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Advanced mathematical and statistical methods in evaluating instrumented indentation measurements
Get PDFThis publicly available research report provides a detailed overview of the results achieved within the TACR project TJ02000203 "Advanced mathematical and statistical methods in evaluating instrumented indentation measurements". The introductory section contains necessary background on instrumented indentation data evaluation procedures using the method due to Oliver and Pharr, as described in ISO 14577 standard. The next section provides detailed derivation of a novel algorithm "OEFPIL" for nonlinear data regression with errors in both variables, as well as guidelines for efficient implementation of the algorithm. The algorithm calculates both the optimum estimate of function parameters and an estimate of the parameter covariance matrix. The algorithm performance is demonstrated on reference data for nonlinear regression, and validated by comparison to another method. In the next section some existing advanced methods for uncertainty propagation (higher-order uncertainty propagation, Latin hypercube sampling for Monte Carlo) are also discussed. The last section presents application of the aforementioned methods for data regression and uncertainty propagation in processing data from instrumented indentation measurements. These methods have been newly added to the the free software tool Niget to improve data fitting of the unloading curve and to provide capability for indenter contact area function calibration. Combination of the regression and uncertainty propagation methods enables a better insight into evaluation of indentation data and provides basis for e.g. identifying main sources of measurement uncertainty or designing measurement strategy. Although the methods were designed and assessed with Oliver and Pharr's evaluation method in mind, they can be easily adapted to other evaluation models, too. All software developed and used in this project is freely available.Tato veřejně dostupná výzkumná zpráva obsahuje detailní přehled o výsledcích dosažených v rámci TAČR projektu TJ02000203 "Pokročilé matematické a statistické metody ve vyhodnocování měření instrumentovanou indentací". Úvodní sekce obsahuje nezbytný úvod k procedurám vyhodnocení dat instrumentované indentace, které využívají metodu Olivera a Pharra, jež je popsána v normě ISO 14577. Další kapitola poskytuje detailní odvození nového algoritmu OEFPIL pro nelineární regresi s chybami v obou proměnných a také návod pro efektivní implementaci algoritmu. Algoritmus počítá jak optimální odhad funkčních parametrů, tak odhad kovarianční matice parametrů. Použití algoritmu je demonstrováno na referenčních datech pro nelineární regresi a je ověřeno porovnáním s jinou metodou. Další kapitola se zabývá některými existujícími pokročilými metodami šíření nejistot (šíření nejistot vyšších řádů a metodou tzv. "Latin hypercube sampling" pro Monte Carlo). V poslední části najdeme aplikace výše zmíněných metod pro datovou regresi a propagaci nejistot ve zpracování dat získaných z měření instrumentovanou indentací. Tyto metody byly nově přidány do zdarma dostupného softwaru Niget k vylepšení prokládání dat odtěžovací křivky a k poskytnutí možnosti kalibrace funkce kontaktní plochy indentoru. Kombinace metod regrese a šíření nejistot dovoluje lepší náhled na vyhodnocování indentačních dat a poskytuje základ pro např. identifikování hlavních zdrojů nejistot měření nebo pro dizajn strategie získávání měření. Ačkoli byly metody navrženy a ověřeny pomocí Oliverovy a Pharrovy metody, mohou být lehce upraveny na jiné vyhodnocovací modely. Všechen software, který byl vyvinut a použit v tomto projektu, je volně dostupný
Semantic parameters, syncretism and counting
Get PDFIn the languages of the world, there appears to be a bi-furcation among languages depending on whether numerals combine with a noun in the singular (e.g., Turkish, Estonian) or plural (e.g., English, Czech). A relatively common approach is to explain this variation by invoking “semantic parameters.” The idea is that the singular (or plural) in a language of the first type does not mean the same thing as in a language of the other type. In this talk, I will suggest an alternative way of thinking about the data. I will give reasons to think that the a noun after numerals has a special grammatical number that should not be unified with the singular or the plural denotation. When the counted noun looks the same as one of these, this is because the special “counting” number is morphologically realized the same as singular or plural (classical syncretism). The evidence for this claim will be drawn from a variety of languages including Serbian, Bulgarian, Ossetic, Saami
