1,219 research outputs found
CCD Readout Electronics for the Subaru Prime Focus Spectrograph
We present details of the design for the CCD readout electronics for the
Subaru Telescope Prime Focus Spectrograph (PFS). The spectrograph is comprised
of four identical spectrograph modules, each collecting roughly 600 spectra.
The spectrograph modules provide simultaneous wavelength coverage over the
entire band from 380 nm to 1260 nm through the use of three separate optical
channels: blue, red, and near infrared (NIR). A camera in each channel images
the multi-object spectra onto a 4k x 4k, 15 um pixel, detector format. The two
visible cameras use a pair of Hamamatsu 2k x 4k CCDs with readout provided by
custom electronics, while the NIR camera uses a single Teledyne HgCdTe 4k x 4k
detector and ASIC Sidecar to read the device.
The CCD readout system is a custom design comprised of three electrical
subsystems: the Back End Electronics (BEE), the Front End Electronics (FEE),
and a Pre-amplifier. The BEE is an off-the-shelf PC104 computer, with an
auxiliary Xilinx FPGA module. The computer serves as the main interface to the
Subaru messaging hub and controls other peripheral devices associated with the
camera, while the FPGA is used to generate the necessary clocks and transfer
image data from the CCDs. The FEE board sets clock biases, substrate bias, and
CDS offsets. It also monitors bias voltages, offset voltages, power rail
voltage, substrate voltage and CCD temperature. The board translates LVDS clock
signals to biased clocks and returns digitized analog data via LVDS. Monitoring
and control messages are sent from the BEE to the FEE using a standard serial
interface. The Pre-amplifier board resides behind the detectors and acts as an
interface to the two Hamamatsu CCDs. The Pre-amplifier passes clocks and biases
to the CCDs, and analog CCD data is buffered and amplified prior to being
returned to the FEE.Comment: 14 pages, 15 figures, SPIE ATI 2014, Montrea
Diagnostic Performance of a Combination Biomarker Algorithm for Rule-Out of Acute Myocardial Infarction at Time of Presentation to the Emergency Department, Using Heart-Type Fatty Acid-Binding Protein and High-Sensitivity Troponin T tests
Risk factors associated with detailed reproductive phenotypes in dairy and beef cows
peer-reviewedThis article was first published in animal, Volume 8, Issue 05, May 2014, pp 695-703, © The Animal Consortium 2014The objective of this study was to identify detailed fertility traits in dairy and beef cattle from transrectal ultrasonography records
and quantify the associated risk factors. Data were available on 148 947 ultrasound observations of the reproductive tract from
75 949 cows in 843 Irish dairy and beef herds between March 2008 and October 2012. Traits generated included (1) cycling at
time of examination, (2) cystic structures, (3) early ovulation, (4) embryo death and (5) uterine score; the latter was measured on a
scale of 1 (good) to 4 (poor) characterising the tone of the uterine wall and fluid present in the uterus. After editing, 72 773
records from 44 415 dairy and beef cows in 643 herds remained. Factors associated with the logit of the probability of a positive
outcome for each of the binary fertility traits were determined using generalised estimating equations; linear mixed model analysis
was used for the analysis of uterine score. The prevalence of cycling, cystic structures, early ovulation and embryo death was
84.75%, 3.87%, 7.47% and 3.84%, respectively. The occurrence of the uterine heath score of 1, 2, 3 and 4 was 70.63%, 19.75%,
8.36% and 1.26%, respectively. Cows in beef herds had a 0.51 odds (95% CI = 0.41 to 0.63, P<0.001) of cycling at the time of
examination compared with cows in dairy herds; stage of lactation at the time of examination was the same in both herd types.
