245 research outputs found
Learning disabilities: description, diagnosis or explanation?
This article explores the semantics of the term, learning disabilities. As currently used, the term often tends to reflect the professional and/or personal interest of the user rather than a concern for the respect and treatment of the child so labeled. The authors suggest that if the field were re-oriented toward learning how to teach these children, it could, perhaps, evolve as an instructional discipline with more tangible benefits for the children, their teachers and their parents
An Environmental Language Approach for Increasing Behavior of Retarded Children
Immediate gains in four areas of language behavior of nine moderately retarded children, achieved through a systematic summer-camp-type activity program, remained significant one year later, report these authors
Non-enzymatic Electrochemical Determination of Glucose Concentration
There are a variety of applications for electrochemistry (including synthetic, physical and analytical chemistry), and here we present an experimental protocol for the non-enzymatic electrochemical quantitation of glucose in liquids that can be used in teaching laboratories. This offers an interesting experiential learning experience that is contextualized through a real world application where comparable technology the students employ touches the lives of humans across the world on a daily basis
Cocaine Use and Liver Disease are Associated with All-Cause Mortality in the Miami Adult Studies in HIV (MASH) Cohort
Acute disseminated encephalomyelitis in children: differential diagnosis from multiple sclerosis on the basis of clinical course
Acute disseminated encephalomyelitis (ADEM) is a demyelinating disease of the central nervous system (CNS) that typically presents as a monophasic disorder associated with multifocal neurologic symptoms and encephalopathy. ADEM is considered an autoimmune disorder that is triggered by an environmental stimulus in genetically susceptible individuals. The diagnosis of ADEM is based on clinical and radiological features. Most children with ADEM initially present with fever, meningeal signs, and acute encephalopathy. The level of consciousness ranges from lethargy to frank coma. Deep and subcortical white-matter lesions and gray-matter lesions such as thalami and basal ganglia on magnetic resonance imaging (MRI) are associated with ADEM. In a child who presents with signs of encephalitis, bacterial and viral meningitis or encephalitis must be ruled out. Sequential MRI is required to confirm the diagnosis of ADEM, as relapses with the appearance of new lesions on MRI may suggest either multiphasic ADEM or multiple sclerosis (MS). Pediatric MS, defined as onset of MS before the age of 16, is being increasingly recognized. MS is characterized by recurrent episodes of demyelination in the CNS separated in space and time. The McDonald criteria for diagnosis of MS include evidence from MRI and allow the clinician to make a diagnosis of clinically definite MS on the basis of the interval preceding the development of new white matter lesions, even in the absence of new clinical findings. The most important alternative diagnosis to MS is ADEM. At the initial presentation, the 2 disorders cannot be distinguished with certainty. Therefore, prolonged follow-up is needed to establish a diagnosis
Molecular gas and star formation in early-type galaxies
We present new mm interferometric and optical integral-field unit (IFU)
observations and construct a sample of 12 E and S0 galaxies with molecular gas
which have both CO and optical maps. The galaxies contain 2 x 10^7 to 5 x 10^9
M\odot of molecular gas distributed primarily in central discs or rings (radii
0.5 to 4 kpc). The molecular gas distributions are always coincident with
distributions of optically-obscuring dust that reveal tightly-wound spiral
structures in many cases. The ionised gas always approximately corotates with
the molecular gas, evidencing a link between these two gas components, yet star
formation is not always the domi- nant ionisation source. The galaxies with
less molecular gas tend to have [O III]/H{\beta} emission-line ratios at high
values not expected for star formation. Most E/S0s with molecular gas have
young or intermediate age stellar populations based on optical colours,
ultraviolet colours and absorption linestrengths. The few that appear purely
old lie close to the limit where such populations would be undetectable based
on the mass fractions of expected young to observed old stars. The 8{\mu}m
polycyclic aromatic hydrocarbon (PAH) and 24{\mu}m emission yield similar star
formation rate estimates of E/S0s, but the total infrared overpredicts the rate
due to a contribution to dust heating from older stars. The radio-far infrared
relation also has much more scatter than for other star-forming galaxies.
