2,495 research outputs found
Recurrence Relations for Strongly q-Log-Convex Polynomials
We consider a class of strongly q-log-convex polynomials based on a
triangular recurrence relation with linear coefficients, and we show that the
Bell polynomials, the Bessel polynomials, the Ramanujan polynomials and the
Dowling polynomials are strongly q-log-convex. We also prove that the Bessel
transformation preserves log-convexity.Comment: 15 page
Prostaglandins A1 and E1 influence gene expression in an established insect cell line (BCIRL-HzAM1 cells)
Prostaglandins (PGs) and other eicosanoids exert important physiological actions in insects and other invertebrates, including influencing ion transport and mediating cellular immune defense functions. Although these actions are very well documented, we have no information on the mechanisms of PGs actions in insect cells. Here we report on the outcomes of experiments designed to test our hypothesis that PGs modulate gene expression in an insect cell line established from pupal ovarian tissue of the moth Helicoverpa zea (BCIRL-HzAM1 cells). We treated cells with either PGA1 or PGE1 for 12 or 24 h then analyzed cell lysates by 2-D electrophoresis. Analysis of the gels by densitometry revealed substantial changes in protein expression in some of the protein spots we analyzed. These spots were processed for mass spectrometric analysis by MALDI TOF/TOF, which yielded in silico protein identities for all 34 spots. The apparent changes in three of the proteins were confirmed by semi-quantative PCR, showing that the changes in mRNA expression were reflected in changes in protein expression. The 34 proteins were sorted into six categories, protein actions, lipid metabolism, signal transduction, protection, cell functions and metabolism. The findings support the hypothesis that one mechanism of PG action in insect cells is the modulation of gene expression
1958 Ruby Yearbook
A digitized copy of the 1958 Ruby, the Ursinus College yearbook.https://digitalcommons.ursinus.edu/ruby/1061/thumbnail.jp
Book Reviews
Review of the following books: Nearby History: Exploring the Past Around You by David E. Kyvig and Myron A. Marty; The Forerunners: The Tragic Story of 156 Down-East Americans Led to Jaffa in 1866 by Charismatic G.J. Adams to Plant the Seeds of Modern Israel by Reed M. Holmes; Islands of Maine: Where America Really Began by Bill Caldwell; Foundations of Northeast Archaeology edited by Dean R. Snow; A Short History of the American Locomotive Builders in the Steam Era by John H. Whit
Effect of suspension systems on the physiological and psychological responses to sub-maximal biking on simulated smooth and bumpy tracks
The aim of this study was to compare the physiological and psychological responses of cyclists riding on a hard tail bicycle and on a full suspension bicycle. Twenty males participated in two series of tests. A test rig held the front axle of the bicycle steady while the rear wheel rotated against a heavy roller with bumps (or no bumps) on its surface. In the first series of tests, eight participants (age 19 – 27 years, body mass 65 – 82 kg) were tested on both the full suspension and hard tail bicycles with and without bumps fitted to the roller. The second series of test repeated the bump tests with a further six participants (age 22 – 31 years, body mass 74 – 94 kg) and also involved an investigation of familiarization effects with the final six participants (age 21 – 30 years, body mass 64 – 80 kg). Heart rate, oxygen consumption (VO<sub>2</sub>), rating of perceived exertion (RPE) and comfort were recorded during 10 min sub-maximal tests. Combined data for the bumps tests show that the full suspension bicycle was significantly different (P < 0.001) from the hard tail bicycle on all four measures. Oxygen consumption, heart rate and RPE were lower on average by 8.7 (s = 3.6) ml · kg<sup>-1</sup> · min<sup>-1</sup>, 32.1 (s = 12.1) beats · min<sup>-1</sup> and 2.6 (s = 2.0) units, respectively. Comfort scores were higher (better) on average by 1.9 (s = 0.8) units. For the no bumps tests, the only statistically significant difference (P = 0.008) was in VO<sub>2</sub>, which was lower for the hard tail bicycle by 2.2 (s = 1.7) ml · kg-1 · min<sup>-1</sup>. The results indicate that the full suspension bicycle provides a physiological and psychological advantage over the hard tail bicycle during simulated sub-maximal exercise on bumps
Gravity model in the Korean highway
We investigate the traffic flows of the Korean highway system, which contains
both public and private transportation information. We find that the traffic
flow T(ij) between city i and j forms a gravity model, the metaphor of physical
gravity as described in Newton's law of gravity, P(i)P(j)/r(ij)^2, where P(i)
represents the population of city i and r(ij) the distance between cities i and
j. It is also shown that the highway network has a heavy tail even though the
road network is a rather uniform and homogeneous one. Compared to the highway
network, air and public ground transportation establish inhomogeneous systems
and have power-law behaviors.Comment: 13 page
Loss of Propiconazole and Its Four Stereoisomers from the Water Phase of Two Soil-Water Slurries as Measured by Capillary Electrophoresis
Propiconazole is a chiral fungicide used in agriculture for control of many fungal diseases on a variety of crops. This use provides opportunities for pollution of soil and, subsequently, groundwater. The rate of loss of propiconazole from the water phase of two different soil-water slurries spiked with the fungicide at 50 mg/L was followed under aerobic conditions over five months; the t1/2 was 45 and 51 days for the two soil slurries. To accurately assess environmental and human risk, it is necessary to analyze the separate stereoisomers of chiral pollutants, because it is known that for most such pollutants, both biotransformation and toxicity are likely to be stereoselective. Micellar electrokinetic chromatography (MEKC), the mode of capillary electrophoresis used for analysis of neutral chemicals, was used for analysis of the four propiconazole stereoisomers with time in the water phase of the slurries. MEKC resulted in baseline separation of all stereoisomers, while GC-MS using a chiral column gave only partial separation. The four stereoisomers of propiconazole were lost from the aqueous phase of the slurries at experimentally equivalent rates, i.e., there was very little, if any, stereoselectivity. No loss of propiconazole was observed from the autoclaved controls of either soil, indicating that the loss from active samples was most likely caused by aerobic biotansformation, with a possible contribution by sorption to the non-autoclaved active soils. MEKC is a powerful tool for separation of stereoisomers and can be used to study the fate and transformation kinetics of chiral pesticides in water and soil
- …