Search

Salmonella is a major foodborne pathogen which causes widespread contamination and infection worldwide. Salmonella Typhimurium is one of the leading serovars responsible for human and animal salmonellosis, globally. The increasing rate of antibiotic resistance in Salmonella Typhimurium poses a significant global concern, and an improved understanding of the distribution of antibiotic resistance patterns in Salmonella Typhimurium is essential for choosing the suitable antibiotic for the treatment of infections. To evaluate the roles of animal and human in antibiotic resistance dissemination, this study aims to categorize 11,447 S. Typhimurium strains obtained across the food-chain, including food animals, retail meats and humans for 21 years in the United States by analyzing minimum inhibitory concentrations (MICs) values for 27 antibiotics. Random Forest Algorithm and Hierarchical Clustering statistics were used to group the strains according to their minimum inhibitory concentration values. Classification and Regression Tree analysis was used to identify the best classifier for human- and animal-populations’ isolates. We found the persistent population or multi-drug resistant strains of S. Typhimurium across the four time periods (1996∼2000, 2001∼2005, 2006∼2010, 2011∼2016). Importantly, we also detected that there was more diversity in the MIC patterns among S. Typhimurium strains isolated between 2011 and 2016, which suggests significant emergence of diversified multi-drug resistant strains. The most frequently observed (43%) antibiotic resistance patterns found in S. Typhimurium were tetra-resistant pattern ASSuT (ampicillin, streptomycin, sulfonamides, and tetracycline) and the penta-resistant pattern ACSSuT (ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline). Animals (mainly swine and bovine) are the major source for these two frequently found antibiotic resistance patterns. The occurrence of antibiotic resistant strains from humans and chicken is alarming. Strains were mostly susceptible to fluoroquinolones. Together, this study helped in understanding the expansion of dynamics of antibiotic resistance of S. Typhimurium and recommended fluoroquinolones as a possible treatment options against S. Typhimurium infection.

Many species of high-altitude plateaus tend to be narrowly distributed along river valleys at lower elevations due to a limitation of suitable habitats. The eastern honeybee (Apis cerana) is such a species and this study explored the effects of long and narrow geographic distributions on honeybee populations. Genetic differentiation and diversity were assessed across populations of the southeastern Qinghai-Tibet Plateau. A total of 492 honeybee samples from eight sampling sites in four valleys were analyzed for the genetic differentiation and diversity of 31 microsatellite loci and mitochondrial tRNAleu-COII fragments. The following results were obtained: (1) Microsatellite genetic differentiation coefficients (FST) ranged from 0.06 to 0.16, and mitochondrial FST estimates ranged from 0.18 to 0.70 for different sampling sites in the same valley, indicating genetic differentiation. (2) Honeybees in adjacent valleys were also genetically differentiated. The FST of microsatellites and mitochondria were 0.04–0.29 and 0.06–0.76, respectively. (3) Likely a result of small population sizes, the observed genetic diversity was low. The observed impedance of honeybee gene flow among valleys increased both genetic differentiation and population numbers in the Qinghai-Tibet Plateau. This study contributes significantly to the current understanding of the mechanism underlying population genetic differentiation and highlights the potential effects of utilizing genetic resources that are subject to the ecological conditions of the long and narrow geographic distributions of plateau-valley landforms.

Osmotolerance or halotolerance are used to describe resistance to sugars and salt, or only salt, respectively. Here, a comprehensive screen of more than 600 different yeast isolates revealed that osmosensitive species were equally affected by NaCl and glucose. However, the relative toxicity of salt became increasingly prominent in more osmoresistant species. We confirmed that growth inhibition by glucose in a laboratory strain of Saccharomyces cerevisiae occurred at a lower water activity (Aw) than by salt (NaCl), and pre-growth in high levels of glucose or salt gave enhanced cross-resistance to either. Salt toxicity was largely due to osmotic stress but with an additive enhancement due to effects of the relevant cation. Almost all of the yeast isolates from the screen were also noted to exhibit hetero-resistance to both salt and sugar, whereby high concentrations restricted growth to a small minority of cells within the clonal populations. Rare resistant colonies required growth for up to 28 days to become visible. This cell individuality was more marked with salt than sugar, a possible further reflection of the ion toxicity effect. In both cases, heteroresistance in S. cerevisiae was strikingly dependent on the GPD1 gene product, important for glycerol synthesis. In contrast, a tps1Δ deletant impaired for trehalose showed altered MIC but no change in heteroresistance. Effects on heteroresistance were evident in chronic (but not acute) salt or glucose stress, particularly relevant to growth on low Aw foods. The study reports diverse osmotolerance and halotolerance phenotypes and heteroresistance across an extensive panel of yeast isolates, and indicates that Gpd1-dependent glycerol synthesis is a key determinant enabling growth of rare yeast subpopulations at low Aw, brought about by glucose and in particular salt.

