Laboratory studies of the effects of Mollusca on alkalinity of their freshwater environment

A series of aquaria containing various combinations of water, sediments, and molluscs was used to investigate the effects of molluscs on alkalinity of the water. Live molluscs acidified the water, and dead decomposing molluscs were associated with an increase in alkalinity in the aquaria. Aquaria containing dead molluscs had more stable alkalinity concentrations than other aquaria when all received additions of natural acid rain (pH 4.1). Nonmolluscan invertebrates liberated acid-neutralizing materials from the sediments but the source was quickly depleted. A hypothesis of temporal disjunction between periods of molluscan acid and base production is given which indicates a potential role for molluscs in the sources and cycling of carbonates in acidifying environments.

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The potential role of blowflies in the transmission of taeniid tapeworm eggs

Parasitology ◽

10.1017/s0031182000056572 ◽

1985 ◽

Vol 91 (1) ◽

pp. 129-143 ◽

Cited By ~ 24

Author(s):

J. R. Lawson ◽

M. A. Gemmell

Keyword(s):

New Zealand ◽

Potential Role ◽

Field Studies ◽

Pitfall Traps ◽

Prevailing Wind ◽

Laboratory Studies ◽

The South ◽

Taenia Hydatigena ◽

Sticky Traps

In laboratory studies with 3 species of Calliphora more than half were shown to ingest eggs of Taenia hydatigena from the surface of clog faeces with a maximum of over 5000 eggs in 1 fly. Most eggs were voided within 48 h and between 38 and 48% of these eggs had lost their embryophores. In field studies carried out in the South Island of New Zealand, traps baited with dog faeces captured the following blowfly species in decreasing order of abundance: Hybopygia varia, Calliphora quadrimaculata, C. hortona and C. stygia. Peak numbers were trapped in January, February and March. Almost 25% of wild flies, caught after feeding for up to 3 mm on dog faeces naturally contaminated with taeniid eggs, had eggs in their intestine. When administered to lambs all 4 species of fly transferred infection. Lambs grazed in winter on plots near kennels that had housed dogs with patent infections of T. hydatigena acquired higher worm burdens than those grazed further away. The burdens were greater downwind of the prevailing wind. After removal of the dogs, blowflies caught in the vicinity contained taeniid eggs but the contents of pitfall traps did not. Blowflies, and to a much lesser degree the insects and dust caught on sticky traps during the presence of the dogs, transferred infection when administered to naive lambs.

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Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

International Astronomical Union Colloquium ◽

10.1017/s025292110001469x ◽

1997 ◽

Vol 161 ◽

pp. 179-187

Author(s):

Clifford N. Matthews ◽

Rose A. Pesce-Rodriguez ◽

Shirley A. Liebman

Keyword(s):

Amino Acids ◽

Solar System ◽

Hydrogen Cyanide ◽

Nitrogen Heterocycles ◽

Laboratory Studies ◽

Heterogeneous Solids ◽

The Many ◽

Comet Halley ◽

The Impact ◽

By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

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TEM visualization of surface replicated acid and base catalyzed sol-gel glasses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010014381x ◽

1986 ◽

Vol 44 ◽

pp. 448-449

Author(s):

George C. Ruben ◽

Merrill W. Shafer

Keyword(s):

Elevated Temperatures ◽

Sol Gel ◽

Basic Medium ◽

Glass Transition Point ◽

Structural Space ◽

Acid And Base ◽

Organometallic Precursors ◽

New Processing ◽

Gel Glasses ◽

Physical Phenomena

Traditionally ceramics have been shaped from powders and densified at temperatures close to their liquid point. New processing methods using various types of sols, gels, and organometallic precursors at low temperature which enable densificatlon at elevated temperatures well below their liquidus, hold the promise of producing ceramics and glasses of controlled and reproducible properties that are highly reliable for electronic, structural, space or medical applications. Ultrastructure processing of silicon alkoxides in acid medium and mixtures of Ludox HS-40 (120Å spheres from DuPont) and Kasil (38% K2O &62% SiO2) in basic medium have been aimed at producing materials with a range of well defined pore sizes (∼20-400Å) to study physical phenomena and materials behavior in well characterized confined geometries. We have studied Pt/C surface replicas of some of these porous sol-gels prepared at temperatures below their glass transition point.

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Case study: Acid rain: Sulfur and power generation

Elements of the p-Block - The Molecular World ◽

10.1039/9781847557841-fp010 ◽

2007 ◽

pp. P010-P011

Keyword(s):

Power Generation ◽

Acid Rain

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POPDC proteins and cardiac function

Biochemical Society Transactions ◽

10.1042/bst20190249 ◽

2019 ◽

Vol 47 (5) ◽

pp. 1393-1404 ◽

Cited By ~ 4

Author(s):

Thomas Brand

Keyword(s):

Potential Role ◽

Striated Muscle ◽

Short Review ◽

Effector Proteins ◽

Muscle Disease ◽

Disease Genes ◽

Protein Protein Interaction ◽

Interaction Partners ◽

And Function

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.

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