761 research outputs found
The Well-Being of Parents and Children in the Minnesota Family Investment Program in Hennepin County, Minnesota, 1998-2002
Hollister, David; Martin, Mary; Toft, Jessica; Yeo, Ji-in; Kim, Youngmin. (2003). The Well-Being of Parents and Children in the Minnesota Family Investment Program in Hennepin County, Minnesota, 1998-2002. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/1333
In Memoriam: Martin Appelt
A memorial dedicated to the life and legacy of our late friend and colleague, curator and senior researcher, Martin Appelt
In Memoriam: Martin Appelt
A memorial dedicated to the life and legacy of our late friend and colleague, curator and senior researcher, Martin Appelt
In Memoriam: Martin Appelt
A memorial dedicated to the life and legacy of our late friend and colleague, curator and senior researcher, Martin Appelt
Pseudo-differential operators with isotropic symbols, Wick and anti-Wick operators, and hypoellipticity
We study the link between ilidos and Wick operators via the Bargmann transform. We deduce a formula for the symbol of the Wick operator in terms of the short-time Fourier transform of the Weyl symbol. This gives characterizations of Wick symbols of ilidos of Shubin type and of infinite order, and results on composition. We prove a series expansion of Wick operators in terms of anti-Wick operators which leads to a sharp Garding inequality and transition of hypoellipticity between Wick and Shubin symbols. Finally we show continuity results for anti-Wick operators, and estimates for the Wick symbols of anti-Wick operators.(c) 2022 The Author(s). Published by Elsevier Masson SAS. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
Participation in urban interaction design for civic engagement
The future of civic engagement is characterised by both technological innovation as well as new technological user practices that are fuelled by trends towards mobile, personal devices; broadband connectivity; open data; urban interfaces; and cloud computing. These technology trends are progressing at a rapid pace, and have led global technology vendors to package and sell the <i>“Smart City”</i> as a centralised service delivery platform predicted to optimise and enhance cities’ key performance indicators – and generate a profitable market. The top-down deployment of these large and proprietary technology platforms have helped sectors such as energy, transport, and healthcare to increase efficiencies. However, an increasing number of scholars and commentators warn of another <i>“IT bubble”</i> emerging. Along with some city leaders, they argue that the top-down approach does not fit the governance dynamics and values of a liberal democracy when applied across sectors. A thorough understanding is required, of the socio-cultural nuances of how people work, live, play across different environments, and how they employ social media and mobile devices to interact with, engage in, and constitute public realms.\ud
\ud
Although the term <i>“slacktivism”</i> is sometimes used to denote a watered down version of civic engagement and activism that is reduced to clicking a “Like” button and signing online petitions, we believe that we are far from witnessing another Biedermeier period that saw people focus on the domestic and the non-political. There is plenty of evidence to the contrary, such as post-election violence in Kenya in 2008, the Occupy movements in New York, Hong Kong and elsewhere, the Arab Spring, Stuttgart 21, Fukushima, the Taksim Gezi Park in Istanbul, and the Vinegar Movement in Brazil in 2013. These examples of civic action shape the dynamics of governments, and in turn, call for new processes to be incorporated into governance structures. Participatory research into these new processes across the triad of people, place and technology is a significant and timely investment to foster productive, sustainable, and liveable human habitats. With this article, we want to reframe the current debates in academia and priorities in industry and government to allow citizens and civic actors to take their rightful centrepiece place in civic movements. This calls for new participatory approaches for co-inquiry and co-design. It is an evolving process with an explicit agenda to facilitate change, and we propose <i>participatory action research (PAR)</i> as an indispensable component in the journey to develop new governance infrastructures and practices for civic engagement.\ud
\ud
We do not limit our definition of civic technologies to tools specifically designed to simply enhance government and governance, such as renewing your car registration online or casting your vote electronically on election day. Rather, we are interested in civic media and technologies that foster citizen engagement in the widest sense, and particularly the participatory design of such civic technologies that strive to involve citizens in political debate and action as well as question conventional approaches to political issues. \ud
\ud
The rationale for this approach is an alternative to smart cities in a <i>“perpetual tomorrow,”</i> based on many weak and strong signals of civic actions revolving around technology seen today. It seeks to emphasise and direct attention to active citizenry over passive consumerism, human actors over human factors, culture over infrastructure, and prosperity over efficiency.\ud
\ud
First, we will have a look at some fundamental issues arising from applying simplistic smart city visions to the kind of a problem a city poses. We focus on the touch points between “the city” and its civic body, the citizens. In order to provide for meaningful civic engagement, the city must provide appropriate interfaces
Structured approach to design of diagnostic test evaluation studies for chronic progressive infections in animals
