Long-range Activity Research Articles

Activity of the German Cockroach, Blattella germanica (L.) (Orthoptera: Blattellidae), at Different Microhabitats in Semi-natural Conditions when Treated with Sublethal Doses of Chlorpyrifos and Permethrin *

Male adults of a mutant, or (orange body), and KNIH (Korea National Institute of Health) strains of the German cockroach, Blattella germanica (L.), were individually treated with chlorpyrifos and permethrin in sublethal doses. Local activity at different microhabitats for harborage, food, water, and other neighbor cockroaches was measured by observing visiting frequency for 4∼5 days continuously after the chemical treatment. Also long-range activity was observed by counting the number of crossing imaginary center-lines within the observation cage during the observation period. The local activity was generally decreased after the treatment of chemicals at most microhabitats. Trends of the activity observed in the control also appeared in response to the chemical treatments; local activity was the highest at harborage, and was low at the other microhabitats. The diel difference observed in the local activity, however, disappeared in the or strain by the treatment of both insecticides. Especially high values in local and long-range activity at scotophase were decreased greatly. In the KNIH strain, the local activity was less affected with chlorpyrifos. Diel difference persisted in the chlorpyrifos treatment, but disappeared in the permethrin treatment. The long-range activity was increased in the chlorpyrifos treatment in the KNIH strain.

Bmp-4 acts as a morphogen in dorsoventral mesoderm patterning in Xenopus.

The marginal zone is a ring of tissue that gives rise to a characteristic dorsoventral pattern of mesoderm in amphibian embryos. Bmp-4 is thought to play an important role in specifying ventral mesodermal fate. Here we show (1) that different doses of Bmp-4 are sufficient to pattern four distinct mesodermal cell types and to pattern gene expression in the early gastrula marginal zone into three domains, (2) that there is a graded requirement for a Bmp signal in mesodermal patterning, and (3) that Bmp-4 has long-range activity which can become graded in the marginal zone by the antagonizing action of noggin. The results argue that Bmp-4 acts as a morphogen in dorsoventral patterning of mesoderm.

Synergism between hypersensitive sites confers long-range gene activation by the beta-globin locus control region.

The human beta-globin locus control region (LCR) consists of four erythroid-specific DNaseI hypersensitive sites (HSs) at the 5' end of the beta-globin cluster. The LCR functions over a long distance on chromosome 11 to regulate transcription and replication of the beta-globin genes. To determine whether the HSs function independently or as an integrated unit, we analyzed the requirements for long-range transcriptional activation. If the HSs function independently, individual HSs would be expected to have long-range activity. In contrast, if long-range activity requires multiple HSs, individual HSs would have a limited functional distance. HS2, HS3, and a miniLCR containing multiple HSs, were separated from a gamma-globin promoter by fragments of phage lambda DNA. After stable transfection into K562 cells, HS2 had strong enhancer activity, but only when positioned close to the promoter. HS3 also had strong enhancer activity, although it was weaker than HS2 and more sensitive to the spacer DNA. The miniLCR had the strongest enhancer activity and functioned even at a distance of 7.3 kb. A model is proposed in which synergistic interactions between HSs confer long-range activation by creating a stable LCR nucleoprotein structure, which is competent for recruiting chromatin-modifying enzymes. These enzymes would mediate the well-characterized activity of the LCR to modulate chromatin structure.

