Evaluation of high pressure water blast with rotating spray bar for removing paint and rubber deposits from airport runways, and review of runway slipperiness problems created by rubber contamination

A high pressure water blast with rotating spray bar treatment for removing paint and rubber deposits from airport runways is studied. The results of the evaluation suggest that the treatment is very effective in removing above surface paint and rubber deposits to the point that pavement skid resistance is restored to trafficked but uncontaminated runway surface skid resistance levels. Aircraft operating problems created by runway slipperiness are reviewed along with an assessment of the contributions that pavement surface treatments, surface weathering, traffic polishing, and rubber deposits make in creating or alleviating runway slipperiness. The results suggest that conventional surface treatments for both portland cement and asphaltic concrete runways are extremely vulnerable to rubber deposit accretions which can produce runway slipperiness conditions for aircraft operations as or more slippery than many snow and ice-covered runway conditions. Pavement grooving surface treatments are shown to be the least vulnerable to rubber deposits accretion and traffic polishing of the surface treatments examined

Denoting and Comparing Leadership Attributes and Behaviors in Group Work

Projects and Practices in Physics (P$^3$) is an introductory physics class at Michigan State University that replaces lectures with a problem based learning environment. To promote the development of group based practices, students all receive group and individual feedback at the end of each week. The groups are comprised of four students, one of which often takes on the role of being the group's "leader." Developing leadership based skills is a specific learning goal of the P$^3$ learning environment and the goal of this research is to examine what leadership-specific actions/traits students in P$^3$ demonstrate while working in their group. The initial phase of this study examined multiple pieces of literature to identify possible characteristics and behaviors that may present themselves in potential leaders -- creating a codebook. This phase of the study applies the codebook to in-class data to compare two tutor-labeled leaders and their leadership styles.Comment: 4 pages, 1 figur

A study of commuter airplane design optimization

Problems of commuter airplane configuration design were studied to affect a minimization of direct operating costs. Factors considered were the minimization of fuselage drag, methods of wing design, and the estimated drag of an airplane submerged in a propellor slipstream; all design criteria were studied under a set of fixed performance, mission, and stability constraints. Configuration design data were assembled for application by a computerized design methodology program similar to the NASA-Ames General Aviation Synthesis Program

Camp Dysentery

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A study of the effect of the periods of gestation and lactation upon the growth and composition of swine

Approved, May 28th 1915, P.F. TrowbridgeTypescriptM.A. University of Missouri 1915Growth is at the base of organic production. In recent years an increasing importance has been attached to its study and to the conditions affecting it. Davenport says: "The importance of the study of growth cannot be over estimated. The maintenance of the human race depends upon that property which protoplasm alone displays of increasing itself for an indefinite time and to an indefinite amount. The supplies of the world are produced largely by growth each year [...] the only thing then that limits growth is the limitations in the conditions of growth." The same author defines organic growth as increase in volume which may result from increase in volume of either the living substance or the formed matter of which organisms are composed. It is well known that there are many factors that influence growth and development. Among these are light, temperature, moisture, oxygen supply, food, climate, season of year, age, and species. Among factors less easily analyzed and explained, but dependent in greater or less degree upon the foregoing, may be mentioned the inherent tendency to reach a certain size and form, cell activities, and glandular secretions and excretions. Certain pathological conditions, pregnancy, and lactation may exert very marked influences on growth and development. The purpose of this study was to find the effect on growth of the conditions of pregnancy and lactation. It seems reasonable to expect that the production of milk would greatly check growth. The common observation of animals becoming thin in flesh while producing milk is sufficient evidence that the food is used for milk production even when there is not an excess over the amount the animal could use for the maintenance of its own body or for the increase of its own substance. It is well established that under conditions of insufficient nutrition, material may be drawn from the tissues for the production of milk

The Effect of gestation and lactation upon the growth and composition of swine

Publication authorized December 9, 1927.Digitized 2007 AES

Multiplication stimulating activity (MSA) can substitute for insulin to stimulate the secretion of testicular transferrin by cultured sertoli cells

Both MSA and insulin were found to stimulate transferrin production in cultured Sertoli cells to the same extent in the absence or presence of follitropin, testosterone, or retinol. Sertoli cells were responsive to 30-fold lower concentrations of MSA than of insulin. MSA and insulin together stimulated transferrin secretion to the same extent as either hormone alone. These results, and what is presently understood about the relationship of MSA and insulin, suggest that insulin can substitute for the action of an MSA-like peptide in the stimulation of testicular transferrin secretion by Sertoli cells

Sertoli cells synthesize and secrete transferrin-like protein

One of the major proteins secreted by Sertoli cells (Band 3) has a molecular weight on sodium dodecyl sulfate-polyacrylamide gels which corresponds to rat serum transferrin. The preparation of Sertoli cell-secreted proteins contains an iron-binding protein with electrophoretic properties on native polyacrylamide gels similar to serum transferrin. Antibodies against Sertoli cell-secreted proteins contain a component which will immunoprecipitate serum transferrin. Antibodies to serum transferrin cross-react with and immunoprecipitate a major component (Band 3) of [35S]-methionine-labeled Sertoli cell-secreted proteins. We propose that testicular transferrin is a major secretory product of Sertoli cells in culture. In addition to transferrin, antiserum to rat serum proteins will immunoprecipitate one other polypeptide from preparations of Sertoli cell-secreted proteins

Sertoli Cells Synthesize and Secrete a Ceruloplasmin-Like Protein

Sertoli cells synthesize and secrete a ceruloplasmin-like protein (testicular ceruloplasmin) that is immunologically similar to serum ceruloplasmin. Rat serum ceruloplasmin was purified and an antiserum was produced to the purified protein which specifically immunoprecipitated a 130,000 dalton protein from rat serum. This ceruloplasmin antiserum was found to also immunoprecipitate a 130,000 dalton protein synthesized and secreted by Sertoli cells. The presence of a protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), was required during the immunoprecipitation procedure to prevent the proteolytic degradation of testicular ceruloplasmin. Immunoprecipitation of proteins secreted by Sertoli cells with an antiserum to rat serum proteins was found to precipitate two proteins, testicular ceruloplasmin and testicular transferrin