Average Dissimilarity Research Articles

Genetic analysis on composition of sulfur-containing amino acids: methionine and cysteine in subtropical maize

Maize grains are deficient in sulfur-containing amino acids such as methionine (Met) and cysteine (Cys). To date, no maize hybrid rich in Met and Cys has been commercialized particulalry in the subtropical regions. In this study, molecular characterization among seven inbreds using 89 SSRs grouped them into three clusters. The average genetic dissimilarity (GD) coefficient and gene diversity among these inbreds were 0.708 and 0.478, respectively. These seven inbreds were crossed in 7 × 7 half-diallel mating design, and the resulting 21 F1 hybrids along with four popular hybrid checks were evaluated across three locations viz., Delhi, Vagarai and Gauria Karma. Genetic analysis revealed that additive gene action predominantly controls Met content of f, while, both additive and non-additive gene action are important for Cys. Met and Cys levels varied from 0.058-0.306% and 0.025-0.126% with mean of 0.196% and 0.060%, respectively. Promising hybrids identified include MGU-MH-20 (Met: 0.306%, Cys: 0.040%, grain yield: 8136kgha-1), MGU-MH-17 (Met: 0.269% Cys: 0.045%, grain yield: 8178kgha-1), MGU-MH-19 (Met: 0.254%, Cys: 0.048%, grain yield: 8588kgha-1), and MGU-MH-18 (Met: 0.253%, Cys: 0.034%, grain yield: 9812kgha-1) were identified. No correlation was observed among Met, Cys, grain yield and GD. This study is the first to examine the genetics of Met and Cys accumulation in maize. Our findings provide valuable insights for the development of high Met and Cys maize cultivars, which are vital to mitigate malnutrition, especially in developing countries.

Functional and phylogenetic β diversities and their link with clustering/overdispersion and uniqueness/redundancy

AbstractIn recent decades, research on biodiversity in community ecology has been marked by the consideration of species' evolutionary histories and functional traits. Among the different spatial levels at which functional or phylogenetic (hereafter FP) diversity can be quantified, the definition of the general concept of between‐community (β) diversity has been given less attention than that of local, within‐community (α) and regional, merged‐community (γ) diversities. Here, we develop a new method for partitioning FP β diversity into elementary components to determine how and why FP β diversity differs from species β diversity, with the latter reflecting only differences in species' abundances between communities. As a reference example, we consider two distinct measures of FP β diversity: Rao's dissimilarity coefficient (Qβ), which expresses the average FP dissimilarity between communities, and its transformation (Eβ), which expresses the effective number of distinct communities. Through analytical partitioning and simulations, we show that Qβ and Eβ are connected differently to typical patterns of community structure. The search for the ecological and evolutionary processes that drive community assembly and the assessment of community resilience and stability have indeed revealed typical community structures: the local clustering of species with similar traits or shared evolutionary histories and the local (α) or regional (γ) presence of functionally or phylogenetically redundant versus unique species. We show that while Qβ and Eβ are both increasing functions of species β diversity and FP γ uniqueness, Qβ increases with FP clustering, while Eβ increases with FP α redundancy. We also show that the component of FP clustering included in Qβ partitioning formula allows the detection of an overall trend of overdispersion or clustering in a dataset without the need to use null models. To facilitate and secure the selection of an index of β diversity for a given study, we call, through our study, for the development of formal and precise definitions for FP β diversity in light of the concepts of clustering versus overdispersion and redundancy versus uniqueness. In particular, we call for further research on when and why FP β diversity should increase with FP clustering.

Allelic Diversity and Development of Breeder-Friendly Marker Specific to floury2 Gene Regulating the Accumulation of α-Zeins and Essential Amino Acids in Maize Kernel.

