3,188 research outputs found
Pre-visual detection of stress in pine forests
Pre-visual, or early, detection of forest stress with particular reference to detection of attacks by pine bark beetles is discussed. Preliminary efforts to obtain early detection of attacks by pine bark beetles, using MSS data from the ERIM M-7 scanner, were not sufficiently successful to demonstrate an operational capability, but indicate that joint processing of the 0.71 to 0.73, 2.00 to 2.60, and 9.3 to 11.7 micrometer bands holds some promise. Ratio processing of transformed data from the 0.45 to 0.52, 1.55 to 2.60, and 4.5 to 5.5 or 9.3 to 11.7 micrometer regions appears even more promising
Forest Species Identification with High Spectral Resolution Data
Data collected over the Sleeping Bear Sand Dunes Test Site and the Saginaw Forest Test Site (Michigan) with the JPL Airborne Imaging Spectrometer and the Collins' Airborne Spectroradiometer are being used for forest species identification. The linear discriminant function has provided higher identification accuracies than have principal components analyses. Highest identification accuracies are obtained in the 450 to 520 nm spectral region. Spectral bands near 1,300, 1,685 and 2,220 nm appear to be important, also
Remote sensing of changes in morphology and physiology of trees under stress Annual progress report
Remote sensing of morphological and physiological changes in trees under stres
Remote sensing of changes in morphology and physiology of trees under stress
Measurements on foliage samples collected from several drought and salt treated plants revealed that leaf thickness decreased with increasing severity of the drought treatment and increased with increasing severity of treatment with NaCl, but remained essentially unaffected by treatment with CaCl2. Airborne data collected by multispectral scanner indicated that false color images provide selective enhancement of a diseased area. Comparison of simulated and actual aerial color and color IR photography revealed that the color renditions of the MSS simulations agreed closely with those of the actual photography
Remote sensing applications in forestry - Remote sensing of changes in morphology and physiology of trees under stress Annual progress report
Remote sensing of changes in morphology and physiology of trees under stres
Nutritional Consequences of Food Insecurity in a Rural New York State County
This study of women with children in a rural county of upstate New York examined the relationships of food insecurity and income with two nutritional consequences (adiposity and fruit and vegetables consumption), and assessed whether disordered eating patterns is a mediator for the effects of food insecurity and income on these nutritional consequences. Each of 193 respondents was interviewed twice in her home. Data were collected on household food stores, socioeconomic and demographic characteristics, methods of obtaining food, food program participation, household expenditures, food intake, the Radimer/Cornell hunger and food insecurity items, height, weight, frequency of fruit and vegetable consumption, and disordered eating patterns. Regression analysis was used to analyze the relationships of body mass index and an obesity classification with height, income, education, single parenthood, employment, food insecurity, disordered eating, and frequency of fruit and vegetable consumption. Regression analysis was also used to examine the relationships of disordered eating and frequency of fruit and vegetable consumption with the other variables. Lower income and unemployment were related to higher adiposity. The effects of income on adiposity were not mediated through disordered eating patterns or through fruit and vegetable consumption. Food insecurity was related to adiposity, and part of this effect of food insecurity was mediated through disordered eating. This mediating effect of disordered eating partially explained why those experiencing the least severe food insecurity were more likely to be overweight than those who were food secure, but those experiencing the most severe food insecurity were less likely to be overweight than those who were food secure. Food insecurity was related to lower fruit and vegetable consumption, but this did not translate into effects on adiposity.
