Science.gov

Sample records for biological isru implications

  1. Developing Biological ISRU: Implications for Life Support and Space Exploration

    NASA Technical Reports Server (NTRS)

    Brown, I. I.; Allen, C. C.; Garrison, D. H.; Sarkisova, S. A.; Galindo, C.; Mckay, David S.

    2010-01-01

    Main findings: 1) supplementing very dilute media for cultivation of CB with analogs of lunar or Martian regolith effectively supported the proliferation of CB; 2) O2 evolution by siderophilic cyanobacteria cultivated in diluted media but supplemented with iron-rich rocks was higher than O2 evolution by same strain in undiluted medium; 3) preliminary data suggest that organic acids produced by CB are involved in iron-rich mineral dissolution; 4) the CB studied can accumulate iron on and in their cells; 4) sequencing of the cyanobacterium JSC-1 genome revealed that this strain possesses molecular features which make it applicable for the cultivation in special photoreactors on Moon and Mars. Conclusion: As a result of pilot studies, we propose, to develop a concept for semi-closed integrated system that uses CB to extract useful elements to revitalize air and produce valuable biomolecules. Such a system could be the foundation of a self-sustaining extraterrestrial outpost (Hendrickx, De Wever et al., 2005; Handford, 2006). A potential advantage of a cyanobacterial photoreactor placed between LSS and ISRU loops is the possibility of supplying these systems with extracted elements and compounds from the regolith. In addition, waste regolith may be transformed into additional products such as methane, biomass, and organic and inorganic soil enrichment for the cultivation of higher plants.

  2. The role of synthetic biology for in situ resource utilization (ISRU).

    PubMed

    Montague, Michael; McArthur, George H; Cockell, Charles S; Held, Jason; Marshall, William; Sherman, Louis A; Wang, Norman; Nicholson, Wayne L; Tarjan, Daniel R; Cumbers, John

    2012-12-01

    A persistent presence in space can either be supported from Earth or generate the required resources for human survival from material already present in space, so called "in situ material." Likely, many of these resources such as water or oxygen can best be liberated from in situ material by conventional physical and chemical processes. However, there is one critical resource required for human life that can only be produced in quantity by biological processes: high-protein food. Here, recent data concerning the materials available on the Moon and common asteroid types is reviewed with regard to the necessary materials to support the production of food from material in situ to those environments. These materials and their suitability as feedstock for the biological production of food are reviewed in a broad and general way such that terminology that is often a barrier to understanding such material by interdisciplinary readers is avoided. The waste products available as in situ materials for feasibility studies on the International Space Station are also briefly discussed. The conclusion is that food production in space environments from in situ material proven to exist there is quite feasible.

  3. The role of synthetic biology for in situ resource utilization (ISRU).

    PubMed

    Montague, Michael; McArthur, George H; Cockell, Charles S; Held, Jason; Marshall, William; Sherman, Louis A; Wang, Norman; Nicholson, Wayne L; Tarjan, Daniel R; Cumbers, John

    2012-12-01

    A persistent presence in space can either be supported from Earth or generate the required resources for human survival from material already present in space, so called "in situ material." Likely, many of these resources such as water or oxygen can best be liberated from in situ material by conventional physical and chemical processes. However, there is one critical resource required for human life that can only be produced in quantity by biological processes: high-protein food. Here, recent data concerning the materials available on the Moon and common asteroid types is reviewed with regard to the necessary materials to support the production of food from material in situ to those environments. These materials and their suitability as feedstock for the biological production of food are reviewed in a broad and general way such that terminology that is often a barrier to understanding such material by interdisciplinary readers is avoided. The waste products available as in situ materials for feasibility studies on the International Space Station are also briefly discussed. The conclusion is that food production in space environments from in situ material proven to exist there is quite feasible. PMID:23140229

  4. In-Situ Resource Utilization (ISRU) Capability Roadmap Progress Review

    NASA Technical Reports Server (NTRS)

    Sanders, Gerald B.; Duke, Michael

    2005-01-01

    A progress review on In-Situ Resource Utilization (ISRU) capability is presented. The topics include: 1) In-Situ Resource Utilization (ISRU) Capability Roadmap: Level 1; 2) ISRU Emphasized Architecture Overview; 3) ISRU Capability Elements: Level 2 and below; and 4) ISRU Capability Roadmap Wrap-up.

  5. In-situ Resource Utilization (ISRU) and Lunar Surface Systems

    NASA Technical Reports Server (NTRS)

    Sanders, Jerry; Larson, Bill; Sacksteder, Kurt

    2007-01-01

    This viewgraph presentation reviews the benefits of In-Situ Resource Utilization (ISRU) on the surface of the moon. Included in this review is the commercialization of Lunar ISRU. ISRU will strongly influence architecture and critical technologies. ISRU is a critical capability and key implementation of the Vision for Space Exploration (VSE). ISRU will strongly effects lunar outpost logistics, design and crew safety. ISRU will strongly effect outpost critical technologies. ISRU mass investment is minimal compared to immediate and long-term architecture delivery mass and reuse capabilities provided. Therefore, investment in ISRU constitutes a commitment to the mid and long term future of human exploration.

  6. Microchannel Reactors for ISRU Applications

    NASA Astrophysics Data System (ADS)

    Carranza, Susana; Makel, Darby B.; Blizman, Brandon; Ward, Benjamin J.

    2005-02-01

    Affordable planning and execution of prolonged manned space missions depend upon the utilization of local resources and the waste products which are formed in manned spacecraft and surface bases. Successful in-situ resources utilization (ISRU) will require component technologies which provide optimal size, weight, volume, and power efficiency. Microchannel reactors enable the efficient chemical processing of in situ resources. The reactors can be designed for the processes that generate the most benefit for each mission. For instance, propellants (methane) can be produced from carbon dioxide from the Mars atmosphere using the Sabatier reaction and ethylene can be produced from the partial oxidation of methane. A system that synthesizes ethylene could be the precursor for systems to synthesize ethanol and polyethylene. Ethanol can be used as a nutrient for Astrobiology experiments, as well as the production of nutrients for human crew (e.g. sugars). Polyethylene can be used in the construction of habitats, tools, and replacement parts. This paper will present recent developments in miniature chemical reactors using advanced Micro Electro Mechanical Systems (MEMS) and microchannel technology to support ISRU of Mars and lunar missions. Among other applications, the technology has been demonstrated for the Sabatier process and for the partial oxidation of methane. Microchannel reactors were developed based on ceramic substrates as well as metal substrates. In both types of reactors, multiple layers coated with catalytic material are bonded, forming a monolithic structure. Such reactors are readily scalable with the incorporation of extra layers. In addition, this reactor structure minimizes pressure drop and catalyst settling, which are common problems in conventional packed bed reactors.

  7. Minimizing Launch Mass for ISRU Processes

    NASA Technical Reports Server (NTRS)

    England, C.; Hallinan, K. P.

    2004-01-01

    The University of Dayton and the Jet Propulsion Laboratory are developing a methodology for estimating the Earth launch mass (ELM) of processes for In-Situ Resource Utilization (ISRU) with a focus on lunar resource recovery. ISRU may be enabling for both an extended presence on the Moon, and for large sample return missions and for a human presence on Mars. To accomplish these exploration goals, the resources recovered by ISRU must offset the ELM for the recovery process. An appropriate figure of merit is the cost of the exploration mission, which is closely related to ELM. For a given production rate and resource concentration, the lowest ELM - and the best ISRU process - is achieved by minimizing capital equipment for both the ISRU process and energy production. ISRU processes incur Carnot limitations and second law losses (irreversibilities) that ultimately determine production rate, material utilization and energy efficiencies. Heat transfer, chemical reaction, and mechanical operations affect the ELM in ways that are best understood by examining the process's detailed energetics. Schemes for chemical and thermal processing that do not incorporate an understanding of second law losses will be incompletely understood. Our team is developing a methodology that will aid design and selection of ISRU processes by identifying the impact of thermodynamic losses on ELM. The methodology includes mechanical, thermal and chemical operations, and, when completed, will provide a procedure and rationale for optimizing their design and minimizing their cost. The technique for optimizing ISRU with respect to ELM draws from work of England and Funk that relates the cost of endothermic processes to their second law efficiencies. Our team joins their approach for recovering resources by chemical processing with analysis of thermal and mechanical operations in space. Commercial firms provide cost inputs for ELM and planetary landing. Additional information is included in the

  8. Plasma Assisted ISRU at Mars

    NASA Technical Reports Server (NTRS)

    Moses, Robert W.; Kuhl, Christopher A.; Templeton, Justin D.

    2005-01-01

    NASA's exploration goals for Mars and Beyond will require new power systems and in situ resource utilization (ISRU) technologies. Regenerative aerobraking may offer a revolutionary approach for in situ power generation and oxygen harvesting during these exploration missions. In theory, power and oxygen can be collected during aerobraking and stored for later use in orbit or on the planet. This technology would capture energy and oxygen from the plasma field that occurs naturally during hypersonic entry using well understood principles of magnetohydrodynamics and oxygen filtration. This innovative approach generates resources upon arrival at the operational site, and thus greatly differs from the traditional approach of taking everything you need with you from Earth. Fundamental analysis, computational fluid dynamics, and some testing of experimental hardware have established the basic feasibility of generating power during a Mars entry. Oxygen filtration at conditions consistent with spacecraft entry parameters at Mars has been studied to a lesser extent. Other uses of the MHD power are presented. This paper illustrates how some features of regenerative aerobraking may be applied to support human and robotic missions at Mars.

  9. Planetary Regolith Delivery Systems for ISRU

    NASA Technical Reports Server (NTRS)

    Mantovani, James G.; Townsend, Ivan I., III

    2012-01-01

    The challenges associated with collecting regolith on a planetary surface and delivering it to an in-situ resource utilization system differ significantly from similar activities conducted on Earth. Since system maintenance on a planetary body can be difficult or impossible to do, high reliability and service life are expected of a regolith delivery system. Mission costs impose upper limits on power and mass. The regolith delivery system must provide a leak-tight interface between the near-vacuum planetary surface and the pressurized ISRU system. Regolith delivery in amounts ranging from a few grams to tens of kilograms may be required. Finally, the spent regolith must be removed from the ISRU chamber and returned to the planetary environment via dust tolerant valves capable of operating and sealing over a large temperature range. This paper will describe pneumatic and auger regolith transfer systems that have already been field tested for ISRU, and discuss other systems that await future field testing.

  10. ISRU Technologies for Mars Life Support

    NASA Technical Reports Server (NTRS)

    Finn, John E.; Sridhar, K. R.

    2000-01-01

    The primary objectives of the Mars Exploration program are to collect data for planetary science in a quest to answer questions related to Origins, to search for evidence of extinct and extant life, and to expand the human presence in the solar system. The public and political engagement that is critical for support of a Mars exploration program is based on all of these objectives. In order to retain and to build public and political support, it is important for NASA to have an integrated Mars exploration plan, not separate robotic and human plans that exist in parallel or in sequence. The resolution stemming from the current architectural review and prioritization of payloads may be pivotal in determining whether NASA will have such a unified plan and retain public support. There are several potential scientific and technological links between the robotic-only missions that have been flown and planned to date, and the robotic + human missions that will come in the future. Taking advantage of and leveraging those links are central to the idea of a unified Mars exploration plan. One such link is in situ resource utilization (ISRU) as an enabling technology to provide consumables such as fuels, oxygen, sweep and utility gases from the Mars atmosphere. ISRU for propellant production and for generation of life support consumables is a key element of human exploration mission plans because of the tremendous savings that can be realized in terms of launch costs and reduction in overall risk to the mission. The Human Exploration and Development of Space (HEDS) Enterprise has supported ISRU technology development for several years, and is funding the MIP and PROMISE payloads that will serve as the first demonstrations of ISRU technology for Mars. In our discussion and presentation at the workshop, we will highlight how the PROMISE ISRU experiment that has been selected by HEDS for a future Mars flight opportunity can extend and enhance the science experiments on board.

  11. Biological Implications of Artificial Illumination.

    ERIC Educational Resources Information Center

    Wurtman, Richard J.

    1968-01-01

    Environmental lighting exerts profound biologic effects on humans and other mammals, in addition to providing the visual stimulus. Light acts on the skin to stimulate the synthesis of Vitamin D. It also acts, through the eyes, to control several glands and many metabolic processes. Light, or its absence, "induces" certain biologic functions. Light…

  12. Biological Implications of Gene-Environment Interaction

    ERIC Educational Resources Information Center

    Rutter, Michael

    2008-01-01

    Gene-environment interaction (G x E) has been treated as both a statistical phenomenon and a biological reality. It is argued that, although there are important statistical issues that need to be considered, the focus has to be on the biological implications of G x E. Four reports of G x E deriving from the Dunedin longitudinal study are used as…

  13. In-Situ Resource Utilization (ISRU) Development Program

    NASA Technical Reports Server (NTRS)

    Sanders, Jerry

    1998-01-01

    The question "Why In-Situ Resource Utilization (ISRU)?" is addressed in this presentation. The reasons given concentrate on Cost reduction, Mass reduction, Risk reduction, the expansion of human exploration and presence and the enabling of industrial exploitation. A review of the Martian and Lunar resources available for ISRU is presented. Other ISRU concepts (i.e., In-Situ Consumable production (ISCP) and In-Situ Propellant Production (ISPP)) are introduced and further explained. The objectives of a Mars ISRU System Technology (MIST) include (1) the characterization of technology and subsystem performance for mission modeling and technology funding planning, (2) reduce risk and concerns arising from sample return and human missions utilizing ISRU, and (3) demonstrate the environmental suitability of ISRU components/processes and systems. A proof of concept demonstration schedule and a facility overview for MIST is presented.

  14. Oxygen production System Models for Lunar ISRU

    NASA Technical Reports Server (NTRS)

    Santiago-Maldonado, Edgardo

    2007-01-01

    In-Situ Resource Utilization (ISRU) seeks to make human space exploration feasible; by using available resources from a planet or the moon to produce consumables, parts, and structures that otherwise would be brought from Earth. Producing these in situ reduces the mass of such that must be launched and doing so allows more payload mass' for each mission. The production of oxygen from lunar regolith, for life support and propellant, is one of the tasks being studied under ISRU. NASA is currently funding three processes that have shown technical merit for the production of oxygen from regolith: Molten Salt Electrolysis, Hydrogen Reduction of Ilmenite, and Carbothermal Reduction. The ISRU program is currently developing system models of, the , abovementioned processes to: (1) help NASA in the evaluation process to select the most cost-effective and efficient process for further prototype development, (2) identify key parameters, (3) optimize the oxygen production process, (4) provide estimates on energy and power requirements, mass and volume.of the system, oxygen production rate, mass of regolith required, mass of consumables, and other important parameters, and (5) integrate into the overall end-to-end ISRU system model, which could be integrated with mission architecture models. The oxygen production system model is divided into modules that represent unit operations (e.g., reactor, water electrolyzer, heat exchanger). Each module is modeled theoretically using Excel and Visual Basic for Applications (VBA), and will be validated using experimental data from on-going laboratory work. This modularity (plug-n-play) feature of each unit operation allows the use of the same model on different oxygen production systems simulations resulting in comparable results. In this presentation, preliminary results for mass, power, volume will be presented along with brief description of the oxygen production system model.

  15. A Nuclear Powered ISRU Mission to Mars

    NASA Astrophysics Data System (ADS)

    Finzi, Elvina; Davighi, Andrea; Finzi, Amalia

    2006-01-01

    Space exploration has always been drastically constrained by the masses that can be launched into orbit; Hence affordable planning and execution of prolonged manned space missions depend upon the utilization of local. Successful in-situ resources utilization (ISRU) is a key element to allow the human presence on Mars or the Moon. In fact a Mars ISRU mission is planned in the Aurora Program, the European program for the exploration of the solar system. Orpheus mission is a technological demonstrator whose purpose is to show the advantages of an In Situ Propellant Production (ISPP). Main task of this work is to demonstrate the feasibility of a nuclear ISPP plant. The mission designed has been sized to launch back form Mars an eventual manned module. The ISPP mission requires two different: the ISPP power plant module and the nuclear reactor module. Both modules reach the escape orbit thanks to the launcher upper stage, after a 200 days cruising phase the Martian atmosphere is reached thanks to small DV propelled manoeuvres, aerobreaking and soft landing. During its operational life the ISPP plant produces. The propellant is produced in one synodic year. 35000 kg of Ethylene are produced at the Martian equator. The resulting systems appear feasible and of a size comparable to other ISRU mission designs. This mission seems challenging not only for the ISPP technology to be demonstrated, but also for the space nuclear reactor considered; Though this seems the only way to allow a permanent human presence on Mars surface.

  16. A Nuclear Powered ISRU Mission to Mars

    SciTech Connect

    Finzi, Elvina; Davighi, Andrea; Finzi, Amalia

    2006-01-20

    Space exploration has always been drastically constrained by the masses that can be launched into orbit; Hence affordable planning and execution of prolonged manned space missions depend upon the utilization of local. Successful in-situ resources utilization (ISRU) is a key element to allow the human presence on Mars or the Moon. In fact a Mars ISRU mission is planned in the Aurora Program, the European program for the exploration of the solar system. Orpheus mission is a technological demonstrator whose purpose is to show the advantages of an In Situ Propellant Production (ISPP). Main task of this work is to demonstrate the feasibility of a nuclear ISPP plant. The mission designed has been sized to launch back form Mars an eventual manned module. The ISPP mission requires two different: the ISPP power plant module and the nuclear reactor module. Both modules reach the escape orbit thanks to the launcher upper stage, after a 200 days cruising phase the Martian atmosphere is reached thanks to small DV propelled manoeuvres, aerobreaking and soft landing. During its operational life the ISPP plant produces. The propellant is produced in one synodic year. 35000 kg of Ethylene are produced at the Martian equator. The resulting systems appear feasible and of a size comparable to other ISRU mission designs. This mission seems challenging not only for the ISPP technology to be demonstrated, but also for the space nuclear reactor considered; Though this seems the only way to allow a permanent human presence on Mars surface.

  17. ISRU Propellant Selection for Space Exploration Vehicles

    NASA Technical Reports Server (NTRS)

    Chen, Timothy T.

    2013-01-01

    Chemical propulsion remains the only viable solution as technically matured technology for the near term human space transportation to Lunar and Mars. Current mode of space travel requires us to "take everything we will need", including propellant for the return trip. Forcing the mission designers to carry propellant for the return trip limits payload mass available for mission operations and results in a large and costly (and often unaffordable) design. Producing propellant via In-Situ Resource Utilization (ISRU) will enable missions with chemical propulsion by the "refueling" of return-trip propellant. It will reduce vehicle propellant mass carrying requirement by over 50%. This mass reduction can translates into increased payload to enhance greater mission capability, reduces vehicle size, weight and cost. It will also reduce size of launch vehicle fairing size as well as number of launches for a given space mission and enables exploration missions with existing chemical propulsion. Mars remains the ultimate destination for Human Space Exploration within the Solar System. The Mars atmospheric consist of 95% carbon dioxide (CO2) and the presence of Ice (water) was detected on Mars surfaces. This presents a basic chemical building block for the ISRU propellant manufacturing. However, the rationale for the right propellant to produce via ISRU appears to be limited to the perception of "what we can produce" as oppose to "what is the right propellant". Methane (CH4) is often quoted as a logical choice for Mars ISRU propellant, however; it is believed that there are better alternatives available that can result in a better space transportation architecture. A system analysis is needed to determine on what is the right propellant choice for the exploration vehicle. This paper examines the propellant selection for production via ISRU method on Mars surfaces. It will examine propellant trades for the exploration vehicle with resulting impact on vehicle performance, size

  18. Mars ISRU for Production of Mission Critical Consumables - Options, Recent Studies, and Current State of the Art

    NASA Technical Reports Server (NTRS)

    Sanders, G. B.; Paz, A.; Oryshchyn, L.; Araghi, K.; Muscatello, A.; Linne, D.; Kleinhenz, J.; Peters, T.

    2015-01-01

    with Mars ISRU systems further substantiated the preliminary results from the Mars DRA 5.0 study. This paper will provide an overview of Mars ISRU consumable production options, the analyses, results, and conclusions from the Mars DRA 5.0 (2007), Mars Collaborative (2013), and Mars ISRU Payload for the Supersonic Retro Propulsion (2014) mission studies, and the current state-of-the-art of Mars ISRU technologies and systems. The paper will also briefly discuss the mission architectural implications associated with Mars resource and ISRU processing options.

  19. Microgravity Materials Research and Code U ISRU

    NASA Technical Reports Server (NTRS)

    Curreri, Peter A.; Sibille, Laurent

    2004-01-01

    The NASA microgravity research program, simply put, has the goal of doing science (which is essentially finding out something previously unknown about nature) utilizing the unique long-term microgravity environment in Earth orbit. Since 1997 Code U has in addition funded scientific basic research that enables safe and economical capabilities to enable humans to live, work and do science beyond Earth orbit. This research has been integrated with the larger NASA missions (Code M and S). These new exploration research focus areas include Radiation Shielding Materials, Macromolecular Research on Bone and Muscle Loss, In Space Fabrication and Repair, and Low Gravity ISRU. The latter two focus on enabling materials processing in space for use in space. The goal of this program is to provide scientific and technical research resulting in proof-of-concept experiments feeding into the larger NASA program to provide humans in space with an energy rich, resource rich, self sustaining infrastructure at the earliest possible time and with minimum risk, launch mass and program cost. President Bush's Exploration Vision (1/14/04) gives a new urgency for the development of ISRU concepts into the exploration architecture. This will require an accelerated One NASA approach utilizing NASA's partners in academia, and industry.

  20. A New Concept in Planetary Exploration: ISRU With Power Bursts

    NASA Astrophysics Data System (ADS)

    Streibech, Douglas; Urdaneta, Mario; Chapman, Patricia; Furfaro, Roberto; Ramohalli, Kumar

    2000-01-01

    The concept of generating power bursts upon demand in space exploration is presented. As acknowledged by two NASA Novel Technology Report (NTR) awards, the concept is new and innovative. As a general background, it must be recalled that power has always been a major limiting factor in exploration, especially in the exploration of far off sites like Mars (contrasted with LEO or GEO). Without the high power ability, no amount of energy (that can only be expended at a low rate, i.e., low power) can accomplish such simple operations as: crushing a rock, hopping over an obstacle, drilling deep, and eventually ascent from the planet to an orbiting craft above, or even the return journey to Earth. The concept presented here is an advance over the much studied In-Situ Resource Utilization (ISRU); we use ISRU for the extraction of the needed fuel and oxidizer from the local resources, store these gases, and expend them rapidly when needed. In the martian scenario, these gases will be carbon monoxide (fuel) and oxygen (oxidizer) extracted from the atmospheric carbon dioxide; subsequently, higher chemistry is possible after the discovery, and utilization of water which enables the production of an entire spectrum of hydrocarbons and carbohydrates. If nitrogen can also be added at a still later date, many more chemicals in the ammonia based family are possible. At SERC (University of Arizona) we have pioneered all of these chemical productions. In another award-winning innovation, an ultra-light weight material, popularly known as muscle wires, is used in a biology-inspired robot called BiRoD. The expenditure of energy in these materials produces power that results in mechanical motion. The short term power generation is thousands of times the average power that was used to harness the local resource in the first place. At the time of this abstract, BiRoD has been designed, assembled, and shown to work in a primitive way, in its component form; new media have carried the high

  1. Vacuum Pyrolysis and Related ISRU Techniques

    NASA Technical Reports Server (NTRS)

    Cardiff, Eric H.; Pomeroy, Brian R.; Banks, Ian S.; Benz, Alexis

    2007-01-01

    A number of ISRU-related techniques have been developed at NASA Goddard Space Flight Center. The focus of the team has been on development of the vacuum pyrolysis technique for the production of oxygen from the lunar regolith. However, a number of related techniques have also been developed, including solar concentration, solar heating of regolith, resistive heating of regolith, sintering, regolith boiling, process modeling, parts manufacturing, and instrumentation development. An initial prototype system was developed to vaporize regolith simulants using a approx. l square meter Fresnel lens. This system was successfully used to vaporize quantities of approx. lg, and both mass spectroscopy of the gasses produced and Scanning Electron Microscopy (SEM) of the slag were done to show that oxygen was produced. Subsequent tests have demonstrated the use of a larger system With a 3.8m diameter reflective mirror to vaporize the regolith. These results and modeling of the vacuum pyrolysis reaction have indicated that the vaporization of the oxides in the regolith will occur at lower temperature for stronger vacuums. The chemical modeling was validated by testing of a resistive heating system that vaporized quantities of approx. 10g of MLS-1A. This system was also used to demonstrate the sintering of regolith simulants at reduced temperatures in high vacuum. This reduction in the required temperature prompted the development of a small-scale resistive heating system for application as a scientific instrument as well as a proof-of principle experiment for oxygen production.

  2. Aquaglyceroporins: implications in adipose biology and obesity.

    PubMed

    Madeira, Ana; Moura, Teresa F; Soveral, Graça

    2015-02-01

    Aquaporins (AQPs) are membrane water/glycerol channels that are involved in many physiological processes. Their primary function is to facilitate the bidirectional transfer of water and small solutes across biological membranes in response to osmotic gradients. Aquaglyceroporins, a subset of the AQP family, are the only mammalian proteins with the ability to permeate glycerol. For a long time, AQP7 has been the only aquaglyceroporin associated with the adipose tissue, which is the major source of circulating glycerol in response to the energy demand. AQP7 dysregulation was positively correlated with obesity onset and adipocyte glycerol permeation through AQP7 was appointed as a novel regulator of adipocyte metabolism and whole-body fat mass. Recently, AQP3, AQP9, AQP10 and AQP11 were additionally identified in human adipocytes and proposed as additional glycerol pathways in these cells. This review contextualizes the importance of aquaglyceroporins in adipose tissue biology and highlights aquaglyceroporins' unique structural features which are relevant for the design of effective therapeutic compounds. We also refer to the latest advances in the identification and characterization of novel aquaporin isoforms in adipose tissue. Finally, considerations on the actual progress of aquaporin research and its implications on obesity therapy are suggested. PMID:25359234

  3. Opportunities for ISRU Applications in the Mars Reference Mission

    NASA Astrophysics Data System (ADS)

    Duke, Michael B.

    1998-01-01

    The use of in-situ resources in the Mars Reference Mission is discussed in this presentation. The objectives of the presentation are to consider whether In Situ Resource Use (ISRU), other than propellants and life support consumables can be useful, and to outline the type of analysis that has to be performed to evaluate the ISRU use, and to suggest some areas for investigation. The presentation also discusses ways to reduce risk, and cost. Possible strategies are posed, including use of robotic systems. The use of robotic systems could reduce total mass required for the mission by producing required material over a long period of time. Several examples are discussed. (1) In the presentation the possible use of ISRU in making concrete for structures is discussed. Using robots to produce, mix, form, and cure the concrete, ISRU concrete may be able to compete with earth supply. (2) The use of robots to grade roads is also discussed. The use of ISRU is more complex than bringing things from Earth.

  4. ISRU in the Context of Future European Human Mars Exploration

    NASA Astrophysics Data System (ADS)

    Baker, A. M.; Tomatis, C.

    2002-01-01

    ISRU or In-Situ Resource Utilisation is the use of Martian resources to manufacture, typically, life support consumables (e.g. water, oxygen, breathing buffer gases), and propellant for a return journey to Earth. European studies have shown that some 4kg of reaction mass must be launched to LEO to send 1kg payload to Mars orbit, with landing on the Mars surface reducing payload mass still further. This results in very high transportation costs to Mars, and still higher costs for returning payloads to Earth. There is therefore a major incentive to reduce payload mass for any form of Mars return mission (human or otherwise) by generating consumables on the surface. ESA through its GSTP programme has been investigating the system level design of a number of mission elements as potential European contributions to an international human Mars exploration mission intended for the 2020-2030 timeframe. One of these is an ISRU plant, a small chemical factory to convert feedstock brought from Earth (hydrogen), and Martian atmospheric gases (CO2 and trace quantities of nitrogen and argon) into methane and oxygen propellant for Earth return and life support consumables, in advance of the arrival of astronauts. ISRU technology has been the subject of much investigation around the world, but little detailed research or system level studies have been reported in Europe. Furthermore, the potential applicability of European expertise, technology and sub- system studies to Martian ISRU is not well quantified. Study work covered in this paper has compared existing designs (e.g. NASA's Design Reference Mission, DLR and Mars Society studies) with the latest ESA derived requirements for human Mars exploration, and has generated a system level ISRU design. This paper will review and quantify the baseline chemical reactions essential for ISRU, including CO2 collection and purification, Sabatier reduction of CO2 with hydrogen to methane and water, and electrolysis of water in the context of

  5. In Situ Resource Utilization (ISRU 3) Technical Interchange Meeting: Abstracts

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This volume contains abstracts that have been accepted for presentation at the In Situ Resource Utilization (ISRU III) Technical Interchange Meeting, February 11-12, 1999, hosted by the Lockheed Martin Astronautics Waterton Facility, Denver, Colorado. Administration and publication support for this meeting were provided by the staff of the Publications and Program Services Department at the Lunar and Planetary Institute.

  6. Martian Atmospheric Dust Mitigation for ISRU Intakes via Electrostatic Precipitation

    NASA Technical Reports Server (NTRS)

    Phillips, James R., III; Pollard, Jacob R. S.; Johansen, Michael R.; Mackey, Paul J.; Clements, J. Sid; Calle, Carlos I.

    2016-01-01

    The Mars 2020 and Mars Sample Return missions expected to fly to Mars within the next ten years will each include an In Situ Resource Utilization (ISRU) system. They convert carbon dioxide in the Martian atmosphere into consumable oxygen at 1% and 20% of the rate required by a full scale human exploration Mars mission, respectively. The ISRU systems will need to draw in the surrounding atmosphere at a rate of 110L/min and 550L/min, respectively, in order to meet their oxygen production goals. Over the duration of each respective mission, a total atmospheric dust mass of 4.86g and 243g will be drawn into each system, respectively. Ingestion of large quantities of dust may interfere with ISRU operations, so a dust mitigation device will be required. The atmospheric volume and dust mass flow rates above will be utilized to simulate Martian environmental conditions in a laboratory electrostatic precipitator being developed to provide active dust mitigation support for atmospheric ISRU systems such as these.

  7. Risk Assessment: Implications for Biologic Education.

    ERIC Educational Resources Information Center

    Ost, David H.

    1995-01-01

    Discusses risk assessment, including risk assessment as a modeling process, models and social values, political decision making, the public, and risk assessment techniques in the biology classroom. (MKR)

  8. Implications of Big Data for cell biology

    PubMed Central

    Dolinski, Kara; Troyanskaya, Olga G.

    2015-01-01

    “Big Data” has surpassed “systems biology” and “omics” as the hottest buzzword in the biological sciences, but is there any substance behind the hype? Certainly, we have learned about various aspects of cell and molecular biology from the many individual high-throughput data sets that have been published in the past 15–20 years. These data, although useful as individual data sets, can provide much more knowledge when interrogated with Big Data approaches, such as applying integrative methods that leverage the heterogeneous data compendia in their entirety. Here we discuss the benefits and challenges of such Big Data approaches in biology and how cell and molecular biologists can best take advantage of them. PMID:26174066

  9. Biological Warfare: Implications for Antimicrobial Use.

    PubMed

    Rubinstein, Ethan; Levi, Itzhak

    2002-02-01

    Biological warfare is intended to incapacitate a large number of individuals at a single exposure, creating epidemic-type disease, death, and social chaos. The organisms with potential for immediate use as bacteriologic weapons are Bacillus anthracis, Brucella melitensis, Yersinia pestis, and Vibrio cholera, all necessitating antibiotic therapy for a cure. It is reasonable, therefore, to assume that a biological attack, or even a hoax, would requiure thousands of individuals over a large area to begin antibiotic therapy. Issues such as antibiotic availability, logistical problems in antibiotic distribution, development of drug resistance, side effects influencing the individual, and adverse effects on the community due to the impact of mass therapy on the ecology, make biological warfare the most apocalyptic scenario for the creation of a "postantibiotic era." PMID:11853654

  10. In Situ Resource Utilization (ISRU II) Technical Interchange Meeting

    NASA Technical Reports Server (NTRS)

    Kaplan, David (Compiler); Saunders, Stephen R. (Compiler)

    1997-01-01

    This volume contains extended abstracts that have been accepted for presentation at the In Situ Resource Utilization (ISRU II) Technical Interchange Meeting, November 18-19, 1997, at the Lunar and Planetary Institute, Houston, Texas. Included are topics which include: Extraterrestrial resources, in situ propellant production, sampling of planetary surfaces, oxygen production, water vapor extraction from the Martian atmosphere, gas generation, cryogenic refrigeration, and propellant transport and storage.

  11. In Situ Resource Utilization (ISRU) Technical Interchange Meeting

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This volume contains abstracts that have been accepted for presentation at the In Situ Resource Utilization (ISRU) Technical Interchange Meeting, February 4-5, 1997, at the Lunar and Planetary Institute, Houston, Texas. Abstracts are arranged in order of presentation at the meetings, with corresponding page numbers shown in the enclosed agenda. Logistics, administration, and publication support for this meeting were provided by the staff of the Publications and Program Services Department at the Lunar and Planetary Institute.

  12. The Biology of Trauma: Implications for Treatment

    ERIC Educational Resources Information Center

    Solomon, Eldra P.; Heide, Kathleen M.

    2005-01-01

    During the past 20 years, the development of brain imaging techniques and new biochemical approaches has led to increased understanding of the biological effects of psychological trauma. New hypotheses have been generated about brain development and the roots of antisocial behavior. We now understand that psychological trauma disrupts homeostasis…

  13. [The ethical implications of conserving biological samples].

    PubMed

    Tazzite, A; Roky, R; Avard, D

    2009-09-01

    The conservation and use of biological samples become more and more frequent all around the world. Biobanks of human body substances (blood, urine, DNA, tissues, cells, etc.), and personal data associated with them are created. They have a double character as they are collections of both human biological samples and personal data. In some cases, the gametes, reproductive tissues, embryos, foetal tissue after abortion or even specimens of dead donors are collected and conserved. Although biobanks raise hopes in both the development of new therapies, new drugs and their integration into clinical medicine, they also point to concerns related to ethical questions such as: the principles of information, the consent of the persons concerned, the confidentiality about the personal data, and in some cases discrimination and stigmatisation. Other ethical aspects could raise gradually as research advance. Research being carried out on human sample requires informed free consent from the person who should be able to consent. The donor must be sufficiently informed about the process of research, the purpose, benefits and the risks involved in participating in this research. In the case of persons unable to give consent such minors or persons with mental disabilities, special measures are undertaken. Once the consent was given, the right of withdrawal has been consistently supported by the various declarations and regulations, but some oppose this right for a number of reasons particularly in the case of research on the samples without risk of physical exposure. In this case the notion of human body integrity is different than in research involving therapeutic or clinical intervention. In the case of withdrawal of consent, the samples should be destroyed, but the anonymous results arising from them and their analysis are not affected. What is the case for future uses? Should the researcher obtain again the consent from the donor for a secondary use of the samples? This is a

  14. Local Citation Analysis of Graduate Biology Theses: Collection Development Implications

    ERIC Educational Resources Information Center

    Miller, Laura Newton

    2011-01-01

    This paper will focus on the citation analysis of graduate masters theses from Carleton University's Biology Department with implications for library collection management decisions. Twenty-five masters theses were studied to determine citation types and percentages, ranking of journals by frequency of citation and by number of authors citing, and…

  15. In-Situ Resource Utilization (ISRU): Surface systems program area of the exploration technology program

    NASA Technical Reports Server (NTRS)

    Mckay, David S.

    1991-01-01

    The topics presented are covered in viewgraph form and include the following: (1) utilization of Lunar and Mars resources; (2) oxygen - an example of cost savings; (3) In Space Resource Utilization (ISRU); (4) basic resource processing methods; (5) planetary mining; (6) raw materials preparation; (7) validation, testbeds, and flight experiments; (8) mission readiness schedule; and (9) ISRU budget guideline.

  16. Topological implications of negative curvature for biological and social networks

    NASA Astrophysics Data System (ADS)

    Albert, Réka; DasGupta, Bhaskar; Mobasheri, Nasim

    2014-03-01

    Network measures that reflect the most salient properties of complex large-scale networks are in high demand in the network research community. In this paper we adapt a combinatorial measure of negative curvature (also called hyperbolicity) to parametrized finite networks, and show that a variety of biological and social networks are hyperbolic. This hyperbolicity property has strong implications on the higher-order connectivity and other topological properties of these networks. Specifically, we derive and prove bounds on the distance among shortest or approximately shortest paths in hyperbolic networks. We describe two implications of these bounds to crosstalk in biological networks, and to the existence of central, influential neighborhoods in both biological and social networks.

  17. Protons @ interfaces: implications for biological energy conversion.

    PubMed

    Mulkidjanian, Armen Y; Heberle, Joachim; Cherepanov, Dmitry A

    2006-08-01

    The review focuses on the anisotropy of proton transfer at the surface of biological membranes. We consider (i) the data from "pulsed" experiments, where light-triggered enzymes capture or eject protons at the membrane surface, (ii) the electrostatic properties of water at charged interfaces, and (iii) the specific structural attributes of proton-translocating enzymes. The pulsed experiments revealed that proton exchange between the membrane surface and the bulk aqueous phase takes as much as about 1 ms, but could be accelerated by added mobile pH-buffers. Since the accelerating capacity of the latter decreased with the increase in their electric charge, it was concluded that the membrane surface is separated from the bulk aqueous phase by a barrier of electrostatic nature. The barrier could arise owing to the water polarization at the negatively charged membrane surface. The barrier height depends linearly on the charge of penetrating ions; for protons, it has been estimated as about 0.12 eV. While the proton exchange between the surface and the bulk aqueous phase is retarded by the interfacial barrier, the proton diffusion along the membrane, between neighboring enzymes, takes only microseconds. The proton spreading over the membrane is facilitated by the hydrogen-bonded networks at the surface. The membrane-buried layers of these networks can eventually serve as a storage/buffer for protons (proton sponges). As the proton equilibration between the surface and the bulk aqueous phase is slower than the lateral proton diffusion between the "sources" and "sinks", the proton activity at the membrane surface, as sensed by the energy transducing enzymes at steady state, might deviate from that measured in the adjoining water phase. This trait should increase the driving force for ATP synthesis, especially in the case of alkaliphilic bacteria.

  18. Calculation of Excavation Force for ISRU on Lunar Surface

    NASA Technical Reports Server (NTRS)

    Zeng, Xiangwu (David); Burnoski, Louis; Agui, Juan H.; Wilkinson, Allen

    2007-01-01

    Accurately predicting the excavation force that will be encountered by digging tools on the lunar surface is a crucial element of in-situ resource utilization (ISRU). Based on principles of soil mechanics, this paper develops an analytical model that is relatively simple to apply and uses soil parameters that can be determined by traditional soil strength tests. The influence of important parameters on the excavation force is investigated. The results are compared with that predicted by other available theories. Results of preliminary soil tests on lunar stimulant are also reported.

  19. Discussion of thermal extraction chamber concepts for Lunar ISRU

    NASA Astrophysics Data System (ADS)

    Pfeiffer, Matthias; Hager, Philipp; Parzinger, Stephan; Dirlich, Thomas; Spinnler, Markus; Sattelmayer, Thomas; Walter, Ulrich

    The Exploration group of the Institute of Astronautics (LRT) of the Technische Universitüt a München focuses on long-term scenarios and sustainable human presence in space. One of the enabling technologies in this long-term perspective is in-situ resource utilization (ISRU). When dealing with the prospect of future manned missions to Moon and Mars the use of ISRU seems useful and intended. The activities presented in this paper focus on Lunar ISRU. This basically incorporates both the exploitation of Lunar oxygen from natural rock and the extraction of solar wind implanted particles (SWIP) from regolith dust. Presently the group at the LRT is examining possibilities for the extraction of SWIPs, which may provide several gaseous components (such as H2 and N2) valuable to a human presence on the Moon. As a major stepping stone in the near future a Lunar demonstrator/ verification experiment payload is being designed. This experiment, LUISE (LUnar ISru Experiment), will comprise a thermal process chamber for heating regolith dust (grain size below 500m), a solar thermal power supply, a sample distribution unit and a trace gas analysis. The first project stage includes the detailed design and analysis of the extraction chamber concepts and the thermal process involved in the removal of SWIP from Lunar Regolith dust. The technique of extracting Solar Wind volatiles from Regolith has been outlined by several sources. Heating the material to a threshold value seems to be the most reasonable approach. The present paper will give an overview over concepts for thermal extraction chambers to be used in the LUISE project and evaluate in detail the pros and cons of each concept. The special boundary conditions set by solar thermal heating of the chambers as well as the material properties of Regolith in a Lunar environment will be discussed. Both greatly influence the design of the extraction chamber. The performance of the chamber concepts is discussed with respect to the

  20. Opportunities for ISRU Applications in the Mars Reference Mission

    NASA Astrophysics Data System (ADS)

    Duke, Michael B.

    1998-01-01

    The NASA Mars Exploration Reference Mission envisions sending three crews of six astronauts to Mars, each for 500-day stays on the surface. In situ Resourse Unitlization (ISRU) has been baselined for the production of propellant for crews leaving the surface, as well as to create reservoirs of water and life-support consumables These applications improve performance (by reducing the mass of hardware and supplies that must be brought to Mars for the propulsion system) and reduce risk (by creating consumables as backups to stores brought from Earth). Similar applications of other types of ISRU-derived materials should be sought and selected if they similarly improve performance or reduce risk. Some possible concepts for consideration, based on a review of the components included in the Reference Mission, include (1) emplacement of a hardened landing pad; (2) construction of a roadway for transporting the nuclear power system to a safe distance from the habitat; (3) radiation shielding for inflatable structures; (4) tanks and plumbing for bioregenerative life-support system; (5) drilling rig; (6) additional access structures for equipment and personnel and unpressurized structures for vehicle storage; (7) utilitarian manufactured products (e.g., stools and benches) for habitat and laboratory; (8) thermal radiators; (9) photovoltaic devices and support structures; and ( 10) external structures for storage and preservation of Mars samples. These may be viewed principally as mission- enhancing concepts for the Reference Mission. Selection would require a clear rationale for performance improvement or risk reduction and a demonstration that the cost of developing and transporting the needed equipment would be recovered within the budget for the program. Additional work is also necessary to ascertain whether early applications of ISRU for these types of purposes could lead to the modification of later missions, allowing the replacement of infrastructure payloads currently

  1. Field Scale Testing of RESOLVE at 2010 ISRU Analog Test

    NASA Technical Reports Server (NTRS)

    Captain, Janine E.; Quinn, J. W.; Moss, T. J.; Weis, K. H.

    2010-01-01

    When mankind returns to the moon, there will be one aspect of the architecture that will totally change how we explore the solar system. For the first time in space exploration, we will take the initial steps towards breaking our reliance on Earth-supplied consumables by extracting resources from planetary bodies. Our first efforts in this area, known as In Situ Resource Utilization (ISRU), will be directed at extracting some of the abundant oxygen found in the lunar regolith. But the "holy grail" of lunar ISRU will be finding an exploitable source of lunar hydrogen. If we can find a source of hydrogen that can be reasonably extracted from the regolith, it would provide a foundation for true independence from Earth consumables. With in-situ hydrogen and oxygen (and/or water) we can produce many of the major consumables needed to travel to and operate on a sustainable lunar outpost. We would have water to drink, oxygen to breath, and rocket propellants and fuel cell reagents to enable extended access and operations across the moon. NASA initiated development of an experiment package named RESOLVE (Regolith & Environment Science and Oxygen & Lunar Volatile Extraction) that could be flown to the rim or into a permanently shadowed crater to answer the questions surrounding elevated hydrogen at the lunar poles.

  2. Resource Prospector: A Lunar Volatiles Prospecting and ISRU Demonstration Mission

    NASA Technical Reports Server (NTRS)

    Colaprete, Anthony

    2015-01-01

    A variety of recent observations have indicated several possible reservoirs of water and other volatiles. These volatiles, and in particular water, have the potential to be a valuable or enabling resource for future exploration. NASA's Human Exploration and Operations Mission Directorate (HEOMD) Advanced Exploration Systems (AES) is supporting the development of Resource Prospector (RP) to explore the distribution and concentration of lunar volatiles prospecting and to demonstrate In-Situ Resource Utilization (ISRU). The mission includes a NASA developed rover and payload, and a lander will most likely be a contributed element by an international partner or the Lunar Cargo Transportation and Landing by Soft Touchdown (CATALYST) initiative. The RP payload is designed to: (1) locate near-subsurface volatiles, (2) excavate and analyze samples of the volatile-bearing regolith, and (3) demonstrate the form. extractability and usefulness of the materials. RP is being designed with thought given to its extensibility to resource prospecting and ISRU on other airless bodies and Mars. This presentation will describe the Resource Prospector mission, the payload and measurements, and concept of operations

  3. Resource Prospector: A lunar volatiles prospecting and ISRU demonstration mission

    NASA Astrophysics Data System (ADS)

    Colaprete, A.

    2015-12-01

    A variety of recent observations have indicated several possible reservoirs of water and other volatiles. These volatiles, and in particular water, have the potential to be a valuable or enabling resource for future exploration. NASA's Human Exploration and Operations Mission Directorate (HEOMD) Advanced Exploration Systems (AES) is supporting the development of Resource Prospector (RP) to explore the distribution and concentration of lunar volatiles prospecting and to demonstrate In-Situ Resource Utilization (ISRU). The mission includes a NASA developed rover and payload, and a lander will most likely be a contributed element by an international partner or the Lunar Cargo Transportation and Landing by Soft Touchdown (CATALYST) initiative. The RP payload is designed to: (1) locate near-subsurface volatiles, (2) excavate and analyze samples of the volatile-bearing regolith, and (3) demonstrate the form, extractability and usefulness of the materials. RP is being designed with thought given to its extensibility to resource prospecting and ISRU on other airless bodies and Mars. This presentation will describe the Resource Prospector mission, the payload and measurements, and concept of operations

  4. New Developments in Mast Cell Biology: Clinical Implications.

    PubMed

    Arthur, Greer; Bradding, Peter

    2016-09-01

    Mast cells (MCs) are present in connective tissue and at mucosal surfaces in all classes of vertebrates. In health, they contribute to tissue homeostasis, host defense, and tissue repair via multiple receptors regulating the release of a vast stockpile of proinflammatory mediators, proteases, and cytokines. However, these potentially protective cells are a double-edged sword. When there is a repeated or long-term stimulus, MC activation leads to tissue damage and dysfunction. Accordingly, MCs are implicated in the pathophysiologic aspects of numerous diseases covering all organs. Understanding the biology of MCs, their heterogeneity, mechanisms of activation, and signaling cascades may lead to the development of novel therapies for many diseases for which current treatments are lacking or are of poor efficacy. This review will focus on updates and developments in MC biology and their clinical implications, with a particular focus on their role in respiratory diseases.

  5. College biology students' conceptions related to the nature of biological knowledge: Implications for conceptual change

    NASA Astrophysics Data System (ADS)

    Ameny, Gloria Millie Apio

    knowledge or course was found to have a statistically significant influence on students' conceptions related to scientific methods, the scope and limits of biological knowledge, the importance of evolution in biology, and students' understanding of homologous and analogous structural features as products of divergent and convergent evolutionary processes. Findings of this study have implications for college biology teaching, student learning, and conceptual change among college biology students.

  6. ISRU Production of Life Support Consumables for a Lunar Base

    NASA Technical Reports Server (NTRS)

    Cooper, Bonnie L.; Simon, Tom

    2007-01-01

    Similar to finding a home on Earth, location is important when selecting where to set up an exploration outpost. Essential considerations for comparing potential lunar outpost locations include: (1) areas nearby that would be useful for In-Situ Resource Utilization (ISRU) oxygen extraction from regolith for crew breathing oxygen as well as other potential uses; (2) proximity to a suitable landing site; (3) availability of sunlight; (4) capability for line-of-sight communications with Earth; (5) proximity to permanently-shadowed areas for potential in-situ water ice; and (6) scientific interest. The Mons Malapert1 (Malapert Mountain) area (85.5degS, 0degE) has been compared to these criteria, and appears to be a suitable location for a lunar outpost.

  7. ISRU System Model Tool: From Excavation to Oxygen Production

    NASA Technical Reports Server (NTRS)

    Santiago-Maldonado, Edgardo; Linne, Diane L.

    2007-01-01

    In the late 80's, conceptual designs for an in situ oxygen production plant were documented in a study by Eagle Engineering [1]. In the "Summary of Findings" of this study, it is clearly pointed out that: "reported process mass and power estimates lack a consistent basis to allow comparison." The study goes on to say: "A study to produce a set of process mass, power, and volume requirements on a consistent basis is recommended." Today, approximately twenty years later, as humans plan to return to the moon and venture beyond, the need for flexible up-to-date models of the oxygen extraction production process has become even more clear. Multiple processes for the production of oxygen from lunar regolith are being investigated by NASA, academia, and industry. Three processes that have shown technical merit are molten regolith electrolysis, hydrogen reduction, and carbothermal reduction. These processes have been selected by NASA as the basis for the development of the ISRU System Model Tool (ISMT). In working to develop up-to-date system models for these processes NASA hopes to accomplish the following: (1) help in the evaluation process to select the most cost-effective and efficient process for further prototype development, (2) identify key parameters, (3) optimize the excavation and oxygen production processes, and (4) provide estimates on energy and power requirements, mass and volume of the system, oxygen production rate, mass of regolith required, mass of consumables, and other important parameters. Also, as confidence and high fidelity is achieved with each component's model, new techniques and processes can be introduced and analyzed at a fraction of the cost of traditional hardware development and test approaches. A first generation ISRU System Model Tool has been used to provide inputs to the Lunar Architecture Team studies.

  8. MicroChannel Reactors for ISRU Applications Using Nanofabricated Catalysts

    NASA Astrophysics Data System (ADS)

    Carranza, Susana; Makel, Darby B.; Vander Wal, Randall L.; Berger, Gordon M.; Pushkarev, Vladimir V.

    2006-01-01

    With the new direction of NASA to emphasize the exploration of the Moon, Mars and beyond, quick development and demonstration of efficient systems for In-Situ Resources Utilization (ISRU) is more critical and timely than ever before. Affordable planning and execution of prolonged manned space missions depend upon the utilization of local resources and the waste products which are formed in manned spacecraft and surface bases. This paper presents current development of miniaturized chemical processing systems that combine microchannel reactor design with nanofabricated catalysts. Carbon nanotubes (CNT) are used to produce a nanostructure within microchannel reactors, as support for catalysts. By virtue of their nanoscale dimensions, nanotubes geometrically restrict the catalyst particle size that can be supported upon the tube walls. By confining catalyst particles to sizes smaller than the CNT diameter, a more uniform catalyst particle size distribution may be maintained. The high dispersion permitted by the vast surface area of the nanoscale material serves to retain the integrity of the catalyst by reducing sintering or coalescence. Additionally, catalytic efficiency increases with decreasing catalyst particle size (reflecting higher surface area per unit mass) while chemical reactivity frequently is enhanced at the nanoscale. Particularly significant is the catalyst exposure. Rather than being confined within a porous material or deposited upon a 2-d surface, the catalyst is fully exposed to the reactant gases by virtue of the nanofabricated support structure. The combination of microchannel technology with nanofabricated catalysts provides a synergistic effect, enhancing both technologies with the potential to produce much more efficient systems than either technology alone. The development of highly efficient microchannel reactors will be applicable to multiple ISRU programs. By selection of proper nanofabricated catalysts, the microchannel reactors can be

  9. Planetary Volatiles Extractor (PVEX) for In Situ Resource Utilization (ISRU) on the Moon

    NASA Astrophysics Data System (ADS)

    Zacny, K.; Indyk, S.; Luczek, K.; Paz, A.

    2016-11-01

    We present test results from various approaches to extracting volatiles from frozen and water-saturated JSC-1a lunar soil simulant in vacuum. We also present ISRU mission architecture that would employ the most promising water extraction approach.

  10. High-Performance Mars Ascent Propulsion Technologies with Adaptability to ISRU and Human Exploration

    NASA Astrophysics Data System (ADS)

    Trinidad, M. A.; Calvignac, J. G.; Lo, A. S.

    2012-06-01

    Northrop Grumman's novel, high performance Mars ascent propulsion system that provides maximized mission flexibility and provides a propulsion technology path to in-situ resource utilization (ISRU) as well as ascent vehicles for human exploration is summarized.

  11. Results from the NASA Capability Roadmap Team for In-Situ Resource Utilization (ISRU)

    NASA Technical Reports Server (NTRS)

    Sanders, Gerald B.; Romig, Kris A.; Larson, William E.; Johnson, Robert; Rapp, Don; Johnson, Ken R.; Sacksteder, Kurt; Linne, Diane; Curreri, Peter; Duke, Michael; Blair, Brad; Gertsch, Leslie; Boucher, Dale; Rice, Eric; Clark, Larry; McCullough, Ed; Zubrin, Robert

    2005-01-01

    On January 14, 2004, the President of the United States unveiled a new vision for robotic and human exploration of space entitled, "A Renewed Spirit of Discovery". As stated by the President in the Vision for Space Exploration (VSE), NASA must "... implement a sustained and affordable human and robotic program to explore the solar system and beyond " and ".. .develop new technologies and harness the moon's abundant resources to allow manned exploration of more challenging environments." A key to fulfilling the goal of sustained and affordable human and robotic exploration will be the ability to use resources that are available at the site of exploration to "live off the land" instead of bringing everything from Earth, known as In-Situ Resource Utilization (ISRU). ISRU can significantly reduce the mass, cost, and risk of exploration through capabilities such as: mission consumable production (propellants, fuel cell reagents, life support consumables, and feedstock for manufacturing & construction); surface construction (radiation shields, landing pads, walls, habitats, etc.); manufacturing and repair with in-situ resources (spare parts, wires, trusses, integrated systems etc.); and space utilities and power from space resources. On January 27th, 2004 the President's Commission on Implementation of U.S. Space Exploration Policy (Aldridge Committee) was created and its final report was released in June 2004. One of the report's recommendations was to establish special project teams to evaluate enabling technologies, of which "Planetary in situ resource utilization" was one of them. Based on the VSE and the commission's final report, NASA established fifteen Capability Roadmap teams, of which ISRU was one of the teams established. From Oct. 2004 to May 2005 the ISRU Capability Roadmap team examined the capabilities, benefits, architecture and mission implementation strategy, critical decisions, current state-of-the-art (SOA), challenges, technology gaps, and risks of

  12. NASA In-Situ Resource Utilization (ISRU) Technology and Development Project Overview

    NASA Technical Reports Server (NTRS)

    Sanders, Gerald B.; Lason, William E.; Sacksteder, Kurt R.; Mclemore, Carole; Johnson, Kenneth

    2008-01-01

    Since the Vision for Space Exploration (VSE) was released in 2004, NASA, in conjunction with international space agencies, industry, and academia, has continued to define and refine plans for sustained and affordable robotic and human exploration of the Moon and beyond. With the goal of establishing a lunar Outpost on the Moon to extend human presence, pursue scientific activities, use the Moon to prepare for future human missions to Mars, and expand Earth s economic sphere, a change in how space exploration is performed is required. One area that opens up the possibility for the first time of breaking our reliance on Earth supplied consumables and learn to live off the land is In-Situ Resource Utilization (ISRU). ISRU, which involves the extraction and processing of space resources into useful products, can have a substantial impact on mission and architecture concepts. In particular, the ability to make propellants, life support consumables, and fuel cell reagents can significantly reduce the cost, mass, and risk of sustained human activities beyond Earth. However, ISRU is an unproven capability for human lunar exploration and can not be put in the critical path of lunar Outpost success until it has been proven. Therefore, ISRU development and deployment needs to take incremental steps toward the desired end state. To ensure ISRU capabilities are available for pre-Outpost and Outpost deployment by 2020, and mission and architecture planners are confident that ISRU can meet initial and long term mission requirements, the ISRU Project is developing technologies and systems in three critical areas: (1) Regolith Excavation, Handling and Material Transportation; (2) Oxygen Extraction from Regolith; and (3) Volatile Extraction and Resource Prospecting, and in four development stages: (I) Demonstrate feasibility; (II) Evolve system w/ improved technologies; (III) Develop one or more systems to TRL 6 before start of flight development; and (IV) Flight development for

  13. In Situ Resource Utilization (ISRU) Experiments for Mars Exploration

    NASA Technical Reports Server (NTRS)

    Marone, Matt

    2005-01-01

    In situ resource utilization can best be described as living off the land. In our case the land is the planet Mars. ISRU is based on the idea that some fraction of the consumables, life support and propellant materials do not have to be flown from earth. Rather, they can be manufactured or extracted from resources already present on Mars. The primary resources on Mars are the atmosphere, polar caps and regolith. The atmosphere of Mars is mostly carbon dioxide as shown in the table below. The proportion of oxygen on the other hand is quite small. Still, there is quite a bit of oxygen in the Martian atmosphere, but it is unfortunately tied up with carbon. Thus, one of the goals of ISRU is the separation of breathable oxygen from the carbon dioxide. Several means of separation have been proposed. We have begun experiments on another approach for production of oxygen with carbon monoxide as a useful by product. Our work on a CO2 separator is described later in this report. Regolith melting is another means of obtaining materials. Two materials of interest are iron and silicon. Iron oxide is plentiful on Mars and is of obvious importance for structural components. Silicon is the foundation of solid state devices. Power generation on Mars may be accomplished using silicon solar cells. There is discussion of the feasibility of in situ production of solar cells. This would require a means of extracting silicon from the regolith. We have conducted several experiments concerning melting and glassification of the Mars soil simulant. Other summer faculty fellows have tried various means of processing the stimulant material. These include furnace melting, microwave melting and laser ablation. We have conducted several furnace melting experiments in both air and carbon dioxide environments. We have also carried out experiments to test spark melting in a carbon dioxide atmosphere. These experiments suggest the possibility of using arc melting in a reducing atmosphere. It is

  14. ISRU Development Strategy and Recent Activities to Support Near and Far Term Missions

    NASA Astrophysics Data System (ADS)

    Baird, Russell S.; Sanders, Gerald B.; Simon, Thomas M.

    2003-01-01

    The practical expansion of humans beyond low Earth orbit into near-Earth space and out into the solar system for exploration, commercialization, tourism, and colonization will require the effective utilization of whatever indigenous resources are available to make these endeavors economically feasible and capable of extended operations. This concept of ``living off the land'' is called In-Situ Resource Utilization (ISRU). The resources available for ISRU applications vary widely, depending upon the location. However, there are resources, technologies, and processes that are common to multiple destinations and ISRU-related applications. These resources range from carbon dioxide (CO2) and water vapor found in human habitats (surface & spacecraft) and in the Martian atmosphere, to water (ice and hydrated minerals) and various oxygen, carbon, and metal-bearing resources found on comets and asteroids, and in planetary surface materials at numerous destinations of interest (Moon, Mars, Titan, and Europa). Many parties are investigating the common technologies and processes to effectively extract and use these resources. This paper will discuss how ISRU is enabling for both near and far term human exploration missions, and present a summary of recent and on-going ISRU work sponsored by the NASA/Johnson Space Center. Technology development activities that will be described in detail include an advanced CO2 freezer acquisition system, a multi-fluid common bulkhead cryogenic storage tank, and a variety of microchannel chemical reactor concepts. Recent advanced Sabatier reactor concept development activities in preparation for later, end-to-end system testing will be described as well. This paper will also discuss an ISRU-based strategy to enable extensive robotic and human surface exploration operations and a related on-going demonstration program for a fuel cell based power plant for rover applications. Technology commonalities between ISRU, life support systems, and Extra

  15. Pathologic and Therapeutic Implications for the Cell Biology of Parkin

    PubMed Central

    Charan, Rakshita A.; LaVoie, Matthew J.

    2015-01-01

    Mutations in the E3 ligase parkin are the most common cause of autosomal recessive Parkinson's disease (PD), but it is believed that parkin dysfunction may also contribute to idiopathic PD. Since its discovery, parkin has been implicated in supporting multiple neuroprotective pathways, many revolving around the maintenance of mitochondrial health quality control and governance of cell survival. Recent advances across the structure, biochemistry, and cell biology of parkin have provided great insights into the etiology of parkin-linked and idiopathic PD and may ultimately generate novel therapeutic strategies to slow or halt disease progression. This review describes the various pathways in which parkin acts and the mechanisms by which parkin may be targeted for therapeutic intervention. PMID:25697646

  16. Telomere biology and telomere diseases: implications for practice and research.

    PubMed

    Young, Neal S

    2010-01-01

    The recent recognition of genetic defects in telomeres and telomere repair in multiple human diseases has practical implications for hematologists and oncologists and their patients; consequences for future clinical research in hematology and other subspecialties; and even importance in the interpretation of animal experiments involving cell propagation. Telomere diseases include constitutional marrow failure as dyskeratosis congenita, some apparently acquired aplastic anemia, myelodysplasia and acute myeloid leukemia; pulmonary fibrosis; and hepatic nodular regenerative hyperplasia and cirrhosis. Accelerated telomere attrition is a likely pathophysiology of cancer arising from chronic inflammation. Telomerase can be modulated by sex hormones, which may explain the activity of androgens in marrow failure. Measurement of telomere length of peripheral blood leukocytes is a simple screening clinical assay. Detection of a mutation in a patient has implications for therapy, prognosis, monitoring, and genetic counseling. For research in hematology and oncology, telomere biology could be assessed as a risk for secondary malignancies and in graft-versus-host disease, for progression in a variety of blood cancers, and as potentially modifiable by hormone replacement strategies.

  17. Cassegrain Solar Concentrator System for ISRU Material Processing

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony J.; Macosko, Robert; Castle, Charles; Sacksteder, Kurt; Suzuki, Nantel H.; Mulherin, James

    2012-01-01

    A 0.5 m diameter Cassegrain concentrator was constructed as a means of providing highly concentrated sunlight for the demonstration processing of lunar simulated regolith and other NASA In-Situ Resource Utilization Project (ISRU) reaction processes. The concentrator is constructed of aluminum with a concentration ratio of approximately 3000 to 1. The concentrator focuses solar energy into a movable tray located behind the concentrator. This tray can hold simulated regolith or any other material and or device to be tested with concentrated solar energy. The tray is movable in one axis. A 2-axis extended optical system was also designed and fabricated. The extended optical system is added to the back of the primary concentrator in place of the moveable test tray and associated apparatus. With this optical system the focused sunlight can be extended from the back of the primary concentrator toward the ground with the added advantage of moving the focal point axially and laterally relative to the ground. This allows holding the focal point at a fixed position on the ground as the primary concentrator tracks the sun. Also, by design, the focal point size was reduced via the extended optics by a factor of 2 and results in a concentration ratio for the system of approximately 6,000 to 1.The designs of both optical systems are discussed. The results from simulated regolith melting tests are presented as well as the operational experience of utilizing the Cassegrain concentrator system.

  18. RESOLVE: Bridge between early lunar ISRU and science objectives

    NASA Astrophysics Data System (ADS)

    Taylor, G.; Sanders, G.; Larson, W.; Johnson, K.

    2007-08-01

    THE NEED FOR RESOURCES: When mankind returns to the moon, there will be an aspect of the architecture that will totally change how we explore the solar system. We will take the first steps towards breaking our reliance on Earth supplied consumables by extracting resources from planetary bodies. Our first efforts in this area, known as In-Situ Resource Utilization (ISRU), will be to extract the abundant oxygen found in the lunar regolith. But the "holy grail" of lunar ISRU will be finding an exploitable source of lunar hydrogen. If we can find a source of extractable hydrogen, it would provide a foundation for true independence from Earth. With in-situ hydrogen (or water) and oxygen we can produce many of the major consumables needed to operate a lunar outpost. We would have water to drink, oxygen to breath, as well as rocket propellants and fuel cell reagents to enable extended access and operations on the moon. These items make up a huge percentage of the mass launched from the Earth. Producing them in-situ would significantly reduce the cost of operating a lunar outpost while increasing payload availability for science. PROSPECTING: The Lunar Prospector found evidence of elevated hydrogen at the lunar poles, and measurements made at these locations from the Clementine mission bistatic radar have been interpreted as correlating to water/ice concentrations. At the South Pole, there is reasonably strong correlation between the elevated areas of hydrogen and permanently shadowed craters. However, there is considerable debate on the form and concentration of this hydrogen since the orbiting satellites had limited resolution and their data can be interpreted in different ways. The varying interpretations are based on differing opinions and theories of lunar environment, evolution, and cometary bombardment within the lunar Science community. The only way to truly answer this question from both a Science and resource availability perspective is to go to the lunar poles

  19. Clinical Implications of Cancer Stem Cell Biology in Hepatocellular Carcinoma

    PubMed Central

    Ji, Junfang; Wang, Xin Wei

    2012-01-01

    Solid tumors are thought to contain cancer stem cells (CSCs) as a distinct population responsible for tumor relapse and metastasis due to their abilities to self renew, differentiate and give rise to a new tumor in local or distant organs. CSCs have been identified in many tumor types, including hepatocellular carcinoma (HCC), the fifth most common and third most deadly malignancy with observable heterogeneity. Numerous studies have shown that hepatic CSCs could be enriched via different cell surface markers, e.g., CD13, CD24, CD44, CD90, CD133, EpCAM (CD326), and OV6. They could also be identified through functional assays such as isolating the side population cells by Hoechst dye staining or screening cells with a high activity of aldehyde dehydrogenase. Functional characterization of hepatic CSCs has revealed several deregulated signaling pathways, such as Wnt/β-catenin, AKT, TGF-beta, IL-6/STAT3 pathways to be critical in inducing “stemness” of HCC and in promoting self-renewal, tumorigenicity and chemoresistance. An increased understanding of the hepatic CSC biology shed light on the development of new diagnostic, prognostic therapeutic strategies in improving HCC clinical management. In this review, we summarized recent evidence including the identification of hepatic CSCs and its underlying biological mechanisms, and discussed potential clinical implications in HCC. PMID:22846863

  20. Initial Biological Damage from Space Radiation: Implications for Development of Biological Countermeasures

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Paloski, William H. (Technical Monitor)

    1999-01-01

    Astronauts are exposed to high-energy nuclear particles originating from the galactic cosmic rays, high-energy protons trapped in the Earth's magnetic field or solar particle events, and secondary radiation produced by nuclear reactions. Important differences between conventional radiation including X-rays or gamma-rays, and high-energy nuclei occur at the level of initial damage to DNA and other potential biological target molecules, and to tissues. Such differences include a large fraction of the initial damage from high charge and energy (HZE) nuclear particles manifested as irreparable lesions including small- and large-scale DNA deletions. Also, low dose-rate exposures in space result in a heterogeneous population of damaged cells distinct from energetic photon irradiation of tissue. We present an overview of the initial biological damage and dose and dose-rate effects produced by ionizing radiation using track structure and nuclear reaction models. Implications of the differences in cellular and tissue damage between conventional radiation and space radiation for the development of biological countermeasures are discussed.

  1. Water Electrolysis for In-Situ Resource Utilization (ISRU)

    NASA Technical Reports Server (NTRS)

    Lee, Kristopher A.

    2016-01-01

    Sending humans to Mars for any significant amount of time will require capabilities and technologies that enable Earth independence. To move towards this independence, the resources found on Mars must be utilized to produce the items needed to sustain humans away from Earth. To accomplish this task, NASA is studying In Situ Resource Utilization (ISRU) systems and techniques to make use of the atmospheric carbon dioxide and the water found on Mars. Among other things, these substances can be harvested and processed to make oxygen and methane. Oxygen is essential, not only for sustaining the lives of the crew on Mars, but also as the oxidizer for an oxygen-methane propulsion system that could be utilized on a Mars ascent vehicle. Given the presence of water on Mars, the electrolysis of water is a common technique to produce the desired oxygen. Towards this goal, NASA designed and developed a Proton Exchange Membrane (PEM) water electrolysis system, which was originally slated to produce oxygen for propulsion and fuel cell use in the Mars Atmosphere and Regolith COllector/PrOcessor for Lander Operations (MARCO POLO) project. As part of the Human Exploration Spacecraft Testbed for Integration and Advancement (HESTIA) project, this same electrolysis system, originally targeted at enabling in situ propulsion and power, operated in a life-support scenario. During HESTIA testing at Johnson Space Center, the electrolysis system supplied oxygen to a chamber simulating a habitat housing four crewmembers. Inside the chamber, oxygen was removed from the atmosphere to simulate consumption by the crew, and the electrolysis system's oxygen was added to replenish it. The electrolysis system operated nominally throughout the duration of the HESTIA test campaign, and the oxygen levels in the life support chamber were maintained at the desired levels.

  2. Models for integrated pest control and their biological implications.

    PubMed

    Tang, Sanyi; Cheke, Robert A

    2008-09-01

    Successful integrated pest management (IPM) control programmes depend on many factors which include host-parasitoid ratios, starting densities, timings of parasitoid releases, dosages and timings of insecticide applications and levels of host-feeding and parasitism. Mathematical models can help us to clarify and predict the effects of such factors on the stability of host-parasitoid systems, which we illustrate here by extending the classical continuous and discrete host-parasitoid models to include an IPM control programme. The results indicate that one of three control methods can maintain the host level below the economic threshold (ET) in relation to different ET levels, initial densities of host and parasitoid populations and host-parasitoid ratios. The effects of host intrinsic growth rate and parasitoid searching efficiency on host mean outbreak period can be calculated numerically from the models presented. The instantaneous pest killing rate of an insecticide application is also estimated from the models. The results imply that the modelling methods described can help in the design of appropriate control strategies and assist management decision-making. The results also indicate that a high initial density of parasitoids (such as in inundative releases) and high parasitoid inter-generational survival rates will lead to more frequent host outbreaks and, therefore, greater economic damage. The biological implications of this counter intuitive result are discussed.

  3. GW bodies: from RNA biology to clinical implications in autoimmunity.

    PubMed

    Herrera-Esparza, Rafael; Pacheco-Tovar, Deyanira; Avalos-Diaz, Esperanza

    2008-01-01

    Evaluation of: Lian S, Fritzler M, Katz J et al. Small interfering RNA-mediated silencing induces target-dependent assembly of GW/P bodies. Mol. Biol. Cell 18, 3375-3387 (2007). GW bodies (GWBs) are also known as mammalian processing bodies and are involved in 5 -3 mRNA degradation. Conversely, siRNA is a powerful tool for silencing genes. Recently, components of RNAi have been associated with GWBs, but as more components of this complex pathway become known, such relationships remain to be clarified. This paper evaluates the induction of GWBs by siRNA transfection. The main results of these studies indicate that siRNA increased the GWBs, such an increase is also dependent on the endogenous expression of the target mRNA; siRNA increases require GW182 or Ago-2 proteins, but not rck/p54 or LSm1. Results of the present studies propose a regulatory function of RNAi in GWB assembly; therefore, cell biology implications of GWBs may open a new area in pathogenic mechanisms of autoimmunity. PMID:20477583

  4. Tutorial in oral antithrombotic therapy: Biology and dental implications

    PubMed Central

    Fakhri, Hamid R.; Janket, Sok J.; Baird, Alison E.; Dinnocenzo, Richard; Meurman, Jukka H.

    2013-01-01

    Objectives: Recent developments of new direct oral anticoagulants that target specific clotting factors necessitate understanding of coagulation biology. The objective of this tutorial is to offer dental professionals a review of coagulation mechanisms and the pharmacodynamics of the conventional and new oral anticoagulants. Also, we summarized the dental implications of the conventional and new anticoagulants. Method: We searched Medline using search terms “antithrombotic”, “antihemostasis” or “anticoagulation” and combined them with the search results of “dental”, “oral surgery” or “periodontal”. We restricted the results to “human” and “English”. Results: The early coagulation cascade, the new cell-based coagulation model, the pharmacokinetics and pharmacodynamics of conventional antithrombotics, and new oral anticoagulants were reviewed. The new direct factor Xa inhibitors and the direct thrombin inhibitor (s), called direct oral anticoagulants (DOAs) have rapid onset of action, fast elimination on cessation, and fewer drug-drug or drug-food interactions than warfarin. However, the lack of antidotes raises concerns that some dental procedures may trigger serious hemorrhagic events. Additionally, careful perioperative withdrawal and resumption protocols for the DOAs are reviewed, because DOAs’ blood levels are dependent on renal function. Also, various reversal strategies in the event of excessive bleedings are summarized. Perioperative management of dental patients taking new DOAs and conventional oral anticoagulants are also discussed. However, the perioperative strategies for DOAs are yet to be validated in randomized trials. Key words:Coagulation cascade, cell-based coagulation model, factor Xa inhibitors, direct thrombin inhibitors, prothrombin complex concentrates. PMID:23524440

  5. Understanding the biological and environmental implications of nanomaterials

    NASA Astrophysics Data System (ADS)

    Lin, Sijie

    of Nano-Eco and Nano-Bio interactions at the cellular level. (6) Chapter 6: Conclusions and future work. The overarching goal of this research is to advance our understanding on the fate of nanomaterials in biological and ecological systems. Knowledge obtained from this dissertation is expected to benefit future research on the implications and applications of engineered nanomaterials.

  6. Sustaining Human Presence on Mars Using ISRU and a Reusable Lander

    NASA Technical Reports Server (NTRS)

    Arney, Dale C.; Jones, Christopher A.; Klovstad, Jordan J.; Komar, D.R.; Earle, Kevin; Moses, Robert; Shyface, Hilary R.

    2015-01-01

    This paper presents an analysis of the impact of ISRU (In-Site Resource Utilization), reusability, and automation on sustaining a human presence on Mars, requiring a transition from Earth dependence to Earth independence. The study analyzes the surface and transportation architectures and compared campaigns that revealed the importance of ISRU and reusability. A reusable Mars lander, Hercules, eliminates the need to deliver a new descent and ascent stage with each cargo and crew delivery to Mars, reducing the mass delivered from Earth. As part of an evolvable transportation architecture, this investment is key to enabling continuous human presence on Mars. The extensive use of ISRU reduces the logistics supply chain from Earth in order to support population growth at Mars. Reliable and autonomous systems, in conjunction with robotics, are required to enable ISRU architectures as systems must operate and maintain themselves while the crew is not present. A comparison of Mars campaigns is presented to show the impact of adding these investments and their ability to contribute to sustaining a human presence on Mars.

  7. Evolution of Regolith Feed Systems for Lunar ISRU 02 Production Plants

    NASA Technical Reports Server (NTRS)

    Mueller, Robert P.; Townsend, Ivan I., III; Mantovani, James G.; Metzger, Philip T.

    2010-01-01

    The In-Situ Resource Utilization (ISRU) project of the NASA Constellation Program, Exploration Technology Development Program (ETDP) has been engaged in the design and testing of various Lunar ISRU O2 production plant prototypes that can extract chemically bound oxygen from the minerals in the lunar regolith. This work demands that lunar regolith (or simulants) shall be introduced into the O2 production plant from a holding bin or hopper and subsequently expelled from the ISRU O2 production plant for disposal. This sub-system is called the Regolith Feed System (RFS) which exists in a variety of configurations depending on the O2 production plant oxygen being used (e.g. Hydrogen Reduction, Carbothermal, Molten Oxide Electrolysis). Each configuration may use a different technology and in addition it is desirable to have heat recuperation from the spent hot regolith as an integral part of the RFS. This paper addresses the various RFS and heat recuperation technologies and system configurations that have been developed under the NASA ISRU project since 2007. In addition current design solutions and lessons learned from reduced gravity flight testing will be discussed.

