191 research outputs found
La fotógrafa Denise Bellon: surrealismo, documentalismo y fotografía humanista
No full textRESUMEN:Entre 1920 y 1940 se desarrolla en Francia un movimiento fotográfico denominado Nouvelle Vision que acoge a un grupo de fotógrafas profesionales de este medio, entre ellas Denise Bellon. Las imágenes de esta autora, estrechamente vinculadas con los artistas de vanguardia, nos servirán para articular conexiones con aspectos relacionados con tres corrientes fotográficas patentes en su trayectoria: el surrealismo, la fotografía humanista y el documentalismo. Para lograr este propósito nos aproximaremos, por un lado, a los rasgos específicos de cada una de estas tendencias fotográficas y por otro, a la obra de Denise Bellon a través del ensayo fílmico Le Souvenir d´un avenir (Recuerdos del porvenir, 2001) donde Yannick Bellon, su hija y el cineasta Chris Marker orquestan una narración cronológica, en la que la imagen fija adquiere status de protagonista absoluta basándose en 25000 negativos registrados entre 1937 y 1956.PALABRAS CLAVE:Fotografía, Denise Bellon, Chris Marker, surrealismo, documentalismo.ABSTRACT:A photographic movement known as Nouvelle Vision that includes a group of professional photographers of this medium, including Denise Bellon, takes place in France between 1920 and 1940. The images of this author, closely associated with the avant-garde artists, will serve us to articulate connections with three photographic trends patents in its career: surrealism, humanistic and documentary photography. To achieve this purpose us approximations, on the one hand, to the specific features of these photographic trends and on the other hand, to the work of Denise Bellon through the film essay Le Souvenir d´un l’avenir (Memories of the Future, 2001) where Yannick Bellon, his daughter and the filmmaker Chris Marker orchestrate a chronological narrative, in which the fixed image acquired status of absolute protagonist based on 25000 negatives between 1937 and 1956.KEYWORDS:Photography, Denise Bellon, Chris Marker, surrealism, documentary.</jats:p
La fotógrafa Denise Bellon: surrealismo, documentalismo y fotografía humanista
No full textA photographic movement known as Nouvelle Vision that includes a group of professional photographers of this medium, including Denise Bellon, takes place in France between 1920 and 1940. The images of this author, closely associated with the avant-garde artists, will serve us to articulate connections with three photographic trends patents in its career: surrealism, humanistic and documentary photography. To achieve this purpose us approximations, on the one hand, to the specific features of these photographic trends and on the other hand, to the work of Denise Bellon through the film essay Le Souvenir d´un l’avenir (Memories of the Future, 2001) where Yannick Bellon, his daughter and the filmmaker Chris Marker orchestrate a chronological narrative, in which the fixed image acquired status of absolute protagonist based on 25000 negatives between 1937 and 1956.Entre 1920 y 1940 se desarrolla en Francia un movimiento fotográfico denominado Nouvelle Vision que acoge a un grupo de fotógrafas profesionales de este medio, entre ellas Denise Bellon. Las imágenes de esta autora, estrechamente vinculadas con los artistas de vanguardia, nos servirán para articular conexiones con aspectos relacionados con tres corrientes fotográficas patentes en su trayectoria: el surrealismo, la fotografía humanista y el documentalismo. Para lograr este propósito nos aproximaremos, por un lado, a los rasgos específicos de cada una de estas tendencias fotográficas y por otro, a la obra de Denise Bellon a través del ensayo fílmico Le Souvenir d´un avenir (Recuerdos del porvenir, 2001) donde Yannick Bellon, su hija y el cineasta Chris Marker orquestan una narración cronológica, en la que la imagen fija adquiere status de protagonista absoluta basándose en 25000 negativos registrados entre 1937 y 1956
Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae
No full textInterspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment.Jennifer R. Bellon, Frank Schmid, Dimitra L. Capone, Barbara L. Dunn, Paul J. Chamber
A breeding strategy to harness flavour diversity of Saccharomyces interspecific hybrids and minimize hydrogen sulphide production
