A comparative study of solubilized proteins from phycomyces blakesleeannus by disc electrophoresis

Mycelial, sporangiophore, and zygospore solubilized protein fractions o Phycomyces blakesleeanus Burgeff were separated on polyacrylamide gels and stained. Protein patterns of 8 and 13 day old mycelia of the + strain were identical as were the patterns of the same two age groups of the - strain. The + mycelia exhibited 9 protein bands while the - strain contained 10 bands. Seven bands were homologous to both strains. Sporangio­phore samples of 5 and 10 day old cultures from + and - strains contained 4 protein bands homologous to all 4 samples. The protein band at 9 mm was also homologous to all mycelial samples. The zygospore preparation yielded 2 protein bands. The band at 9 mrn in this preparation was homologous with all mycelial and sporangiophore samples, while the band at 7 mm was unique to only the zygospore sample

A kinetic study on the oleaginous yeast, Candida curvata D

Candida curvata D was grown in nitrogen-limited broth using both batch and single-stage continuous fermentations. In batch fermentations, the concentrations of cellular nitrogen, nonlipid biomass, and lipid increased more or less sequentially. The concentration of nonlipid biomass was proportional to the concentration of cells, and both concentrations seemed limited by the available nitrogen. A constant ratio of lipid to nonlipid biomass was observed in the batch fermentations during the initial period when most of the accumulation of nonlipid biomass occurred. The percentage of cellular nitrogen in the nonlipid biomass changed dramatically over the course of the batch fermentation and was greatly affected by the dilution rate in steady-state continuous fermentations. Lactose was used both for the accumulation of nonnitrogenous nonlipid biomass and lipid;The specific rates of change in various substrates and products were calculated with respect to the cellular nitrogen concentration. The results for batch fermentations indicated that there was a constant specific rate of lactose uptake. The specific rate of lipid accumulation which increased during the fermentation was accompanied by a parallel decrease in the specific rate of conversion of lactose to nonnitrogenous nonlipid biomass. During the later stage of the fermentation when most of the lipid accumulation occurred, a constant and maximum specific rate of lipid accumulation was observed. This observation was consistent with the hypothesis that a single enzyme step controls the rate of lipid accumulation;The batch and continuous fermentations were satisfactorily described by a kinetic model in which the specific rates of accumulation or uptake were expressed with respect to the cellular nitrogen concentration. The sets of parameters required to describe the batch fermentations and continuous fermentations were significantly different. Estimates from the model showed that a single-stage continuous fermentation required a shorter residence time for the utilization of lactose than a batch fermentation

Population assessment of the vermilion snapper, Rhomboplites aurorubens, from the Southeastern United States

Changes in the age structure and population size of vermilion snapper, Rhornboplites aurorubens, from North Carolina through the Florida Keys were examined using records of landings and size frequencies of fish from commercial, recreational, and headboat fisheries from 1986-1996. Population size in numbers at age was estimated for each year by applying separable virtual population analysis (SVPA) to the landings in numbers at age. SVPA was used to estimate annual, age-specific fishing mortality (F) for four levels of natural mortality (M = 0.20, 0.25, 0.30, and 0.35). Although landings of vermilion snapper for the three fisheries have declined, minimum fish size regulations have resulted in an increase in the mean size of fish landed. Age at entry and age at full recruitment were age-1 andage-3 fDr 1986-1991, compared with age-1 and age-4, respectively, for 1992-1996. Levels of mortality from fishing (F) ranged from 0.38 - 0.61 for the entire period. Current spawning potential ratio (SPR) is 21% or 27% depending on the natural mortality estimate. SPR could be raised to 30% or 40% with a reduction in F, or by increasing the age at entry to the fisheries. The latter could be enhanced now if fishermen, particularly recreational, comply with minimum size regulations. However, released fish mortality, modeled in the assessment at 27%, will continue to make the achievement of 30% and 40% SPR more difficult. (PDF contains 63 pages

Nonlinear stabilitty for steady vortex pairs

In this article, we prove nonlinear orbital stability for steadily translating vortex pairs, a family of nonlinear waves that are exact solutions of the incompressible, two-dimensional Euler equations. We use an adaptation of Kelvin's variational principle, maximizing kinetic energy penalised by a multiple of momentum among mirror-symmetric isovortical rearrangements. This formulation has the advantage that the functional to be maximized and the constraint set are both invariant under the flow of the time-dependent Euler equations, and this observation is used strongly in the analysis. Previous work on existence yields a wide class of examples to which our result applies.Comment: 25 page

