Turbulent Jet Expansion

This report was made to study the velocity distribution in an open, in a partially open, and in a partially expanding jet. The open-jet observations reveal minor systematic discrepancies from Tollmien's theoretical velocity distribution. The shearing-stress distribution for the partially open jet was determined. The value derived for the ratio of mixing distance to jet width was found to be in close agreement with the corresponding value for the open-jet boundary. The streamline pattern in a partially expanding channel was obtained from the observed velocity distribution and plotted, after which the distribution of the mixing distance for this case was also ascertained

Reach for the stars: disentangling quantity and quality of inventors’ productivity in a multifaceted latent variable model

Star inventors generate superior innovation outcomes. Their capacity to invent high-quality patents might be decisive beyond mere productivity. However, the relationship between quantitative and qualitative dimensions has not been exhaustively investigated. The equal odds baseline (EOB) framework can explicitly model this relationship. This work com- bines a theoretical model for creative production with recent calls in the patentometrics lit- erature for multifaceted measurement of the ability to create high-quality patents. The EOB is extended and analyzed through structural equation modeling. Specifically, we compared a multifaceted EOB model with a single latent variable for quality, and a two-dimensional model that distinguishes between technological complexity and value of invention portfo- lios. The two-dimensional model had better fit but weaker factor scores (for the “value” latent variable) than the unidimensional model. These findings suggest that both the uni- and the two-dimensional approaches can be directly used for extending research on star inventors, while for practical high-stakes assessments the two-dimensional model would require further improvements

Development and application of super-resolution fluorescence microscopy

Für eine drastische Erweiterung des Anwendungsfeldes der optischen Mikroskopie sorgte die in den letzten Jahren aufgekommene sogenannte Superauflösungsmikroskopie. Das klassische Modellsystem, um das Auflösungsvermögen derartiger Techniken zu vergleichen und zu quantifizieren, stellen Komponenten des eukaryontischen Zytoskeletts dar. Auch im Rahmen dieser Arbeit wurden derartige Zellstrukturen verwendet und anhand dessen ein quantitativer Wert für die Auflösung der Blink-Mikroskopie erhalten. Das System der Wahl waren dabei Aktinfilamente in vitro, in fixierten und in lebenden Zellen. Darüberhinaus wurde auch ein deutlich systematischerer Ansatz verfolgt, indem eine Matrix aus gezielt angeordneten Farbstoffmolekülen als Vergleichssystem verwendet wurde. Dabei wurde die gezielte Platzierung sowohl virtuell in Monte-Carlo-Simulationen, als auch real mithilfe eines Rasterkraftmikroskops durchgeführt. Die Platzierung von Farbstoffmolekülen durch die Verwendung von Rasterkraftmikroskopie wies allerdings einige Nachteile auf, wie etwa eine sehr aufwändige Durchführung und das Fehlen einer Möglichkeit zur Parallelisierung. Aus diesem Grund wurde im Folgenden auf die sogenannte DNA-Origami-Technik zurück gegriffen, um gezielte Farbstoffanordnungen zu generieren. Diese dienten nun als Testprobe sowohl für die Blink-Mikroskopie, als auch für die superauflösenden Techniken PAINT und SHRImP. Schließlich wurden DNA-Origamis als generelle Auflösungsstandards für die lokalisierungsbasierte Superauflösungsmikroskopie etabliert, wobei zur automatisierten Auswertung ein spezieller Algorithmus entwickelt wurde. Die Erweiterung auf den dreidimensionalen Fall gelang durch die Nutzung von Astigmatismus-basierter 3D-Lokalisierungsmikroskopie und die Verwendung einer speziell dafür designten dreidimensionalen DNA-Origami-Struktur. Die Möglichkeit einer unkomplizierten Auswertung wurde auch in diesem Fall durch die Entwicklung eines automatisierten Detektionsalgorithmus sichergestellt.In recent years the so called super-resolution microscopy yielded to a dramatic increase of applications in optical microscopy. The common used model system to compare and quantify the resolution values of those techniques is given by components of the eukaryotic cytoskeleton. Also within this work those cell structures were used for gaining a quantitative value of the resolution of Blink Microscopy. Thereby the systems of choice were actin filaments in vitro, in stained cells and in living cells. Furthermore a much more systematic approach was carried out by using a matrix of regular arranged dye molecules as a comparison system. Thereby the accurate placement was done virtually in Monte-Carlo-simulations as well as in reality by using an atomic force microscope. However, the arrangement of fluorescent molecules by using an atomic force microscope contains a number of disadvantages, e.g. the quite high effort of the process and the lack of possibilities for parallelization. For this reason in the following the so called DNA origami technique was used for generating specific arrangements of dye molecules. These structures now functioned as calibration probe for Blink Microscopy as well as for the super-resolution techniques PAINT and SHRImP. Finally DNA origamis were established as general resolution standards for localization based super-resolution microscopy. Thereby for automated data analysis a specific algorithm was developed. The expansion to the three-dimensional case succeeded by applying astigmatism-based 3D-localization-microscopy to a specific for this case designed three-dimensional DNA-origami-structure. The option for uncomplicated data analysis was also ensured by developing of an automatic detection algorithm

