The biology, behaviour and control of the field slug, Deroceras reticulatum (Müller)

Deroceras reticulatum (Müller) is the most destructive slug pest of arable crops in Britain. Control on a field scale relies heavily on molluscicide pellets. These are often only partially effective; considerable economic loss and collateral damage still occur. More effective targeting of pellets will depend on accurate predictions of damage severity through a better understanding of population dynamics, reliable estimates of surface activity and behavioural studies to evaluate current control strategies. Lifecycle parameters of D. reticulatum were studied. There was considerable variation in growth even under identical conditions and growth rate was inversely related to survival. For field collected slugs, the association between growth rate and temperature was low but negative for spring hatching individuals; however, this was relatively trivial compared to the high and positive association exhibited by those hatching in autumn. For self-fertilised slugs, egg development took longer and the hatching rate was lower than for slugs laid by field collected adults, but the growth rate was faster. It is suggested that field populations may be composed of fast and slow growers, and that this might be determined by whether eggs are fertilised with auto- or allosperm. An equation was derived to predict female-phase maturity from body weight. Refuge traps sampled approximately one third of the surface active population over a 24 hour period. The timing and number of trap entries and exits did not differ between small and large D. reticulatum. Behavioural studies of D. reticulatum demonstrated that the time elapsed and distance travelled before feeding on bait pellets was shorter when they were broadcast compared to drilled. Soil splash did not reduce pellet efficacy. Trails were more sinuous on fine than coarse seedbeds and were reduced by pellets. The practical implications of these results for assessing and controlling D. reticulatum in arable crops are discussed.EThOS - Electronic Theses Online ServiceSustainable Arable LINK project : Department for the Environment, Food and Rural Affairs (DEFRA) : Home Grown Cereals Authority (HGCA) : Bayer, Lonza and De SangosseGBUnited Kingdo

Postoperative continuous positive airway pressure to prevent pneumonia, re-intubation, and death after major abdominal surgery (PRISM): a multicentre, open-label, randomised, phase 3 trial

Background: Respiratory complications are an important cause of postoperative morbidity. We aimed to investigate whether continuous positive airway pressure (CPAP) administered immediately after major abdominal surgery could prevent postoperative morbidity. Methods: PRISM was an open-label, randomised, phase 3 trial done at 70 hospitals across six countries. Patients aged 50 years or older who were undergoing elective major open abdominal surgery were randomly assigned (1:1) to receive CPAP within 4 h of the end of surgery or usual postoperative care. Patients were randomly assigned using a computer-generated minimisation algorithm with inbuilt concealment. The primary outcome was a composite of pneumonia, endotracheal re-intubation, or death within 30 days after randomisation, assessed in the intention-to-treat population. Safety was assessed in all patients who received CPAP. The trial is registered with the ISRCTN registry, ISRCTN56012545. Findings: Between Feb 8, 2016, and Nov 11, 2019, 4806 patients were randomly assigned (2405 to the CPAP group and 2401 to the usual care group), of whom 4793 were included in the primary analysis (2396 in the CPAP group and 2397 in the usual care group). 195 (8\ub71%) of 2396 patients in the CPAP group and 197 (8\ub72%) of 2397 patients in the usual care group met the composite primary outcome (adjusted odds ratio 1\ub701 [95% CI 0\ub781-1\ub724]; p=0\ub795). 200 (8\ub79%) of 2241 patients in the CPAP group had adverse events. The most common adverse events were claustrophobia (78 [3\ub75%] of 2241 patients), oronasal dryness (43 [1\ub79%]), excessive air leak (36 [1\ub76%]), vomiting (26 [1\ub72%]), and pain (24 [1\ub71%]). There were two serious adverse events: one patient had significant hearing loss and one patient had obstruction of their venous catheter caused by a CPAP hood, which resulted in transient haemodynamic instability. Interpretation: In this large clinical effectiveness trial, CPAP did not reduce the incidence of pneumonia, endotracheal re-intubation, or death after major abdominal surgery. Although CPAP has an important role in the treatment of respiratory failure after surgery, routine use of prophylactic post-operative CPAP is not recommended