Non-Technical Individual Skills are Weakly Connected to the Maturity of Agile Practices

Context: Existing knowledge in agile software development suggests that individual competency (e.g. skills) is a critical success factor for agile projects. While assuming that technical skills are important for every kind of software development project, many researchers suggest that non-technical individual skills are especially important in agile software development. Objective: In this paper, we investigate whether non-technical individual skills can predict the use of agile practices. Method: Through creating a set of multiple linear regression models using a total of 113 participants from agile teams in six software development organizations from The Netherlands and Brazil, we analyzed the predictive power of non-technical individual skills in relation to agile practices. Results: The results show that there is surprisingly low power in using non-technical individual skills to predict (i.e. explain variance in) the mature use of agile practices in software development. Conclusions: Therefore, we conclude that looking at non-technical individual skills is not the optimal level of analysis when trying to understand, and explain, the mature use of agile practices in the software development context. We argue that it is more important to focus on the non-technical skills as a team-level capacity instead of assuring that all individuals possess such skills when understanding the use of the agile practices.Comment: 18 pages, 1 figur

Height-resolved Scaling Properties of Tropospheric Water Vapour based on Airborne Lidar Observations

Two-dimensional vertical water vapour cross sections of the free troposphere between altitudes of 2 and 10 km, measured by nadir-viewing airborne differential-absorption lidar with high spatial resolution, were analyzed using structure functions up to the fifth order. We found scale invariance, i.e. a power-law dependency of structure function on length scale, for scales between 5 and 100 km, for the horizontal time series of water vapour mixing ratio. In contrast to one-dimensional in situ measurements, the two-dimensional water vapor lidar observations allow height-resolved analyses of power-law scaling exponents at a vertical resolution of 200 m. The data reveal significantly different scaling properties above and below an air-mass boundary. They stem from three very dissimilar aircraft campaigns: COPS/ETReC over middle and southern Europe in summer 2007, T-PARC around Japan mostly over sea in late summer 2008, and T-IPY around Spitsbergen over sea in winter 2008. After discarding flight segments with low lidar signals or large data gaps, and after averaging horizontally to a resolution of between 1 and 5 km to obtain a high signal to noise ratio, structure functions were computed for 20 flights at various heights, adding up to a length of more than 300,000 km. The power-law scaling exponents of the structure functions do not show significant latitudinal, seasonal or land/sea dependency, but they do differ between air masses influenced by moist convection and air masses aloft, not influenced. A classification of the horizontal water vapour time series into two groups according to whether the series occurred above or below the level of nearby convective cloud tops could be performed by detecting the cloud top height from the lidar backscatter signal in the corresponding flight segment. We found that the scaling exponents can be divided into two groups depending on the respective air mass: The smoothness of the time series, expressed by the first-order scaling exponent, varies from less than 0.5 in the low-level convectively influenced air masses to values greater than 0.5 and most frequently near 0.6 in the higher-level air above the convective cloud tops. The time series’ intermittency, expressed by the variation of the scaling exponent with increasing order, is larger in convectively influenced air masses. These differences in variability strongly suggest that convection provides a source of moisture variability on small scales. Our results show that the high horizontal and vertical resolution of lidar observations allows a characterisation of the scale dependency of the water vapour field at scales close to and smaller than the smallest resolved scales in modern weather and climate models. This provides both a reference for validation of high resolution models and a basis for the design of stochastic or pdf-based parameterisations of clouds and convection