Maize zeins lack essential amino acids, such as methionine, lysine, and tryptophan. The floury2 (fl2) mutation reduces zein synthesis and increases methionine and lysine content in kernels. In this study, fl2 gene (1612bp) was sequenced in eight wild-type and two mutant inbreds and detected 218 SNPs and 18 InDels. Transversion of C to T at 343bp position caused the substitution of alanine by valine in the fl2 mutant. A PCR-based marker (FL-SNP-CT) was developed, which distinguished the favorable mutant fl2 allele (T) from the wild-type (C) Fl2 allele. Gene-based diversity analysis using seven gene-based InDel markers grouped 48 inbred lines into three major clusters, with an average genetic dissimilarity coefficient of 0.534. The average major allele frequency, gene diversity, heterozygosity, and polymorphism information content of the InDel markers were 0.701, 0.392, 0.039, and 0.318, respectively. Haplotype analysis revealed 29 haplotypes of fl2 gene among these 48 inbreds. Amino acid substitution (Ala-Val) at the signal peptide cleavage site produced unprocessed 24-kDa mutant protein instead of 22-kDa zein found in normal genotype. Eight paralogues of fl2 detected in the study showed variation in exon lengths (616-1170bp) and translation lengths (135-267 amino acids). Orthologue analysis among 15 accessions of Sorghum bicolor and two accessions of Saccharum spontaneum revealed a single exon in fl2 gene, ranging from 267 to 810bp. The study elucidated the molecular basis of fl2 mutation and reported a breeder-friendly marker for molecular breeding programs. This is the first study to characterize fl2 gene in a set of subtropically adapted inbreds.

Structural variability of protist assemblages in surface sediments across Italian Mediterranean marine subregions

Marine sediments host heterogeneous protist communities consisting of both living benthic microorganisms and planktonic resting stages. Despite their key functions in marine ecosystem processes and biogeochemical cycles, their structure and dynamics are largely unknown. In the present study, with a spatially intensive sampling design we investigated benthic protist diversity and function of surface sediment samples from three subregions of the Mediterranean Sea, through an environmental DNA metabarcoding approach targeting the 18S V4 region of rRNA gene. Protists were characterized at the taxonomic level and trophic function, both in terms of alpha diversity and community composition, testing for potential differences among marine subregions and bathymetric groups. Overall, Alveolata and Stramenopiles were the two divisions that dominated the communities. These dominant groups exhibited significant differences among the three Mediterranean subregions in the alpha diversity estimates based on the detected ASVs, for all computed indices (ASV richness, Shannon and Simpson indices). Protist communities were also found to be significantly different in terms of composition at the order rank in the three subregions p-value < 0.01). These differences were mainly driven by Anoecales, Peridiniales, Borokales, Paraliales and Gonyaulacales, which together contributed almost 80% of the average dissimilarity. Anoecales was the dominant order in the Ionian – Central Mediterranean and Adriatic Sea, but with considerably different relative abundances (52% and 36%, respectively), while Borokales was the dominant order in the Western Mediterranean Sea (33%). Similarly, significant differences among the three marine subregions were also highlighted when protist assemblages were examined in terms of trophic function, both in terms of alpha diversity (calculated on the ASVs for each trophic group) and community composition p-value < 0.01. In particular, the Adriatic Sea stood out for having the highest relative abundance of autotrophic/mixotrophic components in the surface sediments analyzed. Conversely, no significant differences in protist assemblages were found among depth groups. This study provided new insights into the taxonomic and trophic composition of benthic protist communities found in Mediterranean surface sediments, revealing geographical differences among regional seas. The results were discussed in relation to the Mediterranean environmental features that could generate the differences among benthic protist communities.

Diversity and Species Composition of Ants in Urban and Suburban Environments in Bejaia City (Algeria)

We conducted an ant inventory in urban and suburban spaces in Bejaia city to deal with this need for more information about ant biodiversity in the Algerian urban environment. The two methods, hand collecting and pitfall traps, are carried out 24 days in three months (May, June, and July) of 2022. In the urban habitats, 2,653 ant individuals were collected, comprising ten species, six genera and three subfamilies. In the suburban habitats, 6,706 ant specimens were collected, comprising 19 species, 11 genera, and three subfamilies. The most abundant subfamilies in both urban and suburban habitats are Formicinae, followed by Myrmicinae and Dolichoderinae. The results showed that suburban habitats are more diversified (H’= 1.72) than urban habitats (H’= 1.25). The equitability values for suburban and urban habitats are moderate, with 0.58 and 0.54, respectively. The Jaccard similarity index value is 0.45, indicating an essential turnover of ant species between urban and suburban habitats. The ant community’s composition differed between sampled sites (NMDS, Stress = 0.013). The average dissimilarity (as per SIMPER) was 90.37%. Four species (T. simrothi, L. cf. grandis, P. cicatricosa, and L. myops) contributed to 70% of the differences between sites of urban and suburban habitats.

