2,911 research outputs found

    Transport Planning in Delft, Netherlands

    Get PDF
    While the Netherlands is known today for the highest bicycling rates in the world, this movement only began in the 1970s. Transportation policy has been one of the critical keys to reducing automobile trips in the Netherlands. Visiting scholar Jan Nederveen will present on transportation planning in the compact, densely populated city of Delft. Delft has been a city since 1246, and the historic street pattern is still visible today. The city has grown to 100,000 residents and covers an area of 5 square kilometers. Twenty years ago, the council decided to change the transportation philosophy from a car-oriented system to a bike city with a car-free historic center. This policy has been very successful, and bikes are now the dominant mode. Delft found a good balance in road design for both cars and bikes. Today, the bike network has reached the point of congestion. Solutions developed for cars are being introduced in the bike network. The presentation will cover the city\u27s transport policy, road design, the concept of a car-free city, and the challenge of reducing bicycle congestion.https://pdxscholar.library.pdx.edu/trec_seminar/1121/thumbnail.jp

    Molecular Pathology of Pheochromocytoma and Paraganglioma Development

    Get PDF

    Molecular Pathology of Pheochromocytoma and Paraganglioma Development

    Get PDF

    Ensemble Monte Carlo simulation of electron transport in AlGaAs/GaAs heterostructures

    Get PDF

    Studying dimerization of Roco proteins in living cells:a tool to better understand Parkinson's Disease

    Get PDF
    This thesis describes the development of a method to measure protein pairing. This is important, among other things, for the protein LRRK2 (pronounced: lark-two) that is involved in Parkinson's Disease (PD). The insights resulting from this research contribute to the development of drugs that can inhibit or prevent Parkinson's disease. In a significant proportion of PD patients, the LRRK2 protein is hyperactive: it carries out a certain chemical reaction too often. Researchers would like to know how this protein activity is regulated and what it depends on so that it can be blocked. Previous experiments with disrupted cells indicated that it is important for protein activity that LRRK2 proteins are attached to each other in pairs ('dimers'). However, this had not yet been studied in living cells. The aim of my research was therefore to measure the pairing of LRRK2 in living cells. Observing protein pairs in their biological context is not easy, however. In my dissertation I adapted a certain microscope technique, in which the light intensity is calculated that each protein particle (provided with a green label) emits. Protein pairs are twice as bright as single proteins, and so we can now see in living cells (common lab cell lines) that LRRK2 'dimers' are indeed present. The next step is to block pairing with substances and observe this in living cells. Ultimately, Parkinson's drugs can be developed that counteract the LRRK2 hyperactivity and thus potentially halt the death of neurons and disease progression

    Molecular pathology op pheochromocytoma and paraganglioma development

    Get PDF
    Pheochromocytomas (PCC) are rare tumours of the adrenal medulla. These tumours are derived from the neural crest, similar to paraganglioma (PGL), which are located in the head and neck region and along the sympathetic chain. Histomorphologically these tumours are identical, although the pathogenesis of these two tumour types are mainly different with a minor overlap between the tumours. In the last decades the genes that are associated with the development of PCC and PGL have been identified. Also, the recognition of germline mutations in patients with PCC and PGL has been improved. In patients with PGL germline mutations are identified in more than 50% of the patients and in PCC the percentage of germline mutations is about 25%. Genes involved in the development of PCC are: the RET oncogene and the tunoursupressorgenes VHL, NF1, SDHB, SDHC en SDHD. In the development of PGL the genes mostly involved the SDHB, SDHC en SDHD genes, but also a small percentage is due to mutations in VHL germline mutations. Very recently the SDHA-F2 gene is identified in a subset of hereditary paraganglioma. No clinical of histological markers are available to predict behaviour of PCC and PGL. Some clinical correlation has been found; in patients with PCC and germline RET mutations malignant behaviour is rare. This is in contrast to patients with PCC and SDHB germline mutations that develop metastasis in a large proportion of patients. In this thesis the molecular aberrations in benign and malignant PCC are described and various techniques that can distinguish a subset of PCC and PGL

