What forms of life could have arisen in the ancient conditions of Mars?
NASA Astrophysics Data System (ADS)
Vidmachenko, A. P.
2017-05-01
The first geological era of Mars - Phyllocyanic - began about 4.5 billion years ago and continued 500-700 million years. Then Mars was similar to the ancient Earth with dense atmosphere and water on the surface. That is he planet was once much more suitable for the existence of life. Then appeared simple forms of life on Earth, and we believe, that the same could happen on Mars. But it is likely that if once life appeared on Mars, it did not disappear without a trace. It could move from the surface of the planet to its interior, to be conserved there in relict fossils, and possibly, survived there in some very simple forms, that then covered by powerful soil emissions. Therefore, its traces should search under the ground in those layers of sedimentary rocks that are refers to the first Phyllocyanic geological epoch.
Life extending control: An interdisciplinary engineering thrust
NASA Technical Reports Server (NTRS)
Lorenzo, Carl F.; Merrill, Walter C.
1991-01-01
The concept of Life Extending Control (LEC) is introduced. Possible extensions to the cyclic damage prediction approach are presented based on the identification of a model from elementary forms. Several candidate elementary forms are presented. These extensions will result in a continuous or differential form of the damage prediction model. Two possible approaches to the LEC based on the existing cyclic damage prediction method, the measured variables LEC and the estimated variables LEC, are defined. Here, damage estimates or measurements would be used directly in the LEC. A simple hydraulic actuator driven position control system example is used to illustrate the main ideas behind LEC. Results from a simple hydraulic actuator example demonstrate that overall system performance (dynamic plus life) can be maximized by accounting for component damage in the control design.
Complex Autocatalysis in Simple Chemistries.
Virgo, Nathaniel; Ikegami, Takashi; McGregor, Simon
2016-01-01
Life on Earth must originally have arisen from abiotic chemistry. Since the details of this chemistry are unknown, we wish to understand, in general, which types of chemistry can lead to complex, lifelike behavior. Here we show that even very simple chemistries in the thermodynamically reversible regime can self-organize to form complex autocatalytic cycles, with the catalytic effects emerging from the network structure. We demonstrate this with a very simple but thermodynamically reasonable artificial chemistry model. By suppressing the direct reaction from reactants to products, we obtain the simplest kind of autocatalytic cycle, resulting in exponential growth. When these simple first-order cycles are prevented from forming, the system achieves superexponential growth through more complex, higher-order autocatalytic cycles. This leads to nonlinear phenomena such as oscillations and bistability, the latter of which is of particular interest regarding the origins of life.
Relicts and models of the RNA world
NASA Astrophysics Data System (ADS)
Lehto, Kirsi; Karetnikov, Alexey
2005-01-01
It is widely believed that the current DNA-RNA-protein-based life forms have evolved from preceding RNA-protein-based life forms, and these again, from mere RNA replicons. By rationale, it can be assumed that the early RNA replicons were fully heterotrophic in terms of obtaining all their building blocks from their environment. In the absence of protein catalysts, their essential life functions had to be mediated by simple functional structures and mechanisms, such as RNA secondary structures, RNA-RNA interactions and RNA-mediated catalysis, and possibly by catalytic minerals or clays. The central role of RNA catalysts in early life forms is supported by the fact that several catalytic RNAs still perform central biological functions in current life forms, and at least some of these may be derived as molecular relicts from the early RNA-based life. The RNA-catalysed metabolic reactions and molecular fossils are more conserved in the eukaryotic life forms than in the prokaryotes, suggesting that the linear eukaryote genomes may more closely resemble the structure and function of the early RNA replicons, than what do the circular prokaryote genomes. Present-day RNA viruses and viroids utilize ultimately simple life strategies, which may be similar to those used by the early RNA replicons. Thus, molecular and functional properties of viruses and viroids may be considered as examples or models of the structures and replication mechanisms, which might have been used for the replication of the early biopolymers.
End of Life Care (Brain Tumors)
... directives once you better understand your condition. Healthcare Power of Attorney This document names a person who ... simple form that covers both advanced directives and power of health care attorney. This Five Wishes form, ...
