73 research outputs found
The thermal stability of alkanethiol self-assembled monolayers on copper for fluxless soldering applications
The ability of alkanethiol monolayers deposited
on copper to prevent surface oxidation has suggested their
application as preservatives for fluxless soldering. However, the
utility of such coatings for this purpose will critically depend
on their ability to continue to preserve the substrate during
exposure to elevated temperatures throughout the electronics
manufacturing process. Consequently, the aim of this paper is to
systematically determine the effect of storage temperature and
duration on the ability of alkanethiol coated copper samples to
undergo fluxless soldering. Similarly, the effect of pre-heating
copper immediately prior to soldering is also investigated. The
effect of reducing atmospheric oxygen concentration during
storage and soldering is also considered as a potential route
to improve the thermal resilience of the coatings. Parallel to
ascertaining these industrially relevant performance parameters,
a quantitative correlation between surface chemistry and solder
wetting is established, and the temperature dependence of the
kinetics of surface oxidation through an alkanethiol barrier layer
is discussed
Automated Gaze-Based Mind Wandering Detection during Computerized Learning in Classrooms
We investigate the use of commercial off-the-shelf (COTS) eye-trackers to automatically detect mind wandering—a phenomenon involving a shift in attention from task-related to task-unrelated thoughts—during computerized learning. Study 1 (N = 135 high-school students) tested the feasibility of COTS eye tracking while students learn biology with an intelligent tutoring system called GuruTutor in their classroom. We could successfully track eye gaze in 75% (both eyes tracked) and 95% (one eye tracked) of the cases for 85% of the sessions where gaze was successfully recorded. In Study 2, we used this data to build automated student-independent detectors of mind wandering, obtaining accuracies (mind wandering F1 = 0.59) substantially better than chance (F1 = 0.24). Study 3 investigated context-generalizability of mind wandering detectors, finding that models trained on data collected in a controlled laboratory more successfully generalized to the classroom than the reverse. Study 4 investigated gaze- and video- based mind wandering detection, finding that gaze-based detection was superior and multimodal detection yielded an improvement in limited circumstances. We tested live mind wandering detection on a new sample of 39 students in Study 5 and found that detection accuracy (mind wandering F1 = 0.40) was considerably above chance (F1 = 0.24), albeit lower than offline detection accuracy from Study 1 (F1 = 0.59), a finding attributable to handling of missing data. We discuss our next steps towards developing gaze-based attention-aware learning technologies to increase engagement and learning by combating mind wandering in classroom contexts
Next generation neural population models
Low-dimensional neural mass models are often invoked to model the coarse-grained activity of large populations of neurons and synapses and have been used to help understand the coordination of large scale brain rhythms. However, they are phenomenological in nature and, although motivated by neurobiological considerations, the absence of a direct link to an underlying biophysical reality is a weakness that means they may not be best suited to capturing some of the rich behaviors seen in real neuronal tissue. In this perspective article I discuss a simple spiking neuron network model that has recently been shown to admit to an exact mean-field description for synaptic interactions. This has many of the features of a neural mass model coupled to an additional dynamical equation that describes the evolution of population synchrony. This next generation neural mass model is ideally suited to understanding the patterns of brain activity that are ubiquitously seen in neuroimaging recordings. Here I review the mean-field equations, the way in which population synchrony, firing rate, and average voltage are intertwined, together with their application in large scale brain modeling. As well as natural extensions of this new approach to modeling the dynamics of neuronal populations I discuss some of the open mathematical challenges in developing a statistical neurodynamics that can generalize the one discussed here
Overmoulding of electronics for end of life recovery