Objective: To investigate the population distribution of intermediate host snails and crabs of Paragonimus along the Jiulongjiang River, Zhangjiang River, and Dongxi River basins in Bopingling Mountain, southern Fujian Province, so as to provide baseline data for researches on parasitic disease prevention and control and enlargement of samples in the parasitic resource bank., Methods: A total of 23 villages in 8 counties (districts) along the Jiulong River, Zhangjiang River, and Dongxi River basins in Zhangzhou City, Fujian Province were selected as survey sites during the period from November 2020 through March 2023, and snail and freshwater crabs were sampled from 1 to 3 streams and ditches neighboring residential areas in each village. Morphological identification of snails was performed according to the external morphological characteristics of collected snail shells, and the unidentified snail species sampled from the natural foci of paragonimiasis in Yunxiao County were subjected to se-quence analysis of the mitochondrial cytochrome oxidase 1 ( CO1 ) gene. The crab species was identified by observing the morphological characteristics of the terminal segment of the first pleopod of male crabs, and Paragonimus cercariae and metacercariae were detected in collected snails., Results: The shells of the unidentified snails sampled from the natural foci of paragonimiasis in Yunxiao County were approximately 50 mm in height and 18 mm in width, thick and solid, long tower cone-shaped, and had 8 to 10 whorls. CO1 gene sequence analysis identified the snail species as Sulcospira hainanensis . A total of 6 freshwater snail species belonging to 5 genera within 3 families, identified 23 survey sites, including Semisulcospira libertina , Paludomus zhangchouensis and S. hainanensis that belonged to the Family Pleurceridae, Tricula fujianensis and T. huaanensis that belonged to the subfamily Triculinae, Family Pomatiopsidae, and Melanoides tuberculata (Family Thiaridae), and 11 species of freshwater crabs belonging to 5 genera within 2 families were identified, including Sinopotamon genus of S. jianglense , S. pinheense , and S. zhangzhouense , Huananpotamon genus of H. planopodum and H. zhangzhouense , Nanhaipotamon genus of N. huaanense and N. longhaiense , and Minpotamon genus of M. nasicum and M. auritum that belonged to the Family Potamidae, and Somanniathelphusa genus of S. huaanensis and S. zhangpuensis (Family Parathelphusidae). In addition, the prevalence of P. westermani cercariae infections was 0.08% (2/2 317) in P. zhangchouensis from Danyan Village in Changtai District and 0.09% (1/1 039) in S. hainanensis from Jinkeng Village in Yunxiao County, and the prevalence of P. westermani metacercariae infections was 25.81% (8/31) in S. jianglense from Danyan Village in Changtai District, and 26.31% (5/19) in S. zhangzhouense from Jinkeng Village in Yunxiao County, respectively., Conclusions: There is a population diversity in the intermediate host snails and crabs along the Jiulongjiang River, Zhangjiang River, and Dongxi River basins in Bopingling Mountain, southern Fujian Province, and P. zhangzhouensis and S. hainanensis are, for the first time, confirmed as the first intermediate hosts of P. westermani .

The leaf-miner moth Cameraria ohridella, a pest in Central Europe, causes severe damage to trees. Host-associated differentiation (HAD) for this species has been suggested previously based on the occurrence of a specific mitochondrial haplotype. We assessed genetic diversity and population structure for sympatrically occurring individuals collected in association with two host species, Ohio buckeye (Aesculus glabra) and horse chestnut (Ae. hippocastanum), using six microsatellite loci (SSR) and mtDNA sequences that encode parts of cytochrome oxidase I and II. To infer population structure and assign individuals to clusters, we employed Bayesian clustering. We further characterized the relationships between genetic distance and geographical distance (IBD) in analyzed samples. Although our results derived from the SSR loci analyses demonstrating that there was no population substructuring caused by the hosts, we found evidence of differences in wing size, which might be attributed to the quality of food resources available to larvae. The population structure with K = 2 cannot be interpreted as the result of IBD; rather, it reflects a population differentiation due to demographic or genetic processes (e.g., an origin of invaders). Although genetic diversity was relatively high (He> 0.5), the population had a deficiency of heterozygotes (FIS > 0), which was most likely due to nonrandom mating and, possibly, a Wahlund effect. A star-like haplotype network and negative Tajima's D support the genetic effect of bottleneck followed by population expansion. Based on presumably neutral markers, we conclude that C. ohridella appeared to be a good model for studying evolution toward a generalist invasive species, rather than HAD. [ABSTRACT FROM AUTHOR]

