Assessment of the Effect of Satureja montana and Origanum virens Essential Oils on Aspergillus flavus Growth and Aflatoxin Production at Different Water Activities

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Aflatoxin contamination of foodstuffs poses a serious risk to food security, and it is essential to search for new control methods to prevent these toxins entering the food chain. Several essential oils are able to reduce the growth and mycotoxin biosynthesis of toxigenic species, although their efficiency is strongly influenced by the environmental conditions. In this work, the effectiveness of Satureja montana and Origanum virens essential oils to control Aspergillus flavus growth was evaluated under three water activity levels (0.94, 0.96 and 0.98 aw) using a Bioscreen C, a rapid in vitro spectrophotometric technique. The aflatoxin concentrations at all conditions tested were determined by HPLC-FLD. Aspergillus flavus growth was delayed by both essential oil treatments. However, only S. montana essential oil was able to significantly affect aflatoxin production, although the inhibition percentages widely differed among water activities. The most significant reduction was observed at 0.96 aw, which is coincident with the conditions in which A. flavus reached the highest levels of aflatoxin production. On the contrary, the treatment with S. montana essential oil was not effective in significantly reducing aflatoxin production at 0.94 aw. Therefore, it is important to study the interaction of the new control compounds with environmental factors before their application in food matrices, and in vitro ecophysiological studies are a good option since they provide accurate and rapid results.Peer reviewedFinal Published versio

Temperature‑induced changes in dough elasticity as a useful tool in defining the firmness of cooked pasta

Semolina with high protein content and strong gluten is recognized as the best raw-material for pasta-products with a good cooking quality, while little consideration has been given to semolina dough elasticity when heating is applied. In this research, a new technique was developed by adapting the Glutograph (Brabender GmbH&Co., Duisburg, Germany) to measure the changes in elasticity induced by heating on a sheeted dough. The information obtained by this procedure was related to the firmness of cooked pasta. Starting from semolina of four durum wheat varieties with differences in protein quantity and quality, dough samples were prepared in a Farinograph at a hydration level of 35 %. Each dough was sheeted by a home-made pasta machine, obtaining disks of 5 cm diameter and 2.1 mm thickness. Stretching (10 s) and relaxation (30 s) cycles were applied repeatedly during the test time, while dough temperature was increased from 30 to 90 \ub0C at 1.2 \ub0C/min. For each peak recorded, stretching and recovery values were calculated and plotted against sample temperature. Both stretching and recovery curves were integrated and the loss of elasticity was calculated. Results showed as high elasticity loss during heating is related to low firmness of the related cooked pasta

Medium Access Control for Wireless Sensor Networks based on Impulse Radio Ultra Wideband

This paper describes a detailed performance evaluation of distributed Medium Access Control (MAC) protocols for Wireless Sensor Networks based on Impulse Radio Ultra Wideband (IR-UWB) Physical layer (PHY). Two main classes of Medium Access Control protocol have been considered: Slotted and UnSlotted with reliability. The reliability is based on Automatic Repeat ReQuest (ARQ). The performance evaluation is performed using a complete Wireless Sensor Networks (WSN) simulator built on the Global Mobile Information System Simulator (GloMoSim). The optimal operating parameters are first discussed for IR-UWB in terms of slot size, retransmission delay and the number of retransmission, then a comparison between IR-UWB and other transmission techniques in terms of reliability latency and power efficiency

Simulation Platform for Wireless Sensor Networks Based on Impulse Radio Ultra Wide Band

Impulse Radio Ultra Wide Band (IR-UWB) is a promising technology to address Wireless Sensor Network (WSN) constraints. However, existing network simulation tools do not provide a complete WSN simulation architecture, with the IR-UWB specificities at the PHYsical (PHY) and the Medium Access Control (MAC) layers. In this paper, we propose a WSN simulation architecture based on the IR-UWB technique. At the PHY layer, we take into account the pulse collision by dealing with the pulse propagation delay. We also modelled MAC protocols specific to IRUWB, for WSN applications. To completely fit the WSN simulation requirements, we propose a generic and reusable sensor and sensing channel model. Most of the WSN application performances can be evaluated thanks to the proposed simulation architecture. The proposed models are implemented on a scalable and well known network simulator: Global Mobile Information System Simulator (GloMoSim). However, they can be reused for all other packet based simulation platforms

Oxytocin at physiological concentrations evokes adrenocorticotropin (ACTH) release from corticotrophs by increasing intracellular free calcium mobilized mainly from intracellular stores. Oxytocin displays synergistic or additive effects on ACTH-releasing factor or arginine vasopressin-induced ACTH secretion, respectively

