A review of elliptical and disc galaxy structure, and modern scaling laws

A century ago, in 1911 and 1913, Plummer and then Reynolds introduced their models to describe the radial distribution of stars in `nebulae'. This article reviews the progress since then, providing both an historical perspective and a contemporary review of the stellar structure of bulges, discs and elliptical galaxies. The quantification of galaxy nuclei, such as central mass deficits and excess nuclear light, plus the structure of dark matter halos and cD galaxy envelopes, are discussed. Issues pertaining to spiral galaxies including dust, bulge-to-disc ratios, bulgeless galaxies, bars and the identification of pseudobulges are also reviewed. An array of modern scaling relations involving sizes, luminosities, surface brightnesses and stellar concentrations are presented, many of which are shown to be curved. These 'redshift zero' relations not only quantify the behavior and nature of galaxies in the Universe today, but are the modern benchmark for evolutionary studies of galaxies, whether based on observations, N-body-simulations or semi-analytical modelling. For example, it is shown that some of the recently discovered compact elliptical galaxies at 1.5 < z < 2.5 may be the bulges of modern disc galaxies.Comment: Condensed version (due to Contract) of an invited review article to appear in "Planets, Stars and Stellar Systems"(www.springer.com/astronomy/book/978-90-481-8818-5). 500+ references incl. many somewhat forgotten, pioneer papers. Original submission to Springer: 07-June-201

Remote detection of invasive alien species

The spread of invasive alien species (IAS) is recognized as the most severe threat to biodiversity outside of climate change and anthropogenic habitat destruction. IAS negatively impact ecosystems, local economies, and residents. They are especially problematic because once established, they give rise to positive feedbacks, increasing the likelihood of further invasions and spread. The integration of remote sensing (RS) to the study of invasion, in addition to contributing to our understanding of invasion processes and impacts to biodiversity, has enabled managers to monitor invasions and predict the spread of IAS, thus supporting biodiversity conservation and management action. This chapter focuses on RS capabilities to detect and monitor invasive plant species across terrestrial, riparian, aquatic, and human-modified ecosystems. All of these environments have unique species assemblages and their own optimal methodology for effective detection and mapping, which we discuss in detail

Prostate cancer early detection: Clinical practice guidelines in oncology™

Since the early 1990s, many variants of the tPSA assay have been introduced to increase the sensitivity of screening programs (cancer detection) while maintaining specificity (elimination of unnecessary biopsies). Again, these guidelines recommend ways that individuals and their physicians can use these new techniques rationally for early detection of prostate cancer. These guidelines are not designed to provide an argument for using population screening programs for prostate cancer, but are meant to provide a vehicle for practicing early detection efforts in an evidence-based, systematic fashion in patients who choose to participate in these programs. Whether to treat a patient on diagnosis is beyond the scope of these guidelines (see NCCN Clinical Practice Guidelines in Oncology: Prostate Cancer [in this issue; to view the most recent version of these guidelines, visit the NCCN Web site at www.NCCN.org]). These guidelines incorporate many new validated findings in addition to the DRE and tPSA test, including percent fPSA, PSAV, cPSA, biopsy pathology, and TRUS-guided biopsy techniques. The panel will re-examine the clinical efficacy of these new modalities annually, and the guidelines will be modified accordingly. In addition, future iterations of these guidelines may incorporate new serum markers currently undergoing clinical investigation. The goal of the NCCN and this guideline panel in updating these algorithms is to help men and clinicians choose a program for early detection of prostate cancer and make decisions about the need for prostate biopsy. Any clinician who uses these guidelines is expected to exercise independent medical judgment in the context of the individual clinical circumstances to determine each patient's need for prostate biopsy. These guidelines will continue to evolve as the field of prostate cancer advances. © Journal of the National Comprehensive Cancer Network