The Binomial Transform of P-Recursive Sequences And the Dilogarithm Function

Using a generalized binomial transform and a novel binomial coefficient identity, we will show that the set of p-recursive sequences is closed under the binomial transform. Using these results, we will derive a new series representation for the dilogarithm function that converges on its domain of analyticity. Finally, we will show that this series representation results in a scheme for numerical evaluation of the dilogarithm function that is accurate, efficient, and stable

Laparoscopic hysterectomy with or without pelvic lymphadenectomy or sampling in a high-risk series of patients with endometrial cancer

BACKGROUND: The purpose of the study was to determine the outcome of all patients with endometrial adenocarcinoma cancer treated by laparoscopic hysterectomy at our institution, many of whom were high-risk for surgery. METHODS: Data was collected by a retrospective search of the case notes and Electronic Patient Records of the thirty eight patients who underwent laparoscopic hysterectomy for endometrial cancer at our institutions. RESULTS: The median body mass index was 30 (range 19–67). Comorbidities were present in 76% (29 patients); 40% (15 patients) had a single comorbid condition, whilst 18% (7 patients) had two, and a further 18% (7 patients) had more than two. Lymphadenectomy was performed in 45% (17 patients), and lymph node sampling in 21% (8 patients). Median operating time was 210 minutes (range 70–360 minutes). Median estimated blood loss was 200 ml (range 50–1000 ml). There were no intraoperative complications. Post-operative complications were seen in 21% (2 major, 6 minor). Blood transfusion was required in 5% (2 patients). The median stay was 4 post-operative nights (range 1–25 nights). In those patients undergoing lymphadenectomy, the mean number of nodes taken was fifteen (range 8–26 nodes). The pathological staging was FIGO stage I 76% (29 patients), stage II 8% (3 patients), stage III 16% (6 patients). The pathological grade was G1 31% (16 patients), G2 45% (17 patients), G3 24% (8 patients). CONCLUSION: Laparoscopic hysterectomy can be safely carried out in patients at high risk for surgery, with no compromise in terms of outcomes, whilst providing all the benefits inherent in minimal access surgery

ZEN2: A narrow J-band search for z~9 Lya emitting galaxies directed towards three lensing clusters

We present the results of a continuing survey to detect Lya emitting galaxies at redshifts z~9: the ZEN ("z equals nine'') survey. We have obtained deep VLT/ISAAC observations in the narrow J-band filter NB119 directed towards three massive lensing clusters: Abell clusters 1689, 1835, and 114. The foreground clusters provide a magnified view of the distant universe and permit a sensitive test for the presence of very high-redshift galaxies. We search for z~9 Lya emitting galaxies displaying a significant narrow-band excess relative to accompanying J-band observations that remain undetected in HST/ACS optical images of each field. No sources consistent with this criterion are detected above the unlensed 90% point-source flux limit of the narrow-band image, F_NB=3.7e-18 ergs/s/cm2. To date, the total coverage of the ZEN survey has sampled a volume at z~9 of approximately 1700 co-moving Mpc3 to a Lya emission luminosity of 1e43 erg/s. We conclude by considering the prospects for detecting z~9 Lya emitting galaxies in light of both observed galaxy properties at z7.Comment: 7 pages, MNRAS accepte

Teaching in Focus: The value of implementing a program-specific teaching support project for staff wellbeing and student success

This work is licensed under a Creative Commons Attribution 4.0 Licence. As an open access journal, articles are free to use, with proper attribution, in educational and other non-commercial settings.This paper reports on a program-level teaching support initiative that was implemented in a Health Sciences undergraduate degree with a large and highly casualised teaching team. It has been argued that to improve student retention and success, universities need to consider implementing comprehensive teaching support models that address institutional, program, and individual level needs. We report on the implementation of our project and reflect on participant feedback, which demonstrated the value of the program for improving staff wellbeing. We argue that introducing support strategies for staff at a local level is essential not only for delivery of high quality learning experiences, but also for staff wellbeing which, in turn, has important implications for student success and retention

Quantitative Genetic Effects of Bottlenecks: Experimental Evidence from a Wild Plant Species, Nigella degenii

Understanding the genetic consequences of changes in population size is fundamental in a variety of contexts, such as adaptation and conservation biology. In the study presented here, we have performed a replicated experiment with the plant Nigella degenii to explore the quantitative genetic effects of a single-founder bottleneck. In agreement with additive theory, the bottleneck reduced the mean (co)variance within lines and caused stochastic, line-specific changes in the genetic (co)variance structure. However, a significant portion of the (co)variance structure was conserved, and 2 characters—leaf and flower (sepal) size—turned out to be positively correlated in all data sets, indicating a potential for correlated evolution in these characters, even after a severe bottleneck. The hierarchical partitioning of genetic variance for flower size was in good agreement with predictions from additive theory, whereas the remaining characters showed an excess of within-line variance and a deficiency of among-line variance. The latter discrepancies were most likely a result of selection, given the small proportion of lines (23%) that remained viable until the end of the experiment. Our results suggest that bottlenecked populations of N. degenii generally have a lower adaptive potential than the ancestral population but also highlight the idiosyncratic nature of bottleneck effects

