60419 research outputs found
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Retrofitting an environmental monitor with a silicon photomultiplier sensor
No full textWe report on the retrofitting of a standard DP2 environmental radiation monitor replacing the photomultiplier tube with a silicon photomultiplier (SiPM). The use of a SiPM has several advantages for a hand-held radiation monitor, including convenient low voltage operation and physical robustness. The SiPM is used to replace the existing photomultiplier tube, and we report the detection efficiency and alpha/beta discrimination performance of the modified probe compared to an unmodified version
Dual Encoder-Decoder based Generative Adversarial Networks for Disentangled Facial Representation Learning
No full textTo learn disentangled representations of facial images, we present a Dual Encoder-Decoder
based Generative Adversarial Network (DED-GAN). In the proposed method, both the generator and
discriminator are designed with deep encoder-decoder architectures as their backbones. To be more specific,
the encoder-decoder structured generator is used to learn a pose disentangled face representation, and the
encoder-decoder structured discriminator is tasked to perform real/fake classification, face reconstruction,
determining identity and estimating face pose. We further improve the proposed network architecture
by minimizing the additional pixel-wise loss defined by the Wasserstein distance at the output of the
discriminator so that the adversarial framework can be better trained. Additionally, we consider face pose
variation to be continuous, rather than discrete in existing literature, to inject richer pose information into
our model. The pose estimation task is formulated as a regression problem, which helps to disentangle
identity information from pose variations. The proposed network is evaluated on the tasks of pose-invariant
face recognition (PIFR) and face synthesis across poses. An extensive quantitative and qualitative evaluation
carried out on several controlled and in-the-wild benchmarking datasets demonstrates the superiority of the
proposed DED-GAN method over the state-of-the-art approaches
Motor Abilities and the Motor Profile in Individuals with Williams Syndrome
No full textObjectives:
Motor difficulties are present across a range of neurodevelopmental disorders, impacting on the development of other domains and on overall quality of life. One population that shows difficulties with their motor abilities is composed of individuals with Williams syndrome (WS). The purposes of the current study were to investigate the motor profile of individuals with WS and to investigate the relationships between physical activity and motor performance in this group.
Methods:
The motor performance of 36 individuals with WS was measured using the Bruininks-Oseretsky Test of Motor Proficiency, second edition (BOT2-SF) short form. Physical activity was also measured using our novel questionnaire. Performance on both measures was compared with that of typically developing (TD) children aged 4 to 7 years (N = 40).
Results:
Results indicate that the individuals with WS (aged 12 to 50 years) performed at the level of TD 4- to 5-year olds with respect to overall motor ability. On examination of the motor profile, a relative strength in upper limb control and a relative weakness in balance were identified for this group. While a correlation was found between motor ability and the amount of physical activity that participants engaged in on a weekly basis in the TD group, no such relationship was found in the WS group.
Conclusions:
The motor problems that individuals with WS show in childhood persist into older childhood and adulthood, and akin to the WS cognitive profile, there are relative strengths and weaknesses in the WS motor profile. The lack of correlation between physical activity and motor ability in the WS group may be due to the lack of opportunity to access age- and ability-appropriate activities
Generalized, massively parallel receiver processing for non-orthogonal signal transmissions.
No full textThe increasing demand for connectivity and throughput, combined with the tight latency requirements of current communication systems, and the existing spectrum limitations, has triggered a paradigm shift towards non-orthogonal signal transmissions where multiple information streams are transmitted using the same time/frequency resources. Despite the promising theoretical gains of such transmissions, the complexity and/or latency requirements of the corresponding receiver processing techniques that are required to translate these gains into throughput make their realization impractical, especially for large numbers of mutually interfering information streams. In addition to the processing complexity/latency increase related to systems’ high dimensionality, the interference matrix of some of the recently proposed non-orthogonal transmission schemes can either be ill-determined or even rank-deficient, making their detection even more challenging. These requirements combined with the saturating speed of processors, motivates a timely requirement for massively parallel processing of such non-orthogonal transmissions. In this context, this thesis introduces a generic, massively parallel and near-optimal processing framework that applies to both well- and ill-determined non-orthogonal systems. In contrast to known approaches, this framework enables practical large uplink multi-user MIMO systems with numbers of concurrently transmitting users that exceed the number of receive antennas by a factor of two or more. In contrast to traditional approaches, the proposed framework, does not require sparse signal transmissions for the detection of non-orthogonal multiple access (NOMA) schemes since it is not based on the “Message Passing” algorithm. Consequently, the proposed framework can enable more efficient NOMA approaches that support more users than existing systems, with better detection performance and practical complexity requirements. In comparison to state-of-the-art detectors for NOMA schemes and non-orthogonal signal waveforms(e.g., Spectrally efficient FDM) the proposed scheme can be up to an order of magnitude less complex and can provide throughput gains of up to 60%.This thesis also introduces a massively parallel soft-input soft-output (SISO) detection design for large MIMO systems capable of bridging the gap between theoretical capacity and achievable throughput, with a processing complexity that can be an order of magnitude lower than that of highly optimized sequential SISO detectors, and a processing latency similar to that of highly sub-optimal, linear, SISO detection approaches. Finally, a massively parallel processing framework is presented that enables extreme grant-free non-orthogonal multiple access. This framework allows reliable and low-overhead user identification and reliable detection/decoding with complexity requirements that can be orders of magnitude lower than existing schemes
