27 research outputs found

    Empirical approaches to improving the use of DNA in crime scene investigative practice

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    This article reports on a collaborative project that explored the targeted use of swabbing evidence sources which, up until now, have not been routinely recovered or utilised for DNA analysis. All genres of the forensic portfolio have undergone significant changes driven by economic, political and technological influencers, which have resulted in an array of interpretations on its frontline delivery, often based on local requirements. The approach reported here pertains to a research project bringing together a collaborative team of researchers, representing practitioners and academics, working in conjunction with forensic service providers. The project reviewed the process of swabbing glove marks at crime scenes, comparing the methods used with DNA profiling outcomes. The findings showed significant benefits in regards to DNA outcomes, providing six detections over a four-month period that were attributable to the swabbing of the glove marks. Furthermore, the study provided key data to guide practice and crime scene methods to meet new operational requirements

    Empirical approaches to improving the use of DNA in crime scene investigative practice

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    At the beginning of the 21st century, rural policy remains one of the most important areas of public policy; huge financial and human resources are devoted to the implementation of this policy measures. The aim of the article is to provide holistic evaluation of the goals, means and key achievements of Lithuanian agricultural policy and to identify possible areas and ways of improvement. The diversity of agricultural policy measures applied in Lithuania after the restoration of independence in 1990 and achievements of the policy are analysed on the basis of new approach – the theory of qualitative structures. The study explores how policy measures to accelerate the process of industrialization in Lithuanian agriculture after the privatization of kolkhozes and sovkhozes have encouraged and supported private farms to implement extensive growth, intensification, specialization, risk management, collaboration and innovation production strategies, and what results they have achieved.XXI a. pradžioje kaimo politika išlieka viena iš svarbiausių viešosios politikos sričių. Šios politikos priemonėms diegti skiriama labai daug finansinių ir žmogiškųjų išteklių. Straipsnio tikslas – holistiškai įvertinti Lietuvos žemės ūkio politikos tikslus, priemones ir pasiekimus, identifikuoti galimas tobulinimo kryptis. Žemės ūkio politikos priemonių, taikytų Lietuvoje po nepriklausomybės atgavimo 1990 m., įvairovė ir pasiekimai analizuojami remiantis kokybinių struktūrų analizės metodu. Aptariama, kaip politikos priemonėmis, siekiant paspartinti industrializacijos procesą Lietuvos žemės ūkyje, ūkininkai buvo skatinami panaudoti šių priemonių kokybinės struktūros galimybes, kad būtų įgyvendinamos ekstensyvaus augimo, intensifikacijos, specializacijos, rizikos valdymo, bendradarbiavimo ir inovacijų strategijos

    Invasion Genetics of the Western Flower Thrips in China: Evidence for Genetic Bottleneck, Hybridization and Bridgehead Effect

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    The western flower thrips, Frankliniella occidentalis (Pergande), is an invasive species and the most economically important pest within the insect order Thysanoptera. F. occidentalis, which is endemic to North America, was initially detected in Kunming in southwestern China in 2000 and since then it has rapidly invaded several other localities in China where it has greatly damaged greenhouse vegetables and ornamental crops. Controlling this invasive pest in China requires an understanding of its genetic makeup and migration patterns. Using the mitochondrial COI gene and 10 microsatellites, eight of which were newly isolated and are highly polymorphic, we investigated the genetic structure and the routes of range expansion of 14 F. occidentalis populations in China. Both the mitochondrial and microsatellite data revealed that the genetic diversity of F. occidentalis of the Chinese populations is lower than that in its native range. Two previously reported cryptic species (or ecotypes) were found in the study. The divergence in the mitochondrial COI of two Chinese cryptic species (or ecotypes) was about 3.3% but they cannot be distinguished by nuclear markers. Hybridization might produce such substantial mitochondrial-nuclear discordance. Furthermore, we found low genetic differentiation (global FST = 0.043, P<0.001) among all the populations and strong evidence for gene flow, especially from the three southwestern populations (Baoshan, Dali and Kunming) to the other Chinese populations. The directional gene flow was further supported by the higher genetic diversity of these three southwestern populations. Thus, quarantine and management of F. occidentalis should focus on preventing it from spreading from the putative source populations to other parts of China

    Novel molecular approach to define pest species status and tritrophic interactions from historical Bemisia specimens

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    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.© The Author(s) 2017. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. The attached file is the published pdf

    Changes to the Fossil Record of Insects through Fifteen Years of Discovery

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    The first and last occurrences of hexapod families in the fossil record are compiled from publications up to end-2009. The major features of these data are compared with those of previous datasets (1993 and 1994). About a third of families (>400) are new to the fossil record since 1994, over half of the earlier, existing families have experienced changes in their known stratigraphic range and only about ten percent have unchanged ranges. Despite these significant additions to knowledge, the broad pattern of described richness through time remains similar, with described richness increasing steadily through geological history and a shift in dominant taxa, from Palaeoptera and Polyneoptera to Paraneoptera and Holometabola, after the Palaeozoic. However, after detrending, described richness is not well correlated with the earlier datasets, indicating significant changes in shorter-term patterns. There is reduced Palaeozoic richness, peaking at a different time, and a less pronounced Permian decline. A pronounced Triassic peak and decline is shown, and the plateau from the mid Early Cretaceous to the end of the period remains, albeit at substantially higher richness compared to earlier datasets. Origination and extinction rates are broadly similar to before, with a broad decline in both through time but episodic peaks, including end-Permian turnover. Origination more consistently exceeds extinction compared to previous datasets and exceptions are mainly in the Palaeozoic. These changes suggest that some inferences about causal mechanisms in insect macroevolution are likely to differ as well

    Occurrence of three genotypic clusters of Bemisia tabaci and the rapid spread of the B biotype in south India

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    The whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), is generally considered to have originated from the Indian subcontinent, although little information has so far been collected on the molecular diversity of populations present in this region. The genetic diversity of B. tabaci populations from Karnataka State, south India was analysed using the random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) technique and partial mitochondrial cytochrome oxidase I (mtCOI) gene sequences (689 bases) of 22 selected samples. A total of 108 whitefly samples analysed by RAPD-PCR produced 89 polymorphic bands, and cluster analyses grouped them according to their geographic origin into ‘north’ and ‘south’ Karnataka. Phylogenetic analysis of mtCOI gene sequences with reference B. tabaci sequences from other Asian countries divided them into three genotypic clusters. Each cluster was supported with high bootstrap values (82–100%) and the individuals belonging to each cluster shared high nucleotide identities (up to 100%). This indicated at least three distinct genotypes, apparently indigenous to India, which are also present in China, Malaysia, Nepal, Pakistan, and Thailand. These coexist with the B biotype, which was first reported in India in 1999, and has since spread rapidly to other states in south India. The B biotype was more common than the indigenous B. tabaci, in locations where it had been present for more than 2 years. This is reminiscent of the situation in the Americas during the early 1990s, where the B biotype replaced existing biotypes and caused unprecedented losses to agriculture
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