Studying Reionization with Ly-alpha Emitters

We show that observations of high-redshift Ly-alpha emitters (LAEs) have the potential to provide definitive evidence for reionization in the near future. Using 200 Mpc radiative transfer simulations, we calculate the effect that patchy reionization has on the line profile, on the luminosity function, and, most interestingly, on the clustering of emitters for several realistic models of reionization. Reionization increases the measured clustering of emitters, and we show that this enhancement would be essentially impossible to attribute to anything other than reionization. Our results motivate looking for the signature of reionization in existing LAE data. We find that for stellar reionization scenarios the angular correlation function of the 58 LAEs in the Subaru Deep Field z = 6.6 photometric sample is more consistent with a fully ionized universe (mean volume ionized fraction x_i = 1) than a universe with x_i 2-sigma confidence level. Measurements in the next year on Subaru will increase their z = 6.6 LAE sample by a factor of five and tighten these limits. If the clustering signature of reionization is detected in a LAE survey, a comparison with a Lyman-break or a H-alpha survey in the same field would confirm the reionization hypothesis. We discuss the optimal LAE survey specifications for detecting reionization, with reference to upcoming programs.Comment: 24 pages, 17 figures, accepted by MNRA

First Light and Reionization: A Conference Summary

The search for the first illuminated astronomical sources in the universe is at the edge of the cosmic frontier. Promising techniques for discovering the first objects and their effects span the electromagnetic spectrum and include gravitational waves. We summarize a workshop on discovering and understanding these sources which was held in May 2005 through the Center for Cosmology at the University of California, Irvine.Comment: to appear in the proceedings of the UC Irvine Workshop on "First Light and Reionization: Theoretical Study and Experimental Detection of the First Luminous Sources", eds. A. Cooray & E. Barton, New Astronomy Reviews; replacement version with references updated, minor errors fixe

Learning from Ninjas: young people’s films as a lens for an expanded view of literacy and language

This article examines young people’s films to provide insights about language and literacy practices. It offers a heuristic for thinking about how to approach data that is collectively produced. It tries to make sense of new ways of knowing that locate the research in the field rather than in the academic domain. The authors develop a lens for looking at films made by young people that acknowledge multiple modes and materiality within their meaning-making practices. We make an argument about the cultural politics of research, to consider how the language and literacy practices of young people are positioned. We argue for more consideration of how language and literacy appear entangled within objects and other stuff within young people’s media productions, so as to trouble disciplinary boundaries within and beyond literacy and language studies

Influence of Rock-Pool Characteristics on the Distribution and Abundance of Inter-Tidal Fishes

Rock pools can be found in inter-tidal marine environments worldwide; however, there have been few studies exploring what drives their, fish species composition, especially in Australia. The rock-pool environment is highly dynamic and offers a unique natural laboratory to study the habitat choices, physiological limitations and adaptations of inter-tidal fish species. In this study rock pools of the Sydney region were sampled to determine how the physical (volume, depth, rock cover and vertical position) and biological (algal cover and predator presence) parameters of pools influence fish distribution and abundance. A total of 27 fish species representing 14 families was observed in tide pools at the four study locations. The five most abundant species were Bathygobius cocosensis, Centropogon australis, Enneapterygius atrogulare, Lepidoblennius haplodactylus and Microcanthus strigatus, which together represented 71% of the total number of fish recorded. Larger rock pools containing more algal and rock ledge cover hosted a larger and more diverse population of fish. Furthermore, certain species were only found in pools with specific characteristics, such as the presence of loose shells, a variety algae or rock cover, suggesting a high degree of habitat specificity. By contrast, some species were ubiquitous and thus can likely tolerate a wide variety of physical conditions

Protective Microbiota: From Localized to Long-Reaching Co-Immunity

Resident microbiota do not just shape host immunity, they can also contribute to host protection against pathogens and infectious diseases. Previous reviews of the protective roles of the microbiota have focused exclusively on colonization resistance localized within a microenvironment. This review shows that the protection against pathogens also involves the mitigation of pathogenic impact without eliminating the pathogens (i.e., “disease tolerance”) and the containment of microorganisms to prevent pathogenic spread. Protective microorganisms can have an impact beyond their niche, interfering with the entry, establishment, growth, and spread of pathogenic microorganisms. More fundamentally, we propose a series of conceptual clarifications in support of the idea of a “co-immunity,” where an organism is protected by both its own immune system and components of its microbiota