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1.
Ann Fam Med ; 2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38914438

ABSTRACT

PURPOSE: Relationship continuity of care has declined across English primary health care, with cross-sectional and longitudinal variations between general practices predicted by population and service factors. We aimed to describe cross-sectional and longitudinal variations across the COVID-19 pandemic and determine whether practice factors predicted the variations. METHODS: We conducted a longitudinal, ecological study of English general practices during 2018-2022 with continuity data, excluding practices with fewer than 750 patients or National Health Service (NHS) payments exceeding £500 per patient. Variables were derived from published data. The continuity measure was the product of weighted responses to 2 General Practice Patient Survey questions. In a multilevel mixed-effects model, the fixed effects were 11 variables' interactions with time: baseline continuity, NHS region, deprivation, location, percentage White ethnicity, list size, general practitioner and nurse numbers, contract type, NHS payments per patient, and percentage of patients seen on the same day as booking. The random effects were practices. RESULTS: Main analyses were based on 6,010 practices (out of 7,190 active practices). During 2018-2022, mean continuity in these practices declined (from 29.3% to 19.0%) and the coefficient of variation across practices increased (from 48.1% to 63.6%). Both slopes were steepest between 2021 and 2022. Practices having more general practitioners and higher percentages of patients seen the same day had slower declines. Practices having higher baseline continuity, located in certain non-London regions, and having higher percentages of White patients had faster declines. The remaining variables were not predictors. CONCLUSIONS: Variables potentially associated with greater appointment availability predicted slower declines in continuity, with worsening declines and relative variability immediately after the COVID-19 lockdown, possibly reflecting surges in demand. To achieve better levels of continuity for those seeking it, practices can increase appointment availability within appointment systems that prioritize continuity.

2.
Biomimetics (Basel) ; 9(5)2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38786466

ABSTRACT

Orb-weaver spiders produce upwards of seven different types of silk, each with unique material properties. We focus on the adhesive within orb-weaving spider webs, aggregate glue silk. These droplets are composed of three main components: water, glycoproteins, and a wide range of low molecular mass compounds (LMMCs). These LMMCs are known to play a crucial role in maintaining the material properties of the glycoproteins, aid in water absorption from the environment, and increase surface adhesion. Orb-weavers within the Cyrtarachninae subfamily are moth specialists and have evolved glue droplets with novel material properties. This study investigated the biochemical composition and diversity of the LMMCs present in the aggregate glue of eight moth-specialist species and compared them with five generalist orb-weavers using nuclear magnetic resonance (NMR) spectroscopy. We hypothesized that the novel drying ability of moth-specialist glue was accompanied by novel LMMCs and lower overall percentages by silk weight of LMMCs. We measured no difference in LMMC weight by the type of prey specialization, but observed novel compositions in the glue of all eight moth-catching species. Further, we quantified the presence of a previously reported but unidentified compound that appears in the glue of all moth specialists. These silks can provide insight into the functions of bioadhesives and inform our own synthetic adhesives.

3.
Genome Biol Evol ; 15(7)2023 07 03.
Article in English | MEDLINE | ID: mdl-37364298

ABSTRACT

Stalk-eyed flies in the genus Teleopsis carry selfish genetic elements that induce sex ratio (SR) meiotic drive and impact the fitness of male and female carriers. Here, we assemble and describe a chromosome-level genome assembly of the stalk-eyed fly, Teleopsis dalmanni, to elucidate patterns of divergence associated with SR. The genome contains tens of thousands of transposable element (TE) insertions and hundreds of transcriptionally and insertionally active TE families. By resequencing pools of SR and ST males using short and long reads, we find widespread differentiation and divergence between XSR and XST associated with multiple nested inversions involving most of the SR haplotype. Examination of genomic coverage and gene expression data revealed seven X-linked genes with elevated expression and coverage in SR males. The most extreme and likely drive candidate involves an XSR-specific expansion of an array of partial copies of JASPer, a gene necessary for maintenance of euchromatin and associated with regulation of TE expression. In addition, we find evidence for rapid protein evolution between XSR and XST for testis expressed and novel genes, that is, either recent duplicates or lacking a Dipteran ortholog, including an X-linked duplicate of maelstrom, which is also involved in TE silencing. Overall, the evidence suggests that this ancient XSR polymorphism has had a variety of impacts on repetitive DNA and its regulation in this species.