  8. Optimized ISRU Propellants for Propulsion and Power Needs for Future Mars Colonization

    NASA Astrophysics Data System (ADS)

    Rice, Eric E.; Gustafson, Robert J.; Gramer, Daniel J.; Chiaverini, Martin J.; Teeter, Ronald R.; White, Brant C.

    2003-01-01

    In recent studies (Rice, 2000, 2002) conducted by ORBITEC for the NASA Institute for Advanced Concepts (NIAC), we conceptualized systems and an evolving optimized architecture for producing and utilizing Mars-based in-situ space resources utilization (ISRU) propellant combinations for future Mars colonization. The propellants are to be used to support the propulsion and power systems for ground and flight vehicles. The key aspect of the study was to show the benefits of ISRU, develop an analysis methodology, as well as provide guidance to propellant system choices in the future based upon what is known today about Mars. The study time frame included an early unmanned and manned exploration period (through 2040) and two colonization scenarios that are postulated to occur from 2040 to 2090. As part of this feasibility study, ORBITEC developed two different Mars colonization scenarios: a low case that ends with a 100-person colony (an Antarctica analogy) and a high case that ends with a 10,000-person colony (a Mars terraforming scenario). A population growth model, mission traffic model, and infrastructure model were developed for each scenario to better understand the requirements of future Mars colonies. Additionally, propellant and propulsion systems design concepts were developed. Cost models were also developed to allow comparison of the different ISRU propellant approaches. This paper summarizes the overall results of the study. ISRU proved to be a key enabler for these colonization missions. Carbon monoxide and oxygen, proved to be the most cost-effective ISRU propellant combination. The entire final reports Phase I and II) and all the details can be found at the NIAC website www.niac.usra.edu.

  9. Book review: Conservation biology of Hawaiian forest birds: Implications for island avifauna

    USGS Publications Warehouse

    Engstrom, R. Todd; van Riper, Charles

    2010-01-01

    Review info: Conservation Biology of Hawaiian Forest Birds: Implications for Island Avifauna. By Thane K. Pratt, Carter T. Atkinson, Paul C. Banko, James D. Jacobi, and Bethany L. Woodworth, Eds., 2009. ISBN 978-0300141085, 707 pp.

  10. Reassessing Biological Threats: Implications for Cooperative Mitigation Strategies

    PubMed Central

    Galloway, Summer Elise; Petzing, Stephanie Rachel; Young, Catharine Grace

    2015-01-01

    Multiple factors ranging from globalization to ecosystem disruption are presenting the global community with evolving biological threats to local, national, and global security that reach beyond the realm of traditional bioweapon threats. As a result, mitigation strategies have adapted necessarily to the increased diversity of biological threats. In general, response and preparedness strategies have largely shifted from being primarily reactive to traditional biological weapons to more proactive in nature. In this review, we briefly explore biological threats through a wider aperture, to embrace a greater appreciation of viral pathogens, antimicrobial resistance, and agricultural pathogens, and their potential to cause civil, economic, and political devastation. In addition, we discuss current mitigation strategies codified by the Global Health Security Agenda and the One Health paradigm as well as some of the available tools to assist with their sustainable implementation. PMID:26649289

  11. Reassessing Biological Threats: Implications for Cooperative Mitigation Strategies.

    PubMed

    Galloway, Summer Elise; Petzing, Stephanie Rachel; Young, Catharine Grace

    2015-01-01

    Multiple factors ranging from globalization to ecosystem disruption are presenting the global community with evolving biological threats to local, national, and global security that reach beyond the realm of traditional bioweapon threats. As a result, mitigation strategies have adapted necessarily to the increased diversity of biological threats. In general, response and preparedness strategies have largely shifted from being primarily reactive to traditional biological weapons to more proactive in nature. In this review, we briefly explore biological threats through a wider aperture, to embrace a greater appreciation of viral pathogens, antimicrobial resistance, and agricultural pathogens, and their potential to cause civil, economic, and political devastation. In addition, we discuss current mitigation strategies codified by the Global Health Security Agenda and the One Health paradigm as well as some of the available tools to assist with their sustainable implementation.

  12. Self Organizing Systems and the Research Implications for Biological Systems

    NASA Astrophysics Data System (ADS)

    Denkins-Taffe, Lauren R.; Alfred, Marcus; Lindesay, James

    2008-03-01

    The knowledge gained from the human genome project, has provided an added opportunity to study the dynamical relationships within biological systems and can lead to an increased knowledge of diseases and subsequent drug discovery. Through computation, methods in which to rebuild these systems are being studied. These methods, which have first been applied to simpler systems: predator-prey, and self sustaining ecosystems can be applied to the study of microscopic biological systems.

  13. Lunar Polar In Situ Resource Utilization (ISRU) as a Stepping Stone for Human Exploration

    NASA Technical Reports Server (NTRS)

    Sanders, Gerald B.

    2013-01-01

    A major emphasis of NASA is to extend and expand human exploration across the solar system. While specific destinations are still being discussed as to what comes first, it is imperative that NASA create new technologies and approaches that make space exploration affordable and sustainable. Critical to achieving affordable and sustainable exploration beyond low Earth orbit (LEO) are the development of technologies and approaches for advanced robotics, power, propulsion, habitats, life support, and especially, space resource utilization systems. Space resources and how to use them, often called In-Situ Resource Utilization (ISRU), can have a tremendous beneficial impact on robotic and human exploration of the Moon, Mars, Phobos, and Near Earth Objects (NEOs), while at the same time helping to solve terrestrial challenges and enabling commercial space activities. The search for lunar resources, demonstration of extraterrestrial mining, and the utilization of resource-derived products, especially from polar volatiles, can be a stepping stone for subsequent human exploration missions to other destinations of interest due to the proximity of the Moon, complimentary environments and resources, and the demonstration of critical technologies, processes, and operations. ISRU and the Moon: There are four main areas of development interest with respect to finding, obtaining, extracting, and using space resources: Prospecting for resources, Production of mission critical consumables like propellants and life support gases, Civil engineering and construction, and Energy production, storage, and transfer. The search for potential resources and the production of mission critical consumables are the primary focus of current NASA technology and system development activities since they provide the greatest initial reduction in mission mass, cost, and risk. Because of the proximity of the Moon, understanding lunar resources and developing, demonstrating, and implementing lunar ISRU

  14. Component and System Sensitivity Considerations for Design of a Lunar ISRU Oxygen Production Plant

    NASA Technical Reports Server (NTRS)

    Linne, Diane L.; Gokoglu, Suleyman; Hegde, Uday G.; Balasubramaniam, Ramaswamy; Santiago-Maldonado, Edgardo

    2009-01-01

    Component and system sensitivities of some design parameters of ISRU system components are analyzed. The differences between terrestrial and lunar excavation are discussed, and a qualitative comparison of large and small excavators is started. The effect of excavator size on the size of the ISRU plant's regolith hoppers is presented. Optimum operating conditions of both hydrogen and carbothermal reduction reactors are explored using recently developed analytical models. Design parameters such as batch size, conversion fraction, and maximum particle size are considered for a hydrogen reduction reactor while batch size, conversion fraction, number of melt zones, and methane flow rate are considered for a carbothermal reduction reactor. For both reactor types the effect of reactor operation on system energy and regolith delivery requirements is presented.

  15. A Review of the Clinical Implications of Breast Cancer Biology

    PubMed Central

    Parsa, Yekta; Mirmalek, Seyed Abbas; Kani, Fatemeh Elham; Aidun, Amir; Salimi-Tabatabaee, Seyed Alireza; Yadollah-Damavandi, Soheila; Jangholi, Ehsan; Parsa, Tina; Shahverdi, Ehsan

    2016-01-01

    Background Histologically similar tumors may have different prognoses and responses to treatment. These differences are due to molecular differences. Hence, in this review, the biological interaction of breast cancer in several different areas is discussed. In addition, the performance and clinical application of the most widely-recognized biomarkers, metastasis, and recurrences from a biological perspective and current global advances in these areas are addressed. Objective This review provides the performance and clinical application of the most widely-recognized biomarkers, metastasis, and recurrences from the biological perspective and current global advances in these areas. Methods PubMed, Scopus, and Google Scholar were searched comprehensively with combinations of the following keywords: “breast cancer,” “biological markers,” and “clinical.” The definition of breast cancer, diagnostic methods, biological markers, and available treatment approaches were extracted from the literature. Results Estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER-2), and Ki-67 are the most well-known biological markers that have important roles in prognosis and response to therapeutic methods. Some studies showed the response of ER-positive and PR-negative tumors to anti-estrogenic treatment to be lower than ER-positive and PR-positive tumors. Patients with high expression of HER-2 and Ki-67 had a poor prognosis. In addition, recent investigations indicated the roles of new biomarkers, such as VEGF, IGF, P53 and P21, which are associated with many factors, such as age, race, and histological features. Conclusion The objective of scientists, from establishing a relationship between cancer biology infrastructures with clinical manifestations, is to find new ways of prevention and progression inhibition and then possible introduction of less dangerous and better treatments to resolve this dilemma of human society. PMID

  16. Experimental Testing and Modeling of a Pneumatic Regolith Delivery System for ISRU

    NASA Technical Reports Server (NTRS)

    Santiago-Maldonado, Edgardo; Dominquez, Jesus A.; Mantovani, James G.

    2011-01-01

    Excavating and transporting planetary regolith are examples of surface activities that may occur during a future space exploration mission to a planetary body. Regolith, whether it is collected on the Moon, Mars or even an asteroid, consists of granular minerals, some of which have been identified to be viable resources that can be mined and processed chemically to extract useful by-products, such as oxygen, water, and various metals and metal alloys. Even the depleted "waste" material from such chemical processes may be utilized later in the construction of landing pads and protective structures at the site of a planetary base. One reason for excavating and conveying planetary regolith is to deliver raw regolith material to in-situ resource utilization (ISRU) systems. The goal of ISRU is to provide expendable supplies and materials at the planetary destination, if possible. An in-situ capability of producing mission-critical substances such as oxygen will help to extend the mission and its success, and will greatly lower the overall cost of a mission by either eliminating, or significantly reducing, the need to transport the same expendable materials from the Earth. In order to support the goals and objectives of present and future ISRU projects, NASA seeks technology advancements in the areas of regolith conveying. Such systems must be effective, efficient and provide reliable performance over long durations while being exposed to the harsh environments found on planetary surfaces. These conditions include contact with very abrasive regolith particulates, exposure to high vacuum or dry (partial) atmospheres, wide variations in temperature, reduced gravity, and exposure to space radiation. Regolith conveying techniques that combine reduced failure modes and low energy consumption with high material transfer rates will provide significant value for future space exploration missions to the surfaces of the moon, Mars and asteroids. Pneumatic regolith conveying has

  17. ISRU at a Lunar Outpost: Implementation and Opportunities for Partnerships and Commercial Development

    NASA Technical Reports Server (NTRS)

    Sanders, Gerald B.; Simon, Thomas; Larson, William E.; Santiago-Maldonado, Edgardo; Sacksteder, Kurt; Linne, Diane; Caruso, John; Easter, Robert

    2007-01-01

    The NASA Lunar Architecture Team (LAT), which was commissioned to help answer the question "how" will humans return to the Moon, and the Synthesis Team and the recently released Global Exploration Strategy, which was commissioned to help answer the question "why" will humans return to the Moon and go on to Mars have identified the ability to extract and use in-situ resources as important to extending human frontiers, reduce dependence on Earth, and further economic and commercial expansion into space. The extraction and processing of space resources into useful products, known as In-Situ Resource Utilization (ISRU), can have a substantial impact on mission and architecture concepts. In particular, the ability to make propellants, life support consumables, and fuel cell reagents can significantly reduce the cost, mass, and risk of sustained human activities beyond Earth. Potential lunar resources include solar wind implanted volatiles, vast quantities of metal and mineral oxides, possible water/ice at the poles, abundant solar energy, regions of permanent light and darkness, the vacuum of space itself, and even scavenging leftover descent propellants and/or trash and waste from human crew activities. Suitable processing can transform these raw resources into useful materials and products. The establishment of a human lunar Outpost, as proposed by NASA at the 2nd Space Exploration Conference in Houston in December 2006, opens up the possibility for the first time of breaking our reliance on Earth supplied consumables and learn to "live off the land". The ISRU phasing and capability incorporation strategy developed during LAT Phase I & II is based on the premise that while ISRU is a critical capability and key to successful implementation of the US Vision for Space Exploration, it is also an unproven capability for human lunar exploration and can not be put in the critical path of architecture success until it has been proven. Therefore, ISRU needs to take incremental

  18. Biological implications of the Weibull and Gompertz models of aging.

    PubMed

    Ricklefs, Robert E; Scheuerlein, Alex

    2002-02-01

    Gompertz and Weibull functions imply contrasting biological causes of demographic aging. The terms describing increasing mortality with age are multiplicative and additive, respectively, which could result from an increase in the vulnerability of individuals to extrinsic causes in the Gompertz model and the predominance of intrinsic causes at older ages in the Weibull model. Experiments that manipulate extrinsic mortality can distinguish these biological models. To facilitate analyses of experimental data, we defined a single index for the rate of aging (omega) for the Weibull and Gompertz functions. Each function described the increase in aging-related mortality in simulated ages at death reasonably well. However, in contrast to the Weibull omega(W), the Gompertz omega(G) was sensitive to variation in the initial mortality rate independently of aging-related mortality. Comparisons between wild and captive populations appear to support the intrinsic-causes model for birds, but give mixed support for both models in mammals.

  19. Biological Implications of Dynamical Phases in Non-equilibrium Networks

    NASA Astrophysics Data System (ADS)

    Murugan, Arvind; Vaikuntanathan, Suriyanarayanan

    2016-03-01

    Biology achieves novel functions like error correction, ultra-sensitivity and accurate concentration measurement at the expense of free energy through Maxwell Demon-like mechanisms. The design principles and free energy trade-offs have been studied for a variety of such mechanisms. In this review, we emphasize a perspective based on dynamical phases that can explain commonalities shared by these mechanisms. Dynamical phases are defined by typical trajectories executed by non-equilibrium systems in the space of internal states. We find that coexistence of dynamical phases can have dramatic consequences for function vs free energy cost trade-offs. Dynamical phases can also provide an intuitive picture of the design principles behind such biological Maxwell Demons.

  20. Mode coupling in living systems: implications for biology and medicine.

    PubMed

    Swain, John

    2008-05-01

    Complex systems, and in particular biological ones, are characterized by large numbers of oscillations of widely differing frequencies. Various prejudices tend to lead to the assumption that such oscillators should generically be very weakly interacting. This paper reviews the basic ideas of linearity and nonlinearity as seen by a physicist, but with a view to biological systems. In particular, it is argued that large couplings between different oscillators of disparate frequencies are common, being present even in rather simple systems which are well-known in physics, although this issue is often glossed over. This suggests new experiments and investigations, as well as new approaches to therapies and human-environment interactions which, without the concepts described here, may otherwise seem unlikely to be interesting. The style of the paper is conversational with a minimum of mathematics, and no attempt at a complete list of references. PMID:18697625

  1. Biological Effects of Listeriolysin O: Implications for Vaccination

    PubMed Central

    Hernández-Flores, K. G.; Vivanco-Cid, H.

    2015-01-01

    Listeriolysin O (LLO) is a thiol-activated cholesterol-dependent pore-forming toxin and the major virulence factor of Listeria monocytogenes (LM). Extensive research in recent years has revealed that LLO exerts a wide array of biological activities, during the infection by LM or by itself as recombinant antigen. The spectrum of biological activities induced by LLO includes cytotoxicity, apoptosis induction, endoplasmic reticulum stress response, modulation of gene expression, intracellular calcium oscillations, and proinflammatory activity. In addition, LLO is a highly immunogenic toxin and the major target for innate and adaptive immune responses in different animal models and humans. Recently, the crystal structure of LLO has been published in detail. Here, we review the structure-function relationship for this fascinating microbial molecule, highlighting the potential uses of LLO in the fields of biomedicine and biotechnology, particularly in vaccination. PMID:25874208

  2. Interactions of nanomaterials and biological systems: implications to personalized nanomedicine☆

    PubMed Central

    Zhang, Xue-Qing; Xu, Xiaoyang; Bertrand, Nicolas; Pridgen, Eric; Swami, Archana; Farokhzad, Omid C.

    2012-01-01

    The application of nanotechnology to personalized medicine provides an unprecedented opportunity to improve the treatment of many diseases. Nanomaterials offer several advantages as therapeutic and diagnostic tools due to design flexibility, small sizes, large surface-to-volume ratio, and ease of surface modification with multivalent ligands to increase avidity for target molecules. Nanomaterials can be engineered to interact with specific biological components, allowing them to benefit from the insights provided by personalized medicine techniques. To tailor these interactions, a comprehensive knowledge of how nanomaterials interact with biological systems is critical. Herein, we discuss how the interactions of nanomaterials with biological systems can guide their design for diagnostic, imaging and drug delivery purposes. A general overview of nanomaterials under investigation is provided with an emphasis on systems that have reached clinical trials. Finally, considerations for the development of personalized nanomedicines are summarized such as the potential toxicity, scientific and technical challenges in fabricating them, and regulatory and ethical issues raised by the utilization of nanomaterials. PMID:22917779

  3. Biological framework for soil aggregation: Implications for ecological functions.

    NASA Astrophysics Data System (ADS)

    Ghezzehei, Teamrat; Or, Dani

    2016-04-01

    Soil aggregation is heuristically understood as agglomeration of primary particles bound together by biotic and abiotic cementing agents. The organization of aggregates is believed to be hierarchical in nature; whereby primary particles bond together to form secondary particles and subsequently merge to form larger aggregates. Soil aggregates are not permanent structures, they continuously change in response to internal and external forces and other drivers, including moisture, capillary pressure, temperature, biological activity, and human disturbances. Soil aggregation processes and the resulting functionality span multiple spatial and temporal scales. The intertwined biological and physical nature of soil aggregation, and the time scales involved precluded a universally applicable and quantifiable framework for characterizing the nature and function of soil aggregation. We introduce a biophysical framework of soil aggregation that considers the various modes and factors of the genesis, maturation and degradation of soil aggregates including wetting/drying cycles, soil mechanical processes, biological activity and the nature of primary soil particles. The framework attempts to disentangle mechanical (compaction and soil fragmentation) from in-situ biophysical aggregation and provides a consistent description of aggregate size, hierarchical organization, and life time. It also enables quantitative description of biotic and abiotic functions of soil aggregates including diffusion and storage of mass and energy as well as role of aggregates as hot spots of nutrient accumulation, biodiversity, and biogeochemical cycles.

  4. Opportunities and Strategies for Testing and Infusion of ISRU in the Evolvable Mars Campaign

    NASA Technical Reports Server (NTRS)

    Mueller, Robert P.; Sibille, Laurent; Mantovani, James; Sanders, Gerald B.; Jones, Christopher A.

    2015-01-01

    HE Evolvable Mars Campaign (EMC) is developing the plans and systems needed for a robust, evolutionary strategy to explore cis-lunar space, the Mars sphere of influence (including the moons of Mars), and the surface of Mars. Recently, the emphasis of NASA's plans has changed to focus on the prolonged pioneering of space, rather than focusing on a single crewed mission as the ultimate goal. A sustainable, pioneering vision of space would include in-situ resource utilization (ISRU) in multiple forms and at multiple destinations: atmospheric capture of Mars CO2 and/or volatiles for consumables and propellants, regolith for bulk and refined materials, and in-situ manufacturing at the Moon, Mars, and other bodies. These resources would enable a reduction in the logistical needs from Earth for future missions, thus preparing the way for a sustained presence on Mars. Although the EMC initially relies only on propellant production for the Mars ascent vehicle via ISRU, one of its primary objectives is to prospect at every EMC destination to understand the potential for ISRU; this will permit true pioneering to be enabled after the first crew arrives at Mars. Recent and ongoing analysis has considered the possible prospecting measurements that can be performed at the asteroid returned to cis-lunar space by the Asteroid Robotic Redirect Mission (ARRM), at the lunar surface, at Phobos and Deimos, and on the surface of Mars to identify available resources for future use. These opportunities will be available on missions currently in the Evolvable Mars Campaign construct, and will also facilitate the testing and demonstration of resource acquisition, processing, storage, and useage technologies that can play a role in later missions. This analysis has also led to the identification of several objectives that should be targeted during the missions building up to and including the initial crewed missions. These objectives are mapped to strategies for incorporating ISRU to support

  5. Biological versus chronological ovarian age: implications for assisted reproductive technology

    PubMed Central

    Alviggi, Carlo; Humaidan, Peter; Howles, Colin M; Tredway, Donald; Hillier, Stephen G

    2009-01-01

    Background Women have been able to delay childbearing since effective contraception became available in the 1960s. However, fertility decreases with increasing maternal age. A slow but steady decrease in fertility is observed in women aged between 30 and 35 years, which is followed by an accelerated decline among women aged over 35 years. A combination of delayed childbearing and reduced fecundity with increasing age has resulted in an increased number and proportion of women of greater than or equal to 35 years of age seeking assisted reproductive technology (ART) treatment. Methods Literature searches supplemented with the authors' knowledge. Results Despite major advances in medical technology, there is currently no ART treatment strategy that can fully compensate for the natural decline in fertility with increasing female age. Although chronological age is the most important predictor of ovarian response to follicle-stimulating hormone, the rate of reproductive ageing and ovarian sensitivity to gonadotrophins varies considerably among individuals. Both environmental and genetic factors contribute to depletion of the ovarian oocyte pool and reduction in oocyte quality. Thus, biological and chronological ovarian age are not always equivalent. Furthermore, biological age is more important than chronological age in predicting the outcome of ART. As older patients present increasingly for ART treatment, it will become more important to critically assess prognosis, counsel appropriately and optimize treatment strategies. Several genetic markers and biomarkers (such as anti-Müllerian hormone and the antral follicle count) are emerging that can identify women with accelerated biological ovarian ageing. Potential strategies for improving ovarian response include the use of luteinizing hormone (LH) and growth hormone (GH). When endogenous LH levels are heavily suppressed by gonadotrophin-releasing hormone analogues, LH supplementation may help to optimize treatment

  6. Understanding the biological and environmental implications of nanomaterials

    NASA Astrophysics Data System (ADS)

    Lin, Sijie

    The last two decades have witnessed the discovery, development, and large-scale manufacturing of novel nanomaterials. While nanomaterials bring in exciting and extraordinary properties in all areas of materials, electronics, mechanics, and medicine, they also could generate potential adverse effects in biological systems and in the environment. The currently limited application of nanomaterials in biological and ecological systems results from the insufficient and often controversial data on describing the complex behaviors of nanomaterials in living systems. The purpose of this dissertation intends to fill such a knowledge void with methodologies from the disciplines of biophysics, biology, and materials science and engineering. Chapter 1 of this dissertation provides a comprehensive review on the structures and properties of carbon nanomaterials (CBNMs), metal oxides, and quantum dots (QDs). This chapter also details the state-of-the-art on the biological applications, ecological applications, and toxicity of nanomaterials. With Chapter 1 serving as a background, Chapters 2-5 present my PhD research, an inquiry on the fate of nanomaterials in biological and ecological systems, on the whole organism and cellular levels. Specifically, CBNMs are introduced to rice plant seedlings and the uptake, translocation and generational transfer of fullerene C70 in the plant compartments are imaged and characterized. The interactions between CBNMs and rice plants on the whole organism level are initiated by the binding between CBNMs and natural organic matter (NOM), driven by the transpiration of water from the roots to the leaves of the plants and mediated by both the physiochemical properties of the CBNMs and plant physiology. In Chapter 3, semiconducting nanocrystals quantum dots (QDs) are introduced to green algae Chlamydomonas to probe the interactions of nanomaterials with ecological systems on the cellular level. The adsorption of QDs onto the algal cell wall is

  7. The photochemistry of fluorescent proteins: implications for their biological applications.

    PubMed

    Seward, Harriet E; Bagshaw, Clive R

    2009-10-01

    Green fluorescent protein from Aequorea victoria, its relatives and derivatives are ubiquitous in their use as biological probes. In this tutorial review, we discuss the photochemistry of this fascinating class of proteins and illustrate some of their advantages and drawbacks in a range of applications. In particular, we focus on the ionisation states of the chromophore and how they are affected by internal and external proton transfer. Light-induced reversible and irreversible events are discussed in terms of the underlying chromophore structure. These phenomena have an influence on the interpretation of FRET (Förster resonance energy transfer), FRAP (fluorescence recovery after photobleaching), as well as single molecule studies.

  8. Multiple biological properties of macelignan and its pharmacological implications.

    PubMed

    Paul, Saswati; Hwang, Jae Kwan; Kim, Hahn Young; Jeon, Won Kyung; Chung, ChiHye; Han, Jung-Soo

    2013-03-01

    Macelignan found in the nutmeg mace of Myristica fragrans obtains increasing attention as a new avenue in treating various diseases. Macelignan has been shown to possess a spectrum of pharmacological activities, including anti-bacterial, anti-inflammatory, anti-cancer, anti-diabetes, and hepatoprotective activities; recently, it has also been shown to have neuroprotective activities. This review summarizes the current research on the biological effects of macelignan derived from M. fragrans, with emphasis on the importance in understanding and treating complex diseases such as cancer and Alzheimer's disease.

  9. Multiple biological properties of macelignan and its pharmacological implications.

    PubMed

    Paul, Saswati; Hwang, Jae Kwan; Kim, Hahn Young; Jeon, Won Kyung; Chung, ChiHye; Han, Jung-Soo

    2013-03-01

    Macelignan found in the nutmeg mace of Myristica fragrans obtains increasing attention as a new avenue in treating various diseases. Macelignan has been shown to possess a spectrum of pharmacological activities, including anti-bacterial, anti-inflammatory, anti-cancer, anti-diabetes, and hepatoprotective activities; recently, it has also been shown to have neuroprotective activities. This review summarizes the current research on the biological effects of macelignan derived from M. fragrans, with emphasis on the importance in understanding and treating complex diseases such as cancer and Alzheimer's disease. PMID:23435944

  10. A brief review of chemical and mineralogical resources on the Moon and likely initial in situ resource utilization (ISRU) applications

    NASA Astrophysics Data System (ADS)

    Anand, M.; Crawford, I. A.; Balat-Pichelin, M.; Abanades, S.; van Westrenen, W.; Péraudeau, G.; Jaumann, R.; Seboldt, W.

    2012-12-01

    In situ resource utilization (ISRU) refers to the in situ generation of consumables for autonomous or human activities from raw materials found on the Moon or other planetary bodies. The use of ISRU on the Moon may provide a means of reducing the cost and risk of human exploration of the Moon and beyond, and an impetus for commercial contributions to lunar exploration. Potential products include O2 and H2O for life support, H2 and O2 for fuel and propellant, and other elements and compounds for metallurgic and chemical production processes. If ISRU is to be applied successfully on the Moon, it is important that landing site selection, surface operations and suitable ISRU technologies are identified using knowledge of the availability and distribution of lunar resources and detailed understanding of the workings of the various processes available. Here, we review current knowledge of chemical and mineralogical resources on the Moon which can be used in the development of ISRU as a realistic component of future lunar exploration.

  11. Glioblastoma Stem-Like Cells—Biology and Therapeutic Implications

    PubMed Central

    Gürsel, Demirkan B.; Shin, Benjamin J.; Burkhardt, Jan-Karl; Kesavabhotla, Kartik; Schlaff, Cody D.; Boockvar, John A.

    2011-01-01

    The cancer stem-cell hypothesis proposes that malignant tumors are likely to encompass a cellular hierarchy that parallels normal tissue and may be responsible for the maintenance and recurrence of glioblastoma multiforme (GBM) in patients. The purpose of this manuscript is to review methods for optimizing the derivation and culturing of stem-like cells also known as tumor stem cells (TSCs) from patient-derived GBM tissue samples. The hallmarks of TSCs are that they must be able to self-renew and retain tumorigenicity. The isolation, optimization and derivation of TSCs as outlined in this review, will be important in understanding biology and therapeutic applications related to these cells. PMID:21796273

  12. Ocean Biological Pump Sensitivities and Implications for Climate Change Impacts

    NASA Technical Reports Server (NTRS)

    Romanou, Anastasia

    2013-01-01

    The ocean is one of the principal reservoirs of CO2, a greenhouse gas, and therefore plays a crucial role in regulating Earth's climate. Currently, the ocean sequesters about a third of anthropogenic CO2 emissions, mitigating the human impact on climate. At the same time, the deeper ocean represents the largest carbon pool in the Earth System and processes that describe the transfer of carbon from the surface of the ocean to depth are intimately linked to the effectiveness of carbon sequestration.The ocean biological pump (OBP), which involves several biogeochemical processes, is a major pathway for transfer of carbon from the surface mixed layer into the ocean interior. About 75 of the carbon vertical gradient is due to the carbon pump with only 25 attributed to the solubility pump. However, the relative importance and role of the two pumps is poorly constrained. OBP is further divided to the organic carbon pump (soft tissue pump) and the carbonate pump, with the former exporting about 10 times more carbon than the latter through processes like remineralization.Major uncertainties about OBP, and hence in the carbon uptake and sequestration, stem from uncertainties in processes involved in OBP such as particulate organicinorganic carbon sinkingsettling, remineralization, microbial degradation of DOC and uptakegrowth rate changes of the ocean biology. The deep ocean is a major sink of atmospheric CO2 in scales of hundreds to thousands of years, but how the export efficiency (i.e. the fraction of total carbon fixation at the surface that is transported at depth) is affected by climate change remains largely undetermined. These processes affect the ocean chemistry (alkalinity, pH, DIC, particulate and dissolved organic carbon) as well as the ecology (biodiversity, functional groups and their interactions) in the ocean. It is important to have a rigorous, quantitative understanding of the uncertainties involved in the observational measurements, the models and the

  13. Trends and implications of biological analyses for agricultural operations

    SciTech Connect

    Ash, D.H.; Salladay, D.G.

    1994-10-01

    State and federal legislatures, regulatory agencies, the agricultural community, and the public at large have increasing concerns about groundwater contamination and other environmental issues. The U.S. Congress has requested all federal agencies working with agriculture to address these issues. Even with current pressures to {open_quotes}cut government spending,{close_quotes} public pressure prevails to clean up polluted sites and to prevent future contamination. Farmers, agrichemical dealers and producers, and related trade associations have voiced concern about regulations affecting their industries. Over the last three decades positive changes have evolved in the disposal or final resolution of agricultural wastes from indiscriminate disposal on land and in water, through regulated land filling and incineration to a point where biological treatment/remediation strategies are coming to the forefront. These biological strategies bring with them different requirements for analytical methods. In March of this year the Environmental Protection Agency (EPA) and ARA organized a work group which met in Cincinnati, Ohio, to discuss the bioremediation of pesticide-laden soil. This work group consisted of EPA researchers, regulators, and administrators; state ag-environmental technologists and program directors; ag-chemical producer, remediation program managers, university ag researchers, USDA researchers, and TVA technologists. Consensus was quickly obtained on the utter unaffordability of current chemical and thermal treatment schemes for agricultural wastes, contaminated soils, and rinsewaters. Consensus was also reached that conventional analytical methods are too expensive and complicated for use in the field demonstration/application of the bioremediation-type processes. Thus the group recommended and supported field agrichemical dealer demonstrations of landfarming and composting with an emphasis on the need to develop low cost, easy toxicological measurements.

  14. Germline PTPRD mutations in Ewing sarcoma: biologic and clinical implications.

    PubMed

    Jiang, Yunyun; Janku, Filip; Subbiah, Vivek; Angelo, Laura S; Naing, Aung; Anderson, Peter M; Herzog, Cynthia E; Fu, Siqing; Benjamin, Robert S; Kurzrock, Razelle

    2013-06-01

    Ewing sarcoma occurs in children, adolescents and young adults. High STAT3 levels have been reported in approximately 50% of patients with Ewing sarcoma, and may be important in tumorigenesis. Protein tyrosine phosphatase delta (PTPRD) is a tumor suppressor that inhibits STAT3 activation. To date, while somatic mutations in PTPRD have been reported in diverse tumors, germline mutations of PTPRD have not been investigated in Ewing sarcoma or other cancers. We identified a novel germline mutation in the PTPRD gene in three of eight patients (37.5%) with metastatic Ewing sarcoma. Although the functional impact in two of the patients is unclear, in one of them the aberration was annotated as a W775stop germline mutation, and would be expected to lead to gene truncation and, hence, loss of the STAT3 dephosphorylation function of PTPRD. Since STAT3 is phosphorylated after being recruited to the insulin growth factor receptor (IGF-1R), suppression of IGF-1R could attenuate the enhanced STAT3 activation expected in the presence of PTPRD mutations. Of interest, two of three patients with germline PTPRD mutations achieved durable complete responses following treatment with IGF-1R monoclonal antibody-based therapies. Our pilot data suggest that PTPRD germline mutations may play a role in the development of Ewing sarcoma, a disease of young people, and their presence may have implications for therapy.

  15. The Microbiome of Animals: Implications for Conservation Biology.

    PubMed

    Bahrndorff, Simon; Alemu, Tibebu; Alemneh, Temesgen; Lund Nielsen, Jeppe

    2016-01-01

    In recent years the human microbiome has become a growing area of research and it is becoming clear that the microbiome of humans plays an important role for human health. Extensive research is now going into cataloging and annotating the functional role of the human microbiome. The ability to explore and describe the microbiome of any species has become possible due to new methods for sequencing. These techniques allow comprehensive surveys of the composition of the microbiome of nonmodel organisms of which relatively little is known. Some attention has been paid to the microbiome of insect species including important vectors of pathogens of human and veterinary importance, agricultural pests, and model species. Together these studies suggest that the microbiome of insects is highly dependent on the environment, species, and populations and affects the fitness of species. These fitness effects can have important implications for the conservation and management of species and populations. Further, these results are important for our understanding of invasion of nonnative species, responses to pathogens, and responses to chemicals and global climate change in the present and future. PMID:27195280

  16. The Microbiome of Animals: Implications for Conservation Biology

    PubMed Central

    Bahrndorff, Simon; Alemu, Tibebu; Alemneh, Temesgen; Lund Nielsen, Jeppe

    2016-01-01

    In recent years the human microbiome has become a growing area of research and it is becoming clear that the microbiome of humans plays an important role for human health. Extensive research is now going into cataloging and annotating the functional role of the human microbiome. The ability to explore and describe the microbiome of any species has become possible due to new methods for sequencing. These techniques allow comprehensive surveys of the composition of the microbiome of nonmodel organisms of which relatively little is known. Some attention has been paid to the microbiome of insect species including important vectors of pathogens of human and veterinary importance, agricultural pests, and model species. Together these studies suggest that the microbiome of insects is highly dependent on the environment, species, and populations and affects the fitness of species. These fitness effects can have important implications for the conservation and management of species and populations. Further, these results are important for our understanding of invasion of nonnative species, responses to pathogens, and responses to chemicals and global climate change in the present and future. PMID:27195280

  17. The Microbiome of Animals: Implications for Conservation Biology.

    PubMed

    Bahrndorff, Simon; Alemu, Tibebu; Alemneh, Temesgen; Lund Nielsen, Jeppe

    2016-01-01

    In recent years the human microbiome has become a growing area of research and it is becoming clear that the microbiome of humans plays an important role for human health. Extensive research is now going into cataloging and annotating the functional role of the human microbiome. The ability to explore and describe the microbiome of any species has become possible due to new methods for sequencing. These techniques allow comprehensive surveys of the composition of the microbiome of nonmodel organisms of which relatively little is known. Some attention has been paid to the microbiome of insect species including important vectors of pathogens of human and veterinary importance, agricultural pests, and model species. Together these studies suggest that the microbiome of insects is highly dependent on the environment, species, and populations and affects the fitness of species. These fitness effects can have important implications for the conservation and management of species and populations. Further, these results are important for our understanding of invasion of nonnative species, responses to pathogens, and responses to chemicals and global climate change in the present and future.

  18. B cell biology: implications for treatment of systemic lupus erythematosus.

    PubMed

    Anolik, J H

    2013-04-01

    B cells are critical players in the orchestration of properly regulated immune responses, normally providing protective immunity without autoimmunity. Balance in the B cell compartment is achieved through the finely regulated participation of multiple B cell populations with different antibody-dependent and independent functions. Both types of functions allow B cells to modulate other components of the innate and adaptive immune system. Autoantibody-independent B cell functions include antigen presentation, T cell activation and polarization, and dendritic cell modulation. Several of these functions are mediated by the ability of B cells to produce immunoregulatory cytokines and chemokines and by their critical contribution to lymphoid tissue development and organization including the development of ectopic tertiary lymphoid tissue. Additionally, the functional versatility of B cells enables them to play either protective or pathogenic roles in autoimmunity. In turn, B cell dysfunction has been critically implicated in the pathophysiology of systemic lupus erythematosus (SLE), a complex disease characterized by the production of autoantibodies and heterogeneous clinical involvement. Thus, the breakdown of B cell tolerance is a defining and early event in the disease process and may occur by multiple pathways, including alterations in factors that affect B cell activation thresholds, B cell longevity, and apoptotic cell processing. Once tolerance is broken, autoantibodies contribute to autoimmunity by multiple mechanisms including immune-complex mediated Type III hypersensitivity reactions, type II antibody-dependent cytotoxicity, and by instructing innate immune cells to produce pathogenic cytokines including IFNα, TNF and IL-1. The complexity of B cell functions has been highlighted by the variable success of B cell-targeted therapies in multiple autoimmune diseases, including those conventionally viewed as T cell-mediated conditions. Given the widespread

  19. Biological maturation of youth athletes: assessment and implications.

    PubMed

    Malina, Robert M; Rogol, Alan D; Cumming, Sean P; Coelho e Silva, Manuel J; Figueiredo, Antonio J

    2015-07-01

    The search for talent is pervasive in youth sports. Selection/exclusion in many sports follows a maturity-related gradient largely during the interval of puberty and growth spurt. As such, there is emphasis on methods for assessing maturation. Commonly used methods for assessing status (skeletal age, secondary sex characteristics) and estimating timing (ages at peak height velocity (PHV) and menarche) in youth athletes and two relatively recent anthropometric (non-invasive) methods (status-percentage of predicted near adult height attained at observation, timing-predicted maturity offset/age at PHV) are described and evaluated. The latter methods need further validation with athletes. Currently available data on the maturity status and timing of youth athletes are subsequently summarised. Selection for sport and potential maturity-related correlates are then discussed in the context of talent development and associated models. Talent development from novice to elite is superimposed on a constantly changing base-the processes of physical growth, biological maturation and behavioural development, which occur simultaneously and interact with each other. The processes which are highly individualised also interact with the demands of a sport per se and with involved adults (coaches, trainers, administrators, parents/guardians).

  20. Pressure effect on inverse temperature transitions: biological implications

    NASA Astrophysics Data System (ADS)

    Urry, Dan W.; Hayes, Larry C.; Channe Gowda, D.; Parker, Timothy M.

    1991-07-01

    Elastic protein-based polymers of the form poly [ fx(VPGXG), fv(VPGVG)], where fx and fv are mole fractions with fx+ fv=1, exhibit inverse temperature transitions in the form of a phase separation in which folding and aggregation of polymer chains into more-ordered states of the condensed (coacervate) phase occurs on raising the temperature. When X = Trp, Phe or Tyr, an increase in pressure causes a substantial increase in the temperature of the transition. The data are interpreted to indicate that water molecules surrounding the aromatic side chains of Trp(W), Phe(F) or Tyr(Y) occupy less volume than water molecules in bulk water. The calculated volume change for poly[0.8(GVGVP), 0.2(GFGVP)], for example, on going from coacervate phase, where hydrophobic associations have largely eliminated waters of hydrophobic hydration, to be dispersed in water where the hydrophobic moieties are surrounded by water is 80 cm 3/mol of mean pentamers or some 400 cm 3/mol of (GFGVP). The results provide an understanding of the source of pressure effects in biological systems and for the capacity to design materials capable of exhibiting baromechanical transduction.

  1. Biology of colorectal pulmonary metastasis: implications for surgical resection.

    PubMed

    Poullis, Michael; Littler, John; Gosney, John

    2012-02-01

    In colorectal cancer, little high grade evidence for cure, life extension, disease modification or palliation achieved by pulmonary metastasectomy exists. This has prompted the pulmonary metastasectomy in colorectal cancer (PulMiCC) trial. Reappraisal of the biological facts on colorectal metastasis may, however, shed light on an alternative avenue of clinical management. Early onset of metastasis, short doubling time and a short disease-free interval are all associated with poor clinical outcomes. Selecting who will be cured (i.e. no occult metastasis) remains the holy grail for pulmonary metastasectomy surgery. Serial CT scans can be utilized to calculate the tumour doubling time by volumetric analysis. Knowing the doubling time and size of the largest metastasis, which by definition is the first cell that has successfully spread from the primary site, the time of initial metastasis can be predicted. More importantly, using the doubling time, calculating the time interval from the primary surgery to the point at which all pulmonary metastases are visible should be possible. Perhaps watchful waiting, with interval CT scanning, followed by pulmonary metastasectomy should be utilized, rather than clinical opinion or randomization in a trial based upon first presentation. PMID:22159245

  2. Mars Simulant Development for In-Situ Resource Utilization (ISRU) Applications

    NASA Technical Reports Server (NTRS)

    Ming, Doug

    2016-01-01

    Current design reference missions for the Evolvable Mars Campaign (EMC) call for the use of in-situ resources to enable human missions to the surface of Mars. One potential resource is water extracted from the Martian regolith. Current Mars' soil analogs (JSC Mars-1) have 5-10 times more water than typical regolith on Mars. Therefore, there is a critical need to develop Mars simulants to be used in ISRU applications that mimic the chemical, mineralogical, and physical properties of the Martian regolith.

  3. Resource Prospector (RP: )A Lunar Volatiles Prospecting and In-Situ Resource Utilization (ISRU) Demonstration Mission

    NASA Technical Reports Server (NTRS)

    Andrews, Daniel

    2016-01-01

    Efficient expansion of human presence beyond low-Earth orbit to asteroids and Mars will require the maximum possible use of local materials, so-called in-situ resources. The moon presents a unique destination to conduct robotic investigations that advance ISRU capabilities, as well as provide significant exploration and science value. Since the moons polar regions have confirmed the presence of volatiles, as revealed by the LCROSS and LRO missions, the next step is to understand the nature and distribution of those candidate resources and how they might be extracted. Recent studies have even indicated that if those volatiles are practically available for harvesting, they could be processed into propellants and human life-support resources, significantly reducing the cost of human missions to Mars maybe by as much as 50!Resource Prospector (RP) is an in-situ resource utilization (ISRU) technology demonstration mission under study by the NASA Human Exploration and Operations Mission Directorates (HEOMD). This clever mission is currently planned to launch as early as 2021 and will demonstrate extraction of oxygen, water and other volatiles, as well measure mineralogical content such as silicon and light metals from lunar regolith.

  4. Trade Study of Excavation Tools and Equipment for Lunar Outpost Development and ISRU

    NASA Astrophysics Data System (ADS)

    Mueller, R. P.; King, R. H.

    2008-01-01

    The NASA Lunar Architecture Team (LAT) has developed a candidate architecture to establish a lunar outpost that includes in-situ resource utilization (ISRU). Outpost development requires excavation for landing and launch sites, roads, trenches, foundations, radiation and thermal shielding, etc. Furthermore, ISRU requires excavation as feed stock for water processing and oxygen production plants. The design environment for lunar excavation tools and equipment including low gravity, cost of launching massive equipment, limited power, limited size, high reliability, and extreme temperatures is significantly different from terrestrial excavation equipment design environment. Consequently, the lunar application requires new approaches to developing excavation tools and equipment in the context of a systems engineering approach to building a Lunar Outpost. Several authors have proposed interesting and innovative general excavation approaches in the literature, and the authors of this paper will propose adaptations and/or new excavation concepts specific to the Lunar Outpost. The requirements for excavation from the LAT architecture will be examined and quantified with corresponding figures of merit and evaluation criteria. This paper will evaluate the proposed approaches using traditional decision making with uncertainty techniques.

  5. ISRU 3D printing for habitats and structures on the Moon

    NASA Astrophysics Data System (ADS)

    Cowley, Aidan

    2016-07-01

    In-situ-resource utilisation (ISRU) in combination with 3D printing may evolve into a key technology for future exploration. Setting up a lunar facility could be made much simpler by using additive manufacturing techniques to build elements from local materials - this would drastically reduce mission mass requirements and act as an excellent demonstrator for ISRU on other planetary bodies. Fabricating structures and components using Lunar regolith is an area of interest for ESA, as evidenced by past successful General Studies Program (GSP) and ongoing technology development studies. In this talk we detail a number of projects looking into the behavior of Lunar regolith simulants, their compositional variants and approaches to sintering such material that are under-way involving EAC, ESTEC and DLR. We report on early studies into utilizing conventional thermal sintering approaches of simulants as well as microwave sintering of these compositions. Both techniques are candidates for developing a 3D printing methodology using Lunar regolith. It is known that the differences in microwave effects between the actual lunar soil and lunar simulants can be readily ascribed to the presence of nanophase metallic Fe, native to Lunar regolith but lacking in simulants. In compostions of simulant with increased Illmenite (FeTiO3) concentrations, we observe improved regolith response to microwave heating, and the readily achieved formation of a glassy melt in ambient atmosphere. The improved response relative to untreated simulant is likely owing to the increased Fe content in the powder mix.

  6. The Development of ISRU and ISSE Technologies Leveraging Canadian Mining Expertise

    NASA Astrophysics Data System (ADS)

    Boucher, Dale S.; Richard, Jim; Dupuis, Erick

    2003-01-01

    F uture space missions to planetary bodies, both manned and robotic, will require the efficient utilization of in-situ resources to ensure longevity and success. In Situ Resources Utilization (ISRU) and In Situ Support Equipment (ISSE), while requiring the development of new technologies and methods for commodity extraction, will still rely upon some method of mining technology for the harvesting and pre-beneficiation of the raw materials prior to processing. The Northern Centre for Advanced Technologies Inc., in partnership with Electric Vehicle Controllers Ltd., is presently engaged in the development and adaptation of existing mining technologies and methodologies for use extra-terrestrially as pre cursor and enabling technologies for ISRU and for use as ISSE in support of longer term missions. More specifically, NORCAT and EVC, in partnership with MD Robotics and under contract to the Canadian Space Agency, are developing a drill and sample handler system for sub surface sampling of planetary bodies, specifically Mars. The partnership brings to the table some formidable world leading expertise in space robotics coupled with world leading expertise in mining technologies.

  7. Asteroid and Lava Tube In Situ Resource Utilization (ISRU) Prospecting Free Flyer Project

    NASA Technical Reports Server (NTRS)

    Falker, John; Zeitlin, Nancy; Mueller, Robert; Dupuis, Michael

    2015-01-01

    This project seeks to develop a small free flyer that can be used to safely and effectively prospect on an Asteroid while being controlled by the crew. This will enable the characterization of the Asteroid for the In Situ Resource Utilization (ISRU). Lava tubes can be explored remotely from the outside Asteroids can contain vast amounts of resources such as water for propellants and metals for feed stocks. Lava Tubes on Mars and the Moon may contain frozen volatile resources. Before the resources can be used, they must be found with a prospecting method. The NASA Agency Asteroid Grand Challenge seeks new ideas for Asteroid retrieval mission technologies for exploration and utilization of asteroids in a Distant Retrograde Orbit (DRO). This project will develop a small free flying platform that can be used to safely and effectively prospect on an Asteroid with limited autonomy while being controlled by the crew. This will enable the characterization of the Asteroid for ISRU. Lava tubes can be explored remotely from the outside as well using this same technology.

  8. Preface: Terrestrial Fieldwork to Support in situ Resource Utilization (ISRU) and Robotic Resource Prospecting for Future Activities in Space

    NASA Astrophysics Data System (ADS)

    Sanders, Gerald B.

    2015-05-01

    Finding, extracting, and using resources at the site of robotic and human exploration activities holds the promise of enabling sustainable and affordable exploration of the Moon, Mars, and asteroids, and eventually allow humans to expand their economy and habitation beyond the surface of the Earth. Commonly referred to as in situ Resource Utilization (ISRU), mineral and volatile resources found in space can be converted into oxygen, water, metals, fuels, and manufacturing and construction materials (such as plastics and concrete) for transportation, power, life support, habitation construction, and part/logistics manufacturing applications. For every kilogram of payload landed on the surface of the Moon or Mars, 7.5-11 kg of payload (mostly propellant) needs to be launched into low Earth orbit. Therefore, besides promising long-term self-sufficiency and infrastructure growth, ISRU can provide significant reductions in launch costs and the number of launches required. Key to being able to use space resources is knowing where they are located, how much is there, and how the resources are distributed. While ISRU holds great promise, it has also never been demonstrated in an actual space mission. Therefore, operations and hardware associated with each ISRU prospecting, excavation, transportation, and processing step must be examined, tested, and finally integrated to enable the end goal of using space resources in future human space missions.

  9. In-situ Resource Utilization (ISRU) to Support the Lunar Outpost and the Rationale for Precursor Missions

    NASA Technical Reports Server (NTRS)

    Simon, Thomas M.

    2008-01-01

    One of the ways that the Constellation Program can differ from Apollo is to employ a live-off-the-land or In-Situ Resource Utilization (ISRU) supported architecture. The options considered over the past decades for using indigenous materials have varied considerably in terms of what resources to attempt to acquire, how much to acquire, and what the motivations are to acquiring these resources. The latest NASA concepts for supporting the lunar outpost have considered many of these plans and compared these options to customers requirements and desires. Depending on the architecture employed, ISRU technologies can make a significant contribution towards a sustainable and affordable lunar outpost. While extensive ground testing will reduce some mission risk, one or more flight demonstrations prior to the first crew's arrival will build confidence and increase the chance that outpost architects will include ISRU as part of the early outpost architecture. This presentation includes some of the options for using ISRU that are under consideration for the lunar outpost, the precursor missions that would support these applications, and a notional timeline to allow the lessons learned from the precursor missions to support outpost hardware designs.

  10. Causal attributions of obese men and women in genetic testing: implications of genetic/biological attributions.

    PubMed

    Hilbert, Anja; Dierk, Jan-Michael; Conradt, Matthias; Schlumberger, Pia; Hinney, Anke; Hebebrand, Johannes; Rief, Winfried

    2009-09-01

    The present study sought to investigate genetic/biological attributions of obesity, their associations with a predisposition to obesity and their crossectional and longitudinal implications for weight regulation in obese individuals presenting for genetic testing and counselling. A total of 421 obese men and women underwent psychological and anthropometric assessment and a mutation screen of the melanocortin-4 receptor gene. At study entry, women revealed more genetic/biological attributions than men on the Revised Illness Perception Questionnaire adapted to obesity (86.2% versus 59.7%). Genetic/biological attributions of obesity were associated in both sexes with a family history of obesity, assessed through Stunkard's Figure Rating Scale. In both sexes, genetic/biological attributions were unrelated to weight regulation beliefs and behaviour (i.e. self-efficacy, controllability beliefs, restrained eating and physical activity), assessed through standardised questionnaires or interview at baseline and at six-month follow-up. In addition, causal attributions and weight regulation beliefs and behaviour were not predictive of body mass index at six-month follow-up. Overall, the results indicate that causal attributions of obesity to genetic/biological factors in obese individuals presenting for genetic screening and counselling are crossectionally and longitudinally unrelated to weight regulation and longer-term weight outcome. Those who attribute their obesity to genetic/biological factors likely have a familial obesity risk. PMID:20205024

  11. A Re-examination of the Fine Structure of the Living Cell and its Implications for Biological Education.

    ERIC Educational Resources Information Center

    Hillman, Harold; Sartory, Peter

    1980-01-01

    Presents a summary of evidence suggesting that certain cellular parts may be artifacts arising during preparation of tissues for electron microscopy and discusses implications of same for biology curriculum and instruction. (SK)

  12. Mars Sample Return and Flight Test of a Small Bimodal Nuclear Rocket and ISRU Plant

    NASA Technical Reports Server (NTRS)

    George, Jeffrey A.; Wolinsky, Jason J.; Bilyeu, Michael B.; Scott, John H.

    2014-01-01

    A combined Nuclear Thermal Rocket (NTR) flight test and Mars Sample Return mission (MSR) is explored as a means of "jump-starting" NTR development. Development of a small-scale engine with relevant fuel and performance could more affordably and quickly "pathfind" the way to larger scale engines. A flight test with subsequent inflight postirradiation evaluation may also be more affordable and expedient compared to ground testing and associated facilities and approvals. Mission trades and a reference scenario based upon a single expendable launch vehicle (ELV) are discussed. A novel "single stack" spacecraft/lander/ascent vehicle concept is described configured around a "top-mounted" downward firing NTR, reusable common tank, and "bottom-mount" bus, payload and landing gear. Requirements for a hypothetical NTR engine are described that would be capable of direct thermal propulsion with either hydrogen or methane propellant, and modest electrical power generation during cruise and Mars surface insitu resource utilization (ISRU) propellant production.

  13. Performance of Adsorption - Based CO2 Acquisition Hardware for Mars ISRU

    NASA Technical Reports Server (NTRS)

    Finn, John E.; Mulloth, Lila M.; Borchers, Bruce A.; Luna, Bernadette (Technical Monitor)

    2000-01-01

    Chemical processing of the dusty, low-pressure Martian atmosphere typically requires conditioning and compression of the gases as first steps. A temperature-swing adsorption process can perform these tasks using nearly solid-state hardware and with relatively low power consumption compared to alternative processes. In addition, the process can separate the atmospheric constituents, producing both pressurized CO2 and a buffer gas mixture of nitrogen and argon. To date we have developed and tested adsorption compressors at scales appropriate for the near-term robotic missions that will lead the way to ISRU-based human exploration missions. In this talk we describe the characteristics, testing, and performance of these devices. We also discuss scale-up issues associated with meeting the processing demands of sample return and human missions.

  14. Photochemical source of biological substrates in sea water: implications for carbon cycling

    NASA Astrophysics Data System (ADS)

    Kieber, David J.; McDaniel, Julie; Mopper, Kenneth

    1989-10-01

    DISSOLVED organic carbon (DOC) in sea water represents one of the largest reservoirs of carbon on the earth1. The main fraction of this DOC is generally believed to be composed of old2, biologi-cally refractory material3 such as humic substances, for which the removal mechanisms remain largely unknown. One potentially important removal process in the ocean that has not been investi-gated is the photochemical breakdown of this DOC in the photic zone to form biologically labile organic products. Here we show that biological uptake of pyruvate is highly correlated to its rate of photochemical production in sea water (r = 0.964), and that the photochemical precursor(s) of pyruvate is from the fraction of DOC having a nominal molecular weight of 500. This is the first evidence that photochemical breakdown of high-molecular-weight marine DOC, which is presumably biologically refractory, results in the production of a compound that is used by plankton as a substrate. Our results have important implications for the oceanic carbon cycle, particularly with respect to planktonic-food-web dynamics and the global carbon budget.

  15. Development and Testing of an ISRU Soil Mechanics Vacuum Test Facility

    NASA Technical Reports Server (NTRS)

    Kleinhenz, Julie E.; Wilkinson, R. Allen

    2014-01-01

    For extraterrestrial missions, earth based testing in relevant environments is key to successful hardware development. This is true for both early component level development and system level integration. For In-Situ Resource Utilization (ISRU) on the moon, hardware must interface with the surface material, or regolith, in a vacuum environment. A relevant test environment will therefore involve a vacuum chamber with a controlled, properly conditioned bed of lunar regolith simulant. However, in earth-based granular media, such as lunar regolith simulant, gases trapped within the material pore structures and water adsorbed to all particle surfaces will release when exposed to vacuum. Early vacuum testing has shown that this gas release can occur violently, which loosens and weakens the simulant, altering the consolidation state. A mid-size chamber (3.66 m tall, 1.5 m inner diameter) at the NASA Glenn Research Center has been modified to create a soil mechanics test facility. A 0.64 m deep by 0.914 m square metric ton bed of lunar simulant was placed under vacuum using a variety of pumping techniques. Both GRC-3 and LHT-3M simulant types were used. Data obtained from an electric cone penetrometer can be used to determine strength properties at vacuum including: cohesion, friction angle, bulk density and shear modulus. Simulant disruptions, caused by off-gassing, affected the strength properties, but could be mitigated by reducing pump rate. No disruptions were observed at pressures below 2.5 Torr, regardless of the pump rate. The slow off-gassing of the soil at low pressure lead to long test times; a full week to reach 10(exp -5) Torr. Robotic soil manipulation would enable multiple ISRU hardware test within the same vacuum cycle. The feasibility of a robotically controlled auger and tamper was explored at vacuum conditions.

  16. Understanding Schizophrenia as a Disorder of Consciousness: Biological Correlates and Translational Implications from Quantum Theory Perspectives

    PubMed Central

    Venkatasubramanian, Ganesan

    2015-01-01

    From neurophenomenological perspectives, schizophrenia has been conceptualized as “a disorder with heterogeneous manifestations that can be integrally understood to involve fundamental perturbations in consciousness”. While these theoretical constructs based on consciousness facilitate understanding the ‘gestalt’ of schizophrenia, systematic research to unravel translational implications of these models is warranted. To address this, one needs to begin with exploration of plausible biological underpinnings of “perturbed consciousness” in schizophrenia. In this context, an attractive proposition to understand the biology of consciousness is “the orchestrated object reduction (Orch-OR) theory” which invokes quantum processes in the microtubules of neurons. The Orch-OR model is particularly important for understanding schizophrenia especially due to the shared ‘scaffold’ of microtubules. The initial sections of this review focus on the compelling evidence to support the view that “schizophrenia is a disorder of consciousness” through critical summary of the studies that have demonstrated self-abnormalities, aberrant time perception as well as dysfunctional intentional binding in this disorder. Subsequently, these findings are linked with ‘Orch-OR theory’ through the research evidence for aberrant neural oscillations as well as microtubule abnormalities observed in schizophrenia. Further sections emphasize the applicability and translational implications of Orch-OR theory in the context of schizophrenia and elucidate the relevance of quantum biology to understand the origins of this puzzling disorder as “fundamental disturbances in consciousness”. PMID:25912536

  17. Understanding schizophrenia as a disorder of consciousness: biological correlates and translational implications from quantum theory perspectives.

    PubMed

    Venkatasubramanian, Ganesan

    2015-04-30

    From neurophenomenological perspectives, schizophrenia has been conceptualized as "a disorder with heterogeneous manifestations that can be integrally understood to involve fundamental perturbations in consciousness". While these theoretical constructs based on consciousness facilitate understanding the 'gestalt' of schizophrenia, systematic research to unravel translational implications of these models is warranted. To address this, one needs to begin with exploration of plausible biological underpinnings of "perturbed consciousness" in schizophrenia. In this context, an attractive proposition to understand the biology of consciousness is "the orchestrated object reduction (Orch-OR) theory" which invokes quantum processes in the microtubules of neurons. The Orch-OR model is particularly important for understanding schizophrenia especially due to the shared 'scaffold' of microtubules. The initial sections of this review focus on the compelling evidence to support the view that "schizophrenia is a disorder of consciousness" through critical summary of the studies that have demonstrated self-abnormalities, aberrant time perception as well as dysfunctional intentional binding in this disorder. Subsequently, these findings are linked with 'Orch-OR theory' through the research evidence for aberrant neural oscillations as well as microtubule abnormalities observed in schizophrenia. Further sections emphasize the applicability and translational implications of Orch-OR theory in the context of schizophrenia and elucidate the relevance of quantum biology to understand the origins of this puzzling disorder as "fundamental disturbances in consciousness".

  18. Molecular biology in marine science: Scientific questions, technological approaches, and practical implications

    SciTech Connect

    1994-12-31

    The ocean plays an important role in regulating the earth`s climate, sustains a large portion of the earth`s biodiversity, is a tremendous reservoir of commercially important substances, and is used for a variety of often conflicting purposes. In recent decades marine scientists have discovered much about the ocean and its organisms, yet many important fundamental questions remain unanswered. Human populations have increased, particularly in coastal regions. As a result, the marine environment in these areas is increasingly disrupted by human activities, including pollution and the depletion of some ecologically and commercially important species. There is a sense of urgency about reducing human impacts on the ocean and a need to understand how altered ecosystems and the loss of marine species and biodiversity could affect society. During the past two decades, the development of sophisticated technologies and instruments for biomedical research has resulted in significant advances in the biological sciences. While some of these technologies have been readily incorporated into the study of marine organisms as models for understanding basic biology, the value of molecular techniques for addressing problems in marine biology and biological oceanography has only recently begun to be appreciated. This report defines critical scientific questions in marine biology and biological oceanography, describes the molecular technologies that could be used to answer these questions, and discusses some of the implications and economic opportunities that might result from this research which could potentially improve the international competitive position of the United States in the rapidly growing area of marine biotechnology. The committee recommends that the federal government provide the infrastructure necessary to use the techniques of molecular biology in the marine sciences.

  19. Biological Role of Dystroglycan in Schwann Cell Function and Its Implications in Peripheral Nervous System Diseases

    PubMed Central

    Masaki, Toshihiro; Matsumura, Kiichiro

    2010-01-01

    Dystroglycan is a central component of the dystrophin-glycoprotein complex (DGC) that links extracellular matrix with cytoskeleton, expressed in a variety of fetal and adult tissues. Dystroglycan plays diverse roles in development and homeostasis including basement membrane formation, epithelial morphogenesis, membrane stability, cell polarization, and cell migration. In this paper, we will focus on biological role of dystroglycan in Schwann cell function, especially myelination. First, we review the molecular architecture of DGC in Schwann cell abaxonal membrane. Then, we will review the loss-of-function studies using targeted mutagenesis, which have revealed biological functions of each component of DGC in Schwann cells. Based on these findings, roles of dystroglycan in Schwann cell function, in myelination in particular, and its implications in diseases will be discussed in detail. Finally, in view of the fact that understanding the role of dystroglycan in Schwann cells is just beginning, future perspectives will be discussed. PMID:20625412

  20. The pediatric sepsis biomarker risk model: potential implications for sepsis therapy and biology.

    PubMed

    Alder, Matthew N; Lindsell, Christopher J; Wong, Hector R

    2014-07-01

    Sepsis remains a major cause of morbidity and mortality in adult and pediatric intensive care units. Heterogeneity of demographics, comorbidities, biological mechanisms, and severity of illness leads to difficulty in determining which patients are at highest risk of mortality. Determining mortality risk is important for weighing the potential benefits of more aggressive interventions and for deciding whom to enroll in clinical trials. Biomarkers can be used to parse patients into different risk categories and can outperform current methods of patient risk stratification based on physiologic parameters. Here we review the Pediatric Sepsis Biomarker Risk Model that has also been modified and applied to estimate mortality risk in adult patients. We compare the two models and speculate on the biological implications of the biomarkers in patients with sepsis.

  1. Environmental and biological applications and implications of soft and condensed nanomaterials

    NASA Astrophysics Data System (ADS)

    Chen, Pengyu

    Recent innovations and growth of nanotechnology have spurred exciting technological and commercial developments of nanomaterails. Their appealing physical and physicochemical properties offer great opportunities in biological and environmental applications, while in the meantime may compromise human health and environmental sustainability through either unintentional exposure or intentional discharge. Accordingly, this dissertation exploits the physicochemical behavior of soft dendritic polymers for environmental remediation and condensed nano ZnO tetrapods for biological sensing (Chapter two-four), and further delineate the environmental implications of such nanomaterials using algae- the major constituent of the aquatic food chain-as a model system (Chapter five). This dissertation is presented as follows. Chapter one presents a general review of the characteristic properties, applications, forces dictating nanomaterials, and their biological and environmental implications of the most produced and studied soft and condensed nanomaterials. In addition, dendritic polymers and ZnO nanomaterials are thoroughly reviewed separately. Chapter two investigates the physicochemical properties of poly(amidoamine)-tris(hydroxymethyl)amidomethane- dendrimer for its potential applications in water purification. The binding mechanisms and capacities of this dendrimer in hosting major environmental pollutants including cationic copper, anionic nitrate, and polyaromatic phenanthrene are discussed. Chapter three exploits a promising use of dendrimers for removal of potentially harmful discharged nanoparticles (NPs). Specifically, fullerenols are used as a model nanomaterial, and their interactions with two different generations of dendrimers are studied using spectrophotometry and thermodynamics methods. Chapter four elucidates two novel optical schemes for sensing environmental pollutants and biological compounds using dendrimer-gold nanowire complex and gold-coated ZnO tetrapods

  2. Propositions of Schroedinger and Dyson: Implications for program development in secondary school biology

    NASA Astrophysics Data System (ADS)

    Kaiser-Antonowich, Roxanne

    The purpose of this study is to ascertain whether there is a linkage between the special case of New Jersey Core Curriculum Content Standards for Science as they represent biology, and the propositions of Schrodinger and Dyson. The aim of the study is to derive implications for program development in secondary school biology. Critical review reveals that the New Jersey Core Curriculum Content Standards for Science do not provide linkage to biology and the propositions of Erwin Schrodinger and Freeman Dyson. If life is characterized by replication and metabolism, then Schrodinger and Dyson present a plausible argument toward describing life as reciprocal forms and functions that characterize a living system. Examination revealed that Schrodinger, in stating that life can be characterized by the processes of replication and metabolism, emphasized replication and virtually ignored metabolism. Dyson also acknowledges the relationship of metabolism to replication. Examination of Dyson revealed that rather than describing metabolism as a characterization of life, he advances the origin of metabolism and its connection to the origin of life. If metabolism and replication characterize life and if the origin of life is within the domain of biology, then Schrodinger's and Dyson's propositions are central to the characterization of biology. If program development for secondary school biology requires accurate description of its domain, then it is necessary to acknowledge the complexity of life forms. There is as yet no universally accepted general description of life and no reasonable consensus for something to be termed living. If the conditions for something to be termed living are the capacity to reproduce self as maintained by Schrodinger, and the capacity for self-organization preserved through natural selection as proposed by Dyson, then these conditions form the basis for program development.

  3. Field Testing of a Pneumatic Regolith Feed System During a 2010 ISRU Field Campaign on Mauna Kea, Hawaii

    NASA Technical Reports Server (NTRS)

    Craft, Jack; Zacny, Kris; Chu, Philip; Wilson, Jack; Santoro, Chris; Carlson, Lee; Maksymuk, Michael; Townsend, Ivan I.; Mueller, Robert P.; Mantovani, James G.

    2010-01-01

    Lunar In Situ Resource Utilization (ISRU) consists of a number of tasks starting with mining of lunar regolith, followed by the transfer of regolith to an oxygen extraction reactor and finally processing the regolith and storing of extracted oxygen. The transfer of regolith from the regolith hopper at the ground level to an oxygen extraction reactor many feet above the surface could be accomplished in different ways, including using a mechanical auger, bucket ladder system or a pneumatic system. The latter system is commonly used on earth when moving granular materials since it offers high reliability and simplicity of operation. In this paper, we describe a pneumatic regolith feed system, delivering feedstock to a Carbothermal reactor and lessons learned from deploying the system during the 2010 ISRU field campaign on the Mauna Kea, Hawaii.

  4. Social origins, biological treatments: The public health implications of common mental disorders in India

    PubMed Central

    Patel, Vikram

    2005-01-01

    Common mental disorders (CMD) is a term used to describe depressive and anxiety disorders. It replaces the old term ‘neuroses’ and is widely used because of the high level of co-morbidity of depression and anxiety, which limits the validity of categorical models of classification of neurotic disorders, particularly in primary care settings. The global public health significance of CMD is highlighted by the fact that in developing countries, depression is the leading cause of years lived with disability in both men and women aged 15–44 years. This oration brings together research evidence, mostly from South Asia, to show that although the aetiology of CMD may lie in the socioeconomic circumstances faced by many patients, biological treatments such as antidepressants may be among the most cost-effective treatments in resource-poor settings. The oration demonstrates the public health implications of CMD by briefly reviewing the burden of CMD in the region and presents evidence linking the risk for CMD associated with two of the region's most important public health risk factors—poverty and gender disadvantage. The oration also presents recent evidence to establish the association of CMD with some of the region's most important public health issues: maternal and child health; and reproductive and sexual health. Next, the evidence for the efficacy of treatments for CMD in developing countries is presented, focusing on a series of recent trials that show that both psychosocial and biological treatments are effective. Finally, the implications for policy and future research are considered.

  5. ISRU Reactant, Fuel Cell Based Power Plant for Robotic and Human Mobile Exploration Applications

    NASA Astrophysics Data System (ADS)

    Baird, Russell S.; Sanders, Gerald; Simon, Thomas; McCurdy, Kerri

    2003-01-01

    Three basic power generation system concepts are generally considered for lander, rover, and Extra-Vehicular Activity (EVA) assistant applications for robotic and human Moon and Mars exploration missions. The most common power system considered is the solar array and battery system. While relatively simple and successful, solar array/battery systems have some serious limitations for mobile applications. For typical rover applications, these limitations include relatively low total energy storage capabilities, daylight only operating times (6 to 8 hours on Mars), relatively short operating lives depending on the operating environment, and rover/lander size and surface use constraints. Radioisotope power systems are being reconsidered for long-range science missions. Unfortunately, the high cost, political controversy, and launch difficulties that are associated with nuclear-based power systems suggests that the use of radioisotope powered landers, rovers, and EVA assistants will be limited. The third power system concept now being considered are fuel cell based systems. Fuel cell power systems overcome many of the performance and surface exploration limitations of solar array/battery power systems and the prohibitive cost and other difficulties associated with nuclear power systems for mobile applications. In an effort to better understand the capabilities and limitations of fuel cell power systems for Moon and Mars exploration applications. NASA is investigating the use of In-Situ Resource Utilization (ISRU) produced reactant, fuel cell based power plants to power robotic outpost rovers, science equipment, and future human spacecraft, surface-excursion rovers, and EVA assistant rovers. This paper will briefly compare the capabilities and limitations of fuel cell power systems relative to solar array/battery and nuclear systems, discuss the unique and enhanced missions that fuel cell power systems enable, and discuss the common technology and system attributes

  6. ISRU Reactant, Fuel Cell Based Power Plant for Robotic and Human Mobile Exploration Applications

    NASA Technical Reports Server (NTRS)

    Baird, Russell S.; Sanders, Gerald; Simon, Thomas; McCurdy, Kerri

    2003-01-01

    Three basic power generation system concepts are generally considered for lander, rover, and Extra-Vehicular Activity (EVA) assistant applications for robotic and human Moon and Mars exploration missions. The most common power system considered is the solar array and battery system. While relatively simple and successful, solar array/battery systems have some serious limitations for mobile applications. For typical rover applications, these limitations include relatively low total energy storage capabilities, daylight only operating times (6 to 8 hours on Mars), relatively short operating lives depending on the operating environment, and rover/lander size and surface use constraints. Radioisotope power systems are being reconsidered for long-range science missions. Unfortunately, the high cost, political controversy, and launch difficulties that are associated with nuclear-based power systems suggests that the use of radioisotope powered landers, rovers, and EVA assistants will be limited. The third power system concept now being considered are fuel cell based systems. Fuel cell power systems overcome many of the performance and surface exploration limitations of solar array/battery power systems and the prohibitive cost and other difficulties associated with nuclear power systems for mobile applications. In an effort to better understand the capabilities and limitations of fuel cell power systems for Moon and Mars exploration applications, NASA is investigating the use of in-Situ Resource Utilization (ISRU) produced reactant, fuel cell based power plants to power robotic outpost rovers, science equipment, and future human spacecraft, surface-excursion rovers, and EVA assistant rovers. This paper will briefly compare the capabilities and limitations of fuel cell power systems relative to solar array/battery and nuclear systems, discuss the unique and enhanced missions that fuel cell power systems enable, and discuss the common technology and system attributes

  7. Long-term Biological Monitoring of an Impaired Stream: Synthesis and Environmental Management Implications

    SciTech Connect

    Peterson, Mark J; Efroymson, Rebecca Ann; Adams, Marshall

    2011-01-01

    The long-term ecological recovery of an impaired stream in response to an industrial facility's pollution abatement actions and the implications of the biological monitoring effort to environmental management is the subject of this special issue of Environmental Management. This final article focuses on the synthesis of the biological monitoring program's components and methods, the efficacy of various biological monitoring techniques to environmental management, and the lessons learned from the program that might be applicable to the design and application of other programs. The focus of the 25-year program has been on East Fork Poplar Creek, an ecologically impaired stream in Oak Ridge, Tennessee with varied and complex stressors from a Department of Energy facility in its headwaters. Major components of the long-term program included testing and monitoring of invertebrate and fish toxicity, bioindicators of fish health, fish contaminant accumulation, and instream communities (including periphyton, benthic macroinvertebrate, and fish). Key parallel components of the program include water chemistry sampling and data management. Multiple lines of evidence suggested positive ecological responses during three major pollution abatement periods. Based on this case study and the related literature, effective environmental management of impaired streams starts with program design that is consistent across space and time, but also adaptable to changing conditions. The biological monitoring approaches used for the program provided a strong basis for assessments of recovery from remedial actions, and the likely causes of impairment. This case study provides a unique application of multidisciplinary and quantitative techniques to address multiple and complex regulatory and programmatic goals, environmental stressors, and remedial actions.

  8. Long-Term Biological Monitoring of an Impaired Stream: Implications for Environmental Management [Special Issue

    SciTech Connect

    Adams, Marshall; Brandt, Craig C; Christensen, Sigurd W; Efroymson, Rebecca Ann; Greeley Jr, Mark Stephen; Ham, Kenneth; Kszos, Lynn A; Loar, James M; McCracken, Kitty; Morris, Gail Wright; Peterson, Mark J; Ryon, Michael G; Smith, John G; Southworth, George R; Stewart, Arthur J

    2011-01-01

    The long-term ecological recovery of an impaired stream in response to an industrial facility's pollution abatement actions and the implications of the biological monitoring effort to environmental management is the subject of this special issue of Environmental Management. This final article focuses on the synthesis of the biological monitoring program's components and methods, the efficacy of various biological monitoring techniques to environmental management, and the lessons learned from the program that might be applicable to the design and application of other programs. The focus of the 25-year program has been on East Fork Poplar Creek, an ecologically impaired stream in Oak Ridge, Tennessee with varied and complex stressors from a Department of Energy facility in its headwaters. Major components of the long-term program included testing and monitoring of invertebrate and fish toxicity, bioindicators of fish health, fish contaminant accumulation, and instream communities (including periphyton, benthic macroinvertebrate, and fish). Key parallel components of the program include water chemistry sampling and data management. Multiple lines of evidence suggested positive ecological responses during three major pollution abatement periods. Based on this case study and the related literature, effective environmental management of impaired streams starts with program design that is consistent across space and time, but also adaptable to changing conditions. The biological monitoring approaches used for the program provided a strong basis for assessments of recovery from remedial actions, and the likely causes of impairment. This case study provides a unique application of multidisciplinary and quantitative techniques to address multiple and complex regulatory and programmatic goals, environmental stressors, and remedial actions.

