The effects of training on errors of perceived direction in perspective displays

An experiment was conducted to determine the effects of training on the characteristic direction errors that are observed when subjects estimate exocentric directions on perspective displays. Changes in five subjects' perceptual errors were measured during a training procedure designed to eliminate the error. The training was provided by displaying to each subject both the sign and the direction of his judgment error. The feedback provided by the error display was found to decrease but not eliminate the error. A lookup table model of the source of the error was developed in which the judgement errors were attributed to overestimates of both the pitch and the yaw of the viewing direction used to produce the perspective projection. The model predicts the quantitative characteristics of the data somewhat better than previous models did. A mechanism is proposed for the observed learning, and further tests of the model are suggested

A helmet mounted display to adapt the telerobotic environment to human vision

A Helmet Mounted Display system has been developed. It provides the capability to display stereo images with the viewpoint tied to subjects' head orientation. The type of display might be useful in a telerobotic environment provided the correct operating parameters are known. The effects of update frequency were tested using a 3D tracking task. The effects of blur were tested using both tracking and pick-and-place tasks. For both, researchers found that operator performance can be degraded if the correct parameters are not used. Researchers are also using the display to explore the use of head movements as part of gaze as subjects search their visual field for target objects

Simulation of Hazards and Poses for a Rocker-Bogie Rover

Provisions for specification of hazards faced by a robotic vehicle (rover) equipped with a rocker-bogie suspension, for prediction of collisions between the vehicle and the hazards, and for simulation of poses of the vehicle at selected positions on the terrain have been incorporated into software that simulates the movements of the vehicle on planned paths across the terrain. The software in question is that of the Web Interface for Telescience (WITS), selected aspects of which have been described in a number of prior NASA Tech Briefs articles. To recapitulate: The WITS is a system of computer software that enables scientists, located at geographically dispersed computer terminals connected to the World Wide Web, to command instrumented robotic vehicles (rovers) during exploration of Mars and perhaps eventually of other planets. The WITS also has potential for adaptation to terrestrial use in telerobotics and other applications that involve computer-based remote monitoring, supervision, control, and planning

Perinatal Exposure to Environmentally Relevant Levels of Bisphenol A Decreases Fertility and Fecundity in CD-1 Mice

Bac k g r o u n d: Perinatal exposure to low-doses of bisphenol A (BPA) results in alterations in the ovary, uterus, and mammary glands and in a sexually dimorphic region of the brain known to be important for estrous cyclicity. Objectives: We aimed to determine whether perinatal exposure to environmentally relevant doses of BPA alters reproductive capacity. Met h o d s: Female CD-1 mice that were exposed to BPA at 0, 25 ng, 250 ng, or 25 µg/kg body weight (BW)/day or diethylstilbestrol (DES) at 10 ng/kg BW/day (positive control) from gestational day 8 through day 16 of lactation were continuously housed with proven breeder males for 32 weeks starting at 2 months of age. At each delivery, pups born to these mating pairs were removed. The cumulative number of pups, number of deliveries, and litter size were recorded. The purity of the BPA used in this and our previous studies was assessed using HPLC, mass spectrometry, and nuclear magnetic resonance. Res u l t s: The forced breeding experiment revealed a decrease in the cumulative number of pups, observed as a nonmonotonic dose–response effect, and a decline in fertility and fecundity over time in female mice exposed perinatally to BPA. The BPA was 97 % pure, with no evidence of contaminatio

A New Rhesus Macaque Assembly and Annotation for Next-Generation Sequencing Analyses

BACKGROUND: The rhesus macaque (Macaca mulatta) is a key species for advancing biomedical research. Like all draft mammalian genomes, the draft rhesus assembly (rheMac2) has gaps, sequencing errors and misassemblies that have prevented automated annotation pipelines from functioning correctly. Another rhesus macaque assembly, CR_1.0, is also available but is substantially more fragmented than rheMac2 with smaller contigs and scaffolds. Annotations for these two assemblies are limited in completeness and accuracy. High quality assembly and annotation files are required for a wide range of studies including expression, genetic and evolutionary analyses. RESULTS: We report a new de novo assembly of the rhesus macaque genome (MacaM) that incorporates both the original Sanger sequences used to assemble rheMac2 and new Illumina sequences from the same animal. MacaM has a weighted average (N50) contig size of 64 kilobases, more than twice the size of the rheMac2 assembly and almost five times the size of the CR_1.0 assembly. The MacaM chromosome assembly incorporates information from previously unutilized mapping data and preliminary annotation of scaffolds. Independent assessment of the assemblies using Ion Torrent read alignments indicates that MacaM is more complete and accurate than rheMac2 and CR_1.0. We assembled messenger RNA sequences from several rhesus tissues into transcripts which allowed us to identify a total of 11,712 complete proteins representing 9,524 distinct genes. Using a combination of our assembled rhesus macaque transcripts and human transcripts, we annotated 18,757 transcripts and 16,050 genes with complete coding sequences in the MacaM assembly. Further, we demonstrate that the new annotations provide greatly improved accuracy as compared to the current annotations of rheMac2. Finally, we show that the MacaM genome provides an accurate resource for alignment of reads produced by RNA sequence expression studies. CONCLUSIONS: The MacaM assembly and annotation files provide a substantially more complete and accurate representation of the rhesus macaque genome than rheMac2 or CR_1.0 and will serve as an important resource for investigators conducting next-generation sequencing studies with nonhuman primates. REVIEWERS: This article was reviewed by Dr. Lutz Walter, Dr. Soojin Yi and Dr. Kateryna Makova

