The morphology of the gut and a qualitative review of digestive enzymes in some New Zealand ophiuroids

The structure of the gut of three New Zealand intertidal ophiuroids, Ophionereis fasciata, Ophiactis resiliens and Ophiopteris antipodum is described. The gut epithelium of all three species contains cells with granular inclusions and deposits of lipid. Glycogen is also detectable in Ophionereis fasciata.
A wide range of digestive enzymes, particularly those hydrolysing glycosidic linkages, is recorded; a greater variety being present in the predominantly algal feeders Ophiactis resiliens and Ophiopteris antipodum. Tests for cellulases however proved negative with all three species.     

Genetic variability in maned wolf based on heterologous short-tandem repeat markers from domestic dog

The maned wolf (Chrysocyon brachyurus) is the largest South American canid. Habitat loss and fragmentation, due to agricultural expansion and predatory hunting, are the main threats to this species. It is included in the official list of threatened wildlife species in Brazil, and is also protected by IUCN and CITES. Highly variable genetic markers such as microsatellites have the potential to resolve genetic relationships at all levels of the population structure (among individuals, demes or metapopulations) and also to identify the evolutionary unit for strategies for the conservation of the species. Tests were carried out to verify whether a class of highly polymorphic tetranucleotide repeats described for the domestic dog effectively amplifies DNA in the maned wolf. All five loci studied were amplified; however, one of these, was shown to be monomorphic in 69 maned wolf samples. The average allele number and estimated heterozygosity per polymorphic locus were 4.3 and 67%, respectively. The genetic variability found for this species, which is considered threatened with extinction, showed similar results when compared to studies of other canids.     

The Setting and Marking of Microbiology Examinations

A rapid, simple method for testing and improving a student's ability to detect and correct misuse of scientific English is described. Performance in such Precision Tests was positively correlated with performance in conventional examinations, and use of these tests in the manner described was followed by an improvement in examination performance. The data discussed in this paper concern the use of Precision Tests in the teaching of biochemistry, but the tests may also prove useful in other biological disciplines.     

Quantitative comparative analysis of complex two-dimensional electropherograms

A protocol is described to detect and assess differences between complex electrophoretic patterns. A semiautomated method is used to collect accurate absolute mobility data from many two-dimensional electropherograms and a computer algorithm has been developed which normalizes and averages these data. The program generates refined numerical maps consisting of the mean electrophoretic mobilities and corresponding confidence limits for each component protein represented in the original two-dimensional electrophoretic pattern. Tests of statistical significance of apparent differences between averaged numerical maps are carried out to evaluate electrophoretic polymorphisms between the ribosomal proteins of two different plant species. Furthermore, using a nonlinear function relating log molecular weight to mobility, precise molecular weight estimates are obtained from measurements of electrophoretic mobilities of proteins in the presence of sodium dodecyl sulfate. Several examples are presented which demonstrate application of these semiautomated analyses to quantitative comparison and interpretation of two dimensional gel electropherograms.     

Characteristics of Enterococcus cecorum strains from the intestines of different animal species

Enterococcus cecorum , originally described as Streptococcus cecorum , from poultry intestines, was isolated from intestinal contents of pigs, cattle, horses, canaries and a mallard duck. Strains from different animal hosts showed differences in biochemical characteristics and can be regarded as belonging to different ecovars of the species. Tests were presented which are useful in the identification of this unusual Enterococcus sp. which lacks the group D antigen and may fail to grow aerobically in the presence of 6·5% NaCl. Enterococcus cecorum appears to be the only cultivable component of the gastrointestinal flora of canaries and was present exclusively in the crop.     

Genome characterization, analysis of virulence and transformation of Microbacterium nematophilum, a coryneform pathogen of the nematode Caenorhabditis elegans

A coryneform bacterium designated Microbacterium nematophilum has previously been reported to act as a pathogen for Caenorhabditis elegans. This bacterium is able to colonize the rectum of infected worms and cause localized swelling, constipation and slowed growth. Additional isolates and analysis of this bacterium are described here. Tests of pathogenicity on other Caenorhabditis nematodes show that M. nematophilum infection is lethal to most species in the genus, in contrast to its relatively mild effects on C. elegans. The size and geometry of the pathogen genome have been determined as a closed circular molecule of 2.85 Mb with high G+C content. Bacteria also harbor a 55 kb plasmid, pMN1, which is largely composed of a lysogenic bacteriophage genome. Mutagenesis experiments have yielded stable avirulent mutants of M. nematophilum. As a first step towards molecular genetic analysis, methods for low-efficiency transformation of M. nematophilum have been developed.     

