The Location of High Knowledge Content Activities in the Canadian Urban System, 1971-1991

Parmi les activités les plus dynamiques au plan de la croissance économique et du développement, plusieurs sont associées à ce qui est communément appelé la « haute technologie ». Dans cet article, nous remettons d’abord en question le concept de « haute technologie » pour lui préférer celui de « niveau élevé en connaissances », un concept moins ambigu, plus facile à opérationnaliser et, surtout, qui témoigne du fait que de telles activités peuvent avoir lieu dans des secteurs économiques reconnus comme traditionnels. Ensuite, grâce à une analyse empirique, nous examinons la localisation des activités à contenu élevé en connaissances dans le système urbain canadien au cours de la période 1971-1991. Plus particulièrement, nous voulons déterminer si ce type d’activité tend à se concentrer ou à se disperser dans le système urbain, question particulièrement importante dans le cas de petites communautés situées en régions périphériques et dont l’essentiel de l’activité économique s’appuie sur des secteurs traditionnels.It is widely recognized that certain activities have a higher capacity than others topromote economic growth and development. Many of these more dynamic activities areoften said to involve “high technology”. In this paper we first question the conceptualand operational utility of the notion “high technology”. We then propose a morestraightforward and more easily measured concept —high knowledge content—,demonstrating that activities of this nature may be found in “low tech” sectors. By means of an empirical analysis, we then attempt to contribute to a better understanding of the locational dynamics of high knowledge content activities within the Canadian urban system over the period 1971-1991. Specifically, we seek to determine if this class of activities is becoming spatially more concentrated or more dispersed across the urban system. The answer to this question is particularly important for smaller communities in peripheral regions whose economic bases are highly dependent upon “low tech” activities

Stability limits and tuning recommendation of the classical current control providing inertia support

The drastic increase in renewable energy sources in power grids has raised stability concerns. A particular concern exists in the ability of the converters to preserve frequency stability, due to their inherent lack of inertia provision. Grid forming converters have been presented as a solution to this issue, however the control structure for such converters is significantly different from the vector current control structures utilized by most installed control-converter systems. The classical current controller with a Phase Locked Loop (PLL) can be modified to provide inertia by including an additional control loop that injects active power in the case of a frequency event. This paper presents a detailed stability study, using a small signal model, and presents a set of controller tuning recommendations for the classical current controller with inertia emulation capability. The investigation found that the classical current and PLL tuning decreases the power that can be provided using the inertia emulation loop. Reducing the current loop time constant can allow for stable inertia emulation with classical vector current control

Limitations and comparisons of small signal modelling techniques in converter dominated medium voltage networks

Grids are seeing changing SCRs, due to increased power converter penetration. This paper assesses several common small signal modelling techniques of varying computational complexity for their accuracy. Each model is tested for its accuracy limitations in response to a power disturbance for varying grid SCRs and X/R ratios and controller damping for distribution networks

Experimental Everglades Virus Infection of Cotton Rats (Sigmodon hispidus)

We characterized Everglades virus infection of cotton rats from South Florida to validate their role as reservoir hosts in the enzootic transmission cycle

Review of MVDC applications, technologies, and future prospects

This paper presents a complete review of MVDC applications and their required technologies. Four main MVDC applications were investigated: rail, shipboard systems, distribution grids, and offshore collection systems. For each application, the voltage and power levels, grid structures, converter topologies, and protection and control structure were reviewed. Case studies of the varying applications as well as the literature were analyzed to ascertain the common trends and to review suggested future topologies. For rail, ship, and distribution systems, the technology and ability to implement MVDC grids is available, and there are already a number of case studies. Offshore wind collection systems, however, are yet able to be implemented. Across the four applications, the MVDC voltages ranged from 5–50 kV DC and tens of MW, with some papers suggesting an upper limit of 100 kV DC and hundreds of MV for distribution networks and offshore wind farm applications. This enables the use of varying technologies at both the lower and high voltage ranges, giving flexibility in the choice of topology that is required required

Venezuelan Equine Encephalitis Virus Infection of Cotton Rats

VEEV killed 2 allopatric populations of cotton rats but not a sympatric population from Florida

Can Healthcare Assistant Training (CHAT) improve the relational care of older people? Study protocol for a pilot cluster-randomised controlled trial