Moehringia grisebachii Janka is a Balkan endemic species spread on the territory of Bulgaria, Romania and Turkey. In the present study were included 17 populations of M. grisebachii from Bulgaria. Morphometric measurements of 24 quantitative traits were performed in all populations. On the base of the data obtained, within population and between population variability was examined. A comparative analysis has been made and similarities and differences have been identified. Dominant in total variability was within populations variability (63.87%). The impact of environmental conditions on measured quantitative traits was reported and as the more important factors the longitude and elevation were pointed out. The results obtained are of importance in the development and updating of the conservation programs for keeping and trust of the genetic diversity and the protected species included in the Red Data Book of Bulgaria. [ABSTRACT FROM AUTHOR]

It is obvious from wider spectrum of successful applications that metaheuristic algorithms are potential solutions to hard optimization problems. Among such algorithms are swarm-based methods like particle swarm optimization and ant colony optimization which are increasingly attracting new researchers. Despite popularity, the core questions on performance issues are still partially answered due to limited insightful analyses. Mere investigation and comparison of end results may not reveal the reasons behind poor or better performance. This study, therefore, performed in-depth empirical analysis by quantitatively analyzing exploration and exploitation of five swarm-based metaheuristic algorithms. The analysis unearthed explanations the way algorithms performed on numerical problems as well as on real-world application of classification using adaptive neuro-fuzzy inference system (ANFIS) trained by selected metaheuristics. The outcome of empirical study suggested that coherence and consistency in the swarm individuals throughout iterations is the key to success in swarm-based metaheuristic algorithms. The analytical approach adopted in this study may be employed to perform component-wise diversity analysis so that the contribution of each component on performance may be determined for devising efficient search strategies. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

K-means clustering combined with genetic algorithm (GA) techniques are used to improve the accuracy of estimation process and to minimize computational effort for solving nonlinear optimization problems. The main purpose of K-means clustering is to exhibit faster convergence which turns into quick evolution. This paper focuses on newly proposed cluster based GA selection techniques for solving unconstrained optimization problems. The K-means cluster based genetic algorithm (GKA) selection techniques comprise of four major stages: clustering, membership probability indexing, fitness evaluation and selection. The hybridization of genetic algorithm and clustering will effectively cater the problem of population diversity and selection pressure. There are two types of GKA selection techniques that are examined, the first selection technique (GKAF) includes two proposed selection operators which are linked with a fixed number of clusters while the second technique (GKAopt) is based on the optimum number of clusters. The main focus of these new selection techniques is to preserve population diversity as well as to avoid local optima. The performance of each technique is evaluated through eleven well known benchmark functions. On the whole, the novel cluster based selection techniques are demonstrated to be extremely efficient and effective for achieving optimum solutions which are verified by simulated results. [ABSTRACT FROM AUTHOR]

The natural environment is a critical factor for the epidemiology of rice blast. To demonstrate the population variation of rice blast field isolates in distinct climates of different years, 57 isolates from rice panicle blast samples in Dawei Mountian district of Hunan province were surveyed from 2013 to 2015. In July and August, the key period for the occurrence of rice panicle blast, there was obvious discrepancy among weather conditions over 3 years. The climate in 2013 was the most arid, better in 2014, and the most suitable was in 2015. For isolates purified in different climates, the pathogenicity assay on twenty-four rice monogenic lines (MLs) showed that the effective resistance (R) genes were Pi5 and Pi1 in 2013; Pi1 in 2014; Pita2, Piz5 and Pi9 in 2015. The genomic analysis based on repetitive element-based polymerase chain reaction (Rep-PCR) also confirmed that there was critical discrepancy among isolates in 3 years. The colony morphology performance at 32 °C high temperature showed that isolates in 2013 were smaller, and with more dense and compact mycelium than isolates in 2014 and 2015. These findings revealed the variation and rich population diversity of the rice blast field fungus under different environments, even in a limited location. [ABSTRACT FROM AUTHOR]

