Mvmotion: a metadata based virtual machine migration in cloud

As one of the most important features of virtualization, virtual machine (VM) migration provides great benefits for load balancing, resources-saving, fault tolerance in modern cloud data centers. Considering the network traffic caused by transferring data during VM migration imposes a huge pressure on network bandwidth of cloud data centers, and by analyzing the characteristic of the transferred data, we found that the redundant data, which is produced between two physical hosts by hosting virtual machines cloned from same VM template, can be reduced to relieve the network traffic pressure. This paper presents a Metadata based VM migration approach (Mvmotion) to reduce the amount of transferred data during migration by utilizing memory de-redundant technique between two physical hosts. Mvmotion utilizes the hash based fingerprints to generate Metadata of memory, which is used to identify redundant memory of VMs between two hosts. Based on the Metadata, the transfer of redundant memory data during migration can be eliminated. Experiment demonstrates that, compare to Xen’s default migration approach, Mvmotion can reduce the total transferred data by 29–97 %, and decreases the migration time by 16–53 %.     

Using the product environmental footprint for supply chain management: lessons learned from a case study on pork

Purpose

The purpose of this study was to test the chain-organization environmental footprint (chain-OEF) approach by applying it to part of a pork production chain in Belgium. The approach is supposed to provide insight into the environmental impact of a specific production chain in an efficient manner by applying pragmatic data collection throughout the chain. This is achieved by allocating the environmental impact of each of the production sites to the product of interest using straightforward allocation rules.

Methods

The cradle-to-gate (up to retail) environmental impact of pork was determined by life cycle assessment (LCA), in line with the product and organisation environmental footprint guidelines (PEF and OEF; European Commission 2013b). Foreground data was gathered at a feed production site, two farmers, a slaughterhouse and a meat processing site. All foreground operations are part of the same pork production chain in Belgium. The chain was completed using background data from Ecoinvent v3.01 (Wernet et al. 2016), Agri-Footprint v1.0 (Blonk 2014), European Life Cycle Database v3.0, LCA Food Database (Nielsen et al. 2003) and OEF Sector Rules Retail (Humbert et al. 2015b). The impact was quantified using the international reference life cycle data system (ILCD) midpoint method for 14 impact categories, but focussing on climate change.

Results and discussion

The total carbon footprint of the cradle-to-gate pork production system equals 0.46 kg CO₂-eq. (100 g pork)^?1. This result is quite similar to that of earlier studies analysing the pork production chain: 0.58 and 0.57 kg CO₂-eq. (100 g pork)^?1 (Bracquené et al. 2011, Agri-Footprint 2014). Most of the carbon footprint was caused by feed production and more specifically, by the feed ingredients and their transport. Grains, soy and palm oil have the largest impact contributions. The farms are responsible for most of the remaining impact. N₂O and CH₄ emissions are the largest cause of greenhouse gas emissions at the farms. Also, in the other 13 considered impact categories, feed production and farming are responsible for more than half of the total impact, mostly followed by meat processing.

Conclusions

Applying the chain-OEF approach in this study has shown that a chain LCA can be performed successfully and pragmatic data collection allows obtaining LCA results relatively fast, especially for small or medium-sized enterprises (SMEs). Whereas data availability was not such an issue, the main bottlenecks identified are data management and the link of LCA to other disciplines such as engineering, policy, etc. which could increase the added value of LCA studies.

     

Product environmental footprint of a cross-laminated timber system: a case study in Italy

Purpose

This study aims to apply the product environmental footprint (PEF) methodology to a wooden wall element, the Massiv–Holz–Mauer® (MHM), in an existing building in Northern Italy. The PEF is a multi-criteria measure of the environmental performance of products throughout their life cycle (European Commission 2013).

Methods

The environmental footprint of the MHM wall element was calculated for the impact categories required by the PEF, using a cradle-to-grave approach. Foreground data was collected at each life stage and completed using data from the Ecoinvent 3.1 database (Wernet et al. 2016). An additional analysis (optional according to the PEF methodology) was conducted for assessing the sustainability of forest management in the sites where wood is extracted from, using data from the forest management plan.