Background People aged 75 years and over account for one in four of all hospital admissions. There has been increasing recognition of problems in the care of older people, particularly in hospitals. Evidence suggests that older people judge the care they receive in terms of kindness, empathy, compassion, respectful communication and being seen as a person not just a patient. These are aspects of care to which we refer when we use the term 'relational care'. Healthcare assistants deliver an increasing proportion of direct care to older people, yet their training needs are often overlooked. Methods/design This study will determine the acceptability and feasibility of a cluster randomised controlled trial of 'Older People's Shoes' a two-day training intervention for healthcare assistants caring for older people in hospital. Within this pilot, two-arm, parallel, cluster randomised controlled trial, healthcare assistants within acute hospital wards are randomised to either the two-day training intervention or training as usual. Registered nurses deliver 'Older People's Shoes' over two days, approximately one week apart. It contains three components: experiential learning about ageing, exploration of older people's stories, and customer care. Outcomes will be measured at the level of patient (experience of emotional care and quality of life during their hospital stay), healthcare assistant (empathy and attitudes towards older people), and ward (quality of staff/patient interaction). Semi-structured interviews of a purposive sample of healthcare assistants receiving the intervention, and all trainers delivering the intervention, will be undertaken to gain insights into the experiences of both the intervention and the trial, and its perceived impact on practice. Trial registration The study was registered as an International Standard Randomised Contolled Trial (ISRCTN10385799) on 29 December 2014

Clustered Coding Variants in the Glutamate Receptor Complexes of Individuals with Schizophrenia and Bipolar Disorder

Current models of schizophrenia and bipolar disorder implicate multiple genes, however their biological relationships remain elusive. To test the genetic role of glutamate receptors and their interacting scaffold proteins, the exons of ten glutamatergic ‘hub’ genes in 1304 individuals were re-sequenced in case and control samples. No significant difference in the overall number of non-synonymous single nucleotide polymorphisms (nsSNPs) was observed between cases and controls. However, cluster analysis of nsSNPs identified two exons encoding the cysteine-rich domain and first transmembrane helix of GRM1 as a risk locus with five mutations highly enriched within these domains. A new splice variant lacking the transmembrane GPCR domain of GRM1 was discovered in the human brain and the GRM1 mutation cluster could perturb the regulation of this variant. The predicted effect on individuals harbouring multiple mutations distributed in their ten hub genes was also examined. Diseased individuals possessed an increased load of deleteriousness from multiple concurrent rare and common coding variants. Together, these data suggest a disease model in which the interplay of compound genetic coding variants, distributed among glutamate receptors and their interacting proteins, contribute to the pathogenesis of schizophrenia and bipolar disorders

Evaluating alternate models to estimate genetic parameters of calving traits in United Kingdom Holstein-Friesian dairy cattle

<p>Abstract</p> <p>Background</p> <p>The focus in dairy cattle breeding is gradually shifting from production to functional traits and genetic parameters of calving traits are estimated more frequently. However, across countries, various statistical models are used to estimate these parameters. This study evaluates different models for calving ease and stillbirth in United Kingdom Holstein-Friesian cattle.</p> <p>Methods</p> <p>Data from first and later parity records were used. Genetic parameters for calving ease, stillbirth and gestation length were estimated using the restricted maximum likelihood method, considering different models i.e. sire (−maternal grandsire), animal, univariate and bivariate models. Gestation length was fitted as a correlated indicator trait and, for all three traits, genetic correlations between first and later parities were estimated. Potential bias in estimates was avoided by acknowledging a possible environmental direct-maternal covariance. The total heritable variance was estimated for each trait to discuss its theoretical importance and practical value. Prediction error variances and accuracies were calculated to compare the models.</p> <p>Results and discussion</p> <p>On average, direct and maternal heritabilities for calving traits were low, except for direct gestation length. Calving ease in first parity had a significant and negative direct-maternal genetic correlation. Gestation length was maternally correlated to stillbirth in first parity and directly correlated to calving ease in later parities. Multi-trait models had a slightly greater predictive ability than univariate models, especially for the lowly heritable traits. The computation time needed for sire (−maternal grandsire) models was much smaller than for animal models with only small differences in accuracy. The sire (−maternal grandsire) model was robust when additional genetic components were estimated, while the equivalent animal model had difficulties reaching convergence.</p> <p>Conclusions</p> <p>For the evaluation of calving traits, multi-trait models show a slight advantage over univariate models. Extended sire models (−maternal grandsire) are more practical and robust than animal models. Estimated genetic parameters for calving traits of UK Holstein cattle are consistent with literature. Calculating an aggregate estimated breeding value including direct and maternal values should encourage breeders to consider both direct and maternal effects in selection decisions.</p