474 research outputs found

    Tools for delivering entomopathogenic fungi to malaria mosquitoes: effects of delivery surfaces on fungal efficacy and persistence.

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    BACKGROUND\ud \ud Entomopathogenic fungi infection on malaria vectors increases daily mortality rates and thus represents a control measure that could be used in integrated programmes alongside insecticide-treated bed nets (ITNs) and indoor residual spraying (IRS). Before entomopathogenic fungi can be integrated into control programmes, an effective delivery system must be developed.\ud \ud METHODS\ud \ud The efficacy of Metarhizium anisopliae ICIPE-30 and Beauveria bassiana I93-825 (IMI 391510) (2 × 10(10) conidia m(-2)) applied on mud panels (simulating walls of traditional Tanzanian houses), black cotton cloth and polyester netting was evaluated against adult Anopheles gambiae sensu stricto. Mosquitoes were exposed to the treated surfaces 2, 14 and 28 d after conidia were applied. Survival of mosquitoes was monitored daily.\ud \ud RESULTS\ud \ud All fungal treatments caused a significantly increased mortality in the exposed mosquitoes, descending with time since fungal application. Mosquitoes exposed to M. anisopliae conidia on mud panels had a greater daily risk of dying compared to those exposed to conidia on either netting or cotton cloth (p < 0.001). Mosquitoes exposed to B. bassiana conidia on mud panels or cotton cloth had similar daily risk of death (p = 0.14), and a higher risk than those exposed to treated polyester netting (p < 0.001). Residual activity of fungi declined over time; however, conidia remained pathogenic at 28 d post application, and were able to infect and kill 73 - 82% of mosquitoes within 14 d.\ud \ud CONCLUSION\ud \ud Both fungal isolates reduced mosquito survival on immediate exposure and up to 28 d after application. Conidia were more effective when applied on mud panels and cotton cloth compared with polyester netting. Cotton cloth and mud, therefore, represent potential substrates for delivering fungi to mosquitoes in the field

    Evaluation of the impact of a school gardening intervention on children's fruit and vegetable intake: a randomised controlled trial.

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    Background: Current academic literature suggests that school gardening programmes can provide an interactive environment with the potential to change children’s fruit and vegetable intake. This is the first cluster randomised controlled trial (RCT) designed to evaluate whether a school gardening programme can have an effect on children’s fruit and vegetable intake. Methods: The trial included children from 23 schools; these schools were randomised into two groups, one to receive the Royal Horticultural Society (RHS)-led intervention and the other to receive the less involved Teacher-led intervention. A 24-hour food diary (CADET) was used to collect baseline and follow-up dietary intake 18 months apart. Questionnaires were also administered to evaluate the intervention implementation. Results: A total of 641 children completed the trial with a mean age of 8.1 years (95% CI: 8.0, 8.4). The unadjusted results from multilevel regression analysis revealed that for combined daily fruit and vegetable intake the Teacher-led group had a higher daily mean change of 8 g (95% CI: −19, 36) compared to the RHS-led group -32 g (95% CI: −60, −3). However, after adjusting for possible confounders this difference was not significant (intervention effect: −40 g, 95% CI: −88, 1; p = 0.06). The adjusted analysis of process measures identified that if schools improved their gardening score by 3 levels (a measure of school gardening involvement - the scale has 6 levels from 0 ‘no garden’ to 5 ‘community involvement’), irrespective of group allocation, children had, on average, a daily increase of 81 g of fruit and vegetable intake (95% CI: 0, 163; p = 0.05) compared to schools that had no change in gardening score. Conclusions: This study is the first cluster randomised controlled trial designed to evaluate a school gardening intervention. The results have found very little evidence to support the claims that school gardening alone can improve children’s daily fruit and vegetable intake. However, when a gardening intervention is implemented at a high level within the school it may improve children’s daily fruit and vegetable intake by a portion. Improving children’s fruit and vegetable intake remains a challenging task

    Not just bricks and mortar: planning hospital cancer services for Aboriginal people

