Introduction

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Testing for image symmetries – with application to confocal microscopy

Statistical tests are introduced for checking whether an image function f(x, y) defined on the unit disc D = {(x, y) : x2 + y2 ≤ 1} is invariant under certain symmetry transformations of D, given that discrete and noisy data are observed. We consider invariance under reflections or under rotations by rational angles, as well as joint invariance under both reflections and rotations. Furthermore, we propose a test for rotational invariance of f(x, y), i.e., for checking whether f(x, y), after transformation to polar coordinates, only depends on the radius and not on the angle. These symmetry relations can be naturally expressed as restrictions for the Zernike moments of the image function f(x, y), i.e., the Fourier coefficients with respect to the Zernike orthogonal basis. Therefore, our test statistics are based on checking whether the estimated Zernike coefficients approximately satisfy those restrictions. This is carried out by forming the L2 distance between the image function and its transformed version obtained by some symmetry transformation. We derive the asymptotic distribution of the test statistics under both the hypothesis of symmetry as well as under fixed alternatives. Furthermore, we investigate the quality of the asymptotic approximations via simulation studies. The usefulness our theory is verified by examining an important problem in confocal microscopy, i.e., we investigate possible imprecise alignments in the optical path of the microscope. For optical systems with rotational symmetry, the theoretical point-spread-function (PSF) is reflection symmetric with respect to two orthogonal axes, and rotationally invariant if the detector plane matches the optical plane of the microscope. We use our tests to investigate whether the required symmetries can indeed be detected in the empirical PSF

Non-Parametric Vertical Box Control Chart For Monitoring The Mean

A new class of non-parametric control charts for detecting the change in the process mean is examined. The method, called a Vertical Box Control Chart (V-Box Chart), offers a simple and quick detection of the mean change in an observed process. No parametric assumption on the distribution function of the process is required. Furthermore, the V-Box Chart outperforms the classical Shewhart control chart by lowering the probability of detection of the out-of-control situation with the zero delay. Theoretical bounds on in-control and out-of-control behaviors of the V-Box Chart are worked out. The developed theory is supported by simulation examples

Un análisis de los efectos predictivos de la tenacidad general y la tenacidad sobre la L2 en la motivación: El efecto mediador del conocimiento auto-percibido de la L2

Following a recent surge of interest in the role of personality traits in second language learning, this study focuses on L2 grit as an important individual difference factor that is gaining growing recognition among second language acquisition researchers. Adopting a mixed-methods approach, we examined the predictive effects of general grit and L2 grit on motivated behavior among 549 advanced Polish university students majoring in English and the extent to which these effects were mediated by self-perceived proficiency. Data were collected by means of the Grit Scale (Duckworth et al., 2007), the L2 Grit Scale (Teimouri et al., 2022), the motivated behavior scale (Taguchi et al., 2009), and semi-structured interviews. Quantitative analysis demonstrated that general grit and L2 grit significantly co-predicted motivated behavior, with the effect of L2 grit being more pronounced. However, differences were found for students representing different proficiency levels. The results were corroborated by qualitative analysis of interview data.Ante el reciente aumento en el interés por el papel que desempeñan los rasgos de personalidad en el aprendizaje de una segunda lengua (L2), el presente trabajo se centra en la tenacidad en la L2 (L2 grit), un factor importante de diferencias individuales cada vez más reconocido entre los investigadores de la adquisición de una L2. Adoptando un enfoque metodológico mixto, se examinaron los efectos predictivos de la tenacidad general y la tenacidad en la L2 sobre la motivación de 549 estudiantes universitarios polacos de Estudios Ingleses con nivel avanzado de conocimiento de la lengua, y se analizó el grado en que dichos efectos estaban mediados por su autopercepción del nivel de conocimiento de la L2. Los datos se recogieron mediante la Escala de Tenacidad (Duckworth et al., 2007), la Escala de Tenacidad en L2 (Teimouri et al., 2022), la Escala de Motivación (Taguchi et al., 2009) y entrevistas semiestructuradas. El análisis cuantitativo demostró que la tenacidad general y la tenacidad en la L2 predijeron de forma conjunta y de manera significativa la motivación de los aprendices, siendo más pronunciado el efecto de la tenacidad en la L2. Sin embargo, se encontraron diferencias entre los participantes dependiendo de su nivel de conocimiento de la L2. Estos resultados se corroboraron mediante el análisis cualitativo de los datos de las entrevistas