Subject(s)
Diptera , X Chromosome , Animals , Female , Male , X Chromosome/genetics , Diptera/genetics , Sex Ratio , Eye , Testis
4.
Proc Natl Acad Sci U S A ; 120(18): e2221528120, 2023 05 02.
Article in English | MEDLINE | ID: mdl-37094147

ABSTRACT

Arthropod silk is vital to the evolutionary success of hundreds of thousands of species. The primary proteins in silks are often encoded by long, repetitive gene sequences. Until recently, sequencing and assembling these complex gene sequences has proven intractable given their repetitive structure. Here, using high-quality long-read sequencing, we show that there is extensive variation-both in terms of length and repeat motif order-between alleles of silk genes within individual arthropods. Further, this variation exists across two deep, independent origins of silk which diverged more than 500 Mya: the insect clade containing caddisflies and butterflies and spiders. This remarkable convergence in previously overlooked patterns of allelic variation across multiple origins of silk suggests common mechanisms for the generation and maintenance of structural protein-coding genes. Future genomic efforts to connect genotypes to phenotypes should account for such allelic variation.


Subject(s)
Butterflies , Fibroins , Spiders , Animals , Silk/chemistry , Amino Acid Sequence , Fibroins/chemistry , Alleles , Insecta/genetics , Butterflies/genetics , Genetic Variation , Spiders/genetics , Insect Proteins/genetics , Phylogeny
5.
J Comp Physiol B ; 193(1): 25-36, 2023 01.
Article in English | MEDLINE | ID: mdl-36342510

ABSTRACT

Spider dragline fibers exhibit incredible mechanical properties, outperforming many synthetic polymers in toughness assays, and possess desirable properties for medical and other human applications. These qualities make dragline fibers popular subjects for biomimetics research. The enormous diversity of spiders presents both an opportunity for the development of new bioinspired materials and a challenge for the identification of fundamental design principles, as the mechanical properties of dragline fibers show both intraspecific and interspecific variations. In this regard, the stress-strain curves of draglines from different species have been shown to be effectively compared by the α* parameter, a value derived from maximum-supercontracted silk fibers. To identify potential molecular mechanisms impacting α* values, here we analyze spider fibroin (spidroin) sequences of the Western black widow (Latrodectus hesperus) and the black and yellow garden spider (Argiope aurantia). This study serves as a primer for investigating the molecular properties of spidroins that underlie species-specific α* values. Initial findings are that while overall motif composition was similar between species, certain motifs and higher level periodicities of glycine-rich region lengths showed variation, notably greater distances between poly-A motifs in A. aurantia sequences. In addition to increased period lengths, A. aurantia spidroins tended to have an increased prevalence of charged and hydrophobic residues. These increases may impact the number and strength of hydrogen bond networks within fibers, which have been implicated in conformational changes and formation of nanocrystals, contributing to the greater extensibility of A. aurantia draglines compared to those of L. hesperus.


Subject(s)
Fibroins , Spiders , Humans , Animals , Fibroins/chemistry , Silk/chemistry , Silk/physiology , Prevalence , Species Specificity
6.
PLoS Genet ; 18(12): e1010537, 2022 12.
Article in English | MEDLINE | ID: mdl-36508456

ABSTRACT

The evolutionary diversification of orb-web weaving spiders is closely tied to the mechanical performance of dragline silk. This proteinaceous fiber provides the primary structural framework of orb web architecture, and its extraordinary toughness allows these structures to absorb the high energy of aerial prey impact. The dominant model of dragline silk molecular structure involves the combined function of two highly repetitive, spider-specific, silk genes (spidroins)-MaSp1 and MaSp2. Recent genomic studies, however, have suggested this framework is overly simplistic, and our understanding of how MaSp genes evolve is limited. Here we present a comprehensive analysis of MaSp structural and evolutionary diversity across species of Argiope (garden spiders). This genomic analysis reveals the largest catalog of MaSp genes found in any spider, driven largely by an expansion of MaSp2 genes. The rapid diversification of Argiope MaSp genes, located primarily in a single genomic cluster, is associated with profound changes in silk gene structure. MaSp2 genes, in particular, have evolved complex hierarchically organized repeat units (ensemble repeats) delineated by novel introns that exhibit remarkable evolutionary dynamics. These repetitive introns have arisen independently within the genus, are highly homogenized within a gene, but diverge rapidly between genes. In some cases, these iterated introns are organized in an alternating structure in which every other intron is nearly identical in sequence. We hypothesize that this intron structure has evolved to facilitate homogenization of the coding sequence. We also find evidence of intergenic gene conversion and identify a more diverse array of stereotypical amino acid repeats than previously recognized. Overall, the extreme diversification found among MaSp genes requires changes in the structure-function model of dragline silk performance that focuses on the differential use and interaction among various MaSp paralogs as well as the impact of ensemble repeat structure and different amino acid motifs on mechanical behavior.


