Tree diversity enhances predation by birds but not by arthropods across climate gradients

Tree diversity can promote both predator abundance and diversity. However, whether this translates into increased predation and top-down control of herbivores across predator taxonomic groups and contrasting environmental conditions remains unresolved. We used a global network of tree diversity experiments (TreeDivNet) spread across three continents and three biomes to test the effects of tree species richness on predation across varying climatic conditions of temperature and precipitation. We recorded bird and arthropod predation attempts on plasticine caterpillars in monocultures and tree species mixtures. Both tree species richness and temperature increased predation by birds but not by arthropods. Furthermore, the effects of tree species richness on predation were consistent across the studied climatic gradient. Our findings provide evidence that tree diversity strengthens top-down control of insect herbivores by birds, underscoring the need to implement conservation strategies that safeguard tree diversity to sustain ecosystem services provided by natural enemies in forests.

Epidemiology of Shingles

One thousand and nineteen patients with acute varicella zoster viral infection were referred to the physiotherapy department for treatment between 1978 and 1986. Sixty per cent were women and 40% were men with a mean age of 58 years (range 9–96 years). The prevalence varied between 1.3 and 1.6 per 1000 per annum. The left side was affected in 52% while the right was affected in 48%. The thoracic dermatomes were the most commonly affected (56%) followed by cervical (17%), lumbar (10%), sacral (5%), and the trigeminal nerve was infected in 12%. There was a significant seasonal (P < 0.001) variation in the prevalence of acute varicella zoster virus infection, most common in the summer and least common in the spring. There was no clustering in time and space so that it is unlikely that the varicella zoster virus is infective or that re-exposure to the virus causes reactivation of the latent virus.

Self-expanding plastic esophageal stents versus jejunostomy tubes for the maintenance of nutrition during neoadjuvant chemoradiation therapy in patients with esophageal cancer: a retrospective study

In patients undergoing chemoradiotherapy for esophageal cancer, the inability to eat may severely impair nutritional status. We conducted a retrospective study to compare the efficacy of the Polyflex self-expanding silicone stent (PS) versus a jejunostomy tube (JT) for maintaining nutrition during neoadjuvant chemoradiation therapy in patients with esophageal cancer who were scheduled for resectional surgery. Thirty-six patients were treated either with PS placement (12 patients) or JT placement (24 patients) prior to receiving an 8-week course of chemoradiation therapy. Patients were interviewed weekly until cessation of therapy. Patient data were collected on procedural success and complication rates, nutritional status, and dysphagia scores. PS placement was successful in 11 of 12 patients (92%), and those 11 patients were able to resume oral nutrition. Dysphagia scores improved from a mean of 3 to 1 in the PS group (P < 0.005) but did not change significantly in the JT group. PS were removed endoscopically without complications prior to the esophagectomies. Albumin levels and weight increased significantly in both the PS and JT groups. There were no significant differences between groups in the procedural success rates (PS 92% vs. JT 100%, P = 0.33), complication rates (PS 22% vs. JT 4%, P = 0.11), mean increase in weight (PS 4.4 kg vs. JT 4.2 kg, P = 0.59), and mean increase in serum albumin (PS 0.62 g/dL vs. JT 0.44 g/dL, P = 0.05). PS is a safe and effective alternative to a surgical JT for maintaining nutrition in this subset of patients.

Testing the growth-differentiation balance hypothesis: dynamic responses of willows to nutrient availability

Here, the growth-differentiation balance hypothesis (GDBH) was tested by quantifying temporal variation in the relative growth rate (RGR), net assimilation rate (NAR), and phenylpropanoid concentrations of two willow species (Salix sericea and Salix eriocephala) across five fertility levels. Initially, RGR increased and total phenylpropanoids declined (although every individual phenolic did not) as fertility increased, but NAR was unaffected. Subsequently, NAR and phenylpropanoids declined in the low fertility treatment, generating a quadratic response of secondary metabolism across the nutrient gradient. As above- and below-ground growth rates equilibrated, NAR and phenylpropanoids increased in the low fertility treatment, re-establishing a negative linear effect of fertility on secondary metabolism. A transient quadratic response of secondary metabolism is predicted when GDBH is integrated with models of optimal phenotypic plasticity, occurring when low NAR imposes carbon constraints on secondary metabolism in low nutrient environments. Once plants acclimate to nutrient limitation, the equilibrium allocation state is predicted to be a negative correlation between growth and secondary metabolism. Although both willow species generally responded according to GDBH, the complexity observed suggests that prediction of the effects of nutrient availability on secondary metabolism (and other plastic responses) in specific cases requires a priori knowledge of the physiological status of the plant and soil nutrient availability.

