4,580 research outputs found
Metrology Camera System of Prime Focus Spectrograph for Subaru Telescope
The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber
spectrograph designed for the prime focus of the 8.2m Subaru telescope. PFS
will cover a 1.3 degree diameter field with 2394 fibers to complement the
imaging capabilities of Hyper SuprimeCam. To retain high throughput, the final
positioning accuracy between the fibers and observing targets of PFS is
required to be less than 10um. The metrology camera system (MCS) serves as the
optical encoder of the fiber motors for the configuring of fibers. MCS provides
the fiber positions within a 5um error over the 45 cm focal plane. The
information from MCS will be fed into the fiber positioner control system for
the closed loop control. MCS will be located at the Cassegrain focus of Subaru
telescope in order to to cover the whole focal plane with one 50M pixel Canon
CMOS camera. It is a 380mm Schmidt type telescope which generates a uniform
spot size with a 10 micron FWHM across the field for reasonable sampling of
PSF. Carbon fiber tubes are used to provide a stable structure over the
operating conditions without focus adjustments. The CMOS sensor can be read in
0.8s to reduce the overhead for the fiber configuration. The positions of all
fibers can be obtained within 0.5s after the readout of the frame. This enables
the overall fiber configuration to be less than 2 minutes. MCS will be
installed inside a standard Subaru Cassgrain Box. All components that generate
heat are located inside a glycol cooled cabinet to reduce the possible image
motion due to heat. The optics and camera for MCS have been delivered and
tested. The mechanical parts and supporting structure are ready as of spring
2016. The integration of MCS will start in the summer of 2016.Comment: 11 pages, 15 figures. SPIE proceeding. arXiv admin note: text overlap
with arXiv:1408.287
Metrology Camera System of Prime Focus Spectrograph for Subaru Telescope
The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber
spectrograph designed for the prime focus of the 8.2m Subaru telescope. The
metrology camera system of PFS serves as the optical encoder of the COBRA fiber
motors for the configuring of fibers. The 380mm diameter aperture metrology
camera will locate at the Cassegrain focus of Subaru telescope to cover the
whole focal plane with one 50M pixel Canon CMOS sensor. The metrology camera is
designed to provide the fiber position information within 5{\mu}m error over
the 45cm focal plane. The positions of all fibers can be obtained within 1s
after the exposure is finished. This enables the overall fiber configuration to
be less than 2 minutes.Comment: 10 pages, 12 figures, SPIE Astronomical Telescopes and
Instrumentation 201
Intimate-Partner and Client-Initiated Violence among Female Street-Based Sex Workers in China: Does a Support Network Help?
Background
Globally, female street-based sex workers are vulnerable to gender-based violence. Previous research has shown having a peer social network can reduce sex workers’ risks of victimization. However, mechanisms of how social network impacts violence among female street-based sex workers are still far from clear.
Methods
Our study was based on data abstracted from a paper-and-pencil survey administered among 218 female street-based sex workers in Shanghai, China. We focused on self-reported client-initiated violence and intimate-partner violence in emotional, physical, and sexual forms. Social networks were characterized by the size and sources of financial and psychosocial support (e.g. family, friends, and peers). Multi-variable logistic regression was used to estimate adjusted odds ratios (AOR) of each type of violence exposure by social network structure after the adjustment of age, education, and years in Shanghai.
Results
The street-based female sex workers in our study were primarily rural-to-urban migrants (95.7%) with an average age of 41 years old. 24.3% and 62.8% of the sex workers reported intimate-partner violence and client-initiated violence respectively. Lack of financial support, as defined by having only one individual or none in her peer support system to help financially, was significantly associated with self-reported intimate-partner violence (AOR: 2.5; 95% CI: 1.1–5.9). Respondents who reported client-initiated violence, by contrast, were more likely to report lacked psychosocial support from family (AOR: 2.2, 95% CI: 1.0–4.6) and peers (AOR: 5.1, 95% CI: 2.2–11).
Conclusion
This study is one of the first to systematically analyze the associations between social network and gender-based violence among street-based female sex worker. We reported a high prevalence of both types of gender-based violence and their complex associations with family, friends, and peer support network. Policies with goals to reduce violence against women may apply these findings to leverage social network in the interventions against gender-based violence
Blind study evaluation illustrates utility of the Ion PGM™ system for use in human identity DNA typing
Aim To perform a blind study to assess the capability of
the Ion Personal Genome Machine® (PGM™) system to sequence
forensically relevant genetic marker panels and to
characterize unknown individuals for ancestry and possible
relatedness.
Methods Twelve genomic samples were provided by a
third party for blinded genetic analysis. For these 12 samples,
the mitochondrial genome and three PGM™ panels
containing human identity single nucleotide polymorphisms
(SNPs), ancestry informative SNPs, and short tandem
repeats (STRs) were sequenced on the PGM™ system
and analyzed.
Results All four genetic systems were run and analyzed on
the PGM™ system in a reasonably quick time frame. Completeness
of genetic profiles, depth of coverage, strand
balance, and allele balance were informative metrics that
illustrated the quality and reliability of the data produced.
SNP genotypes allowed for identification of sex, paternal
lineage, and population ancestry. STR genotypes were
shown to be in complete concordance with genotypes
generated by standard capillary electrophoresis-based
technologies. Variants in the mitochondrial genome data
provided information on population background and maternal
relationships.
Conclusion All results from analysis of the 12 genomic
samples were consistent with sample information provided
by the sample providers at the end of the blinded study.
