Microfocus X-ray scattering investigations of eggshell nanotexture

The avian eggshell is a highly ordered calcitic bioceramic composite, with both inorganic and organic constituents. The interactions between the inorganic and organic components within the structure are poorly understood but are likely to occur at the nanometre level. Thus structural variation at this level may impinge on the overall structural integrity and mechanical performance of the eggshell, and therefore analysis at this level is fundamental in fully understanding this ordered structure. In this study, structural changes in the mineral crystallites were investigated by microfocus small-angle X-ray scattering (µSAXS) using synchrotron radiation. Small-angle X-ray scattering (SAXS) can be used to investigate structures on the nanometre scale such as size, shape, arrangement and internal porosity. A microfocused X-ray beam, 1.5 µm vertically by 7 µm, was used to produce vertical linear scans of the eggshell section. SAXS patterns were taken from the eggshell membrane (inner surface of the eggshell) to the cuticle (outer surface of the eggshell). This allowed textural variations within the eggshell to be mapped. The scattering intensity profile was then used to derive the dimension of scattering objects that define the nanotexture. The nanotexture observed may result from the presence of the organic matrix, which is embedded as intracrystalline particles producing voids within the calcified framework of large (>1 µm) calcite crystals. Porod analysis revealed the average size of a scattering interface to be approximately 4.5 nm with small changes that had a depth-dependent variation. These were largest at the mammillary layer/membrane boundary. The palisade layer displayed a small upward trend in size of scattering object. Parallel scans showed that the textural variations observed within the palisade layer are significant and indicate local subtextures. In addition, many of the patterns exhibit diffuse scattering streaks that could result from reflectivity from the larger crystallite interfaces. Changes in the orientation of diffuse streaks were observed within the different layers, the membranes, mammillary layer, palisade layer, vertical crystal layer and cuticle, indicating certain preferred orientations of the crystallites within the layers. The nanotextural variations that are apparent could have implications at the macroscopic level of the resulting eggshell

Accelerating Deterministic and Stochastic Binarized Neural Networks on FPGAs Using OpenCL

Recent technological advances have proliferated the available computing power, memory, and speed of modern Central Processing Units (CPUs), Graphics Processing Units (GPUs), and Field Programmable Gate Arrays (FPGAs). Consequently, the performance and complexity of Artificial Neural Networks (ANNs) is burgeoning. While GPU accelerated Deep Neural Networks (DNNs) currently offer state-of-the-art performance, they consume large amounts of power. Training such networks on CPUs is inefficient, as data throughput and parallel computation is limited. FPGAs are considered a suitable candidate for performance critical, low power systems, e.g. the Internet of Things (IOT) edge devices. Using the Xilinx SDAccel or Intel FPGA SDK for OpenCL development environment, networks described using the high-level OpenCL framework can be accelerated on heterogeneous platforms. Moreover, the resource utilization and power consumption of DNNs can be further enhanced by utilizing regularization techniques that binarize network weights. In this paper, we introduce, to the best of our knowledge, the first FPGA-accelerated stochastically binarized DNN implementations, and compare them to implementations accelerated using both GPUs and FPGAs. Our developed networks are trained and benchmarked using the popular MNIST and CIFAR-10 datasets, and achieve near state-of-the-art performance, while offering a >16-fold improvement in power consumption, compared to conventional GPU-accelerated networks. Both our FPGA-accelerated determinsitic and stochastic BNNs reduce inference times on MNIST and CIFAR-10 by >9.89x and >9.91x, respectively.Comment: 4 pages, 3 figures, 1 tabl

Simulation and implementation of novel deep learning hardware architectures for resource constrained devices

Corey Lammie designed mixed signal memristive-complementary metal–oxide–semiconductor (CMOS) and field programmable gate arrays (FPGA) hardware architectures, which were used to reduce the power and resource requirements of Deep Learning (DL) systems; both during inference and training. Disruptive design methodologies, such as those explored in this thesis, can be used to facilitate the design of next-generation DL systems

Health care and reference to Vietnam: experiences of immigrants and refugees in Saskatoon

This thesis focuses on the experiences of Vietnamese immigrants and refugees in accessing health care services in Saskatoon. Within Canada, terms such as immigrant and refugee are assigned to reflect the differing circumstances that “newcomers,” i.e. foreign-born residents, arrive under, who are typically classified as either temporary or permanent residents (Gushulak et al. 2011). Research has suggested that newcomers to Canada from non-European countries tend to under-utilize health services (Curtis and MacMinn 2008; Luu, Leung and Nash 2009; O’Mahony and Donnelly 2007; Whitley, Kirmayer and Groleau 2006), while language and cultural differences are cited as barriers to health care (Asanin and Wilson 2008; Gushulak et al. 2011; Kirmayer et al. 1996). Qualitative health research regarding Vietnamese immigrants and refugees in Saskatchewan is currently lacking. The purpose of this study was to elicit a deeper understanding of experiences in accessing health care services through open-ended interviews. A total of 14 interviews were conducted regarding the health care experiences of members of the Vietnamese community in Saskatoon. The aim was to examine the possible socio-cultural determinants affecting the experiences of this study’s participants, to explore whether or not these determinants resulted in health care under-utilization, and to determine areas for future research, particularly, in working to resolve barriers to care for immigrant and refugee groups. Participants iterated the challenges that newcomers face in accessing health care, such as language, cultural, geographical, and socio-economic differences, as identified within the literature. However, the most elaborate responses given by the Vietnamese-born participants in this study were built around references to Vietnam (their country of origin). In particular, they described their experiences in Saskatoon through comparisons of health care and larger socio-economic circumstances in Vietnam. While participants described both positive and negative experiences, the consensus was that health care is generally better in Canada than in Vietnam. This thesis illustrates the value of examining the participants’ descriptions of Vietnam in understanding their experiences with health care in Saskatoon. These findings contribute to a contextual understanding of the socio-cultural determinants affecting the experiences of immigrants and refugees. I follow previous research studies to suggest that the cross-cultural contexts of health and illness need to be continually explored in health research regarding immigrants and refugees