However, despite these biases and additional scatter, the derived star
formation rates locate the E/S0 galaxies within the large range of the
Schmidt-Kennicutt and constant efficiency star formation laws. Thus the star
formation process in E/S0s is not overwhelmingly different than in other
star-forming galaxies, although one of the more reliable tracers (24{\mu}m)
points to a possible lower star-formation efficiency at a given gas surface
density.Comment: submitted to MNRA
The Mid-Infrared High-Ionization Lines from Active Galactic Nuclei and Star-Forming Galaxies
We used Spitzer/IRS spectroscopic data on 426 galaxies including quasars,
Seyferts, LINER and HII galaxies to investigate the relationship among the
mid-IR emission lines. There is a tight linear correlation between the [Ne
V]14.3 um and 24.3 um (97.1 eV) and the [O IV]25.9 um (54.9 eV) high-ionization
emission lines. The correlation also holds for these high-ionization emission
lines and the [Ne III]15.56 um (41 eV) emission line, although only for active
galaxies. We used these correlations to calculate the [Ne III] excess due to
star formation in Seyfert galaxies. We also estimated the [O IV] luminosity due
to star formation in active galaxies and determined that it dominates the [O
IV] emission only if the contribution of the active nucleus to the total
luminosity is below 5%. We find that the AGN dominates the [O IV] emission in
most Seyfert galaxies, whereas star-formation adequately explains the observed
[O IV] emission in optically classified HII galaxies. Finally we computed
photoionization models to determine the physical conditions of the narrow line
region where these high-ionization lines originate. The estimated ionization
parameter range is -2.8 < log U < -2.5 and the total hydrogen column density
range is 20 < log nH (cm-2) < 21.Comment: Accepted for Publication in ApJ, 19 pages, 13 figure
Mid-Infrared Properties of the Swift Burst Alert Telescope Active Galactic Nuclei Sample of the Local Universe. I. Emission-Line Diagnostics
We compare mid-infrared emission-line properties, from high-resolution
Spitzer spectra of a hard X-ray (14 -- 195 keV) selected sample of nearby (z <
0.05) AGN detected by the Burst Alert Telescope (BAT) aboard Swift. The
luminosity distribution for the mid-infrared emission-lines, [O IV] 25.89
micron, [Ne II] 12.81 micron, [Ne III] 15.56 micron and [Ne V] 14.32/24.32
micron, and hard X-ray continuum show no differences between Seyfert 1 and
Seyfert 2 populations, however six newly discovered BAT AGNs are under-luminous
in [O IV], most likely the result of dust extinction in the host galaxy. The
overall tightness of the mid-infrared correlations and BAT fluxes and
luminosities suggests that the emission lines primarily arise in gas ionized by
the AGN. We also compare the mid-infrared emission-lines in the BAT AGNs with
those from published studies of ULIRGs, PG QSOs, star-forming galaxies and
LINERs. We find that the BAT AGN sample fall into a distinctive region when
comparing the [Ne III]/[Ne II] and the [O IV]/[Ne III] ratios. These line
ratios are lower in sources that have been previously classified in the
mid-infrared/optical as AGN than those found for the BAT AGN, suggesting that,
in our X-ray selected sample, the AGN represents the main contribution to the
observed line emission. These ratios represent a new emission line diagnostic
for distinguishing between AGN and star forming galaxies.Comment: 54 pages, 9 Figures. Accepted for publication in The Astrophysical
Journal
Automated detection and staging of malaria parasites from cytological smears using convolutional neural networks
Microscopic examination of blood smears remains the gold standard for laboratory inspection and diagnosis of malaria. Smear inspection is, however, time-consuming and dependent on trained microscopists with results varying in accuracy. We sought to develop an automated image analysis method to improve accuracy and standardization of smear inspection that retains capacity for expert confirmation and image archiving. Here, we present a machine learning method that achieves red blood cell (RBC) detection, differentiation between infected/uninfected cells, and parasite life stage categorization from unprocessed, heterogeneous smear images. Based on a pretrained Faster Region-Based Convolutional Neural Networks (R-CNN) model for RBC detection, our model performs accurately, with an average precision of 0.99 at an intersection-over-union threshold of 0.5. Application of a residual neural network-50 model to infected cells also performs accurately, with an area under the receiver operating characteristic curve of 0.98. Finally, combining our method with a regression model successfully recapitulates intraerythrocytic developmental cycle with accurate lifecycle stage categorization. Combined with a mobile-friendly web-based interface, called PlasmoCount, our method permits rapid navigation through and review of results for quality assurance. By standardizing assessment of Giemsa smears, our method markedly improves inspection reproducibility and presents a realistic route to both routine lab and future field-based automated malaria diagnosis
Fitting the integrated Spectral Energy Distributions of Galaxies
Fitting the spectral energy distributions (SEDs) of galaxies is an almost
universally used technique that has matured significantly in the last decade.
Model predictions and fitting procedures have improved significantly over this
time, attempting to keep up with the vastly increased volume and quality of
available data. We review here the field of SED fitting, describing the
modelling of ultraviolet to infrared galaxy SEDs, the creation of
multiwavelength data sets, and the methods used to fit model SEDs to observed
galaxy data sets. We touch upon the achievements and challenges in the major
ingredients of SED fitting, with a special emphasis on describing the interplay
between the quality of the available data, the quality of the available models,
and the best fitting technique to use in order to obtain a realistic
measurement as well as realistic uncertainties. We conclude that SED fitting
can be used effectively to derive a range of physical properties of galaxies,
such as redshift, stellar masses, star formation rates, dust masses, and
metallicities, with care taken not to over-interpret the available data. Yet
there still exist many issues such as estimating the age of the oldest stars in
a galaxy, finer details ofdust properties and dust-star geometry, and the
influences of poorly understood, luminous stellar types and phases. The
challenge for the coming years will be to improve both the models and the
observational data sets to resolve these uncertainties. The present review will
be made available on an interactive, moderated web page (sedfitting.org), where
the community can access and change the text. The intention is to expand the
text and keep it up to date over the coming years.Comment: 54 pages, 26 figures, Accepted for publication in Astrophysics &
Space Scienc
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