Investigating Primary Source Literacy

Primary source research requires students to acquire specialized research skills. This paper presents results from a user study testing the effectiveness of a Web guide designed to convey the concepts behind “primary source literacy”. The study also evaluated students’ strengths and weaknesses when conducting primary source research

Residual Symmetries Applied to Neutrino Oscillations at NOν\nuA and T2K

The results previously obtained from the model-independent application of a generalized hidden horizontal $\mathbb{Z}_2$ symmetry to the neutrino mass matrix are updated using the latest global fits for the neutrino oscillation parameters. The resulting prediction for the Dirac $CP$ phase $\delta_D$ is in agreement with recent results from T2K. The distribution for the Jarlskog invariant $J_\nu$ has become sharper and appears to be approaching a particular region. The approximate effects of matter on long baseline neutrino experiments are explored, and it is shown how the weak interactions between the neutrinos and the particles that make up the Earth can help to determine the mass hierarchy. A similar strategy is employed to show how NO$\nu$A and T2K could determine the octant of $\theta_a (\equiv \theta_{23})$. Finally, the exact effects of matter are obtained numerically in order to make comparisons with the form of the approximate solutions. From this analysis there emerges some interesting features of the effective mass eigenvalues.Comment: 9 pages, 1 table, 17 figure

Systematic review and meta-analysis of the sero-epidemiological association between Epstein-Barr virus and rheumatoid arthritis

Acknowledgements The authors would like to thank Cynthia Fraser for helping run the literature search, Dr Neil Basu for providing advice on search terms for rheumatoid arthritis and to Xueli Jia, Katie Bannister and Kubra Boza for their help with foreign language papers. The authors would also like to thank the University of Aberdeen librarians at the Foresterhill medical library for their help in locating articles used for this systematic review and meta-analysis.Peer reviewedPublisher PD

The Host Galaxy of GRB980703 at Radio Wavelengths - a Nuclear Starburst in a ULIRG

We present radio observations of GRB980703 at 1.43, 4.86, and 8.46 GHz for the period of 350 to 1000 days after the burst. These radio data clearly indicate that there is a persistent source at the position of GRB980703 with a flux density of approximately 70 $\mu$Jy at 1.43 GHz, and a spectral index, $\beta\approx 0.32$, where $F_\nu\propto \nu^{-\beta}$. We show that emission from the afterglow of GRB980703 is expected to be one to two orders of magnitude fainter, and therefore cannot account for these observations. We interpret this persistent emission as coming from the host galaxy --- the first example of a gamma-ray burst (GRB) host detection at radio wavelengths. We show that emission from an AGN is unlikely, and find that it can be explained as a result of a star-formation rate (SFR) of massive stars (M>5M$_\odot$) of 90 M$_\odot$/yr, which gives a total SFR of $\approx 500$ M$_\odot$/yr. Using the correlation between the radio and far-IR (FIR) luminosities of star-forming galaxies, we find that the host of GRB980703 is at the faint end of the class of Ultra Luminous Infrared Galaxies (ULIRGs), with L_{FIR}\sim few\times 10^{12} L$_\odot$. From the radio measurements of the offset between the burst and the host, and the size of the host, we conclude that GRB980703 occurred near the center of the galaxy in a region of maximum star formation. A comparison of the properties of this galaxy with radio and optical surveys at a similar redshift ($z\approx 1$) reveals that the host of GRB980703 is an average star-forming galaxy. This result has significant implications for the potential use of a GRB-selected galaxy sample for the study of galaxies and the IGM at high redshifts.Comment: Submitted to Ap

Internet and Social Media Access Among Youth Experiencing Homelessness: Mixed-Methods Study.

