Search results for "SAC"
showing 10 items of 3337 documents
Fooled by Data-Mining: The Real-Life Performance of Market Timing with Moving Averages
2013
In this paper, we revisit the myths regarding the superior performance of market timing strategies based on moving average and time-series momentum rules. These active timing strategies are very appealing to investors because of their extraordinary simplicity and because they promise substantial advantages over their passive counterparts (see, for example, the paper by M. Faber (2007) "A Quantitative Approach to Tactical Asset Allocation" published in the Journal of Wealth Management). However, the ``too good to be true" reported performance of these market timing rules raises a legitimate concern as to whether this performance is realistic and whether investors can expect that future perfo…
Fixed Costs Per Shipment
2011
Exporting firms do not only decide how much of their products they ship abroad but also at which frequency. Doing so, they face a trade-off between saving on fixed costs per shipments (by shipping large amounts infrequently) and saving on storage costs (by delivering just in time with small and frequent shipments). The firm's optimal choice defines a mapping from size and frequency of shipments to fixed costs per shipment. We use a unique dataset of Swiss cross-border trade on the transaction level to analyze the size and shape of the underlying fixed costs. The data suggest that for the average Swiss exporter the fixed costs per shipment are economically important: 0.82 percent of the valu…
El componente de selección adversa de la horquilla de precios cotizada: una revisión de los modelos de estimación
2005
-Jose.E.Farinos@uv.es -Ana.M.Ibanez@uv.es Una de las principales preocupaciones en el área de la microestructura del mercado ha sido la estimación de los componentes no observables de la horquilla de precios a partir de las series de datos que proporcionan los mercados financieros, despertando quizá un mayor interés el de selección adversa por la implicaciones que supone la existencia del mismo. Esto ha provocado el desarrollo de numerosos modelos empíricos que, basándose en las propiedades estadísticas de las series de precios, proporcionan dichas estimaciones. La mayor disponibilidad de datos existentes en los mercados ha permitido el desarrollo en los últimos años de modelos basados en t…
Substitution of carcinogenic solvent dichloromethane for the extraction of volatile compounds in a fat-free model food system
2016
International audience; Dichloromethane is known as a very efficient solvent, but, as other halogenated solvents, is recognized as a hazardous product (CMR substance). The objective of the present work is to propose substitution solvent for the extraction of volatile compounds. The most important physico-chemical parameters in the choice of an appropriate extraction solvent of volatile compounds are reviewed. Various solvents are selected on this basis and on their hazard characteristics. The selected solvents, safer than dichloromethane, are compared using the extraction efficiency of volatile compounds from a model food product able to interact with volatile compounds. Volatile compounds …
Yarrowia lipolytica cell wall architecture: interaction of Ywp1, a mycelial protein, with other wall components and the effect of its depletion
1999
Linkages of Ywp1 to other components of the Yarrowia lipolytica mycelial cell wall were studied by extraction with beta-mercaptoethanol and zymolyase (a beta-glucanase complex) and by the use of rabbit polyclonal antibody preparation raised against Ywp1. Ywp1 complexed with an N-glycosylated cell wall protein(s) to form supramolecular complexes through disulphide bridges (extractable with beta-mercaptoethanol) or bonded to beta-1,3-glucan (extractable with zymolyase). The lack of a specific morphological phenotype when YWP1 was knocked out by gene disruption might indicate that other proteins present in the cell wall of Y. lipolytica compensated for its loss. In this mutant, the electrophor…
Il sacro degli altri. Culti e pratiche dei migranti in Sicilia
2018
Il libro riguarda la documentazione fotografica di pratiche cultuali di migranti in Sicilia (cristiani ortodossi, ebrei, musulmani, buddisti, induisti di diversa provenienza, accompagnata da saggi sugli specifici culti documentati. Le foto sono di A. Russo e G. Muccio.
Limitēta skābekļa apstākļos kultivēta rauga anhidrobioze un tās biotehnoloģiskie pielietojumi
2018
Promocijas darba gaitā izvērtētas iespējas uzlabot raugu Saccharomyces cerevisiae kultivētu limitēta skābekļa apstākļos izturību dehidratācijas-rehidratācijas procesā. Izpētīta dažādu vielu - antioksidantu, cukuru, sāls, poliolu - iespējamā ietekme uz šūnu rezistences palielināšanu. Tāpat parādīta iespēja izmantot celulozi saturošu substrātu pēc furfurola izdalīšanas etanola sintēzei. Pētījumos noskaidroti apstākļi enzimātiskās hidrolīzes procesam un papildus priekšapstrādes izmantošanas efektivitāte glikozes iznākuma uzlabošanai, kā arī iegūtā hidrolizāta un dehidratēto raugu izmantošanas iespējas. Promocijas darbā novērotās likumsakarības raugu šūnu atbildes reakcijās uz inkubācijas priek…
Mitochondrial inheritance and fermentative : oxidative balance in hybrids between Saccharomyces cerevisiae and Saccharomyces uvarum.
2008
Breeding between Saccharomyces species is a useful tool for obtaining improved wine yeast strains, combining fermentative features of parental species. In this work, 25 artificial Saccharomyces cerevisiae × Saccharomyces uvarum hybrids were constructed by spore conjugation. A multi-locus PCR‐restriction fragment length polymorphism (PCR‐RFLP) analysis, targeting six nuclear gene markers and the ribosomal region including the 5.8S rRNA gene and the two internal transcribed spacers, showed that the hybrid genome is the result of two chromosome sets, one coming from S. cerevisiae and the other from S. uvarum. Mitochondrial DNA (mtDNA) typing showed uniparental inheritance in all hybrids. Furth…
The mitochondrial genome of fission yeast: inability of all introns to splice autocatalytically, and construction and characterization of an intronle…
1991
In this paper we report the inability of four group I introns in the gene encoding subunit I of cytochrome c oxidase (cox1) and the group II intron in the apocytochrome b gene (cob) to splice autocatalytically. Furthermore we present the characterization of the first cox1 intron in the mutator strain anar-14 and the construction and characterization of strains with intronless mitochondrial genomes. We provide evidence that removal of introns at the DNA level (termed DNA splicing) is dependent on an active RNA maturase. Finally we demonstrate that the absence of introns does not abolish homologous mitochondrial recombination.
Mitochondria inheritance is a key factor for tolerance to dehydration in wine yeast production
2015
UNLABELLED Mitochondria are the cell's powerhouse when organisms are grown in the presence of oxygen. They are also the source of reactive oxygen species that cause damage to the biochemical components of the cell and lead to cellular ageing and death. Under winemaking conditions, Saccharomyces yeasts exclusively have a fermentative metabolism due to the high sugar content of grape must. However, their production as an active dry yeast (ADY) form required aerobic propagation and a dehydration process. In these industrial steps, oxidative stress is particularly harmful for the cell. In this work, we analysed the impact of the mitochondrial genome on oxidative stress response, longevity and d…