Algorithm to layout (ATL) systems for VLSI design

PhD ThesisThe complexities involved in custom VLSI design together with the failure of CAD techniques to keep pace with advances in the fabrication technology have resulted in a design bottleneck. Powerful tools are required to exploit the processing potential offered by the densities now available. Describing a system in a high level algorithmic notation makes writing, understanding, modification, and verification of a design description easier. It also removes some of the emphasis on the physical issues of VLSI design, and focus attention on formulating a correct and well structured design. This thesis examines how current trends in CAD techniques might influence the evolution of advanced Algorithm To Layout (ATL) systems. The envisaged features of an example system are specified. Particular attention is given to the implementation of one its features COPTS (Compilation Of Occam Programs To Schematics). COPTS is capable of generating schematic diagrams from which an actual layout can be derived. It takes a description written in a subset of Occam and generates a high level schematic diagram depicting its realisation as a VLSI system. This diagram provides the designer with feedback on the relative placement and interconnection of the operators used in the source code. It also gives a visual representation of the parallelism defined in the Occam description. Such diagrams are a valuable aid in documenting the implementation of a design. Occam has also been selected as the input to the design system that COPTS is a feature of. The choice of Occam was made on the assumption that the most appropriate algorithmic notation for such a design system will be a suitable high level programming language. This is in contrast to current automated VLSI design systems, which typically use a hardware des~ription language for input. These special purpose languages currently concentrate on handling structural/behavioural information and have limited ability to express algorithms. Using a language such as Occam allows a designer to write a behavioural description which can be compiled and executed as a simulator, or prototype, of the system. The programmability introduced into the design process enables designers to concentrate on a design's underlying algorithm. The choice of this algorithm is the most crucial decision since it determines the performance and area of the silicon implementation. The thesis is divided into four sections, each of several chapters. The first section considers VLSI design complexity, compares the expert systems and silicon compilation approaches to tackling it, and examines its parallels with software complexity. The second section reviews the advantages of using a conventional programming language for VLSI system descriptions. A number of alternative high level programming languages are considered for application in VLSI design. The third section defines the overall ATL system COPTS is envisaged to be part of, and considers the schematic representation of Occam programs. The final section presents a summary of the overall project and suggestions for future work on realising the full ATL system

Improvements in Resilience, Stress, and Somatic Symptoms Following Online Resilience Training: A Dose-Response Effect

OBJECTIVE: To determine if participation in an online resilience program impacts resilience, stress, and somatic symptoms. METHODS: Approximately 600 enrollees in the meQuilibrium resilience program received a series of brief, individually prescribed video, and text training modules in a user-friendly format. Regression models tested how time in the program affected change in resilience from baseline and how changes in resilience affected change in stress and reported symptoms. RESULTS: A significant dose-response was detected, where increases in the time spent in training corresponded to greater improvements in resilience. Degree of change in resilience predicted the magnitude of reduction in stress and symptoms. Participants with the lowest resilience level at baseline experienced greater improvements. CONCLUSION: Interaction with the online resilience training program had a positive effect on resilience, stress, and symptoms in proportion to the time of use

Ground Motions Induced by the March 11, 2018, Implosion of the Capital Plaza Tower, Frankfort, Kentucky

The demolition by implosion of the Capital Plaza Tower in downtown Frankfort provided an opportunity to record seismic waves from a known source of seismic energy in order to observe local ground-motion amplification and resonance within the underlying unconsolidated sediment. The Kentucky Geological Survey deployed three strong-motion accelerographs at approximately equal distances around the tower to record ground motions induced by its collapse. The KGS instruments were installed at sites with different underlying geology: one on bedrock and two on Kentucky River Valley unconsolidated sediments. Using images captured by a high-speed video camera, with timing synchronized with the clock of one of the strong-motion accelerographs, the sequence of ground-motion-inducing events from the tower demolition (blast explosions and the collapsing tower’s impact with the ground) was identified in the ground-motion time histories recorded at the rock site. This allowed the ground motions from the tower collapse recorded at all stations deployed for the event to be isolated and analyzed. The ground motions from the tower collapse recorded at the observation sites were weak and were likely imperceptible to humans. The detected motions, which had modified Mercalli intensities of only I to II at the rock and soil sites, respectively, were unlikely to have caused any damage there. Seismic-wave resonance within the Kentucky River Valley sediment was identified from the analysis of these recordings. The resonance frequencies were similar at all KGS soil sites, and also were similar to those observed on seismographs deployed by the Energy and Environment Cabinet’s Explosives and Blasting Branch. These observations indicate that in the unlikely event of a nearby strong earthquake, shaking is expected to be amplified within the unconsolidated Kentucky River Valley sediments underlying downtown Frankfort

Insights into the evolutionary origins of clostridial neurotoxins from analysis of the Clostridium botulinum strain A neurotoxin gene cluster

