The StarScan plate measuring machine: overview and calibrations

The StarScan machine at the U.S. Naval Observatory (USNO) completed measuring photographic astrograph plates to allow determination of proper motions for the USNO CCD Astrograph Catalog (UCAC) program. All applicable 1940 AGK2 plates, about 2200 Hamburg Zone Astrograph plates, 900 Black Birch (USNO Twin Astrograph) plates, and 300 Lick Astrograph plates have been measured. StarScan comprises of a CCD camera, telecentric lens, air-bearing granite table, stepper motor screws, and Heidenhain scales to operate in a step-stare mode. The repeatability of StarScan measures is about 0.2 micrometer. The CCD mapping as well as the global table coordinate system has been calibrated using a special dot calibration plate and the overall accuracy of StarScan x,y data is derived to be 0.5 micrometer. Application to real photographic plate data shows that position information of at least 0.65 micrometer accuracy can be extracted from course grain 103a-type emulsion astrometric plates. Transformations between "direct" and "reverse" measures of fine grain emulsion plate measures are obtained on the 0.3 micrometer level per well exposed stellar image and coordinate, which is at the limit of the StarScan machine.Comment: 24 pages, 8 figures, accepted for PAS

Temperature dependent transient surface photovoltage spectroscopy of a Cu1.95Zn1.1Sn0.96Se4 kesterite single phase powder

An off-stoichiometric but single phase Cu1.95Zn1.1Sn0.96Se4 kesterite powder was investigated by temperature dependent transient surface photovoltage (SPV) spectroscopy. SPV signals excited at different wavelengths were transformed into SPV spectra that depended on the response time of measurement. Shallow electronic states and states with transition energies at 0.83 eV or 0.78… 0.9 eV were distinguished. The temperature dependence of the band gap of Cu1.95Zn1.1Sn0.96Se4 was obtained. Results were discussed on the basis of defects in Cu-poor and Zn-rich kesterite

Optical constants of Cu2ZnGeS4 bulk crystals

The dielectric functions of Cu2 ZnGeS4 bulk crystals grown by the Bridgman method were measured over the energy range 1.4 to 4.7 eV at room temperature using variable angle spectroscopic ellipsometry. The observed structures in the dielectric functions were adjusted using the Adachi's model and attributed to interband transitions E0, E1A, and E1B at :(000), N (A):2π /a (0.5 0.5 0.5), and T (Z):2π /a (0 0 0.5) points of the first Brillouin zone, respectively. The model parameters (threshold energy, strength, and broadening) have been determined using the simulated annealing algorithm. The decrease in the first gap, E0, has been attributed to a higher Ge-S hybridization. The spectral dependence of the complex refractive index, the absorption coefficient, and the normal-incidence reflectivity were also derived. © 2010 American Institute of Physics.Peer Reviewe

Cu2ZnSnS4 thin film solar cells grown by fast thermal evaporation and thermal treatment

Cu2ZnSnS4 thin films have been produced via rapid thermal evaporation of off-stoichiometric kesterite powder followed by annealing in an Ar atmosphere. Different heating rates were applied during the thermal treatments. The chemical composition and structural properties of the deposited layers as well as the distribution of the elements through the kesterite thin film have been investigated. The initial growth of a SnS secondary phase during evaporation led to the formation of this secondary phase next to the Mo back contact. Solar cell power conversion efficiencies were limited to values about 3 % due to this secondary phase. Furthermore, an increased open circuit voltage was demonstrated by using a Zn(O,S) buffer layerThis work was supported by DAAD project (INTERKEST, Ref: 57050358), Marie Curie-ITN (KESTCELLS, GA: 316488) and MINECO project (SUNBEAM, ENE2013-49136-C4-3-R). RC and ES acknowledge financial support from Spanish MINECO within the Ramón y Cajal program (RYC-2011-08521) and (RYC-2011-09212) respectively. SG also thanks the Government of Spain for the FPI fellowship (BES-2014-068533)

Knowledge-based systems in Japan

This report summarizes a study of the state-of-the-art in knowledge-based systems technology in Japan, organized by the Japanese Technology Evaluation Center (JTEC) under the sponsorship of the National Science Foundation and the Advanced Research Projects Agency. The panel visited 19 Japanese sites in March 1992. Based on these site visits plus other interactions with Japanese organizations, both before and after the site visits, the panel prepared a draft final report. JTEC sent the draft to the host organizations for their review. The final report was published in May 1993

The SND proteins constitute an alternative targeting route to the endoplasmic reticulum.

In eukaryotes, up to one-third of cellular proteins are targeted to the endoplasmic reticulum, where they undergo folding, processing, sorting and trafficking to subsequent endomembrane compartments(1). Targeting to the endoplasmic reticulum has been shown to occur co-translationally by the signal recognition particle (SRP) pathway(2) or post-translationally by the mammalian transmembrane recognition complex of 40 kDa (TRC40)(3,4) and homologous yeast guided entry of tail-anchored proteins (GET)(5,6) pathways. Despite the range of proteins that can be catered for by these two pathways, many proteins are still known to be independent of both SRP and GET, so there seems to be a critical need for an additional dedicated pathway for endoplasmic reticulum relay(7,8). We set out to uncover additional targeting proteins using unbiased high-content screening approaches. To this end, we performed a systematic visual screen using the yeast Saccharomyces cerevisiae(9,10), and uncovered three uncharacterized proteins whose loss affected targeting. We suggest that these proteins work together and demonstrate that they function in parallel with SRP and GET to target a broad range of substrates to the endoplasmic reticulum. The three proteins, which we name Snd1, Snd2 and Snd3 (for SRP-independent targeting), can synthetically compensate for the loss of both the SRP and GET pathways, and act as a backup targeting system. This explains why it has previously been difficult to demonstrate complete loss of targeting for some substrates. Our discovery thus puts in place an essential piece of the endoplasmic reticulum targeting puzzle, highlighting how the targeting apparatus of the eukaryotic cell is robust, interlinked and flexible

