Biological Insights from Single-Particle Tracking in Living Cells

Single-particle tracking is a technique that allows for quantitative analysis of the localization and movement of particles. In this technique, trajectories are constructed by determining and connecting the positions of individual particles from consecutive images. Recent advances have made it possible to track hundreds of particles in an individual cell by labeling the particles of interest with photoactivatable or photoconvertible fluorescent proteins and tracking one or a few at a time. Single-particle tracking can be used to study the diffusion of particles. Here, we use intracellular single-particle tracking and trajectory simulations to study the diffusion of the fluorescent protein mEos2 in living Escherichia coli cells. Our data are consistent with a simple model in which mEos2 diffuses normally at 13 µm2 s−1 in the E. coli cytoplasm. Our approach can be used to study the diffusion of intracellular particles that can be labeled with mEos2 and are present at high copy numbers. Single-particle tracking can also be used to determine whether an individual particle is bound or free if the free particle diffuses significantly faster than its binding targets and remains bound or free for a long time. Here, we use single-particle tracking in living E. coli cells to determine the fractions of free ribosomal subunits, classify individual subunits as free or mRNA-bound, and quantify the degree of exclusion of bound and free subunits separately. We show that, unlike bound subunits, free subunits are not excluded from the nucleoid. This finding strongly suggests that translation of nascent mRNAs can start throughout the nucleoid, which reconciles the spatial separation of DNA and ribosomes with co-transcriptional translation. We also show that, after translation inhibition, free subunit precursors are partially excluded from the compacted nucleoid. This finding indicates that it is active translation that normally allows ribosomal subunits to assemble on nascent mRNAs throughout the nucleoid and that the effects of translation inhibitors are enhanced by the limited access of ribosomal subunits to nascent mRNAs in the compacted nucleoid

Modelling of world oil market An assessment of factors both economic and political affecting world oil production and consumption for the purpose of econometric analysis of historical data & medium term projections

SIGLEAvailable from British Library Document Supply Centre- DSC:D35563/81 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Changing flights in mid-air: a model for safely modifying continuous queries

Continuous queries can run for unpredictably long periods of time. During their lifetime, these queries may need to be adapted either due to changes in application semantics (e.g., the implementation of a new alert detection policy), or due to changes in the system’s behavior (e.g., adapting performance to a changing load). While in previous works query modification has been implicitly utilized to serve specific purposes (e.g., load management), to date no research has been done that defines a general-purpose, reliable, and efficiently implementable model for modifying continuous queries at run-time. In this report, we introduce a punctuation-based framework that can formally express arbitrary lifecycle operations on the basis of input-output mappings and basic control elements such as start or stop of queries. On top of this foundation, we derive all possible query change methods, each providing different levels of correctness guarantees and performance. We further show how these models can be efficiently realized in a state-of-the-art stream processing engine; we also provide experimental results demonstrating the key performance tradeoffs of the change methods

My Private Google Calendar

Everybody loves Google Apps. Google provides highly available web applications that help you communicate, organize and collaborate from anywhere using different interfaces in the most user friendly and efficient way, without being worried about any IT issues. However, some people still hesitate using Google services because of privacy and trust issues. In this paper, we identify privacy issues in GoogleWeb Applications as a particularly vital problem and propose a solution. In our solution a transparent encryption layer is put between the user and the cloud service provider on a site trusted by the user. This layer accesses the request and response messages passed between the two parties in a fine-grained manner. It applies modern cryptography techniques to encrypt the data without sacrificing functionality and portability of the cloud service. This way the trust of the end user can be reobtained and he or she will be encouraged to further enjoy using web applications such as Google Apps without having to worry about privacy issues

The Gaze and Mouse Signal as additional Source for User Fingerprints in Browser Applications

In this work we inspect different data sources for browser fingerprints. We show which disadvantages and limitations browser statistics have and how this can be avoided with other data sources. Since human visual behavior is a rich source of information and also contains person specific information, it is a valuable source for browser fingerprints. However, human gaze acquisition in the browser also has disadvantages, such as inaccuracies via webcam and the restriction that the user must first allow access to the camera. However, it is also known that the mouse movements and the human gaze correlate and therefore, the mouse movements can be used instead of the gaze signal. In our evaluation we show the influence of all possible combinations of the three information sources for user recognition and describe our simple approach in detail. The data and the Matlab code can be downloaded here https://atreus.informatik.uni-tuebingen.de/seafile/d/8e2ab8c3fdd444e1a135/?p=%2FThe%20Gaze%20and%20Mouse%20Signal%20as%20additional%20Source%20...&mode=lis

Management of Common Bile Duct Stones Encountered During Cholecystectomy in Patients With Previous Gastric Bypass

Background: Rapid weight loss following gastric bypass (GBP) predisposes to the development of gallstones, and in those who develop gallstone disease there is a high prevalence of common bile duct stones (CBDS). Furthermore, in these patients, CBDS are difficult to extract due to the altered upper gastrointestinal anatomy following GBP. The aim of the present study was to assess outcome after various management methods applied in the counties of Stockholm and Uppsala, Sweden.Methods: Data from the Swedish Register for Gallstone Surgery and ERCP (GallRiks) and the Swedish Obesity Surgery Register (SoReg) were crossmatched to identify all patients who had undergone gallstone surgery after GBP, where CBDS were found at intraoperative cholangiography, in the Stockholm and Uppsala counties 2009–2013. A retrospective review of patient records was performed for all patients identified.Results: In all, 55 patients were identified. These were managed as follows: expectancy (N = 11); transgastric ERCP (N = 2); laparoscopic choledochotomy (N = 3); open choledochotomy (N = 5); transcystic stone extraction (N = 12); and other approach (N = 13). In nine cases, data on management could not be found. There were nine cases of minor postoperative complication. No retained stones were registered. The operation time was longer for transgastric ERCP (p = 0.002), and the postoperative stay was longer following open and laparoscopic choledochotomy (p &amp;lt; 0.001). There was no statistically significant difference between any of the methods regarding the incidence of postoperative complications (p = 0.098).Discussion: Further development of techniques for managing CBDS discovered in patients undergoing cholecystectomy after previous GBP are needed, as well as more comparative studies with greater statistical power.</jats:p