Furthermore, cows in dairy herds had an inferior uterine score (indicating poorer tone and a greater quantity of uterine fluid
present) compared with cows in beef herds. The likelihood of cycling at the time of examination increased with parity and stage of
lactation, but was reduced in cows that had experienced dystocia in the previous calving. The presence of cystic structures on the
ovaries increased with parity and stage of lactation. The likelihood of embryo/foetal death increased with parity and stage of
lactation. Dystocia was not associated with the presence of cystic structures or embryo death. Uterine score improved with parity
and stage of lactation, while cows that experienced dystocia in the previous calving had an inferior uterine score. Heterosis was
the only factor associated with increased likelihood of early ovulation. The fertility traits identified, and the associated risk factors,
provide useful information on the reproductive status of dairy and beef cows.Funding from the Department of Agriculture, Food and Marine Research Stimulus Fund (RSF 11/S/133) and the OptiMIR project is gratefully acknowledged
The impact of protocol assignment for older adolescents with Hodgkin lymphoma
Background and Purpose: Hodgkin lymphoma (HL) treatment has evolved to reduce or avoid radiotherapy (RT) dose and volume and minimize the potential for late effects. Some older adolescents are treated on adult protocols. The purpose of this study is to examine the protocol assignment of older adolescents and its impact on radiation dose to relevant thoracic structures.
Materials and Methods: Cooperative group data were reviewed and 12 adolescents were randomly selected from a pediatric HL protocol. Treatment plans were generated per one pediatric and two adult protocols. Dose volume histograms for heart, lung, and breast allowed comparison of radiation dose to these sites across these three protocols.
Results: A total of 15.2% of adolescents were treated on adult HL protocols and received significantly higher radiation dosage to heart and lung compared to pediatric HL protocols. Adolescents treated on either pediatric or adult protocols received similar RT dose to breast.
Conclusion: Older adolescents treated on adult HL protocols received higher RT dose to thoracic structures except breast. Level of nodal involvement may impact overall RT dose to breast. The impact of varying field design and RT dose on survival, local, and late effects needs further study for this vulnerable age group
Colwellia psychrerythraea Strains from Distant Deep Sea Basins Show Adaptation to Local Conditions
Many studies have shown that microbes, which share nearly identical 16S rRNA genes, can have highly divergent genomes. Microbes from distinct parts of the ocean also exhibit biogeographic patterning. Here we seek to better understand how certain microbes from the same species have adapted for growth under local conditions. The phenotypic and genomic heterogeneity of three strains of Colwellia psychrerythraeawas investigated in order to understand adaptions to local environments. Colwellia are psychrophilic heterotrophic marine bacteria ubiquitous in cold marine ecosystems. We have recently isolated two Colwellia strains: ND2E from the Eastern Mediterranean and GAB14E from the Great Australian Bight. The 16S rRNA sequence of these two strains were greater than 98.2% identical to the well-characterized C. psychrerythraea 34H, which was isolated from arctic sediments. Salt tolerance, and carbon source utilization profiles for these strains were determined using Biolog Phenotype MicoArrays. These strains exhibited distinct salt tolerance, which was not associated with the salinity of sites of isolation. The carbon source utilization profiles were distinct with less than half of the tested carbon sources being metabolized by all three strains. Whole genome sequencing revealed that the genomes of these three strains were quite diverse with some genomes having up to 1600 strain-specific genes. Many genes involved in degrading strain-specific carbon sources were identified. There appears to be a link between carbon source utilization and location of isolation with distinctions observed between the Colwellia isolate recovered from sediment compared to water column isolates
Hyperspectral imaging for early detection of oxygenation and perfusion changes in irradiated skin
Studies examining acute oxygenation and perfusion changes in irradiated skin are limited. Hyperspectral imaging (HSI), a method of wide-field, diffuse reflectance spectroscopy, provides noninvasive, quantified measurements of cutaneous oxygenation and perfusion. This study examines whether HSI can assess acute changes in oxygenation and perfusion following irradiation. Skin on both flanks of nude mice (n=20) was exposed to 50 Gy of beta radiation from a strontium-90 source. Hyperspectral images were obtained before irradiation and on selected days for three weeks. Skin reaction assessment was performed concurrently with HSI. Desquamative injury formed in all irradiated areas. Skin reactions were first seen on day 7, with peak formation on day 14, and resolution beginning by day 21. HSI demonstrated increased tissue oxygenation on day 1 before cutaneous changes were observed (
Conference report:Improving outcomes for gastrointestinal cancer in the UK
Substantial steps are being made towards early diagnosis. A range of tools are available to help GPs appropriately categorise early symptoms during routine consultations. Various promising new tests and devices are being explored, especially for cancers that frequently present at late stages. The continuing increase in demand on endoscopy services is a major concern, not least because of the shortage of trained practitioners and other healthcare staff. However, screening and collaborative streamlining initiatives might help to improve the relevance of referrals. The question posed in the title of the conference was rhetorical, but a positive answer seems potentially achievable, even in austere times, through facilitating uptake of screening, working to develop the primary-secondary care interface, educating the public and by protecting funds for research
Early and efficient detection of Mycobacterium tuberculosis in sputum by microscopic observation of broth cultures.