The diagnosis of sepsis revisited - a challenge for young medical scientists in the 21st century
2014-01-01
In 1991, a well-meaning consensus group of thought leaders derived a simple definition for sepsis which required the breach of only a few static thresholds. More than 20 years later, this simple definition has calcified to become the gold standard for sepsis protocols and research. Yet sepsis clearly comprises a complex, dynamic, and relational distortion of human life. Given the profound scope of the loss of life worldwide, there is a need to disengage from the simple concepts of the past. There is an acute need to develop 21st century approaches which engage sepsis in its true form, as a complex, dynamic, and relational pattern of death. PMID:24383420
Characteristic Sizes of Life in the Oceans, from Bacteria to Whales.
Andersen, K H; Berge, T; Gonçalves, R J; Hartvig, M; Heuschele, J; Hylander, S; Jacobsen, N S; Lindemann, C; Martens, E A; Neuheimer, A B; Olsson, K; Palacz, A; Prowe, A E F; Sainmont, J; Traving, S J; Visser, A W; Wadhwa, N; Kiørboe, T
2016-01-01
The size of an individual organism is a key trait to characterize its physiology and feeding ecology. Size-based scaling laws may have a limited size range of validity or undergo a transition from one scaling exponent to another at some characteristic size. We collate and review data on size-based scaling laws for resource acquisition, mobility, sensory range, and progeny size for all pelagic marine life, from bacteria to whales. Further, we review and develop simple theoretical arguments for observed scaling laws and the characteristic sizes of a change or breakdown of power laws. We divide life in the ocean into seven major realms based on trophic strategy, physiology, and life history strategy. Such a categorization represents a move away from a taxonomically oriented description toward a trait-based description of life in the oceans. Finally, we discuss life forms that transgress the simple size-based rules and identify unanswered questions.
Where else might be life in the Solar system?
NASA Astrophysics Data System (ADS)
Vidmachenko, A. P.; Steklov, A. F.
2017-05-01
We know that there is life on Earth. But some bacteria live in nearly boiling liquid of an extinct volcano, which is saturated by acids, alkalis and salts in various combinations. The main problem of the modern theory of the origin of life is the emergence from the initial chaotic mixture of chemical elements and simple compounds of polymer systems that can to organize themselves, and their subsequent evolution. The main forms of life on Earth are organisms of cellular structure. Exceptions are viruses, that are non-cellular life forms. If we find somewhere life in the Solar system, most likely, it will be microscopic cells. The most likely candidates for this honorable role are: Jupiter's moon Io, Jupiter's moon Europa, Saturn's moons Titan and Enceladus, Neptune's satellite Triton; on the surface of Pluto also found two cryovolcanoes, spacecraft "Dawn" discovered the vast reserves of water on dwarf planet Ceres; also, on its surface was found a large cryovolcano. The most likely candidate for the presence of life is Mars. These bodies are possible objects in the Solar system, where one can search for life of different forms.
NASA Technical Reports Server (NTRS)
Raup, D. M.; Valentine, J. W.
1983-01-01
There is some indication that life may have originated readily under primitive earth conditions. If there were multiple origins of life, the result could have been a polyphyletic biota today. Using simple stochastic models for diversification and extinction, we conclude: (1) the probability of survival of life is low unless there are multiple origins, and (2) given survival of life and given as many as 10 independent origins of life, the odds are that all but one would have gone extinct, yielding the monophyletic biota we have now. The fact of the survival of our particular form of life does not imply that it was unique or superior.
Liu, Yao; Yang, Bingchang; Dong, Xiaoli; Wang, Yonggang; Xia, Yongyao
2017-12-22
Lithium-ion batteries (LIBs) are being used to power the commercial electric vehicles (EVs). However, the charge/discharge rate and life of current LIBs still cannot satisfy the further development of EVs. Furthermore, the poor low-temperature performance of LIBs limits their application in cold climates and high altitude areas. Herein, a simple prelithiation method is developed to fabricate a new LIB. In this strategy, a Li 3 V 2 (PO 4 ) 3 cathode and a pristine hard carbon anode are used to form a primary cell, and the initial Li + extraction from Li 3 V 2 (PO 4 ) 3 is used to prelithiate the hard carbon. Then, the self-formed Li 2 V 2 (PO 4 ) 3 cathode and prelithiated hard carbon anode are used to form a 4 V LIB. The LIB exhibits a maximum energy density of 208.3 Wh kg -1 , a maximum power density of 8291 W kg -1 and a long life of 2000 cycles. When operated at -40 °C, the LIB can keep 67 % capacity of room temperature, which is much better than conventional LIBs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Prebiotic hydrocarbon synthesis in impacting reduced astrophysical icy mixtures
Koziol, Lucas; Goldman, Nir
2015-04-21
We present results of prebiotic organic synthesis in shock-compressed reducing mixtures of simple ices from quantum molecular dynamics simulations extended to close to chemical equilibrium timescales. Given the relative abundance of carbon in reduced forms in astrophysical ices as well as the tendency of these mixtures to form complex hydrocarbons under the presence of external stimuli, it is possible that cometary impacts on a planetary surface could have yielded a larger array of prebiotic organic compounds than previously investigated. We find that the high pressures and temperatures due to shock compression yield a large assortment of carbon- and nitrogen-bonded extendedmore » structures that are highly reactive with short molecular lifetimes. Expansion and cooling causes these materials to break apart and form a wide variety of stable, potentially life-building compounds, including long-chain linear and branched hydrocarbons, large heterocyclic compounds, and a variety of different amines and exotic amino acids. Lastly, our results help provide a bottom-up understanding of hydrocarbon impact synthesis on the early Earth and its role in producing life-building molecules from simple starting materials.« less
Prebiotic hydrocarbon synthesis in impacting reduced astrophysical icy mixtures
DOE Office of Scientific and Technical Information (OSTI.GOV)
Koziol, Lucas; Goldman, Nir
We present results of prebiotic organic synthesis in shock-compressed reducing mixtures of simple ices from quantum molecular dynamics simulations extended to close to chemical equilibrium timescales. Given the relative abundance of carbon in reduced forms in astrophysical ices as well as the tendency of these mixtures to form complex hydrocarbons under the presence of external stimuli, it is possible that cometary impacts on a planetary surface could have yielded a larger array of prebiotic organic compounds than previously investigated. We find that the high pressures and temperatures due to shock compression yield a large assortment of carbon- and nitrogen-bonded extendedmore » structures that are highly reactive with short molecular lifetimes. Expansion and cooling causes these materials to break apart and form a wide variety of stable, potentially life-building compounds, including long-chain linear and branched hydrocarbons, large heterocyclic compounds, and a variety of different amines and exotic amino acids. Lastly, our results help provide a bottom-up understanding of hydrocarbon impact synthesis on the early Earth and its role in producing life-building molecules from simple starting materials.« less
Feces production as a form of social immunity in an insect with facultative maternal care.
Diehl, Janina M C; Körner, Maximilian; Pietsch, Michael; Meunier, Joël
2015-03-12
Social animals have the unique capability of mounting social defenses against pathogens. Over the last decades, social immunity has been extensively studied in species with obligatory and permanent forms of social life. However, its occurrence in less derived social systems and thus its role in the early evolution of group-living remains unclear. Here, we investigated whether lining nests with feces is a form of social immunity against microbial growth in the European earwig Forficula auricularia, an insect with temporary family life and facultative maternal care. Using a total of 415 inhibition zone assays, we showed that earwig feces inhibit the growth of two GRAM+ bacteria, two fungi, but not of a GRAM- bacteria. These inhibitions did not result from the consumed food or the nesting environment. We then demonstrated that the antimicrobial activity against fungus was higher in offspring than maternal feces, but that this difference was absent against bacteria. Finally, we showed that family interactions inhibited the antibacterial activity of maternal feces against one of the two GRAM+ bacteria, whereas it had no effect on the one of nymphal feces. By contrast, antifungal activities of the feces were independent of mother-offspring interactions. These results demonstrate that social immunity occurs in a species with simple and facultative social life, and thus shed light on the general importance of this process in the evolution of group-living. These results also emphasize that defecation can be under selection for other life-history traits than simple waste disposal.
Urey Prize Lecture - Planetary evolution and the origin of life
NASA Technical Reports Server (NTRS)
Mckay, Christopher P.
1991-01-01
One of the principal questions concerning planetary evolution and life's origins relates to the early-earth organic material's origination in situ, outer solar system importation, or simple irrelevance to the emergence of organisms. Additional considerations encompass the character of interstellar organic material and its relationship to outer solar system organic compounds, and the possibility of life's emergence in the early Mars. Attention is given to the essentiality of liquid water for life-forms, in the role not only of a reaction medium among molecules but that of a basis for hydrophylic and hydrophobic groups' bonding.