    Adjustment of pulmonary O2 uptake, muscle deoxygenation and metabolism during moderate-intensity exercise transitions initiated from low and elevated baseline metabolic rates

    Get PDF
    When instantaneous step-wise transitions within the moderate intensity domain are initiated from elevated metabolic rates, the rate of pulmonary oxygen uptake (V̇O2p) adjustment is slowed, and the V̇O2p gain (ΔV̇O2p /ΔWR) is greater. This study sought to determine the relationship between V̇O2p kinetics and metabolic activity and energy status during step transitions from low and elevated metabolic rates within the moderate intensity domain. Ten young men completed six double-step constant load cycling bouts, consisting of step-wise transitions from 20 W to 45% θL and 45% θL [lower step (LS)] to 90% θL [upper step (US)], one double-step bout included needle biopsies at; baseline, steady-state values and during transitions. Gas exchange was analyzed breath-by-breath and muscle de-oxygenation status ([HHb]) was measured with near infrared spectroscopy. The V̇O2p gain in the US (10.37 ± 1.49) was greater (p2p (τV̇O2p) in the US (34 ± 12) was slower (pamp in the US (3.5 ± 2.6) was decreased (pfree] and [Pi] concentration was increased (p15) and remained elevated relative to baseline through the protocol

    Disorder and interactions in quantum Hall ferromagnets: effects of disorder in Skyrmion physics

    Full text link
    We present a Hartree-Fock study of the competition between disorder and interactions in quantum Hall ferromagnets near ν=1\nu=1. We find that the ground state at ν=1\nu=1 evolves with increasing interaction strength from a quasi-metallic paramagnet, to a partially spin-polarized ferromagnetic Anderson insulator, and to a fully spin-polarized ferromagnet with a charge gap. Away from ν=1\nu=1, the ground state evolves from a conventional Anderson insulator, to a conventional quasiparticle glass, and finally to a ferromagnetic Skyrmion quasiparticle glass. These different regimes can be measured in low-temperature transport and NMR experiments. We present calculations for the NMR spectra in different disorder regimes.Comment: 3 pages, 3 figures, proceedings for EP2DS-14, Prague 200

    Toward a Single Reed Mouthpiece for the Oboe

    No full text
    International audienceReed woodwind instruments differ in both their geometry (mainly cylindrical or mainly conical) and their excitation mechanism (single or double reed). How much of the resulting sound is due to the single/double reed, and how much to the geometry of the instrument? Measurements done by Almeida et al. (J. Acoust. Soc. Am., 121, 1, 536–546, 2007) show that the flow vs pressure characteristic curve of an oboe reed is not that different from that of a clarinet reed, the only difference probably being due to pressure recovery inside the conical staple. Is it possible to make a single reed mouthpiece for an oboe, while keeping the conical staple, that would still give the oboe its characteristic sound? To find it out, a mouthpiece with the following characteristics was made: A standard clarinet B reed can be attached to it, its volume is approximately that of the missing part of the instrument cone, and a standard French oboe staple can be inserted to it, so that it can be inserted in the usual way in any french oboe. In this paper, the first prototype of the mouthpiece is shown. Also, a sound comparison of the oboe sounds played with this mouthpiece and a standard double reed by a professional player is presented

    A Transfer Matrix for the Input Impedance of weakly tapered Cones as of Wind Instruments

    Full text link
    A formula for the local acoustical admittance in a conical waveguide with viscous and thermal losses given by Nederveen in \emph{Acoustical Aspects of Woodwind Instruments} (1969) is rewritten as an impedance transmission matrix. Based on a self-consistent approximation for the cone, it differs from other one-dimensional transmission matrices used in musical acoustics, which implicitly include the loss model of a cylinder. The resonance frequencies of air columns calculated with this new transmission matrix are in better agreement with more comprehensive models. Even for long cones with a slight taper, there is no need to discretize along the axis.Comment: 7 pages, 2 figure
    corecore