Coulomb gap triptych in a periodic array of metal nanocrystals

The Coulomb gap in the single particle density of states (DOS) is a universal consequence of electron-electron interaction in disordered systems with localized electron states. Here we show that in arrays of monodisperse metallic nanocrystals, there is not one but three identical adjacent Coulomb gaps, which together form a structure that we call a "Coulomb gap triptych." We calculate the DOS and the conductivity in two- and three-dimensional arrays using a computer simulation. Unlike in the conventional Coulomb glass models, in nanocrystal arrays the DOS has a fixed width in the limit of large disorder. The Coulomb gap triptych can be studied via tunneling experiments.Comment: 4+ pages, 3 figure

A Methodology for the Indirect Determination and Spatial Resolution of Shear Modulus of PDMS-Silica Elastomers

ABSTRACT: A methodology is described that allows for the spatial resolution of shear modulus in silica-filled PDMS elastomers via 1 H relaxation measurements and stray-field imaging (STRAFI) techniques. Traditional Hahn echoes provide a simple, robust route to the extraction of a proton residual dipolar coupling constant (RDC), a direct measure of chain mobility and a parameter that can be corollated to numerous mechanical properties. Defining a dimensionless RDC eliminates any artifacts associated with low-field measurement and allows the RDC to become independent of field strength. A direct correlation between the NMR determined dimensionless RDC and results from dynamic mechanical analysis are presented, then employed via STRAFI to determine spatial variations in moduli associated with irradiated elastomeric materials. Reliable performance, despite poorly optimized STRAFI conditions, is demonstrated with an error of no more than 22% between the calculated shear modulus and the measured value via DMA

Cavitation clouds created by shock scattering from bubbles during histotripsy

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98656/1/JAS001888.pd

Effect of Kisspeptin on Regulation of Growth Hormone

Kisspeptin ( KP ), a neuroendocrine regulator of reproduction, is hypothesized to be an integrator of metabolism and hormones critical to the regulation of reproduction. Lactation is associated with enhanced growth hormone (GH) responsiveness and reduced fertility. Our study was designed to determine the effects of lactation on KP-stimulated GH and luteinizing hormone (LH) secretion. Five non-lactating and five lactating dairy cows were used in the study. Experiments were conducted with lactating cows at weeks 1, 5 and 11 after parturition. The experimental treatments ( saline and KP [100 and 400 pmol / kg body weight]) were given intravenously and blood was collected and plasma was stored until later assay to determine concentrations of GH, LH, progesterone and non-esterified fatty acids. We found that neither dose of KP stimulated an increase in GH secretion. The low dose of KP increased (P \u3c0. 05) LH concentrations only in lactating cows. The higher dose of KP elicited an increase in circulating LH concentrations in both lactating and non-lactating cows. The lower dose of KP increased (P \u3c 0. 05) the area under the curve for LH only in cows during week 5 of lactation, and the area under the curve of LH following the highest dose of KP was greater (P \u3c 0. 05) in cows during week 5 of lactation than that for the other groups of cows. In summary, lactation status and stage of lactation did not change the sensitivity of the GH system to KP. However, an effect of stage of lactation on KP-stimulated LH secretion was detected in the dairy cows. Study of the KP system during lactation in dairy cows may provide critical insights into the mechanisms for lactation associated changes in the reproductive axis

Robot Sequencing and Visualization Program (RSVP)

The Robot Sequencing and Visualization Program (RSVP) is being used in the Mars Science Laboratory (MSL) mission for downlink data visualization and command sequence generation. RSVP reads and writes downlink data products from the operations data server (ODS) and writes uplink data products to the ODS. The primary users of RSVP are members of the Rover Planner team (part of the Integrated Planning and Execution Team (IPE)), who use it to perform traversability/articulation analyses, take activity plan input from the Science and Mission Planning teams, and create a set of rover sequences to be sent to the rover every sol. The primary inputs to RSVP are downlink data products and activity plans in the ODS database. The primary outputs are command sequences to be placed in the ODS for further processing prior to uplink to each rover. RSVP is composed of two main subsystems. The first, called the Robot Sequence Editor (RoSE), understands the MSL activity and command dictionaries and takes care of converting incoming activity level inputs into command sequences. The Rover Planners use the RoSE component of RSVP to put together command sequences and to view and manage command level resources like time, power, temperature, etc. (via a transparent realtime connection to SEQGEN). The second component of RSVP is called HyperDrive, a set of high-fidelity computer graphics displays of the Martian surface in 3D and in stereo. The Rover Planners can explore the environment around the rover, create commands related to motion of all kinds, and see the simulated result of those commands via its underlying tight coupling with flight navigation, motor, and arm software. This software is the evolutionary replacement for the Rover Sequencing and Visualization software used to create command sequences (and visualize the Martian surface) for the Mars Exploration Rover mission