ERIC Educational Resources Information Center
Bishara, Monica
1990-01-01
Shows how high school students used foam carpet padding to create forms for still-life drawing. Discusses learning to progress from simple-line drawing to a three-dimensional image. Identifies the drawing of shadows, and extreme light and dark values, as points that need to be emphasized repeatedly. (KM)
Phytase, a new life for an “old” enzyme
USDA-ARS?s Scientific Manuscript database
Phytase represents a group of phosphohydrolytic enzymes that initiate stepwise removals of phosphate from phytate. Simple-stomached species such as swine, poultry, and fish require extrinsic phytase to digest phytate: the major form of phosphorus in plant feeds. Consequently, this enzyme is suppleme...
Evolution, Entropy, & Biological Information
ERIC Educational Resources Information Center
Peterson, Jacob
2014-01-01
A logical question to be expected from students: "How could life develop, that is, change, evolve from simple, primitive organisms into the complex forms existing today, while at the same time there is a generally observed decline and disorganization--the second law of thermodynamics?" The explanations in biology textbooks relied upon by…
Energy transduction inside vesicles, photocatalysis by titanium dioxide and formation of NADH
NASA Astrophysics Data System (ADS)
Summers, David; Noveron, Juan; Rodoni, David; Basa, Ranor
A number of theories on the origin and early evolution of life have focused on the role of lipid bilayer membrane structures (vesicles). These vesicles are similar to modern cellular membranes , and have been postulated to have been abiotically formed and spontaneously assemble on the prebiotic Earth to provide compartments for early cellular life. They can contain water-soluble species, concentrate species, and have the potential to catalyze reactions. The origin of the use of photochemical energy to drive metabolism (ie. energy transduction) is also one of the central issues in our attempts to understand the origin and evolution of life. When did energy transduction and photosynthesis begin? What was the original system for capturing photochemical energy? How simple can such a system be? It has been postulated that vesicle structures developed the ability to capture and transduce light, providing energy for reactions. It has been shown that pH gradients can be photo-chemically created, but it has been found difficult to couple these to drive chemical reactions. Minerals can introduce a number of properties to a vesicle system. The incorporation of clay particles into vesicles can provide catalytic activity that mediates both vesicle assembly and RNA oligomerization. It is known that colloidal semiconducting mineral particles can act as photocatalysts and drive redox chemistry. We show that encapsulation of these particles has the potential to provide a source of energy transduction inside vesicles, and thereby drive protocellular chemistry and represent a model system for early photosynthesis. TiO2 particles can be incorporated into vesicles and retain their photoactivity through the dehydration/rehydration cycles that have been shown to be able concentrate species inside a vesicle. It is shown that these can be used to produce biochemical species such as enzymatically active NADH in such structures. This system demonstrates a simple energy source inside vesicles/protocells suitable either for simple prebiotic systems and/or for more complex "protobiochemical" systems. It could act as a precursor to metabolic systems and provide a model of how metabolism could have developed prebiotically in a vesicle based "protocell origin of life". It can provide a source of prebiotic compounds inside vesicles, an environment considered to be of great importance for the origin of life. An energy transduction system that is simple enough to have formed at an early stage of the origin of life (even before the formation of enzymatic or ribozymal activity) makes an autotrophic origin of life easier to envision.
Fatigue and damage tolerance scatter models
NASA Astrophysics Data System (ADS)
Raikher, Veniamin L.
1994-09-01
Effective Total Fatigue Life and Crack Growth Scatter Models are proposed. The first of them is based on the power form of the Wohler curve, fatigue scatter dependence on mean life value, cycle stress ratio influence on fatigue scatter, and validated description of the mean stress influence on the mean fatigue life. The second uses in addition are fracture mechanics approach, assumption of initial damage existence, and Paris equation. Simple formulas are derived for configurations of models. A preliminary identification of the parameters of the models is fulfilled on the basis of experimental data. Some new and important results for fatigue and crack growth scatter characteristics are obtained.
Peptides at Membrane Surfaces and their Role in the Origin of Life
NASA Technical Reports Server (NTRS)
Pohorille, Andrew; Wilson, Michael A.; DeVincenzi, D. (Technical Monitor)
2002-01-01
All ancestors of contemporary cells (protocells) had to transport ions and organic matter across membranous walls, capture and utilize energy and transduce environmental signals. In modern organisms, all these functions are preformed by membrane proteins. We make the parsimonious assumption that in the protobiological milieu the same functions were carried out by their simple analogs - peptides. This, however, required that simple peptides could self-organize into ordered, functional structures. In a series of detailed, molecular-level computer simulations we demonstrated how this is possible. One example is the peptide (LSLLLSL)3 which forms a trameric bundle capable of transporting protons across membranes. Another example is the transmembrane pore of the influenza M2 protein. This aggregate of four identical alpha-helices, each built of 25 amino acids, forms an efficient and selective voltage-gated proton channel. Our simulations explain the gating mechanism in this channel. The channel can be re-engineered into a simple proton pump.
