81 research outputs found
Novel Peptide Sequence (“IQ-tag”) with High Affinity for NIR Fluorochromes Allows Protein and Cell Specific Labeling for In Vivo Imaging
Probes that allow site-specific protein labeling have become critical tools for visualizing biological processes.Here we used phage display to identify a novel peptide sequence with nanomolar affinity for near infrared (NIR) (benz)indolium fluorochromes. The developed peptide sequence ("IQ-tag") allows detection of NIR dyes in a wide range of assays including ELISA, flow cytometry, high throughput screens, microscopy, and optical in vivo imaging.The described method is expected to have broad utility in numerous applications, namely site-specific protein imaging, target identification, cell tracking, and drug development
Gastric transit and small intestinal transit time and motility assessed by a magnet tracking system
<p>Abstract</p> <p>Background</p> <p>Tracking an ingested magnet by the Magnet Tracking System MTS-1 (Motilis, Lausanne, Switzerland) is an easy and minimally-invasive method to assess gastrointestinal transit. The aim was to test the validity of MTS-1 for assessment of gastric transit time and small intestinal transit time, and to illustrate transit patterns detected by the system.</p> <p>Methods</p> <p>A small magnet was ingested and tracked by an external matrix of 16 magnetic field sensors (4 × 4) giving a position defined by 5 coordinates (position: <b>x, y, z, and angle: θ, ϕ)</b>. Eight healthy subjects were each investigated three times: (1) with a small magnet mounted on a capsule endoscope (PillCam); (2) with the magnet alone and the small intestine in the fasting state; and (3) with the magnet alone and the small intestine in the postprandial state.</p> <p>Results</p> <p>Experiment (1) showed good agreement and no systematic differences between MTS-1 and capsule endoscopy when assessing gastric transit (median difference 1 min; range: 0-6 min) and small intestinal transit time (median difference 0.5 min; range: 0-52 min). Comparing experiments (1) and (2) there were no systematic differences in gastric transit or small intestinal transit when using the magnet-PillCam unit and the much smaller magnetic pill. In experiments (2) and (3), short bursts of very fast movements lasting less than 5% of the time accounted for more than half the distance covered during the first two hours in the small intestine, irrespective of whether the small intestine was in the fasting or postprandial state. The mean contraction frequency in the small intestine was significantly lower in the fasting state than in the postprandial state (9.90 min<sup>-1 </sup>vs. 10.53 min<sup>-1</sup>) (p = 0.03).</p> <p>Conclusion</p> <p>MTS-1 is reliable for determination of gastric transit and small intestinal transit time. It is possible to distinguish between the mean contraction frequency of small intestine in the fasting state and in the postprandial state.</p
Technology Diffusion, Abatement Cost and Transboundary Pollution
This paper studies countries' incentives to develop advanced pollution abatement technology when technology may spillover across countries and pollution abatement is a global public good. We are motivated in part by the problem of global warming: a solution to this involves providing a global public good, and will surely require the development and implementation of new technologies. We show that at the Nash equilibrium of a simultaneous-move game with R&D investment and emission abatement, whether the free rider effect prevails and under-investment and excess emissions occur depends on the degree of technology spillovers and the effect of R&D on the marginal abatement costs. There are cases in which, contrary to conventional wisdom, Nash equilibrium investments in emissions reductions exceed the first-best case
The Relationship between Environmental Efficiency and Manufacturing Firm's Growth
This paper investigates the empirical link between emission intensity and economic growth, using a very large data set of 61,219 Italian manufacturing firms over the period 2000-2004. As a measure of lagged environmental performance (efficiency) at firm level we exploit NAMEA sector for CO2, NOx, SOx data over 1990-1999. The paper tests the extent to which (past) environmental efficiency/intensity, which is driven by structural features and firm strategic actions, including responses to policies, influences firms growth. Our results show, first, a typical trade off generally appearing for the three core environmental emissions we analyse: lower environmentally efficiency in the recent past allows higher degrees of freedom to firms and relax the constraints for growth, at least in this short/medium term scenario. Nevertheless, the size of the estimated coefficients is not large. Trade offs are significant for two emission indicators out of two, but quite negligible in terms of impacts, besides the case of CO2. For example, growth is reduced by far less than 0.1% in association to a 1% increase of environmental efficiency. In addition, non-linearity seems to characterise the economic growth-environmental performance relationship. Signals of inverted U shape appear: this may be a signal that both firm strategies and recent policy efforts are affecting the dynamic relationship between environmental efficiency and economic productivity, turning it from an usual trade off to a possible joint complementary/co-dynamics
Illuminating the life of GPCRs