Scoring divergent thinking tests: A review and systematic framework

Divergent thinking tests are often used in creativity research as measures of creative potential. However, measurement approaches across studies vary to a great extent. One facet of divergent thinking measurement that contributes strongly to differences across studies is the scoring of participants’ responses. Most commonly, responses are scored for fluency, flexibility, and originality. However, even with respect to only one dimension (e.g., originality), scoring decisions vary extensively. In the current work, a systematic framework for practical scoring decisions was developed. Scoring dimensions, instruction-scoring fit, adequacy of responses, objectivity (vs. subjectivity), level of scoring (response vs. ideational pool level), and the method of aggregation were identified as determining factors of divergent thinking test scoring. In addition, recommendations and guidelines for making these decisions and reporting the information in papers have been provided

A New Perspective on the Multidimensionality of Divergent Thinking Tasks

In the presented work, a shift of perspective with respect to the dimensionality of divergent thinking (DT) tasks is introduced moving from the question of multidimensionality across DT scores (i.e., fluency, flexibility, or originality) to the question of multidimensionality within one holistic score of DT performance (i.e., snapshot ratings of creative quality). We apply IRTree models to test whether unidimensionality assumptions hold in different task instructions for snapshot scoring of DT tests across Likert-scale points and varying levels of fluency. It was found that evidence for unidimensionality across scale points was stronger with be-creative instructions as compared to be-fluent instructions which suggests better psychometric quality of ratings when be-creative instructions are used. In addition, creative quality latent variables pertaining to low-fluency and high-fluency ideational pools shared around 50% of variance which suggests both strong overlap, and evidence for differentiation. The presented approach allows to further examine the psychometric quality of subjective ratings and to examine new questions with respect to within-item multidimensionality in DT

Super-Resolution Imaging of C-Type Lectin and Influenza Hemagglutinin Nanodomains on Plasma Membranes Using Blink Microscopy

AbstractDendritic cells express DC-SIGN, a C-type lectin (CTL) that binds a variety of pathogens and facilitates their uptake for subsequent antigen presentation. DC-SIGN forms remarkably stable microdomains on the plasma membrane. However, inner leaflet lipid markers are able to diffuse through these microdomains suggesting that, rather than being densely packed with DC-SIGN proteins, an elemental substructure exists. Therefore, a super-resolution imaging technique, Blink Microscopy (Blink), was applied to further investigate the lateral distribution of DC-SIGN. Blink indicates that DC-SIGN, another CTL (CD206), and influenza hemagglutinin (HA) are all localized in small (∼80 nm in diameter) nanodomains. DC-SIGN and CD206 nanodomains are randomly distributed on the plasma membrane, whereas HA nanodomains cluster on length scales up to several microns. We estimate, as a lower limit, that DC-SIGN and HA nanodomains contain on average two tetramers or two trimers, respectively, whereas CD206 is often nonoligomerized. Two-color Blink determined that different CTLs rarely occupy the same nanodomain, although they appear colocalized using wide-field microscopy. What to our knowledge is a novel domain structure emerges in which elemental nanodomains, potentially capable of binding viruses, are organized in a random fashion; evidently, these nanodomains can be clustered into larger microdomains that act as receptor platforms for larger pathogens like yeasts

Polarised Quark Distributions in the Nucleon from Semi-Inclusive Spin Asymmetries

We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range $0.003$1 GeV$^2$. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at $Q^2$=10 GeV$^2$. The polarised $u$ valence quark distribution, $\Delta u_v(x)$, is positive and the polarisation increases with $x$. The polarised $d$ valence quark distribution, $\Delta d_v(x)$, is negative and the non-strange sea distribution, $\Delta \bar q(x)$, is consistent with zero over the measured range of $x$. We find for the first moments $\int_0^1 \Delta u_v(x) dx = 0.77 \pm 0.10 \pm 0.08$, $\int_0^1 \Delta d_v(x) dx = -0.52 \pm 0.14 \pm 0.09$ and $\int_0^1 \Delta \bar q(x) dx= 0.01 \pm 0.04 \pm 0.03$, where we assumed $\Delta \bar u(x) = \Delta \bar d(x)$. We also determine for the first time the second moments of the valence distributions $\int_0^1 x \Delta q_v(x) dx$.Comment: 17 page

Paving the Way to Eureka-Introducing "Dira" as an Experimental Paradigm to Observe the Process of Creative Problem Solving

“Dira” is a novel experimental paradigm to record combinations of behavioral and metacognitive measures for the creative process. This task allows assessing chronological and chronometric aspects of the creative process directly and without a detour through creative products or proxy phenomena. In a study with 124 participants we show that (a) people spend more time attending to selected vs. rejected potential solutions, (b) there is a clear connection between behavioral patterns and self-reported measures, (c) the reported intensity of Eureka experiences is a function of interaction time with potential solutions, and (d) experiences of emerging solutions can happen immediately after engaging with a problem, before participants explore all potential solutions. The conducted study exemplifies how “Dira” can be used as an instrument to narrow down the moment when solutions emerge. We conclude that the “Dira” experiment is paving the way to study the process, as opposed to the product, of creative problem solving

Polarised quark distributions in the nucleon from semi-inclusive spin asymmetries

