883 resultados para First-line


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We present our approach to real-time service-oriented scheduling problems with the objective of maximizing the total system utility. Different from the traditional utility accrual scheduling problems that each task is associated with only a single time utility function (TUF), we associate two different TUFs—a profit TUF and a penalty TUF—with each task, to model the real-time services that not only need to reward the early completions but also need to penalize the abortions or deadline misses. The scheduling heuristics we proposed in this paper judiciously accept, schedule, and abort real-time services when necessary to maximize the accrued utility. Our extensive experimental results show that our proposed algorithms can significantly outperform the traditional scheduling algorithms such as the Earliest Deadline First (EDF), the traditional utility accrual (UA) scheduling algorithms, and an earlier scheduling approach based on a similar model.

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A two-dimensional, 2D, finite-difference time-domain (FDTD) method is used to analyze two different models of multi-conductor transmission lines (MTL). The first model is a two-conductor MTL and the second is a threeconductor MTL. Apart from the MTL's, a three-dimensional, 3D, FDTD method is used to analyze a three-patch microstrip parasitic array. While the MTL analysis is entirely in time-domain, the microstrip parasitic array is a study of scattering parameter Sn in the frequency-domain. The results clearly indicate that FDTD is an efficient and accurate tool to model and analyze multiconductor transmission line as well as microstrip antennas and arrays.

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Aims The pubococcygeal line (PCL) is an important reference line for determining measures of pelvic organ support on sagittal-plane magnetic resonance imaging (MRI); however, there is no consensus on where to place the posterior point of the PCL. As coccyx movement produced during pelvic floor muscle (PFM) contractions may affect other measures, optimal placement of the posterior point is important. This study compared two methods for measuring the PCL, with different posterior points, on T2-weighted sagittal MRI to determine the effect of coccygeal movement on measures of pelvic organ support in older women. Methods MRI of the pelvis was performed in the midsagittal plane, at rest and during PFM contractions, on 47 community-dwelling women 60 and over. The first PCL was measured to the tip of the coccyx (PCLtip) and the second to the sacrococcygeal joint (PCLjnt). Four measures of pelvic organ support were made using each PCL as the reference line: urethrovesical junction height, uterovaginal junction height, M-line and levator plate angle. Results During the PFM contraction the PCLtip shortened and lifted (P < 0.001); the PCLjnt did not change (P > 0.05). The changes in the four measures of pelvic organ support were smaller when measured relative to the PCLtip as compared to those to the PCLjnt (P < 0.001). Conclusions Coccyx movement affected the length and position of the PCLtip, which resulted in underestimates of the pelvic-organ lift produced by the PFM contraction. Therefore, we recommend that the PCL be measured to the sacrococcygeal joint and not to the tip of the coccyx

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Context: The stellar population of the 30 Doradus star-forming region in the Large Magellanic Cloud contains a subset of apparently single, rapidly rotating O-type stars. The physical processes leading to the formation of this cohort are currently uncertain. 

Aims: One member of this group, the late O-type star VFTS 399, is found to be unexpectedly X-ray bright for its bolometric luminosity-in this study we aim to determine its physical nature and the cause of this behaviour. 

Methods: To accomplish this we performed a time-resolved analysis of optical, infrared and X-ray observations. 

Results: We found VFTS 399 to be an aperiodic photometric variable with an apparent near-IR excess. Its optical spectrum demonstrates complex emission profiles in the lower Balmer series and select He i lines-taken together these suggest an OeBe classification. The highly variable X-ray luminosity is too great to be produced by a single star, while the hard, non-thermal nature suggests the presence of an accreting relativistic companion. Finally, the detection of periodic modulation of the X-ray lightcurve is most naturally explained under the assumption that the accretor is a neutron star. 

Conclusions: VFTS 399 appears to be the first high-mass X-ray binary identified within 30 Dor, sharing many observational characteristics with classical Be X-ray binaries. Comparison of the current properties of VFTS 399 to binary-evolution models suggests a progenitor mass 25 M for the putative neutron star, which may host a magnetic field comparable in strength to those of magnetars. VFTS 399 is now the second member of the cohort of rapidly rotating "single" O-type stars in 30 Dor to show evidence of binary interaction resulting in spin-up, suggesting that this may be a viable evolutionary pathway for the formation of a subset of this stellar population.

