Accelerated sea level rise and coastal vulnerability in the Hersonisos coastal region (Crete, Greece)

The IPCC predictions for climate changes in the 21st century assess sea level rise from 5 to 10mm/year due to the Greenhouse effect. We have already entered a period of accelerated temperature and sea level rise and one of the most important impacts of these changes is the severe erosion of the coastal areas. According to Bruun rule, a sea level rise of 1cm induces a coastal retreat of (approximately) 1m in low-lying coastal areas. Taking into consideration the inundation concept, the historical retreat and the Bruun erosion model, the assessment of the coastal setback comes nearer to the response of nature due to climate changes. In the coastal region of the Hersonissos in Crete, Greece and for 21km of its shoreline, the impacts of the above models are considered in order to assess the vulnerability due to the Greenhouse effect. The results are impressive and estimate a coastal retreat of more than 280m up to the end of the century, posing a threat to the coastal infrastructure. In view of the results, decisions and measures should be considered without delay

Towards a national adaptation strategy in view of climate changes

The continuously increasing emissions of CO2 and Methane result in the enhanced greenhouse effect. The IPCC assessments for the 21st century refer to a 3oC increase in temperature and 50 cm rise in sea level on average. It is therefore understood that every nation must create a National Adaptation Strategy to face the impacts of the forthcoming climate changes. For Greece, an adaptation plan should include:The vulnerability index of the coastal regions according to the national development plan.The determination of the procedures towards adaptation in view of climate changes.The determination of the national criteria to face extreme phenomena due to anthropogenic climate changes.The technical and legal action plans.The responsibility of the various public sectors to overcome gaps or overlaps in the actions to mitigate the impact andThe general national adaptation principles.The presentation analyses all the above concepts and proposes specific guidelines to formulate a Greek National Adaptation Strategy to mitigate the impacts of anthropogenic climate changes

Selective BRDFs for High Fidelity Rendering

High fidelity rendering systems rely on accurate material representations to produce a realistic visual appearance. However, these accurate models can be slow to evaluate. This work presents an approach for approximating these high accuracy reflectance models with faster, less complicated functions in regions of an image which possess low visual importance. A subjective rating experiment was conducted in which thirty participants were asked to assess the similarity of scenes rendered with low quality reflectance models, a high quality data-driven model and saliency based hybrids of those images. In two out of the three scenes that were evaluated significant differences were not found between the hybrid and reference images. This implies that in less visually salient regions of an image computational gains can be achieved by approximating computationally expensive materials with simpler analytic models

Audio-visual-olfactory resource allocation for tri-modal virtual environments

© 2019 IEEE. Virtual Environments (VEs) provide the opportunity to simulate a wide range of applications, from training to entertainment, in a safe and controlled manner. For applications which require realistic representations of real world environments, the VEs need to provide multiple, physically accurate sensory stimuli. However, simulating all the senses that comprise the human sensory system (HSS) is a task that requires significant computational resources. Since it is intractable to deliver all senses at the highest quality, we propose a resource distribution scheme in order to achieve an optimal perceptual experience within the given computational budgets. This paper investigates resource balancing for multi-modal scenarios composed of aural, visual and olfactory stimuli. Three experimental studies were conducted. The first experiment identified perceptual boundaries for olfactory computation. In the second experiment, participants (N=25) were asked, across a fixed number of budgets (M=5), to identify what they perceived to be the best visual, acoustic and olfactory stimulus quality for a given computational budget. Results demonstrate that participants tend to prioritize visual quality compared to other sensory stimuli. However, as the budget size is increased, users prefer a balanced distribution of resources with an increased preference for having smell impulses in the VE. Based on the collected data, a quality prediction model is proposed and its accuracy is validated against previously unused budgets and an untested scenario in a third and final experiment

A Calibrated Olfactory Display for High Fidelity Virtual Environments

Olfactory displays provide a means to reproduce olfactory stimuli for use in virtual environments. Many of the designs produced by researchers, strive to provide stimuli quickly to users and focus on improving usability and portability, yet concentrate less on providing high levels of accuracy to improve the fidelity of odour delivery. This paper provides the guidance to build a reproducible and low cost olfactory display which is able to provide odours to users in a virtual environment at accurate concentration levels that are typical in everyday interactions; this includes ranges of concentration below parts per million and into parts per billion. This paper investigates build concerns of the olfactometer and its proper calibration in order to ensure concentration accuracy of the device. An analysis is provided on the recovery rates of a specific compound after excitation. This analysis provides insight into how this result can be generalisable to the recovery rates of any volatile organic compound, given knowledge of the specific vapour pressure of the compound

Population aggregation analysis of three caviar-producing species of sturgeons and implications for the species identification of black caviar.