  9. A fractal model for nuclear organization: current evidence and biological implications

    PubMed Central

    Bancaud, Aurélien; Lavelle, Christophe; Huet, Sébastien; Ellenberg, Jan

    2012-01-01

    Chromatin is a multiscale structure on which transcription, replication, recombination and repair of the genome occur. To fully understand any of these processes at the molecular level under physiological conditions, a clear picture of the polymorphic and dynamic organization of chromatin in the eukaryotic nucleus is required. Recent studies indicate that a fractal model of chromatin architecture is consistent with both the reaction-diffusion properties of chromatin interacting proteins and with structural data on chromatin interminglement. In this study, we provide a critical overview of the experimental evidence that support a fractal organization of chromatin. On this basis, we discuss the functional implications of a fractal chromatin model for biological processes and propose future experiments to probe chromatin organization further that should allow to strongly support or invalidate the fractal hypothesis. PMID:22790985

  10. Cytosol-dependent membrane fusion in ER, nuclear envelope and nuclear pore assembly: biological implications.

    PubMed

    Rafikova, Elvira R; Melikov, Kamran; Chernomordik, Leonid V

    2010-01-01

    Endoplasmic reticulum and nuclear envelope rearrangements after mitosis are often studied in the reconstitution system based on Xenopus egg extract. In our recent work we partially replaced the membrane vesicles in the reconstitution mix with protein-free liposomes to explore the relative contributions of cytosolic and transmembrane proteins. Here we discuss our finding that cytosolic proteins mediate fusion between membranes lacking functional transmembrane proteins and the role of membrane fusion in endoplasmic reticulum and nuclear envelope reorganization. Cytosol-dependent liposome fusion has allowed us to restore, without adding transmembrane nucleoporins, functionality of nuclear pores, their spatial distribution and chromatin decondensation in nuclei formed at insufficient amounts of membrane material and characterized by only partial decondensation of chromatin and lack of nuclear transport. Both the mechanisms and the biological implications of the discovered coupling between spatial distribution of nuclear pores, chromatin decondensation and nuclear transport are discussed.

  11. Subject-specific pedagogical content knowledge: Implications for alternatively and traditionally trained biology teachers

    NASA Astrophysics Data System (ADS)

    Ravgiala, Rebekah Rae

    Theories regarding the development of expertise hold implications for alternative and traditional certification programs and the teachers they train. The literature suggests that when compared to experts in the field of teaching, the behaviors of novices differ in ways that are directly attributed to their pedagogical content knowledge. However, few studies have examined how first and second year biology teachers entering the profession from traditional and alternative training differ in their demonstration of subject-specific pedagogical content knowledge. The research problem in this multicase, naturalistic inquiry investigated how subject-specific pedagogical content knowledge was manifested among first and second year biology teachers in the task of transforming subject matter into forms that are potentially meaningful to students when explicit formal training has been and has not been imparted to them as preservice teachers. Two first year and two second year biology teachers were the subjects of this investigation. Allen and Amber obtained their certification through an alternative summer training institute in consecutive years. Tiffany and Tricia obtained their certification through a traditional, graduate level training program in consecutive years. Both programs were offered at the same northeastern state university. Participants contributed to six data gathering techniques including an initial semi-structured interview, responses to the Conceptions of Teaching Science questionnaire (Hewson & Hewson, 1989), three videotaped biology lessons, evaluation of three corresponding lesson plans, and a final semi-structured interview conducted at the end of the investigation. An informal, end-of-study survey intended to offer participants an opportunity to disclose their thoughts and needs as first year teachers was also employed. Results indicate that while conceptions of teaching science may vary slightly among participants, there is no evidence to suggest that

  12. Occurrence, pathways and implications of biological production of reactive oxygen species in natural waters

    NASA Astrophysics Data System (ADS)

    Zhang, T.; Hansel, C. M.; Voelker, B. M.; Lamborg, C. H.

    2014-12-01

    Reactive oxygen species (ROS), such as superoxide (O2-) and hydrogen peroxide (H2O2) play a critical role in the redox cycling of both toxic (e.g., Hg) and nutrient (e.g., Fe) metals. Despite the discovery of extracellular ROS production in various microbial cultures, including fungi, algae and bacteria, photo-dependent processes are generally considered as the predominant source of ROS in natural waters. Here we show that biological production of ROS is ubiquitous and occurs at a significant rate in freshwater and brackish water environments. Water samples were collected from three freshwater and one brackish water ponds in Cape Cod, Massachusetts, USA, periodically from 2012 to 2014. Production of O2- and H2O2 were measured in dark incubations of natural water using a chemiluminescent and a colorimetric probe, respectively. Rates of biological ROS production were obtained by comparing unfiltered with 0.2-μm filtered samples. The role of biological activity in ROS production was confirmed by the cessation of ROS production upon addition of formaldehyde. In surface water, production rates of O2- ranged from undetectable to 96.0 ± 30.0 nmol L-1 h-1, and production rates of H2O2 varied between 9.9 ± 1.3 nmol L-1 h-1 and 145.6 ± 11.2 nmol L-1 h-1. The maximum production rates of both ROS were observed in mid-summer 2013, which coincides with peak biological activity. ROS production in the water from aphotic zone was greater than in the water from photic zone. Thus, non-light dependent biological processes are likely the major contributors to ROS production in this system. Moreover, O2- production appeared to be enhanced by NADH and inhibited by proteinase-K, suggesting the possible involvement of NADH oxidoreductases in this process. The potential role of different microbial communities in ROS production, and the implications of biological ROS production for mercury speciation will also be discussed.

  13. Preparation of a Frozen Regolith Simulant Bed for ISRU Component Testing in a Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    Klenhenz, Julie; Linne, Diane

    2013-01-01

    In-Situ Resource Utilization (ISRU) systems and components have undergone extensive laboratory and field tests to expose hardware to relevant soil environments. The next step is to combine these soil environments with relevant pressure and temperature conditions. Previous testing has demonstrated how to incorporate large bins of unconsolidated lunar regolith into sufficiently sized vacuum chambers. In order to create appropriate depth dependent soil characteristics that are needed to test drilling operations for the lunar surface, the regolith simulant bed must by properly compacted and frozen. While small cryogenic simulant beds have been created for laboratory tests, this scale effort will allow testing of a full 1m drill which has been developed for a potential lunar prospector mission. Compacted bulk densities were measured at various moisture contents for GRC-3 and Chenobi regolith simulants. Vibrational compaction methods were compared with the previously used hammer compaction, or "Proctor", method. All testing was done per ASTM standard methods. A full 6.13 m3 simulant bed with 6 percent moisture by weight was prepared, compacted in layers, and frozen in a commercial freezer. Temperature and desiccation data was collected to determine logistics for preparation and transport of the simulant bed for thermal vacuum testing. Once in the vacuum facility, the simulant bed will be cryogenically frozen with liquid nitrogen. These cryogenic vacuum tests are underway, but results will not be included in this manuscript.

  14. Human lunar mission capabilities using SSTO, ISRU and LOX-augmented NTR technologies: A preliminary assessment

    NASA Astrophysics Data System (ADS)

    Borowski, Stanley K.

    1995-10-01

    The feasibility of conducting human missions to the Moon is examined assuming the use of three 'high leverage' technologies: (1) a single-stage-to-orbit (SSTO) launch vehicle, (2) 'in-situ' resource utilization (ISRU)--specifically 'lunar-derived' liquid oxygen (LUNOX), and (3) LOX-augmented nuclear thermal rocket (LANTR) propulsion. Lunar transportation system elements consisting of a LANTR-powered lunar transfer vehicle (LTV) and a chemical propulsion lunar landing/Earth return vehicle (LERV) are configured to fit within the 'compact' dimensions of the SSTO cargo bay (diameter: 4.6 m/length: 9.0 m) while satisfying an initial mass in low Earth orbit (IMLEO) limit of approximately 60 t (3 SSTO launches). Using approximately 8 t of LUNOX to 'reoxidize' the LERV for a 'direct return' flight to Earth reduces its size and mass allowing delivery to LEO on a single 20 t SSTO launch. Similarly, the LANTR engine's ability to operate at any oxygen/ hydrogen mixture ratio from 0 to 7 with high specific impulse (approximately 940 to 515 s) is exploited to reduce hydrogen tank volume, thereby improving packaging of the LANTR LTV's 'propulsion' and 'propellant modules'. Expendable and reusable, piloted and cargo missions and vehicle designs are presented along with estimates of LUNOX production required to support the different mission modes. Concluding remarks address the issue of lunar transportation system costs from the launch vehicle perspective.

  15. Multirobot Lunar Excavation and ISRU Using Artificial-Neural-Tissue Controllers

    NASA Astrophysics Data System (ADS)

    Thangavelautham, Jekanthan; Smith, Alexander; Abu El Samid, Nader; Ho, Alexander; Boucher, Dale; Richard, Jim; D'Eleuterio, Gabriele M. T.

    2008-01-01

    Automation of site preparation and resource utilization on the Moon with teams of autonomous robots holds considerable promise for establishing a lunar base. Such multirobot autonomous systems would require limited human support infrastructure, complement necessary manned operations and reduce overall mission risk. We present an Artificial Neural Tissue (ANT) architecture as a control system for autonomous multirobot excavation tasks. An ANT approach requires much less human supervision and pre-programmed human expertise than previous techniques. Only a single global fitness function and a set of allowable basis behaviors need be specified. An evolutionary (Darwinian) selection process is used to `breed' controllers for the task at hand in simulation and the fittest controllers are transferred onto hardware for further validation and testing. ANT facilitates `machine creativity', with the emergence of novel functionality through a process of self-organized task decomposition of mission goals. ANT based controllers are shown to exhibit self-organization, employ stigmergy (communication mediated through the environment) and make use of templates (unlabeled environmental cues). With lunar in-situ resource utilization (ISRU) efforts in mind, ANT controllers have been tested on a multirobot excavation task in which teams of robots with no explicit supervision can successfully avoid obstacles, interpret excavation blueprints, perform layered digging, avoid burying or trapping other robots and clear/maintain digging routes.

  16. Application of an Artificial Neural Tissue Controller to Multirobot Lunar ISRU Operations

    NASA Astrophysics Data System (ADS)

    Thangavelautham, Jekanthan; Smith, Alexander; Boucher, Dale; Richard, Jim; D'Eleuterio, Gabriele M. T.

    2007-01-01

    Automation of mining and resource utilization processes on the Moon with teams of autonomous robots holds considerable promise for establishing a lunar base. We present an Artificial Neural Tissue (ANT) architecture as a control system for autonomous multirobot tasks. An Artificial Neural Tissue (ANT) approach requires much less human supervision and pre-programmed human expertise than previous techniques. Only a single global fitness function and a set of allowable basis behaviors need be specified. An evolutionary (Darwinian) selection process is used to train controllers for the task at hand in simulation and is verified on hardware. This process results in the emergence of novel functionality through the task decomposition of mission goals. ANT based controllers are shown to exhibit self-organization, employ stigmergy (communication mediated through the environment) and make use of templates (unlabeled environmental cues). With lunar in-situ resource utilization (ISRU) efforts in mind, ANT controllers have been tested on a multirobot resource gathering task in which teams of robots with no explicit supervision can successfully avoid obstacles, explore terrain, locate resource material and collect it in a designated area by using a light beacon for reference and interpreting unlabeled perimeter markings.

  17. Human Lunar Mission Capabilities Using SSTO, ISRU and LOX-Augmented NTR Technologies: A Preliminary Assessment

    NASA Technical Reports Server (NTRS)

    Borowski, Stanley K.

    1995-01-01

    The feasibility of conducting human missions to the Moon is examined assuming the use of three 'high leverage' technologies: (1) a single-stage-to-orbit (SSTO) launch vehicle, (2) 'in-situ' resource utilization (ISRU)--specifically 'lunar-derived' liquid oxygen (LUNOX), and (3) LOX-augmented nuclear thermal rocket (LANTR) propulsion. Lunar transportation system elements consisting of a LANTR-powered lunar transfer vehicle (LTV) and a chemical propulsion lunar landing/Earth return vehicle (LERV) are configured to fit within the 'compact' dimensions of the SSTO cargo bay (diameter: 4.6 m/length: 9.0 m) while satisfying an initial mass in low Earth orbit (IMLEO) limit of approximately 60 t (3 SSTO launches). Using approximately 8 t of LUNOX to 'reoxidize' the LERV for a 'direct return' flight to Earth reduces its size and mass allowing delivery to LEO on a single 20 t SSTO launch. Similarly, the LANTR engine's ability to operate at any oxygen/ hydrogen mixture ratio from 0 to 7 with high specific impulse (approximately 940 to 515 s) is exploited to reduce hydrogen tank volume, thereby improving packaging of the LANTR LTV's 'propulsion' and 'propellant modules'. Expendable and reusable, piloted and cargo missions and vehicle designs are presented along with estimates of LUNOX production required to support the different mission modes. Concluding remarks address the issue of lunar transportation system costs from the launch vehicle perspective.

  18. Multirobot Lunar Excavation and ISRU Using Artificial-Neural-Tissue Controllers

    SciTech Connect

    Thangavelautham, Jekanthan; Smith, Alexander; Abu El Samid, Nader; Ho, Alexander; D'Eleuterio, Gabriele M. T.; Boucher, Dale; Richard, Jim

    2008-01-21

    Automation of site preparation and resource utilization on the Moon with teams of autonomous robots holds considerable promise for establishing a lunar base. Such multirobot autonomous systems would require limited human support infrastructure, complement necessary manned operations and reduce overall mission risk. We present an Artificial Neural Tissue (ANT) architecture as a control system for autonomous multirobot excavation tasks. An ANT approach requires much less human supervision and pre-programmed human expertise than previous techniques. Only a single global fitness function and a set of allowable basis behaviors need be specified. An evolutionary (Darwinian) selection process is used to 'breed' controllers for the task at hand in simulation and the fittest controllers are transferred onto hardware for further validation and testing. ANT facilitates 'machine creativity', with the emergence of novel functionality through a process of self-organized task decomposition of mission goals. ANT based controllers are shown to exhibit self-organization, employ stigmergy (communication mediated through the environment) and make use of templates (unlabeled environmental cues). With lunar in-situ resource utilization (ISRU) efforts in mind, ANT controllers have been tested on a multirobot excavation task in which teams of robots with no explicit supervision can successfully avoid obstacles, interpret excavation blueprints, perform layered digging, avoid burying or trapping other robots and clear/maintain digging routes.

  19. Tumor suppressor p16 methylation in multiple myeloma: biological and clinical implications.

    PubMed

    Gonzalez-Paz, Natalia; Chng, Wee J; McClure, Rebecca F; Blood, Emily; Oken, Martin M; Van Ness, Brian; James, C David; Kurtin, Paul J; Henderson, Kimberly; Ahmann, Gregory J; Gertz, Morie; Lacy, Martha; Dispenzieri, Angela; Greipp, Philip R; Fonseca, Rafael

    2007-02-01

    The biological and clinical implications of p16 gene methylation in multiple myeloma (MM) are still unclear despite previous studies. In this comprehensive study, using methylation-specific PCR (MS-PCR), we show that p16 methylation is relatively common and occurs in monoclonal gammopathy of undetermined significance (MGUS; n=17), smoldering multiple myeloma (SMM; n=40), and MM (n=522) at a prevalence of 24%, 28%, and 34%, respectively. However, p16 methylation does not appear to affect gene expression level. In a large cohort of patients with long-term follow-up information (n=439), there was no difference in overall survival between patients with or without p16 methylation. We also found no association between p16 methylation and the main cytogenetic categories, although it was more common among patients with 17p13.1 deletions (p53 locus), a genetic progression event in MM. In addition, p16 methylation has no apparent effect on the cycle because there was also no difference in the plasma cell labeling index (a direct measurement of proliferation) between patients with and without p16 methylation. Our results question a major role for p16 methylation in the oncogenesis of the PC neoplasm, and we now believe p16 methylation may be a marker for overall epigenetic changes associated with disease progression, with no obvious direct biological or clinical consequences. PMID:16840723

  20. Self-Organisation, Thermotropic and Lyotropic Properties of Glycolipids Related to their Biological Implications

    PubMed Central

    Garidel, Patrick; Kaconis, Yani; Heinbockel, Lena; Wulf, Matthias; Gerber, Sven; Munk, Ariane; Vill, Volkmar; Brandenburg, Klaus

    2015-01-01

    Glycolipids are amphiphilic molecules which bear an oligo- or polysaccharide as hydrophilic head group and hydrocarbon chains in varying numbers and lengths as hydrophobic part. They play an important role in life science as well as in material science. Their biological and physiological functions are quite diverse, ranging from mediators of cell-cell recognition processes, constituents of membrane domains or as membrane-forming units. Glycolipids form an exceptional class of liquid-crystal mesophases due to the fact that their self-organisation obeys more complex rules as compared to classical monophilic liquid-crystals. Like other amphiphiles, the supra-molecular structures formed by glycolipids are driven by their chemical structure; however, the details of this process are still hardly understood. Based on the synthesis of specific glycolipids with a clearly defined chemical structure, e.g., type and length of the sugar head group, acyl chain linkage, substitution pattern, hydrocarbon chain lengths and saturation, combined with a profound physico-chemical characterisation of the formed mesophases, the principles of the organisation in different aggregate structures of the glycolipids can be obtained. The importance of the observed and formed phases and their properties are discussed with respect to their biological and physiological relevance. The presented data describe briefly the strategies used for the synthesis of the used glycolipids. The main focus, however, lies on the thermotropic as well as lyotropic characterisation of the self-organised structures and formed phases based on physico-chemical and biophysical methods linked to their potential biological implications and relevance. PMID:26464591

  1. The Mars Oxygen ISRU Experiment (MOXIE) on the yet-to-be-named Mars 2020 Lander

    NASA Astrophysics Data System (ADS)

    Hecht, M. H.; Hoffman, J.; Rapp, D.; Voecks, G.; Lackner, K. S.; Hartvigsen, J.; Yildiz, B.; Smith, P. H.; Pike, W. T.; Graves, C.; De La Torre Juarez, M.; Schreiner, S.; Madsen, M. B.

    2014-12-01

    A major challenge to sample return is the transport to Mars of an adequate supply of fuel and oxidizer (the heavier component) for the return trip. A possible novel architecture would be for the Mars Ascent Vehicle (MAV) to share a platform with a device that would manufacture the oxidizer in situ. Far from fanciful, that hypothetical platform would look very much like the Mars 2020 rover. The Mars Oxygen In Situ Resource Utilization (ISRU) Experiment, MOXIE, will produce 22 g/hr oxygen from atmospheric carbon dioxide using solid oxide electrolysis (SOXE). With proper refrigeration, it could readily fill a MAV tank with high Isp LOx while waiting for rendezvous with a sample acquisition rover. The immediate motivation for MOXIE, however, is as a prototype for a 100:1 scale unit that would serve the same function on an eventual human expedition. If optimistic plans for a crewed mission are realized, it may well carry the second, and far more bountiful, Mars sample return. To make 22 g/hr oxygen from the CO2 in the martian atmosphere, MOXIE must first collect and compress that CO2, while purging other atmospheric components (4-5 vol%) that would otherwise build up and choke the process. Two distinct technologies are under consideration for that function; a batch-process based on condensation by conventional cryocoolers, and an Advanced Technology Option mechanical compressor that would allow more efficient, continuous operation. The SOXE itself derives from solid oxide fuel cell (SOFC) technology, essentially running the fuel cell process in reverse by feeding in electricity and CO2 to produce O2and CO. MOXIE development is supported by the NASA HEOMD and STMD offices. We are particularly grateful to support from JPL and MIT, as well as our partners Ceramatec and Creare, in the preparation of the MOXIE proposal.

  2. ISRU Soil Mechanics Vacuum Facility: Soil Bin Preparation and Simulant Strength Characterization

    NASA Technical Reports Server (NTRS)

    Kleinhenz, Julie; Wilkinson, Allen

    2012-01-01

    Testing in relevant environments is key to exploration mission hardware development. This is true on both the component level (in early development) and system level (in late development stages). During ISRU missions the hardware will interface with the soil (digging, roving, etc) in a vacuum environment. A relevant test environment will therefore involve a vacuum chamber with a controlled, conditioned simulant bed. However, in earth-based granular media, such as lunar soil simulant, gases trapped within the material pore structures and water adsorbed to all particle surfaces will release when exposed to vacuum. Early vacuum testing has shown that this gas release can occur violently, which loosens and weakens the simulant, altering the consolidation state. The Vacuum Facility #13, a mid-size chamber (3.66m tall, 1.5m inner diameter) at the NASA Glenn Research Center has been modified to create a soil mechanics test facility. A 0.64m deep by 0.914m square metric ton bed of lunar simulant was placed under vacuum using a variety of pumping techniques. Both GRC-3 and LHT-3M simulant types have been used. An electric cone penetrometer was used to measure simulant strength properties at vacuum including: cohesion, friction angle, bulk density and shear modulus. Simulant disruptions, caused by off gassing, affected the strength properties, but could be mitigated by reducing pump rate. No disruptions were observed at pressures below 2.5Torr, regardless of the pump rate. However, slow off gassing of the soil lead to long test times, a full week, to reach 10-5Torr. This work highlights the need for robotic machine-simulant hardware and operations in vacuum to expeditiously perform (sub-)systems tests.

  3. Compositional and Microtextural Analysis of Basaltic Feedstock Materials Used for the 2010 ISRU Field Tests, Mauna Kea, Hawaii

    NASA Astrophysics Data System (ADS)

    Marin, N.; Farmer, J. D.; Zacny, K.; Sellar, R. G.; Nunez, J.

    2011-12-01

    This study seeks to understand variations in composition and texture of basaltic pyroclastic materials used in the 2010 International Lunar Surface Operation-In-Situ Resource Utilization Analogue Test (ILSO-ISRU) held on the slopes of Mauna Kea Volcano, Hawaii (1). The quantity and quality of resources delivered by ISRU depends upon the nature of the materials processed (2). We obtained a one-meter deep auger cuttings sample of a basaltic regolith at the primary site for feed stock materials being mined for the ISRU field test. The auger sample was subdivided into six, ~16 cm depth increments and each interval was sampled and characterized in the field using the Multispectral Microscopic Imager (MMI; 3) and a portable X-ray Diffractometer (Terra, InXitu Instruments, Inc.). Splits from each sampled interval were returned to the lab and analyzed using more definitive methods, including high resolution Powder X-ray Diffraction and Thermal Infrared (TIR) spectroscopy. The mineralogy and microtexture (grain size, sorting, roundness and sphericity) of the auger samples were determined using petrographic point count measurements obtained from grain-mount thin sections. NIH Image J (http://rsb.info.nih.gov/ij/) was applied to digital images of thin sections to document changes in particle size with depth. Results from TIR showed a general predominance of volcanic glass, along with plagioclase, olivine, and clinopyroxene. In addition, thin section and XRPD analyses showed a down core increase in the abundance of hydrated iron oxides (as in situ weathering products). Quantitative point count analyses confirmed the abundance of volcanic glass in samples, but also revealed olivine and pyroxene to be minor components, that decreased in abundance with depth. Furthermore, point count and XRD analyses showed a decrease in magnetite and ilmenite with depth, accompanied by an increase in Fe3+phases, including hematite and ferrihydrite. Image J particle analysis showed that the

  4. Fast neutron relative biological effects and implications for charged particle therapy

    PubMed Central

    Jones, B; Underwood, T S A; Carabe-Fernandez, A; Timlin, C; Dale, R G

    2011-01-01

    In two fast neutron data sets, comprising in vitro and in vivo experiments, an inverse relationship is found between the low-linear energy transfer (LET) α/β ratio and the maximum value of relative biological effect (RBEmax), while the minimum relative biological effect (RBEmin) is linearly related to the square root of the low-LET α/β ratio. RBEmax is the RBE at near zero dose and can be represented by the ratio of the α parameters at high- and low-LET radiation exposures. RBEmin is the RBE at very high dose and can be represented by the ratio of the square roots of the β parameters at high- and low-LET radiation exposures. In principle, it may be possible to use the low-LET α/β ratio to predict RBEmax and RBEmin, providing that other LET-related parameters, which reflect intercept and slopes of these relationships, are used. These two limits of RBE determine the intermediate values of RBE at any dose per fraction; therefore, it is possible to find the RBE at any dose per fraction. Although these results are obtained from fast neutron experiments, there are implications for charged particle therapy using protons (when RBE is scaled downwards) and for heavier ion beams (where the magnitude of RBE is similar to that for fast neutrons). In the case of fast neutrons, late reacting normal tissue systems and very slow growing tumours, which have the smallest values of the low-LET α/β ratio, are predicted to have the highest RBE values at low fractional doses, but the lowest values of RBE at higher doses when they are compared with early reacting tissues and fast growing tumour systems that have the largest low-LET α/β ratios. PMID:22374547

  5. Theoretical implications of incorporating relative biological effectiveness into radiobiological equivalence relationships

    PubMed Central

    Dale, R G

    2013-01-01

    Objective: Earlier radiobiological equivalence relationships as derived for low-linear energy transfer (LET) radiations are revisited in the light of newer radiobiological models that incorporate an allowance for relative biological effectiveness (RBE). Methods: Linear-quadratic (LQ) radiobiological equations for calculating biologically effective dose at both low- and high-LET radiations are used to derive new conditions of equivalence between a variety of radiation delivery techniques. The theoretical implications are discussed. Results: The original (pre-LQ) concept of equivalence between fractionated and continuous radiotherapy schedules, in which the same physical dose is delivered in each schedule, inherently assumed that low-LET radiation would be used in both schedules. LQ-based equivalence relationships that allow for RBE and are derived assuming equal total physical dose between schedules are shown to be valid only in limited circumstances. Removing the constraint of equality of total physical dose allows the identification of more general (and more practical) relationships. Conclusion: If the respective schedules under consideration for equivalence both involve radiations of identical LET, then the original equivalence relationships remain valid. However, if the compared schedules involve radiations of differing LET, then new (and more restrictive) equivalence relationships are found to apply. Advances in knowledge: Theoretically derived equivalence relationships based on the LQ model provide a framework for the design and intercomparison of a wide range of clinical techniques including those involving high- and/or low-LET radiations. They also provide a means of testing for the validity of variously assumed tissue repair kinetics. PMID:23385996

  6. Slower tempo of microevolution in island birds: implications for conservation biology.

    PubMed

    Wright, Shane D; Gillman, Len N; Ross, Howard A; Keeling, D Jeanette

    2009-09-01

    Whether microevolution on small islands differs from that on larger landmasses is a key question in biology with substantial implications for species conservation. However, due to the difficulties faced in producing adequately replicated samples and in controlling for confounding variables, prior attempts to examine evolutionary questions relating to habitat area and population size have produced equivocal results. Here we show, using experimental design criteria that reduce the potential for such confounding, that bird species on larger landmasses have higher rates of molecular evolution. The study involves a global dataset of 48 independent contrasts for the cytochrome b gene encompassing all possible paired sister species comparisons (from seven orders and 17 families) that were available at the time of dataset assembly. A more rapid evolutionary tempo in larger areas has important ramifications for biodiversity conservation because it indicates a new imperative, beyond that of simply maintaining preexisting genetic diversity, for securing large areas for threatened species. This result suggests that the trend of confining species to limited refugia is likely to be slowing the tempo of microevolution. That effect might constrain the potential for adaptive shifts in response to changing environments such as those associated with global warming.

  7. Trypanosome species in neo-tropical bats: biological, evolutionary and epidemiological implications.

    PubMed

    Ramírez, Juan David; Tapia-Calle, Gabriela; Muñoz-Cruz, Geissler; Poveda, Cristina; Rendón, Lina M; Hincapié, Eduwin; Guhl, Felipe

    2014-03-01

    Bats (Chiroptera) are the only mammals naturally able to fly. Due to this characteristic they play a relevant ecological role in the niches they inhabit. These mammals spread infectious diseases from enzootic to domestic foci. Rabbies, SARS, fungi, ebola and trypanosomes are the most common pathogens these animals may host. We conducted intensive sampling of bats from the phyllostomidae, vespertilionidae and emballonuridae families in six localities from Casanare department in eastern Colombia. Blood-EDTA samples were obtained and subsequently submitted to analyses of mitochondrial and nuclear genetic markers in order to conduct barcoding analyses to discriminate trypanosome species. The findings according to the congruence of the three molecular markers suggest the occurrence of Trypanosoma cruzi cruzi (51%), T. c. marinkellei (9%), T. dionisii (13%), T. rangeli (21%), T. evansi (4%) and T. theileri (2%) among 107 positive bat specimens. Regarding the T. cruzi DTUs, we observed the presence of TcI (60%), TcII (15%), TcIII (7%), TcIV (7%) and TcBAT (11%) being the first evidence to our concern of the foreseen genotype TcBAT in Colombia. These results allowed us to propose reliable hypotheses regarding the ecology and biology of the bats circulating in the area including the enigmatic question whether TcBAT should be considered a novel DTU. The epidemiological and evolutionary implications of these findings are herein discussed. PMID:23831017

  8. 'Biologizing' Psychopathy: Ethical, Legal, and Research Implications at the Interface of Epigenetics and Chronic Antisocial Conduct.

    PubMed

    Tamatea, Armon J

    2015-10-01

    Epigenetics, a field that links genetics and environmental influences on the expression of phenotypic traits, offers to increase our understanding of the development and trajectory of disease and psychological disorders beyond that thought of traditional genetic research and behavioural measures. By extension, this new perspective has implications for risk and risk management of antisocial behaviour where there is a biological component, such as psychopathy. Psychopathy is a personality disorder associated with repeat displays of antisocial behaviour, and is associated with the disproportionate imposition of harm on communities. Despite advances in our knowledge of psychopathic individuals, the construct remains complex and is hampered by a lack of integration across a range of fundamental domains. The clinical and forensic research on psychopathy is brought into conversation with the emerging field of epigenetics to highlight critical issues of (1) clinical definition and diagnosis, (2) assessment, (3) aetiology of psychopathic phenotypes, and (4) treatment and rehabilitation approaches. Broader ethical and legal questions of the role of epigenetic mechanisms in the management of psychopathy beyond the criminal justice arena are also outlined.

  9. Glutathione in Cerebral Microvascular Endothelial Biology and Pathobiology: Implications for Brain Homeostasis

    PubMed Central

    Li, Wei; Busu, Carmina; Circu, Magdalena L.; Aw, Tak Yee

    2012-01-01

    The integrity of the vascular endothelium of the blood-brain barrier (BBB) is central to cerebrovascular homeostasis. Given the function of the BBB as a physical and metabolic barrier that buffers the systemic environment, oxidative damage to the endothelial monolayer will have significant deleterious impact on the metabolic, immunological, and neurological functions of the brain. Glutathione (GSH) is a ubiquitous major thiol within mammalian cells that plays important roles in antioxidant defense, oxidation-reduction reactions in metabolic pathways, and redox signaling. The existence of distinct GSH pools within the subcellular organelles supports an elegant mode for independent redox regulation of metabolic processes, including those that control cell fate. GSH-dependent homeostatic control of neurovascular function is relatively unexplored. Significantly, GSH regulation of two aspects of endothelial function is paramount to barrier preservation, namely, GSH protection against oxidative endothelial cell injury and GSH control of postdamage cell proliferation in endothelial repair and/or wound healing. This paper highlights our current insights and hypotheses into the role of GSH in cerebral microvascular biology and pathobiology with special focus on endothelial GSH and vascular integrity, oxidative disruption of endothelial barrier function, GSH regulation of endothelial cell proliferation, and the pathological implications of GSH disruption in oxidative stress-associated neurovascular disorders, such as diabetes and stroke. PMID:22745639

  10. Software Architecture to Support the Evolution of the ISRU RESOLVE Engineering Breadboard Unit 2 (EBU2)

    NASA Technical Reports Server (NTRS)

    Moss, Thomas; Nurge, Mark; Perusich, Stephen

    2011-01-01

    The In-Situ Resource Utilization (ISRU) Regolith & Environmental Science and Oxygen & Lunar Volatiles Extraction (RESOLVE) software provides operation of the physical plant from a remote location with a high-level interface that can access and control the data from external software applications of other subsystems. This software allows autonomous control over the entire system with manual computer control of individual system/process components. It gives non-programmer operators the capability to easily modify the high-level autonomous sequencing while the software is in operation, as well as the ability to modify the low-level, file-based sequences prior to the system operation. Local automated control in a distributed system is also enabled where component control is maintained during the loss of network connectivity with the remote workstation. This innovation also minimizes network traffic. The software architecture commands and controls the latest generation of RESOLVE processes used to obtain, process, and quantify lunar regolith. The system is grouped into six sub-processes: Drill, Crush, Reactor, Lunar Water Resource Demonstration (LWRD), Regolith Volatiles Characterization (RVC) (see example), and Regolith Oxygen Extraction (ROE). Some processes are independent, some are dependent on other processes, and some are independent but run concurrently with other processes. The first goal is to analyze the volatiles emanating from lunar regolith, such as water, carbon monoxide, carbon dioxide, ammonia, hydrogen, and others. This is done by heating the soil and analyzing and capturing the volatilized product. The second goal is to produce water by reducing the soil at high temperatures with hydrogen. This is done by raising the reactor temperature in the range of 800 to 900 C, causing the reaction to progress by adding hydrogen, and then capturing the water product in a desiccant bed. The software needs to run the entire unit and all sub-processes; however

  11. Observing and diagnosing biological fluxes and canopy mechanisms with implications for climate change and ecosystem disturbance

    NASA Astrophysics Data System (ADS)

    Reed, David E.

    Improving our predictions of ecosystem responses is an important challenge in ecological science due to the increasing number of stresses applied to biological systems. The assumption that ecosystems are operating in steady-state conditions at annual and longer time scales is far too simple of a model as ecosystems are an integral part of the earth system. Anthropogenic and non-anthropogenic forces acting on ecosystems within the earth system are numerous and include broad external factors such as climate change to specific internal factors such as infestations causing disturbance. This research quantifies changes in biogeochemical cycling and increases understanding of the mechanisms that control these cycles across two major ecosystems of the intermountain west with the broad goal of better predictive power of ecosystem responses. Eddy covariance methods were used to quantify carbon, water and energy fluxes at two different field sites in sagebrush ecosystems and one field site in a lodgepole pine ecosystem, in south-east Wyoming and northern Colorado. These measurements were supported with environmental and micrometeorological measurements in order to better understand physical mechanisms and canopy processes that control these biological fluxes. Results from the sagebrush component of this dissertation show how semi-arid sagebrush canopies interact with the lower atmosphere in ways that can alter environmental control of water loss with changing leaf area. This feedback has large implications combined with the large land area of these ecosystems and predictions of a dryer and more variable precipitation regime in the future. At the higher elevation lodgepole pine site, the ecosystem is undergoing a major mortality disturbance due to native bark beetles. Interestingly, even with ˜80% mortality of the canopy, few changes are observed to carbon and water cycling, as well as water use efficiency and energy cycling at the ecosystem scale. This calls into question

  12. Diverse Basis of β-Catenin Activation in Human Hepatocellular Carcinoma: Implications in Biology and Prognosis

    PubMed Central

    Okabe, Hirohisa; Kinoshita, Hiroki; Imai, Katsunori; Nakagawa, Shigeki; Higashi, Takaaki; Arima, Kota; Uchiyama, Hideaki; Ikegami, Toru; Harimoto, Norifumi; Itoh, Shinji; Ishiko, Takatoshi; Yoshizumi, Tomoharu; Beppu, Toru; Monga, Satdarshan P. S.; Baba, Hideo; Maehara, Yoshihiko

    2016-01-01

    Aim β-catenin signaling is a major oncogenic pathway in hepatocellular carcinoma (HCC). Since β-catenin phosphorylation by glycogen synthase kinase 3β (GSK3β) and casein kinase 1ε (CK1ε) results in its degradation, mutations affecting these phosphorylation sites cause β-catenin stabilization. However, the relevance of missense mutations in non-phosphorylation sites in exon 3 remains unclear. The current study explores significance of such mutations in addition to addressing the clinical and biological implications of β-catenin activation in human HCC. Methods Gene alteration in exon3 of CTNNB1, gene expression of β-catenin targets such as glutamate synthetase (GS), axin2, lect2 and regucalcin (RGN), and protein expression of β-catenin were examined in 125 human HCC tissues. Results Sixteen patients (12.8%) showed conventional missense mutations affecting codons 33, 37, 41, and 45. Fifteen additional patients (12.0%) had other missense mutations in codon 32, 34, and 35. Induction of exon3 mutation caused described β-catenin target gene upregulation in HCC cell line. Interestingly, conventional and non-phosphorylation site mutations were equally associated with upregulation of β-catenin target genes. Nuclear localization of β-catenin was associated with poor overall survival (p = 0.0461). Of these patients with nuclear β-catenin localization, loss of described β-catenin target gene upregulation showed significant poorer overall survival than others (p = 0.0001). Conclusion This study suggests that both conventional and other missense mutations in exon 3 of CTNNB1 lead to β-catenin activation in human HCC. Additionally, the mechanism of nuclear β-catenin localization without upregulation of described β-catenin target genes might be of clinical importance depending on distinct mechanism. PMID:27100093

  13. Seed preferences by rodents in the agri-environment and implications for biological weed control.

    PubMed

    Fischer, Christina; Türke, Manfred

    2016-08-01

    Post-dispersal seed predation and endozoochorous seed dispersal are two antagonistic processes in relation to plant recruitment, but rely on similar preconditions such as feeding behavior of seed consumers and seed traits. In agricultural landscapes, rodents are considered important seed predators, thereby potentially providing regulating ecosystem services in terms of biological weed control. However, their potential to disperse seeds endozoochorously is largely unknown. We exposed seeds of arable plant species with different seed traits (seed weight, nutrient content) and different Red List status in an experimental rye field and assessed seed removal by rodents. In a complementary laboratory experiment, consumption rates, feeding preferences, and potential endozoochory by two vole species (Microtus arvalis and Myodes glareolus) were tested. Seed consumption by rodents after 24 h was 35% in the field and 90% in the laboratory. Both vole species preferred nutrient-rich over nutrient-poor seeds and M. glareolus further preferred light over heavy seeds and seeds of common over those of endangered plants. Endozoochory by voles could be neglected for all tested plant species as no seeds germinated, and only few intact seeds could be retrieved from feces. Synthesis and applications. Our results suggest that voles can provide regulating services in agricultural landscapes by depleting the seed shadow of weeds, rather than facilitating plant recruitment by endozoochory. In the laboratory, endangered arable plants were less preferred by voles than noxious weeds, and thus, our results provide implications for seed choice in restoration approaches. However, other factors such as seed and predator densities need to be taken into account to reliably predict the impact of rodents on the seed fate of arable plants. PMID:27547355

  14. Reductive activation of mitomycin C by thiols: kinetics, mechanism, and biological implications.

    PubMed

    Paz, Manuel M

    2009-10-01

    The clinically used antitumor antibiotic mitomycin C requires a reductive activation to be converted to a bis-electrophile that forms several covalent adducts with DNA, including an interstrand cross-link which is considered to be the lesion responsible for the cytotoxic effects of the drug. Enzymes such as cytochrome P450 reductase and DT-diaphorase have traditionally been implicated in the bioreduction of mitomycin C, but recent reports indicate that enzymes containing a dithiol active site are also involved in the metabolism of mitomycin C. The reductive activation can also be effected in vitro with chemical reductants, but until now, mitomycin C was considered to be inert to thiols. We report here that mitomycin C can, in fact, be reductively activated by thiols. We show that the reaction is autocatalytic and that the end product is a relatively stable aziridinomitosene that can be trapped by adding several nucleophiles after the activation reaction. Kinetic studies show that the reaction is highly sensitive to pH and does not proceed or proceeds very slowly at neutral pH, an observation that explains the unsuccessful results on previous attempts to activate mitomycin C with thiols. The optimum pH for the reactions is around the pK(a) values of the thiols used in the activation. A mechanism for the reaction is hypothesized, involving the initial formation of a thiolate-mitomycin adduct, that then evolves to give the hydroquinone of mitomycin C and disulfide. The results presented here provide a chemical mechanism to explain how some biological dithiols containing an unusually acidic thiol group (deprotonated at physiological pH) participate in the modulation of mitomycin C cytotoxicity.

  15. Aromatic ring-flipping in supercooled water: implications for NMR-based structural biology of proteins.

    PubMed

    Skalicky, J J; Mills, J L; Sharma, S; Szyperski, T

    2001-01-24

    activation parameters obtained at ambient T. This is of keen interest to predict the impact of supercooling for future studies of biological macromolecules, and shows that our approach enables one to conduct NMR-based structural biology at below 0 degrees C in an unperturbed aqueous environment. A search of the BioMagResBank indicated that the overwhelming majority of the Phe and Tyr rings (>95%) are flipping rapidly on the chemical shift time scale at ambient T, while our data for BPTI and activation parameters available for ring-flipping in Iso-2-cytochrome c reveal that in these smaller proteins a total of six out of seventeen rings ( approximately 35%) are "frozen in" at T = -15 degrees C. This suggests that a large fraction of Tyr and Phe rings in globular proteins that are flipping rapidly on the chemical shift time scale at ambient T can be effectively slowed in supercooled water. The present investigation demonstrates that supercooling of protein solutions appears to be an effective means to (i) harvest potential benefits of stalled ring-flipping for refining NMR solution structures, (ii) recruit additional aromatic rings for investigating protein dynamics, and (iii) use multiple slowly flipping rings to probe cold denaturation. The implications for NMR-based structural biology in supercooled water are addressed.

  16. Assessment of temporal variance components and implications for trend assessment in biological monitoring programs

    EPA Science Inventory

    Assessment of temporal trends in biological monitoring programs is often undertaken without an understanding of temporal variability of biological communities. Typically, the within-site variance is unknown and included as part of sampling error. This investigation – designed jo...

  17. Formation of Nanophase Iron in Lunar Soil Simulant for Use in ISRU Studies

    NASA Technical Reports Server (NTRS)

    Liu, Yang; Taylor, Lawrence A.; Hill, Eddy; Day, James D. M.

    2005-01-01

    discovered the presence of abundant np-Fe(sup 0) particles in the glass patinas coating most soil particles. Therefore, the correlation of glass content and magnetic susceptibility can be explained by the presence of the np-Feo particles in glass: small particles contain relatively more np-Fe(sup 0) as glass coatings because the surface area versus mass ratio of the grain size is so increased. The magnetic properties of lunar soil are important in dust mitigation on the Moon (Taylor et al. 2005). Thus material simulating this property is important for testing mitigation methods using electromagnetic field. This np- Fe(sup 0) also produces a unique energy coupling to normal microwaves, such as present in kitchen microwave ovens. Effectively, a portion of lunar soil placed in a normal 2.45 GHz oven will melt at greater than 1200 C before your tea will boil at 100 C, a startling and new discovery reported by Taylor and Meek (2004, 2005). Several methods have been investigated in attempts to make nanophase-sized Feo dispersed within silicate glass; like in the lunar glass. We have been successful in synthesizing such a product and continue to improve on our recipe. We have performed extensive experimentation on this subject to date. Ultimately it will probably be necessary to add this np-Fe(sup 0) bearing silicate glass to lunar soil stimulant, like JSC-1, to actually produce the desired magnetic and microwave coupling properties for use in appropriate ISRU experimentation.

  18. Strengthening the biological weapons convention and implications on the pharmaceutical and biotechnology industry.

    PubMed

    Zabriskie, D

    1998-06-01

    The development, production, stockpiling, and use of biological weapons are banned by the 1972 Biological Weapons Convention (BWC). Reflecting the realities of the Cold War era in which it was negotiated, the BWC lacks means for compliance verification or enforcement. International efforts to remedy this deficiency are accelerating in the face of evidence that covert biological weapon programs are proliferating at the national and subnational levels.

  19. "McLean v. Arkansas" (1982) and Beyond: Implications for Biology Professors

    ERIC Educational Resources Information Center

    Bland, Mark W.; Moore, Randy

    2011-01-01

    To assess current trends of evolution instruction in high schools of the mid-South, we invited Arkansas high school biology teachers from across the state to respond to a survey designed to address this issue. We also asked students enrolled in a freshman-level, nonmajors biology course at a midsize public Arkansas university to recall their…

  20. Synthetic biology in space: considering the broad societal and ethical implications

    NASA Astrophysics Data System (ADS)

    Race, Margaret S.; Moses, Jacob; McKay, Christopher; Venkateswaran, Kasthuri J.

    2012-02-01

    Although the field of synthetic biology is still in its infancy, there are expectations for great advances in the coming decades, both on Earth and potentially in space. Promising applications for long duration space missions include a variety of biologically engineered products and biologically aided processes and technologies, which will undoubtedly be scrutinized for risks and benefits in the broad context of ethical, legal and social realms. By comparing and contrasting features of Earth-based and space-applied synthetic biology, it is possible to identify the likely similarities and differences, and to identify possible challenges ahead for space applications that will require additional research, both in the short and long terms. Using an analytical framework associated with synthetic biology and new technologies on Earth, this paper analyses the kinds of issues and concerns ahead, and identifies those areas where space applications may require additional examination. In general, while Earth- and space-based synthetic biology share many commonalities, space applications have additional challenges such as those raised by space microbiology and environmental factors, legal complications, planetary protection, lack of decision-making infrastructure(s), long duration human missions, terraforming and the possible discovery of extraterrestrial (ET) life. For synthetic biology, the way forward offers many exciting opportunities, but is not without legitimate concerns - for life, environments and society, both on Earth and beyond.

  1. Biological Contributions to Addictions in Adolescents and Adults: Prevention, Treatment and Policy Implications

    PubMed Central

    Potenza, Marc N.

    2012-01-01

    Purpose Despite significant advances in our understanding of the biological bases of addictions, these disorders continue to represent a huge public health burden that is associated with substantial personal suffering. Efforts to target addictions require consideration of how the improved biological understanding of addictions may lead to improved prevention, treatment and policy initiatives. Method In this article, we provide a narrative review of current biological models for addictions with a goal of placing existing data and theories within a translational and developmental framework targeting the advancement of prevention, treatment and policy strategies. Results Data regarding individual differences, intermediary phenotypes, and main and interactive influences of genetic and environmental contributions in the setting of developmental trajectories that may be influenced by addictive drugs or behavior indicate complex underpinnings of addictions. Conclusions Consideration and further elucidation of the biological etiologies of addictions hold significant potential for making important gains and reducing the public health impact of addictions. PMID:23332567

  2. Emergence of the chicken as a model organism: implications for agriculture and biology.

    PubMed

    Burt, D W

    2007-07-01

    Many of the features of the chicken make it an ideal model organism for phylogenetics and embryology, along with applications in agriculture and medicine. The availability of new tools such as whole genome gene expression arrays and single nucleotide polymorphism panels, coupled with the genome sequence, will enhance this position. These advances are reviewed and their implications are discussed.

  3. The emerging role of reactive oxygen and nitrogen species in redox biology and some implications for plasma applications to medicine and biology

    NASA Astrophysics Data System (ADS)

    Graves, David B.

    2012-07-01

    Reactive oxygen species (ROS) and the closely related reactive nitrogen species (RNS) are often generated in applications of atmospheric pressure plasmas intended for biomedical purposes. These species are also central players in what is sometimes referred to as ‘redox’ or oxidation-reduction biology. Oxidation-reduction biochemistry is fundamental to all of aerobic biology. ROS and RNS are perhaps best known as disease-associated agents, implicated in diabetes, cancer, heart and lung disease, autoimmune disease and a host of other maladies including ageing and various infectious diseases. These species are also known to play active roles in the immune systems of both animals and plants and are key signalling molecules, among many other important roles. Indeed, the latest research has shown that ROS/RNS play a much more complex and nuanced role in health and ageing than previously thought. Some of the most potentially profound therapeutic roles played by ROS and RNS in various medical interventions have emerged only in the last several years. Recent research suggests that ROS/RNS are significant and perhaps even central actors in the actions of antimicrobial and anti-parasite drugs, cancer therapies, wound healing therapies and therapies involving the cardiovascular system. Understanding the ways ROS/RNS act in established therapies may help guide future efforts in exploiting novel plasma medical therapies. The importance of ROS and RNS to plant biology has been relatively little appreciated in the plasma biomedicine community, but these species are just as important in plants. It appears that there are opportunities for useful applications of plasmas in this area as well.

  4. Implications of Rheumatic Disease and Biological Response-Modifying Agents in Plastic Surgery.

    PubMed

    Tsai, David M; Borah, Gregory L

    2015-12-01

    The preoperative evaluation for any reconstructive or aesthetic procedure requires a detailed history of existing medical conditions and current home medications. The prevalence of rheumatic diseases such as rheumatoid arthritis, gout, and psoriasis is high, but the impact of these chronic illnesses on surgical outcome and the side effects of the powerful medications used for treatment are often underappreciated. In this review, the authors highlight key perioperative considerations specific to rheumatologic diseases and their associated pharmacologic therapies. In particular, the authors discuss the perioperative management of biological response-modifying agents, which have largely become the new standard of therapy for many rheumatic diseases. The literature reveals three key perioperative concerns with biological therapy for rheumatic disease: infection, wound healing delays, and disease flare. However, data on specific perioperative complications are lacking, and it remains controversial whether withholding biological therapy before surgery is of benefit. The risk of these adverse events is influenced by several factors: age, sex, class of biological agent, duration of exposure, dosage, onset and severity of disease, and type of surgical procedure. Overall, it remains best to develop an individualized plan. In younger patients with recent onset of biological therapy, it is reasonable to withhold therapy based on 3 to 5 half-lives of the specific agent. In older patients with a substantial history of rheumatic disease, the decision to discontinue therapy must be weighed and decided carefully in conjunction with the rheumatologist. PMID:26595025

  5. The impact of childhood maltreatment on biological systems: Implications for clinical interventions.

    PubMed

    Gonzalez, Andrea

    2013-10-01

    Childhood maltreatment represents a significant risk factor for the development of a number of mental and physical health outcomes. Converging evidence suggests that early adversity induces significant and persistent biological changes in individuals ('biological embedding'). The present review focuses on the impact of childhood maltreatment on the hypothalamic-pituitary-adrenal axis and immune system function in both children and adults. Research suggests that childhood maltreatment is associated with hypothalamic-pituitary-adrenal axis dysregulation and diurnal cortisol profiles, as well as stress reactivity. Furthermore, childhood maltreatment is associated with disruptions in various immune system markers including pro- and anti-inflammatory substances, and markers of cell-mediated immunity. The potential of interventions to reduce these negative biological effects in maltreated children is also discussed.

  6. Recent Advances in Molecular Biology of Thyroid Cancer and Their Clinical Implications

    PubMed Central

    Xing, Mingzhao

    2009-01-01

    Synopsis Thyroid cancer is the most common endocrine malignancy with a rapid rising incidence in recent years. Novel efficient management strategies are increasingly needed for this cancer. Remarkable advances have occurred in recent years in understanding the molecular biology of thyroid cancer. This is reflected in several major biological areas of thyroid cancer, including the molecular alterations for the loss of radioiodine avidity of thyroid cancer, the pathogenic role of the MAP kinase and PI3K/Akt pathways and their related genetic alterations, and the aberrant methylation of functionally important genes in thyroid tumorigenesis and pathogenesis. These exciting advances in molecular biology of thyroid cancer provide unprecedented opportunities for the development of molecular-based novel diagnostic, prognostic, and therapeutic strategies for this cancer. PMID:19040974

  7. Export flux and stability as regulators of community composition in pelagic marine biological communities: Implications for regime shifts [review article

    NASA Astrophysics Data System (ADS)

    Laws, Edward

    2004-02-01

    Regime shifts occur when a system transitions from one stable configuration to another. Such abrupt changes in biological communities may reflect small changes in environmental conditions such as temperature, oxygen concentration, or irradiance. Although it seems clear that biological communities are not randomly organized with respect to their functional components, there is disagreement concerning the factors that control that organization. In this paper, I examine the implications of assuming that the composition of pelagic marine biological communities evolves to a condition of maximum stability or resilience. At temperatures of 25 °C or less, a model based on this hypothesis predicts abrupt and discontinuous transitions from configurations associated with low export ratios to configurations associated with high export ratios as the rate of primary production increases. Comparison between field data and model predictions shows very good agreement at low and high production rates, but the field data do not support a step-function transition from low to high export ratios at intermediate rates of production. Instead, the field data are consistent with the assumption that food webs effect the transition between high and low ef ratio modes by reconfiguring themselves in a more-or-less continuous manner. The configurations associated with these transitions are at least locally more resilient than any similar food web structure.

  8. THE INFLUENCE OF CATCHMENT LAND USE ON HYDROGRAPH DYNAMICS AND IMPLICATIONS FOR STREAM BIOLOGICAL ASSEMBLAGES

    EPA Science Inventory

    Catchment land use impacts the rise and fall dynamic of hydrographs, and may also help explain variation in biological assemblages known to be sensitive to flow regime. We collected continuous stream depth records for the 2002 water year (5 min. intervals) from eight streams dra...

  9. Chronological age vs. biological maturation: implications for exercise programming in youth.

    PubMed

    Lloyd, Rhodri S; Oliver, Jon L; Faigenbaum, Avery D; Myer, Gregory D; De Ste Croix, Mark B A

    2014-05-01

    Biological maturation is associated with significant change to a number of physiological and structural processes throughout childhood and, in particular, adolescence. Mismatched rapid growth in the long bones relative to muscular lengthening may disrupt structure, neuromuscular function, and physical performance. Practitioners who work with school-age youth should be aware of the age-related changes that typically take place during a child's development to ensure that their strength and conditioning programming is as safe and effective as possible for enhancing performance and reducing injury risk. Although there are several methods available to assess biological maturation, practitioners who work with youth can benefit from assessment methods that are available and feasible, and that provide utility in the quantification of the degree and stages of biological maturation that affect motor performance in children and adolescents. This article synthesizes the relevant assessment methods and provides a rationale for understanding usable biological maturation assessment tools that can aid in the development of training program design for youth.

  10. Dissertation Citations in Organismal Biology at Southern Illinois University at Carbondale: Implications for Collection Development

    ERIC Educational Resources Information Center

    Nabe, Jonathan; Imre, Andrea

    2008-01-01

    We report on a citation analysis of Ph.D. dissertations in plant biology and zoology at Southern Illinois University Carbondale, undertaken to test the common assumption that scientists favor current research to such an extent that journal backfiles can be de-emphasized in academic library collections. Results demonstrate otherwise. The study is…

  11. Chronological age vs. biological maturation: implications for exercise programming in youth.

    PubMed

    Lloyd, Rhodri S; Oliver, Jon L; Faigenbaum, Avery D; Myer, Gregory D; De Ste Croix, Mark B A

    2014-05-01

    Biological maturation is associated with significant change to a number of physiological and structural processes throughout childhood and, in particular, adolescence. Mismatched rapid growth in the long bones relative to muscular lengthening may disrupt structure, neuromuscular function, and physical performance. Practitioners who work with school-age youth should be aware of the age-related changes that typically take place during a child's development to ensure that their strength and conditioning programming is as safe and effective as possible for enhancing performance and reducing injury risk. Although there are several methods available to assess biological maturation, practitioners who work with youth can benefit from assessment methods that are available and feasible, and that provide utility in the quantification of the degree and stages of biological maturation that affect motor performance in children and adolescents. This article synthesizes the relevant assessment methods and provides a rationale for understanding usable biological maturation assessment tools that can aid in the development of training program design for youth. PMID:24476778

  12. Approaches to Learning by Students in the Biological Sciences: Implications for Teaching

    ERIC Educational Resources Information Center

    Watters, Dianne J.; Watters, James J.

    2007-01-01

    This study is an investigation of the epistemological beliefs and study habits of students undertaking first-year courses in Biological Chemistry and Biochemistry. In particular, we were interested in the relationship between students' epistemological beliefs about learning and knowledge, approaches to learning, and achievement. The study adopted…

  13. Biological cost of fluoroquinolone resistance in Escherichia coli implicated in polyclonal infection.

    PubMed

    Bémer, P; Corvec, S; Guitton, C; Giraudeau, C; Le Gargasson, G; Espaze, E; Drugeon, H

    2007-07-01

    Polyclonal Escherichia coli strains were isolated in a transplanted patient who experienced successive septic shocks. Fluoroquinolone susceptible and resistant strains were corresponding to different PFGE fragment profiles. The gyrA S83L mutation was associated with a reduction in biological fitness. Resistant strain was selected by a long-term single use of ofloxacin.

  14. Developmental Changes in Children's Inductive Inferences for Biological Concepts: Implications for the Development of Essentialist Beliefs

    ERIC Educational Resources Information Center

    Farrar, M. Jeffrey; Boyer-Pennington, Michelle

    2011-01-01

    We examined developmental changes in children's inductive inferences about biological concepts as a function of knowledge of properties and concepts. Specifically, 4- to 5-year-olds and 9- to 10-year-olds were taught either familiar or unfamiliar internal, external, or functional properties about known and unknown target animals. Children were…

  15. High School Biology Teachers' Views on Teaching Evolution: Implications for Science Teacher Educators

    ERIC Educational Resources Information Center

    Hermann, Ronald S.

    2013-01-01

    In the US, there may be few scientific concepts that students maintain preconceived ideas about as strongly and passionately as they do with regard to evolution. At the confluence of a multitude of social, religious, political, and scientific factors lies the biology teacher. This phenomenological study provides insight into the salient aspects of…

  16. Genetic control of chromosome behaviour: Implications in evolution, crop improvement, and human biology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chromosomes and chromosome pairing are pivotal to all biological sciences. The study of chromosomes helps unravel several aspects of an organism. Although the foundation of genetics occurred with the formulation of the laws of heredity in 1865, long before the discovery of chromosomes, their subsequ...

  17. Knowledge and Awareness Concerning Chemical and Biological Terrorism: Continuing Education Implications.

    ERIC Educational Resources Information Center

    Rose, Molly A.; Larrimore, Karen L.

    2002-01-01

    Nurses, physicians, and nursing and medical students (n=291) were surveyed about their awareness of chemical and biological terrorism. Infection control personnel and nurse educators (n=24) were surveyed about terrorism preparation. Fewer than one-quarter of questions were answered correctly, and only about 23% reported confidence in the ability…

  18. Biological cost of fluoroquinolone resistance in Escherichia coli implicated in polyclonal infection.

    PubMed

    Bémer, P; Corvec, S; Guitton, C; Giraudeau, C; Le Gargasson, G; Espaze, E; Drugeon, H

    2007-07-01

    Polyclonal Escherichia coli strains were isolated in a transplanted patient who experienced successive septic shocks. Fluoroquinolone susceptible and resistant strains were corresponding to different PFGE fragment profiles. The gyrA S83L mutation was associated with a reduction in biological fitness. Resistant strain was selected by a long-term single use of ofloxacin. PMID:16884861

  19. Biology of hematopoietic stem cells and progenitors: implications for clinical application.

    PubMed

    Kondo, Motonari; Wagers, Amy J; Manz, Markus G; Prohaska, Susan S; Scherer, David C; Beilhack, Georg F; Shizuru, Judith A; Weissman, Irving L

    2003-01-01

    Stem cell biology is scientifically, clinically, and politically a current topic. The hematopoietic stem cell, the common ancestor of all types of blood cells, is one of the best-characterized stem cells in the body and the only stem cell that is clinically applied in the treatment of diseases such as breast cancer, leukemias, and congenital immunodeficiencies. Multicolor cell sorting enables the purification not only of hematopoietic stem cells, but also of their downstream progenitors such as common lymphoid progenitors and common myeloid progenitors. Recent genetic approaches including gene chip technology have been used to elucidate the gene expression profile of hematopoietic stem cells and other progenitors. Although the mechanisms that control self-renewal and lineage commitment of hematopoietic stem cells are still ambiguous, recent rapid advances in understanding the biological nature of hematopoietic stem and progenitor cells have broadened the potential application of these cells in the treatment of diseases. PMID:12615892

  20. Molecular biology in marine science: Scientific questions, technological approaches, and practical implications

    SciTech Connect

    1994-12-31

    This report describes molecular techniques that could be invaluable in addressing process-oriented problems in the ocean sciences that have perplexed oceanographers for decades, such as understanding the basis for biogeochemical processes, recruitment processes, upper-ocean dynamics, biological impacts of global warming, and ecological impacts of human activities. The coupling of highly sophisticated methods, such as satellite remote sensing, which permits synoptic monitoring of chemical, physical, and biological parameters over large areas, with the power of modern molecular tools for ``ground truthing`` at small scales could allow scientists to address questions about marine organisms and the ocean in which they live that could not be answered previously. Clearly, the marine sciences are on the threshold of an exciting new frontier of scientific discovery and economic opportunity.

  1. Experimental determination of cloud influence on the spectral UV irradiance and implications for biological effects

    NASA Astrophysics Data System (ADS)

    Mateos, David; di Sarra, Alcide; Meloni, Daniela; di Biagio, Claudia; Sferlazzo, Damiano M.

    2011-08-01

    Measurements of UV spectra, total ozone, cloud cover, and cloud optical thickness, obtained at Lampedusa (central Mediterranean), are used to investigate the influence of clouds on the spectral UV irradiance, through the cloud modification factor (CMF), and on five biological processes. The CMF decreases with cloud optical thickness (COT), from about 0.5 for COT˜15 to 0.25 for COT˜45, and decreases with increasing wavelength above 315-320-nm. Observations display an increase in the CMF from 295 to 320-nm, which is related to enhanced absorption by tropospheric ozone due to the long photon path lengths under cloudy conditions. The use of a wavelength independent CMF instead of the experimentally determined spectral curves produces an overestimation of the biological effects of UV irradiance. The overestimation may be as large as 30% for the DNA damage, 20% for vitamin D synthesis, 12% for plant damage, and 8-10% for phytoplankton inhibition and erythema.

  2. The ultraviolet environment of Mars: biological implications past, present, and future.

    PubMed

    Cockell, C S; Catling, D C; Davis, W L; Snook, K; Kepner, R L; Lee, P; McKay, C P

    2000-08-01

    A radiative transfer model is used to quantitatively investigate aspects of the martian ultraviolet radiation environment, past and present. Biological action spectra for DNA inactivation and chloroplast (photosystem) inhibition are used to estimate biologically effective irradiances for the martian surface under cloudless skies. Over time Mars has probably experienced an increasingly inhospitable photobiological environment, with present instantaneous DNA weighted irradiances 3.5-fold higher than they may have been on early Mars. This is in contrast to the surface of Earth, which experienced an ozone amelioration of the photobiological environment during the Proterozoic and now has DNA weighted irradiances almost three orders of magnitude lower than early Earth. Although the present-day martian UV flux is similar to that of early Earth and thus may not be a critical limitation to life in the evolutionary context, it is a constraint to an unadapted biota and will rapidly kill spacecraft-borne microbes not covered by a martian dust layer. Microbial strategies for protection against UV radiation are considered in the light of martian photobiological calculations, past and present. Data are also presented for the effects of hypothetical planetary atmospheric manipulations on the martian UV radiation environment with estimates of the biological consequences of such manipulations.

  3. The ultraviolet environment of Mars: biological implications past, present, and future

    NASA Technical Reports Server (NTRS)

    Cockell, C. S.; Catling, D. C.; Davis, W. L.; Snook, K.; Kepner, R. L.; Lee, P.; McKay, C. P.

    2000-01-01

    A radiative transfer model is used to quantitatively investigate aspects of the martian ultraviolet radiation environment, past and present. Biological action spectra for DNA inactivation and chloroplast (photosystem) inhibition are used to estimate biologically effective irradiances for the martian surface under cloudless skies. Over time Mars has probably experienced an increasingly inhospitable photobiological environment, with present instantaneous DNA weighted irradiances 3.5-fold higher than they may have been on early Mars. This is in contrast to the surface of Earth, which experienced an ozone amelioration of the photobiological environment during the Proterozoic and now has DNA weighted irradiances almost three orders of magnitude lower than early Earth. Although the present-day martian UV flux is similar to that of early Earth and thus may not be a critical limitation to life in the evolutionary context, it is a constraint to an unadapted biota and will rapidly kill spacecraft-borne microbes not covered by a martian dust layer. Microbial strategies for protection against UV radiation are considered in the light of martian photobiological calculations, past and present. Data are also presented for the effects of hypothetical planetary atmospheric manipulations on the martian UV radiation environment with estimates of the biological consequences of such manipulations.

  4. Adaptive evolution of a generalist parasitoid: implications for the effectiveness of biological control agents

    PubMed Central

    Zepeda-Paulo, Francisca A; Ortiz-Martínez, Sebastián A; Figueroa, Christian C; Lavandero, Blas

    2013-01-01

    The use of alternative hosts imposes divergent selection pressures on parasitoid populations. In response to selective pressures, these populations may follow different evolutionary trajectories. Divergent natural selection could promote local host adaptation in populations, translating into direct benefits for biological control, thereby increasing their effectiveness on the target host. Alternatively, adaptive phenotypic plasticity could be favored over local adaptation in temporal and spatially heterogeneous environments. We investigated the existence of local host adaptation in Aphidius ervi, an important biological control agent, by examining different traits related to infectivity (preference) and virulence (a proxy of parasitoid fitness) on different aphid-host species. The results showed significant differences in parasitoid infectivity on their natal host compared with the non-natal hosts. However, parasitoids showed a similar high fitness on both natal and non-natal hosts, thus supporting a lack of host adaptation in these introduced parasitoid populations. Our results highlight the role of phenotypic plasticity in fitness-related traits of parasitoids, enabling them to maximize fitness on alternative hosts. This could be used to increase the effectiveness of biological control. In addition, A. ervi females showed significant differences in infectivity and virulence across the tested host range, thus suggesting a possible host phylogeny effect for those traits. PMID:24062806

  5. Time-dependent degradation of titanium osteoconductivity: an implication of biological aging of implant materials.

    PubMed

    Att, Wael; Hori, Norio; Takeuchi, Masato; Ouyang, Jianyong; Yang, Yang; Anpo, Masakazu; Ogawa, Takahiro

    2009-10-01

    The shelf life of implantable materials has rarely been addressed. We determined whether osteoconductivity of titanium is stable over time. Rat bone marrow-derived osteoblasts were cultured on new titanium disks (immediately after acid-etching), 3-day-old (stored after acid-etching for 3 days in dark ambient conditions), 2-week-old, and 4-week-old disks. Protein adsorption capacity, and osteoblast migration, attachment, spread, proliferation and mineralization decreased substantially on old titanium surfaces in an age-dependent manner. When the 4-week-old implants were placed into rat femurs, the biomechanical strength of bone-titanium integration was less than half that for newly processed implants at the early healing stage. More than 90% of the new implant surface was covered by newly generated bone compared to 58% for 4-week-old implants. This time-dependent biological degradation was also found for machined and sandblasted titanium surfaces and was associated with progressive accumulation of hydrocarbon on titanium surfaces. The new surface could attract osteoblasts even under a protein-free condition, but its high bioactivity was abrogated by masking the surface with anions. These results uncover an aging-like time-dependent biological degradation of titanium surfaces from bioactive to bioinert. We also suggest possible underlying mechanisms for this biological degradation that provide new insights into how we could inadvertently lose, and conversely, maximize the osteoconductivity of titanium-based implant materials.

  6. Biological and chemical terrorism scenarios and implications for detection systems needs

    NASA Astrophysics Data System (ADS)

    Gordon, Susanna P.; Chumfong, Isabelle; Edwards, Donna M.; Gleason, Nathaniel J.; West, Todd; Yang, Lynn

    2007-04-01

    Terrorists intent on causing many deaths and severe disruption to our society could, in theory, cause hundreds to tens of thousands of deaths and significant contamination of key urban facilities by using chemical or biological (CB) agents. The attacks that have occurred to date, such as the 1995 Aum Shinrikyo CB attacks and the 2001 anthrax letters, have been very small on the scale of what is possible. In order to defend against and mitigate the impacts of large-scale terrorist attacks, defensive systems for protection of urban areas and high-value facilities from biological and chemical threats have been deployed. This paper reviews analyses of such scenarios and of the efficacy of potential response options, discusses defensive systems that have been deployed and detectors that are being developed, and finally outlines the detection systems that will be needed for improved CB defense in the future. Sandia's collaboration with San Francisco International Airport on CB defense will also be briefly reviewed, including an overview of airport facility defense guidelines produced in collaboration with Lawrence Berkeley National Laboratory. The analyses that will be discussed were conducted by Sandia National Laboratories' Systems Studies Department in support of the U.S. Department of Homeland Security (DHS) Science and Technology Directorate, and include quantitative analyses utilizing simulation models developed through close collaboration with subject matter experts, such as public health officials in urban areas and biological defense experts.

  7. Chemical model for Viking biology experiments: implications for the composition of the martian regolith

    NASA Astrophysics Data System (ADS)

    Plumb, Robert C.; Tantayanon, Rewat; Libby, Mark; Xu, Wen Wen

    1989-04-01

    THE 1976 Mars Viking biology experiments were designed to detect life by observing the products of biochemical reactions. In the labelled-release (LR) experiments1-4, about 25 nmol of 14C-labelled gases evolved when regolith samples were moistened with nutrient solution. About 22% of the products reabsorbed upon second injection. As a biological test the LR results were positive, although the reabsorption was not readily explained. In the gas-exchange (GEX) experiments, up to 800 nmol of O2 gas was evolved when samples were humidified5,6, suggesting that the martian regolith might contain a strong chemical oxidant which caused the LR results. Several chemical models have been proposed7,8 but no self-consistent explanation of all of the observations has been achieved. Here we propose a chemical model for these biology experiments in which the reactants are an inorganic nitrate salt, which has been partly photolysed by ultraviolet light, and a sparingly soluble metal carbonate such as calcite. The model reproduces the main effects seen, indicating that nitrates are present in the martian regolith as well as calcite (or some other carbonate with similar solubility).

  8. Bone morphogenetic proteins for periodontal and alveolar indications; biological observations - clinical implications.

    PubMed

    Wikesjö, U M E; Qahash, M; Huang, Y-H; Xiropaidis, A; Polimeni, G; Susin, C

    2009-08-01

    Surgical placement of endosseous oral implants is governed by the prosthetic design and by the morphology and quality of the alveolar bone. Nevertheless, often implant placement may be complexed, if at all possible, by alveolar ridge irregularities resulting from periodontal disease, and chronic and acute trauma. In consequence, implant positioning commonly necessitates bone augmentation procedures. One objective of our laboratory is to evaluate the biologic potential of bone morphogenetic proteins (BMP) and other candidate biologics, bone biomaterials, and devices for alveolar ridge augmentation and implant fixation using discriminating large animal models. This focused review illustrates the unique biologic potential, the clinical relevance and perspectives of recombinant human BMP-2 (rhBMP-2) using a variety of carrier technologies to induce local bone formation and implant osseointegration for inlay and onlay indications. Our studies demonstrate a clinically relevant potential of a purpose-designed titanium porous oxide implant surface as stand-alone technology to deliver rhBMP-2 for alveolar augmentation. In perspective, merits and shortcomings of current treatment protocol including bone biomaterials and guided bone regeneration are addressed and explained. We demonstrate that rhBMP-2 has unparalleled potential to augment alveolar bone, and support implant osseointegration and long-term functional loading. Inclusion of rhBMP-2 for alveolar augmentation and osseointegration will not only enhance predictability of existing clinical protocol but also radically change current treatment paradigms.

  9. Adhesion control by inflation: implications from biology to artificial attachment device

    NASA Astrophysics Data System (ADS)

    Dening, Kirstin; Heepe, Lars; Afferrante, Luciano; Carbone, Giuseppe; Gorb, Stanislav N.

    2014-08-01

    There is an increasing demand for materials that incorporate advanced adhesion properties, such as an ability to adhere in a reversible and controllable manner. In biological systems, these features are known from adhesive pads of the tree frog, Litoria caerulea, and the bush-cricket, Tettigonia viridissima. These species have convergently developed soft, hemispherically shaped pads that might be able to control their adhesion through active changing the curvature of the pad. Inspired by these biological systems, an artificial model system is developed here. It consists of an inflatable membrane clamped to the metallic cylinder and filled with air. Pull-off force measurements of the membrane surface were conducted in contact with the membrane at five different radii of curvature r c with (1) a smooth polyvinylsiloxane membrane and (2) mushroom-shaped adhesive microstructured membrane made of the same polymer. The hypothesis that an increased internal pressure, acting on the membrane, reduces the radius of the membrane curvature, resulting in turn in a lower pull-off force, is verified. Such an active control of adhesion, inspired by biological models, will lead to the development of industrial pick-and-drop devices with controllable adhesive properties.

  10. Options for human ``return to the moon'' using tomorrow's SSTO, ISRU, and LOX-augmented NTR technologies

    NASA Astrophysics Data System (ADS)

    Borowski, Stanley K.

    1996-03-01

    The feasibility of conducting human missions to the Moon is examined assuming the use of three ``high leverage'' technologies: (1) a single-stage-to-orbit (SSTO) launch vehicle, (2) ``in-situ'' resource utilization (ISRU)—specifically ``lunar-derived'' liquid oxygen (LUNOX), and (3) LOX-augmented nuclear thermal rocket (LANTR) propulsion. Lunar transportation system elements consisting of a LANTR-powered lunar transfer vehicle (LTV) and a chemical propulsion lunar landing/Earth return vehicle (LERV) are configured to fit within the ``compact'' dimensions of the SSTO cargo bay (diameter: 4.6 m/length: 9.0 m) while satisfying an initial mass in low Earth orbit (IMLEO) limit of ˜60 t (3 SSTO launches). Using ˜8 t of LUNOX to ``reoxidize'' the LERV for a ``direct return'' flight to Earth reduces its size and mass allowing delivery to LEO on a single 20 t SSTO launch. Similarly, the LANTR engine's ability to operate at any oxygen/hydrogen mixture ratio from 0 to 7 with high specific impulse (˜940 to 515 s) is exploited to reduce hydrogen tank volume, thereby improving packaging of the LANTR LTV's ``propulsion'' and ``propellant modules''. Expendable and reusable, piloted and cargo missions and vehicle designs are presented along with estimates of LUNOX production required to support the different mission modes.

  11. Biological and Clinical Implications of Clonal Heterogeneity and Clonal Evolution in Multiple Myeloma

    PubMed Central

    Bianchi, Giada; Ghobrial, Irene M.

