The evolutionary dynamics of insecticide resistance in the whitefly, Bemisia tabaci

The whitefly Bemisia tabaci (Hempitera: Aleyrodidae), is one of most destructive insect pests of agriculture and horticulture worldwide. B. tabaci has an extensive host-plant range, transmits several plant viruses and is a highly invasive species. Managing B. tabaci is therefore extremely problematic and expensive, with a heavy burden placed upon insecticides. Despite a broad spectrum of insecticidal chemistry available for whitefly control, resistance is widespread and insecticide resistance management (IRM) programmes have been introduced to prolong the longevity and efficacy of these compounds. In particular, resistance is commonly associated with two morphologically indistinguishable and invasive populations, known as the B and Q biotypes. The identification of these biotypes using molecular-based diagnostics has become a key feature of IRM programmes. The development of a highthroughput real-time PCR assay which was able to discriminate between B and Q biotypes is described in Chapter 3 of this project. Two major mechanisms of resistance, target-site modification (i. e. pyrethroids and the sodium channel) and enzyme detoxification (i. e. P450-based metabolism of neonicotinoids) have been widely studied in resistant B and Q biotypes of B. tabaci. The evolutionary origins of two 'knockdown resistance' mutations associated with pyrethroid resistance are described in Chapter 4. Furthermore, the neonicotinoid, imidacloprid, is one of the most successful Insecticides registered for B. tabaci; however, reports of resistance are rapidly increasing. The molecular characterisation of imidacloprid resistance in B. tabaci, and in particular, the association of a P450-enzyme (CYP6CM1) with agespecific resistance, is reported in Chapter S. The advancement in our understanding of the molecular mechanisms underlying insecticide resistance is essential to improve management strategies Implemented against this pest

The evolutionary dynamics of insecticide resistance in the whitefly, Bemisia tabaci

The whitefly Bemisia tabaci (Hempitera: Aleyrodidae), is one of most destructive insect pests of agriculture and horticulture worldwide. B. tabaci has an extensive host-plant range, transmits several plant viruses and is a highly invasive species. Managing B. tabaci is therefore extremely problematic and expensive, with a heavy burden placed upon insecticides. Despite a broad spectrum of insecticidal chemistry available for whitefly control, resistance is widespread and insecticide resistance management (IRM) programmes have been introduced to prolong the longevity and efficacy of these compounds. In particular, resistance is commonly associated with two morphologically indistinguishable and invasive populations, known as the B and Q biotypes. The identification of these biotypes using molecular-based diagnostics has become a key feature of IRM programmes. The development of a highthroughput real-time PCR assay which was able to discriminate between B and Q biotypes is described in Chapter 3 of this project. Two major mechanisms of resistance, target-site modification (i. e. pyrethroids and the sodium channel) and enzyme detoxification (i. e. P450-based metabolism of neonicotinoids) have been widely studied in resistant B and Q biotypes of B. tabaci. The evolutionary origins of two 'knockdown resistance' mutations associated with pyrethroid resistance are described in Chapter 4. Furthermore, the neonicotinoid, imidacloprid, is one of the most successful Insecticides registered for B. tabaci; however, reports of resistance are rapidly increasing. The molecular characterisation of imidacloprid resistance in B. tabaci, and in particular, the association of a P450-enzyme (CYP6CM1) with agespecific resistance, is reported in Chapter S. The advancement in our understanding of the molecular mechanisms underlying insecticide resistance is essential to improve management strategies Implemented against this pest

The Effects of Ammonia Inhalants on Anaerobic Performance Following a Simulated American Football Game

Ammonia inhalants (AI) are anecdotally referred to as ergogenic aids in the realm of aggressive team/lifting sports. However, the efficacy of AI usage has yet to be established or reported to our knowledge. Therefore, the purpose of this study was to establish the effects of AI’s on anaerobic performance following a simulated American football game (SAFG) in a climate controlled setting (35.8 °C, 27.5% RH). METHODS: Ten apparently healthy anaerobically trained college-aged males participated dressed in American football apparel, excluding the helmet. Each subject participated in two trials, 136 minutes each, separated by a minimum of 48 hours (AI or control). Each SAFG consisted of a randomized counter-balanced series of sprints. The sprint protocol was made up of a total 12, 9, or 6 sprints, which were experienced each half of the SAFG in a randomized order. The individual sprints consisted of 5 second maximal effort sprints which were followed by 40 seconds of rest, simulating what one would expect in an American football game. The Wingate anaerobic test (WAnT) was performed before and after each SAFG in a neutral temperature (21.3°C, 30.8% RH). Resistance for the 30-second WAnT was calculated at 10% of each respective subject’s weight in kilograms (kg). The AI condition was administered by capsule immediately before the final WAnT. Paired t-tests were used to examine differences in peak power change (ΔPP) and mean power change (ΔMP) from WAnTs performed pre-post-SAFG. α=0.05. RESULTS: The majority of our subjects elicited an increase in PP (9/10 subjects) and MP (8/10 subjects) during the AI condition. The ΔPP in the AI (134±85 W) trial was significantly greater that the control trial (59±108 W) (p≤.05). Likewise, ΔMP in the AI (35±53 W) was significantly greater than the control (-21±65 W) trial (p≤.01). CONCLUSION: These results suggest that the intervention of AI following a bout of fatiguing work is successful in the in the generation of maximal power outputs as well as attenuating fatigue within the WAnT. Thereby, suggesting that when performing a WAnT, utilizing AI as an intervention can increase power output. Further research should be conducted in order to support the findings from the present investigation and possible applications

