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Sensitivity analysis is a useful tool for detecting influential observations
No full textI ran a sensitivity analysis on the original data from "False-positive psychology: Undisclosed flexibility in data collection and analysis allows presenting anything as significant." (Simmons et al., 2011, Psych Science) and found that the intentionally spurious result reported therein was attributable to a single outlier. This is presented as an example of why sensitivity analysis is a useful piece of the analytic toolkit in psychology
Functionaries: A Distributional Approach to Institutional Analysis
No full textThis paper outlines a distributional approach to institutional analysis, reconceptualizing institutions as distributions of knowledge and activity across people. We argue that institutionalization and institutional change are best understood by focusing on actors with the requisite knowledge and motivation to keep institutional patterns going, fix them when they go awry, or transform them when required, here called functionaries. The distributional approach allows us to distinguish between two main types of institutional change often conflated in the literature: Content-based and formal change. Content-based change, the one most often discussed, involves the importation, recombination, or expansion of specific patterns of activity. In contrast, formal change, often neglected in the literature, refers to shifts in the distribution of knowledge and activity within an institution, leading to dynamics of centralization and decentralization of institutional patterns. In this way, the distributional approach highlights the role of functionaries in both institutional stability and change, providing a micro-level perspective on institutional dynamics
Eat Widely, Vote Wisely? Lessons from a Campaign Against Vote Buying in Uganda
No full textWe study a large-scale intervention designed by civil society organizations to reduce vote buying in Uganda’s 2016 elections. We study this intervention in light of a model where incumbents benefit from a first-mover and campaigning advantage, vote buying and on-the-ground canvassing are complementary, and voter reciprocity increases the effectiveness of vote buying. The intervention
undermined reciprocity as well as the drivers of the campaigning advantage of incumbents. As a result, challengers not only canvassed more intensively but also bought more votes in treated locations. Consistent with incumbents being first movers in markets for votes and facing more frictions to adjust their tactics than challengers, their response to the intervention was limited. The intervention ultimately failed to reduce vote buying, but led to short-run electoral gains for challengers and increased service delivery in treated locations
Picosecond Ion Pulses from Adsorbate-Covered Tungsten Nanotips
No full textUltrashort ion pulses enable time-resolved investigation of particle-surface interactions, where some processes following ion impact evolve on picosecond timescales. Accessing these dynamics experimentally requires ion sources capable of delivering precisely timed ion pulses in the same temporal regime. Laser-stimulated desorption (LSD) from metallic nanotips provides such a pathway by exploiting the strong local electric field enhancement as well as nanometric confinement of the emission region [1]. Here, we investigate the temporal characteristics of the ions emitted from a molecular-loaded tungsten nanotip when driven by femtosecond laser pulses.
The ion source consists of an electrochemically etched tungsten nanotip with an apex radius of ~150 nm, operated in ultrahigh vacuum and biased at voltages of up to +6.5 kV. Due to the strong geometric field enhancement at the tip apex, local static fields on the order of ~35–65 MV/cm are achieved in the emission region. Introducing background gases at partial pressures of 10-8–10-6 mbar enables adsorption of molecular species on the tip surface. Upon irradiation with ultraviolet laser pulses of 100 fA. The resulting ions are extracted by the electrostatic field, accelerated to kinetic energies in the sub-10 keV range, and detected using time-of-flight (TOF) spectroscopy.
The measured TOF spectra directly reflect the pulse-to-pulse jitter of the ions. For hydrogen, this results in ion peaks with full-width at half-maximum (FWHM) of less than 100 ps (cf. Fig. 1a). As shown in Fig. 1b, several other adsorbate species were investigated, including deuterium and nitrogen. Under cryogenic cooling of the nanotip, ion emission from weakly bound species such as noble gases including krypton and xenon become observable, indicating the crucial role of surface-adsorption and surface-catalyzed ionization in the emission process. In all cases, the ion arrival time distribution exhibit characteristic asymmetries, suggesting that the temporal structure of the ion pulses is not governed by the femtosecond laser excitation itself, but rather by the emission geometry and subsequent propagation through the strong electrostatic field near the nanotip apex, as expected for heavy ions in contrast to ultrashort electron pulses.