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    <p>Abstract</p> <p>Background</p> <p>Aboriginal people in Australia experience higher mortality from cancer compared with non-Aboriginal Australians, despite an overall lower incidence. A notable contributor to this disparity is that many Aboriginal people do not take up or continue with cancer treatment which almost always occurs within major hospitals.</p> <p>Thirty in-depth interviews with urban, rural and remote Aboriginal people affected by cancer were conducted between March 2006 and September 2007. Interviews explored participants' beliefs about cancer and experiences of cancer care and were audio-recorded, transcribed verbatim and coded independently by two researchers. NVivo7 software was used to assist data management and analysis. Information from interviews relevant to hospital services including and building design was extracted.</p> <p>Findings</p> <p>Relationships and respect emerged as crucial considerations of participants although many aspects of the hospital environment were seen as influencing the delivery of care. Five themes describing concerns about the hospital environment emerged: (i) being alone and lost in a big, alien and inflexible system; (ii) failure of open communication, delays and inefficiency in the system; (iii) practicalities: costs, transportation, community and family responsibilities; (iv) the need for Aboriginal support persons; and (v) connection to the community.</p> <p>Conclusions</p> <p>Design considerations and were identified but more important than the building itself was the critical need to build trust in health services. Promotion of cultural safety, support for Aboriginal family structures and respecting the importance of place and community to Aboriginal patients are crucial in improving cancer outcomes.</p

    Combinations of β-lactam or aminoglycoside antibiotics with plectasin are synergistic against methicillin-sensitive and methicillin-resistant Staphylococcus aureus.

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    Bacterial infections remain the leading killer worldwide which is worsened by the continuous emergence of antibiotic resistance. In particular, methicillin-sensitive (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) are prevalent and the latter can be difficult to treat. The traditional strategy of novel therapeutic drug development inevitably leads to emergence of resistant strains, rendering the new drugs ineffective. Therefore, rejuvenating the therapeutic potentials of existing antibiotics offers an attractive novel strategy. Plectasin, a defensin antimicrobial peptide, potentiates the activities of other antibiotics such as β-lactams, aminoglycosides and glycopeptides against MSSA and MRSA. We performed in vitro and in vivo investigations to test against genetically diverse clinical isolates of MSSA (n = 101) and MRSA (n = 115). Minimum inhibitory concentrations (MIC) were determined by the broth microdilution method. The effects of combining plectasin with β-lactams, aminoglycosides and glycopeptides were examined using the chequerboard method and time kill curves. A murine neutropenic thigh model and a murine peritoneal infection model were used to test the effect of combination in vivo. Determined by factional inhibitory concentration index (FICI), plectasin in combination with aminoglycosides (gentamicin, neomycin or amikacin) displayed synergistic effects in 76-78% of MSSA and MRSA. A similar synergistic response was observed when plectasin was combined with β-lactams (penicillin, amoxicillin or flucloxacillin) in 87-89% of MSSA and MRSA. Interestingly, no such interaction was observed when plectasin was paired with vancomycin. Time kill analysis also demonstrated significant synergistic activities when plectasin was combined with amoxicillin, gentamicin or neomycin. In the murine models, plectasin at doses as low as 8 mg/kg augmented the activities of amoxicillin and gentamicin in successful treatment of MSSA and MRSA infections. We demonstrated that plectasin strongly rejuvenates the therapeutic potencies of existing antibiotics in vitro and in vivo. This is a novel strategy that can have major clinical implications in our fight against bacterial infections

