61 research outputs found

    Exploitation of population dynamics and chemical communication for integrated management of Drosophila suzukii

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    Drosophila suzukii (Matsumura), also known as Spotted Wing Drosophila (SWD), is a vinegar fly belonging to the Diptera order and Drosophilidae family. It is native to South East Asia and it has recently invaded western countries, threating fruits production. Because of its rapid spread, the economic impact has been huge in most of the invaded countries. D. suzukii infestations generate direct and indirect economic impacts. For this reason, deeper information about the biology, ecology, chemical-ecology, genetics and behavior are necessary to better manage the species. This thesis was developed to contribute towards a better understanding of these topics, in order to find a scientifically supported and effective solution. In particular, this work focused on four aspects: 1) analyze the genetic structure of different Italian populations, 2) understand the spread and therefore the capacity of movement of D. suzukii in large and small scale, 3) study the oviposition behavior with an in depth characterization of the chemical volatiles involved in the substrate choice and 4) manipulate the egg-lay behavior thanks to an innovative lure, which can work as an alternative oviposition substrate. In the first chapter, we characterized the genetic structure of the invasive species D. suzukii in Italy. Our analysis showed extensive genetic homogeneity among D. suzukii collected in Italy. The relatively isolated Sicilian population suggests a largely human-mediated migration pattern while the warm climate in this region allows the production of soft fruit, and the associated D. suzukii reproductive season occurring much earlier than on the rest of the peninsula. Understanding seasonal and daily migrations D. suzukii populations is fundamental, since it could help farmers and industries decide where to apply specific management techniques. This was the aim of the third and fourth chapter. Furthermore, the finding of a consistent seasonal and daily movement from the crop to the surrounding vegetation and towards areas with different altitude, may lead to use treatments, especially chemical, in precise periods of the year and in defined zones on the border of the crop. The fifth chapter was focused on the oviposition behaviour of D. suzukii. The goal of this work was to elucidate behavioural and chemical aspects of short-range site selection of this species. In particular experiments evidenced the release of an anal secretion over the fruit surface near the oviposition site, which seems to have an attractant function. The knowledge gained with this study may accelerate establishment of control strategies based on the interference and disruption of the D. suzukii communication during the oviposition processes. Finally, the main target of my sixth chapter had more practical purposes focusing on the identification of new attractants for D. suzukii able to interfere with its movement and, consequently, with the potential to be used as baits for pest monitoring and control. This project, carried out at the Oregon State University, led to the development of new gum matrix as a potential sink for D. suzukii eggs in a commercial-standard cropping system. Taken together, the results presented in this thesis highly contribute to enhancing our understanding of D. suzukii biology, ecology and chemical and to expand integrated pest management option

    Molecular markers for analyses of intraspecific genetic diversity in the Asian Tiger mosquito, Aedes albopictus

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    BACKGROUND: The dramatic worldwide expansion of Aedes albopictus (the Asian tiger mosquito) and its vector competence for numerous arboviruses represent a growing threat to public health security. Molecular markers are crucially needed for tracking the rapid spread of this mosquito and to obtain a deeper knowledge of population structure. This is a fundamental requirement for the development of strict monitoring protocols and for the improvement of sustainable control measures. METHODS: Wild population samples from putative source areas and from newly colonised regions were analysed for variability at the ribosomal DNA internal transcribed spacer 2 (ITS2). Moreover, a new set of 23 microsatellite markers (SSR) was developed. Sixteen of these SSRs were tested in an ancestral (Thailand) and two adventive Italian populations. RESULTS: Seventy-six ITS2 sequences representing 52 unique haplotypes were identified, and AMOVA indicated that most of their variation occurred within individuals (74.36%), while only about 8% was detected among populations. Spatial analyses of molecular variance revealed that haplotype genetic similarity was not related to the geographic proximity of populations and the haplotype phylogeny clearly indicated that highly related sequences were distributed across populations from different geographical regions. The SSR markers displayed a high level of polymorphism both in the ancestral and in adventive populations, and F(ST) estimates suggested the absence of great differentiation. The ancestral nature of the Thai population was corroborated by its higher level of variability. CONCLUSIONS: The two types of genetic markers here implemented revealed the distribution of genetic diversity within and between populations and provide clues on the dispersion dynamics of this species. It appears that the diffusion of this mosquito does not conform to a progressive expansion from the native Asian source area, but to a relatively recent and chaotic propagule distribution mediated by human activities. Under this scenario, multiple introductions and admixture events probably play an important role in maintaining the genetic diversity and in avoiding bottleneck effects. The polymorphic SSR markers here implemented will provide an important tool for reconstructing the routes of invasion followed by this mosquito

