4,225 research outputs found
Enabling Personalized Composition and Adaptive Provisioning of Web Services
The proliferation of interconnected computing devices is fostering the emergence of environments where Web services made available to mobile users are a commodity. Unfortunately, inherent limitations of mobile devices still hinder the seamless access to Web services, and their use in supporting complex user activities. In this paper, we describe the design and implementation of a distributed, adaptive, and context-aware framework for personalized service composition and provisioning adapted to mobile users. Users specify their preferences by annotating existing process templates, leading to personalized service-based processes. To cater for the possibility of low bandwidth communication channels and frequent disconnections, an execution model is proposed whereby the responsibility of orchestrating personalized processes is spread across the participating services and user agents. In addition, the execution model is adaptive in the sense that the runtime environment is able to detect exceptions and react to them according to a set of rules
Frozen shuffle update for an asymmetric exclusion process on a ring
We introduce a new rule of motion for a totally asymmetric exclusion process
(TASEP) representing pedestrian traffic on a lattice. Its characteristic
feature is that the positions of the pedestrians, modeled as hard-core
particles, are updated in a fixed predefined order, determined by a phase
attached to each of them. We investigate this model analytically and by Monte
Carlo simulation on a one-dimensional lattice with periodic boundary
conditions. At a critical value of the particle density a transition occurs
from a phase with `free flow' to one with `jammed flow'. We are able to
analytically predict the current-density diagram for the infinite system and to
find the scaling function that describes the finite size rounding at the
transition point.Comment: 16 page
Long-term weight loss maintenance and management following a VLCD: a 3-year outcome.
Background: Effective weight loss treatment is important as obesity has severe health and socioeconomic repercussions. Emerging evidence suggests that rapid initial weight loss results in better long-term weight loss maintenance. This remains controversial and contradicts current recommendations for slower weight loss. Aim: To determine the effect of a very low calorie diet (VLCD) with group-based behaviour therapy on weight loss and long-term weight management by means of a retrospective database analysis. Methods: Data for this retrospective analysis included participants who embarked on the LighterLife Total VLCD programme between 2007 and 2010, and whose weights at baseline and at least 12 months were available (n = 5965). Results: Data were available for 5965 individuals at 1 year, 2044 at 2 years and 580 at 3 years. At baseline, the majority of individuals were Caucasian (n = 5155), female (n = 5419), â„ 40 years old (n = 4272), 49% were within the body mass index (BMI) range of 30-35 kg/m2 while 51% had a BMI > 35 kg/m2. The average initial weight of the whole cohort was 99.1 kg (SD 16.6). Initial weight and BMI at entry onto programme, as well as numbers of weeks of weight loss were all significantly associated with weight loss achieved on the first weight loss attempt. Weight lost during the initial weight loss phase was the only factor, which was significantly associated with percentage weight loss maintenance for years 1, 2, and 3. Conclusion: The findings of this retrospective analysis suggest that provided a longer term weight loss management programme is adhered to, large amounts of initial weight loss can result in important longer term weight loss maintenance in motivated individuals
Multi-year longitudinal profiles of cortisol and corticosterone recovered from baleen of North Atlantic right whales (Eubalaena glacialis)
© The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in General and Comparative Endocrinology 254 (2017): 50-59, doi:10.1016/j.ygcen.2017.09.009.Research into stress physiology of mysticete whales has been hampered by difficulty in
obtaining repeated physiological samples from individuals over time. We investigated whether
multi-year longitudinal records of glucocorticoids can be reconstructed from serial sampling
along full-length baleen plates (representing ~10 years of baleen growth), using baleen recovered
from two female North Atlantic right whales (Eubalaena glacialis) of known reproductive
history. Cortisol and corticosterone were quantified with immunoassay of subsamples taken
every 4 cm (representing ~60 d time intervals) along a full-length baleen plate from each female.
