Efficient computation of maximal orders in radical (including Kummer) extensions

We describe an algorithm, linear in the degree of the field, for computing a (pseudo) basis for P$P$-maximal orders of radical (which includes Kummer) extensions of global arithmetic fields. We construct our basis in such a way as to further improve maximal order computations in these radical extensions. Using this algorithm for the similar problem of computing maximal orders of class fields is discussed. We give examples of both function fields and number fields comparing the running time of our algorithm to that of the Round 2 or 4 and Fraatz (2005).     

MRT letter: Contrast-enhanced computed tomographic imaging of soft callus formation in fracture healing

Formation of a cartilaginous soft callus at the site of a bone fracture is a pivotal stage in the healing process. Noninvasive, or even nondestructive, imaging of soft callus formation can be an important tool in experimental and pre-clinical studies of fracture repair. However, the low X-ray attenuation of cartilage renders the soft callus nearly invisible in radiographs. This study utilized a recently developed, cationic, iodinated contrast agent in conjunction with micro-computed tomography to identify cartilage in fracture calluses in the femora of C57BL/6J and C3H/HeJ mice. Fracture calluses were scanned before and after incubation in the contrast agent. The set of pre-incubation images was registered against and then subtracted from the set of post-incubation images, resulting in a three-dimensional map of the locations of cartilage in the callus, as labeled by the contrast agent. This map was then compared to histology from a previous study. The results showed that the locations where the contrast agent collected in relatively high concentrations were similar to those of the cartilage. The contrast agent also identified a significant difference between the two strains of mice in the percentage of the callus occupied by cartilage, indicating that this method of contrast-enhanced computed tomography may be an effective technique for nondestructive, early evaluation of fracture healing.     

Extraction of Lanthanides(III) by a Mixture of a Malonamide and a Dialkyl Phosphoric Acid

Several hydrometallurgical processes studied in France for lanthanide/minor actinide separation use a combination of DMDOHEMA and HDEHP as extractants. Although these processes have proved to be reliable, the modeling of their extraction properties remains a difficult task due to a lack of knowledge about the behavior of the mixed DMDOHEMA-HDEHP organic phase. In the present work, it was found that the solvent extraction of Ln(III) ions by a mixture of these extractants exhibits a complex behavior involving a synergistic effect at either 1 M HNO₃ or high metal concentration, and an antagonistic effect on extraction of metal traces at higher pH (> 2). To understand these effects, Ln(III) complexes formed after extraction by DMDOHEMA and/or HDEHP were characterized by several spectroscopic techniques (FT-IR, UV-Vis, ESI-MS, TRLIFS). Results suggested formation of DMDOHEMA-HDEHP adducts and ternary mixed complexes involving both extractants and possibly a nitrate ion.     

Multi-scale 2D tracking of articulated objects using hierarchical spring systems

This paper presents a flexible framework to build a target-specific, part-based representation for arbitrary articulated or rigid objects. The aim is to successfully track the target object in 2D, through multiple scales and occlusions. This is realized by employing a hierarchical, iterative optimization process on the proposed representation of structure and appearance. Therefore, each rigid part of an object is described by a hierarchical spring system represented by an attributed graph pyramid. Hierarchical spring systems encode the spatial relationships of the features (attributes of the graph pyramid) describing the parts and enforce them by spring-like behavior during tracking. Articulation points connecting the parts of the object allow to transfer position information from reliable to ambiguous parts. Tracking is done in an iterative process by combining the hypotheses of simple trackers with the hypotheses extracted from the hierarchical spring systems.     

Reprint of: Multi-scale 2D tracking of articulated objects using hierarchical spring systems

This paper presents a flexible framework to build a target-specific, part-based representation for arbitrary articulated or rigid objects. The aim is to successfully track the target object in 2D, through multiple scales and occlusions. This is realized by employing a hierarchical, iterative optimization process on the proposed representation of structure and appearance. Therefore, each rigid part of an object is described by a hierarchical spring system represented by an attributed graph pyramid. Hierarchical spring systems encode the spatial relationships of the features (attributes of the graph pyramid) describing the parts and enforce them by spring-like behavior during tracking. Articulation points connecting the parts of the object allow to transfer position information from reliable to ambiguous parts. Tracking is done in an iterative process by combining the hypotheses of simple trackers with the hypotheses extracted from the hierarchical spring systems.     