Subject(s)
Fibroins , Spiders , Animals , Silk/genetics , Spiders/genetics , Spiders/metabolism , Mannose-Binding Protein-Associated Serine Proteases/metabolism , Gardens , Fibroins/genetics , Fibroins/chemistry , Fibroins/metabolism
7.
BMC Ecol Evol ; 22(1): 89, 2022 07 09.
Article in English | MEDLINE | ID: mdl-35810286

ABSTRACT

BACKGROUND: Spiders have evolved two types of sticky capture threads: one with wet adhesive spun by ecribellate orb-weavers and another with dry adhesive spun by cribellate spiders. The evolutionary history of cribellate capture threads is especially poorly understood. Here, we use genomic approaches to catalog the spider-specific silk gene family (spidroins) for the cribellate orb-weaver Uloborus diversus. RESULTS: We show that the cribellar spidroin, which forms the puffy fibrils of cribellate threads, has three distinct repeat units, one of which is conserved across cribellate taxa separated by ~ 250 Mya. We also propose candidates for a new silk type, paracribellar spidroins, which connect the puffy fibrils to pseudoflagelliform support lines. Moreover, we describe the complete repeat architecture for the pseudoflagelliform spidroin (Pflag), which contributes to extensibility of pseudoflagelliform axial fibers. CONCLUSIONS: Our finding that Pflag is closely related to Flag, supports homology of the support lines of cribellate and ecribellate capture threads. It further suggests an evolutionary phase following gene duplication, in which both Flag and Pflag were incorporated into the axial lines, with subsequent loss of Flag in uloborids, and increase in expression of Flag in ecribellate orb-weavers, explaining the distinct mechanical properties of the axial lines of these two groups.


Subject(s)
Fibroins , Spiders , Animals , Biological Evolution , Fibroins/genetics , Gene Duplication , Silk/genetics , Spiders/genetics
8.
J Exp Biol ; 225(Suppl1)2022 02 15.
Article in English | MEDLINE | ID: mdl-35119070

ABSTRACT

Morphological structures and extended phenotypes are made possible by materials that are encoded by the genome. Nearly all biomaterials are viscoelastic, which means that to understand performance, one must understand the strain rate-dependent properties of these materials in relevant ecological interactions, as the behavior of a material can vary dramatically and rapidly. Spider silks are an example of materials whose properties vary substantially intra- and inter-specifically. Here, we focus on aggregate silk, which functions as a biological adhesive. As a case study to understand how a material manifests from genome through organism to ecology, we highlight moth-specialist spiders, the Cyrtarachninae, and their glues as an ideal experimental system to investigate the relationship between genomics and ecologically variable performance of a biological material. There is a clear eco-evolutionary innovation that Cyrtarachne akirai and related species have evolved, a unique trait not found in other spiders, a glue which overcomes the scales of moths. By examining traditional orb-weavers, C. akirai and other subfamily members using biomechanical testing and genomic analysis, we argue that we can track the evolution of this novel bioadhesive and comment on the selection pressures influencing prey specialization. The importance of the ecological context of materials testing is exemplified by the poor performance of C. akirai glue on glass and the exceptional spreading ability and adhesive strength on moths. The genetic basis for these performance properties is experimentally tractable because spider silk genes are minimally pleiotropic and advances in genomic technologies now make possible the discovery of complete silk gene sequences.


