REPLY TO VAN ROOTSELAAR'S CRITICISMS OF MY THEORY OF THINGS

Van Rootselaar criticizes some points in my theory of things for being allegedly trivial, others for being mistaken. While some results are indeed mathematically trivial they are not so philosophically. As for the mistakes, some arc undoubtedly there, most can be corrected easily, and others require changes that have been introduced in the final version of the theory. The rest arc not mistakes but misunderstandings, perhaps unavoidable given the brevity of the original paper.     

Correspondence Comments on ‘Robust optimal parametric LQ control with a guaranteed cost bound and applications’

In a recent paper Hu and Loh (1989) addressed the problem of designing robust controllers with guaranteed bounds on a given performance index. The purpose of this note is to point-out several incorrect results presented there.     

MOBILE ENVIRONMENTAL INFORMATION SYSTEMS

This paper presents the foundations for building mobile environmental information systems (MEISs) requiring an interdisciplinary approach. MEISs require expertise from the disciplines of environmental biology, geography, and mobile technology. MEISs show great promise for the acquisition of environmental information using different mobile devices. Automatic mobile acquisition enables the forwarding of the information to central databases for storage, further processing, and transmission to the mobile devices in a form that is useful to the users. Furthermore, these systems have the potential to be used both in the protection of nature, as well as in recreational use in a way that takes the constraints of nature into account. In this paper we describe the preliminary results of the MINNE project and the prototypes currently under research in the project.     

Dehydration and Separation of Grape Pomace in a Fluidized Bed System

Grape pomace components (seed and skin) were separated in a fluidized bed system based on their aerodynamic behavior. The Weibull equation was used to explain the elutriation history. Seed dehydration was characterized by a first period of constant drying rate and a second period in which drying rate decreased following Fick's liquid molecular diffusion model. The order of magnitude of heat and mass transfer parameters, both internal and external, was similar to those reported in the literature.     

Effect of Adjusting the Water Activity to 0.95 with Different Solutes on the Kinetics of Thiamin Loss in a Model System

The kinetics of thiamin degradation in a model system of pH 6.0 and water activity (a_w) 0.95 controlled with NaCl, KC1, glycerol or Na₂SO₄, was studied. The type of solute used to adjust a_w, had a dramatic influence on the rate of degradation of thiamin. The loss of vitamin increased in the following order: NaCl > KCl > glycerol > Na₂SO₄. Activation energies, however, were independent of the type of solute and ranged between24–28 kcallmole.     

ALPHA-LINOLENIC ACID AND LINOLEIC ACID IN SERUM AND TISSUES AFTER FLAXSEED (Linum usitatissimum) OIL IN VIVO ADMINISTRATION

Essential fatty acids can be helpful in the prevention of several pathologies. The bioavailability of acute supplementation of different doses of flaxseed oil was studied by analyzing the level of alpha-linolenic acid (ALA) and linoleic acid (LA) in serum and tissues (adipose, liver) of rats tested at 2, 4, 8 and 16 h after the administration. The amount of flaxseed oil administered at increasing doses corresponded to 1, 2.5 and 5 g ALA/kg of body weight. The corresponding fatty acid methyl esters obtained via direct methylation were quantified using gas chromatography/mass spectrometry. Serum ALA level increased after 1 or 2.5 g/kg. ALA was increased in both adipose and liver tissue 4 h after the administration of 1 g/kg of flaxseed oil. There was no further increase by using a higher oil dosage. LA did not change in serum at the doses used.

PRACTICAL APPLICATIONS

The bioavailability of acute supplementation of increasing doses of flaxseed oil was examined by analyzing the level of alpha-linolenic acid (ALA) (ω3) and linoleic acid (ω6) in serum and tissues (adipose, liver).These data suggest that there is a limiting step in the absorption of these fatty acids and that there is no advantage to take more than 1 g/kg of ALA supplementation. The daily use of flaxseed oil could be a good alternative in some cases to fish oil in the prevention of several pathologies.