No full textIndustrial food-grade yeast strains are selected for traits that enhance their application in quality production processes. Wine yeasts are required to survive in the harsh environment of fermenting grape must, while at the same time contributing to wine quality by producing desirable aromas and flavors. For this reason, there are hundreds of wine yeasts available, exhibiting characteristics that make them suitable for different fermentation conditions and winemaking practices. As wine styles evolve and technical winemaking requirements change, however, it becomes necessary to improve existing strains. This becomes a laborious and costly process when the targets for improvement involve flavor compound production. Here, we demonstrate a new approach harnessing preexisting industrial yeast strains that carry desirable flavor phenotypes - low hydrogen sulfide (H(2) S) production and high ester production. A low-H(2) S Saccharomyces cerevisiae strain previously generated by chemical mutagenesis was hybridized independently with two ester-producing natural interspecies hybrids of S. cerevisiae and Saccharomyces kudriavzevii. Deficiencies in sporulation frequency and spore viability were overcome through use of complementary selectable traits, allowing successful isolation of several novel hybrids exhibiting both desired traits in a single round of selection.Etjen Bizaj, Antonio G. Cordente, Jennifer R. Bellon, Peter Raspor, Chris D. Curtin & Isak S. Pretoriu
Effect of Interspecific Yeast Hybrids for Secondary In-Bottle Alcoholic Fermentation of English Sparkling Wines
No full textIn sparkling winemaking, only a few yeast strains are regularly used for the secondary in-bottle alcoholic fermentation (SiBAF). Recently, advances in yeast development programs have yielded new breeds of interspecific wine yeast hybrids that ferment efficiently while producing novel flavors and aromas. In this work, the chemical and sensorial impacts of the use of interspecific yeast hybrids for SiBAF were studied using three commercial English base wines prepared for SiBAF using two commercial and four novel interspecific hybrids. After 12 months of lees aging, the chemical and macromolecular composition, phenolic profile, foaming, viscosity and sensory properties of the resulting 13 wines were assessed. Chemically, the yeast strains did not result in significant differences in the main wine parameters, while some differences in their macromolecular contents and sensory characteristics were noticeable. The foamability was mostly unaffected by the strain used; however, some effect on the foam stability was noticeable, likely due to the differences in polysaccharides released into the wines by the yeast strains. The wines exhibited different sensory characteristics in terms of aroma and bouquet, balance, finish, overall liking and preference, but these were mostly attributable to the differences in the base wines rather than the strain used for SiBAF. Novel interspecific yeast hybrids can be used for the elaboration of sparkling wines, as they provided wines with chemical characteristics, flavor and aroma attributes similar to those of commonly used commercial Saccharomyces cerevisiae strains
Polymorphisms in the mitochondrial ribosome recycling factor EF-G2mt/MEF2 compromise cell respiratory function and increase atorvastatin toxicity
No full textMitochondrial translation, essential for synthesis of the electron transport chain complexes in the mitochondria, is governed by nuclear encoded genes. Polymorphisms within these genes are increasingly being implicated in disease and may also trigger adverse drug reactions. Statins, a class of HMG-CoA reductase inhibitors used to treat hypercholesterolemia, are among the most widely prescribed drugs in the world. However, a significant proportion of users suffer side effects of varying severity that commonly affect skeletal muscle. The mitochondria are one of the molecular targets of statins, and these drugs have been known to uncover otherwise silent mitochondrial mutations. Based on yeast genetic studies, we identify the mitochondrial translation factor MEF2 as a mediator of atorvastatin toxicity. The human ortholog of MEF2 is the Elongation Factor Gene (EF-G) 2, which has previously been shown to play a specific role in mitochondrial ribosome recycling. Using small interfering RNA (siRNA) silencing of expression in human cell lines, we demonstrate that the EF-G2mt gene is required for cell growth on galactose medium, signifying an essential role for this gene in aerobic respiration. Furthermore, EF-G2mt silenced cell lines have increased susceptibility to cell death in the presence of atorvastatin. Using yeast as a model, conserved amino acid variants, which arise from non-synonymous single nucleotide polymorphisms (SNPs) in the EF-G2mt gene, were generated in the yeast MEF2 gene. Although these mutations do not produce an obvious growth phenotype, three mutations reveal an atorvastatin-sensitive phenotype and further analysis uncovers a decreased respiratory capacity. These findings constitute the first reported phenotype associated with SNPs in the EF-G2mt gene and implicate the human EF-G2mt gene as a pharmacogenetic candidate gene for statin toxicity in humans.Sylvie Callegari, Philip A. Gregory, Matthew J. Sykes, Jennifer Bellon, Stuart Andrews, Ross A. McKinnon and Miguel A. de Barros Lope
