How residual stresses affect the fracture properties of layered thin films

The continued miniaturization effort has revealed exciting new material behavior at small length scales, where pronounced size effects come into play and material properties are subject to change. This has led to the development of miniaturized testing techniques to determine local plastic properties. So far, however, only few efforts regarding the determination of residual stresses and fracture properties in miniaturized systems were made. In this presentation, we will focus on recent developments regarding the measurement of residual stresses and miniaturized fracture properties using FIB based sample preparation and in situ SEM experiments. The depth resolved residual film stresses are determined by an improved stepwise beam layer removal method [1]. From the same film systems, beams are FIB fabricated for miniaturized fracture testing in the SEM [2]. We will discuss the general possibilities, challenges, and benefits of these approaches by examining the internal stresses and fracture properties of single layer and multilayer thin films in the immiscible system Cu-W. Particular emphasis is placed on the effect of residual stresses on the fracture properties. Moreover, possible limitations of commonly used data analysis approaches are addressed, and related improvements using finite element modelling to determine crack-driving forces in the presence of interfaces and residual stresses are presented [3]. Notably, the required material input data in terms of flow behavior for this modeling approach was determined using spherical nanoindentation experiments on single and multilayer films. Finally, the possibility of further miniaturization of such experiments by using in situ TEM is demonstrated [4]

How do dispersal costs and habitat selection influence realized population connectivity?

Despite the importance of dispersal for population connectivity, dispersal is often costly to the individual. A major impediment to understanding connectivity has been a lack of data combining the movement of individuals and their survival to reproduction in the new habitat (realized connectivity). Although mortality often occurs during dispersal (an immediate cost), in many organisms costs are paid after dispersal (deferred costs). It is unclear how such deferred costs influence the mismatch between dispersal and realized connectivity. Through a series of experiments in the field and laboratory, we estimated both direct and indirect deferred costs in a marine bryozoan (Bugula neritina). We then used the empirical data to parameterize a theoretical model in order to formalize predictions about how dispersal costs influence realized connectivity. Individuals were more likely to colonize poor-quality habitat after prolonged dispersal durations. Individuals that colonized poor-quality habitat performed poorly after colonization because of some property of the habitat (an indirect deferred cost) rather than from prolonged dispersal per se (a direct deferred cost). Our theoretical model predicted that indirect deferred costs could result in nonlinear mismatches between spatial patterns of potential and realized connectivity. The deferred costs of dispersal are likely to be crucial for determining how well patterns of dispersal reflect realized connectivity. Ignoring these deferred costs could lead to inaccurate predictions of spatial population dynamics

Geographic information systems in epidemiology – ecology of common vole and distribution of natural foci of tularaemia

KORMAP geographic information system (GIS) was used to analyse the distribution and selected environmental factors related to population levels of Microtus arvalis (a potential reservoir host of F. tularensis) in the Czech Republic and the relation between M. arvalis populations and natural foci of tularaemia in the European hare. Maximum population levels of M. arvalis were in areas from 200 to 399 m above sea, of 40 to 60 days of snow cover annually and of 10 °C of mean annual air temperature. Warm and moderately warm climatic regions differed in the mean M. arvalis population level with high statistical significance (t = 4.97, P = 0.01). M. arvalis did not occur in the cold climatic region and areas of less than 4 °C of mean annual air temperature. The highest and lowest population densities were found in geographic areas of 1800 to 2000 h and up to 1600 h of annual sunshine duration, respectively. M. arvalis population density correlates with high statistical significance with the elevation above sea, annual sunshine duration and mean annual air temperature. It was, however, found that there is no correlation between M. arvalis levels and numbers of natural foci of tularaemia in the European hare (r = 0.0765, n = 396, t = 1.5228). In other words, tularaemia seems to be independent of M. arvalis population density. GIS are suitable for the State Veterinary Administration and they are becoming part of decision-making as knowledge on the geographical aspects of diseases including the distribution of reservoir hosts is essential for disease control. Microtus arvalis, geography of occurrence, population levels, environmental factors, Czech Republic, tularaemi

Operationalizing ecological connectivity in spatial conservation planning with Marxan Connect

1. Globally, protected areas are being established to protect biodiversity and to promote ecosystem resilience. The typical spatial conservation planning process leading to the creation of these protected areas focuses on representation and replication of ecological features, often using decision support tools such as Marxan. Yet, despite the important role ecological connectivity has in metapopulation persistence and resilience, Marxan currently requires manual input or specialized scripts to explicitly consider connectivity. 2. ‘Marxan Connect’ is a new open source, open access Graphical User Interface (GUI) tool designed to assist conservation planners with the appropriate use of data on ecological connectivity in protected area network planning. 3. Marxan Connect can facilitate the use of estimates of demographic connectivity (e.g. derived from animal tracking data, dispersal models, or genetic tools) or structural landscape connectivity (e.g. isolation by resistance). This is accomplished by calculating metapopulation‐relevant connectivity metrics (e.g. eigenvector centrality) and treating those as conservation features or by including the connectivity data as a spatial dependency amongst sites in the prioritization process. 4. Marxan Connect allows a wide group of users to incorporate directional ecological connectivity into conservation planning with Marxan. The solutions provided by Marxan Connect, combined with ecologically relevant post‐hoc testing, are more likely to support persistent and resilient metapopulations (e.g. fish stocks) and provide better protection for biodiversity