Anaerobic fungi (Neocallimastigomycetes) play an important role in fermenting lignin-rich plant biomass into sugars in the rumen of animals, representing a very promising enzyme resource to contribute to the conversion of plant biomass into biofuels. However, current studies about their functions mainly focus on limited species, and little is known about the coordination of different members of the anaerobic fungi in the digestion process of plant fibres. In this study, the community composition of anaerobic fungi in the rumens of yaks at five different time points (1, 3, 5, 7.5 and 24 h after feeding wheat straw) was investigated employing a cultivation-independent method using ITS clone libraries. Comparison of five pairs of primers showed that PCR primer sets could have clear amplification bias and therefore potentially affect the interpretation of the resulting fungal community structure; then two primer sets GM1/MNGM2 and ITS1/ITS4 were selected. Among the 398 sequences from 10 clone libraries, 18 operational taxonomic units (OTUs) of Neocallimastigomycetes were obtained, covering five known genera and one yet uncultured lineage. OTUs belonging to the bulbous-type morphotype (Caecomyces - or Cyllamyces -related) and the rhizoidal genus Neocallimastix were abundant and predominantly present, representing 62.7% and 19.3% OTUs respectively. In all the later samples taken from 3 h to 24 Neocallimastigomycetes h after feeding, a relatively stable community composition was revealed: members of Neocallimastix increased to represent 43.4–49.4% and the bulbous-type morphotype declined to represent 39.5–42.7%. This implies a substantial turnover and synergy between bulbous and rhizoidal morphotypes of anaerobic fungi during the process of fibre digestion. Our study provided the first insight into the in vivo temporal change in the anaerobic fungal community, and the role of Neocallimastigomycetes with a bulbous morphotype in the degradation of plant cell wall in the yak rumen. [ABSTRACT FROM AUTHOR]

• F. gigantica was the main liver fluke in Cambodia as identified by mPCR- PEPCK gene. • All flukes were classified into F. gigantica haplogroup C based on ND1 gene. • Nucleotide diversity of ND1 of Cambodian flukes was higher than that from Thailand. • Nucleotide diversity of Cambodian population was higher than that from Thailand. • Population genetics suggest that F. gigantica spread from Cambodia to other areas. Fasciola gigantica and hybrid Fasciola are distributed throughout Asia. Herein, we investigated the species of the Fasciola fluke distributed in three hotspots of fascioliasis in Cambodia. A total of 92 flukes collected from 21 slaughtered cattle from Kandal (44), Battambang (41), and Kratie (7) Provinces were identified as F. gigantica using multiplex PCR for a nuclear phosphoenolpyruvate carboxykinase (PEPCK) gene. The overall prevalence of F. gigantica infestation was 7.14% (21/294). Phylogenetic as well as population genetics analyses were performed using the mitochondrial NADH dehydrogenase subunit 1 (ND1). The 19 ND1 haplotypes were identified from Cambodian F. gigantica (haplotype diversity, 0.83). All of the haplotypes were classified into F. gigantica haplogroup C, which includes ND1 haplotypes detected from Thailand, Vietnam, Indonesia, Myanmar, and China. Among haplogroup C, novel and unique haplotypes of Cambodia were found in the Battambang and Kandal Provinces, and the nucleotide diversity of the Cambodian population (0.00532) was the highest. Pairwise fixation indices among the F. gigantica populations from these countries indicated that the Cambodian and Thailand populations were related to each other. The highest genetic diversity in the Cambodian population suggests that F. gigantica in Cambodia may be the ancestor of the populations in Southeast Asian countries. Most likely, livestock movement, including Zebu cattle, played an important role in the transmission of F. gigantica. In this study, the hybrid Fasciola flukes that are commonly found in neighboring countries, were not found in Cambodia. Further comprehensive investigations of Fasciola prevalence should be conducted by analyzing a wider range of hosts throughout Cambodia to reach a more solid conclusion about the absence of hybrid flukes. [ABSTRACT FROM AUTHOR]