Results and discussion

The results show that, for most of the environmental indicators, the use phase has the highest environmental impact, followed by the production, end-of-life, raw material acquisition, and construction phases. These results depend on the different duration of the life cycle phases, and on the attribution of the total operational energy of the building to the structural components of the wall, though other factors, such as the efficiency of the heating system, may be responsible. Future PEF sectorial specification should specify how to account for the use phase of structural building components. For the majority of the impact categories, the impact is mainly due to processes that occur in the background system, such as production of capital goods and construction of facilities and storehouses. The wooden material production generates relatively low impacts, thanks to the fact that the wood is sourced locally and from forests where a close-to-nature forest management is adopted, characterized by natural regeneration without the use of fertilizers and pesticides.

Conclusions

This study shows that the PEF methodology can be successfully applied to a single wood supply chain, allowing the identification of the main hotspots and actions for reducing the environmental impacts. The PEF leaves space for additional environmental information, which, for some product categories, may play an important role. In the case of wood products, we suggest the inclusion of an assessment, even qualitative, of the sustainability of forest management.

     

A free energy based computational pathway from chemical templates to lead compounds: a case study of COX-2 inhibitors

Automation of lead compound design in silico given the structure of the protein target and a definition of its active site vies for the top of the wish list in any drug discovery programme. We present here an enumeration of steps starting from chemical templates and propose a solution at the state of the art, in the form of a system independent comprehensive computational pathway. This methodology is illustrated with cyclooxygenase-2 (COX-2) as a target. We built candidate molecules including a few Non Steroidal Anti-inflammatory Drugs (NSAIDs) from chemical templates, passed them through empirical filters to assess drug-like properties, optimized their geometries, derived partial atomic charges via quantum calculations, performed Monte Carlo docking, carried out molecular mechanics and developed free energy estimates with Molecular Mechanics Generalized Born Solvent Accessibility (MMGBSA) methodology for each of the candidate molecules. For the case of aspirin, we also conducted molecular dynamics on the enzyme, the drug and the complex with explicit solvent followed by binding free energy analysis. Collectively, the results obtained from the above studies viz. sorting of drugs from non-drugs, semi-quantitative estimates of binding free energies, amply demonstrate the viability of the strategy proposed for lead selection/design for biomolecular targets.     

Data strategy for environmental assessment of agricultural regions via LCA: case study of a French catchment

Purpose

Various approaches have been carried out to extrapolate environmental assessments of farms to the regional level, some of them oversimplified and thus leading to high uncertainty. Key challenges include selection of a representative sample, construction of a farm/land use typology, the extrapolation strategy and dealing with data limitations. This work proposes a method for addressing these issues by means of statistically supported approaches.

Methods

We applied a novel approach combining a sampling strategy, estimation of farm-level environmental impacts via life cycle assessment (LCA), a farm typology based on principal component analysis, a statistical method for extending the farm sample given data constraints and finally linear extrapolation based on regional production and land use, taking into account the regional import–export balance. The approach was applied to a French case study, the Lieue de Grève catchment in the dairy-intensive Brittany region. A decision flowchart was developed to generalise the approach for similar applications dealing with farm and LCA data constraints. Additionally, innovative farm practices were modelled and their impacts propagated to the regional level.

Results and discussion

The typology developed identified “dairy”, “beef”, “dairy + beef” and “swine” farms as the dominant farm types in the region. While swine farms had the highest mean impacts per hectare, dairy and dairy + beef farms had impacts two to five times as high as those of beef and swine farms, when extrapolated to the entire catchment. Multiple linear regressions based on an extended farm and LCA dataset were used to predict environmental impacts of dairy farms lacking LCA results, thus increasing their sample size before extrapolation. The inclusion of farm and LCA data from a neighbouring region did not contribute to the accuracy of predicted impacts, as determined by comparing them to those of the farm closest to the dairy cluster’s centre, but rather produced significantly larger coefficients of variation. Results of tests of including two extra-regional farm and LCA datasets helped determine decision rules for the decision flowchart. Modelling of innovative agricultural practices yielded regional impacts consistent with previous estimates.

