2,778 research outputs found
Finite size scaling in neural networks
We demonstrate that the fraction of pattern sets that can be stored in
single- and hidden-layer perceptrons exhibits finite size scaling. This feature
allows to estimate the critical storage capacity \alpha_c from simulations of
relatively small systems. We illustrate this approach by determining \alpha_c,
together with the finite size scaling exponent \nu, for storing Gaussian
patterns in committee and parity machines with binary couplings and up to K=5
hidden units.Comment: 4 pages, RevTex, 5 figures, uses multicol.sty and psfig.st
Recommended from our members
Spring 1969
Design Features the Golfer Wants by Geoffrey S. Cornish & William G. Robinson (page 3) How Water Moves in the Soil by Walter H. Gardner (6) Course Care in Winter (8) Spray-on Protein Boosters by S. K. Ries (9) 1969 Turf Conference Program (12) How to Get More Benefits from Our Next Conference (13) Budget Control by Ken Voorhies (15) Turf Analysis Test by Dale Kern (18) Tolerance of Various Turfgrasses to Foliar Applications of Road Salt by W.E. Cordukes (22) He \u27Fitz\u27 the Bill by Gerry Finn (24
Recommended from our members
Fall 1970
How Water Moves in the Soil by Walter H. Gardner (page 3) Editorial (9) Turf Bulletin\u27s Photo Quiz by Fred Cheney (9) Public Relations by Marlin Ball (10) Turf Bulletin\u27s Photo Quiz Answer (11) Climate in the \u2770\u27s by James E. Newman (12) Know Your Seed--Ideas about Seed Quality by A.S. Carter (15)Seed Prices and Handling by Dwight M. Brown (16) Factors influencing Effectiveness of Two Surfactants on Water Repellent Soils by M.A. Mustafa and J. Letey (21
Before the Pandemic Ends: Making Sure This Never Happens Again
Introduction
On 30 January 2020, the World Health Organization (WHO) declared a Global Health Emergency of international concern attendant to the emergence and spread of SARS-CoV-2, nearly two months after the first reported emergence of human cases in Wuhan, China. In the subsequent two months, global, national and local health personnel and infrastructures have been overwhelmed, leading to suffering and death for infected people, and the threat of socio-economic instability and potential collapse for humanity as a whole. This shows that our current and traditional mode of coping, anchored in responses after the fact, is not capable of dealing with the crisis of emerging infectious disease. Given all of our technological expertise, why is there an emerging disease crisis, and why are we losing the battle to contain and diminish emerging diseases?
Part of the reason is that the prevailing paradigm explaining the biology of pathogen-host associations (coevolution, evolutionary arms races) has assumed that pathogens must evolve new capacities - special mutations – in order to colonize new hosts and produce emergent disease (e.g. Parrish and Kawaoka, 2005). In this erroneous but broadly prevalent view, the evolution of new capacities creates new opportunities for pathogens. Further, given that mutations are both rare and undirected, the highly specialized nature of pathogen-host relationships should produce an evolutionary firewall limiting dissemination; by those definitions, emergences should be rare (for a historical review see Brooks et al., 2019). Pathogens, however, have become far better at finding us than our traditional understanding predicts. We face considerable risk space for pathogens and disease that directly threaten us, our crops and livestock – through expanding interfaces bringing pathogens and hosts into increasing proximity, exacerbated by environmental disruption and urban density, fueled by globalized trade and travel. We need a new paradigm that explains what we are seeing.