Potato crop losses can be substantial when conditions for late blight (Phytophthora infestans) development and spread are favourable. In this study, drivers of differences between the P. infestans population structures in Latvia and Lithuania, two neighbouring countries with similar potato‐growing traditions, were investigated. Genotypes of P. infestans and population genetic diversity were analysed using a 12‐plex simple sequence repeat (SSR) marker assay. High genetic diversity was demonstrated in both populations, with population diversity being higher in Latvia. It would appear that local populations established from soilborne oospores early in the season are well adapted to the conditions in the region. However, somewhat greater spread and survival of local clones was detected in Lithuania, suggesting that potato cropping there is more vulnerable to clonal invasion than in Latvia. For effective disease management, current strategies should be adjusted according to the specific pathogen populations in the region, considering the reproduction and survival of the pathogen. Potato growers should implement late blight preventive measures such as longer field rotation to prevent oospore infections, especially in Latvia, and should use more disease resistant cultivars and high‐quality seed potatoes. [ABSTRACT FROM AUTHOR]

Based on the chicken swarm algorithm, this paper proposed an improved version of the chicken swarm algorithm (ECSO), which introducing adaptive mutation strategy for balancing algorithm later decreased diversity of the population and improving the speed of convergence process and introducing random walk strategy preference into hen mobile update process to balance development and exploration stage to enhance the stability of the algorithm, and which introducing leader strategy of updating position of chickens to reduce the blindness of the search algorithm. Finally, it verifies the effectiveness of the improved algorithm by comparing the test benchmark functions with the basic bat algorithm and the chicken swarm algorithm and other improved chicken swarm algorithm. [ABSTRACT FROM AUTHOR]

Many species of high-altitude plateaus tend to be narrowly distributed along river valleys at lower elevations due to a limitation of suitable habitats. The eastern honeybee (Apis cerana) is such a species and this study explored the effects of long and narrow geographic distributions on honeybee populations. Genetic differentiation and diversity were assessed across populations of the southeastern Qinghai-Tibet Plateau. A total of 492 honeybee samples from eight sampling sites in four valleys were analyzed for the genetic differentiation and diversity of 31 microsatellite loci and mitochondrial tRNAleu-COII fragments. The following results were obtained: (1) Microsatellite genetic differentiation coefficients (F ST) ranged from 0.06 to 0.16, and mitochondrial F ST estimates ranged from 0.18 to 0.70 for different sampling sites in the same valley, indicating genetic differentiation. (2) Honeybees in adjacent valleys were also genetically differentiated. The F ST of microsatellites and mitochondria were 0.04–0.29 and 0.06–0.76, respectively. (3) Likely a result of small population sizes, the observed genetic diversity was low. The observed impedance of honeybee gene flow among valleys increased both genetic differentiation and population numbers in the Qinghai-Tibet Plateau. This study contributes significantly to the current understanding of the mechanism underlying population genetic differentiation and highlights the potential effects of utilizing genetic resources that are subject to the ecological conditions of the long and narrow geographic distributions of plateau-valley landforms. [ABSTRACT FROM AUTHOR]

The population diversity and structure of CRISPR-Cas immunity provides key insights into virus-host interactions. Here, we examined two geographically and genetically distinct natural populations of the thermophilic crenarchaeon Sulfolobus islandicus and their interactions with Sulfolobus spindle- shaped viruses (SSVs) and S. islandicus rod-shaped viruses (SIRVs). We found that both virus families can be targeted with high population distributed immunity, whereby most immune strains target a virus using unique unshared CRISPR spacers. In Kamchatka, Russia,we observed high immunity to chronic SSVs that increases over time. In this context, we found that some SSVs had shortened genomes lacking genes that are highly targeted by the S. islandicus population, indicating a potential mechanism of immune evasion. By contrast, in Yellowstone National Park, we found high inter- and intrastrain immune diversity targeting lytic SIRVs and low immunity to chronic SSVs. In this population, we observed evidence of SIRVs evolving immunity through mutations concentrated in the first five bases of protospacers. These results indicate that diversity and structure of antiviral CRISPR-Cas immunity for a single microbial species can differ by both the population and virus type, and suggest that different virus families use different mechanisms to evade CRISPR-Cas immunity. [ABSTRACT FROM AUTHOR]

