69 research outputs found
Hybrid Approach for Alzheimer’s Disease Diagnosis For 3D Brain MR Image
Because of headways in deep learning and clinical imaging innovation, a few specialists are presently utilizing convolutional neural networks (CNNs) to extricate profound level properties from clinical pictures to all the more exactly classify Alzheimer's disease (AD) and expect clinical scores. A limited scale profound learning network called PCANet utilizes principal component analysis (PCA) to make multi-facet channel banks for the incorporated learning of information. Blockwise histograms are made after binarization to get picture ascribes. PCANet is less versatile than different frameworks since the multi-facet channel banks are made involving test information and the produced highlights have aspects during the many thousands or even many thousands. To conquer these issues, we present in this study a PCANet-based, information free organization called the nonnegative matrix factorization tensor decomposition network (NMF-TDNet). To deliver the last picture highlights, we first form higher-request tensors and utilize tensor decomposition (TD) to achieve information dimensionality decrease. Specifically, we foster staggered channel banks for test getting the hang of utilizing nonnegative matrix factorization(NMF) as opposed to PCA. These properties serve as input to the support vector machine (SVM) that our technique employs to diagnose AD, forecast clinical score, and categorise AD
Regression and Classification of Alzheimer’s Disease Diagnosis Using NMF-TDNet Features From 3D Brain MR Image
Because of headways in deep learning and clinical imaging innovation, a few specialists are presently utilizing convolutional neural networks (CNNs) to extricate profound level properties from clinical pictures to all the more exactly classify Alzheimer's disease (AD) and expect clinical scores. A limited scale profound learning network called PCANet utilizes principal component analysis (PCA) to make multi-facet channel banks for the incorporated learning of information. Blockwise histograms are made after binarization to get picture ascribes. PCANet is less versatile than different frameworks since the multi-facet channel banks are made involving test information and the produced highlights have aspects during the many thousands or even many thousands. To conquer these issues, we present in this study a PCANet-based, information free organization called the nonnegative matrix factorization tensor decomposition network (NMF-TDNet). To deliver the last picture highlights, we first form higher-request tensors and utilize tensor decomposition (TD) to achieve information dimensionality decrease. Specifically, we foster staggered channel banks for test getting the hang of utilizing nonnegative matrix factorization(NMF) as opposed to PCA. These properties serve as input to the support vector machine (SVM) that our technique employs to diagnose AD, forecast clinical score, and categorise AD
The Diversity of Diffuse Ly Nebulae around Star-Forming Galaxies at High Redshift
We report the detection of diffuse Ly emission, or Ly halos
(LAHs), around star-forming galaxies at and in the NOAO
Deep Wide-Field Survey Bo\"otes field. Our samples consist of a total of
1400 galaxies, within two separate regions containing spectroscopically
confirmed galaxy overdensities. They provide a unique opportunity to
investigate how the LAH characteristics vary with host galaxy large-scale
environment and physical properties. We stack Ly images of different
samples defined by these properties and measure their median LAH sizes by
decomposing the stacked Ly radial profile into a compact galaxy-like
and an extended halo-like component. We find that the exponential scale-length
of LAHs depends on UV continuum and Ly luminosities, but not on
Ly equivalent widths or galaxy overdensity parameters. The full
samples, which are dominated by low UV-continuum luminosity Ly emitters
(), exhibit LAH sizes of 5kpc. However, the
most UV- or Ly-luminous galaxies have more extended halos with
scale-lengths of 7kpc. The stacked Ly radial profiles decline
more steeply than recent theoretical predictions that include the contributions
from gravitational cooling of infalling gas and from low-level star formation
in satellites. On the other hand, the LAH extent matches what one would expect
for photons produced in the galaxy and then resonantly scattered by gas in an
outflowing envelope. The observed trends of LAH sizes with host galaxy
properties suggest that the physical conditions of the circumgalactic medium
(covering fraction, HI column density, and outflow velocity) change with halo
mass and/or star-formation rates.Comment: published in ApJ, minor proof corrections applie
Lyman-Alpha Escape from Low-Mass, Compact, High-Redshift Galaxies
We investigate the effects of stellar populations and sizes on Ly
escape in 27 spectroscopically confirmed and 35 photometric Lyman-Alpha
Emitters (LAEs) at z 2.65 in seven fields of the Bo\"otes region of
the NOAO Deep Wide-Field Survey. We use deep /WFC3 imaging to supplement
ground-based observations and infer key galaxy properties. Compared to typical
star-forming galaxies (SFGs) at similar redshifts, the LAEs are less massive
(), younger (ages 1
Gyr), smaller ( 1 kpc), less dust-attenuated (E(BV) 0.26
mag), but have comparable star-formation-rates (SFRs ). Some of the LAEs in the sample may be very young galaxies
having low nebular metallicities ()
and/or high ionization parameters (). Motivated by
previous studies, we examine the effects of the concentration of star formation
and gravitational potential on Ly escape, by computing
star-formation-rate surface density, and specific
star-formation-rate surface density, . For a given
, the Ly escape fraction is higher for LAEs with
lower stellar masses. LAEs have higher on average compared
to SFGs. Our results suggest that compact star formation in a low gravitational
potential yields conditions amenable to the escape of Ly photons. These
results have important implications for the physics of Ly radiative
transfer and for the type of galaxies that may contribute significantly to
cosmic reionization.Comment: 36 pages, 15 figures; Accepted for publication in The Astronomical
Journa
Analysis of changing statistical significance from .05 to .005 in foot and ankle randomized controlled trials
