1,768 research outputs found

    Urban transportation: Perspectives on mobility and choice

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    A study of urban transportation systems are presented characterized by intensive scrutiny of many ideas, philosophies, and academic perspectives. This report is intended to communicate some dimensions of the urban transportation problem to the general public

    Boolean delay equations on networks: An application to economic damage propagation

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    We introduce economic models based on Boolean Delay Equations: this formalism makes easier to take into account the complexity of the interactions between firms and is particularly appropriate for studying the propagation of an initial damage due to a catastrophe. Here we concentrate on simple cases, which allow to understand the effects of multiple concurrent production paths as well as the presence of stochasticity in the path time lengths or in the network structure. In absence of flexibility, the shortening of production of a single firm in an isolated network with multiple connections usually ends up by attaining a finite fraction of the firms or the whole economy, whereas the interactions with the outside allow a partial recovering of the activity, giving rise to periodic solutions with waves of damage which propagate across the structure. The damage propagation speed is strongly dependent upon the topology. The existence of multiple concurrent production paths does not necessarily imply a slowing down of the propagation, which can be as fast as the shortest path.Comment: Latex, 52 pages with 22 eps figure

    CD4(+) T cells play a critical role in mediating hypertension in response to placental ischemia

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    Similar to preeclamptic women, hypertension in the chronic Reduced Uterine Perfusion Pressure Rat Model Of Preeclampsia (RUPP) is associated with increased CD4+ T cells, cytokines, sFlt-1 and agonistic autoantibodies to the AngII receptor (AT1-AA). We examined the effect inhibition of T cell co-stimulation in RUPP rats treated with (A) (abatacept, 250 mg/kg, infused i.v. at gestation day 13), on hypertension and sFlt-1, TNF-alpha and AT1-AA. RUPP surgical procedure was performed on day 14. On day 19 MAP increased from 94+2 mmHg in Normal Pregnant (NP) to 123 +/- 3 mmHg in RUPP control rats. This response was attenuated by Abatacept, MAP was 104 +/- 2 mmHg in RUPP +/- A, and 96 +/- 2 mmHg NP +/- A. Percent circulating CD4+ T cells were 66 +/- 3% in RUPPs compared to 55 +/- 3% NP rats (p<0.04) but were normalized in RUPP +/- A rats (54 +/- 3%). The twofold increase in TNF alpha seen in RUPPs (277 +/- 47 pg/ml) was decreased to 80 +/- 18 pg/ml in RUPP+A. Placental sFlt-1 was reduced 70 % to 151 +/- 28 in RUPP +/- A compared 488 +/- 61 pg/ml in RUPP (p<0.001). AT1-AA decreased from 20 +/- 0.8 bpm in control RUPP to 6 +/- 0.7 bpm in RUPP +/- A. We next determined the effect of RUPP in causing hypertension in pregnant T cell deficient rats by examining MAP in NP (123 +/- 5 mmHg) and RUPP athymic nude rats (123 +/- 7 mmHg). In the absence of T cells, hypertension in response to placental ischemia was completely abolished. Collectively these data indicate that CD4+ Tcells in response to placental ischemia play an important role in the pathophysiology of hypertension associated with preeclampsia

    Beta decay of 71,73Co; probing single particle states approaching doubly magic 78Ni

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    Low-energy excited states in 71,73Ni populated via the {\beta} decay of 71,73Co were investigated in an experiment performed at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU). Detailed analysis led to the construction of level schemes of 71,73Ni, which are interpreted using systematics and analyzed using shell model calculations. The 5/2- states attributed to the the f5/2 orbital and positive parity 5/2+ and 7/2+ states from the g9/2 orbital have been identified in both 71,73Ni. In 71Ni the location of a 1/2- {\beta}-decaying isomer is proposed and limits are suggested as to the location of the isomer in 73Ni. The location of positive parity cluster states are also identified in 71,73Ni. Beta-delayed neutron branching ratios obtained from this data are given for both 71,73Co.Comment: Accepted for publication in PR

    Smart homes and their users:a systematic analysis and key challenges

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    Published research on smart homes and their users is growing exponentially, yet a clear understanding of who these users are and how they might use smart home technologies is missing from a field being overwhelmingly pushed by technology developers. Through a systematic analysis of peer-reviewed literature on smart homes and their users, this paper takes stock of the dominant research themes and the linkages and disconnects between them. Key findings within each of nine themes are analysed, grouped into three: (1) views of the smart home-functional, instrumental, socio-technical; (2) users and the use of the smart home-prospective users, interactions and decisions, using technologies in the home; and (3) challenges for realising the smart home-hardware and software, design, domestication. These themes are integrated into an organising framework for future research that identifies the presence or absence of cross-cutting relationships between different understandings of smart homes and their users. The usefulness of the organising framework is illustrated in relation to two major concerns-privacy and control-that have been narrowly interpreted to date, precluding deeper insights and potential solutions. Future research on smart homes and their users can benefit by exploring and developing cross-cutting relationships between the research themes identified

    Middle Ordovician Black River Ostracods from Michigan, Introduction and Part I The Nature of Macronotella

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    293-314http://deepblue.lib.umich.edu/bitstream/2027.42/48341/2/ID182.pd
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