Was the removal of rabbits and house mice from Selvagem Grande beneficial to the breeding of Cory's shearwaters Calonectris diomedea borealis?

The breeding success of Cory's shearwaters Calonectris diomedea borealis at its important Atlantic colony on Selvagern Grande has been monitored periodically at two study plots since 1982. A successful eradication programme was implemented to remove two alien invasive mammals, rabbits Oryctolagus cuniculus and house mice Mus musculus, from the island during 2002. The availability of long-term breeding data for Cory's shearwaters on Selvagern Grande provided a unique opportunity to study the effects of the removal of rabbits and mice on seabird breeding. Annual observation of approximately 400 Cory's nests showed that significantly more birds fledged from both study sites in the five breeding seasons after the eradication than in the 13 seasons prior to it for which reliable breeding data were available. The numbers of young birds present at the time of fledging were an average of 47 and 23% greater than pre-eradication numbers at the two study sites. The eradication of rabbits and mice was simultaneous and, therefore, it was impossible to attribute the increased breeding success of Cory's shearwaters to the removal of one or other species. However, both are known to have adverse impacts on the breeding of nesting seabirds. These observations provide important justification for the implementation of further programmes for the removal of alien invasive mammals from oceanic islands.

Adventitious root formation in anacardium occidentale L. in response to phytohormones and removal of roots

Despite advances in tissue culture techniques, propagation by leafy, softwood cuttings is the preferred, practical system for vegetative reproduction of many tree and shrub species. Species are frequently defined as 'difficult'- or 'easy-to-root' when propagated by conventional cuttings. Speed of rooting is often linked with ease of propagation, and slow-to-root species may be 'difficult' precisely because tissues deteriorate prior to the formation of adventitious roots. Even when roots form, limited development of these may impair the establishment of a cutting. In this study we used softwood cuttings of cashew (Anacardium occidentale), a species considered as 'difficult-to-root'. We aimed to test the hypothesis that speed, and extent of early rooting, is critical in determining success with this species; and that the potential to form adventitious roots will decrease with time in the propagation environment. Using two genotypes, initial rooting rates were examined in the presence or absence of exogenous auxin. In cuttings that formed adventitious roots, either entire roots or root tips were removed, to determine if further root formation/development was feasible. To investigate if subsequent root responses were linked to phytohormone action, a number of cuttings were also treated with either exogenous auxin (indole-3-butyric acid-IBA) or cytokinin (zeatin). Despite the reputation of Anacardium as being 'difficult-to-root', we found high rooting rates in two genotypes (AC 10 and CCP 1001). Removing adventitious roots from cuttings and returning them to the propagation environment, resulted in subsequent re-rooting. Indeed, individual cuttings could develop new adventitious roots on four to five separate occasions over a 9 week period. Data showed that rooting potential increased, not decreased with time in the propagation environment and that cutting viability was unaffected. Root expression was faster (8-15 days) after the removal of previous roots compared to when the cuttings were first stuck (21 days). Exposing cuttings to IBA at the time of preparation, improved initial rooting in AC 10, but not in CCP 1001. Application of IBA once roots had formed had little effect on subsequent development, but zeatin reduced root length and promoted root number and dry matter accumulation. These results challenge our hypothesis, and indicate that rooting potential remains high in Anacardium. The precise mechanisms that regulate the number of adventitious roots expressed, remain to be determined. Nevertheless, results indicate that rooting potential can be high in 'difficult-to-root' species, and suggest that providing supportive environments is the key to expressing this potential. (c) 2006 Elsevier B.V. All rights reserved.

Peroxides in ordered nanoporous silicas: clean alternatives to transition metal oxidants for the removal of toxic gases

Ordered nano-structured MCM-48 silica containing sodium peroxydisulfate is a novel, highly effective material for the decomposition of HCN under ambient conditions.

Peroxydisulfate in MCM-48 silicas: powerful and clean materials for the removal of toxic gases

Sodium persulfate introduced into ordered MCM-48 silicas is described. The resulting materials are compared with existing activated carbon-based systems and MCM-48 containing transition metals such as Cu(II) and Cr(VI) for the decomposition of hydrogen cyanide and cyanogen. MCM-48 materials containing sodium persulfate alone improve on the protection offered by benchmark activated carbon systems and MCM-48 materials containing Cu(II) and Cr(VI), without the health risks associated with these metal ions.