Subject(s)
Moths , Spiders , Animals , Genomics , Moths/genetics , Phenotype , Silk/genetics , Spiders/genetics
9.
Mol Phylogenet Evol ; 139: 106539, 2019 10.
Article in English | MEDLINE | ID: mdl-31226465

ABSTRACT

Genomic datasets sometimes support conflicting phylogenetic relationships when different tree-building methods are applied. Coherent interpretations of such results are enabled by partitioning support for controversial relationships among the constituent genes of a phylogenomic dataset. For the supermatrix (=concatenation) approach, several methods that measure the distribution of support and conflict among loci were introduced over 15 years ago. More recently, partitioned coalescence support (PCS) was developed for phylogenetic coalescence methods that account for incomplete lineage sorting and use the summed fits of gene trees to estimate the species tree. Here, we automate computation of PCS to permit application of this index to genome-scale matrices that include hundreds of loci. Reanalyses of four phylogenomic datasets for amniotes, land plants, skinks, and angiosperms demonstrate how PCS scores can be used to: (1) compare conflicting results favored by alternative coalescence methods, (2) identify outlier gene trees that have a disproportionate influence on the resolution of contentious relationships, (3) assess the effects of missing data in species-tree analysis, and (4) clarify biases in commonly-implemented coalescence methods and support indices. We show that key phylogenomic conclusions from these analyses often hinge on just a few gene trees and that results can be driven by specific biases of a particular coalescence method and/or the differential weight placed on gene trees with high versus low taxon sampling. The attribution of exceptionally high weight to some gene trees and very low weight to other gene trees counters the basic logic of phylogenomic coalescence analysis; even clades in species trees with high support according to commonly used indices (likelihood-ratio test, bootstrap, Bayesian local posterior probability) can be unstable to the removal of only one or two gene trees with high PCS. Computer simulations cannot adequately describe all of the contingencies and complexities of empirical genetic data. PCS scores complement simulation work by providing specific insights into a particular dataset given the assumptions of the phylogenetic coalescence method that is applied. In combination with standard measures of nodal support, PCS provides a more complete understanding of the overall genomic evidence for contested evolutionary relationships in species trees.


Subject(s)
Phylogeny , Animals , Bayes Theorem , Bias , Biological Evolution , Computer Simulation , Genes , Genomics , Lizards/classification , Lizards/genetics , Magnoliopsida/classification , Magnoliopsida/genetics , Plants/classification , Plants/genetics , Probability
10.
Plast Reconstr Surg ; 139(1): 256e-266e, 2017 Jan.
Article in English | MEDLINE | ID: mdl-28027259

ABSTRACT

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Assess the patient's history, clinical examination, and radiographic findings to diagnose and stage basilar joint arthritis. 2. Recall the cause and epidemiology of the condition. 3. Formulate a management plan including nonoperative management, and evaluate the candidacy for surgical treatment. 4. Understand the rationale for the various surgical options available (including rehabilitation), their potential complications, and the evidence related to outcomes. SUMMARY: This article has been prepared to accompany practice-based assessment with ongoing surgical education for the Maintenance of Certification for the American Board of Plastic Surgery. It is designed for clinicians to analyze and structure their care of a patient with arthritis of the trapeziometacarpal joint.


Subject(s)
Finger Joint , Osteoarthritis/therapy , Thumb , Arthroplasty/methods , Evidence-Based Medicine , Humans , Osteoarthritis/diagnosis , Osteoarthritis/rehabilitation , Osteoarthritis/surgery , Postoperative Complications
11.
Mitochondrial DNA B Resour ; 1(1): 425-427, 2016.
Article in English | MEDLINE | ID: mdl-27617305

ABSTRACT

We report the extraction of a bed bug mitogenome from high-throughput sequencing projects originally focused on the nuclear genome of Cimex lectularius. The assembled mitogenome has a similar AT nucleotide composition bias found in other insects. Phylogenetic analysis of all protein-coding genes indicates that C. lectularius is clearly a member of a paraphyletic Cimicomorpha clade within the Order Hemiptera.

12.
Genome Biol Evol ; 8(3): 896-914, 2016 Mar 26.
Article in English | MEDLINE | ID: mdl-26951781

ABSTRACT

Throughout their evolutionary history, genomes acquire new genetic material that facilitates phenotypic innovation and diversification. Developmental processes associated with reproduction are particularly likely to involve novel genes. Abundant gene creation impacts the evolution of chromosomal gene content and general regulatory mechanisms such as dosage compensation. Numerous studies in model organisms have found complex and, at times contradictory, relationships among these genomic attributes highlighting the need to examine these patterns in other systems characterized by abundant sexual selection. Therefore, we examined the association among novel gene creation, tissue-specific gene expression, and chromosomal gene content within stalk-eyed flies. Flies in this family are characterized by strong sexual selection and the presence of a newly evolved X chromosome. We generated RNA-seq transcriptome data from the testes for three species within the family and from seven additional tissues in the highly dimorphic species,Teleopsis dalmanni Analysis of dipteran gene orthology reveals dramatic testes-specific gene creation in stalk-eyed flies, involving numerous gene families that are highly conserved in other insect groups. Identification of X-linked genes for the three species indicates that the X chromosome arose prior to the diversification of the family. The most striking feature of this X chromosome is that it is highly masculinized, containing nearly twice as many testes-specific genes as expected based on its size. All the major processes that may drive differential sex chromosome gene content-creation of genes with male-specific expression, development of male-specific expression from pre-existing genes, and movement of genes with male-specific expression-are elevated on the X chromosome ofT. dalmanni This masculinization occurs despite evidence that testes expressed genes do not achieve the same levels of gene expression on the X chromosome as they do on the autosomes.


