Demographic Tipping Points as Early Indicators of Vulnerability for Slow-Breeding Megafaunal Populations
Contributors: de Silva, Shermin, Leimgruber, Peter
... Decisions based on trends in population abundance and distribution may fail to protect populations of slow-breeding, long-lived megafauna from irrevocable decline if they ignore demographic constraints. For such taxa, we urge that effort be directed at understanding the interactions among vital rates governing population growth rates, rather than on predicting probabilities of extinction. The proximity of a population to demographic tipping points, i.e., where growth rate switches from positive to negative, can signal vulnerability to perturbation long before numbers drop below a point of no return. We define the "demographic safe space" as the combination of key vital rates that support a non-negative growth rate and illustrate this approach for Asian elephants. Through simulations, we find that even with optimal reproduction, Asian elephant populations cannot tolerate annual female mortality rates exceeding 7.5%. If adult mortality is very low (3%/year), populations can tolerate high annual mortality in calves below age 3 (up to 31.5%/year), or slow female reproduction (primiparity at 30 years or average inter-birth interval of up to 7.68 years). We then evaluate the potential impact of current threats, showing that near-optimal reproduction and high calf survival is necessary to offset even modestly increased mortality among adult female age classes. We suggest that rather than rely on simple counts or "viability" assessments, conservation planners for slow-breeding megafauna should consider demographic tipping points and strive to keep populations within their safe spaces.
Contributors: Daemmrich, Arthur
... This article reviews the history of drug manufacturing and changes in the compounding of drugs by pharmacies in the United States and outlines opportunities for new research into the making of medicines. The pharmaceutical industry has long been on the vanguard of globalization, and drug companies restructured their international manufacturing footprints frequently in the 19th and 20th centuries. Firms in the prescription drug sector were among the first to market products internationally, to build manufacturing plants around the world, and to integrate research from laboratories across multiple time zones. Yet, issues of quality and safety have arisen repeatedly and the industry has continued to produce its newest medicines in North America even as technological capabilities increased significantly in China, India, and elsewhere since the 1980s. Compounding pharmacies, by contrast, experienced a steady decline during the second half of the 20th century as medicines arrived from producers in final form. The emergence of individualized therapies, however, is now bringing a resurgence in business for biological labs acting in many ways as compounders. Broadly, as pharmaceutical firms turned to a business model built around research and intellectual property production, and as pharmacists shifted from producing medicines to repackaging them for patients, analysts likewise turned to regulation, pricing, and new product innovation as subjects of their research. As a consequence, pharmaceutical manufacturing is largely ignored in the recent historiography of medicine, pharmacy, and pharmaceuticals, an oversight that should be rectified.
Contributors: Collin, Rachel, Venera-Pontón, Dagoberto E., Driskell, Amy C., Macdonald, Kenneth S., Chan, Kit-Yu Karen, Boyle, Michael J.
... Phoronid larvae, actinotrochs, are beautiful and complicated organisms which have attracted as much, if not more, attention than their adult forms. We collected actinotrochs from the waters of the Pacific and Caribbean coasts of Panama, and used DNA barcoding of mtCOI, as well as 16S and 18S sequences, to estimate the diversity of phoronids in the region. We discovered three operational taxonomic units (OTUs) in the Bay of Panama on the Pacific coast and four OTUs in Bocas del Toro on the Caribbean coast. Not only did all OTUs differ from each other by >10% pairwise distance in COI, but they also differed from all phoronid sequences in GenBank, including the four species for which adults have been reported for the Pacific of Panama, Phoronopsis harmeri, Phoronis psammophila, Phoronis muelleri, and Phoronis hippocrepia. In each ocean region, one common OTU was more abundant and occurred more frequently than other OTUs in our samples. The other five OTUs were relatively rare, with only one to three individuals collected during the entire project. Species accumulation curves were relatively flat but suggest that at least one more species is likely to be present at each site. Actinotrochs from the seven sequenced OTUs had morphologies typical of species with non-brooded planktotrophic development and, in some cases, may be distinguished by differences in pigmentation and the arrangement of blood masses. We found one larva with morphology typical of brooded planktotrophic larvae for which sequencing failed, bringing the total number of potential species detected to eight and representing >50% of the adult species currently recognized globally.
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The shape of biogeography: Endemism, maps, and classification of fish distributions in the western Pacific
Contributors: Parenti, Lynne R.
... NH-Vertebrate Zoology