Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 72
Filter
1.
J Econ Entomol ; 115(6): 1790-1805, 2022 12 14.
Article in English | MEDLINE | ID: mdl-36515109

ABSTRACT

The fall armyworm (FAW) Spodoptera frugiperda (Smith; Lepidoptera: Noctuidae) is present in over 70 countries in Africa, Asia, and Oceania. Its rapid dispersal since 2016 when it was first reported in western Africa, and associated devastation to agricultural productivity, highlight the challenges posed by this pest. Currently, its management largely relies on insecticide sprays and transgenic Bacillus thuringiensis toxins, therefore understanding their responses to these agents and characteristics of any resistance genes enables adaptive strategies. In Australia, S. frugiperda was reported at the end of January 2020 in northern Queensland and by March 2020, also in northern Western Australia. As an urgent first response we undertook bioassays on two Australian populations, one each from these initial points of establishment. To assist with preliminary sensitivity assessment, two endemic noctuid pest species, Helicoverpa armigera (Hübner; Lepidoptera, Noctuidae) and Spodoptera litura (Fabricius; Lepidoptera, Noctuidae), were concurrently screened to obtain larval LC50 estimates against various insecticides. We characterized known resistance alleles from the VGSC, ACE-1, RyR, and ABCC2 genes to compare with published allele frequencies and bioassay responses from native and invasive S. frugiperda populations. An approximately 10× LC50 difference for indoxacarb was detected between Australian populations, which was approximately 28× higher than that reported from an Indian population. Characterization of ACE-1 and VGSC alleles provided further evidence of multiple introductions in Asia, and multiple pathways involving genetically distinct individuals in Australia. The preliminary bioassay results and resistance allele patterns from invasive S. frugiperda populations suggest multiple introductions have contributed to the pest's spread and challenge the axiom of its rapid 'west-to-east' spread.


Subject(s)
Insecticides , Moths , Animals , Spodoptera/genetics , Hemolysin Proteins/pharmacology , Alleles , Endotoxins/genetics , Insecticide Resistance/genetics , Bacterial Proteins/genetics , Australia , Insecticides/pharmacology , Larva , Biological Assay , Zea mays/genetics
2.
Mitochondrial DNA B Resour ; 7(6): 1183-1185, 2022.
Article in English | MEDLINE | ID: mdl-35783040

ABSTRACT

We present the draft mitochondrial genomes (mitogenomes) of two Lepisiota frauenfeldi (Mayr 1855) workers from two separate invasive populations detected in Western Australia (Perth OK569858) and Queensland (Brisbane OK5569859), Australia. The draft mitogenomes ranged between 16,657 and 17,090 bp and contained 37 genes (13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), and two ribosomal RNA (rRNA) genes). As with other arthropod mitogenomes, we observed high A + T content (A: 39.4-39.8%, T: 40.55-41.5%). We confirmed the species identity by molecular diagnostics based on the partial mtCOI gene that showed >99% similarity between the Australian populations and other L. frauenfeldi sequences reported to date, and in the process identified putative origins of the invasive populations as Pakistan and India for the WA and Qld incursions respectively that suggested separate introductions.

3.
Eur J Heart Fail ; 24(4): 681-684, 2022 04.
Article in English | MEDLINE | ID: mdl-35060248

ABSTRACT

AIMS: Little information is available on sex differences in coronary microvascular dysfunction (CMD) in heart failure with preserved ejection fraction (HFpEF). We investigated sex-specific proteomic profiles associated with CMD in patients with HFpEF. METHODS AND RESULTS: Using the prospective multinational PROMIS-HFpEF study (Prevalence of Microvascular Dysfunction in HFpEF; n = 182; 54.6% women), we compared clinical and biomarker correlates of CMD (defined as coronary flow reserve [CFR] <2.5) between men and women with HFpEF. We used lasso penalized regression to analyse 242 biomarkers from high-throughput proximity extension assays, adjusting for age, body mass index, creatinine, smoking and study site. The prevalence of CMD was similarly high in men and women with HFpEF (77% vs. 70%; p = 0.27). Proteomic correlates of CFR differed by sex, with 10 versus 16 non-overlapping biomarkers independently associated with CFR in men versus women, respectively. In men, proteomic correlates of CFR included chemokine ligand 20, brain natriuretic peptide, proteinase 3, transglutaminase 2, pregnancy-associated plasma protein A and tumour necrosis factor receptor superfamily member 14. Among women, the strongest proteomic correlates with CFR were insulin-like growth factor-binding protein 1, phage shock protein D, CUB domain-containing protein 1, prostasin, decorin, FMS-like tyrosine kinase 3, ligand growth differentiation factor 15, spondin-1, delta/notch-like epidermal growth factor-related receptor and tumour necrosis factor receptor superfamily member 13B. Pathway analyses suggested that CMD was related to the inflammation-mediated chemokine and cytokine signalling pathway among men with HFpEF, and the P13-kinase and transforming growth factor-beta signalling pathway among women with HFpEF. CONCLUSION: While the prevalence of CMD among men and women with HFpEF is similar, the drivers of microvascular dysfunction may differ by sex. The current inflammatory paradigm of CMD in HFpEF potentially predominates in men, while derangement in ventricular remodelling and fibrosis may play a more important role in women.