The relatively easy identification of intra-STR allele SNPs offered
the potential for increased discrimination power. The
promising nature of these results warrants full validation
studies of this massively parallel sequencing technology
and its further development for forensic data analysis
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A double masked randomised 4-week, placebo-controlled study in the USA, Thailand and Taiwan to compare the efficacy of oral valganciclovir and topical 2% ganciclovir in the treatment of cytomegalovirus anterior uveitis: study protocol.
IntroductionCytomegalovirus (CMV) anterior uveitis is a recognised cause of anterior uveitis in immunocompetent patients and is preventable cause of vision loss. Ocular sequelae include corneal endothelial damage which can cause corneal oedema and failure, as well as glaucoma. Recurrences of inflammation are common and therefore patients are often exposed to long-term therapy. Oral therapy is available in the form of valganciclovir, although with the caveat of systemic side effects such as bone marrow suppression and renal failure necessitating regular interval laboratory monitoring. Recent reports have demonstrated that topical 2% ganciclovir solution may offer promising treatment outcomes in patients with CMV anterior uveitis with superior safety, cost-effectiveness and convenience profiles. An investigation into the relative equipoise of these therapies is warranted for these reasons.Methods and analysisThe Systemic and Topical Control of Cytomegalovirus Anterior uveitis: Treatment Outcomes (STACCATO) trial is designed as a multicentre, block randomised by site, double-masked, placebo-controlled trial comparing the efficacy of oral valganciclovir, 2% topical ganciclovir and placebo in treating PCR-proven CMV anterior uveitis. Participant clinical evaluation will occur at three study time points by a masked study ophthalmologist over a 28-day period to assess resolution of ocular inflammation (secondary outcome). A control group will provide additional information about the possible impact that the infected host's immune response may play in controlling local viral replication. The primary analysis is an analysis of covariance (three arms) correcting for baseline to compare quantitative CMV viral load in the anterior chamber (AC) aqueous fluid before and 7 days after treatment.Ethics and disseminationThe University of California San Francisco Committee on Human Research and the Khon Kaen University Institutional Review Board have given ethical approval. The results of this trial will be presented at local and international meetings and submitted for peer-reviewed journals for publication.Trial registration numberNCT03576898
Constitutive Gs activation using a single-construct tetracycline-inducible expression system in embryonic stem cells and mice
Abstract Introduction The controlled expression of many genes, including G-protein coupled receptors (GPCRs), is important for delineating gene functions in complex model systems. Binary systems for inducible regulation of transgene expression are widely used in mice. One system is the tTA/TRE expression system, composed of a tetracycline-dependent DNA binding factor and a separate tetracycline operon. However, the requirement for two separate transgenes (one for each tTA or TRE component) makes this system less amenable to models requiring directed cell targeting, increases the risk of multiple transgene integration sites, and requires extensive screening for appropriately-functioning clones. Methods We developed a single, polycistronic tetracycline-inducible expression platform to control the expression of multiple cistrons in mammalian cells. This platform has three basic constructs: regulator, responder, and destination vectors. The modular platform is compatible with both the TetOff (tTA) and TetOn (rtTA) systems. The modular Gateway recombineering-compatible components facilitate rapidly generating vectors to genetically modify mammalian cells. We apply this system to use the elongation factor 1α (EF1α) promoter to drive doxycycline-regulated expression of both the fluorescent marker mCherry and an engineered Gs-coupled GPCR "Rs1" separated by a 2A ribosomal skip site. Results We show that our combined expression construct drives expression of both the mCherry and Rs1 transgenes in a doxycycline-dependent manner. We successfully target the expression construct into the Rosa26 locus of mouse embryonic stem (ES) cells. Rs1 expression in mouse ES cells increases cAMP accumulation via both basal and ligand-induced Gs mechanisms and is associated with increased embryoid body size. Heterozygous mice carrying the Rs1 expression construct showed normal growth and weight, and developed small increases in bone formation that could be observed in the calvaria. Conclusions Our results demonstrate the feasibility of a single-vector strategy that combines both the tTA and TRE tetracycline-regulated components for use in cells and mouse models. Although the EF1α promoter is useful for driving expression in pluripotent cells, a single copy of the EF1α promoter did not drive high levels of mCherry and Rs1 expression in the differentiated tissues of adult mice. These findings indicate that promoter selection is an important factor when developing transgene expression models
Drosophila melanogaster auxilin regulates the internalization of Delta to control activity of the Notch signaling pathway
We have isolated mutations in the Drosophila melanogaster homologue of auxilin, a J-domain–containing protein known to cooperate with Hsc70 in the disassembly of clathrin coats from clathrin-coated vesicles in vitro. Consistent with this biochemical role, animals with reduced auxilin function exhibit genetic interactions with Hsc70 and clathrin. Interestingly, the auxilin mutations interact specifically with Notch and disrupt several Notch-mediated processes. Genetic evidence places auxilin function in the signal-sending cells, upstream of Notch receptor activation, suggesting that the relevant cargo for this auxilin-mediated endocytosis is the Notch ligand Delta. Indeed, the localization of Delta protein is disrupted in auxilin mutant tissues. Thus, our data suggest that auxilin is an integral component of the Notch signaling pathway, participating in the ubiquitin-dependent endocytosis of Delta. Furthermore, the fact that auxilin is required for Notch signaling suggests that ligand endocytosis in the signal-sending cells needs to proceed past coat disassembly to activate Notch
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