Mellein, a Trail Pheromone Component of the Ant Lasius fuliginosus

3,4-Dihydro-8-hydroxy-3-methylisocoumarin (mellein) and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one are among the volatile constituents identified from the hindgut of the formicine ant Lasius (Dendrolasius) fuliginosus Mellein induces trail-following behavior in worker ants of this species and evokes electrophysiological responses from their antennae. The trail-following activity released by (R)-(–)-mellein is significantly higher than that elicited by its (S)-(+) antipode, or the racemic mixture. The above-mentioned pyranone is found also in the honeydew of aphids, the customary diet of this ant species. The pyranone also evokes some trail-following behavior, but its activity is far less pronounced than that of mellein. Apparently, extra pheromone components are present in the hindgut, since the activity of these two constituents, either individually or as a mixture, does not completely account for the total activity released by a hindgut extract containing similar amounts of these two compounds.     

Enabling the generation of web applications from mockups

Mockups are widely used to elicit and validate user requirements in web applications, and several intuitive tools have been developed in recent years, actively involving the end user in the requirements solicitation process. However, most current web development approaches and tools discard mockups after the information‐gathering process, abandoning the opportunity to exploit underlying information in them for autogenerating functional web applications. To overcome this limitation, we have devised a method for deriving the database schema and the logic of the web application from the information contained within mockups. In particular, the method gathers clues on how to organize the data and the control flow of the web application by analyzing the structure and relationships of the widgets in the mockup. Based on the proposed method, we have implemented a tool supporting the generation of web applications abiding by the model‐view‐controller architectural pattern. The tool has been evaluated by involving several end users in the development of web applications for different domains.     

Surface modification of protein nanocontainers and their self-directing character in polymer blends

Tailoring the surfaces of a nanocontainer with polymer brushes that have different affinities to the components of a phase-separating polymer blend should impart self-directing properties to the nanocontainers. Such nanocontainers could then be used to deliver a variety of functional species in tunable amounts and in a site-specific manner to polymer systems. This paper describes the surface modification, subsequent characterization of nanocontainers derived from ferritin, and the effects of surface modification on their self-directing properties in a binary phase-separating homopolymer blend. Wild ferritin was either PEGylated or alkylated by zero-length cross-linking to its surface carboxylate groups that were activated by carbodiimide. Modification was confirmed by ion-exchange chromatography, ζ-potential measurement, and electrospray ionization mass spectrometry. FT-IR spectrometry was used to quantify the extent of PEGylation by ratioing the intensity of the C-O-C asymmetric stretching vibration from the grafted PEG to that of the carbonyl stretching vibration (amide I band) from the protein. Importantly, modified ferritin was soluble in the organic solvent dichloromethane (DCM). Modified ferritin was introduced into a polymer blend of hydrophobic and hydrophilic polymers made up of poly(desaminotyrosyl tyrosine dodecyl ester carbonate) (PDTD) and PEG by solvent casting from solution in the common solvent DCM. Polymer thin films with an average thickness of ∼200 μm were obtained upon evaporation of the solvent. Transmission electron micrographs of microtomed polymer films demonstrated remarkable selectivity of PEGylated ferritin to PEG domains, while alkylated ferritin self-directs to the PDTD matrix.     

Solubility and electrochemical studies of LiFeO2–LiCoO2–NiO materials for the MCFC cathode application

The dissolution of the state-of-the-art lithiated NiO is still considered as one of the main obstacles to the commercialisation of the molten carbonate fuel cell (MCFC). Development of alternative cathode materials has been considered as a main strategy for solving this problem. Ternary compositions of LiFeO₂, LiCoO₂ and NiO are expected to decrease the cathode solubility while ensuring a good electrical conductivity and electrochemical activity towards the oxygen reduction.

In this work, new material compositions in the LiFeO₂–LiCoO₂–NiO ternary system were synthesised using Pechini method and investigating their electrical conductivity by the DC four probe method. Then the influence of the cobalt content in the composition was determined in terms of AC impedance analysis and solubility measurements after 200 h of immersion in Li₂CO₃–Na₂CO₃ at 650 °C. The DC electrical conductivity study reveals the ability of improving the electrical conductivity, adequate for MCFC cathode application, by controlling the Co content of the composition. A special attention was given to the evolution of the open circuit potential as a function of time and to the impedance spectroscopy characterization related to microstructure modifications. Taking into account solubility, electrical conductivity, as well as electrochemical performance in the fuel cell, this study reveals the possibility of using LiFeO₂–LiCoO₂–NiO ternary materials for MCFC cathode.     

Effects of age, milk replacer composition, and rumen function on lipogenesis in adipose tissue of young calves

Rates of utilization of glucose, acetate, and lactate and activities of selected enzymes were determined in vitro to evaluate the effects of age and diet on lipogenesis in perirenal adipose tissue of calves. Three-day-old Holstein bull calves were fed up to 12 wk of age on one of three dietary treatments: a high carbohydrate milk replacer; a high fat milk replacer; and weaning at 6 wk of age from high fat replacer to calf starter. Adipose tissue biopsies were obtained from calves at 2, 5, 8, and 12 wk of age. Rates of fatty acid synthesis and activities of enzymes of the pentose phosphate and citrate cleavage pathways were increased in calves fed high carbohydrate milk replacer. These parameters were decreased in calves fed high fat replacer and were further depressed after weaning. Substrate preference for fatty acid synthesis in all calves was acetate, then lactate, then glucose. With increase in age from 2 to 12 wk, adipose tissue of calves fed milk replacer partitioned more acetate and lactate toward fatty acid synthesis and less toward oxidation. The pentose phosphate cycle was characterized by high rate of recycling and contributed at least 50% of reducing equivalents required for fatty acid synthesis. It appeared that several features of lipogenesis characteristic of functional ruminants are also shared by preruminant calves.     

