Effects of early and late-dry season fires on mortality, dispersal and breeding of malimbe Malimbus scutatus in the Southern Guinea savannah

Inappropriate use of fire in the guinea savannah is one of the main processes threatening its biodiversity and despite its importance in shaping savannah, it remains poorly understood how the frequency, seasonality and intensity of the fire interact to influence the activities of bird species. While species adversely affected by fire have been documented, empirical studies that seek to identify the ecological mechanisms that underpin this decline are rare. This paper examined the effects of early- and late-dry season fires and a control on the mortality, dispersal and breeding of malimbe Malimbus scutatus in Ikwe Wildlife Park and also tested whether the early fire area became a refuge after the late fire. None of the fire treatment caused any increase in mortality. Individuals relocated short distances to unburnt habitat following both fires. Some birds use the early fire area after the late fire. Mayfield (1975) method of estimations of daily egg-survival probability showed no difference (P > 0.05) among the treatments, whereas the daily probability of nestling survival was significantly lower in the late fire area. Results suggested that the reproductive output of malimbe was low following latedry season fire, and this is the main mechanism that explains their decline. This study provides support for the idea of using early-dry season prescribed burning to limit the effect of late-dry season fire on malimbe.Keywords: inappropriate use, threatening, biodiversity, seasonality, poorly understood, nestling survival

The B73 Maize Genome: Complexity, Diversity, and Dynamics

We report an improved draft nucleotide sequence of the 2.3-gigabase genome of maize, an important crop plant and model for biological research. Over 32,000 genes were predicted, of which 99.8% were placed on reference chromosomes. Nearly 85% of the genome is composed of hundreds of families of transposable elements, dispersed nonuniformly across the genome. These were responsible for the capture and amplification of numerous gene fragments and affect the composition, sizes, and positions of centromeres. We also report on the correlation of methylation-poor regions with Mu transposon insertions and recombination, and copy number variants with insertions and/or deletions, as well as how uneven gene losses between duplicated regions were involved in returning an ancient allotetraploid to a genetically diploid state. These analyses inform and set the stage for further investigations to improve our understanding of the domestication and agricultural improvements of maize

General anaesthesia versus local anaesthesia for carotid surgery (GALA): a multicentre, randomised controlled trial

BACKGROUND: The effect of carotid endarterectomy in lowering the risk of stroke ipsilateral to severe atherosclerotic carotid-artery stenosis is offset by complications during or soon after surgery. We compared surgery under general anaesthesia with that under local anaesthesia because prediction and avoidance of perioperative strokes might be easier under local anaesthesia than under general anaesthesia. METHODS: We undertook a parallel group, multicentre, randomised controlled trial of 3526 patients with symptomatic or asymptomatic carotid stenosis from 95 centres in 24 countries. Participants were randomly assigned to surgery under general (n=1753) or local (n=1773) anaesthesia between June, 1999 and October, 2007. The primary outcome was the proportion of patients with stroke (including retinal infarction), myocardial infarction, or death between randomisation and 30 days after surgery. Analysis was by intention to treat. The trial is registered with Current Control Trials number ISRCTN00525237. FINDINGS: A primary outcome occurred in 84 (4.8%) patients assigned to surgery under general anaesthesia and 80 (4.5%) of those assigned to surgery under local anaesthesia; three events per 1000 treated were prevented with local anaesthesia (95% CI -11 to 17; risk ratio [RR] 0.94 [95% CI 0.70 to 1.27]). The two groups did not significantly differ for quality of life, length of hospital stay, or the primary outcome in the prespecified subgroups of age, contralateral carotid occlusion, and baseline surgical risk. INTERPRETATION: We have not shown a definite difference in outcomes between general and local anaesthesia for carotid surgery. The anaesthetist and surgeon, in consultation with the patient, should decide which anaesthetic technique to use on an individual basis. FUNDING: The Health Foundation (UK) and European Society of Vascular Surgery