Sooty Mangabey Genome Sequence Provides Insight into AIDS Resistance in a Natural SIV Host

In contrast to infections with human immunodeficiency virus (HIV) in humans and simian immunodeficiency virus (SIV) in macaques, SIV infection of a natural host, sooty mangabeys (Cercocebus atys), is non-pathogenic despite high viraemia. Here we sequenced and assembled the genome of a captive sooty mangabey. We conducted genome-wide comparative analyses of transcript assemblies from C. atys and AIDS-susceptible species, such as humans and macaques, to identify candidates for host genetic factors that influence susceptibility. We identified several immune-related genes in the genome of C. atys that show substantial sequence divergence from macaques or humans. One of these sequence divergences, a C-terminal frameshift in the toll-like receptor-4 (TLR4) gene of C. atys, is associated with a blunted in vitro response to TLR-4 ligands. In addition, we found a major structural change in exons 3-4 of the immune-regulatory protein intercellular adhesion molecule 2 (ICAM-2); expression of this variant leads to reduced cell surface expression of ICAM-2. These data provide a resource for comparative genomic studies of HIV and/or SIV pathogenesis and may help to elucidate the mechanisms by which SIV-infected sooty mangabeys avoid AIDS

Robust and persistent reactivation of SIV and HIV by N-803 and depletion of CD8+ cells

Human immunodeficiency virus (HIV) persists indefinitely in individuals with HIV who receive antiretroviral therapy (ART) owing to a reservoir of latently infected cells that contain replication-competent virus1–4. Here, to better understand the mechanisms responsible for latency persistence and reversal, we used the interleukin-15 superagonist N-803 in conjunction with the depletion of CD8+ lymphocytes in ART-treated macaques infected with simian immunodeficiency virus (SIV). Although N-803 alone did not reactivate virus production, its administration after the depletion of CD8+ lymphocytes in conjunction with ART treatment induced robust and persistent reactivation of the virus in vivo. We found viraemia of more than 60 copies per ml in all macaques (n = 14; 100%) and in 41 out of a total of 56 samples (73.2%) that were collected each week after N-803 administration. Notably, concordant results were obtained in ART-treated HIV-infected humanized mice. In addition, we observed that co-culture with CD8+ T cells blocked the in vitro latency-reversing effect of N-803 on primary human CD4+ T cells that were latently infected with HIV. These results advance our understanding of the mechanisms responsible for latency reversal and lentivirus reactivation during ART-suppressed infection

The Science of Sleep and Daily Rhythms

Created as part of the BioEd initiative at the Baylor College of Medicine, this fine guide to the science of sleep and daily rhythms was authored by Nancy P. Moreno, Barbara Z. Tharp, and Gregory L. Vogt. The 32-page document is designed for use in a variety of classrooms, and it contains activities, worksheets, and information about how sleep studies are used to improve performance across a wide range of human endeavors. The activities here include "Using a Sundial," "Living Clocks," "Sleep Patterns," and "Investigating Sleep." Each of these activities is explained succinctly and thoroughly, and many do not required specialized equipment. One of the most interesting activities is the sun tracking board which allows students to track the sun's movements with just a bit of cardboard, several writing instruments, a ruler, and some string. Finally, the sleep cycle rhythms activity gets creative, as students are asked to write a few poems about their own sleep patterns

The Web Interface for Telescience (WITS)

The Web Interface for Telescience (WITS) has been developed to enable scientists to participate in planetary rover missions from their home institutions, rather than having to travel to JPL as has been required in the past. A scientist accesses WITS via a commercial web browser. WITS provides various views of the scene including a descent image view which allows the user to see where the rover has been and currently is in a global perspective, a panoramic view which is an overhead view of the area immediately around the rover, and a wedge view which is an image from a rover-mounted camera. Scientists can select science targets in a wedge image and science subtasks to perform at those targets. A mission planner can select rover waypoints to traverse between science targets, and waypoint subtasks to perform at those locations. A public version allows the general public to view the same information and plan their own simulated missions. 1. Introduction Scientists currently have to trave..