Development of eye colors in Drosophila: some properties of the hormones concerned

The substance inducing the production of pigment in the eyes of vermilion brown mutants of Drosophila melanogaster has been shown to be a relatively stable chemical entity possessing true hormone-like activity. A simple method for obtaining hormone solutions has been developed involving extraction of dried wild type Drosophila pupae with ethyl alcohol and water. A logarithmic proportionality has been found to exist between the amount of hormone and the induced eye color. This relationship provides a simple method for the quantitative determination of hormone concentration in given extracts. Larvae and pupae of D. melanogaster contain an intracellular enzyme which inactivates the hormone in the presence of molecular oxygen. The hormone is not oxidized under ordinary conditions with either molecular oxygen or hydrogen peroxide. The hormone has been found to be an amphoteric compound with both acidic and basic groups and with a molecular weight between 400 and 600. The solubility and precipitation reactions of the hormone suggest its amino acid-like nature. However, the instability to heat, acid, and alkali, and its rather restricted occurrence indicate a rather complex specific structure

The importance of respect as a discursive resource in making identity claims: insights from the experiences of becoming a circus director

Though often invoked in the leadership and identity literatures, respect has been poorly articulated. This paper conceptualizes respect as a discursive resource for making identity claims and provides empirical illustration from circus directors’ accounts of becoming managers. Identity claims draw on particular discursive resources and enact recurrent social practices in “specific local historical circumstances” that cohere with “the local moral order”. To claim and to offer respect based on recognition, appraisal, identification, status and other discourses is to participate in such an order, and to make identity claims which are understood as positioning self and others. We provide “transparently observable” illustrations of respect as a discursive resource for forming, maintaining, strengthening, repairing or revising identity claims. An extreme case purposive sample of circus directors provides an organizational site in which identity dynamics are “highly visible”. Within the local moral order of travelling circuses respect is both desired from and conferred upon those whose artistic merit is recognized in both single acts and whole shows. We show that the distinction between appraisal and status as respect discourses evident in the wide social order breaks down in the case of circus. We theorize from this to the importance of respect as a discursive resource in identity claims and to its dependence upon particular accounts of merit

A microbiological method for the determination of choline by use of a mutant of Neurospora

Previous communications from this laboratory have described the production of biochemical mutants in the mold Neurospora by means of ultraviolet and x-rays (1, 2). Such mutants are characterized by the inability to carry out specific chemical syntheses which normally occur in the unmutated, or wild type, strain. In each case which has been genetically analyzed the failure of the synthesis has been found to be related to the mutation of a single gene. The strain to be described, known as No. 34486, or cholineless, arose from a culture of wild type Neurospora crassa which had been irradiated with ultraviolet light. It was found to be unable to grow in a medium containing only salts, sugar, and biotin, but it grew normally on the addition of a mixture of water-soluble vitamins. When the components of the mixture were tested singly, it was found that the addition of choline alone permitted normal growth. Up to the present, no completely satisfactory method for the determination of choline in natural products and tissue extracts has been described. Chemical methods, such as precipitation of the reineckate, lack specificity, while the biological method of Fletcher, Best, and Solandt (3) is time-consuming and difficult, and “possesses many dangerous pitfalls for the chemist” (4). The whole subject has been critically reviewed by Best and Lucas (4). It was therefore of interest to determine whether the Neurospora mutant is a suitable test organism in a quantitative assay for choline. The experiments to be described show that this is the case and form the basis of a simple, sensitive, and specific method for the determination of choline in natural products. By this procedure it is possible to determine choline in a concentration of 0.02 mg. per liter; routine analyses can be run on 100 mg. samples of material

Development of Eye Colors in Drosophila: Extraction of the Diffusible Substances Concerned

The development of eye color in Drosophila is known to involve special diffusible substances [1,2]. A genetically vermilion (v) eye will develop wild-type eye color if it is supplied with v+ substance by transplantation or by injection of body fluid of wild type flies. Similarly a genetically cinnabar (cn) eye will develop the color characteristic of wild type if it is supplied with cn+ substance. The present paper summarizes preliminary experiments made to learn something of the nature of the two substances just mentioned. During the course of our studies, Ephrussi and Harnly [3] have shown that pupal fluid can be freed of living cells by freezing in liquid air without destroying the v+ and cn+ substances. Khouvine, Ephrussi and Harnly [4] have shown further that these substances can be extracted from Calliphora pupae with 95 per cent alcohol-ether mixtures and with 95 per cent alcohol but not with pure ether. They conclude that these substances are not proteins or enzymes, a conclusion confirmed by our work

A possible influence of the spindle fibre on crossing-over in Drosophila

The distribution of genes in the second and third chromosomes of Drosophila melanogaster suggests that crossing-over may be influenced by the spindle fibre at least in neighboring regions. The disparity between the genetic and cytological maps of these chromosomes especially in the spindle fibre regions (Dobzhanzky 2,3) is consistent with such a view

Principles for aerospace manufacturing engineering in integrated new product introduction

This article investigates the value-adding practices of Manufacturing Engineering for integrated New Product Introduction. A model representing how current practices align to support lean integration in Manufacturing Engineering has been defined. The results are used to identify a novel set of guiding principles for integrated Manufacturing Engineering. These are as follows: (1) use a data-driven process, (2) build from core capabilities, (3) develop the standard, (4) deliver through responsive processes and (5) align cross-functional and customer requirements. The investigation used a mixed-method approach. This comprises case studies to identify current practice and a survey to understand implementation in a sample of component development projects within a major aerospace manufacturer. The research contribution is an illustration of aerospace Manufacturing Engineering practices for New Product Introduction. The conclusions will be used to indicate new priorities for New Product Introduction and the cross-functional interactions to support flawless and innovative New Product Introduction. The final principles have been validated through a series of consultations with experts in the sponsoring company to ensure that correct and relevant content has been defined

Vegetation and environmental patterns on soils derived from Hawkesbury Sandstone and Narrabeen substrata in Ku-ring-gai Chase National Park, New South Wales

[Abstract]: The vegetation patterns in the Central Coast region of New South Wales have been extensively studied with respect to single environmental variables, particularly soil nutrients. However, few data are available on the effects of multiple environmental variables. This study examines the relationships between vegetation and multiple environmental variables in natural vegetation on two underlying rock types, Hawkesbury sandstone and Narrabeen group shales and sandstones, in Ku-ring-gai Chase National Park, Sydney. Floristic composition and 17 environmental factors were characterized using duplicate 500 m2 quadrats from fifty sites representing a wide range of vegetation types. The patterns in vegetation and environmental factors were examined through multivariate analyses: indicator species analysis was used to provide an objective classification of plant community types, and the relationships between vegetation and environmental factors within the two soil types were examined through indirect and direct gradient analyses. Eleven plant communities were identified, which showed strong agreement with previous studies. The measured environmental factors showed strong correlations with vegetation patterns: within both soil types, the measured environmental variables explained approximately 32 - 35% of the variation in vegetation. No single measured environmental variable adequately described the observed gradients in vegetation; rather, vegetation gradients showed strong correlations with complex environmental gradients. These complex environmental gradients included nutrient, moisture and soil physical and site variables. These results suggest a simple 'nutrient' hypothesis regarding vegetation patterns in the Central Coast region is inadequate to explain variation in vegetation within soil types

Institutions and moral agency: the case of Scottish Banking

It has been an enduring concern of institutional economics and critical realism to understand how individuals are able to exercise agency in the context of social structures, and to maintain appropriate connections, separations and balances between these two levels of causal power. This paper explores the contribution of Alasdair MacIntyre's neo-Aristotelian philosophy to the topic. Empirical data are provided from the career narratives of senior Scottish bankers recalled in the aftermath of the global financial crisis of 2007/8. The method of the study is interpretive, using themes drawn from MacIntyre's writings. These bankers faced moral choices as tensions developed between their own professional standards and the new corporate goals of the banks. We discuss MacIntyre's understanding of individual moral agency as a narrative quest in the context of different types of institution with different and often conflicting ideas about what constitutes good or right action. Habituation and deliberation are important in enabling action, but fully developed moral agency also depends on individuals being able to make choices in the space opened up by tensions within and between institutions