    2015-01-01

    Clonal heterogeneity and clonal evolution have emerged as critical concepts in the field of oncology over the past four decades, largely thanks to the implementation of novel technologies such as comparative genomic hybridization, whole genome/exome sequencing and epigenetic analysis. Along with the identification of cancer stem cells in the majority of neoplasia, the recognition of intertumor and intratumor variability has provided a novel perspective to understand the mechanisms behind tumor evolution and its implication in terms of treatment failure and cancer relapse or recurrence. First hypothesized over two decades ago, clonal heterogeneity and clonal evolution have been confirmed in multiple myeloma (MM), an incurable cancer of plasma cells, almost universally preceded by a pre-malignant conditioned named monoclonal gammopathy of undetermined significance (MGUS). The genetic events and molecular mechanisms underlying such evolution have been difficult to dissect. Moreover, while a role for the bone marrow microenvironment in supporting MM cell survival, proliferation and drug-resistance has been well established, whether it is directly involved in driving evolution from MGUS to MM is at present unclear. We present in this review a historical excursus on the concepts of clonal heterogeneity and clonal evolution in MM with a special emphasis on their role in the progression from MGUS to MM; the contribution of the microenvironment; and the clinical implications in terms of resistance to treatment and disease relapse/recurrence. PMID:25705146

  12. Chemical studies on tobacco smoke. XXXIII. N' -nitrosonornicotine in tobacco: analysis of possible contributing factors and biologic implications.

    PubMed

    Hecht, S S; Ornaf, R M; Hoffmann, D

    1975-05-01

    A chemical analytic method to determine N'-nitrosonornicotine (NNN) and N' -nitrosoanabasine (NAB) in tobacco was developed. NNN was found in the unburned tobacco of commercial products at concentrations betweeen 0.3 and 88.6 mug/g. The highest levels were observed in highly fermented snuff (29.1 mug/g) and fine-cut chewing tobacco (88.6 mug/g). NAB was not detected (smaller than 0.5 ng/g) in any tobacco examined. Two new tobacco components, N' -carbomethoxynornicotine and N' -carbomethoxyanabasine,were found. Possible origins of NNN in tobacco were discussed, especially in relation to concentrations of nitrite, nitate, and alkaloids, and in relation to pH and curing. Biologic implications, including the possible function of NNN (the first organic carcinogen isolated from unburned tobacco) as a causative factor in cancer of the oral cavity in tobacco chewers and betel quid chewers, were also discussed.

  13. Biological variation in a large sample of mouse lemurs from Amboasary, Madagascar: implications for interpreting variation in primate biology and paleobiology.

    PubMed

    Cuozzo, Frank P; Rasoazanabary, Emilienne; Godfrey, Laurie R; Sauther, Michelle L; Youssouf, Ibrahim Antho; LaFleur, Marni M

    2013-01-01

    template for recognizing the degree of variation manifested in a single primate population, and by implication, they provide minimum values for this species' intraspecific variation. Finally, discordance between different biological systems in our mouse lemur samples illustrates the need to examine multiple systems when conducting taxonomic analyses among living or fossil primates. PMID:23245834

  14. Diffusion of dissolved ions from wet silica sol-gel monoliths: implications for biological encapsulation.

    PubMed

    Dickson, David J; Lassetter, Bethany; Glassy, Benjamin; Page, Catherine J; Yokochi, Alexandre F T; Ely, Roger L

    2013-02-01

    Divalent nickel (Ni(2+)), Cu(II)EDTA, methyl orange, and dichromate were used to investigate diffusion from hydrated silica sol-gel monoliths. The objective was to examine diffusion of compounds on a size regime relevant to supporting biological components encapsulated within silica gel prepared in a biologically compatible process space with no post-gelation treatments. With an initial sample set, gels prepared from tetraethoxysilane were explored in a factorial design with Ni(2+) as the tracer, varying water content during hydrolysis, acid catalyst present during hydrolysis, and the final concentration of silica. A second sample set explored diffusion of all four tracers in gels prepared with aqueous silica precursors and a variety of organically modified siloxanes. Excluding six outliers which displayed significant syneresis, the mean diffusion constant (D(gel)) across the entire process space of sample set 1 was 2.42×10(-10) m(2) s(-1); approximately 24% of the diffusion coefficient of Ni(2+) in unconfined aqueous solution. In sample set 2, the tracer size and not gel hydrophobicity was the primary determinant of changes in diffusion rates. A strong linear inverse correlation was found between tracer size and the magnitude of D(gel). Based on correlation with the tracers used in this investigation, the characteristic 1-h diffusion distance for carbonate species relevant to supporting active phototrophic organisms was approximately 1.5mm. These results support the notion that silica sol-gel formulations may be optimized for a given biological entity of interest with manageable impact to the diffusion of small ions and molecules.

  15. Biological properties of dehydrated human amnion/chorion composite graft: implications for chronic wound healing.

    PubMed

    Koob, Thomas J; Rennert, Robert; Zabek, Nicole; Massee, Michelle; Lim, Jeremy J; Temenoff, Johnna S; Li, William W; Gurtner, Geoffrey

    2013-10-01

    Human amnion/chorion tissue derived from the placenta is rich in cytokines and growth factors known to promote wound healing; however, preservation of the biological activities of therapeutic allografts during processing remains a challenge. In this study, PURION® (MiMedx, Marietta, GA) processed dehydrated human amnion/chorion tissue allografts (dHACM, EpiFix®, MiMedx) were evaluated for the presence of growth factors, interleukins (ILs) and tissue inhibitors of metalloproteinases (TIMPs). Enzyme-linked immunosorbent assays (ELISA) were performed on samples of dHACM and showed quantifiable levels of the following growth factors: platelet-derived growth factor-AA (PDGF-AA), PDGF-BB, transforming growth factor α (TGFα), TGFβ1, basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), placental growth factor (PLGF) and granulocyte colony-stimulating factor (GCSF). The ELISA assays also confirmed the presence of IL-4, 6, 8 and 10, and TIMP 1, 2 and 4. Moreover, the relative elution of growth factors into saline from the allograft ranged from 4% to 62%, indicating that there are bound and unbound fractions of these compounds within the allograft. dHACM retained biological activities that cause human dermal fibroblast proliferation and migration of human mesenchymal stem cells (MSCs) in vitro. An in vivo mouse model showed that dHACM when tested in a skin flap model caused mesenchymal progenitor cell recruitment to the site of implantation. The results from both the in vitro and in vivo experiments clearly established that dHACM contains one or more soluble factors capable of stimulating MSC migration and recruitment. In summary, PURION® processed dHACM retains its biological activities related to wound healing, including the potential to positively affect four distinct and pivotal physiological processes intimately involved in wound healing: cell proliferation, inflammation, metalloproteinase activity and recruitment of progenitor cells. This suggests

  16. Chemical model for Viking biology experiments - Implications for the composition of the Martian regolith

    NASA Technical Reports Server (NTRS)

    Plumb, Robert C.; Tantayanon, Rewat; Libby, Mark; Xu, Wen Wen

    1989-01-01

    The labelled-release and the gas-exchange experiments of the 1976 Mars Viking biology experiment program detected, respectively, C-14 labelled gases and O2 gas. A chemical model is proposed here for these experiments in which the reactants are an inorganic nitrate salt which has been partly photolyzed by ultraviolet light and a sparingly soluble metal carbonate such as calcite. The model reproduces the main effects seen, indicating that nitrates are present in the Martian regolith as well as calcite (or some other carbonate with similar solubility).

  17. New Developments in Peritoneal Fibroblast Biology: Implications for Inflammation and Fibrosis in Peritoneal Dialysis

    PubMed Central

    Witowski, Janusz; Kawka, Edyta; Rudolf, Andras; Jörres, Achim

    2015-01-01

    Uraemia and long-term peritoneal dialysis (PD) can lead to fibrotic thickening of the peritoneal membrane, which may limit its dialytic function. Peritoneal fibrosis is associated with the appearance of myofibroblasts and expansion of extracellular matrix. The extent of contribution of resident peritoneal fibroblasts to these changes is a matter of debate. Recent studies point to a significant heterogeneity and complexity of the peritoneal fibroblast population. Here, we review recent developments in peritoneal fibroblast biology and summarize the current knowledge on the involvement of peritoneal fibroblasts in peritoneal inflammation and fibrosis. PMID:26495280

  18. [The role of Marisa cornuarietis as a biological control agent and its economic and epidemiological implications].

    PubMed

    Ferrer López, J R; Moné, H; Perera de Puga, G; Yong Cong, M

    1991-01-01

    It was determined that M. cornuarietis, a mollusk which has been used as agent for the biological control of the schistosomiasis hosts, may be a plague for rice fields. Each mollusk can consume 0.3 g of this plant in 24 hours, accounting for the destruction of 0.015 m2 of a rice field. On the other hand, it was observed that B. glabrata shows preference for the consumption of M. cornuarietis faeces. This fact favors the vector's growth and reproduction rate and at the same time decreases its mortality.

  19. The State, Potential Distribution, and Biological Implications of Methane in the Martian Crust

    NASA Technical Reports Server (NTRS)

    Max, Michael D.; Clifford, Stephen M.

    2000-01-01

    The search for life on Mars has recently focused on its potential survival in deep (>2 km) subpermafrost aquifers where anaerobic bacteria, similar to those found in deep subsurface ecosystems on Earth, may have survived in an environment that has remained stable for billions of years. An anticipated by-product of this biological activity is methane. The detection of large deposits of methane gas and hydrate in the Martian cryosphere, or as emissions from deep fracture zones, would provide persuasive evidence of indigenous life and confirm the presence of a valuable in situ resource for use by future human explorers.

  20. Coastal inshore waters in the NW Mediterranean: Physicochemical and biological characterization and management implications

    NASA Astrophysics Data System (ADS)

    Flo, Eva; Garcés, Esther; Manzanera, Marta; Camp, Jordi

    2011-07-01

    The physicochemical and biological characteristics of coastal waters form a gradient extending from land to ocean. In the Mediterranean this gradient is particularly large, due to the sea's weak tides. Within coastal waters, those waters in contact with land are called coastal inshore waters (CIW), defined herein as between 0 and 200 m from the shoreline. Here we present the first physicochemical and biological characterization of CIW of the NW Mediterranean Sea. This case study is based on 19 years of data collected from coastal inshore (CIW; 0-200 m), nearshore (CNW; 200-1500 m), and offshore (COW; >1500 m) waters of the Catalan coast. Analyses of these data showed that the physicochemical and biological characteristics of CIW differ significantly from those of CNW and COW due to: (1) significantly higher concentrations of dissolved inorganic nutrients (nitrate = 11.07 μM, nitrite = 0.52 μM, ammonium = 6.43 μM, phosphate = 0.92 μM, silicates = 5.99 μM) and chlorophyll- a (=2.42 μg/L) in CIW than in either CNW or COW (in some cases up to one order of magnitude); (2) a greater variability of dissolved inorganic nutrients and chlorophyll- a in CIW than in CNW and COW, and (3) the presence of a mostly urban population and the effects of river inflows as a primary source of CIW variability but with minimal impact on CNW or COW. In addition, the risk of eutrophication was found to be highest in CIW, placing human and environmental interests at greater risk than in the outermost coastal waters. The results highlight the importance of considering the distinctive physicochemical and biological properties of CIW in future coastal waters studies. This is of major importance in assessments of eutrophication and coastal water quality, not only to identify the pressure-impact relationships but also to allow the timely detection of local environmental problems and thus avoid endangering the unique communities of CIW and ensuring the sustainability of human activities. In

  1. A biological security motivation system for potential threats: are there implications for policy-making?

    PubMed

    Woody, Erik Z; Szechtman, Henry

    2013-01-01

    Research indicates that there is a specially adapted, hard-wired brain circuit, the security motivation system, which evolved to manage potential threats, such as the possibility of contamination or predation. The existence of this system may have important implications for policy-making related to security. The system is sensitive to partial, uncertain cues of potential danger, detection of which activates a persistent, potent motivational state of wariness or anxiety. This state motivates behaviors to probe the potential danger, such as checking, and to correct for it, such as washing. Engagement in these behaviors serves as the terminating feedback for the activation of the system. Because security motivation theory makes predictions about what kinds of stimuli activate security motivation and what conditions terminate it, the theory may have applications both in understanding how policy-makers can best influence others, such as the public, and also in understanding the behavior of policy-makers themselves.

  2. Aluminum-Induced Entropy in Biological Systems: Implications for Neurological Disease

    PubMed Central

    Shaw, Christopher A.; Seneff, Stephanie; Kette, Stephen D.; Tomljenovic, Lucija; Oller, John W.; Davidson, Robert M.

    2014-01-01

    Over the last 200 years, mining, smelting, and refining of aluminum (Al) in various forms have increasingly exposed living species to this naturally abundant metal. Because of its prevalence in the earth's crust, prior to its recent uses it was regarded as inert and therefore harmless. However, Al is invariably toxic to living systems and has no known beneficial role in any biological systems. Humans are increasingly exposed to Al from food, water, medicinals, vaccines, and cosmetics, as well as from industrial occupational exposure. Al disrupts biological self-ordering, energy transduction, and signaling systems, thus increasing biosemiotic entropy. Beginning with the biophysics of water, disruption progresses through the macromolecules that are crucial to living processes (DNAs, RNAs, proteoglycans, and proteins). It injures cells, circuits, and subsystems and can cause catastrophic failures ending in death. Al forms toxic complexes with other elements, such as fluorine, and interacts negatively with mercury, lead, and glyphosate. Al negatively impacts the central nervous system in all species that have been studied, including humans. Because of the global impacts of Al on water dynamics and biosemiotic systems, CNS disorders in humans are sensitive indicators of the Al toxicants to which we are being exposed. PMID:25349607

  3. Biological structure and health implications from tooth size at Mission San Luis de Apalachee.

    PubMed

    Stojanowski, Christopher M; Larsen, Clark S; Tung, Tiffiny A; McEwan, Bonnie G

    2007-02-01

    This study analyzes dental metric variation to examine the biological structure of the native population at Mission San Luis de Apalachee, a late 17th century mission located in the Apalachee Province of Spanish colonial Florida. Three topics are addressed: (1) comparison of tooth sizes among adult and subadults, (2) analysis of the bio-spatial structure of skeletons within the church area, and (3) comparison of phenotypic profiles of individuals interred within coffins in the ritual nucleus of the church: the altar region. Analyses indicate that subadults had smaller average tooth sizes than adults for the posterior dentition that was particularly evident in mandibular nonpolar molars and premolars. This disparity, also documented in two other mission populations, likely represents ontogenetic stress and resulting increased mortality among those most at risk for early death. Analysis of the spatial structure of graves failed to document biological structuring by side of the aisle or by burial row, although some gross differences were evident when front, middle, and rear church burials were compared. Individuals buried in coffins within the same row were phenotypically similar to one another. However, inter-row comparisons indicated lack of phenotypic similarity among all coffin interments. These analyses suggest maintenance of kin-structured burial for elites alone within the San Luis community.

  4. Parasitoid nutritional ecology in a community context: the importance of honeydew and implications for biological control.

    PubMed

    Tena, Alejandro; Wäckers, Felix L; Heimpel, George E; Urbaneja, Alberto; Pekas, Apostolos

    2016-04-01

    One focus of conservation biological control studies has been to improve the nutritional state and fitness of parasitoids by adding nectar and artificial sugars to agroecosystems. This approach has largely overlooked the presence of honeydew, which is likely the primary carbohydrate source available to parasitoids in many agroecosystems. Over the last decade, it has been demonstrated that parasitoids often utilize this sugar source and there is evidence that honeydew can indirectly impact the population dynamics of herbivores through its nutritional value for parasitoids. The consumption of honeydew by parasitoids can shape direct and indirect interactions with other arthropods. The strength of these effects will depend on: first, parasitoid biology, second, the presence of other sugar sources (mainly nectar), third, the quality and quantity of the honeydew, and fourth, the presence and competitive strength of other honeydew consumers such as ants. The combination of these four factors is expected to result in distinct scenarios that should be analyzed for each agroecosystem. This analysis can reveal opportunities to increase the biocontrol services provided by parasitoids. Moreover, honeydew can be a resource-rich habitat for insect pathogens; or contain plant secondary chemicals sequestered by hemipterans or systemic insecticides toxic for the parasitoid. Their presence and effect on parasitoid fitness will need to be addressed in future research. PMID:27436654

  5. Molecular biology in marine science: Scientific questions, technological approaches, and practical implications

    SciTech Connect

    Not Available

    1994-12-31

    The ocean plays an important role in regulating the earth`s climate, sustains a large portion of the earth`s biodiversity, is a tremendous reservoir of commercially important substances, and is used for a variety of often conflicting purposes. In recent decades marine scientists have discovered much about the ocean and its organisms, yet many important fundamental questions remain unanswered. Human populations have increased, particularly in coastal regions. As a result, the marine environment in these areas is increasingly disrupted by human activities, including pollution and the depletion of some ecologically and commercially important species. There is a sense of urgency about reducing human impacts on the ocean and a need to understand how altered ecosystems and the loss of marine species and biodiversity could affect society. This report describes molecular techniques that could be invaluable in addressing process-oriented problems in the ocean sciences that have perplexed oceanographers for decades, such as understanding the basis for biogeochemical processes, recruitment processes, upper-ocean dynamics, biological impacts of global warming, and ecological impacts of human activities. The coupling of highly sophisticated methods, such as satellite remote sensing, which permits synoptic monitoring of chemical, physical, and biological parameters over large areas, with the power of modern molecular tools for ground truthing at small scales could allow scientists to address questions about marine organisms and the ocean in which they live that could not be answered previously.

  6. Histopathology of growth anomaly affecting the coral, Montipora capitata: implications on biological functions and population viability.

    PubMed

    Burns, John H R; Takabayashi, Misaki

    2011-01-01

    Growth anomalies (GAs) affect the coral, Montipora capitata, at Wai'ōpae, southeast Hawai'i Island. Our histopathological analysis of this disease revealed that the GA tissue undergoes changes which compromise anatomical machinery for biological functions such as defense, feeding, digestion, and reproduction. GA tissue exhibited significant reductions in density of ova (66.1-93.7%), symbiotic dinoflagellates (38.8-67.5%), mesenterial filaments (11.2-29.0%), and nematocytes (28.8-46.0%). Hyperplasia of the basal body wall but no abnormal levels of necrosis and algal or fungal invasion was found in GA tissue. Skeletal density along the basal body wall was significantly reduced in GAs compared to healthy or unaffected sections. The reductions in density of the above histological features in GA tissue were collated with disease severity data to quantify the impact of this disease at the colony and population level. Resulting calculations showed this disease reduces the fecundity of M. capitata colonies at Wai'ōpae by 0.7-49.6%, depending on GA severity, and the overall population fecundity by 2.41±0.29%. In sum, GA in this M. capitata population reduces the coral's critical biological functions and increases susceptibility to erosion, clearly defining itself as a disease and an ecological threat. PMID:22205976

  7. Response of an invasive liana to simulated herbivory: implications for its biological control

    NASA Astrophysics Data System (ADS)

    Raghu, S.; Dhileepan, K.; Treviño, M.

    2006-05-01

    Pre-release evaluation of the efficacy of biological control agents is often not possible in the case of many invasive species targeted for biocontrol. In such circumstances simulating herbivory could yield significant insights into plant response to damage, thereby improving the efficiency of agent prioritisation, increasing the chances of regulating the performance of invasive plants through herbivory and minimising potential risks posed by release of multiple herbivores. We adopted this approach to understand the weaknesses herbivores could exploit, to manage the invasive liana, Macfadyena unguis-cati. We simulated herbivory by damaging the leaves, stem, root and tuber of the plant, in isolation and in combination. We also applied these treatments at multiple frequencies. Plant response in terms of biomass allocation showed that at least two severe defoliation treatments were required to diminish this liana's climbing habit and reduce its allocation to belowground tuber reserves. Belowground damage appears to have negligible effect on the plant's biomass production and tuber damage appears to trigger a compensatory response. Plant response to combinations of different types of damage did not differ significantly to that from leaf damage. This suggests that specialist herbivores in the leaf-feeding guild capable of removing over 50% of the leaf tissue may be desirable in the biological control of this invasive species.

  8. Nonbonding interactions of organic halogens in biological systems: implications for drug discovery and biomolecular design.

    PubMed

    Lu, Yunxiang; Wang, Yong; Zhu, Weiliang

    2010-05-14

    Halogenation is an important approach in lead optimization for drug development and about half of the molecules used in high-throughput screening are halogenated. However, there is neither a suitable theoretical algorithm for evaluating the interaction between the halogen atoms of a ligand and its target protein nor a detailed understanding of how a halogen atom interacts with electron-rich atoms or groups of the residues in the binding pocket. In this Perspective, we concentrate on nonbonding interactions of halogens from both crystallographic data and theoretical viewpoints. It is found that organic halogen atoms are favorably involved in a wide variety of noncovalent protein-ligand interactions, such as halogen bonds C-X...O and hydrogen bonds C-X...H, that show remarkable differences in terms of the geometrical and energetic features. In biological molecules, heavier halogens prefer to form linear interactions with oxygen atoms and aromatic pi systems as compared to N or S, while the mean intermolecular distances for these types of halogen bonds increase with the radius or polarizability of halogen atoms, viz., Cl < Br < I. Furthermore, F...H interactions in protein-ligand complexes exhibit disparate behavior relative to X...H (X = Cl, Br, I) counterparts. These observed tendencies of the interactions involving halogens are subsequently rationalized by means of ab initio calculations using small model systems. The results presented herein should be of great use in the rational design of halogenated ligands as inhibitors and drugs as well as in biological engineering.

  9. Monodispersed magnetite nanoparticles optimized for magnetic fluid hyperthermia: Implications in biological systems

    NASA Astrophysics Data System (ADS)

    Khandhar, Amit P.; Ferguson, R. Matthew; Krishnan, Kannan M.

    2011-04-01

    Magnetite (Fe3O4) nanoparticles (MNPs) are suitable materials for Magnetic Fluid Hyperthermia (MFH), provided their size is carefully tailored to the applied alternating magnetic field (AMF) frequency. Since aqueous synthesis routes produce polydisperse MNPs that are not tailored for any specific AMF frequency, we have developed a comprehensive protocol for synthesizing highly monodispersed MNPs in organic solvents, specifically tailored for our field conditions (f = 376 kHz, H0 = 13.4 kA/m) and subsequently transferred them to water using a biocompatible amphiphilic polymer. These MNPs (σavg. = 0.175) show truly size-dependent heating rates, indicated by a sharp peak in the specific loss power (SLP, W/g Fe3O4) for 16 nm (diameter) particles. For broader size distributions (σavg. = 0.266), we observe a 30% drop in overall SLP. Furthermore, heating measurements in biological medium [Dulbecco's modified Eagle medium (DMEM) + 10% fetal bovine serum] show a significant drop for SLP (˜30% reduction in 16 nm MNPs). Dynamic Light Scattering (DLS) measurements show particle hydrodynamic size increases over time once dispersed in DMEM, indicating particle agglomeration. Since the effective magnetic relaxation time of MNPs is determined by fractional contribution of the Neel (independent of hydrodynamic size) and Brownian (dependent on hydrodynamic size) components, we conclude that agglomeration in biological medium modifies the Brownian contribution and thus the net heating capacity of MNPs.

  10. Opto-Mechanical Coupling in Interfaces under Static and Propagative Conditions and Its Biological Implications

    PubMed Central

    Shrivastava, Shamit; Schneider, Matthias F.

    2013-01-01

    Fluorescent dyes are vital for studying static and dynamic patterns and pattern formation in cell biology. Emission properties of the dyes incorporated in a biological interface are known to be sensitive to their local environment. We report that the fluorescence intensity of dye molecules embedded in lipid interfaces is indeed a thermodynamic observable of the system. Opto-mechanical coupling of lipid-dye system was measured as a function of the thermodynamic state of the interface. The corresponding state diagrams quantify the thermodynamic coupling between intensity I and lateral pressure π. We further demonstrate that the coupling is conserved upon varying the temperature T. Notably, the observed opto-mechanical coupling is not limited to equilibrium conditions, but also holds for propagating pressure pulses. The non-equilibrium data show, that fluorescence is especially sensitive to dynamic changes in state such as the LE-LC phase transition. We conclude that variations in the thermodynamic state (here π and T, in general pH, membrane potential V, etc also) of lipid membranes are capable of controlling fluorescence intensity. Therefore, interfacial thermodynamic state diagrams of I should be obtained for a proper interpretation of intensity data. PMID:23861769

  11. Epithelial to mesenchymal transition and the cancer stem cell phenotype: Insights from cancer biology with therapeutic implications for colorectal cancer

    PubMed Central

    Findlay, Victoria J.; Wang, Cindy; Watson, Dennis K.; Camp, E. Ramsay

    2014-01-01

    Although mortality from colorectal cancer (CRC) is decreasing, colorectal cancer is still the second highest cause of cancer related deaths in America. Chemotherapy and radiation therapy now play central roles in our strategies to fight cancer, although we continue to lack novel strategies overcoming therapeutic resistance. Molecular mechanisms of therapeutic resistance in CRC continue to be under intense investigation. In this review, we highlight the recent evidence linking epithelial-to-mesenchymal transition (EMT) with aggressive tumor biology as well as with the cancer stem cells (CSC) across multiple organ systems including colon cancer. Furthermore, in the era of neo-adjuvant treatment, the clinical implications are concerning that our treatments may have the potential to induce more aggressive cancer cells through EMT, perhaps even generating CSCs more capable of metastasis and further resistant to treatment. This concern and potential reality highlights the critical need for further understanding the impact of clinical therapy on the pathobiology of cancer and further supports the need to therapeutically target the CSC. Besides serving as potential biomarkers for aggressive tumor biology and therapeutic resistance, EMT and CSC molecular pathways may highlight novel therapeutic targets as strategies for improving the response to conventional anti-neoplastic agents translating into improved oncologic outcomes. PMID:24787239

  12. Elevated reward-related neural activation as a unique biological marker of bipolar disorder: assessment and treatment implications.

    PubMed

    Nusslock, Robin; Young, Christina B; Damme, Katherine S F

    2014-11-01

    Growing evidence indicates that risk for bipolar disorder is characterized by elevated activation in a fronto-striatal reward neural circuit involving the ventral striatum and orbitofrontal cortex, among other regions. It is proposed that individuals with abnormally elevated reward-related neural activation are at risk for experiencing an excessive increase in approach-related motivation during life events involving rewards or goal striving and attainment. In the extreme, this increase in motivation is reflected in hypomanic/manic symptoms. By contrast, unipolar depression (without a history of hypomania/mania) is characterized by decreased reward responsivity and decreased reward-related neural activation. Collectively, this suggests that risk for bipolar disorder and unipolar depression are characterized by distinct and opposite profiles of reward processing and reward-related neural activation. The objective of the present paper is threefold. First, we review the literature on reward processing and reward-related neural activation in bipolar disorder, and in particular risk for hypomania/mania. Second, we propose that reward-related neural activation reflects a biological marker of differential risk for bipolar disorder versus unipolar depression that may help facilitate psychiatric assessment and differential diagnosis. We also discuss, however, the challenges to using neuroscience techniques and biological markers in a clinical setting for assessment and diagnostic purposes. Lastly, we address the pharmacological and psychosocial treatment implications of research on reward-related neural activation in bipolar disorder. PMID:25241675

  13. The GPR54-Kisspeptin complex in reproductive biology: neuroendocrine significance and implications for ovulation induction and contraception.

    PubMed

    Sills, Eric Scott; Walsh, Anthony P H

    2008-12-01

    KISS1 encodes the kisspeptin (KP) family of peptides which were originally characterised as potent antimetastatic agents in breast cancer and malignant melanoma cells. One member of this family of arginine-phenylalanine amide peptides, KP-54, was subsequently identified as the natural ligand for the G-protein coupled receptor-54 (GPR54). In addition to its importance as a metastatic suppressor, KP has been found to play a major neuroregulatory role in governing endogenous gonadotropin release by its modulation of the hypothalamic-pituitary-gonadal (HPG) axis. In humans, KISS1 mRNA has been localised to the hypothalamic anteroventral periventricular nucleus and arcuate nucleus. Although GPR54 is expressed in human pituitary cells, it is not presently known if gonadotrope cells themselves are targets for significant KP activity. It was recently shown that full disruption of the KP/GPR54 complex resulted in hypogonadotropic hypogonadism. Indeed, evidence now suggests that KP/GPR54 signalling during gestation is necessary for sexual differentiation and implicates activation of the KP/GPR54 complex as the single most important upstream event regulating GnRH release. Several compelling studies have placed KP as the leading candidate molecule responsible for initiating puberty, making this receptor-ligand complex of fundamental importance to the neuroendocrinology of reproduction. Here, we discuss key KP/GPR54 discovery events and present an evolution of KP biology in the context of recent animal and human experimental work. With evidence pointing to proper KP/GPR54 signalling as the principal trigger for activation of GnRH neurons and subsequent ovulation, elucidation of how this pathway is modulated is likely to bring novel pharmacologic strategies for fertility treatment (and contraception) within reach. Because the physiological significance KP is now acknowledged to extend well beyond cancer biology (and may also contribute to the pathophysiology of pre

  14. Molecular Biology of Human Herpesvirus 8: Novel Functions and Virus–Host Interactions Implicated in Viral Pathogenesis and Replication

    PubMed Central

    Cousins, Emily; Nicholas, John

    2014-01-01

    Human herpesvirus 8 (HHV-8), also known as Kaposi’s sarcoma-associated herpesvirus (KSHV), is the second identified human gammaherpesvirus. Like its relative Epstein-Barr virus, HHV-8 is linked to B-cell tumors, specifically primary effusion lymphoma and multicentric Castleman’s disease, in addition to endothelial-derived KS. HHV-8 is unusual in its possession of a plethora of “accessory” genes and encoded proteins in addition to the core, conserved herpesvirus and gammaherpesvirus genes that are necessary for basic biological functions of these viruses. The HHV-8 accessory proteins specify not only activities deducible from their cellular protein homologies but also novel, unsuspected activities that have revealed new mechanisms of virus–host interaction that serve virus replication or latency and may contribute to the development and progression of virus-associated neoplasia. These proteins include viral interleukin-6 (vIL-6), viral chemokines (vCCLs), viral G protein–coupled receptor (vGPCR), viral interferon regulatory factors (vIRFs), and viral antiapoptotic proteins homologous to FLICE (FADD-like IL-1β converting enzyme)-inhibitory protein (FLIP) and survivin. Other HHV-8 proteins, such as signaling membrane receptors encoded by open reading frames K1 and K15, also interact with host mechanisms in unique ways and have been implicated in viral pathogenesis. Additionally, a set of micro-RNAs encoded by HHV-8 appear to modulate expression of multiple host proteins to provide conditions conducive to virus persistence within the host and could also contribute to HHV-8-induced neoplasia. Here, we review the molecular biology underlying these novel virus–host interactions and their potential roles in both virus biology and virus-associated disease. PMID:24008302

  15. Biology and clinical implications of CD133{sup +} liver cancer stem cells

    SciTech Connect

    Ma, Stephanie

    2013-01-15

    Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver, accounting for 80%–90% of all liver cancers. The disease ranks as the fifth most common cancer worldwide and is the third leading cause of all cancer-associated deaths. Although advances in HCC detection and treatment have increased the likelihood of a cure at early stages of the disease, HCC remains largely incurable because of late presentation and tumor recurrence. Only 25% of HCC patients are deemed suitable for curative treatment, with the overall survival at just a few months for inoperable patients. Apart from surgical resection, loco-regional ablation and liver transplantation, current treatment protocols include conventional cytotoxic chemotherapy. But due to the highly resistant nature of the disease, the efficacy of the latter regimen is limited. The recent emergence of the cancer stem cell (CSC) concept lends insight into the explanation of why treatment with chemotherapy often may seem to be initially successful but results in not only a failure to eradicate the tumor but also possibly tumor relapse. Commonly used anti-cancer drugs in HCC work by targeting the rapidly proliferating and differentiated liver cancer cells that constitute the bulk of the tumor. However, a subset of CSCs exists within the tumor, which are more resistant and are able to survive and maintain residence after treatment, thus, growing and self-renewing to generate the development and spread of recurrent tumors in HCC. In the past few years, compelling evidence has emerged in support of the hierarchic CSC model for solid tumors, including HCC. And in particular, CD133 has drawn significant attention as a critical liver CSC marker. Understanding the characteristics and function of CD133{sup +} liver CSCs has also shed light on HCC management and treatment, including the implications for prognosis, prediction and treatment resistance. In this review, a detailed summary of the recent progress

  16. Cancer-Specific Telomerase Reverse Transcriptase (TERT) Promoter Mutations: Biological and Clinical Implications

    PubMed Central

    Liu, Tiantian; Yuan, Xiaotian; Xu, Dawei

    2016-01-01

    The accumulated evidence has pointed to a key role of telomerase in carcinogenesis. As a RNA-dependent DNA polymerase, telomerase synthesizes telomeric DNA at the end of linear chromosomes, and attenuates or prevents telomere erosion associated with cell divisions. By lengthening telomeres, telomerase extends cellular life-span or even induces immortalization. Consistent with its functional activity, telomerase is silent in most human normal somatic cells while active only in germ-line, stem and other highly proliferative cells. In contrast, telomerase activation widely occurs in human cancer and the enzymatic activity is detectable in up to 90% of malignancies. Recently, hotspot point mutations in the regulatory region of the telomerase reverse transcriptase (TERT) gene, encoding the core catalytic component of telomerase, was identified as a novel mechanism to activate telomerase in cancer. This review discusses the cancer-specific TERT promoter mutations and potential biological and clinical significances. PMID:27438857

  17. Physical and biological response of the Arabian Sea to tropical cyclone Phyan and its implications.

    PubMed

    Byju, P; Prasanna Kumar, S

    2011-06-01

    The response to the tropical cyclone Phyan, which developed in the eastern Arabian Sea during 9-11 November 2009, was rapid cooling of sea surface temperature (SST), enhancement of chlorophyll a and two-fold increase in net primary productivity (NPP). Cooling of SST was immediate in response to the strong wind-mixing, and the subsequent upward Ekman pumping sustained the cooling even after the dissipation of Phyan. The biological response mediated by the upward Ekman pumping driven vertical transport of subsurface nutrient showed a time lag of 3-4 days. The CO₂ flux to the atmosphere associated with Phyan was 0.123 Tg C, which accounted for ~85% of the total out-gassing from the eastern Arabian Sea during November. Thus, an increased occurrence of cyclones in a warming environment will lead to an enhanced biomass production and also increase in CO₂ out-gassing.

  18. Rotational dynamics of water molecules near biological surfaces with implications for nuclear quadrupole relaxation.

    PubMed

    Braun, Daniel; Schmollngruber, Michael; Steinhauser, Othmar

    2016-09-21

    Based on Molecular Dynamics simulations of two different systems, the protein ubiquitin dissolved in water and an AOT reverse micelle, we present a broad analysis of the single particle rotational dynamics of water. A comprehensive connection to NQR, which is a prominent experimental method in this field, is developed, based on a reformulation of its theoretical framework. Interpretation of experimental NQR results requires a model which usually assumes that the NQR experiences retardation only in the first hydration shell. Indeed, the present study shows that this first-shell model is correct. Moreover, previous experimental retardation factors are quantitatively reproduced. All of this is seemingly contradicted by results of other methods, e.g., dielectric spectroscopy, responsible for a long-standing debate in this field. Our detailed analysis shows that NQR omits important information contained in overall water dynamics, most notably, the retardation of the water dipole axis in the electric field exerted by a biological surface. PMID:27546227

  19. Risk analysis of chemical, biological, or radionuclear threats: implications for food security.

    PubMed

    Mohtadi, Hamid; Murshid, Antu Panini

    2009-09-01

    If the food sector is attacked, the likely agents will be chemical, biological, or radionuclear (CBRN). We compiled a database of international terrorist/criminal activity involving such agents. Based on these data, we calculate the likelihood of a catastrophic event using extreme value methods. At the present, the probability of an event leading to 5,000 casualties (fatalities and injuries) is between 0.1 and 0.3. However, pronounced, nonstationary patterns within our data suggest that the "reoccurrence period" for such attacks is decreasing every year. Similarly, disturbing trends are evident in a broader data set, which is nonspecific as to the methods or means of attack. While at the present the likelihood of CBRN events is quite low, given an attack, the probability that it involves CBRN agents increases with the number of casualties. This is consistent with evidence of "heavy tails" in the distribution of casualties arising from CBRN events.

  20. The Chemical Biology of Molecular Chaperones--Implications for Modulation of Proteostasis.

    PubMed

    Brandvold, Kristoffer R; Morimoto, Richard I

    2015-09-11

    Protein homeostasis (proteostasis) is inextricably tied to cellular health and organismal lifespan. Aging, exposure to physiological and environmental stress, and expression of mutant and metastable proteins can cause an imbalance in the protein-folding landscape, which results in the formation of non-native protein aggregates that challenge the capacity of the proteostasis network (PN), increasing the risk for diseases associated with misfolding, aggregation, and aberrant regulation of cell stress responses. Molecular chaperones have central roles in each of the arms of the PN (protein synthesis, folding, disaggregation, and degradation), leading to the proposal that modulation of chaperone function could have therapeutic benefits for the large and growing family of diseases of protein conformation including neurodegeneration, metabolic diseases, and cancer. In this review, we will discuss the current strategies used to tune the PN through targeting molecular chaperones and assess the potential of the chemical biology of proteostasis.

  1. Rotational dynamics of water molecules near biological surfaces with implications for nuclear quadrupole relaxation.

    PubMed

    Braun, Daniel; Schmollngruber, Michael; Steinhauser, Othmar

    2016-09-21

    Based on Molecular Dynamics simulations of two different systems, the protein ubiquitin dissolved in water and an AOT reverse micelle, we present a broad analysis of the single particle rotational dynamics of water. A comprehensive connection to NQR, which is a prominent experimental method in this field, is developed, based on a reformulation of its theoretical framework. Interpretation of experimental NQR results requires a model which usually assumes that the NQR experiences retardation only in the first hydration shell. Indeed, the present study shows that this first-shell model is correct. Moreover, previous experimental retardation factors are quantitatively reproduced. All of this is seemingly contradicted by results of other methods, e.g., dielectric spectroscopy, responsible for a long-standing debate in this field. Our detailed analysis shows that NQR omits important information contained in overall water dynamics, most notably, the retardation of the water dipole axis in the electric field exerted by a biological surface.

  2. Haemocompatibility assessment of synthesised platinum nanoparticles and its implication in biology.

    PubMed

    Shiny, P J; Mukherjee, Amitava; Chandrasekaran, N

    2014-06-01

    The growing need for advanced treatment of evolving diseases has become a motivation for this study. Among the noble metals, platinum nanoparticles are of importance because of their catalytic property, antioxidant potential, minimal toxicity and diverse applications. Biological process of synthesis has retained its significance, because it is a simple one-step process yielding stable nanoparticles. Herein, we have synthesised platinum nanoparticles through a green process using the unexplored seaweed Padina gymnospora, a brown alga. The course of synthesis was monitored and the nanoparticles were characterised using UV-visible spectroscopy. The synthesised nanoparticles were studied using TEM, XRD and FTIR. The TEM and XRD studies reveal the size of the nanoparticle to be <35 nm. The catalytic nanoparticles were capable of oxidising NADH to NAD(+). The biocompatibility was tested by haemolytic assay for the furtherance of the application of platinum nanoparticles in medicine. This is the first report on the biogenic synthesis of platinum nanoparticles using seaweed.

  3. HNS+ and HSN+ cations: Electronic states, spin-rovibronic spectroscopy with planetary and biological implications

    NASA Astrophysics Data System (ADS)

    Trabelsi, Tarek; Ben Yaghlane, Saida; Al Mogren, Muneerah Mogren; Francisco, Joseph S.; Hochlaf, Majdi

    2016-08-01

    Ab initio methods in conjunction with a large basis set are used to compute the potential energy surfaces of the 12 lowest electronic states of the HNS+ and HSN+ isomeric forms. These potentials are used in discussions of the metastability of these cations and plausible mechanisms for the H+/H + SN+/SN, S/S+ + NH+/NH, N/N+ + SH+/SH ion-molecule reactions. Interestingly, the low rovibrational levels of HSN+(12A″) and HNS+(12A″) electronically excited ions are predicted to be long-lived. Both ions are suggested to be a suitable candidate for light-sensitive NOṡ donor in vivo and as a possible marker for the detection of intermediates in nitrites + H2S reactions at the cellular level. The full spin rovibronic levels of HNS+ are presented, which may assist in the experimental identification of HNS+ and HSN+ ions and in elucidating their roles in astrophysical and biological media.

  4. Population genetics of Chrysoperla externa (Neuroptera: Chrysopidae) and implications for biological control.

    PubMed

    Lavagnini, T C; Morales, A C; Freitas, S

    2015-11-01

    Green lacewings are insects with great potential to be use in the biological control of agricultural pests, but relatively few studies have attempted to understand the genetic structure of these agents, especially those of predatory insects. The purpose of this study was to characterize genetically populations of C. externa using sequences of subunit I of the cytochrome oxidase, a mitochondrial gene, and examine the population structure of this species in sampled areas in São Paulo state. The results indicate high genetic diversity but no genetic structure, detected by AMOVA analysis, and high levels of haplotype sharing in the network. These genetic patterns could be a consequence of environmental homogeneity provided by agroecosystem (citrus orchard), allowing gene flow among populations. Probably there is a unique population in the area sampled that could be used as a population (genetic) source for mass-reared and posterior release in these farms.

  5. The Tip-Sample Interaction in Atomic Force Microscopy and its Implications for Biological Applications.

    NASA Astrophysics Data System (ADS)

    Baselt, David Randall

    This thesis describes the construction of an atomic force microscope and its application to the study of tip -sample interactions, primarily through the use of friction and hardness (elasticity) imaging. Part one describes the atomic force microscope, which consists of a scanned-cantilever stage (chapter 2); a versatile digital signal processor-based control system with self-optimizing feedback, lock-in amplifier emulation (for hardness imaging), and macro programmability (chapter 3); and image processing software (chapter 4). Part two describes a number of results that have helped to characterize the tip-sample interaction and the contact imaging modes used for its study. Meniscus forces act laterally as well as normally, and that they vary with position (chapter 5). Friction measurements couple with scanner position and feedback, and the meniscus effects friction images (chapter 6). Sliding of the tip over the sample surface introduces slope-dependence into hardness measurements (chapter 7). Dull tips can create prominent topography artifacts even on very flat surfaces (chapter 8). In an investigation of collagen fibrils, AFM has revealed the characteristic 65 nm banding pattern, a second, minor banding pattern, and microfibrils that run along the fibril axis. The distribution of proteoglycans along the fibrils creates a characteristic pattern in friction images. Although imaging in water reduces interaction forces, water can also make biological samples more sensitive to force. However, for robust biological samples imaged in air, tip shape presents a greater obstacle than tip -sample interaction forces to obtaining high-resolution images. Tip contamination increases tip-sample friction and can occasionally improve resolution (chapter 9). For a separate project I have designed a general -purpose nearfield scanning optical microscope (chapter 10).

  6. Epidemiological Implications of Host Biodiversity and Vector Biology: Key Insights from Simple Models.

    PubMed

    Dobson, Andrew D M; Auld, Stuart K J R

    2016-04-01

    Models used to investigate the relationship between biodiversity change and vector-borne disease risk often do not explicitly include the vector; they instead rely on a frequency-dependent transmission function to represent vector dynamics. However, differences between classes of vector (e.g., ticks and insects) can cause discrepancies in epidemiological responses to environmental change. Using a pair of disease models (mosquito- and tick-borne), we simulated substitutive and additive biodiversity change (where noncompetent hosts replaced or were added to competent hosts, respectively), while considering different relationships between vector and host densities. We found important differences between classes of vector, including an increased likelihood of amplified disease risk under additive biodiversity change in mosquito models, driven by higher vector biting rates. We also draw attention to more general phenomena, such as a negative relationship between initial infection prevalence in vectors and likelihood of dilution, and the potential for a rise in density of infected vectors to occur simultaneously with a decline in proportion of infected hosts. This has important implications; the density of infected vectors is the most valid metric for primarily zoonotic infections, while the proportion of infected hosts is more relevant for infections where humans are a primary host.

  7. Removal of polar UV stabilizers in biological wastewater treatments and ecotoxicological implications.

    PubMed

    Molins-Delgado, Daniel; Díaz-Cruz, M Silvia; Barceló, Damià

    2015-01-01

    The present study describes the development, validation and application of a fully automated analytical method based on on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry (on line SPE-HPLC-MS/MS) to assess the removal efficiency in water works and the ecotoxicological implications derived of the two most used benzotriazole-class UV stabilizers (BZTs), namely 1H-benzotriazole (BZT) and 5-methyl-1H-benzotriazole (MeBZT). Influent and effluent wastewater samples from 20 wastewater treatment plants (WWTPs) were analyzed. Removal rates (RE%) and half-lives (t1/2) for each BZTs were calculated and correlated to the hydraulic retention time (HRT) of each plant. Both BZTs were detected in all influent and effluent samples (concentrations in the range 26.7 ng L(-1)-42.9 μg L(-1)), with the highest concentrations corresponding to MeBZT. Results indicated that both compounds were recalcitrant (RE% in the range 11.8-94.7%) and that no clear influence of HRT on removals could be drawn. Finally, the potential environmental risk posed by the levels of BZTs detected was evaluated calculating the hazard quotients (HQs) MeBZT was the only BZTs posing a risk to Vibrio fischeri, Daphnia galeata and Pimephales promelas.

  8. Developmental biology of the innate immune response: implications for neonatal and infant vaccine development

    PubMed Central

    Philbin, Victoria Jane; Levy, Ofer

    2009-01-01

    Molecular characterization of mechanisms by which human pattern recognition receptors (PRRs) detect danger signals has greatly expanded our understanding of the innate immune system. PRRs include Toll-like receptors (TLRs), nucleotide oligomerization domain-like receptors (NLRs), retinoic acid inducible gene-like receptors (RLRs) and C-type lectin receptors (CLRs). Characterization of the developmental expression of these systems in the fetus, newborn and infant is incomplete but has yielded important insights into neonatal susceptibility to infection. Activation of PRRs on antigen-presenting cells enhances co-stimulatory function, and thus PRRs agonists are potential vaccine adjuvants, some of which are already in clinical use. Thus study of PRRs has also revealed how previously mysterious immunomodulators are able to mediate their actions, including the vaccine adjuvant aluminum hydroxide (Alum) whose adjuvant activity depends on its ability to activate a cytosolic protein complex known as the Nacht Domain Leucine-Rich Repeat and PYD-Containing Protein 3 (NALP3) inflammasome leading to IL-1ß production. Progress in characterizing PRRs is thus informing and expanding the design of improved adjuvants. This review summarizes recent developments in the field of innate immunity with special emphasis on developmental expression in the fetus, newborn and infant and its implications for the design of more effective neonatal and infant vaccines. PMID:19918215

  9. The shape of the spatial kernel and its implications for biological invasions in patchy environments.

    PubMed

    Lindström, Tom; Håkansson, Nina; Wennergren, Uno

    2011-05-22

    Ecological and epidemiological invasions occur in a spatial context. We investigated how these processes correlate to the distance dependence of spread or dispersal between spatial entities such as habitat patches or epidemiological units. Distance dependence is described by a spatial kernel, characterized by its shape (kurtosis) and width (variance). We also developed a novel method to analyse and generate point-pattern landscapes based on spectral representation. This involves two measures: continuity, which is related to autocorrelation and contrast, which refers to variation in patch density. We also analysed some empirical data where our results are expected to have implications, namely distributions of trees (Quercus and Ulmus) and farms in Sweden. Through a simulation study, we found that kernel shape was not important for predicting the invasion speed in randomly distributed patches. However, the shape may be essential when the distribution of patches deviates from randomness, particularly when the contrast is high. We conclude that the speed of invasions depends on the spatial context and the effect of the spatial kernel is intertwined with the spatial structure. This implies substantial demands on the empirical data, because it requires knowledge of shape and width of the spatial kernel, and spatial structure.

  10. The shape of the spatial kernel and its implications for biological invasions in patchy environments

    PubMed Central

    Lindström, Tom; Håkansson, Nina; Wennergren, Uno

    2011-01-01

    Ecological and epidemiological invasions occur in a spatial context. We investigated how these processes correlate to the distance dependence of spread or dispersal between spatial entities such as habitat patches or epidemiological units. Distance dependence is described by a spatial kernel, characterized by its shape (kurtosis) and width (variance). We also developed a novel method to analyse and generate point-pattern landscapes based on spectral representation. This involves two measures: continuity, which is related to autocorrelation and contrast, which refers to variation in patch density. We also analysed some empirical data where our results are expected to have implications, namely distributions of trees (Quercus and Ulmus) and farms in Sweden. Through a simulation study, we found that kernel shape was not important for predicting the invasion speed in randomly distributed patches. However, the shape may be essential when the distribution of patches deviates from randomness, particularly when the contrast is high. We conclude that the speed of invasions depends on the spatial context and the effect of the spatial kernel is intertwined with the spatial structure. This implies substantial demands on the empirical data, because it requires knowledge of shape and width of the spatial kernel, and spatial structure. PMID:21047854

  11. Differentiation between osteoarthritis and psoriatic arthritis: implications for pathogenesis and treatment in the biologic therapy era.

    PubMed

    McGonagle, Dennis; Hermann, Kay-Geert A; Tan, Ai Lyn

    2015-01-01

    Rheumatologists have long considered OA and PsA as two completely distinct arthropathies. This review highlights how some forms of generalized OA and PsA may afflict the same entheseal-associated anatomical territories. While degeneration or inflammation may be clearly discernible at the two extremes, there may be a group of patients where differentiation is impossible. Misdiagnosis of a primary degeneration-related pathology as being part of the PsA spectrum could lead to apparent failure of disease-modifying agents, including apparent anti-TNF and apparent IL23/17 axis therapy failure. This is not a reflection of poor clinical acumen, but rather a failure to appreciate that the pathological process overlaps in the two diseases. Whether the category of OA-PsA overlap disease exists or whether it represents the co-occurrence of two common arthropathies that afflict the same anatomical territories has implications for the optimal diagnosis and management of both OA and PsA.

  12. Cancer Stem Cells and Macrophages: Implications in Tumor Biology and Therapeutic Strategies

    PubMed Central

    Sainz, Bruno; Carron, Emily; Vallespinós, Mireia; Machado, Heather L.

    2016-01-01

    Cancer stem cells (CSCs) are a unique subset of cells within tumors with stemlike properties that have been proposed to be key drivers of tumor initiation and progression. CSCs are functionally defined by their unlimited self-renewal capacity and their ability to initiate tumor formation in vivo. Like normal stem cells, CSCs exist in a cellular niche comprised of numerous cell types including tumor-associated macrophages (TAMs) which provides a unique microenvironment to protect and promote CSC functions. TAMs provide pivotal signals to promote CSC survival, self-renewal, maintenance, and migratory ability, and in turn, CSCs deliver tumor-promoting cues to TAMs that further enhance tumorigenesis. Studies in the last decade have aimed to understand the molecular mediators of CSCs and TAMs, and recent advances have begun to elucidate the complex cross talk that occurs between these two cell types. In this review, we discuss the molecular interactions that define CSC-TAM cross talk at each stage of tumor progression and examine the clinical implications of targeting these interactions. PMID:26980947

  13. Grades and Withdrawal Rates in Cell Biology and Genetics Based upon Institution Type for General Biology and Implications for Transfer Articulation Agreements

    ERIC Educational Resources Information Center

    Regier, Kimberly Fayette

    2016-01-01

    General biology courses (for majors) are often transferred from one institution to another. These courses must prepare students for upper division courses in biology. In Colorado, a Biology Transfer Articulation Agreement that includes general biology has been created across the state. An evaluation was conducted of course grades in two upper…

  14. An Advanced Organometallic Lab Experiment with Biological Implications: Synthesis and Characterization of Fe[subscript 2](µ-S[subscript 2])(C0)[subscript 6

    ERIC Educational Resources Information Center

    Barrett, Jacob; Spentzos, Ariana; Works, Carmen

    2015-01-01

    The organometallic complex Fe[subscript 2](µ-S[subscript 2])(CO)[subscript 6] has interesting biological implications. The concepts of bio-organometallic chemistry are rarely discussed at the undergraduate level, but this experiment can start such a conversation and, in addition, teach valuable synthetic techniques. The lab experiment takes a…

  15. Predicting potential global distributions of two Miscanthus grasses: implications for horticulture, biofuel production, and biological invasions.

    PubMed

    Hager, Heather A; Sinasac, Sarah E; Gedalof, Ze'ev; Newman, Jonathan A

    2014-01-01

    In many regions, large proportions of the naturalized and invasive non-native floras were originally introduced deliberately by humans. Pest risk assessments are now used in many jurisdictions to regulate the importation of species and usually include an estimation of the potential distribution in the import area. Two species of Asian grass (Miscanthus sacchariflorus and M. sinensis) that were originally introduced to North America as ornamental plants have since escaped cultivation. These species and their hybrid offspring are now receiving attention for large-scale production as biofuel crops in North America and elsewhere. We evaluated their potential global climate suitability for cultivation and potential invasion using the niche model CLIMEX and evaluated the models' sensitivity to the parameter values. We then compared the sensitivity of projections of future climatically suitable area under two climate models and two emissions scenarios. The models indicate that the species have been introduced to most of the potential global climatically suitable areas in the northern but not the southern hemisphere. The more narrowly distributed species (M. sacchariflorus) is more sensitive to changes in model parameters, which could have implications for modelling species of conservation concern. Climate projections indicate likely contractions in potential range in the south, but expansions in the north, particularly in introduced areas where biomass production trials are under way. Climate sensitivity analysis shows that projections differ more between the selected climate change models than between the selected emissions scenarios. Local-scale assessments are required to overlay suitable habitat with climate projections to estimate areas of cultivation potential and invasion risk.

  16. Eco-evolutionary responses of Bromus tectorum to climate change: implications for biological invasions.

    PubMed

    Zelikova, Tamara J; Hufbauer, Ruth A; Reed, Sasha C; Wertin, Timothy; Fettig, Christa; Belnap, Jayne

    2013-05-01

    implications for B. tectorum invasion dynamics on the Colorado Plateau.

  17. The biology of cancer stem cells and its clinical implication in hepatocellular carcinoma.

    PubMed

    Yoon, Seung Kew

    2012-01-01

    Hepatocellular carcinoma (HCC) is a highly malignant tumor with limited treatment options in its advanced state. The molecular mechanisms underlying HCC remain unclear because of the complexity of its multi-step development process. Cancer stem cells (CSCs) are defined as a small population of cells within a tumor that possess the capability for self-renewal and the generation of heterogeneous lineages of cancer cells. To date, there have been two theories concerning the mechanism of carcinogenesis, i.e., the stochastic (clonal evolution) model and the hierarchical (cancer stem cell-driven) model. The concept of the CSC has been established over the past decade, and the roles of CSCs in the carcinogenic processes of various cancers, including HCC, have been emphasized. Previous experimental and clinical evidence indicated the existence of liver CSCs; however, the potential mechanistic links between liver CSCs and the development of HCC in humans are not fully understood. Although definitive cell surface markers for liver CSCs have not yet been found, several putative markers have been identified, which allow the prospective isolation of CSCs from HCC. The identification and characterization of CSCs in HCC is essential for a better understanding of tumor initiation or progression in relation to signaling pathways. These markers could be used along with clinical parameters for the prediction of chemoresistance, radioresistance, metastasis and survival and may represent potential targets for the development of new molecular therapies against HCC. This review describes the current evidence for the existence and function of liver CSCs and discuss the clinical implications of CSCs in patients demonstrating resistance to conventional anti-cancer therapies, as well as clinical outcomes. Such data may provide a future perspective for targeted therapy in HCC.

  18. Cell and molecular biology of simian virus 40: implications for human infections and disease

    NASA Technical Reports Server (NTRS)

    Butel, J. S.; Lednicky, J. A.

    1999-01-01

    Simian virus 40 (SV40), a polyomavirus of rhesus macaque origin, was discovered in 1960 as a contaminant of polio vaccines that were distributed to millions of people from 1955 through early 1963. SV40 is a potent DNA tumor virus that induces tumors in rodents and transforms many types of cells in culture, including those of human origin. This virus has been a favored laboratory model for mechanistic studies of molecular processes in eukaryotic cells and of cellular transformation. The viral replication protein, named large T antigen (T-ag), is also the viral oncoprotein. There is a single serotype of SV40, but multiple strains of virus exist that are distinguishable by nucleotide differences in the regulatory region of the viral genome and in the part of the T-ag gene that encodes the protein's carboxyl terminus. Natural infections in monkeys by SV40 are usually benign but may become pathogenic in immunocompromised animals, and multiple tissues can be infected. SV40 can replicate in certain types of simian and human cells. SV40-neutralizing antibodies have been detected in individuals not exposed to contaminated polio vaccines. SV40 DNA has been identified in some normal human tissues, and there are accumulating reports of detection of SV40 DNA and/or T-ag in a variety of human tumors. This review presents aspects of replication and cell transformation by SV40 and considers their implications for human infections and disease pathogenesis by the virus. Critical assessment of virologic and epidemiologic data suggests a probable causative role for SV40 in certain human cancers, but additional studies are necessary to prove etiology.

  19. Eco-evolutionary responses of Bromus tectorum to climate change: implications for biological invasions

    USGS Publications Warehouse

    Zelikova, Tamara J.; Hufbauer, Ruth A.; Reed, Sasha C.; Wertin, Timothy M.; Fettig, Christa; Belnap, Jayne

    2013-01-01

    implications for B. tectorum invasion dynamics on the Colorado Plateau.

  20. Predicting Potential Global Distributions of Two Miscanthus Grasses: Implications for Horticulture, Biofuel Production, and Biological Invasions

    PubMed Central

    Hager, Heather A.; Sinasac, Sarah E.; Gedalof, Ze’ev; Newman, Jonathan A.

    2014-01-01

    In many regions, large proportions of the naturalized and invasive non-native floras were originally introduced deliberately by humans. Pest risk assessments are now used in many jurisdictions to regulate the importation of species and usually include an estimation of the potential distribution in the import area. Two species of Asian grass (Miscanthus sacchariflorus and M. sinensis) that were originally introduced to North America as ornamental plants have since escaped cultivation. These species and their hybrid offspring are now receiving attention for large-scale production as biofuel crops in North America and elsewhere. We evaluated their potential global climate suitability for cultivation and potential invasion using the niche model CLIMEX and evaluated the models’ sensitivity to the parameter values. We then compared the sensitivity of projections of future climatically suitable area under two climate models and two emissions scenarios. The models indicate that the species have been introduced to most of the potential global climatically suitable areas in the northern but not the southern hemisphere. The more narrowly distributed species (M. sacchariflorus) is more sensitive to changes in model parameters, which could have implications for modelling species of conservation concern. Climate projections indicate likely contractions in potential range in the south, but expansions in the north, particularly in introduced areas where biomass production trials are under way. Climate sensitivity analysis shows that projections differ more between the selected climate change models than between the selected emissions scenarios. Local-scale assessments are required to overlay suitable habitat with climate projections to estimate areas of cultivation potential and invasion risk. PMID:24945154

  1. Eco-evolutionary responses of Bromus tectorum to climate change: implications for biological invasions

    PubMed Central

    Zelikova, Tamara J; Hufbauer, Ruth A; Reed, Sasha C; Wertin, Timothy; Fettig, Christa; Belnap, Jayne

    2013-01-01

    implications for B. tectorum invasion dynamics on the Colorado Plateau. PMID:23762522

  2. Clinical implications of recent insights into the structural biology of beta2 adrenoceptors.

    PubMed

    Amezcua-Gutierrez, Marcos Antonio; Cipres-Flores, Fabiola Jimena; Trujillo-Ferrara, Jose Guadalupe; Soriano-Ursua, Marvin Antonio

    2012-09-01

    Analysis of the crystal structure of beta-2 adrenoceptors (β2ARs) is providing new insights into the functioning of this receptor and perhaps of G-protein coupled receptors (GPCRs) as a whole. This class of receptors represents the target of at least a third of the drugs on the market and plays an essential role in the study of therapetic drug-response. Among GPCRs, the β2AR is the best understood in terms of function, expression and activation. Regarding the interaction of β2ARs with a specific ligand, polymorphisms, conformational changes and stereoselectivity are important factors. Agonist affinity for β2ARs is influenced by the polymorphisms of these receptors, which in some cases appear to affect susceptibility to disorders. Conformational changes that take place upon the approach of a given ligand, as well as the stereoselectivity of this class of receptors can modify the intrinsic activity of β2ARs (and certainly of other receptors as well). Hence, a deepening understanding of these factors can provide new data on affinity and specifically the key residues involved in recognition of β2AR agonists. The deepening the understanding of the factors involved in ligand affinity for β2ARs will assist in the development of β2AR agonists that are more selective and potent, and that have longer term action. Not only are β2AR agonists employed as therapeutic agents, but also in diagnosis. Currently, the main clinical application of targeting human β2ARs is to treat asthma with bronchodilators. However, they are also used to treat other maladies in their acute or chronic forms, including heart conditions, metabolic disorders and muscle wasting. This review shows the scope and the possible future clinical implications of data from structures of β2ARs.

  3. Biological implications from an autonomous version of Baranyi and Roberts growth model.

    PubMed

    Vadasz, Peter; Vadasz, Alisa S

    2007-03-20

    An autonomous version of Baranyi and Roberts model (Int. J. Food Microbiology, 23, 1994, pp. 277-294) is developed and analyzed to reveal some subtle points, which are difficult to observe accurately from its equivalent non-autonomous form. In particular we are able to provide a meaningful interpretation to the "physiological state of the cells at inoculation", a parameter introduced by Baranyi and Roberts [Baranyi, J., Roberts, T. A., 1994. A dynamic approach to predicting bacterial growth in food. International Journal of Food Microbiology 23, 277-294] that has a profound impact on microbial growth but is not a direct measurable quantity. In addition, the analysis shows that the transient growth depends on the initial cell concentration and the initial growth rate, but is independent of "the history of the cells" and depends only indirectly (via the initial growth rate) on the previous (pre-inoculation) environment. The stationary solution is independent of the initial conditions. A new, more natural, and biologically meaningful formulation of LAG duration is being suggested in terms of initial conditions being in the neighborhood of one of the unstable stationary points revealed by this autonomous version of the model.

  4. Biological rationales and clinical applications of temperature controlled hyperthermia--implications for multimodal cancer treatments.

    PubMed

    Schildkopf, P; Ott, O J; Frey, B; Wadepohl, M; Sauer, R; Fietkau, R; Gaipl, U S

    2010-01-01

    Hyperthermia (HT)--heating the tumor in the range of 40.0- 44.0 °C--combined with radiation (RT) and/or chemotherapy (CT) is a well proven treatment for malignant tumors. The improvement of the techniques for monitoring and adapting of the desired temperatures even in deep seated tumors has led to a renaissance of, now quality-controlled, HT in multimodal tumor therapy approaches. Randomized clinical trials have shown improved disease-free survival and local tumor control without an increase in toxicity for the combined treatment. In this review, we will focus on biological rationales of HT comprising direct cytotoxicity, systemic effects, chemosensitization, radiosensitization, and immune modulation. The latter is a prerequisite for the control of recurrent tumors and micrometastases. Immunogenic tumor cell death forms induced by HT will be introduced. Modulations of the cytotoxic properties of chemotherapeutic agents by HT as well as synergistic effects of HT with RT will be presented in the context of the main aims of anti-tumor therapy. Furthermore, modern techniques for thermal mapping like magnet resonance imaging will be outlined. The effectiveness of HT will be demonstrated by reviewing recent clinical trials applying HT in addition to CT and/or RT. We conclude that hyperthermia is a very potent radio- as well as chemosensitizer, which fosters the induction of immunogenic dead tumor cells leading to local and in special cases also to systemic tumor control.

  5. Lone-pair-π interactions: analysis of the physical origin and biological implications.

    PubMed

    Novotný, Jan; Bazzi, Sophia; Marek, Radek; Kozelka, Jiří

    2016-07-28

    Lone-pair-π (lp-π) interactions have been suggested to stabilize DNA and protein structures, and to participate in the formation of DNA-protein complexes. To elucidate their physical origin, we have carried out a theoretical multi-approach analysis of two biologically relevant model systems, water-indole and water-uracil complexes, which we compared with the structurally similar chloride-tetracyanobenzene (TCB) complex previously shown to contain a strong charge-transfer (CT) binding component. We demonstrate that the CT component in lp-π interactions between water and indole/uracil is significantly smaller than that stabilizing the Cl(-)-TCB reference system. The strong lp(Cl(-))-π(TCB) orbital interaction is characterized by a small energy gap and an efficient lp-π* overlap. In contrast, in lp-π interactions between water and indole or uracil, the corresponding energy gap is larger and the overlap less efficient. As a result, water-uracil and water-indole interactions are weak forces composed by smaller contributions from all energy components: electrostatics, polarization, dispersion, and charge transfer. In addition, indole exhibits a negative electrostatic potential at its π-face, making lp-π interactions less favorable than O-Hπ hydrogen bonding. Consequently, some of the water-tryptophan contacts observed in X-ray structures of proteins and previously interpreted as lp-π interactions [Luisi, et al., Proteins, 2004, 57, 1-8], might in fact arise from O-Hπ hydrogen bonding.

  6. Germination biology of Hibiscus tridactylites in Australia and the implications for weed management

    PubMed Central

    Chauhan, Bhagirath Singh

    2016-01-01

    Hibiscus tridactylites is a problematic broadleaf weed in many crops in Australia; however, very limited information is available on seed germination biology of Australian populations. Experiments were conducted to evaluate the effect of environmental factors on germination and emergence of H. tridactylites. Germination was stimulated by seed scarification, suggesting the inhibition of germination in this species is mainly due to the hard seed coat. Germination was not affected by light conditions, suggesting that seeds of this species are not photoblastic. Germination was higher at alternating day/night temperatures of 30/20 °C (74%) and 35/25 °C (69%) than at 25/15 °C (63%). Moderate salinity and water stress did not inhibit germination of H. tridactylites. Seedling emergence of H. tridactylites was highest (57%) for the seeds buried at a 2 cm depth in the soil; 18% of seedlings emerged from seeds buried at 8 cm but no seedlings emerged below this depth. Soil inversion by tillage to bury weed seeds below their maximum depth of emergence could serve an important tool for managing H. tridactylites. PMID:27174752

  7. Biological and clinical implications of cancer stem cells in primary brain tumors

    PubMed Central

    Maugeri-Saccà, Marcello; Di Martino, Simona; De Maria, Ruggero

    2013-01-01

    Despite therapeutic advances, glioblastoma multiforme (GBM) remains a lethal disease. The infiltrative nature of this disease and the presence of a cellular population resistant to current medical treatments account for the poor prognosis of these patients. Growing evidence indicates the existence of a fraction of cancer cells sharing the functional properties of adult stem cells, including self-renewal and a greater ability to escape chemo-radiotherapy-induced death stimuli. Therefore, these cells are commonly defined as cancer stem cells (GBM-SCs). The initial GBM-SC concept has been challenged, and refined according to the emerging molecular taxonomy of GBM. This allowed to postulate the existence of multiple CSC types, each one driving a given molecular entity. Furthermore, it is becoming increasingly clear that GBM-SCs thrive through a dynamic and bidirectional interaction with the surrounding microenvironment. In this article, we discuss recent advances in GBM-SC biology, mechanisms through which these cells adapt to hostile conditions, pharmacological strategies for selectively killing GBM-SCs, and how novel CSC-associated endpoints have been investigated in the clinical setting. PMID:23355974

  8. Death in the intestinal epithelium-basic biology and implications for inflammatory bowel disease.

    PubMed

    Blander, J Magarian

    2016-07-01

    Every 4-5 days, intestinal epithelial cells (IEC) are terminated as they reach the end of their life. This process ensures that the epithelium is comprised of the fittest cells that maintain an impermeable barrier to luminal contents and the gut microbiota, as well as the most metabolically able cells that conduct functions in nutrient absorption, digestion, and secretion of antimicrobial peptides. IEC are terminated by apical extrusion-or shedding-from the intestinal epithelial monolayer into the gut lumen. Whether death by apoptosis signals extrusion or death follows expulsion by younger IEC has been a matter of debate. Seemingly a minor detail, IEC death before or after apical extrusion bears weight on the potential contribution of apoptotic IEC to intestinal homeostasis as a consequence of their recognition by intestinal lamina propria phagocytes. In inflammatory bowel disease (IBD), excessive death is observed in the ileal and colonic epithelium. The precise mode of IEC death in IBD is not defined. A highly inflammatory milieu within the intestinal lamina propria, rich in the proinflammatory cytokine, TNF-α, increases IEC shedding and compromises barrier integrity fueling more inflammation. A milestone in the treatment of IBD, anti-TNF-α therapy, may promote mucosal healing by reversing increased and inflammation-associated IEC death. Understanding the biology and consequences of cell death in the intestinal epithelium is critical to the design of new avenues for IBD therapy. PMID:27250564

  9. Lone-pair-π interactions: analysis of the physical origin and biological implications.

    PubMed

    Novotný, Jan; Bazzi, Sophia; Marek, Radek; Kozelka, Jiří

    2016-07-28

    Lone-pair-π (lp-π) interactions have been suggested to stabilize DNA and protein structures, and to participate in the formation of DNA-protein complexes. To elucidate their physical origin, we have carried out a theoretical multi-approach analysis of two biologically relevant model systems, water-indole and water-uracil complexes, which we compared with the structurally similar chloride-tetracyanobenzene (TCB) complex previously shown to contain a strong charge-transfer (CT) binding component. We demonstrate that the CT component in lp-π interactions between water and indole/uracil is significantly smaller than that stabilizing the Cl(-)-TCB reference system. The strong lp(Cl(-))-π(TCB) orbital interaction is characterized by a small energy gap and an efficient lp-π* overlap. In contrast, in lp-π interactions between water and indole or uracil, the corresponding energy gap is larger and the overlap less efficient. As a result, water-uracil and water-indole interactions are weak forces composed by smaller contributions from all energy components: electrostatics, polarization, dispersion, and charge transfer. In addition, indole exhibits a negative electrostatic potential at its π-face, making lp-π interactions less favorable than O-Hπ hydrogen bonding. Consequently, some of the water-tryptophan contacts observed in X-ray structures of proteins and previously interpreted as lp-π interactions [Luisi, et al., Proteins, 2004, 57, 1-8], might in fact arise from O-Hπ hydrogen bonding. PMID:27411074

  10. In Situ Biological Contamination Studies of the Moon: Implications for Planetary Protection and Life Detection Missions

    NASA Astrophysics Data System (ADS)

    Glavin, Daniel P.; Dworkin, Jason P.; Lupisella, Mark; Williams, David R.; Kminek, Gerhard; Rummel, John D.

    2010-12-01

    NASA and ESA have outlined visions for solar system exploration that will include a series of lunar robotic precursor missions to prepare for, and support a human return to the Moon, and future human exploration of Mars and other destinations, including possibly asteroids. One of the guiding principles for exploration is to pursue compelling scientific questions about the origin and evolution of life. The search for life on objects such as Mars will require careful operations, and that all systems be sufficiently cleaned and sterilized prior to launch to ensure that the scientific integrity of extraterrestrial samples is not jeopardized by terrestrial organic contamination. Under the Committee on Space Research's (COSPAR's) current planetary protection policy for the Moon, no sterilization procedures are required for outbound lunar spacecraft, nor is there a different planetary protection category for human missions, although preliminary COSPAR policy guidelines for human missions to Mars have been developed. Future in situ investigations of a variety of locations on the Moon by highly sensitive instruments designed to search for biologically derived organic compounds would help assess the contamination of the Moon by lunar spacecraft. These studies could also provide valuable "ground truth" data for Mars sample return missions and help define planetary protection requirements for future Mars bound spacecraft carrying life detection experiments. In addition, studies of the impact of terrestrial contamination of the lunar surface by the Apollo astronauts could provide valuable data to help refine future Mars surface exploration plans for a human mission to Mars.

  11. HNS(+) and HSN(+) cations: Electronic states, spin-rovibronic spectroscopy with planetary and biological implications.

    PubMed

    Trabelsi, Tarek; Ben Yaghlane, Saida; Al Mogren, Muneerah Mogren; Francisco, Joseph S; Hochlaf, Majdi

    2016-08-28

    Ab initio methods in conjunction with a large basis set are used to compute the potential energy surfaces of the 12 lowest electronic states of the HNS(+) and HSN(+) isomeric forms. These potentials are used in discussions of the metastability of these cations and plausible mechanisms for the H(+)/H + SN(+)/SN, S/S(+) + NH(+)/NH, N/N(+) + SH(+)/SH ion-molecule reactions. Interestingly, the low rovibrational levels of HSN(+)(1(2)A″) and HNS(+)(1(2)A″) electronically excited ions are predicted to be long-lived. Both ions are suggested to be a suitable candidate for light-sensitive NO(⋅) donor in vivo and as a possible marker for the detection of intermediates in nitrites + H2S reactions at the cellular level. The full spin rovibronic levels of HNS(+) are presented, which may assist in the experimental identification of HNS(+) and HSN(+) ions and in elucidating their roles in astrophysical and biological media. PMID:27586922

  12. Germination biology of Hibiscus tridactylites in Australia and the implications for weed management.

    PubMed

    Chauhan, Bhagirath Singh

    2016-01-01

    Hibiscus tridactylites is a problematic broadleaf weed in many crops in Australia; however, very limited information is available on seed germination biology of Australian populations. Experiments were conducted to evaluate the effect of environmental factors on germination and emergence of H. tridactylites. Germination was stimulated by seed scarification, suggesting the inhibition of germination in this species is mainly due to the hard seed coat. Germination was not affected by light conditions, suggesting that seeds of this species are not photoblastic. Germination was higher at alternating day/night temperatures of 30/20 °C (74%) and 35/25 °C (69%) than at 25/15 °C (63%). Moderate salinity and water stress did not inhibit germination of H. tridactylites. Seedling emergence of H. tridactylites was highest (57%) for the seeds buried at a 2 cm depth in the soil; 18% of seedlings emerged from seeds buried at 8 cm but no seedlings emerged below this depth. Soil inversion by tillage to bury weed seeds below their maximum depth of emergence could serve an important tool for managing H. tridactylites. PMID:27174752

  13. Death in the intestinal epithelium-basic biology and implications for inflammatory bowel disease.

    PubMed

    Blander, J Magarian

    2016-07-01

    Every 4-5 days, intestinal epithelial cells (IEC) are terminated as they reach the end of their life. This process ensures that the epithelium is comprised of the fittest cells that maintain an impermeable barrier to luminal contents and the gut microbiota, as well as the most metabolically able cells that conduct functions in nutrient absorption, digestion, and secretion of antimicrobial peptides. IEC are terminated by apical extrusion-or shedding-from the intestinal epithelial monolayer into the gut lumen. Whether death by apoptosis signals extrusion or death follows expulsion by younger IEC has been a matter of debate. Seemingly a minor detail, IEC death before or after apical extrusion bears weight on the potential contribution of apoptotic IEC to intestinal homeostasis as a consequence of their recognition by intestinal lamina propria phagocytes. In inflammatory bowel disease (IBD), excessive death is observed in the ileal and colonic epithelium. The precise mode of IEC death in IBD is not defined. A highly inflammatory milieu within the intestinal lamina propria, rich in the proinflammatory cytokine, TNF-α, increases IEC shedding and compromises barrier integrity fueling more inflammation. A milestone in the treatment of IBD, anti-TNF-α therapy, may promote mucosal healing by reversing increased and inflammation-associated IEC death. Understanding the biology and consequences of cell death in the intestinal epithelium is critical to the design of new avenues for IBD therapy.

