9 results on '"Nina Krüger"'
Search Results
2. Study on the properties of wafer-scale grown MoS2 deposited via thermally induced chemical vapor deposition with Mo(CO)6 and H2S precursors
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Armin Klumpp, Rik Hooijer, Nina Krüger, Jamila Boudaden, Florian Wolf, Markus Döblinger, and Thomas Bein
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growth kinetics ,molybdenum disulfide ,Raman assessment ,GIWAXS ,XRD ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Chemical technology ,TP1-1185 - Abstract
To realize profitable applications with 2D-materials the transition from research scale to microelectronic fabrication methods is needed. This means the use of equipment for larger substrates and assessment of the process flows. In this study we demonstrate an effective way to assess MoS _2 as semiconducting material, deposited with the lower priced precursors Mo(CO) _6 and H _2 S on 200 mm silicon wafers. We could show how the evolution of layer quality develops depending on temperature and interface pretreatment. It is not possible to achieve mono-layers of 0.6 nm with high quality due to seeding kinetics and mechanism. In contrast, layers with thicknesses above 3 nm have suitable electrical and optical qualities to proceed with the design of active devices on 200 mm wafers.
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- 2023
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3. What Is Mathematical Giftedness? Associations with Intelligence, Openness, and Need for Cognition
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Kaja Hansen, Mieke Johannsen, Laura Langemeyer, and Nina Krüger
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mathematical giftedness ,fluid intelligence ,openness ,need for cognition ,adolescents ,Social sciences (General) ,H1-99 - Abstract
It is common practice in the educational system to foster high mathematical abilities in schools as well as in specific promotional programs. Still, little is known about the construct of mathematical giftedness itself. In line with intellectual investment theories, our study investigates the relationship between fluid intelligence (figural and numerical), openness, and the need for cognition with mathematical abilities. The current study is based on a sample (N = 115) of seventh graders participating in the application process for a promotion program. The results of our regression analyses show a positive link between fluid intelligence and mathematical abilities. However, neither the association with openness nor the need for cognition reached significance, emphasizing the importance of cognitive abilities for mathematical giftedness. Limitations and further directions are discussed.
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- 2022
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4. Parenting Stress in Fathers: Do We Need Father Specific Reference Samples? And Do They Differ in Regard of Taking Parental Leave?
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Nina Krüger and Johanna Nuria Rüther
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parenting stress ,fathers ,parental leave ,EBI ,psychometric analyses ,Pediatrics ,RJ1-570 - Abstract
The German version of the Parenting stress Index from Abidin, the Eltern-Belastungs-Inventar (EBI) merely provides reference samples of 538 mothers of children in toddlers and preschool age. Although meant to measure parenting stress, there are no father specific reference samples provided. The aim was to investigate differences in parenting stress between fathers and the provided reference samples of German mothers. Furthermore, the aim was to examine potential differences in the perceived stress between fathers who did and those who did not take parental leave. A total of 497 fathers living in Germany, of which more than half took parental leave, filled out the questionnaire via an online survey or the paper-pencil-version. All fathers completed the EBI and provided socio-economic data. The collected data were analyzed in terms of test quality, such as mean and standard deviation, corrected item–total correlation and reliability. Moreover, differences between the provided norm data and our sample were calculated. Analyses showed that fathers reported significantly higher levels of parenting stress than mothers. Furthermore, fathers taking parental leave did not differ significantly from those who did not, regarding their level of education or their perceived parenting stress. In conclusion, as it stands right now, the EBI does not adequately measure parenting stress in fathers, and father specific norms are needed to properly assess their levels of parenting stress. The results concerning parenting stress and parental leave were thus inconclusive. Furthermore, since reducing parenting stress in fathers is beneficial for the child’s development and the welfare of the parents, further studies focusing on fathers’ parenting stress are needed.