Hidden costs of attending Manhattan Public High School

Call number: LD2668 .R4 1951 D75

Ransom

Ransom is an opera in two acts based on the short story The Ransom of Red Chief by O. Henry. A gang of robbers plot their final heist before retiring. During the job, they are discovered and attempt to make a hasty retreat. In the mayhem, one of their own is captured and they kidnap the Sheriff’s two children in return. It turns out that the children are a handful and the criminals are unable to hold onto them any longer. In exchange for getting rid of the kids, they turn themselves in. The opera is written for nine roles and a chorus. The work is accompanied by a chamber orchestra of ten musicians. In its entirety, Ransom lasts approximately one hour and 45 minutes

Micron2 Lab: Microfluidic Microbiology Lab Project

Microbial monitoring during spaceflight is crucial to maintain crew health and ensure water purifications systems are functioning properly. Current protocols for in-flight enumeration of bacteria in potable water systems require culture based methods. In this project, we aim to develop a flight- and microgravity-compatible flow cytometer capable of counting total microbial counts in the water supply and differentiating live from dead bacteria

Potential Vorticity Evolution of a Protoplanetary Disk with An Embedded Protoplanet

We present two-dimensional inviscid hydrodynamic simulations of a protoplanetary disk with an embedded planet, emphasizing the evolution of potential vorticity (the ratio of vorticity to density) and its dependence on numerical resolutions. By analyzing the structure of spiral shocks made by the planet, we show that progressive changes of the potential vorticity caused by spiral shocks ultimately lead to the excitation of a secondary instability. We also demonstrate that very high numerical resolution is required to both follow the potential vorticity changes and identify the location where the secondary instability is first excited. Low-resolution results are shown to give the wrong location. We establish the robustness of a secondary instability and its impact on the torque onto the planet. After the saturation of the instability, the disk shows large-scale non-axisymmetry, causing the torque on the planet to oscillate with large amplitude. The impact of the oscillating torque on the protoplanet's migration remains to be investigated.Comment: 17 pages total with 9 figures (Fig.4,5,9 are in .jpg), accepted to Ap

The feeding habits of the Mazama pocket gopher in the pine region of South-Central Oregon

The objective of this study was to determine the feeding habits of the Mazama pocket gopher (Thomomys mazama Merriam) in the pine region of south-central Oregon. Damage caused by pocket gophers to conifer regeneration was a major incentive for this research. A permanent reference collection, consisting of epithelial tissue from leaves, stems, and roots of local plants mounted on microscope slides, was prepared. Pocket gophers were collected on alternate months from July 1973 through September l974. Species of plants eaten were identified by comparing fragments of epithelial tissue in the stomach contents to the reference collection. Shrubs, common mullein (Verbascum thapsus L.), and ponderosa pine seedlings (Pinus ponderosa Dougl.) also were examined in the field monthly from December 1973 through September 1974 for evidence of above-ground feeding by gophers. The relative abundance of plants on the study area was estimated by frequency of occurrence and percentage cover. Preference indexes for frequently eaten foods were obtained by dividing the precentage composition in the diet by the plant cover on the study area. Stomach content analysis revealed that 31 of the 45 plant species identified on the study area were used as food by gophers. Plant materials eaten included foliage, stems, and roots. Forbs comprised 55 percent of the vegetative cover in July 1973, and 61 percent in July 1974. They constituted 40 percent of the annual diet, and were eaten most heavily during the growing season. The most frequently eaten forbs were spreading groundsmoke (Gayophytum diffusum Mutt.), matted nama (Nama densum Lemmon), knotweed (Polygonum douglasii Greene), common thistle (Cirsium vulgare(Savi) Tenore), goosefoot violet (Viola purpurea Kell.), and velvet lupine (Lupinus leucophyllus Dougl.). Grasses comprised 41 percent of the vegetative cover in July 1973, and 30 percent in July 1974. They constituted 32 percent of the annual diet, and were eaten extensively during the dormant season. Cheatgrass (Bromus tectorum L.) was eaten only in May. Western needlegrass (Stipa occidentalis Thurb.) was eaten most heavily in summer and autumn, and mountain brome (Bromus carinatus H. & A.) was consumed most heavily during the dormant season. Stomach content analysis indicated that woody plants were eaten during the dormant season, but they constituted only a small part of the annual diet. Ponderosa pine was the most heavily eaten woody plant. Field observations supported these results. Evidence of gophers feeding above ground on woody plants was found only from December through April. In general, the diets of gophers collected during the growing season, July and September, were not significantly different. The diets of gophers collected during other sampling periods were significantly different (p<O.O5). Availability and relative abundance of foods were identified as important dietary determinants. In July, when all foods were abundant, vegetative components ranked by preference were perennial forbs, grasses, annual forbs, and woody plants. Perennial forbs were the preferred food, but grasses were the most important food in winter, Results indicated that vegetative a1teration as an indirect method of controlling pocket gopher damage to conifers, should be directed at controlling grasses without stimulating the establishment of perennial herbs