Variations of the soil macrofauna community and corresponding influencing factors in the newly reclaimed coastal area: A case study in Yangtze Estuary, China

Intensive reclamation activity has reshaped global coastal ecosystems. Soil macrofauna, an effective proxy for ecosystem health, has the potential to predict coastal reclamation ecological impact. Previous studies have primarily focused on the long-term (≥ 30 years) soil macrofaunal succession in reclaimed areas. However, composition of the soil macrofauna and its environmental drivers in newly reclaimed areas (< 30 years) remain uncertain. We selected Hengsha Dongtan in the Yangtze Estuary to conduct the study, and four different regions (reclaimed for 13, 8, 4, and 1 year, respectively) were employed to investigate soil macrofaunal composition and corresponding environmental drivers. The results showed that: (1) Terrestrial species millipedes (Paradoxosomatidae sp.), chinch bugs (Dimorphopterus spinolae), and wolf spiders (Pirata subpiraticus) were dominant. Millipedes, chinch bugs, wolf spiders, ants (Myrmecina sp.), and rove beetles (Stenus melanarius and Paederus fuscipes) were major species contributing to the average dissimilarity among regions. (2) The taxonomic composition of soil macrofauna varied over time after reclamation, which showed that the number of species, density, and biomass of soil macrofauna in region 1 (reclaimed for 13 years) was higher than that in regions 2, 3, and 4 (reclaimed for 8, 4, and 1 year). (3) The functional composition of soil macrofauna varied over time after reclamation. The number of species, density, and biomass of the phytophagous and saprophagous groups increased over time, whereas those of the predatory group decreased gradually. (4) Soil pH and total organic carbon content, together with land use, appeared to be key factors that determine soil macrofaunal composition. Overall, our study illustrates the response of soil macrofauna to changes in environmental factors and land use in newly reclaimed areas. Future studies should expand the range of potential factors and comprehensively analyze the mechanisms that maintain soil macrofaunal diversity in reclaimed areas.

Visual Recognition Memory of Scenes Is Driven by Categorical, Not Sensory, Visual Representations.

When we perceive a scene, our brain processes various types of visual information simultaneously, ranging from sensory features, such as line orientations and colors, to categorical features, such as objects and their arrangements. Whereas the role of sensory and categorical visual representations in predicting subsequent memory has been studied using isolated objects, their impact on memory for complex scenes remains largely unknown. To address this gap, we conducted an fMRI study in which female and male participants encoded pictures of familiar scenes (e.g., an airport picture) and later recalled them, while rating the vividness of their visual recall. Outside the scanner, participants had to distinguish each seen scene from three similar lures (e.g., three airport pictures). We modeled the sensory and categorical visual features of multiple scenes using both early and late layers of a deep convolutional neural network. Then, we applied representational similarity analysis to determine which brain regions represented stimuli in accordance with the sensory and categorical models. We found that categorical, but not sensory, representations predicted subsequent memory. In line with the previous result, only for the categorical model, the average recognition performance of each scene exhibited a positive correlation with the average visual dissimilarity between the item in question and its respective lures. These results strongly suggest that even in memory tests that ostensibly rely solely on visual cues (such as forced-choice visual recognition with similar distractors), memory decisions for scenes may be primarily influenced by categorical rather than sensory representations.

