Genetic component of variation in chemical defense ofOreina gloriosa (Coleoptera: Chrysomelidae)

Defensive secretions of adultOreina gloriosa, liberated at the surface of the pronotum and elytra, contain a complex mixture of cardenolides, and ethanolamine. Proportions and concentrations of constituents determined by reverse-phase HPLC show considerable variation among individual beetles. Heritabilities of proportions of five main components were estimated by mother-offspring regression providing a validation of the less reliable full-sib correlation estimates. Average heritabilities based on the two methods were 0.51 and 0.58, respectively, estimated by using offspring of two age groups. Regression estimates of 2- and 10-week-old offspring differed significantly for one secretion constituent (RT16). Heritability estimates of concentrations of 16 secretion components were calculated by full-sib correlation analysis. Average heritability was 0.45, indicating a significant genetic component. Estimates did not differ significantly between the two age groups. We also estimated heritabilities of concentrations by a two-way model including data from offspring of both age groups. Heritability estimates based on this model are thought to correspond approximately to estimates based on samples from natural populations. The average of these estimates was lower (h ² =0.31) than the average heritability of each age group separately (h ² =0.45), suggesting a developmental effect on variation in chemical defense ofO. gloriosa.     

Intestinal Chlamydia in finishing pigs

Gut and blood samples from 119 finishing pigs derived from 11 farms were collected during routine slaughter at an abattoir. Sections of formalin-fixed, paraffin-embedded tissues were labeled immunohistochemically using genus-specific, mouse monoclonal antibody against chlamydial lipopolysaccharide; goat polyclonal antiserum against the major outer membrane protein of Chlamydia trachomatis; and mouse monoclonal antibody against the ovine abortion subtype of C. psittaci. Gut samples from 33 of 111 (29.7%) individual pigs stained positive with the genus-specific monoclonal antibody, and of these 30 of 32 (93.7%) also reacted with the C. trachomatis-specific antiserum. Labeled inclusions were restricted to mature enterocytes of the large intestine in 33 of 111 cases. Infection of small intestinal enterocytes was noted in only one of 82 ileal samples. The blood samples were tested for antichlamydial antibodies by enzyme-linked immunosorbent assay (ELISA) and complement fixation test (CFT). With ELISA, 95 of the 115 sera tested (82.6%) yielded positive antichlamydial reactions. With CFT, 34 of the 119 sera tested (28.6%) were unequivocally positive (> or = 1:10, 100% binding), and 10 (7.6%) yielded doubtful positive reactions (1:10, 50-75% binding). Positive ELISA and CFT titers showed poor agreement (kappa = 0.112), whereas the agreement between positive findings by immunohistochemical labeling and CFT was fair (kappa = 0.205).     

Physiological sources of variation in chemical defense ofOreina gloriosa (Coleoptera: Chrysomelidae)

The defensive secretion of the alpine chrysomelidOreina gloriosa is a complex mixture of mainly cardenolides and tyrosine betaine. Individually sampled secretions of adult laboratory-reared and field-collected beetles were analyzed by reverse-phase HPLC; 16 secretion components were quantified. Quantities and concentrations of different components were significantly affected by the age, sex, and reproductive status of individual beetles. Aging was correlated with marked increases (up to 4.4-fold) and decreases (up to 2.7-fold) of quantities and concentrations of several components. Differences between the sexes were smaller, but quantities of all components and concentrations of several components were larger in laboratory-reared females than in males. There was less of one component of the secretion in mated than unmated females, but the concentrations of four secretion components were higher (up to 1.6-fold) in mated females.     

Axonal growth in evolutionary neurogenesis

Creating ways for neural networks to evolve is an important goal in the field of artificial evolution. The main problem is how to encode the structure and properties of the neural network in the genome. If one overloads the genome with detailed network information, the evolutionary time increases prohibitively. If the genome is too simple, only simple problems can be solved. Since nature has found an efficient evolutionary solution to this problem, it is worth imitating the mechanisms by which biological neural nets are generated. In this article, a model is proposed in which artificial genomes increase the ability of axons to find, deteet, and connect to specific targets. Some initial simulation results for simple tasks are evolved, and the genetic tuning of the developmental processes of artificial evolution is discussed. This work was presented in part at the Fifth International Symposium on Artificial Life and Robotics, Oita, Japan, January 26–28, 2000     

0-homogeneous effect algebras

In the present paper, we introduce a proper superclass of homogeneous effect algebras. We call this superclass as 0-homogeneous effect algebras. We prove that in every 0-homogeneous effect algebra, the set of all sharp elements forms a subalgebra. Every chain-complete 0-homogeneous effect algebra is homogeneous.     

