The control of sea lice in Atlantic salmon by selective breeding

Sea lice threaten the welfare of farmed Atlantic salmon and the sustainability of fish farming across the world. Chemical treatments are the major method of control but drug resistance means that alternatives are urgently needed. Selective breeding can be a cheap and effective alternative. Here, we combine experimental trials and diagnostics to provide a practical protocol for quantifying resistance to sea lice. We then combined quantitative genetics with epidemiological modelling to make the first prediction of the response to selection, quantified in terms of reduced need for chemical treatments. We infected over 1400 young fish with Lepeophtheirus salmonis, the most important species in the Northern Hemisphere. Mechanisms of resistance were expressed early in infection. Consequently, the number of lice per fish and the ranking of families were very similar at 7 and 17 days post infection, providing a stable window for assessing susceptibility to infection. The heritability of lice numbers within this time window was moderately high at 0.3, confirming that selective breeding is viable. We combined an epidemiological model of sea lice infection and control on a salmon farm with genetic variation in susceptibility among individuals. We simulated 10 generations of selective breeding and examined the frequency of treatments needed to control infection. Our model predicted that substantially fewer chemical treatments are needed to control lice outbreaks in selected populations and chemical treatment could be unnecessary after 10 generations of selection. Selective breeding for sea lice resistance should reduce the impact of sea lice on fish health and thus substantially improve the sustainability of Atlantic salmon production.     

MMG measurement: a high-sensitivity microphone-based sensor forclinical use

A high-sensitivity human muscle-vibration measurement (MMG) sensor adapted to clinical use is presented. The muscle vibration phenomenon is modeled and investigated to optimize the measurement technique. The sensor uses an acoustic impedance adaptation technique to convert the skin surface vibration in terms of acoustic pressure, which is sensed by a microphone. The device is calibrated and gives the real amplitude of the vibration. It is also well fitted to measure other physiological vibrations in the 2 Hz-1 kHz range     

Comparison of Thin Films of Titanium Dioxide Deposited by Sputtering and Sol–Gel Methods for Waveguiding Applications

Semiconductors - In this work, TiO2 thin films were deposited onto glass substrate by two different techniques: sol–gel dip-coating (SG) and reactive DC magnetron sputtering (Sput). The...     

A simulation optimization approach in production planning of failure prone manufacturing systems

In this paper, the implementation of a new method to control the production rate of manufacturing systems, based on the combination of stochastic optimal control theory, discrete event simulation, experimental design and response surface methodology is outlined. The system under study consists of several parallel machines, multiple-product manufacturing system. Machines are subject to failures and repairs and their capacity process is assumed to be a finite state Markov chain throughout the analytical control model. The problem is to choose the production rates so as to minimize the expected discounted cost of inventory/backlog over an infinite horizon. We first show that, for constant demand rates and exponential failure and repair times distributions of the machines, the hedging point policy is optimal. The structure of the hedging point policy is then parameterized by factors representing the thresholds of involved products. With such a policy, simulation experiments are combined to experimental design and response surface methodology to estimate the optimal control policy. We obtain that the hedging point policy is also applicable to a wide variety of complex problems including non-exponential failure and repair times distributions and random demand rates. Analytical solutions may not be easily obtained for such complex situations.     

Limitations of Preferential Enrichment: A Case Study on Tryptophan Ethyl Ester Hydrochloride

Since eutomer and distomer show different biological effects, access to pure enantiomers is essential. Preferential enrichment is a relatively new process of chiral resolution developed in the 90s. Extension of its scope was attempted with tryptophan ethyl ester hydrochloride. This salt meets one of the most important requirements for preferential enrichment, namely, a larger solubility for the pure enantiomers with reference to the racemic compound. But, due to the absence of a solid solution, this salt cannot perform preferential enrichment. This impossibility was endorsed by semi‐empirical molecular modeling.     