An updated checklist of Myctophids of Western Indian Ocean with 6 new records

The Western Indian Ocean (WIO) encompass distinct ecosystems with differing oceanographic and biotic characteristics. This paper provides a comprehensive documentation on the myctophid diversity of WIO at depths between 80 and 600 m, based on field data from 74 stations. A total of 59 species of myctophids were recorded from WIO during the study which includes 6 new records. The new records include Bolinichthys nikolayi, Diaphus theta, Lampanyctus crocodilus, Lampanyctus macdonaldi and Lampadena urophaos from Western Equatorial Indian Ocean, and Diaphus similis from South Eastern Arabian Sea. Based on sampling data and the information from secondary data, the number of myctophid species in the WIO is revalidated to 159 species. The myctophid species from the Western Indian Ocean north of 15°S clearly indicates presence of distinct myctophid assemblages in the study area, representing the eco-regions North Eastern Arabian Sea (NEAS), South eastern Arabian Sea (SEAS) and Western equatorial Indian Ocean (WEIO). Present study reports 16 species from NEAS, 45 species from SEAS and 55 species from WEIO. WEIO accounts for 70–90% of the observed species diversity of WIO. Average dissimilarity in species assemblages between NEAS and SEAS was 64%, between SEAS and EIO 75%, and between NEAS and WEIO was 84%. This is the first detailed report on the myctophid species diversity along the 23.5°N latitude (lat), 55°E longitude (long) and 23.5°S lat, 74°E long. Updated checklist of myctophids in the Western Indian Ocean is also included in the paper.

Assessing sequence variation, haplotype analysis and molecular characterisation ofaspartate kinase2(ask2) gene regulating methionine biosynthesis in diverse maize inbreds.

Traditional maize grain is deficient in methionine, an essential amino acid required for proper growth and development in humans and poultry birds. Thus, development of high methionine maize (HMM) assumes great significance in alleviating malnutrition through sustainable and cost-effective approach. Of various genetic loci, aspartate kinase2 (ask2) gene plays a pivotal role in regulating methionine accumulation in maize. Here, we sequenced the entire ask2 gene of 5394bp with 13 exons in five wild and five mutant maize inbreds to understand variation at nucleotide level. Sequence analysis revealed that an SNP in exon-13 caused thymine to adenine transversion giving rise to a favourable mutant allele associated with leucine to glutamine substitution in mutant ASK2 protein. Gene-based diversity analysis with 11 InDel markers grouped 48 diverse inbreds into three major clusters with an average genetic dissimilarity of 0.570 (range, 0.0-0.9). The average major allele frequency, gene diversity and PIC are 0.693, 0.408 and 0.341, respectively. A total of 45 haplotypes of the ask2 gene were identified among the maize inbreds. Evolutionary relationship analysis performed among 22 orthologues grouped them into five major clusters. The number of exons varied from 7 to 17, with lengthvarying from 12 to 495bp among orthologues. ASK2 protein with 565 amino acids was predicted to be in homo-dimeric state with lysine and tartaric acid as binding ligands. Amino acid kinase and ACT domains were found to be conserved in maize and orthologues. The study depicted the presence of enough genetic diversity in ask2 gene in maize, and development of HMM can be accelerated through introgression of favourable allele of ask2 into the parental lines of elite hybrids using molecular breeding.

Does Minimizing Seabed Contact Alleviate the Impacts of Bottom Trawling? An Experimental Study on Bycatch from North-western Bay of Bengal

In light of the ecological concerns associated with bottom trawling in tropical multispecies fisheries, an attempt was undertaken to implement operational modifications in experimental trawling practices aimed at reducing bottom contact. This endeavour was pursued to investigate the resulting effects on bycatch biomass and diversity along the north-western Bay of Bengal. The average total catch rate and bycatch rate in 66 hauls from January 2017 to December 2019 were 35.46 kg/h and 9.70 kg/h respectively. Bycatch biomass was mainly contributed by Teleostei (77.90%), of which the dominant species was Equuilites lineolatus. Temporal variations in bycatch composition were recorded, and average seasonal dissimilarity ranged between 35.03% and 59.61%. Juvenile percentages varied among six commercial species from 1.42 to 28.0, and their occurrences were related to their peak spawning seasons. The trophic index of bycatch calculated was 3.65. Species diversity and richness in bycatch were higher during post-monsoon and summer seasons. Biomass and abundance plots indicated the bycatch fauna to be relatively unstressed during most seasons. Trawling marginally above the bottom had improved ecological outcomes; as evident from the decreased proportion of bycatch to total trawl catch, reduced growth overfishing from lower juvenile proportions and within optima for various diversity indicators.

Algebraic method for multisensor data fusion.