<p>Abstract</p> <p>Background</p> <p>Clostridial neurotoxins (CNTs) are the most deadly toxins known and causal agents of botulism and tetanus neuroparalytic diseases. Despite considerable progress in understanding CNT structure and function, the evolutionary origins of CNTs remain a mystery as they are unique to <it>Clostridium </it>and possess a sequence and structural architecture distinct from other protein families. Uncovering the origins of CNTs would be a significant contribution to our understanding of how pathogens evolve and generate novel toxin families.</p> <p>Results</p> <p>The <it>C. botulinum </it>strain A genome was examined for potential homologues of CNTs. A key link was identified between the neurotoxin and the flagellin gene (CBO0798) located immediately upstream of the BoNT/A neurotoxin gene cluster. This flagellin sequence displayed the strongest sequence similarity to the neurotoxin and NTNH homologue out of all proteins encoded within <it>C. botulinum </it>strain A. The CBO0798 gene contains a unique hypervariable region, which in closely related flagellins encodes a collagenase-like domain. Remarkably, these collagenase-containing flagellins were found to possess the characteristic HEXXH zinc-protease motif responsible for the neurotoxin's endopeptidase activity. Additional links to collagenase-related sequences and functions were detected by further analysis of CNTs and surrounding genes, including sequence similarities to collagen-adhesion domains and collagenases. Furthermore, the neurotoxin's HCRn domain was found to exhibit both structural and sequence similarity to eukaryotic collagen jelly-roll domains.</p> <p>Conclusion</p> <p>Multiple lines of evidence suggest that the neurotoxin and adjacent genes evolved from an ancestral collagenase-like gene cluster, linking CNTs to another major family of clostridial proteolytic toxins. Duplication, reshuffling and assembly of neighboring genes within the BoNT/A neurotoxin gene cluster may have lead to the neurotoxin's unique architecture. This work provides new insights into the evolution of <it>C. botulinum </it>neurotoxins and the evolutionary mechanisms underlying the origins of virulent genes.</p

Estimating the Health Effects of Adding Bicycle and Pedestrian Paths at the Census Tract Level: Multiple Model Comparison

Background: Adding additional bicycle and pedestrian paths to an area can lead to improved health outcomes for residents over time. However, quantitatively determining which areas benefit more from bicycle and pedestrian paths, how many miles of bicycle and pedestrian paths are needed, and the health outcomes that may be most improved remain open questions. Objective: Our work provides and evaluates a methodology that offers actionable insight for city-level planners, public health officials, and decision makers tasked with the question “To what extent will adding specified bicycle and pedestrian path mileage to a census tract improve residents’ health outcomes over time?” Methods: We conducted a factor analysis of data from the American Community Survey, Center for Disease Control 500 Cities project, Strava, and bicycle and pedestrian path location and use data from two different cities (Norfolk, Virginia, and San Francisco, California). We constructed 2 city-specific factor models and used an algorithm to predict the expected mean improvement that a specified number of bicycle and pedestrian path miles contributes to the identified health outcomes. Results: We show that given a factor model constructed from data from 2011 to 2015, the number of additional bicycle and pedestrian path miles in 2016, and a specific census tract, our models forecast health outcome improvements in 2020 more accurately than 2 alternative approaches for both Norfolk, Virginia, and San Francisco, California. Furthermore, for each city, we show that the additional accuracy is a statistically significant improvement (P2 weeks of poor physical health days in the census tract within 1.83% (SD 0.57%). For San Francisco (n=49 census tracts), our approach estimates, on average, that the percentage of individuals who had a stroke in the census tract is within 1.81% (SD 0.52%), and the percentage of individuals with diabetes in the census tract is within 1.26% (SD 0.91%). Conclusions: We propose and evaluate a methodology to enable decision makers to weigh the extent to which 2 bicycle and pedestrian paths of equal cost, which were proposed in different census tracts, improve residents’ health outcomes; identify areas where bicycle and pedestrian paths are unlikely to be effective interventions and other strategies should be used; and quantify the minimum amount of additional bicycle path miles needed to maximize health outcome improvements. Our methodology shows statistically significant improvements, compared with alternative approaches, in historical accuracy for 2 large cities (for 2016) within different geographic areas and with different demographics

Renal safety of zoledronic acid with thalidomide in patients with myeloma: a pharmacokinetic and safety sub-study

BACKGROUND: Cases of impaired renal function have been reported in patients who had been treated with both zoledronic acid and thalidomide for myeloma. Hence, we conducted a safety study of zoledronic acid and thalidomide in myeloma patients participating in a trial of maintenance therapy. METHODS: Twenty-four patients who were enrolled in a large randomized trial of thalidomide vs no thalidomide maintenance therapy for myeloma, in which all patients also received zoledronic acid, were recruited to a pharmacokinetic and renal safety sub-study, and followed for up to 16 months. RESULTS: No significant differences by Wilcoxon rank-sum statistic were found in zoledronic acid pharmacokinetics or renal safety for up to 16 months in patients randomized to thalidomide or not. CONCLUSION: In myeloma patients receiving maintenance therapy, the combination of zoledronic acid and thalidomide appears to confer no additional renal safety risks over zoledronic acid alone

The Contributions of Community-Based Monitoring and Traditional Knowledge to Arctic Observing Networks: Reflections on the State of the Field