With the increasing use of electronic control systems in automotive applications, the environments in which they are required to operate are becoming evermore demanding. For improved functionality and to reduce the number of interconnections it is desirable to place the electronic control units (ECUs) as close as possible to the sensors and actuators they interact with, and they can increasingly be found mounted on engine, transmission and chassis components. The electronics are therefore exposed to high/low temperatures, high humidity, vibration and corrosive fluids. In order to protect the electronics and maintain reliability in safety critical areas, great lengths are taken to mount the devices in ways that will prevent the ingress of moisture, cushion shocks and dissipate heat. Potting of electrical devices with thermosetting polymers has been a commonplace method to install a protective layer over the circuit assemblies, which are often mounted in separate boxes within the vehicle. However, with the drive to reduce vehicle weight and increase recyclability, there has been much interest in the use of overmoulding with thermoplastic polymers, not only to provide protection, but to enable the electronics to be mounted into a structural component of the vehicle thereby saving space and weight and eliminating a level of packaging. While this has been shown to be a practical way forward in terms of reliability, the recyclability of the thermoplastic polymer is compromised by the intermixed electronics that are hard to separate economically
Using routine inpatient data to identify patients at risk of hospital readmission
Background: A relatively small percentage of patients with chronic medical conditions account for a much larger percentage of inpatient costs. There is some evidence that case-management can improve health and quality-of-life and reduce the number of times these patients are readmitted. To assess whether a statistical algorithm, based on routine inpatient data, can be used to identify patients at risk of readmission and who would therefore benefit from case-management
A reassessment of Kelmayisaurus petrolicus, a large theropod dinosaur from the Early Cretaceous of China
The Early Cretaceous fossil record of large−bodied theropods from Asia is poor, hindering comparison of Asian predatory dinosaur faunas with those from other continents. One of the few large Asian theropod specimens from this interval is a partial skull (maxilla and dentary) from the Lianmugin Formation (?Valanginian–Albian), the holotype of Kelmayisaurus petrolicus. Most authors have either considered this specimen as an indeterminate basal tetanuran or a nomen dubium. Weredescribe K. petrolicus and note that it possesses a single autapomorphy (a deep accessory groove on the lateral surface of the anterior dentary), as well as a unique combination of characters that differentiates it from other theropods, affirming its validity. A phylogenetic analysis recovers K. petrolicus as a basal carcharodontosaurid, which is supported by various features: very deep interdental plates (a carcharodontosaurid synapomorphy), fused interdental plates (present in carchardontosaurids and a limited number of other theropods), and the absence of diagnostic features of other clades of large−bodied theropods such as abelisaurids, megalosauroids, and coelurosaurs. As such, Kelmayisaurus is the second known carcharodontosaurid from Asia, and further evidence that this clade represented a global radiation of large−bodied predators during the Early–mid Cretaceous
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Effect of the Growth Assessment Protocol on the DEtection of Small for GestatioNal age fetus: process evaluation from the DESiGN cluster randomised trial
BACKGROUND: Reducing the rate of stillbirth is an international priority. At least half of babies stillborn in high-income countries are small for gestational-age (SGA). The Growth Assessment Protocol (GAP), a complex antenatal intervention that aims to increase the rate of antenatal detection of SGA, was evaluated in the DESiGN type 2 hybrid effectiveness-implementation cluster randomised trial (n = 13 clusters). In this paper, we present the trial process evaluation. METHODS: A mixed-methods process evaluation was conducted. Clinical leads and frontline healthcare professionals were interviewed to inform understanding of context (implementing and standard care sites) and GAP implementation (implementing sites). Thematic analysis of interview text used the context and implementation of complex interventions framework to understand acceptability, feasibility, and the impact of context. A review of implementing cluster clinical guidelines, training and maternity records was conducted to assess fidelity, dose and reach. RESULTS: Interviews were conducted with 28 clinical leads and 27 frontline healthcare professionals across 11 sites. Staff at implementing sites generally found GAP to be acceptable but raised issues of feasibility, caused by conflicting demands on resource, and variable beliefs among clinical leaders regarding the intervention value. GAP was implemented with variable fidelity (concordance of local guidelines to GAP was high at two sites, moderate at two and low at one site), all