541 research outputs found
Temperature-Time History of Subducted Continental-Crust, Mount Olympos Region, Greece
In the Mt. Olympos region of northeastern Greece, continental margin strata and basement rocks were subducted and metamorphosed under blueschist facies conditions, and thrust over carbonate platform strata during Alpine orogenesis. Subsequent exposure of the subducted basement rocks by normal faulting has allowed an integrated study of the timing of metamorphism, its relationship to deformation, and the thermal history of the subducted terrane. Alpine low-grade metamorphic assemblages occur at four structural levels. Three thrust sheets composed of Paleozoic granitic basement and Mesozoic metasedimentary cover were thrust over Mesozoic carbonate rocks and Eocene flysch; thrusting and metamorphism occurred first in the highest thrust sheets and progressed downward as units were imbricated from NE to SW. 40Ar/39Ar spectra from hornblende, white mica, and biotite samples indicate that the upper two units preserve evidence of four distinct thermal events: (1) 293â302 Ma crystallization of granites, with cooling from \u3e550°C to \u3c325°C by 284 Ma; (2) 98â100 Ma greenschist to blueschist-greenschist transition facies metamorphism (Tâź350â500°C) and imbrication of continental thrust sheets; (3) 53â61 Ma blueschist facies metamorphism and deformation of the basement and continental margin units at T\u3c350â400°C; (4) 36â40 Ma thrusting of blueschists over the carbonate platform, and metamorphism at Tâź200â350°C. Only the Eocene and younger events affected the lower two structural packages. A fifth event, indicated by diffusive loss profiles in microcline spectra, reflects the beginning of uplift and cooling to T\u3c100â150°C at 16â23 Ma, associated with normal faulting which continued until Quaternary time. Incomplete resetting of mica ages in all units constrains the temperature of metamorphism during continental subduction to Tâ¤350°C, the closure temperature for Ar in muscovite. The diffusive loss profiles in micas and K-feldspars enable us to âsee throughâ the younger events to older events in the high-T parts of the release spectra. Micas grown during earlier metamorphic events lost relatively small amounts of Ar during subsequent high pressure-low temperature metamorphism. Release spectra from phengites grown during Eocene metamorphism and deformation record the ages of the Ar-loss events. Alpine deformation in northern Greece occurred over a long time span (âź90 Ma), and involved subduction and episodic imbrication of continental basement before, during, and after the collision of the Apulian and Eurasian plates. Syn-subduction uplift and cooling probably combined with intermittently higher cooling rates during extensional events to preserve the blueschist facies mineral assemblages as they were exhumed from depths of \u3e20 km. Extension in the Olympos region was synchronous with extension in the Mesohellenic trough and the Aegean back-arc, and concurrent with westward-progressing shortening in the external Hellenides
Late Cenozoic Structure and Tectonics of the Northern Mojave Desert
In the Fort Irwin region of the northern Mojave desert, late Cenozoic east striking sinistral faults predominate over northwest striking dextral faults of the same age. Kinematic indicators and offset marker units indicate dominantly sinistral strike slip on the east striking portions of the faults and sinistral-thrust slip on northwest striking, moderately dipping segments at the east ends of the blocks. Crustal blocks âź7â10 km wide by âź50 km long are bounded by complex fault zones up to 2 km wide at the edges and ends of each block. Faulting initiated after âź11 Ma, and Quaternary deposits are faulted and folded. We document a minimum of 13 km cumulative sinistral offset in a north-south transect from south of the Bicycle Lake fault to north of the Drinkwater Lake fault. Paleomagnetic results from 50 sites reveal two direction groups in early and middle Miocene rocks. The north-to-northwest declinations of the first group are close to the middle Miocene reference pole. However, rock magnetic studies suggest that both primary and remagnetized directions are present in this group. The northeast declinations of the second group are interpreted as primary and 63.5° Âą 7.6° clockwise from the reference pole and suggest net post middle Miocene clockwise rotation of several of the east trending blocks in the northeast Mojave domain. The Jurassic Independence Dike Swarm in Fort Irwin may be rotated 25â80° clockwise relative to the swarm north of the Garlock fault, thus supporting the inference of clockwise rotation. Using a simple-shear model that combines sinistral slip and clockwise rotation of elongate crustal blocks, we predict âź23° clockwise rotation using the observed fault slip, or one-third that inferred from the paleomagnetic results. The discrepancy between slip and rotation may reflect clockwise bending at the ends of fault blocks, where most of our paleomagnetic sites are located. However, at least 25°â40° of clockwise tectonic rotation is consistent with the observed slip on faults within the domain plus possible ârigid-bodyâ rotation of the region evidenced by clockwise bending of northwest striking domain-bounding faults. Our estimates of sinistral shear and clockwise rotation suggest that approximately half of the 65 km of dextral shear in the Eastern California Shear Zone over the last 10 m.y. occurred within the northeast Mojave Domain. The remainder must be accommodated in adjacent structural domains, e.g., east of the Avawatz Mountains and west of the Goldstone Lake fault. Supporting Appendices 1 and 2 are available on diskette or via Anonymous FTP from kosmos.agu.org, directory APEND (Username -- anonymous, Password = guest). Diskette may be ordered from American Geophysical Union, 2000 Florida Avenue, N.W, Washington, DC 20009 or by phone at 800-966-2481; $15.00. Payment must accompany order