The potency of oxytocin (OT) in evoking ACTH secretion by isolated, superfused rat adenohypophyseal corticotrophs and its enhancement by CRF and arginine vasopressin (AVP) were analyzed. Each secretagogue effectively released ACTH from adenohypophyseal cells when added separately in pulsatile fashion in physiological concentrations based on hypophyseal portal blood (OT, 10 nM; AVP, 0.5 nM; CRF, 0.1 nM). OT released ACTH at concentrations as low as 1 nM. Moreover, a dose- response relationship up to 10 microM was revealed. Combinations of a constant amount of CRF (0.1 nM) with increasing concentrations of OT exerted a synergistic effect on ACTH release. In contrast, OT given in various concentrations in combination with AVP (0.5 nM) produced an additive effect on ACTH release. To study the mechanism of action of OT on ACTH secretion, cytosolic free calcium levels in single pituitary cells exposed to OT or AVP were measured using the calcium-sensitive fluorescent indicator Fura-2. Corticotrophs among mixed adenohypophyseal cell types in the primary cultures were identified by immunocytochemistry. More than 500 cells were individually stimulated with OT or AVP. Basal cytosolic free calcium levels ranged between 80- 130 nM free calcium. The addition of 100 nM OT or 1 microM AVP increased the cytosolic free calcium concentration within 3 sec to values ranging from 500-800 nM. An increase in intracellular calcium ranging from 200-500 nM due to OT could still be observed after extracellular calcium depletion. Taken together, our data demonstrate that physiological concentrations of OT stimulate ACTH secretion, independent of the other ACTH secretagogues, by mobilizing calcium mainly from intracellular stores

A Buffer Stocks Model for Stabilizing Price of Commodity under Limited Time of Supply and Continuous Consumption

Staple foods, in developing countries especially in Indonesia, have extremely volatile among harvest and planting season caused by inelastic of supply-demand and price disparity. When a staple food is shortage in market, it will trigger crisis of economics, political and social because it concerns with food security. This paper develops a buffer stock model for stabilizing price of commodity under limited time of supply and continuous consumption. The performance criterion of model will consider financial loss of producer, consumer and government side when market is interfered by price-stabilization program and price-support program simultaneously. The price fluctuation will be stabilized by market operation where buffer stocks are bought from domestic and import supply point. This paper provides a price band policy that attempts to bound domestic price variation between a set of upper and lower bounds on the level of domestic prices. We consider three sets of problems reflecting different three prices elasticity from 4 period of supply and demand. Numerical examples are found to be consistent with empirical estimates regarding the relationship price elasticity with price band and with government budget for the agenda of assisting household to assure availability a staple food with enough amounts at rational prices. Keywords: buffer stocks, price band, stabilization, limited time of supply, staple foods

A Buffer Stocks Model for Stabilizing Price in Duopoly-Like Market

This paper presents the staple-food distribution problem in agro-industry. There is a great difference of staple-food supplies in the harvest-season and in the planting-season meanwhile the demand is relatively constant. This situation will trigger price-volatility and shortage of staple-food, and it causes opportunity-losses for the stakeholders (producer, consumer, wholesaler/trader, and the government). For stabilizing the price, the government has several stabilization policies; one of them is market-intervention policy by using buffer-stocks schemes. The market-intervention policy should be utilized for improving producer’s profit, for cutting consumer’s expenditure, and for sustaining wholesaler’s margin-profit by implementing price-support and price-stabilization. In duopoly-like market, we assume that there are only two market-players in the distribution system. The objective of this research is to determine the instruments for operating Market-Intervention Program which consist of the quantity, time, and price of the buffer-stocks schemes. The problem was solved using 3 approaches. First, a comparative cost/benefit analysis between free-market and intervention-market can be used to formulate the objective function of each stakeholders. Second, the integration of optimization model and econometrics model were use to develop the decision-variables subject to the expectation of stakeholders, the buffer-stocks requirement, and the dynamics price equilibrium properties. Third, model market with Inventory was applied for solving the market-price equilibrium. The result could be used to analyze such the staple-food distribution system, incorporating the configuration of duo-producers, duo market-buyers, and duo-consumers. Keywords: buffer-stocks, duopoly-like market, market-intervention program, model market with inventory, and staple-food distribution system

Lune, Wyre & Furness Fisheries Advisory Committee 9th September, 1974

This is the report from the Lune, Wyre and Furness Fisheries Advisory Committee meeting, which was held on the 9th September 1974. The report looks at comments of the Regional Fisheries Officer on the report 'Taking Stock', and information including the aims of a report entitled 'Coarse Fisheries'. The report also includes sections on the improvement of fisheries in the River Leven, coarse fish salvage and stocking, fishery prosecutions, and biological work on the River Kent. Fish mortalities are also given as well as fish monitoring figures for areas on the Rivers Lune and Leven for 1974. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996

The Potential Applications of Optical Dating to the Sandy Uplands of East Texas and Northwest Louisiana

The fine, sandy soils of East Texas and Northwest Louisiana have been the source of archaeological debate for some time. This discourse concerns the mode of burial of cultural material in the easily eroded soils and the mechanics of recent (Holocene) landform evolution. Because these deposits are typically well-drained, organic matter does not preserve well, thus hindering the dating of the geomorphic events that figure prominently in their development and the prehistoric occupations which lie buried throughout uplands of this region. A relatively new dating technique, optical dating, has much to offer this region and the archaeological community as it measures the period of time that has elapsed since sand grains were last exposed to sunlight. Hence, it directly dates the time of sediment transportation and deposition. This method is therefore applicable to a number of archaeological and geomorphic processes which may not be dated by traditional methods, owing to the lack of organic matter suitable for radiocarbon dating. In geomorphic contexts, optical dating may be preferred over radiocarbon as it directly dates the time of sedimentation rather than the age of organic matter in features such as buried soils that may be significantly different from the geomorphic event which fossilized the soil