Salmonella is a major foodborne pathogen which causes widespread contamination and infection worldwide. Salmonella Typhimurium is one of the leading serovars responsible for human and animal salmonellosis, globally. The increasing rate of antibiotic resistance in Salmonella Typhimurium poses a significant global concern, and an improved understanding of the distribution of antibiotic resistance patterns in Salmonella Typhimurium is essential for choosing the suitable antibiotic for the treatment of infections. To evaluate the roles of animal and human in antibiotic resistance dissemination, this study aims to categorize 11,447 S. Typhimurium strains obtained across the food-chain, including food animals, retail meats and humans for 21 years in the United States by analyzing minimum inhibitory concentrations (MICs) values for 27 antibiotics. Random Forest Algorithm and Hierarchical Clustering statistics were used to group the strains according to their minimum inhibitory concentration values. Classification and Regression Tree analysis was used to identify the best classifier for human- and animal-populations' isolates. We found the persistent population or multi-drug resistant strains of S. Typhimurium across the four time periods (1996∼2000, 2001∼2005, 2006∼2010, 2011∼2016). Importantly, we also detected that there was more diversity in the MIC patterns among S. Typhimurium strains isolated between 2011 and 2016, which suggests significant emergence of diversified multi-drug resistant strains. The most frequently observed (43%) antibiotic resistance patterns found in S. Typhimurium were tetra-resistant pattern ASSuT (ampicillin, streptomycin, sulfonamides, and tetracycline) and the penta-resistant pattern ACSSuT (ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline). Animals (mainly swine and bovine) are the major source for these two frequently found antibiotic resistance patterns. The occurrence of antibiotic resistant strains from humans and chicken is alarming. Strains were mostly susceptible to fluoroquinolones. Together, this study helped in understanding the expansion of dynamics of antibiotic resistance of S. Typhimurium and recommended fluoroquinolones as a possible treatment options against S. Typhimurium infection. [ABSTRACT FROM AUTHOR]

Genetic algorithm (GA) is an important and effective method to solve the optimization problem, which has been widely used in most practical applications. However, the premature convergence of GA has unexpected effect on the algorithm's performance, the main reason is that the evolution of outstanding individuals multiply rapidly will lead to premature loss of population's diversity. To solve the above problem, a method to qualify the population diversity and similarity between adjacent generations is proposed. Then, according to the evaluation of population diversity and the fitness of individual, the adaptive adjustment of crossover and mutation probability is realized. The results of several benchmark functions show that the proposed algorithm can search the optimal solution of almost all benchmark functions and effectively maintain the diversity of the population. Compared with the existing algorithms, it has greatly improved the convergence speed and the global optimal solution. [ABSTRACT FROM AUTHOR]

This paper proposed a hybrid flower pollination algorithm (refrHFPA) based on refraction principle for the slow convergence rate of flower pollination algorithm and low optimization accuracy. The algorithm firstly used the harmony search algorithm to improve the convergence speed of the algorithm, then it used the refraction principle to improve the diversity of the population, and helped the algorithm to jump out of the local optimal and improved the accuracy of optimization. It used eight test functions to compare other intelligent algorithms, and the results show that the refrHFPA algorithm has a significant improvement in convergence speed and optimization accuracy. [ABSTRACT FROM AUTHOR]

To avoid problems such as premature convergence and falling into a local optimum, this paper proposes an improved real-coded genetic algorithm (RCGA-rdn) to improve the performance in solving numerical function optimization. These problems are mainly caused by the poor search ability of the algorithm and the loss of population diversity. Therefore, to improve the search ability, the algorithm integrates three specially designed operators: ranking group selection (RGS), direction-based crossover (DBX) and normal mutation (NM). In contrast to the traditional strategy framework, RCGA-rdn introduces a new step called the replacement operation, which periodically performs a local initialization operation on the population to increase the population diversity. In this paper, comparisons with several advanced algorithms were performed on 21 complex constrained optimization problems and 10 high-dimensional unconstrained optimization problems to verify the effectiveness of RCGA-rdn. Based on the results, to further verify the feasibility of the algorithm, it was applied to a series of practical engineering optimization problems. The experimental results show that the proposed operations can effectively improve the performance of the algorithm. Compared with the other algorithms, the improved algorithm (RCGA-rdn) has a better search ability, faster convergence speed and can maintain a certain population diversity. [ABSTRACT FROM AUTHOR]

