Probing Proton Strangeness with Time-Like Virtual Compton Scattering

We document that p(gamma,e+e-)p measurements will yield new, important information about the off-shell time-like nucleon form factors, especially in the phi meson region (q^2 = M^2_{phi}) governing the phi N couplings g^{V,T}_{\phi N N}. Calculations for p(gamma,e+e-)p, utilizing vector meson dominance, predict measurable phi enhancements at high |t| compared to the expected phi background production from pi, eta and Pomeron exchange. The phi form factor contribution generates a novel experimental signature for OZI violation and the proton strangeness content. The phi N couplings are determined independently from a combined analysis of the neutron electric form factor and recent high |t| phi photoproduction. The pi, eta and Pomeron transition form factors are also predicted and the observed pi and eta transition moments are reproduced.Comment: 9 pages, 6 figure

The multifrequency behaviour of the recurrent nova RS Ophiuchi

This review concentrates on the multifrequency behaviour of RS Ophiuchi and in particular during its latest outburst. Confirmation of the 1945 outburst, bipolar outflows and its possible fate as a Type Ia Supernova are discussed.Comment: 5 pages, 5 figures, in The Golden Age of Cataclysmic Variables and Related Objects, F. Giovannelli & L. Sabau-Graziati (eds.), Mem. SAIt. 83 N.2 (in press

High-throughput measurement of dictyostelium discoideum macropinocytosis by flow cytometry

Large-scale non-specific fluid uptake by macropinocytosis is important for the proliferation of certain cancer cells, antigen sampling, host cell invasion and the spread of neurodegenerative diseases. The commonly used laboratory strains of the amoeba Dictyostelium discoideum have extremely high fluid uptake rates when grown in nutrient medium, over 90% of which is due to macropinocytosis. In addition, many of the known core components of mammalian macropinocytosis are also present, making it an excellent model system for studying macropinocytosis. Here, the standard technique to measure internalized fluid using fluorescent dextran as a label is adapted to a 96-well plate format, with the samples analyzed by flow cytometry using a high-throughput sampling (HTS) attachment. Cells are fed non-quenchable fluorescent dextran for a pre-determined length of time, washed by immersion in ice-cold buffer and detached using 5 mM sodium azide, which also stops exocytosis. Cells in each well are then analyzed by flow cytometry. The method can also be adapted to measure membrane uptake and phagocytosis of fluorescent beads or bacteria. This method was designed to allow measurement of fluid uptake by Dictyostelium in a high-throughput, labor and resource efficient manner. It allows simultaneous comparison of multiple strains (e.g. knockout mutants of a gene) and conditions (e.g. cells in different media or treated with different concentrations of inhibitor) in parallel and simplifies time-courses.</p

The Integrated Basic Education and Skills Training (I-BEST) Program: Equiping All Adults for the Global Economy

Abstract In 2004, educational leaders in Washington State, recognizing the necessity of rapidly equipping adults with career skills, developed the Integrated Basic Education and Skills Training (I-BEST) program to meet workforce needs. I-BEST is now operational in all 34 of the State’s community colleges. I-BEST is an instructional method which provides basic skills support to ABE and ESL students while they receive career training. I-BEST uniquely pairs a basic skills instructor with a vocational instructor in the classroom at the same time. Previous research on the I-BEST program has been positive, but it has ignored the pivotal role instructors and administrators play in the program’s success. This study explores the perceptions of the instructors and administrators regarding the I-BEST program. The study investigates whether there were differences in the perceptions of the instructors, program managers, and the managers’ immediate supervisors. The group differences were compared using t tests. Statistical differences were observed in areas such as the adequacy of instructor release time, adequacy of student support services, and using employment outcomes to modify instruction. Recommendations include limiting the number of data collection items being tracked, and increasing the number of minority instructors involved in the I-BEST program. Implications of the findings may assist the Washington State Board of Community and Technical Colleges and community college presidents in enhancing the program

