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https://www.readbyqxmd.com/read/28636792/mtf-and-dqe-enhancement-using-an-apodized-aperture-x-ray-detector-design
#1
Tomi F Nano, Terenz Escartin, Elina Ismailova, Karim S Karim, Jan Lindstrȍm, Ho Kyung Kim, Ian A Cunningham
PURPOSE: Acquisition of high-quality x-ray images using low patient exposures requires detectors with high detective quantum efficiency (DQE). We describe a novel apodized-aperture pixel (AAP) design that increases high-frequency modulation transfer function (MTF) and DQE values. The AAP design makes a separation of physical sensor elements from image pixels by using very small sensor elements (e.g. 0.010-0.025 mm) to synthesize desired larger image pixels (e.g. 0.1-0.2 mm). METHODS: A cascaded systems model of signal and noise propagation is developed to describe the benefits of the AAP approach in terms of the MTF, Wiener noise power spectrum (NPS) and DQE...
June 21, 2017: Medical Physics
https://www.readbyqxmd.com/read/28636372/surface-desorption-dielectric-barrier-discharge-ionization-mass-spectrometry
#2
Hong Zhang, Jie Jiang, Na Li, Ming Li, Yingying Wang, Jing He, Hong You
A variant of dielectric-barrier discharge named surface desorption dielectric-barrier discharge ionization (SDDBDI) mass spectrometry was developed for high-efficiency ion transmission and high spatial resolution imaging. In SDDBDI, a tungsten nanotip and the inlet of the mass spectrometer are used as electrodes, and a piece of cover slip is used as a sample plate as well as an insulating dielectric barrier, which simplifies the configuration of instrument and thus the operation. Different from volume dielectric-barrier discharge (VDBD), the microdischarges are generated on the surface at SDDBDI, and therefore the plasma density is extremely high...
June 21, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28636089/geographic-substructure-in-craniometric-estimates-of-admixture-for-contemporary-american-populations
#3
Bridget F B Algee-Hewitt
OBJECTIVES: This study investigates heterogeneity in craniometrically-derived estimates of admixture in order to reveal population substructure in a sample of Black, White, Hispanic, and Native American individuals from the FDB. It reports evidence of spatial trends in population-specific patterns of admixture and contextualizes its results in terms of demographic diversity in the United States. MATERIALS AND METHODS: The FDB was sampled to capture the population variation within forensic casework, skeletal collections, and the U...
June 21, 2017: American Journal of Physical Anthropology
https://www.readbyqxmd.com/read/28635966/testing-models-of-refugial-isolation-colonization-and-population-connectivity-in-two-species-of-montane-salamanders
#4
S M Rovito, S D Schoville
Pleistocene glaciations have profoundly affected patterns of genetic diversity within many species. Temperate alpine organisms likely experienced dramatic range shifts, given that much of their habitat was glaciated during this time. While the effects of glaciations are relatively well understood, the spatial locations of refugia and processes that gave rise to current patterns of diversity are less well known. We use a microsatellite data set to test hypotheses of population connectivity and refugial isolation in the web-toed salamanders (Hydromantes) of the Sierra Nevada...
June 21, 2017: Heredity
https://www.readbyqxmd.com/read/28635416/arsenic-and-fluoride-co-contamination-in-shallow-aquifers-from-agricultural-suburbs-and-an-industrial-area-of-punjab-pakistan-spatial-trends-sources-and-human-health-implications
#5
Abida Farooqi, Jawairia Sultana, Noshin Masood
Release of arsenic (As) and fluoride (F(-)) species into groundwater is a serious health concern around the world. The present study was the first systematic baseline study conducted in Rahim Yar Khan district, Punjab, focusing on As and F(-) contamination in groundwater. A total of 51 representative groundwater samples comprising of 44 samples from agricultural suburbs and 7 from an industrial base were analysed. Statistical parameters, principal component analysis-multiple linear regression (PCA-MLR) and health risk assessment model were used to investigate the hydro geochemistry, spatial patterns, interrelation, source contribution and associated health risks of high As and F(-) in groundwater of the study area...