Sensitivity of feature-based analysis methods of storm tracks to the form of background field removal

For the tracking of extrema associated with weather systems to be applied to a broad range of fields it is necessary to remove a background field that represents the slowly varying, large spatial scales. The sensitivity of the tracking analysis to the form of background field removed is explored for the Northern Hemisphere winter storm tracks for three contrasting fields from an integration of the U. K. Met Office's (UKMO) Hadley Centre Climate Model (HadAM3). Several methods are explored for the removal of a background field from the simple subtraction of the climatology, to the more sophisticated removal of the planetary scales. Two temporal filters are also considered in the form of a 2-6-day Lanczos filter and a 20-day high-pass Fourier filter. The analysis indicates that the simple subtraction of the climatology tends to change the nature of the systems to the extent that there is a redistribution of the systems relative to the climatological background resulting in very similar statistical distributions for both positive and negative anomalies. The optimal planetary wave filter removes total wavenumbers less than or equal to a number in the range 5-7, resulting in distributions more easily related to particular types of weather system. For the temporal filters the 2-6-day bandpass filter is found to have a detrimental impact on the individual weather systems, resulting in the storm tracks having a weak waveguide type of behavior. The 20-day high-pass temporal filter is less aggressive than the 2-6-day filter and produces results falling between those of the climatological and 2-6-day filters.

The effect of calcium removal from milk on casein micelle stability and structure

The total calcium level of raw skimmed milk was reduced by 10, 19, 29, 40 and 51% using Duolite® ion-exchange resin. The products were examined for concentrations of ionic calcium, sodium and potassium and the pH, ethanol stability, micelle diameter and ζ-potential were also measured. Ionic calcium decreased with removal of calcium and pH increased. Calcium removal resulted in an increase in the ethanol stability from 88% to above 100%. Casein micelle diameter increased as calcium was removed. The ζ-potential of the skimmed bulk milk was -24.4 mV, gradually becoming more negative with calcium removal to -30.6 mV after 51% calcium removal. The milk became more translucent as calcium was removed. To investigate the reversibility of this process, calcium chloride was added back to the depleted samples to restore their original total calcium content. At 51% removal, restoration of the total calcium level resulted in formation of clots. At levels of 10 and 19% calcium removal, the ethanol stability remained above 100%, but at higher levels of calcium removal the alcohol stability was adversely affected when the calcium was added back. Adding back calcium resulted in partial restoration of the original casein micelle diameter.

Robustness of mutual information to inter-subject variability for automatic artefact removal from EEG

The externally recorded electroencephalogram (EEG) is contaminated with signals that do not originate from the brain, collectively known as artefacts. Thus, EEG signals must be cleaned prior to any further analysis. In particular, if the EEG is to be used in online applications such as Brain-Computer Interfaces (BCIs) the removal of artefacts must be performed in an automatic manner. This paper investigates the robustness of Mutual Information based features to inter-subject variability for use in an automatic artefact removal system. The system is based on the separation of EEG recordings into independent components using a temporal ICA method, RADICAL, and the utilisation of a Support Vector Machine for classification of the components into EEG and artefact signals. High accuracy and robustness to inter-subject variability is achieved.

Re-creation of heathland on improved pasture using topsoil removal and sulphur amendments: edaphic drivers and impacts on ericoid mycorrhizas

Understanding the factors that drive successful re-creation and restoration of lowland heaths is crucially important for achieving the long-term conservation of this threatened habitat type. In this study we investigated the changes in soil chemistry, plant community and interactions between Calluna vulgaris and symbiotic ericoid mycorrhizas (ERM) that occurred when improved pasture was subjected to one of three treatments (i) acidification with elemental sulphur (ii) acidification with ferrous sulphur (iii) removal of the topsoil. We found that the soil stripping treatment produced the greatest reduction in available phosphate but did not decrease soil pH. Conversely, acidification with elemental sulphur decreased pH but increased availability of phosphate and potentially toxic cations. The elemental sulphur treatment produced plant communities that most closely resembled those on surrounding heaths and acid grasslands. The most important driver was low pH and concomitant increased availability of potentially toxic cations. Plant community development was found to be little related to levels of available soil phosphate, particularly at low pH. The elemental sulphur treatment also produced the best germination and growth of C. vulgaris over 4–5 years. However, this treatment was found to inhibit the development of symbiotic relationships between C. vulgaris and ERM. This may affect the long-term persistence of re-created vegetation and its interactions with other components of heathland communities.