Provably-Secure Time-Bound Hierarchical Key Assignment Schemes

A time-bound hierarchical key assignment scheme is a method to assign time-dependent encryption keys to a set of classes in a partially ordered hierarchy, in such a way that each class can compute the keys of all classes lower down in the hierarchy, according to temporal constraints.     

Zwitterionic‐Coated “Stealth” Nanoparticles for Biomedical Applications: Recent Advances in Countering Biomolecular Corona Formation and Uptake by the Mononuclear Phagocyte System

Nanoparticles represent highly promising platforms for the development of imaging and therapeutic agents, including those that can either be detected via more than one imaging technique (multi‐modal imaging agents) or used for both diagnosis and therapy (theranostics). A major obstacle to their medical application and translation to the clinic, however, is the fact that many accumulate in the liver and spleen as a result of opsonization and scavenging by the mononuclear phagocyte system. This focused review summarizes recent efforts to develop zwitterionic‐coatings to counter this issue and render nanoparticles more biocompatible. Such coatings have been found to greatly reduce the rate and/or extent of non‐specific adsorption of proteins and lipids to the nanoparticle surface, thereby inhibiting production of the “biomolecular corona” that is proposed to be a universal feature of nanoparticles within a biological environment. Additionally, in vivo studies have demonstrated that larger‐sized nanoparticles with a zwitterionic coating have extended circulatory lifetimes, while those with hydrodynamic diameters of ≤5 nm exhibit small‐molecule‐like pharmacokinetics, remaining sufficiently small to pass through the fenestrae and slit pores during glomerular filtration within the kidneys, and enabling efficient excretion via the urine. The larger particles represent ideal candidates for use as blood pool imaging agents, whilst the small ones provide a highly promising platform for the future development of theranostics with reduced side effect profiles and superior dose delivery and image contrast capabilities.     

Interactive faceted search and exploration of open social media data on a touchscreen mobile phone

A central challenge of semantic ambient media applications is designing smart user interfaces that are able to dynamically deal with an a-priori unknown number of data categories and data instances received live from different Linked Open Data sources while at the same time being intuitive and easy to use. In the mobile world, this challenge is even more difficult as the mobile devices have limited interaction possibilities and smaller display size. In this paper, we tackle this challenge and present the user-centered, iterative design of a mobile application for faceted search and exploration of a large, multi-dimensional data set of open social media on a touchscreen mobile phone. The application is called Mobile Facets and provides live retrieval and interactive search and exploration of resources like places, persons, organizations, and events originating from different, integrated social media sources like DBpedia, Eventful, Upcoming, Flickr, and GeoNames. In contrast to existing work, we do not know in advance the number and type of data categories and data instances that will be received as the data is queried live from the sources. While developing Mobile Facets, we have applied a participatory design with a small group of five users. For the final prototype we have conducted a task-based, formative evaluation with 12 additional subjects to investigate the applicability and usability of our Mobile Facets application.     

Photobleaching with phloxine B sensitizer to reduce food matrix interference for detection of Escherichia coli serotype O157:H7 in fresh spinach by flow cytometry

A flow cytometric method (RAPID-B™) with detection sensitivity of one viable cell of Escherichia coli serotype O157:H7 in fresh spinach (Spinacia oleracea) was developed and evaluated. The major impediment to achieving this performance was mistaking autofluorescing spinach particles for tagged target cells. Following a 5 h non-selective enrichment, artificially inoculated samples were photobleached, using phloxine B as a photosensitizer. Samples were centrifuged at high speed to concentrate target cells, then gradient centrifuged to separate them from matrix debris. In external laboratory experiments, RAPID-B and the reference method both correctly detected E. coli O157:H7 at inoculations of ca. 15 cells. In a follow-up study, after 4 cell inoculations of positives and 6 h enrichment, RAPID-B correctly identified 92% of 25 samples. The RAPID-B method limit of detection (LOD) was one cell in 25 g. It proved superior to the reference method (which incorporated real time-PCR, selective enrichment, and culture plating elements) in accuracy and speed.     

Consumer perception of boar meat as affected by labelling information,malodorous compounds and sensitivity to androstenone

This study aimed to assess the influence of two label conditions on the acceptance of boar meat. A central location test was conducted with 145 consumers each assessing 4 pieces of pork loin.     

Culture predicts Mexican Americans' college self-efficacy and college performance.

In hopes of promoting college success among Mexican Americans, researchers have identified factors related to their academic performance. A gap in the literature exists between the interactive role of acculturation, enculturation, and generation status in predicting college self-efficacy and college performance (grade-point average, or GPA). To fill this void, this study investigated the relation of demographic variables (e.g., age, gender, socioeconomic status) and cultural variables (e.g., acculturation, enculturation, generation status) on academic outcomes (e.g., college self-efficacy, college performance) among 408 Mexican-American college students. Results of a series of hierarchical regression analyses indicated socioeconomic status, generation status, enculturation, and acculturation had significant positive effects on college self-efficacy; socioeconomic status and the interaction of higher enculturation and first-generation status were positively and significantly related to GPA. Post-hoc analyses indicated college self-efficacy predicted college performance for students who were second generation and beyond. Implications for research and practice are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Sorption and thermal properties of strongly basic cross‐linked ionic polymer modified with Cr(III) compounds

AV‐17(Cr) material was prepared by modifying a commercial polymer AV‐17 (initially bearing R4N⁺ functional groups) with Cr(III) compounds was investigated. Comparative isotherms characterizing the and ion sorption from solution with pH values of 3 and 8, respectively, at 19°C and 60°C, were obtained using the raw AV‐17(Cl) and the modified AV‐17(Cr) material. The sorption process on AV‐17(Cr) takes place through the coordination of Cr(VI) ions with Cr(III) ions, while on AV‐17(Cl) it is due to an ion exchange mechanism. The sorption isotherms obtained in pH 8 solutions fit perfectly the Langmuir model. The thermodynamic functions ΔG, ΔH, and ΔS characteristic to the adsorption of ions from K₂CrO₄ solutions with pH = 8 were calculated. The active sites belonging to the AV‐17(Cr) material were identified as jarosite type compounds of Cr(III). SEM images show that the Cr(III) compounds are present in the form of ultrafine particles located on the surface and within the bulk phase of the polymer granules. Comparative thermal degradation process of both the AV‐17(Cr) and the AV‐17(Cl) material was conducted in air and in an inert atmosphere (He). The thermal degradation mechanism of sorbent AV‐17(Cr) and exchanger AV‐17(Cl) is proposed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41306.