Xanthomonas campestris pv. campestris (Xcc) is the causal agent of black rot in Brassicaceae. It is widespread in Italy and severe outbreaks occur under conditions that favour disease development. In this study a multilocus sequence typing approach (MLST) based on the partial sequence of seven loci was applied to a selection of strains representative of the main areas of cultivation and hosts. The aim was to investigate whether the long tradition of brassica crops in Italy has influenced the evolution of different Xcc populations. All loci were polymorphic; 14 allelic profiles were identified of which 13 were unique to Italian strains. Based on the seven loci, the most common genotype within the Italian Xcc strains (AP1) was also the most representative genotype found in worldwide Xcc strains. This genotype was included in a new clonal complex in addition to three other clonal complexes already identified in Xcc populations. The phylogenetic reconstruction using a concatenated dataset of four conserved protein‐coding genes, dnaK, fuyA, gyrB and rpoD, showed that the Italian strains belonged to two genetic groups. Physiological races were also investigated for the first time in Italy. The race structure of Xcc was determined by inoculating eight differential Brassica lines belonging to five species and showed that, in Italy, race 4 is the most widespread, followed by races 1 and 6. No correlation was found between allelic profiles, host of isolation, geographical origin and races, although a prevalent race was identified within the same clonal complex. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southern Agriculture is the property of Journal of Southern Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To investigate epigenomic indices of diabetic kidney disease (DKD) susceptibility among high-risk populations with type 2 diabetes mellitus. KDIGO (Kidney Disease: Improving Global Outcomes) clinical guidelines were used to classify people living with or without DKD. Differential gene methylation of DKD was then assessed in a discovery Aboriginal Diabetes Study cohort (PROPHECY, 89 people) and an external independent study from Thailand (THEPTARIN, 128 people). Corresponding mRNA levels were also measured and linked to levels of albuminuria and eGFR. Increased DKD risk was associated with reduced methylation and elevated gene expression in the PROPHECY discovery cohort of Aboriginal Australians and these findings were externally validated in the THEPTARIN diabetes registry of Thai people living with type 2 diabetes mellitus. Novel epigenomic scores can improve diagnostic performance over clinical modelling using albuminuria and GFR alone and can distinguish DKD susceptibility. [ABSTRACT FROM AUTHOR]

Ancylostoma ceylanicum is a zoonotic helminth that is commonly found in domestic dogs and cats throughout Asia but is largely neglected in many countries. This study aimed to confirm the species of hookworm in dogs and soil environments and investigate the evolutionary analyses of A. ceylanicum among Thai and Asian populations. In a total of 299 dog fecal samples and 212 soil samples from 53 temples, the prevalence rates of hookworm infection by microscopic examination were 26.4% (79/299) and 10.4% (22/212) in dog and soil samples, respectively. A PCR-RFLP targeting the ITS region was then utilized to identify the hookworm species. In dogs, A. ceylanicum was the main hookworm species, and the rates of A. ceylanicum and A. caninum infections were 96.6% and 3.5%, respectively. The genetic characterization and diversity indices of the A. ceylanicumcox1 gene among Thai and Asian populations were evaluated. Nine haplotypes were identified from Thai A. ceylanicum, in which the haplotype diversity and the nucleotide diversity were 0.4436 and 0.0036, respectively. The highest nucleotide diversity of Chinese A. ceylanicum populations suggested that it could be the ancestor of the populations. Pairwise fixation indices indicated that Thai A. ceylanicum was closely related to the Malaysian population, suggesting a gene flow between these populations. The temples with hookworm-positive dogs were associated with the presence of hookworm-contaminated soil, as these levels showed an approximately four-fold increase compared with those in temples with hookworm-negative dogs (OR = 4.38, 95% CI: 1.55–12.37). Interestingly, the genotypes of A. ceylanicum in the contaminating soil and infecting dogs were identical. Therefore, increased awareness and concern from the wider public communities with regard to the responsibility of temples and municipal offices to provide proper deworming programs to community dogs should be strongly endorsed to reduce the risk of the transmission of this zoonotic disease. In addition, parasitic examination and treatment should be strongly implemented before dogs are imported and exported worldwide.