Privacy Expectations of Social Media Users: The Role of Informed Consent in Privacy Policies
Social media process (sometimes large amounts of) personal data of their users, usually on the basis of informed consent. In this article, a comparison is made between, on the one hand, existing practices of social media regarding informed consent for using personal data of users and, on the other hand, user expectations with regard to privacy and informed consent. The comparison is made on the basis of a set of criteria for informed consent distilled from an analytical bibliography. Next, the privacy policies of a selection of eight social network sites and user generated content sites are analyzed using this set of criteria for informed consent. User expectations regarding these criteria were derived from survey results of a large EU-wide online survey (N = 8,621, 26 countries) on the awareness, values, and attitudes of social media users regarding privacy. We find that not all privacy policy criteria are important to users, but most criteria that are important to users can be found in most privacy policies.De bescherming van fundamentele rechten in een integrerend Europ
Analytical Solution for the Current Distribution in Multistrand Superconducting Cables
Current distribution in multistrand superconducting cables can be a major concern for stability in superconducting magnets and for field quality in particle accelerator magnets. In this paper we describe multistrand superconducting cables by means of a distributed parameters circuit model. We derive a system of partial differential equations governing current distribution in the cable and we give the analytical solution of the general system. We then specialize the general solution to the particular case of uniform cable properties. In the particular case of a two-strand cable, we show that the analytical solution presented here is identical to the one already available in the literature. For a cable made of N equal strands we give a closed form solution that to our knowledge was never presented before. We finally validate the analytical solution by comparison to numerical results in the case of a step-like spatial distribution of the magnetic field over a short Rutherford cable, both in transient and steady state conditions
Nephrin and CD2AP associate with phosphoinositide 3-OH kinase and stimulate AKT-dependent signaling
Mutations of NPHS1 or NPHS2, the genes encoding nephrin and podocin, as well as the targeted disruption of CD2-associated protein (CD2AP), lead to heavy proteinuria, suggesting that all three proteins are essential for the integrity of glomerular podocytes, the visceral glomerular epithelial cells of the kidney. It has been speculated that these proteins participate in common signaling pathways; however, it has remained unclear which signaling proteins are actually recruited by the slit diaphragm protein complex in vivo. We demonstrate that both nephrin and CD2AP interact with the p85 regulatory subunit of phosphoinositide 3-OH kinase (PI3K) in vivo, recruit PI3K to the plasma membrane, and, together with podocin, stimulate PI3K-dependent AKT signaling in podocytes. Using two-dimensional gel analysis in combination with a phosphoserine-specific antiserum, we demonstrate that the nephrin-induced AKT mediates phosphorylation of several target proteins in podocytes. One such target is Bad; its phosphorylation and inactivation by 14-3-3 protects podocytes against detachment-induced cell death, suggesting that the nephrin-CD2AP-mediated AKT activity can regulate complex biological programs. Our findings reveal a novel role for the slit diaphragm proteins nephrin, CD2AP, and podocin and demonstrate that these three proteins, in addition to their structural functions, initiate PI3K/AKT-dependent signal transduction in glomerular podocytes
Asthma control cost-utility randomized trial evaluation (ACCURATE): the goals of asthma treatment
Contains fulltext :
97659.pdf (publisher's version ) (Open Access)ABSTRACT: BACKGROUND: Despite the availability of effective therapies, asthma
remains a source of significant morbidity and use of health care resources. The
central research question of the ACCURATE trial is whether maximal doses of
(combination) therapy should be used for long periods in an attempt to achieve
complete control of all features of asthma. An additional question is whether
patients and society value the potential incremental benefit, if any,
sufficiently to concur with such a treatment approach. We assessed patient
preferences and cost-effectiveness of three treatment strategies aimed at
achieving different levels of clinical control: 1. sufficiently controlled asthma
2. strictly controlled asthma 3. strictly controlled asthma based on exhaled
nitric oxide as an additional disease marker DESIGN: 720 Patients with mild to
moderate persistent asthma from general practices with a practice nurse, age
18-50 yr, daily treatment with inhaled corticosteroids (more then 3 months usage
of inhaled corticosteroids in the previous year), will be identified via patient
registries of general practices in the Leiden, Nijmegen, and Amsterdam areas in
The Netherlands. The design is a 12-month cluster-randomised parallel trial with
40 general practices in each of the three arms. The patients will visit the
general practice at baseline, 3, 6, 9, and 12 months. At each planned and
unplanned visit to the general practice treatment will be adjusted with support
of an internet-based asthma monitoring system supervised by a central
coordinating specialist nurse. Patient preferences and utilities will be assessed
by questionnaire and interview. Data on asthma control, treatment step, adherence
to treatment, utilities and costs will be obtained every 3 months and at each
unplanned visit. Differences in societal costs (medication, other (health) care
and productivity) will be compared to differences in the number of limited
activity days and in quality adjusted life years (Dutch EQ5D, SF6D, e-TTO, VAS).
