Plant and arthropod community sensitivity to rainfall manipulation but not nitrogen enrichment in a successional grassland ecosystem

Grasslands provide many ecosystem services including carbon storage, biodiversity preservation and livestock forage production. These ecosystem services will change in the future in response to multiple global environmental changes, including climate change and increased nitrogen inputs. We conducted an experimental study over 3 years in a mesotrophic grassland ecosystem in southern England. We aimed to expose plots to rainfall manipulation that simulated IPCC 4th Assessment projections for 2100 (+15 % winter rainfall and −30 % summer rainfall) or ambient climate, achieving +15 % winter rainfall and −39 % summer rainfall in rainfall-manipulated plots. Nitrogen (40 kg ha−1 year−1) was also added to half of the experimental plots in factorial combination. Plant species composition and above ground biomass were not affected by rainfall in the first 2 years and the plant community did not respond to nitrogen enrichment throughout the experiment. In the third year, above-ground plant biomass declined in rainfall-manipulated plots, driven by a decline in the abundances of grass species characteristic of moist soils. Declining plant biomass was also associated with changes to arthropod communities, with lower abundances of plant-feeding Auchenorrhyncha and carnivorous Araneae indicating multi-trophic responses to rainfall manipulation. Plant and arthropod community composition and plant biomass responses to rainfall manipulation were not modified by nitrogen enrichment, which was not expected, but may have resulted from prior nitrogen saturation and/or phosphorus limitation. Overall, our study demonstrates that climate change may in future influence plant productivity and induce multi-trophic responses in grasslands.

Being optimally aroused matters: Effects of a weak stress manipulation on children’s executive functions are moderated by temperament and age

We tested a core assumption of the bidirectional model of executive function (EF) (Blair & Ursache, 2011) indicating that EF is dependent on arousal. From a bottom-up perspective the performance on EF tasks is assumed to be curvilinearly related to arousal, with very high or low levels of arousal impairing EF. N = 107 4-and 6-year-olds’ performance on EF tasks was explored as a function of a weak stress manipulation aiming to raise children’s emotional arousal. EF (Stroop, Flanker, Go/no-go, and Backwards Color Recall) was assessed and stress was induced in half of the children by imposing a mild social evaluative threat. Furthermore, children’s temperament was assessed as a potential moderator. We found that stress effects on children’s EF performance were moderated by age and temperament: 4-year-olds with high Inhibitory Control and high Attentional Focusing were negatively affected by the stressor. However, it is unclear whether these effects were mediated by self-reported arousal. Our findings disconfirmed the hypotheses that adverse effects of the stressor are particularly high in children high on emotional reactivity aspects of temperament and low on self-regulatory aspects of temperament. Further, 6-year-olds did not show any stress effects. Results will be discussed within the framework of the Yerkes-Dodson law and with regard to stress manipulations in children.

Improved Space Object Orbit Determination Using CMOS Detectors

CMOS-sensors, or in general Active Pixel Sensors (APS), are rapidly replacing CCDs in the consumer camera market. Due to significant technological advances during the past years these devices start to compete with CCDs also for demanding scientific imaging applications, in particular in the astronomy community. CMOS detectors offer a series of inherent advantages compared to CCDs, due to the structure of their basic pixel cells, which each contains their own amplifier and readout electronics. The most prominent advantages for space object observations are the extremely fast and flexible readout capabilities, feasibility for electronic shuttering and precise epoch registration,and the potential to perform image processing operations on-chip and in real-time. Here, the major challenges and design drivers for ground-based and space-based optical observation strategies for objects in Earth orbit have been analyzed. CMOS detector characteristics were critically evaluated and compared with the established CCD technology, especially with respect to the above mentioned observations. Finally, we simulated several observation scenarios for ground- and space-based sensor by assuming different observation and sensor properties. We will introduce the analyzed end-to-end simulations of the ground- and spacebased strategies in order to investigate the orbit determination accuracy and its sensitivity which may result from different values for the frame-rate, pixel scale, astrometric and epoch registration accuracies. Two cases were simulated, a survey assuming a ground-based sensor to observe objects in LEO for surveillance applications, and a statistical survey with a space-based sensor orbiting in LEO observing small-size debris in LEO. The ground-based LEO survey uses a dynamical fence close to the Earth shadow a few hours after sunset. For the space-based scenario a sensor in a sun-synchronous LEO orbit, always pointing in the anti-sun direction to achieve optimum illumination conditions for small LEO debris was simulated.

The developmental and evolutionary origins of psychological essentialism lie in sortal object individuation

Cimpian & Salomon (C&S) present promising steps towards understanding the cognitive underpinnings of adult essentialism. However, their approach is less convincing regarding ontogenetic and evolutionary aspects. In contrast to C&S's claim, the so-called inherence heuristic, though perhaps vital in adult reasoning, seems an implausible candidate for the developmental and evolutionary foundations of psychological essentialism. A more plausible candidate is kind-based object individuation that already embodies essentialist modes of thinking and that is present in infants and nonhuman primates.

Promoting Pollinating Insects in Intensive Agricultural Matrices: Field-Scale Experimental Manipulation of Hay-Meadow Mowing Regimes and Its Effects on Bees

Bees are a key component of biodiversity as they ensure a crucial ecosystem service: pollination. This ecosystem service is nowadays threatened, because bees suffer from agricultural intensification. Yet, bees rarely benefit from the measures established to promote biodiversity in farmland, such as agri-environment schemes (AES). We experimentally tested if the spatio-temporal modification of mowing regimes within extensively managed hay meadows, a widespread AES, can promote bees. We applied a randomized block design, replicated 12 times across the Swiss lowlands, that consisted of three different mowing treatments: 1) first cut not before 15 June (conventional regime for meadows within Swiss AES); 2) first cut not before 15 June, as treatment 1 but with 15% of area left uncut serving as a refuge; 3) first cut not before 15 July. Bees were collected with pan traps, twice during the vegetation season (before and after mowing). Wild bee abundance and species richness significantly increased in meadows where uncut refuges were left, in comparison to meadows without refuges: there was both an immediate (within year) and cumulative (from one year to the following) positive effect of the uncut refuge treatment. An immediate positive effect of delayed mowing was also evidenced in both wild bees and honey bees. Conventional AES could easily accommodate such a simple management prescription that promotes farmland biodiversity and is likely to enhance pollination services.

Funktionalität peripherer Wahrnehmung bei Trackingaufgaben

Introduction: Beim Multiple-Object-Tracking müssen mehrere, sich bewegende Zielobjekte visuell verfolgt werden. Dabei scheint es vorteilhaft zu sein, den Blick zwischen den Zielobjekten zu verankern, um Bewegungsinformationen peripher wahrzunehmen (Fehd & Seiffert, 2010). Nach Prüfung dieser Annahme (Experiment 1) wurde getestet, wie gut und schnell auf Bewegungs- und Formveränderungen der Zielobjekte reagiert werden kann (Experiment 2), um die Funktionalität der peripheren Wahrnehmung zu überprüfen. Methods: 14 Teilnehmer hatten die Aufgabe, zum Ende eines Einzelversuchs 4 aus 10 Vierecken wiederzuerkennen, die sich linear für 6 s in einem projizierten Quadrat bewegten. Dabei wurden 3 Geschwindigkeiten (6, 9 und 12°/s) in 9 Blöcken à 15 Versuchen präsentiert, um die Ergebnisse von Fehd und Seiffert (2010) zu replizieren. In Experiment 2 sollten Teilnehmer auf das Anhalten eines Targets oder dessen Formveränderung zur Raute (Manipulation: 0.5 s) mit Knopfdruck reagieren, bei ausbleibender Veränderung hingegen die 4 Zielobjekte wiedererkennen (3 Bedingungen in 10 Blöcken à 12 Versuchen). Durch die Bestimmung von Sakkadenlatenzen (definiert als Zeitraum zwischen Beginn der Objektveränderung und Sakkadenbeginn auf das Objekt) kann bestimmt werden, ob die Veränderung bereits peripher wahrgenommen wurde. Unter anderem aufgrund der Sensitivität der Netzhaut gegenüber Bewegungen wurde erwartet, dass Bewegungsveränderungen häufiger und schneller erkannt werden und dass häufiger bereits reagiert werden kann, bevor der Blick auf dem veränderten Zielobjekt ist. Results: Experiment 1 ergab einen signifikanten Haupteffekt für Geschwindigkeit, F(2,26) = 62.66, p < .01, ηp2 = .83, mit höchsten Richtigkeiten bei 6°/s (58%). Ein Haupteffekt für Blickort, F(2,26) = 76.40, p < .01, ηp2 = .85, zeigt, dass der Blick unabhängig von der Geschwindigkeit länger auf dem Centroid war als auf Targets und Distraktoren. Aufgrund der höchsten Richtigkeiten bei 6°/s wurde diese Geschwindigkeit in Experiment 2 eingesetzt und festgestellt, dass Bewegungsveränderungen häufiger erkannt werden (83 %) als Formveränderungen (59 %), F(1,10) = 17.20, p < .01, ηp2 = .63. Unterschiede in Sakkadenlatenzen, F(1,10) = 6.73, p = .03, ηp2 = .40, deuten auf eine periphere Wahrnehmung der Bewegungsveränderungen hin. Experiment 3 wird zeigen, ob Sakkaden das Monitoring stören. Discussion/Conclusion: Die periphere Wahrnehmung scheint immer dann funktional zu sein, wenn mehrere, für eine Aufgabe relevante Objekte gleichzeitig verfolgt werden müssen und wenn Veränderungen, besonders der Bewegung, schnell erkannt werden müssen. Weitere Untersuchungen sollen zeigen, ob diese Funktionalität der peripheren Wahrnehmung auch im Sport (z.B. beim gleichzeitigen Verfolgen mehrerer Gegenspieler) erkannt werden kann. References: Fehd, H. M. & Seiffert, A. E. (2010). Looking at the center of the targets helps multiple object tracking. Journal of Vision, 10, 1–13.