A Statistical Approach to Illustrate the Challenge of Astrobiology for Public Outreach.
Foucher, Frédéric; Hickman-Lewis, Keyron; Westall, Frances; Brack, André
2017-10-26
In this study, we attempt to illustrate the competition that constitutes the main challenge of astrobiology, namely the competition between the probability of extraterrestrial life and its detectability. To illustrate this fact, we propose a simple statistical approach based on our knowledge of the Universe and the Milky Way, the Solar System, and the evolution of life on Earth permitting us to obtain the order of magnitude of the distance between Earth and bodies inhabited by more or less evolved past or present life forms, and the consequences of this probability for the detection of associated biosignatures. We thus show that the probability of the existence of evolved extraterrestrial forms of life increases with distance from the Earth while, at the same time, the number of detectable biosignatures decreases due to technical and physical limitations. This approach allows us to easily explain to the general public why it is very improbable to detect a signal of extraterrestrial intelligence while it is justified to launch space probes dedicated to the search for microbial life in the Solar System.
A Statistical Approach to Illustrate the Challenge of Astrobiology for Public Outreach
Westall, Frances; Brack, André
2017-01-01
In this study, we attempt to illustrate the competition that constitutes the main challenge of astrobiology, namely the competition between the probability of extraterrestrial life and its detectability. To illustrate this fact, we propose a simple statistical approach based on our knowledge of the Universe and the Milky Way, the Solar System, and the evolution of life on Earth permitting us to obtain the order of magnitude of the distance between Earth and bodies inhabited by more or less evolved past or present life forms, and the consequences of this probability for the detection of associated biosignatures. We thus show that the probability of the existence of evolved extraterrestrial forms of life increases with distance from the Earth while, at the same time, the number of detectable biosignatures decreases due to technical and physical limitations. This approach allows us to easily explain to the general public why it is very improbable to detect a signal of extraterrestrial intelligence while it is justified to launch space probes dedicated to the search for microbial life in the Solar System. PMID:29072614
Comparative muscle development of scyphozoan jellyfish with simple and complex life cycles.
Helm, Rebecca R; Tiozzo, Stefano; Lilley, Martin K S; Lombard, Fabien; Dunn, Casey W
2015-01-01
Simple life cycles arise from complex life cycles when one or more developmental stages are lost. This raises a fundamental question - how can an intermediate stage, such as a larva, be removed, and development still produce a normal adult? To address this question, we examined the development in several species of pelagiid jellyfish. Most members of Pelagiidae have a complex life cycle with a sessile polyp that gives rise to ephyrae (juvenile medusae); but one species within Pelagiidae, Pelagia noctiluca, spends its whole life in the water column, developing from a larva directly into an ephyra. In many complex life cycles, adult features develop from cell populations that remain quiescent in larvae, and this is known as life cycle compartmentalization and may facilitate the evolution of direct life cycles. A second type of metamorphic processes, known as remodeling, occurs when adult features are formed through modification of already differentiated larval structures. We examined muscle morphology to determine which of these alternatives may be present in Pelagiidae. We first examined the structure and development of polyp and ephyra musculature in Chrysaora quinquecirrha, a close relative of P. noctiluca with a complex life cycle. Using phallotoxin staining and confocal microscopy, we verified that polyps have four to six cord muscles that persist in strobilae and discovered that cord muscles is physically separated from ephyra muscle. When cord muscle is removed from ephyra segments, normal ephyra muscle still develops. This suggests that polyp cord muscle is not necessary for ephyra muscle formation. We also found no evidence of polyp-like muscle in P. noctiluca. In both species, we discovered that ephyra muscle arises de novo in a similar manner, regardless of the life cycle. The separate origins of polyp and ephyra muscle in C. quinquecirrha and the absence of polyp-like muscle in P. noctiluca suggest that polyp muscle is not remodeled to form ephyra muscle in Pelagiidae. Life cycle stages in Scyphozoa may instead be compartmentalized. Because polyp muscle is not directly remodeled, this may have facilitated the loss of the polyp stage in the evolution of P. noctiluca.
