Survey of Ground-Dwelling Predaceous and Parasitic Arthropods in Cabbage Fields in Upstate New York

During 1979 and 1981, populations of ground-dwelling predators and parasites in research and commercial cabbage fields in upstate New York were assessed by pitfall trapping to determine species composition, abundance, phenology, and the impact of insecticides on them. Staphylinidae, Phalangida, Carabidae, and Araneida were consistently the most abundant predaceous taxa. Carabids and Staphylinids together comprised 75.9 and 74.1% of all predaceous or parasitic insects in commercial fields during 1979 and 1981, respectively. One of the 32 species of Carabidae captured, Pterostichus melanarius (Illiger), accounted for >50% of the total number of Carabidae. Total number of predators and parasites tended to decline from July through September in both treated and untreated fields, but this decline was hastened by the use of broad-spectrum insecticide

Transition Probabilities for Trichoplusia ni (Lepidoptera: Noctuidae) Larvae on Cabbage as a Function of Microclimate

To identify factors affecting the spatial dynamics of Trichoplusia ni (Hübner) on cabbage, the movements of individual larvae were monitored. Larvae were marked with 32p and released individually, one per plant, on cabbage plants in research plots. Their movements were monitored by recording their position on the plant daily, locating them with a Geiger counter. In the same plots, hourly measurements of temperature and relative humidity were recorded in three different parts of the crop canopy. Transition probabilities for the larvae from and to each of five vertical plant strata were modeled as definite integrals of the Beta probability density function (pdf). The shape parameters for these Beta pdf's were modeled as a function of microclimate, and the necessary parameters to do so were estimated by the method of maximum likelihood. This model predicted the data well and was more efficient than logistic regression. The model predicts that under high temperatures and low vapor pressure deficit (vpd), larvae move down to the shaded, cooler, lower parts of the plant; whereas under low temperatures and high vpd, they moved upward toward the economically important wrapper leaves and cabbage head

Effect of Intraplant Insect Movement on Economic Thresholds

A simulation model was constructed to examine the effects of intraplant spatial dynamics of the lepidopteran pest complex of cabbage on direct damage to the marketable parts of the plant. Diurnal fluctuations in microclimate for different parts of the crop canopy were simulated with sine functions. Larval development rates for each species were simulated with logistic functions of temperature, the development process with time-varying distributed delays, and feeding rates with exponential functions of temperature and larval age. Larval transition probabilities within the crop canopy were modeled with either constants or definite integrals of the Beta probability density function, the shape parameters of which were modeled as functions of temperature. The model provided a good fit to data on changes in intraplant distribution of these larvae and intraplant distribution of feeding damage. Evaluation of model predictions suggests that a threshold population density used for management decisions should not be static, but should be a complex function of species, larval age distribution, and forecast temperatures. A model like the one presented here could serve as that complex functio

Use of the Global Alliance for Musculoskeletal Health survey module for estimating the population prevalence of musculoskeletal pain: Findings from the Solomon Islands

Background: Musculoskeletal (MSK) conditions are common and the biggest global cause of physical disability. The objective of the current study was to estimate the population prevalence of MSK-related pain using a standardized global MSK survey module for the first time. Methods: A MSK survey module was constructed by the Global Alliance for Musculoskeletal Health Surveillance Taskforce and the Global Burden of Disease MSK Expert Group. The MSK module was included in the 2015 Solomon Islands Demographic and Health Survey. The sampling design was a two-stage stratified, nationally representative sample of households. Results: A total of 9214 participants aged 15-49 years were included in the analysis. The age-standardized four-week prevalence of activity-limiting low back pain, neck pain, and hip and/or knee pain was 16.8, 8.9, and 10.8%, respectively. Prevalence tended to increase with age, and be higher in those with lower levels of education. Conclusions: Prevalence of activity-limited pain was high in all measured MSK sites. This indicates an important public health issue for the Solomon Islands that needs to be addressed. Efforts should be underpinned by integration with strategies for other non-communicable diseases, aging, disability, and rehabilitation, and with other sectors such as social services, education, industry, and agriculture. Primary prevention strategies and strategies aimed at self-management are likely to have the greatest and most cost-effective impact

Strain Hardening of Polymer Glasses: Entanglements, Energetics, and Plasticity

Simulations are used to examine the microscopic origins of strain hardening in polymer glasses. While stress-strain curves for a wide range of temperature can be fit to the functional form predicted by entropic network models, many other results are fundamentally inconsistent with the physical picture underlying these models. Stresses are too large to be entropic and have the wrong trend with temperature. The most dramatic hardening at large strains reflects increases in energy as chains are pulled taut between entanglements rather than a change in entropy. A weak entropic stress is only observed in shape recovery of deformed samples when heated above the glass transition. While short chains do not form an entangled network, they exhibit partial shape recovery, orientation, and strain hardening. Stresses for all chain lengths collapse when plotted against a microscopic measure of chain stretching rather than the macroscopic stretch. The thermal contribution to the stress is directly proportional to the rate of plasticity as measured by breaking and reforming of interchain bonds. These observations suggest that the correct microscopic theory of strain hardening should be based on glassy state physics rather than rubber elasticity.Comment: 15 pages, 12 figures: significant revision

Extraction of Intrinsic Fluorescence from Single Fiber Fluorescence Measurements on a Turbid Medium: Experimental Validation

Abstract The detailed mechanisms associated with the influence of scattering and absorption properties on the fluorescence intensity sampled by a single optical fiber have recently been elucidated based on Monte Carlo simulated data. Here we develop an experimental single fiber fluorescence (SFF) spectroscopy setup and validate the Monte Carlo data and semi-empirical model equation that describes the SFF signal as a function of scattering. We present a calibration procedure that corrects the SFF signal for all system-related, wavelength dependent transmission efficiencies to yield an absolute value of intrinsic fluorescence. The validity of the Monte Carlo data and semi-empirical model is demonstrated using a set of fluorescent phantoms with varying concentrations of Intralipid to vary the scattering properties, yielding a wide range of reduced scattering coefficients (μ′s = 0–7 mm −1). We also introduce a small modification to the model to account for the case of μ′s = 0 mm −1 and show its relation to the experimental, simulated and theoretically calculated value of SFF intensity in the absence of scattering. Finally, we show that our method is also accurate in the presence of absorbers by performing measurements on phantoms containing red blood cells and correcting for their absorption properties

Tensile Fracture of Welded Polymer Interfaces: Miscibility, Entanglements and Crazing

Large-scale molecular simulations are performed to investigate tensile failure of polymer interfaces as a function of welding time $t$. Changes in the tensile stress, mode of failure and interfacial fracture energy $G_I$ are correlated to changes in the interfacial entanglements as determined from Primitive Path Analysis. Bulk polymers fail through craze formation, followed by craze breakdown through chain scission. At small $t$ welded interfaces are not strong enough to support craze formation and fail at small strains through chain pullout at the interface. Once chains have formed an average of about one entanglement across the interface, a stable craze is formed throughout the sample. The failure stress of the craze rises with welding time and the mode of craze breakdown changes from chain pullout to chain scission as the interface approaches bulk strength. The interfacial fracture energy $G_I$ is calculated by coupling the simulation results to a continuum fracture mechanics model. As in experiment, $G_I$ increases as $t^{1/2}$ before saturating at the average bulk fracture energy $G_b$. As in previous simulations of shear strength, saturation coincides with the recovery of the bulk entanglement density. Before saturation, $G_I$ is proportional to the areal density of interfacial entanglements. Immiscibiltiy limits interdiffusion and thus suppresses entanglements at the interface. Even small degrees of immisciblity reduce interfacial entanglements enough that failure occurs by chain pullout and $G_I \ll G_b$

Fabrication and Properties of an Anisotropic TiO 2 Dielectric Composite

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65849/1/j.1551-2916.2006.01134.x.pd

The correlates of urinary albumin to creatinine ratio (ACR) in a high risk Australian Aboriginal community

Background: Albuminuria marks renal disease and cardiovascular risk. It was estimated to contribute 75% of the risk of all-cause natural death in one Aboriginal group. The urine albumin/creatinine ratio (ACR) is commonly used as an index of albuminuria. This study aims to examine the associations between demographic factors, anthropometric index, blood pressure, lipid-protein measurements and other biomarkers and albuminuria in a cross-sectional study in a high-risk Australian Aboriginal population. The models will be evaluated for albuminuria at or above the microalbuminuria threshold, and at or above the "overt albuminuria" threshold with the potential to distinguish associations they have in common and those that differ