INFLUENCE OF PANEL INCONSISTENCY ON THE OUTCOME OF SENSORY EVALUATIONS FROM DESCRIPTIVE PANELS

Different types of panelist by treatment interaction are explored to determine how they influence the outcomes of discrimination tests. The study compares the situations where panelists are considered as fixed or random effects over the range of most testing conditions for small panels (5–15 panelists) that replicate their judgements. Magnitude interaction and nonperceivers or nondiscriminators have minor effects on test outcomes. Cross-over interaction increases the chances for a type II error, especially when panelists are considered as random effects. False discrimination increases the chances for a type I error when panelists are considered as fixed effects. Applications of methods to reduce the chances for these errors in the testing for differences among treatments are discussed.     

Optimal systems: I. The vascular system

An approach to quantitative work on optimal systems is considered. Desired optimal principles are utilized in constructing a hypothetical system similar to the organ system considered. A comparison of this constructed system with the anatomical system then gives an indication of the importance of the optimal principles in the form or function of the organ system considered. These ideas are applied to the mammalian vascular system, and limiting values are obtained for some of its important component parts. The constructed system gives good agreement with anatomical data for vessel radii, lengths, and hydrodynamic resistance to flow.     

Biology and Evolution of Beneficial and Detrimental Viruses of Animals, Plants, and Fungi

Virtually every type of organism may serve as a host for viruses. In some hosts, virus presence may be considered beneficial to humans; in other hosts, viruses are considered detrimental. Examples of viruses that are considered beneficial to humans include those that are used for biological control of organisms that themselves are considered detrimental to humans, such as plant pathogenic fungi. Viruses are extremely variable in terms of morphology, structure, and genome organization. However, viruses that attack hosts from different kingdoms may be related, deriving from the same phylogeny. This paper summarizes some of the properties of three related families of viruses that attack hosts in different kingdoms: the animal-infecting Picornaviridae, the plant-infecting Potyviridae, and the fungus-infecting Hypoviridae. Properties of these viruses that set them apart from each other and factors that may affect their evolution are discussed.     

The trace and major element composition of the leaves of some deciduous trees

Summary A number of factors concerned in the sampling of the leaves of deciduous trees for diagnostic purposes are considered.A method is described for sampling leaves prior to the spectrochemical determination of 21 trace and major constituents in order to study seasonal changes. The precision, generally around ± 10 per cent for samples of leaves or leaf blades, including analytical errors, is considered satisfactory for this type of investigation.Some comparisons of leaf blade and petiole contents are made and the effects of removal of surface contamination are considered. Marked differences between petiole and leaf blade contents must be taken into account in diagnostic applications of leaf analysis. For most elements surface contamination is shown to be insignificant even at a site adjoining a main road.     

Selection of microbial mutants tolerant to extreme environmental stress using continuous culture-control design

The design of controllers for a continuous selection technique (BOICS; Brown and Oliver, 1982) is considered. This technique is used to obtain microbial mutants that are tolerant to extreme environmental stress. Applications of BOICS have been hampered by the problem of controller design. In this paper, a modified implementation of BOICS is considered which has a number of practical advantages. A model-based approach to controller design is taken. The case in which the stress is due to an inhibitory substance in the growth environment is considered. The analysis is intended to be applicable to any reasonable combination of organism and inhibitor. Conventional linear and time-invariant controllers are considered. Guidelines for the selection of controller parameters' values are suggested. The application of these guidelines requires that certain process parameters' values be identified. Methods by which these parameters' values can be identified are suggested. Simulation results indicate that the resulting controllers perform satisfactorily. This is confirmed by experimental data from a model selection experiment. A recipe for the design of controllers is a necessary part of a protocol for BOICS. It is hoped that the solution to the controller design problem that is offered in this paper will encourage further applications for the technique.     

Monitoring seasonal variation in apple fruit volatile emissions in situ using solid-phase microextraction

Emissions of volatiles from apple fruits (Malus domestica Borkh.) were monitored in situ over the course of a growing season (from early June to mid September) for two apple varieties, Golden Delicious and Maigold. Results indicate a characteristic time-course of volatile emissions as the sampling date was a statistically significant factor for nine of the 13 compounds considered. The amounts of volatiles collected were greatest early and late in the season. The temporal effect on emissions was generally much larger than the effect of variety, which was significant for only four of the 13 compounds considered. The possible sources of variation which are not explained by the statistical models are discussed, and it is considered that they are most likely related to differences in the emissions from individual fruits.     

