Lightness of Munker-White illusion and Simultaneous-Contrast illusion: Establishing an ordinal lightness relation among minimum and split-frame presentations

The achromatic Munker-White illusion and the Simultaneous-Contrast illusion have been used extensively in vision studies to understand how the figural configuration of a stimulus can affect the perceived lightness of its components in human perception. Yet, previous modeling and psychophysics studies did not directly compare the illusions’ lightness with controlled parameters of minimum stripes and split-frame presentations, which are useful in testing model predictions and in correlating neural firings to final percept in electrophysiology. In our study, subjects performed lightness matching of the four minimum and split-frame presentations of the illusions. We found the lightness order from lightest to darkest to be statistically significant after normalization within each subject: SCB > MWW > SCW > MWB. This is to say that the lighter frame of Simultaneous Contrast (SCB) is lighter than the lighter frame of Munker-White (MWW), which is lighter than the darker frame of Simultaneous Contrast (SCW), which is still lighter than the darker frame of Munker-White (MWB)

Developing citizen science ecosystem:critical factors for quadruple helix stakeholders engagement

Purpose: The purpose of this paper is to provide answers regarding the factors that motivate or discourage the quadruple helix (QH) stakeholders and the wider public in citizen science (CS) activities. The research reveals a current overview of the perceptions, attitudes, concerns and motivation with regard to development of CS ecosystem in four countries: Greece, Lithuania, the Netherlands and Spain. Design/methodology/approach: The researchers deploy a mixed methodology, entailing an in-depth literature review and a large-scale quantitative survey (approximately 2,000 citizens) targeting QH stakeholders and general public from the local national ecosystems. The results contain both descriptive statistics and statistical analysis per country. After the comprehensive overview of drivers and barriers regarding the participation in CS activities in general, the focus is narrowed down on the engagement motivation of different QH stakeholders and the differences in enabling/hindering factors at the local ecosystems. Findings: Depending on the country and the pre-existing level of CS maturity, the results provide a complicated network of factors that unlock or block participation in CS activities. These factors include, to name a few, political maturity, civic engagement, technological infrastructures, economic growth, culture of stakeholder collaboration, psychological stimulus and surplus of resources. The implications of the findings necessitate the alignment of the envisioned CS ecosystem with the local dynamics in each country. Research limitations/implications: The quantitative nature of the survey method, limited sample size and only four countries context are noted as limitations of the study and offer future research potential for longitudinal settings and mixed-methods studies. Originality/value: The results contribute to the wider literature on CS that focuses on perspectives, possibilities and differences in local contexts with respect to the public engagement by developing CS ecosystem. At the same time, its added value lies in the overall practical proposition, and how the latter can effectively and efficiently attract and retain different stakeholder groups and citizens, under a collaborative approach.</p

Climate Change and Student Behavior: Recommendations for the University of Richmond

We, the Environmental Studies Senior Seminar Class of 2008, choose to recognize climate change as an imminent threat. After rigorous examination of the scientific, social, and political aspects of climate change, we initially wanted to help construct the carbon emissions inventory required in the PCC. However, citing their ability to build the inventory through existing University institutions, our administration steered us towards the Scope 3 emissions inventory, a component which focuses on student behavior. While we found Scope 3 too limiting, we decided our goal as a class was to impact student climate change awareness on campus. Therefore, we separated into three “working groups” and developed three distinct projects to meet our goal: 1) develop a database of projects and initiatives other universities have implemented to address climate change; 2) execute a comprehensive survey of the student body’s understanding of global climate change and energy consumption patterns and; 3) present the University of Richmond with options and recommendations for addressing climate change on campus. Our goal is to inspire individual responses to climate change. Raising awareness does not indicate everyone will or should agree with our beliefs and convictions, but it will enable individuals to come to their own conclusions. We wholeheartedly believe climate change is an issue we cannot disregard and we stand by the belief that the risk of doing nothing is the biggest danger of them all. Paper prepared for the Environmental Studies Senior Seminar Faculty Advisor: Dr. David Salisbur