MicroRNAs as theranostic markers in cardiac allograft transplantation: from murine models to clinical practice
Get PDFCongestive heart failure affects about 23 million people worldwide, and cardiac allograft transplantation remains one of the last options for patients with terminal refractory heart failure. Besides the infectious or oncological complications, the prognosis of patients after heart transplantation is affected by acute cellular or antibody-mediated rejection and allograft vasculopathy development. Current monitoring of both conditions requires the performance of invasive procedures (endomyocardial biopsy sampling and coronary angiography or optical coherence tomography, respectively) that are costly, time-demanding, and non-comfortable for the patient. Within this narrative review, we focus on the potential pathophysiological and clinical roles of microRNAs (miRNAs, miRs) in the field of cardiac allograft transplantation. Firstly, we provide a general introduction about the status of cardiac allograft function monitoring and the discovery of miRNAs as post-transcriptional regulators of gene expression and clinically relevant biomarkers found in the extracellular fluid. After this general introduction, information from animal and human studies are summarized to underline the importance of miRNAs both in the pathophysiology of the rejection process, the possibility of its modulation by altering miRNAs levels, and last but not least, about the use of miRNAs in the clinical practice to diagnose or predict the rejection occurrence
Deciding Polynomial Termination Complexity for VASS Programs
Get PDFWe show that for every fixed degree k ≥ 3, the problem whether the termination/counter complexity of a given demonic VASS is O(n^k), Ω(n^k), and Θ(n^k) is coNP-complete, NP-complete, and DP-complete, respectively. We also classify the complexity of these problems for k ≤ 2. This shows that the polynomial-time algorithm designed for strongly connected demonic VASS in previous works cannot be extended to the general case. Then, we prove that the same problems for VASS games are PSPACE-complete. Again, we classify the complexity also for k ≤ 2. Tractable subclasses of demonic VASS and VASS games are obtained by bounding certain structural parameters, which opens the way to applications in program analysis despite the presented lower complexity bounds
Motivace k učení se angličtině ve vztahu ke známkám a studijním aspiracím u žáků základních škol
Get PDFVýzkumů motivace k učení se angličtině a jejího vztahu ke studijním výsledkům a aspiracím u českých žáků je málo. Tato studie si klade za cíl identifikovat vztah mezi úrovní výkonové motivace v angličtině a vybranými studijními výsledky a aspiracemi žáků. Výsledky dotazníkového šetření mezi žáky devátých ročníků základních škol (N = 324) ukazují, že potřeba úspěšného výkonu (PÚV) v angličtině je pozitivním prediktorem a potřeba vyhnutí se neúspěchu (PVN) v angličtině negativním prediktorem všech následujících indikátorů: známky z angličtiny na vysvědčení, získání vyznamenání, budoucí aspirace žáků studovat na g ymnáziu. Pro chlapce byl efekt PÚV na tyto indikátory v průměru nižší a naopak efekt PVN byl v průměru vyšší než pro dívky, nicméně v rámci regresní analýz y se ukázalo, že efekty nejsou statisticky signifikantní. Potvrzení těchto z jištění vyžaduje další výzkum, který by bral v úvahu rozdíly v užívání škál mezi žáky (např. skrze aplikaci metody ukotvujících vinět).Studies on student motivation to learn English as a foreign language (EFL) and its relationship to achievement and study aspirations among Czech students are scarce. This study aims to identify the relationship between student level of EFL achievement motivation and their achievement and study aspirations. The results of a survey among ninth-grade basic school students (N = 324) show that the need for achievement (NfA) in EFL is a positive predictor and the need to avoid failure (NtAF) is a negative predictor of their final grade in English, of receiving a final report card with honors, and of aspiration to study at a grammar school. The effect of NfA on all indicators was, on average, lower for boys than for girls, and the effect of NtAF for boys was, on average, higher, yet the regression analysis showed that the effects were not significant. Further research should reflect the differences in scale usage among students (e.g., by using the anchoring vignette method)
