Operant conditioning of cortical steady potential responses in rats

This study was conducted to determine if amplitudes of rat corticol steady potential (SP) response to an auditory stimulus could be altered by operant conditioning procedures using food reinforcement. The negative SP responses to the 5-sec tone alone diminished with repeated presentation of the stimulus. When food reinforcement was given immediately following the tone, SP response amplitudes increased and stabilized after 4–5 sessions. Thereafter, the animals were required to increase or decrease the amplitudes of response in order to obtain reinforcement. Two of three rats required to increase amplitudes were successful and three of four rats required to decrease amplitudes were successful. It is concluded that changes in cortical SP responses can be operantly conditioned.     

The influence of water depth and flow regime on phytoplankton biomass and community structure in a shallow,lowland river

Hydrobiologia - The taxonomic composition and biomass of phytoplankton in the San Joaquin River, California, were examined in relation to water depth, flow regime, and water chemistry. Without...     

A review of malaria vaccine clinical projects based on the WHO rainbow table

Development and Phase 3 testing of the most advanced malaria vaccine, RTS,S/AS01, indicates that malaria vaccine R&D is moving into a new phase. Field trials of several research malaria vaccines have also confirmed that it is possible to impact the host-parasite relationship through vaccine-induced immune responses to multiple antigenic targets using different platforms. Other approaches have been appropriately tested but turned out to be disappointing after clinical evaluation. As the malaria community considers the potential role of a first-generation malaria vaccine in malaria control efforts, it is an apposite time to carefully document terminated and ongoing malaria vaccine research projects so that lessons learned can be applied to increase the chances of success for second-generation malaria vaccines over the next 10 years. The most comprehensive resource of malaria vaccine projects is a spreadsheet compiled by WHO thanks to the input from funding agencies, sponsors and investigators worldwide. This spreadsheet, available from WHO's website, is known as "the rainbow table". By summarizing the published and some unpublished information available for each project on the rainbow table, the most comprehensive review of malaria vaccine projects to be published in the last several years is provided below.     

Evolution of the electron Langmuir oscillations in an inhomogeneous magnetized plasma

The conditions under which the energy of the electron Langmuir oscillations can escape from the plasma into vacuum are determined in the simplest model of a plane slab of an inhomogeneous cold magnetized plasma in a uniform magnetic field.     

An evaluation of fMLP pocket dimensions and features using formyltetrapeptides.

The formyltetrapeptides for-Met-Leu-Leu-Phe-OMe 1, for-Met-Leu-Aib-Phe-OMe 2, for-Met-Leu-Ac6c-Phe-OMe 3, for-Met-Leu-Pro-Phe-OMe 4, for-Met-Pro-Pro-Phe-OMe 5, for-Met-Aib-Aib-Phe-OMe 6, for-Met-Pro-Aib-Phe-OMe 7 and for-Met-Aib-Pro-Phe-OMe 8 were synthesized and biologically tested on human neutrophils in an attempt to evaluate the specific receptor pocket dimensions and features. Our results indicate that the shift in the Phe residue to the fourth position in these compounds strongly reduces chemotactic response, but is efficacious in triggering superoxide anion production and lysozyme release (order of potency 3 > 2 > 1 > 4 > 6 > 8 > 5 > 7). The potency of the two latter responses correlates well with the affinity data obtained in binding experiments.