Corporate-Supported Research in a Reengineered Technology Organization

A long-range research program complements the shorter-range technology activities that Chevron 's business units fund. OVERVIEW: As pressure to improve short-term financial performance has increased, longer-range research programs, particularly those at a corporate level, have fallen victim to cost-cutting initiatives. This development jeopardizes the technology base that sustains the corporation's businesses in both the short and long term. By designing a corporate longrange research program that is explicitly aligned with corporate business drivers, and the strategy of which is guided by management representatives from the major businesses, a credible and sustainable long-range research program can be developed. A key to success is an emphasis on transferring results of the longer-range program to specific business units as those results mature, and a metric to keep track of this transfer. The metric provides visible evidence of the relevance of the program to the business units of the corporation. In 1990, Chevron carried out a major reorganization and reorientation of the technology functions that support its downstream business. As has been the case with many other companies, this restructuring was part of a corporate-wide effort to reduce costs and improve the efficiency of business operations. The resulting technology organization, Chevron Research and Technology Company (CRTC), was closely aligned with the most important and immediate needs of Chevron's business units. As a part of this reorganization, CRTC evaluated the role and orientation of our corporate-supported research efforts. The result was a reinvigorated corporatesupported Long-Range Research Program that complements the more immediate focus of the technology activities that Chevron's business units fund in support of their individual businesses. The program ensures the health of the corporation's technologies which serve as a platform for the creation of competitive and distinguishing products and processes by a broad range of the company's businesses. In addition, it fosters the development of enabling technologies, often through collaborations with other technology providers, universities and national laboratories. Long-range research refers to research activities that are beyond the time frame or scope of the business plans of Chevron's individual operating companies. Typically, such research provides a foundation of technology from which several individual operating companies can develop specific competitive technologies and applications that can distinguish them from competitors, or it provides enabling technologies that can benefit a range of operating companies. There is no fixed time horizon for this research. The time horizon depends upon the nature and role of the technology and the nature of the particular business that would ultimately build on the results of long-range research to construct a technological position related to its business. Because the research is closely aligned with overall business strategy, individual operating companies often adopt results from the Long-Range Research Program in a relatively short term, even while the research program pursues ultimate goals that are longer term or of much higher risk. Key to Success Six factors have been key to the success of this longrange research program: Integration of the research work into the same organization that carries out shorter-term development and technical service work for the business units while providing for centralized management and accountability for the program as a whole. Strategic guidance by an advisory group composed of representatives from both CRTC and the management of Chevron's major operating companies. Recognition of a clear set of criteria that sets the longrange research activity apart from the shorter-term technology efforts funded directly by the business units. …

Genetic Evidence for a Long-Range Activity That Directs Pollen Tube Guidance in Arabidopsis.

The fertilization process of plants is governed by different kinds of cell-cell interactions. In higher plants, these interactions are required both for recognition of the pollen grain by the female reproductive system and to direct the growth of the pollen tube inside the ovary. Despite many years of study, the signaling mechanisms that guide the pollen tube toward its target, the ovule, are largely unknown. Two distinct types of principles, mechanical and chemotropic, have been suggested to account for the directed growth of the pollen tube. The first of these two types of models implies that the guidance of the pollen tube depends on the architecture and chemical properties of the female reproductive tissues, whereas the latter suggests that the ovule provides a signal for the target-directed growth of the pollen tube. To examine such a role for the ovules, we analyzed the growth path of pollen tubes in mutants defective in ovule development in Arabidopsis. The results presented here provide unique in vivo evidence for an ovule-derived, long-range activity controlling pollen tube guidance. A morphological comparison of the ovule mutants used in this study indicates that within the ovule, the haploid embryo sac plays an important role in this long-range signaling process.

Genetic Evidence for a Long-Range Activity That Directs Pollen Tube Guidance in Arabidopsis

Genetic Evidence for a Long-Range Activity That Directs Pollen Tube Guidance in Arabidopsis

The Origins of Tritium and Helium Effects on the Tensile Properties of Metals

In this paper, the effects of internal tritium and helium on the tensile properties of two austenitic stainless steels and an iron-based superalloys have been studied. The materials tested were, forged 21 Cr-6Ni-9Mn and 304L (tested in the annealed condition and tow forged conditions), and a modified A-286 alloy. The accumulation of {sup 3}He from the radioactive decay of tritium caused an increase in the yield strength and a continuous decrease in the ductility in almost all materials tested. Increased {sup 3}He concentrations also caused a change in fracture mode form ductile rupture to predominantly intergranular fracture. The property changes resulted from {sup 3}He bubble-induced strengthening, which produced a change in deformation mode form long-range dislocation activity to deformation twinning. In the deformation-twinning mode, the {sup 3}He-accelerated fracture initiated at the intersections of deformation twins with grain boundaries. High-strength forged 304L was most resistant to {sup 3}He effects owing to the redistribution of {sup 3}He on dislocations.

