Preliminary study of minimum performance approaches to automated Mars sample return missions Final report, 19 Oct. - 20 Nov. 1970

Alternative mission/system approaches to automated Mars surface sample return based on utilization of Titan 3 or Saturn Intermediate-20 launch vehicle

Distortion or Clarification: Defining Highly Qualified Teachers and the Relationship between Certification and Achievement

Recent studies of the relationship between teacher preparation pathways and student achievement have resulted in similar statistics but contradictory conclusions. These studies as a group have several limits: they sometimes focus on student-level indicators when many policy decisions are made with indicators at the school-level or above, are limited to specific urban locations or grade levels, or neglect the potential influence of building type, as defined as the grade-levels serviced. Using statewide data from the 2004-2005 school year, we examined the relationships between school-level indicators of student achievement on nationally-normed tests and proportions of alternatively certified teachers, while controlling for building type and other relevant covariates. Our findings indicate that the relationship between teacher preparation and student achievement at the school level depends on whether the building mixes multiple grade levels (e.g., elementary and middle). The implications of Missouri's policy change for research and school improvement are discussed with respect to the current high-stakes testing environment

A novel FRET-based screen in high-throughput format to identify inhibitors of malarial and human glucose transporters

The glucose transporter PfHT is essential to the survival of the malaria parasite Plasmodium falciparum and has been shown to be a druggable target with high potential for pharmacological intervention. Identification of compounds against novel drug targets is crucial to combating resistance against current therapeutics. Here, we describe the development of a cell-based assay system readily adaptable to high-throughput screening that directly measures compound effects on PfHT-mediated glucose transport. Intracellular glucose concentrations are detected using a genetically encoded fluorescence resonance energy transfer (FRET)-based glucose sensor. This allows assessment of the ability of small molecules to inhibit glucose uptake with high accuracy (Z′ factor of >0.8), thereby eliminating the need for radiolabeled substrates. Furthermore, we have adapted this assay to counterscreen PfHT hits against the human orthologues GLUT1, -2, -3, and -4. We report the identification of several hits after screening the Medicines for Malaria Venture (MMV) Malaria Box, a library of 400 compounds known to inhibit erythrocytic development of P. falciparum. Hit compounds were characterized by determining the half-maximal inhibitory concentration (IC(50)) for the uptake of radiolabeled glucose into isolated P. falciparum parasites. One of our hits, compound MMV009085, shows high potency and orthologue selectivity, thereby successfully validating our assay for antimalarial screening

A life story in three parts: the use of triptychs to make sense of personal digital data

Many social media platforms support the curation of personal digital data, and, more recently, the use of that data for review and reflection. We explored the process of reflection by asking users to create a meaningful ‘triptych’ of photographs drawn from their Facebook accounts. In a first study, we asked participants to manually trawl their own accounts and select three relevant images, which we then framed and used as an interview probe. In a second study, we designed an automated triptych generation system and assessed participants’ experiences of using this system. We conducted qualitative analyses of participant interviews from both studies. Consistent with other ‘slow technology’ work, we found the act of creating a physical artefact from social media data gave that data new meaning, albeit with notable differences between manual vs automatically generated triptychs. We conclude by discussing possible improvements to the design of the automated triptych system

The multiple ionospheric probe Auroral ionospheric report

Multiple impedance and resonance probe payload for ionospheric property observation in Nike- Apache rocke

Subband population in a single-wall carbon nanotube diode

We observe current rectification in a molecular diode consisting of a semiconducting single-wall carbon nanotube and an impurity. One half of the nanotube has no impurity, and it has a current-voltage (I-V) charcteristic of a typical semiconducting nanotube. The other half of the nanotube has the impurity on it, and its I-V characteristic is that of a diode. Current in the nanotube diode is carried by holes transported through the molecule's one-dimensional subbands. At 77 Kelvin we observe a step-wise increase in the current through the diode as a function of gate voltage, showing that we can control the number of occupied one-dimensional subbands through electrostatic doping.Comment: to appear in Physical Review Letters. 4 pages & 3 figure

Van Hove Singularities in disordered multichannel quantum wires and nanotubes

We present a theory for the van Hove singularity (VHS) in the tunneling density of states (TDOS) of disordered multichannel quantum wires, in particular multi-wall carbon nanotubes. We assume close-by gates which screen off electron-electron interactions. Diagrammatic perturbation theory within a non-crossing approximation yields analytical expressions governing the disorder-induced broadening and shift of VHS's as new subbands are opened. This problem is nontrivial because the (lowest-order) Born approximation breaks down close to the VHS. Interestingly, compared to the bulk case, the boundary TDOS shows drastically altered VHS, even in the clean limit.Comment: 4 pages, 2 figures, accepted with revisions in PR

ISCEV extended protocol for VEP methods of estimation of visual acuity

The International Society for Clinical Electrophysiology of Vision (ISCEV) standard for visual evoked potentials (VEPs) describes a minimum procedure for clinical VEP testing and encourages more extensive testing. This ISCEV extended protocol is an extension to the VEP standard. It describes procedures for recording multiple VEPs to a range of sizes of pattern stimuli to establish the VEP spatial frequency limit (threshold) and for relating this limit to visual acuity