January 1, 2017: Toxicology and Industrial Health
https://www.readbyqxmd.com/read/28635299/prevalence-and-geographic-variations-of-polypharmacy-among-west-virginia-medicaid-beneficiaries
#6
Xue Feng, Xi Tan, Brittany Riley, Tianyu Zheng, Thomas K Bias, James B Becker, Usha Sambamoorthi
BACKGROUND: West Virginia (WV) residents are at high risk for polypharmacy given its considerable chronic disease burdens. OBJECTIVE: To evaluate the prevalence, correlates, outcomes, and geographic variations of polypharmacy among WV Medicaid beneficiaries. METHODS: In this cross-sectional study, we analyzed 2009-2010 WV Medicaid fee-for-service (FFS) claims data for adults aged 18-64 (N=37,570). We defined polypharmacy as simultaneous use of drugs from five or more different drug classes on a daily basis for at least 60 consecutive days in one year...
June 1, 2017: Annals of Pharmacotherapy
https://www.readbyqxmd.com/read/28634448/from-behavioral-facilitation-to-inhibition-the-neuronal-correlates-of-the-orienting-and-reorienting-of-auditory-attention
#7
Faith M Hanlon, Andrew B Dodd, Josef M Ling, Juan R Bustillo, Christopher C Abbott, Andrew R Mayer
Successful adaptive behavior relies on the ability to automatically (bottom-up) orient attention to different locations in the environment. This results in a biphasic pattern in which reaction times (RT) are faster for stimuli that occur in the same spatial location (valid) for the first few hundred milliseconds, which is termed facilitation. This is followed by faster RT for stimuli that appear in novel locations (invalid) after longer delays, termed inhibition of return. The neuronal areas and networks involved in the transition between states of facilitation and inhibition remain poorly understood, especially for auditory stimuli...
2017: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/28634340/dispersal-ability-determines-the-scaling-properties-of-species-abundance-distributions-a-case-study-using-arthropods-from-the-azores
#8
Luís Borda-de-Água, Robert J Whittaker, Pedro Cardoso, François Rigal, Ana M C Santos, Isabel R Amorim, Aristeidis Parmakelis, Kostas A Triantis, Henrique M Pereira, Paulo A V Borges
Species abundance distributions (SAD) are central to the description of diversity and have played a major role in the development of theories of biodiversity and biogeography. However, most work on species abundance distributions has focused on one single spatial scale. Here we used data on arthropods to test predictions obtained with computer simulations on whether dispersal ability influences the rate of change of SADs as a function of sample size. To characterize the change of the shape of the SADs we use the moments of the distributions: the skewness and the raw moments...
June 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28633972/the-neural-basis-of-form-and-form-motion-integration-from-static-and-dynamic-translational-glass-patterns-a-rtms-investigation
#9
Andrea Pavan, Filippo Ghin, Rita Donato, Gianluca Campana, George Mather
A long-held view of the visual system is that form and motion are independently analysed. However, there is physiological and psychophysical evidence of early interaction in the processing of form and motion. In this study, we used a combination of Glass patterns (GPs) and repetitive Transcranial Magnetic Stimulation (rTMS) to investigate in human observers the neural mechanisms underlying form-motion integration. GPs consist of randomly distributed dot pairs (dipoles) that induce the percept of an oriented stimulus...
June 17, 2017: NeuroImage
https://www.readbyqxmd.com/read/28633403/structured-populations-of-sulfolobus-acidocaldarius-with-susceptibility-to-mobile-genetic-elements
#10
Rika E Anderson, Angela Kouris, Christopher H Seward, Kate M Campbell, Rachel J Whitaker
The impact of a structured environment on genome evolution can be determined through comparative population genomics of species that live in the same habitat. Recent work comparing three genome sequences of Sulfolobus acidocaldarius suggested that highly structured, extreme, hot spring environments do not limit dispersal of this thermoacidophile, in contrast to other co-occurring Sulfolobus species. Instead, a high level of conservation among these three S. acidocaldarius genomes was hypothesized to result from rapid, global-scale dispersal promoted by low susceptibility to viruses that sets S...
