3,379 research outputs found
On Critical Relative Distance of DNA Codes for Additive Stem Similarity
We consider DNA codes based on the nearest-neighbor (stem) similarity model
which adequately reflects the "hybridization potential" of two DNA sequences.
Our aim is to present a survey of bounds on the rate of DNA codes with respect
to a thermodynamically motivated similarity measure called an additive stem
similarity. These results yield a method to analyze and compare known samples
of the nearest neighbor "thermodynamic weights" associated to stacked pairs
that occurred in DNA secondary structures.Comment: 5 or 6 pages (compiler-dependable), 0 figures, submitted to 2010 IEEE
International Symposium on Information Theory (ISIT 2010), uses IEEEtran.cl
Foundation Expenses and Compensation: Interim Report 2005
Examines the 10,000 largest foundations and identifies characteristics and operating styles that affect levels of expenses and compensation, including foundation type, size, staffing, scope of activity, and direct charitable activities
What Drives Foundation Expenses & Compensation? Results of a Three-Year Study, Highlights
This brief presents key findings from the latest report of the Foundation Expenses and Compensation Project—the first large-scale, longterm, systematic study of independent, corporate, and community foundations' expense and compensation patterns and the factors behind them. Documenting the varying characteristics of the 10,000 largest U.S. grantmaking foundations, the study finds these differences—including foundation type, size, and operating activities—essential for understanding foundation finances. Not surprisingly, hiring staff and taking on staff-intensive activities raise charitable administrative expenditures relative to charitable distributions, while relying on unpaid board and family members and engaging in less-staff-intensive activities lower them. Most foundation operations, however, are somewhere between these poles
A Hotelling Model for Fixed-Cost Driven Power Generation
This paper links Hotelling's theory, in recent literature applied to an emission constrained environment, with the classical capacity planning framework to describe portfolio time-paths in electricity production. Emission targets are considered by a ceiling on the stock of pollution. We propose conditions for an efficient production portfolio as a subset of available technologies. We then derive potential production portfolio time-paths for a renewable, a fossil and a carbon capturing technology that differ according to their fixed and variable costs, their efficiency and their polluting characteristics. We conclude that the share of the fossil technology will continuously decrease, the scarce resource will be fully exploited. On each constrained path, the stock of pollution will remain at the ceiling for a non-zero time period. Emission targets push down scarcity rents, an option for carbon capturing would decrease societal costs and uphold scarcity rents
Successful treatment of periprosthetic joint infection caused by Granulicatella para-adiacens with prosthesis retention: a case report.
Granulicatella and Abiotrophia spp. are difficult to detect due to their complex nutritional requirements. Infections with these organisms are associated with high treatment failure rates. We report the first implant-associated infection caused by Granulicatella para-adiacens, which was cured with anti-microbial treatment consisting of anti-biofilm-active rifampin and debridement, exchange of mobile parts and retention of the prosthesis.
Patient with a history of left hip arthroplasty presented with acute onset of fever, pain and limited range of motion of the left hip. Arthrocentesis of the affected joint yielded purulent fluid and exchange of mobile parts of the prosthesis, but retention of fixed components was performed. Granulicatella para-adiacens grew from preoperative and intraoperative cultures, including sonication fluid of the removed implant. The transesophageal echocardiography showed a vegetation on the mitral valve; the orthopantogram demonstrated a periapical dental abscess. The patient was treated with intravenous penicillin G and gentamicin for 4 weeks, followed by levofloxacin and rifampin for additional 2 months. At discharge and at follow-up 1, 2 and 5 years later, the patient was noted to have a functional, pain-free, and radiologically stable hip prosthesis and the serum C-reactive protein was normal.
