901 research outputs found
A Faster Implementation of Online Run-Length Burrows-Wheeler Transform
Run-length encoding Burrows-Wheeler Transformed strings, resulting in
Run-Length BWT (RLBWT), is a powerful tool for processing highly repetitive
strings. We propose a new algorithm for online RLBWT working in run-compressed
space, which runs in time and bits of space, where
is the length of input string received so far and is the number of runs
in the BWT of the reversed . We improve the state-of-the-art algorithm for
online RLBWT in terms of empirical construction time. Adopting the dynamic list
for maintaining a total order, we can replace rank queries in a dynamic wavelet
tree on a run-length compressed string by the direct comparison of labels in a
dynamic list. The empirical result for various benchmarks show the efficiency
of our algorithm, especially for highly repetitive strings.Comment: In Proc. IWOCA201
Compressed Data Structures for Dynamic Sequences
We consider the problem of storing a dynamic string over an alphabet
in compressed form. Our representation
supports insertions and deletions of symbols and answers three fundamental
queries: returns the -th symbol in ,
counts how many times a symbol occurs among the
first positions in , and finds the position
where a symbol occurs for the -th time. We present the first
fully-dynamic data structure for arbitrarily large alphabets that achieves
optimal query times for all three operations and supports updates with
worst-case time guarantees. Ours is also the first fully-dynamic data structure
that needs only bits, where is the -th order
entropy and is the string length. Moreover our representation supports
extraction of a substring in optimal time
Effects of broadening and electron overheating in tunnel structures based on metallic clusters
We study the influence of energy levels broadening and electron subsystem
overheating in island electrode (cluster) on current-voltage characteristics of
three-electrode structure. A calculation scheme for broadening effect in
one-dimensional case is suggested. Estimation of broadening is performed for
electron levels in disc-like and spherical gold clusters. Within the
two-temperature model of metallic cluster and by using a size dependence of the
Debye frequency the effective electron temperature as a function of bias
voltage is found approximately. We suggest that the effects of broadening and
electron overheating are responsible for the strong smoothing of
current-voltage curves, which is observed experimentally at low temperatures in
structures based on clusters consisting of accountable number of atoms.Comment: 8 pages, 5 figure
The effects of conjugated linoleic acid isomers cis-9,trans-11 and trans-10,cis-12 on in vitro bovine embryo production and cryopreservation
Conjugated linoleic acid (CLA) isomers can affect the lipid profile and signaling of cells and thereby alter their function. A total of 5,700 bovine oocytes were used in a structured series of experiments to test the effects of CLA cis-9,trans-11 and CLA trans-10,cis-12 in vitro. In experiment 1, high doses of each CLA isomer during in vitro maturation (IVM) were compared with high or low doses during the entire in vitro culture (IVC) of parthenogenetic embryos. High doses of the CLA isomers ranged from 50 to 200 μM and low doses were 15 and 25 μM. In experiment 2, the low doses of each CLA isomer were tested during IVM/IVC on embryos produced by in vitro fertilization (IVF). Experiment 3 compared the effects of 15 μM doses of each CLA isomer during IVM or IVC of IVF embryos. In experiment 4, post-rewarming survival rates and blastomere counts were assessed for embryos supplemented with each CLA isomer during IVM or for 36 h before vitrification. In experiment 1, when either CLA isomer was provided only during IVM, we observed no effects on overall rates of maturation, cleavage, or blastocysts (92.2 ± 1.6%, 78.3 ± 4.1%, and 28.9 ± 5.1%, respectively). However, high doses of each CLA isomer, but not low doses, during the entire embryo culture period decreased blastocyst rates (5-20%) in a dose-dependent manner. Cleavage rates improved with 15 or 50 μM CLA trans-10,cis-12. Progesterone concentrations in maturation media were significantly increased by high doses of each CLA isomer compared with control, but low doses of CLA isomers had no effect. In experiment 2 with IVF embryos, low doses of each CLA isomer did not alter cleavage rates (average 84.9 ± 1.9%) and only 25 μM CLA trans-10,cis-12 during IVC reduced blastocyst rates below those of controls (25.5 ± 2.1 vs. 38.2 ± 2.3%). The lipid content of embryos was increased and relative expression of the BIRC5 (baculoviral IAP repeat containing 5) gene was depressed by CLA trans-10,cis-12. In experiment 3, low doses (15μM) of each CLA isomer during IVC significantly reduced blastocyst rates (20.6 ± 2.4% and 27.7 ± 1.2% vs. 34.18 ± 1.2% for CLA trans-10,cis-12 and CLA cis-9,trans-11 compared with control, respectively) with less effect of each CLA during IVM. In experiment 4, adding 100 μM CLA cis-9,trans-11 during the final 36 h of culture resulted in a high survival rate after rewarming and culture, and the higher embryo blastomere count was comparable to that of control embryos not undergoing vitrification. In conclusion, supplementation with either CLA isomer did not improve embryo production, but inclusion of CLA cis-9,trans-11 before vitrification improved the quality of bovine IVF embryos after rewarming and culture
