L-DOPA functions as a plant pheromone for belowground anti-herbivory communication

While mechanisms of plant-plant communication for alerting neighbouring plants of an imminent insect herbivore attack have been described aboveground via the production of volatile organic compounds (VOCs), we are yet to decipher the specific components of plant-plant signalling belowground. Using bioassay-guided fractionation, we isolated and identified the non-protein amino acid l-DOPA, released from roots of Acyrtosiphon pisum aphid-infested Vicia faba plants, as an active compound in triggering the production of VOCs released aboveground in uninfested plants. In behavioural assays, we show that after contact with l-DOPA, healthy plants become highly attractive to the aphid parasitoid (Aphidius ervi), as if they were infested by aphids. We conclude that l-DOPA, originally described as a brain neurotransmitter precursor, can also enhance immunity in plants.

Could bio-detection dogs be used to limit the spread of COVID-19 by travellers?

The COVID-19 epidemic has had an unprecedented impact on the tourism sector. Trained disease detection dogs could be used for non-invasive screening at border entry points to reduce the likelihood of re-introduction of SARS-CoV-2 and limit the need for the self-isolation of all passengers.

Responses of the putative trachoma vector, Musca sorbens, to volatile semiochemicals from human faeces

The putative vector of trachoma, Musca sorbens, prefers to lay its eggs on human faeces on the ground. This study sought to determine whether M. sorbens females were attracted to volatile odours from human faeces in preference to odours from the faeces of other animals, and to determine whether specific volatile semiochemicals mediate selection of the faeces. Traps baited with the faeces of humans and local domestic animals were used to catch flies at two trachoma-endemic locations in The Gambia and one in Ethiopia. At all locations, traps baited with faeces caught more female M. sorbens than control traps baited with soil, and human faeces was the most successful bait compared with soil (mean rate ratios 44.40, 61.40, 10.50 [P<0.001]; 8.17 for child faeces [P = 0.004]). Odours from human faeces were sampled by air entrainment, then extracts of the volatiles were tested by coupled gas chromatography-electroantennography with laboratory-reared female M. sorbens. Twelve compounds were electrophysiologically active and tentatively identified by coupled mass spectrometry-gas chromatography, these included cresol, indole, 2-methylpropanoic acid, butanoic acid, pentanoic acid and hexanoic acid. It is possible that some of these volatiles govern the strong attraction of M. sorbens flies to human faeces. If so, a synthetic blend of these chemicals, at the correct ratios, may prove to be a highly attractive lure. This could be used in odour-baited traps for monitoring or control of this species in trachoma-endemic regions.

Factors facilitating and constraining the delivery of effective teacher training to promote health and well-being in schools: a survey of current practice and systematic review

Background

Schools are an important setting for health promotion and teachers have an integral role to play in promoting children and young people’s health and well-being. Adequate initial teacher training (ITT) and continuing professional development in health is therefore important.

Objectives

To conduct a survey of initial teacher training providers in England and a systematic review of effectiveness to assess how health and well-being is covered on courses, and to identify barriers and facilitators to effective training.

Methods

Methods included an online questionnaire survey with a sample of 220 ITT course managers in England; interviews with a purposive sample of 19 of the course managers responding to the questionnaire; and a two-stage systematic review comprising a descriptive map of the characteristics of international research studies of health teacher training and a detailed synthesis of a subset of studies specifically on pre-service training. Databases (including MEDLINE, EMBASE, The Campbell Library and PsycINFO) were searched from the period of database inception up to May 2011.