June 14, 2017: Genome Biology and Evolution
https://www.readbyqxmd.com/read/28632903/immunohistochemical-dissection-of-cystic-panfolliculoma-focusing-on-the-expression-of-multiple-hair-follicle-lineage-markers-with-an-insight-into-the-pathogenesis
#11
Masahiro Fukuyama, Yohei Sato, Yoshimi Yamazaki, Manabu Ohyama
Panfolliculoma (PF) is a rare benign tumor with signs of differentiation toward all components of the hair follicle (HF). Cystic panfolliculoma (CPF) is a subset of PF with histological similarity to trichofolliculoma making the differential diagnosis difficult in some cases. Immunohistopathological investigations of PF have been reported; however, previous studies focused mostly on the expression profile of the outer root sheath markers. A panel of antibodies was developed and used for the detection of the expression of cytokeratin (CK) 10, CK13, CK14, CK15, hair-hard keratin (AE13), and EpCAM within the lesion, supporting the differentiation of all epithelial lineages of the HF and the diagnosis of CPF...
June 20, 2017: Journal of Cutaneous Pathology
https://www.readbyqxmd.com/read/28632847/pattern-recognition-analysis-of-age-related-retinal-ganglion-cell-signatures-in-the-human-eye
#12
Nayuta Yoshioka, Barbara Zangerl, Lisa Nivison-Smith, Sieu K Khuu, Bryan W Jones, Rebecca L Pfeiffer, Robert E Marc, Michael Kalloniatis
Purpose: To characterize macular ganglion cell layer (GCL) changes with age and provide a framework to assess changes in ocular disease. This study used data clustering to analyze macular GCL patterns from optical coherence tomography (OCT) in a large cohort of subjects without ocular disease. Methods: Single eyes of 201 patients evaluated at the Centre for Eye Health (Sydney, Australia) were retrospectively enrolled (age range, 20-85); 8 × 8 grid locations obtained from Spectralis OCT macular scans were analyzed with unsupervised classification into statistically separable classes sharing common GCL thickness and change with age...
June 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28632745/evaluating-patterns-and-drivers-of-spatial-change-in-the-recreational-guided-fishing-sector-in-alaska
#13
Maggie N Chan, Anne H Beaudreau, Philip A Loring
Understanding the impacts of recreational fishing on habitats and species, as well as the social and ecological importance of place to anglers, requires information on the spatial distribution of fishing activities. This study documented long-term changes in core fishing areas of a major recreational fishery in Alaska and identified biological, regulatory, social, and economic drivers of spatial fishing patterns by charter operators. Using participatory mapping and in-person interviews, we characterized the spatial footprint of 46 charter operators in the communities of Sitka and Homer since the 1990s...
2017: PloS One
https://www.readbyqxmd.com/read/28632734/choroidal-thickness-in-patients-with-coronary-artery-disease
#14
Meleha Ahmad, Patrick A Kaszubski, Lucy Cobbs, Harmony Reynolds, Roland Theodore Smith
PURPOSE: To evaluate choroidal thickness (CTh) in patients with coronary artery disease (CAD) compared to healthy controls. DESIGN: Cross-sectional. METHODS: Setting: Ambulatory clinic of a large city hospital. Patient population: Thirty-four patients had documented CAD, defined as history of >50% obstruction in at least one coronary artery on cardiac catheterization, positive stress test, ST elevation myocardial infarction, or revascularization procedure...
2017: PloS One
https://www.readbyqxmd.com/read/28632427/speed-of-processing-and-executive-functions-in-adults-with-phenylketonuria-quick-in-finding-the-word-but-not-the-ladybird
#15
Cristina Romani, Anita MacDonald, Sara De Felice, Liana Palermo
A reduction in processing speed is widely reported in phenylketonuria (PKU), possibly due to white matter pathology. We investigated possible deficits and their relationships with executive functions in a sample of 37 early-treated adults with PKU (AwPKUs). AwPKUs were not characterized by a generalized speed deficit, but instead their performance could be explained by two more specific impairments: (a) a deficit in the allocation of visuo-spatial attention that reduced speed in visual search tasks, in some reading conditions and visuo-motor coordination tasks; and (b) a more conservative decision mechanism that slowed down returning an answer across domains...
