Connectivism: a knowledge learning theory for the digital age?

<b>Background</b> The emergence of the internet, particularly Web 2.0 has provided access to the views and opinions of a wide range of individuals opening up opportunities for new forms of communication and knowledge formation. Previous ways of navigating and filtering available information are likely to prove ineffective in these new contexts. Connectivism is one of the most prominent of the network learning theories which have been developed for e-learning environments. It is beginning to be recognised by medical educators. This paper aims to examine connectivism and its potential application.<p></p> <b>Content</b> The conceptual framework and application of connectivism are presented along with an outline of the main criticisms. Its’ potential application in medical education is then considered.<p></p> <b>Conclusions</b> While connectivism provides a useful lens through which teaching and learning using digital technologies can be better understood and managed, further development and testing is required. There is unlikely to be a single theory that will explain learning in technological enabled networks. Educators have an important role to play in online network learning

The analysis of plasmid rearrangements observed in the soil bacterium OR168 after the introduction of transposon Tn5 : a thesis presented in fulfilment of the requirements for the degree of Master of Science in Genetics at Massey University

Transposon Tn5 mutagenesis has been used extensively in Escherichia coli and various other Gram-negative bacteria to produce both random and site directed mutants. The popularity of Tn5 as a mutagen stems from its apparent random insertion into the genome, leading to non-leaky polar mutations. It also confers on many bacteria resistance to aminoglycosides, providing a strong selectable marker. The site of insertion can be mapped by Southern DNA hybridisation against a specific Tn5 probe. Tn5-containing derivatives of the Rhizobia-like soil isolate, OR168, were produced using the broad host-range suicide plasmid vector pSUP1011. After the transfer of pSUP1011 to OR168 via heterogeneric bacterial conjugation, stable OR168::Tn5 exconjugants were selectively isolated at frequencies of approximately 10-4 per recipient. None of the 53 OR168::Tn5 exconjugants screened showed the parental plasmid profile. Visible alterations to the plasmid profile were common with respect to the native plasmid profile. These events generally showed large deletions from, or additions to, the native replicons of OR168. The alterations also included a low incidence of a decrease in plasmid number. Analysis of the exconjugant population shows that the insertion of Tn5 into the genome of OR168 may not be strictly random. It was shown that 66% of OR168::Tn5 exconjugants screened contain a plasmid-borne Tn5 element, with 90% of those involving Tn5 insertion in the same episome. There is evidence that events other than classical conservative transposition have occurred after the introduction of pSUP1011 into the OR168 genome. Screening of the isolated OR168::Tn5 population for pSUP1011 vector sequences revealed the presence of the pSUP1011-derived RP4-mob fragment in 33 of 35 OR168::Tn5 exconjugants containing a plasmid-borne Tn5 element. Analysis also revealed the acquisition of Tn5 alone, presumably by conservative transposition, occurred only twice in the 35 events involving a plasmid target. This suggests that another site within the RP4 fragment can act as a surrogate transposase recognition site. Alternatively, the insertion of the RP4-mob::Tn5 sequence into a plasmid target may involve a site specific recombination process peculiar to the OR168 isolate. No mechanism was elucidated for the formation of many of the alterations in plasmid mobility. Restriction fragment lengths in the immediate vicinity of the anomalous RP4-mob::Tn5 insertion arc identical in different plasmids. This may indicate sequence duplication among the OR 168 plasmids. Such duplication may precipitate, through homologous recombination processes, the plasmid instability observed

Direct protonation of the W–H bonds of Bis(pentamethylcyclopentadienyl)tungsten dihydride

Protonation of (C_5Me_5)_2 WH_2 to give [(C_5Me_5)_2WH_3]+ is proposed to occur by attack at both W–H bonds rather than by direct attack at the d^2 metal centre

SMALL FARMS AND SUSTAINABLE DEVELOPMENT: IS SMALL MORE SUSTAINABLE?

A new, post-industrial, paradigm for agriculture is emerging under the concept of sustainable agriculture. The sustainability paradigm has emerged to solve problems created by the industrial model, primarily environmental pollution and resource base degradation. The role of farm size in this transformation to a more sustainable agriculture is the issue addressed. Using a descriptive approach, and relying on a survey of the literature including emerging paradigms and observations, we conclude that, from a sustainability perspective, the smallest effective size will be the most competitive size for farms, as for other knowledge-based enterprises of the future.Agriculture, Farm size, Paradigms, Sustainability, Environmental Economics and Policy, Farm Management,

International Comparison of the Sources of Productivity Slowdown 1973 1982

This paper uses an integrated model of aggregate supply to analyze the post-1973 slowdown in productivity growth in the seven major OECD economies. Factor substitution, unexpected demand changes, profitability, and inventory disequilibrium all contribute to the explanation, which is based on a three-factor nested aggregate production function, including energy, and postulating Harrod-neutral disembodied technical progress. The model is first applied separately to the seven countries assuming constant (though country-specific) rates of technical progress. This model provides empirical evidence that this rate of progress has in fact slowed down for several of the faster-growing countries, even after adjusting for factor substitution and cyclical factors. The model is therefore re-estimated, and the sources of productivity decline recalculated, on the hypothesis that rates of efficiency growth in other countries are converging to those in the United States.

Fraxinus pennsylvanica Marsh.

https://thekeep.eiu.edu/herbarium_specimens_byname/21154/thumbnail.jp

Acer nigrum Michx.f.

https://thekeep.eiu.edu/herbarium_specimens_byname/5783/thumbnail.jp