Mass production of volume phase holographic gratings for the VIRUS spectrograph array

The Visible Integral-field Replicable Unit Spectrograph (VIRUS) is a baseline array of 150 copies of a simple, fiber-fed integral field spectrograph that will be deployed on the Hobby-Eberly Telescope (HET). VIRUS is the first optical astronomical instrument to be replicated on an industrial scale, and represents a relatively inexpensive solution for carrying out large-area spectroscopic surveys, such as the HET Dark Energy Experiment (HETDEX). Each spectrograph contains a volume phase holographic (VPH) grating with a 138 mm diameter clear aperture as its dispersing element. The instrument utilizes the grating in first-order for 350-550 nm. Including witness samples, a suite of 170 VPH gratings has been mass produced for VIRUS. Here, we present the design of the VIRUS VPH gratings and a discussion of their mass production. We additionally present the design and functionality of a custom apparatus that has been used to rapidly test the first-order diffraction efficiency of the gratings for various discrete wavelengths within the VIRUS spectral range. This device has been used to perform both in-situ tests to monitor the effects of adjustments to the production prescription as well as to carry out the final acceptance tests of the gratings' diffraction efficiency. Finally, we present the as-built performance results for the entire suite of VPH gratings.Comment: 16 pages, 11 figures, 2 tables. To be published in Proc. SPIE, 2014, "Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation", 9151-53. The work presented in this article follows from arXiv:1207:448

Erratum to: Genetic alterations of m6A regulators predict poorer survival in acute myeloid leukemia

Abstract Methylation of N6 adenosine (m6A) is known to be important for diverse biological processes including gene expression control, translation of protein, and messenger RNA (mRNA) splicing. However, its role in the development of human cancers is poorly understood. By analyzing datasets from the Cancer Genome Atlas Research Network (TCGA) acute myeloid leukemia (AML) study, we discover that mutations and/or copy number variations of m6A regulatory genes are strongly associated with the presence of TP53 mutations in AML patients. Further, our analyses reveal that alterations in m6A regulatory genes confer a worse survival in AML. Our work indicates that genetic alterations of m6A regulatory genes may cooperate with TP53 and/or its regulator/downstream targets in the pathogenesis and/or maintenance of AML

Ranchers Diverse in Their Drought Management Strategies

Farm Management, Livestock Production/Industries,

Modeling the SS 433 Jet Bends

We fit Chandra HETGS data obtained for the unusual X-ray binary SS 433. While line strengths and continuum levels hardly change, the jet Doppler shifts show aperiodic variations that probably result from shocks in interactions with the local environment. The X-ray and optical emission line regions are found to be related but not coincident as the optical line emission persists for days while the X-ray emission lines fade in less than 5000 s. The X-ray spectrum of the blue-shifted jet shows over two dozen emission lines from plasma at a variety of temperatures. The emission measure distribution derived from the spectrum can be used to test jet cooling models.Comment: 4 pages, 3 figure, presented at the conference on "Hign Energy Phenomena in Relativistic Outflows", Dublin, September 200

The Chandra Multi-Wavelength Project: Optical Spectroscopy and the Broadband Spectral Energy Distributions of X-ray Selected AGN

From optical spectroscopy of X-ray sources observed as part of ChaMP, we present redshifts and classifications for a total of 1569 Chandra sources from our targeted spectroscopic follow up using the FLWO, SAAO, WIYN, CTIO, KPNO, Magellan, MMT and Gemini telescopes, and from archival SDSS spectroscopy. We classify the optical counterparts as 50% BLAGN, 16% NELG, 14% ALG, and 20% stars. We detect QSOs out to z~5.5 and galaxies out to z~3. We have compiled extensive photometry from X-ray to radio bands. Together with our spectroscopic information, this enables us to derive detailed SEDs for our extragalactic sources. We fit a variety of templates to determine bolometric luminosities, and to constrain AGN and starburst components where both are present. While ~58% of X-ray Seyferts require a starburst event to fit observed photometry only 26% of the X-ray QSO population appear to have some kind of star formation contribution. This is significantly lower than for the Seyferts, especially if we take into account torus contamination at z>1 where the majority of our X-ray QSOs lie. In addition, we observe a rapid drop of the percentage of starburst contribution as X-ray luminosity increases. This is consistent with the quenching of star formation by powerful QSOs, as predicted by the merger model, or with a time lag between the peak of star formation and QSO activity. We have tested the hypothesis that there should be a strong connection between X-ray obscuration and star-formation but we do not find any association between X-ray column density and star formation rate both in the general population or the star-forming X-ray Seyferts. Our large compilation also allows us to report here the identification of 81 XBONG, 78 z>3 X-ray sources and 8 Type-2 QSO candidates. Also we have identified the highest redshift (z=5.4135) X-ray selected QSO with optical spectroscopy.Comment: 17 pages, 16 figures, accepted for publication in ApJS. Full data table and README file can be found online at http://hea-www.harvard.edu/~pgreen/Papers.htm

Role of a Lateral Orbital Frontal Cortex-Basolateral Amygdala Circuit in Cue-Induced Cocaine-Seeking Behavior