Scavenger community response to the removal of a dominant scavenger
The alteration of scavenging communities can reduce basic ecosystem services and increase risks to human and wildlife health. Recent work demonstrated that scavenging communities in agricultural landscapes are extremely efficient: superabundant mesopredators sequestered system energy by dominating scavenging activity. To explore how the disturbance of these communities affects the stability of carrion removal as an ecosystem function, we experimentally manipulated a scavenging community within an agricultural landscape by reducing the abundance of the dominant scavenger, raccoons Procyon lotor. We then monitored the fates of 676 mouse Mus musculus carcasses placed in 13 control and 13 removal woodlots from June 2007 – May 2008. The diversity of vertebrate scavengers did not change between control and removal woodlots and scavenging by invertebrates was unaffected by our experiment. Although Virginia opossums Didelphis virginiana and other scavengers exhibited a functional response when raccoons were reduced in abundance, the increases did not change the proportional allocation of carcasses among scavengers. Finally, the reduced abundance of a major scavenger affected system efficiency. More carcasses remained un-scavenged at the end of trials in removal woodlots than in control woodlots. This experiment demonstrates the vulnerability of a critical ecosystem service, carrion removal, to perturbations of the scavenging community and serves to highlight the method by which scavenger communities may respond to perturbations
Reducing vortex density in superconductors using the ratchet effect
A serious obstacle that impedes the application of low and high temperature
superconductor (SC) devices is the presence of trapped flux. Flux lines or
vortices are induced by fields as small as the Earth's magnetic field. Once
present, vortices dissipate energy and generate internal noise, limiting the
operation of numerous superconducting devices. Methods used to overcome this
difficulty include the pinning of vortices by the incorporation of impurities
and defects, the construction of flux dams, slots and holes and magnetic
shields which block the penetration of new flux lines in the bulk of the SC or
reduce the magnetic field in the immediate vicinity of the superconducting
device. Naturally, the most desirable would be to remove the vortices from the
bulk of the SC. There is no known phenomenon, however, that could form the
basis for such a process. Here we show that the application of an ac current to
a SC that is patterned with an asymmetric pinning potential can induce vortex
motion whose direction is determined only by the asymmetry of the pattern. The
mechanism responsible for this phenomenon is the so called ratchet effect, and
its working principle applies to both low and high temperature SCs. As a first
step here we demonstrate that with an appropriate choice of the pinning
potential the ratchet effect can be used to remove vortices from low
temperature SCs in the parameter range required for various applications.Comment: 7 pages, 4 figures, Nature (in press
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Convective transport of formaldehyde to the upper troposphere and lower stratosphere and associated scavenging in thunderstorms over the central United States during the 2012DC3 study
Use of a liquid nicotine delivery product to promote smoking cessation
<p>Abstract</p> <p>Background</p> <p>Despite access to various pharmacotherapies and counseling support to aid cessation, smokers typically demonstrate quit rates below 50%. This report describes the results of a Phase 2a study exploring the efficacy of a liquid nicotine delivery system as an aid to smoking cessation assessed after 12 weeks of therapy.</p> <p>Methods</p> <p>A single-arm Phase 2a study was conducted. Community-based smokers (ages 18+ years, smoking at least 10 cigarettes daily for the past year and interested in making a quit attempt) were recruited and completed clinic visits at 2 week intervals over the 12 week study period where carbon monoxide levels were assessed and the Smoke-Break product was rated on taste and overall satisfaction. Participants were provided with a supply of liquid nicotine cigarettes (e.g., Smoke-Break) at each clinic visit. A total of 69 smokers were enrolled and received the intervention product (intention to treat group, ITT) and 52 smokers verified participation (according to protocol group, ATP).</p> <p>Results</p> <p>The cessation rate at 12 weeks after the baseline visit, assessed as the bioverified point prevalence of abstinence, was 71.1% (95% confidence interval [CI] 58.8%-83.5%) in the ATP group and 53.6% (41.8%-65.4%) in the ITT group. Participants rated the liquid nicotine delivery system highly and also expressed general satisfaction. Few adverse events were identified with no serious adverse events.</p> <p>Conclusions</p> <p>These results support the efficacy of the liquid nicotine delivery system in smoking cessation. If this nicotine delivery product proves to be effective in larger trials, it could represent an inexpensive, readily accessible and well-tolerated agent to promote smoking cessation.</p> <p>Trial Registration</p> <p>This trial is registered at clinicaltrials.gov as study NCT00715871.</p
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