BACKGROUND: Youth experiencing homelessness are at a risk for a variety of adverse outcomes. Given the widespread use of the internet and social media, these new technologies may be used to address their needs and for outreach purposes. However, little is known about how this group uses these resources. OBJECTIVE: This study investigated how homeless adolescents use these technologies for general and health-related purposes, whether the scope of their use changes with housing status, and their interest in a website dedicated to youth experiencing homelessness. METHODS: A convenience sample of youth aged 18 to 21 years was recruited from a youth-specific homeless shelter. All participants completed a 47-item survey, with 10 individuals completing a semistructured interview. Descriptive statistics, exact testing, logistic regression, and generalized estimating equation modeling was performed for quantitative data analysis. Interviews were transcribed verbatim, and NVivo 10 (QSR International) was employed to facilitate double coding and thematic analysis. RESULTS: A total of 87 participants completed the survey with a mean age of 19.4 (SD 1.1) years. While experiencing homelessness, 56% (49/87) accessed the internet at least once a day, with 86% (75/87) accessing once a week. Access to a smartphone was associated with a 3.03 greater odds of accessing the internet and was the most frequently used device (66% of participants, 57/87). While experiencing homelessness, subjects reported a 68% decreased odds in internet access frequency (odds ratio [OR] 0.32, P\u3c.001), 75% decreased odds in spending greater amounts of time on the internet (OR 0.25, P\u3c.001), and an 87% decreased odds of social media use (OR 0.13, P=.01). Ten participants completed the semistructured interview. Several themes were identified, including (1) changes in internet behaviors while experiencing homelessness, (2) health status as a major concern and reason for Internet use, and (3) interest in a website dedicated to youth experiencing homelessness. While experiencing homelessness, participants indicated their behaviors were more goal-oriented and less focused on leisure or entertainment activities. CONCLUSIONS: While homeless youth experience changes in the frequency, amount of time, and specific uses of the internet and social media, study participants were able to access the internet regularly. The internet was used to search health-related topics. Given the importance of smartphones in accessing the internet, mobile-optimized websites may be an effective method for reaching this group

Some Combinatorial Properties of Hook Lengths, Contents, and Parts of Partitions

This paper proves a generalization of a conjecture of Guoniu Han, inspired originally by an identity of Nekrasov and Okounkov. The main result states that certain sums over partitions p of n, involving symmetric functions of the squares of the hook lengths of p, are polynomial functions of n. A similar result is obtained for symmetric functions of the contents and shifted parts of n.Comment: 20 pages. Correction of some inaccuracies, and a new Theorem 4.

Gamma-ray bursts and X-ray melting of material as a potential source of chondrules and planets

The intense radiation from a gamma-ray burst (GRB) is shown to be capable of melting stony material at distances up to 300 light years which subsequently cool to form chondrules. These conditions were created in the laboratory for the first time when millimeter sized pellets were placed in a vacuum chamber in the white synchrotron beam at the European Synchrotron Radiation Facility (ESRF). The pellets were rapidly heated in the X-ray and gamma-ray furnace to above 1400 C melted and cooled. This process heats from the inside unlike normal furnaces. The melted spherical samples were examined with a range of techniques and found to have microstructural properties similar to the chondrules that come from meteorites. This experiment demonstrates that GRBs can melt precursor material to form chondrules that may subsequently influence the formation of planets. This work extends the field of laboratory astrophysics to include high power synchrotron sources.Comment: 8 pages, 10 figures. Proceedings of the 5th INTEGRAL Workshop, Munich 16-20 February 2004. High resolution figures available at http://bermuda.ucd.ie/%7Esmcbreen/papers/duggan_01.pd

The pre-WDVV ring of physics and its topology

We show how a simplicial complex arising from the WDVV (Witten-Dijkgraaf-Verlinde-Verlinde) equations of string theory is the Whitehouse complex. Using discrete Morse theory, we give an elementary proof that the Whitehouse complex $\Delta_n$ is homotopy equivalent to a wedge of $(n-2)!$ spheres of dimension $n-4$. We also verify the Cohen-Macaulay property. Additionally, recurrences are given for the face enumeration of the complex and the Hilbert series of the associated pre-WDVV ring.Comment: 13 pages, 4 figures, 2 table