791 research outputs found

    Characterizing the sublethal effects of SmartStax PRO dietary exposure on life history traits of the western corn rootworm, \u3ci\u3e Diabrotica virgifera virgifera\u3c/i\u3e LeConte

    Get PDF
    The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is an economically important pest of field corn (Zea mays L.) across the United States (U.S.) Corn Belt. Repeated use of transgenic hybrids expressing Bacillus thuringiensis (Bt) proteins has selected for field-evolved resistance to all current rootworm-active Bt proteins. The newest product available for WCR management is SmartStax® PRO, a rootworm-active pyramid containing Cry3Bb1, Cry34/35Ab1 [now reclassified as Gpp34Ab1/Tpp35Ab1] and a new mode of action, DvSnf7 dsRNA. Understanding the fitness of adult WCR after dietary exposure to SmartStax® PRO will identify potential impacts on WCR population dynamics and inform efforts to optimize resistance management strategies. Therefore, the objective of the present study was to characterize the effect of SmartStax® PRO dietary exposure on WCR life history traits. Adult WCR were collected during 2018 and 2019 from emergence tents placed over replicated field plots of SmartStax® PRO or non-rootworm Bt corn at a site with a history of rootworm-Bt trait use and suspected resistance to Cry3Bb1 and Cry34/35Ab1. Adult survival was reduced by 97.1–99.7% in SmartStax® PRO plots relative to the non-rootworm Bt corn plots during the study. Individual male/female pairs were fed different diets of ear tissue to simulate lifetime or adult exposure. Life history parameters measured included adult longevity, adult head capsule width, lifetime female egg production, and egg viability. Results indicate that lifetime or adult exposure to SmartStax® PRO significantly reduced adult longevity and lifetime egg production. Larval exposure to SmartStax® PRO significantly reduced WCR adult size. Results from this study collectively suggest that SmartStax® PRO may negatively impact WCR life history traits, which may lead to reduced population growth when deployed in an area with WCR resistance to Bt traits

    Cardenolide, Potassium, and Pyrethroid Insecticide Combinations Reduce Growth and Survival of Monarch Butterfly Caterpillars (Lepidoptera: Nymphalidae)

    Get PDF
    The monarch butterfly, Danaus plexippus L., has evolved to be insensitive to milkweed cardenolides via genetic modifications of Na+/K+-ATPase. There is concern for insecticide exposures near agriculture, with little information on monarch caterpillar toxicology. It is unclear how cardenolide insensitivity may affect the sensitivity of monarch caterpillars to pyrethroid insecticides. Additionally, potassium fertilizers may affect monarch caterpillar physiology and cardenolide sequestration. Here, we investigated the growth, survival, and development of caterpillars exposed to the cardenolide ouabain, bifenthrin, and potassium chloride (KCl) alone and in combination. Caterpillars were either exposed to (1) ouabain from third- to fifth-instar stage, (2) KCl at fifth-instar stage, (3) KCl and bifenthrin at fifth-instar stage, or (4) combinations of ouabain at third-instar stage + KCl + bifenthrin at fifth-instar stage. Caterpillar weight, diet consumption, frass, and survival were recorded for the duration of the experiments. It was observed that 1–3 mg ouabain/g diet increased body weight and diet consumption, whereas 50 mg KCl/g diet decreased body weight and diet consumption. Caterpillars feeding on KCl and treated with 0.2 μg/μl bifenthrin consumed significantly less diet compared to individuals provided untreated diet. However, there was no effect on survival or body weight. Combinations of KCl + ouabain did not significantly affect caterpillar survival or body weight following treatment with 0.1 μg/μl bifenthrin. At the concentrations tested, there were no effects observed for bifenthrin sensitivity with increasing cardenolide or KCl concentrations. Further studies are warranted to understand how milkweed-specific cardenolides, at increasing concentrations, and agrochemical inputs can affect monarch caterpillar physiology near agricultural landscapes

    Verbal Initiation, Suppression, and Strategy Use and the Relationship with Clinical Symptoms in Schizophrenia