    The birth of airplane stability theory

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    Airplane stability theory was born at the end of the XIX century and matured around 100 years ago, when airplanes were hardly controllable yet. The success and safety of flights in the pioneer years depended upon largely unknown stability and control characteristics. Understanding the modes of airplane motion has been of paramount importance for the development of aviation. The contributions made by a few scientists in the decades preceding and following the first flight by the Wright brothers set the concepts and equations that, with minor notation aspects, have remained almost unchanged till present day.Magraner Rullan, JP.; Martinez-Val, R. (2014). The birth of airplane stability theory. Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering. 228(9):1498-1506. doi:10.1177/0954410013494139S149815062289PERKINS, C. D. (1970). Development of airplane stability and control technology /1970 Von Karman Lecture/. Journal of Aircraft, 7(4), 290-301. doi:10.2514/3.44167Abzug, M. J., & Larrabee, E. E. (2002). Airplane Stability and Control, Second Edition. doi:10.1017/cbo9780511607141Graham, W. R. (1999). Asymptotic analysis of the classical aircraft stability equations. The Aeronautical Journal, 103(1020), 95-103. doi:10.1017/s0001924000027792Bryan, G. H., & Williams, W. E. (1904). The Longitudinal Stability of Aerial Gliders. Proceedings of the Royal Society of London, 73(488-496), 100-116. doi:10.1098/rspl.1904.0017Wegener, P. P. (1997). What Makes Airplanes Fly? doi:10.1007/978-1-4612-2254-5Pradeep, S., & Kamesh, S. (1999). Does the Phugoid Frequency Depend on Speed? Journal of Guidance, Control, and Dynamics, 22(2), 372-373. doi:10.2514/2.4391Phillips, W. F. (2000). Phugoid Approximation for Conventional Airplanes. Journal of Aircraft, 37(1), 30-36. doi:10.2514/2.2586Pamadi, B. N. (2004). Performance, Stability, Dynamics, and Control of Airplanes, Second Edition. doi:10.2514/4.862274Ananthkrishnan, N., & Ramadevi, P. (2002). Consistent Approximations to Aircraft Longitudinal Modes. Journal of Guidance, Control, and Dynamics, 25(4), 820-824. doi:10.2514/2.4952McRuer, D. T., Graham, D., & Ashkenas, I. (1990). Aircraft Dynamics and Automatic Control. doi:10.1515/978140085598

    Measuring spirometry in a lung cancer screening cohort highlights possible underdiagnosis and misdiagnosis of Chronic Obstructive Pulmonary Disease

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    Introduction: Chronic Obstructive Pulmonary Disease (COPD) is underdiagnosed, and measurement of spirometry alongside low-dose computed tomography (LDCT) screening for lung cancer is one strategy to increase earlier diagnosis of this disease. // Methods: Ever-smokers at high risk of lung cancer were invited to the Yorkshire Lung Screening Trial for a Lung Health Check (LHC) comprising LDCT screening, pre-bronchodilator spirometry and smoking cessation service. In this cross-sectional study we present data on participant demographics, respiratory symptoms, lung function, emphysema on imaging and both self-reported and primary care diagnoses of COPD. Multivariable logistic regression analysis identified factors associated with possible underdiagnosis and misdiagnosis of COPD in this population, with airflow obstruction (AO) defined as FEV1/FVC ratio <0.70. // Results: Of 3,920 LHC attendees undergoing spirometry, 17% had undiagnosed AO with respiratory symptoms, representing potentially undiagnosed COPD. Compared to those with a primary care COPD code, this population had milder symptoms, better lung function, and were more likely to be current smokers (p≤0.001 for all comparisons). Of 836 attendees with a primary care COPD code who underwent spirometry, 19% did not have AO, potentially representing misdiagnosed COPD, although symptom burden was high. // Discussion: Spirometry offered alongside LDCT screening can potentially identify cases of undiagnosed and misdiagnosed COPD. Future research should assess the downstream impact of these findings to determine if any meaningful changes to treatment and outcomes occurs, and also to assess the impact on co-delivering spirometry on other parameters of LDCT screening performance such as participation and adherence. Additionally, work is needed to better understand the aetiology of respiratory symptoms in those with misdiagnosed COPD, to ensure this highly symptomatic group receive evidence-based interventions

    Estimation of the solubility parameters of model plant surfaces and agrochemicals: a valuable tool for understanding plant surface interactions

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    Background Most aerial plant parts are covered with a hydrophobic lipid-rich cuticle, which is the interface between the plant organs and the surrounding environment. Plant surfaces may have a high degree of hydrophobicity because of the combined effects of surface chemistry and roughness. The physical and chemical complexity of the plant cuticle limits the development of models that explain its internal structure and interactions with surface-applied agrochemicals. In this article we introduce a thermodynamic method for estimating the solubilities of model plant surface constituents and relating them to the effects of agrochemicals. Results Following the van Krevelen and Hoftyzer method, we calculated the solubility parameters of three model plant species and eight compounds that differ in hydrophobicity and polarity. In addition, intact tissues were examined by scanning electron microscopy and the surface free energy, polarity, solubility parameter and work of adhesion of each were calculated from contact angle measurements of three liquids with different polarities. By comparing the affinities between plant surface constituents and agrochemicals derived from (a) theoretical calculations and (b) contact angle measurements we were able to distinguish the physical effect of surface roughness from the effect of the chemical nature of the epicuticular waxes. A solubility parameter model for plant surfaces is proposed on the basis of an increasing gradient from the cuticular surface towards the underlying cell wall. Conclusions The procedure enabled us to predict the interactions among agrochemicals, plant surfaces, and cuticular and cell wall components, and promises to be a useful tool for improving our understanding of biological surface interactions