An ESA Robotic Package to Search for Life on Mars
NASA Technical Reports Server (NTRS)
Westall, F.; Brack, A.; Clancy, P.; Hofmann, B.; Horneck, G.; Kurat, G.; Maxwell, J.; Ori, G. G.; Pillinger, C.; Raulin, F.
1999-01-01
Similarities in the early histories of Mars and Earth suggest that life may have arisen on Mars as it did on Earth. The early life forms on Mars were probably simple organisms, similar to terrestrial prokaryotes. In fact, given the early deterioration of the Martian climate, it is unlikely that life on Mars could ever have reached more sophisticated evolution. Based on the present knowledge of Mars, the possibility of extant life at the surface is small. However, given the adaptability of terrestrial prokaryotes under adverse conditions, it is not excluded. Any extant life is hypothesized to reside in the permafrost in a dormant state until "reanimated" by impact-caused hydrothermal activity. Using this rationale, a group of European scientists worked together to conceive a hypothetical strategy to search for life on Mars. A possible configuration for a lander/rover is outlined.
Origins of Life: Open Questions and Debates
NASA Astrophysics Data System (ADS)
Brack, André
2017-10-01
Stanley Miller demonstrated in 1953 that it was possible to form amino acids from methane, ammonia, and hydrogen in water, thus launching the ambitious hope that chemists would be able to shed light on the origins of life by recreating a simple life form in a test tube. However, it must be acknowledged that the dream has not yet been accomplished, despite the great volume of effort and innovation put forward by the scientific community. A minima, primitive life can be defined as an open chemical system, fed with matter and energy, capable of self-reproduction (i.e., making more of itself by itself), and also capable of evolving. The concept of evolution implies that chemical systems would transfer their information fairly faithfully but make some random errors. If we compared the components of primitive life to parts of a chemical automaton, we could conceive that, by chance, some parts self-assembled to generate an automaton capable of assembling other parts to produce a true copy. Sometimes, minor errors in the building generated a more efficient automaton, which then became the dominant species. Quite different scenarios and routes have been followed and tested in the laboratory to explain the origin of life. There are two schools of thought in proposing the prebiotic supply of organics. The proponents of a metabolism-first call for the spontaneous formation of simple molecules from carbon dioxide and water to rapidly generate life. In a second hypothesis, the primeval soup scenario, it is proposed that rather complex organic molecules accumulated in a warm little pond prior to the emergence of life. The proponents of the primeval soup or replication first approach are by far the more active. They succeeded in reconstructing small-scale versions of proteins, membranes, and RNA. Quite different scenarios have been proposed for the inception of life: the RNA world, an origin within droplets, self-organization counteracting entropy, or a stochastic approach merging chemistry and geology. Understanding the emergence of a critical feature of life, its one-handedness, is a shared preoccupation in all these approaches.
Scheiner, Samuel M
2014-02-01
One potential evolutionary response to environmental heterogeneity is the production of randomly variable offspring through developmental instability, a type of bet-hedging. I used an individual-based, genetically explicit model to examine the evolution of developmental instability. The model considered both temporal and spatial heterogeneity alone and in combination, the effect of migration pattern (stepping stone vs. island), and life-history strategy. I confirmed that temporal heterogeneity alone requires a threshold amount of variation to select for a substantial amount of developmental instability. For spatial heterogeneity only, the response to selection on developmental instability depended on the life-history strategy and the form and pattern of dispersal with the greatest response for island migration when selection occurred before dispersal. Both spatial and temporal variation alone select for similar amounts of instability, but in combination resulted in substantially more instability than either alone. Local adaptation traded off against bet-hedging, but not in a simple linear fashion. I found higher-order interactions between life-history patterns, dispersal rates, dispersal patterns, and environmental heterogeneity that are not explainable by simple intuition. We need additional modeling efforts to understand these interactions and empirical tests that explicitly account for all of these factors.
NASA Astrophysics Data System (ADS)
Pezzulo, Giovanni; Levin, Michael
2018-03-01
The free-energy principle (FEP) has been initially proposed as a theory of brain structure and function [1], but its scope is rapidly extending to explain biological phenomena at multiple levels of complexity, from simple life forms and their morphology [2] to complex societal and cultural dynamics [3].
NASA Astrophysics Data System (ADS)
Anderson, S. W.; Libarkin, J. C.; Beilfuss, M.; Dahl, J.; Boone, W. J.
2002-05-01
Approximately 300 questionnaires and 50 interviews were conducted with introductory and non-science major college students from four institutions: a small elite private school, two large state schools, and one small public liberal arts college. