13,304 research outputs found
Automating Carotid Intima-Media Thickness Video Interpretation with Convolutional Neural Networks
Cardiovascular disease (CVD) is the leading cause of mortality yet largely
preventable, but the key to prevention is to identify at-risk individuals
before adverse events. For predicting individual CVD risk, carotid intima-media
thickness (CIMT), a noninvasive ultrasound method, has proven to be valuable,
offering several advantages over CT coronary artery calcium score. However,
each CIMT examination includes several ultrasound videos, and interpreting each
of these CIMT videos involves three operations: (1) select three end-diastolic
ultrasound frames (EUF) in the video, (2) localize a region of interest (ROI)
in each selected frame, and (3) trace the lumen-intima interface and the
media-adventitia interface in each ROI to measure CIMT. These operations are
tedious, laborious, and time consuming, a serious limitation that hinders the
widespread utilization of CIMT in clinical practice. To overcome this
limitation, this paper presents a new system to automate CIMT video
interpretation. Our extensive experiments demonstrate that the suggested system
significantly outperforms the state-of-the-art methods. The superior
performance is attributable to our unified framework based on convolutional
neural networks (CNNs) coupled with our informative image representation and
effective post-processing of the CNN outputs, which are uniquely designed for
each of the above three operations.Comment: J. Y. Shin, N. Tajbakhsh, R. T. Hurst, C. B. Kendall, and J. Liang.
Automating carotid intima-media thickness video interpretation with
convolutional neural networks. CVPR 2016, pp 2526-2535; N. Tajbakhsh, J. Y.
Shin, R. T. Hurst, C. B. Kendall, and J. Liang. Automatic interpretation of
CIMT videos using convolutional neural networks. Deep Learning for Medical
Image Analysis, Academic Press, 201
Ethical difficulties in clinical practice : experiences of European doctors
Background: Ethics support services are growing in Europe to help doctors in dealing with ethical difficulties.
Currently, insufficient attention has been focused on the experiences of doctors who have faced ethical
difficulties in these countries to provide an evidence base for the development of these services.
Methods: A survey instrument was adapted to explore the types of ethical dilemma faced by European
doctors, how they ranked the difficulty of these dilemmas, their satisfaction with the resolution of a recent
ethically difficult case and the types of help they would consider useful. The questionnaire was translated and
given to general internists in Norway, Switzerland, Italy and the UK.
Results: Survey respondents (n = 656, response rate 43%) ranged in age from 28 to 82 years, and averaged
25 years in practice. Only a minority (17.6%) reported having access to ethics consultation in individual
cases. The ethical difficulties most often reported as being encountered were uncertain or impaired decisionmaking
capacity (94.8%), disagreement among caregivers (81.2%) and limitation of treatment at the end of
life (79.3%). The frequency of most ethical difficulties varied among countries, as did the type of issue
considered most difficult. The types of help most often identified as potentially useful were professional
reassurance about the decision being correct (47.5%), someone capable of providing specific advice
(41.1%), help in weighing outcomes (36%) and clarification of the issues (35.9%). Few of the types of help
expected to be useful varied among countries.
Conclusion: Cultural differences may indeed influence how doctors perceive ethical difficulties. The type of
help needed, however, did not vary markedly. The general structure of ethics support services would not have
to be radically altered to suit cultural variations among the surveyed countries
The Employment, Unemployment and Unemployment Compensation Benefits of Immigrants
This report analyzes the employment and unemployment experiences of adult foreign-born
men, both among themselves and in comparison with the native born. The empirical analysis
uses microdata from the 1990 Census of Population. Three dependent variables are
analyzed, weeks worked (employment) in 1989, unemployment status in the reference week
in 1990, and a proxy measure of unemployment compensation benefits received in 1989.
The theoretical model focuses on the job search behavior of the foreign born within the
context of an immigrant adjustment model based on the imperfect transferability of skills and
labor market information acquired prior to immigration. In particular, the model focuses on
the effects on employment and unemployment of schooling, labor market experience, marital
status and the agricultural sector, in addition to English language fluency and country of
origin. The hypotheses developed from the model are found to be consistent with the data.
Employment is significantly lower, and unemployment is significantly higher, among the
foreign born in the U.S. for three or fewer years, but then reaches a level after which there is
little variation by duration of residence. Unemployment problems associated with immigrants
appear to be short-term transitional adjustments
Abradable compressor and turbine seals, volume 2
The applications and advantages of abradable coatings as gas path seals in a general aviation turbofan engine were investigated. Abradable materials were evaluated for the high pressure radial compressor and the axial high and low pressure turbine shrouds
The Unfinished Business of Mutual Fund Reform
The need for further mutual fund reform remains in two major areas. First, there is a need for greater and more effective disclosure of fund charges and greater transparency in the manner in which funds operate. While it is probably overly optimistic to expect that this will make a dramatic difference in investors\u27 preferences for one fund over another, at least it will make it possible for the investor who does care about costs and conflicts of interest to determine how efficiently a particular fund is managed vis-a-vis its competitors. A generation ago, funds with a front end sales load averaging 6% was the norm. Due to increasing publicity and competitive pressures, the no-load fund has replaced the load fund as the norm in the fund industry. Also, the increasing popularity of index funds and ETFs, while still not a majority of fund sales, shows that there are, in fact, investors who are sensitive to the importance of mutual fund expenses and sales charges as an important component of a fund\u27s long-term relative performance. Further education and disclosure, through both the financial press and fund prospectuses, should increase the pressure on funds to operate efficiently and in furtherance of the fiduciary duty which they owe to their investors.
