294 research outputs found
Modeling of vegetated rivers for inbank and overbank flows
Model parameters such as friction factor and eddy viscosity in the Shiono & Knight method (SKM) are considered through experimental data obtained from a vegetated open channel. The experiment was conducted in a rectangular open channel with cylindrical rods as vegetation. Velocity, Reynolds stresses and boundary shear stress were measured with Acoustic Doppler Velocimetry (ADV) and a Preston tube re-spectively. Both friction factor and eddy viscosity were calculated using the measured data and found to be not constant in the shear layer generated by rods. The analytical solutions of SKM to predict velocity and boundary shear stress currently in use were based on the constant assumption of these parameters. In this pa-per a new analytical solution was derived by taking into a variation of these parameters account and was also verified with the experimental data. This solution was also applied to flow in compound channel with vegeta-tion. The new solution gives a good prediction of the lateral distribution of depth-averaged velocity and boundary shear stress in vegetated channels, and it predicts the boundary shear stress better than that of the original solution without considering the secondary flow term in particular
Participatory Radiation Information Monitoring with SNS after Fukushima
ABSTRACT We developed a series of inexpensive but accurate mobile radiation detectors, which we named Pocket Geiger (POKEGA), to address the urgent desire of ordinary people to measure and share radiation levels in their milieus and to discuss the results of the Nuclear Disaster in Fukushima, Japan. This action research reports on a new style of pragmatic model of radiation monitoring, which employs the features of Participatory Design and Participatory Sensing and adopts modern communication platforms such as crowd-funding, open source development, and Facebook. This paper proposes an interaction model between the project management body, and other inclusive corroborators, e.g., ordinary users and experts, and focuses on three development phases of the project: start-up phase, evaluation phase, and operation phase. This paper also considers a reliability assurance model on disaster information sharing between the citizen layer and the official layer by data sharing and discussion activities in the POKEGA community
Existence of Tidal Tails for the Globular Cluster NGC 5824
Context. Several dynamically cold streams have been associated with certain
globular clusters (GCs) based on orbital energies and angular momenta. Some of
these streams are surprisingly far apart from their progenitors and one such
pair is Triangulum and NGC 5824. Triangulum can be considered as a piece of NGC
5824 leading tail since the cluster's future orbit matches with the stream's
track well. The existence of the leading tail for NGC 5824 is the motivation
behind the search for its trailing tail. Aims. Our goal is to confirm the
connection between Triangulum and NGC 5824 and seek the trailing tail of the
cluster. Methods. The selection of member stars of Triangulum is made through
various cuts in metallicity, proper motions (PMs), radial velocity and
color-magnitude diagram (CMD). The selected members are compared in phase space
to a mock stream which models the disruption of NGC 5824. We then try to detect
the trailing tail of the cluster based on a modified matched-filter technique.
Stars are assigned weights using their color differences from the cluster's
locus in CMD. These weights are further scaled based on stars' departures from
expected PMs of the model stream. Results. A total of 26 member stars for
Triangulum are obtained and 16 of them are newly identified. These members are
consistent with the mock stream in the phase space and their metalicity and
position on the CMD are in good agreements with NGC 5824. By applying the
matched-filter, a tenuous trailing tail of the cluster is detected, spanning
50 long on sky. The signature matches with the mock stream's
trajectory well. Conclusions. Our results support that Triangulum stream acts
as a part of the leading tail for NGC 5824. On the trailing side, we have
detected a 50 tail extended from the cluster. The existence of both
leading and trailing tails for the GC NGC 5824 is verified.Comment: Accepted for publication in A&
Red star-forming and blue passive galaxies in clusters
We explore the relation between colour and specific star formation rate
(derived from optical spectra obtained by SDSS DR4) of over 6,000 galaxies
(M_r<=-20.5) in and around low redshift (z<0.12) clusters. Even though most red
galaxies have little or no ongoing star formation, and most blue galaxies are
currently forming stars, there are significant populations of red star-forming
(SF) and blue passive galaxies. This paper examines various properties of
galaxies belonging to the latter two categories. These properties include
