Model Predictive Control-Based Direct Torque Control for Matrix Converter-Fed Induction Motor with Reduced Torque Ripple

To reduce the torque ripple in motors resulting from the use of conventional direct torque control(DTC),a model predictive control(MPC)-based DTC strategy for a direct matrix converter-fed induction motor is proposed in this paper.Two new look-up tables are proposed,these are derived on the basis of the control of the electromagnetic torque and stator flux using all the feasible voltage vectors and their associated switching states.Finite control set model predictive control(FCS-MPC)has then been adopted to select the optimal switching state that minimizes the cost function related to the electromagnetic torque.Finally,the experimental results are shown to verify the reduced torque ripple performance of the proposed MPC-based DTC method.

Territorial Planning for Coastal Zones in Chile:The Need for Geographical-Environmental and Natural Risk Indicators for Spatial Decision Support Systems

Coastal zones are very dynamic and fragile environments, constituting a landscape ever more heterogeneous, fragmented and with increasing levels of complexity due to the changing relationship between man and nature. Integrated coastal zone management therefore requires detailed knowledge of the system and its components, based—to a large extent—on technical and scientific information. However, the information generated must be in line with the political requirements necessary for decision-making and planning. Thus the use of indicators to give a simplified view of the many components of the territory, and at the same time to provide important information about patterns or trends, becomes a tool of the utmost importance. These indicators can be understood as measurable characteristics of the environment, which facilitate comprehension of the processes occurring at different scales and serve as a reference to inform the population and support decision-making. The aim of the present note is to demonstrate briefly the need to develop geographical-environmental and natural risk indicators to facilitate comprehension of the dynamic of spatial and temporal landscape patterns, particularly in coastal environments. This approach offers an historical summary of the natural, socio-economic and political processes which currently make up the territory, and which without doubt will continue to influence it in the future. At the same time, it is proposed that information should be integrated on the basis of this framework with a view to generating spatial decision support systems in a context of planning and integrated management of the coastal zones of Chile.

Photooxidative stress activates a complex multigenic response integrating the phenylpropanoid pathway and ethylene,leading to lignin accumulation in apple(Malus domestica Borkh.)fruit

Photooxidative stress,when combined with elevated temperatures,triggers various defense mechanisms leading to physiological,biochemical,and morphological changes in fruit tissue.Furthermore,during sun damage,apple fruit undergo textural changes characterized by high flesh firmness compared to unexposed fruit.Fuji and Royal Gala apples were suddenly exposed to sunlight on the tree and then sampled for up to 29 days.Cell wall components and lignin biosynthetic pathway analyses were carried out on the fruit tissue.At harvest,Fuji apples with different sun exposure levels,such as exposed to direct sunlight(Exp),shaded(Non-Exp),and with severe sun damage(Sev),were also characterized.In fruit suddenly exposed to sunlight,the expression levels of phenylpropanoid-related genes,phenylalanine ammonia lyase(MdPAL),chalcone synthase(MdCHS),and flavanone-3-hydroxylase(MdF3H),were upregulated in the skin and flesh of Exp and Sev.Exposure had little effect on the lignin-related genes caffeic acid Omethyltransferase 1(MdCOMT1)and cinnamyl alcohol dehydrogenase(MdCAD)in the skin;however,the expression of these genes was highly induced in the flesh of Exp and Sev in both cultivars.Lignin deposition increased significantly in skin with sun injury(Sev);in flesh,this increase occurred late during the stress treatment.Additionally,the ethylene biosynthesis genes 1-aminocyclopropane-1-carboxylate synthase(MdACS)and 1-aminocyclopropane-1-carboxylate oxidase(MdACO)were highly expressed in the skin and flesh tissues but were more upregulated in Sev than in Exp during the time-course experiment,which paralleled the induction of the phenylpropanoid pathway and lignin accumulation.At harvest,flesh from Sev fruit exhibited higher firmness than that from Non-Exp and Exp fruit,although no differences were observed in the alcohol-insoluble residues(AIR)among groups.The fractionation of cell wall polymers revealed an increase in the uronic acid contents of the water-soluble pectin fraction(WSF)in Exp and Sev tissues compared to Non-Exp tissues,while the other pectin-rich fractions,that is,CDTA-soluble(CSF)and Na2CO3-soluble(NSF),were increased only in Sev.The amount of hemicellulose and cellulose did not differ among fruit conditions.These findings suggest that increases in the flesh firmness of apples can be promoted by photooxidative stress,which is associated with the induction of lignin accumulation in the skin and flesh of stressed fruit,with the involvement of stress phytohormones such as ethylene.

