A comment on "What catch data can tell us about the status of global fisheries"

There is considerable interest in the state of the world’s natural fishery resources. The paper by Froese et al. (2012) is a recent example of applying a set of ad hoc decision rules to a time series of catch data in order to assign the world’s fisheries to categories of exploitation and hence make generalisations about their current status. They conclude that the percentage of stocks that are over-exploited is worse than previously reported in FAO (2010). The approach used by Froese et al. is based on an algorithm proposed by Froese and Kesner-Reyes (2002) which has been heavily criticised both on theoretical grounds and from simulation studies (Branch et al. 2011; Daan et al. 2011; Wilberg and Miller 2007). In their recent paper, Froese et al. (2012) produce additional analyses to support their method which assumes that maximum sustainable yield (MSY) lies in the interval (0.5Cmax, Cmax), where Cmax is the maximum observed catch in the time series. Unfortunately, these analyses do not support their contention that MSY for a particular stock is related to maximum catch in a predictable way and renders their conclusions unsaf

A tetrabenzotriazaporphyrin based organic thin film transistor: Comparison with a device of the phthalocyanine analogue

The characteristics of bottom-gate bottom-contact organic thin film field-effect transistors (OTFTs) with 70 nm thick films of solution processed non-peripherally octahexyl-substituted nickel tetrabenzo triazaporphyrin (6NiTBTAP) molecules as active layers on silicon substrates are experimentally studied and the results are compared with the similary configured transistors using the corresponding nickel phthalocyanine (6NiPc) compound. 6NiTBTAP transistors are found to exhibit improved performance over 6NiPc transistors in terms of greater saturation hole mobility, two orders of magnitude higher on/off ratio and lower threshold voltage. This enhanced performance of 6NiTBTAP OTFTs over 6NiPc devices is attributed to improved surface morphology and large grain size of the active 6NiTBTAP film

In situ chemichromic studies of interactions between a lutetium bis-octaalkyl-substituted phthalocyanine and selected biological cofactors

This article is available open access through the publisher’s website at the link below. Copyright @ 2011 The Royal Society.Spin-coated films, approximately 100 nm thick, of a newly synthesized bis[octakis(octyl)phthalocyaninato] lutetium(III) complex on ultrasonically cleaned glass substrates exhibit pronounced chemichromic behaviour with potential application in healthcare. In situ kinetic optical absorption spectroscopic measurements show that the phthalocyanine Q-band is red shifted by 60 nm upon oxidation arising from exposure to bromine vapour. Recovery to the original state is achieved by the treatment of the oxidized films with nicotinamide adenine dinucleotide and l-ascorbic acid (vitamin C) in an aqueous solution containing 1.5 M lithium perchlorate. The neutralization process is found to be governed by first-order kinetics. The linear increase of the reduction rate with increasing concentration of cofactors provides a basis for calibration of analyte concentrations ranging from 3.5 mM down to 0.03 mM.Air Force Office of Scientific Research, Air Force Material Command, USAF and the Leverhulme Trust

Evolving dynamic networks: An underlying mechanism of drug resistance in epilepsy?

This is the final version. Available on open access from Elsevier via the DOI in this recordAt least one-third of all people with epilepsy have seizures that remain poorly controlled despite an increasing number of available anti-epileptic drugs (AEDs). Often, there is an initial good response to a newly introduced AED, which may last up to months, eventually followed by the return of seizures thought to be due to the development of tolerance. We introduce a framework within which the interplay between AED response and brain networks can be explored to understand the development of tolerance. We use a computer model for seizure generation in the context of dynamic networks, which allows us to generate an ‘in silico’ electroencephalogram (EEG). This allows us to study the effect of changes in excitability network structure and intrinsic model properties on the overall seizure likelihood. Within this framework, tolerance to AEDs – return of seizure-like activity – may occur in 3 different scenarios: 1) the efficacy of the drug diminishes while the brain network remains relatively constant; 2) the efficacy of the drug remains constant, but connections between brain regions change; 3) the efficacy of the drug remains constant, but the intrinsic excitability within brain regions varies dynamically. We argue that these latter scenarios may contribute to a deeper understanding of how drug resistance to AEDs may occur.Medical Research Council (MRC)Royal SocietyWellcome TrustEngineering and Physical Sciences Research Council (EPSRC