The investigation of biological systems highly depends on the possibilities that allow scientists to visualize and quantify biomolecules and their related activities in real-time and non-invasively. G-protein coupled receptors represent a family of very dynamic and highly regulated transmembrane proteins that are involved in various important physiological processes. Since their localization is not confined to the cell surface they have been a very attractive "moving target" and the understanding of their intracellular pathways as well as the identified protein-protein-interactions has had implications for therapeutic interventions. Recent and ongoing advances in both the establishment of a variety of labeling methods and the improvement of measuring and analyzing instrumentation, have made fluorescence techniques to an indispensable tool for GPCR imaging. The illumination of their complex life cycle, which includes receptor biosynthesis, membrane targeting, ligand binding, signaling, internalization, recycling and degradation, will provide new insights into the relationship between spatial receptor distribution and function. This review covers the existing technologies to track GPCRs in living cells. Fluorescent ligands, antibodies, auto-fluorescent proteins as well as the evolving technologies for chemical labeling with peptide- and protein-tags are described and their major applications concerning the GPCR life cycle are presented
Voluntary Cleanups and Redevelopment Potential: Lessons from Baltimore, Maryland
Policy has increasingly shifted towards economic incentives and liability attenuation for promoting cleanup and redevelopment of contaminated sites, but little is known about the effectiveness of such policies. An example of such legislation is State Voluntary Cleanup Programs (VCPs), which were established in the US in the 1990s and to date have been implemented in almost every state. We examine Baltimore properties that participated in the Maryland VCP from its inception in 1997 to the end of 2006. Specifically, we examine what type of properties tend to participate in these programs, how these properties compare to other eligible but non-participating sites, and what is the redevelopment potential of VCP properties and implications towards open space conversion. We find that most applicants (66%) actually requested a No Further Action Determination directly, rather than proposing cleanup. VCP properties tend to be industrial, located in industrial areas, and away from residential neighborhoods. In more recent years larger industrial properties have increasingly enrolled in the program. The majority of sites are reused as industrial or commercial. In contrast to Alberini (2007), this suggests that pressure for residential development does not drive VCP participation. Based on differences in zoning requirements, the VCP may reduce demand for potentially contaminating activities on pristine land by as much as 1,238 to 6,444 acres, in Baltimore alone
A Multicriteria Approach for the Evaluation of the Sustainability of Re-Use of Historic Buildings in Venice
The paper presents a multiple criteria model for the evaluation of the sustainability of projects for the economic re-use of historical buildings in Venice. The model utilises the relevant parameters for the appraisal of sustainability, aggregated into three macro-indicators: intrinsic sustainability, context sustainability and economic-financial feasibility. The model has been calibrated by a panel of experts and tested on two reuse hypotheses of the Old Arsenal in Venice. The tests have proven the model to be a useful support in the early stages of evaluation of re-use projects, where economic improvements are to be combined with conservation, as it supports the identification of critical points and the selection of projects, thus providing not only a check-list of variables to be considered, but an appraisal of trade-offs between economic uses and requirements of conservation
Changing the Allocation Rules in the EU ETS: Impact on Competitiveness and Economic Efficiency
We assess five proposals for the future of the EU greenhouse gas Emission Trading Scheme (ETS): pure grandfathering allocation of emission allowances (GF), output-based allocation (OB), auctioning (AU), auctioning with border adjustments (AU-BA), and finally output-based allocation in sectors exposed to international competition combined with auctioning in electricity generation (OB-AU). We look at the impact on production, trade, CO2 leakage and welfare. We use a partial equilibrium model of the EU 27 featuring three sectors covered by the EU ETS - cement, steel and electricity - plus the aluminium sector, which is indirectly impacted through a rise in electricity price. The leakage ratio, i.e. the increase in emissions abroad over the decrease in EU emissions, ranges from around 8% under GF and AU to -2% under AU-BA and varies greatly among sectors. Concerning the overall economic cost, OB appears to be the least efficient policy, even when taking into account its ability to prevent CO2 leakage. On the other hand, this policy minimises production losses and wealth transfers among stakeholders, which is likely to soften oppositions. GF and AU are the most efficient policies from an EU perspective, even when leakage is accounted for. From a world welfare perspective and whatever the emission reduction, AU-BA is the least costly policy, while OB-AU, AU and GF entail similar costs
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