In this contribution, we use Gaussian posterior probability densities to characterize local estimates from distributed sensors, and assume that they all belong to the Riemannian manifold of Gaussian distributions. Our starting point is to introduce a proper Lie algebraic structure for the Gaussian submanifold with a fixed mean vector, and then the average dissimilarity between the fused density and local posterior densities can be measured by the norm of a Lie algebraic vector. Under Gaussian assumptions, a geodesic projection based algebraic fusion method is proposed to achieve the fused density by taking the norm as the loss. It provides a robust fixed point iterative algorithm for the mean fusion with theoretical convergence, and gives an analytical form for the fused covariance matrix. The effectiveness of the proposed fusion method is illustrated by numerical examples.

Factors affecting abundance and primary productivity of phytoplankton in a wetland ecosystem of Bangladesh

Wetlands are the most productive, economically important and hydrologically variable ecosystems. In this study, the abundance of phytoplankton and its primary productivity were evaluated in Dingapota Haor of Bangladesh. A total of 41 phytoplankton genera belong to Chlorophyceae (15), Bacillariaophyceae (14), Cyanophyceae (8) and Euglenophyceae (4) were recorded whereas Bacillariaophyceae (37.02%) was the most dominant. The highest cell density (22.71×104 cell L–1) was recorded in pre-monsoon. Diversity indices were also significantly higher in pre-monsoon. The species diversity, evenness and richness varied from 2.51–3.79, 0.57–0.90 and 4.65–7.50 respectively. Difference in phytoplankton assemblage with an overall average dissimilarity value of 52.56 % was recorded. Cyclotella (3.60%), Bacillaria (3.13%), Volvox (2.95%), Spirulina (2.92%) and Euglena (2.88%) were the five most contributory species to the seasonal variation. Gross Primary Production, Net Primary Production and Community Respiration values ranged from 0.90–2.49, 0.68–1.60 and 0.35–0.89 mgCm–3day–1 respectively. Alkalinity and Chl-a showed significant positive correlation with GPP, NPP and CR. Pre-monsoon was the most productive phase whereas the monsoon season was the least productive. The current study produced valuable baseline data that will aid in the formulation of wetland conservation and management strategies.

Far-reaching displacement effects of artificial light at night in a North American bat community

Artificial light at night (ALAN) is a global pollutant that disrupts circadian rhythmicity and a broad range of physiological processes and behaviors in animals. However, ALAN sensitivity can vary greatly even among closely related species and urgently needs study for much of the world’s nocturnal wildlife, including bats. While an increasing number of bat species have recently been assessed for light tolerance, the spatial extent of ALAN’s influence on bats has received little attention. This information need is a barrier to the protection of bats from ALAN in land-use planning and policy, and the development of best practices that effectively buffer bat habitat from light trespass. To help address this information gap for North America, we experimentally tested the distances up to which ALAN affects presence and activity of light-averse little brown bats (Myotis lucifugus) and big brown bats (Eptesicus fuscus), and the composition of a foraging bat assemblage in Connecticut, USA. We used three residential-scale, white, LED floodlights to expose bat foraging habitat to ALAN and compared acoustic activity of bats at distances of 0, 25, 50, and 75 m from the lights between nights when the lights were on versus off. Little brown bats were present on significantly fewer light than dark nights at every distance. Lighting significantly reduced little brown bat activity overall and at the farthest location from the lights (75 m), where it was only 43% of dark-night activity despite < 1 lx of illuminance. Presence of big brown bats was not significantly affected at any distance. Big brown bat activity on light nights averaged 48–75% of dark-night activity at each distance but was significantly lower only at 0 m. As expected, lighting had no effect on eastern red (Lasiurus borealis) or hoary bat (L. cinereus) presence or activity. Community composition on dark and light nights had an average dissimilarity of 38% and significantly differed at 0 m and 25 m. We conclude the type of ALAN we studied has a disturbance radius of at least 75 m for the little brown bat and up to 25 m for the big brown bat, with a resulting influence on community composition for up to 50 m. Cumulative habitat loss for the imperiled little brown bat caused by ALAN could therefore be substantial. We urge planners and natural resources regulators to consider these footprints when evaluating indirect impacts to bat habitat from current and future sources of ALAN across these species’ ranges.

