1,301 research outputs found
Family C1 cysteine proteases: Biological diversity or redundancy?
Recent progress in the identification and partial characterization of novel genes encoding cysteine proteases of the papain family has considerably increased our knowledge of this family of enzymes. Kinetic data available to date for this large family indicate relatively broad, overlapping specificities for most enzymes, thus inspiring a growing conviction that they may exhibit functional redundancy. This is also supported in part by phenotypes of cathepsin knockout mice and suggests that several proteases can substitute for each other to degrade or process a given substrate. On the other hand, specific functions of one particular protease have also been documented. In addition, differences in cellular distribution and intracellular localization may contribute to defining specific functional roles for some of these proteases
Measuring time perspective in adolescents : can you get the right answer by asking the wrong questions?
Time perspective continues to evolve as a psychological construct. The extant literature suggests that higher future orientation and lower present orientation are associated with better developmental outcomes. However, the extant literature also suggests that issues remain with the measurement of the construct. Recently, a 25-item version of the Zimbardo Time Perspective Inventory (ZTPI-25) was suggested for use based on high internal consistency estimates and good discriminant validity of scores in a sample of Italian adolescents. However, the genesis of this scale is uncertain. The present study examined the factorial validity, reliability, and concurrent validity of ZTPI-25 scores in Slovenian, American, and British adolescents. Results revealed satisfactory concurrent validity based on correlations with measures used in the development of the full ZTPI. However, internal consistency and factorial validity of scores were unsatisfactory. The present study questions the use of the ZTPI-25 with adolescents in the context of conceptual and measurement issues more broadly
Discrete tomography and joint inversion for loosely connected or unconnected physical properties: application to crosshole seismic and georadar data sets
Tomographic inversions of geophysical data generally include an underdetermined component. To compensate for this shortcoming, assumptions or a priori knowledge need to be incorporated in the inversion process. A possible option for a broad class of problems is to restrict the range of values within which the unknown model parameters must lie. Typical examples of such problems include cavity detection or the delineation of isolated ore bodies in the subsurface. In cavity detection, the physical properties of the cavity can be narrowed down to those of air and/or water, and the physical properties of the host rock either are known to within a narrow band of values or can be established from simple experiments. Discrete tomography techniques allow such information to be included as constraints on the inversions. We have developed a discrete tomography method that is based on mixed-integer linear programming. An important feature of our method is the ability to invert jointly different types of data, for which the key physical properties are only loosely connected or unconnected. Joint inversions reduce the ambiguity in tomographic studies. The performance of our new algorithm is demonstrated on several synthetic data sets. In particular, we show how the complementary nature of seismic and georadar data can be exploited to locate air- or water-filled cavitie
An unfolding signifier: London's Baltic Exchange in Tallinn
In the summer of 2007 an unusual cargo arrived at Muuga and Paldiski harbors outside Tallinn. It consisted of nearly 50 containers holding over 1,000 tons of building material ranging from marble columns, staircases and fireplaces, to sculpted allegorical figures, wooden paneling and old-fashioned telephone booths. They were once part of the Baltic Exchange in the City of London. Soon they will become facets of the landscape of Tallinn. The following article charts this remarkable story and deploys this fragmented monument to analyze three issues relating to the Estonian capital: the relocation of the ‘Bronze Soldier’, the demolition of the Sakala Culture Center, and Tallinn’s future role as European Cultural Capital in 2011
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Security and Performance Trade-offs for Data Distribution Service in Flying Ad-Hoc Networks
This paper focuses on the data distribution service(DDS) middleware and its publish/subscribe logic - a topic thathas recently regained popularity in both academia as well asindustry. DDS is a well-known approach based on publish-subscribe logic. Therefore, only brief introduction of the issueis given followed by practical evaluation of current, availableand real implementations from the security and performancepoint of view. The analysis and evaluation is performed toaid comparison of competing DDS implementation, and thuscould serve well as an input to decision-making about whichof these solutions is best suited for a given situation. Finally,the practical performance evaluation is performed via severaldifferent scenarios to effectively compare the currently most-usedDDS implementations
Atomic-scale representation and statistical learning of tensorial properties
This chapter discusses the importance of incorporating three-dimensional
symmetries in the context of statistical learning models geared towards the
interpolation of the tensorial properties of atomic-scale structures. We focus
on Gaussian process regression, and in particular on the construction of
structural representations, and the associated kernel functions, that are
endowed with the geometric covariance properties compatible with those of the
learning targets. We summarize the general formulation of such a
symmetry-adapted Gaussian process regression model, and how it can be
implemented based on a scheme that generalizes the popular smooth overlap of
atomic positions representation. We give examples of the performance of this
framework when learning the polarizability and the ground-state electron
density of a molecule
A Unique Population of Cave Bears (Carnivora: Ursidae) from the Middle Pleistocene of Kents Cavern, England, Based on Dental Morphometrics
The ‘breccia’ stratum from Kents (we follow local tradition in using the form ‘Kents’, without an apostrophe) Cavern, England, has been well known for its rich yield of cave-bear material since excavations began in the mid-19th century. Recent work has established that the bears are of latest MIS 12 or earliest MIS 11 age. A life table based on a collection of 67 molariform teeth is consistent with the use of the cave as a hibernaculum. Univariate and morphological assessment of the teeth shows an unusual range of primitive and more derived characters. Multivariate morphometric analysis of cave-bear teeth from the site demonstrates that these animals, while currently assignable to Ursus deningeri sensu lato, are nevertheless morphologically distinct and not simply late deningeri on a hypothetical chronospecific continuum
Focused Ion Beam Fabrication
Contains reports on five research projects.DARPA/Naval Electronic Systems Command (Contract MDA-903-85-C-0215)Charles Stark Draper Laboratory (Contract DL-H-261827)U.S. Navy - Office of Naval Research (Contract N00014-84-K-0073)Nippon Telephone and TelegraphHitachi Central Research Laborator
Focused Ion Beam Fabrication
Contains reports on four sections of one research project.Microsystems Technology LaboratoriesDefense Advanced Research Projects Agency/Naval Electronics Systems Command (Contract MDA 903-85-C-0215)U.S. Air Force (through Lincoln Laboratory)Defense Advanced Research Projects Agency (through Lincoln Laboratory)Charles Stark Draper Laboratory, Inc. (Contract DL-H-261827)Hitachi Central Research LaboratoryNippon Telegraph & TelephoneU.S. Army Research Office (Contract DAALO3-87-K-0126
Focused Ion Beam Fabrication
Contains reports on ten research projects.U.S. Army Research Office Contract DAAL03-88-K-0108Hughes Research Laboratories FellowshipSEMATECHCharles S. Draper Laboratory Contract DL-H-261827U.S. Army Research Office Contract DAAL03-87-K-0126IBM General Technologies DivisionIBM Research Divisio
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