morphological parameters, internal extinction, spectral features such as
EW(H_delta) and the 4000 ang break, and metallicity. Our analysis shows that
the blue passive galaxies have properties very similar to their SF
counterparts, except that their large range in EW(H_delta) indicates recent
truncation of star formation. The red SF galaxies fall into two broad
categories, one of them being massive galaxies in cluster cores dominated by an
old stellar population, but with evidence of current star formation in the
core. For the remaining red SF galaxies it is evident from various metallicity
measures and mean stellar ages, that their colours result from the predominance
of a metal-rich stellar population. The implication of the properties of these
SF galaxies on environmental studies, like that of the Butcher-Oemler effect,
is discussed.Comment: 13 pages, 11 figures, accepted for publication in MNRA
Recommended from our members
Early progression to active tuberculosis is a highly heritable trait driven by 3q23 in Peruvians
Abstract: Of the 1.8 billion people worldwide infected with Mycobacterium tuberculosis, 5–15% will develop active tuberculosis (TB). Approximately half will progress to active TB within the first 18 months after infection, presumably because they fail to mount an effective initial immune response. Here, in a genome-wide genetic study of early TB progression, we genotype 4002 active TB cases and their household contacts in Peru. We quantify genetic heritability (hg2) of early TB progression to be 21.2% (standard error 0.08). This suggests TB progression has a strong genetic basis, and is comparable to traits with well-established genetic bases. We identify a novel association between early TB progression and variants located in a putative enhancer region on chromosome 3q23 (rs73226617, OR = 1.18; P = 3.93 × 10−8). With in silico and in vitro analyses we identify rs73226617 or rs148722713 as the likely functional variant and ATP1B3 as a potential causal target gene with monocyte specific function
The two eIF4A helicases in Trypanosoma brucei are functionally distinct
Protozoan parasites belonging to the family Trypanosomatidae are characterized by an unusual pathway for the production of mRNAs via polycistronic transcription and trans-splicing of a 5' capped mini-exon which is linked to the 3' cleavage and polyadenylation of the upstream transcript. However, little is known of the mechanism of protein synthesis in these organisms, despite their importance as agents of a number of human diseases. Here we have investigated the role of two Trypanosoma brucei homologues of the translation initiation factor eIF4A (in the light of subsequent experiments these were named as TbEIF4AI and TbEIF4AIII). eIF4A, a DEAD-box RNA helicase, is a subunit of the translation initiation complex eIF4F which binds to the cap structure of eukaryotic mRNA and recruits the small ribosomal subunit. TbEIF4AI is a very abundant predominantly cytoplasmic protein (over 1 x 10(5) molecules/cell) and depletion to similar to 10% of normal levels through RNA interference dramatically reduces protein synthesis one cell cycle following double-stranded RNA induction and stops cell proliferation. In contrast, TbEIF4AIII is a nuclear, moderately expressed protein (similar to 1-2 x 10(4) molecules/cell), and its depletion stops cellular proliferation after approximately four cell cycles. Ectopic expression of a dominant negative mutant of TbEIF4AI, but not of TbEIF4AIII, induced a slow growth phenotype in transfected cells. Overall, our results suggest that only TbEIF4AI is involved in protein synthesis while the properties and sequence of TbEIF4AIII indicate that it may be the orthologue of eIF4AIII, a component of the exon junction complex in mammalian cells
Disruption of Axonal Transport in Motor Neuron Diseases
Motor neurons typically have very long axons, and fine-tuning axonal transport is crucial for their survival. The obstruction of axonal transport is gaining attention as a cause of neuronal dysfunction in a variety of neurodegenerative motor neuron diseases. Depletions in dynein and dynactin-1, motor molecules regulating axonal trafficking, disrupt axonal transport in flies, and mutations in their genes cause motor neuron degeneration in humans and rodents. Axonal transport defects are among the early molecular events leading to neurodegeneration in mouse models of amyotrophic lateral sclerosis (ALS). Gene expression profiles indicate that dynactin-1 mRNA is downregulated in degenerating spinal motor neurons of autopsied patients with sporadic ALS. Dynactin-1 mRNA is also reduced in the affected neurons of a mouse model of spinal and bulbar muscular atrophy, a motor neuron disease caused by triplet CAG repeat expansion in the gene encoding the androgen receptor. Pathogenic androgen receptor proteins also inhibit kinesin-1 microtubule-binding activity and disrupt anterograde axonal transport by activating c-Jun N-terminal kinase. Disruption of axonal transport also underlies the pathogenesis of spinal muscular atrophy and hereditary spastic paraplegias. These observations suggest that the impairment of axonal transport is a key event in the pathological processes of motor neuron degeneration and an important target of therapy development for motor neuron diseases
