1,076 research outputs found
Reconstruction of the spatial dependency of dielectric and geometrical properties of adhesively bonded structures
An inverse problem motivated by the nondestructive testing of adhesively bonded structures used in the aircraft industry is studied. Using transmission line theory, a model is developed which, when supplied with electrical and geometrical parameters, accurately predicts the reflection coefficient associated with such structures. Particular attention is paid to modelling the connection between the structures and the equipment used to measure the reflection coefficient. The inverse problem is then studied and an optimization approach employed to recover these electrical and geometrical parameters from experimentally obtained data. In particular the approach focuses on the recovery of spatially varying geometrical parameters as this is paramount to the successful reconstruction of electrical parameters. Reconstructions of structure geometry using this method are found to be in close agreement with experimental observations
An Essay on Institutional Responsibility: The Indigenous Blacks and Micmac Programme at Dalhousie Law School
Dalhousie Law School, like most other law schools, as a tribute to its graduates and as a manifestation of its traditions, adorns its walls with class photographs of years gone by. However, if one were to stop and scrutinize more carefully these pictures one might want to reconsider the tradition in a more circumspect light. Perhaps one might notice that until the nineteen sixties women were few and far between and that even now they still make up less than half of most graduating classes. More conspicuous still, is the general absence of First Nations peoples from the celebratory pageant. Even more curious, is the partial presence of Blacks in the parade. In the older photographs one does, on occasion, come across Black graduates but, as a little research indicates, many of these turn out to be from Africa or the Caribbean - few are Black Canadians, and even fewer indigenous Black Nova Scotians. As the photographs become more contemporary, even this Black presence declines as African and Caribbean jurisdictions developed their own law schools and the visit to Canada became unnecessary. Although, during the 1980\u27s, the profile of the classes has changed marginally so as to incorporate elements of the so called changing multicultural nature of Canadian society, the presence of Nova Scotian Blacks and First Nations peoples is sparse
Reducing the Democratic Deficit: Representation, Diversity, and the Canadian Judiciary, or Towards a Triple P Judiciary
The authors review the current structures for judicial appointments in Canada and provide statistical information about the results of these mechanisms in respect to diversity of representation on the courts. They are also critical of the fairness and openness of judicial appointments processes. After examining several variants of the dominant liberal view of law and of judges, the authors proffer and articulate a neo-realist theory of law and what they term a bungee cord theory of judging. According to the former, law is inevitably a form of politics; according to the latter, judges are unavoidably political actors. In consequence, the judiciary is properly subject to democratic norms, including especially the norms of representation and diversity. The authors then argue that, judged against those democratic norms, the present systems of judicial appointment (and the judiciary which it has put in place) suffers from what they term a democratic deficit.
After a detailed examination of past attempts to reform this system, of arguments for and against a more democratic and representational approach to judicial selection, and possible models of judicial selection, the authors propose their own reform: the establishment by statute of Judicial Appointments Commissions. Such an approach might help cure the democratic deficit and produce what they dub a Triple-P judiciary, that is, one that is politically accountable, professionally qualified, and proportionally representative
The molecular epidemiology of variant CJD
The emergence of the novel prion diseases bovine spongiform encephalopathy (BSE) and, subsequently, variant Creutzfeldt-Jakob disease (vCJD) in epidemic forms has attracted much scientific attention. The oral transmission of these disorders, the causative relationship of vCJD to BSE and the resistance of the transmissible agents in both disorders to conventional forms of decontamination has caused great public health concern. The size of the still emerging vCJD epidemic is thankfully much lower than some early published estimates. This paper reviews current knowledge of the factors that influence the development of vCJD: the properties of the infectious agent; the route of inoculation and individual susceptibility factors. The current epidemiological data are reviewed, along with relevant animal transmission studies. In terms of genetic susceptibility, the best characterised is the common single nucleotide polymorphism at codon 129 of prion protein gene. Current biomarkers and future areas of research will be discussed. These issues are important in informing precautionary measures and the ongoing monitoring of vCJD
A transcriptional network associated with natural variation in Drosophila aggressive behavior
A genome-wide screen of inbred Drosophila lines together with transcriptional network modeling reveals insights into the genetic bases of heritable aggression
Specific protein-protein binding in many-component mixtures of proteins
Proteins must bind to specific other proteins in vivo in order to function.