To investigate the cause of the observed picosecond pulse width, particle trajectory simulations using SIMION [3] are employed to model ion propagation from the nanotip surface to the detector. By initializing ions at different positions and emission angles on the tip apex, the simulations reproduce the experimentally observed temporal broadening of TOF spectra as seen in Fig. 1c. These results demonstrate that even small variations in initial conditions, which are inherent to emission from a curved nanoscale structure, lead to significant dispersion in flight
122 Symposium on Surface Science
times. Surface geometry and field-driven trajectory effects are therefore identified as dominant contributors to the measured ion arrival-time jitter.
The intrinsic synchronization between the ion pulse and the driving laser, combined with the inherently high brilliance of a nanotip source, makes LSD an attractive approach for pump-probe experiments with picosecond resolution. More generally, this system provides a versatile platform for exploring ultrafast surface processes and ion-surface interactions, bridging surface science and time-resolved ion physics
Have We Ever Been Equal? Women’s Interactions in the Landscape Architecture of Socialist Modernism
No full textThis chapter aims to explore women’s contributions to landscape architecture and urban design from the 1950s to the 1980s in socialist Yugoslavia. As feminist and postfeminist interventions in theoretical perspectives have shown, the historiography of women in modern architecture is a culturally and ideologically constructed narrative. By addressing the questions emerging from gender roles in architecture culture of societal modernisation under socialism, the chapter spotlights the case studies illustrating prominent roles women have played in landscape architecture, from practising architects to activists, critics, and curators. Challenging linear historiographical narratives, the questions emerging from gender open a new perspective for more inclusive architectural history
Untersuchung von radiochromatischen EBT4 Filmen in der Radioonkologie
No full textIn dieser Arbeit wurden die von Ashland (Wilmington, DE, USA) neu entwickelten Gafchromic EBT4 Filme gegen ihre Vorgänger, Gafchromic EBT3, verglichen, um sie als Nachfolger zu validieren.Sowohl in einem 6 MV Photonenstrahl (am Linearbeschleuniger der Medizinischen Universität Wien, Österreich), als auch in einem 148.2 MeV Protonenstrahl (am MedAustron, Wr. Neustadt, Österreich), wurden dosimetrische Charakteristika wie das Ansprechverhalten sowie die Sensitivität der Filme untersucht. Dafür wurden 10 Filme jedes Typs bei 10 Dosiswerten zwischen 0.2 und 10 Gy bestrahlt. In Vorbereitung auf die Messungen im Protonenstrahl wurde die wasseräquivalente Dicke der EBT4 Filme mittels einem Peakfinder (PTW, Freiburg, Deutschland) System bestimmt. Drei verschiedene Kalibrierfunktionen (logarithmisch, rational, sowie ein Polynom vierten Grades) wurden angewandt und deren Residuen verglichen. Die polynomiale Fitfunktion wurde daraufhin als Fitfunktion für alle weiteren Auswertungen verwendet. Die Nachbearbeitung, sowie dosimetrische Evaluierung der Filme erfolgten mit einem intern entwickelten Python Skript, sowohl per „single-channel“ Analyse (mittels eines einzigen Farbkanals) als auch „triple-channel“ Analyse (mittels dreier Farbkanäle). In beiden Strahlenqualitäten wurde das Signal-Rausch-Verhältnis mittels Pixelwert als auch gemessener Dosis bestimmt. Der Einfluss der Filmelagerung unter unterschiedlichen Umgebungsbedingungen (Temperatur, Luftfeuchtigkeit) auf Entwicklung und dosimetrisches Ansprechvertalten von EBT3 und EBT4 wurde untersucht. Hierfür wurden Filme beider Typen an drei Orten gelagert (Büro mit Klimaanlage, Büro ohne Klimaanlage, Kühlschrank), und daraufhin zu drei Zeitpunkten im Laufe von 260 Tagen mit 0.5, 2 und 5 Gy bestrahlt. Nach der Filmkalibrierung im Protonenstrahl wurde die Abhängigkeit des Dosis-Ansprechverhaltens der Filme von linearem Energietransfer (LET) in einem Spread-Out Bragg Peak untersucht. Filme beider Typen wurden in 9 Tiefen im Spread-Out Bragg Peak positioniert und mit der berechneten Dosis sowie des LET des Bestrahlungsplanungssystems RayStation sowie eines Rferenzdetektors verglichen. Außerdem wurde die Energieabhängigkeit von EBT4 in Röntgenstrahlen im kV Bereich mit jener von EBT3 verglichen, indem Filme bei 15, 20, 25, 30, 50, 80, and 100 kV in einer YXLON Maxishot Quelle bestrahlt wurden.EBT4 und EBT3 zeigten ein ähnliches Dosisansprechverhalten und Sensitivität im Photonen- und Protonenstrahl. Zwischen