9,849 research outputs found
Using particle size analysis to determine the hydrophobicity and suspension of fungal conidia with particular relevance to formulation of biopesticide
Fungal formulations are vital for effective biopesticide development. Good formulations help to optimise field efficacy while poor formulations result in product failure. This study aimed to produce a hydrophobicity test that would be appropriate for fungal conidia produced to a commercial quality and determine relative hydrophobicity of fungi from four different genera by using laser diffraction. A particle size analyser was used to determine the hydrophobicity of: three Metarhizium acridum samples, M. anisopliae, Beauveria bassiana, Trichoderma stromaticum, T. harzianum, T. viride and Alternaria eichhorniae conidia, by suspending the conidia in three different liquids: Shellsol T (a mineral oil), water and 0.05 % Tween 80. Hydrophobicity was determined by the size of the particles formed in each of the liquids. All the Metarhizium samples were the most hydrophobic followed by B. bassiana and A. eichhorniae. The Trichoderma samples were the least hydrophobic. As a comparison a phase exclusion assay and a salt-mediated aggregation and sedimentation (SAS) test were performed. It was not possible to get a reliable reading for the B. bassiana, A. eichhorniae and T. viride samples using the phase exclusion assay. The addition of salt in the SAS test did not affect the rate of sedimentation. It was hypothesised that conidia size affected the results of the SAS test that made A. eichhorniae the most hydrophobic conidia. Particle size analysis was a more accurate test for comparing fungi from difference genera compared to the SAS test and phase exclusion assay. PSA was also used to test three emulsions and demonstrated that different formulations had an effect on particle size
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Supply chain implications of sustainable design strategies for electronics products
Increasing legislative and consumer pressures on manufacturers to improve sustainability necessitates that manufacturers consider the overall life cycle and not be scope restricted in creating products. Product strategies to improve sustainability have design implications as many of the decisions made during the design stage will then determine the environmental performance of the final product. Coordination across the supply chain is potentially beneficial as products with improved energy efficiency can be better realised. This paper examines traditional product provision and proposes a sustainable product design process using life cycle assessment (LCA) at key points, as these decision points can provide opportunities for environmental improvements of products. Case studies of consumer and industry products in the electronics sector are examined in terms of improving sustainability by reviewing product architecture and technology solutions. This paper proposes methods and analytical models to better understand sustainable design strategies for manufacturing firms and thus aid manufacturers during the earliest stages of product planning to consider alternative product development approaches which are more sustainable
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Sustainable development strategies for product provision and manufacturing approaches
Manufacturing firms are under many pressures both financially and competitive which focus attention on the performance of their manufacturing processes. In this paper the opportunities for improving the environmental impact of products within the constraints of existing manufacturing infrastructure are examined. Approaches which support sustainability in two aspects are proposed, firstly, the provision of products to the users in ways which extend the product life and secondly, manufacturing approaches which reduce resource usage. The provision and manufacture of products in ways that are truly sustainable are inhibited by three issues: firstly, decisions are predominantly made solely from the perspective of the “vendor” (and do not consider the wider perspective); secondly, that generally the scope of business planning is still rooted in production/manufacturing costs (and not consumption costs) and thirdly, the current performance measures (e.g. KPIs) mainly focus on profitability. The rationale for this conference paper is the argument that there is a need to raise the awareness during the earliest stages of business planning that there may be alternative approaches which are more sustainable. The concepts presented here will underpin further research into performance measures which encompass sustainability and resulting business planning implications
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Fusogenic membrane glycoproteins as a gene therapy for cancer
Gene therapy strategies hold great promise for the treatment of cancer. This work tests the hypothesis that viral fusogenic membrane glycoproteins (FMG) have potential as cytotoxic gene therapy agents. The truncated, hyperfusogenic form of a C-type retrovirus envelope gene: the Gibbon ape leukaemia virus envelope (GALV), and the F and H genes of the paramyxovirus Measles, were the predominate FMG investigated. Initial studies demonstrated the cytotoxicicty of expressing FMG in tumour cells in vitro. Extensive cell death occured following cell-cell fusion and syncitia formation. Comparison with suicide genes indicated superior cell killing with FMG due to a greater bystander effect. FMG killing induced a stress response with induction and upregulation of heat shock proteins. Detailed analysis of cell death following FMG expression and syncitia formation suggested a non-apoptotic, necrotic mechanism. This was independent of the cell cycle. Viral vectors expressing FMG were developed. There was inefficient production of retroviral vectors based on the Moloney murine leukaemia virus expressing GALV. Improved titre was seen from a lentiviral vector expressing GALV. This vector, when injected intratumourally, was able to eradicate small tumours in nude mice. Adenoviral vectors expressing F and H were produced. Intratumoural injection of these vectors resulted in syncitia formation in vivo. Direct intratumoural injection of an H expressing adenoviral vector into human xenograft tumours expressing Measles F resulted in tumour eradication in 30% of mice. Production of an adenoviral vector expressing GALV required a strategy involving Cre recombinase and a transcriptional silencer to overcome the direct cytotoxicity to producer cells.
Co-expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) with FMG by a number of mechanisms was developed. Their particular in vitro properties were analysed in detail.
