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Optimal Systematic Distributed Storage Codes with Fast Encoding  [PDF]
Preetum Nakkiran,K. V. Rashmi,Kannan Ramchandran
Computer Science , 2015,
Abstract: Erasure codes are being increasingly used in distributed-storage systems in place of data-replication, since they provide the same level of reliability with much lower storage overhead. We consider the problem of constructing explicit erasure codes for distributed storage with the following desirable properties motivated by practice: (i) Maximum-Distance-Separable (MDS): to provide maximal reliability at minimum storage overhead, (ii) Optimal repair-bandwidth: to minimize the amount of data needed to be transferred to repair a failed node from remaining ones, (iii) Flexibility in repair: to allow maximal flexibility in selecting subset of nodes to use for repair, which includes not requiring that all surviving nodes be used for repair, (iv) Systematic Form: to ensure that the original data exists in uncoded form, and (v) Fast encoding: to minimize the cost of generating encoded data (enabled by a sparse generator matrix). This paper presents the first explicit code construction which theoretically guarantees all the five desired properties simultaneously. Our construction builds on a powerful class of codes called Product-Matrix (PM) codes. PM codes satisfy properties (i)-(iii), and either (iv) or (v), but not both simultaneously. Indeed, native PM codes have inherent structure that leads to sparsity, but this structure is destroyed when the codes are made systematic. We first present an analytical framework for understanding the interaction between the design of PM codes and the systematic property. Using this framework, we provide an explicit code construction that simultaneously achieves all the above desired properties. We also present general ways of transforming existing storage and repair optimal codes to enable fast encoding through sparsity. In practice, such sparse codes result in encoding speedup by a factor of about 4 for typical parameters.
Systematic conservation planning and adaptive management  [cached]
Stephen D. Holness,Harry C. Biggs
Koedoe : African Protected Area Conservation and Science , 2011, DOI: 10.4102/koedoe.v53i2.1029
Abstract: This article argues that systematic conservation planning (SCP) is an intrinsic part of the adaptive management approach within SANParks and should not be seen as a separate or different initiative. SCP operates within a complex environment that requires a deliberately adaptive approach. The similarities in philosophy, structure and functional elements of the planning process and approach between adaptive management and SCP, as applied within SANParks, are highlighted. The article distils requirements for ensuring that SCP remains strategically adaptive in its approach. Conservation implication: A deliberately adaptive approach to SCP improves its effectiveness in guiding the implementation of conservation actions and is a requirement for effective conservation planning in a complex environment. How to cite this article: Holness, S.D. & Biggs, H.C., 2011, ‘Systematic conservation planning and adaptive management’, Koedoe 53(2), Art. #1029, 9 pages. doi:10.4102/koedoe.v53i2.1029
The Trajectory of Dispersal Research in Conservation Biology. Systematic Review  [PDF]
Don A. Driscoll, Sam C. Banks, Philip S. Barton, Karen Ikin, Pia Lentini, David B. Lindenmayer, Annabel L. Smith, Laurence E. Berry, Emma L. Burns, Amanda Edworthy, Maldwyn J. Evans, Rebecca Gibson, Rob Heinsohn, Brett Howland, Geoff Kay, Nicola Munro, Ben C. Scheele, Ingrid Stirnemann, Dejan Stojanovic, Nici Sweaney, Nélida R. Villase?or, Martin J. Westgate
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0095053
Abstract: Dispersal knowledge is essential for conservation management, and demand is growing. But are we accumulating dispersal knowledge at a pace that can meet the demand? To answer this question we tested for changes in dispersal data collection and use over time. Our systematic review of 655 conservation-related publications compared five topics: climate change, habitat restoration, population viability analysis, land planning (systematic conservation planning) and invasive species. We analysed temporal changes in the: (i) questions asked by dispersal-related research; (ii) methods used to study dispersal; (iii) the quality of dispersal data; (iv) extent that dispersal knowledge is lacking, and; (v) likely consequences of limited dispersal knowledge. Research questions have changed little over time; the same problems examined in the 1990s are still being addressed. The most common methods used to study dispersal were occupancy data, expert opinion and modelling, which often provided indirect, low quality information about dispersal. Although use of genetics for estimating dispersal has increased, new ecological and genetic methods for measuring dispersal are not yet widely adopted. Almost half of the papers identified knowledge gaps related to dispersal. Limited dispersal knowledge often made it impossible to discover ecological processes or compromised conservation outcomes. The quality of dispersal data used in climate change research has increased since the 1990s. In comparison, restoration ecology inadequately addresses large-scale process, whilst the gap between knowledge accumulation and growth in applications may be increasing in land planning. To overcome apparent stagnation in collection and use of dispersal knowledge, researchers need to: (i) improve the quality of available data using new approaches; (ii) understand the complementarities of different methods and; (iii) define the value of different kinds of dispersal information for supporting management decisions. Ambitious, multi-disciplinary research programs studying many species are critical for advancing dispersal research.