The Scope of Published Population Genetic Data for Indo-Pacific Marine Fauna and Future Research Opportunities in the Region

Marine biodiversity reaches its pinnacle in the tropical Indo-Pacific region, with high levels of both species richness and endemism, especially in coral reef habitats. While this pattern of biodiversity has been known to biogeographers for centuries, causal mechanisms remain enigmatic. Over the past 20 yrs, genetic markers have been employed by many researchers as a tool to elucidate patterns of biodiversity above and below the species level, as well as to make inferences about the underlying processes of diversification, demographic history, and dispersal. In a quantitative, comparative framework, these data can be synthesized to address questions about this bewildering diversity by treating species as “replicates.” However, the sheer size of the Indo-Pacific region means that the geographic and genetic scope of many species’ data sets are not complementary. Here, we describe data sets from 116 Indo-Pacific species (108 studies). With a mind to future synthetic investigations, we consider the strengths and omissions of currently published population genetic data for marine fauna of the Indo-Pacific region, as well as the geographic and taxonomic scope of the data, and suggest some ways forward for data collection and collation

Geographic Information Systems in Epidemiology – Ecology of Common Vole and Distribution of Natural Foci of Tularaemia

KORMAP geographic information system (GIS) was used to analyse the distribution and selected environmental factors related to population levels of Microtus arvalis (a potential reservoir host of F. tularensis) in the Czech Republic and the relation between M. arvalis populations and natural foci of tularaemia in the European hare. Maximum population levels of M. arvalis were in areas from 200 to 399 m above sea, of 40 to 60 days of snow cover annually and of 10 °C of mean annual air temperature. Warm and moderately warm climatic regions differed in the mean M. arvalis population level with high statistical significance (t = 4.97, P = 0.01). M. arvalis did not occur in the cold climatic region and areas of less than 4 °C of mean annual air temperature. The highest and lowest population densities were found in geographic areas of 1800 to 2000 h and up to 1600 h of annual sunshine duration, respectively. M. arvalis population density correlates with high statistical significance with the elevation above sea, annual sunshine duration and mean annual air temperature. It was, however, found that there is no correlation between M. arvalis levels and numbers of natural foci of tularaemia in the European hare (r = 0.0765, n = 396, t = 1.5228). In other words, tularaemia seems to be independent of M. arvalis population density. GIS are suitable for the State Veterinary Administration and they are becoming part of decision-making as knowledge on the geographical aspects of diseases including the distribution of reservoir hosts is essential for disease control. Microtus arvalis, geography of occurrence, population levels, environmental factors, Czech Republic, tularaemi

Primer development for detection of Phaseolus vulgaris and Olathe transgenic bean.

Several strategies have been employed for genetically engineering resistance to viruses in transgenic plants. The bean golden mosaic virus (BGMV) is responsible for causing the gold mosaic of common bean (Phaseolus vulgaris L.) and causes severe yield losses due to yellow-green mosaic of leaves, stunted growth and distorted pods. Olathe transgenic bean (Olathe 5.1) was successfully produced by EMBRAPA using the RNA interference (RNAi) concept to silence the rep viral gene in common bean to generate transgenic lines with strong resistance to BGMV. In this work, real time PCR (RT-PCR) method with SYBR Green was developed to detect this newly genetically modified (GM) plant

The DNA of coral reef biodiversity: predicting and protecting genetic diversity of reef assemblages

Conservation of ecological communities requires deepening our understanding of genetic diversity patterns and drivers at community-wide scales. Here, we use seascape genetic analysis of a diversity metric, allelic richness (AR), for 47 reef species sampled across 13 Hawaiian Islands to empirically demonstrate that large reefs high in coral cover harbour the greatest genetic diversity on average. We found that a species’s life history (e.g. depth range and herbivory) mediates response of genetic diversity to seascape drivers in logical ways. Furthermore, a metric of combined multi-species AR showed strong coupling to species richness and habitat area, quality and stability that few species showed individually. We hypothesize that macro-ecological forces and species interactions, by mediating species turnover and occupancy (and thus a site’s mean effective population size), influence the aggregate genetic diversity of a site, potentially allowing it to behave as an apparent emergent trait that is shaped by the dominant seascape drivers. The results highlight inherent feedbacks between ecology and genetics, raise concern that genetic resilience of entire reef communities is compromised by factors that reduce coral cover or available habitat, including thermal stress, and provide a foundation for new strategies for monitoring and preserving biodiversity of entire reef ecosystems