Subject(s)
Heart Failure , Myocardial Ischemia , Biomarkers , Female , Heart Failure/epidemiology , Humans , Ligands , Male , Prospective Studies , Proteomics , Receptors, Tumor Necrosis Factor , Sex Characteristics , Stroke Volume/physiology
4.
Sci Rep ; 11(1): 7923, 2021 04 12.
Article in English | MEDLINE | ID: mdl-33846476

ABSTRACT

The Bemisia cassava whitefly complex includes species that cause severe crop damage through vectoring cassava viruses in eastern Africa. Currently, this whitefly complex is divided into species and subgroups (SG) based on very limited molecular markers that do not allow clear definition of species and population structure. Based on 14,358 genome-wide SNPs from 62 Bemisia cassava whitefly individuals belonging to sub-Saharan African species (SSA1, SSA2 and SSA4), and using a well-curated mtCOI gene database, we show clear incongruities in previous taxonomic approaches underpinned by effects from pseudogenes. We show that the SSA4 species is nested within SSA2, and that populations of the SSA1 species comprise well-defined south-eastern (Madagascar, Tanzania) and north-western (Nigeria, Democratic Republic of Congo, Burundi) putative sub-species. Signatures of allopatric incipient speciation, and the presence of a 'hybrid zone' separating the two putative sub-species were also detected. These findings provide insights into the evolution and molecular ecology of a highly cryptic hemipteran insect complex in African, and allow the systematic use of genomic data to be incorporated in the development of management strategies for this cassava pest.


Subject(s)
Hemiptera/genetics , Hybridization, Genetic , Manihot/parasitology , Africa , Animals , Base Sequence , Electron Transport Complex IV/genetics , Gene Flow , Geography , Mitochondria/genetics , Phylogeny , Population Dynamics , Principal Component Analysis , Species Specificity
5.
Neth Heart J ; 29(7-8): 402-408, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33594591

ABSTRACT

BACKGROUND: Transcatheter atrial septal defect (ASD) and patent foramen ovale (PFO) closure might have opposite short- and long-term haemodynamic consequences compared with restricted interatrial shunt creation, which recently emerged as a potential treatment modality for patients with heart failure with preserved ejection fraction (HFpEF). Given the opposing approaches of ASD and PFO closure versus shunt creation, we investigated the early and sustained cardiac structural and functional changes following transcatheter ASD or PFO closure. METHODS: In this retrospective study, adult secundum-type ASD and PFO patients with complete echocardiography examinations at baseline and at 1­day and 1­year follow-up who also underwent transcatheter closure between 2013 and 2017 at the University Medical Centre Groningen, the Netherlands were included. RESULTS: Thirty-nine patients (mean age 48 ± standard deviation 16 years, 61.5% women) were included. Transcatheter ASD/PFO closure resulted in an early and persistent decrease in right ventricular systolic and diastolic function. Additionally, transcatheter ASD/PFO closure resulted in an early and sustained favourable response of left ventricular (LV) systolic function, but also in deterioration of LV diastolic function with an increase in LV filling pressure (LVFP), as assessed by echocardiography. Age (ß = 0.31, p = 0.009) and atrial fibrillation (AF; ß = 0.24, p = 0.03) were associated with a sustained increase in LVFP after transcatheter ASD/PFO closure estimated by mean E/e' ratio (i.e. ratio of mitral peak velocity of early filling to diastolic mitral annular velocity). In subgroup analysis, this was similar for ASD and PFO closure. CONCLUSION: Older patients and patients with AF were predisposed to sustained increases in left-sided filling pressures resembling HFpEF following ASD or PFO closure. Consequently, these findings support the current concept that creating a restricted interatrial shunt might be beneficial, particularly in elderly HFpEF patients with AF.