Cation substitution varieties of I-II2-III-VI4 semiconductors and their effects on electronic and phononic properties

Quaternary chalcogenides from the semiconducting I-II2-III-VI4 class of systems are relatively unexplored in terms of their electronic and vibrational properties. These multinary systems can be derived from simpler zincblende and wurtzite binary materials as they can accommodate different lattice structures with diverse cation atom arrangements. Here by using first principles simulations, we investigate the electronic and phonon properties of I-II2-III-VI4 systems in terms of their structural and atomic diversity. Common to the parents as well as unique to the specific atomic composition signatures are identified. Distinct structure-property relations for the electronic and phonon band structures are found in order to make predictions for the electronic and thermal transport in these materials. Property trends associated with the average atomic number and mass dissimilarities are identified, which can be used to understand the underlying transport properties in quaternary chalcogenides derived from binary materials.

A Generic, Multimodal Geospatial Data Alignment System for Aerial Navigation

We present a template matching algorithm based on local descriptors for aligning two geospatial products of different modalities with a large area asymmetry. Our system is generic with regards to the modalities of the geospatial products and is applicable to the self-localization of aerial devices such as drones and missiles. This algorithm consists in finding a superposition such that the average dissimilarity of the superposed points is minimal. The dissimilarity of two points belonging to two different geospatial products is the distance between their respective local descriptors. These local descriptors are learned. We performed experiments consisting in estimating a translation between optical (Pléiades) and SAR (Miranda) images onto vector data (OpenStreetMap), onto optical images (DOP) and onto SAR images (KOMPSAT-5). Each remote sensing image to be aligned covered 0.64 km2, and each reference geospatial product spanned over 225 km2. We conducted a total of 381 alignment experiments, with six unique modality combinations. In aggregate, the precision reached was finer than 10 m with 72% probability and finer than 20 m with 96% probability. This is considerably more than with traditional methods such as normalized cross-correlation and mutual information.

Ecological habitat quality assessment of a highly urbanized estuary using macroinvertebrate community diversity and structure

Urban estuaries are subject to a variety of ecological crises caused by humans as a result of rising shore-based human activities. In this study, environmental variables, community composition, structure and diversity indices of benthic macroinvertebrate were studied to assess the ecological health status of an urbanized estuary, Karnaphuli river estuary. The results revealed that dissolved oxygen (DO) was very low, and organic matter was much higher in the estuary. There were significant (p < 0.05) differences among the environmental variables across the sites. 31 taxa were identified yielding a total of 49167 Ind./m2 with overall mean density (±SD) of 159 (±327) Ind./m2. Annelida (61.8%) were the most abundant taxonomic group followed by Polychaeta (34.88%) and Oligochaeta (26.92%). The high abundance of pollution indicator taxa (Tubificidae, Capitellidae) and low abundance of pollution sensitive taxa (Lumbrinidae, Sabellidae, Maldanidae, Nephtyide) indicated detrimental ecological condition. The values of Shannon-Wiener diversity index (1.95–2.63), Pielou’s evenness index (0.60–0.81) and the Margalef diversity index (1.03–2.12) suggested moderate pollution status with extremely low species richness and low abundance in polluted areas. A PERMANOVA showed significant differences in faunal assemblages (F = 2.189, p < 0.001) among sites. Species abundance and density were higher (p = 0.32) at the upper estuary (where pH and salinity were low) and reduced in the middle and lower portion of the estuary which reflected the gradient of pollution level. Cluster analysis (CA) demarcated three distinct communities in terms of species similarity. SIMPER identified the highest average dissimilarity value (66.66%) across all the stations. The Canonical Correspondence Analysis (CCA) results suggested benthic macroinvertebrate community was influenced by environmental variables, for instance, salinity, dissolve oxygen, soil and water pH, total dissolved solids, and sediment texture.