Diagnostic test evaluations (DTEs) for chronic infections are challenging because a protracted incubation period has to be considered in the design of the DTE, and the adverse effects of infection may be widespread and progressive over an animal's entire life. Frequently, the specific purpose of the test is not formally considered when a test is evaluated. Therefore, the result is often a DTE where test sensitivity and specificity estimates are biased, either because of problems with establishing the true infection status or because the test detects another aspect of the infection (and analyte) than originally intended. The objective of this paper is to outline a structured approach to the design and conduct of a DTE for diagnostic tests used for chronic infections in animals, and intended for different purposes. We describe the process from reflections about test purpose and the underlying target condition through considerations of the pathogenesis, and specification of a practical case definition, which can subsequently be used in the DTE for the specific purpose. The process is illustrated by two examples of Mycobacterium avium subsp. paratuberculosis (MAP) infections in cattle. MAP infections are chronic and can result in different adverse effects at different time points during the incubation period. The description provides input on the process and deductive reasoning which are integral parts to develop a high-quality design of a DTE for chronic infectious diseases.ID: S0378113511000381; M3: Article; Accession Number: S0378113511000381; Author: Søren Saxmose Nielsen (a, b, ⁎); Author: Nils Toft (a, b); Author: Ian Andrew Gardner (a, b); Affiliation: Department of Large Animal Sciences, Faculty of Life Sciences, University of Copenhagen, Grønnegårdsvej 8, DK-1870 Frederiksberg C, Denmark; Affiliation: Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; Keyword: Chronic infectious diseases; Keyword: Design strategy; Keyword: Diagnostic test evaluation; Keyword: Paratuberculosis; Number of Pages: 11; Language: English
Hafnium isotopes in TTGs and their zircons : witnesses of the growth of first continents
Ce travail de thèse présente des analyses isotopiques Lu-Hf par MC-ICP-MS combinées de zircons ignés et de roches totales d’une importante collection de granitoïdes archéens appartenant à la suite des Tonalite-Trondhjémite-Granodiorite (TTG) afin d’apporter un regard nouveau sur la croissance de la croûte continentale et tout particulièrement dans le début de l’histoire de la Terre. Nos données indiquent un bon accord général entre les zircons ignés, mesurés par ablation-laser et par solution, avec leurs roche-hôtes. Nous démontrons que le rapport Lu/Hf intégré dans le temps de la source mantellique des TTG est près de la valeur chondritique et n’a pas significativement changée au cours des 4 derniers milliards d’années. Par conséquent, les continents se sont formés à partir d’un matériel primitif non fractionné extrait du manteau profond par l’intermédiaire de panaches qui après fusion partielle ont laissés un résidu appauvri dans le manteau supérieur. Les cristaux de zircon extraits des TTG ont des compositions isotopiques en Hf cohérentes au sein d’une même population alors que le système U-Pb, dans les mêmes grains, est souvent perturbé résultant ainsi en l’obtention de valeurs d’εHf initial erronées. Ce problème est endémique aux cristaux de zircon détritiques archéens et en accord avec des résultats expérimentaux sur la mobilité préférentielle de l’Hf en fonction de celle de l’U et du Pb au sein du zircon. Nous suggérons que ce problème biaise l’enregistrement détritique archéen en faveur de valeurs d’εHf initial négatives qui contrastent avec les valeurs obtenues pour les TTG mais peuvent être expliquées par l’utilisation d’âges 207Pb/206Pb non-magmatiques. Si l’on considère les cristaux de zircon de Jack Hills au vu de ces résultats, la source des continents serait restée inchangée depuis 4,3 Ga.This PhD thesis presents combined whole-rock and single zircon MC-ICP-MS Lu-Hf isotope data for a large collection of Archean granitoids belonging to typical Tonalite-Trondhjemite-Granodiorite (TTG) suites. The data were collected in an attempt to shed new light on early crustal growth. Our data display overall good agreement between Hf isotope compositions of igneous zircons, measured by both laser-ablation and solution chemistry, and their host-rocks. It is shown that the time-integrated Lu/Hf of the mantle source of TTGs is near-chronditic and has not significantly changed over the last 4 Gy. Continents therefore most likely grew from nearly primordial unfractionated material extracted from the deep mantle via rising plumes that left a depleted melt residue in the upper mantle. Zircons extracted from the analyzed TTGs have Hf isotopic compositions broadly consistent within populations, whereas the U-Pb system in the same grains is often disturbed, causing spurious initial εHf values. This problem is endemic to the Archean detrital zircon record and consistent with experimental results bearing on the relative retentivity of Hf vs. U and Pb in zircon. We argue that this behavior biases the Archean zircon record towards negative εHf values, which are at odds with the present TTG data set but can be explained by zircons having non-magmatic 207Pb/206Pb ages. If the Hadean Jack Hills zircons are considered in light of these results, the mantle source of continents has remained unchanged for the last 4.3 Gy
Opportunities in Advanced Space Transportation Systems
Future Programs
Session Chairman: Robert F. Freitag, Deputy Director, Advanced Programs, NASA Headquarters
Session Organizer: Paul D. Toft, Sciences, Technology and Applications Office, NASA, Kennedy Space Cente
Diagonal double Kodaira structures on finite groups
We introduce some special presentations on finite groups, that we call
"diagonal double Kodaira structures" and whose existence is equivalent to the
existence of some special Kodaira fibred surfaces, that we call "diagonal
double Kodaira fibrations". This allows us to rephrase in purely algebraic
terms some results about finite Heisenberg groups, previously obtained in the
recent work of the author with A. Causin, and makes possible to extend them to
the case of arbitrary extra-special -groups.Comment: To appear in the Proceedings of the 2019 ISAAC Congress (Aveiro,
Portugal
- …