Community-based monitoring (CBM) in the Arctic is gaining increasing support from a wide range of interested parties, including community members, scientists, government agencies, and funders. Through CBM initiatives, Arctic residents conduct or are involved in ongoing observing and monitoring activities. Arctic Indigenous peoples have been observing the environment for millennia, and CBM often incorporates traditional knowledge, which may be used independently from or in partnership with conventional scientific monitoring methods. Drawing on insights from the first Arctic Observing Summit, we provide an overview of the state of CBM in the Arctic. The CBM approach to monitoring is centered on community needs and interests. It offers fine-grained, local-scale data that are readily accessible to community and municipal decision makers. In spite of these advantages, CBM initiatives remain little documented and are often unconnected to wider networks, with the result that many practitioners lack a clear sense of the field and how best to support its growth and development. CBM initiatives are implemented within legal and governance frameworks that vary significantly both within and among different national contexts. Further documentation of differences and similarities among Arctic communities in relation to observing needs, interests, and legal and institutional capacities will help assess how CBM can contribute to Arctic observing networks. While CBM holds significant potential to meet observing needs of communities, more investment and experimentation are needed to determine how observations and data generated through CBM approaches might effectively inform decision making beyond the community level.Dans l’Arctique, la surveillance communautaire (SC) reçoit un appui de plus en plus grand de la part de nombreuses parties intéressées, dont les membres de la communauté, les scientifiques, les organismes gouvernementaux et les bailleurs de fonds. Dans le cadre des initiatives de SC, des habitants de l’Arctique effectuent des tâches permanentes d’observation et de surveillance ou participent à de telles tâches. Les peuples indigènes de l’Arctique observent l’environnement depuis des millénaires. Souvent, la SC fait appel aux connaissances traditionnelles, connaissances qui peuvent être employées seules ou conjointement avec les méthodes classiques de surveillance scientifique. Nous nous sommes appuyés sur les connaissances dérivées du premier sommet d’observation de l’Arctique pour donner un aperçu de l’état de la SC dans l’Arctique. La méthode de SC est centrée sur les besoins et les intérêts de la communauté. Elle permet d’obtenir des données à grain fin à l’échelle locale, données qui sont facilement accessibles par la communauté et les preneurs de décisions municipaux. Malgré ces avantages, il existe peu de documentation au sujet des initiatives de SC et souvent, ces initiatives ne sont pas rattachées aux grands réseaux, ce qui fait que bien des intervenants ne comprennent pas clairement ce qui se passe sur le terrain et ne savent pas vraiment comment appuyer la croissance et le développement de la surveillance communautaire. Les initiatives de SC respectent les cadres de référence nécessaires en matière de droit et de gouvernance, et ceux-ci varient considérablement au sein des contextes nationaux. L’enrichissement de la documentation en ce qui a trait aux différences et aux similitudes qui existent entre les communautés de l’Arctique en matière de besoins d’observation, d’intérêts et de capacités juridiques et institutionnelles aidera à déterminer en quoi la SC pourra jouer un rôle au sein des réseaux d’observation de l’Arctique. Bien que la SC ait la possibilité de jouer un rôle important dans les besoins d’observation des communautés, il y a lieu de faire plus d’investissements et d’expériences pour déterminer comment les observations et les données découlant des méthodes de SC pourront favoriser la prise de décisions au-delà des communautés

Complexity of Reconfiguration in Surface Chemical Reaction Networks

We analyze the computational complexity of basic reconfiguration problems for the recently introduced surface Chemical Reaction Networks (sCRNs), where ordered pairs of adjacent species nondeterministically transform into a different ordered pair of species according to a predefined set of allowed transition rules (chemical reactions). In particular, two questions that are fundamental to the simulation of sCRNs are whether a given configuration of molecules can ever transform into another given configuration, and whether a given cell can ever contain a given species, given a set of transition rules. We show that these problems can be solved in polynomial time, are NP-complete, or are PSPACE-complete in a variety of different settings, including when adjacent species just swap instead of arbitrary transformation (swap sCRNs), and when cells can change species a limited number of times (k-burnout). Most problems turn out to be at least NP-hard except with very few distinct species (2 or 3)

Zooming in and out : studying practices by switching theoretical lenses and trailing connections

This paper contributes to re-specifying a number of the phenomena of interest to organisational studies in terms of patterns of socio-material practices and their effects. It does so by outlining a vocabulary and strategy that make up a framework for theorising work and organisational practices. The vocabulary is based on number of sensitising concepts that connote practice as an open-ended, heterogeneous accomplishment which takes place within a specific horizon of sense and a set of concerns which the practice itself brings to bear. The strategy is based on the metaphorical movement of "zooming in" and "zooming out of" practice. The zooming in and out are obtained through switching theoretical lenses and repositioning in the field, so that certain aspects of the practice are fore-grounded while others are bracketed. Building on the results of an extended study of telemedicine, the paper discusses in detail the different elements of the framework and how it enhances our capacity to re-present practice. The paper concludes with some considerations on how the proposed approach can assist us in advancing the research agenda of organizational and work studies