2,067 research outputs found
Histories, Spaces and Heritages at the Transition from the Ottoman Empire to the Greek State: Introduction
The introduction to the outcome of an attempt at an interdisciplinary approach to the transition from the Ottoman Empire to the Greek state via the study of lived space and material culture. Based on a fiveâyear research project hosted in the French School at Athens, this dossier is a collection of individual case studies that set up a framework for the critical discussion of the abovementioned transition
Influence of sodium chloride on wine yeast fermentation performance
This paper concerns research into the influence of salt (sodium chloride) on growth, viability and fermentation performance in a winemaking strain of the yeast, Saccharomyces cerevisiae. Experimental fermentations were conducted in both laboratory-scale and industrial-scale experiments. Preculturing yeasts in elevated levels of sodium chloride, or salt âpreconditioningâ led to improved fermentation performance. This was manifest by preconditioned yeasts having an improved capability to ferment high-sugar containing media with increased cell viability and with elevated levels of produced ethanol. Salt-preconditioning most likely influenced the stress-tolerance of yeasts by inducing the synthesis of key metabolites such as trehalose and glycerol. These compounds may act to improve cellsâ ability to withstand osmostress and ethanol toxicity during fermentations of grape must. Industrial-scale trials using salt-preconditioned yeasts verified the benefit of this novel physiological cell engineering approach to practical winemaking fermentations
Dormancy-Breaking Requirements and Germination for Seeds of Ostrya carpinifolia Scop.
The present research aims at investigating the combined effects of warm stratification (WS)+cold stratification (CS), and gibberellic acid (GA3)+cold stratification (CS) on breaking dormancy and germination in seeds of Ostrya carpinifolia. The seeds were subjected to WS (20-25 °C) for 0, 1 and 2 months and were subsequently cold stratified at 3-5 °C for 0, 1, 2, 3 and 4 months (1st experiment). A further amount of seeds was treated with 500, 1000 or 2000 ppm GA3 for 30 hours and then cold stratified at 3-5 °C for 0, 1, 2, 3 and 4 months (2nd experiment). No germination was observed in the seeds subjected to only WS (1 and 2 months) or CS for 1 month indicating that the seeds of O. carpinifolia are dormant. A 4-month stratification (1 month WS+3 month CS or 4 months CS) fully released dormancy and led to a high germination percentage (94.17 and 98.34% respectively) in a short time (7.12 and 7.00 days respectively). Warm stratification treatment prior to CS, was not required in order to break the seed dormancy of O. carpinifolia and also did not reduce the length of the (total) stratification period required for breaking seed dormancy. Gibberellic acid (GA3) application entirely replaced the CS period required for breaking seed dormancy. The germination of the seeds treated only with 2000 ppm GA3 (0 months of CS) was (94.17%) as high as the germination of the seeds subjected to 4 months of CS (98.34%). It is obvious that the seedcoat of O. carpinifolia seeds was permeable to GA3 and did not mechanically restrict embryo growth, thus, the seeds did not exhibit physical dormancy. Based on dormancy breaking requirements, the O. carpinifolia seeds displayed intermediate physiological dormancy
Use of non-saccharomyces Torulaspora delbrueckii yeast strains in winemaking and brewing
Selected Saccharomyces yeast strains have been used for more than 150 years in brewing and for several decades in winemaking. They are necessary in brewing because of the boiling of the wort, which results in the death of all yeast cells, with the exception of some Belgian style beers (ex. Lambic), where the wort is left to be colonized by indigenous yeast and bacteria from the environment and ferment naturally. In winemaking their use is also pertinent because they provide regular and timely fermentations, inhibit the growth of indigenous spoilage microorganisms and contribute to the desired sensory characters. Even though the use of selected Saccharomyces strains provides better quality assurance in winemaking in comparison to the unknown microbial consortia in the must, it has been debated for a long time now whether the use of selected industrial Saccharomyces strains results in wines with less sensory complexity and âterroirâ character. In previous decades, non-Saccharomyces yeasts were mainly considered as spoilage/problematic yeast, since they exhibited low fermentation ability and other negative traits. In the last decades experiments have shown that there are some non-Saccharomyces strains (Candida, Pichia, Kluyveromyces, Torulaspora, etc) which, even though they are not able to complete the fermentation they can still be used in sequential inoculation-fermentation with Saccharomyces to increase sensory complexity of the wines. Through fermentation in a laboratory scale, we have observed that the overall effects of selected Torulaspora delbrueckii yeast strains, is highly positive, leading to products with pronounced sensory complexity and floral/fruity aroma in winemaking and brewing