Metalinguistic awareness in children with differing language learning experience

Theoretical research concerned with the notion of second language (L2) learning difficulty has resulted in specific criteria that can be used to predict the learning difficulty of different languages in terms of both explicit and implicit knowledge. The characteristics of the constructed language Esperanto suggest that this language has lower explicit and implicit learning difficulty than other languages. It may therefore be a suitable ?starter language? for child L2 learning in the classroom. Specifically, we propose that Esperanto may facilitate the development of metalinguistic awareness and, as a consequence, boost children?s budding capacity for explicit learning. This would be particularly advantageous in the minimal-input setting of the average foreign language classroom. We present findings from an empirical study which compared 11 to 12-year-old English-speaking children who had learned Esperanto and a European L2 (N = 35) with children who had learned various combinations of European and non-European L2s (N = 168) in terms of their performance on a measure of metalinguistic awareness. No significant differences in overall level of metalinguistic awareness were identified, but the Esperanto group significantly outperformed the comparison group on one of the eleven metalinguistic tasks included in the measure. Moreover, the Esperanto group displayed a more homogeneous performance than the other groups of children. This suggests that learning Esperanto may have a lasting levelling effect, reducing differences between children with varying metalinguistic abilities

Interindividual variability of atorvastatin treatment influence on the MPO gene expression in patients after acute myocardial infarction

Myeloperoxidase (MPO) and C-reactive protein (CRP) may play critical roles in generation of oxidative stress and the development of the systemic inflammatory response. The aim of the study was to determine the effect of atorvastatin therapy on the MPO gene expression and its plasma level in relation to lipids level lowering and an anti-inflammatory response in patients after acute myocardial infarction. The research material was represented by 112 samples. Thirty-eight patients with first AMI receiving atorvastatin therapy (40 mg/day) and followed up for one month were involved in the study. The relative MPO gene expression in peripheral blood mononuclear cells (PBMCs) was examined using RT-qPCR in 38 patients before-, 38 patients after-therapy and in 36 patients as the control group. The plasma concentrations of MPO and serum concentrations of biochemical parameters were determined using commercially available diagnostic tests. After one month of atorvastatin therapy, in 60.5% patients a decrease of MPO gene expression, whereas in 39.5% patients an increase, was observed. The plasma MPO levels behaved in the same way as the MPO gene expression. However, the serum lipids and CRP concentrations were significantly lower after one month of atorvastatin therapy in both groups of patients - with decreased and increased MPO gene expression. Atorvastatin exhibited a different effect on MPO gene expression and its plasma level. Short-term atorvastatin therapy resulted in lipid lowering and anti-inflammatory activity in patients after AMI, independently of its effect on MPO gene expression. The molecular mechanisms of this phenomenon are not yet defined and require further research

The Influence of Genetic Variations in the CD86

CD86 molecule is the ligand for both costimulatory (CD28) and coinhibitory (CTLA-4) molecules, and it regulates immune response after allogeneic hematopoietic stem cell transplantation (alloHSCT). Therefore, we postulate that CD86 gene variations might influence the outcome after alloHSCT. Altogether, 295 adult patients (pts) undergoing related (105 pts) and unrelated (190 pts) donor-matched HSCT were genotyped for the following CD86 gene polymorphisms: rs1129055, rs9831894, and rs2715267. Moreover, the donors’ rs1129055 polymorphism was determined. None of the investigated SNPs alone were associated with aGvHD and rate of relapse. However, we showed that rs2715267 SNP influenced overall survival (OS) after alloHSCT. The 24-month OS for the rs271526GG recipients was worse than that for the recipients possessing T allelle (TT or GT genotypes) (p=0.009). Moreover, analysis of gene-gene interaction between CD86 and CTLA-4 showed that having both the A allele for CD86 rs1129055 and the CTLA-4 CT60GG genotype in recipients increased the risk of aGvHD about 3.5 times. Interestingly, the donors’ rs1129055GG genotype and the recipients’ CT60GG genotype also increased the risk of aGvHD about 2.7-fold. We postulate that recipients’ CD86 gene polymorphisms influence the overall survival after alloHSCT and, together with CTLA-4 polymorphisms, might be considered a risk factor for aGvHD

On the almost everywhere properties of the kernel regression estimate

Regression function, kernel estimate, asymptotic expansions, distribution-free properties, asymptotic normality, bandwidth-selection, bias adjustment,

On the distributional properties of GARCH processes

SIGLEAvailable from Bibliothek des Instituts fuer Weltwirtschaft, ZBW, Duesternbrook Weg 120, D-24105 Kiel W 1160 (121) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman