Processing Multispectral Scanner Data Using Correlation Clustering and Nonparametric Classification Techniques

A two-step classification algorithm for processing multispectral scanner data has been developed and tested. The algorithm is carried out by two separate programs called CLUSTX and GROUPX. The program CLUSTX is a single pass clustering algorithm that assigns each pixel, based on its spectral signature, to one of NCLUST clusters. The output of the program CLUSTX is a cluster tape in which a single integer is associated with each pixel, This integer is the cluster number to which the pixel has been assigned by the program

Decomposition of coarse woody debris in a long-term litter manipulation experiment: A focus on nutrient availability

The majority of above-ground carbon in tropical forests is stored in wood, which is returned to the atmosphere during decomposition of coarse woody debris. However, the factors controlling wood decomposition have not been experimentally manipulated over time scales comparable to the length of this process.We hypothesized that wood decomposition is limited by nutrient availability and tested this hypothesis in a long-term litter addition and removal experiment in a lowland tropical forest in Panama. Specifically, we quantified decomposition using a 15-year chronosequence of decaying boles, and measured respiration rates and nutrient limitation of wood decomposer communities.The long-term probability that a dead tree completely decomposed was decreased in plots where litter was removed, but did not differ between litter addition and control treatments. Similarly, respiration rates of wood decomposer communities were greater in control treatments relative to litter removal plots; litter addition treatments did not differ from either of the other treatments. Respiration rates increased in response to nutrient addition (nitrogen, phosphorus, and potassium) in the litter removal and addition treatments, but not in the controls.Established decreases in concentrations of soil nutrients in litter removal plots and increased respiration rates in response to nutrient addition suggest that reduced rates of wood decomposition after litter removal were caused by decreased nutrient availability. The effects of litter manipulations differed directionally from a previous short-term decomposition study in the same plots, and reduced rates of bole decomposition in litter removal plots did not emerge until after more than 6 years of decomposition. These differences suggest that litter-mediated effects on nutrient dynamics have complex interactions with decomposition over time

Chasing Z’s: Sleep Quality and Bedsharing in Teen Moms

Pregnancy and motherhood during adolescence is a major U.S. public health concern, and teen mothers are likely to experience negative consequences given their status as a young mom. One potential intervention method lies within health behaviors, specifically sleep quality and bedsharing practices. Although research demonstrates relationships between specific types of sleep problems and pregnancy, little is known about the prevalence and type of sleep problems and bedsharing intentions for pregnant women from diverse backgrounds. This project aimed to investigate and describe sleep quality, including the factors that might affect sleep during pregnancy, as well as bedsharing intentions during the third trimester of pregnancy in adolescent women from a large Midwestern city. Participants in this study included a sample of female adolescents participating in a larger, longitudinal pilot study testing the feasibility and implementation of a multiple health behavior change intervention. Results of the current study suggest pregnant, adolescent women may experience poor sleep during their third trimester. It was also discovered that teen mothers are likely to choose co-sleeping for reasons such as distance and/access, preparation, and safety. The results of the current study have important implications for the care of these women and their families, as well as their medical care providers

Analysis of developing laminar flows in circular pipes using a higher-order finite-difference technique

A higher-order finite-difference technique is developed to calculate the developing-flow field of steady incompressible laminar flows in the entrance regions of circular pipes. Navier-Stokes equations governing the motion of such a flow field are solved by using this new finite-difference scheme. This new technique can increase the accuracy of the finite-difference approximation, while also providing the option of using unevenly spaced clustered nodes for computation such that relatively fine grids can be adopted for regions with large velocity gradients. The velocity profile at the entrance of the pipe is assumed to be uniform for the computation. The velocity distribution and the surface pressure drop of the developing flow then are calculated and compared to existing experimental measurements reported in the literature. Computational results obtained are found to be in good agreement with existing experimental correlations and therefore, the reliability of the new technique has been successfully tested