Recovery of Bacillus thuringiensis in vegetative form from the phylloplane of clover (Trifolium hybridum) during a growing season

Two media were developed which specifically allow the cultivation of Bacillus thuringiensis while it is in the vegetative as opposed to the spore form. Using these media B. thuringiensis was shown conclusively for the first time to exist in an active form on the phylloplane. The profile of its appearance in vegetative and spore form was followed over a growing season on clover (Trifolium hybridum) in the field. Three simultaneous and sudden rises and declines of both spore and vegetative cell densities were observed. The most common other spore-former on these leaves was Bacillus cereus but the fluctuations in appearance of these two very closely related species were not co-incident. Using specific PCR primers a considerable diversity of cry toxin gene types was found in isolates that had been recovered in vegetative form ([`]vegetative isolates') with the majority possessing multiple [delta]-endotoxin genes while some had only one of those tested. Bioassays against a lepidopteran insect of purified [delta]-endotoxins showed that they were no more potent than those from a laboratory-adapted strain. PCR primers for an internal region of the vip3A gene produced amplification in 70% of the vegetative isolates compared to 25% of the laboratory-adapted strains tested.

Phenotypic variation in shell form in the intertidal acorn barnacle Chthamalus montagui: distribution, response to predators and life history trade-offs.

The acorn barnacle Chthamalus montagui can present strong variation in shell morphology, ranging from flat conic to a highly bent form, caused by a substantial overgrowth of the rostrum plate. Shell shape distribution was investigated between January and May 2004 from geographical to microhabitat spatial scales along the western coast of Britain. Populations studied in the north (Scotland and Isle of Man) showed a higher degree of shell variation compared to those in the south (Wales and south-west England). In the north, C. montagui living at lower tidal levels and in proximity to the predatory dogwhelk, Nucella lapillus, were more bent in profile. Laboratory experiments were conducted to examine behavioural responses, and vulnerability of bent and conic barnacles to predation by N. lapillus. Dogwhelks did not attack one morphotype more than the other, but only 15 % of attacks on bent forms were successful compared to 75 % in conic forms. Dogwhelk effluent reduced the time spent feeding by C. montagui (11 %), but there was no significant difference between conic and bent forms. Examination of barnacle morphology indicated a trade-off in investment in shell structure and feeding appendages associated with being bent, but none with egg or somatic tissue mass. These results are consistent with C. montagui showing an induced defence comparable to that found in its congeners Chthamalus anisopoma and Chthamalus fissus on the Pacific coast of North America, but further work to demonstrate inducibility is required.

DFT and in situ EXAFS investigation of gold/ceria-zirconia low-temperature water gas shift catalysts: Identification of the nature of the active form of gold

A combined experimental and theoretical investigation of the nature of the active form of gold in oxide-supported gold catalysts for the water gas shift reaction has been performed. In situ extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) experiments have shown that in the fresh catalysts the gold is in the form of highly dispersed gold ions. However, under water gas shift reaction conditions, even at temperatures as low as 100 degrees C, the evidence from EXAFS and XANES is only 14 consistent with rapid, and essentially complete, reduction of the gold to form metallic clusters containing about 50 atoms. The presence of Au-Ce distances in the EXAFS spectra, and the fact that about 15% of the gold atoms can be reoxidized after exposure to air at 150 degrees C, is indicative of a close interaction between a fraction (ca. 15%) of the gold atoms and the oxide support. Density functional theory (DFT) calculations are entirely consistent with this model and suggest that an important aspect of the active and stable form of gold under water gas shift reaction conditions is the location of a partially oxidized gold (Audelta+) species at a cerium cation vacancy in the surface of the oxide support. It is found that even with a low loading gold catalysts (0.2%) the fraction of ionic gold under water gas shift conditions is below the limit of detection by XANES (<5%). It is concluded that under water gas shift reaction conditions the active form of gold comprises small metallic gold clusters in intimate contact with the oxide support.

Do pigs form preferential associations?

This investigation examined whether pigs form long-term preferential associations or ‘friendships’ and factors that may influence the formation of these relationships. Thirty-three pigs from 16 litters were housed together from 4 weeks of age. At 10 weeks they were split into two groups of 16 and 17 pigs and each introduced into 3.05 m × 3.66 m observation pens (1st pen). At 17 weeks the two groups swapped pens (2nd pen). The lying patterns of each group were recorded over 3 weeks in both the 1st and 2nd pens. To identify dyads with preferential associations, association indices were calculated for each pair based on their lying patterns and analysed using SOCPROG1.3 and the permutation method [Whitehead, H., 1999. Programs for analysing social structure. SOCPROG 1.2, http://is.dal.cal/~whitelab/index.htm]. Dyads with high association indices for at least 2 out of 3 weeks in either pen, i.e. =0.10 (twice the mean), were classed as having preferential associations. Mantel tests were used to examine the relationship between the relative sex, weight, familiarity and relatedness of a dyad and their level of association and to examine consistency of associations between pens. The existence of preferential associations was identified in both groups, since the standard deviations for the observed half-weight association index means were significantly higher than for the randomly permuted half-weight association index means (P < 0.001). Of the 33 pigs observed, 32 formed preferential associations with one or more pigs in their group, resulting in 50 dyads. Only six dyads (12 pigs) formed preferential associations in both pens, suggesting that the remaining dyads either formed short-term associations only or were simply displaying a shared preference for the same lying location. Levels of association between pens showed no significant correlation. The relative sex, weight, familiarity and relatedness of dyad members also showed no significant correlation with their level of association. These findings suggest that unrelated pigs are capable of forming preferential associations. However, it is unclear whether such associations are widespread or important to pigs, since most dyads’ preferential associations were not consistent between pens.

Discourses on Modernization in the Employment Public Services: Towards a New Form of Governance?

The “crisis of the social issue” in the EU has led to a certain consensus in the need to renew the organizational and institutional model of public administration. The core of the reform implies important administrative changes in most of the European welfare states. Those changes are inspired on theories such as the new public management, management by objectives or partnership. Such changes involve both semantic (“sharing responsibilities”, “effective costs”, or the substitution of “citizen under an administration” by “consumer”) and political (predominance of scattered forms of power and the individualization of responsibilities) transformations which operate in the framework of individuals and State relations. The paradigms of activation and flexicurity have been central in this public administration modernization project. This commitment with new forms of governance of social issues has important consequences for the political and moral foundations of social cohesion, and the Spanish case is not an exception. This paper aims at looking at those representations of “modernization” (as they appear in debates about the employment services restructuring policies) in detail as well as providing references to the trajectory of such reforms of public services since the early eighties to the beginning of the crisis.