Improved chitin production by pretreatment of shrimp shells

Pretreatment of shrimp shells was investigated in order to lower the costs and to improve the sustainability of chitin production. Physical pretreatment comprising drying, grinding and sieving is attractive for the recovery of 50% of shrimp protein as a dry powder. Pretreatment of shells by shearing in acidified water results in the removal of up to 60% of the protein and a reduction of their mineral content without a decrease in the chitin yield. Both pretreatment procedures will lead to cleaner technology for chitin production, to a considerably lower need for chemicals, to useful protein by‐products, and to less‐contaminated industrial effluent. Copyright © 2004 Society of Chemical Industry     

Proper elimination of latent variables

We consider behaviors in which we distinguish two types of variables, manifest variables, the variables that are of interest to the user and latent variables, the variables that are introduced to obtain a first representation. The problem is to find a representation of the manifest behavior, that is, we want to eliminate the latent variables. If the original behavior can be represented by linear differential equations with constant coefficients, then under certain conditions the same is true for the manifest behavior. In this note we formulate and study these conditions. The results are illustrated by means of some examples. As an application we study behaviors in image representation.     

Screening for posttraumatic stress disorder: An evaluation of two self-report scales among crime victims.

The validity of the Impact of Events Scale (IES) and the Posttraumatic Stress Disorder (PTSD) Symptom Scale, Self-Report version (PSS-SR) was examined among crime victims. Both instruments performed well as screeners for PTSD. For the IES, sensitivity ranged between .93 and 1.00; for the PSS-SR, sensitivity ranged between .80 and .90. Specificity for the IES ranged between .78 and .84 and for the PSS-SR ranged between .84 and .88. Some individual items from the 2 scales performed just as well as the total scales. The authors conclude that either of these short self-report instruments or their individual items are suitable as screeners for PTSD, specifically in settings where mental health professionals are unavailable. Cross-validation of these results is necessary because of the small sample size in this study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Technology, society, and culture: A framework for understanding

The many specific studies of science-technology-society relationships fail to provide a general framework for understanding the fundamental transformation that is taking place in human society. An analysis of the central role of culture in traditional societies—and how technology competes with and partially replaces culture as a mediating factor in human experience—can provide the basis for such a framework by thorough recognition of the phenomenon of Technique. This concept also provides some guidance for practical responses to the diverse problems characteristic of our society.     

The referents of trait inferences: The impact of trait concepts versus actor–trait links on subsequent judgments.

The authors investigated the hypothesis that when trait inferences refer to abstract behavior labels they act as a general interpretation frame and lead to assimilation in subsequent judgments of an ambiguous target, whereas when they refer to a specific actor–trait link they will be used as a scale anchor and lead to contrast. Similar to G. B. Moskowitz and R. J. Roman's (see record 1992-31124-001) study, participants who were instructed to memorize trait-implying sentences showed assimilation, and participants who were instructed to form an impression of the actors in these sentences showed contrast. However, exposure to trait-implying sentences that described actors with real names and were accompanied with photos of the actors resulted in contrast under both memorization and impression instructions (Experiment 1). Furthermore, contrast ensued when trait-implying sentences were accompanied with information that suggested a person attribution, whereas assimilation ensued when that information suggested a situation attribution, independent of processing goals (Experiment 2). These findings are interpreted as support for referent-based explanations of the consequences of trait inferences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of processing conditions on glucosinolates in cruciferous vegetables

Summary Glucosinolates are found naturally in cruciferous plants, such asbrassica vegetables, which are important in the human diet. Glucosinolates are readily converted into a range of physiologically active compounds by hydrolysis under the influence of an endogenous thioglucosidase, which becomes active when plant cells are disrupted. Cruciferous vegetables are eaten raw, they are also consumed in the processed form. The influence of processing conditions on glucosinolate degradation and on the type and levels of the reaction products formed is reviewed.