Funktionalität peripherer Wahrnehmung bei Trackingaufgaben

Schlüsselwörter: Multiple-Object-Tracking, Sakkadenlatenz, Erkennungsleistung Einleitung Beim Multiple-Object-Tracking müssen mehrere, sich bewegende Zielobjekte visuell ver-folgt werden. Dabei scheint es vorteilhaft zu sein, den Blick zwischen den Zielobjekten zu verankern, um Bewegungsinformationen peripher wahrzunehmen (Fehd & Seiffert, 2010). Nach Prüfung dieser Annahme (Experiment 1) wurde getestet, wie gut und schnell auf Bewegungs- und Formveränderungen der Zielobjekte reagiert werden kann (Experiment 2), um die Funktionalität der peripheren Wahrnehmung zu überprüfen Methode 14 Teilnehmer hatten die Aufgabe, zum Ende eines Einzelversuchs 4 aus 10 Vierecken wiederzuerkennen, die sich linear für 6 s in einem projizierten Quadrat bewegten. Dabei wurden 3 Geschwindigkeiten (6, 9 und 12°/s) in 9 Blöcken à 15 Versuchen präsentiert, um die Ergebnisse von Fehd und Seiffert (2010) zu replizieren. In Experiment 2 sollten Teilnehmer auf das Anhalten eines Targets oder dessen Formveränderung zur Raute (Manipulation: 0.5 s) mit Knopfdruck reagieren, bei ausbleibender Veränderung hinge-gen die 4 Zielobjekte wiedererkennen (3 Bedingungen in 10 Blöcken à 12 Versuchen). Erwartet wurde, dass Bewegungsveränderungen häufiger und schneller erkannt werden. Ergebnisse Experiment 1 ergab einen signifikanten Haupteffekt für Geschwindigkeit, F(2,26) = 62.66, p < .01, ηp2 = .83, mit höchsten Richtigkeiten bei 6°/s (58%). Ein Haupteffekt für Blickort, F(2,26) = 76.40, p < .01, ηp2 = .85, zeigt, dass der Blick unabhängig von der Geschwindig-keit länger auf dem Centroid war als auf Targets und Distraktoren. Aufgrund der höchs-ten Richtigkeiten bei 6°/s wurde diese Geschwindigkeit in Experiment 2 eingesetzt und festgestellt, dass Bewegungsveränderungen häufiger erkannt werden (83 %) als Form-veränderungen (59 %), F(1,10) = 17.20, p < .01, ηp2 = .63. Unterschiede in Sakkadenla-tenzen, F(1,10) = 6.73, p = .03, ηp2 = .40, deuten auf eine periphere Wahrnehmung der Bewegungsveränderungen hin. Experiment 3 wird zeigen, ob Sakkaden das Monitoring stören. Diskussion Die periphere Wahrnehmung scheint immer dann funktional zu sein, wenn mehrere, für eine Aufgabe relevante Objekte gleichzeitig verfolgt werden müssen und wenn Verände-rungen, besonders der Bewegung, schnell erkannt werden müssen. Weitere Untersu-chungen sollen zeigen, ob diese Funktionalität der peripheren Wahrnehmung auch im Sport (z.B. beim gleichzeitigen Verfolgen mehrerer Gegenspieler) erkannt werden kann. Literatur Fehd, H. M. & Seiffert, A. E. (2010). Looking at the center of the targets helps multiple object tracking. Journal of Vision, 10, 1–13.