Multimodal memory T cell profiling identifies a reduction in a polyfunctional Th17 state associated with tuberculosis progression
Mycobacterium tuberculosis (M.tb) results in 10 million active tuberculosis (TB) cases and 1.5 million deaths each year, making it the world's leading infectious cause of death. Infection leads to either an asymptomatic latent state or TB disease. Memory T cells have been implicated in TB disease progression, but the specific cell states involved have not yet been delineated because of the limited scope of traditional profiling strategies. Furthermore, immune activation during infection confounds underlying differences in T cell state distributions that influence risk of progression. Here, we used a multimodal single-cell approach to integrate measurements of transcripts and 30 functionally relevant surface proteins to comprehensively define the memory T cell landscape at steady state (i.e., outside of active infection). We profiled 500,000 memory T cells from 259 Peruvians > 4.7 years after they had either latent M.tb infection or active disease and defined 31 distinct memory T cell states, including a CD4+CD26+CD161+CCR6+ effector memory state that was significantly reduced in patients who had developed active TB (OR = 0.80, 95% CI: 0.73-0.87, p = 1.21 x 10-6). This state was also polyfunctional; in ex vivo stimulation, it was enriched for IL-17 and IL-22 production, consistent with a Th17-skewed phenotype, but also had more capacity to produce IFNgamma than other CD161+CCR6+ Th17 cells. Additionally, in progressors, IL-17 and IL-22 production in this cell state was significantly lower than in non-progressors. Reduced abundance and function of this state may be an important factor in failure to control M.tb infection. ### Competing Interest Statement The authors have declared no competing interest
Recommended from our members
Application of data fusion techniques and technologies for wearable health monitoring
Technological advances in sensors and communications have enabled discrete integration into everyday objects, both in the home and about the person. Information gathered by monitoring physiological, behavioural, and social aspects of our lives, can be used to achieve a positive impact on quality of life, health, and well-being. Wearable sensors are at the cusp of becoming truly pervasive, and could be woven into the clothes and accessories that we wear such that they become ubiquitous and transparent. To interpret the complex multidimensional information provided by these sensors, data fusion techniques are employed to provide a meaningful representation of the sensor outputs. This paper is intended to provide a short overview of data fusion techniques and algorithms that can be used to interpret wearable sensor data in the context of health monitoring applications. The application of these techniques are then described in the context of healthcare including activity and ambulatory monitoring, gait analysis, fall detection, and biometric monitoring. A snap-shot of current commercially available sensors is also provided, focusing on their sensing capability, and a commentary on the gaps that need to be bridged to bring research to market
Nuclear RNA export factor 7 is localized in processing bodies and neuronal RNA granules through interactions with shuttling hnRNPs
The nuclear RNA export factor (NXF) family proteins have been implicated in various aspects of post-transcriptional gene expression. This study shows that mouse NXF7 exhibits heterologous localization, i.e. NXF7 associates with translating ribosomes, stress granules (SGs) and processing bodies (P-bodies), the latter two of which are believed to be cytoplasmic sites of storage, degradation and/or sorting of mRNAs. By yeast two-hybrid screening, a series of heterogeneous nuclear ribonucleoproteins (hnRNPs) were identified as possible binding partners for NXF7. Among them, hnRNP A3, which is believed to be involved in translational control and/or cytoplasmic localization of certain mRNAs, formed a stable complex with NXF7 in vitro. Although hnRNP A3 was not associated with translating ribosomes, it was co-localized with NXF7 in P-bodies. After exposing to oxidative stress, NXF7 trans-localized to SGs, whereas hnRNP A3 did not. In differentiated neuroblastoma Neuro2a cells, NXF7 was co-localized with hnRNP A3 in cell body and neurites. The amino terminal half of NXF7, which was required for stable complex formation with hnRNP A3, coincided with the region required for localization in both P-bodies and neuronal RNA granules. These findings suggest that NXF7 plays a role in sorting, transport and/or storage of mRNAs through interactions with hnRNP A3
- …