The proteins must bind only to one or a few other proteins of the of order a
thousand proteins typically present in vivo. Using a simple model of a protein,
specific binding in many component mixtures is studied. It is found to be a
demanding function in the sense that it demands that the binding sites of the
proteins be encoded by long sequences of bits, and the requirement for specific
binding then strongly constrains these sequences. This is quantified by the
capacity of proteins of a given size (sequence length), which is the maximum
number of specific-binding interactions possible in a mixture. This calculation
of the maximum number possible is in the same spirit as the work of Shannon and
others on the maximum rate of communication through noisy channels.Comment: 13 pages, 3 figures (changes for v2 mainly notational - to be more in
line with notation in information theory literature
Multi-trait ensemble genomic prediction and simulations of recurrent selection highlight importance of complex trait genetic architecture for long-term genetic gains in wheat
Cereal crop breeders have achieved considerable genetic gain in genetically complex traits, such as grain yield, while maintaining genetic diversity. However, focus on selection for yield has negatively impacted other important traits. To better understand multi-trait selection within a breeding context, and how it might be optimized, we analysed genotypic and phenotypic data from a genetically diverse, 16-founder wheat multi-parent advanced generation inter-cross population. Compared to single-trait models, multi-trait ensemble genomic prediction models increased prediction accuracy for almost 90 % of traits, improving grain yield prediction accuracy by 3–52 %. For complex traits, non-parametric models (Random Forest) also outperformed simplified, additive models (LASSO), increasing grain yield prediction accuracy by 10–36 %. Simulations of recurrent genomic selection then showed that sustained greater forward prediction accuracy optimized long-term genetic gains. Simulations of selection on grain yield found indirect responses in related traits, involving optimized antagonistic trait relationships. We found multi-trait selection indices could effectively optimize undesirable relationships, such as the trade-off between grain yield and protein content, or combine traits of interest, such as yield and weed competitive ability. Simulations of phenotypic selection found that including Random Forest rather than LASSO genetic models, and multi-trait rather than single-trait models as the true genetic model accelerated and extended long-term genetic gain whilst maintaining genetic diversity. These results (i) suggest important roles of pleiotropy and epistasis in the wider context of wheat breeding programmes, and (ii) provide insights into mechanisms for continued genetic gain in a limited genepool and optimization of multiple traits for crop improvement
Limited haplotype diversity underlies polygenic trait architecture across 70 years of wheat breeding
Background Selection has dramatically shaped genetic and phenotypic variation in bread wheat. We can assess the genomic basis of historical phenotypic changes, and the potential for future improvement, using experimental populations that attempt to undo selection through the randomizing effects of recombination. Results We bred the NIAB Diverse MAGIC multi-parent population comprising over 500 recombinant inbred lines, descended from sixteen historical UK bread wheat varieties released between 1935 and 2004. We sequence the founders’ genes and promoters by capture, and the MAGIC population by low-coverage whole-genome sequencing. We impute 1.1 M high-quality SNPs that are over 99% concordant with array genotypes. Imputation accuracy only marginally improves when including the founders’ genomes as a haplotype reference panel. Despite capturing 73% of global wheat genetic polymorphism, 83% of genes cluster into no more than three haplotypes. We phenotype 47 agronomic traits over 2 years and map 136 genome-wide significant associations, concentrated at 42 genetic loci with large and often pleiotropic effects. Around half of these overlap known quantitative trait loci. Most traits exhibit extensive polygenicity, as revealed by multi-locus shrinkage modelling. Conclusions Our results are consistent with a gene pool of low haplotypic diversity, containing few novel loci of large effect. Most past, and projected future, phenotypic changes arising from existing variation involve fine-scale shuffling of a few haplotypes to recombine dozens of polygenic alleles of small effect. Moreover, extensive pleiotropy means selection on one trait will have unintended consequences, exemplified by the negative trade-off between yield and protein content, unless selection and recombination can break unfavorable trait-trait associations
Health screening, cardiometabolic disease and adverse health outcomes in individuals with severe mental illness
Background:
Poor physical health in severe mental illness (SMI) remains a major issue for clinical practice.
Aims:
To use electronic health records of routinely collected clinical data to determine levels of screening for cardiometabolic disease and adverse health outcomes in a large sample (n = 7718) of patients with SMI, predominantly schizophrenia and bipolar disorder.
Method:
We linked data from the Glasgow Psychosis Clinical Information System (PsyCIS) to morbidity records, routine blood results and prescribing data.
Results:
There was no record of routine blood monitoring during the preceding 2 years for 16.9% of the cohort. However, monitoring was poorer for male patients, younger patients aged 16–44, those with schizophrenia, and for tests of cholesterol, triglyceride and glycosylated haemoglobin. We estimated that 8.0% of participants had diabetes and that lipids levels, and use of lipid-lowering medication, was generally high.
Conclusions:
Electronic record linkage identified poor health screening and adverse health outcomes in this vulnerable patient group. This approach can inform the design of future interventions and health policy
Untargeted Metabolite Mapping in 3D Cell Culture Models using High Spectral Resolution FT-ICR Mass Spectrometry Imaging
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