This is the first study to assess patient preferences and cost-effectiveness of
asthma treatment strategies driven by different target levels of asthma control.
Trial registration: Netherlands Trial Registration NTR1756
The Future of Psychopharmacological Enhancements: Expectations and Policies
The hopes and fears expressed in the debate on human enhancement are not always based on a realistic assessment of the expected possibilities. Discussions about extreme scenarios may at times obscure the ethical and policy issues that are relevant today. This paper aims to contribute to an adequate and ethically sound societal response to actual current developments. After a brief outline of the ethical debate concerning neuro-enhancement, it describes the current state of the art in psychopharmacological science and current uses of psychopharmacological enhancement, as well as the prospects for the near future. It then identifies ethical issues regarding psychopharmacological enhancements that require attention from policymakers, both on the professional and on the governmental level. These concern enhancement research, the gradual expansion of medical categories, off-label prescription and responsibility of doctors, and accessibility of enhancers on the Internet. It is concluded that further discussion on the advantages and drawbacks of enhancers on a collective social level is still needed
Developing innovative systems for reinforced masonry walls
The Commission of the European Communities has recently funded a CRAFT research project aimed at developing innovative systems for load and non-load-bearing reinforced masonry walls. The project involves twelve partners coming from four different European countries, among which there are universities and research centres, small and medium enterprises for the production of clay and concrete units and mortars, a company for advanced metal products and industrial associations of brick and block producers.
The development of the reinforced masonry walls is based on the advancement of vertical reinforcement and fastenings, of mortar and concrete and on their integration with special clay and concrete blocks for the definition of new construction systems. The foreseen advantages are: new possibilities for masonry; more economical construction; quality increase for masonry walls; crack-free and earthquake resistant construction. The project follows three steps: assessment of the technical and economical feasibility of the envisaged construction technologies by means of extensive experimental and numerical activities; construction of prototypes as demonstration of the proposed technologies and materials; in situ testing to completely validate the systems.
In the present contribution, an overview of the main objectives and steps of the project is given. Furthermore, the different construction systems that are being developed and designed are described. The main fields of application and the main technical problems encountered for the different construction systems is described, together with the experimental program outlined in order to characterize their mechanical behaviour under different serviceability and ultimate conditions
A method to study the effect of bronchodilators on smoke retention in COPD patients: study protocol for a randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Chronic obstructive pulmonary disease (COPD) is a common disease, associated with cardiovascular disease. Many patients use (long-acting) bronchodilators, whilst they continue smoking alongside. We hypothesised an interaction between bronchodilators and smoking that enhances smoke exposure, and hence cardiovascular disease. In this paper, we report our study protocol that explores the fundamental interaction, i.e. smoke retention.</p> <p>Method</p> <p>The design consists of a double-blinded, placebo-controlled, randomised crossover trial, in which 40 COPD patients smoke cigarettes during both undilated and maximal bronchodilated conditions. Our primary outcome is the retention of cigarette smoke, expressed as tar and nicotine weight. The inhaled tar weights are calculated from the correlated extracted nicotine weights in cigarette filters, whereas the exhaled weights are collected on Cambridge filters. We established the inhaled weight calculations by a pilot study, that included paired measurements from several smoking regimes. Our study protocol is approved by the local accredited medical review ethics committee.</p> <p>Discussion</p> <p>Our study is currently in progress. The pilot study revealed valid equations for inhaled tar and nicotine, with an R<sup>2 </sup>of 0.82 and 0.74 (p < 0.01), respectively. We developed a method to study pulmonary smoke retentions in COPD patients under the influence of bronchodilation which may affect smoking-related disease. This trial will provide fundamental knowledge about the (cardiovascular) safety of bronchodilators in patients with COPD who persist in their habit of cigarette smoking.</p> <p>Trial registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00981851">NCT00981851</a></p
- âŚ