The application of stable isotopes in biomedical research

Many of the ways in which isotopes are used in biomedical research are reviewed. The use of stable isotopes in stable isotope dilution assays, for metabolite identification and in pharmacokinetic studies, is discussed and relevant examples are given to illustrate the various points made. Isotope effects and their implications for future drug design are considered. Some of the toxicity problems associated with the use of stable isotopes are also considered. Finally, a brief subjective view of possible future advances is made.     

Anatomy and evolution in the Macaronesian Sonchus subgenus Dendrosonchus (Compositae: Lactuceae)

The members of the genus Sonchus subgenus Dendrosonchus are woody perennials possessing the pachycaul construction which has been proposed as ancestral to that of modern trees and herbs. The endemic flora of Macaronesia, particularly the Canary Islands, is generally considered to be a Tertiary relict, although an opposing view concerning woody plants of island floras has recently been expressed. The anatomy of Dendrosonchus is examined and trends of evolution can be interpreted from the vessel elements of the secondary xylem. With the use of the length to breadth ratios of vessel elements a gradual trend from primitive to derived is illustrated for the members of each of the two sections of Dendrosonchus , which are considered to have evolved in parallel. The wood rays, features of the cypsela and stem anatomy are also shown to be useful in elucidating the evolution of a small, closely related group of plants. Sonchus arboreus in the section Atalanthus and S. brachylobus in the section Dendrosonchus are similar to the two ancestral types proposed for the subgenus. The most derived species are considered to be S. pinnatus subsp. palmensis in the section Atalanthus and S. acaulis in the section Dendrosonchus. The ancestral type for the genus is considered to have been woody and probably of the Dendrosonchus type.     

Electron transfer mechanisms in electron transfer chains

Mechanisms responsible for the transfer of electrons through mitochondrial and photosynthetic electron transport chains are considered. Mechanisms considered include diffusion, ligand-mediated transfer, tunneling and semiconduction. Perturbations which create satisfactory conditions for electron transfer are also considered. There is a brief discussion of the electron transport chain environment and constituents. Sponsored in part by a grant from the Department of Health, Education, and Welfare (Public Health Service Grant Number 5 R01 RL00480)     

Cytochrome c: gene structure, homology and ancestral relationships.

In this paper, the author notes the recommended definition of the word "homology" (i.e., indicating an ancestral relationship) and the recommended stipulation that "evidence for homology should be explicitly laid out". The postulated homology for somatic and testes-specific isozymes of cytochrome c is then examined, using recent data obtained from the study of cytochrome c genes. Consideration is also given to some newer findings of molecular biology and possibilities are considered for various types of change in the genome of an organism. Possible roles of introns, pseudogenes and multigene families are considered. The relationship of testes-specific cytochrome c to somatic cytochrome c is carefully considered from data obtained in experimental studies of genes of these two isozymes. If one assumes that these isozymes arose as a consequence of a gene duplication, data from rat and mouse genes indicate that the testes-specific isozyme has incorporated more amino acid changes than the somatic isozyme since the time of their divergence. However, when the 15 amino acid differences (testes-specific vs. somatic isozyme) are considered, there is virtually no similarity in these 15 positions of the testes-specific isozyme with any of the hypothetical ancestral sequences of the somatic isozyme. Nucleotide differences in cytochrome c genes have been evaluated by comparing genes for the two rodent cytochrome c isozymes to cytochrome c genes of fruit flies, chickens and humans. Comparisons of nucleotide substitution rates in genes for the two cytochrome c isozymes in rodents confirm the conclusions from amino acid sequence comparisons; namely, that more rapid nucleotide changes have occurred in the testes-specific cytochrome c gene, than in the somatic cytochrome c gene. Possible explanations for these findings are considered.     