Search for B0s oscillations using inclusive lepton events

A search for B0s oscillations is performed using a sample of semileptonic b-hadron decays collected by the ALEPH experiment during 1991-1995. Compared to previous inclusive lepton analyses, the proper time resolution and b-flavour mistag rate are significantly improved. Additional sensitivity to B0s mixing is obtained by identifying subsamples of events having a B0s purity which is higher than the average for the whole data sample. Unbinned maximum likelihood amplitude fits are performed to derive a lower limit of Deltam_s>9.5ps^-1 at 95% CL. Combining with the ALEPH D-s based analyses yields Deltam_s>9.6ps^-1 at 95% CL.Comment: 23 pages, 10 figure

Environmental UVR Levels and Skin Pigmentation Gene Variants Associated with Folate and Homocysteine Levels in an Elderly Cohort

Ultraviolet radiation (UVR) is a ubiquitous exposure which may contribute to decreased folate levels. Skin pigmentation mediates the biological effect of UVR exposure, but its relationship to folate levels is unexamined. Interactions may exist between UVR and pigmentation genes in determining folate status, which may, in turn, impact homocysteine levels, a potential risk factor for multiple chronic diseases. Therefore, independent and interactive influences of environmental UVR and genetic variants related to skin pigmentation (MC1R-rs1805007, IRF4-rs12203592 and HERC2-rs12913832) on folate (red blood cell (RBC) and serum) and homocysteine levels were examined in an elderly Australian cohort (n = 599). Genotypes were assessed by RT/RFLP-PCR, and UVR exposures were assessed as the accumulated erythemal dose rate accumulated over 4 months (4M-EDR). Multivariate analysis found significant negative associations between 4M-EDR and RBC folate (p < 0.001, β = -0.19), serum folate (p = 0.045, β = -0.08) and homocysteine levels (p < 0.001, β = -0.28). Significant associations between MC1R-rs1805007 and serum folate levels (p = 0.020), and IRF4-rs12203592 and homocysteine levels (p = 0.026) occurred but did not remain significant following corrections with confounders. No interactions between 4M-EDR and pigmentation variants in predicting folate/homocysteine levels were found. UVR levels and skin pigmentation-related variants are potential determinants of folate and homocysteine status, although, associations are mixed and complex, with further studies warranted

Cultural and Language Influences on the Interpretation of Spatial Prepositions

Abstract Culture and language can influence the generation and interpretation of spatial language, which would impact the quality of computational spatial language processing. This paper presents three human-subject experiments aimed at investigating these potential influences on the quantitative interpretations of five spatial prepositions. We show that for the languages (English and German) and cultures investigated (Europe and United States) neither language nor culture have a significant influence

Effects of exercise, cognitive, and dual-task interventions on cognition in type 2 diabetes mellitus: A systematic review and meta-analysis

Introduction: Previous evidence has shown significant effects of exercise, cognitive and dual-task training for improving cognition in healthy cohorts. The effects of these types of interventions in type 2 diabetes mellitus is unclear. The aim of this research was to systematically review evidence, and estimate the effect, of exercise, cognitive, and dual-task interventions on cognition in type 2 diabetes mellitus. Method: Electronic databases including PubMed, EMBASE, CINAHL, PsycINFO, SPORTDiscus, and MEDLINE were searched for ongoing and completed interventional trials investigating the effect of either an exercise, cognitive or dual-task intervention on cognition in type 2 diabetes mellitus. Results: Nine trials met the inclusion criteria – one dual-task, two cognitive, and six exercise. Meta-analyses of exercise trials showed no significant effects of exercise on measures of executive function (Stroop task, SMD= -0.31, 95% CI -0.71–0.09, P=0.13, trail making test part A SMD= 0.28, 95% CI -0.20–0.77 P=0.25, trail making test part B SMD= -0.15, 95% CI -0.64–0.34 P=0.54, digit symbol SMD= 0.09, 95% CI -0.39–0.57 P=0.72), and memory (immediate memory SMD= 0.20, 95% CI -0.28–0.69, P=0.41 and delayed memory SMD= -0.06, 95% CI -0.55–0.42, P=0.80). A meta-analysis could not be conducted using cognitive or dual-task data, but individual trials did report a favourable effect of interventions on cognition. Risk of bias was considered moderate to high for the majority of included trials. Conclusions: Meta-analyses of exercise trials identified a small effect size (0.31), which whilst not significant warrants further investigation. Larger and more robust trials are needed that report evidence using appropriate reporting guidelines (e.g. CONSORT) to increase confidence in the validity of results. Trial Registration: Protocol was registered (CRD42017058526) on the International Prospective Register of Systematic Reviews (http://www.crd.york.ac.uk/PROSPERO)