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We report the discovery, tracking, and detection circumstances for 85 trans-Neptunian objects (TNOs) from the first 42 deg2 of the Outer Solar System Origins Survey. This ongoing r-band solar system survey uses the 0.9 deg2 field of view MegaPrime camera on the 3.6 m Canada–France–Hawaii Telescope. Our orbital elements for these TNOs are precise to a fractional semimajor axis uncertainty <0.1%. We achieve this precision in just two oppositions, as compared to the normal three to five oppositions, via a dense observing cadence and innovative astrometric technique. These discoveries are free of ephemeris bias, a first for large trans-Neptunian surveys. We also provide the necessary information to enable models of TNO orbital distributions to be tested against our TNO sample. We confirm the existence of a cold "kernel" of objects within the main cold classical Kuiper Belt and infer the existence of an extension of the "stirred" cold classical Kuiper Belt to at least several au beyond the 2:1 mean motion resonance with Neptune. We find that the population model of Petit et al. remains a plausible representation of the Kuiper Belt. The full survey, to be completed in 2017, will provide an exquisitely characterized sample of important resonant TNO populations, ideal for testing models of giant planet migration during the early history of the solar system.

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Small businesses form a significant share of all businesses and employ a large share of all employees. Therefore, governments are often interested in subsidizing them and especially employment in smaller firms. Nonemployer firms have received special interest, especially in Finland, due to their large share of all businesses. It has been argued that the government should encourage them to hire by subsidizing employment. However, there is no evidence on the effectiveness of such policies. In general, there is surprisingly little evidence on how small firms react to employment subsidies or of employment subsidies targeted according to firm characteristics. The subject of this thesis is the effects of subsidizing the first employee. While theoretical background suggests the subsidy might have efficiency gains, because there might be market inefficiencies that lead to too little employment in small firms. The focus of this research, however, is on the empirical evidence. There was a regional subsidy for hiring the first employee in Finland between 2007 and 2011. Nonemployer firms in the subsidy area were eligible for a wage subsidy for two years when they hired the first employee. The design of the subsidy enables studying the effects in a natural experiment framework that are nowadays popular in public economics. It can be shown that the area without the subsidy provides a good counterfactual to the area where the subsidy was available. Therefore, the effects of the subsidy can be estimated with difference-in-differences method. This method compares the change in the subsidy area to the change in the area without the subsidy. The data used is firm level data spanning from 2000 to 2013. The data is provided by the Finnish Tax Administration including tax declarations by all Finland based companies. The effects for hiring decisions are estimated by examining the effects for alternative variables such as employment, wage expenditure and turnover. According to the results, the subsidy did not have statistically significant effect on any of the variables of interest. Therefore, it can be concluded that the subsidy did not increase hires in nonemployer firms. This implies that the labour demand elasticity of nonemployer firms is very small. The results are in line with previous literature on the effectiveness of general employment subsidies in Scandinavia that suggest that labour demand elasticity is rather small resulting in small or no effects of employment subsidies. However, my research provides new evidence on labour demand of nonemployer firms especially that has not been studied before. The results are in line with the observation that most nonemployer firms are self-employed persons who are not interested in growing their business to employ others as well, but only provide for themselves. Because of this employment subsidies to the self-employed are not particularly well targeted. The theoretical grounds for the subsidy actually hold for other small firms as well, so it can be argued the subsidy would be more effective if it was extended for hiring the first few employees.

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Like many other higher educat ion schools, ISCAP`s population has grown at a rate of almost 100% in the end of the twentieth century. Its administrative structures were reinforced, but it was not in the same proportion. Face to face with the inability to resolve the problem, the administration decided to implement a computer based system, available in the Internet. In a first stage, in 1997, the system was implemented as a services support. The next stage, in 1999, proposes to increase student services quality. A project that aims to bring student services available on the Internet begins to be developed.