Effect of heat treatment on foaming properties of ostrich (Struthio camelus) egg white proteins

The effect of heat-treatment on foaming properties of ostrich albumen was investigated. At pH 7.5, coagulation of ovotransferrin (OT) resulted in minimum foaming capacity (FC) and maximum foam density (FD). While both exposure of sulfhydryl groups of ovalbumin (OV) and OT-OV interactions improved FC at lower pH, neither of them had beneficial effect on FC at pH 9. At pH 9, FC and FD were mildly affected by heat-treatment because of less aggregation of OT, then FC decreased due to covalent aggregates composed of ovomucin and OV, but at higher temperatures, higher level of OV unfolding resulted in enhanced FC.     

Role of end-groups and catalyst in polyester cyclodepolymerization and cycle-chain equilibria

The influence of polyesters end-groups on cyclic oligoester formation is investigated using a series of hydroxy-, carboxy- and methylester-terminated aliphatic polyesters, in the presence of various ester interchange catalysts. The presence of hydroxy end-groups is the preponderant factor on cyclodepolymerization kinetics. This indicates that the main reaction is the intramolecular hydroxy–ester interchange reaction between hydroxy end-groups and ester functions in the chain. Carboxy-ester and ester–ester interchanges play a minor role, as the cycle-chain equilibrium is reached only very slowly when carboxy- or ester-terminated polyesters are reacted. High temperature and the presence of tin catalysts are also favorable factors, while, as expected, dilution shifts the equilibrium toward the formation of high yields of cyclic oligoesters. A mechanism is proposed, based on the reverse of the “coordination-insertion” mechanism established for the ring-opening polymerization of lactones.     

Novel Tacrine‐Grafted Ugi Adducts as Multipotent Anti‐Alzheimer Drugs: A Synthetic Renewal in Tacrine–Ferulic Acid Hybrids

Herein we describe the design, multicomponent synthesis, and biological, molecular modeling and ADMET studies, as well as in vitro PAMPA‐blood–brain barrier (BBB) analysis of new tacrine–ferulic acid hybrids (TFAHs). We identified (E)‐3‐(hydroxy‐3‐methoxyphenyl)‐N‐{8[(7‐methoxy‐1,2,3,4‐tetrahydroacridin‐9‐yl)amino]octyl}‐N‐[2‐(naphthalen‐2‐ylamino)2‐oxoethyl]acrylamide (TFAH 10 n ) as a particularly interesting multipotent compound that shows moderate and completely selective inhibition of human butyrylcholinesterase (IC₅₀=68.2 nM ), strong antioxidant activity (4.29 equiv trolox in an oxygen radical absorbance capacity (ORAC) assay), and good β‐amyloid (Aβ) anti‐aggregation properties (65.6 % at 1:1 ratio); moreover, it is able to permeate central nervous system (CNS) tissues, as determined by PAMPA‐BBB assay. Notably, even when tested at very high concentrations, TFAH 10 n easily surpasses the other TFAHs in hepatotoxicity profiling (59.4 % cell viability at 1000 μM ), affording good neuroprotection against toxic insults such as Aβ_1–40, Aβ_1–42, H₂O₂, and oligomycin A/rotenone on SH‐SY5Y cells, at 1 μM . The results reported herein support the development of new multipotent TFAH derivatives as potential drugs for the treatment of Alzheimer′s disease.     

High-accuracy position and orientation measurement of extended two-dimensional surfaces by a phase-sensitive vision method

We introduced recently phase measurements usually performed in interferometry to the domain of image processing and intelligent vision [IEEE Trans. Instrum. Meas. 49, 867 (2000)]. Our purpose is to sense with a high accuracy the position, orientation, and displacement of two-dimensional (2D) surfaces observed by a static vision system. We report on significant improvements of the method. Experimental measurements reveal a peak-valley noise of approximately 10(-2) CCD pixel, corresponding approximately to a 10(-3) period of the phase reference pattern. Then the observation of 10 microm scaled features enables an accuracy of a few nm in the position sensing of the phase reference pattern for the extended 2D measurement range.