In summary this thesis represents the initial studies of a group of genes with their novel application as gene therapy agents for the treatment of cancer. Incorporation of FMG in the development of cytotoxic and immunomodulatory gene therapy strategies hold significant promise and merit further development
Capacitors can radiate - some consequences of the two-capacitor problem with radiation
We fill a gap in the arguments of Boykin et al [American Journal of Physics,
Vol 70 No. 4, pp 415-420 (2002)] by not invoking an electric current loop (i.e.
magnetic dipole model) to account for the radiation energy loss, since an
obvious corollary of their results is that the capacitors should radiate
directly even if the connecting wires are shrunk to zero length. That this is
so is shown here by a direct derivation of capacitor radiation using an
oscillating electric dipole radiator model for the capacitors as well as the
alternative less widely known magnetic 'charge' current loop representation for
an electric dipole [see for example "Electromagnetic Waves" by S.A.Schlekunoff,
van Nostrand (1948)]. Implications for Electromagnetic Compliance (EMC) issues
as well as novel antenna designs further motivate the purpose of this paper.Comment: 5 Pages with No figure
Refining pathological evaluation of neoadjuvant therapy for adenocarcinoma of the esophagus
AIM: To assess tumour regression grade (TRG) and lymph node downstaging to help define patients who benefit from neoadjuvant chemotherapy.METHODS: Two hundred and eighteen consecutive patients with adenocarcinoma of the esophagus or gastro-esophageal junction treated with surgery alone or neoadjuvant chemotherapy and surgery between 2005 and 2011 at a single institution were reviewed. Triplet neoadjuvant chemotherapy consisting of platinum, fluoropyrimidine and anthracycline was considered for operable patients (World Health Organization performance status ? 2) with clinical stage T2-4 N0-1. Response to neoadjuvant chemotherapy (NAC) was assessed using TRG, as described by Mandard et al. In addition lymph node downstaging was also assessed. Lymph node downstaging was defined by cN1 at diagnosis: assessed radiologically (computed tomography, positron emission tomography, endoscopic ultrasonography), then pathologically recorded as N0 after surgery; ypN0 if NAC given prior to surgery, or pN0 if surgery alone. Patients were followed up for 5 years post surgery. Recurrence was defined radiologically, with or without pathological confirmation. An association was examined between t TRG and lymph node downstaging with disease free survival (DFS) and a comprehensive range of clinicopathological characteristics.RESULTS: Two hundred and eighteen patients underwent esophageal resection during the study interval with a mean follow up of 3 years (median follow up: 2.552, 95%CI: 2.022-3.081). There was a 1.8% (n = 4) inpatient mortality rate. One hundred and thirty-six (62.4%) patients received NAC, with 74.3% (n = 101) of patients demonstrating some signs of pathological tumour regression (TRG 1-4) and 5.9% (n = 8) having a complete pathological response. Forty four point one percent (n = 60) had downstaging of their nodal disease (cN1 to ypN0), compared to only 15.9% (n = 13) that underwent surgery alone (pre-operatively overstaged: cN1 to pN0), (P < 0.0001). Response to NAC was associated with significantly increased DFS (mean DFS; TRG 1-2: 5.1 years, 95%CI: 4.6-5.6 vs TRG 3-5: 2.8 years, 95%CI: 2.2-3.3, P < 0.0001). Nodal down-staging conferred a significant DFS advantage for those patients with a poor primary tumour response to NAC (median DFS; TRG 3-5 and nodal down-staging: 5.533 years, 95%CI: 3.558-7.531 vs TRG 3-5 and no nodal down-staging: 1.114 years, 95%CI: 0.961-1.267, P < 0.0001).CONCLUSION: Response to NAC in the primary tumour and in the lymph nodes are both independently associated with improved DFS
Temporal stability and transferability of models of willingness to pay for flood control and wetland conservation
This study investigates the temporal stability and transferability of dichotomous choice willingness to pay responses and their determinants from two large-scale contingent valuation surveys in the area of flood control and wetland conservation. The study considers a time period between surveys which is more than double that considered in previous test-retest analyses. Whereas such previous studies have reported stable values over relatively short time periods, the present study finds a statistically significant decrease in real willingness to pay over this more extended time period. Analyses of model transfer between the two survey periods indicate that models derived solely from economic-theoretic determinants pass transferability tests. However, expanding these models to include more ad hoc, transitory factors yields nontransferable models. This provides a guide for future analyses. Copyright 2005 by the American Geophysical Union
Self-force of a point charge in the space-time of a symmetric wormhole
We consider the self-energy and the self-force for an electrically charged
particle at rest in the wormhole space-time. We develop general approach and
apply it to two specific profiles of the wormhole throat with singular and with
smooth curvature. The self-force for these two profiles is found in manifest
form; it is an attractive force. We also find an expression for the self-force
in the case of arbitrary symmetric throat profile. Far from the throat the
self-force is always attractive.Comment: 18 pages, 3 figures Comments: corrected pdf, enlarged pape
Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 3: Support of the design process
The user requirements for computer support of the IPAD design process are identified. The user-system interface, language, equipment, and computational requirements are considered
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