A synecological framework for systematic conservation planning  [cached]
Joaquín Hortal,Jorge M Lobo
Biodiversity Informatics , 2006,
Abstract: Biodiversity conservation design, though difficult with fragmentary or insufficient biological data, can be planned and evaluated with several methods. One of them, the complementarity criterion, is commonly used nowadays to deal with the distribution of number of species (i.e., an autoecological approach). At the same time, the patchiness and spatial bias of available distribution data has also been dealt with through distribution modelling. However, both the uncertainty of the ranges estimated, and the changes in species distribution in response to changing climates, limit single-species the biodiversity attribute to be used in complementarity strategies. Several technical and theoretical advantages of composite biodiversity variables (i.e., a synecological approach) may, however, make them ideal biodiversity indicators for conservation area selection. The drawbacks associated with current biodiversity data are discussed herein, along with the possible advantages and disadvantages of conservation planning through a synecological or autoecological approach.
Basil conservation affected by cropping season, harvest time and storage period
Silva, Franceli da;Santos, Ricardo Henrique Silva;Andrade, Nélio José de;Barbosa, Luiz Cláudio Almeida;Casali, Vicente Wagner Dias;Lima, Renato Ribeiro de;Passarinho, Ricardo Vaz de Melo;
Pesquisa Agropecuária Brasileira , 2005, DOI: 10.1590/S0100-204X2005000400002
Abstract: fresh basil (ocimum basilicum l.) is used in food, phytotherapic industry, and in traditional therapeutic, due to its essential oil content and composition. nevertheless basil can not be kept for long periods after harvest and its quality can be reduced. this work aimed to assess the influence of the season and harvest time in the postharvest conservation of basil stored for different periods. basil was harvested at 8 am and 4 pm both in august/1999 and january/2000. cuttings were conditioned in pvc packages and stored for 3, 6, and 9 days. during storage, chlorophyll content, essential oil content and composition were determined as well as microbiological analyses were carried out. harvest season and the days of storage influenced the final content of essential oil. there was a linear decrease in the content of essential oil, in the chlorophyll content and in the number of mold and yeast colonies during storage. there was no effect of cropping season or harvest hour on essential oil composition, but the eugenol and linalool content increased during storage. coliforms were under 0.3 mpn g-1 and the number of staphylococcus aureus was under 1.0x102 ufc g-1.
Studies of systematic limitations in the EDM searches at storage rings  [PDF]
Artem Saleev,Nikolai Nikolaev,Frank Rathmann
Physics , 2015,
Abstract: Searches of the electric dipole moment (EDM) at a pure magnetic ring, like COSY, encounter strong background coming from magnetic dipole moment (MDM). The most troubling issue is the MDM spin rotation in the so-called imperfection, radial and longitudinal, B-fields. To study the systematic effects of the imperfection fields at COSY we proposed the original method which makes use of the two static solenoids acting as artificial imperfections. Perturbation of the spin tune caused by the spin kicks in the solenoids probes the systematic effect of cumulative spin rotation in the imperfection fields all over the ring. The spin tune is one of the most precise quantities measured presently at COSY at $10^{-10}$ level. The method has been successfully tested in September 2014 run at COSY, unravelling strength of spin kicks in the ring's imperfection fields at the level of $10^{-3} rad$.