Human wild-type SEDL protein functionally complements yeast Trs20p but some naturally occurring SEDL mutants do not
No full textX-linked spondyloepiphyseal dysplasia tarda (SEDT, or SEDL) is a primary skeletal dysplasia affecting mostly spinal vertebral bodies and epiphyses. Previously, we have identified the SEDL gene and determined the spectrum of 21 different SEDL causing mutations. The SEDL gene is a highly conserved gene with an as yet unknown function. The yeast SEDL protein ortholog, Trs20p, has been isolated as a member of a large multi-protein complex ( approximately 10 proteins) called transport protein particle (TRAPP), which is involved in endoplasmic reticulum (ER)-to-Golgi transport. While the SEDL gene mutations cause a tissue-specific (epiphyses) and relatively mild phenotype, the Trs20p function is essential for the yeast cell. We now provide evidence that recombinant human SEDL protein is able to functionally complement the Saccharomyces cerevisiae TRS20 (TRAPP subunit 20 gene) knockout mutant. This finding strongly supports the speculated conserved nature of the SEDL/Trs20p function. To shed further light on the SEDL/Trs20p protein function, five different naturally occurring SEDL gene mutations have been tested in complementation studies. While two truncation mutations (157delAT and C271T) and one missense mutation (G139T) were unable to rescue the trs20Delta lethal phenotype, two other missense mutations (C218T and T389A) did complement trs20Delta. Interestingly, there is no obvious correlation between the nature and position of the SEDL mutation and the clinical severity of the disorder among the human SEDL patients. Although the identification of complementing SEDL gene mutations may suggest the existence of subtle phenotypic differences among SEDL patients, it might also point towards the identification of SEDL protein residues/domains specific for normal, vertebrate bone growth.Jozef Gécz, Marie A. Shaw, Jennifer R. Bellon, Miguel de Barros Lope
A Novel Approach to Isolating Improved Industrial Interspecific Wine Yeasts Using Chromosomal Mutations as Potential Markers for Increased Fitness
No full textWine yeast breeding programs utilizing interspecific hybridization deliver cost-effective tools to winemakers looking to differentiate their wines through the development of new wine styles. The addition of a non-Saccharomyces cerevisiae genome to a commercial wine yeast can generate novel phenotypes ranging from wine flavor and aroma diversity to improvements in targeted fermentation traits. In the current study we utilized a novel approach to screen isolates from an evolving population for increased fitness in a S. cerevisiae × S. uvarum interspecific hybrid previously generated to incorporate the targeted phenotype of lower volatile acidity production. Sequential grape-juice fermentations provided a selective environment from which to screen isolates. Chromosomal markers were used in a novel approach to identify isolates with potential increased fitness. A strain with increased fitness relative to its parents was isolated from an early timepoint in the evolving population, thereby minimizing the risk of introducing collateral mutations and potentially undesirable phenotypes. The evolved strain retained the desirable fermentation trait of reduced volatile acidity production, along with other winemaking traits of importance while exhibiting improved fermentation kinetics.Jennifer R. Bellon, Christopher M. Ford, Anthony R. Borneman and Paul J. Chamber
Effect of Critical Illness on Triglyceride Absorption
No full textAdequate nutrition support for critically ill patients optimizes outcome, and enteral feeding is the preferred route of nutrition. Small intestinal glucose absorption is frequently impaired in critical illness. Despite lipid being a major constituent of liquid nutrient administered, there is little information about lipid absorption during critical illness.To determine small intestinal lipid, as well as glucose, absorption in critical illness compared with health.Twenty-nine mechanically ventilated critically ill patients and 16 healthy volunteers were studied. Liquid nutrient (60 mL, 1 kcal/mL), containing 200 µL ¹³C-triolein and 3 g 3-O-methyl-glucose (3-OMG), was infused directly into the duodenum at a rate of 2 kcal/min. Exhaled ¹³CO₂ and serum 3-OMG concentrations were measured at timed intervals over 360 minutes. Lipid absorption was measured as the cumulative percentage dose (cPDR) of ¹³CO₂ recovered at 360 minutes. Glucose absorption was measured as the area under the 3-OMG concentration curve. Data are median (range) and analyzed using the Mann-Whitney U and Pearson correlation tests.Lipid absorption was markedly less in the critically ill (cPDR¹³CO₂: patients, 22.6% [0%-100%] vs healthy participants, 40.7% [5.3%-84.7%]; P = .018). While glucose absorption was less at 60 minutes in the critically ill (3-OMG60: 13.2 [3.5-29.5] vs 21.1 [9.3-31.9] mmol/L·min; P = .003), this was not apparent at 360 minutes (3-OMG360: 92.7 [54.5-147.9] vs 107.9 [64.0-168.7] mmol/L·min; P = .126). There was no relationship between lipid and glucose absorption.Small intestinal absorption of lipid is diminished during critical illness.Yasmine Ali Abdelhamid, Caroline E. Cousins, Jennifer A. Sim, Max S. Bellon, Nam Q. Nguyen, Michael Horowitz, Marianne J. Chapman and Adam M. Dean
