14,664 research outputs found
Which interval is most crucial to presentation and survival in gastroesophageal cancer: a systematic review
Aim: The aim of this study was to identify the most crucial interval to encourage earlier diagnosis in with gastroesophageal cancer and to identify potential factors effecting this interval. Background: Gastroesophageal malignancy is the eighth most commonly presenting cancer with one of the worst survival rates. Identifying the most crucial period for intervention to inform earlier diagnosis is an important step towards improving survival. Design: Mixed methods literature review. Data Sources: CINAHL, MEDLINE and Academic search primer online databases were searched using keywords and inclusion/exclusion criteria. Empirical evidence published between 2000–2016 with a focus on gastroesophageal cancer presentation and survival was reviewed to inform this study. Review methods: Twelve studies were extracted for further review. Selected studies were appraised and presented through Olensen's “delay interval” framework to inform the most crucial interval to survival in gastroesophageal cancer. Results: The findings identify the patient interval as the most critical period for encouraging earlier presentation and reducing advanced stage presentation in gastroesophageal cancer. The article also highlighted some methodological limitations to cancer research, such as a lack of consensus in definitions which prevent statistical meta-analysis of cancer data, survivor bias in gastroesophageal cancer studies and a significant lack of qualitative evidence to reveal patient experience in presenting with this cancer. Conclusion: Further research into the patient interval is required to elicit information on how and why patients present with their cancer symptoms
I/O Schedulers for Proportionality and Stability on Flash-Based SSDs in Multi-Tenant Environments
The use of flash based Solid State Drives (SSDs) has expanded rapidly into the cloud computing environment. In cloud computing, ensuring the service level objective (SLO) of each server is the major criterion in designing a system. In particular, eliminating performance interference among virtual machines (VMs) on shared storage is a key challenge. However, studies on SSD performance to guarantee SLO in such environments are limited. In this paper, we present analysis of I/O behavior for a shared SSD as storage in terms of proportionality and stability. We show that performance SLOs of SSD based storage systems being shared by VMs or tasks are not satisfactory. We present and analyze the reasons behind the unexpected behavior through examining the components of SSDs such as channels, DRAM buffer, and Native Command Queuing (NCQ). We introduce two novel SSD-aware host level I/O schedulers on Linux, called A & x002B;CFQ and H & x002B;BFQ, based on our analysis and findings. Through experiments on Linux, we analyze I/O proportionality and stability in multi-tenant environments. In addition, through experiments using real workloads, we analyze the performance interference between workloads on a shared SSD. We then show that the proposed I/O schedulers almost eliminate the interference effect seen in CFQ and BFQ, while still providing I/O proportionality and stability for various I/O weighted scenarios
Being Knowledgeable of Sociable?: Differences in Relative Importance of Cognitive and Non-Cognitive Skills
This paper develops a model of college admissions that emphasizes their role as a human capital evaluation method. Given multiple dimensions of human capital, di¤erent pattens of human capital evaluation and develpment emerge as equilibria. These equilibria with a varying emphasis on di¤erent aspects of human capital can match an observed di¤erence in college admission patterns between East Asian countries and the U.S. The model has a macroeconomic implication about the relationship between measured human capital and economic performances. We demonstrate the support for this implication through cross-country regressions.
Distribution of Caustic-Crossing Intervals for Galactic Binary-Lens Microlensing Events
Detection of caustic crossings of binary-lens gravitational microlensing
events is important because by detecting them one can obtain useful information
both about the lens and source star. In this paper, we compute the distribution
of the intervals between two successive caustic crossings, , for
Galactic bulge binary-lens events to investigate the observational strategy for
the optimal detection and resolution of caustic crossings. From this
computation, we find that the distribution is highly skewed toward short
and peaks at days. For the maximal detection
of caustic crossings, therefore, prompt initiation of followup observations for
intensive monitoring of events will be important. We estimate that under the
strategy of the current followup observations with a second caustic-crossing
preparation time of days, the fraction of events with resolvable
caustic crossing is . We find that if the followup observations can
be initiated within 1 day after the first caustic crossing by adopting more
aggressive observational strategies, the detection rate can be improved into
.Comment: total 6 pages, including 5 Figures and no Table, submitted to MNRA
Role Playing Learning for Socially Concomitant Mobile Robot Navigation
In this paper, we present the Role Playing Learning (RPL) scheme for a mobile
robot to navigate socially with its human companion in populated environments.