The use of pyrheliometers for continuous measurements of an effective air pollution mixing depth

Information on the magnitude of the mixing depth is important for forecasting levels of pollutant concentrations over a given area. To date mixing depth information has been obtained by means of sensors mounted in an aircraft or carried aloft by balloons. At best, the information provided has been sporadic.This paper describes techniques using combinations of either pyrheliometers or pyranometers to provide continuous recordings of the mixing depth. Various techniques are described for obtaining these measurements. The most attractive of these consists of two pairs of pyrheliometers on equatorial mounts; one pair is located on a tall building and another pair near the ground. One instrument of each pair has a 4000–4500 Å filter and the other, a 5500–6000 Å filter. By considering ratios of the solar radiation recorded by combinations of these pyrheliometers, it is possible to determine the depth of the aerosol mixing layer under the assumption that the aerosol concentration is approximately uniformly mixed within the mixing layer and drops to a very small value above it. Variations from this aerosol distribution can be handled when three or four pairs of instruments are used at various heights with the greatest height approaching 1000 ft.The correlation technique involving the crossing of two pyranometer fields of view is also discussed. In this method, one pyranometer has a conical field of view of about degree directed upward. The second pyranometer, also with a narrow field of view, is located about 1000–2000 ft away. The fields of view of the two pyranometers are made to intersect. The second pyranometer is designed to scan by changing its elevation angle so that the height of a common volume of the two intersecting fields of view varies from a level near the ground to several thousand feet. The covariance between the signals recorded by the two instruments would change as the common volume passed from air with a high concentration of aerosol to clean air. By noting the height at which the changes occur, it should be possible to determine both the height of the aerosol mixing layer and also the presence of aerosol layers above the primary ground base layers.     

Using the peptide BP100 as a cell-penetrating tool for the chemical engineering of actin filaments within living plant cells

The delivery of externally applied macromolecules or nanoparticles into living cells still represents a critically limiting step before the full capabilities of chemical engineering can be explored. Molecular transporters such as cell-penetrating peptides, peptoids, and other mimetics can be used to carry cargo across the cellular membrane, but it is still difficult to find suitable sequences that operate efficiently for any particular type of cell. Here we report that BP100 (KKLFKKILKYL-amide), originally designed as an antimicrobial peptide against plant pathogens, can be employed as a fast and efficient cell-penetrating agent to transport fluorescent test cargoes into the cytosol of walled plant cells. The uptake of BP100 proceeds slightly more slowly than the endocytosis of fluorescent dextranes, but BP100 accumulates more efficiently and to much higher levels (by an order of magnitude). The entry of BP100 can be efficiently blocked by latrunculin B; this suggests that actin filaments are essential to the uptake mechanism. To test whether this novel transporter can also be used to deliver functional cargoes, we designed a fusion construct of BP100 with the actin-binding Lifeact peptide (MGVADLIKKFESISKEE). We demonstrated that the short BP100 could transport the attached 17-residue sequence quickly and efficiently into tobacco cells. The Lifeact construct retained its functionality as it successfully labeled the actin bundles that tether the nucleus in the cell center.     

Passage of Trojan Peptoids into Plant Cells

Efficient drug delivery is essential for many therapeutic applications. In this context, Trojan peptoids have attracted attention as powerful tools to deliver bioactive molecules into living cells. Certain cell‐penetrating peptides, peptide mimetics, and peptoids have been shown to be endowed with a transport function and the structural features of this function have been characterized. However, most of the research has been done by using mammalian cell cultures as model organisms and the actual cellular mechanism of membrane passage has not been elucidated. Plant cells, which are encased in a cellulosic cell wall and differ in membrane composition, represent an alternative experimental system to address this issue, but so far, have attracted only little attention for both peptide‐ and peptoid‐based carrier systems. Moreover, efficient delivery of nonproteinaceous bioactive macromolecules into living plant cells could complement genetic engineering in biotechnological applications, such as metabolic engineering and molecular farming. In the present study, we investigated carrier peptoids with or without guanidinium side chains with regard to their uptake into plant cells, the cellular mechanism of uptake, and intracellular localization. We can show that in contrast to polyamine peptoids (polylysine‐like) fluorescently labeled polyguanidine peptoids (polyarginine‐like) enter rapidly into tobacco BY‐2 cells without affecting the viability of these cells. A quantitative comparison of this uptake with endocytosis of fluorescently labeled dextranes indicates that the main uptake of the guanidinium peptoids occurs between 30–60 min after the start of incubation and clearly precedes endocytosis. Dual visualization with the endosomal marker FM4‐64 shows that the intracellular guanidinium peptoid is distinct from endocytotic vesicles. Once the polyguanidine peptoids have entered the cell, they associate with actin filaments and microtubules. By pharmacological manipulation of the cytoskeleton we tested whether the association with the cytoskeleton is necessary for uptake, and observed that the actin inhibitor latrunculin B as well as the microtubule inhibitor oryzalin impaired uptake and intracellular spread of the guanidinium carrier to a certain extent. These findings are discussed with respect to the potential mechanisms of uptake and with respect to the potential of Trojan peptoids as tools for metabolic engineering in plant biotechnology.