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Accurate species identification is crucial for developing conservation strategies for freshwater mussels, one of the most imperiled faunas in the world. Traditionally, mussel species description primarily relied on conchological characters. However, shell morphology has great variability, which leads to the complexity of species delimitation. As endemic species to China, Lamprotula caveata was originally described by Heude (1877). Lamprotula quadrangulosus and Lamprotula contritus were considered for synonymization of L. caveata based on shell variants in the early 20th century, which has been long debated due to lack of rigorous molecular analysis. Moreover, great morphological variation caused doubt whether there are cryptic species. In this study, we used a combined phylogenetic and morphometric approach to verify the validity of the synonymization of L. caveata. The results of molecular species delimitation showed that two molecular operational taxonomic units (MOTUs) were identified in Lamprotula spp., including the L. leaii lineage and the complex lineage (L. quadrangulosa, L. cornuumlunae, L. contritus, and L. caveata). Phylogenetic analyses revealed that L. cornuumlunae formed a basal monophyletic clade, whose divergence time was relatively recent (4.26 Ma [95% HPD = 1.91–7.22 Ma]), and L. contritus, L. caveata, and L. quadrangulosa formed a large polytomy group with very shallow branches. In the previous study, we have demonstrated the validity of L. cornuumlunae. The molecular evidences supported that the complex (L. quadrangulosa + L. contritus + L. caveata) was a valid species; L. quadrangulosa and L. contritus were synonyms of L. caveata. In addition, three morphospecies (L. quadrangulosa, L. contritus, and L. caveata) were aggregated without clear differentiation based on shell morphometric analysis. We confirmed multiple phenotypes in L. caveata for species identification and presumed that the phenotypic plasticity was a response to specific habitats. This study clarified the diversity and phylogeny of the Lamprotula group, which is a crucial step for developing new conservation and management strategies for this imperiled group. [ABSTRACT FROM AUTHOR]

Dams and diversions are a primary threat to freshwater fish biodiversity, including the loss of species and restructuring of communities, often resulting in taxonomic homogenization (increased similarity) over time. Mitigating these impacts requires a strong scientific understanding of both patterns and drivers of fish diversity. Here, we test whether different components of fish biodiversity have changed in response to major dam construction, and whether these patterns are predictable as a function of key environmental factors in the Gan River Basin, China. The results showed that total and native species alpha diversity have declined from the historical period (pre-dam) to the current period (post-dam). A total of 29 native species are lost, while 6 alien species were gained over time. We found evidence for fish faunal homogenization in the Gan River Basin, with a slight (1%) increase in taxonomic similarity among river basins from the historical period to the current period. Additionally, we revealed significant associations between drainage length, drainage area, and average air temperature, and alpha and beta fish diversity. This study provides new insight into the patterns and drivers of fish biodiversity change in the broader Yangtze River Basin and helps inform management efforts seeking to slow, and even reverse, current trajectories of biodiversity change. [ABSTRACT FROM AUTHOR]