Mechanical Properties of a Wood Flour-PET Composite Through Computational Homogenisation

This work proposes to study the effective elastic properties(EEP)of a wood-plastic composite(WPC)made from polyethylene terephthalate(PET)and Chilean Radiate pine’s wood our,using nite element simulations of a representative volume element(RVE)with periodic boundary conditions.Simulations are validated through a static 3-point bending test,with specimens obtained by extruding and injection.The effect of different weight fractions,space orientations and sizes of particles are here examined.Numerical predictions are empirically conrmed in the sense that composites with more wood our content and bigger size,have higher elastic modulus.However,these results are very sensitive to the orientation of particles.Voigt and Reuss mean-eld homogenisation approaches are also given as upper and lower limits.Experimental tests evidence that exural strengths and ultimate tensile elongations decrease respect to 100%PET,but these properties can be enhanced considering particle-size distributions instead of a xed size of wood our.

A generalization of the half-normal distribution

In this paper we introduce an extension of the half-normal distribution in order to model a great variety of non-negative data. Its hazard rate function can be decreasing or increasing, depending on its parameters. Some properties of this new distribution are presented. For example, we give a general expression for the moments and a stochastic representation. Also, the cumulative distribution function, the hazard rate function, the survival function and the quantile function can be easily evaluated. Maximum likelihood estimators can be computed by using numerical procedures. Finally, a real-life dataset has been presented to illustrate its applicability.

Apple Extracts Present Catabolic and Hipocolesterolemic Effect in Mice

Dyslipidemia is highly prevalent in the Chilean population: about 40% have total cholesterol levels over 200 mg/dl and 25% are obese (BMI > 30) which produces an increased risk of cardiovascular disease and deaths. Over consumption of foods rich in lipids and carbohydrates unchains these events, due to the high amount of lipid accumulation in adipocytes. These cells are capable of producing a large number of mediators of inflammation and adipokines which in large quantities can compromise the overall metabolism. Apple has been shown to stop these events. We used CF-1 mice that were fed on a high-fat diet which leads to a metabolic status similar to dyslipidemia. Different types of apple waste were direct from orchard and fruit industry. Extracts obtained were characterized and administered in drinking water. At the end of the 40-day experimental period, biochemical parameters in animals were measured and the weight of white adipose tissue (WAT) was quantified. The results were compared with the normal diet and fat diet controls. All apple extracts decrease total and LDL cholesterol to levels similar to normal control and decrease WAT. Apple extracts may be an effective protector against development of risk factors in cardiovascular disease in the Chilean population.

Arylated analogues of cypronazole: fungicidal effect and activity on human fibroblasts. Docking analysis and molecular dynamics simulations