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- 2022
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5. Structural Equation Modeling of Common Cognitive Abilities in Preschool-Aged Children Using WPPSI-IV and BRIEF-P
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Sören Fiedler, Nina Krüger, and Monika Daseking
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intelligence ,executive functioning ,WPPSI-IV ,BRIEF-P ,children ,preschoolers ,Pediatrics ,RJ1-570 - Abstract
Various studies have addressed the relationship between intelligence and executive functions (EF). There is widespread agreement that EF in preschool children is a unitary construct in which the subordinate factors of Updating, Inhibition, and Shifting are still undifferentiated and correlate moderately with a general factor of intelligence (g). The aim of this study is to investigate the common structural relationship between these two constructs using confirmatory factor analysis. Furthermore, we intend to close the gap of more daily life-associated executive functions and replicate findings in preschool-aged children. Data from a sample of N = 124 average developed children without severe impairments (aged 4 years 0 months–6 years 11 months) were analyzed using the data pool of the standardization and validation studies on the German Wechsler Preschool and Primary Scale of Intelligence—Fourth Edition. Additionally, Executive functions were assessed using a standardized parent-completed questionnaire (BRIEF-P) on their children’s everyday behavior. A second-order factor solution revealed that a model with a loading of the common factor of general intelligence (g-factor) onto the EF factor fits the data best. To specify possible method effects due to different sources of measurements, a latent method factor was generated. The results indicate a heterogeneous method effect and a decreasing factor loading from g on to EF while controlling for the method factor.
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- 2022
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6. Integrating Semi-Supervised Learning with an Expert System for Vegetation Cover Classification Using Sentinel-2 and RapidEye Data
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Nasir Farsad Layegh, Roshanak Darvishzadeh, Andrew K. Skidmore, Claudio Persello, and Nina Krüger
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semi-supervised learning ,expert system ,object-based image analysis ,Sentinel-2 ,vegetation cover ,image classification ,Science - Abstract
In complex classification tasks, such as the classification of heterogeneous vegetation covers, the high similarity between classes can confuse the classification algorithm when assigning the correct class labels to unlabelled samples. To overcome this problem, this study aimed to develop a classification method by integrating graph-based semi-supervised learning (SSL) and an expert system (ES). The proposed method was applied to vegetation cover classification in a wetland in the Netherlands using Sentinel-2 and RapidEye imagery. Our method consisted of three main steps: object-based image analysis (OBIA), integration of SSL and an ES (SSLES), and finally, random forest classification. The generated image objects and the related features were used to construct the graph in SSL. Then, an independently developed and trained ES was used in the labelling stage of SSL to reduce the uncertainty of the process, before the final classification. Different spectral band combinations of Sentinel-2 were then considered to improve the vegetation classification. Our results show that integrating SSL and an ES can result in significantly higher classification accuracy (83.6%) compared to a supervised classifier (64.9%), SSL alone (71.8%), and ES alone (69.5%). Moreover, utilisation of all Sentinel-2 red-edge spectral band combinations yielded the highest classification accuracy (overall accuracy of 83.6% with SSLES) compared to the inclusion of other band combinations. The results of this study indicate that the utilisation of an ES in the labelling process of SSL improves the reliability of the process and provides robust performance for the classification of vegetation cover.
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- 2022
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7. Investigating the Relation of Intelligence and Executive Functions in Children and Adolescents with and without Intellectual Disabilities
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Mieke Johannsen and Nina Krüger
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cognitive abilities ,intelligence ,executive functioning ,structural relation ,intellectual disabilities ,Intelligence and Development Scales-2 ,Pediatrics ,RJ1-570 - Abstract
Despite their separate research traditions, intelligence and executive functioning (EF) are both theoretically and empirically closely related to each other. Based on a subsample of 8- to 20-year-olds of the standardization and validation sample (N = 1540) of an internationally available instrument assessing both cognitive abilities, this study aimed at investigating a comprehensive structural model of intelligence and EF tasks and at gaining insight into whether this comprehensive model is applicable across sexes and age groups as well as to a subsample of participants with (borderline) intellectual disabilities (IQ ≤ 85, n = 255). The results of our exploratory factor analysis indicated one common EF factor that could be sufficiently integrated into the intelligence model within our confirmatory factor analyses. The results suggest that the EF factor can be added into the model as a sixth broad ability. The comprehensive model largely showed measurement invariance across sexes and age groups but did not converge within the subsample of participants with (borderline) intellectual disabilities. The results and implications are discussed in light of the current literature.
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- 2022
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8. Phylogenetic characterization of β-tubulins and development of pyrosequencing assays for benzimidazole resistance in cattle nematodes.