We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range $0.003$1~GeV$^2$. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at $Q^2$=10~GeV$^2$. The polarised $u$ valence quark distribution, $\Delta u_v(x)$, is positive and the polarisation increases with $x$. The polarised $d$ valence quark distribution, $\Delta d_v(x)$, is negative and the non-strange sea distribution, $\Delta \bar q(x)$, is consistent with zero over the measured range of $x$. We find for the first moments $\int_0^1 \Delta u_v(x) {\rm d}x = 0.77 \pm 0.10 \pm 0.08$, $\int_0^1 \Delta d_v(x) {\rm d}x = -0.52 \pm 0.14 \pm 0.09$ and $\int_0^1 \Delta \bar q(x) {\rm d}x= 0.01 \pm 0.04 \pm 0.03$, where we assumed $\Delta \bar u(x) = \Delta \bar d(x)$. We also determine for the first time the second moments of the valence distributions $\int_0^1 x \Delta q_v(x) {\rm d}x$.We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range $0.003$1 GeV$^2$. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at $Q^2$=10 GeV$^2$. The polarised $u$ valence quark distribution, $\Delta u_v(x)$, is positive and the polarisation increases with $x$. The polarised $d$ valence quark distribution, $\Delta d_v(x)$, is negative and the non-strange sea distribution, $\Delta \bar q(x)$, is consistent with zero over the measured range of $x$. We find for the first moments $\int_0^1 \Delta u_v(x) dx = 0.77 \pm 0.10 \pm 0.08$, $\int_0^1 \Delta d_v(x) dx = -0.52 \pm 0.14 \pm 0.09$ and $\int_0^1 \Delta \bar q(x) dx= 0.01 \pm 0.04 \pm 0.03$, where we assumed $\Delta \bar u(x) = \Delta \bar d(x)$. We also determine for the first time the second moments of the valence distributions $\int_0^1 x \Delta q_v(x) dx$.We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range $0.003$1 GeV$^2$. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at $Q^2$=10 GeV$^2$. The polarised $u$ valence quark distribution, $\Delta u_v(x)$, is positive and the polarisation increases with $x$. The polarised $d$ valence quark distribution, $\Delta d_v(x)$, is negative and the non-strange sea distribution, $\Delta \bar q(x)$, is consistent with zero over the measured range of $x$. We find for the first moments $\int_0^1 \Delta u_v(x) dx = 0.77 \pm 0.10 \pm 0.08$, $\int_0^1 \Delta d_v(x) dx = -0.52 \pm 0.14 \pm 0.09$ and $\int_0^1 \Delta \bar q(x) dx= 0.01 \pm 0.04 \pm 0.03$, where we assumed $\Delta \bar u(x) = \Delta \bar d(x)$. We also determine for the first time the second moments of the valence distributions $\int_0^1 x \Delta q_v(x) dx$.We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range $0.003$1 GeV$^2$. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at $Q^2$=10 GeV$^2$. The polarised $u$ valence quark distribution, $\Delta u_v(x)$, is positive and the polarisation increases with $x$. The polarised $d$ valence quark distribution, $\Delta d_v(x)$, is negative and the non-strange sea distribution, $\Delta \bar q(x)$, is consistent with zero over the measured range of $x$. We find for the first moments $\int_0^1 \Delta u_v(x) dx = 0.77 \pm 0.10 \pm 0.08$, $\int_0^1 \Delta d_v(x) dx = -0.52 \pm 0.14 \pm 0.09$ and $\int_0^1 \Delta \bar q(x) dx= 0.01 \pm 0.04 \pm 0.03$, where we assumed $\Delta \bar u(x) = \Delta \bar d(x)$. We also determine for the first time the second moments of the valence distributions $\int_0^1 x \Delta q_v(x) dx$.We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range $0.003$1 GeV$^2$. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at $Q^2$=10 GeV$^2$. The polarised $u$ valence quark distribution, $\Delta u_v(x)$, is positive and the polarisation increases with $x$. The polarised $d$ valence quark distribution, $\Delta d_v(x)$, is negative and the non-strange sea distribution, $\Delta \bar q(x)$, is consistent with zero over the measured range of $x$. We find for the first moments $\int_0^1 \Delta u_v(x) dx = 0.77 \pm 0.10 \pm 0.08$, $\int_0^1 \Delta d_v(x) dx = -0.52 \pm 0.14 \pm 0.09$ and $\int_0^1 \Delta \bar q(x) dx= 0.01 \pm 0.04 \pm 0.03$, where we assumed $\Delta \bar u(x) = \Delta \bar d(x)$. We also determine for the first time the second moments of the valence distributions $\int_0^1 x \Delta q_v(x) dx$.We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range 0.0031 GeV 2 . Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at Q 2 =10 GeV 2 . The polarised u valence quark distribution, Δu v ( x ), is positive and the polarisation increases with x . The polarised d valence quark distribution, Δd v ( x ), is negative and the non-strange sea distribution, Δ q ̄ (x) , is consistent with zero over the measured range of x . We find for the first moments ∫ 0 1 Δu v (x) d x=0.77±0.10±0.08 , ∫ 0 1 Δd v (x) d x=−0.52±0.14±0.09 and ∫ 0 1 Δ q ̄ (x) d x=0.01±0.04±0.03 , where we assumed Δ u ̄ (x)=Δ d ̄ (x) . We also determine for the first time the second moments of the valence distributions ∫ 0 1 xΔq v (x) d x