  14. In Situ Biological Contamination Studies of the Moon: Implications for Planetary Protection and Life Detection Missions

    NASA Technical Reports Server (NTRS)

    Glavin, Daniel P.; Dworkin, Jason P.; Lupisella, Mark; Williams, David R.; Kminek, Gerhard; Rummel, John D.

    2010-01-01

    NASA and ESA have outlined visions for solar system exploration that will include a series of lunar robotic precursor missions to prepare for, and support a human return to the Moan, and future human exploration of Mars and other destinations, including possibly asteroids. One of the guiding principles for exploration is to pursue compelling scientific questions about the origin and evolution of life. The search for life on objects such as Mars will require careful operations, and that all systems be sufficiently cleaned and sterilized prior to launch to ensure that the scientific integrity of extraterrestrial samples is not jeopardized by terrestrial organic contamination. Under the Committee on Space Research's (COSPAR's) current planetary protection policy for the Moon, no sterilization procedures are required for outbound lunar spacecraft, nor is there a different planetary protection category for human missions, although preliminary C SPAR policy guidelines for human missions to Mars have been developed. Future in situ investigations of a variety of locations on the Moon by highly sensitive instruments designed to search for biologically derived organic compounds would help assess the contamination of the Moon by lunar spacecraft. These studies could also provide valuable "ground truth" data for Mars sample return missions and help define planetary protection requirements for future Mars bound spacecraft carrying life detection experiments. In addition, studies of the impact of terrestrial contamination of the lunar surface by the Apollo astronauts could provide valuable data to help refine future: Mars surface exploration plans for a human mission to Mars.

  15. Glucocorticoids as a biological substrate of reward: physiological and pathophysiological implications.

    PubMed

    Piazza, P V; Le Moal, M

    1997-12-01

    The observations presented in this review suggest that glucocorticoids are one of the biological substrates of reward. These hormones are secreted in response to rewarding stimuli, such as food, a receptive sexual partner or drugs of abuse. Furthermore, manipulations of the secretion of glucocorticoids modify reward-related behaviours, and administration of these hormones, in the range of physiological stress levels, has positive reinforcing effects. The rewarding effects of glucocorticoids are probably mediated by a glucocorticoid-induced stimulation of the mesencephalic dopaminergic transmission, one of the principal neural substrates of reward. It is proposed that the rewarding effects of glucocorticoids play the role of counteracting the aversive effects of external aggressions, allowing a better coping with threatening situations. However, a sustained increase in the secretion of these hormones, or an hypersensitivity to their rewarding effects, could determine reward-related pathologies, such as a predisposed state to develop drug-abuse. In conclusion, through their reward-related effects, glucocorticoids may play a key role in tuning adaptation to stress and in determining reward-related behavioral pathologies. PMID:9495563

  16. Toward the laboratory identification of [O,N,S,S] isomers: Implications for biological NO chemistry

    NASA Astrophysics Data System (ADS)

    Ayari, Tarek; Jaidane, Nejm-Eddine; Al Mogren, Muneerah Mogren; Francisco, Joseph S.; Hochlaf, Majdi

    2016-06-01

    Benchmark ab initio calculations are performed to investigate the stable isomers of [O,N,S,S]. These computations are carried out using coupled cluster (RCCSD(T)) and explicitly correlated coupled cluster methods (RCCSD(T)-F12). In addition to the already known cis isomer of SSNO, nine other stable forms are predicted. The most stable isomer is cis-OSNS. Nine structures are chain bent-bent with relatively large dipole moments which make them detectable, as cis-SSNO, by infrared, far-infrared, and microwave spectroscopies. We found also a C2v isomer (NS2O). Since these species are strongly suggested to play an important role as intermediates during the bioactive reaction products of the NO/H2S interaction, the rotational and vibrational spectroscopic parameters are presented to help aid the in vivo identification and assignment of these spectra. Results from this work show that [O,N,S,S] may play key roles during nitric oxide transport and deliver in biological media, as well as, provide an explanation for the weak characteristic of disulfide bridges within proteins.

  17. Biologic sequelae of IκB kinase (IKK) inhibition in multiple myeloma: therapeutic implications

    PubMed Central

    Hideshima, Teru; Chauhan, Dharminder; Kiziltepe, Tanyel; Ikeda, Hiroshi; Okawa, Yutaka; Podar, Klaus; Raje, Noopur; Protopopov, Alexei; Munshi, Nikhil C.; Richardson, Paul G.; Carrasco, Ruben D.

    2009-01-01

    Nuclear factor-κB (NF-κB) has an important role in multiple myeloma (MM) cell pathogenesis in the context of the bone marrow (BM) microenvironment. In NF-κB signaling cascades, IκB kinase α (IKKα) and IKKβ are key molecules that predominantly mediate noncanonical and canonical pathways, respectively. In this study, we examined the biologic sequelae of the inhibition of IKKα versus IKKβ in MM cell lines. All MM cell lines have constitutive canonical NF-κB activity, and a subset of MM cell lines shows noncanonical NF-κB activity. Adhesion to BM stromal cells further activates both canonical and noncanonical NF-κB activity. IKKβ inhibitor MLN120B blocks canonical pathway and growth of MM cell lines but does not inhibit the noncanonical NF-κB pathway. Although IKKα knockdown induces significant growth inhibition in the cell lines with both canonical and noncanonical pathways, it does not inhibit NF-κB activation. Importantly, IKKα down-regulation decreases expression of β-catenin and aurora-A, which are known to mediate MM cell growth and survival. Finally, IKKβ inhibitor enhances the growth inhibition triggered by IKKα down-regulation in MM cells with both canonical and noncanonical NF-κB activity. Combination therapy targeting these kinases therefore represents a promising treatment strategy in MM. PMID:19270264

  18. Modeling of intraluminal heating of biological tissue: implications for treatment of benign prostatic hyperplasia.

    PubMed

    Anvari, B; Rastegar, S; Motamedi, M

    1994-09-01

    A computer model for predicting the thermal response of a biological tissue to different intraluminal heating modalities is presented. A practical application of the model is to calculate the temperature distributions during thermal coagulation of prostate by contact heating and radiative heating. The model uses a two-dimensional axisymmetric diffusion approximation method to calculate the light distribution during radiative heating. The traditional Pennes' bio-heat equation is used to calculate the temperatures in the presence of blood flow. An implicit finite difference scheme with nonuniform grid spacings is used to solve the diffusion equation for light distribution and the bio-heat equation. Model results indicate that the radiative heating of prostate by Nd:YAG (1064 mm) and diode (810 mm) lasers can be a more effective and efficient means of coagulating a large volume of prostate, as compared to contact heating of the tissue. Blood perfusion is shown to provide a considerable heat sink as the laser exposure time is increased. Surface cooling by irrigation during the laser irradiation of tissue is shown to be an effective method for delaying tissue explosion and obtaining a large volume of coagulated tissue. The model also shows that the volume of the coagulated tissue is appreciably altered by a change in the rate of energy deposition.

  19. Degradation of biological weapons agents in the environment: implications for terrorism response.

    PubMed

    Stuart, Amy L; Wilkening, Dean A

    2005-04-15

    We investigate the impact on effective terrorism response of the viability degradation of biological weapons agents in the environment. We briefly review the scientific understanding and modeling of agent environmental viability degradation. In general, agent susceptibility to viability loss is greatest for vegetative bacteria, intermediate for viruses, and least for bacterial spores. Survival is greatest in soil and progressively decreases in the following environments: textiles, water, hard surfaces, and air. There is little detailed understanding of loss mechanisms. We analyze the time behavior and sensitivity of four mathematical models that are used to represent environmental viability degradation (the exponential, probability, and first- and second-order catastrophic decay models). The models behave similarly at short times (<30 min for our example case) but diverge to significantly different values at intermediate to long times. Hence, for a release event in which the majority of atmospheric exposure or deposition occurs oververy short times, the current response models likely provide a good representation of the hazard. For longer time phenomena, including decontamination, the current model capabilities are likely insufficient. Finally, we implement each model in a simple numerical integration of anthrax dispersion, viability degradation, and dose response. Decay models spanning the current knowledge of airborne degradation result in vastly different predicted hazard areas. This confounds attempts to determine necessary medical and decontamination measures. Hence,the current level of understanding and representation of environmental viability degradation in response models is inadequate to inform appropriate emergency response measures.

  20. Mauna Kea, Hawaii as an Analogue Site for Future Planetary Resource Exploration: Results from the 2010 ILSO-ISRU Field-Testing Campaign

    NASA Technical Reports Server (NTRS)

    ten Kate, I. L.; Armstrong, R.; Bernhardt, B.; Blummers, M.; Boucher, D.; Caillibot, E.; Captain, J.; Deleuterio, G.; Farmer, J. D.; Glavin, D. P.; Hamilton, J. C.; Klingelhoefer, G.; Morris, R. V.; Nunez, J. I.; Quinn, J. W.; Sanders, G. B.; Sellar, R. G.; Sigurdson, L.; Taylor, R.; Zacny, K.

    2010-01-01

    Within the framework of the International Lunar Surface Operation - In-Situ Resource Utilization Analogue Test held on January 27 - February 11, 2010 on the Mauna Kea volcano in Hawaii, a number of scientific instrument teams collaborated to characterize the field site and test instrument capabilities outside laboratory environments. In this paper, we provide a geological setting for this new field-test site, a description of the instruments that were tested during the 2010 ILSO-ISRU field campaign, and a short discussion for each instrument about the validity and use of the results obtained during the test. These results will form a catalogue that may serve as reference for future test campaigns. In this paper we provide a description and regional geological setting for a new field analogue test site for lunar resource exploration, and discuss results obtained from the 2010 ILSO-ISRU field campaign as a reference for future field-testing at this site. The following instruments were tested: a multispectral microscopic imager, MMI, a Mossbauer spectrometer, an evolved gas analyzer, VAPoR, and an oxygen and volatile extractor called RESOLVE. Preliminary results show that the sediments change from dry, organic-poor, poorly-sorted volcaniclastic sand on the surface, containing basalt, iron oxides and clays, to more water- and organic-rich, fine grained, well-sorted volcaniclastic sand, primarily consisting of iron oxides and depleted of basalt and clays. Furthermore, drilling experiments showed a very close correlation between drilling on the Moon and drilling at the test site. The ILSO-ISRU test site was an ideal location for testing strategies for in situ resource exploration at the lunar or martian surface.

  1. Development of an Electrostatic Precipitator to Remove Martian Atmospheric Dust from ISRU Gas Intakes During Planetary Exploration Missions

    NASA Technical Reports Server (NTRS)

    Clements, J. Sidney; Thompson, Samuel M.; Cox, Nathan D.; Johansen, Michael R.; Williams, Blakeley S.; Hogue, Michael D.; Lowder, M. Loraine; Calle, Carlos I.

    2011-01-01

    Manned exploration missions to Mars will need dependable in situ resource utilization (ISRU) for the production of oxygen and other commodities. One of these resources is the Martian atmosphere itself, which is composed of carbon dioxide (95.3%), nitrogen (2.7%), argon (1.6%), oxygen (0.13%), carbon monoxide (0.07%), and water vapor (0.03%), as well as other trace gases. However, the Martian atmosphere also contains relatively large amounts of dust, uploaded by frequent dust devils and high Winds. To make this gas usable for oxygen extraction in specialized chambers requires the removal of most of the dust. An electrostatic precipitator (ESP) system is an obvious choice. But with an atmospheric pressure just one-hundredth of Earth's, electrical breakdown at low voltages makes the implementation of the electrostatic precipitator technology very challenging. Ion mobility, drag forces, dust particle charging, and migration velocity are also affected because the low gas pressure results in molecular mean free paths that are approximately one hundred times longer than those at Earth .atmospheric pressure. We report here on our efforts to develop this technology at the Kennedy Space Center, using gases with approximately the same composition as the Martian atmosphere in a vacuum chamber at 9 mbars, the atmospheric pressure on Mars. We also present I-V curves and large particle charging data for various versions of wire-cylinder and rod-cylinder geometry ESPs. Preliminary results suggest that use of an ESP for dust collection on Mars may be feasible, but further testing with Martian dust simulant is required.

  2. The 2010 ILSO-ISRU Field Test at Mauna Kea, Hawaii: Results from the Miniaturised Mossbauer Spectrometers Mimos II and Mimos IIA

    NASA Technical Reports Server (NTRS)

    Klingelhoefer, G.; Morris, R. V.; Blumers, M.; Bernhardt, B.; Graff, T.

    2011-01-01

    For the advanced Moessbauer instrument MIMOS IIA, the new detector technologies and electronic components increase sensitivity and performance significantly. In combination with the high energy resolution of the SDD it is possible to perform X-ray fluorescence analysis simultaneously to Moessbauer spectroscopy. In addition to the Fe-mineralogy, information on the sample's elemental composition will be gathered. The ISRU 2010 field campaign demonstrated that in-situ Moessbauer spectroscopy is an effective tool for both science and feedstock exploration and process monitoring. Engineering tests showed that a compact nickel metal hydride battery provided sufficient power for over 12 hr of continuous operation for the MIMOS instruments.

  3. Biological Implications in Cassava for the Production of Amylose-Free Starch: Impact on Root Yield and Related Traits

    PubMed Central

    Karlström, Amanda; Calle, Fernando; Salazar, Sandra; Morante, Nelson; Dufour, Dominique; Ceballos, Hernán

    2016-01-01

    Cassava (Manihot esculenta, Crantz) is an important food security crop, but it is becoming an important raw material for different industrial applications. Cassava is the second most important source of starch worldwide. Novel starch properties are of interest to the starch industry, and one them is the recently identified amylose-free (waxy) cassava starch. Waxy mutants have been found in different crops and have been often associated with a yield penalty. There are ongoing efforts to develop commercial cassava varieties with amylose-free starch. However, little information is available regarding the biological and agronomic implications of starch mutations in cassava, nor in other root and tuber crops. In this study, siblings from eight full-sib families, segregating for the waxy trait, were used to determine if the mutation has implications for yield, dry matter content (DMC) and harvest index in cassava. A total of 87 waxy and 87 wild-type starch genotypes from the eight families were used in the study. The only significant effect of starch type was on DMC (p < 0.01), with waxy clones having a 0.8% lower content than their wild type counterparts. There was no effect of starch type on fresh root yield (FRY), adjusted FRY and harvest index. It is not clear if lower DMC is a pleiotropic effect of the waxy starch mutation or else the result of linked genes introgressed along with the mutation. It is expected that commercial waxy cassava varieties will have competitive FRYs but special efforts will be required to attain adequate DMCs. This study contributes to the limited knowledge available of the impact of starch mutations on the agronomic performance of root and tuber crops. PMID:27242813

  4. Biological Implications in Cassava for the Production of Amylose-Free Starch: Impact on Root Yield and Related Traits.

    PubMed

    Karlström, Amanda; Calle, Fernando; Salazar, Sandra; Morante, Nelson; Dufour, Dominique; Ceballos, Hernán

    2016-01-01

    Cassava (Manihot esculenta, Crantz) is an important food security crop, but it is becoming an important raw material for different industrial applications. Cassava is the second most important source of starch worldwide. Novel starch properties are of interest to the starch industry, and one them is the recently identified amylose-free (waxy) cassava starch. Waxy mutants have been found in different crops and have been often associated with a yield penalty. There are ongoing efforts to develop commercial cassava varieties with amylose-free starch. However, little information is available regarding the biological and agronomic implications of starch mutations in cassava, nor in other root and tuber crops. In this study, siblings from eight full-sib families, segregating for the waxy trait, were used to determine if the mutation has implications for yield, dry matter content (DMC) and harvest index in cassava. A total of 87 waxy and 87 wild-type starch genotypes from the eight families were used in the study. The only significant effect of starch type was on DMC (p < 0.01), with waxy clones having a 0.8% lower content than their wild type counterparts. There was no effect of starch type on fresh root yield (FRY), adjusted FRY and harvest index. It is not clear if lower DMC is a pleiotropic effect of the waxy starch mutation or else the result of linked genes introgressed along with the mutation. It is expected that commercial waxy cassava varieties will have competitive FRYs but special efforts will be required to attain adequate DMCs. This study contributes to the limited knowledge available of the impact of starch mutations on the agronomic performance of root and tuber crops. PMID:27242813

  5. Biological Implications in Cassava for the Production of Amylose-Free Starch: Impact on Root Yield and Related Traits.

    PubMed

    Karlström, Amanda; Calle, Fernando; Salazar, Sandra; Morante, Nelson; Dufour, Dominique; Ceballos, Hernán

    2016-01-01

    Cassava (Manihot esculenta, Crantz) is an important food security crop, but it is becoming an important raw material for different industrial applications. Cassava is the second most important source of starch worldwide. Novel starch properties are of interest to the starch industry, and one them is the recently identified amylose-free (waxy) cassava starch. Waxy mutants have been found in different crops and have been often associated with a yield penalty. There are ongoing efforts to develop commercial cassava varieties with amylose-free starch. However, little information is available regarding the biological and agronomic implications of starch mutations in cassava, nor in other root and tuber crops. In this study, siblings from eight full-sib families, segregating for the waxy trait, were used to determine if the mutation has implications for yield, dry matter content (DMC) and harvest index in cassava. A total of 87 waxy and 87 wild-type starch genotypes from the eight families were used in the study. The only significant effect of starch type was on DMC (p < 0.01), with waxy clones having a 0.8% lower content than their wild type counterparts. There was no effect of starch type on fresh root yield (FRY), adjusted FRY and harvest index. It is not clear if lower DMC is a pleiotropic effect of the waxy starch mutation or else the result of linked genes introgressed along with the mutation. It is expected that commercial waxy cassava varieties will have competitive FRYs but special efforts will be required to attain adequate DMCs. This study contributes to the limited knowledge available of the impact of starch mutations on the agronomic performance of root and tuber crops.

  6. Ontogeny of taste preferences: basic biology and implications for health12345

    PubMed Central

    Mennella, Julie A

    2014-01-01

    Health initiatives address childhood obesity in part by encouraging good nutrition early in life. This review highlights the science that shows that children naturally prefer higher levels of sweet and salty tastes and reject lower levels of bitter tastes than do adults. Thus, their basic biology does not predispose them to favor the recommended low-sugar, low-sodium, vegetable-rich diets and makes them especially vulnerable to our current food environment of foods high in salt and refined sugars. The good news is that sensory experiences, beginning early in life, can shape preferences. Mothers who consume diets rich in healthy foods can get children off to a good start because flavors are transmitted from the maternal diet to amniotic fluid and mother's milk, and breastfed infants are more accepting of these flavors. In contrast, infants fed formula learn to prefer its unique flavor profile and may have more difficulty initially accepting flavors not found in formula, such as those of fruit and vegetables. Regardless of early feeding mode, infants can learn through repeated exposure and dietary variety if caregivers focus on the child's willingness to consume a food and not just the facial expressions made during feeding. In addition, providing complementary foods low in salt and sugars may help protect the developing child from excess intake later in life. Early-life experiences with healthy tastes and flavors may go a long way toward promoting healthy eating, which could have a significant impact in addressing the many chronic illnesses associated with poor food choice. PMID:24452237

  7. Unsaturated Glycerophospholipids Mediate Heme Crystallization: Biological Implications for Hemozoin Formation in the Kissing Bug Rhodnius prolixus

    PubMed Central

    Stiebler, Renata; Majerowicz, David; Knudsen, Jens; Gondim, Katia C.; Wright, David W.; Egan, Timothy J.; Oliveira, Marcus F.

    2014-01-01

    Hemozoin (Hz) is a heme crystal produced by some blood-feeding organisms, as an efficient way to detoxify heme derived from hemoglobin digestion. In the triatomine insect Rhodnius prolixus, Hz is essentially produced by midgut extracellular phospholipid membranes known as perimicrovillar membranes (PMVM). Here, we investigated the role of commercial glycerophospholipids containing serine, choline and ethanolamine as headgroups and R. prolixus midgut lipids (RML) in heme crystallization. All commercial unsaturated forms of phospholipids, as well as RML, mediated fast and efficient β-hematin formation by means of two kinetically distinct mechanisms: an early and fast component, followed by a late and slow one. The fastest reactions observed were induced by unsaturated forms of phosphatidylethanolamine (uPE) and phosphatidylcholine (uPC), with half-lives of 0.04 and 0.7 minutes, respectively. β-hematin crystal morphologies were strikingly distinct among groups, with uPE producing homogeneous regular brick-shaped crystals. Interestingly, uPC-mediated reactions resulted in two morphologically distinct crystal populations: one less representative group of regular crystals, resembling those induced by uPE, and the other largely represented by crystals with numerous sharp edges and tapered ends. Heme crystallization reactions induced by RML were efficient, with a heme to β-hematin conversion rate higher than 70%, but clearly slower (t1/2 of 9.9–17.7 minutes) than those induced by uPC and uPE. Interestingly, crystals produced by RML were homogeneous in shape and quite similar to those mediated by uPE. Thus, β-hematin formation can be rapidly and efficiently induced by unsaturated glycerophospholipids, particularly uPE and uPC, and may play a role on biological heme crystallization in R. prolixus midgut. PMID:24586467

  8. Biological implications of the hydrodynamics of swimming at or near the surface and in shallow water.

    PubMed

    Blake, R W

    2009-03-01

    The origins and effects of wave drag at and near the surface and in shallow water are discussed in terms of the dispersive waves generated by streamlined technical bodies of revolution and by semi-aquatic and aquatic animals with a view to bearing on issues regarding the design and function of autonomous surface and underwater vehicles. A simple two-dimensional model based on energy flux, allowing assessment of drag and its associated wave amplitude, is applied to surface swimming in Lesser Scaup ducks and is in good agreement with measured values. It is argued that hydrodynamic limitations to swimming at speeds associated with the critical Froude number ( approximately 0.5) and hull speed do not necessarily set biological limitations as most behaviours occur well below the hull speed. From a comparative standpoint, the need for studies on the hull displacement of different forms is emphasized. For forms in surface proximity, drag is a function of both Froude and Reynolds numbers. Whilst the depth dependence of wave drag is not particularly sensitive to Reynolds number, its magnitude is, with smaller and slower forms subject to relatively less drag augmentation than larger, faster forms that generate additional resistance due to ventilation and spray. A quasi-steady approach to the hydrodynamics of swimming in shallow water identifies substantial drag increases relative to the deeply submerged case at Froude numbers of about 0.9 that could limit the performance of semi-aquatic and aquatic animals and autonomous vehicles. A comparative assessment of fast-starting trout and upside down catfish shows that the energy losses of fast-starting fish are likely to be less for fish in surface proximity in deep water than for those in shallow water. Further work on unsteady swimming in both circumstances is encouraged. Finally, perspectives are offered as to how autonomous surface and underwater vehicles in surface proximity and shallow water could function to avoid

  9. Urinary creatinine concentrations in the U.S. population: implications for urinary biologic monitoring measurements.

    PubMed

    Barr, Dana B; Wilder, Lynn C; Caudill, Samuel P; Gonzalez, Amanda J; Needham, Lance L; Pirkle, James L

    2005-02-01

    Biologic monitoring (i.e., biomonitoring) is used to assess human exposures to environmental and workplace chemicals. Urinary biomonitoring data typically are adjusted to a constant creatinine concentration to correct for variable dilutions among spot samples. Traditionally, this approach has been used in population groups without much diversity. The inclusion of multiple demographic groups in studies using biomonitoring for exposure assessment has increased the variability in the urinary creatinine levels in these study populations. Our objectives were to document the normal range of urinary creatinine concentrations among various demographic groups, evaluate the impact that variations in creatinine concentrations can have on classifying exposure status of individuals in epidemiologic studies, and recommend an approach using multiple regression to adjust for variations in creatinine in multivariate analyses. We performed a weighted multivariate analysis of urinary creatinine concentrations in 22,245 participants of the Third National Health and Nutrition Examination Survey (1988-1994) and established reference ranges (10th-90th percentiles) for each demographic and age category. Significant predictors of urinary creatinine concentration included age group, sex, race/ethnicity, body mass index, and fat-free mass. Time of day that urine samples were collected made a small but statistically significant difference in creatinine concentrations. For an individual, the creatinine-adjusted concentration of an analyte should be compared with a "reference" range derived from persons in a similar demographic group (e.g., children with children, adults with adults). For multiple regression analysis of population groups, we recommend that the analyte concentration (unadjusted for creatinine) should be included in the analysis with urinary creatinine added as a separate independent variable. This approach allows the urinary analyte concentration to be appropriately adjusted for

  10. Subnuclear organization and trafficking of regulatory proteins: implications for biological control and cancer.

    PubMed

    Stein, G S; van Wijnen, A J; Stein, J L; Lian, J B; Montecino, M; Zaidi, K; Javed, A

    2000-01-01

    The regulated and regulatory components that interrelate nuclear structure and function must be experimentally established. A formidable challenge is to define further the control of transcription factor targeting to acceptor sites associated with the nuclear matrix. It will be important to determine whether acceptor proteins are associated with a pre-existing core-filament structural lattice or whether a compositely organized scaffold of regulatory factors is dynamically assembled. An inclusive model for all steps in the targeting of proteins to subnuclear sites cannot yet be proposed. However, this model must account for the apparent diversity of intranuclear targeting signals. It is also important to assess the extent to which regulatory discrimination is mediated by subnuclear domain-specific trafficking signals. Furthermore, the checkpoints that monitor subnuclear distribution of regulatory factors and the sorting steps that ensure both structural and functional fidelity of nuclear domains in which replication and expression of genes occur must be biochemically and mechanistically defined. There is emerging recognition that placement of regulatory components of gene expression must be temporally and spatially coordinated to facilitate biological control. The consequences of breaches in nuclear structure-function relationships are observed in an expanding series of diseases that include cancer [Weis et al., 1994; Rogaia et al., 1997; Yano et al., 1997; Rowley, 1998; Zeng et al., 1998; McNeil et al., 1999; Tao and Levine, 1999a] and neurological disorders [Skinner et al., 1997]. As the repertoire of architecture-associated regulatory factors and cofactors expands, workers in the field are becoming increasingly confident that nuclear organization contributes significantly to control of transcription. To gain increased appreciation for the complexities of subnuclear organization and gene regulation, we must continue to characterize mechanisms that direct

  11. Aetiopathogenesis and pathophysiology of bulimia nervosa: biological bases and implications for treatment.

    PubMed

    Brambilla, F

    2001-01-01

    Bulimia nervosa is an eating disorder characterised by recurrent episodes of binge eating and associated efforts to purge the ingested calories through self-induced vomiting, laxative or diuretic abuse, fasting or intensive exercise. The aetiopathogenesis and pathophysiology of the disorder are currently unclear. Biological bases have been proposed repeatedly, based on several lines of evidence: hunger, satiety and food choice are regulated by neurotransmitters and neuropeptides, and impairment of eating habits may be related to alterations in the secretion of these chemicals; genetic studies suggest that these neurotransmitter systems are dysfunctional in individuals with bulimia nervosa; and the frequent comorbidity of bulimia nervosa with major depressive and obsessive-compulsive disorders, conditions in which multiple alterations of brain biochemical functions have been demonstrated. Data in the literature suggest that levels of noradrenaline (norepinephrine) and serotonin (5-hydroxytryptamine; 5-HT) are lower in individuals with bulimia nervosa than in healthy controls. Levels of dopamine are similar to, or lower than, those in controls. After remission of the disorder, noradrenergic function returns to that seen in controls, whereas dopaminergic and serotonergic function rebound to levels higher than in controls. Among the neuropeptides, alterations in the levels of neuropeptide Y, peptide YY, beta-endorphin, corticotrophin-releasing hormone, somatostatin, cholecystokinin and vasopressin have been found in the symptomatic phase of bulimia nervosa, with a return to levels seen in controls after remission. Pharmacological treatment of bulimia nervosa that is directed at correction of the neurochemical alterations observed is difficult because of the complexity of the impairments. However, such treatment is necessary and should be continued long after symptomatic remission to ensure reinstitution of cerebral biochemical homeostasis.

  12. Transmitting biological effects of stress in utero: implications for mother and offspring.

    PubMed

    Reynolds, Rebecca M; Labad, Javier; Buss, Claudia; Ghaemmaghami, Pearl; Räikkönen, Katri

    2013-09-01

    The developing foetus makes adaptations to an adverse in utero environment which may lead to permanent changes in structure and physiology, thus 'programming' the foetus to risk of ill health in later life. Epidemiological studies have shown associations between low birth weight, a surrogate marker of an adverse intrauterine environment, and a range of diseases in adult life including cardiometabolic and psychiatric disease. These associations do not apply exclusively to low birth weight babies but also to newborns within the normal birth weight range. Early life stress, including stressors in the prenatal and early postnatal period, is a key factor that can have long-term effects on offspring health. Animal studies show this is mediated through changes in the maternal and foetal hypothalamic-pituitary-adrenal axes resulting in foetal exposure to excess glucocorticoids. Data in humans are more limited but support that the biological effects of stress in utero may be transmitted through changes in glucocorticoid action or metabolism. Common contemporary physical and social stressors of maternal obesity and socio-economic deprivation impact on the maternal response to pregnancy and the prevailing hormonal milieu that the developing foetus will be exposed to. Prenatal stress may also be compounded by early postnatal stresses such as childhood maltreatment with resultant adverse effects for the offspring. Understanding of the mechanisms whereby these stressors are transmitted from mother to foetus will not only improve our knowledge of normal foetal development but will also help identify novel pathways for early intervention either in the periconceptional, pregnancy or the early postpartum period. PMID:23810315

  13. The ultraviolet history of the terrestrial planets - implications for biological evolution

    NASA Astrophysics Data System (ADS)

    Cockell, Charles S.

    2000-02-01

    A radiative transfer model is employed to investigate the comparative surface ultraviolet (UV) radiation histories of Earth, Mars and Venus from 4.5 Ga to the present and thus their comparative theoretical photobiological histories. Earth probably began with a period of higher ultraviolet radiation fluxes during the anoxic Archean. During the early Proterozoic UV fluxes declined as oxygen partial pressures and thus ozone column abundance rose, but the ozone column became subject to stochastic depletion events caused principally by impact events and possibly large-scale volcanism and less frequently, close cosmic events such as supernovae. In contrast Mars has been subject to a history dominated by a slow increase in solar luminosity and a reduction in partial pressures of CO 2, both of which have resulted in an increase in UV flux. The UV radiation history of Venus has been dominated by the greenhouse effect through which high partial pressures of CO 2 made the surface UV radiation environment clement. These distinct histories influence the potential comparative evolutionary photobiology of the three planets. On Earth, life transitioned from the Archean, when tolerance to UV radiation, particularly for exposed organisms, must have been high to a more photobiologically clement era. In this latter era the predominant evolutionary selection pressure is one that allows for tolerance of sudden and unpredictable increases in UVB radiation above seasonal and diurnal maxima caused by exogenous perturbation of the ozone column. In the case of Mars, the UV radiation flux has increased over time. Today the biologically effective irradiances to DNA are not considerably different from those that are calculated for Archean Earth. If the planet suffered an atmospheric collapse then it may have been subject to an ultraviolet crisis at some point in its past when DNA-weighted irradiance would have increased three to five-fold. Venus transitioned into a photobiologically clement era

  14. Energy implications of mechanical and mechanical–biological treatment compared to direct waste-to-energy

    SciTech Connect

    Cimpan, Ciprian Wenzel, Henrik

    2013-07-15

    Highlights: • Compared systems achieve primary energy savings between 34 and 140 MJ{sub primary}/100 MJ{sub input} {sub waste.} • Savings magnitude is foremost determined by chosen primary energy and materials production. • Energy consumption and process losses can be upset by increased technology efficiency. • Material recovery accounts for significant shares of primary energy savings. • Direct waste-to-energy is highly efficient if cogeneration (CHP) is possible. - Abstract: Primary energy savings potential is used to compare five residual municipal solid waste treatment systems, including configurations with mechanical (MT) and mechanical–biological (MBT) pre-treatment, which produce waste-derived fuels (RDF and SRF), biogas and/or recover additional materials for recycling, alongside a system based on conventional mass burn waste-to-energy and ash treatment. To examine the magnitude of potential savings we consider two energy efficiency levels (state-of-the-art and best available technology), the inclusion/exclusion of heat recovery (CHP vs. PP) and three different background end-use energy production systems (coal condensing electricity and natural gas heat, Nordic electricity mix and natural gas heat, and coal CHP energy quality allocation). The systems achieved net primary energy savings in a range between 34 and 140 MJ{sub primary}/100 MJ{sub input} {sub waste}, in the different scenario settings. The energy footprint of transportation needs, pre-treatment and reprocessing of recyclable materials was 3–9.5%, 1–18% and 1–8% respectively, relative to total energy savings. Mass combustion WtE achieved the highest savings in scenarios with CHP production, nonetheless, MBT-based systems had similarly high performance if SRF streams were co-combusted with coal. When RDF and SRF was only used in dedicated WtE plants, MBT-based systems totalled lower savings due to inherent system losses and additional energy costs. In scenarios without heat

  15. Extracorporeal blood oxygenation and ozonation: clinical and biological implications of ozone therapy.

    PubMed

    Di Paolo, N; Gaggiotti, E; Galli, F

    2005-01-01

    Some lines of evidence have suggested that the challenge to antioxidants and biomolecules provoked by pro-oxidants such as ozone may be used to generate a controlled stress response of possible therapeutic relevance in some immune dysfunctions and chronic, degenerative conditions. Immune and endothelial cells have been proposed to be elective targets of the positive molecular effects of ozone and its derived species formed during blood ozonation. On the bases of these underlying principles and against often prejudicial scepticism and concerns about its toxicity, ozone has been used in autohemotherapy (AHT) for four decades with encouraging results. However, clinical application and validation of AHT have been so far largely insufficient. Latterly, a new and more effective therapeutic approach to ozone therapy has been established, namely extracorporeal blood oxygenation and ozonation (EBOO). This technique, first tested in vitro and then in vivo in sheep and humans (more than 1200 treatments performed in 82 patients), is performed with a high-efficiency apparatus that makes it possible to treat with a mixture of oxygen-ozone (0.5-1 microg/ml oxygen) in 1 h of extracorporeal circulation up to 4800 ml of heparinized blood without technical or clinical problems, whereas only 250 ml of blood can be treated with ozone by AHT. The EBOO technique can be easily adapted for use in hemodialysis also. The standard therapeutic cycle lasts for 7 weeks in which 14 treatment sessions of 1 h are performed. After a session of EBOO, the interaction of ozone with blood components results in 4-5-fold increased levels of thiobarbituric acid reactants and a proportional decrease in plasma protein thiols without any appreciable erythrocyte haemolysis. On the basis of preliminary in vitro evidence, these simple laboratory parameters may represent a useful complement in the routine monitoring of biological compliance to the treatment. The clinical experience gained so far confirms the

  16. Student learning style preferences in college-level biology courses: Implications for teaching and academic performance

    NASA Astrophysics Data System (ADS)

    Sitton, Jennifer Susan

    Education research has focused on defining and identifying student learning style preferences and how to incorporate this knowledge into teaching practices that are effective in engaging student interest and transmitting information. One objective was determining the learning style preferences of undergraduate students in Biology courses at New Mexico State University by using the online VARK Questionnaire and an investigator developed survey (Self Assessed Learning Style Survey, LSS). Categories include visual, aural, read-write, kinesthetic, and multimodal. The courses differed in VARK single modal learning preferences (p = 0.035) but not in the proportions of the number of modes students preferred (p = 0.18). As elsewhere, the majority of students were multimodal. There were similarities and differences between LSS and VARK results and between students planning on attending medical school and those not. Preferences and modalities tended not to match as expected for ratings of helpfulness of images and text. To detect relationships between VARK preferred learning style and academic performance, ANOVAs were performed using modality preferences and normalized learning gains from pre and post tests over material taught in the different modalities, as well as on end of semester laboratory and lecture grades. Overall, preference did not affect the performance for a given modality based activity, quiz, or final lecture or laboratory grades (p > 0.05). This suggests that a student's preference does not predict an improved performance when supplied with material in that modality. It is recommended that methods be developed to aid learning in a variety of modalities, rather than catering to individual learning styles. Another topic that is heavily debated in the field of education is the use of simulations or videos to replace or supplement dissections. These activities were compared using normalized learning gains from pre and post tests, as well as attitude surveys

  17. Twenty years of invasion: a review of round goby Neogobius melanostomus biology, spread and ecological implications.

    PubMed

    Kornis, M S; Mercado-Silva, N; Vander Zanden, M J

    2012-02-01

    are presented; most pressing are evaluating the economic effects of N. melanostomus invasion, determining long-term population level effects of egg predation on game-fish recruitment and comparing several variables (density, ecological effects morphology and life history) among invaded ecosystems. This review provides a central reference as researchers continue studying N. melanostomus, often as examples for advancing basic ecology and invasion biology.

  18. A Transcriptomic Analysis of Echinococcus granulosus Larval Stages: Implications for Parasite Biology and Host Adaptation

    PubMed Central

    Parkinson, John; Wasmuth, James D.; Salinas, Gustavo; Bizarro, Cristiano V.; Sanford, Chris; Berriman, Matthew; Ferreira, Henrique B.; Zaha, Arnaldo; Blaxter, Mark L.; Maizels, Rick M.; Fernández, Cecilia

    2012-01-01

    Background The cestode Echinococcus granulosus - the agent of cystic echinococcosis, a zoonosis affecting humans and domestic animals worldwide - is an excellent model for the study of host-parasite cross-talk that interfaces with two mammalian hosts. To develop the molecular analysis of these interactions, we carried out an EST survey of E. granulosus larval stages. We report the salient features of this study with a focus on genes reflecting physiological adaptations of different parasite stages. Methodology/Principal Findings We generated ∼10,000 ESTs from two sets of full-length enriched libraries (derived from oligo-capped and trans-spliced cDNAs) prepared with three parasite materials: hydatid cyst wall, larval worms (protoscoleces), and pepsin/H+-activated protoscoleces. The ESTs were clustered into 2700 distinct gene products. In the context of the biology of E. granulosus, our analyses reveal: (i) a diverse group of abundant long non-protein coding transcripts showing homology to a middle repetitive element (EgBRep) that could either be active molecular species or represent precursors of small RNAs (like piRNAs); (ii) an up-regulation of fermentative pathways in the tissue of the cyst wall; (iii) highly expressed thiol- and selenol-dependent antioxidant enzyme targets of thioredoxin glutathione reductase, the functional hub of redox metabolism in parasitic flatworms; (iv) candidate apomucins for the external layer of the tissue-dwelling hydatid cyst, a mucin-rich structure that is critical for survival in the intermediate host; (v) a set of tetraspanins, a protein family that appears to have expanded in the cestode lineage; and (vi) a set of platyhelminth-specific gene products that may offer targets for novel pan-platyhelminth drug development. Conclusions/Significance This survey has greatly increased the quality and the quantity of the molecular information on E. granulosus and constitutes a valuable resource for gene prediction on the parasite genome

  19. Mars as the parent body of the CI carbonaceous chondrites and implications for Mars biological and climatic history

    NASA Astrophysics Data System (ADS)

    Brandenburg, John E.

    1997-07-01

    The hypothesis that CI meteorites have an origin on Mars is presented along with supporting data and implications. A Martian origin for the CI will support Martian biogenesis and effect assessments of Martian histories, suggesting Mars and Earth evolved in parallel in both biologic and geologic realms for a long period. The CI containing a Martian pattern of oxygen isotopes and mineralogy indicative of deposition by liquid water. The CI contain no evidence of hypervelocity impact, but contain space-exposed olivine grains and are thus regolith material, indicating their formation under a planetary atmosphere. They contain organic matter similar to that found in Martian meteorites, ALH84001 and EETA79001. A scenario of formation of CI meteorites as being water altered late planetary accretion material is proposed. The 4.5 Gyr age of the CI, matching ALH84001, and their high concentration of organic matter, including possible fossil bacteria, strongly supports the hypothesis of early Martian biogenesis. With CI plus ALH84001 being old, and the SNCs being young, the Martian crustal age dichotomy is now well reflected in Martian meteorite ages. This suggests Mars has a strongly bimodal pattern of crustal ages, either very old or very young with liquid water moving on the planets surface until late in the planets history.

  20. The effect of TNFalpha blockade on the antinuclear antibody profile in patients with chronic arthritis: biological and clinical implications.

    PubMed

    De Rycke, L; Baeten, D; Kruithof, E; Van den Bosch, F; Veys, E M; De Keyser, F

    2005-01-01

    Since the first proof of efficacy of TNFalpha blockade, both the number of patients treated worldwide and the number of indications for treatment with TNFalpha blockers have grown steadily. Surprisingly, the profound immunomodulation induced by anti-TNFalpha therapy is associated with a relatively low incidence of immune-related complications such as lupus-like syndromes and demyelinating disease. This contrasts sharply with the prominent induction of autoantibodies such as antinuclear antibodies (ANA) and anti-dsDNA antibodies during TNFalpha blockade. Although this phenomenon has been recognized for several years, the clinical and biological implications are not yet fully understood. In this review, recent studies analysing the effect of TNFalpha blockade (infliximab and etanercept) on the ANA profile in autoimmune arthritis will be discussed. Taken together, these reports indicate that the prominent ANA and anti-dsDNA autoantibody response is 1) not a pure class effect of TNFalpha blockers, 2) independent of the disease background, 3) largely restricted to the induction of short-term IgM anti-dsDNA antibodies, and 4) not associated with other serological or clinically relevant signs of lupus. Nevertheless, a careful follow-up of patients treated with TNFalpha blockers remains mandatory, including monitoring for lupus-like characteristics.

  1. Biological soil crusts exhibit a dynamic response to seasonal rain and release from grazing with implications for soil stability

    USGS Publications Warehouse

    Jimenez, Aguilar A.; Huber-Sannwald, E.; Belnap, J.; Smart, D.R.; Arredondo, Moreno J.T.

    2009-01-01

    In Northern Mexico, long-term grazing has substantially degraded semiarid landscapes. In semiarid systems, ecological and hydrological processes are strongly coupled by patchy plant distribution and biological soil crust (BSC) cover in plant-free interspaces. In this study, we asked: 1) how responsive are BSC cover/composition to a drying/wetting cycle and two-year grazing removal, and 2) what are the implications for soil erosion? We characterized BSC morphotypes and their influence on soil stability under grazed/non-grazed conditions during a dry and wet season. Light- and dark-colored cyanobacteria were dominant at the plant tussock and community level. Cover changes in these two groups differed after a rainy season and in response to grazing removal. Lichens with continuous thalli were more vulnerable to grazing than those with semi-continuous/discontinuous thalli after the dry season. Microsites around tussocks facilitated BSC colonization compared to interspaces. Lichen and cyanobacteria morphotypes differentially enhanced resistance to soil erosion; consequently, surface soil stability depends on the spatial distribution of BSC morphotypes, suggesting soil stability may be as dynamic as changes in the type of BSC cover. Longer-term spatially detailed studies are necessary to elicit spatiotemporal dynamics of BSC communities and their functional role in biotically and abiotically variable environments. ?? 2009 Elsevier Ltd.

  2. Predation of Biomphalaria and non-target molluscs by the crayfish Procambarus clarkii: implications for the biological control of schistosomiasis.

    PubMed

    Hofkin, B V; Hofinger, D M; Koech, D K; Loker, E S

    1992-12-01

    The North American crayfish Procambarus clarkii was examined under laboratory conditions for its ability to prey on Biomphalaria pfeifferi and B. glabrata, molluscan intermediate hosts of human schistosomiasis, and other, non-target gastropod species. Both male and female adult crayfish significantly reduced survival of neonate snails, even though alternative animal and plant foods were both available. In subsequent experiments, no differences in snail consumption were detected, for either adult or juvenile crayfish, in the presence or absence of a plant food alternative. Both adult and juvenile crayfish were able to consume small (2.5 mm) and large (17.5 mm) B. glabrata, suggesting that no size refuge from predation exists. Both adult and juvenile crayfish consumed Biomphalaria egg masses, although this consumption was significantly greater for juveniles. Procambarus clarkii adults were unable to consume substantial numbers of the relatively thick-shelled prosobranch snails Pila ovata and Lanistes carinatus. Crayfish did consume a third prosobranch, Melanoides tuberculata, and the pulmonate snail Physa acuta, but at a lower rate relative to consumption of Biomphalaria. Physa acuta, itself of North American origin, responded to the presence of crayfish by rapidly leaving the water and thereby avoided predation. Implications of these results for the biological control of schistosome-transmitting snails in East Africa are discussed.

  3. A Systems Biology Comparison of Ovarian Cancers Implicates Putative Somatic Driver Mutations through Protein-Protein Interaction Models

    PubMed Central

    Yang, Mary Qu; Elnitski, Laura

    2016-01-01

    Ovarian carcinomas can be aggressive with a high mortality rate (e.g., high-grade serous ovarian carcinomas, or HGSOCs), or indolent with much better long-term outcomes (e.g., low-malignant-potential, or LMP, serous ovarian carcinomas). By comparing LMP and HGSOC tumors, we can gain insight into the mechanisms underlying malignant progression in ovarian cancer. However, previous studies of the two subtypes have been focused on gene expression analysis. Here, we applied a systems biology approach, integrating gene expression profiles derived from two independent data sets containing both LMP and HGSOC tumors with protein-protein interaction data. Genes and related networks implicated by both data sets involved both known and novel disease mechanisms and highlighted the different roles of BRCA1 and CREBBP in the two tumor types. In addition, the incorporation of somatic mutation data revealed that amplification of PAK4 is associated with poor survival in patients with HGSOC. Thus, perturbations in protein interaction networks demonstrate differential trafficking of network information between malignant and benign ovarian cancers. The novel network-based molecular signatures identified here may be used to identify new targets for intervention and to improve the treatment of invasive ovarian cancer as well as early diagnosis. PMID:27788148

  4. Integrated Bio-ISRU and Life Support Systems at the Lunar Outpost: Concept and Preliminary Results

    NASA Technical Reports Server (NTRS)

    Brown, I. I.; Garrison, D. H.; Allen, C. C.; Pickering, K.; Sarkisova, S. A.; Galindo, C., Jr.; Pan, D.; Foraker, E.; Mckay, D. S.

    2009-01-01

    We continue the development of our concept of a biotechnological loop for in-situ resource extraction along with propellant and food production at a future lunar outpost, based on the cultivation of litholytic cyanobacteria (LCB) with lunar regolith (LR) in a geobioreactor energized by sunlight. Our preliminary studies have shown that phototropic cultivation of LCB with simulants of LR in a low-mineralized medium supplemented with CO2 leads to rock dissolution (bioweathering) with the resulting accumulation of Fe, Mg and Al in cyanobacterial cells and in the medium. LCB cultivated with LR simulants produces more O2 than the same organisms cultivated in a high-mineralized medium. The loss of rock mass after bioweathering with LCB suggests the release of O from regolith. Further studies of chemical pathways of released O are required. The bioweathering process is limited by the availability of CO2, N, and P. Since lunar regolith is mainly composed of O, Si, Ca, Al and Mg, we propose to use organic waste to supply a geobioreactor with C, N and P. The recycling of organic waste, including urine, through a geobioreactor will allow for efficient element extraction as well as oxygen and biomass production. The most critical conclusion is that a biological life support system tied to a geobioreactor might be more efficient for supporting an extraterrestrial outpost than a closed environmental system.

  5. Nicotine dose-concentration relationship and pregnancy outcomes in rat: Biologic plausibility and implications for future research

    SciTech Connect

    Hussein, Jabeen; Farkas, Svetlana; MacKinnon, Yolanda; Ariano, Robert E.; Sitar, Daniel S.; Hasan, Shabih U. . E-mail: hasans@ucalgary.ca

    2007-01-01

    Cigarette smoke (CS) exposure during pregnancy can lead to profound adverse effects on fetal development. Although CS contains several thousand chemicals, nicotine has been widely used as its surrogate as well as in its own right as a neuroteratogen. The justification for the route and dose of nicotine administration is largely based on inferential data suggesting that nicotine 6 mg/kg/day infused continuously via osmotic mini pumps (OMP) would mimic maternal CS exposure. We provide evidence that 6 mg/kg/day nicotine dose as commonly administered to pregnant rats leads to plasma nicotine concentrations that are 3-10-fold higher than those observed in moderate to heavy smokers and pregnant mothers, respectively. Furthermore, the cumulative daily nicotine dose exceeds by several hundred fold the amount consumed by human heavy smokers. Our study does not support the widely accepted notion that regardless of the nicotine dose, a linear nicotine dose-concentration relationship exists in a steady-state OMP model. We also show that total nicotine clearance increases with advancing pregnancy but no significant change is observed between the 2nd and 3rd trimester. Furthermore, nicotine infusion even at this extremely high dose has little effect on a number of maternal and fetal biologic variables and pregnancy outcome suggesting that CS constituents other than nicotine mediate the fetal growth restriction in infants born to smoking mothers. Our current study has major implications for translational research in developmental toxicology and pharmacotherapy using nicotine replacement treatment as an aid to cessation of cigarette smoking in pregnant mothers.

  6. Clinical and biological implications of ancestral and non-ancestral IDH1 and IDH2 mutations in myeloid neoplasms.

    PubMed

    Molenaar, R J; Thota, S; Nagata, Y; Patel, B; Clemente, M; Przychodzen, B; Hirsh, C; Viny, A D; Hosano, N; Bleeker, F E; Meggendorfer, M; Alpermann, T; Shiraishi, Y; Chiba, K; Tanaka, H; van Noorden, C J F; Radivoyevitch, T; Carraway, H E; Makishima, H; Miyano, S; Sekeres, M A; Ogawa, S; Haferlach, T; Maciejewski, J P

    2015-11-01

    Mutations in isocitrate dehydrogenase 1/2 (IDH1/2(MT)) are drivers of a variety of myeloid neoplasms. As they yield the same oncometabolite, D-2-hydroxyglutarate, they are often treated as equivalent, and pooled. We studied the validity of this approach and found IDH1/2 mutations in 179 of 2119 myeloid neoplasms (8%). Cross-sectionally, the frequencies of these mutations increased from lower- to higher risk disease, thus suggesting a role in clinical progression. Variant allelic frequencies indicated that IDH1(MT) and IDH2(MT) are ancestral in up to 14/74 (19%) vs 34/99 (34%; P=0.027) of cases, respectively, illustrating the pathogenic role of these lesions in myeloid neoplasms. IDH1/2(MT) was associated with poor overall survival, particularly in lower risk myelodysplastic syndromes. Ancestral IDH1(MT) cases were associated with a worse prognosis than subclonal IDH1(MT) cases, whereas the position of IDH2(MT) within clonal hierarchy did not impact survival. This may relate to distinct mutational spectra with more DNMT3A and NPM1 mutations associated with IDH1(MT) cases, and more ASXL1, SRSF2, RUNX1, STAG2 mutations associated with IDH2(MT) cases. Our data demonstrate important clinical and biological differences between IDH1(MT) and IDH2(MT) myeloid neoplasms. These mutations should be considered separately as their differences could have implications for diagnosis, prognosis and treatment with IDH1/2(MT) inhibitors of IDH1/2(MT) patients. PMID:25836588

  7. High abundances of oxalic, azelaic, and glyoxylic acids and methylglyoxal in the open ocean with high biological activity: Implication for secondary OA formation from isoprene

    NASA Astrophysics Data System (ADS)

    Bikkina, Srinivas; Kawamura, Kimitaka; Miyazaki, Yuzo; Fu, Pingqing

    2014-05-01

    Atmospheric dicarboxylic acids (DCA) are a ubiquitous water-soluble component of secondary organic aerosols (SOA), which can act as cloud condensation nuclei (CCN), affecting the Earth's climate. Despite the high abundances of oxalic acid and related compounds in the marine aerosols, there is no consensus on what controls their distributions over the open ocean. Marine biological productivity could play a role in the production of DCA, but there is no substantial evidence to support this hypothesis. Here we present latitudinal distributions of DCA, oxoacids and α-dicarbonyls in the marine aerosols from the remote Pacific. Their concentrations were found several times higher in more biologically influenced aerosols (MBA) than less biologically influenced aerosols. We propose isoprene and unsaturated fatty acids as sources of DCA as inferred from significantly higher abundances of isoprene-SOA tracers and azelaic acid in MBA. These results have implications toward the reassessment of climate forcing feedbacks of marine-derived SOA.

  8. Gaps in college biology students' understanding of photosynthesis: Implications for human constructivist learning theory and college classroom practice

    NASA Astrophysics Data System (ADS)

    Griffard, Phyllis Baudoin

    1999-11-01

    The main research question of this study was: What gaps in biochemical understanding are revealed by a range of university introductory biology students as they work through a critically acclaimed multimedia program on photosynthesis, and what are the corresponding implications for elaboration of the Ausubel-Novak-Gowin Learning Theory (ANG, now Human Constructivism)? Twelve students, mixed for ability, gender and ethnicity, were recruited from two sections of "Bio 101." Before and after instruction in photosynthesis, in-depth clinical interviews were conducted during which participants completed a range of cognitive tasks such as sorting, concept mapping, explaining and predicting. Some tasks involved interacting with a computer simulation of photosynthesis. This study primarily employed qualitative case study and verbal analysis methods. Verbal analysis of the clinical interviews revealed numerous gaps that were categorized into typologies. The two major categories were propositional gaps and processing gaps. Propositional gaps were evident in development of participants' concepts, links and constructs. Significant among these were conceptual distance gaps and continuity of matter gaps. Gaps such as convention gaps and relative significance gaps seem to be due to naivete in the discipline. Processing gaps included gaps in graphic decoding skills and relevant cognitive habits such as self-monitoring and consulting prior knowledge. Although the gaps were easier to detect and isolate with the above-average participants, all participants showed evidence of at least some of these gaps. Since some gaps are not unexpected at all but the highest literacy levels, not all the gaps identified are to be considered deficiencies. The gaps identified support the attention given by ANG theorists to the role of prior knowledge and metacognition as well as the value of graphic organizers in knowledge construction. In addition, this study revealed numerous gaps in graphic decoding

  9. The ISRU Field Tests 2010 and 2012 at Mauna Kea, Hawaii: Results from the Miniaturised Mossbauer Spectrometers Mimos II and Mimos IIA

    NASA Technical Reports Server (NTRS)

    Klingelhoefer, G.; Morris, R. V.; Blumers, M; Bernhardt, B.; Graff, T.

    2014-01-01

    The 2010 and 2012 In-Situ Resource Utilization Analogue Test (ISRU) [1] on the Mauna Kea volcano in Hawai'i was coordinated by the Northern Centre for Advanced Technology (NORCAT) in collaboration with the Canadian Space Agency (CSA), the German Aerospace Center (DLR), and the National Aeronautics and Space Administration (NASA), through the PISCES program. Several instruments were tested as reference candidates for future analogue testing at the new field test site at the Mauna Kea volcano in Hawai'i. The fine-grained, volcanic nature of the material is a suitable lunar and martian analogue, and can be used to test excavation, site preparation, and resource utilization techniques. The 2010 location Pu'u Hiwahine, a cinder cone located below the summit of Mauna Kea (19deg45'39.29" N, 155deg28'14.56" W) at an elevation of 2800 m, provides a large number of slopes, rock avalanches, etc. to perform mobility tests, site preparation or resource prospecting. Besides hardware testing of technologies and systems related to resource identification, also in situ science measurements played a significant role in integration of ISRU and science instruments. For the advanced Mössbauer instrument MIMOS IIA, the new detector technologies and electronic components increase sensitivity and performance significantly. In combination with the high energy resolution of the SDD it is possible to perform Xray fluorescence analysis simultaneously to Mössbauer spectroscopy. In addition to the Fe-mineralogy, information on the sample's elemental composition will be gathered. The 2010 and 2012 field campaigns demonstrated that in-situ Mössbauer spectroscopy is an effective tool for both science and feedstock exploration and process monitoring. Engineering tests showed that a compact nickel metal hydride battery provided sufficient power for over 12 hr of continuous operation for the MIMOS instruments.

  10. The Redox Chemistry and Chemical Biology of H2S, Hydropersulfides and Derived Species: Implications to Their Possible Biological Activity and Utility

    PubMed Central

    Ono, Katsuhiko; Akaike, Takaake; Sawa, Tomohiro; Kumagai, Yoshito; Wink, David A.; Tantillo, Dean J.; Hobbs, Adrian J.; Nagy, Peter; Xian, Ming; Lin, Joseph; Fukuto, Jon M.

    2014-01-01

    Hydrogen sulfide (H2S) is an endogenously generated and putative signaling/effector molecule. In spite of its numerous reported functions, the chemistry by which it elicits its functions is not understood. Moreover, recent studies allude to the existence of other sulfur species besides H2S that may play critical physiological roles. Herein, the basic chemical biology of H2S as well as other related or derived species is discussed and reviewed. A particular focus of this review are the per- and poly-sulfides which are likely in equilibrium with free H2S and which may be important biological effectors themselves. PMID:25229186

  11. Cell cycle status in AML blast cells from peripheral blood, bone marrow aspirates and trephines and implications for biological studies and treatment.

    PubMed

    Sellar, Rob S; Fraser, Laura; Khwaja, Asim; Gale, Rosemary E; Marafioti, Teresa; Akarca, Ayse; Hubank, Mike; Brooks, Tony; Stoeber, Kai; Williams, Gareth; Linch, David C

    2016-07-01

    Using immunohistochemistry and flow cytometry to define phases of the cell cycle, this study shows that a high proportion of acute myeloid leukaemia (AML) blasts obtained from trephine biopsies are cycling, whereas >95% of peripheral blood-derived blasts are arrested in G1 . Results obtained from bone marrow aspirates are more similar to those from blood rather than from trephine biopsies. These differences were confirmed by gene expression profiling in a patient with high count AML. This has implications for cell cycle and other biological studies using aspirates rather than trephine biopsies and for the use of cell mobilising agents before chemotherapy. PMID:27061724

  12. Comparative life-history traits of three phytoseiid mites associated with Tetranychus urticae (Acari: Tetranychidae) colonies in clementine orchards in eastern Spain: implications for biological control.

    PubMed

    Abad-Moyano, Raquel; Pina, Tatiana; Ferragut, Francisco; Urbaneja, Alberto

    2009-02-01

    The management of Tetranychus urticae, a key pest of clementine trees, is mainly based on the use of acaricides. However, more environmentally safe measures, such as biological control, are being encouraged. Life-history traits of the three most abundant phytoseiid mites associated with T. urticae on this crop (Euseius stipulatus, Phytoseiulus persimilis and Neoseiulus californicus) were studied. The experiments were performed under laboratory conditions (25 degrees C, 80 +/- 5% RH and 16:8 h (L:D)) on clementine leaves and T. urticae as prey. Euseius stipulatus could not complete its life cycle, whereas P. persimilis and N. californicus completed it satisfactorily. The estimated intrinsic rate of increase (rm) was significantly higher for P. persimilis (0.344 day(-1)) than for N. californicus (0.244 day(-1)) and both were higher than the rm value of T. urticae on clementine leaves. Implications of these results for the biological control of T. urticae in this crop are discussed.

  13. Warming and increased precipitation frequency on the Colorado Plateau: Implications for biological soil crusts and soil processes

    USGS Publications Warehouse

    Zelikova, Tamara J.; Housman, David C.; Grote, Ed E.; Neher, Deborah A.; Belnap, Jayne

    2012-01-01

    Taken together, our results highlight the limited effects of warming alone on biological soil crust communities and soil chemistry, but demonstrate the substantially larger effects of altered summertime precipitation.

  14. Policy implications of select student characteristics and their influence on the Florida biology end-of-course assessment

    NASA Astrophysics Data System (ADS)

    Bertolotti, Janine Cecelia

    In an attempt to improve student achievement in science in Florida, the Florida Department of Education implemented end-of-course (EOC) assessments in biology during the 2011-2012 academic school year. Although this first administration would only account for 30% of the student's overall final course grade in biology, subsequent administrations would be accompanied by increasing stakes for students, teachers, and schools. Therefore, this study sought to address gaps in empirical evidence as well as discuss how educational policy will potentially impact on teacher evaluation and professional development, student retention and graduation rates, and school accountability indicators. This study explored four variables- reading proficiency, ethnicity, socioeconomic status, and gender- to determine their influence and relationship on biology achievement on the Biology I EOC assessment at a Title 1 school. To do so, the results of the Biology I EOC assessment administered during the Spring 2012 school year was obtained from a small, rural Title 1 high school in North Florida. Additional data regarding each student's qualification for free and reduced-price lunch, FCAT Reading developmental scale scores, FCAT Reading level, grade level, gender, and ethnicity were also collected for the causal-comparative exploratory study. Of the 178 students represented, 48% qualified for free and reduced-price lunch, 54% were female, and 55% scored at FCAT Reading level 3 or higher. Additionally, 59% were White and 37% Black. A combination of descriptive statistics and other statistical procedures such as independent samples one-tailed t-test, one-way ANOVAs, ANCOVAs, multipleregression, and a Pearson r correlation was utilized in the analysis, with a significance level set at 0.05. Results indicate that of all four variables, FCAT Reading proficiency was the sole variable, after adjusting for other variables; that had a significant impact on biology achievement. Students with higher

  15. The implications of non-linear biological oscillations on human electrophysiology for electrohypersensitivity (EHS) and multiple chemical sensitivity (MCS).

    PubMed

    Sage, Cindy

    2015-01-01

    The 'informational content' of Earth's electromagnetic signaling is like a set of operating instructions for human life. These environmental cues are dynamic and involve exquisitely low inputs (intensities) of critical frequencies with which all life on Earth evolved. Circadian and other temporal biological rhythms depend on these fluctuating electromagnetic inputs to direct gene expression, cell communication and metabolism, neural development, brainwave activity, neural synchrony, a diversity of immune functions, sleep and wake cycles, behavior and cognition. Oscillation is also a universal phenomenon, and biological systems of the heart, brain and gut are dependent on the cooperative actions of cells that function according to principles of non-linear, coupled biological oscillations for their synchrony. They are dependent on exquisitely timed cues from the environment at vanishingly small levels. Altered 'informational content' of environmental cues can swamp natural electromagnetic cues and result in dysregulation of normal biological rhythms that direct growth, development, metabolism and repair mechanisms. Pulsed electromagnetic fields (PEMF) and radiofrequency radiation (RFR) can have the devastating biological effects of disrupting homeostasis and desynchronizing normal biological rhythms that maintain health. Non-linear, weak field biological oscillations govern body electrophysiology, organize cell and tissue functions and maintain organ systems. Artificial bioelectrical interference can give false information (disruptive signaling) sufficient to affect critical pacemaker cells (of the heart, gut and brain) and desynchronize functions of these important cells that orchestrate function and maintain health. Chronic physiological stress undermines homeostasis whether it is chemically induced or electromagnetically induced (or both exposures are simultaneous contributors). This can eventually break down adaptive biological responses critical to health

  16. Network-based discovery through mechanistic systems biology. Implications for applications--SMEs and drug discovery: where the action is.

    PubMed

    Benson, Neil

    2015-08-01

    Phase II attrition remains the most important challenge for drug discovery. Tackling the problem requires improved understanding of the complexity of disease biology. Systems biology approaches to this problem can, in principle, deliver this. This article reviews the reports of the application of mechanistic systems models to drug discovery questions and discusses the added value. Although we are on the journey to the virtual human, the length, path and rate of learning from this remain an open question. Success will be dependent on the will to invest and make the most of the insight generated along the way.

  17. The implications of non-linear biological oscillations on human electrophysiology for electrohypersensitivity (EHS) and multiple chemical sensitivity (MCS).

    PubMed

    Sage, Cindy

    2015-01-01

    The 'informational content' of Earth's electromagnetic signaling is like a set of operating instructions for human life. These environmental cues are dynamic and involve exquisitely low inputs (intensities) of critical frequencies with which all life on Earth evolved. Circadian and other temporal biological rhythms depend on these fluctuating electromagnetic inputs to direct gene expression, cell communication and metabolism, neural development, brainwave activity, neural synchrony, a diversity of immune functions, sleep and wake cycles, behavior and cognition. Oscillation is also a universal phenomenon, and biological systems of the heart, brain and gut are dependent on the cooperative actions of cells that function according to principles of non-linear, coupled biological oscillations for their synchrony. They are dependent on exquisitely timed cues from the environment at vanishingly small levels. Altered 'informational content' of environmental cues can swamp natural electromagnetic cues and result in dysregulation of normal biological rhythms that direct growth, development, metabolism and repair mechanisms. Pulsed electromagnetic fields (PEMF) and radiofrequency radiation (RFR) can have the devastating biological effects of disrupting homeostasis and desynchronizing normal biological rhythms that maintain health. Non-linear, weak field biological oscillations govern body electrophysiology, organize cell and tissue functions and maintain organ systems. Artificial bioelectrical interference can give false information (disruptive signaling) sufficient to affect critical pacemaker cells (of the heart, gut and brain) and desynchronize functions of these important cells that orchestrate function and maintain health. Chronic physiological stress undermines homeostasis whether it is chemically induced or electromagnetically induced (or both exposures are simultaneous contributors). This can eventually break down adaptive biological responses critical to health

  18. Network-based discovery through mechanistic systems biology. Implications for applications--SMEs and drug discovery: where the action is.

    PubMed

    Benson, Neil

    2015-08-01

    Phase II attrition remains the most important challenge for drug discovery. Tackling the problem requires improved understanding of the complexity of disease biology. Systems biology approaches to this problem can, in principle, deliver this. This article reviews the reports of the application of mechanistic systems models to drug discovery questions and discusses the added value. Although we are on the journey to the virtual human, the length, path and rate of learning from this remain an open question. Success will be dependent on the will to invest and make the most of the insight generated along the way. PMID:26464089

  19. In Situ Resource Utilization (ISRU) on the Moon: Moessbauer Spectroscopy as a Process Monitor for Oxygen Production. Results from a Field Test on Mauna Kea Volcano, Hawaii

    NASA Technical Reports Server (NTRS)

    Morris, R.V.; Schroder, C.; Graff, T.G.; Sanders, G.B.; Lee, K.A.; Simon, T.M.; Larson, W.E.; Quinn, J.W.; Clark, L.D.; Caruso, J.J.

    2009-01-01

    Essential consumables like oxygen must to be produced from materials on the lunar surface to enable a sustained, long-term presence of humans on the Moon. The Outpost Precursor for ISRU and Modular Architecture (OPTIMA) field test on Mauna Kea, Hawaii, facilitated by the Pacific International Space Center for Exploration Systems (PISCES) of the University of Hawaii at Hilo, was designed to test the implementation of three hardware concepts to extract oxygen from the lunar regolith: Precursor ISRU Lunar Oxygen Testbed (PILOT) developed by Lockheed Martin in Littleton, CO; Regolith & Environmental Science and Oxygen & Lunar Volatiles Extraction (RESOLVE) developed at the NASA Kennedy Space Center in Cape Canaveral, FL; and ROxygen developed at the NASA Johnson Space Center in Houston, TX. The three concepts differ in design, but all rely on the same general principle: hydrogen reduction of metal cations (primarily Fe2+) bonded to oxygen to metal (e.g., Fe0) with the production of water. The hydrogen source is residual hydrogen in the fuel tanks of lunar landers. Electrolysis of the water produces oxygen and hydrogen (which is recycled). We used the miniaturized M ssbauer spectrometer MIMOS II to quantify the yield of this process on the basis of the quantity of Fe0 produced. Iron M ssbauer spectroscopy identifies iron-bearing phases, determines iron oxidation states, and quantifies the distribution of iron between mineral phases and oxidation states. The oxygen yield can be calculated by quantitative measurements of the distribution of Fe among oxidation states in the regolith before and after hydrogen reduction. A M ssbauer spectrometer can also be used as a prospecting tool to select the optimum feedstock for the oxygen production plants (e.g., high total Fe content and easily reduced phases). As a demonstration, a MIMOS II backscatter spectrometer (SPESI, Germany) was mounted on the Cratos rover (NASA Glenn Research Center in Cleveland, OH), which is one of

  20. Evaluation of the biological differences of canine and human factor VIII in gene delivery: Implications in human hemophilia treatment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The canine is the most important large animal model for testing novel hemophilia A(HA) treatment. It is often necessary to use canine factor VIII (cFIII) gene or protein for the evaluation of HA treatment in the canine model. However, the different biological properties between cFVIII and human FVII...

  1. Hg2+ interference with the structure of tobacco etch virus protease (TEVp) and its implications for biological engineering

    NASA Astrophysics Data System (ADS)

    Wang, Jing-Zhang; Ren, Si-Yan; Zhu, Guo-Fei; Xi, Lei; Han, Yong-Guang; Luo, Yue; Du, Lin-Fang

    2013-11-01

    Tobacco etch virus protease (TEVp) has specific and highly-conserved enzymatic activity, and is frequently applied in the fields of biology and biotechnology. Hg2+ can be utilized to purify target proteins in metal-chelate affinity chromatography. However, because Hg2+ has special biological toxity, it may endanger the stability of TEVp and hinder the utilization of TEVp in the related research. We determined the effects of Hg2+ on the structure of TEVp by means of intrinsic fluorescence, synchronous fluorescence, Fourier transform infrared (FTIR), and circular dichroism (CD) spectroscopies. The fluorescence emission and the synchronous fluorescence spectra suggested that Hg2+ induced the increased hydrophobicity around both of the tryptophan and the tyrosine residues in TEVp. Hg2+ mainly quenched the fluorescence of TEVp in a static process, with the possible formation of a complex (approximate molar ratio of 1:1), and the electrostatic force was the main binding force between TEVp and Hg2+. The FTIR and CD spectra suggested that Hg2+ induced the increased content of β-sheet in TEVp, indicating that Hg2+ may bind to the catalytic residues His46 and Cys151 in TEVp and promote TEVp to form a more compact structure. The Hg2+-induced structural changes of TEVp may potentially inhibit the catalytic activity of TEVp. These findings are beneficial for the intensive understanding of the factors that influence the stability of TEVp, and are helpful for the efficient and effective application of TEVp in the fields of biology and biological engineering.

  2. Positionings of Racial, Ethnic, and Linguistic Minority Students in High School Biology Class: Implications for Science Education in Diverse Classrooms

    ERIC Educational Resources Information Center

    Ryu, Minjung

    2015-01-01

    In the present study, I analyze ethnographic data from a year-long study of two Advanced Placement (AP) Biology classes that enrolled students with diverse racial, ethnic, and linguistic backgrounds. Specifically, I consider participation, positioning, and learning of newcomer Korean students in the focal classes. Building on the notion of figured…

  3. Papers presented to the Conference on Large Body Impacts and Terrestrial Evolution: Geological, Climatological, and Biological Implications

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The effects of large impacts on the environment are discussed and include thermal effects, atmospheric effects, changes in ocean temperatures, and geomagnetic anomalies. Biological factors such as extinction and increases in mutation development were investigated. Geological anomalies studied include stratigraphic gaps, extinction of entire boundary layers from the geological record, and geochemical oddities. Evidence was examined for impact cratering throughout the world.

  4. Modulation of the Bioactive Conformation of Transforming Growth Factor β: Possible Implications of Cation Binding for Biological Function

    NASA Astrophysics Data System (ADS)

    Bocharov, Eduard V.; Pavlov, Konstantin V.; Blommers, Marcel J. J.; Arvinte, Tudor; Arseniev, Alexander S.

    In any organism, very precisely adjusted interaction and exchange of information between cells is continuously required. These cooperative interactions involve numerous cytokines, acting through corresponding sets of cell-surface receptors. The transforming growth factor β (TGF-β) superfamily includes a variety of structurally related multifunctional cytokines that play critical roles in maintaining cellular homeostasis and controlling cell fate. Response of a cell to a specific signal it receives should depend upon the current state of the environment, including concentrations of biologically relevant ions. One of the most biologically active ions, calcium, acts upon a specific calcium signaling system that operates over a wide temporal range and regulates many cellular processes in continuous “cross-talk” with the TGF-β signaling system. In addition to that, the structural and dynamical properties of TGF-β molecules, along with detected direct interaction of them with the biologically relevant cations suggest another level of fine regulation of TGF-β activity. The fact that both mono- and divalent cations bind in the same low-affinity sites implies that some competition of cations for interaction with TGF-β can also occur in vivo, contributing to the diversity of TGF-β biological functions.

  5. Clinical implications of basic science discoveries: janus resurrected--two faces of B cell and plasma cell biology.

    PubMed

    Woodle, E S; Rothstein, D M

    2015-01-01

    B cells play a complex role in the immune response. In addition to giving rise to plasma cells (PCs) and promoting T cell responses via antigen presentation, they perform immunoregulatory functions. This knowledge has created concerns regarding nonspecific B cell depletional therapy because of the potential to paradoxically augment immune responses. Recent studies now indicate that PCs have immune functions beyond immunoglobulin synthesis. Evidence for a new role for PCs as potent regulatory cells (via IL-10 and IL-35 production) is discussed including the implications for PC-targeted therapies currently being developed for clinical transplantation.

  6. Epigenetics and its Implications for Plant Biology 2. The ‘Epigenetic Epiphany’: Epigenetics, Evolution and Beyond

    PubMed Central

    GRANT-DOWNTON, R. T.; DICKINSON, H. G.

    2006-01-01

    • Scope In the second part of a two-part review, the ubiquity and universality of epigenetic systems is emphasized, and attention is drawn to the key roles they play, ranging from transducing environmental signals to altering gene expression, genomic architecture and defence. • Key Issues The importance of transience versus heritability in epigenetic marks is examined, as are the potential for stable epigenetic marks to contribute to plant evolution, and the mechanisms generating novel epigenetic variation, such as stress and interspecific hybridization. • Future Prospects It is suggested that the ramifications of epigenetics in plant biology are immense, yet unappreciated. In contrast to the ease with which the DNA sequence can be studied, studying the complex patterns inherent in epigenetics poses many problems. Greater knowledge of patterns of epigenetic variation may be informative in taxonomy and systematics, as well as population biology and conservation. PMID:16260442

  7. Evidence for two-dimensional solitary sound waves in a lipid controlled interface and its implications for biological signalling.

    PubMed

    Shrivastava, Shamit; Schneider, Matthias F

    2014-08-01

    Biological membranes by virtue of their elastic properties should be capable of propagating localized perturbations analogous to sound waves. However, the existence and the possible role of such waves in communication in biology remain unexplored. Here, we report the first observations of two-dimensional solitary elastic pulses in lipid interfaces, excited mechanically and detected by FRET. We demonstrate that the nonlinearity near a maximum in the susceptibility of the lipid monolayer results in solitary pulses that also have a threshold for excitation. These experiments clearly demonstrate that the state of the interface regulates the propagation of pulses both qualitatively and quantitatively. Finally, we elaborate on the striking similarity of the observed phenomenon to nerve pulse propagation and a thermodynamic basis of cell signalling in general.

  8. Increased dielectric constant in the water treated by extremely low frequency electromagnetic field and its possible biological implication

    NASA Astrophysics Data System (ADS)

    Shen, Xun

    2011-12-01

    Water is the most abundant compound on the surface of the Earth, and can be considered to be the most important molecule in living systems. Water plays a variety of cellular functions, being the solvent of most biological molecules, a substrate and product of enzymatic catalysis, an important component of macromolecules, and more. Because of importance of water in life, many physical and chemical treatments were invented to improve the quality of drinking water. Among them, the treatment with electromagnetic field is a well-known, but much debatable physical method. Although electromagnetic field has been utilized for treating water for 80 years, many reports on beneficial biological effect of electromagnetic field-treated water were either anecdotal or less convincing. To explore if there is any physical base for understanding possible biological effects of electromagnetic field-treated water, dielectric relaxation spectra of deionized water treated with an extremely low frequency electromagnetic (ELFEM) field were measured and compared with that of untreated water. It was surprisingly found that the dielectric constant of the ELFEM field-treated water was 3.7% higher than the control over the frequency range of 1-10 GHz, which indicates a higher molecular polarization occurs in the ELFEM field-treated water. Electrostatic and thermodynamic analysis shows that proteins or other biomacromolecules would have more reduced free energy when they are hydrated in high dielectric constant water. Since free energy is of crucial importance for stability of proteins, protein folding and its conformational change, as well as catalytic activity of enzymes, the free energy reduction of the biomacromolecules hydrated with higher dielectric constant water may be responsible for many possible biological effects of electromagnetic field treated water.

  9. Strategies for quantifying C60 fullerenes in environmental and biological samples and implications for studies in environmental health and ecotoxicology

    PubMed Central

    Pycke, Benny F.G.; Benn, Troy M.; Herckes, Pierre; Westerhoff, Paul; Halden, Rolf U.

    2010-01-01

    Fullerenes are sphere-like molecules with unique physico-chemical properties, which render them of particular interest in biomedical research, consumer products and industrial applications. Human and environmental exposure to fullerenes is not a new phenomenon, due to a long history of hydrocarbon-combustion sources, and will only increase in the future, as incorporation of fullerenes into consumer products becomes more widespread for use as anti-aging, anti-bacterial or anti-apoptotic agents. An essential step in the determination of biological effects of fullerenes (and their surface-functionalized derivatives) is establishment of exposure-assessment techniques. However, in ecotoxicological studies, quantification of fullerenes is performed infrequently because robust, uniformly applicable analytical approaches have yet to be identified, due to the wide variety of sample types. Moreover, the unique physico-chemistry of fullerenes in aqueous matrices requires reassessment of conventional analytical approaches, especially in more complex biological matrices (e.g., urine, blood, plasma, milk, and tissue). Here, we present a review of current analytical approaches for the quantification of fullerenes and propose a consensus approach for determination of these nanomaterials in a variety of environmental and biological matrices. PMID:21359100

  10. The chemical fate of the Cd/Se/Te-based quantum dot 705 in the biological system: toxicity implications

    NASA Astrophysics Data System (ADS)

    Lin, Chia-Hua; Chang, Louis W.; Chang, Han; Yang, Mo-Hsiung; Yang, Chung-Shi; Lai, Wan-Hau; Chang, Wan-Hsuan; Lin, Pinpin

    2009-05-01

    QD705 is a cadmium/selenium/tellurium (Cd/Se/Te)-based quantum dot with good potential for biomedical applications. Although the biological fate of QD705 is established, its chemical fate in the biological system is still unknown. Since the chemical nature of Cd in QD705 (either stays as bounded Cd or becomes free Cd) is closely related to the toxicity of this nanocrystal, information on its chemical fate is critically needed. In this study we investigated the chemical fate of QD705 in the kidneys of mice. We used the molar ratio of Cd and Te (increased Cd/Te ratio signifies increased Cd release from QD705) and the induction of tissue metallothionein (MT) as markers for elevated free Cd in tissues. Our study indicated that 100% of QD705 (measured as Cd) was still retained in the body 16 weeks after exposure, with significant time redistribution to the kidneys. Furthermore, there were an elevation in both the molar Cd/Te ratio and MT-1 expression in the kidneys, suggesting that free Cd was released from QD705. Thus QD705 is not as stable or biologically inert as many may have once believed. Our study demonstrated that free Cd indeed can be released from QD705 in the kidneys and increases the risk of renal toxicity.

  11. Material and energy balances of an integrated biological hydrogen production and purification system and their implications for its potential to reduce greenhouse gas emissions.

    PubMed

    Fukushima, Yasuhiro; Huang, Yu-Jung; Chen, Jhen-Wei; Lin, Hung-Chun; Whang, Liang-Ming; Chu, Hsin; Lo, Young-Chong; Chang, Jo-Shu

    2011-09-01

    The materials and energy in an integrated biological hydrogen production and purification system involving hydrolysis, dark fermentation, photo fermentation, CO2 fixation and anaerobic digestion are balanced by integrating the results from multiple experiments, simulations and the literature. The findings are two fold. First, using 1000 kg rice straw as a substrate, 19.8 kg H2 and 138.0 kg CH4 are obtained. The net energy balance (NEB) and net energy ratio (NER) are -738.4 kWh and 77.8%, respectively, both of which imply an unfavorable energy production system. Opportunities to improve the performance particularly lie in the photo fermentation process. Second, greenhouse gas emissions are evaluated for various options. The results were comparable with the emission inventory of electricity generated from fossil fuels. NEB and NER under a zero-carbon-emission constraint were discussed in detail to clarify completely the implications of the energy and material balances on greenhouse gas emissions.

  12. Evidence for biological activity in mineralization of secondary sulphate deposits in a basaltic environment: implications for the search for life in the Martian subsurface

    SciTech Connect

    C. Doc Richardson; Nancy W. Hinman; Jill R. Scott

    2013-10-01

    Evidence of microbial activity associated with mineralization of secondary Na-sulphate minerals (thenardite, mirabilite) in the basaltic subsurface of Craters of the Moon National Monument (COM), Idaho were examined by scanning electron microscopy, X-ray diffraction, laser desorption Fourier transform ion cyclotron resonance mass spectrometry (LD-FTICR-MS), Fourier transform infrared spectroscopy (FTIR) and isotope ratio mass spectrometry. Peaks suggestive of bio/organic compounds were observed in the secondary Na-sulphate deposits by LD-FTICR-MS. FTIR provided additional evidence for the presence of bio/organic compounds. Sulphur fractionation was explored to assist in determining if microbes may play a role in oxidizing sulphur. The presence of bio/organic compounds associated with Na-sulphate deposits, along with the necessity of oxidizing reduced sulphur to sulphate, suggests that biological activity may be involved in the formation of these secondary minerals. The secondary Na-sulphate minerals probably form from the overlying basalt through leached sodium ions and sulphate ions produced by bio-oxidation of Fe-sulphide minerals. Since the COM basalts are one of the most comparable terrestrial analogues for their Martian counterparts, the occurrence of biological activity in the formation of sulphate minerals at COM has direct implications for the search for life on Mars. In addition, the presence of caves on Mars suggests the importance of these environments as possible locations for growth and preservation of microbial activity. Therefore, understanding the physiochemical pathways of abiotic and biotic mineralization in the COM subsurface and similar basaltic settings has direct implications for the search for extinct or extant life on Mars.

  13. Getting the most out of parasitic helminth transcriptomes using HelmDB: implications for biology and biotechnology.

    PubMed

    Mangiola, Stefano; Young, Neil D; Korhonen, Pasi; Mondal, Alinda; Scheerlinck, Jean-Pierre; Sternberg, Paul W; Cantacessi, Cinzia; Hall, Ross S; Jex, Aaron R; Gasser, Robin B

    2013-12-01

    Compounded by a massive global food shortage, many parasitic diseases have a devastating, long-term impact on animal and human health and welfare worldwide. Parasitic helminths (worms) affect the health of billions of animals. Unlocking the systems biology of these neglected pathogens will underpin the design of new and improved interventions against them. Currently, the functional annotation of genomic and transcriptomic sequence data for socio-economically important parasitic worms relies almost exclusively on comparative bioinformatic analyses using model organism- and other databases. However, many genes and gene products of parasitic helminths (often >50%) cannot be annotated using this approach, because they are specific to parasites and/or do not have identifiable homologs in other organisms for which sequence data are available. This inability to fully annotate transcriptomes and predicted proteomes is a major challenge and constrains our understanding of the biology of parasites, interactions with their hosts and of parasitism and the pathogenesis of disease on a molecular level. In the present article, we compiled transcriptomic data sets of key, socioeconomically important parasitic helminths, and constructed and validated a curated database, called HelmDB (www.helmdb.org). We demonstrate how this database can be used effectively for the improvement of functional annotation by employing data integration and clustering. Importantly, HelmDB provides a practical and user-friendly toolkit for sequence browsing and comparative analyses among divergent helminth groups (including nematodes and trematodes), and should be readily adaptable and applicable to a wide range of other organisms. This web-based, integrative database should assist 'systems biology' studies of parasitic helminths, and the discovery and prioritization of novel drug and vaccine targets. This focus provides a pathway toward developing new and improved approaches for the treatment and control

  14. [General biological phenomenon of cation deposit by chyme structures and its implications for creation of enteral nutrition mixtures].

    PubMed

    Ivanov, A A; Poliakova, E P; Ksenofontov, D A

    2012-01-01

    General regularity of mineral elements distribution in enteral digesta of animals with different types of digestion is described. It was established that Mn, Zn, Cu and Ca are commonly concentrated in mucosal structures of digesta. Their concentrations dramatically increase while moving digesta from small intestine to large gut. Potassium and sodium are not so intensively conjugated with enteral mucosa. It is speculated that described phenomenon can be estimated as a general biological law and can be applied for enteral nutritional mixture composition improvement. PMID:22808796

  15. Are Internet use and video-game-playing addictive behaviors? Biological, clinical and public health implications for youths and adults

    PubMed Central

    Yau, Yvonne H. C.; Crowley, Michael J.; Mayes, Linda C.; Potenza, Marc N.

    2013-01-01

    Internet use and video-game playing are experiencing rapid growth among both youth and adult populations. Research suggests that a minority of users experience symptoms traditionally associated with substance-related addictions. Mental health professionals, policy makers and the general public continue to debate the issue of Internet addiction (IA) and problematic video-game playing (PVG). This review identifies existing studies into the clinical and biological characteristics of these disorders that may help guide decisions as to whether or not IA and PVG should be grouped together with substance use disorders (SUDs). PMID:24288435

  16. Are Internet use and video-game-playing addictive behaviors? Biological, clinical and public health implications for youths and adults.

    PubMed

    Yau, Yvonne H C; Crowley, Michael J; Mayes, Linda C; Potenza, Marc N

    2012-09-01

    Internet use and video-game playing are experiencing rapid growth among both youth and adult populations. Research suggests that a minority of users experience symptoms traditionally associated with substance-related addictions. Mental health professionals, policy makers and the general public continue to debate the issue of Internet addiction (IA) and problematic video-game playing (PVG). This review identifies existing studies into the clinical and biological characteristics of these disorders that may help guide decisions as to whether or not IA and PVG should be grouped together with substance use disorders (SUDs).

  17. Warming and increased precipitation frequency on the Colorado Plateau: implications for biological soil crusts and soil processes

    SciTech Connect

    Zelikova, Tamara J.; Housman, David C.; Grote, Ed E.; Neher, Deborah A.; Belnap, Jayne

    2012-01-20

    Changes in temperature and precipitation are expected to influence ecosystem processes worldwide. Despite their globally large extent, few studies to date have examined the effects of climate change in desert ecosystems, where biological soil crusts are key nutrient cycling components. The goal of this work was to assess how increased temperature and frequency of summertime precipitation affect the contributions of crust organisms to soil processes. With a combination of experimental 2°C warming and altered summer precipitation frequency applied over 2 years, we measured soil nutrient cycling and the structure and function of crust communities. We saw no change in crust cover, composition, or other measures of crust function in response to 2°C warming and no effects on any measure of soil chemistry. In contrast, crust cover and function responded to increased frequency of summer precipitation, shifting from moss to cyanobacteria-dominated crusts; however, in the short timeframe we measured, there was no accompanying change in soil chemistry. Total bacterial and fungal biomass was also reduced in watered plots, while the activity of two enzymes increased, indicating a functional change in the microbial community. Taken together, our results highlight the limited effects of warming alone on biological soil crust communities and soil chemistry, but demonstrate the substantially larger effects of altered summertime precipitation.

  18. Differential expression of p63 isotypes (DeltaN and TA) in salivary gland neoplasms: biological and diagnostic implications.

    PubMed

    Maruya, Shin-Ichiro; Kies, Merrill S; Williams, Michelle; Myers, Jeffery N; Weber, Randal S; Batsakis, John G; El-Naggar, Adel K

    2005-07-01

    To determine the association between the expression of p63 gene isoforms (TA and DeltaN) and salivary gland tumorigenesis, we performed reverse transcription-polymerase chain reaction analysis of these markers in 71 benign and malignant salivary gland neoplasms. The results were correlated with the expression of Notch ligand JAG1 gene and the clinicopathologic features and the full-length p63 protein expression by immunohistochemistry. Both p63 isoforms were either negative or weakly expressed in normal salivary gland tissues. TAp63 was highly expressed in most benign tumors and was either negative or weakly positive in most carcinomas. Conversely, DeltaNp63 was negative or faintly positive in most benign neoplasms and was highly expressed in adenoid cystic, mucoepidermoid, and myoepithelial carcinomas. Immunohistochemical analysis using anti-full-length p63 protein showed ubiquitous nuclear staining in basal and myoepithelial cells in both benign and malignant neoplasms. JAG1 was expressed in most benign and malignant tumors and did not correlate with p63 isoforms expression. We conclude that (1) p63 isoforms are differentially expressed in most benign and malignant tumors and may play distinct biological roles in certain salivary gland neoplasms; (2) p63 immunostaining do not correlate with the isoforms expression; and (3) isoform-specific antibodies are required for better cellular localization and biological correlations.

  19. Changing tides for Lake Erie: the biogeochemical evolution of a Laurentian Great Lake and implications for biological communities of the future (Invited)

    NASA Astrophysics Data System (ADS)

    Wilhelm, S.; Steffen, M.; Belisle, B. S.; Dearth, S.; Campbell, M.; Boyer, G. L.; Watson, S.; Bourbonniere, R. A.; DeBruyn, J.; Campagna, S.

    2013-12-01

    Lake Erie is perhaps the most anthropogenically influenced of all the Laurentian Great Lakes. The history of the lake clearly demonstrates one where external loads of phosphorous drove primary production to a point where the lake was declared dead in the 1970's. The lake however, is also one of the greatest environmental success stories, as abatement programs had seen this system begin to return to health until the mid-1990's. In recent years, however, new cyanobacterial blooms of the potentially toxic cyanobacterium Microcystis have dominated the water column in late-summer months. Driven by a combination of changes in water column chemistry and regional climate, Lake Erie is no longer predictably P-limited through summer months and in some cases experiments have clearly shown that within the lake primary productivity is now N-limited. Experimentally, our goal has been to couple water column geochemistry with biomolecular pathways in cells to have the biology tell us which elements are driving community structure and function. Using community level transcriptomics and metabolomics, our observations suggest that changes in the chemical species of nitrogen, and especially the presence of urea, may be controlling the biological community structure of microbial communities in Lake Erie and may in part shape the extent of toxic cyanobacterial blooms. Moreover, data from multiple sampling surveys now demonstrates that additives designed to shape nutrient use in terrestrial environments may be influencing nitrogen cycles within the lake. Coupled to historical data sets dating back decades, we will discuss how seemingly minor alterations in system geochemistry over time have major biological implications for regional stakeholders. MODIS image of Lake Erie algal bloom in 2012

  20. Redefining Relative Biological Effectiveness in the Context of the EQDX Formalism: Implications for Alpha-Particle Emitter Therapy

    PubMed Central

    Hobbs, Robert F.; Howell, Roger W.; Song, Hong; Baechler, Sébastien; Sgouros, George

    2014-01-01

    Alpha-particle radiopharmaceutical therapy (αRPT) is currently enjoying increasing attention as a viable alternative to chemotherapy for targeting of disseminated micrometastatic disease. In theory, αRPT can be personalized through pre-therapeutic imaging and dosimetry. However, in practice, given the particularities of α-particle emissions, a dosimetric methodology that accurately predicts the thresholds for organ toxicity has not been reported. This is in part due to the fact that the biological effects caused by α-particle radiation differ markedly from the effects caused by traditional external beam (photon or electron) radiation or β-particle emitting radiopharmaceuticals. The concept of relative biological effectiveness (RBE) is used to quantify the ratio of absorbed doses required to achieve a given biological response with alpha particles versus a reference radiation (typically a beta emitter or external beam radiation). However, as conventionally defined, the RBE varies as a function of absorbed dose and therefore a single RBE value is limited in its utility because it cannot be used to predict response over a wide range of absorbed doses. Therefore, efforts are underway to standardize bioeffect modeling for different fractionation schemes and dose rates for both nuclear medicine and external beam radiotherapy. Given the preponderant use of external beams of radiation compared to nuclear medicine in cancer therapy, the more clinically relevant quantity, the 2 Gy equieffective dose, EQD2(α/β), has recently been proposed by the ICRU. In concert with EQD2(α/β), we introduce a new, redefined RBE quantity, named RBE2(α/β), as the ratio of the two linear coefficients that characterize the α particle absorbed dose-response curve and the low-LET megavoltage photon 2 Gy fraction equieffective dose-response curve. The theoretical framework for the proposed new formalism is presented along with its application to experimental data obtained from

  1. Biological effects and subsequent economic effects and losses from marine pollution and degradations in marine environments: Implications from the literature.

    PubMed

    Ofiara, Douglas D; Seneca, Joseph J

    2006-08-01

    This paper serves as the missing piece in a more fuller understanding about economic losses from marine pollution, and demonstrates what losses have been estimated in the literature. Biological effects from marine pollution are linked with resulting economic effects and losses. The merging of these two areas is usually absent in studies of marine pollution losses. The literature has examined several effects due to marine pollution: damages due to harvest closures-restrictions, damages from consumption of unsafe seafood, damages due to decreased recreational activity, and damages related to waterfront real estate adjacent to contaminated water. Overall, marine pollution can and has resulted in sizable economic effects and losses. On the basis of the literature there is adequate justification for public policy actions to curb marine pollution, require inspection of seafood for toxic substances, and preserve marine water quality and sensitive marine environments.

  2. Cell Biological and Functional Characterization of the Vaccinia Virus F10 Kinase: Implications for the Mechanism of Virion Morphogenesis

    PubMed Central

    Punjabi, Almira; Traktman, Paula

    2005-01-01

    The vaccinia virus F10 protein is one of two virally encoded protein kinases. A phenotypic analysis of infections involving a tetracycline-inducible recombinant (vΔiF10) indicated that F10 is involved in the early stages of virion morphogenesis, as previously reported for the mutants ts28 and ts15. The proteins encoded by ts28 and ts15 have primary defects in enzymatic activity and thermostability, respectively. Using a transient complementation assay, we demonstrated that the enzymatic activity of F10 is essential for its biological function and that both its enzymatic and biological functions depend upon N-terminal sequences that precede the catalytic domain. An execution point analysis indicated that in addition to its role at the onset of morphogenesis, F10 is also required at later stages, when membrane crescents surround virosomal contents and develop into immature virions. The F10 protein is phosphorylated in vivo, appears to be tightly associated with intracellular membranes, and can bind to specific phosphoinositides in vitro. When F10 is repressed or impaired, the phosphorylation of several cellular and viral proteins appears to increase in intensity, suggesting that F10 may normally intersect with cellular signaling cascades via the activation of a phosphatase or the inhibition of another kinase. These cascades may drive the F10-induced remodeling of membranes that accompanies virion biogenesis. Upon the release of ts28-infected cultures from a 40°C-induced block, a synchronous resumption of morphogenesis that culminates in the production of infectious virus can be observed. The pharmacological agents H89 and cerulenin, which are inhibitors of endoplasmic reticulum exit site formation and de novo lipid synthesis, respectively, block this recovery. PMID:15681420

  3. Biological implications of lab-on-a-chip devices fabricated using multi-jet modelling and stereolithography processes

    NASA Astrophysics Data System (ADS)

    Zhu, Feng; Macdonald, Niall; Skommer, Joanna; Wlodkowic, Donald

    2015-06-01

    Current microfabrication methods are often restricted to two-dimensional (2D) or two and a half dimensional (2.5D) structures. Those fabrication issues can be potentially addressed by emerging additive manufacturing technologies. Despite rapid growth of additive manufacturing technologies in tissue engineering, microfluidics has seen relatively little developments with regards to adopting 3D printing for rapid fabrication of complex chip-based devices. This has been due to two major factors: lack of sufficient resolution of current rapid-prototyping methods (usually >100 μm ) and optical transparency of polymers to allow in vitro imaging of specimens. We postulate that adopting innovative fabrication processes can provide effective solutions for prototyping and manufacturing of chip-based devices with high-aspect ratios (i.e. above ration of 20:1). This work provides a comprehensive investigation of commercially available additive manufacturing technologies as an alternative for rapid prototyping of complex monolithic Lab-on-a-Chip devices for biological applications. We explored both multi-jet modelling (MJM) and several stereolithography (SLA) processes with five different 3D printing resins. Compared with other rapid prototyping technologies such as PDMS soft lithography and infrared laser micromachining, we demonstrated that selected SLA technologies had superior resolution and feature quality. We also for the first time optimised the post-processing protocols and demonstrated polymer features under scanning electronic microscope (SEM). Finally we demonstrate that selected SLA polymers have optical properties enabling high-resolution biological imaging. A caution should be, however, exercised as more work is needed to develop fully bio-compatible and non-toxic polymer chemistries.

  4. Unexpected Changes in Functionality and Surface Coverage for Au Nanoparticle PEI Conjugates: Implications for Stability and Efficacy in Biological Systems.

    PubMed

    Cho, Tae Joon; Pettibone, John M; Gorham, Justin M; Nguyen, Thao M; MacCuspie, Robert I; Gigault, Julien; Hackley, Vincent A

    2015-07-14

    Cationic polyethylenimine conjugated gold nanoparticles (AuNP-PEI) are a widely studied vector for drug delivery and an effective probe for interrogating NP-cell interactions. However, an inconsistent body of literature currently exists regarding the reproducibility of physicochemical properties, colloidal stability, and efficacy for these species. To address this gap, we systematically examined the preparation, stability, and formation mechanism of PEI conjugates produced from citrate-capped AuNPs. We considered the dependence on relative molar mass, Mr, backbone conformation, and material source. The conjugation mechanism of Au-PEI was probed using attenuated total reflectance FTIR and X-ray photoelectron spectroscopy, revealing distinct fates for citrate when interacting with different PEI species. The differences in residual citrate, PEI properties, and sample preparation resulted in distinct products with differentiated stability. Overall, branched PEI (25 kDa) conjugates exhibited the greatest colloidal stability in all media tested. By contrast, linear PEI (25 kDa) induced agglomeration. Colloidal stability of the products was also observed to correlate with displaced citrate, which supports a glaring knowledge gap that has emerged regarding the role of this commonly used carboxylate species as a "place holder" for conjugation with ligands of broad functionalities. We observed an unexpected and previously unreported conversion of amine functional groups to quaternary ammonium species for 10 kDa branched conjugates. Results suggest that the AuNP surface catalyzes this conversion. The product is known to manifest distinct processes and uptake in biological systems compared to amines and may lead to unintentional toxicological consequences or decreased efficacy as delivery vectors. Overall, comprehensive physicochemical characterization (tandem spectroscopy methods combined with physical measurements) of the conjugation process provides a methodology for

  5. Pulmonary adenocarcinoma: implications of the recent advances in molecular biology, treatment and the IASLC/ATS/ERS classification

    PubMed Central

    Thakur, Priyanka; Bhardwaj, Bhaskar; Susheela, Sridhar Papaiah; Madabhavi, Irappa

    2014-01-01

    A decade ago, lung cancer could conveniently be classified into two broad categories—either the small cell lung carcinoma (SCLC), or the non-small cell lung carcinoma (NSCLC), mainly to assist in further treatment related decision making. However, the understanding regarding the eligibility of adenocarcinoma histology for treatments with agents such as pemetrexed and bevacizumab made it a necessity for NSCLC to be classified into more specific sub-groups. Then, the availability of molecular targeted therapy with oral tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib not only further emphasized the need for accurate sub-classification of lung cancer, but also heralded the important role of molecular profiling of lung adenocarcinomas. Given the remarkable advances in molecular biology, oncology and radiology, a need for felt for a revised classification for lung adenocarcinoma, since the existing World Health Organization (WHO) classification of lung cancer, published in the year 2004 was mainly a pathological system of classification. Thus, there was a combined effort by the International Association for the Study of Lung Cancer (IASLC), the American Thoracic Society (ATS) and the European Respiratory Society (ERS) with an effort to inculcate newly established perspectives from clinical, molecular and radiological aspects in evolving a modern classification for lung adenocarcinomas. This review provides a summary of the recent advances in molecular biology and molecular targeted therapy with respect to lung adenocarcinoma. Also, a brief summation of the salient recommendations provided in the IASLC/ATS/ERS classification of lung adenocarcinomas is provided. Lastly, a discussion regarding the future prospects with lung adenocarcinoma is included. PMID:25349702

  6. Evaluation of the biological differences of canine and human factor VIII in gene delivery: implications in human hemophilia treatment.

    PubMed

    Wang, Q; Dong, B; Firrman, J; Wu, W; Roberts, S; Moore, A R; Liu, L S; Chin, M P S; Diao, Y; Kost, J; Xiao, W

    2016-07-01

    The canine is the most important large animal model for testing novel hemophilia A (HA) treatment. It is often necessary to use canine factor VIII (cFIII) gene or protein for the evaluation of HA treatment in the canine model. However, different biological properties between cFVIII and human FVIII (hFVIII) indicated that the development of novel HA treatment may require careful characterization of non-human FVIII. To investigate whether the data obtained using cFVIII can translate to HA treatment in human, we analyzed the differential biological properties of canine heavy chain (cHC) and light chain (cLC) by comparing with human heavy chain (hHC) and light chain (hLC). The secretion of cHC was 5-30-fold higher than hHC, with or without light chains (LCs). cHC+hLC group exhibited ~18-fold increase in coagulation activity compared with hHC+hLC delivery by recombinant adeno-associated viral vectors. Unlike hHC, the secretion of cHC was independent of LCs. cLC improves the specific activity of FVIII by two- to threefold compared with hLC. Moreover, the cLC, but not cHC, contributes to the higher stability of cFVIII. Our results suggested that the cFVIII expression results in the canine model should be interpreted with caution as the cHC secreted more efficiently than hHC and cLC exhibited a more active and stable phenotype than hLC. PMID:27064790

  7. The inactivation principle: mathematical solutions minimizing the absolute work and biological implications for the planning of arm movements.

    PubMed

    Berret, Bastien; Darlot, Christian; Jean, Frédéric; Pozzo, Thierry; Papaxanthis, Charalambos; Gauthier, Jean Paul

    2008-10-01

    An important question in the literature focusing on motor control is to determine which laws drive biological limb movements. This question has prompted numerous investigations analyzing arm movements in both humans and monkeys. Many theories assume that among all possible movements the one actually performed satisfies an optimality criterion. In the framework of optimal control theory, a first approach is to choose a cost function and test whether the proposed model fits with experimental data. A second approach (generally considered as the more difficult) is to infer the cost function from behavioral data. The cost proposed here includes a term called the absolute work of forces, reflecting the mechanical energy expenditure. Contrary to most investigations studying optimality principles of arm movements, this model has the particularity of using a cost function that is not smooth. First, a mathematical theory related to both direct and inverse optimal control approaches is presented. The first theoretical result is the Inactivation Principle, according to which minimizing a term similar to the absolute work implies simultaneous inactivation of agonistic and antagonistic muscles acting on a single joint, near the time of peak velocity. The second theoretical result is that, conversely, the presence of non-smoothness in the cost function is a necessary condition for the existence of such inactivation. Second, during an experimental study, participants were asked to perform fast vertical arm movements with one, two, and three degrees of freedom. Observed trajectories, velocity profiles, and final postures were accurately simulated by the model. In accordance, electromyographic signals showed brief simultaneous inactivation of opposing muscles during movements. Thus, assuming that human movements are optimal with respect to a certain integral cost, the minimization of an absolute-work-like cost is supported by experimental observations. Such types of optimality

  8. Evaluation of the biological differences of canine and human factor VIII in gene delivery: implications in human hemophilia treatment

    PubMed Central

    Wang, Qizhao; Dong, Biao; Firrman, Jenni; Wu, Wenman; Roberts, Sean; Moore, Andrea Rossi; Liu, LinShu; Chin, Mario P.S.; Diao, Yong; Kost, Joseph; Xiao, Weidong

    2016-01-01

    The canine is the most important large animal model for testing novel hemophilia A(HA) treatment. It is often necessary to use canine factor VIII (cFIII) gene or protein for the evaluation of HA treatment in the canine model. However, the different biological properties between cFVIII and human FVIII(hFVIII) indicated that the development of novel HA treatment may require careful characterization of non-human FVIII. To investigate whether the data obtained using cFVIII can translate to HA treatment in human, we analyzed the differential biological properties of canine heavy chain (cHC) and light chain (cLC) by comparing with human HC (hHC) and LC (hLC). The secretion of cHC was 5~30 fold higher than hHC, with or without LCs. cHC+hLC group exhibited ~18-fold increase in coagulation activity compared with hHC+hLC delivery by recombinant adeno-associated viral vectors. Unlike hHC, the secretion of cHC was independent of LCs. cLC improves the specific activity of FVIII by 2~3-fold compared with hLC. Moreover, the cLC but not cHC, contributes the high stability of cFVIII. Our results suggested that the cFVIII expression results in the canine model should be interpreted with caution as the cHC secreted more efficiently than hHC and cLC exhibited a more active and stable phenotype than hLC. PMID:27064790

  9. Model studies of the precipitation of silica in the presence of aluminium; implications for biology and industry.

    PubMed

    Perry, C C; Keeling-Tucker, T

    2000-03-01

    The unique chemical affinity between the oxides of silicon and aluminium has been cited as a potential route for the amelioration of the detrimental effects of aluminium in the environment and in biological systems. A greater understanding of silicon-aluminium interactions may assist in this endeavour and also provide a means of overcoming silica fouling problems encountered by industry which are exacerbated by the presence of aluminium. It is also conceivable that this increased knowledge may demonstrate a positive use for aluminium in the processing of the silicon dioxide phase. In this study we report the effect of aluminium ions, derived from aluminium chloride, on silicic acid species obtained from potassium catecholato complexes of silicon at circumneutral pH at the molar ratios 1000Si:Al, 100Si:Al and 50Si:Al. Silica and low levels of aluminium-rich silica materials were formed with Si:Al ratios of about 3.5:1 comparable with the element ratios detected in senile plaques and aluminium-rich scale. A kinetic study showed that aluminium in the reaction medium slowed down the rate of formation of one of the silica species formed early in the condensation process, e.g. trimers, but increased the rate at which silicic acid was removed from sub 1 nm diameter particles. The materials precipitated in the presence of aluminium were composed of smaller particles and aggregates with smaller pores (Si100:Al and Si50:Al systems) or larger pores (Si1000:Al) compared to the control. The nature of the interactions responsible for these differences is discussed. The effects described here demonstrate the ability of silica and aluminium to interact under conditions such as those found in biological systems. That silica reacts with aluminium in the presence of catechol supports the protective role assigned to silicon.

  10. The inactivation principle: mathematical solutions minimizing the absolute work and biological implications for the planning of arm movements.

    PubMed

    Berret, Bastien; Darlot, Christian; Jean, Frédéric; Pozzo, Thierry; Papaxanthis, Charalambos; Gauthier, Jean Paul

    2008-10-01

    An important question in the literature focusing on motor control is to determine which laws drive biological limb movements. This question has prompted numerous investigations analyzing arm movements in both humans and monkeys. Many theories assume that among all possible movements the one actually performed satisfies an optimality criterion. In the framework of optimal control theory, a first approach is to choose a cost function and test whether the proposed model fits with experimental data. A second approach (generally considered as the more difficult) is to infer the cost function from behavioral data. The cost proposed here includes a term called the absolute work of forces, reflecting the mechanical energy expenditure. Contrary to most investigations studying optimality principles of arm movements, this model has the particularity of using a cost function that is not smooth. First, a mathematical theory related to both direct and inverse optimal control approaches is presented. The first theoretical result is the Inactivation Principle, according to which minimizing a term similar to the absolute work implies simultaneous inactivation of agonistic and antagonistic muscles acting on a single joint, near the time of peak velocity. The second theoretical result is that, conversely, the presence of non-smoothness in the cost function is a necessary condition for the existence of such inactivation. Second, during an experimental study, participants were asked to perform fast vertical arm movements with one, two, and three degrees of freedom. Observed trajectories, velocity profiles, and final postures were accurately simulated by the model. In accordance, electromyographic signals showed brief simultaneous inactivation of opposing muscles during movements. Thus, assuming that human movements are optimal with respect to a certain integral cost, the minimization of an absolute-work-like cost is supported by experimental observations. Such types of optimality

  11. Variation in the biological properties of HIV-1 R5 envelopes: implications of envelope structure, transmission and pathogenesis

    PubMed Central

    Duenas-Decamp, Maria José; Peters, Paul J; Repik, Alexander; Musich, Thomas; Gonzalez-Perez, Maria Paz; Caron, Catherine; Brown, Richard; Ball, Jonathan; Clapham, Paul R

    2010-01-01

    HIV-1 R5 viruses predominantly use CCR5 as a coreceptor to infect CD4+ T cells and macrophages. While R5 viruses generally infect CD4+ T cells, research over the past few years has demonstrated that they vary extensively in their capacity to infect macrophages. Thus, R5 variants that are highly macrophage tropic have been detected in late disease and are prominent in brain tissue of subjects with neurological complications. Other R5 variants that are less sensitive to CCR5 antagonists and use CCR5 differently have also been identified in late disease. These latter variants have faster replication kinetics and may contribute to CD4 T-cell depletion. In addition, R5 viruses are highly variable in many other properties, including sensitivity to neutralizing antibodies and inhibitors that block HIV-1 entry into cells. Here, we review what is currently known about how HIV-1 R5 viruses vary in cell tropism and other properties, and discuss the implications of this variation on transmission, pathogenesis, therapy and vaccines. PMID:20930940

  12. Non-migratory breeding by isolated green sea turtles (Chelonia mydas) in the Indian Ocean: biological and conservation implications.

    PubMed

    Whiting, Scott D; Murray, Wendy; Macrae, Ismail; Thorn, Robert; Chongkin, Mohammad; Koch, Andrea U

    2008-04-01

    Green sea turtles (Chelonia mydas) are renowned for their long-distance migrations but have less fame for short-distance migrations or non-migratory behavior. We present satellite telemetric evidence from Cocos (Keeling) Islands, Indian Ocean for the first predominantly non-migratory green sea turtle (C. mydas) population. The mean migration distance from the nesting beach to the foraging grounds was 35.5 km with a maximum mean transit time of 3.4 days. The behavior of this population has major implications for our general understanding of green turtle behavior and their life cycle and for conservation. Firstly, these results indicate a level of juvenile or adult non-breeding homing behavior from the open ocean to foraging grounds adjacent to their natal nesting beach. Secondly, a non-migratory breeding phase reduces the consumption of reproductive energy utilized, potentially resulting in higher fecundity for this population. Thirdly, the close proximity of the nesting and foraging habitats allows for uniformity in management and conservation strategies rarely possible for wide-ranging green turtle populations. PMID:18046497

  13. Non-migratory breeding by isolated green sea turtles (Chelonia mydas) in the Indian Ocean: biological and conservation implications.

    PubMed

    Whiting, Scott D; Murray, Wendy; Macrae, Ismail; Thorn, Robert; Chongkin, Mohammad; Koch, Andrea U

    2008-04-01

    Green sea turtles (Chelonia mydas) are renowned for their long-distance migrations but have less fame for short-distance migrations or non-migratory behavior. We present satellite telemetric evidence from Cocos (Keeling) Islands, Indian Ocean for the first predominantly non-migratory green sea turtle (C. mydas) population. The mean migration distance from the nesting beach to the foraging grounds was 35.5 km with a maximum mean transit time of 3.4 days. The behavior of this population has major implications for our general understanding of green turtle behavior and their life cycle and for conservation. Firstly, these results indicate a level of juvenile or adult non-breeding homing behavior from the open ocean to foraging grounds adjacent to their natal nesting beach. Secondly, a non-migratory breeding phase reduces the consumption of reproductive energy utilized, potentially resulting in higher fecundity for this population. Thirdly, the close proximity of the nesting and foraging habitats allows for uniformity in management and conservation strategies rarely possible for wide-ranging green turtle populations.

  14. Non-migratory breeding by isolated green sea turtles ( Chelonia mydas) in the Indian Ocean: biological and conservation implications

    NASA Astrophysics Data System (ADS)

    Whiting, Scott D.; Murray, Wendy; Macrae, Ismail; Thorn, Robert; Chongkin, Mohammad; Koch, Andrea U.

    2008-04-01

    Green sea turtles ( Chelonia mydas) are renowned for their long-distance migrations but have less fame for short-distance migrations or non-migratory behavior. We present satellite telemetric evidence from Cocos (Keeling) Islands, Indian Ocean for the first predominantly non-migratory green sea turtle ( C. mydas) population. The mean migration distance from the nesting beach to the foraging grounds was 35.5 km with a maximum mean transit time of 3.4 days. The behavior of this population has major implications for our general understanding of green turtle behavior and their life cycle and for conservation. Firstly, these results indicate a level of juvenile or adult non-breeding homing behavior from the open ocean to foraging grounds adjacent to their natal nesting beach. Secondly, a non-migratory breeding phase reduces the consumption of reproductive energy utilized, potentially resulting in higher fecundity for this population. Thirdly, the close proximity of the nesting and foraging habitats allows for uniformity in management and conservation strategies rarely possible for wide-ranging green turtle populations.

  15. Adsorption of small biological molecules on silica from diluted aqueous solutions: Quantitative characterization and implications to the Bernal's hypothesis

    NASA Astrophysics Data System (ADS)

    Basiuk, Vladimir A.; Gromovoy, Taras Yu.; Khil'Chevskaya, Elena G.

    1995-08-01

    To describe quantitatively the adsorption of prebiotically important compounds of low molecular weight (amino acids, short linear peptides, cyclic dipeptides, the Krebs's cycle and other carboxylic acids, nucleosides and related phosphates) on silica surface from diluted neutral aqueous solutions, equilibrium constants (K) and free energies (-ΔG) of adsorption were determined from the retention values measured by means of high-performance liquid chromatography on a silica gel column and from the isotherms measured under static conditions. For most carboxylic acids (including amino acids and linear peptides) -ΔG values were negative and K<1, thus showing very weak adsorption. Cyclic dipeptides (2,5-piperazinediones) exhibited higher adsorbability; -ΔG>0 and K>1 were found for most of them. Influence of the structure of α-substituent on the adsorbability is analyzed. A linear dependence of -ΔG on the number of aliphatic carbon atoms in a sorbate molecule was found for the series of aliphatic bifunctional amino acids, related dipeptides and 2,5-piperazinediones, as well as for the row from glycine to triglycyl glycine. The adsorption of nucleosides and their phosphates is characterized by much higherK and -ΔG values (of the order of 102 and 104, respectively). The adsorption data available from our work and literature are summarized and discussed with implications to the Bernal's hypothesis on the roles of solid surfaces in the prebiotic formation of biopolymers from monomeric ‘building blocks’.

  16. Physico-chemical and biological characterization of anopheline mosquito larval habitats (Diptera: Culicidae): implications for malaria control

    PubMed Central

    2013-01-01

    Background A fundamental understanding of the spatial distribution and ecology of mosquito larvae is essential for effective vector control intervention strategies. In this study, data-driven decision tree models, generalized linear models and ordination analysis were used to identify the most important biotic and abiotic factors that affect the occurrence and abundance of mosquito larvae in Southwest Ethiopia. Methods In total, 220 samples were taken at 180 sampling locations during the years 2010 and 2012. Sampling sites were characterized based on physical, chemical and biological attributes. The predictive performance of decision tree models was evaluated based on correctly classified instances (CCI), Cohen’s kappa statistic (κ) and the determination coefficient (R2). A conditional analysis was performed on the regression tree models to test the relation between key environmental and biological parameters and the abundance of mosquito larvae. Results The decision tree model developed for anopheline larvae showed a good model performance (CCI = 84 ± 2%, and κ = 0.66 ± 0.04), indicating that the genus has clear habitat requirements. Anopheline mosquito larvae showed a widespread distribution and especially occurred in small human-made aquatic habitats. Water temperature, canopy cover, emergent vegetation cover, and presence of predators and competitors were found to be the main variables determining the abundance and distribution of anopheline larvae. In contrast, anopheline mosquito larvae were found to be less prominently present in permanent larval habitats. This could be attributed to the high abundance and diversity of natural predators and competitors suppressing the mosquito population densities. Conclusions The findings of this study suggest that targeting smaller human-made aquatic habitats could result in effective larval control of anopheline mosquitoes in the study area. Controlling the occurrence of mosquito larvae via drainage

  17. Climatic, tectonic, and biological factors affecting the oxidation state of the atmosphere and oceans: Implications for Phanerozoic O2 evolution

    NASA Astrophysics Data System (ADS)

    Ozaki, K.; Tajika, E.

    2015-12-01

    also shed light on the causal linkage between the critical biological evolution (such as an establishment of biological pump and advent of land plant) and the oxidation state of the atmosphere and oceans.

  18. Extension of the biological effective dose to the MIRD schema and possible implications in radionuclide therapy dosimetry.

    PubMed

    Baechler, Sébastien; Hobbs, Robert F; Prideaux, Andrew R; Wahl, Richard L; Sgouros, George

    2008-03-01

    In dosimetry-based treatment planning protocols, patients with rapid clearance of the radiopharmaceutical require a larger amount of initial activity than those with slow clearance to match the absorbed dose to the critical organ. As a result, the dose-rate to the critical organ is higher in patients with rapid clearance and may cause unexpected toxicity compared to patients with slow clearance. In order to account for the biological impact of different dose-rates, radiobiological modeling is beginning to be applied to the analysis of radionuclide therapy patient data. To date, the formalism used for these analyses is based on kinetics derived from activity in a single organ, the target. This does not include the influence of other source organs to the dose and dose-rate to the target organ. As a result, only self-dose irradiation in the target organ contributes to the dose-rate. In this work, the biological effective dose (BED) formalism has been extended to include the effect of multiple source organ contributions to the net dose-rate in a target organ. The generalized BED derivation has been based on the Medical Internal Radionuclide Dose Committee (MIRD) schema assuming multiple source organs following exponential effective clearance of the radionuclide. A BED-based approach to determine the largest safe dose to critical organs has also been developed. The extended BED formalism is applied to red marrow dosimetry, as well as kidney dosimetry considering the cortex and the medulla separately, since both those organs are commonly dose limiting in radionuclide therapy. The analysis shows that because the red marrow is an early responding tissue (high alpha/beta), it is less susceptible to unexpected toxicity arising from rapid clearance of high levels of administered activity in the marrow or in the remainder of the body. In kidney dosimetry, the study demonstrates a complex interplay between clearance of activity in the cortex and the medulla, as well as the

  19. Consumption habits of pregnant women and implications for developmental biology: a survey of predominantly Hispanic women in California

    PubMed Central

    2013-01-01

    Background Healthy post-pregnancy outcomes are contingent upon an informed regimen of prenatal care encouraging healthy maternal consumption habits. In this article, we describe aspects of maternal intake of food, drink, and medication in a population of predominantly Hispanic women in Southern California. Potential implications for unhealthy prenatal dietary choices are discussed. Methods The Food, Beverage, and Medication Intake Questionnaire (FBMIQ) measures common practices of maternal consumption during pregnancy. The FBMIQ was administered to English and Spanish speaking pregnant and recently pregnant (36 weeks pregnant - 8 weeks post-partum) women over the age of 18 who were receiving care from a private medical group in Downey CA. Results A total of 200 women completed the FBMIQ. Consumption habits of healthy foods and beverages, unhealthy foods, unhealthy beverages, and medication are characterized in this article. Data indicate widespread consumption of fresh fruit, meats, milk and juice and indicate most women used prenatal vitamin supplements. Studies in developmental neuroscience have shown that certain substances may cause teratogenic effects on the fetus when ingested by the mother during pregnancy. Those potentially harmful substances included in our study were Bisphenol-A (BPA), methylmercury, caffeine, alcohol and certain medications. Our results show that a proportion of the women surveyed in our study consumed BPA, methylmercury, caffeine, alcohol, and certain medications at varied levels during pregnancy. This represents an interesting finding and suggests a disconnect between scientific data and general recommendations provided to pregnant mothers by obstetricians. Conclusions The results of our study demonstrate that a proportion of pregnant women consume substances that are potentially teratogenic and may impact the health and well being of the offspring. It is important to appraise healthy and unhealthy consumption habits in order to

  20. The biology of zinc transport in mammary epithelial cells: implications for mammary gland development, lactation, and involution.

    PubMed

    McCormick, Nicholas H; Hennigar, Stephen R; Kiselyov, Kirill; Kelleher, Shannon L

    2014-03-01

    Zinc plays a critical role in a vast array of cellular functions including gene transcription, protein translation, cell proliferation, differentiation, bioenergetics, and programmed cell death. The mammary gland depends upon tight coordination of these processes during development and reproduction for optimal expansion, differentiation, and involution. For example, zinc is required for activation of matrix metalloproteinases, intracellular signaling cascades such as MAPK and PKC, and the activation of both mitochondrial-mediated apoptosis and lysosomal-mediated cell death. In addition to functional needs, during lactation the mammary gland must balance providing optimal zinc for cellular requirements with the need to secrete a substantial amount of zinc into milk to meet the requirements of the developing neonate. Finally, the mammary gland exhibits the most profound example of programmed cell death, which is driven by both apoptotic and lysosomal-mediated cell death. Two families of zinc-specific transporters regulate zinc delivery for these diverse functions. Members of the ZIP family of zinc transporters (ZIP1-14) import zinc into the cytoplasm from outside the cell or from subcellular organelles, while members of the ZnT family (ZnT1-10) export zinc from the cytoplasm. Recently, the ion channel transient receptor potential mucolipin 1 (TRPML1) has also been implicated in zinc transport. Herein, we review our current understanding of the molecular mechanisms through which mammary epithelial cells utilize zinc with a focus on the transport of zinc into discrete subcellular organelles for specific cellular functions during mammary gland development, lactation, and involution.

  1. Renal artery nerve distribution and density in the porcine model: biologic implications for the development of radiofrequency ablation therapies.

    PubMed

    Tellez, Armando; Rousselle, Serge; Palmieri, Taylor; Rate, William R; Wicks, Joan; Degrange, Ashley; Hyon, Chelsea M; Gongora, Carlos A; Hart, Randy; Grundy, Will; Kaluza, Greg L; Granada, Juan F

    2013-12-01

    Catheter-based renal artery denervation has demonstrated to be effective in decreasing blood pressure among patients with refractory hypertension. The anatomic distribution of renal artery nerves may influence the safety and efficacy profile of this procedure. We aimed to describe the anatomic distribution and density of periarterial renal nerves in the porcine model. Thirty arterial renal sections were included in the analysis by harvesting a tissue block containing the renal arteries and perirenal tissue from each animal. Each artery was divided into 3 segments (proximal, mid, and distal) and assessed for total number, size, and depth of the nerves according to the location. Nerve counts were greatest proximally (45.62% of the total nerves) and decreased gradually distally (mid, 24.58%; distal, 29.79%). The distribution in nerve size was similar across all 3 sections (∼40% of the nerves, 50-100 μm; ∼30%, 0-50 μm; ∼20%, 100-200 μm; and ∼10%, 200-500 μm). In the arterial segments ∼45% of the nerves were located within 2 mm from the arterial wall whereas ∼52% of all nerves were located within 2.5 mm from the arterial wall. Sympathetic efferent fibers outnumbered sensory afferent fibers overwhelmingly, intermixed within the nerve bundle. In the porcine model, renal artery nerves are seen more frequently in the proximal segment of the artery. Nerve size distribution appears to be homogeneous throughout the artery length. Nerve bundles progress closer to the arterial wall in the distal segments of the artery. This anatomic distribution may have implications for the future development of renal denervation therapies.

  2. Stratified and nonstratified areas in the North Sea: Long-term variability and biological and policy implications

    NASA Astrophysics Data System (ADS)

    van Leeuwen, Sonja; Tett, Paul; Mills, David; van der Molen, Johan

    2015-07-01

    The European Unions' Marine Strategy Framework Directive aims to limit anthropogenic influences in the marine environment. But marine ecosystems are characterized by high variability, and it is not trivial to define its natural state. Here, we use the physical environment as a basis for marine classification, as it determines the conditions in which organisms must operate to survive and thrive locally. We present a delineation of the North Sea into five distinct regimes, based on multidecadal stratification characteristics. Results are based on a 51 year simulation of the region using the coupled hydrobiogeochemical model GETM-ERSEM-BFM. The five identified regimes are: permanently stratified, seasonally stratified, intermittently stratified, permanently mixed, and Region Of Freshwater Influence (ROFI). The areas characterized by these regimes show some interannual variation in geographical coverage, but are overall remarkable stable features within the North Sea. Results also show that 29% of North Sea waters fail to classify as one of the defined stratification regimes, due to high interannual variability. Biological characteristics of these regimes differ from diatom-based food webs in areas with prolonged stratification to Phaeocystis-dominated food webs in areas experiencing short-lived or no stratification. The spatial stability of the identified regimes indicates that carefully selected monitoring locations can be used to represent a substantive area of the North Sea.

  3. Bones as biofuel: a review of whale bone composition with implications for deep-sea biology and palaeoanthropology.

    PubMed

    Higgs, Nicholas D; Little, Crispin T S; Glover, Adrian G

    2011-01-01

    Whales are unique among vertebrates because of the enormous oil reserves held in their soft tissue and bone. These 'biofuel' stores have been used by humans from prehistoric times to more recent industrial-scale whaling. Deep-sea biologists have now discovered that the oily bones of dead whales on the seabed are also used by specialist and generalist scavenging communities, including many unique organisms recently described as new to science. In the context of both cetacean and deep-sea invertebrate biology, we review scientific knowledge on the oil content of bone from several of the great whale species: Balaenoptera musculus, Balaenoptera physalus, Balaenoptera borealis, Megaptera novaeangliae, Eschrichtius robustus, Physeter macrocephalus and the striped dolphin, Stenella coeruleoalba. We show that data collected by scientists over 50 years ago during the heyday of industrial whaling explain several interesting phenomena with regard to the decay of whale remains. Variations in the lipid content of bones from different parts of a whale correspond closely with recently observed differences in the taphonomy of deep-sea whale carcasses and observed biases in the frequency of whale bones at archaeological sites.

  4. Antioxidant role of amyloid β protein in cell-free and biological systems: implication for the pathogenesis of Alzheimer disease.

    PubMed

    Sinha, Maitrayee; Bhowmick, Pritha; Banerjee, Anindita; Chakrabarti, Sasanka

    2013-03-01

    In contrast to many studies showing the pro-oxidative nature of amyloid peptide, this work shows that aggregated Aβ42 peptide in varying concentrations (2-20 μM) in cell-free systems inhibits the formation of hydroxyl radicals and H(2)O(2) from a mixture of iron (20 μM FeSO(4)) and ascorbate (2mM) as measured by benzoate hydroxylation assay and coumarin carboxylic acid assay. Aggregated Aβ42 in similar concentrations further prevents protein and lipid oxidation in isolated rat brain mitochondria incubated alone or with FeSO(4) and ascorbate. Moreover, mitochondria exposed to FeSO(4) and ascorbate show enhanced formation of reactive oxygen species and this phenomenon is also abolished by aggregated Aβ42. It is suggested that the antioxidant property of Aβ42 in various systems is mediated by metal chelation and it is nearly as potent as a typical metal chelator, such as diethylenetriaminepentaacetic acid, in preventing oxidative damage. However, aggregated Aβ42 causes mitochondrial functional impairment in the form of membrane depolarization and a loss of phosphorylation capacity without involving reactive oxygen species in the process. Thus, the present results suggest that the amyloid peptide exhibits a protective antioxidant role in biological systems, but also has toxic actions independent of oxidative stress. PMID:23041348

  5. Experimental derivation of relative biological effectiveness of A-bomb neutrons in Hiroshima and Nagasaki and implications for risk assessment.

    PubMed

    Sasaki, M S; Nomura, T; Ejima, Y; Utsumi, H; Endo, S; Saito, I; Itoh, T; Hoshi, M

    2008-07-01

    Epidemiological data on the health effects of A-bomb radiation in Hiroshima and Nagasaki provide the framework for setting limits for radiation risk and radiological protection. However, uncertainty remains in the equivalent dose, because it is generally believed that direct derivation of the relative biological effectiveness (RBE) of neutrons from the epidemiological data on the survivors is difficult. To solve this problem, an alternative approach has been taken. The RBE of polyenergetic neutrons was determined for chromosome aberration formation in human lymphocytes irradiated in vitro, compared with published data for tumor induction in experimental animals, and validated using epidemiological data from A-bomb survivors. The RBE of fission neutrons was dependent on dose but was independent of the energy spectrum. The same RBE regimen was observed for lymphocyte chromosome aberrations and tumors in mice and rats. Used as a weighting factor for A-bomb survivors, this RBE system was superior in eliminating the city difference in chromosome aberration frequencies and cancer mortality. The revision of the equivalent dose of A-bomb radiation using DS02 weighted by this RBE system reduces the cancer risk by a factor of 0.7 compared with the current estimates using DS86, with neutrons weighted by a constant RBE of 10.

  6. Warming and increased precipitation frequency on the Colorado Plateau: Implications for biological soil crusts and soil processes

    SciTech Connect

    Zelikova TJ; Hosman DC; Grote EE; Neher DA; Belnap J

    2011-03-21

    Frequent hydration and drying of soils in arid systems can accelerate desert carbon and nitrogen mobilization due to respiration, microbial death, and release of intracellular solutes. Because desert microinvertebrates can mediate nutrient cycling, and the autotrophic components of crusts are known to be sensitive to rapid desiccation due to elevated temperatures after wetting events, we studied whether altered soil temperature and frequency of summer precipitation can also affect the composition of food web consumer functional groups. We conducted a two-year field study with experimentally-elevated temperature and frequency of summer precipitation in the Colorado Plateau desert, measuring the change in abundance of nematodes, protozoans, and microarthropods. We hypothesized that microfauna would be more adversely affected by the combination of elevated temperature and frequency of summer precipitation than either effect alone, as found previously for phototrophic crust biota. Microfauna experienced normal seasonal fluctuations in abundance, but the effect of elevated temperature and frequency of summer precipitation was statistically non-significant for most microfaunal groups, except amoebae. The seasonal increase in abundance of amoebae was reduced with combined elevated temperature and increased frequency of summer precipitation compared to either treatment alone, but comparable with control (untreated) plots. Based on our findings, we suggest that desert soil microfauna are relatively more tolerant to increases in ambient temperature and frequency of summer precipitation than the autotrophic components of biological soil crust at the surface.

  7. Nitric oxide and redox regulation in the liver: part II. Redox biology in pathologic hepatocytes and implications for intervention.

    PubMed

    Diesen, Diana L; Kuo, Paul C

    2011-05-01

    Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are created in normal hepatocytes and are critical for normal physiologic processes, including oxidative respiration, growth, regeneration, apoptosis, and microsomal defense. When the levels of oxidation products exceed the capacity of normal antioxidant systems, oxidative stress occurs. This type of stress, in the form of ROS and RNS, can be damaging to all liver cells, including hepatocytes, Kupffer cells, stellate cells, and endothelial cells, through induction of inflammation, ischemia, fibrosis, necrosis, apoptosis, or through malignant transformation by damaging lipids, proteins, and/or DNA. In Part I of this review, we will discuss basic redox biology in the liver, including a review of ROS, RNS, and antioxidants, with a focus on nitric oxide as a common source of RNS. We will then review the evidence for oxidative stress as a mechanism of liver injury in hepatitis (alcoholic, viral, nonalcoholic). In Part II of this review, we will review oxidative stress in common pathophysiologic conditions, including ischemia/reperfusion injury, fibrosis, hepatocellular carcinoma, iron overload, Wilson's disease, sepsis, and acetaminophen overdose. Finally, biomarkers, proteomic, and antioxidant therapies will be discussed as areas for future therapeutic interventions.

  8. Electrophilic Activation of Oxidized Sulfur Ligands and Implications for the Biological Activity of Ruthenium(II) Arene Anticancer Complexes.

    PubMed

    Sriskandakumar, Thamayanthy; Behyan, Shirin; Habtemariam, Abraha; Sadler, Peter J; Kennepohl, Pierre

    2015-12-01

    Surprisingly, the anticancer activity of half-sandwich Ru arene complexes [(η(6)-arene)Ru(en)Cl](+) appears to be promoted and not inhibited by binding to the intracellular thiol glutathione. Labilization of the Ru-S bond allowing DNA binding appeared to be initiated by oxygenation of the thiolate ligand, although oxidation by itself did not seem to weaken the Ru-S bond. In this study, we have investigated the solvation and acidic perturbations of mono (sulfenato) and bis (sulfinato) oxidized species of [(η(6)-arene)Ru(en) (SR)](+) complex in the presence of Brønsted and Lewis acids. Sulfur K-edge X-ray absorption spectroscopy together with density functional theory calculations show that solvation and acidic perturbation of sulfenato species produce a significant decrease in the S3p character of the Ru-S bond (Ru4dσ* ← S1s charge donation). Also there is a drastic fall in the overall ligand charge donation to the metal center in both sulfenato and sulfinato species. Our investigation clearly shows that mono oxidized sulfenato species are most susceptible to ligand exchange, hence providing a possible pathway for in vivo activation and biological activity.

  9. In Situ Biological Contamination Studies of the Moon: Implications for Future Planetary Protection and Life Detection Missions

    NASA Technical Reports Server (NTRS)

    Glavin, Daniel P.; Dworkin, Jason P.; Lupisella, Mark; Kminek, Gerhard; Rummel, John D.

    2010-01-01

    NASA and ESA have outlined visions for solar system exploration that will include a series of lunar robotic precursor missions to prepare for, and support a human return to the Moon, and future human exploration of Mars and other destinations. One of the guiding principles for exploration is to pursue compelling scientific questions about the origin and evolution of life. The search for life on objects such as Mars will require that all spacecraft and instrumentation be sufficiently cleaned and sterilized prior to launch to ensure that the scientific integrity of extraterrestrial samples is not jeopardized by terrestrial organic contamination. Under the Committee on Space Research's (COSPAR's) current planetary protection policy for the Moon, no sterilization procedures are required for outbound lunar spacecraft, nor is there yet a planetary protection category for human missions. Future in situ investigations of a variety of locations on the Moon by highly sensitive instruments designed to search for biologically derived organic compounds would help assess the contamination of the Moon by lunar spacecraft. These studies could also provide valuable "ground truth" data for Mars sample return missions and help define planetary protection requirements for future Mars bound spacecraft carrying life detection experiments. In addition, studies of the impact of terrestrial contamination of the lunar surface by the Apollo astronauts could provide valuable data to help refine future Mars surface exploration plans for a human mission to Mars.

  10. Evolutionary and biological implications of dental mesial drift in rodents: the case of the Ctenodactylidae (Rodentia, Mammalia).

    PubMed

    Gomes Rodrigues, Helder; Solé, Floréal; Charles, Cyril; Tafforeau, Paul; Vianey-Liaud, Monique; Viriot, Laurent

    2012-01-01

    Dental characters are importantly used for reconstructing the evolutionary history of mammals, because teeth represent the most abundant material available for the fossil species. However, the characteristics of dental renewal are presently poorly used, probably because dental formulae are frequently not properly established, whereas they could be of high interest for evolutionary and developmental issues. One of the oldest rodent families, the Ctenodactylidae, is intriguing in having longstanding disputed dental formulae. Here, we investigated 70 skulls among all extant ctenodactylid genera (Ctenodactylus, Felovia, Massoutiera and Pectinator) by using X-ray conventional and synchrotron microtomography in order to solve and discuss these dental issues. Our study clearly indicates that Massoutiera, Felovia and Ctenodactylus differ from Pectinator not only by a more derived dentition, but also by a more derived eruptive sequence. In addition to molars, their dentition only includes the fourth deciduous premolars, and no longer bears permanent premolars, conversely to Pectinator. Moreover, we found that these premolars are lost during adulthood, because of mesial drift of molars. Mesial drift is a striking mechanism involving migration of teeth allowed by both bone remodeling and dental resorption. This dental innovation is to date poorly known in rodents, since it is only the second report described. Interestingly, we noted that dental drift in rodents is always associated with high-crowned teeth favoring molar size enlargement. It can thus represent another adaptation to withstand high wear, inasmuch as these rodents inhabit desert environments where dust is abundant. A more accurate study of mesial drift in rodents would be very promising from evolutionary, biological and orthodontic points of view.

  11. Reproductive biology and implications for management of the spangled emperor Lethrinus nebulosus in the southern Arabian Gulf.

    PubMed

    Grandcourt, E M; Al Abdessalaam, T Z; Francis, F; Al Shamsi, A T

    2010-12-01

    The reproductive biology of the spangled emperor Lethrinus nebulosus in the southern Arabian Gulf was determined from the examination of 781 individuals collected between September 2008 and August 2009. There was no histological evidence of adult sex change, and sex ratios did not differ significantly from unity across all size and age classes. Testes had an ovarian structure and a remnant lumen which was not used for sperm transport; furthermore, residual oocytes were observed in the testes of some immature, resting and developing males. A dramatic change in the sex ratio of the smallest and youngest size and age classes suggested that juvenile female to male sex change occurred between 21·0 cm fork length (L(F)) and 24·0 cm L(F) at 1 year of age. The combination of histological evidence with the sexual composition of the size and age structures suggests a non-functional protogynous hermaphroditic sexual pattern, which is analogous to functional gonochorism. The spawning season was well defined, occurring once a year during March, April and early May. Peaks in spawning occurred after full moons, there was a cessation in spawning activity after new moons and spawning was completed within three lunar cycles. The distribution of males over the entire size and age ranges and the absence of inactive mature females during the spawning season suggested that the population was not constrained by sperm limitation. Size-specific and age-specific reproductive potential indicated that conventional regulations that equate the mean size at first capture to sexual maturation are unsuitable for the management of L. nebulosus. The maximum recorded age (11 years), small mean size and young age at sexual maturation (L(m50) = 26·7 cm L(F), 2·1 years, for females and 19·4 cm L(F), 0·5 years, for males) may be a direct result of intensive demersal fishing in the southern Arabian Gulf. PMID:21155780

  12. Study of a possible magnetite biosignature in Martian meteorite ALH84001: Implications for the biological toxicology of Mars

    NASA Astrophysics Data System (ADS)

    Thomas-Keprta, Kathie Louise

    "Why do we have such a longstanding fascination with Mars? Very simply put, it's about life. The search for life elsewhere in our Solar System has been a major driver for exploring Mars, pretty much since we began seriously looking at that planet."1 The major objective of this work is to describe signs of possible life, that is biosignatures, in rocks from Mars if indeed they are present. Biosignatures are specific identifiable properties that result from living things; they may be implanted in the environment and may persist even if the living thing is no longer present. Over 100 mineral biosignatures have been discussed in the literature; however, only one, magnetite, is addressed by this study. Magnetite is found in many rock types on earth and in meteorites. Previous studies of terrestrial magnetite have used few properties, such as size and chemical composition, to determine one of the modes of origins for magnetite (e.g., biogenic, inorganic). This study has established a rigorous set of six criteria for the identification of intracellularly precipitated biogenic magnetite. These criteria have been applied to a subpopulation of magnetites embedded within carbonates in Martian meteorite ALH84001. These magnetites are found to be chemically and physically indistinguishable from those produced by magnetotactic bacteria strain MV-1, hence, they were likely formed by biogenic processes on ancient Mars. These criteria may be also used to distinguish origins for magnetites from terrestrial samples with complex or unknown histories. The presence of purported past life on early Mars suggests that, if life once began it may still exist today, possibly in oases in the Martian subsurface. Future manned missions should consider potential hazards of an extant biological environment(s) on Mars. 1 Quote attributed to Jack Farmer of Arizona State University in discussing NASA's program of Mars Exploration (see "Deciphering Mars: Follow the Water," Astrobiology Magazine Sept

  13. Simultaneous ac and dc magnetic field measurements in residential areas: Implications for resonance theories of biological effects

    SciTech Connect

    Wong, P.S.; Sastre, A.

    1995-10-01

    The goal of this study was to obtain data that could be used to evaluate the applicability of ``resonance`` theories of biological effects in residential settings. The authors first describe a measurement system which allows the study of ac and dc magnetic fields simultaneously in space and in time. Sample measurements were taken near two power lines, two objects and in two residential homes. The results show that the earth`s (dc) magnetic field was unaffected near power lines. The compass orientation of the power line influenced the relative values of the ac components parallel and perpendicular to the dc field. The electric heating system greatly affected the ac field levels in the home, causing the levels to increase from less than 1 mG to a maximum of 7.5 mG during heating. The magnitudes of the dc field in the two homes varied from about 380 to 650 mG, with the larger variations near metallic or magnetic objects such as the refrigerator or a metallic air duct. The earth`s field was elevated above its natural level within a distance of 8 feet from a subcompact passenger car, e.g., the level changed from about 540 to 1,100 mG beside the headlight. A steel chair changed the earth`s field by up to 60 mG within a distance of one foot. These results suggest that some of the narrow ``resonances`` described in laboratory studies may be difficult to observe against the variations in do field amplitude and direction resulting from the presence of everyday metallic objects.

  14. Clustering amino acid contents of protein domains: biochemical functions of proteins and implications for origin of biological macromolecules.

    PubMed

    Torshin, I Y

    2001-04-01

    Structural classes of protein domains correlate with their amino acid compositions. Several successful algorithms (that use only amino acid composition) have been elaborated for the prediction of structural class or potential biochemical significance. This work deals with dynamic classification (clustering) of the domains on the basis of their amino acid composition. Amino acid contents of domains from a non-redundant PDB set were clustered in 20-dimensional space of amino acid contents. Despite the variations of an empirical parameter and non-redundancy of the set, only one large cluster (tens-hundreds of proteins) surrounded by hundreds of small clusters (1-5 proteins), was identified. The core of the largest cluster contains at least 64% DNA (nucleotide)-interacting protein domains from various sources. About 90% of the proteins of the core are intracellular proteins. 83% of the DNA/nucleotide interacting domains in the core belong to the mixed alpha-beta folds (a+b, a/b), 14% are all-alpha (mostly helices) and all-beta (mostly beta-strands) proteins. At the same time, when core domains that belong to one organism (E.coli) are considered, over 80% of them prove to be DNA/nucleotide interacting proteins. The core is compact: amino acid contents of domains from the core lie in relatively narrow and specific ranges. The core also contains several Fe-S cluster-binding domains, amino acid contents of the core overlap with ferredoxin and CO-dehydrogenase clusters, the oldest known proteins. As Fe-S clusters are thought to be the first biocatalysts, the results are discussed in relation to contemporary experiments and models dealing with the origin of biological macromolecules. The origin of most primordial proteins is considered here to be a result of co-adsorption of nucleotides and amino acids on specific clays, followed by en-block polymerization of the adsorbed mixtures of amino acids.

  15. Climate and Physical Disturbance Effects on the Spectral Signatures of Biological Soil Crusts: Implications for Future Dryland Energy Balance

    NASA Astrophysics Data System (ADS)

    Rutherford, W. A.; Flagg, C.; Painter, T. H.; Okin, G. S.; Belnap, J.; Reed, S.

    2014-12-01

    Drylands comprise ≈40% of the terrestrial Earth surface and observations suggest they can respond markedly to climate change. A vital component of dryland ecosystems are biological soil crusts (biocrusts) - a network of surface soil lichens, mosses, and cyanobacteria - that perform critical ecosystem functions, such as stabilizing soil and fixing carbon and nitrogen. Yet, our understanding of the role biocrusts play in dryland energy balance remains poor. Changes in climate can rapidly affect biocrust communities and we have long known that biocrusts respond dramatically to physical disturbance, such as human trampling and grazing animals. Associated changes in biocrust cover often result in increased bare soil; creating higher surface reflectance. We used spectral solar reflectance measurements in two manipulative experiments to compare the effects of climate and physical disturbance on biocrusts of the Colorado Plateau We measured reflectance at two heights: at crust surface and 1 m above. The climate disturbance site has four treatments: control, warming (4°C), altered precipitation, and warming plus altered precipitation. The physical disturbance site was trampled by foot annually since 1998. At the climate experiment, the largest change in reflectance was in the altered precipitation treatment (35% increase) at the surface-level, and the smallest difference was in the warmed (17% increase) at the meter-level. Physical disturbance differences were 10% at meter-level and 25% at surface-level. Unexpectedly, these results suggest that, via effects on biocrust communities, climate change could have a larger effect on dryland energy balance relative to physical disturbance, and result in more radiation from drylands returned to the atmosphere. Biocrusts cover large portions of the Earth's surface and, to our knowledge, these are the first data showing climate-induced changes to biocrust reflectance, with negative feedback in the global energy balance.

  16. Evidence for biogenic processes during formation of ferromanganese crusts from the Pacific Ocean: implications of biologically induced mineralization.

    PubMed

    Wang, Xiao-Hong; Schlossmacher, Ute; Natalio, Filipe; Schröder, Heinz C; Wolf, Stephan E; Tremel, Wolfgang; Müller, Werner E G

    2009-01-01

    Ferromanganese [Fe/Mn] crusts formed on basaltic seamounts, gain considerable economic importance due to their high content of Co, Ni, Cu, Zn and Pt. The deposits are predominantly found in the Pacific Ocean in depths of over 1000m. They are formed in the mixing layer between the upper oxygen-minimum zone and the lower oxygen-rich bottom zone. At present an almost exclusive abiogenic origin of crust formation is considered. We present evidence that the upper layers of the crusts from the Magellan Seamount cluster are very rich in coccoliths/coccolithophores (calcareous phytoplankton) belonging to different taxa. Rarely intact skeletons of these unicellular algae are found, while most of them are disintegrated into their composing prisms or crystals. Studies on the chemical composition of crust samples by high resolution SEM combined with an electron probe microanalyzer (EPMA) revealed that they are built of distinct stacked piles of individual compartments. In the center of such piles Mn is the dominant element, while the rims of the piles are rich in Fe (mineralization aspect). The compartments contain coccospheres usually at the basal part. Energy dispersive X-ray spectroscopy (EDX) analyses showed that those coccospheres contain, as expected, CaCO3 but also Mn-oxide. Detailed analysis displayed on the surface of the coccolithophores a high level of CaCO3 while the concentration of Mn-oxide is relatively small. With increasing distance from the coccolithophores the concentration of Mn-oxide increases on the expense of residual CaCO3. We conclude that coccoliths/coccolithophores are crucial for the seed/nucleation phase of crust formation (biomineralization aspect). Subsequently, after the biologically induced mineralization phase Mn-oxide deposition proceeds "auto"catalytically. PMID:19443230

  17. Carbon exchange in biological soil crust communities under differential temperatures and soil water contents: implications for global change

    USGS Publications Warehouse

    Grote, Edmund E.; Belnap, Jayne; Housman, David C.; Sparks, Jed P.

    2010-01-01

    Biological soil crusts (biocrusts) are an integral part of the soil system in arid regions worldwide, stabilizing soil surfaces, aiding vascular plant establishment, and are significant sources of ecosystem nitrogen and carbon. Hydration and temperature primarily control ecosystem CO2 flux in these systems. Using constructed mesocosms for incubations under controlled laboratory conditions, we examined the effect of temperature (5-35 1C) and water content (WC, 20-100%) on CO2 exchange in light cyanobacterially dominated) and dark cyanobacteria/lichen and moss dominated) biocrusts of the cool Colorado Plateau Desert in Utah and the hot Chihuahuan Desert in New Mexico. In light crusts from both Utah and New Mexico, net photosynthesis was highest at temperatures 430 1C. Net photosynthesis in light crusts from Utah was relatively insensitive to changes in soil moisture. In contrast, light crusts from New Mexico tended to exhibit higher rates of net photosynthesis at higher soil moisture. Dark crusts originating from both sites exhibited the greatest net photosynthesis at intermediate soil water content (40-60%). Declines in net photosynthesis were observed in dark crusts with crusts from Utah showing declines at temperatures 425 1C and those originating from New Mexico showing declines at temperatures 435 1C. Maximum net photosynthesis in all crust types from all locations were strongly influenced by offsets in the optimal temperature and water content for gross photosynthesis compared with dark respiration. Gross photosynthesis tended to be maximized at some intermediate value of temperature and water content and dark respiration tended to increase linearly. The results of this study suggest biocrusts are capable of CO2 exchange under a wide range of conditions. However, significant changes in the magnitude of this exchange should be expected for the temperature and precipitation changes suggested by current climate models.

  18. Evidence for biogenic processes during formation of ferromanganese crusts from the Pacific Ocean: implications of biologically induced mineralization.

    PubMed

    Wang, Xiao-Hong; Schlossmacher, Ute; Natalio, Filipe; Schröder, Heinz C; Wolf, Stephan E; Tremel, Wolfgang; Müller, Werner E G

    2009-01-01

    Ferromanganese [Fe/Mn] crusts formed on basaltic seamounts, gain considerable economic importance due to their high content of Co, Ni, Cu, Zn and Pt. The deposits are predominantly found in the Pacific Ocean in depths of over 1000m. They are formed in the mixing layer between the upper oxygen-minimum zone and the lower oxygen-rich bottom zone. At present an almost exclusive abiogenic origin of crust formation is considered. We present evidence that the upper layers of the crusts from the Magellan Seamount cluster are very rich in coccoliths/coccolithophores (calcareous phytoplankton) belonging to different taxa. Rarely intact skeletons of these unicellular algae are found, while most of them are disintegrated into their composing prisms or crystals. Studies on the chemical composition of crust samples by high resolution SEM combined with an electron probe microanalyzer (EPMA) revealed that they are built of distinct stacked piles of individual compartments. In the center of such piles Mn is the dominant element, while the rims of the piles are rich in Fe (mineralization aspect). The compartments contain coccospheres usually at the basal part. Energy dispersive X-ray spectroscopy (EDX) analyses showed that those coccospheres contain, as expected, CaCO3 but also Mn-oxide. Detailed analysis displayed on the surface of the coccolithophores a high level of CaCO3 while the concentration of Mn-oxide is relatively small. With increasing distance from the coccolithophores the concentration of Mn-oxide increases on the expense of residual CaCO3. We conclude that coccoliths/coccolithophores are crucial for the seed/nucleation phase of crust formation (biomineralization aspect). Subsequently, after the biologically induced mineralization phase Mn-oxide deposition proceeds "auto"catalytically.

  19. In situ biological resources: Soluble nutrients and electrolytes in carbonaceous asteroids/meteorites. Implications for astroecology and human space populations

    NASA Astrophysics Data System (ADS)

    Mautner, Michael N.