Motivation and Achievement in English as a Foreign Language
Get PDFMotivation is a key factor connected with successful EFL learning and is a central focus of the current research. Motivation studies repeatedly show the connection ofmotivation to acquired EFL skills. They show that motivation differs based on gender, age, school type, and across countries. Our study analyses the level of students’ achievement motivation in EFL and its relationship to their grades and aspiration. The sample was constructed by using the probability sampling of lower secondary schools in the Czech region of South Moravia and consisted of 26 schools (i.e., 25 of 9th grade classes, 462 students). In this analysis, 324 students were included (172 female). The Achievement Motivation Questionnaire (Hrabal & Pavelková, 2010) was used, measuring the need for achievement (NfA, 7 items) and the need to avoid failure (NtAF, 7 items) on a 5-point response scale. The reported grade in English, receiving a final report card with honours, and aspiration to study at an upper secondary comprehensive school were measured by a questionnaire and analysed as dummy variables. Data analysis included logistic regression models computed in software R (glm function with probit specification). The need for achievement (NfA) in EFL was found to be a positive predictor and the need to avoid failure (NtAF) was found to be a negative predictor of student final grade in English, receiving a final reportcard with honours, and aspiration to study at an upper secondary comprehensive school. The effect of NfA on all three variables was, on average, lower for males than for females, and the effect of NtAF formales was, on average, higher. In accordance with previous studies, our findings confirm the relation between reported motivation in EFL and English achievement. Also, previous studies conclude that domain-specific instruments predict indicators of achievement in particular domains better than domain-general instruments (Michel et al., 2020). Our instrument measuring NfA and NtAF was successfully predicting not only English achievement, but also general learning achievement (i.e. receiving a final report card with honours) and aspiration to study at an elite upper secondary comprehensive school. Our further research will consider the scale usage differences among students by using the anchoring vignette method.Výzkumů motivace k učení se angličtině a jejího vztahu ke studijním výsledkům a aspiracím u českých žáků je málo. Tato studie si klade za cíl identifikovat vztah mezi úrovní výkonové motivace v angličtině a vybranými studijními výsledky a aspiracemi žáků. Výsledky dotazníkového šetření mezi žáky devátých ročníků základních škol (N = 324) ukazují, že potřeba úspěšného výkonu (PÚV) v angličtině je pozitivním prediktorem a potřeba vyhnutí se neúspěchu (PVN) v angličtině negativním prediktorem všech následujících indikátorů: známky z angličtiny na vysvědčení, získání vyznamenání, budoucí aspirace žáků studovat na g ymnáziu. Pro chlapce byl efekt PÚV na tyto indikátory v průměru nižší a naopak efekt PVN byl v průměru vyšší než pro dívky, nicméně v rámci regresní analýz y se ukázalo, že efekty nejsou statisticky signifikantní. Potvrzení těchto z jištění vyžaduje další výzkum, který by bral v úvahu rozdíly v užívání škál mezi žáky (např. skrze aplikaci metody ukotvujících vinět).Motivation is a key factor connected with successful EFL learning and is a central focus of the current research. Motivation studies repeatedly show the connection ofmotivation to acquired EFL skills. They show that motivation differs based on gender, age, school type, and across countries. Our study analyses the level of students’ achievement motivation in EFL and its relationship to their grades and aspiration. The sample was constructed by using the probability sampling of lower secondary schools in the Czech region of South Moravia and