A Naturalistic Study of Long-term Working Memory Capacity for Meaningful Visual and Auditory Stimuli

The purpose of this study was to explore long-term working memory in experts in an information-rich, dynamic domain. Of particular interest were strategies experts use to enhance long-term working memory capacity when working with verbal versus aural information. Three air traffic control instructors participated in four complex air traffic control scenarios, two radar scenarios in which information was presented visually and two non-radar scenarios in which information presentation was purely aural. Participants recalled traffic situation information at two points during and at the end of each scenario. Recall data for each scenario type were assessed in terms of evidence about information chunking and organizational strategies, the role of long-term working memory in extending working memory capacity, and the format of traffic situation information held in long-term working memory. Patterns of recall were consistent with template-based explanations of information organization and the use of information chunking within templates. Data were consistent with Ericsson and Kintsch\u27s (1995) model of long-term working memory in that working memory capacity seemed to be extended by the storing of traffic situation information in long-term working memory templates from which it seemed to be selectively and readily accessed and brought into working memory. Traffic situation information tended to be recalled in different orders for radar compared with non-radar scenarios, although the general organizational structure of the information seemed similar. Information, regardless of whether presented visually or aurally, tended to be recalled based on aircraft position, which seemed to prime other aircraft attributes which, in turn, seemed to prime yet other aircraft attributes. The results of this research have the potential to contribute to the long-term working memory, working memory, and expertise literatures. For example, they suggest hypotheses about expert and novice long-term working memory capacity that could be pursued in future research. To this end, the present study will be replicated using novice air traffic controllers. The comparison of novice and expert recall patterns has the potential to shed light on differences in information storage and recall strategies and could have implications for training air traffic controllers. The study additionally could hold implications for the design of NextGen air traffic control products and systems in other complex work domains. These results could shed light on display design for those systems by suggesting which information can or should be displayed within an aircraft\u27s data tag and which can or should be presented aurally

An Examination of Long-Term Working Memory Capacity

The purpose of this research was to explore experts’ memory capacity and the strategies experts use to achieve that capacity. Expert air traffic controllers were asked to recall traffic information during two radar and two nonradar scenarios. During radar scenarios, air traffic information was communicated aurally and displayed visually. During nonradar scenarios, air traffic information was communicated aurally only. Qualitative recall data assessment revealed an average capacity of five to eight aircraft in radar scenarios and three to six in nonradar scenarios, with two to three details recalled for most recalled aircraft. Recalled details and order of detail recall were highly consistent across experts, which suggest that aircraft details were organized and stored within larger conceptual knowledge structures. Recall patterns were additionally suggestive of frames containing slots designated for holding specific data types, structures described by Klein’s Data/Frame Model of Sensemaking. The extent of information recalled and its organization are additionally consistent with the use of long term working memory to extend working memory capacity; however, they do not rule out the use of working memory alone. Differences between radar and nonradar conditions were observed. Greater overall recall and greater and earlier recall of certain data-tag elements were observed in radar scenarios. In nonradar scenarios, greater and earlier recall of assigned actions were observed. Evaluation of experts’ descriptions of their recall processes suggested primarily visuospatial information encoding in both conditions and a lack of support for differences in the use of visuospatial or verbal encoding

Targeted massively parallel sequencing of autism spectrum disorder-associated genes in a case control cohort reveals rare loss-of-function risk variants

