The cosmological information of shear peaks: beyond the abundance

We study the cosmological information of weak lensing (WL) peaks, focusing on two other statistics besides their abundance: the stacked tangential-shear profiles and the peak-peak correlation function. We use a large ensemble of simulated WL maps with survey specifications relevant to future missions like Euclid and LSST, to explore the three peak probes. We find that the correlation function of peaks with high signal-to-noise (S/N) measured from fields of size 144 sq. deg. has a maximum of ~0.3 at an angular scale ~10 arcmin. For peaks with smaller S/N, the amplitude of the correlation function decreases, and its maximum occurs on smaller angular scales. We compare the peak observables measured with and without shape noise and find that for S/N~3 only ~5% of the peaks are due to large-scale structures, the rest being generated by shape noise. The covariance matrix of the probes is examined: the correlation function is only weakly covariant on scales < 30 arcmin, and slightly more on larger scales; the shear profiles are very correlated for theta > 2 arcmin, with a correlation coefficient as high as 0.7. Using the Fisher-matrix formalism, we compute the cosmological constraints for {Om_m, sig_8, w, n_s} considering each probe separately, as well as in combination. We find that the correlation function of peaks and shear profiles yield marginalized errors which are larger by a factor of 2-4 for {Om_m, sig_8} than the errors yielded by the peak abundance alone, while the errors for {w, n_s} are similar. By combining the three probes, the marginalized constraints are tightened by a factor of ~2 compared to the peak abundance alone, the least contributor to the error reduction being the correlation function. This work therefore recommends that future WL surveys use shear peaks beyond their abundance in order to constrain the cosmological model.Comment: 15 pages, 10 figures, submitted to MNRA

Nurses Alumni Association Bulletin, Fall 1999

1999-2000 Meeting Dates Calendar 2000 Annual Luncheon-Meeting Notice Fall Social Officers and Committee Chairs Bulletin Publication Committee The President\u27s Message Treasurer\u27s Report News About Our Graduates History of The Nurses Relief Fund Nurses Wear White Memories of My Nurse Training Days Scholarship Funds At Work Second Janet C. Hindson Award Rib Ticklers Happy Birthday Fiftieth Anniversary Resume Alumni Association Meetings Alumni Office News Committee Reports Bulletin Nominating Relief Fund Scholarship Social Development Luncheon Photos In Memoriam, Names of Deceased Graduates Class News Janet C. Hindson Memorial Award (How to Submit Names) Scholarship Fund Application Certification Reimbursement Application Relief Fund Application Pins, Transcripts, Class Address List, Change of Address Forms Campus Ma

Nurses Alumni Association Bulletin, Fall 1998

1998-1999 Meeting Date Calendar 1999 Annual Luncheon & Meeting Notice Fall Social Officers and Committee Chairs Bulletin Publication Committee The President\u27s Message Treasurer\u27s Report News About Our Graduates Highlight Of 1998 Operation Smile Scholarship Funds At Work Romania Trip Double Honors Doris Bowman Memorial Service For Janet Hindson A time for everything On the Lighter Side Twenty Ways to Kill an Organization Happy Birthday Fiftieth Anniversary Resume Alumni Association Meetings Alumni Office News Committee Reports Bulletin By-Laws Relief Fund Social Scholarship Development Nominating Luncheon Photos In Memoriam, Names of Deceased Graduates Class News Certification Reimbursement Application Relief Fund Application Scholarship Fund Application (new) Pins, Transcripts, Class Address List, Change of Address Forms Campus Ma

Perceptions of Quality in Journalism and Communications Education: A Delphi Study

This article provides information on a study on the perceptions of quality in journalism and communications education. In many academic disciplines, including communications, accreditation has been the ruling paradigm of quality assurance for many years. Accreditation standards often have been used to measure many characteristics of institutions, but such standards may not be capable of identifying and measuring the true quality of institutional excellence. The study gathered information from a selected group of participants about those characteristics students, faculty and practitioners consider to be necessary components of high quality programs. The study also examined whether the accreditation standards used for journalism and communications programs reflect the characteristics the constituent groups perceive as representing quality. The study, which was conducted in 1994, used the Delphi research methodology. The Delphi method is characterized by anonymous responses from a panel of experts, multiple interactions, and convergence of responses. Participants for this study included individuals who were affiliated with journalism and communications programs accredited by the Accrediting Council for Education in Journalism and Mass Communications (ACEJMC), and media practitioners who were members of professional organizations that had an association with the ACEJMC

