We use comparable micro level panel data for 14 countries and a set of identically specified empirical models to investigate the relationship between exports and productivity. Our overall results are in line with the big picture that is by now familiar from the literature: exporters are more productive than non-exporters when observed and unobserved heterogeneity is controlled for, and these ex...

Lipopolysaccharide (LPS) extracts obtained from Treponema hyodysenteriae of serogroups A, B, D and E, and from T. innocens were examined by SDS-polyacrylamide gel electrophoresis (SDS-PAGE), silver-staining, and immunoblotting with hyperimmune rabbit sera. All organisms possessed multiple LPS bands, but their position and number differed. Immunoblotting of LPS with grouping sera identified thre...

We investigate issues surrounding an old question of Yates’ as to the existence of a minimal degree with no strong minimal cover, specifically with respect to the hyperimmune-free degrees.

We give natural examples of factors of the Muchnik lattice which capture intuitionistic propositional logic (IPC), arising from the concepts of lowness, 1-genericity, hyperimmune-freeness and computable traceability. This provides a purely computational semantics for IPC.

BACKGROUND Brucellosis is the most common bacterial zoonosis, and serological tests are routinely used in brucellosis control and eradication programs. In order to improve the accuracy of serological diagnostic method used in bovine brucellosis detection, this study developed an improved competitive ELISA with higher specificity and good sensitivity. RESULTS This study prepared 12 monoclonal ...

brain derived neurotrophic factor (bdnf) is a neurotrophin acting at several levels in the brain. additionally, bdnf was shown to be responsible for the survival, maintenance and growth of neurons. also, bdnf plays an important role in synaptic plasticity and memory processes. in activity-dependent synaptic plasticity, bdnf enhances long-term potentiation (ltp) in the hippocampus but blocks the...