Skeletal matrices, muci, and the origin of invertebrate calcification.

The sudden appearance of calcified skeletons among many different invertebrate taxa at the Precambrian-Cambrian transition may have required minor reorganization of preexisting secretory functions. In particular, features of the skeletal organic matrix responsible for regulating crystal growth by inhibition may be derived from mucous epithelial excretions. The latter would have prevented spontaneous calcium carbonate overcrusting of soft tissues exposed to the highly supersaturated Late Proterozoic ocean [Knoll, A. H., Fairchild, I. J. & Swett, K. (1993) Palaios 8, 512-525], a putative function for which we propose the term "anticalcification." We tested this hypothesis by comparing the serological properties of skeletal water-soluble matrices and mucous excretions of three invertebrates--the scleractinian coral Galaxea fascicularis and the bivalve molluscs Mytilus edulis and Mercenaria mercenaria. Crossreactivities recorded between muci and skeletal water-soluble matrices suggest that these different secretory products have a high degree of homology. Furthermore, freshly extracted muci of Mytilus were found to inhibit calcium carbonate precipitation in solution.

A nonpeptide agonist of the invertebrate receptor for SchistoFLRFamide (PDVDHVFLRFamide), a member of a subfamily of insect FMRFamide-related peptides.

We describe a nonpeptide mimetic analog of an invertebrate peptide receptor. Benzethonium chloride (Bztc) is an agonist of the SchistoFLRFamide (PDVDHVFLRFamide) receptors found on locust oviducts. Bztc competitively displaces [125I-labeled Y1]SchistoFLRFamide binding to both high- and low-affinity receptors of membrane preparations. Bztc mimics the physiological effects of SchistoFLRFamide on locust oviduct, by inhibiting myogenic and induced contractions in a dose-dependent manner. Bztc is therefore recognized by the binding and activation regions of the SchistoFLRFamide receptors. This discovery provides a unique opportunity within insects to finally target a peptide receptor for the development of future pest management strategies.

Habituation of an invertebrate escape reflex due to modulation by higher centers rather than local events.

Learning is widely thought to result from altered potency of synapses within the neural pathways that mediate the learned behavior. Support for this belief, which pervades current physiological and computational thinking, comes especially from the analysis of cases of simple learning in invertebrates. Here, evidence is presented that in one such case, habituation of crayfish escape, the learning is more due to onset of tonic descending inhibition than to the intrinsic depression of circuit synapses to which it was previously attributed. Thus, the altered performance seems to depend at least as much on events in higher centers as on local plasticity.

Improving Colorado Mountain Highway Culvert Stream Crossings for Trout Passage

Highways can be effective barriers to animal migration. Where highways cross over streams, a passageway, typically a culvert, not designed for fish access can cut off an organism from miles of habitat. Traditional methods of culvert design, to convey floodwaters, reduced access to aquatic and riparian range. The Colorado Department of Transportation likely has numerous culverts that restrict aquatic passage. This paper provides guidance to CDOT for assessment of stream geomorphic conditions affecting culvert performance for fish passage, understanding aquatic organism habitat requirements, and incorporating ecological parameters into culvert designs that benefit fish and other organisms. A case study illustrates culvert problems in a difficult geomorphic setting including a fish passage assessment to evaluate stream stability for long-term culvert reliability.

How old are fossils? / by Sharat K. Roy, Asst. Curator of Invertebrate Paleontology.

no.9(1927)

Report on the Hydroida : collected during the exploration of the Gulf Stream by L. F. de Pourtalès, assistant United States Coast Survey / by Geo. J. Allman, M.D., LL.D., ...

v.5:no.2 (1877)

Analysis of Hyporheic Flow Induced by a Bar in a Gravel Stream: an Experimental Study

Thesis (Master, Civil Engineering) -- Queen's University, 2016-06-01 00:03:02.939

On Ukrainian Gas Transit and South Stream. There may be more than meets the eye. CEPS Commentaries, 21 March 2014

The EU relies to a considerable degree on imports to meet its demand for natural gas. Whereas Norwegian export pipelines are directly connected to the EU gas system, a major share of Russian gas flows through the Ukrainian territory before reaching consumers located other consumers located down in the supply chain (e.g. Slovakia, Hungary or Italy). But is the Ukrainian gas transit route still a risk? Will the construction of the South Stream pipeline further reduce the importance of Ukraine as a transit country? Or is there more at stake here than meets the eye?