Conclusions

This approach provides a generalisable approach for farm typologies, data handling and regional extrapolation of farm-level LCAs, applicable to estimate environmental impacts of any agricultural area if requirements of a representative farm sample are met. We demonstrate the utility of the method for estimating effects of innovative agricultural practices on a region’s impacts by modelling practices on virtual farms and extrapolating their results.

     

Species richness, environmental heterogeneity and area: a case study based on land snails in Skyros archipelago (Aegean Sea, Greece)

Aim To test the performance of the choros model in an archipelago using two measures of environmental heterogeneity. The choros model is a simple, easy‐to‐use mathematical relationship which approaches species richness as a combined function of area and environmental heterogeneity. Location The archipelago of Skyros in the central Aegean Sea (Greece). Methods We surveyed land snails on 12 islands of the archipelago. We informed the choros model with habitat data based on natural history information from the land snail species assemblage. We contrast this with habitat information taken from traditional vegetation classification to study the behaviour of choros with different measures of environmental heterogeneity. R² values and Akaike's information criterion (AIC) were used to compare the choros model and the Arrhenius species–area model. Path analysis was used to evaluate the variance in species richness explained by area and habitat diversity. Results Forty‐two land snail species were recorded, living in 33 different habitat types. The choros model with habitat types had more explanatory power than the classic species–area model and the choros model using vegetation types. This was true for all islands of the archipelago, as well as for the small islands alone. Combined effects of area and habitat diversity primarily explain species richness in the archipelago, but there is a decline when only small islands are considered. The effects of area are very low both for all the islands of the archipelago, and for the small islands alone. The variance explained by habitat diversity is low for the island group as a whole, but significantly increases for the small islands. Main conclusions The choros model is effective in describing species‐richness patterns of land snails in the Skyros Archipelago, incorporating ecologically relevant information on habitat occupancy and area. The choros model is more effective in explaining richness patterns on small islands. When using traditional vegetation types, the choros model performs worse than the classic species–area relationship, indicating that use of proxies for habitat diversity may be problematic. The slopes for choros and Arrhenius models both assert that, for land snails, the Skyros Archipelago is a portion of a larger biogeographical province. The choros model, informed by ecologically relevant habitat measures, in conjunction with path analysis points to the importance of habitat diversity in island species richness.     

Assessing the influence of environmental heterogeneity on bird spacing patterns: a case study with two raptors

Testing for aggregation or regularity in point patterns is difficult in the presence of spatial variation in abundance due to environmental heterogeneity. Using a recently developed method generalizing Ripley's K function for non homogeneous point patterns, we test the aggregation of the nests in two species of birds (little owl and Montagu's harrier) exhibiting heterogeneous distributions in response to landscape structure. We compare the results obtained under different null models accounting for environmental heterogeneity at large and/or small spatial scales.
Whereas both species were initially found to form clusters at some scale, taking spatial heterogeneity into account revealed that 1) territorial little owls showed no clustering of territories when habitat availability was considered; 2) semi-colonial harriers still formed significant clusters, but part of the aggregation in this species could be explained by landscape structure alone. Our results highlight that it is feasible and highly recommended to account for non-stationarity when testing for aggregation. Further, provided that sufficient knowledge of the study system is available, this approach helps to identify behavioural and environmental components of spatial variation in abundance. Additionally, we demonstrate that accounting for large or small-scale heterogeneity affects the perception of spacing behaviours differently, so that both need to be considered.     

Management and conservation of the land crab Cardisoma guanhumi (Crustacea: Gecarcinidae) based on environmental and fishery factors: a case study in Brazil

Wetlands Ecology and Management - A mangrove ecosystem encompasses two environments, a larger flooding area with a characteristic wetland forest, and a less flooded area, more saline with little or...     

