Comparative bioactivity of selected extracts from Meliaceae and some commercial botanical insecticides against two noctuid caterpillars, <Emphasis Type="Italic">Trichoplusia ni</Emphasis> and <Emphasis Type="Italic">Pseudaletia unipuncta</Emphasis>

Plant-derived extracts and phytochemicals have long been a subject of research in an effort to develop alternatives to conventional insecticides but with reduced health and environmental impacts. In this review we compare the bioactivities of some plant extracts with those of commercially available botanical insecticides against two important agricultural pests, the cabbage looper, Trichoplusia ni and the armyworm, Pseudaletia unipuncta. Test materials included extracts of Azadirachta indica (neem), A. excelsa (sentang), Melia volkensii, M. azedarach (Chinaberry) and Trichilia americana, (all belonging to the family Meliaceae) along with commercial botanical insecticides ryania, pyrethrum, rotenone and essential oils of rosemary and clove leaf. Most of the extracts and botanicals tested proved to be strong growth inhibitors, contact toxins and significant feeding deterrents to both lepidopteran species. However, there were interspecific differences with T. ni generally more susceptible to the botanicals than the armyworm, P. unipuncta. All botanicals were more inhibitory to growth and toxic (through feeding) to T. ni than to P. unipuncta, except for M. azedarach which was more toxic to P. unipuncta than to T. ni. Athough, pyrethrum was the most toxic botanical to both noctuids, A. indica, A. excelsa, and M. volkensii were more toxic than ryania, rotenone, clove oil and rosemary oil for T. ni. As feeding deterrents, pyrethrum was the most potent against T. ni, whereas A. indica was the most potent against the armyworm. Based upon growth inhibition, chronic toxicity, and antifeedant activity, some of these plant extracts have levels of activity that compare favorably to botanical products currently in commercial use and have potential for development as commercial insecticides.     

黄土高原半干旱偏旱区草粮轮作田土壤水分恢复效应模拟

采用实地调查和EPIC模型相结合的方法,模拟研究了黄土高原半干旱偏旱区不同草粮轮作模式的土壤水分恢复效应.结果表明：多年生苜蓿地和苜蓿翻耕后种植粮食作物农田0～10 m土层土壤湿度调查值与模拟值间的相关系数均超过0.9（P<0.01）,相对均方根误差在0.05～0.16,相对误差均低于10%;模拟与实测的土壤湿度剖面分布变化趋势一致.在黄土高原半干旱偏旱区,苜蓿地深层土壤干层恢复难度较大,在种植苜蓿期间应避免8～10 m土层土壤湿度降到5.7%以下.苜蓿地适宜种植年限为4～6 a,最长不应超过8 a.苜蓿翻耕后适宜采用马铃薯→马铃薯→春小麦轮作模式进行土壤水分恢复,32～33 a后可以再次种植苜蓿.     

Does Video Gaming Affect Orthopaedic Skills Acquisition? A Prospective Cohort-Study

Introduction

Previous studies have suggested that there is a positive correlation between the extent of video gaming and efficiency of surgical skill acquisition on laparoscopic and endovascular surgical simulators amongst trainees. However, the link between video gaming and orthopaedic trauma simulation remains unexamined, in particular dynamic hip screw (DHS) stimulation.

Objective

To assess effect of prior video gaming experience on virtual-reality (VR) haptic-enabled DHS simulator performance.

Methods

38 medical students, naïve to VR surgical simulation, were recruited and stratified relative to their video gaming exposure. Group 1 (n = 19, video-gamers) were defined as those who play more than one hour per day in the last calendar year. Group 2 (n = 19, non-gamers) were defined as those who play video games less than one hour per calendar year. Both cohorts performed five attempts on completing a VR DHS procedure and repeated the task after a week. Metrics assessed included time taken for task, simulated flouroscopy time and screw position. Median and Bonett-Price 95% confidence intervals were calculated for seven real-time objective performance metrics. Data was confirmed as non-parametric by the Kolmogorov-Smirnov test. Analysis was performed using the Mann-Whitney U test for independent data whilst the Wilcoxon signed ranked test was used for paired data. A result was deemed significant when a two-tailed p-value was less than 0.05.

Results

All 38 subjects completed the study. The groups were not significantly different at baseline. After ten attempts, there was no difference between Group 1 and Group 2 in any of the metrics tested. These included time taken for task, simulated fluoroscopy time, number of retries, tip-apex distance, percentage cut-out and global score.

Conclusion

Contrary to previous literature findings, there was no correlation between video gaming experience and gaining competency on a VR DHS simulator.     

Countrywide Survey for MERS-Coronavirus Antibodies in Dromedaries and Humans in Pakistan

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a zoonotic pathogen capable of causing severe respiratory disease in humans. Although dromedary camels are considered as a major reservoir host, the MERS-CoV infection dynamics in camels are not fully understood. Through surveillance in Pakistan, nasal (n = 776) and serum (n = 1050)samples were collected from camels between November 2015 and February 2018. Samples were collected from animal markets, free-roaming herds and abattoirs. An in-house ELISA was developed to detect IgG against MERS-CoV. A total of 794 camels were found seropositive for MERS-CoV. Prevalence increased with the age and the highest seroprevalence was recorded in camels aged [ 10 years (81.37%) followed by those aged 3.1–10 years (78.65%) and B 3 years (58.19%).Higher prevalence was observed in female (78.13%) as compared to male (70.70%). Of the camel nasal swabs, 22 were found to be positive by RT-qPCR though with high Ct values. Moreover, 2,409 human serum samples were also collected from four provinces of Pakistan during 2016–2017. Among the sampled population, 840 humans were camel herders.Although we found a high rate of MERS-CoV antibody positive dromedaries (75.62%) in Pakistan, no neutralizing antibodies were detected in humans with and without contact to camels.     

The impact of aromatase mechanism on other P450s

Experimental findings from a number of laboratories have converged to show that the conversion of androgens into oestrogen, catalysed by aromatase, involves three distinct reactions which occur at a single active site. That each one of these reactions belongs to a different generic type was revealed by chemical consideration, together with our ¹⁸O-experiments. In particular, these findings high-lighted the fact that the third reaction in the sequence occurs by a novel process for which a number of plausible mechanisms have been considered. The scrutiny of these mechanisms has involved either studies on aromatase itself, or on related enzymes which catalyse the aromatase type of cleavage reaction as generalized in equation 1:

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The acyl-carbon cleavage reaction of equation 1 is catalysed by sterol 14-demethylases, accounts for several side-chain fission products formed by CYP17 (17-hydroxylase-17,20-lyase), and constitutes a weak property of certain drug metabolizing P450s, when given aliphatic aldehydes as substrates. From cumulative studies on these enzymes, consensus is beginning to emerge that the acyl-carbon fission may be promoted by the Fe^III---OOH intermediate, formed during the catalytic cycles of P450s. The precedent for the direct involvement of the Fe^III---OOH species in the reaction of equation 1 is influencing our thinking regarding the mechanism of the conventional hydroxylation reaction. The status of knowledge surrounding the current debate on these issues will be reviewed.     

Ameliorative symbiosis of endophyte (Penicillium funiculosum LHL06) under salt stress elevated plant growth of Glycine max L.

Experiments were conducted to investigate the role of a newly isolated endophytic fungus GMC-2A on physiology of host plant (Glycine max. L cv. Hwangkeum-kong) growing under salinity stress. GMC-2A was identified as a new strain of Penicillium funiculosum on the basis of sequence homology and phylogenetic analysis of D1/D2 regions of 28S rDNA. Preliminary screening experiment showed that the culture filtrate (CF) of GMC-2A promoted the growth of Waito-C, a dwarf gibberellin (GA) biosynthesis mutant rice cultivar. Analysis of fungal CF revealed the presence of GAs (GA₁ 1.53 ng/ml; GA₄ 9.34 ng/ml; GA₈ 1.21 ng/ml; GA₉ 37.87 ng/ml) and indole acetic acid (14.85 μg/ml). GMC-2A also showed high phosphate solubilization of tricalcium phosphate. Besides that, GMC-2A application enhanced soybean seed germination as compared to control. Under salinity stress (70 and 140 mM), GMC-2A significantly promoted the soybean growth attributes (shoot length, shoot fresh/dry biomass, chlorophyll content, photosynthesis rate and leaf area) in comparison to control treatments. We also observed low endogenous abscisic acid and elevated jasmonic acid contents in GMC-2A treated plants under salt stress. GMC-2A treatment significantly enhanced levels of isoflavones (34.22% and 75.37%) under salinity stress as compared to control. In conclusion, P. funiculosum LHL06 has significantly ameliorated the adverse effects of salinity induced abiotic stress, and re-programmed soybean to higher growth and isoflavone biosynthesis.