Freshwater mussels (Mollusca: Bivalvia: Unionida) have a broad global distribution on every continent except Antarctica. However, owing to human activities, the diversity of freshwater mussels is seriously globally threatened. China is an important global biodiversity hotspot for this fauna.This article comprehensively reviews the 99 currently recognized species in China, collating for the first time their systematics, distribution, life‐history traits, habitat preferences, conservation status, and main threats to suggest future management actions.The review showed that the taxonomic status and species validity of many freshwater mussels are still not well resolved. The freshwater mussel diversity in the Yangtze River Basin is higher than that in other freshwater habitats in China. Life history characteristics and habitat preferences are poorly known for most species.Only half of the total number of species in China have been assessed for their conservation status. Among those assessed, around half of them are threatened with extinction with more than 10% being considered as Data Deficient.The key threats identified as potentially related to species declines are pollution, habitat loss and fragmentation, loss of access to host fishes and overharvesting of mussels or their host fishes.The review shows that there is a strong geographical bias in the amount of knowledge available for freshwater mussels, with most of the available data being concentrated in the middle and lower reaches of the Yangtze basin. Almost no data are available for these taxa north of the Yellow River basin and in the west and south‐west regions of China.To make future conservation and management more effective we suggest that efforts should be concentrated on: (i) increasing the amount of research on basic ecological and life‐history features, including growth, life‐span, reproductive cycle, host fish identification and habitat requirements of each species; (ii) establishing the interspecific and intraspecific genetic diversity patterns of Chinese freshwater mussels, to clarify their taxonomy, systematics and phylogeny, and to understand the phylogeography and population structure of each species; and (iii) urgently establishing protected areas for fish and mussels in locations of high species richness, such as Poyang Lake and Dongting Lake, and also in regions with high levels of endemism or genetic uniqueness, such as Guangxi Province, Yunnan Province and Heilongjiang Province. In addition, the need for habitat restoration and the conservation of freshwater mussels has become urgent in China, and an integrated systematic conservation and management plan should be developed and effectively implemented. [ABSTRACT FROM AUTHOR]

Background: Classification of parasitic bopyrids has traditionally been based on morphological characteristics, but phylogenetic relationships have remained elusive due to limited information provided by morphological data and tendency for loss of morphological features as a result of parasitic lifestyle. Subfamily Argeiinae was separated from Bopyrinae based on morphological evidence, although the assignment of all genera has not been phylogenetically evaluated. Bopyroides hippolytes has been traditionally classified in Bopyrinae, but divergent morphological characters make this assignment questionable. To investigate the relationship of bopyrines, we sequenced the complete mitochondrial genome of B. hippolytes and four mitochondrial genes of two other Bopyrinae. Results: The phylogenetic trees based on separate and combined cox1and 18S sequence data recovered Bopyridae as robustly monophyletic, but Bopyrinae as polyphyletic. Bopyroides hippolytes was a close sister to Argeia pugettensis, type species to Argeiinae. Mitochondrial phylogenomics also suggested that B. hippolytes was close to Argeiinae. We also found a novel gene order in B. hippolytes compared to other isopods. Conclusions: Bopyroides hippolytes should be excluded from the Bopyrinae and has a close affinity with Argeia pugettensis based on molecular and morphological data. The conserved syntenic blocks of mitochondrial gene order have distinctive characteristics at a subordinal level and may be helpful for understanding the higher taxonomic level relationships of Isopoda. [ABSTRACT FROM AUTHOR]

In this paper, we formulate an age-structured HIV model, in which the influence of humoral immunity and the infection age of the infected cells are considered. The model is governed by three ordinary differential equations and two first-ordered partial differential equations and admits three equilibria: disease-free, immune-inactivated and immune-activated equilibria. We introduce two important thresholds: the basic reproduction number R 0 and immune-activated reproduction number R 1 and further show the global stability of above three equilibria in terms of R 0 and R 1 , respectively. The numerical simulations are presented to illustrate our results. [ABSTRACT FROM AUTHOR]

Freshwater mussels are one of the most diverse groups of freshwater organisms as well as one of the most endangered groups of organisms on Earth. Freshwater mussels have a life history that greatly influences their geographical distribution, genetic structure, and demographic characteristics. Here, we describe and compare the spatial genetic structure and diversity of 5 freshwater mussel species with different brooding periods and uses of larval parasitism. These 5 species co-occur in tributaries in Poyang Lake in south central China, and we studied their populations in the Gan and Fuhe Rivers, which are both large tributaries of Poyang Lake. Cytochrome c oxidase subunit-I (COI) haplotype richness and diversity of species with a spring or summer glochidia brooding period (Lamprotula caveata , Nodularia douglasiae , and Solenaia oleivora) were greater than richness and diversity in species with a winter brooding period (Anemina arcaeformis , S. carinata). In addition, the COI haplotype richness and diversity of A. arcaeformis , which does not have a parasitic portion of its life cycle, was lower than 3 species that require a host fish to complete their life cycles (L. caveata , N. douglasiae , and S. oleivora) and was higher than S. carinata. We also used the COI sequences and microsatellite datasets to determine whether the populations of each of the 5 species in the Gan and Fuhe Rivers are admixed or genetically distinct. Genetic differentiation was evident among collection populations of L. caveata , N. douglasiae , and S. carinata and largely absent in A. arcaeformis and S. oleivora. We conclude that differences in genetic diversity and patterns of genetic structure in these sympatric species could result from the different life-history attributes of these species, particularly timing and length of the brooding period, nonparasitic vs parasitic life cycles, and different host fish requirements. Therefore, we suggest increased emphasis on life history and reproductive biology research and urge managers to consider that these traits differ among freshwater mussels when making management decisions for the conservation of genetic and species diversity. [ABSTRACT FROM AUTHOR]

