Effects of uncertainty on manual tracking performance

Transient phenomena and target acquisition modes associated with interrupted observations during ground-to-air AA tracking were investigated. Using a two-axes control stick, the subjects tracked a computer-generated airplane image on a CRT display. The airplane image excuted a low-level straight pass. At certain pseudo-random times during each 25-second run, the screen was blanked for a period of one second. When the target image reappeared, the subjects reacquired it and continued tracking, attempting to minimize vector RMS error for the entire run (including the blanked period). The results reveal an increase both in tracking error and in error variance during the blanked period, only when the target disappears while in the crossover region. Blanking at other times effected increased variance but had no effect on the mean error. A blanking period just before crossover produced an increase lag while a blanking just after crossover resulted in a lead and thus made the error curve more symmetric

Investigation of long noncoding RNAs in the p53 response to oncogenic stress

The tumor suppressor protein p53 plays a central role in sensing and responding to cellular stress, and loss of normal p53 activity is a feature of most human cancers. P53, functioning as a transcription factor, regulates a wide network of genes that coalesce to drive many diverse tumor suppressive cellular processes. Despite three decades of extensive study, it is unclear which p53 targets are most critical for these tumor suppressive functions and under which biological contexts. More recent studies have revealed that the p53 network is not solely comprised of protein coding genes but also includes many long noncoding RNAs (lncRNAs), which are an abundant but poorly characterized class of heterogenous RNA molecules. This work aimed to expand our understanding of the role of lncRNAs in the p53 transcriptional network and the importance of these diverse RNAs in various p53-regulated processes and/or tumor suppression.  We focused on characterizing the p53 response to stress generated by hyperactive oncogenes (i.e. oncogenic stress), which is an important but understudied facet of p53-mediated tumor suppression. By performing genome-wide analysis of p53 regulation across a panel of cancer cell lines established from a genetically-engineered mouse model of p53-driven lung adenocarcinoma, sarcoma, and lymphoma, we uncovered oncogenic stress-specific, tumor type-specific, and p53 outcome-specific patterns of p53 gene activation and repression, including the activation of several novel and previously described lncRNAs. We interrogated the contributions of many of these lncRNAs to p53 pathway function, using a number of locus-specific genetic and molecular approaches to down- or upregulate lncRNA expression in vitro. These characterization efforts revealed that local gene regulation, also known as cis-regulation, is the dominant mode of action for lncRNAs within the p53 network, in contrast to most previous reports on individual p53-regulated lncRNAs. We show that this regulation is largely in the positive direction, suggesting that lncRNAs do not significantly contribute to p53-mediated gene repression, and demonstrate that lncRNA cis-regulation can be important for p53-dependent growth arrest in certain tumor contexts. Altogether, this work provides novel insights into the p53 response across different cellular contexts and clarifies the contributions of lncRNAs to the p53 tumor suppressor network. Namely, we propose that lncRNAs primarily serve as an important fine-tuning regulatory mechanism. As such, this work has broader implications on the mechanisms by which lncRNAs as a class may influence other complex transcriptional networks important in human health and disease

FMP study of pilot workload. Qualification of workload via instrument scan

Various methods of measuring a pilot's mental workload are discussed. Scanning the various flight instruments with good scan pattern and other verbal tasks during instrument landings is given special attention for measuring pilot workload

Visual scanning behavior and pilot workload

An experimental paradigm and a set of results which demonstrate a relationship between the level of performance on a skilled man-machine control task, the skill of the operator, the level of mental difficulty induced by an additional task imposed on the basic control task, and visual scanning performance. During a constant, simulated piloting task, visual scanning of instruments was found to vary as a function of the level of difficulty of a verbal mental loading task. The average dwell time of each fixation on the pilot's primary instrument increased as a function of the estimated skill level of the pilots, with novices being affected by the loading task much more than the experts. The results suggest that visual scanning of instruments in a controlled task may be an indicator of both workload and skill

Visual scanning behavior and pilot workload

Sophisticated man machine interaction often requires the human operator to perform a stereotyped scan of various instruments in order to monitor and/or control a system. For situations in which this type of stereotyped behavior exists, such as certain phases of instrument flight, scan pattern was shown to be altered by the imposition of simultaneous verbal tasks. A study designed to examine the relationship between pilot visual scan of instruments and mental workload is described. It was found that a verbal loading task of varying difficulty causes pilots to stare at the primary instrument as the difficulty increases and to shed looks at instruments of less importance. The verbal loading task also affected the rank ordering of scanning sequences. By examining the behavior of pilots with widely varying skill levels, it was suggested that these effects occur most strongly at lower skill levels and are less apparent at high skill levels. A graphical interpretation of the hypothetical relationship between skill, workload, and performance is introduced and modelling results are presented to support this interpretation

Entropy, instrument scan and pilot workload

Correlation and information theory which analyze the relationships between mental loading and visual scanpath of aircraft pilots are described. The relationship between skill, performance, mental workload, and visual scanning behavior are investigated. The experimental method required pilots to maintain a general aviation flight simulator on a straight and level, constant sensitivity, Instrument Landing System (ILS) course with a low level of turbulence. An additional periodic verbal task whose difficulty increased with frequency was used to increment the subject's mental workload. The subject's looppoint on the instrument panel during each ten minute run was computed via a TV oculometer and stored. Several pilots ranging in skill from novices to test pilots took part in the experiment. Analysis of the periodicity of the subject's instrument scan was accomplished by means of correlation techniques. For skilled pilots, the autocorrelation of instrument/dwell times sequences showed the same periodicity as the verbal task. The ability to multiplex simultaneous tasks increases with skill. Thus autocorrelation provides a way of evaluating the operator's skill level

Ancestral QTL Alleles from Wild Emmer Wheat Enhance Root Development under Drought in Modern Wheat

A near-isogenic line (NIL-7A-B-2), introgressed with a quantitative trait locus (QTL) on chromosome 7AS from wild emmer wheat (Triticum turgidum ssp. dicoccoides) into the background of bread wheat (T. aestivum L.) cv. BarNir, was recently developed and studied in our lab. NIL-7A-B-2 exhibited better productivity and photosynthetic capacity than its recurrent parent across a range of environments. Here we tested the hypothesis that root-system modifications play a major role in NIL-7A-B-2’s agronomical superiority. Root-system architecture (dry matter and projected surface area) and shoot parameters of NIL-7A-B-2 and ‘BarNir’ were evaluated at 40, 62, and 82 days after planting (DAP) in a sand-tube experiment, and root tip number was assessed in a ‘cigar-roll’ seedling experiment, both under well-watered and water-limited (WL) treatments. At 82 DAP, under WL treatment, NIL-7A-B-2 presented greater investment in deep roots (depth 40–100 cm) than ‘BarNir,’ with the most pronounced effect recorded in the 60–80 cm soil depth (60 and 40% increase for root dry matter and surface area, respectively). NIL-7A-B-2 had significantly higher root-tip numbers (∼48%) per plant than ‘BarNir’ under both treatments. These results suggest that the introgression of 7AS QTL from wild emmer wheat induced a deeper root system under progressive water stress, which may enhance abiotic stress resistance and productivity of domesticated wheat