The infinite dilution short-range and long-range activity coefficient of ions in a solvent of polarizable hard spheres

The infinite dilution activity coefficient of ions in a solvent of polarizable hard spheres is divided into two parts: short range and long range. The ions are treated as hard spheres with point charges and the solvent molecules are treated as polarizable hard spheres. The diameters of ions may be different than the diameter of polarizable particles.

Material Compatibility and Systems Considerations in Thermal EOR Environments Containing High-Pressure Oxygen

Summary Corrosion is a concern in all thermal EOR projects. In oxygen firefloods, corrosion and the compatibility of metallic and nonmetallic materials with high-pressure oxygen have to be addressed. A materials-selection baseline is evolving from laboratory corrosion and compatibility testing performed to support ongoing oxygen-fireflood projects. Introduction Thermal techniques currently account for more than two-thirds of the oil recovered through EOR. Although steam dominates commercial production, air fireflooding also is used commercially. Oxygen fireflooding is relatively new and, depending on reservoir characteristics, can provide cost and process benefits over steam processes or air fireflooding. Greenwich Oil's Forest Hill project in Texas, which started in Nov. 1985, is the first commercial oxygen fireflood. This project uses an oxygen injection pressure of about 3,000 psi [20.7 MPa], while Canadian fireflooding pilots have used pressures of about 1,000 psi [6.9 MPa]. Higher pressures probably will be required for future applications. Surface systems to supply steam, air, and oxygen are commercially available, proven, and safe. While there are similarities in materials considerations for well equipment and tubulars for the three EOR techniques, important differences exist. Oxygen firefloods necessitate close attention to the particulars of materials per-formance. Therefore, technical cooperation between the oilfield per-formance. Therefore, technical cooperation between the oilfield operator and oxygen supplier regarding design and operating procedures for the oxygen injection system, injection wells, and procedures for the oxygen injection system, injection wells, and production wells is required to ensure durable and safe fireflood systems. production wells is required to ensure durable and safe fireflood systems. Corrosion resistance and oxygen compatibility are primary considerations in materials selection and design of systems durable enough for long-term oxygen firefloods. Accordingly, we have developed information on corrosion behavior, oxygen compatibility, and systems considerations to provide a sound basis for materials selection. This long-range activity has focused on the variables that affect these considerations. Materials Our ongoing program has included testing of a wide variety of materials for specific fireflood applications. Both downhole and surface systems were considered. Materials considerations for downhole equipment are site-specific because of such variances as reservoir fluid corrosivity, injection pressure, and oxygen purity. The alloys selected for this pressure, and oxygen purity. The alloys selected for this discussion (Table 1) represent a considerable variation in alloy content and relative cost. Because localized corrosion modes were considered significant in other studies, highly alloyed materials with increased molybdenum levels have been included. Fireflood systems require nonmetallic materials in such components as wellheads, valves, and packers. The compatibility of these materials with oxygen varies considerably. Table 2 shows the nonmetallics included in this study; hydrocarbon oil was included for comparisons and for demonstration of the effect of oxygen pressure on the autoignition characteristics of a hydrocarbon. pressure on the autoignition characteristics of a hydrocarbon.

Communication Research and Development Policy: Agenda Dynamics in an African Setting

It is essential to implement an overarching conceptual framework if the purposes of research and development in African communication are to be realized. communication research which adapts the framework of agenda dynamics to the African context can be pivotal in shaping the development strategies of the continent in a manner consistent with the identified goals. Agenda dynamics is an integrative model focusing on the internal dynamics of several different agendas as well as on the relationships among and external influences on them. In adapting the agenda-dynamics model to the African context it is necessary to identify the 6 agendas whose operation and interaction virtually define development communications: the small group or interpersonal agenda; the traditional media agenda; the urban media agenda; the opinion agendas of the urban elite and non-elite; and the public policy agenda. A focus on such agendas reinforces the significance of research fact finding and planning as forerunners of any long-range development activity. Other advantages of adapting this framework are identified. (authors modified)

