Batrachoseps attenuatus

Number of Pages: 6Integrative BiologyGeological Science

Bringing the Field into the Classroom by Using Dynamic Digital Maps to Engage Undergraduate Students in Petrology Research

This article describes the use of Dynamic Digital Maps (DDMs) in undergraduate petrology courses. A DDM is a stand-alone computer program that presents interactive geologic maps, digital images, movies, animations, text and data. DDMs were developed for use in two undergraduate research projects, and impacts on student learning were evaluated by administering assessments on students before and after participation in one of the projects. Researchers found significant gains in both students' confidence in their ability to do research and to understand petrology, and noted that DDMs are versatile and can potentially be adapted effectively from 100-level introductory geology labs to research-oriented gradute level courses and in a variety of geologic subdisciplines. Educational levels: Graduate or professional, Graduate or professional

Evaluation of semen collected from commercial rams by electro-ejaculation

Annual ram pre-breeding soundness examinations (PBSE) are accepted as an integral component of veterinary flock health planning to identify rams not capable of achieving high conception rates. This preliminary study collected information from 280 rams presented to five veterinarians for routine PBSE on commercial farms in England in 2013. The study compared the outcome of a physical examination, which included palpation of external genitalia, with the gross and progressive motility of the semen produced by electro-ejaculation

Fabrication development of lightweight honeycomb-sandwich structures for extraterrestrial planetary probe missions

Lightweight resin fiber glass honeycomb sandwich structure fabrication and comparison with aluminum structures for planetary probe

Tensile Properties of Five Low-Alloy and Stainless Steels Under High-Heating-Rate and Constant-Temperature Conditions

Tensile properties of five low-alloy and stainless steels under high heating rate and constant temperatur

Waves on a plasma column : the display and measurement of space charge waves on the positive column of a mercury vapour discharge

Thesis (M.Sc.) -- University of Adelaide, Dept. of Physics, 196

Anuran artifacts of preservation: 27 years later

Measurements made on preserved anuran specimens are often used in studies of systematics, ecology and evolution. Here, we examine the effect of preservation on one of the most common measurement of frogs, snout-urostyle length (SUL). Preservation had significanteffects on the SUL of 13 of the 14 species of North American frogs included in this study, with all species decreasing in SUL by 0.31-5.62%. Smaller frog species did not shrink proportionally more or less than larger species. Absolute shrinkage was correlated with SUL and was greater in larger species. Within species, percent shrinkage was not significantly correlated with SUL in 10 species, but significantly greater for larger individuals in 3 species, and decreased with size in 1 species. Absolute shrinkage was statistically greater for larger individuals in 4 species. Our results agree with studies of morphological permutations in fish which show that most preservation-related changes take place within the first few months after initial preservation. We suggest that the potential consequences of using preserved specimens in research must be considered and that future studies continue to examine preservation effects, not only on frogs, but on all preserved specimens used in scientific investigations

Effects of Exogenous Yeast and Bacteria on the Microbial Population Dynamics and Outcomes of Olive Fermentations.

In this study, we examined Sicilian-style green olive fermentations upon the addition of Saccharomyces cerevisiae UCDFST 09-448 and/or Pichia kudriazevii UCDFST09-427 or the lactic acid bacteria (LAB) Lactobacillus plantarum AJ11R and Leuconostoc pseudomesenteroides BGM3R. Olives containing S. cerevisiae UCDFST 09-448, a strain able to hydrolyze pectin, but not P. kudriazevii UCDFST 09-427, a nonpectinolytic strain, exhibited excessive tissue damage within 4 weeks. DNA sequencing of fungal internal transcribed spacer (ITS) regions and comparisons to a yeast-specific ITS sequence database remarkably showed that neither S. cerevisiae UCDFST 09-448 nor P. kudriazevii UCDFST 09-427 resulted in significant changes to yeast species diversity. Instead, Candida boidinii constituted the majority (>90%) of the total yeast present, independent of whether S. cerevisiae or P. kudriazevii was added. By comparison, Lactobacillus species were enriched in olives inoculated with potential starter LAB L. plantarum AJ11R and L. pseudomesenteroides BGM3R according to community 16S rRNA gene sequence analysis. The bacterial diversity of those olives was significantly reduced and resembled control fermentations incubated for a longer period of time. Importantly, microbial populations were highly dynamic at the strain level, as indicated by the large variations in AJ11R and BGM3R cell numbers over time and reductions in the numbers of yeast isolates expressing polygalacturonase activity. These findings show the distinct effects of exogenous spoilage and starter microbes on indigenous communities in plant-based food fermentations that result in very different impacts on product quality. IMPORTANCE Food fermentations are subject to tremendous selective pressures resulting in the growth and persistence of a limited number of bacterial and fungal taxa. Although these foods are vulnerable to spoilage by unintended contamination of certain microorganisms, or alternatively, can be improved by the deliberate addition of starter culture microbes that accelerate or beneficially modify product outcomes, the impact of either of those microbial additions on community dynamics within the fermentations is not well understood at strain-specific or global scales. Herein, we show how exogenous spoilage yeast or starter lactic acid bacteria confer very different effects on microbial numbers and diversity in olive fermentations. Introduced microbes have long-lasting consequences and result in changes that are apparent even when levels of those inoculants and their major enzymatic activities decline. This work has direct implications for understanding bacterial and fungal invasions of microbial habitats resulting in pivotal changes to community structure and function

Welded Titanium Case for Space-Probe Rocket Motor

Early in 1958, the Jet Propulsion Laboratory of the California Institute of Technology was requested to participate in a lunar-probe mission code-named Juno II which would place a 15-lb Instrumented payload (Pioneer IV) in the vicinity of the moon. The vehicle was to use the same high-speed upper-stage assembly as flown on the successful Jupiter-C configuration; however, the first-stage booster was to be a Jupiter rather than a Redstone. An analysis of the intended flight and payload configuration Indicated that the feasibility of accomplishing the mission was questionable and that additional performance would have to be obtained if the mission was to be feasible. Since the most efficient way of Increasing the performance of a staged vehicle is to increase the performance of the last stage, a study of possible ways of doing this was made.. Because of the time schedule placed on this effort It was decided to reduce the weight of the fourth-stage rocket-motor case by substituting the annealed 6Al--4V titanium alloy for the Type 410 stainless steel. Although this introduced an unfamiliar material, It reduced the changes in design and fabrication techniques. This particular titanium alloy was chosen on the basis of previous tests which proved the suitability of the alloy as a pressure-vessel material when used at an annealed yield strength of about 120, 000 psi. The titanium-case fourth stage of Juno U is shown with the payload and on the missile in Fig. 1; the stainless-steel motor cases used in the Jupiter-C vehicle are shown in Fig. 2. The fourth-stage motor case has a diameter of 6 in., a length of approximately 38 in. center dot and a nominal cylindrical wall thickness of 0.025 in. As shown in Fig. 1, the case serves as the structural support of the payload and is aligned to the upper stage assembly through an alignment ring. The nozzle is threaded into the end of the motor case, and is of the ceramic-coated steel design. Figure 3 shows a comparison of the components used to make the stainless steel and the 6A1--4V titanium alloy cases. The forward dome and aft fitting for the stainless steel assembly were fabricated from a combination of forged, spun and machined parts.. In order to facilitate the fabrication of the titanium alloy motor ) these components were machined from a large-diameter billet