Substitution effects in intramolecular furan cycloadditions

The intramolecular Diels-Alder reaction of furan (IMDAF) provides a high degree of structural complexity in one step. However, reaction reversibility issues and the lower reactivity of furan in comparison to non-aromatic dienes prevent more widespread use of furan as a diene component in such reactions. Initial efforts to develop a new mode of organocatalysis which we hoped would facilitate IMDAF reaction was unfortunately unsuccessful, thus alternative means of IMDAF facilitation were investigated. For the first time, a comprehensive synthetic and computational study of the effect of halogen substitution on the IMDAF reaction has been undertaken. We have successfully demonstrated that halogenation of the furan moiety facilitates the IMDAF reaction (displaying increased reactivity to the non-halogenated analogue, regardless of halogen position), whereas dienophile halogenation hinders it. Additionally, careful selection of the position of the halogen on the furan can somewhat overcome the detrimental effect of having a halogen on the dienophile leading to highly functionalised cycloadducts with potential for further modification. Computational data produced by Martin Paterson and Justyna McKinlay support the idea that frontier molecular orbital effects cannot explain the experimental observations and we thus believe that the reactions are controlled by the interplay of three factors: positive charge stabilisation in the transition state and product, steric effects and a dipolar interaction term identified by the high level calculations. Finally, we have briefly demonstrated that nitro groups on the furan moiety also facilitate the IMDAF reaction whereas acyl groups appear to hinder the reaction. STEREOCHEMICAL ABSTRACT Any chiral compounds included in this thesis are racemic in nature. However, for clarity, such mixtures are schematically represented by drawings of only one of the enantiomers.EPSR

Integrated Serologic Surveillance of Population Immunity and Disease Transmission.

Antibodies are unique among biomarkers in their ability to identify persons with protective immunity to vaccine-preventable diseases and to measure past exposure to diverse pathogens. Most infectious disease surveillance maintains a single-disease focus, but broader testing of existing serologic surveys with multiplex antibody assays would create new opportunities for integrated surveillance. In this perspective, we highlight multiple areas for potential synergy where integrated surveillance could add more value to public health efforts than the current trend of independent disease monitoring through vertical programs. We describe innovations in laboratory and data science that should accelerate integration and identify remaining challenges with respect to specimen collection, testing, and analysis. Throughout, we illustrate how information generated through integrated surveillance platforms can create new opportunities to more quickly and precisely identify global health program gaps that range from undervaccination to emerging pathogens to multilayered health disparities that span diverse communicable diseases

