Effects of ⁶⁰Co gamma irradiation on the reproductive performance of the brine shrimp, Artemia

The brine shrimp, Artemia, was used as an experimental organism to study the effects of ⁶⁰Co gamma irradiation on the reproductive performance of an animal population. The total reproductive ability of the brine shrimp was fractionated into various components and the effects of irradiation on each of these components was then determined by studies of reproductive behavior in individual pair matings. In this study, the components identified were the number of broods produced per pair, the number of nauplii voided per pair, the number of nauplii voided per brood, the survival of nauplii to sexual maturity, the number of mature adults produced per brood, and finally the number of mature adults produced per pair. All component parameters of total reproductive performance were shown to be affected by irradiation. However, the number of broods per pair was shown to be the factor most affected by doses of 1200 rads or less. The final parameter, the number of mature adults produced per pair, is really the measurement of the net reproductive potential of Artemia. The net reproduction was also examined by making counts of the total population contained in three liter population cultures, and contrasted to the results obtained with the pair mating studies. It was demonstrated that the population cultures may be maintained by using only a small part of the reproductive potential exhibited in the pair matings. Therefore, we find that the results of pair matings must necessarily be used to assess the amount that the reproductive potential of Artemia is decreased due to various doses of irradiation. It was determined that for Artemia irradiated at the most sensitive stage, a dose of 2100 rads produced sterility. At less sensitive stages, more than 3000 rads would be required to produce sterility. In a single experiment, Artemia irradiated with 300 rads gave an indication of a slight enhancement of reproductive ability as compared to the control animals. In all cases, doses of 600 rads or less showed little effect on the reproductive ability of this species

Houve um holocausto chileno? Campos de concentração, genocídio político e a ditadura de Pinochet

This essay discusses the Pinochet Dictatorship’s human rights violations. We argue that the Chilean military’s torture, disappearance, and execution of a significant part of its population, with development of a State terrorism and institutionalized racist practices constitute a holocaust. The U.S.-sponsored military regime killed with an allconsuming ideological obsession, and displayed a bureaucratic dedication to eliminating communism.Este ensaio discute as violações de direitos humanos na ditadura Pinochet. Argumentamos que a tortura, desaparecimento e execução de milhares de chilenos pelos militares, com implantação de terrorismo de Estado e práticas racistas institucionalizadas, constituem um “holocausto”. Patrocinado pelos EUA, o regime militar matou com uma obsessão ideológica destruidora e mostrou eficiência burocrática para eliminar o comunismo

A grab-sample study of the benthic invertebrates of the Columbia River Estuary

The report provides benthic invertebrate densities and sediment texture data for 48 stations in the Columbia River estuary (Columbia River mile 0-28) sampled by grab sampler between 31 August 1975 and 22 January 1976

Implementation and performance of SIBYLS: a dual endstation small-angle X-ray scattering and macromolecular crystallography beamline at the Advanced Light Source.

The SIBYLS beamline (12.3.1) of the Advanced Light Source at Lawrence Berkeley National Laboratory, supported by the US Department of Energy and the National Institutes of Health, is optimized for both small-angle X-ray scattering (SAXS) and macromolecular crystallography (MX), making it unique among the world's mostly SAXS or MX dedicated beamlines. Since SIBYLS was commissioned, assessments of the limitations and advantages of a combined SAXS and MX beamline have suggested new strategies for integration and optimal data collection methods and have led to additional hardware and software enhancements. Features described include a dual mode monochromator [containing both Si(111) crystals and Mo/B(4)C multilayer elements], rapid beamline optics conversion between SAXS and MX modes, active beam stabilization, sample-loading robotics, and mail-in and remote data collection. These features allow users to gain valuable insights from both dynamic solution scattering and high-resolution atomic diffraction experiments performed at a single synchrotron beamline. Key practical issues considered for data collection and analysis include radiation damage, structural ensembles, alternative conformers and flexibility. SIBYLS develops and applies efficient combined MX and SAXS methods that deliver high-impact results by providing robust cost-effective routes to connect structures to biology and by performing experiments that aid beamline designs for next generation light sources

The novel MAPT mutation K298E:mechanisms of mutant tau toxicity, brain pathology and tau expression in induced fibroblast-derived neurons