    2014-12-01

    Ecosystems in space will need in-situ bioavailable nutrients. The measured nutrients in meteorites allow experiment-based estimates of nutrients in asteroids, and of the biomass and populations that can be derived from these in situ bioresources. In this respect, we found that carbonaceous chondrite meteorites can support microorganisms and plant cultures, suggesting that similar asteroid materials are also biologically fertile. The sustainable biomass and populations are determined by the available resource materials, their yields of nutrients and biomass, the biomass needed to support human populations, the duration of the ecosystem, and wastage. The bioavailable C, N, and electrolytes in carbonaceous chondrite meteorites vary as CM2>CR2>CV3>CO3>CK4>CK5 in correlation with petrologic type, including aqueous alteration. Their average bioavailable C, N, K and P can yield 2.4, 3.5, 2.5, and 0.08 g biomass/kg resource material, respectively, showing phosphorus as the limiting nutrient. On this basis, soluble nutrients in a 100 km radius, 1019 kg resource asteroid can sustain an ecosystem of 108 kg biomass and a human population of 10,000 for >109 years, and its total nutrient contents can sustain a population of one million, by replacing a wastage of 1% of the biomass per year. Overall, the total nutrient contents of the 1022 kg carbonaceous asteroids can yield a biomass of 1020 kg that supports a steady-state human population of one billion during the habitable future of the Solar System, contributing a time-integrated biomass of 1022 kg-years. These astroecology estimates use experimental data on nutrients in asteroids/meteorites to quantify the sustainable biomass and human populations in this and similar solar systems.

  20. Bone lead as a new biologic marker of lead dose: recent findings and implications for public health.

    PubMed Central

    Hu, H

    1998-01-01

    Measurements of lead in bone have recently become the focus of research because a) bone lead levels serve as a cumulative dosimeter of lead exposure over many years (because of lead's long residence time in bone), and cumulative exposure may be more predictive of chronic toxicity than recent exposure, which is what blood lead levels mostly reflect; b) there is suspicion that heightened bone turnover (e.g. during pregnancy, lactation, and aging) may liberate enough stored lead to pose a significant threat of delayed toxicity; and c) although lead exposure has largely declined in the United States over the past 10 to 15 years, decades of heavy environmental pollution have resulted in significant accumulation of lead in bone among most members of the general U.S. population. Epidemiologic research on the impact of lead stored in bone is now possible with the development of 109Cd K-X-ray fluorescence (KXRF) instruments for the in vivo measurement of lead in bone. In this paper, the KXRF method will be briefly reviewed, followed by a summary of several Superfund-supported studies (and others) of blood lead and KXRF-measured bone lead in which these measures are compared as biologic markers of lead dose. Measurement of bone lead in epidemiologic studies has proved useful in exposure assessment studies, i.e., in identifying factors that contribute most to retained body lead burden, and in investigating cumulative lead exposure as a risk factor for poor health outcomes such as hypertension, kidney impairment, cognitive impairment, behavioral disturbances, and adverse reproductive outcomes. Images Figure 1 PMID:9703479

  1. Computational Fluid Dynamic Simulations of Maternal Circulation: Wall Shear Stress in the Human Placenta and Its Biological Implications

    PubMed Central

    Lecarpentier, E.; Bhatt, M.; Bertin, G. I.; Deloison, B.; Salomon, L. J.; Deloron, P.; Fournier, T.; Barakat, A. I.; Tsatsaris, V.

    2016-01-01

    Introduction In the human placenta the maternal blood circulates in the intervillous space (IVS). The syncytiotrophoblast (STB) is in direct contact with maternal blood. The wall shear stress (WSS) exerted by the maternal blood flow on the STB has not been evaluated. Our objective was to determine the physiological WSS exerted on the surface of the STB during the third trimester of pregnancy. Material and Methods To gain insight into the shear stress levels that the STB is expected to experience in vivo, we have formulated three different computational models of varying levels of complexity that reflect different physical representations of the IVS. Computations of the flow fields in all models were performed using the CFD module of the finite element code COMSOL Multiphysics 4.4. The mean velocity of maternal blood in the IVS during the third trimester was measured in vivo with dynamic MRI (0.94±0.14 mm.s-1). To investigate if the in silico results are consistent with physiological observations, we studied the cytoadhesion of human parasitized (Plasmodium falciparum) erythrocytes to primary human STB cultures, in flow conditions with different WSS values. Results The WSS applied to the STB is highly heterogeneous in the IVS. The estimated average values are relatively low (0.5±0.2 to 2.3±1.1 dyn.cm-2). The increase of WSS from 0.15 to 5 dyn.cm-2 was associated with a significant decrease of infected erythrocyte cytoadhesion. No cytoadhesion of infected erythrocytes was observed above 5 dyn.cm-2 applied for one hour. Conclusion Our study provides for the first time a WSS estimation in the maternal placental circulation. In spite of high maternal blood flow rates, the average WSS applied at the surface of the chorionic villi is low (<5 dyn.cm-2). These results provide the basis for future physiologically-relevant in vitro studies of the biological effects of WSS on the STB. PMID:26815115

  2. Long-term sea surface temperature baselines—time series, spatial covariation and implications for biological processes

    NASA Astrophysics Data System (ADS)

    MacKenzie, Brian R.; Schiedek, Doris

    2007-12-01

    affect perceptions of biological responses to temperature fluctuations. The documentation that the coastally measured temperatures co-vary with those measured opportunistically in offshore areas suggests that the coastal data, which have been measured daily using standardized methods and instruments, contain much of the variability seen at larger spatial scales. We conclude that both types of time series can facilitate assessments of how species and ecosystems have responded to past temperature changes and how they may react to future temperature changes.

  3. Biology and the Government

    ERIC Educational Resources Information Center

    Reid, Roger D.

    1969-01-01

    Emphasizes the social implications of biological knowledge and discusses two main government roles in biology: (1) a creative and supportive role, including support of education and research, (2) control, regulation and protection related to the applications of biological knowledge. Public control is considered necessary in areas such as food and…

  4. Bio-ISRU Concepts using microorganisms to release O2 and H2 on Moon and Mars

    NASA Astrophysics Data System (ADS)

    Slenzka, Klaus; Kempf, Juergen

    life support system embedded in a permanent Moon or Mars base. This method demonstrates a low energetic oxygen release, a serious alternative to high the energetic oxygen separation of the ilmenite process, fluorination process, melting hydrol-ysis, vacuum distillation or photo dissociation, respectively. Not only oxygen production of the biological processes should be in focus of space application. Also the metal oxide reducing component of the process might run batteries to provide energy to devices of a Moon or Mars base.

  5. Robotic Subsurface Analyzer and Sample Handler for Resource Reconnaissance and Preliminary Site Assessment for ISRU Activities at the Lunar Cold Traps

    NASA Technical Reports Server (NTRS)

    Gorevan, S. P.; Wilson, J.; Bartlett, P.; Powderly, J.; Lawrence, D.; Elphic, R.; Mungas, G.; McCullough, E.; Stoker, C.; Cannon, H.

    2004-01-01

    Since the 1960s, claims have been made that water ice deposits should exist in permanently shadowed craters near both lunar poles. Recent interpretations of data from the Lunar Prospector-Neutron Spectrometer (LP- NS) confirm that significant concentrations of hydrogen exist, probably in the form of water ice, in the permanently shadowed polar cold traps. Yet, due to the large spatial resolution (45-60 Ian) of the LP-NS measurements relative to these shadowed craters (approx.5-25 km), these data offer little certainty regarding the precise location, form or distribution of these deposits. Even less is known about how such deposits of water ice might effect lunar regolith physical properties relevant to mining, excavation, water extraction and construction. These uncertainties will need to be addressed in order to validate fundamental lunar In Situ Resource Utilization (ISRU) precepts by 2011. Given the importance of the in situ utilization of water and other resources to the future of space exploration a need arises for the advanced deployment of a robotic and reconfigurable system for physical properties and resource reconnaissance. Based on a collection of high-TRL. designs, the Subsurface Analyzer and Sample Handler (SASH) addresses these needs, particularly determining the location and form of water ice and the physical properties of regolith. SASH would be capable of: (1) subsurface access via drilling, on the order of 3-10 meters into both competent targets (ice, rock) and regolith, (2) down-hole analysis through drill string embedded instrumentation and sensors (Neutron Spectrometer and Microscopic Imager), enabling water ice identification and physical properties measurements; (3) core and unconsolidated sample acquisition from rock and regolith; (4) sample handling and processing, with minimized contamination, sample containerization and delivery to a modular instrument payload. This system would be designed with three mission enabling goals, including: (1

  6. Characterization and reactivity of the weakly bound complexes of the [H, N, S]{sup −} anionic system with astrophysical and biological implications

    SciTech Connect

    Trabelsi, T.; Ajili, Y.; Ben Yaghlane, S.; Jaidane, N.-E.; Mogren Al-Mogren, M.; Francisco, J. S.; Hochlaf, M.

    2015-07-21

    We investigate the lowest electronic states of doublet and quartet spin multiplicity states of HNS{sup −} and HSN{sup −} together with their parent neutral triatomic molecules. Computations were performed using highly accurate ab initio methods with a large basis set. One-dimensional cuts of the full-dimensional potential energy surfaces (PESs) along the interatomic distances and bending angle are presented for each isomer. Results show that the ground anionic states are stable with respect to the electron detachment process and that the long range parts of the PESs correlating to the SH{sup −} + N, SN{sup −} + H, SN + H{sup −}, NH + S{sup −}, and NH{sup −} + S are bound. In addition, we predict the existence of long-lived weakly bound anionic complexes that can be formed after cold collisions between SN{sup −} and H or SH{sup −} and N. The implications for the reactivity of these species are discussed; specifically, it is shown that the reactions involving SH{sup −}, SN{sup −}, and NH{sup −} lead either to the formation of HNS{sup −} or HSN{sup −} in their electronic ground states or to autodetachment processes. Thus, providing an explanation for why the anions, SH{sup −}, SN{sup −}, and NH{sup −}, have limiting detectability in astrophysical media despite the observation of their corresponding neutral species. In a biological context, we suggest that HSN{sup −} and HNS{sup −} should be incorporated into H{sub 2}S-assisted heme-catalyzed reduction mechanism of nitrites in vivo.

  7. Using Course Syllabi to Assess Research Expectations of Biology Majors: Implications for Further Development of Information Literacy Skills in the Curriculum

    ERIC Educational Resources Information Center

    Dinkelman, Andrea L.

    2010-01-01

    This article describes an analysis of course syllabi from selected courses in the biology curriculum at Iowa State University. The purpose of this research was to learn about the numbers and types of information literacy assignments given to students majoring in biology. Overall, the most common assignment type for biology majors was a lab report…

  8. Openness to and preference for attributes of biologic therapy prior to initiation among patients with rheumatoid arthritis: patient and rheumatologist perspectives and implications for decision making

    PubMed Central

    Bolge, Susan C; Goren, Amir; Brown, Duncan; Ginsberg, Seth; Allen, Isabel

    2016-01-01

    Purpose Despite American College of Rheumatology recommendations, appropriate and timely initiation of biologic therapies does not always occur. This study examined openness to and preference for attributes of biologic therapies among patients with rheumatoid arthritis (RA), differences in patients’ and rheumatologists’ perceptions, and discussions around biologic therapy initiation. Patients and methods A self-administered online survey was completed by 243 adult patients with RA in the US who were taking disease-modifying antirheumatic drugs (DMARDs) and had never taken, but had discussed biologic therapy with a rheumatologist. Patients were recruited from a consumer panel (n=142) and patient advocacy organization (n=101). A separate survey was completed by 103 rheumatologists who treated at least 25 patients with RA per month with biologic therapy. Descriptive and bivariate analyses were conducted separately for patients and rheumatologists. Attributes of biologic therapy included route of administration (intravenous infusion or subcutaneous injection), frequency of injections/infusions, and duration of infusion. Results Over half of patients (53.1%) were open to both intravenous infusion and subcutaneous injection, whereas rheumatologists reported 40.7% of patients would be open to both. Only 26.3% of patients strongly preferred subcutaneous injection, whereas rheumatologists reported 35.2%. Discrepancies were even more pronounced among specific patient types (eg, older vs younger patients and Medicare recipients). Among patients, 23% reported initiating discussion about biologics and 54% reported their rheumatologist initiated the discussion. A majority of rheumatologists reported discussing in detail several key aspects of biologics, whereas a minority of patients reported the same. Conclusion Preferences differed among patients with RA from rheumatologists’ perceptions of these preferences for biologic therapy, including greater openness to intravenous

  9. Responses of an idiobiont ectoparasitoid, Spathius galinae, to host larvae parasitized by the koinobiont endoparasitoid Tetrastichus planipennisi: implications for biological control of emerald ash borer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding interspecific competition among insect parasitoids is important in designing classical biological control programs that involve multiple species introductions. Spathius galinae, a new idiobiont ectoparasitoid from the Russian Far East, is currently being considered for introduction to ...

  10. Multiparasitism by Tetrastichus planipennisi (Hymenoptera: Eulophidae) and Spathius agrili (Hymenoptera:Braconidae): Implication for biological control of the Emerald Ash Borer (Coleoptera: Buprestidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interspecific competition among different species of insect parasitoids may affect the establishment or efficacies of these species in biological control of targeted pests. The endoparasitoid Tetrastichus planipennisi Yang and the ectoparasitoid Spathius agrili Yang, two gregarious larval parasito...

  11. Mating disruption by aerial application of sex pheromone against the invasive light brown apple moth and implications for the management of biological invasions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biological invasions resulting from international trade can have major ecological and economic impacts. Eradication can be a viable strategy during the early stage of an invasion but there is a need for the development of suitable tactics that are both effective and have minimal non-target effects. ...

  12. Population Genomics and the Statistical Values of Race: An Interdisciplinary Perspective on the Biological Classification of Human Populations and Implications for Clinical Genetic Epidemiological Research.

    PubMed

    Maglo, Koffi N; Mersha, Tesfaye B; Martin, Lisa J

    2016-01-01

    The biological status and biomedical significance of the concept of race as applied to humans continue to be contentious issues despite the use of advanced statistical and clustering methods to determine continental ancestry. It is thus imperative for researchers to understand the limitations as well as potential uses of the concept of race in biology and biomedicine. This paper deals with the theoretical assumptions behind cluster analysis in human population genomics. Adopting an interdisciplinary approach, it demonstrates that the hypothesis that attributes the clustering of human populations to "frictional" effects of landform barriers at continental boundaries is empirically incoherent. It then contrasts the scientific status of the "cluster" and "cline" constructs in human population genomics, and shows how cluster may be instrumentally produced. It also shows how statistical values of race vindicate Darwin's argument that race is evolutionarily meaningless. Finally, the paper explains why, due to spatiotemporal parameters, evolutionary forces, and socio-cultural factors influencing population structure, continental ancestry may be pragmatically relevant to global and public health genomics. Overall, this work demonstrates that, from a biological systematic and evolutionary taxonomical perspective, human races/continental groups or clusters have no natural meaning or objective biological reality. In fact, the utility of racial categorizations in research and in clinics can be explained by spatiotemporal parameters, socio-cultural factors, and evolutionary forces affecting disease causation and treatment response. PMID:26925096

  13. Population Genomics and the Statistical Values of Race: An Interdisciplinary Perspective on the Biological Classification of Human Populations and Implications for Clinical Genetic Epidemiological Research

    PubMed Central

    Maglo, Koffi N.; Mersha, Tesfaye B.; Martin, Lisa J.

    2016-01-01

    The biological status and biomedical significance of the concept of race as applied to humans continue to be contentious issues despite the use of advanced statistical and clustering methods to determine continental ancestry. It is thus imperative for researchers to understand the limitations as well as potential uses of the concept of race in biology and biomedicine. This paper deals with the theoretical assumptions behind cluster analysis in human population genomics. Adopting an interdisciplinary approach, it demonstrates that the hypothesis that attributes the clustering of human populations to “frictional” effects of landform barriers at continental boundaries is empirically incoherent. It then contrasts the scientific status of the “cluster” and “cline” constructs in human population genomics, and shows how cluster may be instrumentally produced. It also shows how statistical values of race vindicate Darwin's argument that race is evolutionarily meaningless. Finally, the paper explains why, due to spatiotemporal parameters, evolutionary forces, and socio-cultural factors influencing population structure, continental ancestry may be pragmatically relevant to global and public health genomics. Overall, this work demonstrates that, from a biological systematic and evolutionary taxonomical perspective, human races/continental groups or clusters have no natural meaning or objective biological reality. In fact, the utility of racial categorizations in research and in clinics can be explained by spatiotemporal parameters, socio-cultural factors, and evolutionary forces affecting disease causation and treatment response. PMID:26925096

  14. Trade-offs in parasitism efficiency and brood size mediate parasitoid coexistence, with implications for biological control of the invasive emerald ash borer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parasitoids often are selected for use as biological control agents because of their high host specificity, yet such host specificity can result in strong interspecific competition. However, few studies have examined if and how various extrinsic factors (such as parasitism efficiency) influence the ...

  15. Microbial Mats in the Tswaing Impact Crater: Results of a South African Exobiology Expedition and Implications for the Search for Biological Molecules on Mars

    NASA Technical Reports Server (NTRS)

    Cockell, C. S.; Brandt, D.; Hand, K.; Lee, P. C.

    2001-01-01

    We describe microbial mats from the Tswaing impact crater in South Africa. The mats provide insights into the unique biological characteristics of impact craters and can help strategies for the search for biomolecules on Mars. Additional information is contained in the original extended abstract.

  16. The dynamic range of biologic functions and variation of many environmental cues may be declining in the modern age: implications for diseases and therapeutics.

    PubMed

    Yun, Anthony J; Bazar, Kimberly A; Gerber, Anthony; Lee, Patrick Y; Daniel, Stephanie M

    2005-01-01

    We hypothesize that declining dynamic range and variation of environmental cues may contribute to health dysfunctions, and that judicious expansion of biologic dynamic ranges may be beneficial. Three disparate examples involving the endocrine, autonomic, and musculoskeletal systems are discussed. Daytime sheltering, optical shading, and nighttime use of artificial light may reduce circadian luminal variation. The resulting melatonin alterations may contribute to systemic dysfunctions. Loss of temporal variation of other hormones may contribute to biologic dysfunctions, especially those involving the hypothalamic-pituitary axis. Reduced variation of physical exertion, environmental stressors, and thermal gradients that characterize modern lifestyles may reduce the autonomic dynamic range resulting in lowered heart rate variability and a myriad of systemic dysfunctions. The health benefits of activities such as exercise, meditation, acupuncture, coitus, and laughter may operate through increasing autonomic variability. Reduced physical exertion also accounts for declining dynamic range of musculoskeletal function. The resulting muscle atrophy, fat infiltration, and sarcomere shortening may not only have deleterious local effects, but may also be involved in systemic metabolic dysfunctions such as insulin resistance. The extent to which our endogenous systems rely on environmental variation for self-tuning and the impact that under-utilization of compensatory mechanisms has on biologic function are not well understood. Modern therapeutic approaches generally result in reversion to the mean of physiologic functions and may buffer against variation. For example, beta-blockers are given to reduce adrenergic excess, insulin to treat insulin insufficiency, serotonin-reuptake inhibitors for depression, and refractive lenses for myopia. By undermining the demand for native compensatory functions, such therapeutic strategies may actually impair future ability to respond to

  17. The influence of the biological pump on ocean chemistry: implications for long-term trends in marine redox chemistry, the global carbon cycle, and marine animal ecosystems.

    PubMed

    Meyer, K M; Ridgwell, A; Payne, J L

    2016-05-01

    The net export of organic matter from the surface ocean and its respiration at depth create vertical gradients in nutrient and oxygen availability that play a primary role in structuring marine ecosystems. Changes in the properties of this 'biological pump' have been hypothesized to account for important shifts in marine ecosystem structure, including the Cambrian explosion. However, the influence of variation in the behavior of the biological pump on ocean biogeochemistry remains poorly quantified, preventing any detailed exploration of how changes in the biological pump over geological time may have shaped long-term shifts in ocean chemistry, biogeochemical cycling, and ecosystem structure. Here, we use a 3-dimensional Earth system model of intermediate complexity to quantitatively explore the effects of the biological pump on marine chemistry. We find that when respiration of sinking organic matter is efficient, due to slower sinking or higher respiration rates, anoxia tends to be more prevalent and to occur in shallower waters. Consequently, the Phanerozoic trend toward less bottom-water anoxia in continental shelf settings can potentially be explained by a change in the spatial dynamics of nutrient cycling rather than by any change in the ocean phosphate inventory. The model results further suggest that the Phanerozoic decline in the prevalence ocean anoxia is, in part, a consequence of the evolution of larger phytoplankton, many of which produce mineralized tests. We hypothesize that the Phanerozoic trend toward greater animal abundance and metabolic demand was driven more by increased oxygen concentrations in shelf environments than by greater food (nutrient) availability. In fact, a lower-than-modern ocean phosphate inventory in our closed system model is unable to account for the Paleozoic prevalence of bottom-water anoxia. Overall, these model simulations suggest that the changing spatial distribution of photosynthesis and respiration in the oceans has

  18. The influence of the biological pump on ocean chemistry: implications for long-term trends in marine redox chemistry, the global carbon cycle, and marine animal ecosystems.

    PubMed

    Meyer, K M; Ridgwell, A; Payne, J L

    2016-05-01

    The net export of organic matter from the surface ocean and its respiration at depth create vertical gradients in nutrient and oxygen availability that play a primary role in structuring marine ecosystems. Changes in the properties of this 'biological pump' have been hypothesized to account for important shifts in marine ecosystem structure, including the Cambrian explosion. However, the influence of variation in the behavior of the biological pump on ocean biogeochemistry remains poorly quantified, preventing any detailed exploration of how changes in the biological pump over geological time may have shaped long-term shifts in ocean chemistry, biogeochemical cycling, and ecosystem structure. Here, we use a 3-dimensional Earth system model of intermediate complexity to quantitatively explore the effects of the biological pump on marine chemistry. We find that when respiration of sinking organic matter is efficient, due to slower sinking or higher respiration rates, anoxia tends to be more prevalent and to occur in shallower waters. Consequently, the Phanerozoic trend toward less bottom-water anoxia in continental shelf settings can potentially be explained by a change in the spatial dynamics of nutrient cycling rather than by any change in the ocean phosphate inventory. The model results further suggest that the Phanerozoic decline in the prevalence ocean anoxia is, in part, a consequence of the evolution of larger phytoplankton, many of which produce mineralized tests. We hypothesize that the Phanerozoic trend toward greater animal abundance and metabolic demand was driven more by increased oxygen concentrations in shelf environments than by greater food (nutrient) availability. In fact, a lower-than-modern ocean phosphate inventory in our closed system model is unable to account for the Paleozoic prevalence of bottom-water anoxia. Overall, these model simulations suggest that the changing spatial distribution of photosynthesis and respiration in the oceans has

  19. [Do the glutamate excitotoxicity theory and potential free radicals implication in schizophrenia aetiopathogenesis provide a new enlightenment to links between: genome, environment and biology in the determinism of that disorder?].

    PubMed

    Nguimfack Mbodie, P C

    2002-01-01

    The aetiopathogenesis of schizophrenia constitutes nowadays one of the major points of interest for researchers on this cosmopolitan disorder which involves about 1% of the world population and which significantly alters the social functioning of the individual. Numerous studies have focused on the role played by genome, environmental factors and biology in the development of symptoms. The neurodevelopmental theory is an illustration with the perinatal period considered as the main provider of environmental factors (hypertension, infections, bleedings during pregnancy, acute and chronic fetal distress.). Many authors found significant associations between such factors, the occurrence of brain lesions and finally schizophrenic symptoms. Although no convincing genetic model had been established to date for schizophrenia, nevertheless it appears that a predisposition not inheritable under the mendelian mode exists and authors showed that disease gets more and more severe over schizophrenic descendants. The risk to be schizophrenic being a first degree relative of the schizophrenic person is about ten time superior than in general population. Indeed, this risk is also about ten time superior in biological parents of schizophrenic adoptees than in biological parents of healthy adoptees. Studies done in monozygotic comparing to dizygotic twins are in favour of an important role played by genetic factors more than socioeducational or psychological factors. Concerning biology, the dopaminergic hypothesis remains shared by numerous authors although direct links with incriminated factors are not well established. Now is suspected the glutamate excitotoxicity with implication of free radicals in schizophrenia. These free radicals are products of various enzymatic activations led by overstimulation of post synaptic receptors (NMDA and AMPA) by the excess glutamate. Therefore, according to that concept, some amino acids as glutamate and derivatives could have through free

  20. Depth of the biologically active zone in upland habitats at the Hanford Site, Washington: Implications for remediation and ecological risk management.

    PubMed

    Sample, Bradley E; Lowe, John; Seeley, Paul; Markin, Melanie; McCarthy, Chris; Hansen, Jim; Aly, Alaa H

    2015-01-01

    Soil invertebrates, mammals, and plants penetrate and exploit the surface soil layer (i.e., the biologically active zone) to varying depths. As the US Department of Energy remediates radioactive and hazardous wastes in soil at the Hanford Site, a site-specific definition of the biologically active zone is needed to identify the depth to which remedial actions should be taken to protect the environment and avoid excessive cleanup expenditures. This definition may then be considered in developing a point of compliance for remediation in accordance with existing regulations. Under the State of Washington Model Toxic Control Act (MTCA), the standard point of compliance for soil cleanup levels with unrestricted land use is 457 cm (15 ft) below ground surface. When institutional controls are required to control excavations to protect people, MTCA allows a conditional point of compliance to protect biological resources based on the depth of the biologically active zone. This study was undertaken to identify and bound the biologically active zone based on ecological resources present at the Hanford Site. Primary data were identified describing the depths to which ants, mammals, and plants may exploit the surface soil column at the Hanford Site and other comparable locations. The maximum depth observed for harvester ants (Pogonomyrmex spp.) was 270 cm (8.9 ft), with only trivial excavation below 244 cm (8 ft). Badgers (Taxidea taxus) are the deepest burrowing mammal at the Hanford Site, with maximum burrow depths of 230 cm (7.6 ft); all other mammals did not burrow below 122 cm (4 ft). Shrubs are the deepest rooting plants with rooting depths to 300 cm (9.8 ft) for antelope bitterbrush (Purshia tridentata). The 2 most abundant shrub species did not have roots deeper than 250 cm (8.2 ft). The deepest rooted forb had a maximum root depth of 240 cm (7.9 ft). All other forbs and grasses had rooting depths of 200 cm (6.6 ft) or less. These data indicate that the biologically

  1. Depth of the biologically active zone in upland habitats at the Hanford Site, Washington: Implications for remediation and ecological risk management.

    PubMed

    Sample, Bradley E; Lowe, John; Seeley, Paul; Markin, Melanie; McCarthy, Chris; Hansen, Jim; Aly, Alaa H

    2015-01-01

    Soil invertebrates, mammals, and plants penetrate and exploit the surface soil layer (i.e., the biologically active zone) to varying depths. As the US Department of Energy remediates radioactive and hazardous wastes in soil at the Hanford Site, a site-specific definition of the biologically active zone is needed to identify the depth to which remedial actions should be taken to protect the environment and avoid excessive cleanup expenditures. This definition may then be considered in developing a point of compliance for remediation in accordance with existing regulations. Under the State of Washington Model Toxic Control Act (MTCA), the standard point of compliance for soil cleanup levels with unrestricted land use is 457 cm (15 ft) below ground surface. When institutional controls are required to control excavations to protect people, MTCA allows a conditional point of compliance to protect biological resources based on the depth of the biologically active zone. This study was undertaken to identify and bound the biologically active zone based on ecological resources present at the Hanford Site. Primary data were identified describing the depths to which ants, mammals, and plants may exploit the surface soil column at the Hanford Site and other comparable locations. The maximum depth observed for harvester ants (Pogonomyrmex spp.) was 270 cm (8.9 ft), with only trivial excavation below 244 cm (8 ft). Badgers (Taxidea taxus) are the deepest burrowing mammal at the Hanford Site, with maximum burrow depths of 230 cm (7.6 ft); all other mammals did not burrow below 122 cm (4 ft). Shrubs are the deepest rooting plants with rooting depths to 300 cm (9.8 ft) for antelope bitterbrush (Purshia tridentata). The 2 most abundant shrub species did not have roots deeper than 250 cm (8.2 ft). The deepest rooted forb had a maximum root depth of 240 cm (7.9 ft). All other forbs and grasses had rooting depths of 200 cm (6.6 ft) or less. These data indicate that the biologically

  2. Biological Threats

    MedlinePlus

    ... Thunderstorms & Lightning Tornadoes Tsunamis Volcanoes Wildfires Main Content Biological Threats Biological agents are organisms or toxins that ... Centers for Disease Control and Prevention . Before a Biological Threat Unlike an explosion, a biological attack may ...

  3. Examining the reproducibility of stable isotope ratios in the marine bivalve, Astarte borealis, from populations in the White Sea, Russia: implications for biological consequences of climate change

    NASA Astrophysics Data System (ADS)

    McNabb, Justin; Surge, Donna

    2015-04-01

    Shells of the marine bivalve, Astarte, are uniquely suited to investigate links between environmental/climate change and biological consequences because of their change in size and biogeographic distribution through time. For example, are there corresponding changes in lifespan and biogeographic distribution depending on warm vs. cold climate states? Does warm vs. cold climate state result in longer or shorter lifespans? Early studies of Astarte have documented a decrease in shell size through geologic time. Modern specimens are much smaller than those from the mid Pliocene at similar latitudes. Astarte had a wide latitudinal and cosmopolitan distribution in the western North Atlantic during the Oligocene to Pliocene. During the early Pleistocene, most of the warm-water species became extinct, and today, their biogeographic distribution is mostly restricted to the northern Pacific, Atlantic, and Arctic Oceans. To answer questions linking biological consequences and climate change, we must first decipher ontogenetic changes in shell growth of modern specimens. Preliminary data using isotope sclerochronology identified slowed shell growth from late summer to winter in modern specimens from the White Sea, Russia, possibly triggered by increasing freshwater input and decreasing temperatures. Here, we present new data examining the reproducibility of isotopic time series and season of slowed growth among modern individuals collected at the same time from the same population.

  4. VERTEX: biological implications of total attenuation and chlorophyll and phycoerythrin fluorescence distributions along a 2000 m deep section in the Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Broenkow, William W.; Yuen, Marilyn A.; Yarbrough, Mark A.

    1992-04-01

    A 2000 m deep section of total attenuation and chlorophyll and phycoerythrin fluorescence from 26° to 59°N latitude in the northeast Pacific is discussed in terms of inferred biological processes. Photic zone distributions of these quantities vary from nutrient-limited conditions in the subtropics to light-limited conditions in the subarctic. Phycoerythrin-containing organisms, probably Synechococcus, contribute to a strong, near-surface orange fluorescence signal in the Gulf of Alaska. We now recognize that the fluorescence minimum (about 300 m) between the photic zone and the tertiary fluorescence maximum may be related to secondary producers that "repackage" organic matter produced in the photic zone. The tertiary fluorescence maximum (about 1000 m) is a continuous feature of the oxygen minimum zone in the North Pacific. The presence of phycoerythrin in the tertiary maximum is consistent with heterotrophic cyanobacteria and other unidentified microbial assemblages in the oxygen minimum, though there is no strong biological evidence that this is true.

  5. Development of garlic bioactive compounds analytical methodology based on liquid phase microextraction using response surface design. Implications for dual analysis: Cooked and biological fluids samples.

    PubMed

    Ramirez, Daniela Andrea; Locatelli, Daniela Ana; Torres-Palazzolo, Carolina Andrea; Altamirano, Jorgelina Cecilia; Camargo, Alejandra Beatriz

    2017-01-15

    Organosulphur compounds (OSCs) present in garlic (Allium sativum L.) are responsible of several biological properties. Functional foods researches indicate the importance of quantifying these compounds in food matrices and biological fluids. For this purpose, this paper introduces a novel methodology based on dispersive liquid-liquid microextraction (DLLME) coupled to high performance liquid chromatography with ultraviolet detector (HPLC-UV) for the extraction and determination of organosulphur compounds in different matrices. The target analytes were allicin, (E)- and (Z)-ajoene, 2-vinyl-4H-1,2-dithiin (2-VD), diallyl sulphide (DAS) and diallyl disulphide (DADS). The microextraction technique was optimized using an experimental design, and the analytical performance was evaluated under optimum conditions. The desirability function presented an optimal value for 600μL of chloroform as extraction solvent using acetonitrile as dispersant. The method proved to be reliable, precise and accurate. It was successfully applied to determine OSCs in cooked garlic samples as well as blood plasma and digestive fluids. PMID:27542503

  6. Photoisomerization of antiaggregation pheromone verbenone: Biological and practical implications with respect to the mountain pine beetle,Dendroctonus ponderosae Hopkins (Coleoptera: Scolytidae).

    PubMed

    Kostyk, B C; Borden, J H; Gries, G

    1993-08-01

    Release of the antiaggregation pheromone, verbenone, at 3.8 mg/ day from a concentrated source within a multiple-funnel trap completely inhibited response by the mountain pine beetle (MPB),Dendroctonus ponderosae Hopkins, to attractive semiochemical lures. When aerial applications were simulated and verbenone was released at the same rate from beads lying in a 2×2-m area on the forest floor 15-35 cm below a trap, the response of the MPB was inhibited by only 50%. This reduced inhibition may be explained in part by the photoisomerism of verbenone. When exposed to full sunlight on two occasions, the times required for 50% of verbenone vapors to be converted to chrysanthenone were 75 and 100 min, respectively. Trap and tree-baiting experiments indicated no biological activity of chrysanthenone. Rapid photoisomerization could reduce the concentration of verbenone below biologically active levels and would allow the MPB to colonize trees close to already occupied hosts, contributing to the characteristic clumped distribution of MPB attack. The rate of verbenone photoisomerization may vary according to geographic location, stand elevation and density, and should be considered before verbenone is applied to control the MPB and other bark beetles.

  7. Development of garlic bioactive compounds analytical methodology based on liquid phase microextraction using response surface design. Implications for dual analysis: Cooked and biological fluids samples.

    PubMed

    Ramirez, Daniela Andrea; Locatelli, Daniela Ana; Torres-Palazzolo, Carolina Andrea; Altamirano, Jorgelina Cecilia; Camargo, Alejandra Beatriz

    2017-01-15

    Organosulphur compounds (OSCs) present in garlic (Allium sativum L.) are responsible of several biological properties. Functional foods researches indicate the importance of quantifying these compounds in food matrices and biological fluids. For this purpose, this paper introduces a novel methodology based on dispersive liquid-liquid microextraction (DLLME) coupled to high performance liquid chromatography with ultraviolet detector (HPLC-UV) for the extraction and determination of organosulphur compounds in different matrices. The target analytes were allicin, (E)- and (Z)-ajoene, 2-vinyl-4H-1,2-dithiin (2-VD), diallyl sulphide (DAS) and diallyl disulphide (DADS). The microextraction technique was optimized using an experimental design, and the analytical performance was evaluated under optimum conditions. The desirability function presented an optimal value for 600μL of chloroform as extraction solvent using acetonitrile as dispersant. The method proved to be reliable, precise and accurate. It was successfully applied to determine OSCs in cooked garlic samples as well as blood plasma and digestive fluids.

  8. Cold shock: biological implications and a method for approximating transient environmental temperatures in the near-field region of a thermal discharge.

    PubMed

    Pilati, D A

    1976-11-01

    Biological data on the temperature preferences of fish indicate that, in general, they will be attracted to thermal discharges in the winter. This attraction to warmer temperatures increases their vulnerability to cold shock if the discharge heat source is discontinued. A scheme is proposed to predict the near-field thermal plume environmental temperatures during a power transient. This method can be applied to any jet discharge for which a steady-state model exists. The proposed transient model has been applied to an operating reactor. The predicted results illustrate how very rapidly the maximum temperatures decrease after an abrupt shutdown. This model can be employed to help assess the impact where cold shock may be a problem. Such predictions could also be the basis for restrictions on scheduled midwinter plant shutdowns.

  9. Evaluation of biological endpoints in crop plants after exposure to non-steroidal anti-inflammatory drugs (NSAIDs): implications for phytotoxicological assessment of novel contaminants.

    PubMed

    Schmidt, Wiebke; Redshaw, Clare H

    2015-02-01

    Human pharmaceuticals have been detected in the terrestrial environment at µg to mg kg(-1) concentrations. Repeated application of sewage sludge (biosolids) and increasing reclaimed wastewater use for irrigation could lead to accumulation of these novel contaminants in soil systems. Despite this, potential phytotoxicological effects on higher plants have rarely been evaluated. These studies aimed to test effects upon germination, development, growth and physiology of two crop plants, namely radish (Raphanus sativus Spakler 3) and lettuce (Lactuca sativa All Year Around), after exposure to different, but structurally related non-steroidal anti-inflammatory drugs (NSAIDs) at environmentally relevant concentrations. A range of biological endpoints comprising biomass, length, water content, specific root and shoot length, root to shoot ratio, daily progress of stages of cell elongation and organ emergence (primary root, hypocotyl elongation, cotyledon emergence, cotyledon opening, and no change), as well as photosynthetic measurements were evaluated. Compounds from the fenamic acid class were found to affect R. sativus root endpoints (root length and water content), while ibuprofen affected early root development of L. sativa. In general, phytotoxicological effects on root endpoints demonstrated that impacts upon higher plants are not only compound specific, but also differ between plant species. It was found that the usage of a wide range of biological endpoints (all simple, cost-effective and ecologically relevant) were beneficial in detecting differences in plant responses to NSAID exposure. Due to paucity and discrepancy within the few previously available phytotoxicological studies with pharmaceuticals, it is now essential to allocate time and resources to consider development of suitable chronic toxicity tests, and some suggestions regarding this are presented. PMID:25463873

  10. Surface polyethylene glycol conformation influences the protein corona of polyethylene glycol-modified single-walled carbon nanotubes: potential implications on biological performance.

    PubMed

    Sacchetti, Cristiano; Motamedchaboki, Khatereh; Magrini, Andrea; Palmieri, Graziana; Mattei, Maurizio; Bernardini, Sergio; Rosato, Nicola; Bottini, Nunzio; Bottini, Massimo

    2013-03-26

    Investigation of the nanoparticle protein corona, the shell of plasma proteins formed around nanoparticles immediately after they enter the bloodstream, is a benchmark in the study of the applications of nanoparticles in all fields of medicine, from pharmacology to toxicology. We report the first investigation of the protein corona adsorbed onto single-walled carbon nanotubes modified with 2 kDa molecular weight polyethylene glycol chains [PEG(2k)-modified SWCNTs or PEG2-SWCNTs] by using a large-scale gel-based proteomics method on biological replicates. More than 240 plasma proteins were selected, and their differences were analyzed among PEG2-SWCNTs differing in surface charge and PEG conformation. The protein corona of PEG2-SWCNTs showed that coagulation proteins, immunoglobulins, apolipoproteins, and proteins of the complement system were among the proteins bound by PEG2-SWCNTs and that their recruitment was independent from the isoelectric point, molecular weight, total hydrophobicity, and number of polyaromatic residues of the proteins. Statistical analysis on protein relative abundance revealed that PEG conformation had a higher influence on the PEG2-SWCNTs' protein corona repertoire than nanotube surface charge. PEG conformation also affected the biological performance of PEG2-SWCNTs. A change in PEG conformation from mushroom to mushroom-brush transition affected the competitive adsorption of the major constituents of the protein corona of PEG2-SWCNTs and promoted shorter blood circulation time, faster renal excretion, and higher relative spleen versus liver uptake of PEG2-SWCNTs. Our data suggest that the protein corona, along with steric stabilization, may mediate the action of PEG conformation on the pharmacokinetic profile of PEG-modified SWCNTs. PMID:23413928

  11. Evaluation of biological endpoints in crop plants after exposure to non-steroidal anti-inflammatory drugs (NSAIDs): implications for phytotoxicological assessment of novel contaminants.

    PubMed

    Schmidt, Wiebke; Redshaw, Clare H

    2015-02-01

    Human pharmaceuticals have been detected in the terrestrial environment at µg to mg kg(-1) concentrations. Repeated application of sewage sludge (biosolids) and increasing reclaimed wastewater use for irrigation could lead to accumulation of these novel contaminants in soil systems. Despite this, potential phytotoxicological effects on higher plants have rarely been evaluated. These studies aimed to test effects upon germination, development, growth and physiology of two crop plants, namely radish (Raphanus sativus Spakler 3) and lettuce (Lactuca sativa All Year Around), after exposure to different, but structurally related non-steroidal anti-inflammatory drugs (NSAIDs) at environmentally relevant concentrations. A range of biological endpoints comprising biomass, length, water content, specific root and shoot length, root to shoot ratio, daily progress of stages of cell elongation and organ emergence (primary root, hypocotyl elongation, cotyledon emergence, cotyledon opening, and no change), as well as photosynthetic measurements were evaluated. Compounds from the fenamic acid class were found to affect R. sativus root endpoints (root length and water content), while ibuprofen affected early root development of L. sativa. In general, phytotoxicological effects on root endpoints demonstrated that impacts upon higher plants are not only compound specific, but also differ between plant species. It was found that the usage of a wide range of biological endpoints (all simple, cost-effective and ecologically relevant) were beneficial in detecting differences in plant responses to NSAID exposure. Due to paucity and discrepancy within the few previously available phytotoxicological studies with pharmaceuticals, it is now essential to allocate time and resources to consider development of suitable chronic toxicity tests, and some suggestions regarding this are presented.

  12. Sexual Preferences in Nutrient Utilization Regulate Oxygen Consumption and Reactive Oxygen Species Generation in Schistosoma mansoni: Potential Implications for Parasite Redox Biology.

    PubMed

    Oliveira, Matheus P; Correa Soares, Juliana B R; Oliveira, Marcus F

    2016-01-01

    Schistosoma mansoni, one of the causative agents of human schistosomiasis, has a unique antioxidant network that is key to parasite survival and a valuable chemotherapeutic target. The ability to detoxify and tolerate reactive oxygen species increases along S. mansoni development in the vertebrate host, suggesting that adult parasites are more exposed to redox challenges than young stages. Indeed, adult parasites are exposed to multiple redox insults generated from blood digestion, activated immune cells, and, potentially, from their own parasitic aerobic metabolism. However, it remains unknown how reactive oxygen species are produced by S. mansoni metabolism, as well as their biological effects on adult worms. Here, we assessed the contribution of nutrients and parasite gender to oxygen utilization pathways, and reactive oxygen species generation in whole unpaired adult S. mansoni worms. We also determined the susceptibilities of both parasite sexes to a pro-oxidant challenge. We observed that glutamine and serum importantly contribute to both respiratory and non-respiratory oxygen utilization in adult worms, but with different proportions among parasite sexes. Analyses of oxygen utilization pathways revealed that respiratory rates were high in male worms, which contrast with high non-respiratory rates in females, regardless nutritional sources. Interestingly, mitochondrial complex I-III activity was higher than complex IV specifically in females. We also observed sexual preferences in substrate utilization to sustain hydrogen peroxide production towards glucose in females, and glutamine in male worms. Despite strikingly high oxidant levels and hydrogen peroxide production rates, female worms were more resistant to a pro-oxidant challenge than male parasites. The data presented here indicate that sexual preferences in nutrient metabolism in adult S. mansoni worms regulate oxygen utilization and reactive oxygen species production, which may differently contribute

  13. Sexual Preferences in Nutrient Utilization Regulate Oxygen Consumption and Reactive Oxygen Species Generation in Schistosoma mansoni: Potential Implications for Parasite Redox Biology

    PubMed Central

    Oliveira, Matheus P.; Correa Soares, Juliana B. R.; Oliveira, Marcus F.

    2016-01-01

    Schistosoma mansoni, one of the causative agents of human schistosomiasis, has a unique antioxidant network that is key to parasite survival and a valuable chemotherapeutic target. The ability to detoxify and tolerate reactive oxygen species increases along S. mansoni development in the vertebrate host, suggesting that adult parasites are more exposed to redox challenges than young stages. Indeed, adult parasites are exposed to multiple redox insults generated from blood digestion, activated immune cells, and, potentially, from their own parasitic aerobic metabolism. However, it remains unknown how reactive oxygen species are produced by S. mansoni metabolism, as well as their biological effects on adult worms. Here, we assessed the contribution of nutrients and parasite gender to oxygen utilization pathways, and reactive oxygen species generation in whole unpaired adult S. mansoni worms. We also determined the susceptibilities of both parasite sexes to a pro-oxidant challenge. We observed that glutamine and serum importantly contribute to both respiratory and non-respiratory oxygen utilization in adult worms, but with different proportions among parasite sexes. Analyses of oxygen utilization pathways revealed that respiratory rates were high in male worms, which contrast with high non-respiratory rates in females, regardless nutritional sources. Interestingly, mitochondrial complex I-III activity was higher than complex IV specifically in females. We also observed sexual preferences in substrate utilization to sustain hydrogen peroxide production towards glucose in females, and glutamine in male worms. Despite strikingly high oxidant levels and hydrogen peroxide production rates, female worms were more resistant to a pro-oxidant challenge than male parasites. The data presented here indicate that sexual preferences in nutrient metabolism in adult S. mansoni worms regulate oxygen utilization and reactive oxygen species production, which may differently contribute

  14. Overwintering hosts for the exotic leafroller parasitoid, Colpoclypeus florus: implications for habitat manipulation to augment biological control of leafrollers in pome fruits.

    PubMed

    Pfannenstiel, R S; Unruh, T R; Brunner, J F

    2010-01-01

    Thirty sites of managed and native habitats were surveyed for leafrollers (Lepidoptera: Tortricidae) in the apple producing region of central Washington State and northern Oregon from September through November 1997-2000 to discover species that supported overwintering by the parasitoid Colpoclypeus florus (Walker) (Hymenoptera: Eulophidae). C. florus, a species introduced from Europe, requires medium to large host larvae late in autumn on which to overwinter, and few leafroller species display this biology. Over the four years, five potential C. florus hosts were collected, including: Ancylis comptana (Froelich), Xenotemna pallorana (Robinson), and Syndemis sp. (Tortricidae), Filatima sp. (Gelechiidae), and Caloptilia burgessiellia (Zeller) (Gracillariidae). Of these, A. comptana, Syndemis sp., and Filatima sp. have been confirmed as overwintering hosts for C. florus. During the four years, the Syndemis sp. was rare and observed at only one location feeding on redosier dogwood, Cornus sericea L. (Cornales: Cornaceae) although, at this location, many of the larvae collected were parasitized by C. florus. Filatima sp. was common in the Yakima valley feeding on balsam poplar, Populus balsamifera L. ssp. trichocarpa (Torr. & Gray ex Hook) Brayshaw (Malpighiales: Salicaceae) but was rarely parasitized. A. comptana, however, was collected at many locations in central Washington and was frequently found as an overwintering host for C. florus. A. comptana was found feeding on two Rosaceae: Wood's rose, Rosa woodsii Lindl., and strawberry, Fragaria ananassa Duchesne (Rosales: Rosaceae). Based on the number of host larvae collected, A. comptana appears to be the primary overwintering host for C. florus in Washington. Introduction of A. comptana populations to near-orchard habitats may facilitate biological control of leafrollers that are orchard pests.

  15. A paradigm for viewing biologic systems as scale-free networks based on energy efficiency: implications for present therapies and the future of evolution.

    PubMed

    Yun, Anthony J; Lee, Patrick Y; Doux, John D

    2006-01-01

    A network constitutes an abstract description of the relationships among entities, respectively termed links and nodes. If a power law describes the probability distribution of the number of links per node, the network is said to be scale-free. Scale-free networks feature link clustering around certain hubs based on preferential attachments that emerge due either to merit or legacy. Biologic systems ranging from sub-atomic to ecosystems represent scale-free networks in which energy efficiency forms the basis of preferential attachments. This paradigm engenders a novel scale-free network theory of evolution based on energy efficiency. As environmental flux induces fitness dislocations and compels a new meritocracy, new merit-based hubs emerge, previously merit-based hubs become legacy hubs, and network recalibration occurs to achieve system optimization. To date, Darwinian evolution, characterized by innovation sampling, variation, and selection through filtered termination, has enabled biologic progress through optimization of energy efficiency. However, as humans remodel their environment, increasing the level of unanticipated fitness dislocations and inducing evolutionary stress, the tendency of networks to exhibit inertia and retain legacy hubs engender maladaptations. Many modern diseases may fundamentally derive from these evolutionary displacements. Death itself may constitute a programmed adaptation, terminating individuals who represent legacy hubs and recalibrating the network. As memes replace genes as the basis of innovation, death itself has become a legacy hub. Post-Darwinian evolution may favor indefinite persistence to optimize energy efficiency. We describe strategies to reprogram or decommission legacy hubs that participate in human disease and death.

  16. Selective resistance of LDL core lipids to iron-mediated oxidation. Implications for the biological properties of iron-oxidized LDL.

    PubMed

    Tribble, D L; Chu, B M; Levine, G A; Krauss, R M; Gong, E L

    1996-12-01

    Although the nature and consequences of oxidative changes in the chemical constituents of low density lipoproteins (LDLs) have been extensively examined, the physical dynamics of LDL oxidation and the influence of physical organization on the biological effects of oxidized LDLs have remained relatively unexplored. To address these issues, in the present studies we monitored surface- and core-specific peroxidative stress relative to temporal changes in conjugated dienes (CDs), particle charge (an index of oxidative protein modification), and LDL-macrophage interactions. Peroxidative stress in LDL surface and core compartments was evaluated with the site-specific, oxidation-labile fluorescent probes parinaric acid (PnA) and PnA cholesteryl ester (PnCE), respectively. When oxidation was initiated by Cu2+, oxidative loss of the core probe (PnCE) closely followed that of the surface probe (PnA), as indicated by the time to 50% probe depletion (t1/2; 15.5 +/- 7.8 and 30.4 +/- 12 minutes for PnA and PnCE, respectively). Both probes were more resistant in LDL exposed to Fe3+ (t1/2, 53.2 +/- 8.1 and 346.7 +/- 155.4 minutes), although core probe resistance was much greater with this oxidant (PnCE t1/2/PnA t1/2 5.8 vs 2.0 for Cu2+). Despite differences in the rate and extent of oxidative changes in Cu(2+)- versus Fe(3+)-exposed LDLs, PnCE loss occurred in close correspondence with CD formation and appeared to precede changes in particle charge under both conditions. Exposure of LDLs to hemin, a lipophilic Fe(3+)-containing porphyrin that becomes incorporated into the LDL particle, resulted in rapid loss of PnCE and simultaneous changes in particle, charge, even at concentrations that yielded increases in CDs and thiobarbituric acid-reactive substances similar to those obtained with free Fe3+. These results suggest that oxidation of the LDL hydrophobic core occurs in conjunction with accelerated formation of CDs and may be essential for LDL protein modification. In accordance

  17. The application of SRF vs. RDF classification and specifications to the material flows of two mechanical-biological treatment plants of Rome: Comparison and implications.

    PubMed

    Di Lonardo, Maria Chiara; Franzese, Maurizio; Costa, Giulia; Gavasci, Renato; Lombardi, Francesco

    2016-01-01

    This work assessed the quality in terms of solid recovered fuel (SRF) definitions of the dry light flow (until now indicated as refuse derived fuel, RDF), heavy rejects and stabilisation rejects, produced by two mechanical biological treatment plants of Rome (Italy). SRF classification and specifications were evaluated first on the basis of RDF historical characterisation methods and data and then applying the sampling and analytical methods laid down by the recently issued SRF standards. The results showed that the dry light flow presented a worst SRF class in terms of net calorific value applying the new methods compared to that obtained from RDF historical data (4 instead of 3). This lead to incompliance with end of waste criteria established by Italian legislation for SRF use as co-fuel in cement kilns and power plants. Furthermore, the metal contents of the dry light flow obtained applying SRF current methods proved to be considerably higher (although still meeting SRF specifications) compared to those resulting from historical data retrieved with RDF standard methods. These differences were not related to a decrease in the quality of the dry light flow produced in the mechanical-biological treatment plants but rather to the different sampling procedures set by the former RDF and current SRF standards. In particular, the shredding of the sample before quartering established by the latter methods ensures that also the finest waste fractions, characterised by higher moisture and metal contents, are included in the sample to be analysed, therefore affecting the composition and net calorific value of the waste. As for the reject flows, on the basis of their SRF classification and specification parameters, it was found that combined with the dry light flow they may present similar if not the same class codes as the latter alone, thus indicating that these material flows could be also treated in combustion plants instead of landfilled. In conclusion, the

  18. Genetic Differentiation among Maruca vitrata F. (Lepidoptera: Crambidae) Populations on Cultivated Cowpea and Wild Host Plants: Implications for Insect Resistance Management and Biological Control Strategies

    PubMed Central

    Agunbiade, Tolulope A.; Coates, Brad S.; Datinon, Benjamin; Djouaka, Rousseau; Sun, Weilin; Tamò, Manuele; Pittendrigh, Barry R.

    2014-01-01

    Maruca vitrata Fabricius (Lepidoptera: Crambidae) is a polyphagous insect pest that feeds on a variety of leguminous plants in the tropics and subtropics. The contribution of host-associated genetic variation on population structure was investigated using analysis of mitochondrial cytochrome oxidase 1 (cox1) sequence and microsatellite marker data from M. vitrata collected from cultivated cowpea (Vigna unguiculata L. Walp.), and alternative host plants Pueraria phaseoloides (Roxb.) Benth. var. javanica (Benth.) Baker, Loncocarpus sericeus (Poir), and Tephrosia candida (Roxb.). Analyses of microsatellite data revealed a significant global FST estimate of 0.05 (P≤0.001). The program STRUCTURE estimated 2 genotypic clusters (co-ancestries) on the four host plants across 3 geographic locations, but little geographic variation was predicted among genotypes from different geographic locations using analysis of molecular variance (AMOVA; among group variation −0.68%) or F-statistics (FSTLoc = −0.01; P = 0.62). These results were corroborated by mitochondrial haplotype data (φSTLoc = 0.05; P = 0.92). In contrast, genotypes obtained from different host plants showed low but significant levels of genetic variation (FSTHost = 0.04; P = 0.01), which accounted for 4.08% of the total genetic variation, but was not congruent with mitochondrial haplotype analyses (φSTHost = 0.06; P = 0.27). Variation among host plants at a location and host plants among locations showed no consistent evidence for M. vitrata population subdivision. These results suggest that host plants do not significantly influence the genetic structure of M. vitrata, and this has implications for biocontrol agent releases as well as insecticide resistance management (IRM) for M. vitrata in West Africa. PMID:24647356

  19. Genetic differentiation among Maruca vitrata F. (Lepidoptera: Crambidae) populations on cultivated cowpea and wild host plants: implications for insect resistance management and biological control strategies.

    PubMed

    Agunbiade, Tolulope A; Coates, Brad S; Datinon, Benjamin; Djouaka, Rousseau; Sun, Weilin; Tamò, Manuele; Pittendrigh, Barry R

    2014-01-01

    Maruca vitrata Fabricius (Lepidoptera: Crambidae) is a polyphagous insect pest that feeds on a variety of leguminous plants in the tropics and subtropics. The contribution of host-associated genetic variation on population structure was investigated using analysis of mitochondrial cytochrome oxidase 1 (cox1) sequence and microsatellite marker data from M. vitrata collected from cultivated cowpea (Vigna unguiculata L. Walp.), and alternative host plants Pueraria phaseoloides (Roxb.) Benth. var. javanica (Benth.) Baker, Loncocarpus sericeus (Poir), and Tephrosia candida (Roxb.). Analyses of microsatellite data revealed a significant global FST estimate of 0.05 (P≤0.001). The program STRUCTURE estimated 2 genotypic clusters (co-ancestries) on the four host plants across 3 geographic locations, but little geographic variation was predicted among genotypes from different geographic locations using analysis of molecular variance (AMOVA; among group variation -0.68%) or F-statistics (FSTLoc = -0.01; P = 0.62). These results were corroborated by mitochondrial haplotype data (φSTLoc = 0.05; P = 0.92). In contrast, genotypes obtained from different host plants showed low but significant levels of genetic variation (FSTHost = 0.04; P = 0.01), which accounted for 4.08% of the total genetic variation, but was not congruent with mitochondrial haplotype analyses (φSTHost = 0.06; P = 0.27). Variation among host plants at a location and host plants among locations showed no consistent evidence for M. vitrata population subdivision. These results suggest that host plants do not significantly influence the genetic structure of M. vitrata, and this has implications for biocontrol agent releases as well as insecticide resistance management (IRM) for M. vitrata in West Africa.

  20. An update: improvements in imaging perfluorocarbon-mounted plant leaves with implications for studies of plant pathology, physiology, development and cell biology.

    PubMed

    Littlejohn, George R; Mansfield, Jessica C; Christmas, Jacqueline T; Witterick, Eleanor; Fricker, Mark D; Grant, Murray R; Smirnoff, Nicholas; Everson, Richard M; Moger, Julian; Love, John

    2014-01-01

    Plant leaves are optically complex, which makes them difficult to image by light microscopy. Careful sample preparation is therefore required to enable researchers to maximize the information gained from advances in fluorescent protein labeling, cell dyes and innovations in microscope technologies and techniques. We have previously shown that mounting leaves in the non-toxic, non-fluorescent perfluorocarbon (PFC), perfluorodecalin (PFD) enhances the optical properties of the leaf with minimal impact on physiology. Here, we assess the use of the PFCs, PFD, and perfluoroperhydrophenanthrene (PP11) for in vivo plant leaf imaging using four advanced modes of microscopy: laser scanning confocal microscopy (LSCM), two-photon fluorescence microscopy, second harmonic generation microscopy, and stimulated Raman scattering (SRS) microscopy. For every mode of imaging tested, we observed an improved signal when leaves were mounted in PFD or in PP11, compared to mounting the samples in water. Using an image analysis technique based on autocorrelation to quantitatively assess LSCM image deterioration with depth, we show that PP11 outperformed PFD as a mounting medium by enabling the acquisition of clearer images deeper into the tissue. In addition, we show that SRS microscopy can be used to image PFCs directly in the mesophyll and thereby easily delimit the "negative space" within a leaf, which may have important implications for studies of leaf development. Direct comparison of on and off resonance SRS micrographs show that PFCs do not to form intracellular aggregates in live plants. We conclude that the application of PFCs as mounting media substantially increases advanced microscopy image quality of living mesophyll and leaf vascular bundle cells.

  1. Spermiogenesis and modified sperm morphology in the "seepworm" Methanoaricia dendrobranchiata (Polychaeta: Orbiniidae) from a methane seep environment in the Gulf of Mexico: implications for fertilization biology.

    PubMed

    Eckelbarger, Kevin J; Young, Craig M

    2002-10-01

    Spermatogenesis and mature sperm morphology have been described along with limited observations of the ovary in Methanoaricia dendrobranchiata, an orbiniid polychaete associated with dense populations of the mussel Bathymodiolus childressi at brine pools on the Louisiana slope, Gulf of Mexico. The species is gonochoric with gonads serially repeated in numerous segments and each associated with a nexus of blood vessels at the base of the parapodia. In the female, synchronous, intraovarian egg development occurs with the release from the ovary of large, yolky eggs into the coelom at first meiotic metaphase. Sperm develop in the coelom as free-floating, plasmodial clones interconnected via an anuclear cytophore. At the end of spermiogenesis, mature spermatozoa float freely in the coelom. The mature spermatozoon differs significantly from that of shallow-water orbiniid species by possessing an elongated nucleus and a greatly elongated and curved acrosome reaching 19.5 microm in length. The spermatozoon resembles an ent-aquasperm and may not fertilize the eggs directly in seawater in the classical manner. We hypothesize that the unusual spermatozoon morphology in this species has evolved due to the hypoxic environment in which the adults live and that fertilization biology is likely modified in some way to minimize sperm exposure to high levels of hydrogen sulfide. An analysis of life-history features in shallow-water orbiniids is used to infer reproductive features in M. dendrobranchiata that could not be directly documented.

  2. Use of a cytogenetic whole-genome comparison to resolve phylogenetic relationships among three species: implications for mammalian systematics and conservation biology.

    PubMed

    Yu, Hon-Tsen; Ma, Gwo-Chin; Lee, Dong-Jay; Chin, Shih-Chien; Chen, Ting-Li; Tsao, Hsien-Shao; Lin, Wen-Hsiang; Wu, Sheng-Hai; Lin, Chyi-Chyang; Chen, Ming

    2012-05-01

    The objective was to apply a novel modification of a genome-wide, comparative cytogenetic technique (comparative genomic hybridization, comparative genomic hybridization (CGH)), to study species belonging to the myrmecophagous (ant/termite eating) mammalian orders/superorders (Pholidota, Tubulidentata, Carnivora, and Xenarthra), as a model for other applications in mammalian systematics and conservation biology. In this study, CGH was applied to high-quality metaphase spreads of pangolin (Pholidota), using probes of sloth and canine (Xenarthra and Carnivora, respectively) genomic DNA labeled with different fluorophores, thereby facilitating analysis of the visible color spectrum on pangolin karyotypes. Our results posited that pholidotes are closer to carnivores than to xenarthrans, which confirmed the current consensus that myrmecophagy in these mammalian lineages was more likely because of homoplasy (convergent evolution) than being an ancestral character. Since the modified CGH technique used is genome-wide, has chromosome-level resolution, and does not need full genome sequencing, it has considerable potential in systematics and other fields. PMID:22192390

  3. The MUC1 oncomucin regulates pancreatic cancer cell biological properties and chemoresistance. Implication of p42–44 MAPK, Akt, Bcl-2 and MMP13 pathways

    SciTech Connect

    Tréhoux, Solange; Duchêne, Bélinda; Jonckheere, Nicolas; Van Seuningen, Isabelle

    2015-01-16

    Highlights: • Loss of MUC1 decreases proliferation and tumor growth via β-catenin and p42–44 MAPK. • Inhibition of MUC1 decreases cell migration and invasion through MMP13. • Loss of MUC1 decreases survival and increases apoptosis via Akt and Bcl-2 pathways. • Loss of MUC1 sensitizes cells to gemcitabine and 5-Fluorouracil chemotherapeutic drugs. - Abstract: MUC1 is an oncogenic mucin overexpressed in several epithelial cancers, including pancreatic ductal adenocarcinoma, and is considered as a potent target for cancer therapy. To this aim, we undertook to study MUC1 biological effects on pancreatic cancer cells and identify pathways mediating these effects. Our in vitro experiments indicate that inhibiting MUC1 expression decreases cell proliferation, cell migration and invasion, cell survival and increases cell apoptosis. Moreover, lack of MUC1 in these cells profoundly altered their sensitivity to gemcitabine and 5-Fluorouracil chemotherapeutic drugs. In vivo MUC1-KD cell xenografts in SCID mice grew slower. Altogether, we show that MUC1 oncogenic mucin alters proliferation, migration, and invasion properties of pancreatic cancer cells and that these effects are mediated by p42–44 MAPK, Akt, Bcl-2 and MMP13 pathways.

  4. Use of a cytogenetic whole-genome comparison to resolve phylogenetic relationships among three species: implications for mammalian systematics and conservation biology.

    PubMed

    Yu, Hon-Tsen; Ma, Gwo-Chin; Lee, Dong-Jay; Chin, Shih-Chien; Chen, Ting-Li; Tsao, Hsien-Shao; Lin, Wen-Hsiang; Wu, Sheng-Hai; Lin, Chyi-Chyang; Chen, Ming

    2012-05-01

    The objective was to apply a novel modification of a genome-wide, comparative cytogenetic technique (comparative genomic hybridization, comparative genomic hybridization (CGH)), to study species belonging to the myrmecophagous (ant/termite eating) mammalian orders/superorders (Pholidota, Tubulidentata, Carnivora, and Xenarthra), as a model for other applications in mammalian systematics and conservation biology. In this study, CGH was applied to high-quality metaphase spreads of pangolin (Pholidota), using probes of sloth and canine (Xenarthra and Carnivora, respectively) genomic DNA labeled with different fluorophores, thereby facilitating analysis of the visible color spectrum on pangolin karyotypes. Our results posited that pholidotes are closer to carnivores than to xenarthrans, which confirmed the current consensus that myrmecophagy in these mammalian lineages was more likely because of homoplasy (convergent evolution) than being an ancestral character. Since the modified CGH technique used is genome-wide, has chromosome-level resolution, and does not need full genome sequencing, it has considerable potential in systematics and other fields.

  5. Plasmalogen enrichment in exosomes secreted by a nematode parasite versus those derived from its mouse host: implications for exosome stability and biology.

    PubMed

    Simbari, Fabio; McCaskill, Jana; Coakley, Gillian; Millar, Marissa; Maizels, Rick M; Fabriás, Gemma; Casas, Josefina; Buck, Amy H

    2016-01-01

    , which has not been widely reported and could have implications for the biochemical or immunomodulatory properties of EVs. Further comparative analyses such as those described here will shed light on diversity in the molecular properties of EVs that enable them to function in cross-species communication. PMID:27389011

  6. Plasmalogen enrichment in exosomes secreted by a nematode parasite versus those derived from its mouse host: implications for exosome stability and biology

    PubMed Central

    Simbari, Fabio; McCaskill, Jana; Coakley, Gillian; Millar, Marissa; Maizels, Rick M.; Fabriás, Gemma; Casas, Josefina; Buck, Amy H.

    2016-01-01

    , which has not been widely reported and could have implications for the biochemical or immunomodulatory properties of EVs. Further comparative analyses such as those described here will shed light on diversity in the molecular properties of EVs that enable them to function in cross-species communication. PMID:27389011

  7. Iridoid and secoiridoid glycosides in a hybrid complex of bush honeysuckles (Lonicera spp., Caprifolicaceae): implications for evolutionary ecology and invasion biology.

    PubMed

    Whitehead, Susan R; Bowers, M Deane

    2013-02-01

    Interspecific hybridization among non-native plant species can generate genotypes that are more reproductively successful in the introduced habitat than either parent. One important mechanism that may serve as a stimulus for the evolution of invasiveness in hybrids is increased variation in secondary metabolite chemistry, but still very little is known about patterns of chemical trait introgression in plant hybrid zones. This study examined the occurrence of iridoid and secoiridoid glycosides (IGs), an important group of plant defense compounds, in three species of honeysuckle, Lonicera morrowii A. Gray, Lonicera tatarica L., and their hybrid Lonicera×bella Zabel. (Caprifoliaceae), all of which are considered invasive in various parts of North America. Hybrid genotypes had a diversity of IGs inherited from both parent species, as well as one component not detected in either parent. All three species were similar in that overall concentrations of IGs were significantly higher in fruits than in leaves, and several compounds that were major components of fruits were never found in leaves. However, specific patterns of quantitative distribution among leaves, unripe fruits, and ripe fruits differed among the three species, with a relatively higher allocation to fruits in the hybrid species than for either parent. These patterns likely have important consequences for plant interactions with antagonistic herbivores and pathogens as well as mutualistic seed dispersers, and thus the potential invasiveness of hybrid and parental species in their introduced range. Methods established here for quantitative analysis of IGs will allow for the exploration of many compelling research questions related to the evolutionary ecology and invasion biology of these and other related species in the genus Lonicera.

  8. Solution structure of the biologically relevant G-quadruplex element in the human c-MYC promoter. Implications for G-quadruplex stabilization.

    PubMed

    Ambrus, Attila; Chen, Ding; Dai, Jixun; Jones, Roger A; Yang, Danzhou

    2005-02-15

    The nuclease hypersensitivity element III(1) (NHE III(1)) of the c-MYC promoter strongly controls the transcriptional activity of the c-MYC oncogene. The purine-rich strand of the NHE III(1) element has been shown to be a silencer element for c-MYC transcription upon formation of a G-quadruplex structure. We have determined the predominant G-quadruplex structure of this silencer element in potassium solution by NMR. The G-quadruplex structure adopts an intramolecular parallel-stranded quadruplex conformation with three guanine tetrads and three side loops, including two single-nucleotide side loops and one double-nucleotide side loop, that connect the four guanine strands. The three side loops are very stable and well-defined. The 3'-flanking sequence forms a stable fold-back stacking conformation capping the top end of the G-quadruplex structure. The 5'-flanking A and G bases cap the bottom end of the G-quadruplex, with the adenine stacking very well with the bottom tetrad. This paper reports the first solution structure of a G-quadruplex found to form in the promoter region of an oncogene (c-MYC). This G-quadruplex structure is extremely stable, with a similar melting temperature (>85 degrees C) to that of the wild-type 27-mer purine-rich NHE III(1) sequence of the c-MYC promoter. This predominant quadruplex structure has been shown to be biologically relevant, and the structural information revealed in this research provides an important basis for the design of new drug candidates that specifically target the c-MYC G-quadruplex structure and modulate gene expression. PMID:15697230

  9. Bioenergetics in human evolution and disease: implications for the origins of biological complexity and the missing genetic variation of common diseases

    PubMed Central

    Wallace, Douglas C.

    2013-01-01

    Two major inconsistencies exist in the current neo-Darwinian evolutionary theory that random chromosomal mutations acted on by natural selection generate new species. First, natural selection does not require the evolution of ever increasing complexity, yet this is the hallmark of biology. Second, human chromosomal DNA sequence variation is predominantly either neutral or deleterious and is insufficient to provide the variation required for speciation or for predilection to common diseases. Complexity is explained by the continuous flow of energy through the biosphere that drives the accumulation of nucleic acids and information. Information then encodes complex forms. In animals, energy flow is primarily mediated by mitochondria whose maternally inherited mitochondrial DNA (mtDNA) codes for key genes for energy metabolism. In mammals, the mtDNA has a very high mutation rate, but the deleterious mutations are removed by an ovarian selection system. Hence, new mutations that subtly alter energy metabolism are continuously introduced into the species, permitting adaptation to regional differences in energy environments. Therefore, the most phenotypically significant gene variants arise in the mtDNA, are regional, and permit animals to occupy peripheral energy environments where rarer nuclear DNA (nDNA) variants can accumulate, leading to speciation. The neutralist–selectionist debate is then a consequence of mammals having two different evolutionary strategies: a fast mtDNA strategy for intra-specific radiation and a slow nDNA strategy for speciation. Furthermore, the missing genetic variation for common human diseases is primarily mtDNA variation plus regional nDNA variants, both of which have been missed by large, inter-population association studies. PMID:23754818

  10. Structure of the Type III Pantothenate Kinase from Bacillus Anthracis at 2.0 A Resolution: Implications for Coenzyme A-Dependent Redox Biology

    SciTech Connect

    Nicely,N.; Parsonage, D.; Paige, C.; Newton, G.; Fahey, R.; Leonardi, R.; Jackowski, S.; Mallett, T.; Claiborne, A.

    2007-01-01

    Coenzyme A (CoASH) is the major low-molecular weight thiol in Staphylococcus aureus and a number of other bacteria; the crystal structure of the S. aureus coenzyme A-disulfide reductase (CoADR), which maintains the reduced intracellular state of CoASH, has recently been reported [Mallett, T.C., Wallen, J.R., Karplus, P.A., Sakai, H., Tsukihara, T., and Claiborne, A. (2006) Biochemistry 45, 11278-89]. In this report we demonstrate that CoASH is the major thiol in Bacillus anthracis; a bioinformatics analysis indicates that three of the four proteins responsible for the conversion of pantothenate (Pan) to CoASH in Escherichia coli are conserved in B. anthracis. In contrast, a novel type III pantothenate kinase (PanK) catalyzes the first committed step in the biosynthetic pathway in B. anthracis; unlike the E. coli type I PanK, this enzyme is not subject to feedback inhibition by CoASH. The crystal structure of B. anthracis PanK (BaPanK), solved using multiwavelength anomalous dispersion data and refined at a resolution of 2.0 {angstrom}, demonstrates that BaPanK is a new member of the Acetate and Sugar Kinase/Hsc70/Actin (ASKHA) superfamily. The Pan and ATP substrates have been modeled into the active-site cleft; in addition to providing a clear rationale for the absence of CoASH inhibition, analysis of the Pan-binding pocket has led to the development of two new structure-based motifs (the PAN and INTERFACE motifs). Our analyses also suggest that the type III PanK in the spore-forming B. anthracis plays an essential role in the novel thiol/disulfide redox biology of this category A biodefense pathogen.

  11. Warming reduces the growth and diversity of biological soil crusts in a semi-arid environment: implications for ecosystem structure and functioning

    PubMed Central

    Escolar, Cristina; Martínez, Isabel; Bowker, Matthew A.; Maestre, Fernando T.

    2012-01-01

    Biological soil crusts (BSCs) are key biotic components of dryland ecosystems worldwide that control many functional processes, including carbon and nitrogen cycling, soil stabilization and infiltration. Regardless of their ecological importance and prevalence in drylands, very few studies have explicitly evaluated how climate change will affect the structure and composition of BSCs, and the functioning of their constituents. Using a manipulative experiment conducted over 3 years in a semi-arid site from central Spain, we evaluated how the composition, structure and performance of lichen-dominated BSCs respond to a 2.4°C increase in temperature, and to an approximately 30 per cent reduction of total annual rainfall. In areas with well-developed BSCs, warming promoted a significant decrease in the richness and diversity of the whole BSC community. This was accompanied by important compositional changes, as the cover of lichens suffered a substantial decrease with warming (from 70 to 40% on average), while that of mosses increased slightly (from 0.3 to 7% on average). The physiological performance of the BSC community, evaluated using chlorophyll fluorescence, increased with warming during the first year of the experiment, but did not respond to rainfall reduction. Our results indicate that ongoing climate change will strongly affect the diversity and composition of BSC communities, as well as their recovery after disturbances. The expected changes in richness and composition under warming could reduce or even reverse the positive effects of BSCs on important soil processes. Thus, these changes are likely to promote an overall reduction in ecosystem processes that sustain and control nutrient cycling, soil stabilization and water dynamics. PMID:23045707

  12. Soluble metals in the atmosphere and their biological implications. A study to identify important aerosol components by statistical analysis of PIXE data.

    PubMed

    Winchester, J W

    1990-01-01

    Multivariate statistical analysis has been applied to time series measurements of aerosol elemental composition from PIXE analysis of filter samples, and principal components have been resolved that represent distinct particle types in an external mixture in the atmosphere. In this study, it is argued that a combination of chemical and statistical analyses of the data may be more powerful in determining chemical species in atmospheric aerosols than studied that employ mainly direct chemical analysis of chemical species in unresolved mixtures of aerosol particle samples. Sulfur is generally associated with mineral dust elements. It is reasoned that the association may represent sulfuric acid coatings on particles that can lead to mineral dissolution and solubilization of significant amounts of aluminum, iron, and other metals. Upon wet or dry deposition to the surface, the fluxes of these metals in biologically-available form may be sufficient to affect primary productivity in the world ocean and cause ecological damage in lakes. As a consequence, the fluxes of biogenic trace gases to the atmosphere may be changed, possibly leading to changes in the tropospheric concentration of ozone. The inputs to lakes of soluble aluminum, which is toxic to fish, may be partly by deposition directly from the atmosphere, thus not limited to leaching of soils by acid deposition. Human inhalation of soluble aluminum and other solubilized mineral metals may account, in part, for the observed geographic pattern of deaths attributed to chronic obstructive pulmonary disease (COPD) that show high rates in cities of the Western US and the southeast region, but low in most of the midwest and northeast.