Young people: a phenomenographic investigation into the ways they experience information

This study investigates the ways young people experience information. Having an understanding of what information means to young people is important for educators and library and information science (LIS) professionals if they are to develop information literacy skills in young people. To date the literature has revealed that scant attention has been paid to this area. This research study addresses a gap in the knowledge. The study used a phenomenographic research approach to elicit and describe the qualitatively different ways in which young people experienced information. A purposeful sample of forty one young people aged eleven to eighteen years participated in the study. The data, which were gathered through drawings and semi structured interviews, were subjected to a rigorous process of phenomenographic analysis. The outcome of phenomenographic analysis is an outcome space consisting of a finite set of categories of description which, with their relationships, explain the different ways people experience phenomena in the world. In this study six ways of experiencing information were identified: knowledge of sources of information; receiving information; process of finding information; store of unprocessed information; processing information; and use of information. The findings highlighted the fact that young people thought about information to a degree that has not always been acknowledged. In addition the findings challenged a number of commonly held assumptions, which have in the past invited criticism, for instance young people’s attitude to ‘cutting and pasting’ information and their poor evaluation of academic information. The findings also revealed a previously unrecognised type of information behaviour described in sub-category A of Category Two, ‘receiving information knowingly’. As a result of this research a more comprehensive picture of the way young people experience information to that currently available has been revealed, however the research also revealed the incompleteness of this picture and suggests the need for further research

Consultation with children and young people with experience of domestic abuse on Scottish Government National Domestic Abuse Delivery Group draft proposals : main report

Findings and Conclusions: Major Themes • There was support in principle from young people for all of the proposals • Young people gave careful consideration to the proposals and to how they might operate in practice; they expressed some caution about supporting them unreservedly until it was demonstrated they would work in practice • In relation to all of the proposals young people had concerns about confidentiality and privacy, about to the ability to control the flow of personal information, and there were concerns about trust • Participants expressed the importance of the proposals contributing to young people being and feeling safe

Towards optimal estimation of the galaxy power spectrum

The galaxy power spectrum encodes a wealth of information about cosmology and the matter fluctuations. Its unbiased and optimal estimation is therefore of great importance. In this paper, we generalize the framework of Feldman et al. (1994) to take into account the fact that galaxies are not simply a Poisson sampling of the underlying dark matter distribution. Besides finite survey-volume effects and flux limits, our optimal estimation scheme incorporates several of the key tenets of galaxy formation: galaxies form and reside exclusively in dark matter haloes; a given dark matter halo may host several galaxies of various luminosities; galaxies inherit part of their large-scale bias from their host halo. Under these broad assumptions, we prove that the optimal weights do not explicitly depend on galaxy luminosity, other than through defining the maximum survey volume and effective galaxy density at a given position. Instead, they depend on the bias associated with the host halo; the first and second factorial moments of the halo occupation distribution; a selection function, which gives the fraction of galaxies that can be observed in a halo of mass M at position {r} in the survey; and an effective number density of galaxies. If one wishes to reconstruct the matter power spectrum, then, provided the model is correct, this scheme provides the only unbiased estimator. The practical challenges with implementing this approach are also discussed

Measuring primordial non-Gaussianity through weak lensing peak counts

We explore the possibility of detecting primordial non-Gaussianity of the local type using weak lensing peak counts. We measure the peak abundance in sets of simulated weak lensing maps corresponding to three models f_NL={0, +100, -100}. Using survey specifications similar to those of Euclid and without assuming any knowledge of the lens and source redshifts, we find the peak functions of the non-Gaussian models with f_NL=+-100 to differ by up to 15% from the Gaussian peak function at the high-mass end. For the assumed survey parameters, the probability of fitting an f_NL=0 peak function to the f_NL=+-100 peak functions is less than 0.1%. Assuming the other cosmological parameters known, f_NL can be measured with an error \Delta f_NL ~ 13. It is therefore possible that future weak lensing surveys like Euclid and LSST may detect primordial non-Gaussianity from the abundance of peak counts, and provide complementary information to that obtained from the cosmic microwave background.Comment: 4 pages, 1 figur