Waste to Energy: Environmental and Local Government Concerns

The problem we are confronting here is immense-literally mountains of trash and garbage. With these words, Representative William S. Moorhead accurately described a current American dilemma-what to do with the four billion tons of solid waste annually produced by Americans. Concurrent with the problem of increasing quantities of waste are the problems of decreasing availability of land fill space and an ever-rising demand for energy. The existence of these problems is leading federal, state, and local governments to take a second look at their municipal solid waste and to realize that waste is something more than an undesirable by-product of urban life which is to be dumped as quickly as possible. One solution to their problems could be a program of resource recovery, \u27 accomplished by a facility which converts waste to energy

A Computational Model to Predict In Vivo Lower Limb Kinetics and Assess Total Knee Arthroplasty Design Parameters

Evaluating total knee arthroplasty implant design success generally requires many years of patient follow-up studies which are both inefficient and costly. Although computational modeling is utilized during the implant design phase, it has yet to be fully utilized in order to predict the post-implantation kinetics associated with various design parameters. The objective of this study was to construct a three-dimensional computational model of the human lower limb that could predict in vivo kinetics based upon input subject specific kinematics. The model was constructed utilizing Kane’s theory of dynamics and applied to two clinical sub-studies. Firstly, axial tibiofemoral forces were compared over a deep knee bend between normal knee subjects and those with implanted knees. Secondly, kinematics were obtained for a sample subject undergoing a deep knee bend, and the amount of femoral rollback experienced by the subject (-1.86 mm) was varied in order to evaluate the subsequent change in the axial tibiofemoral contact force and the quadriceps force. The mean axial tibiofemoral contact force was 1.35xBW and 2.99xBW for the normal and implanted subjects, respectively, which was a significant difference (p = 0.0023). The sample subject experienced a decrease in both the axial tibiofemoral contact force (-8.97%) and the quadriceps load (-11.84%) with an increase of femoral rollback to -6 mm. A decrease in rollback to 6 mm led to increases in both the contact force (22.45%) and the quadriceps load (27.14%). These initial studies provide evidence that this model accurately predicts in vivo kinetics and that kinetics depend on implant design and patient kinematics

Development of a High Throughput Assay to Optimize Hematopoietic Differentiation of Human Pluripotent Stem Cells

Human embryonic stem cells (hESCs) offer the potential to develop in vitro protocols for the generation of any human somatic cell. In order for protocols to allow for both comprehension of underlying developmental mechanics and future clinical application, they will need to rely upon efficient differentiation of cells without the reliance upon animal-derived components. This thesis presents the development of a 96-well plate culture system that allows 4-color, flow cytometry based high throughput screening of defined, serum-free hESC differentiation conditions. In the first portion, broad applicability is proven by demonstrating highly efficient differentiation toward the three primary germ layers. Using four separate biomarkers, we were able to distinguish between ectoderm, endoderm, mesoderm and pluripotent hESCs. We demonstrated the ability to perform both cytokine screens and siRNA-mediated knockdown in this assay. In the second portion, we establish conditions to apply this assay to study hematopoietic differentiation. We performed numerous cytokine and inhibitor screens to develop a stepwise protocol that generates high yields of primitive megakaryocyte-erythromyeloid progenitors and megakaryocytes after 8 and 11 days of embryoid body differentiation, respectively. This work provides a novel tool to streamline the development of hESC differentiation protocols and advances the hematopoietic field towards future hESC-derived therapies

Pulsed Nuclear Space Propulsion and International Law: Some Preliminary

Pulsed Nuclear Space Propulsion, researched in the 1950s and 1960s by such eminent physicists as Freeman Dyson, Ted Taylor, Theodore von Karman, and Hans Bethe, involves propelling large spacecraft using compact nuclear explosions from specialized atomic devices. This technology is often known by the name of the Air Force project in which it was developed: Orion. It has long been believed that the 1962 Limited Test Ban Treaty prohibits the use of nuclear pulse space propulsion. After a survey of the Orion project and its results and a review of the applicable law, this Article concludes that language in the 1967 Outer Space Treaty may override the Test Ban agreement to permit non-weapons use of nuclear explosives for propulsion. With a new space race taking place and with important actors such as China not subject to the Test Ban Treaty at all, the subject of pulsed nuclear space propulsion deserves another look

Changes in the North Atlantic Oscillation over the 20th century

The North Atlantic Oscillation explains a large fraction of the climate variability across the North Atlantic from the eastern seaboard of North America across the whole of Europe. Many studies have linked the North Atlantic Oscillation to climate extremes in this region, especially in winter, which has motivated considerable study of this pattern of variability. However, one overlooked feature of how the North Atlantic Oscillation has changed over time is the explained variance of the pattern. Here we show that there has been a considerable increase in the percentage of variability explained by the North Atlantic Oscillation (NAO) over the 20th century from 32 % in 1930 to 53 % by the end of the 20th century. Whether this change is due to natural variability, a forced response to climate change, or some combination remains unclear. However, we found no evidence for a forced response from an ensemble of 50 Coupled Model Intercomparison Project Phase 6 (CMIP6) models. These models did all show substantial internal variability in the strength of the North Atlantic Oscillation, but it was biased towards being too high compared to the reanalysis and with too little variation over time. Since there is a direct connection between the North Atlantic Oscillation and climate extremes over the region, this has direct consequences for both the long-term projection and near-term prediction of changes to climate extremes in the region.</p

The E. coli SufS–SufE sulfur transfer system is more resistant to oxidative stress than IscS–IscU

AbstractDuring oxidative stress in Escherichia coli, the SufABCDSE stress response pathway mediates iron–sulfur (Fe–S) cluster biogenesis rather than the Isc pathway. To determine why the Suf pathway is favored under stress conditions, the stress response SufS–SufE sulfur transfer pathway and the basal housekeeping IscS–IscU pathway were directly compared. We found that SufS–SufE cysteine desulfurase activity is significantly higher than IscS–IscU at physiological cysteine concentrations and after exposure to H2O2. Mass spectrometry analysis demonstrated that IscS–IscU is more susceptible than SufS–SufE to oxidative modification by H2O2. These important results provide biochemical insight into the stress resistance of the Suf pathway