Buprofezin Resistance in B-biotype Bemisia tabaci

Laboratory selection of an Australian B-biotype Bemisia tabaci population with the insect growth regulator buprofezin rapidly produced high levels of buprofezin resistance (in excess of 2000-fold) after 4 applications. An unselected B-biotype B. tabaci population was originally 11-fold resistant to buprofezin. mechanism studies showed two mechanisms of resistance. Buprofezin resistant B-biotype B. tabaci had higher esterase activity and additional esterase bands compared to a buprofezin unselected B-biotype and native Australian non B-biotype B. tabaci strains. Esterase from buprofezin resistant B-biotype B. tabaci was inhibited both in vitro and in vivo by buprofezin to a far greater degree (2- fold) than in the non buprofezin selected B. tabaci strain. Esterase from insecticide susceptible native non B-biotype B. tabaci and SUD-S strains was uninhibited by buprofezin. Esterase mediated sequestration of buprofezin is proposed as a mechanism of resistance to buprofezin in B. tabaci. This is the first report of a resistance mechanism to buprofezin in B. tabaci. Other insecticides with novel modes of action were investigated for effects on B. tabaci esterases. Pyriproxyfen inhibited esterase activity in vitro in both resistant and non selected B-biotype strains and this implied cross-resistance was confirmed by bioassay. Novaluron and pymetrozine also inhibited esterase in buprofezin resistant B. tabaci, but not in the unselected population. Fenoxycarb did not inhibit esterase activity in either strain. Acetylcholinesterase (AChE) studies showed a new mode of action for IGRs and a second buprofezin resistance mechanism. Buprofezin resistant B-biotype B. tabaci AChE had a different electrophoretic mobility to both the unselected and non Bbiotype strains. Buprofezin inhibited AChE activity in the non selected B-biotype population, but not in resistant B. tabaci. The mutant form of AChE in B-biotype B. tabaci appeared to be unrelated to previously discovered AChE variants. Results also showed that another IGR (novaluron) inhibited AChE activity in nonbuprofezin selected strain, but buprofezin resistant AChE was unaffected. Experiments indicated no significant differences in mono-oxygenase activity in either the buprofezin unselected or resistant B. tabaci strains. The speed with which B. tabaci were selected for high levels of buprofezin resistance, and the potential for cross-resistance between insect growth regulators is a warning that buprofezin should be used sparingly against B. tabaci and in rotation with other insecticides. The results have already provided essential information for the whitefly insecticide resistance management strategy in central Queensland. With the escalating problem of B-biotype B. tabaci in many Australian crop production systems, including cotton, an effective management strategy is vital

The potential impact of climate change on 'Nezara viridula' (L.) (Hemiptera: Pentatomidae) and its parasitoid, 'Trichopoda giacomelii' Blanchard (Diptera: Tachinidae) in Cambodia and Australia: Ecological, behavioural and physiological assessments

'Nezara viridula' (L.) (Hemiptera: Pentatomidae) is a cosmopolitan, polyphagous heteropteran insect that causes economic damage to many crop species worldwide. Despite several interventions attempts, 'N. viridula' has remained a significant pest in certain regions of Cambodia and eastern Australia, particularly those where soybean and nut crops are cultivated. Recently, 'Trichopoda giacomelii' Blanchard (Diptera: Tachinidae), a species native to Argentina was established in Australia as an effective biological control agent for 'N. viridula' in one instance. However, with predicted climate change, the range of the pest could expand or change and the relationship between the pest and the parasitoid could also change in response to altered temperature and precipitation regimes. Changed climatic conditions could affect the pest status and geographic range of 'N. viridula' as well as the efficacy of the parasitoid. Climate change will potentially affect the interactions between factors such as temperature, humidity, light, food, and the wellbeing of the pest and the parasitoid and the relationship between the two. The aims of this study were (i) to evaluate the sampling methods of arthropods on soybean crops in Cambodia, in terms of accuracy of the use of the two main sampling methods: sweep netting and beat sheeting; (ii) to measure the effect of changed temperature and moisture regimes on 'N. viridula' and 'T. giacomelii' life cycles in populations from contrasting climatic regimes (Breeza and Grafton); (iii) to measure the effect of changed temperature and moisture regimes on the ability of the parasitoids to parasitize 'N. viridula'; and (iv) to investigate the various physiological variables of 'N. viridula' under the stress of temperature