    Get PDF
    Objectives: Individuals with schizophrenia have difficulties on measures of executive functioning such as initiation and suppression of responses and strategy development and implementation. The current study thoroughly examines performance on the Hayling Sentence Completion Test (HSCT) in individuals with schizophrenia, introducing novel analyses based on initiation errors and strategy use, and association with lifetime clinical symptoms. Methods: The HSCT was administered to individuals with schizophrenia (N=77) and age-and sex-matched healthy controls (N=45), along with background cognitive tests. The standard HSCT clinical measures (initiation response time, suppression response time, suppression errors), composite initiation and suppression error scores, and strategy-based responses were calculated. Lifetime clinical symptoms formal thought disorder (FTD), positive, negative were calculated using the Lifetime Dimensions of Psychosis Scale. Results: After controlling for baseline cognitive differences, individuals with schizophrenia were significantly impaired on the suppression response time and suppression error scales. For the novel analyses, individuals with schizophrenia produced a greater number of initiation errors and subtly wrong errors, and produced fewer responses indicative of developing an appropriate strategy. Strategy use was negatively correlated with FTD symptoms in individuals with schizophrenia. Conclusions: The current study provides further evidence for deficits in the initiation and suppression of verbal responses in individuals with schizophrenia. Moreover, an inability to attain a strategy at least partly contributes to increased semantically connected errors when attempting to suppress responses. The association between strategy use and FTD points to the involvement of executive deficits in disorganized speech in schizophrenia

    Abdominal Obesity Associated To Medical-Related Absenteeism At A Company Of Metal-Mechanical Industry In Cali, Colombia

    Get PDF
    Con el objetivo de examinar la frecuencia de obesidad abdominal y el ausentismo laboral por causa médica, se realizó un estudio transversal en 185 varones pertenecientes a una industria metalmecánica. En ellos, además de datos sociodemográficos, se recogió datos antropométricos y se midió la circunferencia de cintura (CC) en centímetros como indicador de obesidad abdominal. Se encontró, además de una alta frecuencia de obesidad abdominal (28,7%), que los trabajadores con obesidad abdominal presentaron mayor frecuencia, mayor tiempo y mayores costos por las incapacidades médicas. Se concluye que la obesidad abdominal en esta muestra fue altamente frecuente; no obstante, al tratarse de un riesgo reversible, las empresas podrían beneficiarse, en términos de ausentismo laboral, de programas preventivo promocionales destinados a controlar este problemaThe aim of this study was examined the abdominal obesity prevalence and association with medical-related absenteeism. A cross-sectional study in 185 men from the metal-mechanical industry was conducted. Sociodemografic and antropometrics data of was gathered, waist circumference was measured as an indicator of abdominal obesity. The prevalence of central obesity was 28.7 %. Subjects with higher values of central obesity showed higher frequency, higher duration and higher costs of medical-related absenteeism, however, this relationship was not significant. We conclude that abdominal obesity is highly frequent in this sample; however, since it’s a reversible risk, enterprises could get benefits from preventive and promotional programs destiny to control this problem

    Barriers and facilitators to implementing dementia care mapping in care homes: results from the DCMâ„¢ EPIC trial process evaluation

    Get PDF
    Background Psychosocial person-centred interventions are considered best practice for addressing complex behaviours and care needs such as agitation and anxiety, and for improving the quality of life of people with dementia in care homes. Dementia Care Mapping (DCMâ„¢) is an established practice development tool and process aimed to help care home staff deliver more person-centred care. To date, few studies have evaluated the efficacy of DCMâ„¢ and have found mixed results. These results are suggested to be the outcome of intervention implementation, which may be impacted by a range of factors. This study reports the barriers and facilitators to DCMâ„¢ implementation in care homes found during the process evaluation conducted as part of a randomized controlled trial. Methods Eighteen of the 31 DCMâ„¢ intervention care homes were recruited to participate in the embedded process evaluation. Semi-structured interviews were conducted with 83 participants, comprising care home managers, trained DCMâ„¢ users (mappers), expert external mappers, staff members, relatives, and residents. Results Barriers and facilitators to DCMâ„¢ implementation were found at the mapper level (e.g. motivation and confidence), the DCMâ„¢ intervention level (e.g. understanding of DCMâ„¢) and the care home level (e.g. staffing issues, manager support). Further barriers caused by the burden of trial participation were also identified (e.g. additional paperwork). Conclusions Implementing DCMâ„¢ is complex and a greater consideration of potential barriers and facilitators in planning future studies and in practice could help improve implementation

    Stylasterid corals: a new paleotemperature archive

    Get PDF
    Stylasterids are a ubiquitous deep-sea coral taxon that build their skeletons from either calcite, aragonite, or both. Yet, robust geochemical proxy data from these corals are limited. In this study, 95 modern stylasterids, spanning a wide range of depths (63 to 2894 m) and ambient seawater temperatures (0 to 17 °C), were tested for their potential use as paleoceanographic archives. Stable oxygen and carbon isotopic composition (O and C) were measured from the main trunk of all specimens and five specimens were further sub-sampled to assess internal chemical variability. The isotope data show non-equilibrium precipitation from seawater for both O and C, with the growing tips of colonies yielding the isotopically lowest values. Overall, the calcitic corals showed lower isotope values for O and C than aragonitic specimens. Within the aragonite corals, we present a O:temperature calibration that exhibits a significant linear relationship with the equation Ocoral-seawater = −0.22(°C) + 3.33(±0.06) across a temperature range of 0 to 30 °C, using samples from this study and published data. This work highlights the potential application of stylasterid coral O data to reconstruct paleo seawater temperature

