35,902 research outputs found
The contribution of services and other sectors to Australian productivity growth 1980-2004
Radiative transfer of synchrotron radiation through a compressed random magnetic field
The generally low polarization levels present in extragalactic radio sources suggest magnetic fields that are largely turbulent, presumably maintained by turbulence motion of the underlying plasma. The polarization of radio emission is often generated as the plasma is compressed by shock waves, and this type of configuration has been widely applied, from the cores of AGN to the lobes of classical double radio sources. Here we note that, in the absence of Faraday rotation, the synchrotron radiative transfer equations for such a configuration, separate, leading to relatively simple solutions for opaque or partially opaque sources. Expressions for the emission and absorption coefficients are derived, and, although in general, these must be evaluated numerically, the process is much simpler than a full numerical solution of the transfer equations
Numerical analysis of shells. Volume 3 - Engineer's program manual for ''STARS-2'' - Shell Theory Automated for Rotational Structures-2, digital computer program
Manual of engineering programming information for Shell Theory Automated for Rotational Structures /STARS 2/ - Vol.
Multiphoton Processes in Driven Mesoscopic Systems
We study the statistics of multi-photon absorption/emission processes in a
mesoscopic ring threaded by an harmonic time-dependent flux . For this
sake, we demonstrate a useful analogy between the Keldysh quantum kinetic
equation for the electrons distribution function and a Continuous Time Random
Walk in energy space with corrections due to interference effects. Studying the
probability to absorb/emit quanta per scattering event, we
explore the crossover between ultra-quantum/low-intensity limit and
quasi-classical/high-intensity regime, and the role of multiphoton processes in
driving it.Comment: 6 pages, 5 figures, extended versio
The limits of spatial resolution achievable using a 30kHz multibeam sonar: model predictions and field results
A Simrad EM300 multibeam sonar was used to attempt to resolve small (-5m high) targets in 450m of water. The targets had previously been surveyed using a deeply towed 59 kHz sidescan sonar. Using multisector active yaw, pitch and roll compensation, together with dynamically altering angular sectors, the sonar is capable of maintaining sounding densities of as tight as 10m spacing in these water depths. This is significantly smaller than the largest dimension of the projected beam footprints (1 6-64m). The observed data suggest that the targets are intermittently resolved. The field results compare well to the output of a numerical model which reproduces the imaging geometry. Possible variations in the imaging geometry are implemented in the model, comparing equiangular and equidistant beam spacings, differing angular sectors and all the different combinations of transmit and receive beam widths that are available for this model of sonar. While amplitude detection is significantly aliased by targets smaller than the across track beam footprint, under conditions where the signal to noise ratio is favorable, phase detection can be used to reduce the minimum size of target observed to about the scale of the across track beam width. Thus having the beam spacing at the scale is justifiable. The phase distortion due to smaller targets, however, is generally averaged out
Cryptic MHC Polymorphism Revealed but Not Explained by Selection on the Class IIB Peptide-Binding Region
The immune genes of the major histocompatibility complex (MHC) are characterized by extraordinarily high levels of nucleotide and haplotype diversity. This variation is maintained by pathogen-mediated balancing selection that is operating on the peptide-binding region (PBR). Several recent studies have found, however, that some populations possess large clusters of alleles that are translated into virtually identical proteins. Here, we address the question of how this nucleotide polymorphism is maintained with little or no functional variation for selection to operate on. We investigate circa 750â850 bp of MHC class II DAB genes in four wild populations of the guppy Poecilia reticulata. By sequencing an extended region, we uncovered 40.9% more sequences (alleles), which would have been missed if we had amplified the exon 2 alone. We found evidence of several gene conversion events that may have homogenized sequence variation. This reduces the visible copy number variation (CNV) and can result in a systematic underestimation of the CNV in studies of the MHC and perhaps other multigene families. We then focus on a single cluster, which comprises 27 (of a total of 66) sequences. These sequences are virtually identical and show no signal of selection. We use microsatellites to reconstruct the populations' demography and employ simulations to examine whether so many similar nucleotide sequences can be maintained in the populations. Simulations show that this variation does not behave neutrally. We propose that selection operates outside the PBR, for example, on linked immune genes or on the âsheltered loadâ that is thought to be associated to the MHC. Future studies on the MHC would benefit from extending the amplicon size to include polymorphisms outside the exon with the PBR. This may capture otherwise cryptic haplotype variation and CNV, and it may help detect other regions in the MHC that are under selection
Directed Random Walk on the Lattices of Genus Two
The object of the present investigation is an ensemble of self-avoiding and
directed graphs belonging to eight-branching Cayley tree (Bethe lattice)
generated by the Fucsian group of a Riemann surface of genus two and embedded
in the Pincar\'e unit disk. We consider two-parametric lattices and calculate
the multifractal scaling exponents for the moments of the graph lengths
distribution as functions of these parameters. We show the results of numerical
and statistical computations, where the latter are based on a random walk
model.Comment: 17 pages, 8 figure
New Goldstone multiplet for partially broken supersymmetry
The partial spontaneous breaking of rigid N=2 supersymmetry implies the
existence of a massless N=1 Goldstone multiplet. In this paper we show that the
spin-(1/2,1) Maxwell multiplet can play this role. We construct its full
nonlinear transformation law and find the invariant Goldstone action. The
spin-1 piece of the action turns out to be of Born-Infeld type, and the full
superfield action is duality invariant. This leads us to conclude that the
Goldstone multiplet can be associated with a D-brane solution of superstring
theory for p=3. In addition, we find that N=1 chirality is preserved in the
presence of the Goldstone-Maxwell multiplet. This allows us to couple it to N=1
chiral and gauge field multiplets. We find that arbitrary Kahler and
superpotentials are consistent with partially broken N=2 supersymmetry.Comment: Latex, 13 pages. Version to appear in Phys. Rev.
