Deep Sea Microplastic Pollution Extends Out to Sediments in the Northeast Atlantic Ocean Margins

Microplastics are ubiquitous emerging contaminants found in every habitat surveyed, building upon international databases globally. Costs and accessibility often correlate to few deep sea sediment surveys, restricting the number of stations within a given sampling area. An extensive survey of the Porcupine Seabight, Porcupine Bank, the Goban Spur, and south-western canyons resulted in identifying microplastics in deep sea sediment surface layers from 33 of the 44 stations sampled (75%), with a total of 83 particles (74 synthetic and 9 natural) recorded. No microplastic hotspots were identified, and abundances (kg d.w.^-1) were not correlated with distance from land, depth, or the presence of macrolitter on the seafloor. Understanding the sources of deep sea microplastics, such as marine traffic, is crucial to developing effective mitigation strategies as well as further monitoring campaigns targeting microplastic pollution in areas with significant deep sea biodiversity such as the Porcupine Seabright.

Bald's Leechbook and the Physica Plinii

The study of the sources of the Anglo-Saxon medical texts began more than a hundred years ago with T.O. Cockayne's monumental edition of most of the medical, magical and herbal material extant in Old English. Cockayne demonstrated that the most significant text in this corpus, the late ninth-century compilation known as Bald's Leechbook, drew on an impressive range of Latin source materials. Recent work by C.H. Talbot and M.L. Cameron has further extended our knowledge of the classical texts which underlie the Leechbook. Among the significant sources is the text known as the Physica Plinii. Although the Physica survives in several recensions, there has as yet been no systematic study of the relationship between these recensions and the version of the Latin text used by the Old English compiler. The present article investigates Bald's Leechbook as a witness to the history of the Physica Plinii, and demonstrates the complexity of the transmission of the latter work.

Influence of infused prolactin on hormone binding to tissue slices

The influence of circulating prolactin on the binding of labeled hormone to tissue slices in vitro was investigated in rats bearing dimethylbenzanthracene-induced mammary tumors. Prolactin was infused into four animals over four 30-min periods to give serum levels ranging from 20 to 2000 ng/ml. Serial biopsies of liver and tumor were taken during infusion, and binding of labeled prolactin and insulin measured in tissue slices. Whereas insulin binding remained constant, prolactin binding was significantly depressed in both tissues when samples were obtained at serum prolactin levels greater than 300 ng/ml. This decrease was due to diminished numbers of available binding sites rather than a change in binding-site affinity for prolactin. The data indicate that under the conditions of this experiment, endogenous circulating prolactin may interfere with in vitro measurements of hormone uptake when serum levels excee 300 ng/ml.