118 research outputs found
Mutations in FRMD7, a newly identified member of the FERM family, cause X-linked idiopathic congenital nystagmus.
Idiopathic congenital nystagmus is characterized by involuntary, periodic, predominantly horizontal oscillations of both eyes. We identified 22 mutations in FRMD7 in 26 families with X-linked idiopathic congenital nystagmus. Screening of 42 singleton cases of idiopathic congenital nystagmus (28 male, 14 females) yielded three mutations (7%). We found restricted expression of FRMD7 in human embryonic brain and developing neural retina, suggesting a specific role in the control of eye movement and gaze stability
The New Horizons Spacecraft
The New Horizons spacecraft was launched on 19 January 2006. The spacecraft
was designed to provide a platform for seven instruments that will collect and
return data from Pluto in 2015. The design drew on heritage from previous
missions developed at The Johns Hopkins University Applied Physics Laboratory
(APL) and other missions such as Ulysses. The trajectory design imposed
constraints on mass and structural strength to meet the high launch
acceleration needed to reach the Pluto system prior to the year 2020. The
spacecraft subsystems were designed to meet tight mass and power allocations,
yet provide the necessary control and data handling finesse to support data
collection and return when the one-way light time during the Pluto flyby is 4.5
hours. Missions to the outer solar system require a radioisotope thermoelectric
generator (RTG) to supply electrical power, and a single RTG is used by New
Horizons. To accommodate this constraint, the spacecraft electronics were
designed to operate on less than 200 W. The spacecraft system architecture
provides sufficient redundancy to provide a probability of mission success of
greater than 0.85, even with a mission duration of over 10 years. The
spacecraft is now on its way to Pluto, with an arrival date of 14 July 2015.
Initial inflight tests have verified that the spacecraft will meet the design
requirements.Comment: 33 pages, 13 figures, 4 tables; To appear in a special volume of
Space Science Reviews on the New Horizons missio
Long-range and rapid transport of individual nano-objects by a hybrid electrothermoplasmonic nanotweezer
Plasmon-enhanced optical trapping is being actively studied to provide efficient manipulation of nanometre-sized objects. However, a long-standing issue with previously proposed solutions is how to controllably load the trap on-demand without relying on Brownian diffusion. Here, we show that the photo-induced heating of a nanoantenna in conjunction with an applied a.c. electric field can initiate rapid microscale fluid motion and particle transport with a velocity exceeding 10 μm s -1 , which is over two orders of magnitude faster than previously predicted. Our electrothermoplasmonic device enables on-demand long-range and rapid delivery of single nano-objects to specific plasmonic nanoantennas, where they can be trapped and even locked in place. We also present a physical model that elucidates the role of both heat-induced fluidic motion and plasmonic field enhancement in the plasmon-assisted optical trapping process. Finally, by applying a d.c. field or low-frequency a.c. field (below 10 Hz) while the particle is held in the trap by the gradient force, the trapped nano-objects can be immobilized into plasmonic hotspots, thereby providing the potential for effective low-power nanomanufacturing on-chip
Pathogenic Activation of Mesenchymal Stem Cells Is Induced by the Disease Microenvironment in Systemic Sclerosis
Objective:
In systemic sclerosis (SSc), a persistent tissue repair process leads to progressive fibrosis of the skin and internal organs. The role of mesenchymal stem cells (MSCs), which characteristically initiate and regulate tissue repair, has not been fully evaluated. We undertook this study to investigate whether dividing metakaryotic MSCs are present in SSc skin and to examine whether exposure to the disease microenvironment activates MSCs and leads to transdifferentiation.
Methods:
Skin biopsy material from patients with recent-onset diffuse SSc was examined by collagenase spread of 1-mm–thick surface-parallel sections, in order to identify dividing metakaryotic stem cells in each tissue plane. Adipose-derived MSCs from healthy controls were treated with dermal blister fluid (BF) from patients with diffuse SSc and profiled by next-generation sequencing, or they were evaluated for phenotypic changes relevant to SSc. Differential responses of dermal fibroblasts were studied in parallel.
Results:
MSC-like cells undergoing active metakaryotic division were identified in SSc sections (but not control sections) most prominently in the deep dermis and adjacent to damaged microvessels, in both clinically involved and uninvolved skin. Furthermore, exposure to SSc BF caused selective MSC activation, inducing a myofibroblast signature, while reducing signatures of vascular repair and adipogenesis and enhancing migration and contractility. Microenvironmental factors implicated in inducing transdifferentiation included the profibrotic transforming growth factor β, the presence of lactate, and mechanosensing, while the microenvironment Th2 cytokine, interleukin-31, enhanced osteogenic commitment (calcinosis).