Stepanenko D. S.,Tarusova N. V.,Gogunska P. V.
Bìologì?nij Vìsnik Melìtopol?s?kogo Der?avnogo Pedagogì?nogo Universitetu ìmenì Bogdana Hmel?nic?kogo , 2011,
Abstract: The article devoted to the problem of conservation by means of ecologically
Possible Systematic Effects in Fomblin Coated Storage Cell Neutron Lifetime Measurements  [PDF]
Steve K. Lamoreaux
Physics , 2006,
Abstract: A new neutron lifetime experiment employing frozen Fomblin has produced a result in significant disagreement with previous experiments that used liquid Fomblin near room temperature. This new experiment is subject to very few corrections, so the source of the discrepancy is a mystery. Here we theoretically investigate several possible systematic effects for near-room-temperature storage experiments. By considering the combined effect of gravity with the usual ultracold neutron losses together with surface wave scattering loss and ultracold spectral evoltuion, a correction to a previous neutron lifetime experiment is found to be insignificantly small.
Selecting Focal Songbird Species for Biodiversity Conservation Assessment: Response to Forest Cover Amount and Configuration  [cached]
Robert S. Rempel
Avian Conservation and Ecology , 2007,
Abstract: Conservation of biodiversity is now a firmly entrenched objective of sustainable forest management, and emulating natural disturbance has been widely adopted as a conservation strategy. Yet the foundation for this approach is still very much a hypothesis based on first principles, and there has been little rigorous testing of the approach. In addition, practical constraints mean that the full range and character of natural patterns can never be implemented, so decisions must still be made in setting forest management targets and levels. An alternative, but complementary approach is to select a focal group of species and use their habitat requirements to define the range of conditions that should be maintained on the landscape. In this study, I used a balanced factorial sample design to test the effect of landscape vs. local scale factors for explaining relative abundance of 30 forest songbird species in boreal Ontario, and then examined components of variance, and used multivariate analysis and logistic regression to describe these relationships in more detail. Based on statistically defendable inferences and habitat model coefficients, 13 species were selected, with habitat associations ranging from high to low edge density, homogeneous to heterogeneous forest matrix, hardwood to softwood dominated overstory, young to old stands, and open to closed canopy. I found that variations in amount and configuration of mature forest cover had relatively little influence on the overall boreal forest songbird community, but that individual species differ in their response to these variables. To be successful, biodiversity conservation strategies must emulate the patterns created through natural disturbance by maintaining the full range of forest cover homogeneity and heterogeneity on the landscape. The habitat requirements for Alder Flycatcher, Black-and-white Warbler, Bay-breasted Warbler, Blackburnian Warbler, Brown Creeper, Common Yellowthroat, Chestnut-sided Warbler, Least Flycatcher, Ovenbird, Red-breasted Nuthatch, Red-eyed Vireo, Winter Wren, and White-throated Sparrow describe a broad range of habitat conditions that, at a minimum, describe necessary coarse-filter conditions to sustain the boreal songbird community in Ontario. This suite of species can also serve in developing a "bioassay" to evaluate the effectiveness of forest policy to conserve biodiversity through emulation of natural disturbance.
Endangered TCM Resources: Systematic Appraisal and Conservation

Yan Zhifeng,Zhang Bengang,Chen Shilin,Zhang Zhao,

世界科学技术-中医药现代化 , 2006,
Abstract: The paper discusses the status quo of the endangered medicinal plants in China, and associated research efforts. To protect the resources of traditional Chinese medicines, and advocate for a sustainable utilization, a Systematic Appraisal and Conservation Framework is proposed, with insights, methods, and appraisal indicators.
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