The TALE Factors and Nuclear Factor Y Cooperate to Drive Transcription at Zygotic Genome Activation

The TALE factors, comprising the pbx and prep/meis gene families, are transcription factors (TFs) vital to the proper formation of anterior anatomical structures during embryonic development. Although best understood as essential cofactors for tissue-specific TFs such as the hox genes during segmentation, the TALE factors also form complexes with nuclear factor Y (NFY) in the early zygote. In zebrafish, Pbx4, Prep1, and NFY are maternally deposited and can access their DNA binding sites in compact chromatin. Our results suggest that TALE/NFY complexes have a unique role in early embryonic development which is distinct from each factor’s independent functions at later stages. To characterize these TALE/NFY complexes, we employed high-throughput transcriptomic and genomic techniques in zebrafish embryos. Using dominant negatives to disrupt the function of each factor, we find that they display similar, but not identical, loss-of-function phenotypes and co-regulate genes involved in transcription regulation and embryonic development. Independently, the TALE factors regulate homeobox genes and NFY governs cilia-related genes. ChIP-seq analysis at zygotic genome activation reveals that the TALE factors occupy DECA sites adjacent to CCAAT boxes near genes expressed early in development and involved with transcription regulation. Finally, DNA elements containing TALE and NFY binding sites drive reporter gene expression in transgenic zebrafish, and disruption of TALE/NFY binding via mutation or dominant negatives eliminates this expression. Taken together, this data suggests that the TALE factors and NFY cooperate to regulate a set of development and transcription control genes in early zygotic development but also have independent roles after gastrulation

The provision of public elementary schools in and around the city of Durham

The last thirty years of the nineteenth century saw an enormous expansion in the supply of schools for the children of the working classes. This occurred as a result of the Elementary education Act of 1870. Which create school boards in each district to supply public elementary schools to fill the large gaps exiting in the voluntary system. To study in detail the progress of this period one small region of the country was selected, I.E an area of one hundred square miles or so of country Durham, with the city of Durham at its centre. The development of the provision of public elementary schools in this area, together with the associated problems, has been traced in each district, throughout the thirty seven districts involved, with the help of local records and the files of the Ministry of education. Apart from the city, where there was adequate educational provision, it was essentially a region of small communities each dependent upon local pit for existence. The provision of efficient schools in these mining villages in 1870 was very poor, there being only 2,500 places for over 10,000 children. The religious bodies and the colliery owners made strenuous efforts to remedy this situation. By 1875, when the first compulsorily formed board was elected, the number of places outside the city had been more than tripled, but a deficiency still existed. The position was aggravated by the increasing population (the number of children in the area increased by 6,000 between 1871 and 1901), and the migratory character of the inhabitants. Building of new schools and enlargement of existing ones continued steadily until 1902, by which time a total of 25,000 places was available. This great increase in quantity was accompanied by a corresponding improvement in quality. Standards of construction and staffing were raised, the range of subjects constantly enlarged, and the schools made altogether happier and more efficient places

The effects of Above Real-Time Training (ARTT) in an F-16 simulator

In this application of above real-time training (ARTT), 24 mission-capable F-16 pilots performed three tasks on a part-task F-16A flight simulator under varying levels of time compression (i.e., 1.0x, 1.5x, 2.0x, and random). All subjects were then tested in a real-time (1.0x) environment. The three tasks under study were an emergency procedure (EP) task, a one versus two air combat maneuvering (ACM) task, and a stern conversion or air intercept task. All ARTT pilots performed the EP task with 28 percent greater accuracy and were better at dealing with a simultaneous MIG threat, reflected by a six-fold increase in the number of MIG kills compared to a real-time control group. In the stern conversion task, there were no statistical differences between groups. In the ACM task, those pilots trained in the mixed time accelerations were faster to acquire lock and were faster to kill both MIG threats than the other groups. These findings are generally consistent with previous findings that show positive effects of task variations (including time variations) during training. Also discussed are related research findings that support the benefits of ARTT and ARTT's impact on emergency procedure training. Further, a synthesis of multidiscipline research outlining the underlying theoretical basis for ARTT is presented. A proposed model of ARTT based on an analogy to Einstein's theory of special relativity is suggested. Conclusions and an outline of future research directions are presented. Successful current commercialization efforts are related as well as future efforts

Duration and exposure to virtual environments: Sickness curves during and across sessions