Development of white mustard (Sinapis alba L.) essential oil,a food preservative

White mustard essential oil (WMEO) has antimicrobial properties due to the presence of p-hydroxybenzyl isothiocyanate (p-HBITC). WMEO containing about 8% p-HBITC was made on a commercial scale as it is not commercially available. When characterised by HPLC/high resolution mass spectrometry, the triacylglycerols of WMEO and white mustard oil were found to be identical. Non-triacylglycerol components of WMEO could be directly traced back to those occurring naturally in the Brassicaceae family and enhanced by the presence of p-HBITC. New HPLC methods for analysing p-HBITC and its hydrolytic products showed that p-HBITC hydrolysis was slower under acidic conditions. The non-sulphur containing hydrolytic products p-hydroxybenzyl alcohol (p-HBA), p-hydroxybenzyl cyanide (p-HBCN) and p-cresol, were also quantitatively analysed. Commercial production of WMEO containing p-HBITC is feasible and will also result in defatted and deheated mustard flour with about 44% protein as a byproduct.     

Sex pheromone of tomato pestScrobipalpuloides absoluta (Lepidoptera: Gelechiidae)

The sex attractant ofScrobipalpuloides absoluta females is a 90:10 mixture of (3E,8Z,11Z)-3,8,11-tetradecatrien-1-yl acetate and (3E,8Z)-3,8-tetradecadien-1-yl acetate. Tetradecadienyl acetates bearing 8Z,11Z; 3E,8Z; and 3E,11Z double bonds were synthesized by stereospecific procedures; the mass spectral and gas chromatographic properties of the 3E,8Z isomer were found to be congruent with those of the tetradecadienyl acetate fromS. absoluta. In wind tunnel bioassays, a 10:1 mixture of synthetic (3E,8Z,11Z)-3,8,11-tetradecatrien-1-yl acetate and (3E,8Z)-3,8-tetradecadien-1-yl acetate was highly attractive toS. absoluta males. Interestingly, the presence of (8Z,11Z)-8,11-tetradecadien-1-yl acetate (10%) inhibited the response to (3E,8Z,11Z)-3,8,11-tetradecatrien-1-yl acetate completely.     

Growth, health, and blood glucose concentrations of calves fed high-glucose or high-fat milk replacers

The influence of age, carbohydrate-fat ratios of milk replacers, and development of ruminal function on growth, health, and blood glucose concentrations were evaluated in calves. Colostrum-fed, 3-day-old Holstein bull calves were fed to 12 wk on one of three dietary treatments: 1) a high carbohydrate, low fat (60.5% glucose, 9.5% lactose, and 3% lard) milk replacer; 2) a low carbohydrate, high fat (23% glucose, 12.5% lactose, and 30% lard) milk replacer; and 3) weaning at 6 wk of age from high-fat replacer to a standard calf starter. The high fat milk replacer was superior to low fat milk replacer for total weight gains and efficiency of feed conversion. Rates of weight gain of starter calves were similar to those of calves fed low fat. Calves fed the diet with low fat had a high incidence of diarrhea, an occasional outbreak of a yeast-related ethanol intoxication syndrome, and high concentrations of glucose in urine. Irrespective of milk replacer composition or development of ruminal function, plasma and whole blood glucose concentrations declined rapidly in the first 6 wk. Corpuscular glucose declined steadily with age in all calves. This age-related decrease of blood glucose concentration of calves seems to be a constitutive phenomenon.     

Cooking Oil: A Home Fire Hazard in Alberta, Canada

This paper begins with a brief statistical analysis to establish the significant contribution of cooking equipment fires to fire losses and injuries in Canadian homes. Due to lack of comprehensive fire loss data for Canadian homes, further analysis is focused on Alberta data. The most frequent ignition scenario, based on a top-down analysis of Alberta home fires, was the ignition of overheated cooking oil in pots, deep-fat fryers, or pans heated on stove tops. These fires also accounted for the majority of home fire injuries. Fire characteristics of cooking oils, which point to the importance of maintaining oil temperatures below their flash points, and thermostatically controlled deep-fat fryers as the best available solution to the problem are discussed.     

Chemical and behavioral studies on dufour gland contents ofManica rubida (Hymenoptera: Formicidae)

The Dufour gland ofManica rubida contains a simple mixture of (Z, E)-α-farnesene and (Z, E)-α-homofarnesene with tiny amounts of other faraesene, homofarnesene, and bishomofarnesene isomers. The gland also contains a mixture of very volatile compounds, chiefly acetone, with smaller amounts of acetaldehyde, ethanol, propanol, isobutyraldehyde, butenone, and butanone. The workers ofM. rubida are not attracted to these highly volatile compounds as are workers ofMyrmica species, butM. rubida workers show a strong increase of linear speed when stimulated by a freshly isolated gland. This response of increased speed of bothM. rubida andM. trubra to their own or each other's Dufour gland secretion is consistent with the presence of the farnesenes in them both.