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Der Einfluß von Prozeßbedingungen auf Glucosinolate in Cruciferen-Gemüse

Zusammenfassung Glucosinolate kommen naturgemäß in Kreuzblütlern vor, wie z. B. inBrassica-Gemüse, welche einen wesentlichen Bestandteil der Nahrung bilden. Glucosinolate werden leicht umgesetzt in eine Reihe physiologisch aktiver Verbindungen unter Einfluß einer endogenen Thioglucosidase, welche aktiv wird, wenn das pflanzliche Gewebe zerstört wird. Die Cruciferen-Gemüse werden roh, aber auch in verarbeiteter Form, gegessen. Der Einfluß der Verarbeitung auf den Abbau der Glucosinolate, sowie auf Art und Menge der gebildeten Reaktionssprodukte, wird besprochen.

     

The rely-guarantee method for verifying shared variable concurrent programs

Compositional proof systems for shared variable concurrent programs can be devised by including the interference information in the specifications. The formalism falls into a category calledrely-guarantee (orassumption-commitment), in which a specification is explicitly (syntactically) split into two corresponding parts. This paper summarises existing work on the rely-guarantee method and gives a systematic presentation. A proof system for partial correctness is given first, thereafter it is demonstrated how the relevant rules can be adapted to verify deadlock freedom and convergence. Soundness and completeness, of which the completeness proof is new, are studied with respect to an operational model. We observe that the rely-guarantee method is in a sense a reformulation of the classical non-compositional Owicki & Gries method, and we discuss throughout the paper the connection between these two methods.The research was partially supported by Esprit-BRA project 6021 (REACT).     

Fundamental aspects of energy conservation policy

The formulation of a governmental energy conservation policy requires that the issues involved be fundamentally analyzed. Information transfer, more intensive use of data, and good housekeeping can all contribute to reduced energy use. Our major choice, however, is between producing the present mix of materials, commodities, and services more efficiently or decreasing demand for them. The first option is referred to as the “technical fix”, the second one as “change of lifestyle”. If the first option fails, changes in life-style might become mandatory.This paper deals with the technical fix approach. Higher capital investment can lead to a decrease in direct use of energy. Both the cost and the energy involved in these investments are analyzed along a conservation path, and a limited number of constants is used to describe the changes along this path. These constants can also be used to feed technological information into macroeconomic analysis.The time scales involved pose the major problem to achieving conservation by means of a technological fix. An increase in the price of energy will lead to higher capital investments in accordance with the economic lifecycles in the different sectors. For applications with a short life-time, such as in the transport sector, energy conservation will mainly take place through the construction of new equipment. In sectors with long lifetime investments (e.g. buildings), retrofitting will be important.Including the indirect energy requirements in the conservation study leads to some important conclusions. It can be demonstrated that the thermodynamic limit is not the ultimate limit for conservation. An energy minimum is obtained, which corresponds to a use of energy higher than the thermodynamic limit. It is also impossible to reduce or eliminate some components of the present energy supply system and at the same time to introduce a new decentralized supply system.A crucial aspect of the technological fix approach is that within the present rules, capital investments for saving direct energy can only be made after the increase in energy price has taken place or when it can be firmly anticipated on a short term. At this point, however, the time needed for making these capital investments is lacking and adverse economic consequences can be expected.It is therefore the major task of governmental policy to induce conservation before it is economically acceptable or possible. This requires some form of government interaction. The theory developed in this paper provides a method by which to rank the options according to the energy saved per dollar of public funds invested. This measures the difference between the objectives of the private sector and those of society.The longer this policy is postponed, the larger is the risk that conservation will have to be achieved in an emergency program. In that situation the indirect energy necessary for the capital construction might jeopardize the short-term goals.     

Limited-Dose Electron Microscopy Reveals the Crystallinity of Fibrous C–S–H Phases

Using electron diffraction, we demonstrate that the fibrous calcium–silicate–hydrates (C–S–H) of tricalciumsilicate (C₃S) hydration possess a crystalline structure. The crystalline nature was revealed by limiting the electron dose, which is common in electron microscopy of biomacromolecules. Compared with room temperature, the fading of the electron diffraction patterns at −175°C occurs at an electron dose that is about one order of magnitude higher. A combination of low-dose and cryo-protection methods offers the possibility to investigate the structures of water-containing cement phases by high-resolution electron microscopy in a close-to-native state.