Nord Stream on the liberalising EU gas market. OSW Point of View, March 2010

Nord Stream increases Gazprom’s flexibility as far its export routes are concerned; it enables them to be changed with regard to the market or political situation. Nevertheless, this expensive pipeline may contribute to a further drop in the price competitiveness of Russian gas. Accordingly, increasing the attractiveness of Russian fuel and ensuring profitable sales is steadily becoming the main challenge for Gazprom in the EU against a backdrop of increasing competitiveness on the market.

The declared end of South Stream and why nobody seems to care. CEPS Commentary, 5 December 2014

More than seven years after the South Stream pipeline project was first announced in June 2007, it finally seems to have been dropped by Russia’s President Vladimir Putin on his visit to Turkey this week. This CEPS Commentary looks at the ostensible reasons for President Putin’s decision as well as on what’s potentially behind them. It concludes that the EU may actually benefit from this decision in being able to secure more gas with less political interference from Russia.

At any price: Russia is embarking on the construction of South Stream. OSW Commentary No. 98, 2012-12-07

Gazprom is determined to continue its efforts to build the South Stream gas pipeline regardless of the slump on the European gas market and the fact that there is sufficient capacity already in the existing transport infrastructure. The official inauguration of the maritime section of South Stream was held on 7 December this year, but the construction itself will commence in 2014. The agreements concluded so far, both intergovernmental and between corporations, are necessary for the launch of the construction of the new pipeline, but still do not guarantee that the project will be completed on time. First of all, some legal problems have yet to be resolved, such as the evaluation of the compliance of the planned actions with the ‘third energy package’ or the fact that ecological surveys required under European law need to be carried out. Secondly, given the present situation on the European gas market and medium-term forecasts, the high cost of implementation of this project and the maintenance expenses of existing pipelines – which are not being used to full capacity – the new project seems to be unfeasible. However, Gazprom’s determination in its efforts to build the pipeline proves that Russia is ready to take a high economic risk to maintain its dominant position on the European gas supply market; it will restrict the possibilities of alternative infrastructural projects being implemented (above all, the EU’s Southern Corridor) and use the construction of new pipelines as an instrument of political pressure on the present transit countries (especially Ukraine).

Turkish Stream and its implications for the EU. European Policy Brief No. 34, March 2015

“A first assessment is that this would not work”, EC Vice-President in charge of Energy Union Mr. Maros Sefcovic said in an interview with The Wall Street Journal at the World Economic Forum in Davos on the 22nd of January. He was commenting on the recent announcement by President Vladimir Putin and Gazprom’s Alexei Miller. Indeed, the Russian gas giant’s CEO announced that South Stream would be replaced by a new project, Turkish Stream, linking Russia to the European part of Turkey and this in addition to the existing 16 billion cubic meters (bcm) Blue stream. This policy brief looks at the various implications this new reality could have for Europe’s energy security.

Nord Stream expansion: what does it mean for Europe? EPC Commentary, 2 July 2015

Two announcements in sequence have shaken the energy debate on 18 and 19 June. Gazprom announced the signature of a Memorandum of Understanding with Shell, Exon and OMV for the construction of strings 3 and 4 of Nord Stream, aiming at doubling the current 55 bcm capacity of the corridor running in the Baltic sea bed and connecting the Russian terminal of Vyborg to Germany. On the day after, a €2 bn deal between Russia and Greece was signed for extending the Turkish Stream project into Greek territory. ...