Tests for heritable genetic damage and for evidence of gonadal exposure in mammals

Tests for the induction of genetic damage in mammalian germ cells provide the data needed for human genetic risk assessment and are used as standards for judging the ability of shorter-term tests to predict genetic hazard. In this review, 15 mammalian germ-cell tests and their variants are described. These tests are of two general types: (a) those designed to detect certain classes of genetic damage (gene mutations, chromosome breakage and/or rearrangement, and chromosome mis-segregation), regardless of whether or not the endpoint scored has any significance to human health, and (b) those designed to detect phenotypes that have human health implications, while the nature of the genetic damage is not usually known. Exposure to a mutagenic agent presents no genetic hazard if the chemical or its metabolites fail to reach the reproductive cells. Tests for gonadal exposure are, therefore, important, as preliminaries or components of studies on germ-cell mutagenicity. Seven of these tests and their variants are briefly described in the second part of the paper.     

Bayesian estimation and testing of gene frequencies

This article explains estimation of gene frequencies from a Bayesian viewpoint using prior information. How to obtain Bayes estimators and the highest posterior density credible sets (Bayesian counterpart to classical confidence intervals) for gene frequencies is described. Tests of hypotheses are also discussed. A readily available mathematical application package is used to demonstrate the mathematical computations.     

A design for studying the clustering of plant or animal species using quadrat sizes in geometric progression

An experimental design involving randomly selected quadrats with areas in geometric progression is discussed. The procedure is suggested when the clustering habits of a plant or animal species ate unknown. Several models for the number of individuals per unit area are considered. Tests for these distributions versus random dispersal are given, along with techniques for estimating cluster area and number of individuals per cluster. Illustrations are included.     

A Novel Method of Automatic Plant Species Identification Using Sparse Representation of Leaf Tooth Features

Automatic species identification has many advantages over traditional species identification. Currently, most plant automatic identification methods focus on the features of leaf shape, venation and texture, which are promising for the identification of some plant species. However, leaf tooth, a feature commonly used in traditional species identification, is ignored. In this paper, a novel automatic species identification method using sparse representation of leaf tooth features is proposed. In this method, image corners are detected first, and the abnormal image corner is removed by the PauTa criteria. Next, the top and bottom leaf tooth edges are discriminated to effectively correspond to the extracted image corners; then, four leaf tooth features (Leaf-num, Leaf-rate, Leaf-sharpness and Leaf-obliqueness) are extracted and concatenated into a feature vector. Finally, a sparse representation-based classifier is used to identify a plant species sample. Tests on a real-world leaf image dataset show that our proposed method is feasible for species identification.     

Differentiation between genera Rhodococcus and Nocardia by susceptibility testing to kanamycin and some other antituberculosis agents

The test for susceptibility to kanamycin is useful for differentiating between the genera Rhodococcus and Nocardia. All rhodococci except R. equi, R. erythropolis, and R. aurantiacus are susceptible to kanamycin, whereas all nocardiae except N. otitidis-caviarum are resistant to kanamycin. Tests for susceptibility to rifampicin, streptomycin, and minocycline also are useful for differentiating among the species of each genus.     

Passage des corps d'inclusion de virus d'une polyédrie nucléaire dans le tube digestif d'un orthoptère détritivore,Acheta domesticus L.

Summary Passage of nuclear polyhedral virus inclusion bodies in the gut of the detritiphagous OrthopteronA. domesticus is described. Histological studies permitted following the rate of passage and the elimination time of the inclusion bodies. Tests of virulency, carried out on newly hatched larvae ofB. mori, showed that inclusion bodies remained virulent and apparently unaffected by the digestive activities to which they had been exposed. These results suggest thatGryllus species can act as disseminators of insect viruses under field conditions.      

Drosophila virilis and its cosmopolitan relatives in urban islands

Populations of brewery Drosophila have been studied for 2 years. Species distributions diner between breweries, and are very different from those found in woodland and fruitmarkets. It is suggested that breweries form 'urban islands'. One of the commonest species found in breweries appears to be Drosophila virilis , which has not previously been found in Britain. Tests on various characteristics, including courtship song, have shown conclusively that this species is a strain of D. virilis.     

Safety and immunotoxicity assessment of immunomodulatory monoclonal antibodies

Most therapeutic monoclonal antibodies (mAbs) licensed for human use or in clinical development are indicated for treatment of patients with cancer and inflammatory/autoimmune disease, and as such are designed to directly interact with the immune system. A major hurdle for the development and early clinical investigation of many of these immunomodulatory mAbs is their inherent risk for adverse immune-mediated drug reactions in humans such as infusion reactions, cytokine storms, immunosuppression and autoimmunity. A thorough understanding of the immunopharmacology of a mAb in humans and animals is required to both anticipate the clinical risk of adverse immunotoxicological events and to select a safe starting dose for first-in-human (FIH) clinical studies. This review summarizes the most common adverse immunotoxicological events occurring in humans with immunomodulatory mAbs and outlines non-clinical strategies to define their immunopharmacology and assess their immunotoxic potential, as well as reduce the risk of immunotoxicity through rational mAb design. Tests to assess the relative risk of mAb candidates for cytokine release syndrome, innate immune system (dendritic cell) activation and immunogenicity in humans are also described. The importance of selecting a relevant and sensitive toxicity species for human safety assessment in which the immunopharmacology of the mAb is similar to that expected in humans is highlighted, as is the importance of understanding the limitations of the species selected for human safety assessment and supplementation of in vivo safety assessment with appropriate in vitro human assays. A tiered approach to assess effects on immune status, immune function and risk of infection and cancer, governed by the mechanism of action and structural features of the mAb, is described. Finally, the use of immunopharmacology and immunotoxicity data in determining a minimum anticipated biologic effect Level (MABEL) and in the selection of safe human starting dose is discussed.     

