Argonne National Laboratory Reports

The germanium-lithium argon scanning system (GLASS) was installed in EBR-II to monitor and analyze the gamma activity of the reactor cover gas and the reactor building air. GLASS has the capability to identify and measure 20 or more gamma peaks. Applied to the reactor cover gas, this capability has proven useful in identifying the source of fission-gas leakage from fuel elements. The gamma-peak data can clearly distinguish a carbide-fuel source from an oxide-fuel source and can often help distinguish and oxide-fuel source from a metallic-fuel source

DESIGN AND HAZARDS REPORT FOR THE ARGONNE FAST SOURCE REACTOR (AFSR)

The Argonne Fast Source Reactor is designed to operate at low power (nominally 1000 watts) to supply neutron fluxes, both fast and thermal, for laboratory experiments. It is built around a cylindrical core (with vertical axis) of solid, highly enriched uranium approximately 4 1/2 in. in diam. by 4/4 in. high. The blanket is of solid depleted uranium with a minimum thickness of eight in.; its outer form is cylindrical, 20 5/8 in. in diam. by 20 5/8 in. high. The reactor, contained in a shield of high density concrete of minimum thickness 4 1/2 ft, is freestanding on the floor of the reactor building. A graphite thermal column 4 x 4 x 6 ft is provided. All control and safety mechanisms are located in a pit beneath the reactor. The hazards associated with operation of the reactor have been analyzed. A number of potentially dangerous circumstances were studied to determine the probable severity of the resultant excursions. As an upper limit, a detailed study was made of the extreme case in which the reactor, overloaded by five kilograms of U/sup 235/, goes critical at the air cylinder speed of 18 in./min. It is estimated that the excursion would amount to 3.6 x 10/sup 17/ fissions. This is expected to destroy the core and eject all core material into the pit where it burns, greatly adding to the total energy of the excursion. No rupture of reactor shield or building is expected. The reactor pit and reactor building will be heavily contaminated and some radioactive material will escape from the building. It is nearly certain that the maximum radiation dose to personnel outside the reactor building will not exceed 15 roentgens. (auth

Applications of a versatile new instrument module

The authors have found a number of interesting applications for the Pulse Arrival Time Recording Module (PATRM). This CAMAC module is capable of recording the arrival time of up to 4 million pulses. The result is a list of 32-bit binary numbers in which each number represents the arrival time of a single pulse expressed in terms of the number of {open_quotes}ticks{close_quotes} of a 10MHz clock which have elapsed since the beginning of the count. The versatility arises from the fact that the data list can be analyzed by whatever algorithm the authors can put into software, and that they can {open_quotes}play it back{close_quotes} as many times as desired. The authors already have the following applications: (1) Neutron multiplicity counting in waste assay. (2) Study of dead-time recovery and double pulsing in individual channels. (3) Auto-correlation analysis for Rossi-{alpha} measurements in critical systems. (4) Variable channel width multichannel scaler for delayed neutron counting. (5) Cross-correlation analysis and conventional multi-scaling. (6) Time dependent multiplicity measurements during neutron interrogation. The authors expect in the coming year to test an updated version of the PATRM which will incorporate a 100MH clock and label each pulse with the channel from which it came. The device will be configured as a single PC card installable in any high performance IBM type computer

Coupled ecological and management connectivity across administrative boundaries in undeveloped landscapes

Human-induced ecological boundaries, or anthropogenic ecotones, may arise where administrative boundaries meet on undeveloped lands. Landscape-level ecological processes related to factors such as fire, invasive species, grazing, resource extraction, wildlife, and water may be affected due to unique management strategies adopted by each administrative unit. Over time, different management can result in discernible ecological differences (e.g., species composition or soil characteristics). Thus, fragmentation in the management landscape can correspond to ecological fragmentation. Different ecological patterns may emerge due to an increase in the number of management units in a region, or due to an increase in the number of different types of management units in the region. Temporal effects and collaboration history can also affect the emergence of ecotones. We use conceptual models to explore the relationship between these aspects of management fragmentation and the anthropogenic ecotones between management parcels. We then use examples of different management challenges to explore how anthropogenic ecotones can disrupt ecological flows. Our models suggest that cross-boundary collaboration that enhances management connectivity is likely essential to ecological connectivity in the face of environmental and social change

Quantifying ecological variation across jurisdictional boundaries in a management mosaic landscape