  13. Biological differences between brackish and fresh water-derived Aedes aegypti from two locations in the Jaffna peninsula of Sri Lanka and the implications for arboviral disease transmission.

    PubMed

    Ramasamy, Ranjan; Jude, Pavilupillai J; Veluppillai, Thabothiny; Eswaramohan, Thampoe; Surendran, Sinnathamby N

    2014-01-01

    The mainly fresh water arboviral vector Aedes aegypti L. (Diptera: Culicidae) can also undergo pre-imaginal development in brackish water of up to 15 ppt (parts per thousand) salt in coastal areas. We investigated differences in salinity tolerance, egg laying preference, egg hatching and larval development times and resistance to common insecticides in Ae. aegypti collected from brackish and fresh water habitats in Jaffna, Sri Lanka. Brackish water-derived Ae. aegypti were more tolerant of salinity than fresh water-derived Ae. aegypti and this difference was only partly reduced after their transfer to fresh water for up to five generations. Brackish water-derived Ae. aegypti did not significantly discriminate between 10 ppt salt brackish water and fresh water for oviposition, while fresh water-derived Ae. aegypti preferred fresh water. The hatching of eggs from both brackish and fresh water-derived Ae. aegypti was less efficient and the time taken for larvae to develop into pupae was prolonged in 10 ppt salt brackish water. Ae. aegypti isolated from coastal brackish water were less resistant to the organophosphate insecticide malathion than inland fresh water Ae. aegypti. Brackish and fresh water-derived Ae. aegypti however were able to mate and produce viable offspring in the laboratory. The results suggest that development in brackish water is characterised by pertinent biological changes, and that there is restricted genetic exchange between coastal brackish and inland fresh water Ae. aegypti isolates from sites 5 km apart. The findings highlight the need for monitoring Ae. aegypti developing in coastal brackish waters and extending vector control measures to their habitats.

  14. De Novo Transcriptome Analysis of Oncomelania hupensis after Molluscicide Treatment by Next-Generation Sequencing: Implications for Biology and Future Snail Interventions

    PubMed Central

    Zhao, Qin Ping; Xiong, Tao; Xu, Xing Jian; Jiang, Ming Sen; Dong, Hui Fen

    2015-01-01

    The freshwater snail Oncomelania hupensis is the only intermediate host of Schistosoma japonicum, which causes schistosomiasis. This disease is endemic in the Far East, especially in mainland China. Because niclosamide is the only molluscicide recommended by the World Health Organization, 50% wettable powder of niclosamide ethanolamine salt (WPN), the only chemical molluscicide available in China, has been widely used as the main snail control method for over two decades. Recently, a novel molluscicide derived from niclosamide, the salt of quinoid-2',5-dichloro-4'-nitro-salicylanilide (Liu Dai Shui Yang An, LDS), has been developed and proven to have the same molluscicidal effect as WPN, with lower cost and significantly lower toxicity to fish than WPN. The mechanism by which these molluscicides cause snail death is not known. Here, we report the next-generation transcriptome sequencing of O. hupensis; 145,008,667 clean reads were generated and assembled into 254,286 unigenes. Using GO and KEGG databases, 14,860 unigenes were assigned GO annotations and 4,686 unigenes were mapped to 250 KEGG pathways. Many sequences involved in key processes associated with biological regulation and innate immunity have been identified. After the snails were exposed to LDS and WPN, 254 unigenes showed significant differential expression. These genes were shown to be involved in cell structure defects and the inhibition of neurohumoral transmission and energy metabolism, which may cause snail death. Gene expression patterns differed after exposure to LDS and WPN, and these differences must be elucidated by the identification and annotation of these unknown unigenes. We believe that this first large-scale transcriptome dataset for O. hupensis will provide an opportunity for the in-depth analysis of this biomedically important freshwater snail at the molecular level and accelerate studies of the O. hupensis genome. The data elucidating the molluscicidal mechanism will be of great

  15. Warming reduces the growth and diversity of biological soil crusts in a semi-arid environment: implications for ecosystem structure and functioning.

    PubMed

    Escolar, Cristina; Martínez, Isabel; Bowker, Matthew A; Maestre, Fernando T

    2012-11-19

    Biological soil crusts (BSCs) are key biotic components of dryland ecosystems worldwide that control many functional processes, including carbon and nitrogen cycling, soil stabilization and infiltration. Regardless of their ecological importance and prevalence in drylands, very few studies have explicitly evaluated how climate change will affect the structure and composition of BSCs, and the functioning of their constituents. Using a manipulative experiment conducted over 3 years in a semi-arid site from central Spain, we evaluated how the composition, structure and performance of lichen-dominated BSCs respond to a 2.4°C increase in temperature, and to an approximately 30 per cent reduction of total annual rainfall. In areas with well-developed BSCs, warming promoted a significant decrease in the richness and diversity of the whole BSC community. This was accompanied by important compositional changes, as the cover of lichens suffered a substantial decrease with warming (from 70 to 40% on average), while that of mosses increased slightly (from 0.3 to 7% on average). The physiological performance of the BSC community, evaluated using chlorophyll fluorescence, increased with warming during the first year of the experiment, but did not respond to rainfall reduction. Our results indicate that ongoing climate change will strongly affect the diversity and composition of BSC communities, as well as their recovery after disturbances. The expected changes in richness and composition under warming could reduce or even reverse the positive effects of BSCs on important soil processes. Thus, these changes are likely to promote an overall reduction in ecosystem processes that sustain and control nutrient cycling, soil stabilization and water dynamics.

  16. Biological differences between brackish and fresh water-derived Aedes aegypti from two locations in the Jaffna peninsula of Sri Lanka and the implications for arboviral disease transmission.

    PubMed

    Ramasamy, Ranjan; Jude, Pavilupillai J; Veluppillai, Thabothiny; Eswaramohan, Thampoe; Surendran, Sinnathamby N

    2014-01-01

    The mainly fresh water arboviral vector Aedes aegypti L. (Diptera: Culicidae) can also undergo pre-imaginal development in brackish water of up to 15 ppt (parts per thousand) salt in coastal areas. We investigated differences in salinity tolerance, egg laying preference, egg hatching and larval development times and resistance to common insecticides in Ae. aegypti collected from brackish and fresh water habitats in Jaffna, Sri Lanka. Brackish water-derived Ae. aegypti were more tolerant of salinity than fresh water-derived Ae. aegypti and this difference was only partly reduced after their transfer to fresh water for up to five generations. Brackish water-derived Ae. aegypti did not significantly discriminate between 10 ppt salt brackish water and fresh water for oviposition, while fresh water-derived Ae. aegypti preferred fresh water. The hatching of eggs from both brackish and fresh water-derived Ae. aegypti was less efficient and the time taken for larvae to develop into pupae was prolonged in 10 ppt salt brackish water. Ae. aegypti isolated from coastal brackish water were less resistant to the organophosphate insecticide malathion than inland fresh water Ae. aegypti. Brackish and fresh water-derived Ae. aegypti however were able to mate and produce viable offspring in the laboratory. The results suggest that development in brackish water is characterised by pertinent biological changes, and that there is restricted genetic exchange between coastal brackish and inland fresh water Ae. aegypti isolates from sites 5 km apart. The findings highlight the need for monitoring Ae. aegypti developing in coastal brackish waters and extending vector control measures to their habitats. PMID:25170879

  17. Biology First: A History of the Grade Placement of High School Biology

    ERIC Educational Resources Information Center

    Sheppard, Keith; Robbins, Dennis M.

    2006-01-01

    This article outlines the history of the high school "general biology" course and details how biology came to be placed first in the traditional order of science subjects (biology-chemistry-physics). The article briefly discusses the implications of the development of this sequence for the present day biology course.

  18. Systems biology, emergence and antireductionism.

    PubMed

    Kesić, Srdjan

    2016-09-01

    This study explores the conceptual history of systems biology and its impact on philosophical and scientific conceptions of reductionism, antireductionism and emergence. Development of systems biology at the beginning of 21st century transformed biological science. Systems biology is a new holistic approach or strategy how to research biological organisms, developed through three phases. The first phase was completed when molecular biology transformed into systems molecular biology. Prior to the second phase, convergence between applied general systems theory and nonlinear dynamics took place, hence allowing the formation of systems mathematical biology. The second phase happened when systems molecular biology and systems mathematical biology, together, were applied for analysis of biological data. Finally, after successful application in science, medicine and biotechnology, the process of the formation of modern systems biology was completed. Systems and molecular reductionist views on organisms were completely opposed to each other. Implications of systems and molecular biology on reductionist-antireductionist debate were quite different. The analysis of reductionism, antireductionism and emergence issues, in the era of systems biology, revealed the hierarchy between methodological, epistemological and ontological antireductionism. Primarily, methodological antireductionism followed from the systems biology. Only after, epistemological and ontological antireductionism could be supported. PMID:27579007

  19. Systems biology, emergence and antireductionism.

    PubMed

    Kesić, Srdjan

    2016-09-01

    This study explores the conceptual history of systems biology and its impact on philosophical and scientific conceptions of reductionism, antireductionism and emergence. Development of systems biology at the beginning of 21st century transformed biological science. Systems biology is a new holistic approach or strategy how to research biological organisms, developed through three phases. The first phase was completed when molecular biology transformed into systems molecular biology. Prior to the second phase, convergence between applied general systems theory and nonlinear dynamics took place, hence allowing the formation of systems mathematical biology. The second phase happened when systems molecular biology and systems mathematical biology, together, were applied for analysis of biological data. Finally, after successful application in science, medicine and biotechnology, the process of the formation of modern systems biology was completed. Systems and molecular reductionist views on organisms were completely opposed to each other. Implications of systems and molecular biology on reductionist-antireductionist debate were quite different. The analysis of reductionism, antireductionism and emergence issues, in the era of systems biology, revealed the hierarchy between methodological, epistemological and ontological antireductionism. Primarily, methodological antireductionism followed from the systems biology. Only after, epistemological and ontological antireductionism could be supported.

  20. Effect of Cu(2+)-complexation on the scavenging ability of chrysin towards photogenerated singlet molecular oxygen (O2((1)Δg)). Possible biological implications.

    PubMed

    Muñoz, Vanesa A; Ferrari, Gabriela V; Montaña, M Paulina; Miskoski, Sandra; García, Norman A

    2016-09-01

    Visible-light irradiation of aqueous-ethanolic solutions of Riboflavin (Rf) in the individual presence of the flavone chrysin (Chr) and its complex with Cu(2+) ([Chr2Cu]; 2:1 L:M) generates singlet molecular oxygen O2((1)Δg), that concomitantly interact with both flavone derivatives. Overall (kt) and reactive (kr) rate constants in the order of 10(7)M(-1)s(-1) were determined for the process. Metal chelation greatly enhances the scavenging ability of [Chr2Cu] towards O2((1)Δg) through a mechanism dominated, in >80%, by the physical component. In this way, practically all O2((1)Δg) is deactivated by the complex without significant loss of the quencher. The isolated flavone quenches O2((1)Δg) in a prevailing reactive fashion. The very low value exhibited by [Chr2Cu] for the kr/kt ratio constitutes a positive quality for antioxidative protectors in biological media, where elevated local concentration and high reactivity of significant molecules make them initial targets for O2((1)Δg) aggression. Finally, two interesting properties in the field of free radicals scavenging by [Chr2Cu] must be mentioned. In first place metal chelation itself, in the obvious sense of free metal ion withdrawal from the oxidizable medium, prevents the initiation of a free radical-mediated oxidation processes through mechanisms of Fenton or lipid peroxidation. In addition, the incorporation of Cu adds to [Chr2Cu] the ability of a free radical scavenger, already described for similar Cu-chelate compounds. This collection of beneficial properties positions the complex as a remarkably promising bioprotector towards ROS-mediated oxidation. A quantification of the efficiency on the initial anti-oxidative effect exerted by Chr and [Chr2Cu] towards tryptophan was carried out. The amino acid is an archetypal molecular model, commonly employed to monitor oxidative degradation of proteinaceous media. It was efficiently photoprotected against O2((1)Δg)-mediated photooxidation by [Chr2Cu]. PMID

  1. Biological and geochemical controls on diel dissolved inorganic carbon cycling in a low-order agricultural stream: implications for reach scales and beyond

    USGS Publications Warehouse

    Bohlke, Johnkarl F.; Tobias, Craig

    2011-01-01

    Movement of dissolved inorganic carbon (DIC) through the hydrologic cycle is an important component of global carbon budgets, but there is considerable uncertainty about the controls of DIC transmission from landscapes to streams, and through river networks to the oceans. In this study, diel measurements of DIC, d13C-DIC, dissolved oxygen (O2), d18O-O2, alkalinity, pH, and other parameters were used to assess the relative magnitudes of biological and geochemical controls on DIC cycling and flux in a nutrient-rich, net autotrophic stream. Rates of photosynthesis (P), respiration (R), groundwater discharge, air–water exchange of CO2, and carbonate precipitation/dissolution were quantified through a time-stepping chemical/isotope (12C and 13C, 16O and 18O) mass balance model. Groundwater was the major source of DIC to the stream. Primary production and carbonate precipitation were equally important sinks for DIC removed from the water column. The stream was always super-saturated with respect to carbonate minerals, but carbonate precipitation occurred mainly during the day when P increased pH. We estimated more than half (possibly 90%) of the carbonate precipitated during the day was retained in the reach under steady baseflow conditions. The amount of DIC removed from the overlying water through carbonate precipitation was similar to the amount of DIC generated from R. Air–water exchange of CO2 was always from the stream to the atmosphere, but was the smallest component of the DIC budget. Overall, the in-stream DIC reactions reduced the amount of CO2 evasion and the downstream flux of groundwater-derived DIC by about half relative to a hypothetical scenario with groundwater discharge only. Other streams with similar characteristics are widely distributed in the major river basins of North America. Data from USGS water quality monitoring networks from the 1960s to the 1990s indicated that 40% of 652 stream monitoring stations in the contiguous USA were at or above

  2. Biological and geochemical controls on diel dissolved inorganic carbon cycling in a low-order agricultural stream: Implications for reach scales and beyond

    USGS Publications Warehouse

    Tobias, C.; Böhlke, J.K.

    2011-01-01

    Movement of dissolved inorganic carbon (DIC) through the hydrologic cycle is an important component of global carbon budgets, but there is considerable uncertainty about the controls of DIC transmission from landscapes to streams, and through river networks to the oceans. In this study, diel measurements of DIC, ??13C-DIC, dissolved oxygen (O2), ??18O-O2, alkalinity, pH, and other parameters were used to assess the relative magnitudes of biological and geochemical controls on DIC cycling and flux in a nutrient-rich, net autotrophic stream. Rates of photosynthesis (P), respiration (R), groundwater discharge, air-water exchange of CO2, and carbonate precipitation/dissolution were quantified through a time-stepping chemical/isotope (12C and 13C, 16O and 18O) mass balance model. Groundwater was the major source of DIC to the stream. Primary production and carbonate precipitation were equally important sinks for DIC removed from the water column. The stream was always super-saturated with respect to carbonate minerals, but carbonate precipitation occurred mainly during the day when P increased pH. We estimated more than half (possibly 90%) of the carbonate precipitated during the day was retained in the reach under steady baseflow conditions. The amount of DIC removed from the overlying water through carbonate precipitation was similar to the amount of DIC generated from R. Air-water exchange of CO2 was always from the stream to the atmosphere, but was the smallest component of the DIC budget. Overall, the in-stream DIC reactions reduced the amount of CO2 evasion and the downstream flux of groundwater-derived DIC by about half relative to a hypothetical scenario with groundwater discharge only. Other streams with similar characteristics are widely distributed in the major river basins of North America. Data from USGS water quality monitoring networks from the 1960s to the 1990s indicated that 40% of 652 stream monitoring stations in the contiguous USA were at or above

  3. Solution structure of the cytoplasmic domain of the human CD4 glycoprotein by CD and 1H NMR spectroscopy: implications for biological functions.

    PubMed

    Wray, V; Mertins, D; Kiess, M; Henklein, P; Trowitzsch-Kienast, W; Schubert, U

    1998-06-01

    The human T cell receptor CD4 is a type I integral membrane glycoprotein that is involved in T cell activation and also acts as the primary coreceptor for human immunodeficiency viruses (HIV). Here the structure of a synthetic 38 amino acid peptide corresponding to the complete cytoplasmic domain of CD4 (CD4CYTO) has been investigated under a variety of solution conditions using a combination of circular dichroism and homonuclear two-dimensional 1H nuclear magnetic resonance spectroscopy. In the presence of the membrane mimetic 2,2,2-trifluoroethanol (TFE), a conformational change of CD4CYTO from a random coil to an alpha-helical structure was observed. In keeping with this, CD4CYTO has the potential to associate with membranes as demonstrated by binding studies of in vitro phosphorylated CD4CYTO with microsomal membranes. Both chemical shift and nuclear Overhauser enhancement data in 50% 2,2, 2-trifluoroethanol solution provide direct experimental evidence for the predominance of a short amphiphatic alpha-helix that is approximately 4 turns in length and extends from positions Arg-402 to Lys-417. The present data provide, for the first time, compelling experimental evidence that only a fraction of CD4CYTO has a propensity for adopting secondary structure under conditions that are assumed to exist at or near to the membrane surface and that this alpha-helical structure is located in the membrane-proximal region of CD4CYTO. The N-terminal residues, that link the alpha-helix to the transmembrane anchor of CD4, and a substantial C-terminal portion (14-18 residues) of CD4CYTO are unstructured under the solution conditions investigated. Correlation of our structural data with recent studies on the biological activity of CD4CYTO indicates that the alpha-helix is of crucial importance for the interaction of CD4 with Nef and Vpu in the process of HIV-mediated CD4 down-regulation.

  4. Systems biology-based analysis implicates a novel role for vitamin D metabolism in the pathogenesis of age-related macular degeneration

    PubMed Central

    2011-01-01

    validated and replicated in the extended family cohort, an unrelated case-control cohort from central Greece and a prospective nested case-control population from the Nurse's Health Study and Health Professionals Follow-Up Studies, which included patients with all subtypes of AMD for a total of 2,528 individuals. Single point variants in CYP24A1 (the gene encoding the catabolising enzyme of the vitamin D pathway) were demonstrated to influence AMD risk after controlling for smoking history, sex and age in all populations, both separately and, more importantly, in a meta-analysis. This is the first report demonstrating a genetic association between vitamin D metabolism and AMD risk. These findings were also supplemented with expression data from human donor eyes and human retinal cell lines. These data not only extend previous biological studies in the AMD field, but further emphasise common antecedents between several disorders with an inflammatory/immunogenic component such as cardiovascular disease, cancer and AMD. PMID:22155603

  5. Nutrient and biological conditions of selected small streams in the Edwards Plateau, central Texas, 2005-06, and implications for development of nutrient criteria

    USGS Publications Warehouse

    Mabe, Jeffrey A.

    2007-01-01

    During the summers of 2005 and 2006 the U.S. Geological Survey, in cooperation with the Texas Commission on Environmental Quality, evaluated nutrient and biological conditions in small streams in parts of the Edwards Plateau of Central Texas. Land-cover analysis was used to select 15 small streams that represented a gradient of conditions with the potential to affect nutrient concentrations across the study area, which comprises two of four subregions of the Edwards Plateau ecoregion. All 15 streams were sampled for water properties, nutrients, algae, benthic invertebrates, and fish in summer 2005, and eight streams were resampled in summer 2006. Streams that did not receive wastewater effluent had relatively low nutrient concentrations and were classified as oligotrophic; streams receiving wastewater effluent had relatively high nutrient concentrations and were classified as eutrophic. Nutrient concentrations measured in the least-disturbed streams closely matched the U.S. Environmental Protection Agency nutrient criteria recommendations based on estimated reference concentrations. Nitrogen/phosphorus ratios indicated streams not affected by wastewater effluent might be limited by phosphorus concentrations. Algal indicators of nutrient condition were closely related to dissolved nitrogen concentrations and streamflow conditions. Ambient dissolved nitrogen concentrations (nitrite plus nitrate) were positively correlated with benthic algal chlorophyll-a concentrations. The correlation of benthic algal chlorophyll-a with instantaneous nitrite plus nitrate load was stronger than correlations with ambient nutrients. Increased nutrient concentrations were associated with increased macroalgae cover, wider diel dissolved oxygen ranges, and reduced diel dissolved oxygen minimums. Benthic invertebrate aquatic life use scores generally were classified as High to Exceptional in study streams despite the influence of urbanization or wastewater effluent. Reductions in aquatic

  6. Biological Technicians

    MedlinePlus

    ... Biological technicians typically need a bachelor’s degree in biology or a closely related field. It is important ... Biological technicians typically need a bachelor’s degree in biology or a closely related field. It is important ...

  7. Biological Filters.

    ERIC Educational Resources Information Center

    Klemetson, S. L.

    1978-01-01

    Presents the 1978 literature review of wastewater treatment. The review is concerned with biological filters, and it covers: (1) trickling filters; (2) rotating biological contractors; and (3) miscellaneous reactors. A list of 14 references is also presented. (HM)

  8. Biological Agents

    MedlinePlus

    ... to Z Index Contact Us FAQs What's New Biological Agents This page requires that javascript be enabled ... and Health Topics A-Z Index What's New Biological agents include bacteria, viruses, fungi, other microorganisms and ...

  9. Taurine: its biological role and clinical implications.

    PubMed

    Chesney, R W

    1985-01-01

    More than simply cataloging the numerous experimental models in which taurine plays a modulating role, this discussion aims at stimulating further investigation of the potential clinical value of this abundant sulfur amino acid. Both the biomedical investigator and clinician must be struck by the enormous amount of taurine floating freely in the intracellular water of the cells. In cardiac tissue alone, taurine levels of 20 mM or higher may be found. Given this abundance of taurine, why is our understanding of its function so elusive? Although it is clear taurine is important in conjugating bile acids to form water-soluble bile salts, only a fraction of available taurine is used for this function, predominantly in young animals and children. While taurine conjugation is the preferred route of bile acid conjugation in the young, changes in adults given 250 mg of taurine daily for two to three weeks are insignificant. Total pool size of bile acid and chenodeoxycholic acid declines. Unchanged are the rate of bile acid synthesis or the secretion rates of biliary cholesterol, bile acid and phospholipids. Biliary cholesterol saturation also stays the same. The finding that taurine availability protects against cholestasis induced by monohydroxy bile acids remains confined to guinea pigs. The abundance of taurine suggests it may be an osmoregulator of cell volume, and there is convincing evidence that it serves this function in fish. Taurine may play this role in the brain under high osmotic states such as hypernatremia, dehydration and uremia. Evidence is strong that taurine is vital in maintaining retinal function, which may explain why taurine is so abundant in human breast milk. Prolonged TPN feeding of infants demonstrates the importance of taurine in retinal development. We have begun to appreciate the role of the kidney in conserving taurine and how this is perturbed in the neonatal period. Taurine has recently been added to infant formulas (about 50 mg/L). Cataloging what we know of taurine function, however, produces a list of "maybes." Now is the time for exhaustive, careful taurine research that will produce more definite answers.

  10. The ovary: basic biology and clinical implications.

    PubMed

    Richards, Joanne S; Pangas, Stephanie A

    2010-04-01

    The classical view of ovarian follicle development is that it is regulated by the hypothalamic-pituitary-ovarian axis, in which gonadotropin-releasing hormone (GnRH) controls the release of the gonadotropic hormones follicle-stimulating hormone (FSH) and luteinizing hormone (LH), and that ovarian steroids exert both negative and positive regulatory effects on GnRH secretion. More recent studies in mice and humans indicate that many other intra-ovarian signaling cascades affect follicular development and gonadotropin action in a stage- and context-specific manner. As we discuss here, mutant mouse models and clinical evidence indicate that some of the most powerful intra-ovarian regulators of follicular development include the TGF-beta/SMAD, WNT/FZD/beta-catenin, and RAS/ERK1/2 signaling pathways and the FOXO/FOXL2 transcription factors.

  11. Biological implications of the 1996 controlled flood

    NASA Astrophysics Data System (ADS)

    Valdez, Richard A.; Shannon, Joseph P.; Blinn, Dean W.

    The 1996 controlled flood provided evidence that elevated releases from Glen Canyon Dam can enhance short-term primary and secondary production of aquatic resources of the Colorado River in Grand Canyon National Park. The flood scoured substantial proportions of benthic algae and macroinvertebrates and removed fine sediments from the channel, which ultimately stimulated primary productivity and consumer biomass. Channel margin sand deposits buried riparian vegetation and leaf litter, entraining nutrients for later incorporation into the upper trophic levels. The flood restructured high-stage sand bars and associated eddy return channels (i.e., backwaters used as nurseries by native and non-native fish), but many were short-lived because reattachment bars were eroded shortly after the flood. The flood was of insufficient magnitude to permanently suppress non-native fish populations, even though there was significant population depletion at some collecting sites. Pre-spawning aggregations, spawning ascents of tributaries, and habitat use by native fishes were unaffected by the flood. Adult rainbow trout (Oncorhynchus mykiss) in the Lees Ferry tailwater fishery were also unaffected, but the proportion of juveniles <152 mm total length decreased by 10% a strong year class following the flood indicated replacement through successful reproduction.

  12. Biological Implications of the Nuclear Age.

    ERIC Educational Resources Information Center

    Atomic Energy Commission, Oak Ridge, TN. Div. of Technical Information.

    Reported are the proceedings of an interdisciplinary symposium on the effects on the biosphere of the release of radiation from the use of nuclear energy. Papers given include discussions of the use of radioisotopes in medicine, the benefits and possible consequences of peaceful applications of nuclear explosives, methods of estimating maximum…

  13. Dimensions of systems biology.

    PubMed

    Huang, S; Wikswo, J

    2006-01-01

    Systems biology, possibly the latest sub-discipline of biology, has arisen as a result of the shockwave of genomic and proteomic data that has appeared in the past few years. However, despite ubiquitous initiatives that carry this label, there is no precise definition of systems biology other than the implication of a new, all-encompassing, multidisciplinary endeavor. Here we propose that systems biology is more than the integration of biology with methods of the physical and computational sciences, and also more than the expansion of the single-pathway approach to embracing genome-scale networks. It is the discipline that specifically addresses the fundamental properties of the complexity that living systems represent. To facilitate the discussion, we dissect and project the multifaceted systems complexity of living organisms into five dimensions: (1) molecular complexity; (2) structural complexity; (3) temporal complexity; (4) abstraction and emergence; and (5) algorithmic complexity. This "five-dimensional space" may provide a framework for comparing, classifying, and complementing the vast diversity of existing systems biology programs and their goals, and will also give a glimpse of the magnitude of the scientific problems associated with unraveling the ultimate mysteries of life.

  14. [Biological weapons].

    PubMed

    Kerwat, K; Becker, S; Wulf, H; Densow, D

    2010-08-01

    Biological weapons are weapons of mass destruction that use pathogens (bacteria, viruses) or the toxins produced by them to target living organisms or to contaminate non-living substances. In the past, biological warfare has been repeatedly used. Anthrax, plague and smallpox are regarded as the most dangerous biological weapons by various institutions. Nowadays it seems quite unlikely that biological warfare will be employed in any military campaigns. However, the possibility remains that biological weapons may be used in acts of bioterrorism. In addition all diseases caused by biological weapons may also occur naturally or as a result of a laboratory accident. Risk assessment with regard to biological danger often proves to be difficult. In this context, an early identification of a potentially dangerous situation through experts is essential to limit the degree of damage.

  15. Will extreme climatic events facilitate biological invasions?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extreme climatic events, such as intense heat waves, hurricanes, floods and droughts, can dramatically affect ecological and evolutionary processes, and more extreme events are projected with ongoing climate change. However, the implications of these events for biological invasions, which themselves...

  16. Granular Materials and Risks in ISRU

    NASA Technical Reports Server (NTRS)

    Behringer, Robert P.; Wilki8nson, R. Allen

    2004-01-01

    Working with soil, sand, powders, ores, cement and sintered bricks, excavating, grading construction sites, driving off-road, transporting granules in chutes and pipes, sifting gravel, separating solids from gases, and using hoppers are so routine that it seems straightforward to execute these operations on the Moon and Mars as we do on Earth. We discuss how little these processes are understood and point out the nature of trial-and-error practices that are used in today s massive over-design. Nevertheless, such designs have a high failure rate. Implementation and extensive incremental scaling up of industrial processes are routine because of the inadequate predictive tools for design. We present a number of pragmatic scenarios where granular materials play a role, the risks involved, what some of the basic issues are, and what understanding is needed to greatly reduce the risks. This talk will focus on a particular class of granular flow issues, those that pertain to dense materials, their physics, and the failure problems associated with them. In particular, key issues where basic predictability is lacking include stability of soils for the support of vehicles and facilities, ability to control the flow of dense materials (jamming and flooding/unjamming at the wrong time), the ability to predict stress profiles (hence create reliable designs) for containers such as bunkers or silos. In particular, stress fluctuations, which are not accounted for in standard granular design models, can be very large as granular materials flows, and one result is frequent catastrophic failure of granular devices.

  17. Granular Materials and Risks In ISRU

    NASA Technical Reports Server (NTRS)

    Behringer, Robert P.; Wilkinson, R. Allen

    2004-01-01

    Working with soil, sand, powders, ores, cement and sintered bricks, excavating, grading construction sites, driving off-road, transporting granules in chutes and pipes, sifting gravel, separating solids from gases, and using hoppers are so routine that it seems straightforward to execute these operations on the Moon and Mars as we do on Earth. We discuss how little these processes are understood and point out the nature of trial-and-error practices that are used in today's massive over-design. Nevertheless, such designs have a high failure rate. Implementation and extensive incremental scaling up of industrial processes are routine because of the inadequate predictive tools for design. We present a number of pragmatic scenarios where granular materials play a role, the risks involved, what some of the basic issues are, and what understanding is needed to greatly reduce the risks. This talk will focus on a particular class of granular flow issues, those that pertain to dense materials, their physics, and the failure problems associated with them. In particular, key issues where basic predictability is lacking include stability of soils for the support of vehicles and facilities, ability to control the flow of dense materials (jamming and flooding/unjamming at the wrong time), the ability to predict stress profiles (hence create reliable designs) for containers such as bunkers or silos. In particular, stress fluctuations, which are not accounted for in standard granular design models, can be very large as granular materials flows, and one result is frequent catastrophic failure of granular devices.

  18. ISRU Technologies for Mars Life Support

    NASA Technical Reports Server (NTRS)

    Finn, John E.; Kliss, Mark; Sridhar, K. R.; Iacomini, Christie

    2001-01-01

    Life support systems can take advantage of elements in the atmosphere of Mars to provide for necessary consumables such as oxygen and buffer gas for makeup of leakage. In situ consumables production (ISCP) can be performed effectively in conjunction with in situ propellant production, in which oxygen and methane are manufactured for rocket fuel. This project considers ways of achieving the optimal system objectives from the two sometimes competing objectives of ISPP and ISCP. In previous years we worked on production of a nitrogen-argon buffer gas as a by- product of the CO2 acquisition and compression system. Recently we have been focusing on combined electrolysis of water vapor and carbon dioxide. Combined electrolysis of water vapor and carbon dioxide is essential for reducin,o the complexity of a combined ISPP/ISCP plant. Using a solid oxide electrolysis cell (SOEC) for this combined process would be most advantageous for it allows mainly gas phase reactions, O2 gas delivered from the electrolyzer is free of any H2O vapor, and SOE is already a proven technology for pure CO2 electrolysis. Combined SOEC testing is conducted at The University of Arizona in the Space Technologies Laboratory (STL) of the Aerospace and Mechanical Engineering Department.

  19. Employing ISRU Models to Improve Hardware Design

    NASA Technical Reports Server (NTRS)

    Linne, Diane L.

    2010-01-01

    An analytical model for hydrogen reduction of regolith was used to investigate the effects of several key variables on the energy and mass performance of reactors for a lunar in-situ resource utilization oxygen production plant. Reactor geometry, reaction time, number of reactors, heat recuperation, heat loss, and operating pressure were all studied to guide hardware designers who are developing future prototype reactors. The effects of heat recuperation where the incoming regolith is pre-heated by the hot spent regolith before transfer was also investigated for the first time. In general, longer reaction times per batch provide a lower overall energy, but also result in larger and heavier reactors. Three reactors with long heat-up times results in similar energy requirements as a two-reactor system with all other parameters the same. Three reactors with heat recuperation results in energy reductions of 20 to 40 percent compared to a three-reactor system with no heat recuperation. Increasing operating pressure can provide similar energy reductions as heat recuperation for the same reaction times.

  20. Systems Biology

    SciTech Connect

    Wiley, H S.

    2006-06-01

    The biology revolution over the last 50 years has been driven by the ascendancy of molecular biology. This was enthusiastically embraced by most biologists because it took us into increasingly familiar territory. It took mysterious processes, such as the replication of genetic material and assigned them parts that could be readily understood by the human mind. When we think of ''molecular machines'' as being the underlying basis of life, we are using a paradigm derived from everyday experience. However, the price that we paid was a relentless drive towards reductionism and the attendant balkanization of biology. Now along comes ''systems biology'' that promises us a solution to the problem of ''knowing more and more about less and less''. Unlike molecular biology, systems biology appears to be taking us into unfamiliar intellectual territory, such as statistics, mathematics and computer modeling. Not surprisingly, systems biology has met with widespread skepticism and resistance. Why do we need systems biology anyway and how does this new area of research promise to change the face of biology in the next couple of decades?

  1. Is synthetic biology mechanical biology?

    PubMed

    Holm, Sune

    2015-12-01

    A widespread and influential characterization of synthetic biology emphasizes that synthetic biology is the application of engineering principles to living systems. Furthermore, there is a strong tendency to express the engineering approach to organisms in terms of what seems to be an ontological claim: organisms are machines. In the paper I investigate the ontological and heuristic significance of the machine analogy in synthetic biology. I argue that the use of the machine analogy and the aim of producing rationally designed organisms does not necessarily imply a commitment to mechanical biology. The ideal of applying engineering principles to biology is best understood as expressing recognition of the machine-unlikeness of natural organisms and the limits of human cognition. The paper suggests an interpretation of the identification of organisms with machines in synthetic biology according to which it expresses a strategy for representing, understanding, and constructing living systems that are more machine-like than natural organisms.

  2. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1982

    1982-01-01

    Describes laboratory procedures, demonstrations, and classroom activities/materials, including use of dwarf cichlids (fishes) in secondary school biology, teaching edge effects on stomatal diffusion, computer program on effects of selection on gene frequencies, biological oxidation/reduction reactions, short cuts with Drosophila, computer program…

  3. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1978

    1978-01-01

    Presents experiments, demonstrations, activities and ideas relating to various fields of biology to be used in biology courses in secondary schools. Among those experiments presented are demonstrating the early stages of ferns and mosses and simple culture methods for fern prothalli. (HM)

  4. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1982

    1982-01-01

    Presents procedures, exercises, demonstrations, and information on a variety of biology topics including labeling systems, biological indicators of stream pollution, growth of lichens, reproductive capacity of bulbous buttercups, a straw balance to measure transpiration, interaction of fungi, osmosis, and nitrogen fixation and crop production. (DC)

  5. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1983

    1983-01-01

    Describes laboratory procedures, demonstrations, and classroom activities/materials, including chi-square tests on a microcomputer, an integrated biology game, microscope slides of leaf stomata, culturing soil nematodes, technique for watering locust egg-laying tubes, hazards of biological chemicals (such as benzene, benzidene, calchicine,…

  6. Biological Oceanography

    NASA Astrophysics Data System (ADS)

    Dyhrman, Sonya

    2004-10-01

    The ocean is arguably the largest habitat on the planet, and it houses an astounding array of life, from microbes to whales. As a testament to this diversity and its importance, the discipline of biological oceanography spans studies of all levels of biological organization, from that of single genes, to organisms, to their population dynamics. Biological oceanography also includes studies on how organisms interact with, and contribute to, essential global processes. Students of biological oceanography are often as comfortable looking at satellite images as they are electron micrographs. This diversity of perspective begins the textbook Biological Oceanography, with cover graphics including a Coastal Zone Color Scanner image representing chlorophyll concentration, an electron micrograph of a dinoflagellate, and a photograph of a copepod. These images instantly capture the reader's attention and illustrate some of the different scales on which budding oceanographers are required to think. Having taught a core graduate course in biological oceanography for many years, Charlie Miller has used his lecture notes as the genesis for this book. The text covers the subject of biological oceanography in a manner that is targeted to introductory graduate students, but it would also be appropriate for advanced undergraduates.

  7. Biological scaling and physics.

    PubMed

    Rau, A R P

    2002-09-01

    Kleiber's law in biology states that the specific metabolic rate (metabolic rate per unit mass) scales as M- 1/4 in terms of the mass M of the organism. A long-standing puzzle is the (- 1/4) power in place of the usual expectation of (- 1/3) based on the surface to volume ratio in three-dimensions. While recent papers by physicists have focused exclusively on geometry in attempting to explain the puzzle, we consider here a specific law of physics that governs fluid flow to show how the (- 1/4) power arises under certain conditions. More generally, such a line of approach that identifies a specific physical law as involved and then examines the implications of a power law may illuminate better the role of physics in biology.

  8. BIOLOGICAL WARFARE

    PubMed Central

    Beeston, John

    1953-01-01

    The use of biological agents as controlled weapons of war is practical although uncertain. Three types of agents are feasible, including pathogenic organisms and biological pests, toxins, and synthetic hormones regulating plant growth. These agents may be chosen for selective effects varying from prolonged incipient illness to death of plants, man and domestic animals. For specific preventive and control measures required to combat these situations, there must be careful and detailed planning. The nucleus of such a program is available within the existing framework of public health activities. Additional research and expansion of established activities in time of attack are necessary parts of biological warfare defense. PMID:13059641

  9. Biological post

    PubMed Central

    Kumar, B. Suresh; Kumar, Senthil; Mohan Kumar, N. S.; Karunakaran, J. V.

    2015-01-01

    Anterior tooth fracture as a result of traumatic injuries, is frequently encountered in endodontic practice. Proper reconstruction of extensively damaged teeth can be achieved through the fragment reattachment procedure known as “biological restoration.” This case report refers to the esthetics and functional recovery of extensively damaged maxillary central incisor through the preparation and adhesive cementation of “biological post” in a young patient. Biological post obtained through extracted teeth from another individual–represent a low-cost option and alternative technique for the morphofunctional recovery of extensively damaged anterior teeth. PMID:26538952

  10. Biology Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Twelve new experiments in biology are described by teachers for use in classrooms. Broad areas covered include enzyme action, growth regulation, microscopy, respiration, germination, plant succession, leaf structure and blood structure. Explanations are detailed. (PS)

  11. Bottle Biology.

    ERIC Educational Resources Information Center

    CSTA Journal, 1995

    1995-01-01

    Provides hands-on biology activities using plastic bottles that allow students to become engaged in asking questions, creating experiments, testing hypotheses, and generating answers. Activities explore terrestrial and aquatic systems. (MKR)

  12. Biology Notes

    ERIC Educational Resources Information Center

    School Science Review, 1973

    1973-01-01

    Some helpful ideas are proposed for use by biology teachers. Topics included are Food Webs,'' Key to Identification of Families,'' Viruses,'' Sieve Tube,'' Woodlice,'' Ecology of Oak Leaf Roller Moth,'' and Model Making.'' (PS)

  13. Biology Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Ten ideas that have been tried out by the authors in schools are presented for biology teachers. The areas covered include genetics, dispersal of seeds, habituation in earthworms, respiration, sensory neurons, fats and oils. A reading list is provided. (PS)

  14. NEO Targets for Biological In Situ Resource Utilization

    NASA Astrophysics Data System (ADS)

    Grace, J. M.; Ernst, S. M.; Navarrete, J. U.; Gentry, D.

    2014-12-01

    We are investigating a mission architecture concept for low-cost pre-processing of materials on long synodic period asteroids using bioengineered microbes delivered by small spacecraft. Space exploration opportunities, particularly those requiring a human presence, are sharply constrained by the high cost of launching resources such as fuel, construction materials, oxygen, water, and foodstuffs. Near-Earth asteroids (NEAs) have been proposed for supporting a human space presence. However, the combination of high initial investment requirements, delayed potential return, and uncertainty in resource payoff currently prevents their effective utilization.Biomining is the process in which microorganisms perform useful material reduction, sequestration or separation. It is commonly used in terrestrial copper extraction. Compared to physical and chemical methods of extraction it is slow, but very low cost, thus rendering economical even very poor ores. These advantages are potentially extensible to asteroid in situ resource utilization (ISRU).One of the first limiting factors for the use of biology in these environments is temperature. A survey of NEA data was conducted to identify those NEAs whose projected interior temperatures remained within both potential (-5 - 100 ºC) and preferred (15 - 45 ºC) ranges for the minimum projected time per synodic period without exceeding 100 ºC at any point. Approximately 2800 of the 11000 NEAs (25%) are predicted to remain within the potential range for at least 90 days, and 120 (1%) in the preferred range.A second major factor is water availability and stability. We have evaluated a design for a small-spacecraft-based injector which forces low-temperature fluid into the NEA interior, creating potentially habitable microniches. The fluid contains microbes genetically engineered to accelerate the degradation rates of a desired fraction of the native resources, allowing for more efficient material extraction upon a subsequent

  15. Biological monitoring of radiation exposure

    NASA Astrophysics Data System (ADS)

    Horneck, G.

    1998-11-01

    Complementary to physical dosimetry, biological dosimetry systems have been developed and applied which weight the different components of environmental radiation according to their biological efficacy. They generally give a record of the accumulated exposure of individuals with high sensitivity and specificity for the toxic agent under consideration. Basically three different types of biological detecting/monitoring systems are available: (i) intrinsic biological dosimeters that record the individual radiation exposure (humans, plants, animals) in measurable units. For monitoring ionizing radiation exposure, in situ biomarkers for genetic (e.g. chromosomal aberrations in human lymphocytes, germ line minisatellite mutation rates) or metabolic changes in serum, plasma and blood (e.g. serum lipids, lipoproteins, lipid peroxides, melatonin, antibody titer) have been used. (ii) Extrinsic biological dosimeters/indicators that record the accumulated dose in biological model systems. Their application includes long-term monitoring of changes in environmental UV radiation and its biological implications as well as dosimetry of personal UV exposure. (iii) Biological detectors/biosensors for genotoxic substances and agents such as bacterial assays (e.g. Ames test, SOS-type test) that are highly sensitive to genotoxins with high specificity. They may be applicable for different aspects in environmental monitoring including the International Space Station.

  16. Biological Oceanography

    NASA Technical Reports Server (NTRS)

    Abbott, M. R.

    1984-01-01

    Within the framework of global biogeochemical cycles and ocean productivity, there are two areas that will be of particular interest to biological oceanography in the 1990s. The first is the mapping in space time of the biomass and productivity of phytoplankton in the world ocean. The second area is the coupling of biological and physical processes as it affects the distribution and growth rate of phytoplankton biomass. Certainly other areas will be of interest to biological oceanographers, but these two areas are amenable to observations from satellites. Temporal and spatial variability is a regular feature of marine ecosystems. The temporal and spatial variability of phytoplankton biomass and productivity which is ubiquitous at all time and space scales in the ocean must be characterized. Remote sensing from satellites addresses these problems with global observations of mesocale (2 to 20 days, 10 to 200 km) features over a long period of time.

  17. Biological preconcentrator

    DOEpatents

    Manginell, Ronald P.; Bunker, Bruce C.; Huber, Dale L.

    2008-09-09

    A biological preconcentrator comprises a stimulus-responsive active film on a stimulus-producing microfabricated platform. The active film can comprise a thermally switchable polymer film that can be used to selectively absorb and desorb proteins from a protein mixture. The biological microfabricated platform can comprise a thin membrane suspended on a substrate with an integral resistive heater and/or thermoelectric cooler for thermal switching of the active polymer film disposed on the membrane. The active polymer film can comprise hydrogel-like polymers, such as poly(ethylene oxide) or poly(n-isopropylacrylamide), that are tethered to the membrane. The biological preconcentrator can be fabricated with semiconductor materials and technologies.

  18. Biological monitoring

    SciTech Connect

    Miller, S.

    1984-06-01

    Recent research is reviewed from books, international committees and symposia which describes the usefulness of biological monitoring for exposure to such compounds as organometallic chemicals, carbon monoxide and cyanide. The types of analyses include the following measurements: the concentration of the chemical in various biological media such as blood, urine, and expired air; the concentration of metabolites of the individual chemical in the same media; and determination of nonadverse biological changes resulting from the reaction of the organism to exposure. A main goal of such monitoring is to ensure that the current or past levels of worker exposure are safe, so that such exposure does not involve an unacceptable health risk. It considers routes other than absorption by the lungs and is a good method for evaluating individual exposures.

  19. Biological rhythms

    NASA Technical Reports Server (NTRS)

    Halberg, F.

    1975-01-01

    An overview is given of basic features of biological rhythms. The classification of periodic behavior of physical and psychological characteristics as circadian, circannual, diurnal, and ultradian is discussed, and the notion of relativistic time as it applies in biology is examined. Special attention is given to circadian rhythms which are dependent on the adrenocortical cycle. The need for adequate understanding of circadian variations in the basic physiological indicators of an individual (heart rate, body temperature, systolic and diastolic blood pressure, etc.) to ensure the effectiveness of prophylactic and therapeutic measures is stressed.

  20. Systems biology approach to bioremediation

    SciTech Connect

    Chakraborty, Romy; Wu, Cindy H.; Hazen, Terry C.

    2012-06-01

    Bioremediation has historically been approached as a ‘black box’ in terms of our fundamental understanding. Thus it succeeds and fails, seldom without a complete understanding of why. Systems biology is an integrated research approach to study complex biological systems, by investigating interactions and networks at the molecular, cellular, community, and ecosystem level. The knowledge of these interactions within individual components is fundamental to understanding the dynamics of the ecosystem under investigation. Finally, understanding and modeling functional microbial community structure and stress responses in environments at all levels have tremendous implications for our fundamental understanding of hydrobiogeochemical processes and the potential for making bioremediation breakthroughs and illuminating the ‘black box’.

  1. Scaffolded biology.

    PubMed

    Minelli, Alessandro

    2016-09-01

    Descriptions and interpretations of the natural world are dominated by dichotomies such as organism vs. environment, nature vs. nurture, genetic vs. epigenetic, but in the last couple of decades strong dissatisfaction with those partitions has been repeatedly voiced and a number of alternative perspectives have been suggested, from perspectives such as Dawkins' extended phenotype, Turner's extended organism, Oyama's Developmental Systems Theory and Odling-Smee's niche construction theory. Last in time is the description of biological phenomena in terms of hybrids between an organism (scaffolded system) and a living or non-living scaffold, forming unit systems to study processes such as reproduction and development. As scaffold, eventually, we can define any resource used by the biological system, especially in development and reproduction, without incorporating it as happens in the case of resources fueling metabolism. Addressing biological systems as functionally scaffolded systems may help pointing to functional relationships that can impart temporal marking to the developmental process and thus explain its irreversibility; revisiting the boundary between development and metabolism and also regeneration phenomena, by suggesting a conceptual framework within which to investigate phenomena of regular hypermorphic regeneration such as characteristic of deer antlers; fixing a periodization of development in terms of the times at which a scaffolding relationship begins or is terminated; and promoting plant galls to legitimate study objects of developmental biology. PMID:27287514

  2. Bottle Biology.

    ERIC Educational Resources Information Center

    Jager, Peter

    1993-01-01

    Describes activities which utilize plastic drink bottles and are designed to foster the development of a wide range of biological and ecological concepts. Includes instructions for making a model compost column and presents a model that illustrates open versus closed ecosystems. (DDR)

  3. Biologic Vaccines

    PubMed Central

    ADAMS, KATHERINE T.

    2009-01-01

    The threat of new disease pandemics has spurred the development of biologic vaccines, which promise tremendous improvements in global and local health. Several lend themselves to the prevention or treatment of chronic diseases. But the uncertainties of whom to vaccinate raise the question of whether the health care system can make these promising products viable. PMID:22478749

  4. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1979

    1979-01-01

    Organized by topic is a reading list for A- and S-level biology. Described are experiments for measuring rate of water uptake in a shoot; questions to aid students in designing experiments; rise of overhead projection to demonstrate osmosis and blood cell counting; and microbial manufacture of vinegar. (CS)

  5. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1980

    1980-01-01

    Describes equipment, activities, and experiments useful in biology and environmental education instruction, including, among others, sampling in ecology using an overhead projector, the slide finder as an aid to microscopy, teaching kidney function, and teaching wildlife conservation-sand dune systems. (SK)

  6. Biology Notes

    ERIC Educational Resources Information Center

    School Science Review, 1976

    1976-01-01

    Describes nine biology experiments, including osmosis, genetics; oxygen content of blood, enzymes in bean seedlings, preparation of bird skins, vascularization in bean seedlings, a game called "sequences" (applied to review situations), crossword puzzle for human respiration, and physiology of the woodlouse. (CS)

  7. Scaffolded biology.

    PubMed

    Minelli, Alessandro

    2016-09-01

    Descriptions and interpretations of the natural world are dominated by dichotomies such as organism vs. environment, nature vs. nurture, genetic vs. epigenetic, but in the last couple of decades strong dissatisfaction with those partitions has been repeatedly voiced and a number of alternative perspectives have been suggested, from perspectives such as Dawkins' extended phenotype, Turner's extended organism, Oyama's Developmental Systems Theory and Odling-Smee's niche construction theory. Last in time is the description of biological phenomena in terms of hybrids between an organism (scaffolded system) and a living or non-living scaffold, forming unit systems to study processes such as reproduction and development. As scaffold, eventually, we can define any resource used by the biological system, especially in development and reproduction, without incorporating it as happens in the case of resources fueling metabolism. Addressing biological systems as functionally scaffolded systems may help pointing to functional relationships that can impart temporal marking to the developmental process and thus explain its irreversibility; revisiting the boundary between development and metabolism and also regeneration phenomena, by suggesting a conceptual framework within which to investigate phenomena of regular hypermorphic regeneration such as characteristic of deer antlers; fixing a periodization of development in terms of the times at which a scaffolding relationship begins or is terminated; and promoting plant galls to legitimate study objects of developmental biology.

  8. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1983

    1983-01-01

    Describes laboratory procedures, demonstrations, and classroom activities/materials, including water relation exercise on auxin-treated artichoke tuber tissue; aerobic respiration in yeast; an improved potometer; use of mobiles in biological classification, and experiments on powdery mildews and banana polyphenol oxidase. Includes reading lists…

  9. (Biological dosimetry)

    SciTech Connect

    Preston, R.J.

    1990-12-17

    The traveler attended the 1st International Conference on Biological Dosimetry in Madrid, Spain. This conference was organized to provide information to a general audience of biologists, physicists, radiotherapists, industrial hygiene personnel and individuals from related fields on the current ability of cytogenetic analysis to provide estimates of radiation dose in cases of occupational or environmental exposure. There is a growing interest in Spain in biological dosimetry because of the increased use of radiation sources for medical and occupational uses, and with this the anticipated and actual increase in numbers of overexposure. The traveler delivered the introductory lecture on Biological Dosimetry: Mechanistic Concepts'' that was intended to provide a framework by which the more applied lectures could be interpreted in a mechanistic way. A second component of the trip was to provide advice with regard to several recent cases of overexposure that had been or were being assessed by the Radiopathology and Radiotherapy Department of the Hospital General Gregorio Maranon'' in Madrid. The traveler had provided information on several of these, and had analyzed cells from some exposed or purportedly exposed individuals. The members of the biological dosimetry group were referred to individuals at REACTS at Oak Ridge Associated Universities for advice on follow-up treatment.

  10. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1981

    1981-01-01

    Outlines a variety of laboratory procedures, techniques, and materials including construction of a survey frame for field biology, a simple tidal system, isolation and applications of plant protoplasts, tropisms, teaching lung structure, and a key to statistical methods for biologists. (DS)

  11. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1981

    1981-01-01

    Presents content information and/or laboratory procedures and experiments on different biology topics including small-scale cultivation of watercress and its use in water-culture experiments, microbiology of the phylloplane, use of mouthbrooders in science class, and the gene. (DC)

  12. Biology Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1984

    1984-01-01

    Presents information on the teaching of nutrition (including new information relating to many current O-level syllabi) and part 16 of a reading list for A- and S-level biology. Also includes a note on using earthworms as a source of material for teaching meiosis. (JN)

  13. Sverdrup's Biology

    NASA Astrophysics Data System (ADS)

    McGowan, J.

    2002-12-01

    Sverdrup's contribution to Biological Oceanography were more than merely substantial, they were of fundamental importance. His plan for the training of graduate students at Scripps did not recognize the traditional division of the basic disciplines into separate categories of physics, chemistry, biology and geology. He insisted that Oceanography was a multi-disciplinary subject and that all entering students should study all four subjects. Today this is not very unusual but it was in the early 50s when I took those courses. We biologists carried away from those courses an appreciation of the importance of both spatial and temporal scale. It was of clear relevance to problems of oceanic population and community biology. But there was still more to his biology. He is responsible for a very simple, but very elegant model of the regulation of oceanic primary productivity. The elements of this model are found today in the ten or so highly derivative models. He also published a map predicting global ocean productivity based on the ideas in the model plus some wonderfully intuitive thinking. This map does not differ strongly from those glorious false color ones being published today.

  14. Marine Biology

    ERIC Educational Resources Information Center

    Dewees, Christopher M.; Hooper, Jon K.

    1976-01-01

    A variety of informational material for a course in marine biology or oceanology at the secondary level is presented. Among the topics discussed are: food webs and pyramids, planktonic blooms, marine life, plankton nets, food chains, phytoplankton, zooplankton, larval plankton and filter feeders. (BT)

  15. Cancer Biology

    ERIC Educational Resources Information Center

    Dominiecki, Mary E.

    2004-01-01

    University of Colorado's Virtual Student Fellowship available at and developed by Bakemeier, Richard F. This website is designed to give students applying for a fellowship an overview of basic topics in biology and how they are used by cancer researchers to develop new treatments.

  16. Monod and the spirit of molecular biology.

    PubMed

    Morange, Michel

    2015-06-01

    The founders of molecular biology shared views on the place of biology within science, as well as on the relations of molecular biology to Darwinism. Jacques Monod was no exception, but the study of his writings is particularly interesting because he expressed his point of view very clearly and pushed the implications of some of his choices further than most of his contemporaries. The spirit of molecular biology is no longer the same as in the 1960s but, interestingly, Monod anticipated some recent evolutions of this discipline.

  17. IKK Biology

    PubMed Central

    Liu, Fei; Xia, Yifeng; Parker, Aaron S.; Verma, Inder M.

    2012-01-01

    Summary The inhibitor of nuclear factor-κB (IκB) kinase (IKK) complex is the master regulator of the NF-κB signaling pathway. The activation of the IKK complex is a tightly regulated, highly stimulus-specific, and target-specific event that is essential for the plethora of functions attributed to NF-κB. More recently, NF-κB independent roles of IKK members have brought increased complexity to its biological function. This review highlights some of the major advances in the studies of the process of IKK activation and the biological roles of IKK family members, with a focus on NF-κB independent functions. Understanding these complex processes is essential for targeting IKK for therapeutics. PMID:22435559

  18. Crusts: biological

    USGS Publications Warehouse

    Belnap, Jayne; Elias, Scott A.

    2013-01-01

    Biological soil crusts, a community of cyanobacteria, lichens, mosses, and fungi, are an essential part of dryland ecosystems. They are critical in the stabilization of soils, protecting them from wind and water erosion. Similarly, these soil surface communities also stabilized soils on early Earth, allowing vascular plants to establish. They contribute nitrogen and carbon to otherwise relatively infertile dryland soils, and have a strong influence on hydrologic cycles. Their presence can also influence vascular plant establishment and nutrition.

  19. Marine biology

    SciTech Connect

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index.

  20. Biological-Community Composition in Small Streams and its Relations to Habitat, Nutrients, and Land Use in Agriculturally Dominated Landscapes in Indiana and Ohio, 2004, and Implications for Assessing Nutrient Conditions in Midwest Streams

    USGS Publications Warehouse

    Caskey, Brian J.; Frey, Jeffrey W.

    2009-01-01

    The objective of this study was to relate algal-, invertebrate-, and fish-community composition to habitat, nutrients, and land-use variables in small streams in agriculturally dominated landscapes of the Midwest in Indiana and Ohio. Thirty sample locations were selected from a single ecoregion; all were small wadable streams within agriculturally dominated landscapes with similar substrate and canopy. Biological and nutrient samples were collected during stable flow conditions in August 2004. Canonical correspondence analysis was used to determine which variables most influenced each community. Total phosphorus concentrations significantly influenced the depositional-targeted habitat algal-diatom community and the richest-targeted habitat invertebrate community. Multivariate statistical analysis showed that habitat variables were more influential to the richest-targeted habitat algal-diatom and fish communities than nutrient concentrations. Although the nutrient concentrations measured during this study indicate that most streams were not eutrophic, the biological communities were dominated by eutrophic species, suggesting streams sampled were eutrophic. Consequently, it was concluded that biological relations to nutrients in agriculturally dominated landscapes are complex and habitat variables should be included in biological assessments of nutrient conditions in agriculturally dominated landscapes.

  1. The Biological Universe Revisited

    NASA Astrophysics Data System (ADS)

    Dick, Steven J.

    2005-01-01

    Cosmic Evolution has been seen as leading to two possible world views: a physical universe in which life is rare or unique to Earth, and a biological universe, in which the processes of cosmic evolution commonly end in life. These two worldviews now hang in the balance, in the same way that the heliocentric and geocentric worldviews were in the balance four hundred years ago when Galileo wrote his Dialogue on the Two Chief World Systems (1632). Astrobiology is the science that will decide which of the two modern astronomical worldviews is true. A third world view, the postbiological universe, is also possible and deserves more discussion. The confirmation of one of these worldviews will have profound implications for human destiny.

  2. Biological membranes

    PubMed Central

    Watson, Helen

    2015-01-01

    Biological membranes allow life as we know it to exist. They form cells and enable separation between the inside and outside of an organism, controlling by means of their selective permeability which substances enter and leave. By allowing gradients of ions to be created across them, membranes also enable living organisms to generate energy. In addition, they control the flow of messages between cells by sending, receiving and processing information in the form of chemical and electrical signals. This essay summarizes the structure and function of membranes and the proteins within them, and describes their role in trafficking and transport, and their involvement in health and disease. Techniques for studying membranes are also discussed. PMID:26504250

  3. Exploring the strength, mode, dynamics, and kinetics of binding interaction of a cationic biological photosensitizer with DNA: implication on dissociation of the drug-DNA complex via detergent sequestration.

    PubMed

    Paul, Bijan Kumar; Guchhait, Nikhil

    2011-10-20

    The present study aims at exploring a detailed characterization of the binding interaction of a promising cancer cell photosensitizer, harmane (HM), with DNA extracted from herring sperm. The polarity-sensitive prototropic transformation of HM, a naturally occurring, fluorescent, drug-binding alkaloid, β-carboline, is remarkably modified upon interaction with DNA and is manifested through significant modulations on the absorption and emission profiles of HM. From the series of studies undertaken in the present program, for example, absorption; steady-state emission; the effect of chaotrope (urea); iodide ion-induced steady-state fluorescence quenching; circular dichroism (CD); and helix melting from absorption spectroscopy; the mode of binding of HM into the DNA helix has been substantiated to be principally intercalative. Concomitantly, a discernible dependence of the photophysics of the DNA-bound drug on the medium ionic strength indicates that electrostatic attraction should not be ignored in the interaction. Efforts have also been delivered to delineate the dynamical aspects of the interaction, such as modulation in time-resolved fluorescence decay and rotational relaxation dynamics of the drug within the DNA environment. In view of the prospective biological applications of HM, the issue of facile dissociation of intercalated HM from the DNA helix also comprises a crucial prerequisite for the functioning as an effective therapeutic agent. In this context, our results imply that the concept of detergent-sequestered dissociation of the drug from the drug-DNA complex can be a prospective strategy through an appropriate choice of the detergent molecule. The utility of the present work resides in exploring the potential applicability of the fluorescence property of HM for studying its interactions with a relevant biological target, for example, DNA. In addition, the methods and techniques used in the present work can also be exploited to study the interaction of

  4. Structural Biology Fact Sheet

    MedlinePlus

    ... Home > Science Education > Structural Biology Fact Sheet Structural Biology Fact Sheet Tagline (Optional) Middle/Main Content Area What is structural biology? Structural biology is a field of science focused ...

  5. Biology Cognitive Preferences of Preservice Biology Teachers.

    ERIC Educational Resources Information Center

    Cheng, Yeong-Jing

    1991-01-01

    The Biology Cognitive Preference Inventory (BCPI) for investigating the biology cognitive preference styles of 143 students in the biology teacher education program was developed and validated. The cognitive preferences include factual information or recall, principles, questioning, and applications. Preservice biology teachers exhibited a strong…

  6. Simulating Biological and Non-Biological Motion

    ERIC Educational Resources Information Center

    Bruzzo, Angela; Gesierich, Benno; Wohlschlager, Andreas

    2008-01-01

    It is widely accepted that the brain processes biological and non-biological movements in distinct neural circuits. Biological motion, in contrast to non-biological motion, refers to active movements of living beings. Aim of our experiment was to investigate the mechanisms underlying mental simulation of these two movement types. Subjects had to…

  7. Biological Literacy in a College Biology Classroom.

    ERIC Educational Resources Information Center

    Demastes, Sherry; Wandersee, James H.

    1992-01-01

    Examines the proposed definition of biological literacy as the understanding of a small number of pervasive biological principles appropriate to making informed personal and societal decisions. Utilizes the content of a major daily newspaper to adjust biology instruction to focus on this notion of biological literacy. Discusses benefits and…

  8. Kinetic Modeling of Biological Systems

    PubMed Central

    Petzold, Linda; Pettigrew, Michel F.

    2010-01-01

    The dynamics of how the constituent components of a natural system interact defines the spatio-temporal response of the system to stimuli. Modeling the kinetics of the processes that represent a biophysical system has long been pursued with the aim of improving our understanding of the studied system. Due to the unique properties of biological systems, in addition to the usual difficulties faced in modeling the dynamics of physical or chemical systems, biological simulations encounter difficulties that result from intrinsic multiscale and stochastic nature of the biological processes. This chapter discusses the implications for simulation of models involving interacting species with very low copy numbers, which often occur in biological systems and give rise to significant relative fluctuations. The conditions necessitating the use of stochastic kinetic simulation methods and the mathematical foundations of the stochastic simulation algorithms are presented. How the well-organized structural hierarchies often seen in biological systems can lead to multiscale problems, and possible ways to address the encountered computational difficulties are discussed. We present the details of the existing kinetic simulation methods, and discuss their strengths and shortcomings. A list of the publicly available kinetic simulation tools and our reflections for future prospects are also provided. PMID:19381542

  9. Biology and the Individual in Society

    ERIC Educational Resources Information Center

    Manier, Edward

    1970-01-01

    Discusses the interaction of biological knowledge and human values, emphasizing problems raised by man's ability to control human evolution. Analyzes moral and religious concerns about eugenic artificial insemination or nuclear transplantation, including implications for the structure of the family and the basis of parenthood. (EB)

  10. Molecular ferroelectrics: where electronics meet biology

    PubMed Central

    Li, Jiangyu; Liu, Yuanming; Zhang, Yanhang; Cai, Hong-Ling; Xiong, Ren-Gen

    2013-01-01

    In the last several years, we have witnessed significant advances in molecular ferroelectrics, with ferroelectric properties of molecular crystals approaching those of barium titanate. In addition, ferroelectricity has been observed in biological systems, filling an important missing link in bioelectric phenomena. In this perspective, we will present short historical notes on ferroelectrics, followed by overview on the fundamentals of ferroelectricity. Latest development in molecular ferroelectrics and biological ferroelectricity will then be highlighted, and their implications and potential applications will be discussed. We close by noting molecular ferroelectric as an exciting frontier between electronics and biology, and a number of challenges ahead are also noted. PMID:24018952

  11. Molecular ferroelectrics: where electronics meet biology.

    PubMed

    Li, Jiangyu; Liu, Yuanming; Zhang, Yanhang; Cai, Hong-Ling; Xiong, Ren-Gen

    2013-12-28

    In the last several years, we have witnessed significant advances in molecular ferroelectrics, with the ferroelectric properties of molecular crystals approaching those of barium titanate. In addition, ferroelectricity has been observed in biological systems, filling an important missing link in bioelectric phenomena. In this perspective, we will present short historical notes on ferroelectrics, followed by an overview of the fundamentals of ferroelectricity. The latest developments in molecular ferroelectrics and biological ferroelectricity will then be highlighted, and their implications and potential applications will be discussed. We close by noting molecular ferroelectric as an exciting frontier between electronics and biology, and a number of challenges ahead are also described.

  12. Mechanism of biological effects observed in honey bees (Apis mellifera, L. ) hived under extra-high-voltage transmission lines: implications derived from bee exposure to simulated intense electric fields and shocks

    SciTech Connect

    Bindokas, V.P.; Gauger, J.R.; Greenberg, B.

    1988-01-01

    This work explores mechanisms for disturbance of honey bee colonies under a 765 kV, 60-Hz transmission line (electric (E) field = 7 kV/m) observed in previous studies. Proposed mechanisms fell into two categories: direct bee perception of enhanced in-hive E fields and perception of shock from induced currents. The adverse biological effects could be reproduced in simulations where only the worker bees were exposed to shock or to E field in elongated hive entranceways (= tunnels). We now report the results of full-scale experiments using the tunnel exposure scheme, which assesses the contribution of shock and intense E field to colony disturbance. Exposure of worker bees (1400 h) to 60-Hz E fields including 100 kV/m under moisture-free conditions within a nonconductive tunnel causes no deleterious affect on colony behavior. Exposure of bees in conductive (e.g., wet) tunnels produces bee disturbance, increased mortality, abnormal propolization, and possible impairment of colony growth. We propose that this substrate dependence of bee disturbance is the result of perception of shock from coupled body currents and enhanced current densities postulated to exist in the legs and thorax of bees on conductors. Similarly, disturbance occurs when bees are exposed to step-potential-induced currents. At 275-350 nA single bees are disturbed; at 600 nA bees begin abnormal propolization behavior; and stinging occurs at 900 nA. We conclude that biological effects seen in bee colonies under a transmission line are primarily the result of electric shock from induced hive currents. This evaluation is based on the limited effects of E-field exposure in tunnels, the observed disturbance thresholds caused by shocks in tunnels, and the ability of hives exposed under a transmission line to source currents 100-1,000 times the shock thresholds.

  13. The anatomy and ontogeny of the head, neck, pectoral, and upper limb muscles of Lemur catta and Propithecus coquereli (primates): discussion on the parallelism between ontogeny and phylogeny and implications for evolutionary and developmental biology.

    PubMed

    Diogo, Rui; Molnar, Julia L; Smith, Timothy D

    2014-08-01

    Most anatomical studies of primates focus on skeletal tissues, but muscular anatomy can provide valuable information about phylogeny, functional specializations, and evolution. Herein, we present the first detailed description of the head, neck, pectoral, and upper limb muscles of the fetal lemuriforms Lemur catta (Lemuridae) and Propithecus coquereli (Indriidae). These two species belong to the suborder Strepsirrhini, which is often presumed to possess some plesiomorphic anatomical features within primates. We compare the muscular anatomy of the fetuses with that of infants and adults and discuss the evolutionary and developmental implications. The fetal anatomy reflects a phylogenetically more plesiomorphic condition in nine of the muscles we studied and a more derived condition in only two, supporting a parallel between ontogeny and phylogeny. The derived exceptions concern muscles with additional insertions in the fetus which are lost in adults of the same species, that is, flexor carpi radialis inserts on metacarpal III and levator claviculae inserts on the clavicle. Interestingly, these two muscles are involved in movements of the pectoral girdle and upper limb, which are mainly important for activities in later stages of life, such as locomotion and prey capture, rather than activities in fetal life. Accordingly, our findings suggest that some exceptions to the "ontogeny parallels phylogeny" rule are probably driven more by ontogenetic constraints than by adaptive plasticity.

  14. Cell biology perspectives in phage biology.

    PubMed

    Ansaldi, Mireille

    2012-01-01

    Cellular biology has long been restricted to large cellular organisms. However, as the resolution of microscopic methods increased, it became possible to study smaller cells, in particular bacterial cells. Bacteriophage biology is one aspect of bacterial cell biology that has recently gained insight from cell biology. Despite their small size, bacteriophages could be successfully labeled and their cycle studied in the host cells. This review aims to put together, although non-extensively, several cell biology studies that recently pushed the elucidation of key mechanisms in phage biology, such as the lysis-lysogeny decision in temperate phages or genome replication and transcription, one step further.

  15. A Bioethics Course for Biology and Science Education Students.

    ERIC Educational Resources Information Center

    Bryant, John; la Velle, Linda Baggott

    2003-01-01

    Points out the importance of awareness among biologists and biology teachers of the ethical and social implications of their work. Describes the bioethics module established at the University of Exeter mainly targeting students majoring in biology and science education. (Contains 18 references.) (Author/YDS)

  16. Biosecurity and Open-Source Biology: The Promise and Peril of Distributed Synthetic Biological Technologies.

    PubMed

    Evans, Nicholas G; Selgelid, Michael J

    2015-08-01

    In this article, we raise ethical concerns about the potential misuse of open-source biology (OSB): biological research and development that progresses through an organisational model of radical openness, deskilling, and innovation. We compare this organisational structure to that of the open-source software model, and detail salient ethical implications of this model. We demonstrate that OSB, in virtue of its commitment to openness, may be resistant to governance attempts.

  17. Cancer research meets evolutionary biology

    PubMed Central

    Pepper, John W; Scott Findlay, C; Kassen, Rees; Spencer, Sabrina L; Maley, Carlo C

    2009-01-01

    There is increasing evidence that Darwin's theory of evolution by natural selection provides insights into the etiology and treatment of cancer. On a microscopic scale, neoplastic cells meet the conditions for evolution by Darwinian selection: cell reproduction with heritable variability that affects cell survival and replication. This suggests that, like other areas of biological and biomedical research, Darwinian theory can provide a general framework for understanding many aspects of cancer, including problems of great clinical importance. With the availability of raw molecular data increasing rapidly, this theory may provide guidance in translating data into understanding and progress. Several conceptual and analytical tools from evolutionary biology can be applied to cancer biology. Two clinical problems may benefit most from the application of Darwinian theory: neoplastic progression and acquired therapeutic resistance. The Darwinian theory of cancer has especially profound implications for drug development, both in terms of explaining past difficulties, and pointing the way toward new approaches. Because cancer involves complex evolutionary processes, research should incorporate both tractable (simplified) experimental systems, and also longitudinal observational studies of the evolutionary dynamics of cancer in laboratory animals and in human patients. Cancer biology will require new tools to control the evolution of neoplastic cells. PMID:25567847

  18. Anion binding in biological systems

    NASA Astrophysics Data System (ADS)

    Feiters, Martin C.; Meyer-Klaucke, Wolfram; Kostenko, Alexander V.; Soldatov, Alexander V.; Leblanc, Catherine; Michel, Gurvan; Potin, Philippe; Küpper, Frithjof C.; Hollenstein, Kaspar; Locher, Kaspar P.; Bevers, Loes E.; Hagedoorn, Peter-Leon; Hagen, Wilfred R.

    2009-11-01

    We compare aspects of biological X-ray absorption spectroscopy (XAS) studies of cations and anions, and report on some examples of anion binding in biological systems. Brown algae such as Laminaria digitata (oarweed) are effective accumulators of I from seawater, with tissue concentrations exceeding 50 mM, and the vanadate-containing enzyme haloperoxidase is implicated in halide accumulation. We have studied the chemical state of iodine and its biological role in Laminaria at the I K edge, and bromoperoxidase from Ascophyllum nodosum (knotted wrack) at the Br K edge. Mo is essential for many forms of life; W only for certain archaea, such as Archaeoglobus fulgidus and the hyperthermophilic archaeon Pyrococcus furiosus, and some bacteria. The metals are bound and transported as their oxo-anions, molybdate and tungstate, which are similar in size. The transport protein WtpA from P. furiosus binds tungstate more strongly than molybdate, and is related in sequence to Archaeoglobus fulgidus ModA, of which a crystal structure is known. We have measured A. fulgidus ModA with tungstate at the W L3 (2p3/2) edge, and compared the results with the refined crystal structure. XAS studies of anion binding are feasible even if only weak interactions are present, are biologically relevant, and give new insights in the spectroscopy.

  19. Plant biology in the future.

    PubMed

    Bazzaz, F A

    2001-05-01

    In the beginning of modern plant biology, plant biologists followed a simple model for their science. This model included important branches of plant biology known then. Of course, plants had to be identified and classified first. Thus, there was much work on taxonomy, genetics, and physiology. Ecology and evolution were approached implicitly, rather than explicitly, through paleobotany, taxonomy, morphology, and historical geography. However, the burgeoning explosion of knowledge and great advances in molecular biology, e.g., to the extent that genes for specific traits can be added (or deleted) at will, have created a revolution in the study of plants. Genomics in agriculture has made it possible to address many important issues in crop production by the identification and manipulation of genes in crop plants. The current model of plant study differs from the previous one in that it places greater emphasis on developmental controls and on evolution by differential fitness. In a rapidly changing environment, the current model also explicitly considers the phenotypic variation among individuals on which selection operates. These are calls for the unity of science. In fact, the proponents of "Complexity Theory" think there are common algorithms describing all levels of organization, from atoms all the way to the structure of the universe, and that when these are discovered, the issue of scaling will be greatly simplified! Plant biology must seriously contribute to, among other things, meeting the nutritional needs of the human population. This challenge constitutes a key part of the backdrop against which future evolution will occur. Genetic engineering technologies are and will continue to be an important component of agriculture; however, we must consider the evolutionary implications of these new technologies. Meeting these demands requires drastic changes in the undergraduate curriculum. Students of biology should be trained in molecular, cellular, organismal

  20. Astrosociological Implications of Astrobiology (Revisited)

    NASA Astrophysics Data System (ADS)

    Pass, Jim

    2010-01-01

    Supporters of astrobiology continue to organize the field around formalized associations and organizations under the guise of the so-called ``hard'' sciences (e.g., biology and the related physical/natural sciences). The so-called ``soft'' sciences-including sociology and the other social sciences, the behavioral sciences, and the humanities-remain largely separated from this dynamically growing field. However, as argued in this paper, space exploration involving the search for extraterrestrial life should be viewed as consisting of two interrelated parts (i.e., two sides of the same coin): astrobiology and astrosociology. Together, these two fields broadly combine the two major branches of science as they relate to the relationship between human life and alien life, as appropriate. Moreover, with a formalized system of collaboration, these two complimentary fields would also focus on the implications of their research to human beings as well as their cultures and social structures. By placing the astrosociological implications of astrobiology at a high enough priority, scientists interested in the search for alien life can augment their focus to include the social, cultural, and behavioral implications that were always associated with their work (yet previously overlooked or understated, and too often misunderstood). Recognition of the astrosociological implications expands our perception about alien life by creating a new emphasis on their ramifications to human life on Earth.