Particulate amino acids in the sea: Effects of primary productivity and biological decomposition

We measured the flux of amino acids associated with sinking particles collected by sediment traps at two Pacific Ocean sites. These results were compared with results from six other sites where we and others have measured amino acid fluxes. This comparison shows that the flux of amino acids on sinking particles is related to primary productivity. This relationship exists in spite of differences in the oceanic regimes sampled and in the sediment traps, bactericides, and amino acid analysis techniques used. The amount of particulate amino acids leaving the euphotic zone in areas of higher productivity is a higher proportion of the primary production than in less productive areas. And, a larger amount of particulate amino acids reaches deeper waters in more productive areas. However, the particulate amino acids leaving the euphotic zone decompose faster with depth in more productive areas. Faster decomposition below the surface waters in areas of high productivity suggests that (1) decomposition of particulate organic matter may be mediated more by zooplankton and less by microbial processes than in areas of lower productivity, or (2) phytoplankton growing in more productive areas are more easily remineralized than those growing in less productive areas

The vertical flux of particulate organic nitrogen in the sea: Decomposition of amino acids in the Peru upwelling area and the equatorial Atlantic

Marine particulate matter samples were collected in moored and free-drifting sediment traps deployed off the coast of Peru during February, 1978. Three types of amino acids were analyzed in these samples: free extractable amino acids (FEA), hydrolyzed extractable amino acids (HEA) and total hydrolyzed amino acids (fHA). FEA and HEA were also analyzed in moored trap samples from the PARFLUX E station in the equatorial Atlantic Ocean...

A Second-Generation Device for Automated Training and Quantitative Behavior Analyses of Molecularly-Tractable Model Organisms

A deep understanding of cognitive processes requires functional, quantitative analyses of the steps leading from genetics and the development of nervous system structure to behavior. Molecularly-tractable model systems such as Xenopus laevis and planaria offer an unprecedented opportunity to dissect the mechanisms determining the complex structure of the brain and CNS. A standardized platform that facilitated quantitative analysis of behavior would make a significant impact on evolutionary ethology, neuropharmacology, and cognitive science. While some animal tracking systems exist, the available systems do not allow automated training (feedback to individual subjects in real time, which is necessary for operant conditioning assays). The lack of standardization in the field, and the numerous technical challenges that face the development of a versatile system with the necessary capabilities, comprise a significant barrier keeping molecular developmental biology labs from integrating behavior analysis endpoints into their pharmacological and genetic perturbations. Here we report the development of a second-generation system that is a highly flexible, powerful machine vision and environmental control platform. In order to enable multidisciplinary studies aimed at understanding the roles of genes in brain function and behavior, and aid other laboratories that do not have the facilities to undergo complex engineering development, we describe the device and the problems that it overcomes. We also present sample data using frog tadpoles and flatworms to illustrate its use. Having solved significant engineering challenges in its construction, the resulting design is a relatively inexpensive instrument of wide relevance for several fields, and will accelerate interdisciplinary discovery in pharmacology, neurobiology, regenerative medicine, and cognitive science

A Genome-wide Drosophila Screen for Heat Nociception Identifies α2δ3 as an Evolutionarily Conserved Pain Gene

Worldwide, acute and chronic pain affects 20% of the adult population and represents an enormous financial and emotional burden. Using genome-wide neuronal-specific RNAi knock-down in Drosophila, we report a global screen for an innate behavior and identify hundreds of novel genes implicated in heat nociception, including the α2δ-family calcium channel subunit straightjacket (stj). Mice mutant for the stj ortholog CACNA2D3 (α2δ3) also exhibit impaired behavioral heat pain sensitivity. In addition, in humans, α2δ3 SNP variants associate with reduced sensitivity to acute noxious heat and chronic back pain. Functional imaging in α2δ3 mutant mice revealed impaired transmission of thermal pain evoked signals from the thalamus to higher order pain centers. Intriguingly, in α2δ3 mutant mice thermal pain and tactile stimulation triggered strong cross-activation or synesthesia of brain regions involved in vision, olfaction, and hearing

Applying behavioral insights to increase rural and remote internships: Results from two Randomized Controlled Trials

Worldwide, organizations struggle to attract professionals in rural and remote (R&R) areas. Undertaking a placement in an R&R area as part of a program of study has been shown to increase the likelihood of graduates taking up positions in locations that are difficult to staff. We applied behavioral insights to develop low cost, scalable interventions to encourage pre-service teachers to undertake internships in R&R areas of Australia. We tested the effectiveness of removing behavioral barriers when researching R&R areas and adding social triggers to make the R&R opportunity relevant. Our first randomized controlled trial (RCT) tested the use of personalized communication from an influential messenger to highlight the benefits of an R&R internship. Our second RCT tested the offer of social support by allowing pre-service teachers to complete the R&R internship with a “buddy”, rather than alone. Our behavioral approaches trebled R&R internship applications in RCT 1. These findings provide insights for cost-effectively increasing R&R internships in teaching, healthcare or social work