MRI On the Fly: Accelerating MRI Imaging Using LDA Classification with LDB Feature Extraction

To improve MRI acquisition time, we explored the uses of linear discriminant analysis (LDA), and local discriminant bases (LDB) for the task of classifying MRI images using a minimal set of signal acquisitions. Our algorithm has both off-line and on-line components. The off-line component uses the k-basis algorithm to partition a set of training images (all from a particular region of a patient) into classes. For each class, we find a basis by applying the best basis algorithm on the images in that class. We keep these bases to be used by the on-line process. We then apply LDB to the training set with the class assignments, determining the best discriminant basis for the set. We rank the basis coordinates according to discriminating power, and retain the top M coordinates for the on-line algorithm. We keep the top M coordinates, which index the basis functions with the most discriminating capability, for on-line purposes. Finally, we train LDA on these transformed coordinates, producing a classifier for the images. With the off-line requirements complete, we can take advantage of the simplicity and speed of the on-line mechanism to acquire an image in a similar region of the patient. We need acquire only the M important coordinates of the image in the discriminant basis to create a ``scout image.\u27\u27 This image, which can be acquired quickly since M is much much smaller than the number of measurements needed to fill in the values of the 256 by 256 pixels, is then sent through the map furnished by LDA which in turn assigns a class to the image. Returning to the list of bases that we kept from the k-bases algorithm, we find the optimal basis for the particular class at hand. We then acquire the image using that optimal basis, omitting the coefficients with the least truncation error. The complete image can then be quickly reconstructed using the inverse wavelet packet transform. The power of our algorithm is that the on-line task is fast and simple, while the computational complexity lies mostly in the off-line task that needs to be done only once for images in a certain region. In addition, our algorithm only makes use of the flexibility of MRI hardware, so no modifications in hardware design are needed

The Construction of a Partially Regular Solution to the Landau-Lifshitz-Gilbert Equation in R2\mathbb{R}^2

We establish a framework to construct a global solution in the space of finite energy to a general form of the Landau-Lifshitz-Gilbert equation in $\mathbb{R}^2$. Our characterization yields a partially regular solution, smooth away from a 2-dimensional locally finite Hausdorff measure set. This construction relies on approximation by discretization, using the special geometry to express an equivalent system whose highest order terms are linear and the translation of the machinery of linear estimates on the fundamental solution from the continuous setting into the discrete setting. This method is quite general and accommodates more general geometries involving targets that are compact smooth hypersurfaces.Comment: 43 pages, 2 figure

Philosophy of Law in the Arctic

This is rather the first book with a title Philosophy of Law in the Arctic in the literature. This philosophy of law is a very wide and cross-disciplinary area of research: between law, philosophy, anthropology, history, cultural ecology or environmental studies. I have no doubts that we have done such kind of philosophy in the academia so far, not using this term, but keeping up with the concept, the idea. The book is a result of research conducted by many members of the Sub-group of Philosophy of Law in the Arctic (the University of the Arctic). This team seems a very interdisciplinary academic group. Our cooperation bears fruit. The aim of the book is to define and systematise Arctic legal philosophy problems. In this book, there are five thematic parts. Each part consists of two-five short articles (we can call them also chapters or papers). These are the sixteen short articles all together. Each article consists of between six and fourteen pages. So going further, what we see in the book then is, in fact, a set of both theoretical and practical papers. The topics of these papers (chapters) are different as the authors are different while representing a wide-ranging scope of academic disciplines or specialisations. Each paper is followed by a relevant bibliography, which might be helpful for other scholars interested in the field. The seventeen writers come from such countries as Finland (4), Norway (1), Canada (3), Poland (3), Japan (2), Austria (1), Ireland (1), and England (2). Some of them have Arctic indigenous roots (3). In the end of the book, there is a very original attachment - the map of Arctic Canada.https://digitalcommons.schulichlaw.dal.ca/faculty_books/1052/thumbnail.jp