The development and evolution of Saccharomyces interspecific hybrids for improved, industry relevant, phenotypes
No full textThis thesis describes a progression of experimental work from proof of concept (ie can laboratory generated interspecific yeast strains be developed for industrial application) through to realisation of the potential of novel interspecific wine yeast for improved outputs in the winery. A competitive market requires winemakers to not only be aware of production costs, but also to find market niches by differentiating their wine styles. Developing new yeast with improved fermentation traits and/or potential to produce diverse wine flavours and aromas can provide tools to the winemaker that are readily and easily utilised in the winery without any extra (or costly) processing intervention. With consumer reluctance to the acceptance of genetically modified organisms, yeast breeding remains an important technique for yeast strain development. Traditionally, yeast breeding programs have centred around mating between different Saccharomyces cerevisiae yeast strains. Incorporating a higher level of genomic diversity into a Saccharomyces cerevisiae wine yeast by hybridisation with other Saccharomyces species has the potential to deliver novel flavour and aroma profiles through the production of a wider range of yeast-derived, flavour-active metabolites. This research reports on the development of laboratory-generated yeast interspecific hybrids created by natural breeding techniques. Initially, interspecific hybrids between species most closely related to S. cerevisiae were assessed. Grape juice fermentation by hybrids from crosses between a commercial S. cerevisiae wine yeast and either Saccharomyces paradoxus or Saccharomyces kudriavzevii showed that the hybrids had robust fermentation properties and produced wines with different concentrations of aromatic products relative to the commercial wine yeast parent. Progeny from crosses utilising a more divergent species (Saccharomyces mikatae) were fermentation competent and could deliver wines with novel flavours and aromas, including flavour compounds more commonly associated with non- Saccharomyces species. Next, a targeted approach to determine whether hybrids could be generated with a predictable phenotype that could address an explicit problematic fermentation trait was used. Elevated volatile acidity levels when producing dessert wines from highsugar juices pose a challenge to winemakers. Hybrids from a mating with a S. cerevisiae wine yeast and Saccharomyces uvarum (a species previously reported to produce wines with low concentrations of acetic acid) displayed the desired targeted phenotypes; strong fermentation properties in high-sugar juice and wines with low volatile acidity. Subsequent experiments indicated that the hybrids were less robust in grape juice than their S. cerevisiae wine yeast parent. With this in mind, it was decided to attempt to increase fitness of one S. cerevisiae x S. uvarum hybrid by an adaptive evolution approach in grape juice. To avoid the problem of selecting end-point collateral mutations that shape phenotypes in addition to that which is targeted, isolates were progressively screened from the evolving population. An evolved isolate with loss of S. uvarum Chromosome 14 (the overriding chromosomal alteration) but no other detectable changes in karyotype demonstrated that loss of S. uvarum Chromosome 14 alone conferred increased fitness. Fermentation kinetics showed that the evolved strain had an increased fermentation performance relative to the original hybrid and retained the desirable fermentation trait of the parent: wines with low volatile acidity. This research establishes that Saccharomyces interspecific hybridisation can deliver tools to the winemaking industry in the realm of wine style differentiation through the formation of novel yeast volatile fermentation metabolite profiles, and improved yeast fermentation properties. In addition, adopting an evolutionary approach in a fermentative context can deliver increased fitness to a wine yeast interspecific hybrid.Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 201
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