Triadimefon(TDM)and cyproconazole(CPZ)are two triazoles widely used as fungicides.Several azoles were synthe-sised starting from commercial TDM and CPZ.The compounds were evaluated against phytopathogenic filamentous fungi,including Aspergillus fumigatus(AF),A.niger(AN),A.ustus(AU),A.japonicus(AJ),A.terreus(AT),Fusarium oxyspo-rum and Botrytis cinerea isolated from grapevine in the province of San Juan,Argentina.Three of the synthesised compounds(1-(Biphenyl-4-yloxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-one,1;2-(Biphenyl-4-yl)-3-cyclopropyl-1-(1H-1,2,4-triazol-1-yl)butan-2-ol,3;3-Cyclopropyl-2-(4’-fluorobiphenyl-4-yl)-1-(1H-1,2,4-triazol1-yl)butan-2-ol,4)presented remarkable in vitro fungicidal properties,with better effects than TDM and CPZ on some of the target fungi.Cytotoxicity was assessed using human lung fibroblasts MRC5.Derivative 1,with IC50 values of 389.4μM,was less toxic towards MRC-5 human lung fibroblasts than commercial TDM(248.5μM)and CPZ(267.4μM).Docking analysis and molecular dynamics simulations suggest that the compounds present the same interaction in the binding pocket of the CYP51B enzyme and with the same amino acids as CPZ.The derivatives investigated could be considered broad-spectrum but with some selectivity towards imperfect fungi.

Chlorophyll, anthocyanin, and gas exchange changes assessed by spectroradiometry in Fragaria chiloensis under salt stress

Chlorophyll and anthocyanin contents provide a valuable indicator of the status of a plant’s physiology, but to be more widely utilized it needs to be assessed easily and non‐destructively. This is particularly evident in terms of assessing and exploiting germplasm for plant‐breeding programs. We report, for the first time, experiments with Fragaria chiloensis（L.）Duch. and the estimation of the effects of response to salinity stress（0, 30, and 60 mmol NaCl/L） in terms of these pigments content and gas exchange. It is shown that both pigments（which interestingly, themselves show a high correlation） give a good indication of stress response. Both pigments can be accurately predicted using spectral reflectance indices（SRI）;however, the accuracy of the predictions was slightly improved using multilinear regression analysis models and genetic algorithm analysis. Specifically for chlorophyll content, unlike other species, the use of published SRI gave better indications ofstress response than Normalized Difference Vegetation Index.The effect of salt on gas exchange is only evident at the highest concentration and some SRI gave better prediction performance than the known Photochemical Reflectance Index. This information will therefore be useful for identifying tolerant genotypes to salt stress for incorporation in breeding programs.

Distributed Differences Structures Underlie Gating between the Kin Channel KAT1 and the Kout Channel SKOR

The family of voltage-gated （Shaker-like） potassium channels in plants includes both inward-rectifying （Kin） channels that allow plant cells to accumulate K＋ and outward-rectifying （Kout） channels that mediate K＋ efflux. Despite their dose structural similarities, Kin and Kout channels differ in their gating sensitivity towards voltage and the extracellular K＋ concentration. We have carried out a systematic program of domain swapping between the Kout channel SKOR and the Kin channel KAT1 to examine the impacts on gating of the pore regions, the S4, S5, and the S6 helices. We found that, in particular, the N-terminal part of the S5 played a critical role in KAT1 and SKOR gating. Our findings were supported by molecular dynamics of KAT1 and SKOR homology models. In silico analysis revealed that during channel opening and closing, displacement of certain residues, especially in the S5 and S6 segments, is more pronounced in KAT1 than in SKOR. From our analysis of the S4-S6 region, we conclude that gating （and K＋-sensing in SKOR） depend on a number of structural elements that are dispersed over this -145-residue sequence and that these place additional constraints on configurational rearrangement of the channels during gating.

Feeding behavior, life history, and virus transmission ability of Bemisia tabaci Mediterranean species (Hemiptera: Aleyrodidae) under elevated CO2