Subject(s)
Evolution, Molecular , Selection, Genetic/genetics , Sex Determination Processes , Spermatogenesis/genetics , Animals , Dosage Compensation, Genetic , Drosophila melanogaster/genetics , Female , Gene Expression Regulation, Developmental , Genes, X-Linked , High-Throughput Nucleotide Sequencing , Male , Testis/growth & development , Transcriptome/genetics , X Chromosome/genetics
13.
Tech Hand Up Extrem Surg ; 19(2): 64-7, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25929417

ABSTRACT

Longitudinal defects of the finger that extend beyond 1 phalangeal segment such as wounds that expose the flexor tendon are challenging to reconstruct because of their elongated shape. We present the use of segmental V-Y flaps to reconstruct these defects. These are ≥2 V-Y flaps orientated transversely and advanced segmentally to close the defect avoiding a linear scar. Nineteen patients had soft-tissue defects of the digits successfully reconstructed with segmental V-Y flaps in this retrospective case series. There were no total or partial flap failures and all flaps retained sensation. Segmental V-Y flaps are a safe method for reconstructing digital defects and are particularly useful in the reconstruction of longitudinal defects. They have the advantages of being homodigital, sensate, technically easy; allow direct closure of the donor site and break up linear defects that might otherwise lead to contractures.


Subject(s)
Finger Injuries/surgery , Plastic Surgery Procedures/methods , Soft Tissue Injuries/surgery , Surgical Flaps , Humans , Retrospective Studies , Surgical Flaps/blood supply , Surgical Flaps/innervation
14.
Insect Mol Biol ; 24(2): 139-54, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25524309

ABSTRACT

Insects are the most diverse group of organisms on the planet. Variation in gene expression lies at the heart of this biodiversity and recent advances in sequencing technology have spawned a revolution in researchers' ability to survey tissue-specific transcriptional complexity across a wide range of insect taxa. Increasingly, studies are using a comparative approach (across species, sexes and life stages) that examines the transcriptional basis of phenotypic diversity within an evolutionary context. In the present review, we summarize much of this research, focusing in particular on three critical aspects of insect biology: morphological development and plasticity; physiological response to the environment; and sexual dimorphism. A common feature that is emerging from these investigations concerns the dynamic nature of transcriptome evolution as indicated by rapid changes in the overall pattern of gene expression, the differential expression of numerous genes with unknown function, and the incorporation of novel, lineage-specific genes into the transcriptional profile.


Subject(s)
Insecta/genetics , Transcriptome/genetics , Animals , Base Sequence , Biological Evolution , Female , Gene Expression , Gene Expression Regulation, Developmental , Genetic Variation , Insecta/growth & development , Insecta/physiology , Male , Phenotype , RNA/genetics , Sex Characteristics , Stress, Physiological
15.
PLoS Genet ; 10(5): e1004362, 2014.
Article in English | MEDLINE | ID: mdl-24832132

ABSTRACT

Although sex chromosome meiotic drive has been observed in a variety of species for over 50 years, the genes causing drive are only known in a few cases, and none of these cases cause distorted sex-ratios in nature. In stalk-eyed flies (Teleopsis dalmanni), driving X chromosomes are commonly found at frequencies approaching 30% in the wild, but the genetic basis of drive has remained elusive due to reduced recombination between driving and non-driving X chromosomes. Here, we used RNAseq to identify transcripts that are differentially expressed between males carrying either a driving X (XSR) or a standard X chromosome (XST), and found hundreds of these, the majority of which are X-linked. Drive-associated transcripts show increased levels of sequence divergence (dN/dS) compared to a control set, and are predominantly expressed either in testes or in the gonads of both sexes. Finally, we confirmed that XSR and XST are highly divergent by estimating sequence differentiation between the RNAseq pools. We found that X-linked transcripts were often strongly differentiated (whereas most autosomal transcripts were not), supporting the presence of a relatively large region of recombination suppression on XSR presumably caused by one or more inversions. We have identified a group of genes that are good candidates for further study into the causes and consequences of sex-chromosome drive, and demonstrated that meiotic drive has had a profound effect on sequence evolution and gene expression of X-linked genes in this species.


