50 research outputs found
Second order coherent power spectra
The relationship between second order stochastic processes and coherent power spectra are explored for developed grain size frequency distributions of silver halide emulsion/developer combinations. Although Wiener spectra represent incoherent power spectra, the coherent case has been unresolved due to the difficulty of filtering the optical system effect. The emulsion plates were exposed with a uniform irradiance distribution from an incoherent tungsten source to create a series of uniform density samples. Conventional processing chemistry is utilized with substitution of different developer types, from predominantly physical development to direct chemical development. The exposed and processed density samples were liquid gated with refractive index matching fluid and inserted at the front focal plane of a conventional on-axis Fourier transform system. The power spectra are ensemble and frequency domain averaged at the Fourier transform plane with a special annular ring detector. The coherent nature of the optical analyzer necessitates consideration of the interaction or interference of the power spectra for the optical system, and the spectra of the input transmittance sample. An algorithm was derived to estimate the power spectra of just the input grain distributions, which was applied to all of the measured spectra of the emulsion/developer combinations. The calculated spectra demonstrate significant power shifts from the low spatial frequency region with increasing power levels as a function of increasing developed grain size. The bandwidths of the power distributions are inversely proportional to developed grain size with the larger grains the predominant factor. The midpoints of the power spectra also shifted toward increasing spatial frequencies for decreasing values of developed grain size. The peak power levels for each emulsion/developer family were proportional to those predicted by the well known random checkerboard granularity model. Theoretical power spectra models are demonstrated for both second order and first order auto-regressive stochastic models. The second order process reveals a significant shift in the power distribution away from the low frequency region analogous to the calculated coherent power spectra. The power functions for the first order process are centered at zero spatial frequency, similar to conventional Wiener spectra. It is shown that a first order complex transmittance model transforms to the power spectra proportional to second-order stochastic processes when the real and imaginary parts are correlated. Although the filtered and measured coherent spectra are strongly dependent upon the developed grain size frequency distributions, the significant departure in shape and location of the spectra is related to the functional change from first order to second-order stochastic process characteristics
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Identifying Motor, Emotional-Behavioral, and Cognitive Deficits that Comprise the Triad of HD Symptoms from Patient, Caregiver, and Provider Perspectives
Background: The objective of this study was to identify important attributes associated with the triad of symptoms (cognition, emotionalâbehavioral, and motor) of Huntington's disease (HD) from patient, caregiver, and medical provider perspectives to facilitate development of a new diseaseâspecific, healthârelated quality of life (HRQOL) instrument.
Methods: We conducted a targeted literature review of HD and HRQOL instruments, expert surveys, and patient and caregiver phoneâbased interviews to extract information on the symptoms and issues most relevant to the HD symptom triad (HD triad). The data collected from these sources were used to generate themes and subdomains and to develop an integrated schema that highlights the key dimensions of the triad.
Results: The search identified the following areas: emotional functioning/behavioral changes (e.g., positive emotions, sadness/depression); cognitive functioning (e.g., memory/learning, attention/comprehension); physical functioning (e.g., motor functioning, medication); social functioning (e.g., leisure, interpersonal relationships); endâofâlife concerns/planning; and gene testing. Fifteen individuals diagnosed with HD and 16 HD caregivers, recruited from several Huntington's Disease Society of America support group networks, completed phone interviews. Nineteen US medical providers who specialize in HD completed the online survey. Twentyâsix subdomains of the HD symptom triad (seven cognition, 12 emotionalâbehavioral, and seven motor) emerged relatively consistently across patient, caregiver, and provider samples. These included movements/chorea, memory impairment, depression, and anxiety.
Discussion: Based on an integrated, mixedâmethods approach, important HD triad symptom were identified and organized into a guiding schema. These patientâ, caregiverâ, and providerâtriangulated data served as the basis for development of a HDâspecific HRQOL instrument, the HDâPROâTRIADâą
Carbon Sequestration in Synechococcus Sp.: From Molecular Machines to Hierarchical Modeling
The U.S. Department of Energy recently announced the first five grants for the Genomes to Life (GTL) Program. The goal of this program is to "achieve the most far-reaching of all biological goals: a fundamental, comprehensive, and systematic understanding of life." While more information about the program can be found at the GTL website (www.doegenomestolife.org), this paper provides an overview of one of the five GTL projects funded, "Carbon Sequestration in Synechococcus Sp.: From Molecular Machines to Hierarchical Modeling." This project is a combined experimental and computational effort emphasizing developing, prototyping, and applying new computational tools and methods to ellucidate the biochemical mechanisms of the carbon sequestration of Synechococcus Sp., an abundant marine cyanobacteria known to play an important role in the global carbon cycle. Understanding, predicting, and perhaps manipulating carbon fixation in the oceans has long been a major focus of biological oceanography and has more recently been of interest to a broader audience of scientists and policy makers. It is clear that the oceanic sinks and sources of CO2 are important terms in the global environmental response to anthropogenic atmospheric inputs of CO2 and that oceanic microorganisms play a key role in this response. However, the relationship between this global phenomenon and the biochemical mechanisms of carbon fixation in these microorganisms is poorly understood. The project includes five subprojects: an experimental investigation, three computational biology efforts, and a fifth which deals with addressing computational