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Janina Demeler, Nina Krüger, Jürgen Krücken, Vera C von der Heyden, Sabrina Ramünke, Ursula Küttler, Sandra Miltsch, Michael López Cepeda, Malcolm Knox, Jozef Vercruysse, Peter Geldhof, Achim Harder, and Georg von Samson-Himmelstjerna
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Medicine ,Science - Abstract
Control of helminth infections is a major task in livestock production to prevent health constraints and economic losses. However, resistance to established anthelmintic substances already impedes effective anthelmintic treatment in many regions worldwide. Thus, there is an obvious need for sensitive and reliable methods to assess the resistance status of at least the most important nematode populations. Several single nucleotide polymorphisms (SNPs) in the β-tubulin isotype 1 gene of various nematodes correlate with resistance to benzimidazoles (BZ), a major anthelmintic class. Here we describe the full-length β-tubulin isotype 1 and 2 and α-tubulin coding sequences of the cattle nematode Ostertagia ostertagi. Additionally, the Cooperia oncophora α-tubulin coding sequence was identified. Phylogenetic maximum-likelihood analysis revealed that both isotype 1 and 2 are orthologs to the Caenorhabditis elegans ben-1 gene which is also associated with BZ resistance upon mutation. In contrast, a Trichuris trichiura cDNA, postulated to be β-tubulin isotype 1 involved in BZ resistance in this human parasite, turned out to be closely related to C. elegans β-tubulins tbb-4 and mec-7 and would therefore represent the first non-ben-1-like β-tubulin to be under selection through treatment with BZs. A pyrosequencing assay was established to detect BZ resistance associated SNPs in β-tubulin isotype 1 codons 167, 198 and 200 of C. oncophora and O. ostertagi. PCR-fragments representing either of the two alleles were combined in defined ratios to evaluate the pyrosequencing assay. The correlation between the given and the measured allele frequencies of the respective SNPs was very high. Subsequently laboratory isolates and field populations with known resistance status were analyzed. With the exception of codon 167 in Cooperia, increases of resistance associated alleles were detected for all codons in at least one of the phenotypically resistant population. Pyrosequencing provides a fast, inexpensive and sensitive alternative to conventional resistance detection methods.
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- 2013
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9. SLO-1-channels of parasitic nematodes reconstitute locomotor behaviour and emodepside sensitivity in Caenorhabditis elegans slo-1 loss of function mutants.
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Claudia Welz, Nina Krüger, Monika Schniederjans, Sandra M Miltsch, Jürgen Krücken, Marcus Guest, Lindy Holden-Dye, Achim Harder, and Georg von Samson-Himmelstjerna
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Immunologic diseases. Allergy ,RC581-607 ,Biology (General) ,QH301-705.5 - Abstract
The calcium-gated potassium channel SLO-1 in Caenorhabditis elegans was recently identified as key component for action of emodepside, a new anthelmintic drug with broad spectrum activity. In this study we identified orthologues of slo-1 in Ancylostoma caninum, Cooperia oncophora, and Haemonchus contortus, all important parasitic nematodes in veterinary medicine. Furthermore, functional analyses of these slo-1 orthologues were performed using heterologous expression in C. elegans. We expressed A. caninum and C. oncophora slo-1 in the emodepside-resistant genetic background of the slo-1 loss-of-function mutant NM1968 slo-1(js379). Transformants expressing A. caninum slo-1 from C. elegans slo-1 promoter were highly susceptible (compared to the fully emodepside-resistant slo-1(js379)) and showed no significant difference in their emodepside susceptibility compared to wild-type C. elegans (p = 0.831). Therefore, the SLO-1 channels of A. caninum and C. elegans appear to be completely functionally interchangeable in terms of emodepside sensitivity. Furthermore, we tested the ability of the 5' flanking regions of A. caninum and C. oncophora slo-1 to drive expression of SLO-1 in C. elegans and confirmed functionality of the putative promoters in this heterologous system. For all transgenic lines tested, expression of either native C. elegans slo-1 or the parasite-derived orthologue rescued emodepside sensitivity in slo-1(js379) and the locomotor phenotype of increased reversal frequency confirming the reconstitution of SLO-1 function in the locomotor circuits. A potent mammalian SLO-1 channel inhibitor, penitrem A, showed emodepside antagonising effects in A. caninum and C. elegans. The study combined the investigation of new anthelmintic targets from parasitic nematodes and experimental use of the respective target genes in C. elegans, therefore closing the gap between research approaches using model nematodes and those using target organisms. Considering the still scarcely advanced techniques for genetic engineering of parasitic nematodes, the presented method provides an excellent opportunity for examining the pharmacofunction of anthelmintic targets derived from parasitic nematodes.
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- 2011
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