The Effect of Insecticide Synergists on the Response of Scabies Mites to Pyrethroid Acaricides

Synergists are commonly used in combination with pesticides to suppress metabolism-based resistance and increase the efficacy of the agents. They are also useful as tools for laboratory investigation of specific resistance mechanisms based on their ability to inhibit specific metabolic pathways. To determine the role of metabolic degradation as a mechanism for acaricide resistance in human scabies, PBO (piperonyl butoxide), DEF (S,S,S-tributyl phosphorotrithioate) and DEM (diethyl maleate) were used with permethrin as synergists in a bioassay of mite killing. A statistically significant difference in survival time of permethrin-resistant Sarcoptes scabiei variety canis was noted when any of the three synergists were used in combination with permethrin compared to survival time of mites exposed to permethrin alone (p<0.0001). These results indicate the potential utility of synergists in reversing tolerance to pyrethroid-based acaricides (i.e. the addition of synergists to permethrin-containing topical acaricide cream commonly used to treat scabies). To further verify specific metabolic pathways being inhibited by these synergists, enzyme assays were developed to measure esterase, glutathione S-transferase (GST) and cytochrome P450 monooxygenase activity in scabies mites. Results of in vitro enzyme inhibition experiments showed lower levels of esterase activity with DEF; lower levels of GST activity with DEM and lower levels of cytochrome monooxygenase activity with PBO. These findings indicate a metabolic mechanism as mediating pyrethroid resistance in scabies mites

Creativity and commerce: Michael Klinger and new film history

The crisis in film studies and history concerning their legitimacy and objectives has provoked a reinvigoration of scholarly energy in historical enquiry. 'New film history' attempts to address the concerns of historians and film scholars by working self-reflexively with an expanded range of sources and a wider conception of 'film' as a dynamic set of processes rather than a series of texts. The practice of new film history is here exemplified through a detailed case study of the independent British producer Michael Klinger (active 1961-87) with a specific focus on his unsuccessful attempt to produce a war film, Green Beach, based on a memoir of the Dieppe raid (August 1942). This case study demonstrates the importance of analysing the producer's role in understanding the complexities of film-making, the continual struggle to balance the competing demands of creativity and commerce. In addition, its subject matter - an undercover raid and a Jewish hero - disturbed the dominant myths concerning the Second World War, creating what turned out to be intractable ideological as well as financial problems. The paper concludes that the concerns of film historians need to engage with broader cultural and social histories. © 2010 Taylor & Francis

Procalcitonin Is Not a Reliable Biomarker of Bacterial Coinfection in People With Coronavirus Disease 2019 Undergoing Microbiological Investigation at the Time of Hospital Admission

Abstract Admission procalcitonin measurements and microbiology results were available for 1040 hospitalized adults with coronavirus disease 2019 (from 48 902 included in the International Severe Acute Respiratory and Emerging Infections Consortium World Health Organization Clinical Characterisation Protocol UK study). Although procalcitonin was higher in bacterial coinfection, this was neither clinically significant (median [IQR], 0.33 [0.11–1.70] ng/mL vs 0.24 [0.10–0.90] ng/mL) nor diagnostically useful (area under the receiver operating characteristic curve, 0.56 [95% confidence interval, .51–.60]).</jats:p

Implementation of corticosteroids in treating COVID-19 in the ISARIC WHO Clinical Characterisation Protocol UK:prospective observational cohort study

