Can a 3+2 Oscillation Model Explain the NuTeV Electroweak Results?

The weak mixing angle result from NuTeV falls three standard deviations above the value determined by global electroweak fits. It has been suggested that one possible explanation for this result could be the oscillation of electron neutrinos in the NuTeV beam to sterile neutrinos. This article examines several cases of masses and mixings for 3+2 neutrino oscillation models which fit the current oscillation data at 99% CL. We conclude that electron to sterile neutrino oscillations can account for only up to a third of a standard deviation between the NuTeV determination of the weak mixing angle and the standard model.Comment: 3 pages, 2 figures, submitted to Brief Report

Dealing with change in process choreographies: Design and implementation of propagation algorithms

Enabling process changes constitutes a major challenge for any process-aware information system. This not only holds for processes running within a single enterprise, but also for collaborative scenarios involving distributed and autonomous partners. In particular, if one partner adapts its private process, the change might affect the processes of the other partners as well. Accordingly, it might have to be propagated to concerned partners in a transitive way. A fundamental challenge in this context is to find ways of propagating the changes in a decentralized manner. Existing approaches are limited with respect to the change operations considered as well as their dependency on a particular process specification language. This paper presents a generic change propagation approach that is based on the Refined Process Structure Tree, i.e., the approach is independent of a specific process specification language. Further, it considers a comprehensive set of change patterns. For all these change patterns, it is shown that the provided change propagation algorithms preserve consistency and compatibility of the process choreography. Finally, a proof-of-concept prototype of a change propagation framework for process choreographies is presented. Overall, comprehensive change support in process choreographies will foster the implementation and operational support of agile collaborative process scenarios

Multiplex shRNA screening of germ cell development by in vivo transfection of mouse testis

Spermatozoa are one of the few mammalian cell types that cannot be fully derived in vitro, severely limiting the application of modern genomic techniques to study germ cell biology. The current gold standard approach of characterizing single-gene knockout mice is slow as generation of each mutant line can take 6–9 months. Here, we describe an in vivo approach to rapid functional screening of germline genes based on a new nonsurgical, nonviral in vivo transfection method to deliver nucleic acids into testicular germ cells. By coupling multiplex transfection of short hairpin RNA (shRNA) constructs with pooled amplicon sequencing as a readout, we were able to screen many genes for spermatogenesis function in a quick and inexpensive experiment. We transfected nine mouse testes with a pilot pool of RNA interference (RNAi) against well-characterized genes to show that this system is highly reproducible and accurate. With a false negative rate of 18% and a false positive rate of 12%, this method has similar performance as other RNAi screens in the well-described Drosophila model system. In a separate experiment, we screened 26 uncharacterized genes computationally predicted to be essential for spermatogenesis and found numerous candidates for follow-up studies. Finally, as a control experiment, we performed a long-term selection screen in neuronal N2a cells, sampling shRNA frequencies at five sequential time points. By characterizing the effect of both libraries on N2a cells, we show that our screening results from testis are tissue-specific. Our calculations indicate that the current implementation of this approach could be used to screen thousands of protein-coding genes simultaneously in a single mouse testis. The experimental protocols and analysis scripts provided will enable other groups to use this procedure to study diverse aspects of germ cell biology ranging from epigenetics to cell physiology. This approach also has great promise as an applied tool for validating diagnoses made from medical genome sequencing, or designing synthetic biological sequences that can act as potent and highly specific male contraceptives

Trinitrophenol Reactive T-Cell Hybridomas Recognize Antigens That Require Antigen Processing

