Identifying tree populations for conservation action through geospatial analyses

Rapid development of information and communication technologies has made it possible to easily collect georeferenced information on species and their environment, and to use it for analyzing biological diversity, its distribution and threats to it. Such analyses can importantly inform development of conservation strategies and priorities, especially across countries or species distribution ranges (Guarino et al. 2002). Data for spatial analyses on species or genetic diversity and its distribution are collected in specifically designed studies, obtained from existing records of species occurrence, or both. Observations may be complemented by species distribution modelling, where the potential occurrence of a species is predicted based on its documented geographic distribution and climate in those areas. Results on the distribution of diversity, documented or modelled, can then be compared, for example, with existing protected areas, rates of forest degradation, threats of environmental changes, or socio-economic indicators, to identify priority tree populations and tailor strategies for their conservation and sustainable use (Pautasso 2009). In this paper recent case studies on spatial biodiversity analyses across the tropics are presented, demonstrating how such analyses can help to identify most unique or most threatened populations of a tree species for conservation actions. Insights on initiating collaborative research on diversity and distributions of important Asian tree species are also discussed

Genetic considerations in ecosystem restoration using native tree species. State of the World’s Forest Genetic Resources – Thematic Study.

There is renewed interest in the use of native tree species in ecosystem restoration for their biodiversity benefits. Growing native tree species in production systems (e.g. plantation forests and subsistence agriculture) can also ensure landscape functionality and support for human livelihoods. Achieving these full benefits requires consideration of genetic aspects that are often neglected, such as suitability of germplasm to the site, quality and quantity of the genetic pool used and regeneration potential. Understanding the extent and nature of gene flow across fragmented agro-ecosystems is also crucial to successful ecosystem restoration. We review the role of genetic considerations in a wide range of ecosystem restoration activities involving trees and evaluate how different approaches take, or could take, genetic aspects into account, leading towards the identification and selection of the most appropriate methods

P2P Media Streaming with HTML5 and WebRTC

Abstract-Video-on-demand (VoD) services, such as YouTube, generate most of the Internet traffic today, and the popularity of video services is growing. Service and CDN providers have to invest more and more in distribution networks, which creates pressure to innovate novel approaches. Peer-to-peer (P2P) streaming is a viable alternative that is scalable and can meet the increasing demand. The emerging HTML5 standard introduces APIs that give web browsers an ability to communicate directly with each other in real time. New standards also enable a setup, where browsers can act as P2P nodes. This paper reviews whether the new HTML5 and WebRTC standards are a fit for P2P video streaming, evaluates the performance challenges and proposes solutions. Preliminary analysis indicates that HTML5 can be applied to VoD, but there are concerns

Sustaining tropical timber trees in production forests of Asia - ensuring their genetic viability

Sustainable timber production in approximately 400 million hectares of production forests in the tropics would be enhanced by incorporating genetic conservation measures in their management. This factsheet, based on a scientific review, explains why tropical Asian timber species are particularly vulnerable to logging and habitat fragmentation and what policymakers and forest managers can do to maintain productivity and resilience of timber trees in Asian production forests

Effects of Transmitters and Amyloid-Beta Peptide on Calcium Signals in Rat Cortical Astrocytes: Fura-2AM Measurements and Stochastic Model Simulations

BACKGROUND: To better understand the complex molecular level interactions seen in the pathogenesis of Alzheimer's disease, the results of the wet-lab and clinical studies can be complemented by mathematical models. Astrocytes are known to become reactive in Alzheimer's disease and their ionic equilibrium can be disturbed by interaction of the released and accumulated transmitters, such as serotonin, and peptides, including amyloid- peptides (A). We have here studied the effects of small amounts of A25-35 fragments on the transmitter-induced calcium signals in astrocytes by Fura-2AM fluorescence measurements and running simulations of the detected calcium signals. METHODOLOGY/PRINCIPAL FINDINGS: Intracellular calcium signals were measured in cultured rat cortical astrocytes following additions of serotonin and glutamate, or either of these transmitters together with A25-35. A25-35 increased the number of astrocytes responding to glutamate and exceedingly increased the magnitude of the serotonin-induced calcium signals. In addition to A25-35-induced effects, the contribution of intracellular calcium stores to calcium signaling was tested. When using higher stimulus frequency, the subsequent calcium peaks after the initial peak were of lower amplitude. This may indicate inadequate filling of the intracellular calcium stores between the stimuli. In order to reproduce the experimental findings, a stochastic computational model was introduced. The model takes into account the major mechanisms known to be involved in calcium signaling in astrocytes. Model simulations confirm the principal experimental findings and show the variability typical for experimental measurements. CONCLUSIONS/SIGNIFICANCE: Nanomolar A25-35 alone does not cause persistent change in the basal level of calcium in astrocytes. However, even small amounts of A25-35, together with transmitters, can have substantial synergistic effects on intracellular calcium signals. Computational modeling further helps in understanding the mechanisms associated with intracellular calcium oscillations. Modeling the mechanisms is important, as astrocytes have an essential role in regulating the neuronal microenvironment of the central nervous system