THE EFFECT OF LABELING INTENSITY, ESTIMATED BY REAL-TIME CONFOCAL LASER SCANNING MICROSCOPY, ON FLOW CYTOMETRIC APPEARANCE AND IDENTIFICATION OF IMMUNOCHEMICALLY LABELED MARINE DINOFLAGELLATES

Two different fluorescein isothiocyanate (FITC) conjugates were used to analyze the effect of labeling intensity on the flow cytometric appearance of marine dinoflagellates labeled with antibodies that specifically recognized the outer cell wall. Location of the labeling was revealed by epifluorescence and real-time confocal laser scanning microscopy using an anti-rabbit IgG/FITC-conjugated secondary antiserum. Flow cytometric measurements showed that cells of Prorocentrum species labeled this way could not always be distinguished from unlabeled cells. The labeling intensity increased several times when a biotinylated anti-rabbit IgG secondary antiserum was used in combination with a streptavidin/FITC conjugate. Flow cytometry indicated that the labeling intensity had increased 50%, which resulted in an improved separation of clusters of labeled and unlabeled cells

Vloeistof-vloeistofekstraksie-ondersoek van molibdeen (V1)-ewewigte

Thesis(M.Sc.) -- Universiteit van Stellenbosch, 1986.Full text to be digitised and attached to bibliographic record

Vitreous haemorrhage and other ocular complications of a persistent hyaloid artery

Contains fulltext : 23348___.PDF (publisher's version ) (Open Access

Development of an oxygen measurement system as a management tool in horticulture

Gases (e.g. oxygen) in the root environment are an important factor for plant development. This study aims to show whether it is possible to obtain an overview of oxygen profiles within the root zone using a limited amount of oxygen measurements in the root environment. A further aim was to demonstrate whether this technology can be used to develop a measurement tool for practical use. Therefore, a multioxygen sensor was constructed, and measurements were carried at two locations. In the greenhouse, oxygen measurements were carried during growth of roses at various horizontal and vertical positions in pots, filled with stone wool blocks. In the field, oxygen levels were detected in 3 L pots in a Rhododendron crop using peat as a growing medium. Here, optical oxygen sensors were positioned at 3 cm above the bottom, and also in the middle of the pots. The results indicate that it is possible to develop an oxygen measuring strategy which can be used to determine a representative pattern of oxygen levels in growing media. Relationships between and related growth conditions will be described, and it will be discussed for which cultivation systems oxygen measurements should have priority

The role of genetic diversity in the evolution and maintenance of environmentally-cued, male alternative reproductive tactics

Abstract Background Alternative reproductive tactics (ARTs) are taxonomically pervasive strategies adopted by individuals to maximize reproductive success within populations. Even for conditionally-dependent traits, consensus postulates most ARTs involve both genetic and environmental interactions (GEIs), but to date, quantifying genetic variation underlying the threshold disposing an individual to switch phenotypes in response to an environmental cue has been a difficult undertaking. Our study aims to investigate the origins and maintenance of ARTs within environmentally disparate populations of the microscopic bulb mite, Rhizoglyphus robini, that express ‘fighter’ and ‘scrambler’ male morphs mediated by a complex combination of environmental and genetic factors. Results Using never-before-published individual genetic profiling, we found all individuals across populations are highly inbred with the exception of scrambler males in stressed environments. In fact within the poor environment, scrambler males and females showed no significant difference in genetic differentiation (Fst) compared to all other comparisons, and although fighters were highly divergent from the rest of the population in both poor or rich environments (e.g., Fst, STRUCTURE), fighters demonstrated approximately three times less genetic divergence from the population in poor environments. AMOVA analyses further corroborated significant genetic differentiation across subpopulations, between morphs and sexes, and among subpopulations within each environment. Conclusion Our study provides new insights into the origin of ARTs in the bulb mite, highlighting the importance of GEIs: genetic correlations, epistatic interactions, and sex-specific inbreeding depression across environmental stressors. Asymmetric reproductive output, coupled with the purging of highly inbred individuals during environmental oscillations, also facilitates genetic variation within populations, despite evidence for strong directional selection. This cryptic genetic variation also conceivably facilitates stable population persistence even in the face of spatially or temporally unstable environmental challenges. Ultimately, understanding the genetic context that maintains thresholds, even for conditionally-dependent ARTs, will enhance our understanding of within population variation and our ability to predict responses to selection

Strategically Flexible Production: the Multi-focused Manufacturing Paradigm

Defines a new manufacturing paradigm and investigates its adoption and performances, within the assembly industry on a global basis. The definition of the paradigm is based on a set of basic principles to design and manage production systems which discard the traditional way of organizing manufacturing activities, and pool companies which pursue different manufacturing strategies and implement different innovative techniques. The paradigm is characterized by the simultaneous implementation of three principles: strategic multi‐focusedness, integration of business processes across functions, and process ownership. Starting from an operationalization based on fuzzy logic, explores the hypotheses about the adoption and the performance improvements of the multi‐focused manufacturing paradigm using a sample from the International Manufacturing Strategy Survey (IMSS) database. The paradigm has been adopted widely across countries and industries involved in the IMSS survey. Shows that process ownership is poorly implemented by most of the companies at the moment, while multi‐focusedness and integration are more on hand. Companies which have adopted the paradigm are improving their performance significantly better and quicker than partial or non‐adopters. Highlights different possible patterns that the companies can follow to reach core adoption of the multi‐focused manufacturing paradigm