Prefrontal regions orchestrate suppression of emotional memories via a two-phase process

Whether memories can be suppressed has been a controversial issue in psychology and cognitive neuroscience for decades. We found evidence that emotional memories are suppressed via two time-differentiated neural mechanisms: (i) an initial suppression by the right inferior frontal gyrus over regions supporting sensory components of the memory representation (visual cortex, thalamus), followed by (ii) right medial frontal gyrus control over regions supporting multimodal and emotional components of the memory representation (hippocampus, amygdala), both of which are influenced by fronto-polar regions. These results indicate that memory suppression does occur and, at least in nonpsychiatric populations, is under the control of prefrontal regions.     

The Plasmodium falciparum genome--a blueprint for erythrocyte invasion

Erythrocyte invasion by Plasmodium falciparum involves multiple ligand-receptor interactions and numerous apparent redundancies. The genome sequence of this parasite reveals new gene families encoding proteins that appear to mediate erythrocyte invasion.     

Potential phytotoxicity of diquat accumulated by aquatic plants and sediments

The adsorption and desorption of Reglone A^R to freshwater algae, Myriophyllum spicatum and a soil-sand mixture, singly and in combination was examined to investigate the potential for phytotoxicity of diquat residues in aquatic sediments. The diquat adsorption capacity of the aquatic plants ranged from 0.6 to 2.4 mg diquat g dry wt^?1. Forty to seventy percent of the adsorbed diquat could be desorbed with 5 M ammonium chloride. The adsorption capacity of the soil system was about 2.5 mg diquat g dry wt^?1 and approximately 35% of this diquat could be desorbed. Reglone^R inhibited the growth of blue-green algae (Anabaena flos-aquae and Anacystis nidulans) at concentrations greater than 0.03 ppm. Eukaryotic algae were less sensitive, growth of Navicula pelliculosa was inhibited at concentrations exceeding 0.3 ppm and Chlorella vulgaris was unaffected by 3 ppm Reglone. In the presence of soil, growth inhibition by Reglone was eliminated. Reglone was added to a water-soil mixture system at levels up to 334 ppm to simulate chronic usage. Anabaena flos-aquae or Lemna sp. were used to bioassay the availability of the diquat adsorbed to this soil system. Significant growth inhibition of both bioassay plants was observed in soil treated with 33.4 ppm Reglone and the 334 ppm treatment was lethal. These experiments suggest that residual phytotoxicity becomes apparent in this soil system at about 7% of the diquat adsorption capacity. The Reglone adsorption-desorption isotherm of a natural, organic lake sediment was measured to predict the number of Reglone treatments at the recommended application rate before residual phytotoxicity would become apparent.     

Limb‐sparing in dogs using patient‐specific,three‐dimensional‐printed endoprosthesis for distal radial osteosarcoma: A pilot study

Limb‐sparing for distal radial osteosarcoma has a high rate of complications. Using personalized three‐dimensional (3D)‐printed implants might improve outcome. The goals of this study were to optimize use of patient‐specific, 3D‐printed endoprostheses for limb‐sparing in dogs in the clinical environment and to report the outcome. This was a pilot study where five client‐owned dogs were enrolled. Computed tomography (CT) of the thoracic limbs was performed, which was used to create patient‐specific endoprostheses and cutting guides, and repeated on the day of surgery. Intra‐arterial (IA) carboplatin was introduced in the clinical management. Limb‐sparing was performed. Outcome measures were time required to produce the endoprosthesis and cutting guide, fit between cutting guide and endoprosthesis with host bones, gait analysis, size of the tumour, percent tumour necrosis, complications, disease‐free interval (DFI) and survival time (ST). Four dogs received IA carboplatin. Excessive tumour growth between planning CT and surgery did not occur in any dog. The interval between the CT and surgery ranged from 14 to 70 days. Fit between the cutting‐guide and endoprosthesis with the host bones was good to excellent. At least one complication occurred in all dogs. Two dogs were euthanized with STs of 192 and 531 days. The other dogs were alive with a follow up of 534 to 575 days. IA chemotherapy is a promising strategy to minimize the risk of excessive tumour growth while waiting for the endoprosthesis and cutting‐guide to be made. The design of the cutting‐guide was critical for best fit of the endoprosthesis with host bones.     

Local management to support local fisheries: Rāhui (temporary closure) and bag limits for blackfoot abalone (Haliotis iris) in southern New Zealand

1. Spatially discrete stocks that vary in life history traits on a reef-to-reef scale present a challenge for fisheries managers. Nationally or regionally applied one-size-fits-all approaches to management fail to account for this variability, and when coupled with fishing pressure this can result in serial depletion and localized extinction.
2. Where mechanisms for local management exist, as they do in New Zealand via customary protection areas (Taiāpure Local Fisheries, Mātaitai Reserves), managers have the opportunity to trial tools on scales relevant to the stocks managed. This study assesses the effect of bag limits and a rāhui (temporary closure) in managing the spatially discrete, and culturally important, blackfoot abalone (Haliotis iris, pāua) in the East Otago Taiāpure, in southern New Zealand.
3. Using surveys spanning 8 years and 26 sites, the rāhui was found to have had mixed results: halting the decline in pāua density at 0 m but not 0.5 m depths. The rāhui did, however, result in an increase in the percentage of individuals above the minimum legal size at both depths.
4. Where bag limits alone had been applied, pāua densities and the percentage of legal-sized individuals continued to decline over the 8-year period, with the loss of large individuals, translating into a decline in estimated egg production.
5. Growth estimates from mark–recapture and surveys of juvenile abundance at sites inside and outside the rāhui highlight the fine-scale variability in pāua life history even within this local area. This suggests there may be biological impediments to pāua management using bag limits alone.
6. Though pāua restoration efforts have had mixed results to date, this study highlights the potential for legally empowered local managers and communities to respond to fisheries declines in their own local area in an action-driven, adaptable, and timely way.

     

Contrasting climate velocity impacts in warm and cool locations show that effects of marine warming are worse in already warmer temperate waters

Species responses to climate change are often measured at broad spatiotemporal scales, which can miss the fine-scale changes that are most relevant to conservation and fisheries management. We develop a scaleable geostatistical approach to assess how juvenile and adult fish distributions have been shaped by changes in bottom temperature and dissolved oxygen over a recent decade of warming in the northeast Pacific. Across 38 demersal fishes, biomass trends were associated negatively with warming and positively with dissolved oxygen, but when trends in both biomass and climate were converted to velocities—the speed and direction a population would have to move to maintain consistent conditions—the effect of temperature change differed depending on local conditions. In the warmest locations, warming velocities were associated with negative biotic velocities for 19 of 69 species-maturity combinations, and yet were almost always associated with stable or positive biotic velocities in the coolest locations (64 of 69). These spatially consistent biomass declines (negative biotic velocities) in the warmest locations and increases in cooler locations suggest a redistribution of species with the potential for new ecological and fisheries interactions. After controlling for temperature, the more spatially consistent effects of dissolved oxygen were often negative, suggesting a mechanism other than hypoxia avoidance—potentially changes in primary production. Our approach identifies the species and locations that are most sensitive to observed changes in the environment at any scale, thus facilitating future vulnerability assessments.     

A photographic-planimetric method for measuring bivalves

A simple photographic method is described for the accurate measurement of length and breadth in bivalves. The use of an electronic planimeter to measure planar area is also described.