Abstract: We describe a reliable method for the identification of the species source for caviar. The assay is based on the identification of diagnostic nucleotide positions in the mitochondrial Análisis de Agregación de Poblaciones de Tres Especies de Esturiones Productoras de Caviar y sus Implicaciones en la Identificación de Especies de Caviar Negro Resumen: Describimos un método confiable para la identificación de las especies fuente de caviar. La prueba se basa en la identificación de posiciones diagnóstico de nucleótidos en el gen citocromo b de una base de datos de secuencias de 20 de las 25 especies de esturiones vivientes. La colección de datos se basa en PCR y puede identificar fácilmente los estados de diversas posiciones diagnóstico de nucleótidos del gen citocromo b de las tres especies comerciales de esturiones mas importantes productoras de caviar

Research Tools to Investigate Movements, Migrations, and Life History of Sturgeons (Acipenseridae), with an Emphasis on Marine-Oriented Populations

Worldwide, sturgeons (Acipenseridae) are among the most endangered fishes due to habitat degradation, overfishing, and inherent life history characteristics (long life span, late maturation, and infrequent spawning). As most sturgeons are anadromous, a considerable portion of their life history occurs in estuarine and marine environments where they may encounter unique threats (e.g., interception in non-target fisheries). Of the 16 marine-oriented species, 12 are designated as Critically Endangered by the IUCN, and these include species commercially harvested. We review important research tools and techniques (tagging, electronic tagging, genetics, microchemistry, observatory) and discuss the comparative utility of these techniques to investigate movements, migrations, and life-history characteristics of sturgeons. Examples are provided regarding what the applications have revealed regarding movement and migration and how this information can be used for conservation and management. Through studies that include Gulf (Acipenser oxyrinchus desotoi) and Green Sturgeon (A. medirostris), we illustrate what is known about well-studied species and then explore lesser-studied species. A more complete picture of migration is available for North American sturgeon species, while European and Asian species, which are among the most endangered sturgeons, are less understood. We put forth recommendations that encourage the support of stewardship initiatives to build awareness and provide key information for population assessment and monitoring

Research Tools to Investigate Movements, Migrations, and Life History of Sturgeons (Acipenseridae), with an Emphasis on Marine-Oriented Populations

Worldwide, sturgeons (Acipenseridae) are among the most endangered fishes due to habitat degradation, overfishing, and inherent life history characteristics (long life span, late maturation, and infrequent spawning). As most sturgeons are anadromous, a considerable portion of their life history occurs in estuarine and marine environments where they may encounter unique threats (e.g., interception in non-target fisheries). Of the 16 marine-oriented species, 12 are designated as Critically Endangered by the IUCN, and these include species commercially harvested. We review important research tools and techniques (tagging, electronic tagging, genetics, microchemistry, observatory) and discuss the comparative utility of these techniques to investigate movements, migrations, and life-history characteristics of sturgeons. Examples are provided regarding what the applications have revealed regarding movement and migration and how this information can be used for conservation and management. Through studies that include Gulf (Acipenser oxyrinchus desotoi) and Green Sturgeon (A. medirostris), we illustrate what is known about well-studied species and then explore lesser-studied species. A more complete picture of migration is available for North American sturgeon species, while European and Asian species, which are among the most endangered sturgeons, are less understood. We put forth recommendations that encourage the support of stewardship initiatives to build awareness and provide key information for population assessment and monitoring

Population structure, connectivity, and demographic history of an apex marine predator, the bull shark <i>Carcharhinus leucas</i>

Knowledge of population structure, connectivity, and effective population size remains limited for many marine apex predators, including the bull shark Carcharhinus leucas. This large‐bodied coastal shark is distributed worldwide in warm temperate and tropical waters, and uses estuaries and rivers as nurseries. As an apex predator, the bull shark likely plays a vital ecological role within marine food webs, but is at risk due to inshore habitat degradation and various fishing pressures. We investigated the bull shark\u27s global population structure and demographic history by analyzing the genetic diversity of 370 individuals from 11 different locations using 25 microsatellite loci and three mitochondrial genes (CR, nd4, and cytb). Both types of markers revealed clustering between sharks from the Western Atlantic and those from the Western Pacific and the Western Indian Ocean, with no contemporary gene flow. Microsatellite data suggested low differentiation between the Western Indian Ocean and the Western Pacific, but substantial differentiation was found using mitochondrial DNA. Integrating information from both types of markers and using Bayesian computation with a random forest procedure (ABC‐RF), this discordance was found to be due to a complete lack of contemporary gene flow. High genetic connectivity was found both within the Western Indian Ocean and within the Western Pacific. In conclusion, these results suggest important structuring of bull shark populations globally with important gene flow occurring along coastlines, highlighting the need for management and conservation plans on regional scales rather than oceanic basin scale

The Dilemma of the Illegibility of State Visions: The Greek Coastal Legislation

In the last decades there has been an increasing concern about the nature and results of coastal dynamics, especially coastal erosion and its adverse effects on social and economic livelihoods. The impacts differ world wide not only in magnitude and frequency, but also in vulnerability of different coastal regions and populations which are related to the degree to which social structures have evolved. Depending on the local situation, different integrated coastal zone management approaches can be implemented. However, general issues, such as the notion of social equity, sustainability and setback lines have remained a cornerstone in most of these approaches. The Greek state visions regarding protection and development of its coastal areas have been “presented ” in the law 2971/2001. The law regulates the limits of the seashore and beach zones and related matters. Marginal issues on coastal protection have been abstractly taken into account which by no means can create an environmental friendly and sustainable coastal development. Development close to the sea and damage to natural dune system such as bulldozing dunes to improve sea views and sand extraction have created widespread coastal hazard problems. Many houses, properties and coastal infrastructure are now threatened b