Early, efficient and inexpensive methods for the detection of pulmonary tuberculosis are urgently needed for effective patient management as well as to interrupt transmission. These methods to detect M. tuberculosis in a timely and affordable way are not yet widely available in resource-limited settings. In a developing-country setting, we prospectively evaluated two methods for culturing and detecting M. tuberculosis in sputum. Sputum samples were cultured in liquid assay (micro broth culture) in microplate wells and growth was detected by microscopic observation, or in Löwenstein-Jensen (LJ) solid media where growth was detected by visual inspection for colonies. Sputum samples were collected from 321 tuberculosis (TB) suspects attending Bugando Medical Centre, in Mwanza, Tanzania, and were cultured in parallel. Pulmonary tuberculosis cases were diagnosed using the American Thoracic Society diagnostic standards. There were a total of 200 (62.3%) pulmonary tuberculosis cases. Liquid assay with microscopic detection detected a significantly higher proportion of cases than LJ solid culture: 89.0% (95% confidence interval [CI], 84.7% to 93.3%) versus 77.0% (95% CI, 71.2% to 82.8%) (p = 0.0007). The median turn around time to diagnose tuberculosis was significantly shorter for micro broth culture than for the LJ solid culture, 9 days (interquartile range [IQR] 7-13), versus 21 days (IQR 14-28) (p<0.0001). The cost for micro broth culture (labor inclusive) in our study was US 11.35 per sample for the LJ solid culture. The liquid assay (micro broth culture) is an early, feasible, and inexpensive method for detection of pulmonary tuberculosis in resource limited settings
Mechanisms involved in the adaptation of Escherichia coli O157:H7 to the host intestinal microenvironment
Host adaptation of pathogens may increase intra- and interspecies transmission. We showed previously that the passage of a clinically isolated enterohemorrhagic Escherichia coli (EHEC) O157 strain (125/99) through the gastrointestinal tract of mice increases its pathogenicity in the same host. In this work, we aimed to elucidate the underlying mechanism(s) involved in the patho-adaptation of the stool-recovered (125RR) strain. We assessed the global transcription profile by microarray and found almost 100 differentially expressed genes in 125RR strain compared with 125/99 strain. We detected an overexpression of Type Three Secretion System (TTSS) proteins at the mRNA and protein levels and demonstrated increased adhesion to epithelial cell lines for the 125RR strain. Additional key attributes of the 125RR strain were: increased motility on semisolid agar, which correlated with an increased fliC mRNA level; reduced Stx2 production at the mRNA and protein levels; increased survival at pH 2.5, as determined by acid resistance assays. We tested whether the overexpression of the LEE-encoded regulator (ler) in trans in the 125/99 strain could recreate the increased pathogenicity observed in the 125RR strain. As anticipated ler overexpression led to increased expression of TTSS proteins and bacterial adhesion to epithelial cells in vitro but also increased mortality and intestinal colonization in vivo. We conclude that this host-adaptation process required changes in several mechanisms that improved EHEC O157 fitness in the new host. The research highlights some of the bacterial mechanisms required for horizontal transmission of these zoonotic pathogens between their animal and human populations.Fil: Fernández Brando, Romina Jimena. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: MaCateer, Sean P.. University of Edinburgh; Reino UnidoFil: Montañez Culma, Leidy Johanna. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Cortés Araya, Yennifer. University of Edinburgh; Reino UnidoFil: Tree, Jai. University of Edinburgh; Reino UnidoFil: Bernal, Alan Mauro. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Fuentes, Federico. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Fitzgerald, Stephen. University of Edinburgh; Reino UnidoFil: Pineda, Gonzalo Ezequiel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Ramos, Maria Victoria. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Gally, David. University of Edinburgh; Reino UnidoFil: Palermo, Marina Sandra. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin
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