Optoacoustic solitons in Bragg gratings
Optical gap solitons, which exist due to a balance of nonlinearity and
dispersion due to a Bragg grating, can couple to acoustic waves through
electrostriction. This gives rise to a new species of ``gap-acoustic'' solitons
(GASs), for which we find exact analytic solutions. The GAS consists of an
optical pulse similar to the optical gap soliton, dressed by an accompanying
phonon pulse. Close to the speed of sound, the phonon component is large. In
subsonic (supersonic) solitons, the phonon pulse is a positive (negative)
density variation. Coupling to the acoustic field damps the solitons'
oscillatory instability, and gives rise to a distinct instability for
supersonic solitons, which may make the GAS decelerate and change direction,
ultimately making the soliton subsonic.Comment: 5 pages, 3 figure
Observation of the geology and geomorphology of the 1999 Marsokhod test site
The Marsokhod rover returned data from six stations that were used to decipher the geomorphology and geology of a region not previously visited by members of the geomorphology field team. Satellite images and simulated descent images provided information about the regional setting. The landing zone was on an alluvial apron flanking a mountain block to the west and a playa surface to the east. Rover color images, infrared spectra analysis of the mountains, and the apron surface provided insight into the rock composition of the nearby mountains. From the return data the geomorphology team interpreted the region to consist of compressionally deformed, ancient marine sediments and igneous rocks exposed by more recent extensional tectonics. Unconsolidated alluvial materials blanket the lower flanks of the mountains. Bn ancient shoreline cut into alluvial material marks a high stand of water during a past, wetter climate period. Playa sediments floor a present-day, seasonally, dry lake. Observations made by the rover using panoramic and close-up (hand specimens-scale) image data and color scene data confirmed the presence of boulders, cobbles, and fines of various provinces. Rover traverses to sites identified as geologically distinct, such as fan, channel, shoreline, and playa, provided useful clues to the geologic interpretations. Analysis of local rocks was given concert only through comparison with distant geologic features. These results demonstrated the importance of a multifaceted approach to site interpretation through comparison of interpretations derived by differing geologic techniques
Compressed Suffix Arrays for Massive Data
We present a fast space-efficient algorithm for constructing compressed suffix arrays (CSA). The algorithm requires O(n log n) time in the worst case, and only O(n) bits of extra space in addition to the CSA. As the basic step, we describe an algorithm for merging two CSAs. We show that the construction algorithm can be parallelized in a symmetric multiprocessor system, and discuss the possibility of a distributed implementation. We also describe a parallel implementation of the algorithm, capable of indexing several gigabytes per hour
Effective connectivity reveals strategy differences in an expert calculator
Mathematical reasoning is a core component of cognition and the study of experts defines the upper limits of human cognitive abilities, which is why we are fascinated by peak performers, such as chess masters and mental calculators. Here, we investigated the neural bases of calendrical skills, i.e. the ability to rapidly identify the weekday of a particular date, in a gifted mental calculator who does not fall in the autistic spectrum, using functional MRI. Graph-based mapping of effective connectivity, but not univariate analysis, revealed distinct anatomical location of “cortical hubs” supporting the processing of well-practiced close dates and less-practiced remote dates: the former engaged predominantly occipital and medial temporal areas, whereas the latter were associated mainly with prefrontal, orbitofrontal and anterior cingulate connectivity. These results point to the effect of extensive practice on the development of expertise and long term working memory, and demonstrate the role of frontal networks in supporting performance on less practiced calculations, which incur additional processing demands. Through the example of calendrical skills, our results demonstrate that the ability to perform complex calculations is initially supported by extensive attentional and strategic resources, which, as expertise develops, are gradually replaced by access to long term working memory for familiar material
TOpic: rare and special cases, the real "Strange cases"
Introduction: The bladder hernia represents approximately 1-3% of
all inguinal hernias, where patients aged more than 50 years have a
higher incidence (10%). Many factors contribute to the development of a bladder hernia,
including the presence of a urinary outlet obstruction causing chronic
bladder distention, the loss of bladder tone, pericystitis, the perivesical
bladder fat protrusion and the obesity
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