Lack of evidence for western flower thrips biotypes base don intra and inter-strain variation in gut bacteria

Western flower thrips is a polyphagous insect, which during the last 30 years has become a world wide pest. It was found earlier that these thrips are associated with a type of Erwinia species gut bacteria. In this study we examine the variation of bacteria within and between thrips individuals and try to find evidence for biotypes in western flower thrips regarding the type of gut bacteria. The existence of biotypes in this thrips species has been suggested by different authors. For example, thrips populations have been found that differ in resistance against pesticides and in their ability to transmit plant viruses. With biotypes we mean groups of individuals (strains, populations, lines) of a species which differ in one or more traits with other groups of that species. The gut bacteria of thrips are acquired by young thrips larvae via the host plant and have a beneficial effect on thrips development and oviposition. We studied thrips strains from different countries and host plants, and the isofemale lines that were created from them, on bean plant leaves. All thrips lines that we studied contained Erwinia species gut bacteria. Morphological and biochemical characteristics of gut bacteria from the thrips isofemale lines were similar to the Erwinia type strain from the reference, a thrips strain cultured on chrysanthemum in Amsterdam (TAC 93.XII.8). Per isofemale line we studied five thrips individuals and per thrips we studied four bacterial colonies, with RAPD markers. The genetic variation between bacteria isolated from thrips was as large among isofemale lines as within isofemale lines. No evidence for thrips biotypes was found. Bacteria within one thrips individual show a stronger degree of similarity than bacteria from different thrips individuals within a single rearing. This is probably due to a bottleneck caused by the limited number of successful infections of bacteria into the gut of the thrip

In vivo (31)P magnetic resonance spectroscopy and morphometric analysis of the perfused vascular architecture of human glioma xenografts in nude mice.

The relationship between the bioenergetic status of human glioma xenografts in nude mice and morphometric parameters of the perfused vascular architecture was studied using (31)P magnetic resonance spectroscopy (MRS), fluorescence microscopy and two-dimensional digital image analysis. Two tumour lines with a different vascular architecture were used for this study. Intervascular distances and non-perfused area fractions varied greatly between tumours of the same line and tumours of different lines. The inorganic phosphate-nucleoside triphosphate (P(i)/NTP) ratio increased rapidly as mean intervascular distances increased from 100 microm to 300 microm. Two morphometric parameters - the percentage of intervascular distances larger than 200 microm (ivd200) and the non-perfused area fraction at a distance larger than 100 microm from a nearest perfused vessel (area100), - were deduced from these experiments and related to the P(i)/NTP ratio of the whole tumour. It is assumed that an aerobic to anaerobic transition influences the bioenergetic status, i.e. the P(i)/NTP ratio increased linearly with the percentage of ivd200 and the area100

Strategizing as multi-modal and rhetorical discursive practice: a case study of the BHP Billiton's failed acquisition of Rio Tinto

This thesis took a discourse approach to analyze BHP Billiton’s failed acquisition of Rio Tinto in 2007-08 to better understand what happens during strategizing. The research highlighted the structure and dynamics of the discourse, as well as the role of time and context in the social construction of meaning in strategizing. In doing so, the thesis provided new insights into how actors were able to influence such important strategic events. The thesis adopted a multi-modal discourse analytic framework and analyzed media reports, corporate videos, press releases and communications to shareholders, as well as slides and full transcripts of key presentations by both BHP and Rio leadership. The analysis identified the main internal and external actors as either decision-makers (BHP’s leadership, shareholders, competition regulators) or influencers (Rio’s leadership, analysts, media, customers). It further identified a range of multi-modal discursive practices and rhetorical strategies that were brought to bear to negotiate the meaning of three key constructs that shaped the discourse, that is, the additional value pool, the fair share exchange ratio, and the impact on competition. Further, the findings showed how time and context were discursively constructed and influenced the meaning of the three key constructs. These findings enabled a number of contributions to the discourse and M&A literature. While most research into acquisition discourses has routinely ignored the pre-acquisition discourse, this thesis focused on the period preceding the transaction. An initial contribution was to show that, in a pre-acquisition discourse, external actors were not a passive audience but played a significant role as rhetor and audience. Also, while previous empirical studies of discourse have emphasized the role of language, this thesis considered multi-modal discursive practices, including speech, writing, imagery, location and calculative devices. The thesis made a further contribution by showing how actors worked to persuade each other through multi-layered rhetorical strategies that were also brought to bear through non-linguistic modes. This contribution was extended by showing how these practices functioned as transgression markers that signaled convergence or divergence of meaning of the key constructs. A detailed analysis of calculative devices enabled further contributions. An initial contribution was that it showed how calculative devices developed as boundary objects over four stages: identification, calculation, negotiation, and objectification. Further, the thesis showed how calculative devices were imbued with logos and ethos through, for example, the calculative logic, accounting standards and data sources that were woven together in the symbolic manipulations of the device. Lastly, the thesis showed how calculative devices acted as boundary objects, and made a contribution to theory by proposing a third criterion, legitimacy, to complement widely acknowledged criteria of adaptability and commonality. In addition to these dynamics, the thesis outlined a discursive epistemology of strategizing through its analysis of the role of time and context in the social construction of meaning in strategizing. While the role of time and context is widely acknowledged in organizational discourse, it remained unclear what was specific to strategizing. The thesis argued that the purpose of strategizing is to construct and negotiate new or improved options for a preferred future and the actions to bring this about, and made a contribution to a discursive epistemology of strategizing by showing how temporal and contextual work in strategizing extends the horizon of discourses that relate to the future and discourses that relate to the broader discourse. This reconstructs the tapestry of interwoven discourses that make up the local strategy discourse, and creates new strategic options