Results

The overall response rate for the survey was 34%. The majority (89%) of respondents agreed that it was either important or very important to cover health within the ITT curriculum. The most commonly covered topics on courses wereEvery Child Matters(100%), child protection (100%), emotional health (99%) and antibullying (97%). Fewer course managers reported covering healthy eating (63%), sex and relationships (62%), drugs (56%), alcohol (41%) and smoking (34%). Many interviewees expressed a holistic view of education and believed that health was important in the ITT curriculum. However, there was variability in how health was addressed across and within institutions. Trainee teachers' experience of addressing child health on school placement was also variable. Facilitators to covering health included interests and backgrounds of ITT staff; staff health-related professional experience; availability of health expertise from external agencies; supportive government policy frameworks; and interprofessional and interdepartmental working. The main barriers were limited curriculum time; health being perceived to be a lower priority than other aspects of training; health no longer a high government priority in education; and lack of funding. A total of 170 studies met the eligibility criteria for the descriptive map. The majority covered teacher training in relation to sexual and reproductive health, drugs and alcohol or mental and emotional health. A total of 21 publications (20 studies) were prioritised for the synthesis. All were evaluations of health training for pre-service teachers, and just under half were from the UK. Twelve studies reported outcomes (impact of training on teachers, but not pupils), many of which were single cohort before-and-after studies. Sixteen studies reported processes. Following training there were some increases in trainee teachers' factual knowledge of health and a general increase in their confidence to address health issues. In general, training was acceptable and well received by trainees. Evidence suggested that effective training should include practical experience and skills and be personally relevant and take into account individual needs. Barriers to health training identified from the studies included lack of time, balancing breadth and depth, and variation in training provision.

Conclusions

Among those surveyed there appears to be general support for health and well-being in ITT. However, further research on the longer-term impact of ITT around health and well-being is needed, particularly in the early career period. The main limitation of this research was the low response rate (34%) to the survey.

Study registration

PROSPERO number CRD42012001977.

Funding

The National Institute for Health Research Public Health Research programme.

Scanning electron microscopy of foreleg tarsal sense organs of the poultry red mite, Dermanyssus gallinae (DeGeer) (Acari:Dermanyssidae)

Scanning electron microscopy (SEM) studies on the poultry red mite, Dermanyssus gallinae (DeGeer), showed that the tip of the foreleg tarsus of both sexes and early instar stages (larvae, protonymph and deutonymph) bears a cluster of 10 blunt peg-type sensillae. Diversity in size, shape and surface features of the wall of these sensillae characterize the sensilla complex (sensory field). Two short setae (1 and 2) with smooth walls lack detectable pores, whereas three medium-sized setae (4, 5 and 8) bear pores in the wall. Four medium or long setae (3, 6, 7 and 9) have longitudinal grooves or ribs in the wall, whilst one seta (10) possesses both pores and grooves in the wall. Based on the morphology, it is suggested that the porous setae could be olfactory receptors, and the grooved setae could be mechanoreceptors.

Identification of Two Sex Pheromone Components of the Potato Aphid, Macrosiphum euphorbiae (Thomas)

Females of the potato aphid Macrosiphum euphorbiae exhibit typical calling behavior, with virgin female oviparae raising their back legs off the substrate to release sex pheromone from glands on the tibia. Airborne collections from calling oviparae were analyzed by GC and GC-MS to determine if, like the majority of aphids examined to date, they produced (1R,4aS,7S,7aR)-nepetalactol (1) and (4aS,7S,7aR)-nepetalactone (2). Both components were present and produced in ratios that varied with age from 4:1 to 2:1. The relative stereochemical configurations of these components were determined by GC-coinjection of the aphid-derived sample with synthetic standards on both HP-1 and DB-Wax GC columns. The absolute stereochemical configuration of the nepetalactol (determined from approximately 15 microg of material in an air entrainment sample) was determined as (1R,4aS,7S,7aR)-1 by derivatization of the aphid sample with (S)-(+)-alpha-methoxy-alpha-(trifluoromethyl)phenylacetyl chloride (Mosher's acid chloride) to generate a diastereoisomer that was compared to synthetic samples by NMR spectroscopy and GC. In bioassays in the wind tunnel, M. euphorbiae males responded to potato plants with oviparae but not to unattacked plants or those infested with parthenogenetically reproducing apterae. In no-choice laboratory bioassays, the same level of male response was observed to virgins and to the 3:1-5:1 synthetic blends of nepetalactol (1):nepetalactone (2). However, the time taken to reach the source was significantly less to virgin females than to the synthetic pheromone blends. In all cases, males walked rather than flew to the source. Males showed lower responses to a 1:1 synthetic mixture and did not respond to either of the components when presented alone. Under field conditions, few M. euphorbiae males were captured in traps baited with different ratios of the synthetic pheromone. Possible reasons for the different responses under laboratory and field conditions are discussed.