consisted of 26 schools (i.e., 25 of 9th grade classes, 462 students). In this analysis, 324 students were included (172 female). The Achievement Motivation Questionnaire (Hrabal & Pavelková, 2010) was used, measuring the need for achievement (NfA, 7 items) and the need to avoid failure (NtAF, 7 items) on a 5-point response scale. The reported grade in English, receiving a final report card with honours, and aspiration to study at an upper secondary comprehensive school were measured by a questionnaire and analysed as dummy variables. Data analysis included logistic regression models computed in software R (glm function with probit specification). The need for achievement (NfA) in EFL was found to be a positive predictor and the need to avoid failure (NtAF) was found to be a negative predictor of student final grade in English, receiving a final reportcard with honours, and aspiration to study at an upper secondary comprehensive school. The effect of NfA on all three variables was, on average, lower for males than for females, and the effect of NtAF formales was, on average, higher. In accordance with previous studies, our findings confirm the relation between reported motivation in EFL and English achievement. Also, previous studies conclude that domain-specific instruments predict indicators of achievement in particular domains better than domain-general instruments (Michel et al., 2020). Our instrument measuring NfA and NtAF was successfully predicting not only English achievement, but also general learning achievement (i.e. receiving a final report card with honours) and aspiration to study at an elite upper secondary comprehensive school. Our further research will consider the scale usage differences among students by using the anchoring vignette method
Gas-Phase Reaction Kinetics of the Ortho and Ipso Adducts 1,2,4,5-Tetramethylbenzene-OH with O-2
Get PDFThe reversible reaction of OH radicals with 1,2,4,5-tetramethylbenzene (1245-TeMB, durene) leads to adducts at the substituted (ipso) and unsubstituted (ortho) positions of the ring. By the use of flash photolysis for production and resonance fluorescence for detection of OH, the gas-phase reactions of O-2 with these adducts were investigated over the temperature range of 300-340 K in He at 200 mbar. The decay of OH, generated by pulsed vacuum-UV photolysis of H2O, was monitored under slow-flow conditions in the presence of 1245-TeMB and O-2 at concentrations of up to 19 X 10(12) CM-3 and 2 X 10(16) cm(-3), respectively. Triexponential OH decays resulted from the unimolecular decomposition of the two adducts, representing OH reservoirs with different stabilities. In the presence of O-2, additional adduct loss pathways exist, leading to faster OH consumption. Triexponential functions fitted to these decays were analyzed to obtain rate constants for the reactions of O-2 with both adducts. Rate constants in the range of (4-13) x 10(-15) and (0.3-3) x 10(-15) cm(3)s(-1) were obtained for the ortho and the ipso adducts, respectively, depending on temperature and assumptions regarding details of the underlying mechanism of adduct isomer formation and isomerization. At O-2 concentrations exceeding about 1 x 10(16) cm(-3), deviations from a linear dependence of the adduct loss rates on the O-2 concentration indicate an even more complex mechanism. The validity of the rate constants is therefore confined to O-2 concentrations below 1 X 10(16) cm(-3). The adduct + O-2 rate constants for 1245-TeMB are greater than the corresponding previously obtained rate constants for benzene, toluene, and p- and m-xylene but smaller than those for hexamethylbenzene. The results are discussed in terms of the current knowledge about the mechanism of OH-induced degradation of aromatic compounds in the presence of O-2
Stabilization of Haloalkane Dehalogenase Structure by Interfacial Interaction with Ionic Liquids