Second, in order to protect less sophisticated investors from being sold unsuitable funds with high fees and mediocre performance, the need exists for the strengthening of fiduciary duties owed by fund managers and financial advisors to ensure that they put investors\u27 interests ahead of their own. With the defined contribution retirement plan rapidly becoming the primary vehicle for retirement savings for millions of individuals, the need for strong and effective mutual fund regulation now is more compelling than it has ever been
Abradable compressor and turbine seals, volume 1
The application and advantages of abradable coatings as gas-path seals in a general aviation turbine engine were evaluated for use on the high-pressure compressor, the high-pressure turbine, and the low-pressure turbine shrouds. Topics covered include: (1) the initial selection of candidate materials for interim full-scale engine testing; (2) interim engine testing of the initially selected materials and additional candidate materials; (3) the design of the component required to adapt the hardware to permit full-scale engine testing of the most promising materials; (4) finalization of the fabrication methods used in the manufacture of engine test hardware; and (5) the manufacture of the hardware necessary to support the final full-scale engine tests
The structural and diagenetic evolution of injected sandstones: examples from the Kimmeridgian of NE Scotland
Abstract: Injected sandstones occurring in the Kimmeridgian of NE Scotland along the bounding Great Glen
and Helmsdale faults formed when basinal fluids moved upward along the fault zones, fluidizing Oxfordian
sands encountered at shallow depth and injecting them into overlying Kimmeridgian strata. The orientation of
dykes, in addition to coeval faults and fractures, was controlled by a stress state related to dextral strike-slip
along the bounding fault zones. Diagenetic studies of cements allow the reconstruction of the fluid flow
history. The origin of deformation bands in sandstone dykes and sills was related to the contraction of the
host-rocks against dyke and sill walls following the initial stage of fluidized flow, and these deformation bands
are the earliest diagenetic imprint. Early non-ferroan calcite precipitated in injection structures at temperatures
between 70 and 100 8C, indicating that it precipitated from relatively hot basinal fluids that drove injection.
Coeval calcite-filled fractures show similar temperatures, suggesting that relatively hot fluids were responsible
for calcite precipitation in any permeable pathway created by dextral simple shear along the faults. During
progressive burial, percolating sea water was responsible for completely cementing the still relatively porous
injected sandstones with a second generation of ferroan calcite, which contains fluid inclusions with
homogenization temperatures below 50 8C. During this phase, depositional host sandstones were also
cemented
Extreme value statistics and return intervals in long-range correlated uniform deviates
We study extremal statistics and return intervals in stationary long-range
correlated sequences for which the underlying probability density function is
bounded and uniform. The extremal statistics we consider e.g., maximum relative
to minimum are such that the reference point from which the maximum is measured
is itself a random quantity. We analytically calculate the limiting
distributions for independent and identically distributed random variables, and
use these as a reference point for correlated cases. The distributions are
different from that of the maximum itself i.e., a Weibull distribution,
reflecting the fact that the distribution of the reference point either
dominates over or convolves with the distribution of the maximum. The
functional form of the limiting distributions is unaffected by correlations,
although the convergence is slower. We show that our findings can be directly
generalized to a wide class of stochastic processes. We also analyze return
interval distributions, and compare them to recent conjectures of their
functional form
Growth to early adulthood following extremely preterm birth: the EPICure study.
OBJECTIVE: To investigate growth trajectories from age 2.5 to 19 years in individuals born before 26 weeks of gestation (extremely preterm; EP) compared with term-born controls. METHODS: Multilevel modelling of growth data from the EPICure study, a prospective 1995 birth cohort of 315 EP participants born in the UK and Ireland and 160 term-born controls recruited at school age. Height, weight, head circumference and body mass index (BMI) z-scores were derived from UK standards at ages 2.5, 6, 11 and 19 years. RESULTS: 129 (42%) EP children were assessed at 19 years. EP individuals were on average 4.0 cm shorter and 6.8 kg lighter with a 1.5 cm smaller head circumference relative to controls at 19 years. Relative to controls, EP participants grew faster in weight by 0.06 SD per year (95% CI 0.05 to 0.07), in head circumference by 0.04 SD (95% CI 0.03 to 0.05), but with no catch-up in height. For the EP group, because of weight catch-up between 6 and 19 years, BMI was significantly elevated at 19 years to +0.32 SD; 23.4% had BMI >25 kg/m2 and 6.3% >30 kg/m2 but these proportions were similar to those in control subjects. EP and control participants showed similar pubertal development in early adolescence, which was not associated with height at 19 years in either study group. Growth through childhood was related to birth characteristics and to neonatal feeding practices. CONCLUSIONS: EP participants remained shorter and lighter and had smaller head circumferences than reference data or controls in adulthood but had elevated BMI
Detection of Noble Gas Scintillation Light with Large Area Avalanche Photodiodes (LAAPDs)
Large Area Avalanche Photodiodes (LAAPDs) were used for a series of
systematic measurements of the scintillation light in Ar, Kr, and Xe gas.
Absolute quantum efficiencies are derived. Values for Xe and Kr are consistent
with those given by the manufacturer. For the first time we show that argon
scintillation (128 nm) can be detected at a quantum efficiency above 40%.
Low-pressure argon gas is shown to emit significant amounts of non-UV
radiation. The average energy expenditure for the creation of non-UV photons in
argon gas at this pressure is measured to be below 378 eV.Comment: 16 pages, 7 figure
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