Subject(s)
Biological Evolution , Meiosis/genetics , Sex Chromosomes/genetics , X Chromosome/genetics , Animals , Diptera/genetics , Female , Genes, X-Linked , High-Throughput Nucleotide Sequencing , Male , Sex Ratio
16.
Tech Hand Up Extrem Surg ; 18(2): 98-101, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24667687

ABSTRACT

This article describes a novel technique of suspending the first metacarpal after trapeziectomy with a palmaris longus tendon graft in the specific situation of a patient with Eaton and Lambert stage IV thumb base osteoarthritis with proximal subluxation of the first metacarpal and ulnar translation of the carpus on the radius, such that without suspension the first metacarpal would articulate with the radial styloid after trapeziectomy. The advantage of the palmaris longus tendon graft as opposed to techniques using the flexor carpi radialis or abductor pollicis longus tendons is that this technique anchors the first metacarpal in a more distal position than the latter techniques allow. No complications were encountered and the patient remains pain-free at 6 months with improved pinch and grip strength and function.


Subject(s)
Arthroplasty/methods , Carpometacarpal Joints/surgery , Joint Dislocations/surgery , Osteoarthritis/surgery , Tendons/transplantation , Thumb/surgery , Humans , Trapezium Bone/surgery , Wrist Joint/surgery
17.
Risk Anal ; 34(1): 4-16, 2014 01.
Article in English | MEDLINE | ID: mdl-23834916

ABSTRACT

Utility functions in the form of tables or matrices have often been used to combine discretely rated decision-making criteria. Matrix elements are usually specified individually, so no one rule or principle can be easily stated for the utility function as a whole. A series of five matrices are presented that aggregate criteria two at a time using simple rules that express a varying degree of constraint of the lower rating over the higher. A further nine possible matrices were obtained by using a different rule either side of the main axis of the matrix to describe situations where the criteria have a differential influence on the outcome. Uncertainties in the criteria are represented by three alternative frequency distributions from which the assessors select the most appropriate. The output of the utility function is a distribution of rating frequencies that is dependent on the distributions of the input criteria. In pest risk analysis (PRA), seven of these utility functions were required to mimic the logic by which assessors for the European and Mediterranean Plant Protection Organization arrive at an overall rating of pest risk. The framework enables the development of PRAs that are consistent and easy to understand, criticize, compare, and change. When tested in workshops, PRA practitioners thought that the approach accorded with both the logic and the level of resolution that they used in the risk assessments.

18.
PLoS One ; 8(8): e71255, 2013.
Article in English | MEDLINE | ID: mdl-23951120

ABSTRACT

Harmful non-indigenous species (NIS) impose great economic and environmental impacts globally, but little is known about their impacts in Southeast Asia. Lack of knowledge of the magnitude of the problem hinders the allocation of appropriate resources for NIS prevention and management. We used benefit-cost analysis embedded in a Monte-Carlo simulation model and analysed economic and environmental impacts of NIS in the region to estimate the total burden of NIS in Southeast Asia. The total annual loss caused by NIS to agriculture, human health and the environment in Southeast Asia is estimated to be US$33.5 billion (5(th) and 95(th) percentile US$25.8-39.8 billion). Losses and costs to the agricultural sector are estimated to be nearly 90% of the total (US$23.4-33.9 billion), while the annual costs associated with human health and the environment are US$1.85 billion (US$1.4-2.5 billion) and US$2.1 billion (US$0.9-3.3 billion), respectively, although these estimates are based on conservative assumptions. We demonstrate that the economic and environmental impacts of NIS in low and middle-income regions can be considerable and that further measures, such as the adoption of regional risk assessment protocols to inform decisions on prevention and control of NIS in Southeast Asia, could be beneficial.