Context Large landscapes exhibit natural heterogeneity. Land management can impose additional variation, altering ecosystem patterns. Habitat characteristics may reflect these management factors, potentially resulting in habitat differences that manifest along jurisdictional boundaries. Objectives We characterized the patchwork of habitats across a case study landscape, the Grand Canyon Protected Area-Centered Ecosystem. We asked: how do ecological conditions vary across different types of jurisdictional boundaries on public lands? We hypothesized that differences in fire and grazing, because they respond to differences in management over time, contribute to ecological differences by jurisdiction. Methods We collected plot-scale vegetation and soils data along boundaries between public lands units surrounding the Grand Canyon. We compared locations across boundaries of units managed differently, accounting for vegetation type and elevation differences that pre-date management unit designations. We used generalized mixed effects models to evaluate differences in disturbance and ecology across boundaries. Results Jurisdictions varied in evidence of grazing and fire. After accounting for these differences, some measured vegetation and soil properties also differed among jurisdictions. The greatest differences were between US Forest Service wilderness and Bureau of Land Management units. For most measured variables, US Forest Service non-wilderness units and National Park Service units were intermediate. Conclusions In this study, several ecological properties tracked jurisdictional boundaries, forming a predictable patchwork of habitats. These patterns likely reflect site differences that pre-date jurisdictions as well as those resulting from different management histories. Understanding how ecosystem differences manifest at jurisdictional boundaries can inform resource management, conservation, and cross-boundary collaborations

Impact of the roll out of comprehensive emergency obstetric care on institutional birth rate in rural Nepal

© 2017 The Author(s). Background: Increasing institutional births rates and improving access to comprehensive emergency obstetric care are central strategies for reducing maternal and neonatal deaths globally. While some studies show women consider service availability when determining where to deliver, the dynamics of how and why institutional birth rates change as comprehensive emergency obstetric care availability increases are unclear. Methods: In this pre-post intervention study, we surveyed two exhaustive samples of postpartum women before and after comprehensive emergency obstetric care implementation at a hospital in rural Nepal. We developed a logistic regression model of institutional birth factors through manual backward selection of all significant covariates within and across periods. Qualitatively, we analyzed birth stories through immersion crystallization. Results: Institutional birth rates increased after comprehensive emergency obstetric care implementation (from 30 to 77%, OR 7.7) at both hospital (OR 2.5) and low-level facilities (OR 4.6, p < 0.01 for all). The logistic regression indicated that comprehensive emergency obstetric care availability (OR 5.6), belief that the hospital is the safest birth location (OR 44.8), safety prioritization in decision-making (OR 7.7), and higher income (OR 1.1) predict institutional birth (p ≤ 0.01 for all). Qualitative analysis revealed comprehensive emergency obstetric care awareness, increased social expectation for institutional birth, and birth planning as important factors. Conclusion: Comprehensive emergency obstetric care expansion appears to have generated significant demand for institutional births through increased safety perceptions and birth planning. Increasing comprehensive emergency obstetric care availability increases birth safety, but it may also be a mechanism for increasing the institutional birth rate in areas of under-utilization

Ganglioside composition and histology of a spontaneous metastatic brain tumour in the VM mouse

Glycosphingolipid abnormalities have long been implicated in tumour malignancy and metastasis. Gangliosides are a family of sialic acid-containing glycosphingolipids that modulate cell–cell and cell–matrix interactions. Histology and ganglioside composition were examined in a natural brain tumour of the VM mouse strain. The tumour is distinguished from other metastatic tumour models because it arose spontaneously and metastasizes to several organs including brain and spinal cord after subcutaneous inoculation of tumour tissue in the flank. By electron microscopy, the tumour consisted of cells (15 to 20 μm in diameter) that had slightly indented nuclei and scant cytoplasm. The presence of smooth membranes with an absence of junctional complexes was a characteristic ultrastructural feature. No positive immunostaining was found for glial or neuronal markers. The total ganglioside sialic acid content of the subcutaneously grown tumour was low (12.6 ± 0.9 μg per 100 mg dry wt, n= 6 separate tumours) and about 70% of this was in the form of N-glycolylneuraminic acid. In contrast, the ganglioside content of the cultured VM tumour cells was high (248.4 ± 4.4 μg, n= 3) and consisted almost exclusively of N-acetylneuraminic acid. The ganglioside pattern of the tumour grown subcutaneously was complex, while GM3, GM2, GM1, and GD1a were the major gangliosides in the cultured tumour cells. This tumour will be a useful natural model for evaluating the role of gangliosides and other glycolipids in tumour cell invasion and metastasis. © 2001 Cancer Research Campaign http://www.bjcancer.co