BACKGROUND: Autism spectrum disorder (ASD) is highly heritable, yet genome-wide association studies (GWAS), copy number variation screens, and candidate gene association studies have found no single factor accounting for a large percentage of genetic risk. ASD trio exome sequencing studies have revealed genes with recurrent de novo loss-of-function variants as strong risk factors, but there are relatively few recurrently affected genes while as many as 1000 genes are predicted to play a role. As such, it is critical to identify the remaining rare and low-frequency variants contributing to ASD. METHODS: We have utilized an approach of prioritization of genes by GWAS and follow-up with massively parallel sequencing in a case-control cohort. Using a previously reported ASD noise reduction GWAS analyses, we prioritized 837 RefSeq genes for custom targeting and sequencing. We sequenced the coding regions of those genes in 2071 ASD cases and 904 controls of European white ancestry. We applied comprehensive annotation to identify single variants which could confer ASD risk and also gene-based association analysis to identify sets of rare variants associated with ASD. RESULTS: We identified a significant over-representation of rare loss-of-function variants in genes previously associated with ASD, including a de novo premature stop variant in the well-established ASD candidate gene RBFOX1. Furthermore, ASD cases were more likely to have two damaging missense variants in candidate genes than controls. Finally, gene-based rare variant association implicates genes functioning in excitatory neurotransmission and neurite outgrowth and guidance pathways including CACNAD2, KCNH7, and NRXN1. CONCLUSIONS: We find suggestive evidence that rare variants in synaptic genes are associated with ASD and that loss-of-function mutations in ASD candidate genes are a major risk factor, and we implicate damaging mutations in glutamate signaling receptors and neuronal adhesion and guidance molecules. Furthermore, the role of de novo mutations in ASD remains to be fully investigated as we identified the first reported protein-truncating variant in RBFOX1 in ASD. Overall, this work, combined with others in the field, suggests a convergence of genes and molecular pathways underlying ASD etiology. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13229-015-0034-z) contains supplementary material, which is available to authorized users

The Interaction between Early Life Epilepsy and Autistic-Like Behavioral Consequences: A Role for the Mammalian Target of Rapamycin (mTOR) Pathway

Early life seizures can result in chronic epilepsy, cognitive deficits and behavioral changes such as autism, and conversely epilepsy is common in autistic children. We hypothesized that during early brain development, seizures could alter regulators of synaptic development and underlie the interaction between epilepsy and autism. The mammalian Target of Rapamycin (mTOR) modulates protein translation and is dysregulated in Tuberous Sclerosis Complex, a disorder characterized by epilepsy and autism. We used a rodent model of acute hypoxia-induced neonatal seizures that results in long term increases in neuronal excitability, seizure susceptibility, and spontaneous seizures, to determine how seizures alter mTOR Complex 1 (mTORC1) signaling. We hypothesized that seizures occurring at a developmental stage coinciding with a critical period of synaptogenesis will activate mTORC1, contributing to epileptic networks and autistic-like behavior in later life. Here we show that in the rat, baseline mTORC1 activation peaks during the first three postnatal weeks, and induction of seizures at postnatal day 10 results in further transient activation of its downstream targets phospho-4E-BP1 (Thr37/46), phospho-p70S6K (Thr389) and phospho-S6 (Ser235/236), as well as rapid induction of activity-dependent upstream signaling molecules, including BDNF, phospho-Akt (Thr308) and phospho-ERK (Thr202/Tyr204). Furthermore, treatment with the mTORC1 inhibitor rapamycin immediately before and after seizures reversed early increases in glutamatergic neurotransmission and seizure susceptibility and attenuated later life epilepsy and autistic-like behavior. Together, these findings suggest that in the developing brain the mTORC1 signaling pathway is involved in epileptogenesis and altered social behavior, and that it may be a target for development of novel therapies that eliminate the progressive effects of neonatal seizures

The role of leadership in salespeople’s price negotiation behavior

Salespeople assume a key role in defending firms’ price levels in price negotiations with customers. The degree to which salespeople defend prices should critically depend upon their leaders’ influence. However, the influence of leadership on salespeople’s price defense behavior is barely understood, conceptually or empirically. Therefore, building on social learning theory, the authors propose that salespeople might adopt their leaders’ price defense behavior given a transformational leadership style. Furthermore, drawing on the contingency leadership perspective, the authors argue that this adoption fundamentally depends on three variables deduced from the motivation–ability–opportunity (MAO) framework, that is, salespeople’s learning motivation, negotiation efficacy, and perceived customer lenience. Results of a multi-level model using data from 92 salespeople and 264 salesperson–customer interactions confirm these predictions. The first to explore contingencies of salespeople’s adoption of their transformational leaders’ price negotiation behaviors, this study extends marketing theory and provides actionable guidance to practitioners