Functional imaging in neuroenhancement

Increasingly demanding tasks, competition for competence and time pressure have lead to attempts of neuroenhancement (NE) among students and employees. NE is designed to increase cognitive abilities by modulating brain processes through the use of pharmaceutics. Substances such as methylphenidate (i.e. Ritalin®), modafinil (i.e. Vigil®) and caffeine are common candidates for enhancing cognitive abilities such as executive functions, inhibition control and memory (Wood et al., 2014). Until today, there has not been a study investigating memory enhancement in functional magnetic resonance imaging (fMRI). Using fMRI, 48 healthy participants were tested for drug effects in a single-dose, double-blind and randomized study using a declarative memory task. During memory recall, methylphenidate dependent deactivations were found in the fronto-parietal and temporal regions whereas no BOLD alterations were seen during encoding. On the behavioral level, methylphenidate enhanced subject’s judgement confidence and performance during late recall. During encoding, caffeine led to deactivations in the precentral gyrus whereas modafinil did not show any BOLD signal alterations at all. To get an overview over the existing neuroimaging literature, all published studies on the effects of the aforementioned drug agents were reviewed in addition. In line with this study, previous publications emphasized that methylphenidate seems to alter task relevant brain areas. Our main finding of task-related deactivations may point to the reduction of task-functioning distractions. Thereby, we conclude a drug-dependent increase of efficiency in data processing.Zunehmende Arbeitsbelastung, erhöhter Zeitdruck und größere Verantwortung haben dazu geführt, dass für Studenten und Arbeitnehmer das Phänomen Neuroenhancement (NE) eine zunehmende Relevanz erlangt hat. Darunter wird die Steigerung der kognitiven Leistung durch pharmazeutischen Eingriff auf zentralnervöse Prozesse verstanden. Substanzen wie z.B. Methylphenidat (Ritalin®), Modafinil (Vigil®) und Koffein gelten als aussichtsreiche Kandidaten zur Leistungssteigerung, die möglicherweise Einfluss auf kognitive Prozesse, wie z.B. Exekutive Funktionen, Inhibitionskontrolle und Gedächtnis ausüben können (Wood et al., 2014). Keine bisher publizierte Studie hat den Fokus auf neuronale Korrelate der deklarativen Gedächtnissteigerung gelegt. Aus dem Grund sind zusätzlich alle bisher veröffentlichten bildgebenden Studien zu Methylphenidat, Modafinil und Koffein zu einer strukturierten Übersicht zusammengefasst worden. Mittels funktionaler Magnetresonanztomographie (fMRT) wurden 48 gesunde Probanden, doppelt verblindet und randomisiert auf Steigerung der deklarativen Gedächtnisleistung getestet. Obwohl die Wirksamkeit der drei Substanzen ausführlich für klinische Patientenpopulationen untersucht wurde, gibt es kaum Wissen über die möglichen behavioralen und neuronalen Auswirkungen auf gesunde, erwachsene Menschen. Entgegen der Erwartung, dass die getesteten Substanzen klassische Gedächtnis assoziierte Regionen aktivieren, wurden unterschiedliche substanzspezifische Effekte gefunden. Wahrend des Abrufs von Gedächtnisinhalten deaktivierte Methylphenidat fronto-parietale und temporale Regionen. Dagegen führte die Applikation von Koffein zu einer verringerten BOLD Antwort im Gyrus Präcentralis während der Lernphase. Modafinil führte zu keiner Veränderung im Vergleich zu Placebo. Auf Verhaltensebene förderte Methylphenidat den späten Abruf von Gedächtnisinhalten, wohingegen die beiden anderen Substanzen keine Effekte hinsichtlich der Lernleistung vorwiesen. Vor dem Hintergrund bisheriger bildgebender Studien zeigt die vorliegende Arbeit, dass Neuroenhancement neben der Aktivierung leistungsrelevanter Gehirnregionen auch durch Reduzierung von störenden Einwirkungen funktionieren kann und damit womöglich die Effektivität der Informationsverarbeitung erhöht

When Transaction-Level Wage Transparency Can Increase Consumer Preference

Firms are usually reluctant to disclose information about the production costs of their goods and services; however, some firms have recently started to disclose cost information to consumers. This research examines the consequences of disclosing transaction-level wage information on consumer preferences. Six experiments, both in field and lab settings across multiple service domains, document that disclosing a service worker’s compensation can increase consumer preference for that firm’s service if the compensation is sufficiently high (i.e., perceived as fair by consumers). This greater preference for services provided in a fair-wage setting is driven by consumers’ feelings of anticipated guilt and higher expectations concerning quality. Available social norms regarding fair compensation and the nature of the service worker (human vs. non- human) are both identified as important boundary conditions of the proposed process. This research offers a first step toward understanding the psychological and behavioral consequences of disclosing transaction-level wage information to consumers, thereby enabling managers to better identify when they should disclose wage information as part of their marketing strategy. This research also informs policy makers on how to encourage social preferences and consumer choices in order to promote fair outcomes for consumers, firms, and workers