Habitat fragmentation is one of the main threats to biodiversity. Barriers to dispersal caused by anthropogenic habitat alteration may affect phylogeographic patterns in freshwater mussels. Knowledge of the phylogenetic and phylogeographic patterns of unionoids is vital to inform protection of their biodiversity.Here, we assessed influences of dams and their environmental effects on the genetic diversity and population connectivity of a broadly distributed freshwater mussel, Nodularia douglasiae, in Poyang Lake Basin.The results showed high genetic diversity in areas without dams and low genetic diversity in areas with dams. High genetic differentiation and low gene flow were found among the 11 populations. Genetic variation was significantly correlated with dissolved oxygen levels.The observation of low genetic diversity in populations separated by dams indicated that those populations were subjected to genetic erosion and demographic decline because they are disconnected from other populations with higher diversity. High genetic differentiation and low gene flow among the 11 populations could be correlated with anthropogenic habitat alteration.These results indicated that anthropogenic habitat alterations have led to the decline in freshwater mussel diversity. Therefore, we recommend maintaining favourable habitat conditions and connectivity of rivers or lakes, and strengthening study of life histories with host‐test experiments to identify potential host fish species to strengthen the knowledge base underpinning freshwater mussel conservation. [ABSTRACT FROM AUTHOR]

Freshwater mussels provide important functions and services for aquatic ecosystems, but populations of many species have been extirpated. Information on biodiversity plays an important role in the conservation and management of freshwater mussels. The Xin River Basin is a biodiversity hotspot for freshwater mussels in China, with more than 43 species known, but populations of which are decreasing. Here, we quantify the diversity of freshwater mussels in the middle and lower reaches of the Xin River Basin and study the correlation of habitat characteristics and freshwater mussel diversity. Compared to the historical period, the number of species, density, and biomass of freshwater mussels decreased 33%, 83%, and 82% in the current period, respectively. Fifty two percent of recorded species were empty shells, and 14 native freshwater mussels were not found in the study area. Four species are currently listed as vulnerable species using IUCN criteria and their global status. The assemblage structure of freshwater mussels exhibits significant spatial differences, and there was a correlation with substrate and physicochemical parameters. The main tributary of the Xin River with higher freshwater mussel diversity should be established as one large protected area because the nestedness component was the main pattern of beta diversity. These results indicated freshwater mussel diversity was declining rapidly, which can help focus conservation effort for freshwater mussel biodiversity. [ABSTRACT FROM AUTHOR]

A vector-borne disease is caused by a range of pathogens and transmitted to hosts through vectors. To investigate the multiple effects of the spatial heterogeneity, the temperature sensitivity of extrinsic incubation period and intrinsic incubation period, and the seasonality on disease transmission, we propose a nonlocal reaction-diffusion model of vector-borne disease with periodic delays. We introduce the basic reproduction number R0 for this model and then establish a threshold-type result on its global dynamics in terms of R0. In the case where all the coefficients are constants, we also prove the global attractivity of the positive constant steady state when R0>1. Numerically, we study the malaria transmission in Maputo Province, Mozambique. [ABSTRACT FROM AUTHOR]

