Zika Virus: Can Artificial Contraception Be Condoned?

As the Zika virus pandemic continues to bring worry and fear to health officials and medical scientists, Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) have recommended that residents of the Zika-infected countries, e.g., Brazil, and those who have traveled to the area should delay having babies which may involve artificial contraceptive, particularly condom. This preventive policy, however, is seemingly at odds with the Roman Catholic Church’s position on the contraceptive. As least since the promulgation of Paul VI’s 1968 encyclical, Humanae Vitae, the Church has explicitly condemned artificial birth control as intrinsic evil. However, the current pontiff, Pope Francis, during his recent visit to Latin America, remarked that the use of artificial contraception may not be in contradiction to the teaching of Humanae Vitae while drawing a parallel between the current Zika Crisis and the 1960’s Belgian Congo Nun Controversy. The pope mentioned that the traditional ethical principle of the lesser of two evils may be the doctrine that justified the exceptions. The authors of this paper attempt to expand the theological rationale of the pope’s suggestion. In so doing, the authors rely on casuistical reasoning as an analytic tool that compares the Belgian Congo Nun case and the given Zika case, and suggest that the former is highly similar to, if not the same as, the latter in terms of normative moral feature. That is, in both cases the use of artificial contraception is theologically justified in reference to the criteria that the doctrine of the lesser of two evils requires. The authors wish that the paper would provide a solid theological-ethical ground based on which condom-use as the most immediate and effective preventive measure can be recommended in numerous Catholic hospitals as well as among Catholic communities in the world, particularly the most Zika-affected and largest Catholic community in the world, Brazil – 123 million present Brazilian citizens are reported to be Roman Catholic

Pseudoephenamine: A Practical Chiral Auxiliary for Asymmetric Synthesis

Pseudoephenamine is shown to be a versatile chiral auxiliary for asymmetric synthesis. It is free from regulatory restrictions and exhibits remarkable stereocontrol in alkylation reactions, especially those that form quaternary carbon centers. Amides derived from pseudoephenamine exhibit a high propensity to be crystalline substances and provide sharp, well-defined peaks in NMR spectra.Chemistry and Chemical Biolog

R^2 Corrections for 5D Black Holes and Rings

We study higher-order corrections to two BPS solutions of 5D supergravity, namely the supersymmetric black ring and the spinning black hole. Due in part to our current relatively limited understanding of F-type terms in 5D supergravity, the nature of these corrections is less clear than that of their 4D cousins. Effects of certain $R^2$ terms found in Calabi-Yau compactification of M-theory are specifically considered. For the case of the black ring, for which the microscopic origin of the entropy is generally known, the corresponding higher order macroscopic correction to the entropy is found to match a microscopic correction, while for the spinning black hole the corrections are partially matched to those of a 4D $D0-D2-D6$ black hole.Comment: 9 page

What physics determines the peak of the IMF? Insights from the structure of cores in radiation-magnetohydrodynamic simulations

As star-forming clouds collapse, the gas within them fragments to ever-smaller masses. Naively one might expect this process to continue down to the smallest mass that is able to radiate away its binding energy on a dynamical time-scale, the opacity limit for fragmentation, at ∼0.01 M⊙. However, the observed peak of the initial mass function (IMF) lies a factor of 20–30 higher in mass, suggesting that some other mechanism halts fragmentation before the opacity limit is reached. In this paper we analyse radiation-magnetohydrodynamic simulations of star cluster formation in typical Milky Way environments in order to determine what physical process limits fragmentation in them. We examine the regions in the vicinity of stars that form in the simulations to determine the amounts of mass that are prevented from fragmenting by thermal and magnetic pressure. We show that, on small scales, thermal pressure enhanced by stellar radiation heating is the dominant mechanism limiting the ability of the gas to further fragment. In the brown dwarf mass regime, ∼0.01 M⊙, the typical object that forms in the simulations is surrounded by gas whose mass is several times its own that is unable to escape or fragment, and instead is likely to accrete. This mechanism explains why ∼0.01 M⊙ objects are rare: unless an outside agent intervenes (e.g. a shock strips away the gas around them), they will grow by accreting the warmed gas around them. In contrast, by the time stars grow to masses of ∼0.2 M⊙, the mass of heated gas is only tens of percent of the central star mass, too small to alter its final mass by a large factor. This naturally explains why the IMF peak is at ∼0.2 M⊙

Aboveground biomass corresponds strongly with drone-derived canopy height but weakly with greenness (NDVI) in a shrub tundra landscape

This is the author accepted manuscript. The final version is available from IOP Publishing via the DOI in this recordData accessibility: The data that support the findings of this study are openly available at the following DOI: https://doi.org/10.5285/61C5097B-6717-4692-A8A4-D32CCA0E61A9)Arctic landscapes are changing rapidly in response to warming, but future predictions are hindered by difficulties in scaling ecological relationships from plots to biomes. Unmanned aerial systems (UAS, hereafter 'drones') are increasingly used to observe Arctic ecosystems over broader extents than can be measured using ground-based approaches and facilitate the interpretation of coarse-grained remotely-sensed datasets. However, more information is needed about how drone-acquired remote sensing observations correspond with ecosystem attributes such as aboveground biomass. Working across a willow shrub-dominated alluvial fan at a focal study site in the Canadian Arctic, we conducted peak season drone surveys with a RGB camera and multispectral multi camera array to derive photogrammetric reconstructions of canopy and normalised difference vegetation index (NDVI) maps along with in situ point intercept measurements and biomass harvests from 36, 0.25 m2 plots. We found high correspondence between canopy height measured using in situ point intercept compared to drone-photogrammetry (concordance correlation coefficient = 0.808), although the photogrammetry heights were positively biased by 0.14 m relative to point intercept heights. Canopy height was strongly and linearly related to aboveground biomass, with similar coefficients of determination for point framing (R2 = 0.92) and drone-based methods (R2 = 0.90). NDVI was positively related to aboveground biomass, phytomass and leaf biomass. However, NDVI only explained a small proportion of the variance in biomass (R2 between 0.14 and 0.23 for logged total biomass) and we found moss cover influenced the NDVI-phytomass relationship. Biomass is challenging to infer from drone-derived NDVI, particularly in ecosystems where bryophytes cover a large proportion of the land surface. Our findings suggest caution with broadly attributing change in fine-grained NDVI to biomass differences across biologically and topographically complex tundra landscapes. By comparing structural, spectral and on-the-ground ecological measurements, we can improve understanding of tundra vegetation change as inferred from remote sensing.Natural Environment Research Council (NERC)Dartmouth CollegeAarhus University Research FoundationEuropean Union Horizon 202