Lovers' box: Designing for reflection within romantic relationships

We present the Lovers' box, a digital artefact designed to engage romantic couples in reflections on their relationship. By adopting perspectives from social psychology and interaction design, the work examines the role of reflection through the use of a non-traditional digital artefact that acts as a site for enduring attachments of personal emotional significance. To this end, we respond to previous research work on reflection through design, in the development of four Lovers' boxes whose purposes and meanings are completed through reflections both by romantic couples and their integration in everyday lives. A field study was conducted involving five couples in new relationships who were asked to exchange video messages (co-created with a digital media artist) using the Lovers' box over a period of five weeks. Our findings demonstrated: (1) that the creation, exchange and display of messages embedded in the digital artefact served as both mirrors and sources for reflection concerning couples' relationships; (2) the rich manner in which the Lovers' box became meaningful to participants, as they perceived it as keepsake or digital storybook of their meaningful experiences, experienced it as an enjoyable shared hobby with their partner and saw it as providing them a snapshot into the beloved person's mind and thoughts; and (3) how the potential for new castings of digital artefacts might support our personal and emotional lives.     

Updating the attitudes toward computer usage scale using American undergraduate students

The Attitudes Toward Computer Usage Scale (ATCUS) was first developed in 1986 by [Popovich, P. M., Hyde, K. R., Zakrajsek, T., & Blumer, C. (1987). The development of the attitudes toward computer usage scale. Educational and Psychological Measurement, 47, 261–269.] using American undergraduates and has since been with a variety of populations over the past 20 years. However, many changes in the technological landscape have occurred since its development, thus creating a need for an updated scale. During the course of a three-part study, the ATCUS v. 2.0 was developed with psychometric properties similar to that of the original ATCUS. The addition of more up-to-date items to serves to enhance the usefulness and practicality of this instrument. The ATCUS v. 2.0 was found to have both high internal consistency, alpha = .83 and test–retest reliability, r = .93.     

Large-scale antibody profiling of human blood sera: The future of molecular diagnosis

Despite the progress in cancer diagnosis the timely detection of many cancer types is still a grand challenge. For various human cancer types including lung cancer, prostate cancer, and breast cancer, several groups recently demonstrated that autoantibody profiling might be a promising approach towards earlier and more accurate cancer diagnosis. In this paper, we confirm the ability of autoantibody profiling as a diagnostic test by providing evidence that not only cancer sera can be distinguished well from normal controls, but also from sera of patients with noncancerous diseases. Altogether, we screened blood sera of 191 cancer patients, 60 physiologically unaffected controls, and 177 sera of patients with noncancerous diseases for more than 1800 immunogenic clones. The measured autoantibody fingerprints were evaluated using a novel image analysis pipeline. For 13 antigens, statistically significant (p<0.05) and at least two-fold elevated immuno-reactivity in cancer sera compared to normal sera could be observed. Nine of these antigens also showed increased reactivity compared to sera of patients with other diseases, including the tumor marker vimentin. Supervised discrimination between cancer and normal sera by using linear Support Vector Machines was possible with an accuracy of 94.04%, a specificity of 83.38%, and a sensitivity of 97.44%. Here, our so-called MIMM (minimally invasive multiple marker) approach showed no significant difference in the classification accuracy between low and higher tumor grades. The classification in healthy and diseased sera showed an even higher accuracy of 96.12% while the discrimination in cancer sera and diseased controls revealed an accuracy of 69.58%. These results demonstrate that autoantibody profiling offers the possibility of cancer screening for a variety of different cancer types as well as inflammatory diseases at an early disease stage.      

Comparing attitudes towards computer usage by undergraduates from 1986 to 2005

The importance and use of computers has increased dramatically over the last two decades. The Attitudes Towards Computer Usage Scale (ATCUS) was developed in 1986 [Popovich, P. M., Hyde, K. R., Zakrajsek, T., & Blumer, C. (1987). The development of the attitudes toward computer usage scale. Educational and Psychological Measurement, 47, 261–269.] and used in a variety of settings over the years. In order to examine how computer attitudes have changed from 1986 to 2005, the ATCUS was given to 254 male and female current undergraduate students. When comparing the 1986 with 2005 results, the amount of time spent using a computer was still positively related to computer attitudes; however, the number of college computer courses was not. There is no longer a significant relationship among any of the factors with college computer courses. Males and females no longer significantly differ in their attitudes toward computers, number of college computer courses, amount of time spent using computers, or degree of self-reported computer anxiety. Implications are discussed.     

Infrared conductivity in the normal state of cuprate thin films

This paper summarizes the main features of the infrared conductivity spectra in the 500–7000 cm^–1 range derived from room-temperature reflectivity measurements performed on a variety of thin films (YBa₂Cu₃O₇, BiSrCaCuO). The conductivity of these samples decreases with frequency as a power law with an exponent 0.7, and the scattering rate increases linearly with frequency. A detailed comparison with the conductivity for the marginal Fermi liquid (Abrahams, Littlewood, and Varma) and for the Luttinger liquid (Anderson) is performed. In the former case, the effect of temperature appears crucial even in this energy range (T) and allows one to achieve satisfactory fits. In the latter case, both the conductivity and the scattering rate may be accounted for by a single parameter.