Conclusion:
Dividing MSC-like cells are present in the SSc disease microenvironment where multiple factors, likely acting in concert, promote transdifferentiation and lead to a complex and resistant disease state
Mutations in FRMD7, a newly identified member of the FERM family, cause X-linked idiopathic congenital nystagmus
Idiopathic congenital nystagmus (ICN) is characterised by involuntary, periodic, predominantly horizontal, oscillations of both eyes. We identified 22 mutations in FRMD7 in 26 families with X-linked idiopathic congenital nystagmus. Screening of 42 ICN singleton cases (28 male, 14 females) yielded three mutations (7%). We found restricted expression of FRMD7 in human embryonic brain and developing neural retina suggesting a specific role in the control of eye movement and gaze stability
The topography of mutational processes in breast cancer genomes.
Somatic mutations in human cancers show unevenness in genomic distribution that correlate with aspects of genome structure and function. These mutations are, however, generated by multiple mutational processes operating through the cellular lineage between the fertilized egg and the cancer cell, each composed of specific DNA damage and repair components and leaving its own characteristic mutational signature on the genome. Using somatic mutation catalogues from 560 breast cancer whole-genome sequences, here we show that each of 12 base substitution, 2 insertion/deletion (indel) and 6 rearrangement mutational signatures present in breast tissue, exhibit distinct relationships with genomic features relating to transcription, DNA replication and chromatin organization. This signature-based approach permits visualization of the genomic distribution of mutational processes associated with APOBEC enzymes, mismatch repair deficiency and homologous recombinational repair deficiency, as well as mutational processes of unknown aetiology. Furthermore, it highlights mechanistic insights including a putative replication-dependent mechanism of APOBEC-related mutagenesis
An FDA bioinformatics tool for microbial genomics research on molecular characterization of bacterial foodborne pathogens using microarrays
<p>Abstract</p> <p>Background</p> <p>Advances in microbial genomics and bioinformatics are offering greater insights into the emergence and spread of foodborne pathogens in outbreak scenarios. The Food and Drug Administration (FDA) has developed a genomics tool, ArrayTrack<sup>TM</sup>, which provides extensive functionalities to manage, analyze, and interpret genomic data for mammalian species. ArrayTrack<sup>TM</sup> has been widely adopted by the research community and used for pharmacogenomics data review in the FDA’s Voluntary Genomics Data Submission program. </p> <p>Results</p> <p>ArrayTrack<sup>TM</sup> has been extended to manage and analyze genomics data from bacterial pathogens of human, animal, and food origin. It was populated with bioinformatics data from public databases such as NCBI, Swiss-Prot, KEGG Pathway, and Gene Ontology to facilitate pathogen detection and characterization. ArrayTrack<sup>TM</sup>’s data processing and visualization tools were enhanced with analysis capabilities designed specifically for microbial genomics including flag-based hierarchical clustering analysis (HCA), flag concordance heat maps, and mixed scatter plots. These specific functionalities were evaluated on data generated from a custom Affymetrix array (FDA-ECSG) previously developed within the FDA. The FDA-ECSG array represents 32 complete genomes of <it>Escherichia coli</it> and<it> Shigella.</it> The new functions were also used to analyze microarray data focusing on antimicrobial resistance genes from <it>Salmonella</it> isolates in a poultry production environment using a universal antimicrobial resistance microarray developed by the United States Department of Agriculture (USDA).</p> <p>Conclusion</p> <p>The application of ArrayTrack<sup>TM</sup> to different microarray platforms demonstrates its utility in microbial genomics research, and thus will improve the capabilities of the FDA to rapidly identify foodborne bacteria and their genetic traits (e.g., antimicrobial resistance, virulence, etc.) during outbreak investigations. ArrayTrack<sup>TM</sup> is free to use and available to public, private, and academic researchers at <url>http://www.fda.gov/ArrayTrack</url>. </p
GISTIC2.0 facilitates sensitive and confident localization of the targets of focal somatic copy-number alteration in human cancers
We describe methods with enhanced power and specificity to identify genes targeted by somatic copy-number alterations (SCNAs) that drive cancer growth. By separating SCNA profiles into underlying arm-level and focal alterations, we improve the estimation of background rates for each category. We additionally describe a probabilistic method for defining the boundaries of selected-for SCNA regions with user-defined confidence. Here we detail this revised computational approach, GISTIC2.0, and validate its performance in real and simulated datasets
Parental Child Care in Single Parent, Cohabiting, and Married Couple Families: Time Diary Evidence from the United States and the United Kingdom
Simulating Bacterial Growth, Competition, and Resistance with Agent-Based Models and Laboratory Experiments
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