Anion recognition based on halogen bonding: a case study of macrocyclic imidazoliophane receptors

The structures and properties of noncovalent interactions involving three imidazoliophane receptors 1-3 and halide anions have been investigated by means of density functional theory calculations. To account for the influence of the solvent environment, the implicit polarized continuum model was also employed. For the halogenated cyclophane receptors 1 and 2, the halide ions are held by a bidentate array of halogen bonds (C-Br/C-I...X(-)), while multiple hydrogen-bonding interactions (C-H...X(-)) are present in the complexes of the nonhalogenated macrocyclic receptor 3. To accommodate the negatively charged guest anions, the structures of 1 and 2 fully reorganize into a calix-like shape, while both the imidazole and benzene rings in 3 tend to point towards the anions and thus rotate to form a cage-like shape. In both the gas phase and aqueous solution, the binding affinities of the anions for halogen-bonding receptors 1 and 2 become stronger than those for hydrogen-bonding receptor 3. The results reported here should prove to be of great value in the design and synthesis of effective and selective anion receptors based on halogen bonding.     

MedPost: a part-of-speech tagger for bioMedical text

SUMMARY: We present a part-of-speech tagger that achieves over 97% accuracy on MEDLINE citations. AVAILABILITY: Software, documentation and a corpus of 5700 manually tagged sentences are available at ftp://ftp.ncbi.nlm.nih.gov/pub/lsmith/MedPost/medpost.tar.gz     

Modelling the economic and environmental performance of engineering products: a materials selection case study

Purpose

Life cycle assessment (LCA) studies allow understanding all relevant processes and environmental impacts involved in the life cycle of products. However, in order to fully assess their sustainability, these studies should be complemented by economic (LCC) and societal analyses. In this context, the present work aims at assessing all costs (internal and external) and the environmental performance associated to the full life cycle of specific engineering products. These products are lighting columns for roadway illumination made with three different materials: a glass fibre reinforced polymer composite, steel and aluminium.

Methods

The LCA/LCC integrated methodology used was based in a ??cradle-to-grave?? assessment which considers the raw materials production, manufacture, on-site installation, use and maintenance, dismantlement and end-of-life (EoL) of the lighting columns. The fossil fuels environmental impact category was selected as the key environmental impact indicator to perform the integrated environmental and cost analysis.

Results

The potential total costs obtained for the full life cycle of the lighting columns demonstrated that the one made in steel performs globally worse than those made in composite or aluminium. Although the three systems present very similar internal costs, the steel column has higher external costs in the use phase that contribute for its higher total cost. This column has very high costs associated to safety features, since it constitutes a significant risk to the life of individuals. The raw material and column production stages are the main contributors for the total internal life cycle costs. The EoL treatment is a revenue source in all systems because it generates energy (in the case of the composite incineration) or materials (in the case of metal recycling). The composite and aluminium lighting columns present similar ??cradle-to-grave?? life cycle total cost. However, until the dismantlement phase, the aluminium column presents the highest environmental impact, whereas in the EoL treatment phase this scenario is reversed. The ??cradle-to-grave?? life cycle potential total cost and the environmental impact (fossil fuels) indicator of the steel lighting column are higher than those of the other columns.

Conclusions

Even though the uncertainties in the LCC are larger if external costs are included, their consideration when modelling the economic performance of engineering products increases the probability of developing a more sustainable solution from a societal perspective.     

LCA for assessing environmental benefit of eco-design strategies and forest wood short supply chain: a furniture case study

Purpose

Eco-innovation strategies are increasingly adopted to ensure the minimization of environmental impacts. Nonetheless, only a comprehensive integrated assessment along the life cycle stages of a product may ensure a robust analysis of the benefit of the innovation. The object of the present study is the environmental assessment of furniture prototypes produced using certified wood and integrating eco-design criteria in their conception. The aim of the study was twofold: firstly, to evaluate the environmental profile of the furniture, highlighting possible hot spots of impacts, and secondly, to evaluate the capability of life cycle assessment (LCA) to identify the environmental benefit associated to the adoption of eco-innovation strategies, such as the following: ensuring short supply chain from raw material to production; using wood coming from certified forests (according to PEFC scheme); and the implementation of eco-design principles, also associated with green public procurement requirements.