    Correction to: Pulpotomy for the Management of Irreversible Pulpitis in Mature Teeth (PIP): a feasibility study

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    Background Progression of dental caries can result in irreversible pulpal damage. Partial irreversible pulpitis is the initial stage of this damage, confined to the coronal pulp whilst the radicular pulp shows little or no sign of infection. Preserving the pulp with sustained vitality and developing minimally invasive biologically based therapies are key themes within contemporary clinical practice. However, root canal treatment involving complete removal of the pulp is often the only option (other than extraction) given to patients with irreversible pulpitis, with substantial NHS and patient incurred costs. The European Society of Endodontology’s (ESE 2019) recent consensus statement recommends full pulpotomy, where the inflamed coronal pulp is removed with the goal of keeping the radicular pulp vital, as a more minimally invasive technique, potentially avoiding complex root canal treatment. Although this technique may be provided in secondary care, it has not been routinely implemented or evaluated in UK General Dental Practice. Method This feasibility study aims to identify and assess in a primary care setting the training needs of general dental practitioners and clinical fidelity of the full pulpotomy intervention, estimate likely eligible patient pool and develop recruitment materials ahead of the main randomised controlled trial comparing the clinical and cost-effectiveness of full pulpotomy compared to root canal treatment in pre/molar teeth of adults 16 years and older showing signs indicative of irreversible pulpitis. The feasibility study will recruit and train 10 primary care dentists in the full pulpotomy technique. Dentists will recruit and provide full pulpotomy to 40 participants (four per practice) with indications of partial irreversible pulpitis. Discussion The Pulpotomy for the Management of Irreversible Pulpitis in Mature Teeth (PIP) study will address the lack of high-quality evidence in the treatment of irreversible pulpitis, to aid dental practitioners, patients and policymakers in their decision-making. The PIP feasibility study will inform the main study on the practicality of providing both training and provision of the full pulpotomy technique in general dental practice. Trial registration ISRCTN Registry, ISRCTN17973604. Registered on 28 January 2021. Protocol version Protocol version: 1; date: 03.02.202

    Towards a muon collider

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    A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

    Towards a Muon Collider

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    A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work.Comment: 118 pages, 103 figure

    Erratum:Towards a muon collider

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    Towards a muon collider

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    A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

    Erratum: Towards a muon collider

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    The original online version of this article was revised: The additional reference [139] has been added. Tao Han’s ORICD ID has been incorrectly assigned to Chengcheng Han and Chengcheng Han’s ORCID ID to Tao Han. Yang Ma’s ORCID ID has been incorrectly assigned to Lianliang Ma, and Lianliang Ma’s ORCID ID to Yang Ma. The original article has been corrected

    Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses

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    To understand neurological complications of COVID-19 better both acutely and for recovery, we measured markers of brain injury, inflammatory mediators, and autoantibodies in 203 hospitalised participants; 111 with acute sera (1–11 days post-admission) and 92 convalescent sera (56 with COVID-19-associated neurological diagnoses). Here we show that compared to 60 uninfected controls, tTau, GFAP, NfL, and UCH-L1 are increased with COVID-19 infection at acute timepoints and NfL and GFAP are significantly higher in participants with neurological complications. Inflammatory mediators (IL-6, IL-12p40, HGF, M-CSF, CCL2, and IL-1RA) are associated with both altered consciousness and markers of brain injury. Autoantibodies are more common in COVID-19 than controls and some (including against MYL7, UCH-L1, and GRIN3B) are more frequent with altered consciousness. Additionally, convalescent participants with neurological complications show elevated GFAP and NfL, unrelated to attenuated systemic inflammatory mediators and to autoantibody responses. Overall, neurological complications of COVID-19 are associated with evidence of neuroglial injury in both acute and late disease and these correlate with dysregulated innate and adaptive immune responses acutely
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