Chromosomal Deficiencies and the Embryonic Development of Drosophila Melanogaster

Chromosome aberrations have marked effects upon the development of an organism. Many such aberrations are lethal. In Drosophila this is particularly true of chromosomal deficiencies, as first described by Bridges [2]. A more detailed study of the effects of such aberrations made by Li [3] shows that in all the cases he investigated deficiencies are lethal in the homozygous condition the organisms dying in the egg or larval stages. Heterozygous deficiencies result in death in later stages, although many are not lethal. A few exceptional cases of viable homozygous deficiencies have been described [4,5]. In such instances the deficiencies are among the smallest known, probably for very few genes. These facts emphasize the importance of the chromosomes in the developmental processes. Just what the chromosomal functions may be, however, is by no means clear; nor is the role of the individual gene evident. An ideal approach, such as the removal of one gene at a time, then of combinations of genes, to determine the part played by each and its interactions with others, presents many practical difficulties. The existence of numerous deficiencies, however, makes an approximation to this approach possible by the study of the effects of larger or smaller blocks of genes. The present study is concerned with the effects of certain deficiencies upon the embryonic development of D. melanogaster. The deficiencies used involved greater or lesser portions of the X-chromosome, ranging from the total absence of the X to a small deficiency involving relatively few "bands" as seen in the salivary gland chromosome. The technique of Huettner and Rabinowitz [6] was used, in a somewhat modified form, for the observation of living eggs, and details of internal structure were studied by means of sectioned material. Only timed eggs were used. Usually females were allowed to lay for half an hour and the eggs allowed to develop to the desired stage at a temperature of 22-23°C

Deriving Value from a Commodity Process: A Case Study of the Strategic Planning and Management of a Call Center

The paper unravels the prevalent paradigm that differentiates between the management of a core competence and commodity processes. A case study is conducted to examine the strategic planning and management of a call center. The aim is to illustrate that a commodity process, such as handling customers’ complaints and enquiries, can be significantly beneficial to the business, if a clear value-creating strategy is articulated and a valuecreating activity system is established. Findings derived from this study suggest that a call center can provide substantial added value to the business and be managed differently through devising an appropriate intellectual capital management approach

Evidence for strain-specific exometabolomic responses of the coccolithophore Emiliania huxleyi to grazing by the dinoflagellate oxyrrhis marina

© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Marine Science 3 (2016): 1, doi:10.3389/fmars.2016.00001.The coccolithophore Emiliania huxleyi forms massive blooms and plays a critical role in global elemental cycles, sequestering significant amounts of atmospheric carbon dioxide on geological time scales via production of calcium carbonate coccoliths and emitting dimethyl sulfoniopropionate (DMSP), which has the potential for increasing atmosph-eric albedo. Because grazing in pelagic systems is a major top-down force structuring microbial communities, the influence of grazers on E. huxleyi populations has been of interest to researchers. Roles of DMSP (and related metabolites) in interactions between E. huxleyi and protist grazers have been investigated, however, little is known about the release of other metabolites that may influence, or be influenced by, such grazing interactions. We used high-resolution mass spectrometry in an untargeted approach to survey the suite of low molecular weight compounds released by four different E. huxleyi strains in response to grazing by the dinoflagellate Oxyrrhis marina. Overall, a strikingly small number of metabolites were detected from E. huxleyi and O. marina cells, but these were distinctly informative to construct metabolic footprints. At most, E. huxleyi strains shared 25% of released metabolites. Furthermore, there appeared to be no unified metabolic response in E. huxleyi strains to grazing; rather, these responses were strain specific. Concentrations of several metabolites also positively correlated with grazer activities, including grazing, ingestion, and growth rates; however, no single metabolite responded uniformly across all strains of E. huxleyi tested. Regardless, grazing clearly transformed the constituents of dissolved organic matter produced by these marine microbes. This study addresses several technical challenges, and presents a platform to further study the influence of chemical cues in aquatic systems and demonstrates the impact of strain diversity and grazing on the complexity of dissolved organic matter in marine systems.Funding for this work was provided by the Gordon and Betty Moore Foundation, Grant #3301 awarded to A Vardi, BAS. Van Mooy, K Bidle, MJ, and TM. Additional funding for this work was provided by an award from the Flatley Discovery Lab to TM