sites achieved the target to train > 75% staff using face-to-face methods, but only one site trained > 75% staff using e-learning methods; a median of 84% (range 78–87%) of women were correctly risk stratified at the five implementing sites. Most sites achieved high scores for reach (median 94%, range 62–98% of women had a customised growth chart), but generally, low scores for dose (median 31%, range 8–53% of low-risk women and median 5%, range 0–17% of high-risk women) were monitored for SGA as recommended. CONCLUSIONS: Implementation of GAP was generally acceptable to staff but with issues of feasibility that are likely to have contributed to variation in implementation strength. Leadership and resourcing are fundamental to effective implementation of clinical service changes, even when such changes are well aligned to policy mandated service-change priorities. TRIAL REGISTRATION: Primary registry and trial identifying number: ISRCTN 67698474. Registered 02/11/16. https://doi.org/10.1186/ISRCTN67698474
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Science Communication in a Digital Age: Social Media and the American Fisheries Society
Social media platforms are effective tools used
to help communicate and increase involvement in cultural, political,
and scientific circles. In 2012, an ad hoc committee was
established to explore online fisheries science communication
and how social media platforms can be utilized by the American
Fisheries Society (AFS). A survey was disseminated to all AFS
units (chapters, sections, divisions) and student subunits to better
understand the current use of social media within the AFS.
A relatively high response rate (82%) provided some confidence
in the survey results—namely, that nearly 69% or more of units
and subunits used social media. Facebook was the dominant
platform used (59%; all others < 15%) and almost exclusively
(97%) for the purpose of communication. Education, outreach,
and member recruitment were other reasons for social media
use. Finally, whether units currently use social media or not at
all, it was recommended that AFS-led workshops and assistance
would increase the usefulness of social media
Effect of the Growth Assessment Protocol on the DEtection of Small for GestatioNal age fetus: process evaluation from the DESiGN cluster randomised trial
Background
Reducing the rate of stillbirth is an international priority. At least half of babies stillborn in high-income countries are small for gestational-age (SGA). The Growth Assessment Protocol (GAP), a complex antenatal intervention that aims to increase the rate of antenatal detection of SGA, was evaluated in the DESiGN type 2 hybrid effectiveness-implementation cluster randomised trial (n = 13 clusters). In this paper, we present the trial process evaluation.
Methods
A mixed-methods process evaluation was conducted. Clinical leads and frontline healthcare professionals were interviewed to inform understanding of context (implementing and standard care sites) and GAP implementation (implementing sites). Thematic analysis of interview text used the context and implementation of complex interventions framework to understand acceptability, feasibility, and the impact of context. A review of implementing cluster clinical guidelines, training and maternity records was conducted to assess fidelity, dose and reach.
Results
Interviews were conducted with 28 clinical leads and 27 frontline healthcare professionals across 11 sites. Staff at implementing sites generally found GAP to be acceptable but raised issues of feasibility, caused by conflicting demands on resource, and variable beliefs among clinical leaders regarding the intervention value. GAP was implemented with variable fidelity (concordance of local guidelines to GAP was high at two sites, moderate at two and low at one site), all sites achieved the target to train > 75% staff using face-to-face methods, but only one site trained > 75% staff using e-learning methods; a median of 84% (range 78–87%) of women were correctly risk stratified at the five implementing sites. Most sites achieved high scores for reach (median 94%, range 62–98% of women had a customised growth chart), but generally, low scores for dose (median 31%, range 8–53% of low-risk women and median 5%, range 0–17% of high-risk women) were monitored for SGA as recommended.
Conclusions
Implementation of GAP was generally acceptable to staff but with issues of feasibility that are likely to have contributed to variation in implementation strength. Leadership and resourcing are fundamental to effective implementation of clinical service changes, even when such changes are well aligned to policy mandated service-change priorities.
Trial registration
Primary registry and trial identifying number: ISRCTN 67698474. Registered 02/11/16. https://doi.org/10.1186/ISRCTN67698474
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