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Background: Wheat 1BL/1RS translocation lines are planted around the world for their disease resistance and high yield. Most of them are poor in bread making, which is partially caused by ω-secalins that are encoded by the ω-secalin gene family, which is located on the short arm of rye chromosome 1R (1RS). However, information on the structure and evolution of the ω-secalin gene family is still limited. Results: We first generated a physicalmap of the ω-secalin gene family covering 195 kb of the Sec-1 locus based on sequencing three bacterial artificial chromosome (BAC) clones of the 1BL/1RS translocation wheat cultivar Shimai 15. A BAC contig was constructed spanning 168 kb of the Sec-1 locus on 1RS. Twelve ω-secalin genes were arranged in a head-to-tail fashion, separated by 8.2–21.6 kb spacers on the contig, whereas six other ω-secalin genes were arranged head-to-tail, separated by 8.2–8.4 kb of spacers on clone BAC125. The 18 ω-secalin genes can be classified into six types among which eight ω-secalin genes were expressed during seed development. The ω-secalin genes with the 1074-bp open reading frame (ORF) represented the main population. Except for two pseudogenes, the N-terminal of the ω-secalin gene was conserved, whereas variations in the C-terminal led to a change in ORF length. The spacers can be sorted into two classes. Class-1 spacers contained conserved and non-conservative sequences. Conclusion: The ω-secalin gene family consisted of at least 18 members in the 1BL/1RS translocation line cv. Shimai 15. Eight ω-secalin genes were expressed during seed development. Eighteen members may originate from a progenitor with a 1,074-bp ORF. The spacers differed in length and sequence conservation.

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Aims The pubococcygeal line (PCL) is an important reference line for determining measures of pelvic organ support on sagittal-plane magnetic resonance imaging (MRI); however, there is no consensus on where to place the posterior point of the PCL. As coccyx movement produced during pelvic floor muscle (PFM) contractions may affect other measures, optimal placement of the posterior point is important. This study compared two methods for measuring the PCL, with different posterior points, on T2-weighted sagittal MRI to determine the effect of coccygeal movement on measures of pelvic organ support in older women. Methods MRI of the pelvis was performed in the midsagittal plane, at rest and during PFM contractions, on 47 community-dwelling women 60 and over. The first PCL was measured to the tip of the coccyx (PCLtip) and the second to the sacrococcygeal joint (PCLjnt). Four measures of pelvic organ support were made using each PCL as the reference line: urethrovesical junction height, uterovaginal junction height, M-line and levator plate angle. Results During the PFM contraction the PCLtip shortened and lifted (P < 0.001); the PCLjnt did not change (P > 0.05). The changes in the four measures of pelvic organ support were smaller when measured relative to the PCLtip as compared to those to the PCLjnt (P < 0.001). Conclusions Coccyx movement affected the length and position of the PCLtip, which resulted in underestimates of the pelvic-organ lift produced by the PFM contraction. Therefore, we recommend that the PCL be measured to the sacrococcygeal joint and not to the tip of the coccyx

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The current work aimed to study the antitumour activity of a phenolic extract of the edible mushroom Leccinum vulpinum Watling, rich essentially in hydroxybenzoic acids. In a first approach, the mushroom extract was tested against cancer cell growth by using four human tumour cell lines. Given the positive results obtained in these initial screening experiments and the evidence of some studies for an inverse relationship between mushroom consumption and breast cancer risk, a detailed study of the bioactivity of the extract was carried out on MCF-7 cells. Once the selected cell line to precede the work was the breast adenocarcinoma cell line, the human breast non-malignant cell line MCF-10A was used as control. Overall, the extract decreased cellular proliferation and induced apoptosis. Furthermore, the results also suggest that the extract causes cellular DNA damage. Data obtained highlight the potential of mushrooms as a source of biologically active compounds, particularly with antitumour activity.

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Despite the wide swath of applications where multiphase fluid contact lines exist, there is still no consensus on an accurate and general simulation methodology. Most prior numerical work has imposed one of the many dynamic contact-angle theories at solid walls. Such approaches are inherently limited by the theory accuracy. In fact, when inertial effects are important, the contact angle may be history dependent and, thus, any single mathematical function is inappropriate. Given these limitations, the present work has two primary goals: 1) create a numerical framework that allows the contact angle to evolve naturally with appropriate contact-line physics and 2) develop equations and numerical methods such that contact-line simulations may be performed on coarse computational meshes.

Fluid flows affected by contact lines are dominated by capillary stresses and require accurate curvature calculations. The level set method was chosen to track the fluid interfaces because it is easy to calculate interface curvature accurately. Unfortunately, the level set reinitialization suffers from an ill-posed mathematical problem at contact lines: a ``blind spot'' exists. Standard techniques to handle this deficiency are shown to introduce parasitic velocity currents that artificially deform freely floating (non-prescribed) contact angles. As an alternative, a new relaxation equation reinitialization is proposed to remove these spurious velocity currents and its concept is further explored with level-set extension velocities.