The continuous rise of CO2 concentrations in the atmosphere is reducing plant nutritional quality for herbivores and indirectly affects their performance.The whitefly(Bemisia tabaci,Gennadius)is a major worldwide pest of agricultural crops causing significant yield losses.This study investigated the plant‐mediated indirect effects of elevated CO2 on the feeding behavior and life history of B.tabaci Mediterranean species.Eggplants were grown under elevated and ambient CO2 concentrations for 3 weeks after which plants were either used to monitor the feeding behavior of whiteflies using the Electrical Penetration Graph technique or to examine fecundity and fertility of whiteflies.Plant leaf carbon,nitrogen,phenols and protein contents were also analyzed for each treatment.Bemisia tabaci feeding on plants exposed to elevated CO2 showed a longer phloem ingestion and greater fertility compared to those exposed to ambient CO2 suggesting that B.tabaci is capable of compensating for the plant nutritional deficit.Additionally,this study looked at the transmission of the virus Tomato yellow leaf curl virus(Begomovirus)by B.tabaci exposing source and receptor tomato plants to ambient or elevated CO2 levels before or after virus transmission tests.Results indicate that B.tabaci transmitted the virus at the same rate independent of the CO2 levels and plant treatment.Therefore,we conclude that B.tabaci Mediterranean species prevails over the difficulties that changes in CO2 concentrations may cause and it is predicted that under future climate change conditions,B.tabaci would continue to be considered a serious threat for agriculture worldwide.

Risk Models for the Prize Collecting Steiner Tree Problems with Interval Data

Given a connected graph G=（V,E）with a nonnegative cost on each edge in E,a nonnegative prize at each vertex in V,and a target set V′V,the Prize Collecting Steiner Tree（PCST）problem is to find a tree T in G interconnecting all vertices of V′such that the total cost on edges in T minus the total prize at vertices in T is minimized.The PCST problem appears frequently in practice of operations research.While the problem is NP-hard in general,it is polynomial-time solvable when graphs G are restricted to series-parallel graphs.In this paper,we study the PCST problem with interval costs and prizes,where edge e could be included in T by paying cost xe∈[c e,c＋e]while taking risk（c＋e xe）/（c＋e c e）of malfunction at e,and vertex v could be asked for giving a prize yv∈[p v,p＋v]for its inclusion in T while taking risk（yv p v）/（p＋v p v）of refusal by v.We establish two risk models for the PCST problem with interval data.Under given budget upper bound on constructing tree T,one model aims at minimizing the maximum risk over edges and vertices in T and the other aims at minimizing the sum of risks over edges and vertices in T.We propose strongly polynomial-time algorithms solving these problems on series-parallel graphs to optimality.Our study shows that the risk models proposed have advantages over the existing robust optimization model,which often yields NP-hard problems even if the original optimization problems are polynomial-time solvable.

Annotated expressed sequence tags and xenobiotic detoxification in the aphid Myzus persicae （Sulzer）

Aphids （Hemiptera： Aphididae） are phytophagous insects that are important agricultural pests. The enormous negative economic impacts caused by aphids worldwide are well known, and are mostly due to their high multiplication rate and the transmission of phytopathogenic viruses. Aphid management strategies mainly involve chemical treatments which are pollutants and are increasingly inefficient, since aphids have developed multiple insecticide-resistant mechanisms. Among the most economically important species is the green peach aptfid Myzus persicae Sulzer （Aphididae： Macrosiphini）, which is able to colonize a wide range of host plants belonging to many different families, and transmits numerous plant viruses. Because of its large prevalence, M. persicae has been the target of massive insecticide treatments; consequently, it has evolved several insecticide-resistant mechanisms. In this work, a collection of expressed genes from M. persicae is presented in order to identify putative genes involved in xenobiotic detoxification. After cDNA cloning and sequencing, 959 expressed sequence tags （EST） were annotated. Most sequences matched known genes corresponded to metabolism proteins （26%）, ribosomal proteins （ 23 % ） and structural proteins （8%）. Among them, several sequences corresponded to proteins putatively involved in sensing, degradation or detoxification of plant xenobiotic products.

Ecophysiological basis of the Jack-and-Master strategy:Taraxacum officinale(dandelion)as an example of a successful invader

Aims Successful invasive plants are often assumed to display significant levels of phenotypic plasticity.Three possible strategies by which phenotypic plasticity may allow invasive plant species to thrive in changing environments have been suggested:(i)via plasticity in morphological or physiological traits,invasive plants are able to maintain a higher fitness than native plants in a range of environ-ments,including stressful or low-resource habitats:a‘Jack-of-all-trades’strategy;(ii)phenotypic plasticity allows the invader to better exploit resources available in low stress or favorable habitats,show-ing higher fitness than native ones:a‘Master-of-some’strategy and(iii)a combination of these abilities,the‘Jack-and-Master’strategy.Methods We evaluated these strategies in the successful invader Taraxacum officinale in a controlled experiment mimicking natural environmen-tal gradients.We set up three environmental gradients consisting of factorial arrays of two levels of temperature/light,temperature/water and light/water,respectively.We compared several ecophysiologi-cal traits,as well as the reaction norm in fitness-related traits,in both T.officinale and the closely related native Hypochaeris thrin-cioides subjected to these environmental scenarios.Important Findings Overall,T.officinale showed significantly greater accumulation of biomass and higher survival than the native H.thrincioides,with this difference being more pronounced toward both ends of each gradient.T.officinale also showed significantly higher plasticity than its native counterpart in several ecophysiological traits.Therefore,T.officinale exhibits a Jack-and-Master strategy as it is able to main-tain higher biomass and survival in unfavorable conditions,as well as to increase fitness when conditions are favorable.We suggest that this strategy is partly based on ecophysiological responses to the environment,and that it may contribute to explaining the successful invasion of T.officinale across different habitats.

Industrial Pollution Governance in Beijing-Tianjin-Hebei Based on Industrial Relocation

Industrial relocation and ecological subsidy are viewed as effective ways to overcome transboundary industrial pollution. In this paper, we study the transboundary industrial pollution control problem in the Beijing-Tianjin-Hebei region in the context of industrial relocation. Firstly, we construct an economic model of pollution control with relevant variables such as environmental tax and environmental damage coefficient. Secondly, we solve the economic contributions by using the proportional split-off solution. Finally, we compare the optimal relocation quantity and welfare functions in both cooperative and non-cooperative cases. Our research finds that: 1) The optimal strategy is closely related to utility coefficient, environmental loss coefficient and incentive intensity coefficient.2) The welfare function and the optimal relocation quantity in the cooperative case are significantly greater than those in the non-cooperative case. Based on the analysis, some suggestions are provided for transboundary industrial pollution management.

MillenniumDB:An Open-Source Graph Database System

In this systems paper,we present MillenniumDB:a novel graph database engine that is modular,persistent,and open source.MillenniumDB is based on a graph data model,which we call domain graphs,that provides a simple abstraction upon which a variety of popular graph models can be supported,thus providing a flexible data management engine for diverse types of knowledge graph.The engine itself is founded on a combination of tried and tested techniques from relational data management,state-of-the-art algorithms for worst-case-optimal joins,as well as graph-specific algorithms for evaluating path queries.In this paper,we present the main design principles underlying MillenniumDB,describing the abstract graph model and query semantics supported,the concrete data model and query syntax implemented,as well as the storage,indexing,query planning and query evaluation techniques used.We evaluate MillenniumDB over real-world data and queries from the Wikidata knowledge graph,where we find that it outperforms other popular persistent graph database engines(including both enterprise and open source alternatives)that support similarqueryfeatures.

Diversity, frequency, and geographic distribution of facultative bacterial endosymbionts in introduced aphid pests

