. The sensor has been used in collaboration with VIIRS researchers to explore these mission areas and side-by-side results will be presented illustrating the capabilities as well as the limitations of small aperture LEO CubeSat systems
Validation of Inverse Seasonal Peak Mortality in Medieval Plagues, Including the Black Death, in Comparison to Modern Yersinia pestis-Variant Diseases
Background: Recent studies have noted myriad qualitative and quantitative inconsistencies between the medieval Black Death (and subsequent ‘‘plagues’’) and modern empirical Y. pestis plague data, most of which is derived from the Indian and Chinese plague outbreaks of A.D. 1900615 years. Previous works have noted apparent differences in seasonal mortality peaks during Black Death outbreaks versus peaks of bubonic and pneumonic plagues attributed to Y. pestis infection, but have not provided spatiotemporal statistical support. Our objective here was to validate individual observations of this seasonal discrepancy in peak mortality between historical epidemics and modern empirical data. Methodology/Principal Findings: We compiled and aggregated multiple daily, weekly and monthly datasets of both Y. pestis plague epidemics and suspected Black Death epidemics to compare seasonal differences in mortality peaks at a monthly resolution. Statistical and time series analyses of the epidemic data indicate that a seasonal inversion in peak mortality does exist between known Y. pestis plague and suspected Black Death epidemics. We provide possible explanations for this seasonal inversion. Conclusions/Significance: These results add further evidence of inconsistency between historical plagues, including the Black Death, and our current understanding of Y. pestis-variant disease. We expect that the line of inquiry into the disputed cause of the greatest recorded epidemic will continue to intensify. Given the rapid pace of environmental change in th
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