Diaphragm action in light steel framing by sheathing boards
No full textThis paper presents the results of shear tests on light steel walls with two types of higher specification OSB/3 board and comparison with elastic theory based on the fixing shear stiffness. The tests were performed to BS EN 594 and showed that the design shear resistance was determined as 5.1 kN/m wall length for a limiting deflection of 0.003H or 4.3 kN/m for a limiting deflection of H/500, where H is the wall height. With plasterboard on the opposite face, the shear stiffness increased by 29%, but these results were more variable. For a single test on a wall with the OSB/3 board on one side and X bracing on the opposite face, the design shear resistance is 5.6 kN/m for a limiting deflection of H/500. For a flame retardant form of OSB/3 board, the stiffness was 21% higher than for the first series of OSB/3 tests. An elastic theory is presented to determine the limiting shear force as a function of the shear stiffness of the fixings between the boards and the C sections, which was provided from small-scale push tests. The results are compared with finite element models and a comparison with the test configurations is presented
CONVERGENCE RATE ESTIMATES FOR THE LOW MACH AND ALFVEN NUMBER THREE-SCALE SINGULAR LIMIT OF COMPRESSIBLE IDEAL MAGNETOHYDRODYNAMICS
No full textConvergence rate estimates are obtained for singular limits of the compressible ideal magnetohydrodynamics equations, in which the Mach and Alfven numbers tend to zero at different rates. The proofs use a detailed analysis of exact and approximate fast, intermediate, and slow modes together
with improved estimates for the solutions and their time derivatives, and the time-integration method. When the small parameters are related by a power law the convergence rates are positive powers of the Mach number, with the power varying depending on the component and the norm. Exceptionally, the convergence rate for two components involve the ratio of the two parameters, and that rate is proven to be sharp via corrector terms. Moreover, the convergence rates for the case of a power-law relation
between the small parameters tend to the two-scale convergence rate as the power tends to one. These
results demonstrate that the issue of convergence rates for three-scale singular limits, which was not
addressed in the authors' previous paper, is much more complicated than for the classical two-scale
singular limits
The effect of urbanization on sleep, sleep/wake routine, and metabolic health of residents in the Amazon region of Brazil
No full textInactivation of the gene encoding the cationic antimicrobial peptide resistance factor MprF increases biofilm formation but reduces invasiveness of Listeria monocytogenes
No full textAims
To understand the genetics involved in surface attachment and biofilm formation of Listeria monocytogenes.
Methods and Results
An in vitro screen of a Himar1 transposon library of L. monocytogenes strain 15G01 identified three transposants that produced significantly different biofilm levels when compared to the wild-type strain; two mutants exhibited enhanced biofilm formation and one produced less biofilm biomass than the wild-type. The mutant 15G01 mprF::Himar1, which had a transposon insertion in the mprF gene, was selected 29 for further analysis. The mutant produced a more densely populated biofilm on solid surfaces such as 30 stainless steel and polystyrene, as determined using scanning electron and light microscopy. The 15G01 31 mprF::Himar1 mutant remained viable in biofilms, but showed an increase in sensitivity to the cationic 32 antimicrobial gallidermin. The mutant also displayed reduced invasiveness in CaCo-2 intestinal cells, 33 suggesting virulence properties are compromised by the inactivation of mprF. 34
Conclusions 35
Biofilm formation and gallidermin resistance of L. monocytogenes is influenced by mprF, but this trait is 36 associated with a compromise in invasiveness. 37
Significance 38
The presence of pathogenic microorganisms in the food processing environment can cause a significant 39 problem, especially when these microorganisms are established as biofilms. This study shows that the 40 inactivation of the mprF gene results in enhanced biofilm formation and abiotic surface attachment of 41 Listeria monocytogenes
Use of amount-of-substance terminology and equations in field desorption theory
No full textThis note proposes that the theories of field evaporation and field desorption, as used
in atom-probe microscopy and related atomic-level contexts, should be consistently
formulated in terms of a set of "seven-dimensional (7-D)" formulae and equations
that involve the physical quantity "amount of substance", but make use of an atomiclevel
constant effectively equal to "one atom" (or, more generally, "one entity"). It is
argued that the term "count" should be introduced as an alternative name (more
suited to atomic-level contexts) for the quantity "amount of substance". For field
evaporation/desorption theories, relevant definitions and formulae are proposed, and
compared with the "six-dimensional" system (based on the dimensionless quantity
"number of atoms/entities") sometimes used in the literature. Advantages of using a
7-D system are noted. It is argued that there is also an increasing need for a
comprehensive system of official nomenclature for atomic-level constants and units,
for all three of the extensive quantities "mass", "electric charge" and "amount of
substance". It is also argued that, in the longer term, considerations of the kind being
proposed here for field evaporation/desorption theories might usefully be applied
more generally in atomic-level rate theory
Who really cares? Introducing an ‘Ethics of Care’ to debates on transformative value co-creation
No full textThis paper introduces an “ethics of care” lens to the literature on Transformative Services Research (TSR) to
understand how service users and providers co-create transformational value and well-being. In considering six
food poverty organizations—categorized as market-oriented, faith-oriented, or neighborhood-oriented—the
authors argue that the intention behind enacting an ethics of care drives different possibilities for transformative
value. The analysis is organized in line with Tronto’s (1993; 2001) phases of caring, and makes connections
between values that drive the organization’s work, emerging subjectivities, practices that unfold as a result, and
ultimately the value that is co-created. The findings show that caring relations must be considered “in situ,” as an
organization’s values and practices are what determine the potential for transformative value
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