In this work, the dielectric spectroscopy and dynamic mechanical thermal spectroscopy of neat epoxy and epoxy nanocomposites modified by boehmite, γ‐alumina and α‐alumina nanoparticles, respectively, were investigated. The dielectric behavior of epoxy resin was significantly affected by the incorporation of α‐alumina nanofiller. The values of real and imaginary part of relative permittivity of epoxy/α‐alumina nanocomposite were even lower than these of neat epoxy. On the contrary, these values of boehmite and γ‐alumina nanocomposites were higher than these of neat epoxy. The glass transition temperature (Tg) determined by dynamic mechanical thermal analysis (DMA) was obviously decreased when boehmite nanofiller was added into the epoxy nanocomposite. The value of Tg was slightly decreased by γ‐alumina and apparently increased by α‐alumina nanofiller. These changes of performance may be attributed to that the existence of α‐alumina nanoparticles restricted the mobility of polymer molecular chains. POLYM. COMPOS., 39:2307–2319, 2018. © 2016 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

The Yangtze River drainage in China is among the most species rich rivers for freshwater mussels (order Unionida) on Earth with at least 68 species known. The freshwater mussels of the Yangtze River face a variety of threats with indications that species are declining in abundance and area of occupancy. This study represents the first analyses of the genetic structure and diversity for the common and widespread freshwater mussel Nodularia douglasiae based on microsatellite DNA genotypes and mitochondrial DNA sequences. Phylogenetic analysis a fragment of the COI mitochondrial gene indicated that N. douglasiae collected from across the middle and lower Yangtze River drainage are monophyletic with N. douglasiae from Japan, Russia, and South Korea. The results of the analysis of both the mtDNA and microsatellite datasets indicated that the seven collection locations of N. douglasiae in the middle and lower Yangtze River drainage showed high genetic diversity, significant genetic differentiation and genetic structure, and stable population dynamics over time. Moreover, we found that the connections among tributaries rivers and lakes in the Yangtze River drainage were important in maintaining gene flow among locations that N. douglasiae inhabits. An understanding of the genetic structure and diversity of a widespread species like N. douglasiae could be used as a surrogate to better understand the populations of other freshwater mussel species that are more rare in the Yangtze River drainage. At the same time, these results could provide a basis for the protection of genetic diversity and management of unionid mussels diversity and other aquatic organisms in the system. [ABSTRACT FROM AUTHOR]

Since a vehicle logo is the clearest indicator of a vehicle manufacturer, most vehicle manufacturer recognition (VMR) methods are based on vehicle logo recognition. Logo recognition can be still a challenge due to difficulties in precisely segmenting the vehicle logo in an image and the requirement for robustness against various imaging situations simultaneously. In this paper, a convolutional neural network (CNN) system has been proposed for VMR that removes the requirement for precise logo detection and segmentation. In addition, an efficient pretraining strategy has been introduced to reduce the high computational cost of kernel training in CNN-based systems to enable improved real-world applications. A data set containing 11 500 logo images belonging to 10 manufacturers, with 10 000 for training and 1500 for testing, is generated and employed to assess the suitability of the proposed system. An average accuracy of 99.07% is obtained, demonstrating the high classification potential and robustness against various poor imaging situations. [ABSTRACT FROM PUBLISHER]

Biomphalaria straminea is an invasive species in China and is one of the intermediate hosts of Schistosoma mansoni which results in the spread of schistosomiasis. Herein, we firstly report the complete mitochondrial genome of B. straminea. The full length of the mitochondrial genome is 13,652 bp. It consists of 37 typical animal mitochondrial genes, comprising 13 protein-coding genes, 22 transfer RNA genes, and two ribosomal RNA genes. The contents of each base in the complete mitochondrial genome are 33.28% A, 42.01% T, 10.85% C, and 13.87% G, with a high A + T content of 75.29%. Phylogenetic analysis showed that the relationship of B. straminea and Biomphalaria tenagophila was more closed. [ABSTRACT FROM AUTHOR]