Genetic basis of phenotypic correlations among growth traits in hybrid willow (Salix dasycladosxS. viminalis) grown under two water regimes

Phenotypic correlations and quantitative trait loci (QTL) for important growth traits and a surrogate of intrinsic water-use efficiency (leaf delta(13)C) were analysed in a willow pedigree of 92 full-sibling clones grown under two water regimes. The major objective was to examine the genetic basis of the phenotypic correlations. Cuttings of Salix were glasshouse-grown during one growing season. The relative growth rate (RGR) and underlying traits were assessed. QTL analysis was conducted based on an available linkage map for Salix. Leaf area productivity and leaf nitrogen productivity were more important in determining RGR than leaf area ratio and specific leaf area. However, phenotypic correlations among growth traits partly varied between the two environments. QTL were detected for most growth traits, among them many common QTL for different traits. The QTL pattern reflected the phenotypic correlation pattern. None of the QTL for the complex traits was consistent across the different environments. The results demonstrate a genetic basis for phenotypic correlations among growth traits in Salix, and provide evidence for the existence of 'master switches' regulating some of the traits.

Epidural steroid injection for nerve root compression

We have assessed whether an epidural steroid injection is effective in the treatment of symptoms due to compression of a nerve root in the lumbar spine by carrying out a prospective, randomised, controlled trial in which patients received either an epidural steroid injection or an intramuscular injection of local anaesthetic and steroid. We assessed a total of 93 patients according to the Oxford pain chart and the Oswestry disability index and followed up for a minimum of two years. All the patients had been categorised as potential candidates for surgery.

There was a significant reduction in pain early on in those having an epidural steroid injection but no difference in the long term between the two groups. The rate of subsequent operation in the groups was similar.

QTL analyses of drought tolerance and growth for a Salix dasyclados x Salix viminalis hybrid in contrasting water regimes

Quantitative trait loci (QTL) for growth traits and water-use efficiency have been identified in two water regimes (normal and drought-treated) and for a treatment index. A tetraploid hybrid F2 population originating from a cross between a Salix dasyclados clone (SW901290) and a Salix viminalis clone ('Jorunn') was used in the study. The growth response of each individual including both above and below ground dry-matter production (i.e. shoot length, shoot diameter, aboveground and root dry weight, internode length, root dry weight/total dry weight, relative growth rate and leaf nitrogen content) was analysed in a replicated block experiment with two water treatments. A composite interval mapping approach was used to estimate number of QTL, the magnitude of the QTL and their position on genetic linkage maps. QTL specific for each treatment and for the treatment index were found, but QTL common across the treatments and the treatment index were also detected. Each QTL explained from 8% to 29% of the phenotypic variation, depending on trait and treatment. Clusters of QTL for different traits were mapped close to each other at several linkage groups, indicating either a common genetic base or tightly linked QTL. Common QTL identified between treatments and treatment index in the complex trait dry weight can be useful tools in the breeding and selection for drought stress tolerance in Salix.

Bacillus thuringiensis variety kurstaki x aizawai applied to spruce flowers reduced Dioryctria abietella (Lepidoptera: Pyralidae) infestation without affecting seed quality

We investigated the effects of Bacillus thuringiensis variety kurstaki x aizawai (Bt) on infestation levels of two lepidopteran insects as well as on seed quality in Norway spruce, Picea abies L. (Karst.) in central Sweden. Spruce flowers (female strobili) were sprayed with a 0.2% suspension (wt:wt) of the Bt preparation Turex 50 WP, 25,000 IU/mg in water. To expose even those lepidopteran larvae that feed exclusively embedded within the cone tissue, the Bt treatment was applied to open flowers, before they closed and developed into cones. The experimental design included three main factors: treatment (untreated control, water, or Bt), spruce genotype (three clones), and spraying time (spraying before, during, and after the phase of highest pollen receptivity). The Bt treatment reduced the proportion of cones infested by the cone worm Dioryctria abietella Den. et Schiff. (Lepidoptera: Pyralidae) from approximately 30 to 15%. There was no statistically significant treatment effect on the infestation rate of Cydia strobilella (L.) (Lepidoptera: Tortricidae). The Bt variety kurstaki x aizawai treatment caused no reduction in seed quality as measured by seed weight or percentage of nonfilled seeds. There was no difference in number of seeds per cone between the Bt-treated and untreated control cones. There was a significant effect of genotype on insect infestation rates, as well as on number of seeds per cone and seed weight. Neither level of insect damage nor any seed quality parameters were affected by time of application of the treatments.

