3,391 research outputs found
Data management of nanometre scale CMOS device simulations
In this paper we discuss the problems arising in managing and curating the data generated by simulations of nanometre scale CMOS (Complementary Metal–Oxide Semiconductor) transistors, circuits and systems and describe the software and operational techniques we have adopted to address them. Such simulations pose a number of challenges including, inter alia, multiTByte data volumes, complex datasets with complex inter-relations between datasets, multi-institutional collaborations including multiple specialisms and a mixture of academic and industrial partners, and demanding security requirements driven by commercial imperatives. This work was undertaken as part of the NanoCMOS project. However, the problems, solutions and experience seem likely to be of wider relevance, both within the CMOS design community and more generally in other disciplines
The Liberal Legacy of Bush v. Gore
This article examines the last ten years of the Rehnquist Court, which was divided evenly by the Court\u27s highly controversial intervention in the 2000 presidential election, Bush v. Gore. I compare the Court\u27s record before and after that decision both qualitatively and quantitatively, and argue that the Court shifted noticeably to the left, particularly in high-profile cases, after Bush v. Gore, as conservative Justices showed a greater willingness to side with their liberal colleagues to reach liberal results. I hypothesize that this may have reflected an effort, conscious or subconscious, to restore the Court\u27s legitimacy by counteracting images of a partisan body divided along political lines. I also suggest that the same interest in restoring the legitimacy of the Court may have contributed to the Court\u27s substantive emphasis on the values of the rule of law, which was particularly evident in the Court\u27s enemy combatant decisions of 2004 (and for that matter, more recently, in the Court\u27s decision on military tribunals in Hamdan v. Rumsfeld). This liberal legacy of Bush v. Gore illustrates one of the checking functions on judicial supremacy - namely the need to maintain the appearance (and reality) that law is distinct from politics. Whether the Bush v. Gore effect will continue with the Roberts Court remains to be seen
A systematic review of financial debt in adolescents and young adults: Prevalence, correlates and associations with crime
The Norwegian Application of the Contracts Act Section 36
Published version available at https://kluwerlawonline.com/journalarticle/European+Review+of+Private+Law/28.3/ERPL2020032The article presents the general clause in the Norwegian Contracts Act section 36. The background and the purpose are explained, and the article provides an overview over the relevant case law, which indicates that the general clause serves different functions in the Norwegian contract law
Is there a transition flux? Incorporating a research element into an undergraduate engineering laboratory
It is frequently remarked that the modern student has an excellent ability to recall information but cannot think independently and does not show initiative. While the secondary school curriculum is a major factor in this regard, it must be said that large parts of the third level experience perpetuate this problem. However, increased use of active learning, problem based learning and research-based learning should help to encourage independent thinking. In most degree courses in Engineering/Science, a final year project is the first true taste of scientific research encountered by undergraduate students. The final year research project can often prove an extremely daunting task, and the amount of time and effort required by the undergraduate student to settle into this new type of work can be detrimental to the work of the student on core subjects that are assessed by written examination.
We present here the incorporation of real research into an engineering laboratory module taught in the third year of a Biotechnology degree program. This is achieved by challenging the students with a hypothesis to be investigated using the laboratory session, rather than the traditional prescriptive approach resulting in a defined laboratory report. Each laboratory group conducts their experiment using unique experimental conditions and the results are collated into a body of work to challenge the hypothesis presented to the students. The students learn to disseminate their results effectively by including the requirement that the report be constructed in the form of a journal article.
By adopting this approach to teaching in the laboratory, students are introduced at an earlier stage to the skills needed to conduct meaningful scientific research. In particular, it encourages students to evaluate experimental data without bias. By performing experiments for which the outcome is not known in advance, student interest and enthusiasm is significantly increased
Earthquake Nucleation Processes Across Different Scales and Settings
Extended nucleation phases of earthquakes have been regularly observed, yet the underlying mechanisms governing the initiation phase of rupture are yet to be understood in detail. Currently two end member models exist to explain earthquake nucleation: one model claiming that the nucleation phase of a small earthquake is indistinguishable from that of a large one, while the other proposes fundamental differences in the underlying process. Previous studies have been using the same seismological observations to argue for either model, leaving the need of further investigations into the nucleation behavior of earthquakes across scales and different settings. The thesis at hand contributes to the current discussion on earthquake nucleation by providing additional observational evidence for extended nucleation phases, complex rupture interaction and growth across a number of different scales and settings. Here, earthquake nucleation is investigated for three different scenarios, each with varying degrees of complexity: 1) the controlled case of induced seismicity in hydraulic stimulations of geothermal reservoirs, where rupture growth is assumed to be primarily governed by anthropogenic activity, 2) the partly-controlled setting of a geothermal field with a long history of fluid injection and production, and 3) the uncontrolled case of natural seismicity in the central Sea of Marmara, where earthquake nucleation is purely governed by the regional tectonics.