6.
Bioinspir Biomim ; 14(3): 036006, 2019 02 27.
Article in English | MEDLINE | ID: mdl-30721890

ABSTRACT

The clap-and-fling effect, first observed in a number of insects, serves as a lift-enhancing mechanism for bio-inspired flapping wing micro aerial vehicles (MAV). In our comprehensive literature survey, we observe that the effect manifests differently in insects and contemporary MAVs; insects have active control over the angle of attack and stroke plane of the wing, whereas a number of kinematic parameters of an MAV's flexible wings are determined passively. Although there is consensus that flinging motion significantly enhances aerodynamic lift, the effect of clapping motion is not well-studied. To address this gap, we experimentally quantify the contribution of clapping motion using force measurement and particle image velocimetry. No significant enhancement in lift was observed due to clapping motion, because the momentum jet was too weak. However, the kinematics and flow conditions in our study were notably different from those in the previous studies on insect models. The wings of the MAV are flexible, and deform passively. Hence, the clapping of the trailing edges, and the appearance of a trailing edge momentum jet, was delayed and significantly suppressed. Using force measurement and CFD simulations, it was also found that the lesser the distance between the leading edges of the wings at the end of clap, the higher is the lift due to the subsequent fling.


Subject(s)
Flight, Animal/physiology , Insecta/physiology , Models, Biological , Wings, Animal/physiology , Aircraft , Animals , Aviation , Biomechanical Phenomena
7.
Transplant Proc ; 50(8): 2333-2337, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30316353

ABSTRACT

Retroperitoneoscopic right living donor nephrectomy (RLDN) provides direct access to the renal hilum without the need to mobilize the colon. However, factors such as lack of anatomic landmarks to guide orientation, smaller working space, and steep learning curve provided a debate against this approach. In this retrospective study, we reviewed our single-center experience of retroperitoneoscopic RLDN. MATERIALS AND METHODS: Between January 2015 and January 2017, 10 patients underwent retroperitoneoscopic RLDN by a single surgeon at the National University Hospital, Singapore. Baseline demographics, intraoperative parameters, and both donor and recipient outcomes were retrieved from the database. RESULTS: Mean (SD) age was 52.7 (13.8) years, mean (SD) body mass index was 25.2 (2.9) kg/m2, mean (SD) operating time was 196.8 (38.0) minutes, mean (SD) warm ischemic time was 5.1 (2.1) minutes, and mean (SD) blood loss was 43 (25.0) mL. Mean (SD) renal vein length was 10 (2.5) mm, and mean (SD) renal artery length was 6 (1.8 mm). One patient had to be converted to laparoscopic transperitoneal nephrectomy. No donors developed complications. Mean (SD) hospital stay was 3.5 (1.1) days. All transplanted right kidneys had immediate graft function with no complications. Mean (SD) serum creatinine (at 1 year) was 103.6 (20.3) µmol/L. There is no graft loss among the recipient after 1 year. CONCLUSIONS: Right donor nephrectomy can be performed safely using retroperitoneoscopic approach. Retroperitoneoscopy offers advantages, especially in a patient who previously had transabdominal surgery or high body mass index. However, transperitoneal approach may be preferable in anomalous situations because it provides instinctive orientation from anatomic landmarks and a greater working space.


Subject(s)
Kidney Transplantation/methods , Laparoscopy/methods , Living Donors , Nephrectomy/methods , Tissue and Organ Harvesting/methods , Adult , Female , Humans , Male , Middle Aged , Operative Time , Retroperitoneal Space/surgery , Retrospective Studies
8.
Bull Entomol Res ; 108(5): 565-582, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29433589

