11,745 research outputs found
Is re-farming the answer to the spectrum shortage conundrum?
Radio spectrum has become one of the engines of economic growth. However, rapid technological change, ever increasing demands for new wireless services and the nature of spectrum as a scarce resource necessitate an urgent re-examination of issues such as congestion and interference. This paper argues that the traditional administrative spectrum management approach is unlikely to overcome these issues, thereby resulting in growing technical and economic inefficiencies. As countries review their spectrum policies - a process that is generically referred to as radio spectrum policy reform - to counter these inefficiencies, modifications to the radio frequency allocations and assignments are beginning to be implemented by way of radio spectrum re-farming? This phenomenon forms the subject matter of this paper
Scalable wavelet-based coding of irregular meshes with interactive region-of-interest support
This paper proposes a novel functionality in wavelet-based irregular mesh coding, which is interactive region-of-interest (ROI) support. The proposed approach enables the user to define the arbitrary ROIs at the decoder side and to prioritize and decode these regions at arbitrarily high-granularity levels. In this context, a novel adaptive wavelet transform for irregular meshes is proposed, which enables: 1) varying the resolution across the surface at arbitrarily fine-granularity levels and 2) dynamic tiling, which adapts the tile sizes to the local sampling densities at each resolution level. The proposed tiling approach enables a rate-distortion-optimal distribution of rate across spatial regions. When limiting the highest resolution ROI to the visible regions, the fine granularity of the proposed adaptive wavelet transform reduces the required amount of graphics memory by up to 50%. Furthermore, the required graphics memory for an arbitrary small ROI becomes negligible compared to rendering without ROI support, independent of any tiling decisions. Random access is provided by a novel dynamic tiling approach, which proves to be particularly beneficial for large models of over 10(6) similar to 10(7) vertices. The experiments show that the dynamic tiling introduces a limited lossless rate penalty compared to an equivalent codec without ROI support. Additionally, rate savings up to 85% are observed while decoding ROIs of tens of thousands of vertices
Heavy Meson Spectroscopy at Beta=6.0
We present results of a quenched calculation of the heavy-light and
quarkonium spectrum using the tadpole improved clover action. We resolve
completely the triplet chi P-states in quarkonium systems, and obtain evidence
for fine structure of the heavy-light P-states. Approximate scaling of the
hyperfine splittings is observed, producing results that are significantly
below experiment.Comment: Contribution to Lattice 97 proceedings: 3 pages, 7 postscript
figures, LaTeX2e, uses espcrc2.st
Low implantation depth during TAVR increases the pressure exerted on the atrioventricular conduction system: a biomechanical analysis
TDP1/TOP1 ratio as a promising indicator for the response of small cell lung cancer to topotecan
BACKGROUND AND OBJECTIVE
Small cell lung cancer (SCLC) is one of the most challenging tumors to treat due to high proliferation rate, early metastatic dissemination and rapid development of chemotherapy resistance. The current treatment protocols involve the use of topoisomerase 1 (TOP1) poisons such as irinotecan and topotecan in combination with platinum-based compounds. TOP1 poisons kill cancer cells by trapping TOP1 on DNA, generating lethal DNA double-strand breaks. A potential mechanism employed by cancer cells to resist killing by TOP1 poisons is to overexpress enzymes involved in the repair of TOP1-DNA breaks. Tyrosyl DNA phosphodiesterase 1 (TDP1) is a key player in this process and despite its importance, no data is currently available to correlate TDP1 protein and mRNA levels with catalytic activity in SCLC. In addition, it is not known if TDP1 and TOP1 protein levels correlate with the cellular response of SCLC to TOP1 based therapies.
METHODS AND RESULTS
We report a remarkable variation in TDP1 and TOP1 protein levels in a panel of SCLC cell lines. TDP1 protein level correlates well with TDP1 mRNA and TDP1 catalytic activity, as measured by two newly developed independent activity assays, suggesting the potential utility of immunohistochemistry in assessing TDP1 levels in SCLC tissues. We further demonstrate that whilst TDP1 protein level alone does not correlate with topotecan sensitivity, TDP1/TOP1 ratio correlates well with sensitivity in 8 out of 10 cell lines examined.
CONCLUSION
This study provides the first cellular analyses of TDP1 and TOP1 in SCLC and suggests the potential utility of TDP1/TOP1 ratio to assess the response of SCLC to topotecan. The establishment and validation of an easy-to-use TDP1 enzymatic assay in cell extracts could be exploited as a diagnostic tool in the clinic. These findings may help in stratifying patients that are likely to benefit from TOP1 poisons and TDP1 inhibitors currently under development
RuleCNL: A Controlled Natural Language for Business Rule Specifications
Business rules represent the primary means by which companies define their
business, perform their actions in order to reach their objectives. Thus, they
need to be expressed unambiguously to avoid inconsistencies between business
stakeholders and formally in order to be machine-processed. A promising
solution is the use of a controlled natural language (CNL) which is a good
mediator between natural and formal languages. This paper presents RuleCNL,
which is a CNL for defining business rules. Its core feature is the alignment
of the business rule definition with the business vocabulary which ensures
traceability and consistency with the business domain. The RuleCNL tool
provides editors that assist end-users in the writing process and automatic
mappings into the Semantics of Business Vocabulary and Business Rules (SBVR)
standard. SBVR is grounded in first order logic and includes constructs called
semantic formulations that structure the meaning of rules.Comment: 12 pages, 7 figures, Fourth Workshop on Controlled Natural Language
(CNL 2014) Proceeding
Wrinkling, creasing, and folding in fiber-reinforced soft tissues
Many biological tissues develop elaborate folds during growth and development. The onset of this folding is often understood in relation to the creasing and wrinkling of a thin elastic layer that grows whilst attached to a large elastic foundation. In reality, many biological tissues are reinforced by fibres and so are intrinsically anisotropic. However, the correlation between the fiber directions and the pattern formed during growth is not well understood. Here, we consider the stability of a two-layer tissue composed of a thin hyperelastic strip adhered to an elastic half-space in which are embedded elastic fibers. The combined object is subject to a uniform compression and, at a critical value of this compression, buckles out of the plane — it wrinkles. We characterize the wrinkle wavelength at onset as a function of the fiber orientation both computationally and analytically and show that the onset of surface instability can be either promoted or inhibited as the fiber stiffness increases, depending on the fibre angle. However, we find that the structure of the resulting folds is approximately independent of the fiber orientation. We also explore numerically the formation of large creases in fiber-reinforced tissue in the post-buckling regime
13C NMR study of the effect of aerobic treatment of olive mill wastewater (OMW) on its lipid-free content
Olive mill wastewater was treated by an aerobic bio-process at different values of pH (with or without addition of lime), for 45 days on a laboratory scale, to evaluate the reduction of the organic load. The lipid content showed an appreciable change in relation to the applied treatment both for total lipids and for the different fractions (neutral lipids, monoglycerides and phospholipids). 13C NMR spectroscopy was performed on initial and final samples both raw and after lipid extraction. The main spectral differences were observed in the C-alkyl region (0–50 ppm), in the C O-alkyl/N-alkyl region (50–110 ppm), and in the C-carboxylic (160–200 ppm) region, providing information on the alterations occurring in the different biochemical entities composing this complex biomatrix (e.g. lipids and carbohydrates) according to the treatment
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