417 research outputs found
Microscopic description of Gamow-Teller transitions in middle pf--shell nuclei by a realistic shell model calculation
GT transitions in nuclei are studied in terms of a large-scale
realistic shell-model calculation, by using Towner's microscopic parameters.
values to low-lying final states are reproduced with a reasonable
accuracy. Several gross properties with respect to the GT transitions are
investigated with this set of the wavefunctions and the operator. While the
calculated total GT strengths show no apparent disagreement with the
measured ones, the calculated total GT strengths are somewhat larger than
those obtained from charge-exchange experiments. Concerning the Ikeda sum-rule,
the proportionality of to persists to an excellent
approximation, with a quenching factor of 0.68. For the relative GT
strengths among possible isospin components, the lowest isospin component
gathers greater fraction than expected by the squared CG coefficients of the
isospin coupling. It turns out that these relative strengths are insensitive to
the size of model space. Systematics of the summed values are
discussed for each isospin component.Comment: IOP-LaTeX 23 pages, to appear in J. Phys. G., 5 Postscript figures
available upon reques
Origin and evolution of eukaryotic transcription factors
Transcription factors (TFs) have a central role in genome regulation directing gene transcription through binding specific DNA sequences. Eukaryotic genomes encode a large diversity of TF classes, each defined by unique DNA-interaction domains. Recent advances in genome sequencing and phylogenetic placement of diverse eukaryotic and archaeal species are re-defining the evolutionary history of eukaryotic TFs. The emerging view from a comparative genomics perspective is that the Last Eukaryotic Common Ancestor (LECA) had an extensive repertoire of TFs, most of which represent eukaryotic evolutionary novelties. This burst of TF innovation coincides with the emergence of genomic nuclear segregation and complex chromatin organization
Low-Spin Spectroscopy of 50Mn
The data on low spin states in the odd-odd nucleus 50Mn investigated with the
50Cr(p,ngamma)50Mn fusion evaporation reaction at the FN-TANDEM accelerator in
Cologne are reported. Shell model and collective rotational model
interpretations of the data are given.Comment: 7 pages, 2 figures, to be published in the proceedings of the
"Bologna 2000 - Structure of the Nucleus at the Dawn of the Century"
Conference, (Bologna, Italy, May 29 - June 3, 2000
Evolution and Classification of Myosins, a Paneukaryotic Whole-Genome Approach
notes: PubMed ID: 24443438© The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.Myosins are key components of the eukaryotic cytoskeleton, providing motility for a broad diversity of cargoes. Therefore, understanding the origin and evolutionary history of myosin classes is crucial to address the evolution of eukaryote cell biology. Here, we revise the classification of myosins using an updated taxon sampling that includes newly or recently sequenced genomes and transcriptomes from key taxa. We performed a survey of eukaryotic genomes and phylogenetic analyses of the myosin gene family, reconstructing the myosin toolkit at different key nodes in the eukaryotic tree of life. We also identified the phylogenetic distribution of myosin diversity in terms of number of genes, associated protein domains and number of classes in each taxa. Our analyses show that new classes (i.e., paralogs) and domain architectures were continuously generated throughout eukaryote evolution, with a significant expansion of myosin abundance and domain architectural diversity at the stem of Holozoa, predating the origin of animal multicellularity. Indeed, single-celled holozoans have the most complex myosin complement among eukaryotes, with paralogs of most myosins previously considered animal specific. We recover a dynamic evolutionary history, with several lineage-specific expansions (e.g., the myosin III-like gene family diversification in choanoflagellates), convergence in protein domain architectures (e.g., fungal and animal chitin synthase myosins), and important secondary losses. Overall, our evolutionary scheme demonstrates that the ancestral eukaryote likely had a complex myosin repertoire that included six genes with different protein domain architectures. Finally, we provide an integrative and robust classification, useful for future genomic and functional studies on this crucial eukaryotic gene family.LeverhulmeBBSRCERCMINECONERCGordon and Betty Moore Foundatio
The structure of the sd shell nuclei : (IV). 20Ne, 21Ne, 22Ne, 22Na and 24Mg
The shell model with the phenomenological effective interaction is applied to study level structures of 20Ne, 21Ne, 22Ne, 22Na and 24Mg. The full basis in the sd shell is taken in 20Ne to diagonalize the energy matrices. This example confirms that SU3 symmetry and the super-multiplet provide a very good way of truncation. This truncation is used to calculate level schemes of many nuclei beyond 20Ne. Even though deviations of the effective interaction from the pure Q-Q interaction and the spin-orbit interaction break the SU3 symmetry and the super-multiplet, the main components of calculated wave functions in low-lying energies can be very well labelled by these two symmetries. Generally, good agreement with observations is found. Particularly, the lowest rotational bands are nicely explained. Exceptions are the level structure of 22Na and in 19O and 21Ne, which are too low in the calculation, and the K = 2 bands in 22Ne and 24Mg, which are again too low in the calculation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32858/1/0000235.pd
