620 research outputs found
A recurrent mosaic mutation of SMO, encoding the hedgehog signal transducer smoothened, is the major cause of Curry-Jones syndrome
Curry-Jones syndrome (CJS) is a multisystem disorder characterized by patchy skin lesions, polysyndactyly, diverse cerebral malformations, unicoronal craniosynostosis, iris colobomas, microphthalmia, and intestinal malrotation with myofibromas or hamartomas. Cerebellar medulloblastoma has been described in a single affected individual; in another, biopsy of skin lesions showed features of trichoblastoma. The combination of asymmetric clinical features, patchy skin manifestations, and neoplastic association previously led to the suggestion that this could be a mosaic condition, possibly involving hedgehog (Hh) signaling. Here, we show that CJS is caused by recurrent somatic mosaicism for a nonsynonymous variant in SMO (c.1234C>T [p.Leu412Phe]), encoding smoothened (SMO), a G-protein-coupled receptor that transduces Hh signaling. We identified eight mutation-positive individuals (two of whom had not been reported previously) with highly similar phenotypes and demonstrated varying amounts of the mutant allele in different tissues. We present detailed findings from brain MRI in three mutation-positive individuals. Somatic SMO mutations that result in constitutive activation have been described in several tumors, including medulloblastoma, ameloblastoma, and basal cell carcinoma. Strikingly, the most common of these mutations is the identical nonsynonymous variant encoding p.Leu412Phe. Furthermore, this substitution has been shown to activate SMO in the absence of Hh signaling, providing an explanation for tumor development in CJS. This raises therapeutic possibilities for using recently generated Hh-pathway inhibitors. In summary, our work uncovers the major genetic cause of CJS and illustrates strategies for gene discovery in the context of low-level tissue-specific somatic mosaicism
The Evolution of Expressing and Exchanging Cyber-Investigation Information in a Standardized Form
The growing number of investigations involving digital traces from various data sources is driving the demand for a standard way to represent and exchange pertinent information. Enabling automated combination and correlation of cyber-investigation information from multiple systems or organizations enables more efficient and comprehensive analysis, reducing the risk of mistakes and missed opportunities. These needs are being met by the evolving open-source, community-developed specification language called CASE, the Cyber-investigation Analysis Standard Expression. CASE leverages the Unified Cyber Ontology (UCO), which abstracts and expresses concepts that are common across multiple domains. This paper introduces CASE and UCO, explaining how they improve upon prior related work. The value of fully-structured data, representing provenance, and action lifecycles are discussed. The guiding principles of CASE and UCO are presented, and illustrative examples of CASE are provided using the default JSON-LD serialization
Pathogenesis of Scleroderma
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65784/1/j.1365-4362.1984.tb05678.x.pd
Lattice Boltzmann simulations of soft matter systems
This article concerns numerical simulations of the dynamics of particles
immersed in a continuum solvent. As prototypical systems, we consider colloidal
dispersions of spherical particles and solutions of uncharged polymers. After a
brief explanation of the concept of hydrodynamic interactions, we give a
general overview over the various simulation methods that have been developed
to cope with the resulting computational problems. We then focus on the
approach we have developed, which couples a system of particles to a lattice
Boltzmann model representing the solvent degrees of freedom. The standard D3Q19
lattice Boltzmann model is derived and explained in depth, followed by a
detailed discussion of complementary methods for the coupling of solvent and
solute. Colloidal dispersions are best described in terms of extended particles
with appropriate boundary conditions at the surfaces, while particles with
internal degrees of freedom are easier to simulate as an arrangement of mass
points with frictional coupling to the solvent. In both cases, particular care
has been taken to simulate thermal fluctuations in a consistent way. The
usefulness of this methodology is illustrated by studies from our own research,
where the dynamics of colloidal and polymeric systems has been investigated in
both equilibrium and nonequilibrium situations.Comment: Review article, submitted to Advances in Polymer Science. 16 figures,
76 page
The decatenation checkpoint
The decatenation checkpoint delays entry into mitosis until the chromosomes have been disentangled. Deficiency in or bypass of the decatenation checkpoint can cause chromosome breakage and nondisjunction during mitosis, which results in aneuploidy and chromosome rearrangements in the daughter cells. A deficiency in the decatenation checkpoint has been reported in lung and bladder cancer cell lines and may contribute to the accumulation of chromosome aberrations that commonly occur during tumour progression. A checkpoint deficiency has also been documented in cultured stem and progenitor cells, and cancer stem cells are likely to be derived from stem and progenitor cells that lack an effective decatenation checkpoint. An inefficient decatenation checkpoint is likely to be a source of the chromosome aberrations that are common features of most tumours, but an inefficient decatenation checkpoint in cancer stem cells could also provide a potential target for chemotherapy
Resilience in education: An example from primary school in Fiji and technical vocational education and training