First, the temporal evolution of seismicity and the growth of observed moment magnitudes for a range of past and present hydraulic stimulation projects associated with the creation of enhanced geothermal systems are analyzed. They reveal a clear linear relation between injected fluid volume/hydraulic energy and cumulative seismic moments. For most projects studied, the observations are in good agreement with existing physical models that predict a relation between injected fluid volume and maximum seismic moment of induced events. This suggests that seismicity results from a stable, pressure controlled rupture process at least for an extended injection period. Overall evolution of seismicity is independent of tectonic stress regime and is most likely governed by reservoir specific parameters, such as the preexisting structural inventory. In contrast, a few stimulations reveal unbound increase in seismic moment suggesting that for these cases evolution of seismicity is mainly controlled by stress field, the size of tectonic faults and fault connectivity. The uncertainty over whether or not a transition between behavior is likely to occur at any point during the injection is what motivates the need for a next generation monitoring and traffic-light system accounting for the possibility of unstable rupture propagation from the very beginning of injection by observing the entire seismicity evolution at high resolution for an immediate reaction in injection strategy. Furthermore, the majority of pressure-controlled stimulations shows the potential of actively controlling the size of induced earthquakes, if an injection protocol is chosen based on continuous feedback from a near-real-time seismic monitoring system.
Second, moderate sized earthquakes at The Geysers geothermal field (California), where years of injection and production across hundreds of wells have led to a unique physical environment, are studied. While overall seismicity at The Geysers is generally governed by anthropogenic activities, contributions of individual wells or injection activities are hard to distinguish, thus making detailed managing of occurring magnitudes challenging. New high-resolution seismicity catalogs framing the occurrence of 20 ML > 2.5 earthquakes were created. The seismicity catalogs were developed using a matched filter algorithm, including automatic determination of P and S phase onsets and their inversion for absolute hypocenter locations with corresponding uncertainties. The selected 20 sequences sample different hypocentral depths and hydraulic conditions within the field. Seismic activity and magnitude frequency distributions displayed by the different earthquake sequences are correlated with their location within the reservoir. Sequences located in the northwestern part of the reservoir show overall increased seismic activity and low b values, while the southeastern part is dominated by decreased seismic activity and higher b values. Periods of high injection coincide with high b values and vice versa. These observations potentially reflect varying differential and mean stresses and damage of the reservoir rocks across the field. Additionally, a systematic search for seismicity localization using a multi-step cross-correlation analysis was performed. No evidence for increased correlation between the occurring seismicity and the mainshock for any of the 20 sequences could be seen, indicating that each main nucleation spot was seismically silent prior to the main rupture. However, a number of highly inter-correlated earthquakes for sequences below the reservoir and during high injection activity is observed. Under these conditions, the seismicity surrounding the future mainshock source region is more concentrated and might be evidence for a cascading nucleation process. About 50% of analyzed sequences exhibit no change in seismicity rate in response to the large main event. However, we find complex waveforms at the onset of the main earthquake, suggesting that small ruptures spontaneously grow into or trigger larger events, consistent with a cascading type nucleation.
Third, the spatiotemporal evolution of seismicity during a sequence of moderate (MW4.7 and MW5.8) earthquakes occurring in September 2019 at the transition between a creeping and a locked segment of the North Anatolian Fault in the central Sea of Marmara (Turkey) was analyzed. A matched filter technique was applied to continuous waveforms from the regional network, substantially reducing the magnitude threshold for detection. Sequences of foreshocks preceding the two mainshocks are clearly seen, exhibiting different behaviors: a migration of the seismicity along the entire fault segment on the long-term and a concentration around the epicenters of the large events on the short-term. Suggesting that both seismic and aseismic slip during the foreshock sequences change the stress state on the fault, bringing it closer to failure. Furthermore, the observations also suggest that the MW4.7 event contributed to weaken the fault as part of the preparation process of the MW5.8 earthquake.
Combining the results obtained from different settings, it becomes apparent that, regardless of the tectonic setting and degree of anthropogenic control over the seismicity, there is a wide range of complex nucleation behaviours not yet explained by any of the current models of earthquake nucleation. A simplistic view of earthquake nucleation as either a deterministic or a stochastic process seems inconsistent with the obtained results and fails to account for a more complex nucleation behaviour. Observations from The Geysers and the western Sea of Marmara earthquake sequence, suggest that both cascade triggering and aseismic slip can play major roles in the nucleation of moderate sized earthquakes. Both mechanisms seem to jointly contribute to fault initiation, even within the same rock volume. A separation of the two mechanisms can potentially be thought of at The Geysers, where cascade triggering seems to dominate in highly damaged parts of the reservoir, suggesting that the anthropogenic activity can at least partially influence the nucleation behavior of the occurring seismicity. This would be in agreement with the results obtained from analysis of hydraulic stimulations, where during the pressure-controlled phase of injection rupture growth is controlled by the injected fluid
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Medicinal plants used by women in Mecca: urban, Muslim and gendered knowledge
Background: This study explores medicinal plant knowledge and use among Muslim women in the city of Mecca,
Saudi Arabia. Ethnobotanical research in the region has focused on rural populations and male herbal healers in
cities, and based on these few studies, it is suggested that medicinal plant knowledge may be eroding. Here, we
document lay, female knowledge of medicinal plants in an urban centre, interpreting findings in the light of the
growing field of urban ethnobotany and gendered knowledge and in an Islamic context.
Methods: Free-listing, structured and semi-structured interviews were used to document the extent of medicinal
plant knowledge among 32 Meccan women. Vernacular names, modes of preparation and application, intended
therapeutic use and emic toxicological remarks were recorded. Women were asked where they learnt about
medicinal plants and if and when they preferred using medicinal plants over biomedical resources. Prior informed consent was always obtained. We compared the list of medicinal plants used by these Meccan women with medicinal plants previously documented in published literature.
Results: One hundred eighteen vernacular names were collected, corresponding to approximately 110 plants, including one algae. Of these, 95 were identified at the species level and 39 (41%) had not been previously cited in Saudi Arabian medicinal plant literature. Almost one half of the plants cited are food and flavouring plants. Meccan women interviewed learn about medicinal plants from their social network, mass media and written sources, and combine biomedical and medicinal plant health care. However, younger women more often prefer biomedical resources and learn from written sources and mass media.
Conclusions: The fairly small number of interviews conducted in this study was sufficient to reveal the singular body of medicinal plant knowledge held by women in Mecca and applied to treat common ailments. Plant availability in local shops and markets and inclusion in religious texts seem to shape the botanical diversity used by the Meccan women interviewed, and the use of foods and spices medicinally could be a global feature of urban ethnobotany. Ethnobotanical knowledge among women in Islamic communities may be changing due to access to mass media and biomedicine. We recognise the lack of documentation of the diversity of medicinal plant knowledge in the Arabian Peninsula and an opportunity to better understand gendered urban and rural knowledge
Bayesian Brains and the Rényi Divergence
Under the Bayesian brain hypothesis, behavioral variations can be attributed to different priors over generative model parameters. This provides a formal explanation for why individuals exhibit inconsistent behavioral preferences when confronted with similar choices. For example, greedy preferences are a consequence of confident (or precise) beliefs over certain outcomes. Here, we offer an alternative account of behavioral variability using Rényi divergences and their associated variational bounds. Rényi bounds are analogous to the variational free energy (or evidence lower bound) and can be derived under the same assumptions. Importantly, these bounds provide a formal way to establish behavioral differences through an α parameter, given fixed priors. This rests on changes in α that alter the bound (on a continuous scale), inducing different posterior estimates and consequent variations in behavior. Thus, it looks as if individuals have different priors and have reached different conclusions. More specifically, α→0+ optimization constrains the variational posterior to be positive whenever the true posterior is positive. This leads to mass-covering variational estimates and increased variability in choice behavior. Furthermore, α→+∞ optimization constrains the variational posterior to be zero whenever the true posterior is zero. This leads to mass-seeking variational posteriors and greedy preferences. We exemplify this formulation through simulations of the multiarmed bandit task. We note that these α parameterizations may be especially relevant (i.e., shape preferences) when the true posterior is not in the same family of distributions as the assumed (simpler) approximate density, which may be the case in many real-world scenarios. The ensuing departure from vanilla variational inference provides a potentially useful explanation for differences in behavioral preferences of biological (or artificial) agents under the assumption that the brain performs variational Bayesian inference
The Bronchoalveolar Lavage Proteome- Phenotypic associations to smoking and divergence towards development of COPD
Proteomic analysis of bronchoalveolar lavage (BAL) fluid from smokers at risk of developing chronic obstructive pulmonary disease (COPD) and never smokers is described. COPD is currently the world's fourth leading cause of death and its prevalence is increasing. The leading cause of COPD is smoking and an estimated 600 million people in the world suffer from COPD which makes it the world's most common chronic disease. The aim of this thesis was to explore and characterize the BAL proteome of never smokers and smokers. The hypotheses were that the BAL proteome reflect smoking habits in subjects, and that smokers susceptible to COPD development have a specific proteome. In order to relate the measurement of protein expression with clinical phenotypes we have developed and utilized an interdisciplinary toolbox that includes protein separation (two-dimensional gel electrophoresis and liquid chromatography), mass spectrometry identification and statistical methods for multivariate analysis. The study material used in this thesis consisted of age matched men all born in 1933, living in one city differing by lifelong smoking history. These were compared by clinical function measurements and histological assessment at the same relative time points. A follow up study after 6-7 years identified a group of subjects who had progressed to COPD GOLD stage 2. Those with COPD shared a distinct protein expression profile in the baseline BAL sample which could be identified using multivariate analysis. This pattern was not observed in BAL samples of asymptomatic smokers free of COPD at the 6-7 year follow-up. The results suggest that specific patterns of protein expression occur in the airways of smokers susceptible to COPD disease progression, before the disease is clinically measurable
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