Background: Misinterpretation of p-values in RCTs is extremely problematic since they are the core basis for high levels of recommendation in clinical practice guidelines, especially Orthopaedics. Benjamin et al. proposed a universal protocol change, moving statistical significance from a p-value of .05 to .005 to combat the misinterpretation that is happening in medical literature. In this study, we are looking to evaluate the effect of the protocol suggested by Benjamin et al. on foot and ankle-related RCTs in the top 3 Foot and Ankle-related journals.Methods: We conducted a Pubmed search looking at studies published from January 1st, 2016 to November 10, 2021, in the following three journals; Foot and Ankle International, Journal of Foot and Ankle Surgery, and Foot & Ankle International. The inclusion criteria for the study were RCTs published in the above journals with specifically stated primary endpoints. If a study has multiple primary endpoints, all were included. Exclusion criteria were any study that was not prospective and randomized by design, also any study that did not state primary endpoints was excluded. Two authors extracted the data using a pilot-tested Google form, any disagreements or questions were resolved by published methodologic orthopaedic authors.Results: Of the 222 endpoints, 101 endpoints (45.5%; 101/222) were at or below the .05 threshold while 121 endpoints (54.5%; 121/222) were above the .05 threshold. We also found that 59 endpoints (26.6%; 59/222) were below .005.Conclusion: Our results suggest that changing the threshold for statistical significance from .05 to .005 in foot and ankle RCTs would heavily alter literature published in the field. By implementing this methodology, it is a promising measure to be able to increase RCT quality until a more substantial solution can be found. With that being said, caution must be taken when interpreting our results, also requiring further evaluation
COVID 19 and its effects on pediatric orthopaedic clinical trials
Background: Clinical trials for the treatment of pediatric orthopaedics are critical to enhance the quality of life of these children. In response to the COVID-19 pandemic, the FDA updated guidance on conducting clinical trials to prioritize patient safety; however the degree to which the pandemic disrupted pediatric orthopaedic-related clinical trials is unknown. Thus, our objective is to quantify the number of these trials disrupted due to the COVID-19 pandemic.Methods: We searched ClinicalTrials.gov for ongoing and discontinued trials between 01/01/2020 - 10/31/2021. Trials were screened for relevance to the study and the number of participants, trial location, funding source, and reason for discontinuation. Associations between reasons for termination, funding source, trial location, and the number of participants enrolled were evaluated using MannWhitney U tests or ANOVA, where appropriate.Results: Our search returned 544 trials, of which 128 were included with a total of 15,194 participants. Of the included Pediatric trials of orthopaedic conditions, 9 were discontinued with a total of 497 participants. Of the 9 discontinued trials, 1 of 3 stated COVID-19 as a reason. Mann-Whitney U tests and ANOVA showed no statistically significant difference in enrollment between trials discontinued due to COVID-19 compared to other discontinued trials, nor among funding or location.Conclusion: Our study shows 33% of discontinued pediatric orthopaedic-related clinical trials cited COVID-19 as a reason for discontinuation; however, only 12% of all children enrolled in discontinued trials. Findings from this study highlight the importance of developing strategies for safely continuing clinical research amid global emergencies that will almost certainly arise in the future
The Overdense Environment of a Large Lyman-alpha Nebula at z~2.7
Large nebulae (>50 kpc) emitting strongly in Lya (also known as Lya
``blobs'') are likely signposts of ongoing massive galaxy formation. The
relative rarity of these sources and their discovery in well-studied galaxy
overdensities suggest that they may be associated with regions of high galaxy
density. One of the largest Lya nebulae, discovered at a redshift of z~2.7 via
its strong mid-infrared emission, provides an unbiased test of this
association. We have carried out a deep intermediate-band imaging survey for
Lya-emitting galaxies (LAEs) within a 30'x26' field of view around this Lya
nebula. This is the first study of the environment of a Lya nebula found
without a priori knowledge of its surroundings. We find that the nebula is
located in an overdense region, at least 20x50 1/h_70 comoving Mpc in size,
showing a factor of ~3 LAE number density enhancement relative to the edge of
the field. Given the predicted number of such overdensities, we rule out the
possibility of a chance coincidence at the <1% level. This study, in
conjunction with previous work, provides strong confirmation of the association
between the largest Lya nebulae and overdense regions of the Universe.Comment: Accepted for publication in ApJL; 8 pages, 4 figures, emulateapj
forma
A Lyman Break Galaxy in the Epoch of Reionization from Hubble Space Telescope (HST) Grism Spectroscopy
Slitless grism spectroscopy from space offers dramatic advantages for studying high redshift galaxies: high spatial resolution to match the compact sizes of the targets, a dark and uniform sky background, and simultaneous observation over fields ranging from five square arcminutes (HST) to over 1000 square arcminutes (Euclid). Here we present observations of a galaxy at z = 6.57 the end of the reioinization epoch identified using slitless HST grism spectra from the PEARS survey (Probing Evolution And Reionization Spectroscopically) and reconfirmed with Keck + DEIMOS. This high redshift identification is enabled by the depth of the PEARS survey. Substantially higher redshifts are precluded for PEARS data by the declining sensitivity of the ACS grism at greater than lambda 0.95 micrometers. Spectra of Lyman breaks at yet higher redshifts will be possible using comparably deep observations with IR-sensitive grisms
Health care policy and regulatory implications on medical device innovations: a cardiac rhythm medical device industry perspective
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