Methodologies to determine digestion of starch in ponies

Cereal and legume starch frequently constitute the majority of the concentrate portion of diets for equines yet large intakes of starch can be associated with changes to the hindgut environment. Cereal and legume grains are often subjected to some form of physical processing with a view to increasing their digestibility and this has been the subject of a number of studies. However, there are few reports of the effects of such processing on either the hindgut environment or the site of starch degradation in the equine. Therefore, the objectives of this thesis were twofold, firstly to investigate the effects of physical processing of grains on intra-caecal fermentation parameters and secondly to develop in sacco methodologies to enable degradation parameters of processed cereals to be determined in different segments of the equine digestive tract. In the first set of experiments three caecally fistulated ponies were offered 4 kg DM per day of either 100% hay cubes (HC) or one of three diets consisting of 50:50 barley:HC mix. The barley in the mixed diets was either rolled (RB), micronised (MB) or extruded (EB). Inclusion of RB in the diet significantly (P<0.05) reduced intra-caecal pH and acetate molar proportions whilst lactate concentration and propionate molar proportions were increased (P<0.05) compared with the HC diet measured 5 hours post feeding. Physical processing of grains did not alter their total tract in vivo apparent digestibility nor their digestible energy (average 14.8 MJ/kg DM) or digestible crude protein (average 86 g/kg DM) contents. Mean retention times (MRT) of digesta were determined for the four diets and were similar at 46.1, 42.3, 46.9 and 43.0 h for HC, RB, MB and EB respectively. In the second set of experiments micronised or extruded barley, maize and peas were incubated in situ in the caecum of ponies to determine their degradation parameters. Compared to unprocessed feeds, micronisation significantly increased (P<0.05) the effective degradability (ED) of starch (STC) but reduced the ED of crude protein (CP) in barley and maize. Likewise extrusion of maize increased and decreases the ED of maize starch and CP respectively. However, extrusion of barley had no effect on the ED of the STC fraction but decreased that of the CP. Neither extrusion or micronisation had an effect on the ED of starch or protein in peas. It was noted that incubation sequence had no significant effect on any of the measured degradation parameters of these starch-based feeds. In a third set of experiments a mobile bag technique was developed to determine the degradation parameters of the above feedstuffs both precaecally and over the whole digestive tract of ponies. Bags were administered directly into the stomach of two caecally fistulated ponies via a naso-gastric tube. The bags were then retrieved either at the ileo-caecal junction via a magnet placed in the caecal fistula or in the faeces. Site of recovery of bags had a significant effect (P<0.05) on DM, STC and CP losses and these effects were particularly marked for maize. Both micronisation and extrusion increased pre-caecal DM and STC losses from barley, maize and peas compared to unprocessed grains. Micronisation and extrusion of maize resulted in increased pre-caecal and decreased total tract losses of CP compared to unprocessed maize. Precaecal degradation parameters for barley were determined demonstrating an increase in the ED of DM for barleys which had been micronised or extruded. The lower ED of unprocessed barley in the pre-caecal segment of the equine digestive tract may account for the differences in intra-caecal fermentation parameters recorded in the first set of experiments. Further development of in sacco techniques should allow the digestion of feedstuff in the equine digestive tract to be partitioned enabling the identification of processing methods which minimise alterations in intra-caecal fermentation parameters

Perceptions of Corruption and Campaign Finance: When Public Opinion Determines Constitutional Law

This study tests the empirical assumptions about American public opinion found in the Supreme Court’s opinions concerning campaign finance reform. The area of campaign finance is a unique one in First Amendment law because the Court has allowed the mere appearance of a problem (in this case, “corruption”) to justify the curtailment of recognized First Amendment rights of speech and association. Since Buckley v. Valeo, defendants in campaign finance cases have proffered various types of evidence to support the notion that the public perceives a great deal of corruption produced by the campaign finance system. Most recently, in McConnell v. FEC, in which the Court upheld the McCain-Feingold campaign finance law, both the Department of Justice and the plaintiffs conducted and submitted into evidence public opinion polls measuring the public’s perception of corruption. This article examines the data presented in that case, but also examines forty years of survey data of public attitudes toward corruption in government. We argue that trends in public perception of corruption may have little to do with the campaign finance system. The share of the population describing government as corrupt went down even as soft money contributions skyrocketed. Moreover, the survey data suggest that an individual’s perception of corruption derives to some extent from that person’s (1) position in society (race, income, education level); (2) opinion of the incumbent President and performance of the economy over the previous year; (3) attitudes concerning taxation and “big government”; and (4) propensity to trust other people, in general. Although we conclude that, indeed, a large majority of Americans believe that the campaign finance system contributes to corruption in government, the data do not suggest that campaign finance reform will have an effect on these attitudes

Digital, analog, and memristive implementation of Spike-based Synaptic Plasticity

Synaptic platicity is believed to play an essential role in learning and memory in the brain. To date, many plasticity algorithms have been devised, some of which confirmed in electrophysiological experiments. Perhaps the most popular synaptic platicity rule, or learning algorithm, among neuromorphic engineers is the Spike Timing Dependent Plasticity (STDP). The conventional form of STDP has been implemented in various forms by many groups and using different hardware approaches. It has been used for applications such as pattern classification. Hoever, a newer form of STDP, which elicits synaptic efficacy modification based on the timing among a triplet of pre- and post-synaptic spikes, has not been well explored in hardware

Modeling and simulating in-memory memristive deep learning systems: an overview of current efforts

Deep Learning (DL) systems have demonstrated unparalleled performance in many challenging engineering applications. As the complexity of these systems inevitably increase, they require increased processing capabilities and consume larger amounts of power, which are not readily available in resource-constrained processors, such as Internet of Things (IoT) edge devices. Memristive In-Memory Computing (IMC) systems for DL, entitled Memristive Deep Learning Systems (MDLSs), that perform the computation and storage of repetitive operations in the same physical location using emerging memory devices, can be used to augment the performance of traditional DL architectures; massively reducing their power consumption and latency. However, memristive devices, such as Resistive Random-Access Memory (RRAM) and Phase-Change Memory (PCM), are difficult and cost-prohibitive to fabricate in small quantities, and are prone to various device non-idealities that must be accounted for. Consequently, the popularity of simulation frameworks, used to simulate MDLS prior to circuit-level realization, is burgeoning. In this paper, we provide a survey of existing simulation frameworks and related tools used to model large-scale MDLS. Moreover, we perform direct performance comparisons of modernized open-source simulation frameworks, and provide insights into future modeling and simulation strategies and approaches. We hope that this treatise is beneficial to the large computers and electrical engineering community, and can help readers better understand available tools and techniques for MDLS development