Reducing Medical Errors for Patients with Substance Use Disorders with a Medical Information Card
Background
Approximately 98,000 Americans perish annually due to medical errors and adverse events associated with the limited access to or incomplete pertinent patient health information (Centers for Disease Control and Prevention [CDC], 2022; Obrien et al., 2021). Pertinent patient health information includes patientsâ allergies, current medications, current medical diagnosis, blood type, insurance, and emergency contact. The purpose of this project was to examine the efficacy in using File of Life cards in reducing medical errors among patients with substance use disorders (SUDs), and the perception of patients and healthcare providers ease of use, satisfaction of using the File of Life cards, and improving medical decision making and preventing errors.
Method
A two-month quality improvement project was conducted at a clinic in the Northern Midwest. Patients were individually educated about and received a File of Life card during their Medication Assistance Treatment (MAT) appointments. Questionnaires were distributed to patients and the healthcare staff. Patientsâ electronic health records (EHRs) were analyzed to determine the number of times they visited the local ED and the number of reported medical inconsistencies or errors during this QI projectâs implementation.
Results
Among patients, 16% used their cards and 100% perceived the cards easy to use and useful with their care. Two patients visited the local ED and no medical errors were reported. Among healthcare providers, 100% perceived the cards easy to use, 87% considered the cards useful with medical decision making, 93% considered the cards useful in preventing medical errors, and 0% encountered any of the patients that received the cards.
Conclusion
File of Life cards may improve medical decision making and decrease medical errors. They may help improve patientsâ overall satisfaction and confidence with their healthcare. However, no statistical analysis was conducted due to no pre-qualitative data, short duration, and small sample size. Therefore, a larger sample size, and longer duration of time is needed to confirm these findings
Mapping a Continental Shelf and Slope in the 1990s: A Tale of Three Multibeams
Increasing societal pressures on the U.S. continental shelves adjacent to dense population centers have brought to light the lack of accurate base maps in these areas. Existing bathymetric maps and random sidescan sonar surveys are either not accurate enough or do not provide the coverage necessary to make policy decisions. Until the mid 1990s, it was not financially prudent nor technically efficient to map the shallow shelves. However, the availability of high-resolution multibeam mapping systems now allow efficient and accurate mapping of the continental margins. In 1996 the U.S. Geological Survey began a large-scale seafloor mapping campaign on the continental shelf and slope adjacent to Los Angeles, CA. The first survey used a Kongsberg Simrad EM1000 (95 kHz). The survey continued in 1998 by mapping the slope and proximal basins from Newport to Long Beach, CA, using a Kongsberg Simrad EM300 (30 kHz). The area was completed in May 1999 by mapping the entire shelf adjacent to Long Beach, CA using an EM3000D (a dual-headed 300-kHz system). The mapping used both INS from the vehicle motion sensor and DGPS to provide position accuracies of ~1 m. All the data were processed in the field in near realtime using software developed at the Univ. of New Brunswick. Because of the different systems used and the range of water depths, the spatial resolution of the processed data varies from \u3c0.5 m on the inner shelf to 8 m on the basin floors.
Perspective overviews of backscatter draped over bathymetry reveals a host of geological features unknown to exist in this area. These features include shallow, linear gullys, barchan dunes, small-scale bedforms in shallow troughs, major canyon system complexes, large- and smallscale mass movements, faults, and large areas of outcrop. The effects on sediment transport of man-made features, such as sewer outfall pipes and dredge-disposal fields, are clearly delineated on the new maps. The maps provide the fundamental base maps for studies as varied as those involving benthic habitats, marine disposal sites, sediment transport, and tectonic ma
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