Although simulator sickness is known to increase with protracted exposure and to diminish with repeated sessions, limited systematic research has been performed in these areas. This study reviewed the few studies with sufficient information available to determine the effect-that exposure duration and repeated exposure have on motion sickness. This evaluation confirmed that longer exposures produce more symptoms and that total sickness subsides over repeated exposures. Additional evaluation was performed to investigate the precise form of this relationship and to determine whether the same form was generalizable across varied simulator environments. The results indicated that exposure duration and repeated exposures are significantly linearly related to sickness outcomes (duration being positively related and repetition negatively related to total sickness). This was true over diverse systems and large subject pools. This result verified the generalizability of-the relationships among sickness, exposure duration, and repeated exposures. Additional research is indicated to determine the optimal length of a single exposure and the optimal intersession interval to facilitate adaptation

Toward systematic control of cybersickness

Visually induced motion sickness, or cybersickness, has been well documented in all kinds of vehicular simulators and in many virtual environments. It probably occurs in all virtual environments. Cybersickness has many known determinants, including (a short list) field-of-view, flicker, transport delays, duration of exposure, gender, and susceptibility to motion sickness. Since many of these determinants can be controlled, a major objective in designing virtual environments is to hold cybersickness below a specified level a specified proportion of the time. More than 20 years ago C. W. Simon presented a research strategy based on fractional factorial experiments that was capable in principle of realizing this objective. With one notable exception, however, this strategy was not adopted by the human factors community. The main reason was that implementing Simon\u27s strategy was a major undertaking, very time-consuming, and very costly. In addition, many investigators were not satisfied that Simon had adequately addressed issues of statistical reliability. The present paper proposes a modified Simonian approach to the sate objective (holding cybersickness below specified standards) with some loss in the range of application but a greatly reduced commitment of resources

Configural Scoring of Simulator Sickness, Cybersickness and Space Adaptation Syndrome: Similarities and Differences?

From a survey of ten U.S. Navy flight simulators a large number (N > 1,600 exposures) of self-reports of motion sickness symptomatology were obtained. Using these data, scoring algorithms were derived, which permit examination of groups of individuals that can be scored either for 1) their total sickness experience in a particular device; or, 2) according to three separable symptom clusters which emerged from a Factor Analysis. Scores from this total score are found to be proportional to other global motion sickness symptom checklist scores with which they correlate (r = 0.82). The factors that surfaced from the analysis include clusters of symptoms referable as nausea, oculomotor disturbances, and disorientation (N, 0, and D). The factor scores may have utility in differentiating the source of symptoms in different devices. The present chapter describes our experience with the use of both of these types of scores and illustrates their use with examples from flight simulators, space sickness and virtual environments

TALE and NF-Y co-occupancy marks enhancers of developmental control genes during zygotic genome activation in zebrafish [preprint]

Animal embryogenesis is initiated by maternal factors, but zygotic genome activation (ZGA) shifts control to the embryo at early blastula stages. ZGA is thought to be mediated by specialized maternally deposited transcription factors (TFs), but here we demonstrate that NF-Y and TALE – TFs with known later roles in embryogenesis – co-occupy unique genomic elements at zebrafish ZGA. We show that these elements are selectively associated with early-expressed genes involved in transcriptional regulation and possess enhancer activity in vivo. In contrast, we find that elements individually occupied by either NF-Y or TALE are associated with genes acting later in development – such that NF-Y controls a cilia gene expression program while TALE TFs control expression of hox genes. We conclude that NF-Y and TALE have a shared role at ZGA, but separate roles later during development, demonstrating that combinations of known TFs can regulate subsets of key developmental genes at vertebrate ZGA

NaviFields: relevance fields for adaptive VR navigation

Virtual Reality allow users to explore virtual environments naturally, by moving their head and body. However, the size of the environments they can explore is limited by real world constraints, such as the tracking technology or the physical space available. Existing techniques removing these limitations often break the metaphor of natural navigation in VR (e.g. steering techniques), involve control commands (e.g., teleporting) or hinder precise navigation (e.g., scaling user's displacements). This paper proposes NaviFields, which quantify the requirements for precise navigation of each point of the environment, allowing natural navigation within relevant areas, while scaling users' displacements when travelling across non-relevant spaces. This expands the size of the navigable space, retains the natural navigation metaphor and still allows for areas with precise control of the virtual head. We present a formal description of our NaviFields technique, which we compared against two alternative solutions (i.e., homogeneous scaling and natural navigation). Our results demonstrate our ability to cover larger spaces, introduce minimal disruption when travelling across bigger distances and improve very significantly the precise control of the viewpoint inside relevant areas