To capture contact-line physics, two classical boundary conditions, the Navier-slip velocity boundary condition and a fixed contact angle, are implemented in direct numerical simulations (DNS). DNS are found to converge only if the slip length is well resolved by the computational mesh. Unfortunately, since the slip length is often very small compared to fluid structures, these simulations are not computationally feasible for large systems. To address the second goal, a new methodology is proposed which relies on the volumetric-filtered Navier-Stokes equations. Two unclosed terms, an average curvature and a viscous shear VS, are proposed to represent the missing microscale physics on a coarse mesh.

All of these components are then combined into a single framework and tested for a water droplet impacting a partially-wetting substrate. Very good agreement is found for the evolution of the contact diameter in time between the experimental measurements and the numerical simulation. Such comparison would not be possible with prior methods, since the Reynolds number Re and capillary number Ca are large. Furthermore, the experimentally approximated slip length ratio is well outside of the range currently achievable by DNS. This framework is a promising first step towards simulating complex physics in capillary-dominated flows at a reasonable computational expense.

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BACKGROUND: In the Arkhangelsk region of Northern Russia, multidrug-resistant (MDR) tuberculosis (TB) rates in new cases are amongst the highest in the world. In 2014, MDR-TB rates reached 31.7% among new cases and 56.9% among retreatment cases. The development of new diagnostic tools allows for faster detection of both TB and MDR-TB and should lead to reduced transmission by earlier initiation of anti-TB therapy. STUDY AIM: The PROVE-IT (Policy Relevant Outcomes from Validating Evidence on Impact) Russia study aimed to assess the impact of the implementation of line probe assay (LPA) as part of an LPA-based diagnostic algorithm for patients with presumptive MDR-TB focusing on time to treatment initiation with time from first-care seeking visit to the initiation of MDR-TB treatment rather than diagnostic accuracy as the primary outcome, and to assess treatment outcomes. We hypothesized that the implementation of LPA would result in faster time to treatment initiation and better treatment outcomes.

METHODS: A culture-based diagnostic algorithm used prior to LPA implementation was compared to an LPA-based algorithm that replaced BacTAlert and Löwenstein Jensen (LJ) for drug sensitivity testing. A total of 295 MDR-TB patients were included in the study, 163 diagnosed with the culture-based algorithm, 132 with the LPA-based algorithm.

RESULTS: Among smear positive patients, the implementation of the LPA-based algorithm was associated with a median decrease in time to MDR-TB treatment initiation of 50 and 66 days compared to the culture-based algorithm (BacTAlert and LJ respectively, p<0.001). In smear negative patients, the LPA-based algorithm was associated with a median decrease in time to MDR-TB treatment initiation of 78 days when compared to the culture-based algorithm (LJ, p<0.001). However, several weeks were still needed for treatment initiation in LPA-based algorithm, 24 days in smear positive, and 62 days in smear negative patients. Overall treatment outcomes were better in LPA-based algorithm compared to culture-based algorithm (p = 0.003). Treatment success rates at 20 months of treatment were higher in patients diagnosed with the LPA-based algorithm (65.2%) as compared to those diagnosed with the culture-based algorithm (44.8%). Mortality was also lower in the LPA-based algorithm group (7.6%) compared to the culture-based algorithm group (15.9%). There was no statistically significant difference in smear and culture conversion rates between the two algorithms.

CONCLUSION: The results of the study suggest that the introduction of LPA leads to faster time to MDR diagnosis and earlier treatment initiation as well as better treatment outcomes for patients with MDR-TB. These findings also highlight the need for further improvements within the health system to reduce both patient and diagnostic delays to truly optimize the impact of new, rapid diagnostics.

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By means of evidence-based practice, this paper describes the residential-school component of an accredited online (distance education) undergraduate engineering program in Australia, with a particular focus on how the residential school program is implemented at freshman year. During these residential schools, activities were organised around the respective engineering courses undertaken by students during the semester. Elements considered suitable and worthwhile for inclusion in residential-school programs included: • In-person engagement with academic lecturers, • Practical and laboratory learning activities, • Presentations and interaction with guest speakers from industry, • Industry-based site visits, • Engagement in sole and group-based learning and assessment activities on campus, and • Social interaction with other students. After running pilot residential schools for two years, it was found that a workable format consisted in a two-week residential experience in the first semester, linked to two key freshman courses, Fundamentals of Technology Management, and Engineering Physics. On-campus and online students’ academic grades were compared for both courses over the years 2005 to 2012. We found that for physics lab, on-campus students’ grades tended to be higher than those for online students, and vice versa for technology management. We also conclude that when carefully designed, residential schools for online students do enhance learning for both online students and their on-campus counterparts.