1,042 research outputs found
This is the tricky part: When directions become difficult
Automated route guidance systems, both web-based systems and en-route systems, have become commonplace in recent years. These systems often replace humangenerated directions, which are often incomplete, vague, or in error. However, humangenerated directions have the ability to differentiate between easy and complex steps through language in a way that is more difficult in automated systems. This article examines a set of human-generated verbal directions to better understand why some parts of directions are perceived as being more difficult than the remaining steps. Insights from this analysis will lead to recommendations to improve the next generation of automated route guidance systems
A Constraint Programming Approach for Non-Preemptive Evacuation Scheduling
Large-scale controlled evacuations require emergency services to select
evacuation routes, decide departure times, and mobilize resources to issue
orders, all under strict time constraints. Existing algorithms almost always
allow for preemptive evacuation schedules, which are less desirable in
practice. This paper proposes, for the first time, a constraint-based
scheduling model that optimizes the evacuation flow rate (number of vehicles
sent at regular time intervals) and evacuation phasing of widely populated
areas, while ensuring a nonpreemptive evacuation for each residential zone. Two
optimization objectives are considered: (1) to maximize the number of evacuees
reaching safety and (2) to minimize the overall duration of the evacuation.
Preliminary results on a set of real-world instances show that the approach can
produce, within a few seconds, a non-preemptive evacuation schedule which is
either optimal or at most 6% away of the optimal preemptive solution.Comment: Submitted to the 21st International Conference on Principles and
Practice of Constraint Programming (CP 2015). 15 pages + 1 reference pag
New structures to solve aggregated queries for trips over public transportation networks
Representing the trajectories of mobile objects is a hot topic from the
widespread use of smartphones and other GPS devices. However, few works have
focused on representing trips over public transportation networks (buses,
subway, and trains) where a user's trips can be seen as a sequence of stages
performed within a vehicle shared with many other users. In this context,
representing vehicle journeys reduces the redundancy because all the passengers
inside a vehicle share the same arrival time for each stop. In addition, each
vehicle journey follows exactly the sequence of stops corresponding to its
line, which makes it unnecessary to represent that sequence for each journey.
To solve data management for transportation systems, we designed a conceptual
model that gave us a better insight into this data domain and allowed us the
definition of relevant terms and the detection of redundancy sources among
those data. Then, we designed two compact representations focused on users'
trips (TTCTR) and on vehicle trips (AcumM), respectively. Each approach owns
some strengths and is able to answer some queries efficiently.
We include experimental results over synthetic trips generated from accurate
schedules obtained from a real network description (from the bus transportation
system of Madrid) to show the space/time trade-off of both approaches. We
considered a wide range of different queries about the use of the
transportation network such as counting-based or aggregate queries regarding
the load of any line of the network at different times.Comment: This research has received funding from the European Union's Horizon
2020 research and innovation programme under the Marie Sk{\l}odowska-Curie
Actions H2020-MSCA-RISE-2015 BIRDS GA No. 69094
AKL1, a botanical mixture for the treatment of asthma: a randomised, double-blind, placebo-controlled, cross-over study
BACKGROUND: Despite effective treatments, asthma outcomes remain suboptimal. Interest exists in complementary therapies, particularly in herbal remedies for asthma treatment, currently with inconclusive evidence of efficacy. The encapsulated botanical mixture AKL1 has anecdotal evidence of effectiveness in asthma. METHODS: We performed a randomised controlled cross over study comparing the effectiveness of AKL1 with indistinguishable placebo as add-on therapy in patients uncontrolled on standard asthma treatment. Thirty two adult asthmatics completed a 36 week trial consisting of a 4 week single blind run in period, during which placebo was added to usual treatment, a 12 week double blind active phase in which subjects received AKL1 or placebo, a single blind 8 week washout period receiving placebo and a final 12 week double blind cross-over active treatment phase. Daily diaries were kept of peak expiratory flow and symptoms, and spirometry, validated symptom and health status questionnaire scores and adverse events were monitored at study visits. Paired T tests were used to compare the effects of placebo and AKL1 on outcomes. Changes in outcome measures over treatment phases are presented as means and 95% confidence intervals (CI) of means. RESULTS: No significant differences in lung function (active-placebo) were found (Forced Expiratory Volume in 1 second: mean difference [95% CI] = 0.01 [-0.12 to 0.14] L, p = 0.9. Peak Expiratory Flow: -4.08 [-35.03 to 26.89]. L/min, p = 0.8). Trends to clinical improvements favouring active treatment were however consistently seen in the patient-centered outcomes: Asthma Control Questionnaire mean difference (active β placebo) [95% CI] = -0.35 [-0.78 to 0.07], p = 0.10, Asthma Quality of Life Questionnaire mean difference 0.42 [-0.08 to 0.93], p = 0.09, Leicester Cough Questionnaire mean difference 0.49, [-0.18 to 1.16], p = 0.15. Nine exacerbations occurred during placebo treatment and five whilst on AKL1. No significant adverse events were noted. CONCLUSION: AKL1 treatment was well tolerated. No significant improvements in lung function, symptoms, or quality of life were seen, although consistent trends were seen to improvements in patient-centered outcomes. Further studies are needed
Where Snow is a Landmark: Route Direction Elements in Alpine Contexts