Get PDFIonic liquids attracted interest as green alternatives to replace conventional organic solvents in protein stability studies. They can play an important role in the stabilization of enzymes such as haloalkane dehalogenases that are used for biodegradation of warfare agents and halogenated environmental pollutants. Three-dimensional crystals of haloalkane dehalogenase variant DhaA80 (T148L+G171Q+A172V+C176F) from Rhodococcus rhodochrous NCIMB 13064 were grown and soaked with the solutions of 2-hydroxyethylammonium acetate and 1-butyl-3-methylimidazolium methyl sulfate. The objective was to study the structural basis of the interactions between the ionic liquids and the protein. The diffraction data were collected for the 1.25 angstrom resolution for 2-hydroxyethylammonium acetate and 1.75 angstrom resolution for 1-butyl-3-methylimidazolium methyl sulfate. The structures were used for molecular dynamics simulations to study the interactions of DhaA80 with the ionic liquids. The findings provide coherent evidence that ionic liquids strengthen both the secondary and tertiary protein structure due to extensive hydrogen bond interactions
Local Self-Government in Slovakia
Get PDFThe goal of this chapter is to summarize the developments of the local self-government system in Slovakia and evaluate the conformity of its current status with the principles of the European Charter of Local Self-Government
Runes from Lany (Czech Republic) - The oldest inscription among Slavs. A new standard for multidisciplinary analysis of runic bones
Get PDFWhen Roman administration and legions gradually withdrew from the outer provinces after the fall of the Western Roman Empire, they created a power void filled by various groups. The dynamic Migration Period that followed is usually considered to have ended when the Germanic Lombards allegedly left Central Europe and were replaced by Slavs. Whether or how Slavic and Germanic tribes interacted, however, is currently disputed. Here we report the first direct archaeological find in support of a contact: a bone fragment dated to similar to 600 AD incised with Germanic runes but found in Lany, Czechia, a contemporaneous settlement associated with Slavs. We documented and authenticated this artifact using a combined approach of use-wear analysis with SEM microscopy, direct radiocarbon dating, and ancient DNA analysis of the animal bone, thereby setting a new standard for the investigation of runic bones. The find is the first older fuark inscription found in any non-Germanic context and suggests that the presumed ancestors of modern Slavic speakers encountered writing much earlier than previously thought.Když se římská správa a legie po pádu Západořímské říše postupně stáhly z vnějších provincií, vytvořilo se mocenské vakuum vyplněné různými skupinami. Dynamické období migrace, které následovalo, se obvykle považuje za ukončené v okamžiku, když germánští Longobardi údajně opustili střední Evropu a byli nahrazeni Slovany. Zda nebo jak na sebe vzájemně působily slovanské a germánské kmeny, se v současné době diskutuje. Zde publikujeme první přímý archeologický nález na podporu kontaktu: fragment kosti datovaný okolo roku 600 n.l. s vyrytými germánskými runami, který však byl nalezen v na sídlišti v Lánech (jižní Morava), na sídlišti spojeném se Slovany. Tento artefakt jsme dokumentovali a ověřili pomocí kombinace různých metod: tafonomie s mikroskopií SEM, datování radiokarbonovou metodou a analýzou aDNA zvířecí kosti, čímž jsme stanovili nový standard pro výzkum runových kostí. Nález je prvním nápisem staršího futharku nalezeným v jiném než germánském kontextu, což naznačuje, že se předkové slovansky mluvících obyvatel střední Evropy setkali s písmem mnohem dříve, než se dříve myslelo.When Roman administration and legions gradually withdrew from the outer provinces after the fall of the Western Roman Empire, they created a power void filled by various groups. The dynamic Migration Period that followed is usually considered to have ended when the Germanic Lombards allegedly left Central Europe and were replaced by Slavs. Whether or how Slavic and Germanic tribes interacted, however, is currently disputed. Here we report the first direct archaeological find in support of a contact: a bone fragment dated to similar to 600 AD incised with Germanic runes but found in Lany, Czechia, a contemporaneous settlement associated with Slavs. We documented and authenticated this artifact using a combined approach of use-wear analysis with SEM microscopy, direct radiocarbon dating, and ancient DNA analysis of the animal bone, thereby setting a new standard for the investigation of runic bones. The find is the first older fuark inscription found in any non-Germanic context and suggests that the presumed ancestors of modern Slavic speakers encountered writing much earlier than previously thought