infrastructure challenges of relevance to this project and the Genomes to Life program as a whole. Our experimental effort is designed to provide biology and data to drive the computational efforts and includes significant investment in developing new experimental methods for uncovering protein partners, characterizing protein complexes, identifying new binding domains. We will also develop and apply new data measurement and statistical methods for analyzing microarray experiments. Our computational efforts include coupling molecular simulation methods with knowledge discovery from diverse biological data sets for high-throughput discovery and characterization of protein-protein complexes and developing a set of novel capabilities for inference of regulatory pathways in microbial genomes across multiple sources of information through the integration of computational and experimental technologies. These capabilities will be applied to Synechococcus regulatory pathways to characterize their interaction map and identify component proteins in these pathways. We will also investigate methods for combining experimental and computational results with visualization and natural language tools to accelerate discovery of regulatory pathways. Furthermore, given that the ultimate goal of this effort is to develop a systems-level of understanding of how the Synechococcus genome affects carbon fixation at the global scale, we will develop and apply a set of tools for capturing the carbon fixation behavior of complex of Synechococcus at different levels of resolution. Finally, because the explosion of data being produced by high-throughput experiments requires data analysis and models which are more computationally complex, more heterogeneous, and require coupling to ever increasing amounts of experimentally obtained data in varying formats, we have also established a companion computational infrastructure to support this effort as well as the Genomes to Life program as a whole.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63164/1/153623102321112746.pd
Optical Properties Of High Refractive Index Thin Films Processed At Low-Temperature
This study reports on the first development of high refractive index thin film materials processed at temperatures not greater than 100 degrees celsius. Three materials were synthesised by the solâgel technique, each employing different transition metal precursors (niobium, tantalum and vanadium alkoxides). The optical properties of these materials were characterised by ellipsometry and the propagation losses at 638 nm were measured by the prism coupling method. It is shown that refractive indices as high as 1.870, 2.039 and 2.308 are obtained from niobium-, tantalum- and vanadium-based materials respectively, attributed to the influence of the transition metal atomic size on the condensation reactions
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Identification, genomic structure, and screening of the vacuolar proton-ATPase membrane sector-associated protein M8-9 gene within the COD1 critical region (Xp11.4)
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A novel compound heterozygous mutation in the cellular retinaldehyde-binding protein gene (RLBP1) in a patient with retinitis punctata albescens.
PurposeTo describe a patient with retinitis punctata albescens (RPA) associated with compound heterozygosity for two novel mutations in the RLBP1 encoding cellular retinaldehyde-binding protein (CRALBP).DesignObservational case report.MethodsThe proband underwent a complete ophthalmic examination and leukocyte genomic DNA samples were obtained from him and his parents. The RLBP1 exons were analyzed by direct sequencing of PCR-amplified fragments.ResultsThe patient had a clinical phenotype suggestive of slowly progressive RPA, characterized by numerous yellow-white dots in the fundus. The RLBP1 sequence analysis revealed a novel compound heterozygotic mutation of Gly145Asp and Ile200Thr transmitted from the mother and father, respectively. Analysis of 100 control chromosomes showed no individuals with these sequence alterations.ConclusionsOnly eight RLBP1 mutations have been reported to date, and here we describe two novel mutations. These additional mutations will aid ongoing functional studies and add to our understanding of the molecular pathology pertaining to RLBP1-associated retinopathies
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A novel RPGR exon ORF15 mutation in a family with X-linked retinitis pigmentosa and Coats'-like exudative vasculopathy.
PurposeTo describe the ophthalmic and genetic findings in a family with X-linked retinitis pigmentosa (RP) and Coats'-like exudative vasculopathy.DesignObservational case series.MethodsFamily members underwent comprehensive ophthalmologic examination. Leukocyte genomic DNA samples were obtained and screened for RPGR (RP3) mutations by direct polymerase chain reaction sequencing.ResultsThe proband had RP with bilateral Coats'-like vasculopathy and was treated with fluorescein-potentiated argon laser therapy. The findings in two other affected male patients and three obligate carrier female patients were within the clinical spectrum of a typical X-linked-recessive RP. A novel nonsense RPGR exon ORF15 mutation (912G>T) was found to segregate with RP in this family.ConclusionsThis report expands the clinical heterogeneity spectrum caused by RPGR mutations and our knowledge concerning the molecular pathologic condition that pertains to Coats'-like RP. Consistent with the literature, Coats' response was not observed in all family members who were affected by RP, which suggests the involvement of other genetic and/or environmental factors
Effect of vaccine effectiveness and safety on COVID-19 vaccine acceptance in Detroit, Michigan, July 2020
This study examined whether future COVID-19 vaccine acceptance differed based on an experimental manipulation of the vaccine safety and effectiveness profile. Data come from the Detroit Metro Area Community Study, a population-based study conducted July 15â20, 2020. Participants were asked whether they would get a new COVID-19 vaccine after being randomly assigned information about the vaccineâs effectiveness (50% or 95%) and chance of fever (5% or 20%). Among 1,117 Detroiters, 51.3% would accept a COVID-19 vaccine that is 50% effective and 77.1% would accept a vaccine that is 95% effective. Women and adults â„65 were more accepting of a vaccine; Black Detroiters were less accepting. Believing vaccines to be important, effective, and safe was associated with higher acceptance. Uptake of a COVID-19 may be limited, depending on perceived vaccine effectiveness and general attitudes toward vaccines. Public health approaches to modifying these attitudes will be especially important in the Black community