Vascularity and perfusion of human gliomas xenografted in the athymic nude mouse.

The vascularisation and perfusion of seven subcutaneously xenografted human glioma lines established from surgical specimens has been analysed using an anti-collagen type IV antibody to visualise the vascular walls in combination with a perfusion marker (Hoechst 33342). A computer-based digital image processing system was employed for quantitative analysis of the parameters. The vascular architecture of individual tumours belonging to the same tumour line showed a consistent similarity, while substantial differences occurred between the various tumour lines derived from different patients. Despite the presence of a large inter-tumour variation in vascular area as a proportion of the tumour area, this vascular parameter clearly showed tumour line-specific characteristics. The perfused fraction of the tumour vessels also showed a large inter-tumour variation for all tumour lines ranging from 20% to 85%, but the majority of tumours of all lines had perfusion fractions of more than 55%. Despite large variation, the perfused vascular area as a proportion of the tumour cross-sectional area exhibited clear tumour line-specific tendencies. These observations suggest that consistent differences in vascular parameters are present between glioma xenograft lines, although the tumour lines all originated from histologically similar human high-grade gliomas. These differences may have important consequences for treatment and clinical behaviour of this type of tumour

Toxocara vitulorum & Fasciola gigantica in cattle and buffalo in northern Laos

LUZIA RAST – PhD THESIS… abstract Toxocara vitulorum & Fasciola gigantica in Cattle and Buffalo in Northern Laos In South-East Asia agricultural production including livestock is predominately produced within mixed smallholder farming systems. These mostly operate at subsistence levels. Cattle and buffalo are typically kept as assets rather than for optimal production purposes. Economic growth and urbanisation in the region continues to lead to increased demand for red meat products. This provides opportunities and pressures for smallholder farmers to increase their livestock outputs and supply this market with consistent and high quality products. Laos is well placed to supply this increasing regional demand but constraints inhibiting optimal production outputs from smallholder farming systems need to be addressed. These constraints include low capacity animal health systems, lack of infrastructure, traditional low input/low output farming methods and endemic livestock diseases. There is limited documentation about disease prevalence in large ruminants and basic production benchmarks such as reproductive, morbidity and mortality rates. Anecdotal reports indicate that Fasciola gigantica and Toxocara vitulorum are endemic in Laos and contribute to substantial production losses. This is despite the availability of relative cheap and simple treatment technology for T.vitulorum and substantial past research investment in the region on both parasites. The research presented in this thesis contributes to knowledge on the prevalence of T.vitulorum and F.gigantica in cattle and buffalo and the impact of these parasitic infections on production in mixed smallholder farming systems in northern Laos, which are typical for many other parts of South-East Asia. It further contributes to defining and documenting basic large ruminant production parameters within these production systems and quantifies the financial impact of T.vitulorum treatment of calves. Importantly this research identified a large gap in knowledge and in the sustained adoption of effective control practices for large ruminant internal parasites and explored pathways and gives recommendations to address this. The thesis presents data from seven separate field studies completed in northern Laos between 2009 and 2012. Two cross-sectional field surveys were conducted and results showed that both T.vitulorum in cattle and buffalo calves and F.gigantica in adult cattle and buffalo had high apparent prevalence (22.6% and 17.2% respectively) and were geographically widespread throughout northern Laos. Results further indicated that both parasites affected cattle and buffalo at similar levels and that no specific clinical signs were associated with either parasite. This was in line with past research on F.gigantica infection but not for T.vitulorum with limited past research and anecdotal reports indicating that Toxocariasis causes diarrhoea and rough coats in calves and especially so in buffalo calves. Slaughterhouse surveys were conducted in five main provincial slaughterhouses in northern Laos. Results showed a prevalence of faecal eggs for F.gigantica (34.1%) plus liver lesions consistent with F.gigantica infection in 71.0% of slaughtered cattle and buffalo providing further evidence of the endemic nature of this parasite and its potential clinical impact across northern Laos. Additional findings of the slaughterhouse surveys were that a large proportion of slaughtered female animals were pregnant (44% cattle, 47% buffalo), 9.8% of slaughtered animals had FMD lesions and meat inspectors were rarely present for the entire slaughter process with no condemnation of any products. Two separate farmer surveys on a sample of farmers that had their large ruminants tested for either T.vitulorum or F.gigantica were conducted using face-to-face semi-structured interviews. Results of the T.vitulorum farmer survey (n=273) showed that there was a relative high rate of awareness (62.3%) about this parasite amongst farmers and that specific knowledge about its epidemiology and potential clinical impact was lacking. Only 2.5% of farmers used pyrantel treatment of calves at the recommended age and dose rate. Results of the farmer survey (n=326) for F.gigantica showed smallholders had very limited knowledge about Fasciolosis in large ruminants despite 20.6% reporting having seen leaf shaped parasites in livers of slaughtered cattle or buffalo in the past. None of the interviewed farmers treated larger ruminants to control liver fluke. Analyses of large ruminant production data found annual calf morbidity and mortality rates of 42.6% (CI 0.38-0.47) and 37.3% (CI 0.33-0.42) respectively; and adult morbidity and mortality rates of 7.4% (CI 0.06-0.09) and 2.8% (CI 0.003-0.05) respectively. Further, results showed low reproductive performance of 0.6 and 0.4 calf per year for cattle and buffalo respectively with first calving ages of 36 months reported for both species. Two separate field treatment trials were conducted. For T.vitulorum calves were treated when they were 90% reduction of faecal egg counts in adult cattle and buffalo four, eight and twelve weeks post treatment compared to untreated animals. In addition there was a trend of increased weight gain in treated buffalo compared to the untreated control group indicating that treatment of Fasciolosis may result in heavier buffalo. Financial analysis using partial budgeting and data from our surveys showed that there was a large net benefit of USD 3.69-14.86 per calf for treatment with pyrantel (12.5 mg/kg) once only between 14-21 days of age compared to no treatment. It was concluded that both T.vitulorum and F.gigantica are endemic in northern Laos and contribute to substantial production losses in this area. Smallholder farmers still keep large ruminants mostly as an asset and there is also a large knowledge gap amongst smallholder producers about internal parasites, their health and production effects and effective control methods. This knowledge gap and the lack of commercial driver contribute to the deficit of widespread adoption of parasite control methods by smallholder farmers despite their availability and known effectiveness. These results suggest, especially for T.vitulorum that if recommended control methods were widely adopted, large ruminant production output from smallholder farming systems could be increased through reduced calf morbidity and mortality rates

Comparing aversive and appetitive learning performances in individual honeybees

Background A neurobiological perspective has become accepted as a valuable approach for understanding anti-social behaviour. There is literature to suggest that, in non-offending populations, psychological treatments affect both neurobiological measures and clinical presentation. A theoretical position to this effect has been adopted with respect to offender treatment, but there has been no systematic review of empirical literature on this point. Aims This study aimed to ascertain from published literature firstly whether there is evidence of change in neuropsychological or physiological measures after behavioural treatments/programmes for people with anti-social behaviour and secondly whether these neurobiological changes are associated with behavioural change. Method A systematic search strategy was formulated to include studies considering neurobiological factors', anti-social population', treatment' and treatment outcome'. The Maryland Scientific Methods Scale was used to select relevant studies of sufficient methodological quality. Results Eleven studies were found, only one with adults. Overall, the values of specific neurobiological risk factors, particularly of basal cortisol, become less abnormal following intervention. There was some evidence for a link between change in neurobiological functioning and behavioural improvement. Conclusions Findings, although provisional, may provide new insights into the underlying mechanisms of interventions for anti-social behaviour. Future studies that include pre-treatment neurobiological assessment could help reveal physical vulnerabilities that interventions should target to improve treatment efficacy, and provide for objective, independent corroboration of change