Population Dynamics of the Polychaetous Annelids of an Intertidal Habitat in Upper Old Tampa Bay,Florida

Following an extensive red-tide induced mass mortality of the benthic macrofauna of a sandy intertidal habitat, the population dynamics of the polychaete species were studied. Detailed studies of the 12 most abundant species are presented. Data concerning total population levels, reproduction, recruitment, distribution within the intertidal zone, and gut content analyses are integrated in order to explain the observed spatial and temporal patterns of distribution and abundance. Potential competive interactions for food are considered to be the most important factor for explaining the observed ecological patterns. The polychaete species studied are divided into three trophic guilds: an omnivorous guild that feeds predaciously and as non-selective deposit feeders, a surface feeding guild consisting of species usually considered to be selective surface deposit feeders, and a subsurface feeding guild usually considered as non-selective infaunal deposit feeders. Within and between guild interactions are discussed.     

Legal Regulation of Plant Genome Editing with the CRISPR/Cas9 Technology as an Example

The product-oriented and the process-oriented legal approaches to the regulation of genome editing technologies, CRISPR/Cas9 in particular, are considered. The relevant legislation of the United States and the European Union and some international treaties are analyzed. The issue of genome editing that is within the scope of GMO legislation and general legislation on risk assessment and regulation is addressed. The issue of patenting of gene editing technologies in the legislation of the United States and the European Union and under international law is considered. “Patent wars” between research teams that developed the CRISPR/Cas9 technology are described. The possibilities of obtaining patent protection for plants produced by genome editing are considered.     

Dimerization of helical β-peptides in solution

Molecular simulations are used to examine the aggregation behavior of several β-peptides in explicit water. The particular peptides considered here adopt a helical, rodlike conformation in aqueous solution. Four distinct molecular sequences are considered. Earlier experimental studies have revealed the formation of ordered and disordered aggregates for such molecules, depending on sequence. The simulations reported here, which are conducted by resorting to metadynamics techniques, lead to free energy surfaces for dimerization of the peptides in water as a function of separation and relative orientation. Such surfaces are used to identify the molecular origins for the behaviors observed in the experiments.     

Infraspecific categories in fungi

The problems facing the mycologist centre on the difficulty of distinguishing between the individual and the population, the degree of host or substratum specialization and the limited range of morphological characters available for use as denning taxa. The use of the categories 'variety' and 'forma specialis' is considered, and examples are given of their application in the cereal rusts and in the genera Phoma and Fusarium. Micro-evolutionary trends in Auricula auricula are also considered and are used to illustrate how amenable fungi are to studies on speciation.     

Infraspecific categories in fungi

The problems facing the mycologist centre on the difficulty of distinguishing between the individual and the population, the degree of host or substratum specialization and the limited range of morphological characters available for use as denning taxa. The use of the categories 'variety' and 'forma specialis' is considered, and examples are given of their application in the cereal rusts and in the genera Phoma and Fusarium. Micro-evolutionary trends in Auricula auricula are also considered and are used to illustrate how amenable fungi are to studies on speciation.     

The Treatment of Missing Values in Logistic Regression

The efficiencies of the estimators in the linear logistic regression model are examined using simulations under six missing value treatments. These treatments use either the maximum likelihood or the discriminant function approach in the estimation of the regression coefficients. Missing values are assumed to occur at random. The cases of multivariate normal and dichotomous independent variables are both considered. We found that in general, there is no uniformly best method. However, mean substitution and discriminant function estimation using existing pairs of values for correlations turn out to be favourable for the cases considered.     

Panorama de l’infertilité masculine

This paper reviews new epidemiological, etiological and therapeutic aspects of male infertility. Because of the great improvement in the efficacy of assisted reproductive techology due to ICSI, the recently discovered genetic causes of male infertility have to be considered. While studies concerning the role of xenobiotics in disrupting endocrine regulation of testicular functions are in progress, genetic causes of male infertility has been discovered. Microdeletions of the long arm of the Y chromosome account for a substantial part of unexplained spermatogenic failures. Mutations of CFTR gene are involved in bilateral agenesis of vas deferens. This condition might be considered as a mild form of cystic fibrosis. These genetic defects together with chromosmal abnormalities, which are known to be responsible for spermatogenic failures, should be considered as potential sources of reproductive abnormalities of more global pathology transmissible to children who can be obtained by ICSI with ejaculated, epididymal or testicular sperm.