Facultative bacterial endosymbionts in insects have been under intense study during the last years. Endosymbionts can modify the insect＇s phenotype, conferring adap- tive advantages under environmental stress. This seems particularly relevant for a group of worldwide agricultural aphid pests, because endosymbionts modify key fitness-related traits, including host plant use, protection against natural enemies and heat tolerance. Aimed to understand the role of facultative endosymbionts on the success of introduced aphid pests, the distribution and abundance of 5 facultative endosymbionts （Hamiltonella defensa, Regiella insecticola, Serratia symbiotica, Rickettsia and Spiroplasma） were stud- ied and compared in 4 cereal aphids （Sitobion avenae, Diuraphis noxia, Metopolophium dirhodum and Schizaphis graminium） and in the pea aphid Acyrthosiphon pisum complex from 2 agroclimatic zones in Chile. Overall, infections with faeultative endosymbionts exhibited a highly variable and characteristic pattern depending on the aphid species/host race and geographic zone, which could explain the success of aphid pest populations after their introduction. While S. symbiotica and H. defensa were the most frequent endosym- bionts carried by the A. pisum pea-race and A. pisum alfalfa-race aphids, respectively, the most frequent facultative endosymbiont carried by all cereal aphids was R. insecticola. Interestingly, a highly variable composition of endosymbionts carried by S. avenae was also observed between agroclimatic zones, suggesting that endosymbionts are responding differentially to abiotic variables （temperature and precipitations）. In addition, our findings constitute the first report of bacterial endosymbionts in cereal aphid species not screened before, and also the first report of aphid endosymbionts in Chile.

The fungal UmSrt1 and maize ZmSUT1 sucrose transporters battle for plant sugar resources

The biotrophic fungus Ustilago maydis causes corn smut disease, inducing tumor formation in its host Zea mays. Upon infection, the fungal hyphae invaginate the plasma membrane of infected maize ceils, establishing an interface where pathogen and host are separated only by their plasma membranes. At this interface the fungal and maize sucrose transporters, UmSrtl and ZmSUT1, compete for extracellular sucrose in the corn smut/maize pathos- ystem. Here we biophysically characterized ZmSUT1 and UmSrtl in Xenopus oocytes with respect to their voltage-, pH- and substrate-dependence and determined affinities toward protons and sucrose. In contrast to ZmSUT% UmSrtl has a high affinity for sucrose and is relatively pH- and voltage-independent. Using these quantitative parameters, we developed a mathematical model to simulate the competition for extracellular sucrose at the contact zone between the fungus and the host plant. This approach revealed that UmSrtl exploits the apoplastic sucrose resource, which forces the plant transporter into a sucrose export mode providing the fungus with sugar from the phloem. Importantly, the high sucrose concen- tration in the phloem appeared disadvantageous for the ZmSUT1 preventing sucrose recovery from the apoplastic space in the fungus/plant interface.

Positive interactions by cushion plants in high mountains:fact or artifact?

Positive interactions are defined as non-trophic interactions where at least one of the interacting species is benefited in terms of fitness and the other remains unaffected.Nevertheless,the bidirectional feedbacks between species may be positive,neutral or negative.Thus,if facilitated species induce negative effects on their‘nurses’,the assumed definition of positive interactions could be reconsidered.Methods We assessed if ecological interactions between cushions of Azorella madreporica and their facilitated species are positive.Specifically,we tested if cover of facilitated species has any costs for cushion plants from an ecophysiological perspective,and if these costs increase with the amount of cover of facilitated species.In addition,through pathway analysis and correlations,we assessed if cover and richness of facilitated species have a direct and/or indirect effect on the fitness of cushion plants.Important Findings We found that facilitated plant species induced a significant cost for their nurses(cushion plants),and this cost increases with cover of the facilitated species.Additionally,the facilitated species exert a strong direct negative effect on the cushion’s fitness and a moderate indirect negative cost evident through the nutrient status and physiological performance of cushion plants.We thus contribute evidence that positive interactions between high mountain cushion plants of central Chile and their‘facilitated’species may be an artifact more than a fact,especially when bidirectional effects are considered;contrasting with the majority of studies that document only one side of the interaction.

Isolation and characterization of nine microsatellite loci from Aphelinus mali （Hymenoptera： Aphelinidae）, a parasitoid of Eriosoma lanigerum （Hemiptera： Aphididae）

Nine novel microsatellite markers are presented for Aphelinus mali, a parasitoid of the woolly apple aphid Eriosoma lanigerum. Loci were characterized for 28 individuals from a single orchard in central Chile. Seven loci were polymorphic within A. mali （3-6 alleles per locus; observed heterozygosity ranging from 0.04 to 0.57） and are therefore useful for population genetic studies within this species.