Synchronization Through Uncorrelated Noise in Excitatory-Inhibitory Networks

© 2022 Rebscher, Obermayer and Metzner. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)Gamma rhythms play a major role in many different processes in the brain, such as attention, working memory, and sensory processing. While typically considered detrimental, counterintuitively noise can sometimes have beneficial effects on communication and information transfer. Recently, Meng and Riecke showed that synchronization of interacting networks of inhibitory neurons in the gamma band (i.e., gamma generated through an ING mechanism) increases while synchronization within these networks decreases when neurons are subject to uncorrelated noise. However, experimental and modeling studies point towardz an important role of the pyramidal-interneuronal network gamma (PING) mechanism in the cortex. Therefore, we investigated the effect of uncorrelated noise on the communication between excitatory-inhibitory networks producing gamma oscillations via a PING mechanism. Our results suggest that, at least in a certain range of noise strengths and natural frequency differences between the regions, synaptic noise can have a supporting role in facilitating inter-regional communication, similar to the ING case for a slightly larger parameter range. Furthermore, the noise-induced synchronization between networks is generated via a different mechanism than when synchronization is mediated by strong synaptic coupling. Noise-induced synchronization is achieved by lowering synchronization within networks which allows the respective other network to impose its own gamma rhythm resulting in synchronization between networks.Peer reviewedFinal Published versio

a simple tool for the analysis of periodic cotyledon and leaf movement in Arabidopsis thaliana

Background The analysis of circadian leaf movement rhythms is a simple yet effective method to study effects of treatments or gene mutations on the circadian clock of plants. Currently, leaf movements are analysed using time lapse photography and subsequent bioinformatics analyses of leaf movements. Programs that are used for this purpose either are able to perform one function (i.e. leaf tip detection or rhythm analysis) or their function is limited to specific computational environments. We developed a leaf movement analysis tool—PALMA—that works in command line and combines image extraction with rhythm analysis using Fast Fourier transformation and non-linear least squares fitting. Results We validated PALMA in both simulated time series and in experiments using the known short period mutant sensitivity to red light reduced 1 (srr1-1). We compared PALMA with two established leaf movement analysis tools and found it to perform equally well. Finally, we tested the effect of reduced iron conditions on the leaf movement rhythms of wild type plants. Here, we found that PALMA successfully detected period lengthening under reduced iron conditions. Conclusions PALMA correctly estimated the period of both simulated and real-life leaf movement experiments. As a platform-independent console-program that unites both functions needed for the analysis of circadian leaf movements it is a valid alternative to existing leaf movement analysis tools

Two-phase flow experiments in a model of the hot leg of a pressurised water reactor

In order to investigate the two-phase flow behaviour in a complex reactor-typical geometry and to supply suitable data for CFD code validation, a model of the hot leg of a pressurised water reactor was built at FZD. The hot leg model is operated in the pressure chamber of the TOPFLOW test facility, which is used to perform high-pressure experiments under pressure equilibrium with the inside atmosphere of the chamber. This technique makes it possible to visualise the two-phase flow through large windows, also at reactor-typical pressure levels. In order to optimise the optical observation possibilities, the test section was designed with a rectangular cross-section. Experiments were performed with air and water at 1.5 and 3.0 bar at room temperature as well as with steam and water at 15, 30 and 50 bar and the corresponding saturation temperature (i.e. up to 264°C). The total of 194 runs are divided into 4 types of experiments covering stationary co-current flow, counter-current flow, flow without water circulation and transient counter-current flow limitation (CCFL) experiments. This report provides a detailed documentation of the experiments including information on the experimental setup, experimental procedure, test matrix and on the calibration of the measuring devices. The available data is described and data sheets were arranged for each experiment in order to give an overview of the most important parameters. For the cocurrent flow experiments, water level histograms were arranged and used to characterise the flow in the hot leg. In fact, the form of the probability distribution was found to be sensitive to the boundary conditions and, therefore, is useful for the CFD comparison. Furthermore, the flooding characteristics of the hot leg model plotted in terms of the classical Wallis parameter or Kutateladze number were found to fail to properly correlate the data of the air/water and steam/water series. Therefore, a modified Wallis parameter is proposed, which takes the effect of viscosity into account