ABSTRACT

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a pest species complex that causes widespread damage to cassava, a staple food crop for millions of households in East Africa. Species in the complex cause direct feeding damage to cassava and are the vectors of multiple plant viruses. Whilst significant work has gone into developing virus-resistant cassava cultivars, there has been little research effort aimed at understanding the ecology of these insect vectors. Here we assess critically the knowledge base relating to factors that may lead to high population densities of sub-Saharan African (SSA) B. tabaci species in cassava production landscapes of East Africa. We focus first on empirical studies that have examined biotic or abiotic factors that may lead to high populations. We then identify knowledge gaps that need to be filled to deliver sustainable management solutions. We found that whilst many hypotheses have been put forward to explain the increases in abundance witnessed since the early 1990s, there are little published data and these tend to have been collected in a piecemeal manner. The most critical knowledge gaps identified were: (i) understanding how cassava cultivars and alternative host plants impact population dynamics and natural enemies; (ii) the impact of natural enemies in terms of reducing the frequency of outbreaks and (iii) the use and management of insecticides to delay the development of resistance. In addition, there are several fundamental methodologies that need to be developed and deployed in East Africa to address some of the more challenging knowledge gaps.


Subject(s)
Hemiptera/physiology , Manihot , Africa, Eastern , Animals , Farms , Manihot/growth & development , Population Density
9.
PLoS One ; 13(1): e0190555, 2018.
Article in English | MEDLINE | ID: mdl-29364919

ABSTRACT

Once considered a single species, the whitefly, Bemisia tabaci, is a complex of numerous morphologically indistinguishable species. Within the last three decades, two of its members (MED and MEAM1) have become some of the world's most damaging agricultural pests invading countries across Europe, Africa, Asia and the Americas and affecting a vast range of agriculturally important food and fiber crops through both feeding-related damage and the transmission of numerous plant viruses. For some time now, researchers have relied on a single mitochondrial gene and/or a handful of nuclear markers to study this species complex. Here, we move beyond this by using 38,041 genome-wide Single Nucleotide Polymorphisms, and show that the two invasive members of the complex are closely related species with signatures of introgression with a third species (IO). Gene flow patterns were traced between contemporary invasive populations within MED and MEAM1 species and these were best explained by recent international trade. These findings have profound implications for delineating the B. tabaci species status and will impact quarantine measures and future management strategies of this global pest.


Subject(s)
Hemiptera/genetics , Agriculture , Animals , Genome-Wide Association Study
10.
Chaos ; 27(10): 103115, 2017 Oct.
Article in English | MEDLINE | ID: mdl-29092457

ABSTRACT

It is interesting and of significant importance to investigate how network structures co-evolve with opinions. In this article, we show that, a simple model integrating consensus formation, link rewiring, and opinion change allows complex system dynamics to emerge, driving the system into a dynamic equilibrium with the co-existence of diversified opinions. Specifically, similar opinion holders may form into communities yet with no strict community consensus; and rather than being separated into disconnected communities, different communities are connected by a non-trivial proportion of inter-community links. More importantly, we show that the complex dynamics may lead to different numbers of communities at the steady state with a given tolerance between different opinion holders. We construct a framework for theoretically analyzing the co-evolution process. Theoretical analysis and extensive simulation results reveal some useful insights into the complex co-evolution process, including the formation of dynamic equilibrium, the transition between different steady states with different numbers of communities, and the dynamics between opinion distribution and network modularity.

11.
BMC Biol ; 15(1): 63, 2017 07 31.
Article in English | MEDLINE | ID: mdl-28756777

ABSTRACT

BACKGROUND: Helicoverpa armigera and Helicoverpa zea are major caterpillar pests of Old and New World agriculture, respectively. Both, particularly H. armigera, are extremely polyphagous, and H. armigera has developed resistance to many insecticides. Here we use comparative genomics, transcriptomics and resequencing to elucidate the genetic basis for their properties as pests. RESULTS: We find that, prior to their divergence about 1.5 Mya, the H. armigera/H. zea lineage had accumulated up to more than 100 more members of specific detoxification and digestion gene families and more than 100 extra gustatory receptor genes, compared to other lepidopterans with narrower host ranges. The two genomes remain very similar in gene content and order, but H. armigera is more polymorphic overall, and H. zea has lost several detoxification genes, as well as about 50 gustatory receptor genes. It also lacks certain genes and alleles conferring insecticide resistance found in H. armigera. Non-synonymous sites in the expanded gene families above are rapidly diverging, both between paralogues and between orthologues in the two species. Whole genome transcriptomic analyses of H. armigera larvae show widely divergent responses to different host plants, including responses among many of the duplicated detoxification and digestion genes. CONCLUSIONS: The extreme polyphagy of the two heliothines is associated with extensive amplification and neofunctionalisation of genes involved in host finding and use, coupled with versatile transcriptional responses on different hosts. H. armigera's invasion of the Americas in recent years means that hybridisation could generate populations that are both locally adapted and insecticide resistant.