The efficacy of supplying supplemental cobalt, selenium and vitamin B₁₂ via the oral drench route in sheep

Cobalt and selenium are essential trace elements required for ruminants. There are many different methods of supplementation available to sheep including boluses, in feed, free access minerals, pasture dressing and oral drenches. Recent changes in European legislation have resulted in a reduction in the maximum permitted level (MPL) of cobalt to be included in ruminant diets from 2 mg/kg at 88% DM to 1 mg/kg at 88% DM with a suggested supplementary rate of 0.3 mg Co/kg at 88% DM. This study aimed to determine the efficacy of cobalt plus/minus vitamin B₁₂ and selenium supplementation from oral drenching over a 13 day time period. Seven groups of grass silage fed Suffolk cross mule lambs (n=56) were randomly allocated to one of 7 treatments, a 5 ml oral drench containing 700, 2300, 12000 mg Co/l, with or without 2300 mg vitamin B₁₂/l in a factoral design, with an additional control group which received no drench. All drenches also contained selenium at 625 mg/l. Lambs were weighed on days 0 and 13. The lambs were sampled by jugular venepuncture on days 0, 1, 2, 3, 4, 5, 6, 7, 9, 11 and 13, with samples analysed for plasma selenium and cobalt by ICP-MS, erythrocyte glutathione peroxidase by colourimetric assay and vitamin B₁₂ by immunoassay. The results showed that cobalt via a drench was able to raise plasma cobalt in a dose dependent manner, with each dose level significantly higher than the previous level at all post drenching time points (P<0.05). However, the cobalt containing drenches did not significantly raise vitamin B₁₂ concentrations in the plasma. Vitamin B₁₂ containing drenches were able to elevate vitamin B₁₂ in the plasma for a period of 7 days (P<0.05). The selenium content of the drench was able to significantly raise the plasma selenium from day 1 throughout the rest of the trial (day 13) (P<0.001). A significant increase in erythrocyte glutathione peroxidase activity of the sheep did eventually occur at day 13 (P<0.05). In summary, the addition of vitamin B₁₂ via the drench route resulted in a short term elevation (7 days) of plasma vitamin B₁₂ concentrations whereas cobalt sulphate alone was unable to significantly raise vitamin B₁₂ concentrations within this trial in sheep with marginally adequate cobalt status, despite elevating plasma cobalt concentrations. The drench route was also able to elevate plasma selenium concentrations from a marginal selenium status

Extinctions of North American Fishes During the past Century

Extinctions of 3 genera, 27 species, and 13 subspecies of fishes from North America are documented during the past 100 years. Extinctions are recorded from all areas except northern Canada and Alaska. Regions suffering the greatest loss are the Great Lakes, Great Basin, Rio Grande, Valley of Mexico, and Parras Valley in Mexico. More than one factor contributed to the decline and extinction of 82% of the fishes. Physical habitat alteration was the most frequently cited causal factor (73%). Detrimental effects of introduced species also were cited in 68% of the extinctions. Chemical habitat alteration (including pollution) and hybridization each were cited in 38% of the extinctions, and overharvesting adversely affected 15% of the fishes. This unfortunate and unprecedented rate of loss of the fishery resource is expected to increase as more of the native fauna of North America becomes endangered or threatened.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141989/1/fsh0022.pd

GRB Spikes Could Resolve Stars

GRBs vary more rapidly than any other known cosmological phenomena. The lower limits of this variability have not yet been explored. Improvements in detectors would reveal or limit the actual rate of short GRBs. Were microsecond "spike" GRBs to exist and be detectable, they would time-resolve stellar mass objects throughout the universe by their gravitational microlensing effect. Analyzing the time structure of sufficient numbers of GRB spikes would reveal or limit $\Omega_{star}$, $\Omega_{MACHO}$, and/or $\Omega_{baryon}$.Comment: 18 pages, 2 figures, in press: ApJ (Letters