‘SeaStats’: hard figures on sea and coast

Looking for reliable figures on our seas and coasts? In need of that particular number to finish your introduction or presentation? ‘SeaStats’ offers interesting facts, each with a direct link to the source document and author(s). The primary criteria for selection are 1) reliability and quality of the source and 2) relevance of the figures. ‘SeaStats’ is a bilingual product that allows for a thematic search through 9 topics and 40 subtopics that are relevant marine, coastal and estuarine themes. ‘SeaStats’ wishes to a) facilitate the search for reliable anecdotic information on seas and coasts, with a focus on figures and numbers and 2) provide an additional exposure of marine and coastal research results to a wider public. Figures can be looked up through the 9 different symbols in the start-screen www.vliz.be/cijfers_beleid/zeecijfers (Dutch and English) or by filling in specific search terms. Take this example; you want to know the exact length of the Belgian coastline? Follow the symbol ‘Sea of space’ on the start-screen, click on ‘geography’, or use the search term ‘coastline’. The result of your search will inform you that there are 3 different and www.vliz.be/docs/Zeecijfers/seabordernl.pdf, where each alternative is explained. Source documents are by preference full texts of publications documented in IMIS, on relevant Belgian research or relating to the Belgian part of the North Sea, the Scheldt Estuary and the Belgian coastal zone

Challenges in commercializing biomimetic membranes

The discovery of selective water channel proteins—aquaporins—has prompted growing interest in using these proteins, as the building blocks for designing new types of membranes. However, as with any other new and potentially disruptive technology, barriers for successful market entry exist. One category includes customer-related barriers, which can be influenced to some extent. Another category includes market-technical-related barriers, which can be very difficult to overcome by an organization/company aiming at successfully introducing their innovation on the market—in particular if both the organization and the technology are at early stages. Often, one faces barriers from both these categories at the same time, which makes it necessary to gain insight of the particular market when introducing a new innovative product. In this review we present the basic concepts and discuss some of these barriers and challenges associated with introducing biomimetic aquaporin membranes. These include technical issues in membrane production and product testing. Then we discuss possible business models for introducing new technologies in general, followed by a presentation of beach-head market segments relevant for biomimetic aquaporin membranes

Functional significance of the taper of vertebrate cone photoreceptors

© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of General Physiology 139 (2012): 159-187, doi:10.1085/jgp.201110692.Vertebrate photoreceptors are commonly distinguished based on the shape of their outer segments: those of cones taper, whereas the ones from rods do not. The functional advantages of cone taper, a common occurrence in vertebrate retinas, remain elusive. In this study, we investigate this topic using theoretical analyses aimed at revealing structure–function relationships in photoreceptors. Geometrical optics combined with spectrophotometric and morphological data are used to support the analyses and to test predictions. Three functions are considered for correlations between taper and functionality. The first function proposes that outer segment taper serves to compensate for self-screening of the visual pigment contained within. The second function links outer segment taper to compensation for a signal-to-noise ratio decline along the longitudinal dimension. Both functions are supported by the data: real cones taper more than required for these compensatory roles. The third function relates outer segment taper to the optical properties of the inner compartment whereby the primary determinant is the inner segment’s ability to concentrate light via its ellipsoid. In support of this idea, the rod/cone ratios of primarily diurnal animals are predicted based on a principle of equal light flux gathering between photoreceptors. In addition, ellipsoid concentration factor, a measure of ellipsoid ability to concentrate light onto the outer segment, correlates positively with outer segment taper expressed as a ratio of characteristic lengths, where critical taper is the yardstick. Depending on a light-funneling property and the presence of focusing organelles such as oil droplets, cone outer segments can be reduced in size to various degrees. We conclude that outer segment taper is but one component of a miniaturization process that reduces metabolic costs while improving signal detection. Compromise solutions in the various retinas and retinal regions occur between ellipsoid size and acuity, on the one hand, and faster response time and reduced light sensitivity, on the other.This work was funded by the Natural Sciences and Engineering Research Council of Canada Discovery Grant 238886 and a Grass-Marine Biological Laboratory Sabbatical Fellowship in Neurosciences to I. Novales Flamarique.2012-07-1

Determination of melamine, ammeline, ammelide and cyanuric acid in infant formula purchased in Canada by liquid chromatography-tandem mass spectrometry

A liquid chromatography-tandem mass spectrometry-based isotope dilution method was developed for the analysis of the triazine compounds melamine (MEL), ammeline (AMN), ammelide (AMD) and cyanuric acid (CYA) in infant formula samples purchased in Canada in 2008 for the purpose of a combined exposure and risk assessment. Infant formula samples were extracted with 1:1 acetonitrile–water, cleaned up on disposable ion-exchange solid-phase extraction cartridges, and analysed by ultra-high-performance liquid chromatography-tandem mass spectrometry. MEL and CYA were detected in almost all infant formula products: the highest concentrations observed were 0.32 mg kg−1 MEL and 0.45 mg kg−1 CYA. Samples that were relatively high in MEL in this survey tended to be low in CYA, and vice versa. Concentrations of AMN and AMD were very low in all samples. The total of MEL-related compounds (sum of all four analytes) in all samples was below the interim standard of 0.5 mg kg−1 for infant formula products established by Health Canada

Cytodifferentiation of photoreceptors in larval goldfish: Delayed maturation of rods

This study describes the differentiation of photoreceptors in larval goldfish retina. The earliest photoreceptors to differentiate were cones; 3 H-fucose labeled cone but not rod outer segments in larval as well as adult goldfish. All major cone types known to be present in the adult goldfish retina (double cones, long and short single cones) were found in the larval retina by 2 days after hatching. The cones matured rapidly; within a few days they had well-developed outer segments and synaptic pedicles that were smaller, but otherwise similar to those in adults. Rods were slower to mature. Their outer segments were at first short, wide, and misshapen; only as they grew longer and narrower did they become straight and properly aligned. Rod spherules were first seen in fish older than 1 month; immature rods contained perinuclear synaptic ribbons and invaginating processes penetrated the cell body. These results suggest that the influence of rods and cones on visual function in larval goldfish may be quite different from the adult.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50026/1/902360108_ftp.pd

Temporally correlated expression of nAChR genes during development of the mammalian retina

In situ hybridizations and RNase protection assays have been used to characterize nicotinic acetylcholine receptor (nAChR) gene expression in the developing and adult rat retina. At the earliest time examined (embryonic day 13) a low level of [alpha]-3 and [beta]-4 gene expression could be detected. During the next 48 hr there was a dramatic induction of the [alpha]-3, [alpha]-4, [beta]-2, [beta]-3 and [beta]-4 genes in the recently differentiated retinal ganglion cells. By post-natal day 4 we detected nAChR gene expression in the inner nuclear layer. In the adult retina, in situ hybridizations showed these genes are expressed by cells residing in the ganglion and inner nuclear layers. These results suggest a common regulatory mechanism for the induction of nAChR expression in retinal ganglion cells during development. In addition, the variety of nAChR genes expressed in the retina imply a relatively large number of different types of nAChRs can be expressed by these cells.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30138/1/0000515.pd