Investigation of variables in turbine erosion, influence of aerodynamic and geometric parameters

Influence of aerodynamic and geometric parameters in turbine erosio

Global Saturation of Regularization Methods for Inverse Ill-Posed Problems

In this article the concept of saturation of an arbitrary regularization method is formalized based upon the original idea of saturation for spectral regularization methods introduced by A. Neubauer in 1994. Necessary and sufficient conditions for a regularization method to have global saturation are provided. It is shown that for a method to have global saturation the total error must be optimal in two senses, namely as optimal order of convergence over a certain set which at the same time, must be optimal (in a very precise sense) with respect to the error. Finally, two converse results are proved and the theory is applied to find sufficient conditions which ensure the existence of global saturation for spectral methods with classical qualification of finite positive order and for methods with maximal qualification. Finally, several examples of regularization methods possessing global saturation are shown.Comment: 29 page

Cytogenetical studies of three Vitis species

The aim of this study was to determine the genomic relationship between Vitis vinifera, V. rotundifolia and V. rupestris. The hybrid between V. vinifera and V. rotundifolia (RT88-2) was almost sterile, whereas the hybrid between V. vinifera and V. rupestris (RP88-14) was fertile. A low percentage (0.52%) of the F1 hybrid (RT88-2) seed germinated, provided that V. vinifera was the seed parent. The result of this one way ability to cross could possibly be attributed to the incompatibility between the cytoplasm of V. rotundifolia and the chromosomes of V. vinifera. The F1 hybrid RT88-2 had 39 chromosomes of which 19 were derived from V. vinifera and 20 from V. rotundifolia. The homology differs between the genomes of V. vinifera and V. rotundifolia. The sterility of the F1 hybrid was chromosomal and was reflected in the abnormal meiosis and lower chiasma frequency. The F1 hybrid RP88-14 had normal meiosis and a chiasma, frequency similar to that of the parents. This could be attributed to the fact that the parents (V. vinifera and V. rupestris) have the same chromosome number and are closely related

Generalized Qualification and Qualification Levels for Spectral Regularization Methods

The concept of qualification for spectral regularization methods for inverse ill-posed problems is strongly associated to the optimal order of convergence of the regularization error. In this article, the definition of qualification is extended and three different levels are introduced: weak, strong and optimal. It is shown that the weak qualification extends the definition introduced by Mathe and Pereverzev in 2003, mainly in the sense that the functions associated to orders of convergence and source sets need not be the same. It is shown that certain methods possessing infinite classical qualification, e.g. truncated singular value decomposition (TSVD), Landweber's method and Showalter's method, also have generalized qualification leading to an optimal order of convergence of the regularization error. Sufficient conditions for a SRM to have weak qualification are provided and necessary and sufficient conditions for a given order of convergence to be strong or optimal qualification are found. Examples of all three qualification levels are provided and the relationships between them as well as with the classical concept of qualification and the qualification introduced by Mathe and Perevezev are shown. In particular, spectral regularization methods having extended qualification in each one of the three levels and having zero or infinite classical qualification are presented. Finally several implications of this theory in the context of orders of convergence, converse results and maximal source sets for inverse ill-posed problems, are shown.Comment: 20 pages, 1 figur

Review: Monsters

A review of the 2021 book by Barry Windsor-Smith, “Monsters,” for inclusion in ARLIS/NA's 2021 Notable Graphic Novels Review

Larval Duration, Settlement, and Larval Growth Rates of the Endangered Tidewater Goby (Eucyclogobius newberryi) and the Arrow Goby (Clevelandia ios) (Pisces, Teleostei)

The early life history of the federally endangered tidewater goby (Eucyclogobius newberryi) and its sister species the arrow goby (Clevelandia ios) has been poorly documented to date. Both are endemic to estuarine habitats throughout the California coast, however, habitat use differs between these two species. The arrow goby is commonly found in fully marine tidal bays and mudflats. The tidewater goby, however, prefers lagoons with some degree of seasonal isolation from the sea. Here, we used otoliths to examine the larval duration, size at settlement, and growth rates of newly settled gobies collected from 18 estuaries in California. The tidewater goby had a larval duration that was ~2 days shorter than the arrow goby (23.95 vs. 26.11 days, respectively), but a larger size at settlement based on back-calculated size (12.38 vs. 10.00 mm SL) due to a faster larval growth rate (2.86 vs. 2.60 μm/day-1). There are several reasons that could explain these differences in larval traits, such as differences in temperature or food resources between the two estuary types, or the faster, annual life cycle of the tidewater goby relative to the arrow goby

Plasma leptin, but not adiponectin, is associated with cognitive impairment in older adults

BACKGROUND: Leptin and adiponectin are adipose-tissue derived hormones primarily involved in glucose, lipid, and energy metabolism, inflammation, and atherosclerosis. Both adipokines may cross the blood-brain barrier but evidence on their roles in cognitive impairment is limited and conflicting. Here, we determined associations of plasma adipokine concentration with cognitive impairment in older adults. METHODS: Cross-sectional analysis of baseline data from 669 participants aged ≥65 years of the Biomarker Development for Postoperative Cognitive Impairment in the Elderly (BioCog) study were recruited 2014–2017 at study sites in Berlin, Germany and Utrecht, the Netherlands. Cognitive impairment was defined as the lowest tertile of a cognitive summary score derived from six neuropsychological tests. RESULTS: After adjustment for age, sex, fasting, BMI, diabetes, hypertension, cerebrovascular disease, and coronary heart disease, higher leptin concentrations and a higher leptin/adiponectin ratio (LAR) were associated with a higher odds of cognitive impairment (OR per 1 SD higher leptin concentration, 1.33; 95 % CI 1.05, 1.69; p = 0.02; OR per 1 SD higher LAR, 1.26; 95 % CI 1.01, 1.57; p = 0.04). Sensitivity analyses determined that these findings were driven by the non-obese group (BMI < 30 kg/m2), whereas leptin and LAR were not associated with cognitive impairment in the obese group (BMI ≥ 30 kg/m2). Soluble leptin receptor, leptin/soluble leptin receptor ratio, total adiponectin and high-molecular weight adiponectin concentrations were each not associated with impairment. CONCLUSIONS: With leptin as a known promoter of atherosclerosis and inflammation, our findings point to a pathogenic role of leptin in age-related cognitive impairment that may be limited to non-obese individuals and warrants further investigation