Subject(s)
Genome, Insect , Herbivory , Moths/genetics , Animals , Gene Expression Profiling , Genomics , Introduced Species , Larva/genetics , Larva/growth & development , Moths/classification , Moths/growth & development , Sequence Analysis, DNA
12.
Genet Mol Res ; 16(3)2017 Aug 17.
Article in English | MEDLINE | ID: mdl-28829894

ABSTRACT

We provided the first scientific record of Melanagromyza sojae (Zehntner, 1900), through molecular characterization of partial mtDNA COI gene, that confirms the occurrence of this pest in Paraguay. Previously reported in Brazil, an outbreak of larvae of M. sojae known as the soybean stem fly (SSF) that belongs to the family Agromyzidae, was also noted in soybean fields from the Canindeyú, Alto Paraná and Itapúa Departments in Paraguay. This pest is highly polyphagous, attacking various host plant species from the family Fabaceae, such as soybean and other beans. The implications of SSF detection in Paraguay are discussed in relation to the current soybean cultivation practices from this agriculturally important South American region, including Brazil.


Subject(s)
Diptera/genetics , Glycine max/parasitology , Animals , DNA, Mitochondrial/chemistry , DNA, Mitochondrial/genetics , Diptera/pathogenicity , Electron Transport Complex IV/genetics , Insect Proteins/genetics , Paraguay
14.
Sci Rep ; 7(1): 429, 2017 03 27.
Article in English | MEDLINE | ID: mdl-28348369

ABSTRACT

Museum specimens represent valuable genomic resources for understanding host-endosymbiont/parasitoid evolutionary relationships, resolving species complexes and nomenclatural problems. However, museum collections suffer DNA degradation, making them challenging for molecular-based studies. Here, the mitogenomes of a single 1912 Sri Lankan Bemisia emiliae cotype puparium, and of a 1942 Japanese Bemisia puparium are characterised using a Next-Generation Sequencing approach. Whiteflies are small sap-sucking insects including B. tabaci pest species complex. Bemisia emiliae's draft mitogenome showed a high degree of homology with published B. tabaci mitogenomes, and exhibited 98-100% partial mitochondrial DNA Cytochrome Oxidase I (mtCOI) gene identity with the B. tabaci species known as Asia II-7. The partial mtCOI gene of the Japanese specimen shared 99% sequence identity with the Bemisia 'JpL' genetic group. Metagenomic analysis identified bacterial sequences in both Bemisia specimens, while hymenopteran sequences were also identified in the Japanese Bemisia puparium, including complete mtCOI and rRNA genes, and various partial mtDNA genes. At 88-90% mtCOI sequence identity to Aphelinidae wasps, we concluded that the 1942 Bemisia nymph was parasitized by an Eretmocerus parasitoid wasp. Our approach enables the characterisation of genomes and associated metagenomic communities of museum specimens using 1.5 ng gDNA, and to infer historical tritrophic relationships in Bemisia whiteflies.


Subject(s)
DNA, Mitochondrial/chemistry , DNA, Mitochondrial/genetics , Fossils , Hemiptera/genetics , Animals , Asia , Bacteria/genetics , Electron Transport Complex IV/genetics , High-Throughput Nucleotide Sequencing , Hymenoptera/genetics , Metagenomics , Sequence Analysis, DNA , Sequence Homology
15.
Mol Ecol ; 25(21): 5296-5311, 2016 11.
Article in English | MEDLINE | ID: mdl-27661785