Route directions research has mostly focused on urban space so far, highlighting human concepts of street networks based on a range of recurring elements such as route segments, decision points, landmarks and actions. We explored the way route directions reflect the features of space and activity in the context of mountaineering. Alpine route directions are only rarely segmented through decision points related to reorientation; instead, segmentation is based on changing topography. Segments are described with various degrees of detail, depending on difficulty. For landmark description, direction givers refer to properties such as type of surface, dimension, colour of landscape features; terrain properties (such as snow) can also serve as landmarks. Action descriptions reflect the geometrical conceptualization of landscape features and dimensionality of space. Further, they are very rich in the semantics of manner of motion
On the power and the systematic biases of the detection of chromosomal inversions by paired-end genome sequencing
One of the most used techniques to study structural variation at a genome level is paired-end mapping (PEM). PEM has the advantage of being able to detect balanced events, such as inversions and translocations. However, inversions are still quite difficult to predict reliably, especially from high-throughput sequencing data. We simulated realistic PEM experiments with different combinations of read and library fragment lengths, including sequencing errors and meaningful base-qualities, to quantify and track down the origin of false positives and negatives along sequencing, mapping, and downstream analysis. We show that PEM is very appropriate to detect a wide range of inversions, even with low coverage data. However, % of inversions located between segmental duplications are expected to go undetected by the most common sequencing strategies. In general, longer DNA libraries improve the detectability of inversions far better than increments of the coverage depth or the read length. Finally, we review the performance of three algorithms to detect inversions -SVDetect, GRIAL, and VariationHunter-, identify common pitfalls, and reveal important differences in their breakpoint precisions. These results stress the importance of the sequencing strategy for the detection of structural variants, especially inversions, and offer guidelines for the design of future genome sequencing projects
13C-direct detected NMR experiments for the sequential J-based resonance assignment of RNA oligonucleotides
We present here a set of 13C-direct detected NMR experiments to facilitate the resonance assignment of RNA oligonucleotides. Three experiments have been developed: (1) the (H)CC-TOCSY-experiment utilizing a virtual decoupling scheme to assign the intraresidual ribose 13C-spins, (2) the (H)CPC-experiment that correlates each phosphorus with the C4β² nuclei of adjacent nucleotides via J(C,P) couplings and (3) the (H)CPC-CCH-TOCSY-experiment that correlates the phosphorus nuclei with the respective C1β²,H1β² ribose signals. The experiments were applied to two RNA hairpin structures. The current set of 13C-direct detected experiments allows direct and unambiguous assignment of the majority of the hetero nuclei and the identification of the individual ribose moieties following their sequential assignment. Thus, 13C-direct detected NMR methods constitute useful complements to the conventional 1H-detected approach for the resonance assignment of oligonucleotides that is often hindered by the limited chemical shift dispersion. The developed methods can also be applied to large deuterated RNAs
Effective Rheology of Bubbles Moving in a Capillary Tube
We calculate the average volumetric flux versus pressure drop of bubbles
moving in a single capillary tube with varying diameter, finding a square-root
relation from mapping the flow equations onto that of a driven overdamped
pendulum. The calculation is based on a derivation of the equation of motion of
a bubble train from considering the capillary forces and the entropy production
associated with the viscous flow. We also calculate the configurational
probability of the positions of the bubbles.Comment: 4 pages, 1 figur
Sarco/Endoplasmic Reticulum Ca2+-ATPases (SERCA) Contribute to GPCR-Mediated Taste Perception
The sense of taste is important for providing animals with valuable information about the qualities of food, such as nutritional or harmful nature. Mammals, including humans, can recognize at least five primary taste qualities: sweet, umami (savory), bitter, sour, and salty. Recent studies have identified molecules and mechanisms underlying the initial steps of tastant-triggered molecular events in taste bud cells, particularly the requirement of increased cytosolic free Ca2+ concentration ([Ca2+]c) for normal taste signal transduction and transmission. Little, however, is known about the mechanisms controlling the removal of elevated [Ca2+]c from the cytosol of taste receptor cells (TRCs) and how the disruption of these mechanisms affects taste perception. To investigate the molecular mechanism of Ca2+ clearance in TRCs, we sought the molecules involved in [Ca2+]c regulation using a single-taste-cell transcriptome approach. We found that Serca3, a member of the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) family that sequesters cytosolic Ca2+ into endoplasmic reticulum, is exclusively expressed in sweet/umami/bitter TRCs, which rely on intracellular Ca2+ release for signaling. Serca3-knockout (KO) mice displayed significantly increased aversive behavioral responses and greater gustatory nerve responses to bitter taste substances but not to sweet or umami taste substances. Further studies showed that Serca2 was mainly expressed in the T1R3-expressing sweet and umami TRCs, suggesting that the loss of function of Serca3 was possibly compensated by Serca2 in these TRCs in the mutant mice. Our data demonstrate that the SERCA family members play an important role in the Ca2+ clearance in TRCs and that mutation of these proteins may alter bitter and perhaps sweet and umami taste perception
Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV
The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of βs = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pTβ₯20 GeV and pseudorapidities {pipe}Ξ·{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}Ξ·{pipe}<0. 8) for jets with 60β€pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2β€{pipe}Ξ·{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. Β© 2013 CERN for the benefit of the ATLAS collaboration
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