June 20, 2017: Cognitive Neuropsychology
https://www.readbyqxmd.com/read/28632205/speckle-modulating-optical-coherence-tomography-in-living-mice-and-humans
#16
Orly Liba, Matthew D Lew, Elliott D SoRelle, Rebecca Dutta, Debasish Sen, Darius M Moshfeghi, Steven Chu, Adam de la Zerda
Optical coherence tomography (OCT) is a powerful biomedical imaging technology that relies on the coherent detection of backscattered light to image tissue morphology in vivo. As a consequence, OCT is susceptible to coherent noise (speckle noise), which imposes significant limitations on its diagnostic capabilities. Here we show speckle-modulating OCT (SM-OCT), a method based purely on light manipulation that virtually eliminates speckle noise originating from a sample. SM-OCT accomplishes this by creating and averaging an unlimited number of scans with uncorrelated speckle patterns without compromising spatial resolution...
June 20, 2017: Nature Communications
https://www.readbyqxmd.com/read/28631988/evidence-of-practice-effect-in-cantab-spatial-working-memory-test-in-a-cohort-of-patients-with-mild-cognitive-impairment
#17
Federica Cacciamani, Nicola Salvadori, Paolo Eusebi, Viviana Lisetti, Elisa Luchetti, Paolo Calabresi, Lucilla Parnetti
The Cambridge Neuropsychological Test Automated Battery (CANTAB) is a system of neuropsychological tests frequently used to track the progression of cognitive deficits in mild cognitive impairment (MCI) and Alzheimer's disease (AD). We investigated test-retest reliability in seven CANTAB tests. Twenty-five MCI patients, with either AD-like or conflicting/normal cerebrospinal fluid profiles underwent three testing sessions at 6-month intervals, including the following tests: Reaction Time and Rapid Visual Information Processing (assessing attention and reaction times); Delayed Matching-to-Sample, Paired Associates Learning, Spatial Recognition Memory and Pattern Recognition Memory (assessing memory); Spatial Working Memory (assessing executive functions)...
February 22, 2017: Applied Neuropsychology. Adult
https://www.readbyqxmd.com/read/28631376/scale-of-human-mobility-in-the-southern-andes-argentina-and-chile-a-new-framework-based-on-strontium-isotopes
#18
Ramiro Barberena, Víctor A Durán, Paula Novellino, Diego Winocur, Anahí Benítez, Augusto Tessone, María N Quiroga, Erik J Marsh, Alejandra Gasco, Valeria Cortegoso, Gustavo Lucero, Carina Llano, Kelly J Knudson
OBJECTIVES: The goal of this article is to assess the scale of human paleomobility and ecological complementarity between the lowlands and highlands in the southern Andes during the last 2,300 years. By providing isotope results for human bone and teeth samples, we assess a hypothesis of "high residential mobility" suggested on the basis of oxygen isotopes from human remains. METHODS: We develop an isotopic assessment of human mobility in a mountain landscape combining strontium and oxygen isotopes...
June 20, 2017: American Journal of Physical Anthropology
https://www.readbyqxmd.com/read/28631320/spatial-patterns-and-broad-scale-weather-cues-of-beech-mast-seeding-in-europe
#19
Giorgio Vacchiano, Andrew Hacket-Pain, Marco Turco, Renzo Motta, Janet Maringer, Marco Conedera, Igor Drobyshev, Davide Ascoli
Mast seeding is a crucial population process in many tree species, but its spatio-temporal patterns and drivers at the continental scale remain unknown . Using a large dataset (8000 masting observations across Europe for years 1950-2014) we analysed the spatial pattern of masting across the entire geographical range of European beech, how it is influenced by precipitation, temperature and drought, and the temporal and spatial stability of masting-weather correlations. Beech masting exhibited a general distance-dependent synchronicity and a pattern structured in three broad geographical groups consistent with continental climate regimes...
July 2017: New Phytologist
https://www.readbyqxmd.com/read/28630884/evaluation-of-a-high-resolution-patient-specific-model-of-the-electrically-stimulated-cochlea
#20
Ahmet Cakir, Robert T Dwyer, Jack H Noble
Cochlear implants (CIs) are surgically implanted medical devices used to treat individuals with severe-to-profound sensorineural hearing loss. Although these devices have been remarkably successful at restoring audibility, many patients experience poor outcomes. Our group has developed the first image-guided CI programming technique where the electrode positions are found in CT images and used to estimate neural activation patterns, which is unique information that audiologists can use to define patient-specific processor settings...
April 2017: Journal of Medical Imaging
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