RAAS Blockade as First-Line Antihypertensive Therapy among People with CKD
Hypertension among people with chronic kidney disease is highly prevalent and remains often poorly controlled. To adequately control blood pressure (BP), a combination antihypertensive drug therapy is often required. The choice of the appropriate antihypertensive regimen should be individualized according to the patient clinical characteristics, the severity of chronic kidney disease (CKD), the levels at which BP should be targeted and the presence or absence of proteinuria. In proteinuric CKD, solid evidence from large-scaled randomized trials suggest that agents blocking the renin-angiotensin-aldosterone system (RAAS) should be the antihypertensive therapy of first choice, given their superiority over the other antihypertensive drug classes in reducing proteinuria and delaying nephropathy progression to end-stage-renal-disease (ESRD). In contrast, inhibition of the RAAS is shown to have no additional benefits towards renoprotection in people with non-proteinuric CKD. Combined RAAS blockade as an alternative approach to gain additive reduction in proteinuria and greater retardation of renal function decline is shown to be associated with increased risk of hypotension, serious hyperkalemia and acute kidney injury. In this chapter, we discuss the role of RAAS blockade as first-line antihypertensive therapy among people with proteinuric and non-proteinuric nephropathy, providing an overview of the evidence derived from large-scaled renal outcome trials
Efficient Sampling from Feasible Sets of SDPs and Volume Approximation
We present algorithmic, complexity, and implementation results on the problem
of sampling points from a spectrahedron, that is the feasible region of a
semidefinite program. Our main tool is geometric random walks. We analyze the
arithmetic and bit complexity of certain primitive geometric operations that
are based on the algebraic properties of spectrahedra and the polynomial
eigenvalue problem. This study leads to the implementation of a broad
collection of random walks for sampling from spectrahedra that experimentally
show faster mixing times than methods currently employed either in theoretical
studies or in applications, including the popular family of Hit-and-Run walks.
The different random walks offer a variety of advantages , thus allowing us to
efficiently sample from general probability distributions, for example the
family of log-concave distributions which arise in numerous applications. We
focus on two major applications of independent interest: (i) approximate the
volume of a spectrahedron, and (ii) compute the expectation of functions coming
from robust optimal control. We exploit efficient linear algebra algorithms and
implementations to address the aforemen-tioned computations in very high
dimension. In particular, we provide a C++ open source implementation of our
methods that scales efficiently, for the first time, up to dimension 200. We
illustrate its efficiency on various data sets
Monitoring individual cell death using time-lapse microscopy: Application to stochastic modeling of microbial inactivation
FORCE-VELOCITY RELATIONSHIP BETWEEN SPRINTING AND JUMPING TESTING PROCEDURES
The aim of this study was to examine the relationship between the mechanical characteristics of the horizontal and vertical Force-velocity (F-v) profile as well as the performance variables of the sprinting and jumping testing procedures. Twenty high-level sprinters performed two maximal sprints and squat jumps against multiple external loads. Our main findings revealed very large correlations for maximal mechanical power output (Pmax) (r=0.72), as well as for performance variables between the sprinting and jumping tasks (r=-0.81) and large correlations for maximal velocity (V0) (r=0.66). The maximal force (F0) and the slope of the F-v relationship (F-v slope) were not significantly correlated between both tasks. These results suggest that both testing procedures should be performed in order to gain a deeper insight into the maximal mechanical properties and function of the lower-body muscles in high-level sprinters
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