Simulation of humidity control and greenhouse temperature tracking in a growth chamber using a passive air conditioning unit

In this paper, we define a dynamic discrete model of a passive air conditioning unit, without the more typical compression or absorption-refrigeration cycle. The unit is composed of heat exchangers, a positioning system and humid corrugated pads. The aim of the study was to follow the temperature in a greenhouse and to replicate it with a desired and stable relative humidity in a ventilated growth chamber. A control law, based on a quadratic criterion and dynamic programming, taking output error and energy consumption minimisation into account, was used to control the behaviour of the unit in spite of air intake disturbances. The results of the simulation indicate that the air conditioning unit can produce a variable climate in the growth chamber, with a wide range of relative humidity setpoints.     

Fibrinolytic enzymes in Asian traditional fermented foods

Cardiovascular diseases, such as heart attack and stroke, are the leading causes of death in North America. According to data provided by the World Health Organization in 2000, heart diseases are responsible for 29% of the total mortality rate in the world. Since cardiovascular diseases have a major impact on an individual’s quality of life, a tremendous amount of research has been done in the area of prevention and the treatment of the diseases. Fibrinolytic enzymes are agents that dissolve fibrin clots. Recently many food derived fibrinolytic enzymes have been found in various traditional Asian foods. Fibrinolytic enzymes can be found in a variety of foods, such as Japanese Natto, Tofuyo, Korean Chungkook-Jang soy sauce, and edible honey mushroom. Enzymes have been purified from these foods, and their physiochemical properties have been characterized. Fermented shrimp paste, a popular Asian seasoning, was shown to have strong fibrinolytic activity. These novel fibrinolytic enzymes derived from traditional Asian foods are useful for thrombolytic therapy. They will provide an adjunct to the costly fibrinolytic enzymes that are currently used in managing heart disease, since large quantities of enzyme can be conveniently and efficiently produced. In addition, these enzymes have significant potential for food fortification and nutraceutical applications, such that their use could effectively prevent cardiovascular diseases.     

Detection of acylated homoserine lactones in gram-negative proteolytic psychrotrophic bacteria isolated from cooled raw milk

Through a mechanism called quorum sensing, bacteria are able to express specific genes in response to population density. Cell-to-cell communication in bacteria is mediated by signal molecules such as acylated homoserine lactones (AHLs). This work aimed to detect AHL production in Gram-negative psychrotrophic bacteria isolated from raw milk. A total of 84.9% of the bacteria were identified as AHL producers eliciting a diversity of responses in the AHL-monitor systems. These results demonstrate that AHL-production is common among psychrotrophic bacteria isolated from milk, and indicate that quorum sensing may play an important role in the spoilage of this product.     

Study of fuel insolubles: Formation conditions and characterization of copper compounds

The solids formed in the systems containing copper in different oxidation states, in the presence and absence of hexanoic acid and dodecanethiol, together and separately, at room temperature, were studied. The experiments were performed in a mineral oil matrix, free of sulfur compounds and metals; a diesel oil matrix; and the reagents alone, without any matrix. The deposits formed were analyzed by elemental analysis (EA), infrared spectroscopy (IR), thermogravimetric analysis (TGA) and total copper by inductively coupled plasma-optical emission spectrometry (ICP-OES), for their identification and determination of the probable structures. In samples containing both hexanoic acid and dodecanethiol, when there is copper(I), anhydrous copper(II) hexanoate is preferentially formed, but in samples of copper(II), copper(II) mercaptate is formed first. In samples of metallic copper in mineral oil matrix, no deposit formations occur. In all cases in which deposits were formed, they were the same as in diesel oil matrix.     

The Food Choice Questionnaire: Factorial invariant over western urban populations?

To assess the degree of measurement invariance of the Food Choice Questionnaire (FCQ) across western urban populations, it was filled out by demographically comparable samples in Canada (163 English speaking students, original version), Belgium (Flanders, N = 176, Dutch translation), and Italy (N = 163, Italian translation). Reliability of the FCQ-scales was moderate to good, but sometimes differed from the normative values. Item analysis pinpointed items with skewed distributions and low item-total correlations. Subsequent confirmatory and exploratory factor analyses revealed a suboptimal fit for the FCQ-model in all samples, with small to considerable divergences from the original configuration. The findings do not support the generalizability of the FCQ’s factor structure, but suggest that its items and underlying constructs may have different connotations across western urban populations. Explanations for the lack of convergence in factor structure and implications for research are discussed.     

The Cold Chain,one link in Canada’s food safety initiatives

The Cold Chain has always played an important role in food safety within the global market. The Canadian government has recognized it has an important role in the food continuum. In partnership with industry, national voluntary enhanced food safety systems, based on Codex Alimentarius (HACCP) principles, are being developed within Canada. These efforts will contribute towards food safety and will build confidence in foodstuffs grown, prepared and sold at all levels of trade and abroad.