Cocaine addiction is a disease characterized by chronic relapse despite long periods of abstinence. The lateral orbitofrontal cortex (lOFC) and basolateral amygdala (BLA) promote cocaine-seeking behavior in response to drug-associated conditioned stimuli (CS) and share dense reciprocal connections. Hence, we hypothesized that monosynaptic projections between these brain regions mediate CS-induced cocaine-seeking behavior. Male Sprague-Dawley rats received bilateral infusions of a Cre-dependent adeno-associated viral (AAV) vector expressing enhanced halorhodopsin 3.0 fused with a reporter protein (NpHR-mCherry) or a control AAV (mCherry) plus optic fiber implants into the lOFC (Experiment 1) or BLA (Experiment 2). The same rats also received bilateral infusions of a retrogradely transported AAV vector expressing Cre recombinase (Retro-Cre-GFP) into the BLA (Experiment 1) or lOFC (Experiment 2). Thus, NpHR-mCherry or mCherry expression was targeted to lOFC neurons that project to the BLA or to BLA neurons that project to the lOFC in different groups. Rats were trained to lever press for cocaine infusions paired with 5-s CS presentations. Responding was then extinguished. At test, response-contingent CS presentation was discretely coupled with optogenetic inhibition (5-s laser activation) or no optogenetic inhibition while lever responding was assessed without cocaine/food reinforcement. Optogenetic inhibition of lOFC to BLA, but not BLA to lOFC, projections in the NpHR-mCherry groups disrupted CS-induced reinstatement of cocaine-seeking behavior relative to (i) no optogenetic inhibition or (ii) manipulations in mCherry control or (iii) NpHR-mCherry food control groups. These findings suggest that the lOFC sends requisite input to the BLA, via monosynaptic connections, to promote CS-induced cocaine-seeking behavior

Projected effects of disruptions to human immunodeficiency virus (HIV) prevention services during the coronavirus disease 2019 pandemic among Black/African American men who have sex with men in an Ending the HIV Epidemic priority jurisdiction

BACKGROUND: Disruptions in access to in-person human immunodeficiency virus (HIV) preventive care during the coronavirus disease 2019 (COVID-19) pandemic may have a negative impact on our progress towards the Ending the HIV Epidemic goals in the United States. METHODS: We used an agent-based model to simulate HIV transmission among Black/African American men who have sex with men in Mississippi over 5 years to estimate how different reductions in access affected the number of undiagnosed HIV cases, new pre-exposure prophylaxis (PrEP) starts, and HIV incidence. RESULTS: We found that each additional 25% decrease in HIV testing and PrEP initiation was associated with decrease of 20% in the number of cases diagnosed and 23% in the number of new PrEP starts, leading to a 15% increase in HIV incidence from 2020 to 2022. CONCLUSIONS: Unmet need for HIV testing and PrEP prescriptions during the COVID-19 pandemic may temporarily increase HIV incidence in the years immediately after the disruption period

ASCT2 regulates glutamine uptake and cell growth in endometrial carcinoma

Glutamine commonly becomes a conditionally essential amino acid in cancer. Glutamine is supplied to the cell by transporters such as ASCT2 (SLC1A5), which is frequently upregulated in multiple cancers. Here we investigated the expression of ASCT2 in endometrial carcinoma, and evaluated the contribution of ASCT2 to glutamine uptake and endometrial cancer cell growth. Analysis of human gene expression data showed that ASCT2 was significantly upregulated in both endometrioid and serous subtypes of endometrial carcinoma, compared to normal, age-matched endometrium. Furthermore, immunohistochemical staining of primary human endometrioid adenocarcinomas showed that tumours stain positive for ASCT2 in either a uniform or mosaic expression pattern, while normal adjacent glands appeared predominantly negative for ASCT2 staining. Chemical inhibition of glutamine transport by benzylserine or GPNA led to a significant decrease in endometrial cancer cell growth and spheroid cross-sectional area. ASCT2 knockdown recapitulated the decrease of cell growth and spheroid cross-sectional area in HEC1A cells, suggesting a reliance on ASCT2-mediated glutamine uptake. ASCT2 knockdown in Ishikawa cells led to lower glutamine uptake and cell growth, but did not affect spheroid area. Ishikawa cells express higher levels of the glutamine transporter SNAT1 compared to HEC1A cells, suggesting these cells may rely on both ASCT2 and SNAT1 for glutamine uptake. Since SNAT1 is also significantly upregulated in the endometrioid and serous subtypes, these data indicate that ASCT2 and SNAT1 could be used as markers of malignancy, and/or potential therapeutic targets in patients with endometrial carcinoma

The evolution of plasticity at geographic range edges

Acknowledgments This article is the product of a working group funded by a grant from the Quebec Centre for Biodiversity Sciences to J-P.L. and K.E.M. J-P.L. is funded by a Concordia University Research Chair and an NSERC Discovery Grant (RGPIN-2015-06081). D.L. is supported by the Sustainability and Energy Research Initiative PhD grant. K.E.M. is supported by an NSERC Discovery Grant (RGPIN-2019-04239). C.J.G., A.L.A., and C.S. are funded by NSERC Discovery Grants. T.U. is supported by the UBC International Doctoral Fellowship.Peer reviewedPostprin

On the redshift of the blazar PKS0447-439

PKS0447-439 is one of the BL Lacertae objects that have been detected at very high energy. There has been a recent report of a lower limit of z>1.246 for the redshift of this blazar, challenging the current paradigm in which very high-energy gamma-rays cannot freely propagate in the z>1 universe. In this research note, we present a new MagE/Magellan spectrum of PKS0447-439 with exquisite signal-to-noise (S/N>150 at 6500A). Our analysis confirms the presence of the previously-reported absorption line at 6280A, which we identify, however, with a known telluric absorption, invalidating the claim that this blazar lies at z>1. Since no other extragalactic spectral features are detected, we cannot establish a redshift based on our spectrum.Comment: 3 pages, 2 figures. Research note. A&A accepte