The genomes of two key bumblebee species with primitive eusocial organization

Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

Bim Nuclear Translocation and Inactivation by Viral Interferon Regulatory Factor

Viral replication efficiency is in large part governed by the ability of viruses to counteract pro-apoptotic signals induced by infection of the host cell. Human herpesvirus 8 (HHV-8) uses several strategies to block the host's innate antiviral defenses via interference with interferon and apoptotic signaling. Contributors include the four viral interferon regulatory factors (vIRFs 1–4), which function in dominant negative fashion to block cellular IRF activities in addition to targeting IRF signaling-induced proteins such as p53 and inhibiting other inducers of apoptosis such as TGFβ receptor-activated Smad transcription factors. Here we identify direct targeting by vIRF-1 of BH3-only pro-apoptotic Bcl-2 family member Bim, a key negative regulator of HHV-8 replication, to effect its inactivation via nuclear translocation. vIRF-1-mediated relocalization of Bim was identified in transfected cells, by both immunofluorescence assay and western analysis of fractionated cell extracts. Also, co-localization of vIRF-1 and Bim was detected in nuclei of lytically infected endothelial cells. In vitro co-precipitation assays using purified vIRF-1 and Bim revealed direct interaction between the proteins, and Bim-binding residues of vIRF-1 were mapped by deletion and point mutagenesis. Generation and experimental utilization of Bim-refractory vIRF-1 variants revealed the importance of vIRF-1:Bim interaction, specifically, in pro-replication and anti-apoptotic activity of vIRF-1. Furthermore, blocking of the interaction with cell-permeable peptide corresponding to the Bim-binding region of vIRF-1 confirmed the relevance of vIRF-1:Bim association to vIRF-1 pro-replication activity. To our knowledge, this is the first report of an IRF protein that interacts with a Bcl-2 family member and of nuclear sequestration of Bim or any other member of the family as a means of inactivation. The data presented reveal a novel mechanism utilized by a virus to control replication-induced apoptosis and suggest that inhibitory targeting of vIRF-1:Bim interaction may provide an effective antiviral strategy

B2B Channel Partner Programs: Disentangling Indebtedness from Gratitude

Many suppliers invest heavily in channel partner programs that incentivize selling and learning. The authors conduct a multi-wave field study to investigate the roles of indebtedness and gratitude in transforming these investments into returns. The results show that indebtedness has negative effects on commitment to the supplier, as well as the reseller's sales effort. Gratitude however attenuates the effects of indebtedness on sales effort and commitment, and thus offers a buffer against indebtedness' negative effects. Indebtedness and gratitude thus play key roles in channel partner programs. In addition, the results highlight the importance of perceived motives as they differentially predict these two states. Benevolent motives are found to increase gratitude, though ulterior motives do not detract from it. Ulterior motives do however increase indebtedness. Finally, the results also reveal how entitlement negatively impacts channel partner programs: It decreases the positive effect of perceived program value on partner gratitude while increasing the effect of ulterior motives on indebtedness. This study thus assesses the simultaneous yet contrasting role of gratitude and indebtedness, as well as the complexity associated with realizing the full benefits of channel partner programs. The findings have implications for suppliers, marketers, and further research

Optical imaging and spectroscopy for the study of the human brain: status report.

This report is the second part of a comprehensive two-part series aimed at reviewing an extensive and diverse toolkit of novel methods to explore brain health and function. While the first report focused on neurophotonic tools mostly applicable to animal studies, here, we highlight optical spectroscopy and imaging methods relevant to noninvasive human brain studies. We outline current state-of-the-art technologies and software advances, explore the most recent impact of these technologies on neuroscience and clinical applications, identify the areas where innovation is needed, and provide an outlook for the future directions

A prospective, open-label, randomized trial of doxycycline versus azithromycin for the treatment of uncomplicated murine typhus

Murine typhus, or infection with Rickettsia typhi, is a global but neglected disease without randomized clinical trials to guide antibiotic therapy.; A prospective, open, randomized trial was conducted in nonpregnant, consenting inpatient adults with rapid diagnostic test evidence of uncomplicated murine typhus at 2 hospitals in Vientiane, Laos. Patients were randomized to 7 days (D7) or 3 days (D3) of oral doxycycline or 3 days of oral azithromycin (A3). Primary outcome measures were fever clearance time and frequencies of treatment failure and relapse.; Between 2004 and 2009, the study enrolled 216 patients (72 per arm); 158 (73.2%) had serology/polymerase chain reaction (PCR)-confirmed murine typhus, and 52 (24.1%) were R. typhi PCR positive. The risk of treatment failure was greater for regimen A3 (22.5%; 16 of 71 patients) than for D3 (4.2%; 3 of 71) or D7 (1.4%; 1 of 71) (P < .001). Among R. typhi PCR-positive patients, the area under the time-temperature curve and the fever clearance time were significantly higher for A3 than for D3 (1.8- and 1.9-fold higher, respectively; P = .005) and D7 (1.5- and 1.6-fold higher; P = .02). No patients returned with PCR-confirmed R. typhi relapse.; In Lao adults, azithromycin is inferior to doxycycline as oral therapy for uncomplicated murine typhus. For doxycycline, 3- and 7-day regimens have similar efficacy. Azithromycin use in murine typhus should be reconsidered. Investigation of genomic and phenotypic markers of R. typhi azithromycin resistance is needed.; ISRCTN47812566