A complementary neutron and anomalous x-ray diffraction study

Distinguishing the scattering contributions of isoelectronic atomic species by means of conventional x-ray- and/or electron diffraction techniques is a difficult task. Such a problem occurs when determining the crystal structure of compounds containing different types of atoms with equal number of electrons. We propose a new structural model of Cu(InxGa1−x)3Se5 which is valid for the entire compositional range of the CuIn3Se5–CuGa3Se5 solid solution. Our model is based on neutron and anomalous x-ray diffraction experiments. These complementary techniques allow the separation of scattering contributions of the isoelectronic species Cu+ and Ga3+, contributing nearly identically in monoenergetic x-ray diffraction experiments. We have found that CuIII3Se5 (III=In,Ga) in its room temperature near-equilibrium modification exhibits a modified stannite structure (space group I4¯2m). Different occupation factors of the species involved, Cu+, In3+, Ga3+, and vacancies have been found at three different cationic positions of the structure (Wyckoff sites 2a, 2b, and 4d) depending on the composition of the compound. Significantly, Cu+ does not occupy the 2b site for the In-free compound, but does for the In-containing case. Structural parameters, including lattice constants, tetragonal distortions, and occupation factors are given for samples covering the entire range of the CuIn3Se5–CuGa3Se5 solid solution. At the light of the result, the denotation of Cu-poor 1:3:5 compounds as chalcopyrite-related materials is only valid in reference to their composition

Timing of Invasive Mechanical Ventilation and Death in Critically Ill Adults With Covid-19: A Multicenter Cohort Study

PURPOSE: To investigate if the timing of initiation of invasive mechanical ventilation (IMV) for critically ill patients with COVID-19 is associated with mortality. MATERIALS AND METHODS: The data for this study were derived from a multicenter cohort study of critically ill adults with COVID-19 admitted to ICUs at 68 hospitals across the US from March 1 to July 1, 2020. We examined the association between early (ICU days 1-2) versus late (ICU days 3-7) initiation of IMV and time-to-death. Patients were followed until the first of hospital discharge, death, or 90 days. We adjusted for confounding using a multivariable Cox model. RESULTS: Among the 1879 patients included in this analysis (1199 male [63.8%]; median age, 63 [IQR, 53-72] years), 1526 (81.2%) initiated IMV early and 353 (18.8%) initiated IMV late. A total of 644 of the 1526 patients (42.2%) in the early IMV group died, and 180 of the 353 (51.0%) in the late IMV group died (adjusted HR 0.77 [95% CI, 0.65-0.93]). CONCLUSIONS: In critically ill adults with respiratory failure from COVID-19, early compared to late initiation of IMV is associated with reduced mortality

Effect of the oral application of a highly selective MMP-13 inhibitor in three different animal models of rheumatoid arthritis

OBJECTIVE: In the present study we evaluated the decrease of cartilage destruction by a novel orally active and specific MMP-13 inhibitor in three different animal models of rheumatoid arthritis (RA). MATERIALS AND METHODS: The SCID mouse co-implantation model of RA, collagen-induced arthritis (CIA) model in mice and the antigen induced arthritis model (AIA) in rabbits were used. RESULTS: In the SCID mouse co-implantation model this inhibitor resulted in reduced cartilage destruction by 75%. In the CIA model of RA, the MMP-13 inhibitor resulted in a significant and dose dependent decrease in clinical symptoms as well as of cartilage erosion by 38% (30 mg/kg), 28% (10 mg/kg) and 21% (3 mg/kg). No significant effects were observed in the AIA model. No toxic effects were observed in all three animal models. CONCLUSION: Although several MMPs in concert with other proteinases play a role in the process of cartilage destruction, there is a need for highly selective MMP inhibitors to reduce severe side effects that occur with non-specific inhibitors. Significant inhibition of MMP-13 reduced cartilage erosions in two out of three tested animal models of RA. These results strongly support the development of this class of drugs to reduce or halt joint destruction in patients with RA

Climbers for Bat Conservation: creating a citizen science program in Red River Gorge Kentucky

In recent years, North American bat populations have been presented with new conservation threats including white-nose syndrome. As these threats continue to impact bats it is important to locate and study these populations. Though most bats tend to roost and hibernate in caves, still many roost in cracks, crevices, and other hard to reach places. Rock climbers recreate on a large array of rock features that are inaccessible or unknown to bat biologists and could serve as a valuable resource in identifying the location of bat species for conservation efforts. Yet, developing and maintaining a productive relationship between recreationists and the conservation community can be challenging, making environmental communication vital to successful collaborative efforts. We explored rock climbers' willingness to participate in a citizen science program for reporting bat sightings through Climbers for Bat Conservation (CBC) while at Red River Gorge (RRG), Kentucky. We utilized a mixed methods case study consisting of a world café facilitated dialog with members of a local climbing organization, bat biologists, land managers, and landowners (n = 18) as well as semi-structured interview data (n = 12) collected at a local climbing festival. Results indicate mutual importance given to bats, climbing, and conservation from world café attendees. Additionally, attendees identified three key parts of a bat observation that would be critical data for rock climbers to report which included presence of a bat, the location, and the climbing route name. Finally, attendees identified having a local climbing ranger or climbing liaison as important to organizing other climbers to submit data. Interview data revealed that the most mentioned barriers to submitting a bat report were awareness of CBC, time, convenience, forgetfulness, fear of route closures, and access to a phone. A discussion follows detailing how this information may be used to further the design and implementation of a citizen science program as well as increase climber engagement at RRG