In both whales, corticosterone was significantly elevated during known pregnancies (inferred
from calf sightings and necropsy data) as compared to intercalving intervals; cortisol was
significantly elevated during pregnancies in one female but not the other. Within intercalving
intervals, corticosterone was significantly elevated during the first year (lactation year) and/or
the second year (post-lactation year) as compared to later years of the intercalving interval, while
cortisol showed more variable patterns. Cortisol occasionally showed brief high elevations
(âspikesâ) not paralleled by corticosterone, suggesting that the two glucocorticoids might be
differentially responsive to certain stressors. Generally, immunoreactive corticosterone was
present in higher concentration in baleen than immunoreactive cortisol; corticosterone:cortisol
ratio was usually >4 and was highly variable in both individuals. Further investigation of baleen
cortisol and corticosterone profiles could prove fruitful for elucidating long-term, multi-year
patterns in stress physiology of large whales, determined retrospectively from stranded or
archived specimens.This work was supported by the Eppley Foundation for Research, the NOAA Marine Mammal
Health and Stranding Program, the Woods Hole Oceanographic Institution Ocean Life Institute,
and the New England Aquarium
Longitudinal progesterone profiles in baleen from female North Atlantic right whales (Eubalaena glacialis) match known calving history
© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Conservation Physiology 4 (2016): cow014, doi:10.1093/conphys/cow014.Reproduction of mysticete whales is difficult to monitor, and basic parameters, such as pregnancy rate and inter-calving interval, remain unknown for many populations. We hypothesized that baleen plates (keratinous strips that grow downward from the palate of mysticete whales) might record previous pregnancies, in the form of high-progesterone regions in the sections of baleen that grew while the whale was pregnant. To test this hypothesis, longitudinal baleen progesterone profiles from two adult female North Atlantic right whales (Eubalaena glacialis) that died as a result of ship strike were compared with dates of known pregnancies inferred from calf sightings and post-mortem data. We sampled a full-length baleen plate from each female at 4â
cm intervals from base (newest baleen) to tip (oldest baleen), each interval representing âŒ60â
days of baleen growth, with high-progesterone areas then sampled at 2 or 1â
cm intervals. Pulverized baleen powder was assayed for progesterone using enzyme immunoassay. The date of growth of each sampling location on the baleen plate was estimated based on the distance from the base of the plate and baleen growth rates derived from annual cycles of stable isotope ratios. Baleen progesterone profiles from both whales showed dramatic elevations (two orders of magnitude higher than baseline) in areas corresponding to known pregnancies. Baleen hormone analysis shows great potential for estimation of recent reproductive history, inter-calving interval and general reproductive biology in this species and, possibly, in other mysticete whales.This work was supported by the Eppley Foundation for Research, the National Oceanographic and Atmospheric Administration Marine Mammal Health and Stranding Program and the Woods Hole Oceanographic Institution Ocean Life Institute
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Compositional and entropy indirect noise generated in subsonic non-isentropic nozzles
Abstract
Gonville and Caius College;
EPSRC/DTA studentship (University of Cambridge);
Qualcomm/DTA Studentship;
Royal Academy of Engineering Research Fellowships Scheme;
EPSRC grant EP/K02924X/
Realistic following behaviors for crowd simulation
International audienceWhile walking through a crowd, a pedestrian experiences a large number of interactions with his neighbors. The nature of these interactions is varied, and it has been observed that macroscopic phenomena emerge from the combination of these local interactions. Crowd models have hitherto considered collision avoidance as the unique type of interactions between individuals, few have considered walking in groups. By contrast, our paper focuses on interactions due to the following behaviors of pedestrians. Following is frequently observed when people walk in corridors or when they queue. Typical macroscopic stop-and-go waves emerge under such traffic conditions. Our contributions are, first, an experimental study on following behaviors, second, a numerical model for simulating such interactions, and third, its calibration, evaluation and applications. Through an experimental approach, we elaborate and calibrate a model from microscopic analysis of real kinematics data collected during experiments. We carefully evaluate our model both at the microscopic and the macroscopic levels. We also demonstrate our approach on applications where following interactions are prominent
Inverse Compton Scenarios for the TeV Gamma-Ray Emission of the Galactic Centre
The intense Compton cooling of ultra-relativistic electrons in the
Klein-Nishina regime in radiation dominated environments, such as that found in
the Galactic Centre, may result in radically different electron spectra than
those produced by Synchrotron cooling. We explore these effects and their
impact on the X-ray and gamma-ray spectra produced in electron accelerators in
this region in comparison to elsewhere in our galaxy. We discuss the broad-band
emission expected from the newly discovered pulsar wind nebula G 359.95-0.04
and the possible relationship of this X-ray source to the central TeV gamma-ray
source HESS J1745-290. Finally we discuss the possible relationship of the
Galactic Centre INTEGRAL source IGR J1745.6-2901 to the TeV emission.Comment: 10 pages, 7 figures, to appear in ApJ 65
Accurate calibration of test mass displacement in the LIGO interferometers
We describe three fundamentally different methods we have applied to
calibrate the test mass displacement actuators to search for systematic errors
in the calibration of the LIGO gravitational-wave detectors. The actuation
frequencies tested range from 90 Hz to 1 kHz and the actuation amplitudes range
from 1e-6 m to 1e-18 m. For each of the four test mass actuators measured, the
weighted mean coefficient over all frequencies for each technique deviates from
the average actuation coefficient for all three techniques by less than 4%.
This result indicates that systematic errors in the calibration of the
responses of the LIGO detectors to differential length variations are within
the stated uncertainties.Comment: 10 pages, 6 figures, submitted on 31 October 2009 to Classical and
Quantum Gravity for the proceedings of 8th Edoardo Amaldi Conference on
Gravitational Wave
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