Methods

LCA has been applied in a case study related to the wood furniture sector in the alpine region of Northern Italy. Every activity was modeled using primary data, related to the inputs and outputs of the processes, provided directly by the designers and by woodworking firms. Input data related to forestry activities and wood extraction were collected and processed in a previous phase of the study. The life cycle of a prototype school desk from the cradle-to-gate perspective was analyzed. A woodworking plant was examined in detail, dividing the whole manufacturing process into four phases: panels production, woodworking, painting and steel parts processing. The system boundaries included all the activities which take place inside the plant as well as energy inputs, transports and ancillary products used.

Results and discussion

The results highlighted that the working phases showing the greatest environmental burdens were the production of solid wood panels and the processing of iron parts. No concerns about chemicals, glues and paints were raised, due to the eco-design principles implemented in the production of the furniture. The choice of a short supply chain allowed for drastic reductions in the impacts associated to long-distance transports. Three sensitivity analyses were carried out to test the robustness of results concerning the following: (1) glue options, (2) drying phase and VOC emissions, and (3) transport options.

Conclusions

This study proves to which extent eco-design criteria implemented in practice improve the environmental performance of products. All positive effects due to decisions taken in school desk design and conception were supported by evidence.     

A HIVE model for regional integrated environmental risk assessment: A case study in China

Regional environmental risk assessment has been a significant means of environmental management and decision-making. To assess the regional integrated environmental risk at a nationwide scale, a new index system named the Hazard, Intensity, Vulnerability, and Effectiveness (HIVE) model was designed and evolved from previous researches. The HIVE model consisted of a relatively complete framework with accessible indexes related to environment and social economy, and it considered different risk sources, pathways, and receptors as well as the influence of the risk control. As an important segment of the assessment process, a simple gridding information diffusion method was also proposed to assess the diffusion effect of risk factors in nationwide rivers. Taking China as a case study, this study calculated the environmental risk value of every sub-unit. Through the clustering function of Statistical Package for Social Sciences and the visual representation of a geographic information system, the study area was divided into nine zones that were visualized on maps according to their different risk levels and risk characteristics. This study also identified the dominant factors of each zone, which could provide the foundation for regional environmental management. Moreover, the results implied some significant correlations between risk system components and the regional social economy in China.     

Optimization of biodiesel supply chains based on small farmers: a case study in Brazil

This article presents a methodology for conceiving and planning the development of an optimized supply chain of a biodiesel plant sourced from family farms and taking into consideration agricultural, logistic, industrial, and social aspects. This model was successfully applied to the production chain of biodiesel fuel from castor oil in the semi-arid region of Brazil. Results suggest important insights related to the optimal configuration of the crushing units, regarding its location, technology, and when it should be available, as well as the configuration of the production zones along the planning horizon considered. Moreover, a sensitivity analysis is performed in order to measure how possible variations in the considered conjecture can affect the robustness of the solutions.     

Prediction of quantitative phenotypes based on genetic networks: a case study in yeast sporulation

Background  

An exciting application of genetic network is to predict phenotypic consequences for environmental cues or genetic perturbations. However, de novo prediction for quantitative phenotypes based on network topology is always a challenging task.     

Segmental gracilis free flap based on secondary pedicles: anatomical study and clinical series

The gracilis muscle has been used extensively in reconstructive surgery, based on the proximal dominant pedicle. In the literature, little attention has been paid to the secondary distal pedicles. The distribution of the secondary pedicles of the gracilis muscle was investigated in 20 cadaver thighs. The mean number of secondary pedicles was 2.2 (range, two to three). When two pedicles were present-the most common situation-they were located at a mean distance of 12.4 and 17.5 cm from the knee joint line. The most proximal secondary pedicle was injected with barium sulfate in five specimens, and constant and abundant connections with the main pedicle were noted. A series of seven clinical cases of segmental gracilis free muscle flaps based on a secondary pedicle is reported. The flaps were successfully transferred to reconstruct traumatic defects of limited size, with one case of partial necrosis caused by a technical error. The morbidity of this flap is minimal, the scar is well hidden, the muscle need not be sacrificed, elevation is fast and straightforward under tourniquet control, and the pedicle is sizable. This flap should be considered a viable option when a small, straightforward free flap is needed.