Fusarium species are the most detrimental pathogens of soybean root rot worldwide, causing large loss in soybean production. Maize/soybean relay strip intercropping has significant advantages on the increase of crop yields and efficient use of agricultural resources, but its effects on the occurrence and pathogen population of soybean root rot are rarely known. In this study, root rot was investigated in the fields of the continuous maize/soybean strip relay intercropping and soybean monoculture. Fusarium species were isolated from diseased soybean roots and identified based on sequence analysis of translation elongation factor 1α (EF-1α) and RNA polymerase II second largest subunit (RPB2), and the diversity and pathogenicity of these species were also analyzed. Our results showed that intercropping significantly decreased soybean root rot over monoculture. A more diverse Fusarium population including Fusarium solani species complex (FSSC), F. incarnatum-equiseti species complex (FIESC), F. oxysporum, F. fujikuroi, F. proliferatum and F. verticillioides, F. graminearum and F. asiaticum was identified from intercropping while FSSC, FIESC, F. oxysporum, F. commune, F. asiaticum and F. meridionale were found from monoculture. All Fusarium species caused soybean root infection but exhibited distinct aggressiveness. The most aggressive F. oxysporum was more frequently isolated in monoculture than intercropping. FSSC and FIESC were the dominant species complex and differed in their aggressiveness. Additionally, F. fujikuroi, F. proliferatum and F. verticillioides were specifically identified from intercropping with weak or middle aggressiveness. Except for F. graminearum, F. meridionale and F. asiaticum were firstly reported to cause soybean root rot in China. This study indicates maize/soybean relay strip intercropping can reduce soybean root rot, change the diversity and aggressiveness of Fusarium species, which provides an important reference for effective management of this disease.

This research represents a detailed insight into the modern and popular hybridization of deterministic chaotic dynamics and evolutionary computation. It is aimed at the influence of chaotic sequences on the performance of four selected Differential Evolution (DE) variants. The variants of interest were: original DE/Rand/1/ and DE/Best/1/ mutation schemes, simple parameter adaptive jDE, and the recent state of the art version SHADE. Experiments are focused on the extensive investigation of the different randomization schemes for the selection of individuals in DE algorithm driven by the nine different two-dimensional discrete deterministic chaotic systems, as the chaotic pseudorandom number generators. The performances of DE variants and their chaotic/non-chaotic versions are recorded in the one-dimensional settings of 10D and 15 test functions from the CEC 2015 benchmark, further statistically analyzed.

Abstract Didelphis albiventris are found throughout Northeast and Central Brazil to central-southern Uruguay and it was subject of few studies in a population level. Given this, the present study investigated the genetic variability of the species using the mitochondrial molecular marker cytochrome oxidase c subunit I. We analyzed samples from the different biomes within three Brazilian regions: Northeast (Caatinga , Cerrado, and Atlantic Forest), Southeast (Cerrado , Atlantic Forest, Cerrado/Atlantic Forest, and Cerrado/Caatinga ecotones) and South (Pampa and Atlantic Forest). Software BAPs retrieved five distinct demes: dm 1, dm 2, and dm 5 that occurs in South, Northeast and Southeast regions respectively and the dm 3 and dm 4 are wide distributed in Northeast and Southeast. Population analysis performed with AMOVA, haplotype network and Mantel test estimated the veracity of the demes. The FST shows structuring for the five demes, with dm 1 (South region) isolated from the others, however the other analysis showed the Northeast/Southeast demes (dm 2-5) united, diagnosing gene flow between them, mainly at the transitional zones, in areas as far away as areas with similar latitude interval (Southeast vs South) that was not detected gene flow. In the haplotype network, the mutational steps was conclusive in split dm1 from dm 2-5 with 15 mutational steps and the Mantel test was moderated, which is explained by genetic similarity despite the great geographic distances (Northeast/Southeast). Thus, our analysis recognized two different lineages (South and Northeast/Southeast) and indicate that the biomes were not decisive in their isolation. The sharing of demes at the transitional zones and in areas with high latitudinal intervals reflects a recent ancestral polymorphism for D. albiventris. The plasticity in the occupation of the space by this species contributes in its wide dispersion capability, that is, geographical distribution. Our results revealed important implications for the management of D. albiventris in these transitional zones areas where demes were shared.

The employment of specific genes, which determine host resistance to avirulent pathotypes of the pathogen, is not recommended for protecting barley against powdery mildew (Blumeria graminis f.sp. hordei). However, most barley varieties still possess specific resistance genes to this pathogen. The effectiveness of such resistances was determined by assessing virulence frequency using randomly collected Czech population samples of 521 pathogen isolates from the air tested on 29 barley differential varieties over a four-year period. Most virulence frequencies did not show major changes, but the frequencies on the winter cv. Laverda and the spring cv. Kangoo greatly increased. The highest virulence frequency in all four years was on the resistance Ru2 in Kompolti 4. The period of sampling the air population and associated changes in the proportion of spores that developed on spring and winter varieties with different resistances are one of causes of the changes in virulence frequencies. It was also found out that the virulence complexity of pathotypes with the frequency > 1 was markedly lower than the complexity of pathotypes with the frequency of 1. This could indicate the higher fitness of pathotypes with fewer virulences.