Pangea: A Workbench for Statically Analyzing Multi-Language Software Corpora

Software corpora facilitate reproducibility of analyses, however, static analysis for an entire corpus still requires considerable effort, often duplicated unnecessarily by multiple users. Moreover, most corpora are designed for single languages increasing the effort for cross-language analysis. To address these aspects we propose Pangea, an infrastructure allowing fast development of static analyses on multi-language corpora. Pangea uses language-independent meta-models stored as object model snapshots that can be directly loaded into memory and queried without any parsing overhead. To reduce the effort of performing static analyses, Pangea provides out-of-the box support for: creating and refining analyses in a dedicated environment, deploying an analysis on an entire corpus, using a runner that supports parallel execution, and exporting results in various formats. In this tool demonstration we introduce Pangea and provide several usage scenarios that illustrate how it reduces the cost of analysis.

The Moldable Inspector: a framework for domain-specific object inspection

Answering run-time questions in object-oriented systems involves reasoning about and exploring connections between multiple objects. Developer questions exercise various aspects of an object and require multiple kinds of interactions depending on the relationships between objects, the application domain and the differing developer needs. Nevertheless, traditional object inspectors, the essential tools often used to reason about objects, favor a generic view that focuses on the low-level details of the state of individual objects. This leads to an inefficient effort, increasing the time spent in the inspector. To improve the inspection process, we propose the Moldable Inspector, a novel approach for an extensible object inspector. The Moldable Inspector allows developers to look at objects using multiple interchangeable presentations and supports a workflow in which multiple levels of connecting objects can be seen together. Both these aspects can be tailored to the domain of the objects and the question at hand. We further exemplify how the proposed solution improves the inspection process, introduce a prototype implementation and discuss new directions for extending the Moldable Inspector.

Detecting single-target changes in multiple object tracking: The case of peripheral vision.

In sports games, it is often necessary to perceive a large number of moving objects (e.g., the ball and players). In this context, the role of peripheral vision for processing motion information in the periphery is often discussed especially when motor responses are required. In an attempt to test the basal functionality of peripheral vision in those sports-games situations, a Multiple Object Tracking (MOT) task that requires to track a certain number of targets amidst distractors, was chosen. Participants’ primary task was to recall four targets (out of 10 rectangular stimuli) after six seconds of quasi-random motion. As a second task, a button had to be pressed if a target change occurred (Exp 1: stop vs. form change to a diamond for 0.5 s; Exp 2: stop vs. slowdown for 0.5 s). While eccentricities of changes (5-10° vs. 15-20°) were manipulated, decision accuracy (recall and button press correct), motor response time as well as saccadic reaction time were calculated as dependent variables. Results show that participants indeed used peripheral vision to detect changes, because either no or very late saccades to the changed target were executed in correct trials. Moreover, a saccade was more often executed when eccentricities were small. Response accuracies were higher and response times were lower in the stop conditions of both experiments while larger eccentricities led to higher response times in all conditions. Summing up, it could be shown that monitoring targets and detecting changes can be processed by peripheral vision only and that a monitoring strategy on the basis of peripheral vision may be the optimal one as saccades may be afflicted with certain costs. Further research is planned to address the question whether this functionality is also evident in sports tasks.

Detecting single-target changes in multiple object tracking: The case of peripheral vision

In sports games, it is often necessary to perceive a large number of moving objects (e.g., the ball and players). In this context, the role of peripheral vision for processing motion information in the periphery is often discussed especially when motor responses are required. In an attempt to test the capability of using peripheral vision in those sports-games situations, a Multiple-Object-Tracking task that requires to track a certain number of targets amidst distractors, was chosen to determine the sensitivity of detecting target changes with peripheral vision only. Participants’ primary task was to recall four targets (out of 10 rectangular stimuli) after six seconds of quasi-random motion. As a second task, a button had to be pressed if a target change occurred (Exp 1: stop vs. form change to a diamond for 0.5 s; Exp 2: stop vs. slowdown for 0.5 s). Eccentricities of changes (5-10° vs. 15-20°) were manipulated, decision accuracy (recall and button press correct), motor response time and saccadic reaction time (change onset to saccade onset) were calculated and eye-movements were recorded. Results show that participants indeed used peripheral vision to detect changes, because either no or very late saccades to the changed target were executed in correct trials. Moreover, a saccade was more often executed when eccentricities were small. Response accuracies were higher and response times were lower in the stop conditions of both experiments while larger eccentricities led to higher response times in all conditions. Summing up, it could be shown that monitoring targets and detecting changes can be processed by peripheral vision only and that a monitoring strategy on the basis of peripheral vision may be the optimal one as saccades may be afflicted with certain costs. Further research is planned to address the question whether this functionality is also evident in sports tasks.