Shedding Light on the Galaxy Luminosity Function

From as early as the 1930s, astronomers have tried to quantify the statistical nature of the evolution and large-scale structure of galaxies by studying their luminosity distribution as a function of redshift - known as the galaxy luminosity function (LF). Accurately constructing the LF remains a popular and yet tricky pursuit in modern observational cosmology where the presence of observational selection effects due to e.g. detection thresholds in apparent magnitude, colour, surface brightness or some combination thereof can render any given galaxy survey incomplete and thus introduce bias into the LF. Over the last seventy years there have been numerous sophisticated statistical approaches devised to tackle these issues; all have advantages -- but not one is perfect. This review takes a broad historical look at the key statistical tools that have been developed over this period, discussing their relative merits and highlighting any significant extensions and modifications. In addition, the more generalised methods that have emerged within the last few years are examined. These methods propose a more rigorous statistical framework within which to determine the LF compared to some of the more traditional methods. I also look at how photometric redshift estimations are being incorporated into the LF methodology as well as considering the construction of bivariate LFs. Finally, I review the ongoing development of completeness estimators which test some of the fundamental assumptions going into LF estimators and can be powerful probes of any residual systematic effects inherent magnitude-redshift data.Comment: 95 pages, 23 figures, 3 tables. Now published in The Astronomy & Astrophysics Review. This version: bring in line with A&AR format requirements, also minor typo corrections made, additional citations and higher rez images adde

Dendritic cells and epithelial cells: linking innate and adaptive immunity in asthma

Dendritic cells (DCs) are generally held responsible for initiating and maintaining allergic T helper 2 (TH2)-cell responses to inhaled allergens in asthma. Although the epithelium was initially considered to function solely as a physical barrier, it is now seen as a central player in the T H 2-cell sensitization process by influencing the function of DCs. Clinically relevant allergens, as well as known environmental and genetic risk factors for allergy and asthma, often interfere directly or indirectly with the innate immune functions of airway epithelial cells and DCs. A better understanding of these interactions, ascertained from human and animal studies, might lead to better prevention and treatment of asthma

Plant products with antifungal activity. From field to biotechnology strategies

In this chapter, informations on the recent advances regarding antifungal activity of natural products obtained from plants collected directly from their natural habitat or from plant cell and organ, cultures have been reported. The biotechnological approaches could increase uniformity and predictability of the extracts and overcome problems associated with geographical, seasonal, and environmental variations. Human fungal pathogens are the cause of severe diseases associated with high morbidity and mortality. The major human fungal pathogens are Candida species, dermatophytes, Aspergillus species, and Cryptococcus neoformans. Side effects and resistance are frequently attributed to the current antifungal agents. Moreover, the treatments often require long-term therapy and are not resolving. Plants represent a source of antifungal agents, but up to date, the number of new phytochemicals reaching the market is very low. This review attempts to summarize the current status of botanical screening efforts, as well as in vitro and in vivo studies on antifungal activity of plant products. Despite the currently non-uniform regulatory framework in all the states, the plant-derived products are increasingly in demand for their effectiveness. The basic conclusion from these studies is that rigorous, well-designed clinical trials are needed to validate the effectiveness and safety of plant extracts for their use as antifungals