Eastern Shore Community College

Carrageenans are major gel forming polysaccharides in the extracellular matrix of the red macroalga Chondrus crispus. These galactans are made of linear chains of repetitive disaccharide motifs based on d-galactose residues alternately linked by β-1,4 and α-1,3 glycosidic bonds. A definite number of disaccharide motifs are known, based on their regular sulfations and the presence of a 3,6-anhydro bridge. While these motifs are variable as a function of species, life cycle phases, or seasons, our understanding of the in vivo regulation of carrageenan fine structures is still limited. Characterized hydrolytic enzymes (κ-, ι- and λ-carrageenases) are powerful tools for identifying glycan structures in extracted ECMs. Their use, combined to chromatography and high-resolution mass spectrometry, allowed us to refine our understanding of carrageenan variability in the phases of C. crispus. We provide the first demonstration that κ/ι carrabiose motifs are not limited to gametophytes, but are also present in tetrasporophytes, together with over- and under-sulfated λ-motifs. Our findings highlight a more complex carrageenan composition than previously described in this model system. These results are further discussed in the light of recent transcriptomic data and suggest that the historical hypotheses on the biosynthetic pathway of carrageenans in red algae may need revision. HypothesisCombined characterized hydrolytic enzymes to chromatography and high-resolution mass spectrometry can refine our understanding of carrageenan variability in the phases of C. crispus.

In 1993 Clare Boylan edited a collection of essays by diverse writers on the act of writing entitled The Agony and the Ego. The Art and Strategy of Fiction Writing Explored. Here, Boylan takes the double stance of an outsider, as a critic, and of an insider, as a writer, and her concern with other writers’ work highlights her own preoccupation with writing and creativity, thus providing an interesting insight into her own fiction too. Besides writing seven novels and three collections of short stories, Clare Boylan also produced personal, autobiographical and critical pieces in a variety of essays and newspaper articles. She also showed a rigorous stance as editor in the thorough and engaging Literary Companion to Cats (1994). In particular, Boylan’s non-fiction work includes essays on Kate O’Brien and Molly Keane, as well as an introduction to Maeve Brennan’s posthumous novella The Visitor. Her critical work shows rigorous attention to texts and imagery, but also patterns of affinities with the writers she takes into account. The purpose of this essay is to analyse samples of Clare Boylan’s critical work vis-à-vis her own fiction. Significant cross-references can be identified which cast new perspectives on her literary work.

Ammonia (NH3), dust and odor emissions from animal feeding operations (AFOs) can cause atmospheric pollution and disputes with neighbors. The objectives of this study were to: (1) re-design the ARS Air Scrubber to improve NH3 removal efficiency, (2) conduct full-scale testing of the scrubber under controlled conditions, (3) evaluate the efficacy of various acids for scrubbing NH3, and (4) determine the effects of air flow rate and NH3 concentration on scrubber performance. A full-scale prototype was constructed and a series of experiments were conducted under various conditions. Acid salts, such as aluminum sulfate (alum), sodium bisulfate, potassium bisulfate, ferric chloride and ferric sulfate were found to work as well as strong acids (hydrochloric, phosphoric and sulfuric) for capturing NH3. The efficiency of the scrubber for capturing NH3 decreased as the ventilation rate increased from over 90% at flow rates of 5,097 m3 hr-1 to around 55% at 16,141 m3 hr-1. However, the mass of N captured by the scrubber tripled as flow rates increased from 5,097 to 16,141 m3 hr-1. Similarly, there was a slight reduction in NH3 removal efficiency as inflow NH3 levels were increased from 10 µL L-1 to 75 µL L-1, whereas the mass of N captured increased from 25 g N hr-1 to around 200 g N hr-1. This technology could result in the capture of a significant amount of the N lost from AFOs, while simultaneously reducing emissions of dust and odors, which would improve the social and environmental sustainability of poultry and swine production.

Abstract Regression analyses were used to survey the effects of extractable NO3‐N, P, K, Ca, Mg, and soil pH on electrical conductivity (EC) in a 1: 1: 1 (v/v/v) peat‐sand‐perlite azalea (Rhododendron sp.) growing medium amended with soluble 21–3–6 (N‐P‐K) or slow‐release 18–3–6 fertilizer sources. Simple linear correlations indicated a high degree of relationship between NO3‐N, P, and K versus EC (r=0.95**, 0.79**, and 0.79**, respectively). Partial regression coefficients suggested that NO.‐N was the primary ionic species affecting EC. The correlations between EC versus P and K were apparently related to their intercorrelation with NO3 ‐N, associated with the use of N‐P‐K fertilizers. These relationships were constant across fertilizer sources. The results demonstrate a potential for the use of soil EC in the estimation of NO3‐N in soilless rooting media.