A prospective methicillin resistant staphylococcus aureus typing system for infection control : design and effectiveness

The uptake of Gadomer-17, as probed by fast dynamic T(1) measurements, was used to assess the vascular permeability surface-area product per leakage volume of tissue (k(Tofts)) of human glioma xenografts implanted in mice. With this approach we could discriminate between two types of glioma xenograft lines with a known difference in the perfused vascular architecture and degree of hypoxia. The T(1) data were analyzed according to the Tofts-Kermode compartment model. The fast-growing E102 tumor demonstrated a homogeneous distribution of the vascular permeability surface area across the tumor (mean k(Tofts) value = 0.18 +/- 0.05 min(-1)). The slowly growing E106 tumor showed a more heterogeneous pattern. Three perfused tumor areas with differences in vascular permeability surface area could be distinguished: a well-perfused periphery with high k(Tofts) values (0.24 +/- 0.04 min(-1)), perfused capillaries inside the tumor with low k(Tofts) values (0.108 +/- 0.026 min(-1)), and perfused capillaries adjacent to necrotic regions with high k(Tofts) values (0.29 +/- 0.10 min(-1)). On a different series of tumors, the hypoxic fractions were measured, and these were significantly higher in E106 tumors (0.14 +/- 0.05) compared to tumors of the E102 line (0.03 +/- 0.02)

Studies on breeding dwarf poinsettias (Euphorbia pulcherrima Willd.) and the influence of infective agents

BACKGROUND: Hypoxia, metabolism, and growth factor signaling are important prognostic features in most solid tumors. The purpose of this study was to determine whether head and neck squamous cell carcinoma (HNSCC) xenografts show similar biological and molecular characteristics as the primary tumor they originate from. METHODS: Eighteen HNSCC primary tumor-xenograft pairs were immunofluorescently stained for pimonidazole (hypoxia), carbonic anhydrase IX (CAIX), glucose transporter-1 (GLUT-1), monocarboxylate transporter-1 (MCT-1), monocarboxylate transporter-4 (MCT-4), epidermal growth factor receptor (EGFR), and phosphorylated protein kinase B (pAKT). RESULTS: Although no correlation was found for the amount of hypoxia, significant correlations between primary tumors and xenografts were observed for both the percentage of cells positive for expression and the hypoxia-related expression pattern of CAIX, GLUT-1, and MCT-1. For EGFR and MCT-4, the intensity of expression was correlated. No correlation was observed for pAKT. CONCLUSION: Xenografts did not always resemble the primary tumor they originate from, but the xenografts did represent the variability in expression levels and patterns observed in the primary tumors

Multiparameter analysis of vasculature, perfusion and proliferation in human tumour xenografts.

A method is presented in this report for concurrent analysis of vascular architecture, blood perfusion and proliferation characteristics in whole-tumour cross-sections of human larynx carcinoma and glioblastoma xenografts. Tumours were implanted subcutaneously in nude mice. After i.v. injection with Hoechst 33342 and bromodeoxyuridine (BrdUrd) as perfusion and proliferation markers, animals were killed. An antiendothelial antibody (9F1) was used to delineate vascular structures. Cross-sections were analysed by a multistep immune staining and a computer-controlled microscope scanning method. Each tumour section was stained and scanned four times (Hoechst, 9F1, BrdUrd and Fast Blue for all nuclei). When these images were combined, vasculature, perfusion and proliferation parameters were analysed. The labelling index (LI) was defined as the ratio of the BrdUrd-labelled area to the total nuclear area. The LI based on manual counting and the LI calculated by flow cytometry (FCM) were in good agreement with the LI based on surface analysis. LI decreased at increasing distance from its nearest vessel. In the vicinity of perfused vessels, the LI was 30-70% higher than near non-perfused vessels. This method shows that both vasculature/perfusion and proliferation characteristics can be measured in the same whole-tumour section in a semiautomatic way. This could be applied in clinical practice to identify combined human tumour characteristics that predict for a favourable response to treatment modifications