Psammophytes as traps for beach litter in the Strait of Messina (Mediterranean Sea)

In the present paper, for the first time, the presence of beach litter in dunal plants has been verified in a Strait area in an island. The aims of the present study were to evaluate if the psammophytes can act as a trap for the beached litter, to compare beach litter in plants located in beaches with different anthropogenic impacts, and to describe a new approach (namely clean patch index, CPI) to evaluated the cleanliness of dunal plants. In total 738 macro litter items, belonging to 7 litter categories were found in the study area. The main litter category collected was plastic, followed by ceramic, glass, paper/cardboard, metal, sanitary waste, and medical waste. Our results showed that psammophytes acted as a sink for the beach litter by trapping it. The CPI was higher in the dunal plants than in the relative control patches. The average dissimilarity between “Montorsoli” and “Pylon” beaches was 88.7%. The highest contribution to the dissimilarity between the two beaches was the construction material, followed by polystyrene and plastic pieces. Our data could be important for the implementation of the monitoring program within the Marine Strategy Framework Directive, and may also contribute to the development of specific management of the clean-up measures as well as implement National and Regional action plans.

Efficient keyword search on graph data for finding diverse and relevant answers

PurposeThis paper studies a keyword search over graph-structured data used in various fields such as semantic web, linked open data and social networks. This study aims to propose an efficient keyword search algorithm on graph data to find top-k answers that are most relevant to the query and have diverse content nodes for the input keywords.Design/methodology/approachBased on an aggregative measure of diversity of an answer set, this study proposes an approach to searching the top-k diverse answers to a query on graph data, which finds a set of most relevant answer trees whose average dissimilarity should be no lower than a given threshold. This study defines a diversity constraint that must be satisfied for a subset of answer trees to be included in the solution. Then, an enumeration algorithm and a heuristic search algorithm are proposed to find an optimal solution efficiently based on the diversity constraint and an A* heuristic. This study also provides strategies for improving the performance of the heuristic search method.FindingsThe results of experiments using a real data set demonstrate that the proposed search algorithm can find top-k diverse and relevant answers to a query on large-scale graph data efficiently and outperforms the previous methods.Originality/valueThis study proposes a new keyword search method for graph data that finds an optimal solution with diverse and relevant answers to the query. It can provide users with query results that satisfy their various information needs on large graph data.

Tool wear prediction method based on the SVM-Clara model

Abstract To reduce the damage of mechanical parts during machining, a tool wear prediction method based on the SVM-Clara model is proposed. By analyzing the support vector machine (SVM) and Clara algorithm, using regular prediction data or unobservable data, the average dissimilarity of all objects is concentrated, and the characteristics of the overall data are accurately represented. Randomly select data samples from the overall data samples according to a certain proportion, and standardize them to improve the clustering quality. Find the best objective function to minimize the damage function and make the predicted value closer to the actual value. Through experiments, it is proved that the method in this paper can accurately predict the tool wear condition, the mean square error value is 0.03, the prediction method is better, and the production efficiency is ensured.

Assessing Genetic Distinctness and Redundancy of Plant Germplasm Conserved Ex Situ Based on Published Genomic SNP Data

Assessing genetic distinctness and redundancy is an important part of plant germplasm characterization. Over the last decade, such assessment has become more feasible and informative, thanks to the advances in genomic analysis. An attempt was made here to search for genebank germplasm with published genomic data and to assess their genetic distinctness and redundancy based on average pairwise dissimilarity (APD). The effort acquired 12 published genomic data sets from CIMMYT, IPK, USDA-ARS, IRRI, and ICRISAT genebanks. The characterized collections consisted of 661 to 55,879 accessions with up to 2.4 million genome-wide SNPs. The assessment generated an APD estimate for each sample. As a higher or lower APD is indicative of more genetic distinctness or redundance for an accession, respectively, these APD estimates helped to identify the most genetically distinct and redundant groups of 100 accessions each and a genetic outlier group with APD estimates larger than five standard deviations in each data set. An APD-based grouping of the conserved germplasm in each data set revealed among-group variances ranging from 1.5 to 53.4% across all data sets. Additional analyses showed that these APD estimations were more sensitive to SNP number, minor allele frequency, and missing data. Generally, 5000 to 10,000 genome-wide SNPs were required for an effective APD analysis. These findings together are encouraging and useful for germplasm management, utilization, and conservation, particularly in the genetic categorization of conserved germplasm.