High-mobility solution-processed copper phthalocyanine-based organic field-effect transistors

© 2011 National Institute for Materials ScienceSolution-processed films of 1,4,8,11,15,18,22,25-octakis(hexyl) copper phthalocyanine (CuPc6) were utilized as an active semiconducting layer in the fabrication of organic field-effect transistors (OFETs) in the bottom-gate configurations using chemical vapour deposited silicon dioxide (SiO2) as gate dielectrics. The surface treatment of the gate dielectric with a self-assembled monolayer of octadecyltrichlorosilane (OTS) resulted in values of 4×10−2 cm2 V−1 s−1 and 106 for saturation mobility and on/off current ratio, respectively. This improvement was accompanied by a shift in the threshold voltage from 3V for untreated devices to −2V for OTS treated devices. The trap density at the interface between the gate dielectric and semiconductor decreased by about one order of magnitude after the surface treatment. The transistors with the OTS treated gate dielectrics were more stable over a 30-day period in air than untreated ones.Technology Strategy Board, UK (Project No: TP/6/EPH/6/S/K2536J)

Understanding and optimising an identification/brief advice (IBA) service about alcohol in the community pharmacy setting

This is the final report of an evaluation into the identification/brief advice (IBA) service about alcohol in community pharmacy settings in the North West of England. Since 2007, almost 100 pharmacies in the North West have - at some point - been commissioned to provide an identification and brief advice (IBA) service for alcohol. This evaluation sought to understand how the service had been adapted for and implemented in the community pharmacy setting, and how its potential might be maximised. Its aims were: 1. To characterise, consolidate and optimise both the constant and variable elements of the pharmacy alcohol identification/brief advice (IBA) service in NHS Northwest, and 2. To inform planning for current and future pharmacy based services promoting safe consumption of alcohol. The evaluation was split into three main workstreams, supported by a preliminary scoping phase, and combined quantitative and qualitative methods: • Descriptive and comparative statistical analysis of pharmacy alcohol IBA data; • In-pharmacy work, including observation of staff engagement with customers, recording consultations between staff and customers, follow-up telephone interviews with customers, and group feedback interviews with pharmacy staff; • Stakeholder engagement through self-completion surveys, semi-structured interviews and a workshop. This report gives the background to the project, and details the methods, results and implications

Hydrazine compounds inhibit glycation of low-density lipoproteins and prevent the in vitro formation of model foam cells from glycolaldehyde-modified low-density lipoproteins

Aims/hypothesis: Previous studies have shown that glycation of LDL by methylglyoxal and glycolaldehyde, in the absence of significant oxidation, results in lipid accumulation in macrophage cells. Such 'foam cells' are a hallmark of atherosclerosis. In this study we examined whether LDL glycation by methylglyoxal or glycolaldehyde, and subsequent lipid loading of cells, can be inhibited by agents that scavenge reactive carbonyls. Such compounds may have therapeutic potential in diabetes-associated atherosclerosis. Materials and methods: LDL was glycated with methylglyoxal or glycolaldehyde in the absence or presence of metformin, aminoguanidine, Girard's reagents P and T, or hydralazine. LDL modification was characterised by changes in mobility (agarose gel electrophoresis), cross-linking (SDS-PAGE) and loss of amino acid residues (HPLC). Accumulation of cholesterol and cholesteryl esters in murine macrophages was assessed by HPLC. Results: Inhibition of LDL glycation was detected with equimolar or greater concentrations of the scavengers over the reactive carbonyl. This inhibition was structure-dependent and accompanied by a modulation of cholesterol and cholesteryl ester accumulation. With aminoguanidine, Girard's reagent P and hydralazine, cellular sterol levels returned to control levels despite incomplete inhibition of LDL modification. Conclusions/ interpretation: Inhibition of LDL glycation by interception of the reactive aldehydes that induce LDL modification prevents lipid loading and model foam cell formation in murine macrophage cells. Carbonyl-scavenging reagents, such as hydrazines, may therefore help inhibit LDL glycation in vivo and prevent diabetes-induced atherosclerosis. © Springer-Verlag 2006