    Targeting OGG1 and PARG radiosensitises head and neck cancer cells to high-LET protons through complex DNA damage persistence

    Get PDF
    Complex DNA damage (CDD), containing two or more DNA lesions within one or two DNA helical turns, is a signature of ionising radiation (IR) and contributes significantly to the therapeutic effect through cell killing. The levels and complexity of CDD increases with linear energy transfer (LET), however, the specific cellular response to this type of DNA damage and the critical proteins essential for repair of CDD is currently unclear. We performed an siRNA screen of ~240 DNA damage response proteins to identify those specifically involved in controlling cell survival in response to high-LET protons at the Bragg peak, compared to low-LET entrance dose protons which differ in the amount of CDD produced. From this, we subsequently validated that depletion of 8-oxoguanine DNA glycosylase (OGG1) and poly(ADP-ribose) glycohydrolase (PARG) in HeLa and head and neck cancer cells leads to significantly increased cellular radiosensitivity specifically following high-LET protons, whilst no effect was observed after low-LET protons and X-rays. We subsequently confirmed that OGG1 and PARG are both required for efficient CDD repair post-irradiation with high-LET protons. Importantly, these results were also recapitulated using specific inhibitors for OGG1 (TH5487) and PARG (PDD00017273). Our results suggest OGG1 and PARG play a fundamental role in the cellular response to CDD and indicate that targeting these enzymes could represent a promising therapeutic strategy for the treatment of head and neck cancers following high-LET radiation

    c-Fms-Mediated Differentiation and Priming of Monocyte Lineage Cells Play a Central Role in Autoimmune Arthritis

    Get PDF
    Introduction: Tyrosine kinases are key mediators of multiple signaling pathways implicated in rheumatoid arthritis (RA). We previously demonstrated that imatinib mesylate--a Food and Drug Administration (FDA)-approved, antineoplastic drug that potently inhibits the tyrosine kinases Abl, c-Kit, platelet-derived growth factor receptor (PDGFR), and c-Fms--ameliorates murine autoimmune arthritis. However, which of the imatinib-targeted kinases is the principal culprit in disease pathogenesis remains unknown. Here we examine the role of c-Fms in autoimmune arthritis. Methods: We tested the therapeutic efficacy of orally administered imatinib or GW2580, a small molecule that specifically inhibits c-Fms, in three mouse models of RA: collagen-induced arthritis (CIA), anti-collagen antibody-induced arthritis (CAIA), and K/BxN serum transfer-induced arthritis (K/BxN). Efficacy was evaluated by visual scoring of arthritis severity, paw thickness measurements, and histological analysis. We assessed the in vivo effects of imatinib and GW2580 on macrophage infiltration of synovial joints in CIA, and their in vitro effects on macrophage and osteoclast differentiation, and on osteoclast-mediated bone resorption. Further, we determined the effects of imatinib and GW2580 on the ability of macrophage colony-stimulating factor (M-CSF; the ligand for c-Fms) to prime bone marrow-derived macrophages to produce tumor necrosis factor (TNF) upon subsequent Fc receptor ligation. Finally, we measured M-CSF levels in synovial fluid from patients with RA, osteoarthritis (OA), or psoriatic arthritis (PsA), and levels of total and phosphorylated c-Fms in synovial tissue from patients with RA. Results: GW2580 was as efficacious as imatinib in reducing arthritis severity in CIA, CAIA, and K/BxN models of RA. Specific inhibition of c-Fms abrogated (i) infiltration of macrophages into synovial joints of arthritic mice; (ii) differentiation of monocytes into macrophages and osteoclasts; (iii) osteoclast-mediated bone resorption; and (iv) priming of macrophages to produce TNF upon Fc receptor stimulation, an important trigger of synovitis in RA. Expression and activation of c-Fms in RA synovium were high, and levels of M-CSF were higher in RA synovial fluid than in OA or PsA synovial fluid. Conclusions: These results suggest that c-Fms plays a central role in the pathogenesis of RA by mediating the differentiation and priming of monocyte lineage cells. Therapeutic targeting of c-Fms could provide benefit in RA
    • …
    corecore