In vitro culture of growing mouse oocytes

A method is described for in vitro culture of naked growing mouse oocytes for at least four days. Tests for metabolic function indicate that the oocytes increase in volume, accumulate glucose-6-phosphate dehydrogenase, and maintain a steady level of 3H-uridine and 3H-leucine incorporation.     

Effects of epistasis on tests for linkage in self-pollinated species

Summary Tests for linkage based on covariances among relatives in self-pollinated species are usually based upon an assumption that epistasis is not important. This study was conducted to determine the impact of epistasis on, and to investigate the sensitivity of, such tests. Thirty covariances were calculated for each of ten non-epistatic and ten epistatic genetic models with varying probabilities of recombination between two coupling or repulsion loci. Each set of covariances was tested for linkage by comparing covariances calculated for the model with those expected for an additive-dominance model with no linkage. Results showed that the test for linkage is quite insensitive to the effects of linkage due to the disproportionate influence of inbreeding. Repulsion linkages should be easier to detect than coupling linkages for all models. Epistasis was found to mimic or counteract the effects of linkage. Tests for linkage based on covariances within a hierarchical mating design appear to be insensitive to linkage and may confuse the effects of linkage and epistasis.     

Threatened reef corals of the world

A substantial proportion of the world's living species, including one-third of the reef-building corals, are threatened with extinction and in pressing need of conservation action. In order to reduce biodiversity loss, it is important to consider species' contribution to evolutionary diversity along with their risk of extinction for the purpose of setting conservation priorities. Here I reconstruct the most comprehensive tree of life for the order Scleractinia (1,293 species) that includes all 837 living reef species, and employ a composite measure of phylogenetic distinctiveness and extinction risk to identify the most endangered lineages that would not be given top priority on the basis of risk alone. The preservation of these lineages, not just the threatened species, is vital for safeguarding evolutionary diversity. Tests for phylogeny-associated patterns show that corals facing elevated extinction risk are not clustered on the tree, but species that are susceptible, resistant or resilient to impacts such as bleaching and disease tend to be close relatives. Intensification of these threats or extirpation of the endangered lineages could therefore result in disproportionate pruning of the coral tree of life.     

Multilocus sequence analysis of Penicillium and Eupenicillium species

Taxonomy of Hyphomycetes has always been a challenging problem, with experts viewing species in different ways and modifying the taxonomy of groups to reflect their best evaluation of species limits and concepts. The advent of phylogenetic analysis, relatively easy DNA sequencing techniques and PCR has provided an opportunity for mycology to move from a strictly morphological analysis of species to phylogenetic analysis of DNA sequences. Phylogenetic theory dictates that data from different loci will produce congruent or at least non-contradictory evolutionary histories of a clonal lineage. Tests of tree congruence such as the index of association can show whether lineages are clonal, and has revealed that some species long thought to be clonal are cryptically recombining. Genealogical concordance phylogenetic species recognition allows unambiguous identification of species boundaries.     

A simple method for assaying contact toxicities of insecticides,with results of tests of some organic compounds against Calandra granaria L

A simple method of testing the contact action of insecticides either as residual dry deposits or as oil films is described. Tests with crystalline deposits of D.D.T. indicated that this method of assay was not sufficiently sensitive for practical use, but tests with oil films could be used. Some of the factors governing the toxicity of D.D.T. in the two systems are discussed, and the results of tests with several organic compounds are given.     

A method of estimating the numbers of soil protozoa,especially amoebae,based on their differential feeding on bacteria

Cultural methods of estimating protozoal numbers in soil based on a dilution technique have suffered from two main sources of error: first, the use of too few replicate cultures and, secondly, the uncertain quality of the bacterial food supply. A method is described of using glass cells to set up 8 replicate cultures in one Petri dish, employing pure bacterial cultures spread over a non-nutrient agar base to provide a standard and suitable food for the Protozoa. The selection and testing of suitable bacterial strains as food supply is described. Tests for the 'recovery' of counted suspensions of Protozoa added to sterilized soil were made; the results of these are given and the limits of experimental error in the method are discussed.