6,211 research outputs found
MRI/TRUS data fusion for brachytherapy
BACKGROUND: Prostate brachytherapy consists in placing radioactive seeds for
tumour destruction under transrectal ultrasound imaging (TRUS) control. It
requires prostate delineation from the images for dose planning. Because
ultrasound imaging is patient- and operator-dependent, we have proposed to fuse
MRI data to TRUS data to make image processing more reliable. The technical
accuracy of this approach has already been evaluated. METHODS: We present work
in progress concerning the evaluation of the approach from the dosimetry
viewpoint. The objective is to determine what impact this system may have on
the treatment of the patient. Dose planning is performed from initial TRUS
prostate contours and evaluated on contours modified by data fusion. RESULTS:
For the eight patients included, we demonstrate that TRUS prostate volume is
most often underestimated and that dose is overestimated in a correlated way.
However, dose constraints are still verified for those eight patients.
CONCLUSIONS: This confirms our initial hypothesis
Modular detergents tailor the purification and structural analysis of membrane proteins including G-protein coupled receptors
Detergents enable the purification of membrane proteins and are indispensable reagents instructural biology. Even though a large variety of detergents have been developed in the lastcentury, the challenge remains to identify guidelines that allowfine-tuning of detergents forindividual applications in membrane protein research. Addressing this challenge, here weintroduce the family of oligoglycerol detergents (OGDs). Native mass spectrometry (MS)reveals that the modular OGD architecture offers the ability to control protein purificationand to preserve interactions with native membrane lipids during purification. In addition to abroad range of bacterial membrane proteins, OGDs also enable the purification and analysisof a functional G-protein coupled receptor (GPCR). Moreover, given the modular design ofthese detergents, we anticipatefine-tuning of their properties for specific applications instructural biology. Seen from a broader perspective, this represents a significant advance forthe investigation of membrane proteins and their interactions with lipids
RG Flows and Stability in Defect Field Theories
We investigate defects in scalar field theories in four and six dimensions in
a double-scaling (semiclassical) limit, where bulk loops are suppressed and
quantum effects come from the defect coupling. We compute -functions up
to four loops and find that fixed points satisfy dimensional disentanglement --
i.e. their dependence on the space dimension is factorized from the coupling
dependence -- and discuss some physical implications. We also give an
alternative derivation of the functions by computing systematic
logarithmic corrections to the Coulomb potential. In this natural scheme,
functions turn out to be a gradient of a `Hamiltonian' function . We also obtain closed formulas for the dimension of scalar operators and
show that instabilities do not occur for potentials bounded from below. The
same formulas are reproduced using Rigid Holography.Comment: 35 pages, 1 figure; v2: added reference
Defects, Rigid Holography and -theorems
We consider a general scalar QFT with a linear defect in and a
surface defect in . Using holography and the Hamilton-Jacobi
formalism, we show that the functions controlling the defect RG flow
are the gradient of the entropy function. In the case of conformal field
theories, this allows the proof that the relevant -functions decrease
monotonically along the RG flow. We provide evidence that this property also
holds in the full quantum theory for general scalar field theories. An
obstruction to the gradient property seems to appear at two loop order when
fermions are added.Comment: 6 pages, no figures; v2: published versio
Analisis Karakteristik Dan Biaya Kecelakaan Lalu Lintas Di Kota Kupang
Kecelakaan lalu lintas merupakan indikator utama tingkat keselamatan jalan raya. Kota Kupang sebagai ibukota Propinsi Nusa Tenggara Timur (NTT) adalah salah satu daerah penyumbang angka kecelakaan terbesar di NTT. Penelitian ini disusun untuk mengetahui karakteristik kecelakaan lalu lintas, besar biaya kecelakaan lalu lintas pada ruas jalan di Kota Kupang, serta besar santunan yang harus dibayarkan oleh PT Jasa Raharja. Data yang digunakan adalah data jumlah kecelakaan lalu lintas Kota Kupang sepanjang tahun 2010-2013.
Hasil analisis deskriptif menunjukkan bahwa karakteristik kecelakaan lalu lintas yang dominan terjadi adalah pada hari Minggu (22%), pukul 12.01–18.00 WITA (38%), posisi tabrakan depan - depan (30%), tipe tabrakan ganda (82%), jenis kelamin laki-laki (77%), usia 17 tahun - 30 tahun (64%), profesi Swasta (48%), pendidikan terakhir SMA (48%), dan tidak memiliki SIM (76%). Analisis biaya korban kecelakaan lalu lintas (BBKO) dengan metode The Gross Output menunjukkan bahwa ruas jalan Timor Raya dengan panjang 11 kilometer merupakan ruas jalan dengan BBKO terbesar yaitu Rp.13.196.013.148,-, dimana biaya kecelakaan per kilometernya yang paling tinggi adalah pada tahun 2013 yaitu sebesar Rp. 514,013,928/ km. Jumlah total santunan (maksimal) Jasa Raharja yang harus dibayarkan kepada korban kecelakaan lalu lintas di kota Kupang periode tahun 2011–2013 ialah sebesar Rp.4.905.000.000.-.
Traffic accident is a major indicator of road safety level. Kupang city as the capital of East Nusa Tenggara (NTT) is one of the largest contributors to the number of traffic accidents in the province. This research was to determine the characteristics of traffic accidents, the accident cost, and the compensation to be paid by PT Jasa Raharja (the state insurance company). The data of traffic accidents were taken throughout year 2010 to 2013.
The descriptive analysis results showed that the dominant traffic accidents occurred on Sunday (22 %) , at 12:01 to 18:00 pm (38 %), head-on collisions (30 %), two-vehicle collisions (82 %), involve male (77 %), 17 - 30 years old (64 %), work at private sector (48 %), senior high school graduate (48 %), and does not have a driver's license (76 %). The accident cost analysis used The Gross Output method showed that Timor Raya road, with a length of 11 kilometers, has the highest traffic accident cost that is Rp.13.196.013.148, where the highest accident cost per kilometer was in year 2013 that is Rp.514,013,928/km. The total amount of (maximum) compensation should be paid by PT Jasa Raharja, to the traffic accident victims in Kupang city at year 2011 to 2013, is Rp.4.905.000.000.-
Optimal Grid Drawings of Complete Multipartite Graphs and an Integer Variant of the Algebraic Connectivity
How to draw the vertices of a complete multipartite graph on different
points of a bounded -dimensional integer grid, such that the sum of squared
distances between vertices of is (i) minimized or (ii) maximized? For both
problems we provide a characterization of the solutions. For the particular
case , our solution for (i) also settles the minimum-2-sum problem for
complete bipartite graphs; the minimum-2-sum problem was defined by Juvan and
Mohar in 1992. Weighted centroidal Voronoi tessellations are the solution for
(ii). Such drawings are related with Laplacian eigenvalues of graphs. This
motivates us to study which properties of the algebraic connectivity of graphs
carry over to the restricted setting of drawings of graphs with integer
coordinates.Comment: Appears in the Proceedings of the 26th International Symposium on
Graph Drawing and Network Visualization (GD 2018
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