Offsprings of a point vortex

The distribution engendered by successive splitting of one point vortex are considered. The process of splitting a vortex in three using a reverse three-point vortex collapse course is analysed in great details and shown to be dissipative. A simple process of successive splitting is then defined and the resulting vorticity distribution and vortex populations are analysed

Draft genome sequence of the plant-pathogenic soil fungus Rhizoctonia solani anastomosis group 3 strain Rhs1AP

The soil fungus Rhizoctonia solani is a pathogen of agricultural crops. Here, we report on the 51,705,945 bp draft consensus genome sequence of R. solani strain Rhs1AP. A comprehensive understanding of the heterokaryotic genome complexity and organization of R. solani may provide insight into the plant disease ecology and adaptive behavior of the fungus

RESTORATION WORKFLOWS BY MEANS OF PHOTOGRAMMETRY: THE CASE STUDY OF PASHAS BRIDGE

The restoration of cultural heritage sites is a complex and challenging process, particularly when the structure holds significant historical and cultural value. This paper refers to the first stages of the restoration study of Pashas Bridge, one of the largest stone bridges in Greece that was destroyed during World War II and further damaged by an earthquake in 1995. The project was assigned to multiple research groups from the Aristotle University of Thessaloniki (AUTh) for a period of 18 months by the Greek Ministry of Culture and Sports. To restore the bridge effectively, it is essential to accurately record, document, and assess its current condition. Through the use of photogrammetry, which creates 3D models of objects or structures using images, and unmanned aerial vehicles (UAVs) which assisted in capturing multiple shots with various angles of the bridge, a detailed 3D model of the bridge’s current condition was generated. In addition to these technical approaches, historical research and documentation were utilized to understand the bridge's cultural heritage value. The process included an examination of historical photographs and records related to the bridge, with a constant effort to discover additional information about its history and importance. Ultimately, the restoration process of Pashas Bridge serves as a valuable case study for the effective restoration of cultural heritage sites. Through utilizing these resources, the team aims to restore the bridge to its former glory, preserving its cultural heritage value and ensuring its place as a valuable and integral part of the community for generations to come

Motion of Three Vortices near Collapse

A system of three point vortices in an unbounded plane has a special family of self-similarly contracting or expanding solutions: during the motion, vortex triangle remains similar to the original one, while its area decreases (grows) at a constant rate. A contracting configuration brings three vortices to a single point in a finite time; this phenomenon known as vortex collapse is of principal importance for many-vortex systems. Dynamics of close-to-collapse vortex configurations depends on the way the collapse conditions are violated. Using an effective potential representation, a detailed quantitative analysis of all the different types of near-collapse dynamics is performed when two of the vortices are identical. We discuss time and length scales, emerging in the problem, and their behavior as the initial vortex triangle is approaching to an exact collapse configuration. Different types of critical behaviors, such as logarithmic or power-law divergences are exhibited, which emphasizes the importance of the way the collapse is approached. Period asymptotics for all singular cases are presented as functions of the initial vortices configurations. Special features of passive particle mixing by a near-collapse flows are illustrated numerically.Comment: 45 pages, 22 figures Last version of the paper with all update

Jets, Stickiness and Anomalous Transport

Dynamical and statistical properties of the vortex and passive particle advection in chaotic flows generated by four and sixteen point vortices are investigated. General transport properties of these flows are found anomalous and exhibit a superdiffusive behavior with typical second moment exponent (\mu \sim 1.75). The origin of this anomaly is traced back to the presence of coherent structures within the flow, the vortex cores and the region far from where vortices are located. In the vicinity of these regions stickiness is observed and the motion of tracers is quasi-ballistic. The chaotic nature of the underlying flow dictates the choice for thorough analysis of transport properties. Passive tracer motion is analyzed by measuring the mutual relative evolution of two nearby tracers. Some tracers travel in each other vicinity for relatively large times. This is related to an hidden order for the tracers which we call jets. Jets are localized and found in sticky regions. Their structure is analyzed and found to be formed of a nested sets of jets within jets. The analysis of the jet trapping time statistics shows a quantitative agreement with the observed transport exponent.Comment: 17 pages, 17 figure