‘Doing the right thing’: factors influencing GP prescribing of antidepressants and prescribed doses

Background: Antidepressant prescribing continues to increase, with 5-16% of adults receiving antidepressants annually. Total prescribing growth is due in part to increased long-term use, greater selective serotonin re-uptake inhibitor (SSRI) use and the use of higher SSRI doses. Evidence does not support routine use of higher SSRI doses for depression treatment, and factors influencing the use of such doses are not well known. The aim of this study was to explore factors influencing GPs’ use of antidepressants and their doses to treat depression.Methods: Semi-structured interviews with a purposive sample of 28 practising GPs; sampled by antidepressant prescribing volume, practice size and deprivation level. A topic guide drawing on past literature was used with enough flexibility to allow additional themes to emerge. Interviews were audio-recorded and transcribed verbatim.Framework analysis was employed. Constant comparison and disconfirmation were carried out across transcripts,with data collection being interspersed with analysis by three researchers. The thematic framework was thensystematically applied to the data and conceptualised into an overarching explanatory model.Results: Depression treatment involved ethical and professional imperatives of ‘doing the right thing’ for individuals by striving to achieve the ‘right care fit’. This involved medicalised and non-medicalised patient-centred approaches.Factors influencing antidepressant prescribing and doses varied over time from first presentation, to antidepressant initiation and longer-term treatment. When faced with distressed patients showing symptoms of moderate to severe depression GPs were confident prescribing SSRIs which they considered as safe and effective medicines, andethically and professionally appropriate.Many GPs were unaware that higher doses lacked greater efficacy and onset of action occurred within 1-2 weeks,preferring to wait 8-12 weeks before increasing or switching. Ongoing pressures to maintain prescribing (e.g. fear of depression recurrence), few perceived continuation problems (e.g. lack of safety concerns) and lack of proactive medication review (e.g. patients only present in crisis), all combine to further drive antidepressant prescribing growth over time.Conclusions: GPs strive to ‘do the right thing’ to help people. Antidepressants are only a single facet of depression treatment. However, increased awareness of drug limitations and regular proactive reviews may help optimise care

Beyond Genre: Classifying Virtual Reality Experiences

12 pagesBecause virtual reality (VR) shares common features with video games, consumer content is usually classified according to traditional game genres and standards. However, VR offers different experiences based on the medium’s unique affordances. To account for this disparity, the paper presents a comparative analysis of titles from the Steam digital store across three platform types: VR only, VR supported, and non-VR. We analyzed data from a subset of the most popular applications within each category (N=141, 93, and 1217, respectively). The three classification types we analyzed were academic game genres, developer defined categories, and user-denoted tags. Results identify the most common content classifications (e.g., Action and Shooter within VR only applications), the relative availability of each between platforms (e.g., Casual is more common in VR only than VR supported or non-VR), general platform popularity (e.g., VR only received less positive ratings than VR supported and nonVR), and which content types are associated with higher user ratings across platforms (e.g., Action and Music/Rhythm are most positively rated in VR only). Our findings ultimately provide a foundational framework for future theoretical constructions of classification systems based on content, market, interactivity, sociality, and service dependencies, which underlay how consumer VR is currently categorized

Isolation of Angola-like Marburg virus from Egyptian rousette bats from West Africa.

Marburg virus (MARV) causes sporadic outbreaks of severe Marburg virus disease (MVD). Most MVD outbreaks originated in East Africa and field studies in East Africa, South Africa, Zambia, and Gabon identified the Egyptian rousette bat (ERB; Rousettus aegyptiacus) as a natural reservoir. However, the largest recorded MVD outbreak with the highest case-fatality ratio happened in 2005 in Angola, where direct spillover from bats was not  shown. Here, collaborative studies by the Centers for Disease Control and Prevention, Njala University, University of California, Davis USAID-PREDICT, and the University of Makeni identify MARV circulating in ERBs in Sierra Leone. PCR, antibody and virus isolation data from 1755 bats of 42 species shows active MARV infection in approximately 2.5% of ERBs. Phylogenetic analysis identifies MARVs that are similar to the Angola strain. These results provide evidence of MARV circulation in West Africa and demonstrate the value of pathogen surveillance to identify previously undetected threats