An improved method for detecting substrate preferences shown by mosquitoes that exhibit 'skip oviposition'

Abstract. A new method is described for detecting and characterizing ovi-position-substrate preferences among insects (e.g. Aedes aegypti ) that customarily disperse the eggs of a single batch among several sites (i.e. that exhibit 'skip oviposition'). The method entails recording the distribution of eggs by individual females provided initially with an array of identical sites, thus eliminating possible effects of position preference and female density, and then placing one test site into the array. A preferred substrate can be identified promptly in this way without having to count eggs.     

First report of heteroecism in Stereostratum corticioides,the causal agent of bamboo culm rust

An aecidium-type rust fungus, which causes rust disease in Choerospondias axillaris (Anacardiaceae), was found on Kyusyu Is., Japan. A sequence analysis of genomic ribosomal DNA showed that this rust fungus genetically matches Stereostratum corticioides, a causal agent of culm rust disease of bamboos and broadleaf bamboos. Inoculation experiments and further nucleotide sequence analyses that included additional fungal material showed that the aecidium-type rust fungus is conspecific with S. corticioides, a species whose spermogonial and aecial stages were previously unknown. Thus, we demonstrated heteroecism in S. corticioides for the first time. We also propose that the binomial Puccinia corticioides should be revived to replace S. corticioides.     

Testing Multivariate Normality in Series Experiments of Incomplete Blocks by Generalized Shapiro-Wilk Test

In this paper, we verify our assumption about multivariate normality in series experiments of incomplete blocks by the generalized Shapiro-Wilk test. This test utilizes transformations of mean yields of the investigated varieties and the generated random variables according to Durbin's randomization principle.     

Reproductive biology of the European Cuckoo Cuculus canorus: early insights, persistent errors and the acquisition of knowledge

The brood parasitic habits of the European Cuckoo Cuculus canorus have excited wonder, disbelief and speculation since the fourth century BC. Accurate knowledge of cuckoo biology, however, accumulated only slowly and mostly since 1700. The aim of this study is to review six main topics: (1) the placement of cuckoo eggs in host nests; (2) cuckoo ‘clutch’ size; (3) cuckoo egg characteristics, mimicry and rejection; (4) choice of hosts; (5) eviction of eggs and chicks; and (6) the reasons why cuckoos are brood parasites and are incapable of rearing their own young. Early errors in reporting cuckoo biology were often a consequence of poor or incomplete observations leading to erroneous interpretations. Many of the early observers were egg collectors who focussed almost exclusively on the egg-laying period, thus ignoring cuckoo chick biology. Major landmarks in cuckoo studies included the facts that: (1) cuckoo eggs often resembled those of their hosts (1760s) and that this mimicry was adaptive (1850s); (2) hosts sometimes evicted cuckoo eggs (1770s); (3) female cuckoos laid individually distinctive eggs and that specific cuckoo gentes may exist (1850s); and (4) although well recognised that cuckoo chicks were reared alone, prior to Jenner’s work in the 1780s female cuckoo parents were thought to either eat or evict the host eggs or young. Jenner’s results was more readily accepted in Britain than in Germany. Between 1700 and 1859, cuckoo brood parasitism was difficult to reconcile with the prevalent conceptual framework of physico-theology (later known as the argument from design). Thereafter, Darwin’s idea of natural selection provided a superior conceptual framework, which in conjunction with experimental testing of specific hypotheses has continued to advance our understanding of brood parasitism. Our knowledge of cuckoo biology is far from complete, however, and we predict that continuing research often incorporating new technologies will refine and extend our understanding of the cuckoo’s extraordinary biology.     

Mixture models of soybean growth and herbivore performance in response to nitrogen–sulphur–phosphorous nutrient interactions

1. It is widely established that plant-mineral nutrition is an important determinant of herbivore developmental performance and behavioural preference. Unfortunately, the specific effects of minerals on herbivory have been variable and few unifying principles have emerged. Advances in this area may be impeded in part by an experimental approach that emphasises single nutrients without regard to nutrient ratios. 2. In this study, mixture-design experiments were adapted to the study of mineral nutrition and herbivore performance. The interactive effects of nitrogen, sulphur, and phosphorous on the development of soybean looper (Pseudoplusia includens) and two-spotted spider mite (Tetranychus urticae) feeding on soybeans (Glycine max) were quantified by polynomial regression. 3. Although significant effects of individual minerals were measured, the actual responses to these nutrients depended on the proportions of the other components in the nutrient solution. For example, over a range of decreasing nitrogen concentration, resulting soybean looper pupal mass first declined then increased when replaced by a high sulphur : phosphorous blend, but just the opposite response was measured when replaced with high phosphorous : sulphur ratio. 4. Moreover, responses to mineral proportions were generally nonlinear and the effects of mineral proportion were not only species-specific, but varied for different responses within a species. 5. These studies demonstrate that understanding the role of mineral nutrients in host-plant quality requires that mineral proportions be considered in addition to concentration. Mixture modelling, which is largely unknown to ecologists, is a powerful new tool that could significantly advance the study of the interactive effects of mixture components, such as in plant-nutrient blends.     

Detection of Interactive Effects in Carcinogenesis

The multistage theory for cancer is used to derive models for independent effects and for interactive effects of two carcinogenic agents. The derivation assumes that a tumor is of single cell origin and that a normal cell is transformed to a cancer cell by undergoing a finite number of irreversible, heritable, mutation-like transitions. The interactions enter the proposed models at the level of single cell transition rates rather than, as is conventional, at the level of animal response proportions. Suggestions are given for the design and analysis of fixed time, binary response, two factor, cancer bioassay experiments.     

Kinetic and structural changes in HsmtPheRS,induced by pathogenic mutations in human FARS2

Mutations in the mitochondrial aminoacyl‐tRNA synthetases (mtaaRSs) can cause profound clinical presentations, and have manifested as diseases with very selective tissue specificity. To date most of the mtaaRS mutations could be phenotypically recognized, such that clinicians could identify the affected mtaaRS from the symptoms alone. Among the recently reported pathogenic variants are point mutations in FARS2 gene, encoding the human mitochondrial PheRS. Patient symptoms range from spastic paraplegia to fatal infantile Alpers encephalopathy. How clinical manifestations of these mutations relate to the changes in three‐dimensional structures and kinetic characteristics remains unclear, although impaired aminoacylation has been proposed as possible etiology of diseases. Here, we report four crystal structures of HsmtPheRS mutants, and extensive MD simulations for wild‐type and nine mutants to reveal the structural changes on dynamic trajectories of HsmtPheRS. Using steady‐state kinetic measurements of phenylalanine activation and tRNA^Phe aminoacylation, we gained insight into the structural and kinetic effects of mitochondrial disease‐related mutations in FARS2 gene.