Bottom trawl fishing footprints on the world’s continental shelves

Bottom trawlers land around 19 million tons of fish and invertebrates annually, almost one-quarter of wild marine landings. The extent of bottom trawling footprint (seabed area trawled at least once in a specified region and time period) is often contested but poorly described. We quantify footprints using high-resolution satellite vessel monitoring system (VMS) and logbook data on 24 continental shelves and slopes to 1,000-m depth over at least 2 years. Trawling footprint varied markedly among regions: from 50% in some European seas. Overall, 14% of the 7.8 million-km2 study area was trawled, and 86% was not trawled. Trawling activity was aggregated; the most intensively trawled areas accounting for 90% of activity comprised 77% of footprint on average. Regional swept area ratio (SAR; ratio of total swept area trawled annually to total area of region, a metric of trawling intensity) and footprint area were related, providing an approach to estimate regional trawling footprints when high-resolution spatial data are unavailable. If SAR was ≤0.1, as in 8 of 24 regions, there was >95% probability that >90% of seabed was not trawled. If SAR was 7.9, equal to the highest SAR recorded, there was >95% probability that >70% of seabed was trawled. Footprints were smaller and SAR was ≤0.25 in regions where fishing rates consistently met international sustainability benchmarks for fish stocks, implying collateral environmental benefits from sustainable fishing

The Open Anchoring Quest Dataset: Anchored Estimates from 96 Studies on Anchoring Effects

People’s estimates are biased toward previously considered numbers (anchoring). We have aggregated all available data from anchoring studies that included at least two anchors into one large dataset. Data were standardized to comprise one estimate per row, coded according to a wide range of variables, and are available for download and analyses online (https://metaanalyses.shinyapps.io/OpAQ/). Because the dataset includes both original and meta-data it allows for fine-grained analyses (e.g., correlations of estimates for different tasks) but also for meta-analyses (e.g., effect sizes for anchoring effects)

Recombination behaviour at the ultrathin polypyrrole film silicon interface investigated by in situ pulsed photoluminescence

We investigated the change in Si surface recombination behaviour during the electrodeposition of ultrathin polypyrrole PPy films onto Si surfaces by means of in situ pulsed photoluminescence PL spectroscopy. The quenching of the band gap related PL is lower better passivation when the electrodeposition is performed in a less acidic solution by use of potential pulse sequences. In situ infrared spectroscopic ellipsometry IR SE was applied for the first time to PPy electrodeposition. IR SE and PL measurements confirm negligible formation of SiOx species at the Si PPy interface although aqueous electrolytes were use

Self-assembly of electrically conducting biopolymer thin films by cellulose regeneration in gold nanoparticle aqueous dispersions

Electrically conducting cellulose films comprising interconnected networks of gold nanoparticles were prepared by a facile self-assembly procedure. The hybrid films were produced by immersing spin-coated viscous N-methylmorpholine- N-oxide/dimethyl sulfoxide solutions of cellulose into aqueous dispersions of gold nanoparticles of variable concentration. Regeneration of an intact cellulose fiber matrix with integrated gold nanoparticles occurred spontaneously to produce self-supporting, defect-free metallized films, 2.5-12 μm in thickness and with nanoparticle loadings of up to 44 wt . The hybrid films displayed surface plasmon resonance bands consistent with discrete or uniaxially coupled nanoparticles depending on the extent of gold loading. Stress/strain measurements indicated that the cellulose films were not mechanically compromised by the incorporation of the gold nanoparticles, which were stabilized within the biopolymer matrix by interactions with the ether oxygen and hydroxyl groups of d-glucopyranose (FTIR spectrosopy results). Room temperature Van der Pauw measurements indicated that the hybrid films were electrically conducting above a gold nanoparticle loading of 20 wt . In addition, measurements of resistivity from 4.2 to 300 K showed a transformation from metallic band-like conduction (44 wt ) to Mott-type carrier hopping behavior at lower gold nanoparticle loadings (33 wt ) and low temperatures (T < 100 K). Given the widespread nature of the existing cellulose industry, self-supporting gold nanoparticle/cellulose hybrid films could have diverse applications in smart papers and textiles, as well as in numerous devices involving microelectronic components, catalysts and chemical sensors. © 2010 American Chemical Society