BACKGROUND: Dexamethasone was the first intervention proven to reduce mortality in patients with COVID-19 being treated in hospital. We aimed to evaluate the adoption of corticosteroids in the treatment of COVID-19 in the UK after the RECOVERY trial publication on June 16, 2020, and to identify discrepancies in care. METHODS: We did an audit of clinical implementation of corticosteroids in a prospective, observational, cohort study in 237 UK acute care hospitals between March 16, 2020, and April 14, 2021, restricted to patients aged 18 years or older with proven or high likelihood of COVID-19, who received supplementary oxygen. The primary outcome was administration of dexamethasone, prednisolone, hydrocortisone, or methylprednisolone. This study is registered with ISRCTN, ISRCTN66726260. FINDINGS: Between June 17, 2020, and April 14, 2021, 47 795 (75·2%) of 63 525 of patients on supplementary oxygen received corticosteroids, higher among patients requiring critical care than in those who received ward care (11 185 [86·6%] of 12 909 vs 36 415 [72·4%] of 50 278). Patients 50 years or older were significantly less likely to receive corticosteroids than those younger than 50 years (adjusted odds ratio 0·79 [95% CI 0·70–0·89], p=0·0001, for 70–79 years; 0·52 [0·46–0·58], p80 years), independent of patient demographics and illness severity. 84 (54·2%) of 155 pregnant women received corticosteroids. Rates of corticosteroid administration increased from 27·5% in the week before June 16, 2020, to 75–80% in January, 2021. INTERPRETATION: Implementation of corticosteroids into clinical practice in the UK for patients with COVID-19 has been successful, but not universal. Patients older than 70 years, independent of illness severity, chronic neurological disease, and dementia, were less likely to receive corticosteroids than those who were younger, as were pregnant women. This could reflect appropriate clinical decision making, but the possibility of inequitable access to life-saving care should be considered. FUNDING: UK National Institute for Health Research and UK Medical Research Council

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Vitamin D insufficiency in COVID-19 and influenza A, and critical illness survivors: a cross-sectional study

Objectives: The steroid hormone vitamin D has roles in immunomodulation and bone health. Insufficiency is associated with susceptibility to respiratory infections. We report 25-hydroxy vitamin D (25(OH)D) measurements in hospitalised people with COVID-19 and influenza A and in survivors of critical illness to test the hypotheses that vitamin D insufficiency scales with illness severity and persists in survivors. Design: Cross-sectional study. Setting and participants: Plasma was obtained from 295 hospitalised people with COVID-19 (International Severe Acute Respiratory and emerging Infections Consortium (ISARIC)/WHO Clinical Characterization Protocol for Severe Emerging Infections UK study), 93 with influenza A (Mechanisms of Severe Acute Influenza Consortium (MOSAIC) study, during the 2009–2010 H1N1 pandemic) and 139 survivors of non-selected critical illness (prior to the COVID-19 pandemic). Total 25(OH)D was measured by liquid chromatography-tandem mass spectrometry. Free 25(OH)D was measured by ELISA in COVID-19 samples. Outcome measures: Receipt of invasive mechanical ventilation (IMV) and in-hospital mortality. Results: Vitamin D insufficiency (total 25(OH)D 25–50 nmol/L) and deficiency (<25 nmol/L) were prevalent in COVID-19 (29.3% and 44.4%, respectively), influenza A (47.3% and 37.6%) and critical illness survivors (30.2% and 56.8%). In COVID-19 and influenza A, total 25(OH)D measured early in illness was lower in patients who received IMV (19.6 vs 31.9 nmol/L (p<0.0001) and 22.9 vs 31.1 nmol/L (p=0.0009), respectively). In COVID-19, biologically active free 25(OH)D correlated with total 25(OH)D and was lower in patients who received IMV, but was not associated with selected circulating inflammatory mediators. Conclusions: Vitamin D deficiency/insufficiency was present in majority of hospitalised patients with COVID-19 or influenza A and correlated with severity and persisted in critical illness survivors at concentrations expected to disrupt bone metabolism. These findings support early supplementation trials to determine if insufficiency is causal in progression to severe disease, and investigation of longer-term bone health outcomes