ABSTRACT

Helicoverpa armigera is a major agricultural pest that is distributed across Europe, Asia, Africa and Australasia. This species is hypothesized to have spread to the Americas 1.5 million years ago, founding a population that is at present, a distinct species, Helicoverpa zea. In 2013, H. armigera was confirmed to have re-entered South America via Brazil and subsequently spread. The source of the recent incursion is unknown and population structure in H. armigera is poorly resolved, but a basic understanding would highlight potential biosecurity failures and determine the recent evolutionary history of region-specific lineages. Here, we integrate several end points derived from high-throughput sequencing to assess gene flow in H. armigera and H. zea from populations across six continents. We first assemble mitochondrial genomes to demonstrate the phylogenetic relationship of H. armigera with other Heliothine species and the lack of distinction between populations. We subsequently use de novo genotyping-by-sequencing and whole-genome sequences aligned to bacterial artificial chromosomes, to assess levels of admixture. Primarily, we find that Brazilian H. armigera are derived from diverse source populations, with strong signals of gene flow from European populations, as well as prevalent signals of Asian and African ancestry. We also demonstrate a potential field-caught hybrid between H. armigera and H. zea, and are able to provide genomic support for the presence of the H. armigera conferta subspecies in Australasia. While structure among the bulk of populations remains unresolved, we present distinctions that are pertinent to future investigations as well as to the biosecurity threat posed by H. armigera.


Subject(s)
Gene Flow , Genetics, Population , Moths/genetics , Animals , Brazil , Genome, Insect , Genome, Mitochondrial , Genotype , Hybridization, Genetic , Phylogeny
16.
Genet Mol Res ; 15(2)2016 Jul 12.
Article in English | MEDLINE | ID: mdl-27420989

ABSTRACT

Soybean Stem Fly (SSF), Melanagromyza sojae (Zehntner), belongs to the family Agromyzidae and is highly polyphagous, attacking many plant species of the family Fabaceae, including soybean and other beans. SSF is regarded as one of the most important pests in soybean fields of Asia (e.g., China, India), North East Africa (e.g., Egypt), parts of Russia, and South East Asia. Despite reports of Agromyzidae flies infesting soybean fields in Rio Grande do Sul State (Brazil) in 1983 and 2009 and periodic interceptions of SSF since the 1940s by the USA quarantine authorities, SSF has not been officially reported to have successfully established in the North and South Americas. In South America, M. sojae was recently confirmed using morphology and its complete mitochondrial DNA (mtDNA) was characterized. In the present study, we surveyed the genetic diversity of M. sojae, collected directly from soybean host plants, using partial mtDNA cytochrome oxidase I (COI) gene, and provide evidence of multiple (>10) maternal lineages in SSF populations in South America, potentially representing multiple incursion events. However, a single incursion involving multiple-female founders could not be ruled out. We identified a haplotype that was common in the fields of two Brazilian states and the individuals collected from Australia in 2013. The implications of SSF incursions in southern Brazil are discussed in relation to the current soybean agricultural practices, highlighting an urgent need for better understanding of SSF population movements in the New World, which is necessary for developing effective management options for this significant soybean pest.


Subject(s)
Diptera/genetics , Polymorphism, Genetic , Animal Distribution , Animals , Brazil , Diptera/physiology , Electron Transport Complex IV/genetics , Founder Effect , Haplotypes , Insect Proteins/genetics
17.
Ultrason Sonochem ; 33: 190-196, 2016 11.
Article in English | MEDLINE | ID: mdl-27245970

ABSTRACT

Physical absorption process is always nullified by the presence of cavitation under low frequency ultrasonic irradiation. In the present study, high frequency ultrasonic of 1.7MHz was used for the physical absorption of CO2 in a water batch system under elevated pressure. The parameters including ultrasonic power and initial feed pressure for the system have been varied from 0 to 18W and 6 to 41bar, respectively. The mass transfer coefficient has been determined via the dynamic pressure-step method. Besides, the actual ultrasonic power that transmitted to the liquid was measured based on calorimetric method prior to the absorption study. Subsequently, desorption study was conducted as a comparison with the absorption process. The mechanism for the ultrasonic assisted absorption has also been discussed. Based on the results, the mass transfer coefficient has increased with the increasing of ultrasonic power. It means that, the presence of streaming effect and the formation of liquid fountain is more favorable under high frequency ultrasonic irradiation for the absorption process. Therefore, high frequency ultrasonic irradiation is suggested to be one of the potential alternatives for the gas separation process with its promising absorption enhancement and compact design.