Although considered a difficult-to-treat organism, we report a successful treatment of the Granulicatella hip prosthesis infection with prosthesis retention and a prolonged antibiofilm therapy including rifampin. The periapical dental abscess is considered the primary focus of hematogenously infected hip prosthesis, underlining the importance treatment of periodontitis prior to arthroplasty and of proper oral hygiene for prevention of hematogenous infection after arthroplasty
Draft Genome Sequence and Complete Plasmid Sequence of Acinetobacter lwoffii F78, an Isolate with Strong Allergy-Protective Properties
The hygiene hypothesis states that the tremendous increase in atopic diseases correlates significantly with less contact to microbes in childhood. Here, we report the draft genome sequence of Acinetobacter lwoffii F78, a rural cowshed isolate with strong allergy-protective properties that contains an 8,579-bp plasmid
Towards Knowledge-Enriched Path Computation
Directions and paths, as commonly provided by navigation systems, are usually
derived considering absolute metrics, e.g., finding the shortest path within an
underlying road network. With the aid of crowdsourced geospatial data we aim at
obtaining paths that do not only minimize distance but also lead through more
popular areas using knowledge generated by users. We extract spatial relations
such as "nearby" or "next to" from travel blogs, that define closeness between
pairs of points of interest (PoIs) and quantify each of these relations using a
probabilistic model. Subsequently, we create a relationship graph where each
node corresponds to a PoI and each edge describes the spatial connection
between the respective PoIs. Using Bayesian inference we obtain a probabilistic
measure of spatial closeness according to the crowd. Applying this measure to
the corresponding road network, we obtain an altered cost function which does
not exclusively rely on distance, and enriches an actual road networks taking
crowdsourced spatial relations into account. Finally, we propose two routing
algorithms on the enriched road networks. To evaluate our approach, we use
Flickr photo data as a ground truth for popularity. Our experimental results --
based on real world datasets -- show that the paths computed w.r.t.\ our
alternative cost function yield competitive solutions in terms of path length
while also providing more "popular" paths, making routing easier and more
informative for the user.Comment: Accepted as a short paper at ACM SIGSPATIAL GIS 201
The improvement of Mo/4H-SiC Schottky diodes via a P2O5 surface passivation treatment
Molybdenum (Mo)/4H-silicon carbide (SiC) Schottky barrier diodes have been fabricated with a phosphorus pentoxide (P2O5) surface passivation treatment performed on the SiC surface prior to metallization. Compared to the untreated diodes, the P2O5-treated diodes were found to have a lower Schottky barrier height by 0.11 eV and a lower leakage current by two to three orders of magnitude. Physical characterization of the P2O5-treated Mo/SiC interfaces revealed that there are two primary causes for the improvement in electrical performance. First, transmission electron microscopy imaging showed that nanopits filled with silicon dioxide had formed at the surface after the P2O5 treatment that terminates potential leakage paths. Second, secondary ion mass spectroscopy revealed a high concentration of phosphorus atoms near the interface. While only a fraction of these are active, a small increase in doping at the interface is responsible for the reduction in barrier height. Comparisons were made between the P2O5 pretreatment and oxygen (O2) and nitrous oxide (N2O) pretreatments that do not form the same nanopits and do not reduce leakage current. X-ray photoelectron spectroscopy shows that SiC beneath the deposited P2O5 oxide retains a Si-rich interface unlike the N2O and O2 treatments that consume SiC and trap carbon at the interface. Finally, after annealing, the Mo/SiC interface forms almost no silicide, leaving the enhancement to the subsurface in place, explaining why the P2O5 treatment has had no effect on nickel- or titanium-SiC contacts
Readout of GEM Detectors Using the Medipix2 CMOS Pixel Chip
We have operated a Medipix2 CMOS readout chip, with amplifying, shaping and
charge discriminating front-end electronics integrated on the pixel-level, as a
highly segmented direct charge collecting anode in a three-stage gas electron
multiplier (Triple-GEM) to detect the ionization from Fe X-rays and
electrons from Ru. The device allows to perform moderate energy
spectroscopy measurements (20 % FWHM at 5.9 keV -rays) using only digital
readout and two discriminator thresholds. Being a truly 2D-detector, it allows
to observe individual clusters of minimum ionizing charged particles in
(70:30) and (70:30) mixtures and to achieve excellent
spatial resolution for position reconstruction of primary clusters down to
, based on the binary centroid determination method.Comment: 18 pages, 14 pictures. submitted to Nuclear Instruments and Methods
in Physics Research
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