Auditing a new lung cancer service

The Adelaide and Meath Hospital (AMNCH) is a new hospital, with the respiratory service established in 1999. We report on our experience with lung cancer in this short time. We conducted a retrospective chart audit, identifying patients from the Oncology Nurse patient list, of lung cancer cases diagnosed in 2001-2002. In 2001, 47 cases were diagnosed, with 71 cases diagnosed in 2002. Time to tissue diagnosis was 14.8, 2-46 (mean, range, one subject skewing the data) days. Diagnosis by tissue type was as follows: non-small cell carcinoma (NSCLC) n=92 (77.9%), small cell lung carcinoma (SCLC) n=17 (14.4%), mesothelioma n=2 (17%), carcinoid n=1 (0.8%) and no tissue diagnosis n=6 (5.1%). Staging of NSCLC: stage 1a n=3 (3.2%), stage 1b n=6 (6.5%), stage 2a n=5 (5.4%), stage 2b n=2 (2.2%), stage 3a n=10 (10.9%), stage 3b n=22 (23.9%) and stage 4 n=44 (47.8%). Staging of SCLC: limited stage n=5 (29.4%), extensive stage n=12 (70.6%). Positive emission tomography (PET) was employed in the staging of 22 patients. In these patients PET up-staged the disease in 8 patients, and management was unchanged in 8 patients. We conclude that 1. the relatively new respiratory service in AMNCH is handling increasing numbers of lung cancer cases, 2. cases are diagnosed within an acceptable time-frame, 3. rate of tissue diagnosis is comparable to national figures, 4. most patients present with advanced disease and 5. PET is a useful imaging modality for detection of cancer spread in selected patients.

Pain in venous leg ulcers

A prospective study was conducted to assess the prevalence, severity and diagnostic utility of pain in patients with venous leg ulcers. A semi-structured questionnaire was completed by 140 consecutive patients in two specialist centres caring for patients with leg ulcers. A high proportion (64%) of the 94 patients with ulcers of purely venous aetiology reported severe pain; 50% of these patients were taking either mild analgesia or none at all. In 10 of 72 cases, leg elevation made the pain worse. Venous ulcers are painful. Pain in three distinct locations was reported by patients-within ulcers, around ulcers and elsewhere in the leg. The presence of severe pain does not necessarily indicate arterial disease or infection. Pain is, in general, inadequately controlled in these patients.

A comparison of ibuprofen arginine with morphine sulphate for pain relief after orthopaedic surgery

In a randomized, double-blind, double-dummy, single-dose, parallel-group study, oral ibuprofen arginine (400 mg) was compared with intramuscular (i.m.) morphine sulphate (5 or 10 mg) for post-operative pain relief after orthopaedic surgery in 120 patients. The study medication was administered post-operatively at the time when each patient first requested pain relief for moderate to severe pain. Assessment of pain intensity and pain relief was made using standard visual analogue scales and verbal rating scores. In all three groups, there was a reduction in pain compared with baseline, measured by visual analogue scales and verbal rating scores, at all time points up to completion of the study at 240 min. For example, visual analogue scales decreased by 35 (10-52) mm at 1 h in the morphine 5 mg group, 24 (12-39) mm in morphine 10 mg group and 21 (8-38) mm in the ibuprofen arginine group (median and inter-quartile range). Verbal rating scores showed a similar pattern. Comparing the groups over the whole study period using the sum of pain intensity differences showed no significant differences in pain experience between the groups. Assessment of total pain relief also showed no significant differences. The incidence and types of side effect seen were similar in the three groups.

Single-dose, randomized, double-blind, double-dummy cross-over comparison of extradural and i.v. clonidine in chronic pain

We studied 10 patients with chronic back pain who had claimed benefit with a previous extradural dose of clonidine 150 micrograms combined with local anaesthetic. We compared a single dose of clonidine 150 micrograms given by either the extradural or i.v. route in a double-blind, randomized, double-dummy and cross-over fashion, with 80% power to detect a difference in the analgesic effect of the two routes. Pain intensity, pain relief, adverse effects, mood, sedation and vital signs were assessed by a nurse observer. I.v. clonidine produced significantly (P < 0.04) greater analgesia than extradural clonidine in one of the five analgesic outcome measures. Clonidine given by either route produced statistically significant sedation and significant decreases in arterial pressure and heart rate. In this study, extradural clonidine had no significant clinical advantages compared with i.v. clonidine; clonidine 150 micrograms by either route produced a high incidence of adverse effects.