Subject(s)
Agriculture/economics , Cost-Benefit Analysis/statistics & numerical data , Developing Countries/economics , Health Care Costs/statistics & numerical data , Introduced Species/economics , Animals , Asia, Southeastern , Columbidae/physiology , Humans , Insecta/pathogenicity , Insecta/physiology , Introduced Species/statistics & numerical data , Monte Carlo Method , Plant Weeds/physiology , Rodentia/physiology , Viruses/growth & development
19.
PLoS One ; 8(3): e59826, 2013.
Article in English | MEDLINE | ID: mdl-23527273

ABSTRACT

Stalk-eyed flies (family Diopsidae) are a model system for studying sexual selection due to the elongated and sexually dimorphic eye-stalks found in many species. These flies are of additional interest because their X chromosome is derived largely from an autosomal arm in other flies. To identify candidate genes required for development of dimorphic eyestalks and investigate how sex-biased expression arose on the novel X, we compared gene expression between males and females using oligonucleotide microarrays and RNA from developing eyestalk tissue or adult heads in the dimorphic diopsid, Teleopsis dalmanni. Microarray analysis revealed sex-biased expression for 26% of 3,748 genes expressed in eye-antennal imaginal discs and concordant sex-biased expression for 86 genes in adult heads. Overall, 415 female-biased and 482 male-biased genes were associated with dimorphic eyestalk development but not differential expression in the adult head. Functional analysis revealed that male-biased genes are disproportionately associated with growth and mitochondrial function while female-biased genes are associated with cell differentiation and patterning or are novel transcripts. With regard to chromosomal effects, dosage compensation occurs by elevated expression of X-linked genes in males. Genes with female-biased expression were more common on the X and less common on autosomes than expected, while male-biased genes exhibited no chromosomal pattern. Rates of protein evolution were lower for female-biased genes but higher for genes that moved on or off the novel X chromosome. These findings cannot be due to meiotic sex chromosome inactivation or by constraints associated with dosage compensation. Instead, they could be consistent with sexual conflict in which female-biased genes on the novel X act primarily to reduce eyespan in females while other genes increase eyespan in both sexes. Additional information on sex-biased gene expression in other tissues and related sexually monomorphic species could confirm this interpretation.


Subject(s)
Diptera/metabolism , Evolution, Molecular , Gene Expression Regulation, Developmental/physiology , Head/growth & development , Sex Characteristics , X Chromosome/genetics , Analysis of Variance , Animals , DNA Primers/genetics , Diptera/genetics , Diptera/growth & development , Dosage Compensation, Genetic/genetics , Female , Genetic Association Studies , Imaginal Discs/metabolism , Male , Oligonucleotide Array Sequence Analysis
20.
PLoS One ; 7(10): e43366, 2012.
Article in English | MEDLINE | ID: mdl-23056174

ABSTRACT

Pest Risk Analyses (PRAs) are conducted worldwide to decide whether and how exotic plant pests should be regulated to prevent invasion. There is an increasing demand for science-based risk mapping in PRA. Spread plays a key role in determining the potential distribution of pests, but there is no suitable spread modelling tool available for pest risk analysts. Existing models are species specific, biologically and technically complex, and data hungry. Here we present a set of four simple and generic spread models that can be parameterised with limited data. Simulations with these models generate maps of the potential expansion of an invasive species at continental scale. The models have one to three biological parameters. They differ in whether they treat spatial processes implicitly or explicitly, and in whether they consider pest density or pest presence/absence only. The four models represent four complementary perspectives on the process of invasion and, because they have different initial conditions, they can be considered as alternative scenarios. All models take into account habitat distribution and climate. We present an application of each of the four models to the western corn rootworm, Diabrotica virgifera virgifera, using historic data on its spread in Europe. Further tests as proof of concept were conducted with a broad range of taxa (insects, nematodes, plants, and plant pathogens). Pest risk analysts, the intended model users, found the model outputs to be generally credible and useful. The estimation of parameters from data requires insights into population dynamics theory, and this requires guidance. If used appropriately, these generic spread models provide a transparent and objective tool for evaluating the potential spread of pests in PRAs. Further work is needed to validate models, build familiarity in the user community and create a database of species parameters to help realize their potential in PRA practice.


Subject(s)
Coleoptera/physiology , Insect Control/statistics & numerical data , Models, Biological , Zea mays/parasitology , Algorithms , Animals , Climate , Computer Simulation , Ecosystem , Europe , Geography , Host-Parasite Interactions , Insect Control/methods , Plants/parasitology , Population Dynamics , Risk Assessment
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