Linked interpolation for Reissner-Mindlin plate elements: Part I—A simple quadrilateral

In most plate elements using the Reissner-Mindlin assumptions, the interpolations used for the lateral displacements (w) and the rotation (θ) involve the independent representation of each variable by its nodal values, usually with identical interpolations. To ensure a higher order of expansion for displacement w its representation is linked in the present paper with both sets of nodal variables. Conditions necessary for the use of such expansions are established here and the paper shows the development of a linear quadrilateral element (Q4BL) whose performance and robustness are good (although it possesses one singularity if only three degrees of freedom are prescribed). In Part II we apply the identical formulation to develop a triangular element (T3BL) which performs equally well and is fully robust.     

Survival of pine sawflies in cocoon stage in relation to resin acid content of larval food

Several experiments were conducted to determine whether the ingestion of diterpenoids (resin acids) by pine sawfly larvae influences the survival of postlarval stages. Larvae of two diprionid sawfly species were reared on shoots of two Scots pine clones, one with a low (1.5% dry wt) concentration of resin acids and the other with a high (5.2% dry wt) concentration. No significant treatment-related differences were found in any of the experiments with respect to (1) resistance against parasitoids, (2) preference of predatory shrews and carabids, and (3) apparency of cocoons in the field to predators. A preference of sawfly prepupae to spin cocoon in feces from larvae reared on high resin acid needles was found. Possible explanations for these results are discussed. Detection of an unknown compound, possibly a breakdown product of the major resin acid in pine needles (pinifolic acid), in prepupae indicate that resin acids may be metabolized by the sawflies.     

Time course of incorporation of 20-carbon polyunsaturated fatty acids in a human keratinocyte cell line

Human keratinocytes (NCTC 2544) in culture were labeled with equal amounts of either¹⁴C-arachidonic acid,¹⁴C-dihomo-γ-linolenic acid or¹⁴C-eicosapentaenoic acid. At various time points, the incubations were stopped and the distribution of the¹⁴C-fatty acids was analyzed. All these eicosanoid precursor fatty acids were effectively incorporated into the cellular lipids of the keratinocytes, and the major radiolabeled individual lipid fraction was phosphatidylethanolamine. The distributions of arachidonic acid and dihomo-γ-linolenic acid within cellular lipids were rather the same. However, less eicosapentaenoic acid than either arachidonic acid or dihomo-γ-linolenic acid was incorporated into the phospholipids and, correspondingly, more eicosapentaenoic acid was incorporated into the nonphosphorus lipids. In the phosphatidylinositol + phosphatidylserine fraction, there was significantly less eicosapentaenoic acid than either arachidonic acid or dihomo-γ-linolenic acid. The present study suggests that these eicosanoid precursor fatty acids are effectively incorporated into the human keratinocytes and that the pattern of incorporation and distribution of eicosapentaenoic acid appears to differ slightly from that of either arachidonic acid or dihomo-γ-linolenic acid.     

Single-chip image sensors with a digital processor array

The architectures, implementation and applications of two smart sensors, LAPP and PASIC, are described. The basic idea of these two designs is to integrate an image sensor array with a digital processor array in a single chip. The integrated camera-and-processor eliminates the bottleneck of sequential image read-out that characterizes conventional systems. They provide fast, compact and economic solutions for tasks such as industrial inspection, optical character recognition and robot vision.     

Studies on the interaction between hyaluronan and a rat colon cancer cell line

We have developed a method to assess the actual mitochondrial ATP synthesis in cells (fibroblasts and Ehrlich ascites tumor cells). This method relies on gentle permeabilization of the cells, inhibition of nonmitochondrial ATP synthesis systems (glycolysis and adenylate kinase), and the inhibition of all ATPase activities (ATP hydrolysis) by decreasing the cytosolic magnesium concentration with EDTA. We have simultaneously measured the rate of respiration, and the ATP/O values obtained with this method are similar to those obtained with isolated mitochondria using the same respiratory substrates. This method is highly appropriate for dealing with small amounts of tissue such as human biopsies.     

Extending Global IP Connectivity for Ad Hoc Networks

Ad hoc networks have thus far been regarded as stand-alone networks without assumed connectivity to wired IP networks and the Internet. With wireless broadband communications and portable devices with appropriate CPU, memory and battery performance, ad hoc connectivity will become more feasible and demand for global connectivity through ad hoc networking is likely to rapidly grow. In this paper we propose an algorithm and describe a developed prototype for connectivity between an ad hoc network running the ad hoc on-demand distance-vector protocol and a wired IP network where mobile IP is used for mobility management. Implementation issues and performance metrics are also discussed.     

Nerve growth factor released by CD40 ligand-transfected l cells: implications for functional and phenotypic studies on CD40+ cells

The mycoparasite Humicola fuscoatra NRRL 22980 was isolated from a sclerotium of Aspergillus flavus that had been buried in a cornfield near Tifton, Ga. When grown on autoclaved rice, this fungus produced the antifungal metabolites monorden, monocillin IV, and a new monorden analog. Each metabolite produced a clear zone of inhibition surrounding paper assay disks on agar plates seeded with conidia of A. flavus. Monorden was twice as inhibitory to A. flavus mycelium extension (MIC > 28 microg/ml) as monocillin IV (MIC > 56 microg/ml). Cerebrosides C and D, metabolites known to potentiate the activity of cell wall-active antibiotics, were separated from the ethyl acetate extract but were not inhibitory to A. flavus when tested as pure compounds. This is the first report of natural products from H. fuscoatra.     

DIVE—A platform for multi-user virtual environments

The Distributed Interactive Virtual Environment (DIVE) is an experimental software platform for the development of multi-user virtual reality applications. DIVE uses active replication and reliable multicast protocols to distribute data between participants. The distribution model enables a large number of users and applications to participate and interact in the same virtual environment. The DIVE platform offers a wide range of interaction support and user-related abstractions to ease the task of application and user interface construction.     

Subjective Indoor Air Quality in Schools in Relation to Exposure

Abstract This paper presents data on indoor air quality in schools as perceived by those working in them and relates these data to exposure measurements. Data on subjective air quality, domestic exposures and health aspects were gathered by means of a questionnaire which was sent to all personnel in 38 schools; it was completed by 1410 persons (85’4 of the total). Data on exposure were gathered by exposure measurements in classrooms. The results indicate that 53% of the personnel perceived the indoor air quality as bad or very bad. It was perceived as worse by those who were younger, those who were dissatisfied with their psychosocial work climate and those who were not exposed to tobacco smoke at home. In older school buildings and buildings with displacement ventilation there was less dissatisfaction with the air quality. There were no significant relations between complaints and air exchange rate or concentration of carbon dioxide. The air quality was perceived as worse at higher levels of exposure to a number of airborne compounds including volatile organic compounds, moulds, bacteria and respirable dust. It was concluded that exposure to indoor pollutants affects perception even at the low concentrations normally found indoors in nonindustrial buildings.     

Waste reduction through process optimization and development

In this article, the possibilities of optimizing metallurgical processes based on minimization for waste reduction and application requirements for the reuse of waste products are discussed together with the possibilities of treating existing waste in direct connection with the process involved. Some results from ongoing projects on controlled dust generation and an outline of an ongoing research program are also described.