Thick Walled Multiple Opening Reinforced Concrete Conduits

The Department of The Army Corps of Engineers, Engineering Division, Civil Works, Contract No. DACW-73-70-C-003

A potential role for restricted intertactical heritability in preventing intralocus conflict

Intralocus sexual conflict, which arises when the same trait has different fitness optima in males and females, reduces population growth rates. Recently, evolutionary biologists have recognized that intralocus conflict can occur between morphs or reproductive tactics within a sex and that intralocus tactical conflict might constrain tactical dimorphism and population growth rates just as intralocus sexual conflict constrains sexual dimorphism and population growth rates. However, research has only recently focused on sexual and tactical intralocus conflict simultaneously, and there is no formal theory connecting the two. We present a graphical model of how tactical and sexual conflict over the same trait could constrain both sexual and tactical dimorphisms. We then use Coho salmon (Oncorhynchus kisutch), an important species currently protected under the Endangered Species Act, to investigate the possibility of simultaneous sexual and tactical conflict. Larger Coho males gain access to females through fighting while smaller males are favored through sneaking tactics, and female reproductive success is positively correlated with length. We tested for antagonistic selection on length at maturity among sexes and tactics and then used parent–offspring regression to calculate sex- and tactic-specific heritabilities to determine whether and where intralocus conflict exists. Selection on length varied in intensity and form among tactics and years. Length was heritable between dams and daughters (h2 ± 95% CI = 0.361 ± 0.252) and between fighter males and their fighter sons (0.867 ± 0.312), but no other heritabilities differed significantly from zero. The lack of intertactical heritabilities in this system, combined with similar selection on length among tactics, suggests the absence of intralocus conflict between sexes and among tactics, allowing for the evolution of sexual and tactical dimorphisms. Our results suggest that Coho salmon populations are unlikely to be constrained by intralocus conflict or artificial selection on male tactic

Exploring factors associated with persistent postural-perceptual dizziness(PPPD): A mixed-methods approach

Persistent Postural-Perceptual Dizziness (PPPD) is a functional (non-organic), debilitating neuro-vestibular condition characterised by chronic episodes of visually induced dizziness (Bronstein, 1995; Staab et al., 2017). Symptoms are triggered by situations of visuo-vestibular conflict, intense visual environments and active and passive motion (Bronstein, 2004; Pavlou, 2010). PPPD is thought to develop due to an over reliance on vision for postural control mechanisms (Bronstein, 1995). The aim of this Thesis was to explore factors associated with PPPD. The aim of Chapter 2 was to explore how individuals with PPPD make sense of their symptoms and condition and to better understand the lived experiences of PPPD, including the psycho-social impacts of the condition. Findings suggest identity loss, dismissal and non-belief, poor psychological well-being, out of body experiences and processes of sense-making are factors associated with PPPD. Shared themes included poor metal well-being, sensory overload, sleep impairments and PPPD not affecting television/movie watching. The aim of Chapter 3 was to test if short-term exposure to optokinetic stimulation can produce changes in markers of visual dependence and to establish the promise of multi-media technology for producing recalibration effects. Findings suggest that passively viewing movies are the most effective optokinetic stimulus for recalibration effects. The aim of Chapter 4 was to explore the relationships between self-reported PPPD symptoms and performance on traditionally used laboratory measures of visual dependence in the non-clinical student and sub-clinical student populations. Findings suggest that PPPD symptoms do not correlate with levels of visual dependence. Furthermore, traditional measures of visual dependence also failed to correlate. Taken together, this Thesis provides the scientific community with a deeper understanding of factors associated with PPPD in clinical and non-clinical communitie

The Influence of Personality on Code Reuse

The ubiquity and necessity of computer software requires programmers to reuse extant code to keep up with increasing software demands. Researchers have started to investigate the underlying psychological processes and the programmer characteristics affecting code reuse. The present study investigated the role of programmer personality (propensity to trust, suspicion propensity) on willingness to reuse code. Programmers were recruited through Amazon’s Mechanical Turk. Programmers completed propensity to trust and suspicion personality inventories and were subsequently presented with 18 pieces of computer code containing transparency and reputation manipulations. The results demonstrated that propensity to trust did not influence willingness to reuse code. However, facets of suspicion propensity did affect reuse willingness. Programmers lower in trait mal-intent perceptions and higher in cognitive activity were more likely to report they would reuse code. Implications and applications are discussed

Transport through an impurity tunnel coupled to a Si/SiGe quantum dot

Achieving controllable coupling of dopants in silicon is crucial for operating donor-based qubit devices, but it is difficult because of the small size of donor-bound electron wavefunctions. Here we report the characterization of a quantum dot coupled to a localized electronic state, and we present evidence of controllable coupling between the quantum dot and the localized state. A set of measurements of transport through this device enable the determination of the most likely location of the localized state, consistent with an electronically active impurity in the quantum well near the edge of the quantum dot. The experiments we report are consistent with a gate-voltage controllable tunnel coupling, which is an important building block for hybrid donor and gate-defined quantum dot devices.Comment: 5 pages, 3 figure

Gaia: Establishing the world’s first climate Command and Control (C2) centre

Establishing Gaia, a Command-and-Control Centre focused on climate activity, based in Wales. It aims to apply command and control principles to the evolving map of climate data and explore how such data can be integrated with policy, and with other information: resources and vulnerabilities to influence behaviour change on a regional and national level

Would you fix this code for me? Effects of repair source and commenting on trust in code repair

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Automation and autonomous systems are quickly becoming a more engrained aspect of modern society. The need for effective, secure computer code in a timely manner has led to the creation of automated code repair techniques to resolve issues quickly. However, the research to date has largely ignored the human factors aspects of automated code repair. The current study explored trust perceptions, reuse intentions, and trust intentions in code repair with human generated patches versus automated code repair patches. In addition, comments in the headers were manipulated to determine the effect of the presence or absence of comments in the header of the code. Participants were 51 programmers with at least 3 years’ experience and knowledge of the C programming language. Results indicated only repair source (human vs. automated code repair) had a significant influence on trust perceptions and trust intentions. Specifically, participants consistently reported higher levels of perceived trustworthiness, intentions to reuse, and trust intentions for human referents compared to automated code repair. No significant effects were found for comments in the headers

Direct observation of quantum criticality in Ising spin chains

We use NMR quantum simulators to study antiferromagnetic Ising spin chains undergoing quantum phase transitions. Taking advantage of the sensitivity of the systems near criticality, we detect the critical points of the transitions using a direct measurement of the Loschmidt echo. We test our simulators for spin chains of even and odd numbers of spins, and compare the experimental results to theoretical predictions