Protein antigens must be taken up, processed, and displayed on the surface of antigen-presenting cells in association with major histocompatibility complex molecules before they can be recognized by T cells. Whether recognition of the haptens used to study allergic contact hypersensitivity in murine models similarly requires processing has not been determined. We analyzed whether presentation of trinitrophenol to trinitrophenol reactive T-cell hybridomas requires antigen processing by studying the effects of inhibitors of antigen processing and presentation on tile ability of a syngeneic B-cell tumor (A20) to present trinitrophenol to a series of interleukin-2 producing, trinitrophenol specific, major histocompatibility complex class II-restricted T-cell hybridomas.The ability of trinitrophenol modified A20 cells to stimulate the hybridomas was completely inhibited by rnonoclonal, anti-trinitrophenol, or anti-Ia antibodies and was significantly reduced by paraformaldehyde fixation immediately after trinitrophenol modification. Trinitrophenol-modified A20 cultured at 37°C for 2h prior to fixation was significantly more effective at stimulating the hybridomas than trinitrophenol-modified A20 to present trinitrophenol was inhibited by chloroquine. Paraformaldehyde fixation and chloroquine treatment had similar effects on the ability of trinitrophenol modified lymph node dendritic cells to stimulate the trinitrophenol specific hybridomas. Paraformaldehyde fixation and chloroquine treatment had similar effects on the ability of A20 cells to present ovalbumin to ovalbumin-specific hybridomas as they had on the ability of trinitrophenol modified A20 cells to present trinitrophenol to the trinitrophenol specific hybridomas. One of seven T-cell hybridomas responded to trinitrophenol modified ovalbumin but not other trinitrophenol modified proteins. These results suggest that, at least in part, T cells in the contact hypersensitivity response to trinitrophenol recognize antigens that require processing and that trinitrophenol modified proteins can be recognized

Recent updates on incubation of drug craving: a mini-review

Cue-induced drug craving progressively increases after prolonged withdrawal from drug self-administration in laboratory animals, a behavioral phenomenon termed 'incubation of drug craving.' Studies over the years have revealed several important neural mechanisms contributing to incubation of drug craving. In this mini-review, we first discuss three excellent Addiction Biology publications on incubation of drug craving in both human and laboratory animals. We then review several key publications from the past year on behavioral and mechanistic findings related to incubation of drug craving

Flavor Structure of the Nucleon Sea

The recent progress on our understanding of the flavor structure of unpolarized and polarized nucleon sea is reviewed. The large flavor asymmetry between the up and down sea quark distributions is now well established. This asymmetry strongly suggests the importance of the mesonic degrees of freedom in the description of the nucleon sea. The strong connection between the flavor structure and the spin structure of the nucleon sea is emphasized. Possible future measurements for testing various theoretical models are also discussed.Comment: 5pages, 4 figures, Invited talk presented at the QNP2002 conference, Julich, June 200

Law Libraries and Laboratories: The Legacies of Langdell and His Metaphor

Law Librarians and others have often referred to Harvard Law School Dean C.C. Langdell’s statements that the law library is the lawyer’s laboratory. Professor Danner examines the context of what Langdell through his other writings, the educational environment at Harvard in the late nineteenth century, and the changing perceptions of university libraries generally. He then considers how the “laboratory metaphor” has been applied by librarians and legal scholars during the twentieth century and into the twenty-first. The article closes with thoughts on Langdell’s legacy for law librarians and the usefulness of the laboratory metaphor

Hardness of porous nanocrystalline Co-Ni electrodeposits

The Hall-Petch relationship can fail when the grain size is below a critical value of tens of nanometres. This occurs particularly for coatings having porous surfaces. In this study, electrodeposited nanostructured Co-Ni coatings from four different nickel electroplating baths having grain sizes in the range of 11-23 nm have been investigated. The finest grain size, approximately 11 nm, was obtained from a coating developed from the nickel sulphate bath. The Co-Ni coatings have a mixed face centred cubic and hexagonal close-packed structures with varying surface morphologies and different porosities. A cluster-pore mixture model has been proposed by considering no contribution from pores to the hardness. As the porosity effect was taken into consideration, the calculated pore-free hardness is in agreement with the ordinary Hall-Petch relationship even when the grain size is reduced to 11 nm for the Co-Ni coatings with 77±2 at% cobalt. The present model was applied to other porous nanocrystalline coatings, and the Hall-Petch relationship was maintained. © 2013 The Korean Institute of Metals and Materials and Springer Science+Business Media Dordrecht. © KIM and Springer