Additional section headers:
The Stockholm Paradigm
The DAMA Protocol
A Sense of Urgency and Long-Term Commitment
Reference
Interval estimation and optimal design for the within-subject coefficient of variation for continuous and binary variables
BACKGROUND: In this paper we propose the use of the within-subject coefficient of variation as an index of a measurement's reliability. For continuous variables and based on its maximum likelihood estimation we derive a variance-stabilizing transformation and discuss confidence interval construction within the framework of a one-way random effects model. We investigate sample size requirements for the within-subject coefficient of variation for continuous and binary variables. METHODS: We investigate the validity of the approximate normal confidence interval by Monte Carlo simulations. In designing a reliability study, a crucial issue is the balance between the number of subjects to be recruited and the number of repeated measurements per subject. We discuss efficiency of estimation and cost considerations for the optimal allocation of the sample resources. The approach is illustrated by an example on Magnetic Resonance Imaging (MRI). We also discuss the issue of sample size estimation for dichotomous responses with two examples. RESULTS: For the continuous variable we found that the variance stabilizing transformation improves the asymptotic coverage probabilities on the within-subject coefficient of variation for the continuous variable. The maximum like estimation and sample size estimation based on pre-specified width of confidence interval are novel contribution to the literature for the binary variable. CONCLUSION: Using the sample size formulas, we hope to help clinical epidemiologists and practicing statisticians to efficiently design reliability studies using the within-subject coefficient of variation, whether the variable of interest is continuous or binary
Accretion onto black holes formed by direct collapse
One possible scenario for the formation of massive black holes (BHs) in the
early Universe is from the direct collapse of primordial gas in atomic-cooling
dark matter haloes in which the gas is unable to cool efficiently via molecular
transitions. We study the formation of such BHs, as well as the accretion of
gas onto these objects and the high energy radiation emitted in the accretion
process, by carrying out cosmological radiation hydrodynamics simulations. In
the absence of radiative feedback, we find an upper limit to the accretion rate
onto the central object which forms from the initial collapse of hot (~ 10^4 K)
gas of the order of 0.1 MSun per year. This is high enough for the formation of
a supermassive star, the immediate precursor of a BH, with a mass of the order
of 10^5 MSun. Assuming that a fraction of this mass goes into a BH, we track
the subsequent accretion of gas onto the BH self-consistently with the high
energy radiation emitted from the accretion disk. Using a ray-tracing algorithm
to follow the propagation of ionizing radiation, we model in detail the
evolution of the photoionized region which forms around the accreting BH. We
find that BHs with masses of the order of 10^4 MSun initially accrete at close
to the Eddington limit, but that the accretion rate drops to of order 1 percent
of the Eddington limit after ~ 10^6 yr, due to the expansion of the gas near
the BH in response to strong photoheating and radiation pressure. One signature
of the accretion of gas onto BHs formed by direct collapse, as opposed to
massive Pop III star formation, is an extremely high ratio of the luminosity
emitted in He II 1640 to that emitted in H_alpha (or Ly_alpha); this could be
detected by the James Webb Space Telescope. Finally, we briefly discuss
implications for the coevolution of BHs and their host galaxies.Comment: 16 pages; 17 figures, slightly reduced quality; MNRAS in pres
Astrometry and geodesy with radio interferometry: experiments, models, results
Summarizes current status of radio interferometry at radio frequencies
between Earth-based receivers, for astrometric and geodetic applications.
Emphasizes theoretical models of VLBI observables that are required to extract
results at the present accuracy levels of 1 cm and 1 nanoradian. Highlights the
achievements of VLBI during the past two decades in reference frames, Earth
orientation, atmospheric effects on microwave propagation, and relativity.Comment: 83 pages, 19 Postscript figures. To be published in Rev. Mod. Phys.,
Vol. 70, Oct. 199
1959: Abilene Christian College Bible Lectures - Full Text
UNTO ALL THE WORLD”
Being the Abilene Christian College Annual Bible Lectures 1959
Price: $3.00
Published by
FIRM FOUNDATION PUBLISHING HOUSE
Box 77 Austin, Texa
Early star-forming galaxies and the reionization of the Universe
Star forming galaxies represent a valuable tracer of cosmic history. Recent
observational progress with Hubble Space Telescope has led to the discovery and
study of the earliest-known galaxies corresponding to a period when the
Universe was only ~800 million years old. Intense ultraviolet radiation from
these early galaxies probably induced a major event in cosmic history: the
reionization of intergalactic hydrogen. New techniques are being developed to
understand the properties of these most distant galaxies and determine their
influence on the evolution of the universe.Comment: Review article appearing in Nature. This posting reflects a submitted
version of the review formatted by the authors, in accordance with Nature
publication policies. For the official, published version of the review,
please see http://www.nature.com/nature/archive/index.htm
Survival of patients with newly diagnosed high-grade myeloid neoplasms who do not meet standard trial eligibility
Few patients with cancer, including those with acute myeloid leukemia and high-grade myeloid neoplasms, participate in clinical trials. Broadening standard eligibility criteria may increase clinical trial participation. In this retrospective single-center analysis, we identified 442 consecutive newly diagnosed patients from 2014 to 2016. Patients were considered eligible if they had performance status 0-2, normal renal and hepatic function, no recent solid tumor, left ventricular ejection fraction (EF) ≥ 50%, and no history of congestive heart failure (CHF) or myocardial infarction (MI); ineligible patients failed to meet one or more of these criteria. We included 372 patients who received chemotherapy. Ineligible patients represented 40% of the population and had a 1-79-fold greater risk of death (95% CI 1.37, 2.33) than eligible patients. Very few patients had cardiac co-morbidities, including 2% with low EF, 4% with prior CHF, and 5% with prior MI. In multivariable analysis, ineligibility was associated with decreased survival [HR 1-44 (95% CI 1-07, 1-93)]. Allogeneic transplantation, performed in 150 patients (40%), was associated with improved survival [HR 0-66, 95% CI (0-48, 0-91)]. Therefore, standard eligibility characteristics identify a patient population with improved survival. Further treatment options are needed for patients considered ineligible for clinical trials
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