Genetic determinants of heel bone properties: genome-wide association meta-analysis and replication in the GEFOS/GENOMOS consortium

Quantitative ultrasound of the heel captures heel bone properties that independently predict fracture risk and, with bone mineral density (BMD) assessed by X-ray (DXA), may be convenient alternatives for evaluating osteoporosis and fracture risk. We performed a meta-analysis of genome-wide association (GWA) studies to assess the genetic determinants of heel broadband ultrasound attenuation (BUA; n = 14 260), velocity of sound (VOS; n = 15 514) and BMD (n = 4566) in 13 discovery cohorts. Independent replication involved seven cohorts with GWA data (in silico n = 11 452) and new genotyping in 15 cohorts (de novo n = 24 902). In combined random effects, meta-analysis of the discovery and replication cohorts, nine single nucleotide polymorphisms (SNPs) had genome-wide significant (P < 5 × 10(-8)) associations with heel bone properties. Alongside SNPs within or near previously identified osteoporosis susceptibility genes including ESR1 (6q25.1: rs4869739, rs3020331, rs2982552), SPTBN1 (2p16.2: rs11898505), RSPO3 (6q22.33: rs7741021), WNT16 (7q31.31: rs2908007), DKK1 (10q21.1: rs7902708) and GPATCH1 (19q13.11: rs10416265), we identified a new locus on chromosome 11q14.2 (rs597319 close to TMEM135, a gene recently linked to osteoblastogenesis and longevity) significantly associated with both BUA and VOS (P < 8.23 × 10(-14)). In meta-analyses involving 25 cohorts with up to 14 985 fracture cases, six of 10 SNPs associated with heel bone properties at P < 5 × 10(-6) also had the expected direction of association with any fracture (P < 0.05), including three SNPs with P < 0.005: 6q22.33 (rs7741021), 7q31.31 (rs2908007) and 10q21.1 (rs7902708). In conclusion, this GWA study reveals the effect of several genes common to central DXA-derived BMD and heel ultrasound/DXA measures and points to a new genetic locus with potential implications for better understanding of osteoporosis pathophysiology

Using Enhanced Flight Vision Systems (EFVS) for Low-Visibility Taxi in Transport Category Aircraft

Two studies (using Boeing 777 and 737 simulators) examined flight crews’ use of an Enhanced Flight Vision System (EFVS) for low-visibility taxi operations. Twenty-five flight crews completed 21 short taxi scenarios under combinations of the following: Runway visual range (RVR: 300, 500, and 1000 ft); EFVS on head-up display (on/off); Airport infrastructure - 3 levels. The use of EFVS produced fewer route deviations, most at 300 feet RVR with edge lights and standard centerline or routes with LVO/SMGCS “enhancements” (without centerline lights). Larger turn angles and lower visibilities were associated with slower rates of travel. Crews detected the obstacle on the right-side most of the time and twice that of the left-side obstacle. Regardless of EFVS, crews had more route deviations on larger (\u3e90 degrees) turns and right turns, possibly from loss of visual references in the turn. Recommendations are provided regarding benefits and limitations of EFVS for low-visibility taxi with suggestions for additional research

Eco-Dolphin – Cooperative Fleet for Surveillance Mission

The Society for Industrial & Applied Mathematics (SIAM) student chapter at ERAU has been working on the design, construction and testing of three highly integrated and streamlined autonomous underwater vehicles, called Eco-Dolphins. The multidisciplinary team provides hands on research experience to members through Analysis, Computation and Experimentation (ACE). The Leverage lab is used to conduct preliminary research on electrical and mechanical systems. The engineering composites lab is utilized for the fabrication of Eco-Dolphins. Underwater experiments are conducted in the Universities Nonlinear Wave lab. The Blue Eco-Dolphin’s manufacturing phase will be completed by the summer of 2014, for testing in littoral waters, of central Florida. The three sequential (yellow, blue, and red) vehicles allow for accurate navigation data to be sent, a unique buoy network. The combined fleet shall cooperatively fulfill multitask missions, through advanced surveillance and environmental monitoring. The Eco-Dolphins promise will be a unique, highly optimized and a competitive underwater vehicle fleet