7,111 research outputs found
Considering Convergence: A Policy Dialogue About Behavioral Genetics, Neuroscience, and Law
Garland and Frankel issue a call for scientists, lawyers, courts and lawmakers to begin a critical dialogue about the implications of scientific discoveries and technological advances in criminal law, behavioral genetics and neuroscience
Submerged culture production of 5\u27-phosphodiesterase by streptomyces albus
The flavor enhancing properties of certain 5\u27-ribonucleotides have been known for some time. In 1913, Kodama (20)* reported on the seasoning effect of inosine-5-phosphate (5’-IMP). This compound was also identified as one of the important beef flavor precursors by Batzer and LandMann (3). Kuninaka (21) found that guanosine-5-phosphate (5\u27-GMP) and xanthine-5-phosphate (5\u27-XMP) also had a flavoring effect similar to 5’-IMP. Snake venom (16) and intestional mucosa (6) were known as sources of 5\u27-phosphodiesterase capable of hydrolyzing the phosphate ester link-ages of ribonucleic acid (RNA) to produce 5\u27-ribonucleotides. Recently, it has been discovered that many microorganisms (22,23,25,26,27) produce 5\u27-phosphodiesterase. Therefore, it has become possible to use certain microorganisms as sources of 5\u27-phosphodiesterase for use in production of 5\u27-ribonucleotides from RNA. With this in mind, a strain of Strep-tomyces albus, known to produce 5\u27-phosphodiesterase in submerged cul-ture (23), was studied to determine the effects of various factors (pH, temperature, and nutrients) on growth and enzyme production and to scale up production from laboratory to pilot-plant quantity
THE SLOW COMPONENT OF OXYGEN UPTAKE AND THE MEAN POWER FREQUENCY OF EMG DURING HEAW INTENSITY EXERCISE
The purpose of this study was to elucidate the mechanisms causing the slow component of oxygen uptake (VO2), by investigating changes in exercising muscle electrical activity. Volunteers performed square-wave dynamic knee extension exercise. Surface EMG of the rectus femoris was used to measure mean power frequency (MPF) and integrated (IEMG) values for each contraction. VO2 was measured breath-by-breath using a mass spectrometer. During 'heavy' intensity exercise eliciting a VO2 slow component and muscle fatigue, there was no decrease in MPF, which contrasts with 'severe' exercise where the MPF decreased as muscle fatigue occurred. Results from this study suggest a change in fibre recruitment from slow-twitch to oxygen-inefficient high-frequency fasttwitch fibres during fatiguing exercise as the cause of the VO2 slow component
Matching small functions using centroid jitter and two beam position monitors
Matching to small beta functions is required to preserve emittance in plasma
accelerators. The plasma wake provides strong focusing fields, which typically
require beta functions on the mm-scale, comparable to those found in the final
focusing of a linear collider. Such beams can be time consuming to
experimentally produce and diagnose. We present a simple, fast, and noninvasive
method to measure Twiss parameters in a linac using two beam position monitors
only, relying on the similarity of the beam phase space and the jitter phase
space. By benchmarking against conventional quadrupole scans, the viability of
this technique was experimentally demonstrated at the FLASHForward
plasma-accelerator facility.Comment: 8 pages, 7 figure
The Evolution of Luminous Compact Blue Galaxies: Disks or Spheroids?
Luminous compact blue galaxies (LCBGs) are a diverse class of galaxies
characterized by high luminosities, blue colors, and high surface brightnesses.
Residing at the high luminosity, high mass end of the blue sequence, LCBGs sit
at the critical juncture of galaxies that are evolving from the blue to the red
sequence. Yet we do not understand what drives the evolution of LCBGs, nor how
they will evolve. Based on single-dish HI observations, we know that they have
a diverse range of properties. LCBGs are HI-rich with M(HI)=10^{9-10.5} M(sun),
have moderate M(dyn)=10^{10-12} M(sun), and 80% have gas depletion timescales
less than 3 Gyr. These properties are consistent with LCBGs evolving into
low-mass spirals or high mass dwarf ellipticals or dwarf irregulars. However,
LCBGs do not follow the Tully-Fisher relation, nor can most evolve onto it,
implying that many LCBGs are not smoothly rotating, virialized systems. GMRT
and VLA HI maps confirm this conclusion revealing signatures of recent
interactions and dynamically hot components in some local LCBGs, consistent
with the formation of a thick disk or spheroid. Such signatures and the high
incidence of close companions around LCBGs suggest that star formation in local
LCBGs is likely triggered by interactions. The dynamical masses and apparent
spheroid formation in LCBGs combined with previous results from optical
spectroscopy are consistent with virial heating being the primary mechanism for
quenching star formation in these galaxies.Comment: 4 pages, 1 figure, to appear in "Hunting for the Dark: The Hidden
Side of Galaxy Formation", Malta, 19-23 Oct. 2009, eds. V.P. Debattista &
C.C. Popescu, AIP Conf. Se
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