In the Pacific, the capacity of curriculum writers for integrating the content of climate change into their curricula and/or taught Resilience [Climate Change Adaptation (CCA) & Disaster Risk Reduction (DRR)] in education is limited. This paper described the findings of a 2018 study on the integration of climate change into primary and secondary schoolsā curricula and taught resilience in education in TVET. It involves teachers (nā=ā30) from Kadavu and Levuka islands, curriculum writers and editors from the Ministry of Education, GIZ, SPC, and USPāin Fiji. An exploratory design was used to explore the curricula for Fiji and the EU PacTVET project at SPC. Information was collected from workshops and training events, interviews and project documents. Using BEKA (Benchmarking, Evidencing, Knowing, Applying) and the concept of ako (e.g. to study or educate), a model of climate change and resilience in education was designed as part of this research to help Pacific schools with their curricula. These results indicate how behavioural changes may shape Resilience, thus placing them in a better position to achieve the UNFCCC, the SDGs, the Sendai Framework and the Framework for Resilient Development in the Pacific (FRDP) targets and objectives by 2030 and beyond
A First- and Second-Order Motion Energy Analysis of Peripheral Motion Illusions Leads to Further Evidence of āFeature Blurā in Peripheral Vision
Anatomical and physiological differences between the central and peripheral visual systems are well documented. Recent findings have suggested that vision in the periphery is not just a scaled version of foveal vision, but rather is relatively poor at representing spatial and temporal phase and other visual features. Shapiro, Lu, Huang, Knight, and Ennis (2010) have recently examined a motion stimulus (the ācurveball illusionā) in which the shift from foveal to peripheral viewing results in a dramatic spatial/temporal discontinuity. Here, we apply a similar analysis to a range of other spatial/temporal configurations that create perceptual conflict between foveal and peripheral vision.To elucidate how the differences between foveal and peripheral vision affect super-threshold vision, we created a series of complex visual displays that contain opposing sources of motion information. The displays (referred to as the peripheral escalator illusion, peripheral acceleration and deceleration illusions, rotating reversals illusion, and disappearing squares illusion) create dramatically different perceptions when viewed foveally versus peripherally. We compute the first-order and second-order directional motion energy available in the displays using a three-dimensional Fourier analysis in the (x, y, t) space. The peripheral escalator, acceleration and deceleration illusions and rotating reversals illusion all show a similar trend: in the fovea, the first-order motion energy and second-order motion energy can be perceptually separated from each other; in the periphery, the perception seems to correspond to a combination of the multiple sources of motion information. The disappearing squares illusion shows that the ability to assemble the features of Kanisza squares becomes slower in the periphery.The results lead us to hypothesize āfeature blurā in the periphery (i.e., the peripheral visual system combines features that the foveal visual system can separate). Feature blur is of general importance because humans are frequently bringing the information in the periphery to the fovea and vice versa
A High-Density EEG Investigation into Steady State Binaural Beat Stimulation
Binaural beats are an auditory phenomenon that has been suggested to alter physiological and cognitive processes including vigilance and brainwave entrainment. Some personality traits measured by the NEO Five Factor Model have been found to alter entrainment using pulsing light stimuli, but as yet no studies have examined if this occurs using steady state presentation of binaural beats for a relatively short presentation of two minutes. This study aimed to examine if binaural beat stimulation altered vigilance or cortical frequencies and if personality traits were involved. Thirty-one participants were played binaural beat stimuli designed to elicit a response at either the Theta (7 Hz) or Beta (16 Hz) frequency bands while undertaking a zero-back vigilance task. EEG was recorded from a high-density electrode cap. No significant differences were found in vigilance or cortical frequency power during binaural beat stimulation compared to a white noise control period. Furthermore, no significant relationships were detected between the above and the Big Five personality traits. This suggests a short presentation of steady state binaural beats are not sufficient to alter vigilance or entrain cortical frequencies at the two bands examined and that certain personality traits were not more susceptible than others
Natural moissanite (SiC) ā a low temperature mineral formed from highly fractionated ultra-reducing COH-fluids
Correlates of ObsessiveāCompulsive Disorder in a Sample of HIV-Positive, Methamphetamine-using Men Who have Sex with Men
Substance use has been identified as a risk factor for elevated levels of obsessiveācompulsive disorder (OCD). This study examined methamphetamine use and sexual risk behaviors as correlates of OCD in a sample of 245 HIV-positive men having sex with men (MSM) in San Diego, CA. In a logistic regression analysis, OCD was associated with greater frequency of methamphetamine use, more depressive symptoms, seeking out risky venues and risky sexual partners when āhighā on methamphetamine, and reporting fewer sex acts in the past 2Ā months. These data suggest the need for increased awareness and understanding of the role that OCD may play in the drug use behaviors and risky sexual practices of methamphetamine users
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