Frontotemporal lobar degeneration (FTLD) consists of a group of neurodegenerative diseases characterized by behavioural and executive impairment, language disorders and motor dysfunction. About 20-30 % of cases are inherited in a dominant manner. Mutations in the microtubule-associated protein tau gene (MAPT) cause frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17T). Here we report a novel MAPT mutation (K298E) in exon 10 in a patient with FTDP-17T. Neuropathological studies of post-mortem brain showed widespread neuronal loss and gliosis and abundant deposition of hyperphosphorylated tau in neurons and glia. Molecular studies demonstrated that the K298E mutation affects both protein function and alternative mRNA splicing. Fibroblasts from a skin biopsy of the proband taken at post-mortem were directly induced into neurons (iNs) and expressed both 3-repeat and 4-repeat tau isoforms. As well as contributing new knowledge on MAPT mutations in FTDP-17T, this is the first example of the successful generation of iNs from skin cells retrieved post-mortem

Biological baseline data, Youngs Bay, Oregon, 1974

This report presents biological baseline information gathered during the research project, "Physical, Chemical and Biological Studies on Youngs Bay." Youngs Bay is a shallow embayment located on the south shore of the Columbia River, near Astoria, Oregon. Nearby portions of the Youngs River, Lewis and Clark River, Columbia River, and Skipanon Waterway were also included in the study

2007 Annual progress report synopsis of the Center for Structures of Membrane Proteins

A synopsis of the 2007 annual progress report for the Center for Structures of Membrane Proteins, a specialized center of the Protein Structure Initiative

Analysis of benthic infauna communities and sedimentation patterns of a proposed fill site and nearby regions in the Columbia River Estuary

The Port of Astoria has proposed to fill a 32.4 hectare inter- and subtidal area at the mouth of Youngs Bay, Columbia River, Oregon. The possible effects of this fill on the biota and sedimentation patterns of this area were studied from 31 August 1975 to 29 February 1976. Part I, the biological studies, analyzed the quantity of benthic life at the fill site in comparison to that in the lower 28 miles of the Columbia River estuary. The sediment textures of benthos samples were analyzed to determine sediment-fauna relations; salinity-temperature measurements were made at selected sites. Fish life at the fill site was also sampled to determine species composition and the relation of fish stomach contents to benthic life. Studies on sedimentation patterns (based on dredging records, photographs, and sediment samples taken in Slip 2 of the port docks) aimed at identifying undesirable sediment deposits which might occur because of the fill. The dominant benthic taxa at most stations were amphipods and polychaetes, although oligochaetes were abundant at some muddy stations. Amphipod densities in the lower river varied from about 200/m2 in deep areas to between 5,000 and 50,000/m2 in shallow, fine sediment areas such as Youngs Bay and extensive shoaling areas. These areas of high density, which include the fill site, were dominated by the tube-building amphipod Corophium. Twenty-five species of fish have been captured in this and previous work in Youngs Bay. Food habit studies have shown Corophium to be eaten in large quantities by many of these species. Using density estimates and river bathymetry as guides, it was very roughly estimated that 0.8 percent of the amphipod standing crop in the study area (CRM 0-28) occurred at the fill site, which represents 0.09 percent of this area. Net sediment transport seems to be from the Columbia River into Youngs Bay, but transport out of Youngs Bay does occur and may contribute greatly to sediment deposition in Slips 1 and 2. Sediment samples from Slip 2 were mud, but this changed abruptly to coarse sand at the slip mouth. This shows that slip sediments arise from suspended fine mud and not from coarser-grained bed-load sediments. There is little that can be done to prevent such deposition. The proposed extension would probably not affect this problem, but might alter the flow of water around the port. More extensive investigations of circulation and suspended sediment content should be made

Ecological and radioecological studies in the Columbia River Estuary and adjacent Pacific Ocean

This report represents the progress in "Ecological and Radioecological Studies in the Columbia River Estuary and Adjacent Pacific Ocean" for the period 1 April 1975 through 31 March 1976. This research has been supported with funds from the Division of Biomedical and Environmental Research, U.S. Energy Research and Development Administration through Contract AT(45-1)-2227, Task Agreement 12. Our current research activities are dealt with in a descriptive fashion in the section on Research in Progress. The Research Completed section of the report includes manuscripts which have been submitted for publication during the reporting period, as well as reprints of papers published during this same period