18.
Genet Mol Res ; 15(2)2016 Apr 07.
Article in English | MEDLINE | ID: mdl-27173209

ABSTRACT

Since its detection in Brazil in 2013, the Old World cotton bollworm Helicoverpa armigera has been reported in Argentina, Paraguay, and Bolivia. Here we present evidence extending the South American range of H. armigera to Uruguay, using polymerase chain reaction and sequencing of the partial mitochondrial DNA (mtDNA) cytochrome oxidase I region. Molecular characterization of this gene region from individuals from Paraguay also supports previous morphological identification of H. armigera in Paraguay. Shared mtDNA haplotypes in H. armigera from Brazil, Uruguay, and Paraguay were identified. Additional surveying of populations in this region will be imperative to better monitor and understand factors that are underpinning its presence and successful adaptation in these South American regions. We discuss our findings with respect to the development of resistance pest management strategies of this invasive insect pest in a predominantly monoculture soybean crop landscape in the Southern Cone region.


Subject(s)
DNA, Mitochondrial/genetics , Electron Transport Complex IV/genetics , Insect Proteins/genetics , Lepidoptera/genetics , Adaptation, Physiological/genetics , Animals , Lepidoptera/pathogenicity , Lepidoptera/physiology , Paraguay , Uruguay
19.
PLoS One ; 11(1): e0146699, 2016.
Article in English | MEDLINE | ID: mdl-26771743

ABSTRACT

Culicoides brevitarsis is a vector of the bluetongue virus (BTV), which infects sheep and cattle. It is an invasive species in Australia with an assumed Asian/South East Asian origin. Using one mitochondrial marker (i.e., part of the cytochrome oxidase subunit I gene) and six nuclear markers, we inferred population genetic structure and possible incursion pathways for Australian C. brevitarsis. Nine mitochondrial haplotypes, with low nucleotide sequence diversity (0.0-0.7%) among these, were identified in a sample of 70 individuals from seven sites. Both sets of markers revealed a homogeneous population structure, albeit with evidence of isolation by distance and two genetically distinct clusters distributed along a north-to-south cline. No evidence of a cryptic species complex was found. The geographical distribution of the mitochondrial haplotypes is consistent with at least two incursion pathways into Australia since the arrival of suitable livestock hosts. By contrast, 15 mitochondrial haplotypes, with up to four times greater nucleotide sequence diversity (0.0-2.9%) among these, were identified in a sample of 16 individuals of the endemic C. marksi (sampled from a site in South Australia and another in New South Wales). A phylogenetic tree inferred using the mitochondrial marker revealed that the Australian and Japanese samples of C. brevitarsis are as evolutionarily different from one another as some of the other Australian species (e.g., C. marksi, C. henryi, C. pallidothorax) are. The phylogenetic tree placed four of the species endemic to Australia (C. pallidothorax, C. bundyensis, C. marksi, C. henryi) in a clade, with a fifth such species (C. bunrooensis) sharing a common ancestor with that clade and a clade comprising two Japanese species (C. verbosus, C. kibunensis).


Subject(s)
Ceratopogonidae/genetics , Insect Vectors/genetics , Animals , Australia , Bluetongue virus/physiology , Cattle , Ceratopogonidae/classification , Ceratopogonidae/virology , Genetics, Population , Haplotypes/genetics , Insect Vectors/classification , Sheep
20.
Article in English | MEDLINE | ID: mdl-24960562

ABSTRACT

The complete length of the Asia I member of the Bemisia tabaci species complex mitochondrial DNA genome (mitogenome) is 15,210 bp (GenBank accession no. KJ778614) with an A-T biased nucleotide composition (A: 32.7%; T: 42.4%; G: 14.0%; C: 10.8%). The mitogenome consists of 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), 2 ribosomal RNA (rRNAs) and a 467 bp putative control region which also includes the A+T rich repeat region. All PCGs have an ATA (n = 8) or ATG (n = 5) start codon. Gene synteny of Asia I is overall similar to B. afer and two other members of the B. tabaci species complex Mediterranean and New World 1, and contains the tRNA-Ser2 located between the Cytb and ND1 genes found in Mediterranean and New World 1, but which is absent in B. afer. The orientation of the tRNA-Arg in Asia I is on the "plus" strand and differed from Mediterranean which is found on the "minus" strand. The Asia I mitogenome size is currently ranked the second smallest after B. afer (14,968 bp) followed by New World 1 (15,322 bp) and Mediterranean (15,632 bp).


Subject(s)
DNA, Mitochondrial/genetics , Genome, Mitochondrial/genetics , Hemiptera/genetics , Animals , Asia , Codon/genetics , Phylogeny , RNA, Ribosomal/genetics , RNA, Transfer/genetics
SELECTION OF CITATIONS
SEARCH DETAIL
...