54,472 research outputs found
Identification and nucleotide sequences of mxaA, mxaC, mxaK, mxaL, and mxaD genes from Methylobacterium extorquens AM1
The DNA sequence for a 4.4-kb HindIII-XhoI Methylobacterium extorquens AM1 DNA fragment that is known to contain three genes (mxaAKL) involved in incorporation of calcium into methanol dehydrogenase (I. W. Richardson and C. Anthony, Biochem. J. 287:709-7115, 1992) was determined. Five complete open reading frames and two partial open reading frames were found, suggesting that this region contains previously unidentified genes. A combination of sequence analysis, mutant complementation data, and gene expression studies showed that these genes correspond to mxaSACKLDorf1. Of the three previously unidentified genes (mxaC, mxaD, and orf1), mutant complementation studies showed that mxaC is required for methanol oxidation, while the function of the other two genes is still unknown
Preferences for Prenatal Tests for Cystic Fibrosis: A Discrete Choice Experiment to Compare the Views of Adult Patients, Carriers of Cystic Fibrosis and Health Professionals
As new technologies enable the development of non-invasive prenatal diagnosis (NIPD) for cystic fibrosis (CF), research examining stakeholder views is essential for the preparation of implementation strategies. Here, we compare the views of potential service users with those of health professionals who provide counselling for prenatal tests. A questionnaire incorporating a discrete choice experiment examined preferences for key attributes of NIPD and explored views on NIPD for CF. Adult patients (n = 92) and carriers of CF (n = 50) were recruited from one children’s and one adult NHS specialist CF centre. Health professionals (n = 70) were recruited via an e-mail invitation to relevant professional bodies. The key attribute affecting service user testing preferences was no miscarriage risk, while for health professionals, accuracy and early testing were important. The uptake of NIPD by service users was predicted to be high and includes couples that would currently decline invasive testing. Many service users (47%) and health professionals (55.2%) thought the availability of NIPD for CF would increase the pressure to undergo prenatal testing. Most service users (68.5%) thought NIPD for CF should be offered to all pregnant women, whereas more health professionals (68.2%) thought NIPD should be reserved for known carrier couples. The implications for clinical practice are discussed
PLANNING SOLAR HEATING FOR POULTRY - A LINEAR PROGRAMMING APPROACH
Livestock Production/Industries,
IRS 16SW - A New Comoving Group of Young Stars in the Central Parsec of the Milky Way
One of the most perplexing problems associated with the supermassive black
hole at the center of our Galaxy is the origin of the young stars in its close
vicinity. Using proper motion measurements and stellar number density counts
based on 9 years of diffraction-limited K(2.2 micron)-band speckle imaging at
the W. M. Keck 10-meter telescopes, we have identified a new comoving group of
stars, which we call the IRS 16SW comoving group, located 1.9" (0.08 pc, in
projection) from the central black hole. Four of the five members of this
comoving group have been spectroscopically identified as massive young stars,
specifically He I emission-line stars and OBN stars. This is the second young
comoving group within the central parsec of the Milky Way to be recognized and
is the closest, by a factor of 2, in projection to the central black hole.
These comoving groups may be the surviving cores of massive infalling star
clusters that are undergoing disruption in the strong tidal field of the
central supermassive black hole.Comment: 10 pages, 1 figure, accepted for ApJL, uses emulateap
Investigation of conventional and Super-X divertor configurations of MAST Upgrade using SOLPS
One of the first studies of MAST Upgrade divertor configurations with
SOLPS5.0 are presented. We focus on understanding main prospects associated
with the novel geometry of the Super-X divertor (SXD). This includes a
discussion of the effect of magnetic flux expansion and volumetric power losses
on the reduction of target power loads, the effect of divertor geometry on the
divertor closure and distribution of neutral species and radiation in the
divertor, the role of the connection length in broadening the target wetted
area. A comparison in conditions typical for MAST inter-ELM H-mode plasmas
confirms improved performance of the Super-X topology resulting in
significantly better divertor closure with respect to neutrals (the atomic flux
from the target increased by a factor of 6, but the atomic flux from the
divertor to the upper SOL reduced by a factor of 2), increased radiation volume
and increased total power loss (a factor of 2) and a reduction of target power
loads through both magnetic flux expansion and larger volumetric power loss in
the divertor (a factor of 5-10 in attached plasmas). The reduction of the
target power load by SXD further increases with collisionality (high density or
detached regimes) thanks to larger importance of volumetric power losses. It is
found that a cold divertor plasma leads to stronger parallel temperature
gradients in the SOL which drive more parallel heat flux, meaning that the
effectiveness of perpendicular transport in spreading the power at the target
can be reduced, and this needs to be taken into account in any optimisation.Comment: 32 pages, 23 figures. This is an author-created, un-copyedited
version of an article accepted for publication in PPCF. IOP Publishing Ltd
and IAEA are not responsible for any errors or omissions in this version of
the manuscript or any version derived from i
Unique research challenges for high-speed civil transports
Market growth and technological advances are expected to lead to a generation of long-range transports that cruise at supersonic or even hypersonic speeds. Current NASA/industry studies will define the market windows in terms of time frame, Mach number, and technology requirements for these aircraft. Initial results indicate that, for the years 2000 to 2020, economically attractive vehicles could have a cruise speed up to Mach 6. The resulting research challenges are unique. They must be met with technologies that will produce commercially successful and environmentally compatible vehicles where none have existed. Several important areas of research were identified for the high-speed civil transports. Among these are sonic boom, takeoff noise, thermal management, lightweight structures with long life, unique propulsion concepts, unconventional fuels, and supersonic laminar flow
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