ELVIS: Entertainment-led video summaries
© ACM, 2010. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in ACM Transactions on Multimedia Computing, Communications, and Applications, 6(3): Article no. 17 (2010) http://doi.acm.org/10.1145/1823746.1823751Video summaries present the user with a condensed and succinct representation of the content of a video stream. Usually this is achieved by attaching degrees of importance to low-level image, audio and text features. However, video content elicits strong and measurable physiological responses in the user, which are potentially rich indicators of what video content is memorable to or emotionally engaging for an individual user. This article proposes a technique that exploits such physiological responses to a given video stream by a given user to produce Entertainment-Led VIdeo Summaries (ELVIS). ELVIS is made up of five analysis phases which correspond to the analyses of five physiological response measures: electro-dermal response (EDR), heart rate (HR), blood volume pulse (BVP), respiration rate (RR), and respiration amplitude (RA). Through these analyses, the temporal locations of the most entertaining video subsegments, as they occur within the video stream as a whole, are automatically identified. The effectiveness of the ELVIS technique is verified through a statistical analysis of data collected during a set of user trials. Our results show that ELVIS is more consistent than RANDOM, EDR, HR, BVP, RR and RA selections in identifying the most entertaining video subsegments for content in the comedy, horror/comedy, and horror genres. Subjective user reports also reveal that ELVIS video summaries are comparatively easy to understand, enjoyable, and informative
Salient Regions for Query by Image Content
Much previous work on image retrieval has used global features such as colour and texture to describe the content of the image. However, these global features are insufficient to accurately describe the image content when different parts of the image have different characteristics. This paper discusses how this problem can be circumvented by using salient interest points and compares and contrasts an extension to previous work in which the concept of scale is incorporated into the selection of salient regions to select the areas of the image that are most interesting and generate local descriptors to describe the image characteristics in that region. The paper describes and contrasts two such salient region descriptors and compares them through their repeatability rate under a range of common image transforms. Finally, the paper goes on to investigate the performance of one of the salient region detectors in an image retrieval situation
Recent Development of Electrospinning for Drug Delivery
Several promising techniques have been developed to overcome the poor solubility and/or membrane permeability properties of new drug candidates, including different fiber formation methods. Electrospinning is one of the most commonly used spinning techniques for fiber formation, induced by the high voltage applied to the drug-loaded solution. With modifying the characteristics of the solution and the spinning parameters, the functionality-related properties of the formulated fibers can be finely tuned. The fiber properties (i.e., high specific surface area, porosity, and the possibility of controlling the crystallineâamorphous phase transitions of the loaded drugs) enable the improved rate and extent of solubility, causing a rapid onset of absorption. However, the enhanced molecular mobility of the amorphous drugs embedded into the fibers is also responsible for their physicalâchemical instability. This Special Issue will address new developments in the area of electrospun nanofibers for drug delivery and wound healing applications, covering recent advantages and future directions in electrospun fiber formulations and scalability. Moreover, it serves to highlight and capture the contemporary progress in electrospinning techniques, with particular attention to the industrial feasibility of developing pharmaceutical dosage forms. All aspects of small molecule or biologics-loaded fibrous dosage forms, focusing on the processability, structures and functions, and stability issues, are included
What does touch tell us about emotions in touchscreen-based gameplay?
This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 ACM. It is posted here by permission of ACM for your personal use. Not for redistribution.Nowadays, more and more people play games on touch-screen mobile phones. This phenomenon raises a very interesting question: does touch behaviour reflect the playerâs emotional state? If possible, this would not only be a valuable evaluation indicator for game designers, but also for real-time personalization of the game experience. Psychology studies on acted touch behaviour show the existence of discriminative affective profiles. In this paper, finger-stroke features during gameplay on an iPod were extracted and their discriminative power analysed. Based on touch-behaviour, machine learning algorithms were used to build systems for automatically discriminating between four emotional states (Excited, Relaxed, Frustrated, Bored), two levels of arousal and two levels of valence. The results were very interesting reaching between 69% and 77% of correct discrimination between the four emotional states. Higher results (~89%) were obtained for discriminating between two levels of arousal and two levels of valence
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