Relations between El Nino/Southern Oscillation anomalies and wildland fire activity in the United States

The 1982–1983 El Nino resulted in climatic anomalies on a global scale, including record high wildland fire activity in Indonesia and record low activity in the United States. This paper describes the El Nino/Southern Oscillation phenomena and possible teleconnections to United States weather. Because precursors of an El Nino may be evident several months before the onset of an event, the phenomena has potential for long-range fire activity predictions. Using 53 years of data, we tested the hypothesis that El Nino events affect annual fire occurrence and area burned in the United States. We found a statistically significant relation between El Nino events and decreased fire activity in the South. Results for the North-Central and Eastern states are weak or inconsistent. There is no evidence for any relation with the Pacific Coast or Rocky Mountain states. Despite the coarse, exploratory nature of this study, the results are sufficiently encouraging to warrant more detailed examination.

Optical Tracking and Telemetry for Nocturnal Field Studies

A miniaturized optical telemetry transmitter for small animals was designed, constructed, and field-tested on free-ranging nocturnal crabs. The device produces accurately timed flashes that can be used for individual tagging, tracking, and telemetry. When observed with a night vision scope, the flashes are visible for several hundred meters. Transmitters are inexpensive, relative simple, and rugged. Weight is less than 1 g, and working life is about 4 weeks with 4 g of hearing aid batteries. J. WILDL. MANAGE. 41(2):309-312 Little information exists concerning the behavior and ecology of nocturnal animals, due to the difficulty of observing unrestrained subjects in the dark. The optical device described here was developed to overcome some of the limitations of radiotelemetry for a study of ghost crabs (Ocypode quadrata). Radiotelemetry has been used successfully for long-range tracking (Cochran and Lord 1963), activity monitoring (Knowlton et al. 1968, Osgood and Weigl 1972) and tracing movements of mice (Rawson and Hartline 1964) and voles (Chute et al. 1974). However, the fixes provided by radio, even of animals held in an enclosure under an antenna grid (Chute et al. 1974) are approximate due to the 2-6 m wavelengths used. It is virtually impossible to localize precisely free-ranging animals by radiotriangulation without disturbing them, due to the necessity of taking bearings from several positions at close range. Exact localization and direct observation of nocturnal behavior require seeing in the dark. The image intensifiers (starlight scopes) developed recently make this possible even in faint moonlight. Unfortunately most nocturnal animals are cryptically colored. Starlight scopes cannot create image contras where there is no target contrast; in fact, starlight scopes lose existing chromatic contrast by producing a monochromatic image. I found that ghost crabs, which are hard to see on their natural background by daylight, were impossible to see at night unless moving, even with a good-quality s arlig t cope (Noctron IV, Varo, Inc.). The circuit described here overcomes this difficulty by producing a timed flashing light, visible to the unaided eye at close ranges, and capable of extending the useful range of a starlight scope to distances at which the subject animal would be total y undetectable. In actual use it survived exposure to surf and sand, and permit ed individual recognition and tracking of crabs from distances of up to 300 m in the field, for periods of several weeks. The circuit is quite flexible, and may be modified to telemeter I channel of data.

Papain, vitamin A, lysosomes, and endotoxin. An essay on useful irrelevancies in the study of tissue damage.

I should say, at the outset, that this paper, with its rather tedious and—now that I think of it—essentially stuffy title, is not intended to clear up the matter of the inflammatory reaction. Indeed, I shall not even make a definition of inflammation, a term I have never really understood. I will not undertake to solve the Shwartzman reaction, even though this problem, like King Charles' head, has been stuck in my mind for over 15 years. These are, in my view, inviolable secrets of nature, designed by Providence to keep experimental pathologists contentedly engaged for whole lifetimes, and not to be solved. They are, in their way, assurances of long-range laboratory activity which are equivalent to Oliver Wendell Holmes' prescription for longevity: to have a chronic incurable disease and take good care of it. I hope, instead, to illustrate some of the ways in which biological systems, especially those