den Filmtypen wurde kein signifikanter Unterschied in deren Kalibriergenauigkeit gefunden. Für das Signal-Rausch-Verhältnis im Bezug auf die Pixelwerte wurde eine Verbesserung für EBT4 im Photonenstrahl im gesamten untersuchten Dosisbereich gefunden. Im Protonenstrahl war diese Verbesserung nur für Dosen über 1 Gy zu sehen. Das Signal-Rausch-Verhältnis im Bezug auf gemessene Dosis zeigte für EBT4 eine signifikante Verbesserung bei Dosen >1.5 Gy und Verschlechterung unter 1.5 Gy im roten Kanal für beide Strahlenqualitäten. Eine Auswertung mit ``triple-channel'' Analyse hatte eine Erhöhung der Differenzen zwischen EBT3 und EBT4 zur Folge. Die überwiegende Mehrheit der Differenzen zwischen Signal-Rausch-Verhältnissen beider Filmtypen war statistisch signifikant mit p1.5 Gy and worsening below 1.5 Gy in the red channel for both beam qualities, with larger differences between film types for triple-channel evaluations. The vast majority of SNR differences between film types was statistically significant with p<0.05 in a two-sided Wilcoxon Rank-Sum test. The WET of EBT4 corresponded to that of EBT3, at 0.36 mm. No significant difference between film types was observed in the spread-out Bragg Peak of a proton beam. The a maximal under-response was –4.9% for EBT3 and –5.6% for EBT4 in single-channel evaluation, and –7.3% for EBT3 and –7.1% for EBT4 in triple-channel evaluation. Both film types showed a similar under-response to kilovoltage X-rays when dosimetrically evaluated with a calibration curve established in megavoltage X-rays. Films stored at all locations showed a tendency toward increase in optical density and film response to exposure over time, primarily visible at lower doses, but not statistically significant. EBT4 showed a slightly higher sensitivity for environmental changes. For both film types, the lowest change in optical density and dose response was observed at 10°C storage temperature.Overall, our data show EBT4 presents a suitable successor to EBT3, with an improvement in signal to noise behaviour at the higher end of examined dose levels and similar constraints regarding its usage in kV X-rays as well as high linear energy transfer regions of proton beams
Reforming EU Pension Systems: Equity and Sustainability in Conflict
No full textPopulation ageing increases old-age dependency and strains pension budgets. We compare Austria and Germany (PAYG-DB) with Italy and Poland (NDC), showing how design and parameters (retirement age, accrual rules, minimum benefits) shape demographic risk and redistribution. We build an open-economy CGE model with heterogeneous life courses (education, fertility, health, employment and mortality shocks), two-gender demography, and a pension-point representation that nests PAYG-DB and NDC. Using microsimulations and Bayesian melding, we calibrate each country and assess four reforms: minimum pension benefits (MinPB), progressive benefits (PPB), delayed retirement (DR), and a sustainability factor (SF). DR and SF typically strengthen growth and financial sustainability, whereas MinPB/PPB reduce inequality but may increase contribution needs; equity and sustainability therefore may diverge
RF arbitrary waveform generator
No full textWe report a photonic-based radio frequency (RF) arbitrary waveform generator (AWG) using a soliton crystal micro-comb source with a free spectral range (FSR) of 48.9 GHz. The comb source provides over 80 wavelengths, or channels, that we use to successfully achieve arbitrary waveform shapes including square waveforms with a tunable duty ratio ranging from 10% to 90%, sawtooth waveforms with a tunable slope ratio of 0.2 to 1, and a symmetric concave quadratic chirp waveform with an instantaneous frequency of sub GHz. We achieve good agreement between theory and experiment, validating the effectiveness of this approach towards realizing high-performance, broad bandwidth, nearly user-defined RF waveform generation
Sound-induced motion in chimpanzees does not imply shared ancestry for music or dance
No full textThis letter is in reply to Hattori & Tomonaga (2020), who report that seven captive chimpanzees moved in response to piano sounds, more so than in silence. On this basis, they argue, "some biological foundation for dancing existed in the common ancestor of humans and chimpanzees ~6 million years ago". Music's universality suggests it has deep phylogenetic roots; understanding music-like behavior in non-human animals is therefore valuable for understanding the evolution of music. But the paper's claim of shared ancestry for music or dance is unjustified