Neural networks (NN) are constructed to parameterize a stochastic policy that
directly maps sensory data collected by the robot to its velocity outputs,
while respecting a set of social norms. An efficient simulative learning
environment is built with maps and pedestrians trajectories collected from a
number of real-world crowd data sets. In each learning iteration, a robot
equipped with the NN policy is created virtually in the learning environment to
play itself as a companied pedestrian and navigate towards a goal in a socially
concomitant manner. Thus, we call this process Role Playing Learning, which is
formulated under a reinforcement learning (RL) framework. The NN policy is
optimized end-to-end using Trust Region Policy Optimization (TRPO), with
consideration of the imperfectness of robot's sensor measurements. Simulative
and experimental results are provided to demonstrate the efficacy and
superiority of our method
Women’s leadership in local government in the Caribbean
Women and men are traditionally cast in different roles, with males being leaders in the workplace, home and government. In contrast, communities promote women as caregivers who support male leaders and shape future generations as mothers, mentors and teachers. In recognition of this societal view of women that often led to inequality and inequity, the UNDP listed Gender Equality and empowering women as one of eight Millennium Development Goals. The post-2015 Sustainable Development Goals, adopted by the United Nations in autumn 2015, also included gender equality and empowering women as Goal 5.In its work in the Caribbean, the Caribbean Local Economic Development Project (CARILED) examined gender as it relates to micro, small and medium enterprise (MSME) development in six Caribbean countries. The findings of this study showed gender gaps for both male and female entrepreneurs in different areas of development. Traditionally gendered roles for MSME sectors, access to financing and lack of adequate guidance or community support were some areas that affected men and women differently in the region. The study outlines ways in which male and female leaders can address traditional gender roles by identifying priority areas for development, creating an enabling environment for start-ups and expansion, and fostering a policy and legislative base that facilitates ease of doing business. The recommendations further describe the public–private partnerships needed to successfully meet gender gaps, and the importance of both elected officials and technocrats in inter alia community engagement and advocacy towards local economic development.The importance of gender equality among elected officials and technocrats, and the influence gender has on determining priority areas of focus within local government strategic plans for communities are also set out within this paper.
Origin of Negative Density and Modulus in Acoustic Metamaterials
This paper provides a review and fundamental physical interpretation for the
effective densities and moduli of acoustic metamaterials. We introduce the
terminology of hidden force and hidden source of volume: the effective density
or modulus is negative when the hidden force or source of volume is larger
than, and operates in antiphase to, respectively, the force or volume change
that would be obtained in their absence. We demonstrate this ansatz for some
established acoustic metamaterials with elements based on membranes, Helmholtz
resonators, springs and masses. The hidden force for membrane-based acoustic
metamaterials, for instance, is the force from the membrane tension. The hidden
source for a Helmholtz-resonator-based metamaterial is the extra air volume
injected from the resonator cavity. We also explain the analogous concepts for
pure mass-and-spring systems, in which case hidden forces can arise from masses
and springs fixed inside other masses, whereas hidden sources - more aptly
termed hidden expanders of displacement in this case - can arise from light
rigid trusses coupled to extra degrees of freedom for mechanical motion such as
the case of coupling to masses that move at right angles to the
wave-propagation direction. This overall picture provides a powerful tool for
conceptual understanding and design of new acoustic metamaterials, and avoids
common pitfalls involved in determining the effective parameters of such
materials.Comment: 15 pages, 10 figure
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