    Resistance of Foxp3+ Regulatory T Cells to Nur77-Induced Apoptosis Promotes Allograft Survival

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    The NR4A nuclear receptor family member Nur77 (NR4A1) promotes thymocyte apoptosis during negative selection of autoreactive thymocytes, but may also function in mature extrathymic T cells. We studied the effects of over-expression of Nur77 on the apoptosis of murine peripheral T cells, including thymic-derived Foxp3+ regulatory (Treg) cells. Overexpression of Nur77 in the T cell lineage decreased numbers of peripheral CD4 and CD8 T cells by ∼80% compared to wild-type (WT) mice. However, the proportions of Treg cells were markedly increased in the thymus (61% of CD4+Foxp3+ singly positive thymocytes vs. 8% in WT) and secondary lymphoid organs (40–50% of CD4+Foxp3+ T cells vs. 7–8% in WT) of Nur77 transgenic (Nur77Tg) mice, and immunoprecipitation studies showed Nur77 was associated with a recently identified HDAC7/Foxp3 transcriptional complex. Upon activation through the T cell receptor in vitro or in vivo, Nur77Tg T cells showed only marginally decreased proliferation but significantly increased apoptosis. Fully allogeneic cardiac grafts transplanted to Nur77Tg mice survived long-term with well-preserved structure, and recipient splenocytes showed markedly enhanced apoptosis and greatly reduced anti-donor recall responses. Allografts in Nur77Tg recipients had significantly increased expression of multiple Treg-associated genes, including Foxp3, Foxp1, Tip60 and HDAC9. Allograft rejection was restored by CD25 monoclonal antibody therapy, indicating that allograft acceptance was dependent upon Treg function in Nur77Tg recipients. These data show that compared to conventional CD4 and CD8 T cells, Foxp3+ Tregs are relatively resistant to Nur77-mediated apoptosis, and that tipping the balance between the numbers of Tregs and responder T cells in the early period post-transplantation can determine the fate of the allograft. Hence, induced expression of Nur77 might be a novel means to achieve long-term allograft survival

    Dose distribution in the thyroid gland following radiation therapy of breast cancer-a retrospective study

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    <p>Abstract</p> <p>Purpose</p> <p>To relate the development of post-treatment hypothyroidism with the dose distribution within the thyroid gland in breast cancer (BC) patients treated with loco-regional radiotherapy (RT).</p> <p>Methods and materials</p> <p>In two groups of BC patients postoperatively irradiated by computer tomography (CT)-based RT, the individual dose distributions in the thyroid gland were compared with each other; Cases developed post-treatment hypothyroidism after multimodal treatment including 4-field RT technique. Matched patients in Controls remained free for hypothyroidism. Based on each patient's dose volume histogram (DVH) the volume percentages of the thyroid absorbing respectively 20, 30, 40 and 50 Gy were then estimated (V20, V30, V40 and V50) together with the individual mean thyroid dose over the whole gland (MeanTotGy). The mean and median thyroid dose for the included patients was about 30 Gy, subsequently the total volume of the thyroid gland (VolTotGy) and the absolute volumes (cm<sup>3</sup>) receiving respectively < 30 Gy and ≥ 30 Gy were calculated (Vol < 30 and Vol ≥ 30) and analyzed.</p> <p>Results</p> <p>No statistically significant inter-group differences were found between V20, V30, V40 and V50Gy or the median of MeanTotGy. The median VolTotGy in Controls was 2.3 times above VolTotGy in Cases (ρ = 0.003), with large inter-individual variations in both groups. The volume of the thyroid gland receiving < 30 Gy in Controls was almost 2.5 times greater than the comparable figure in Cases.</p> <p>Conclusions</p> <p>We concluded that in patients with small thyroid glands after loco-radiotherapy of BC, the risk of post-treatment hypothyroidism depends on the volume of the thyroid gland.</p
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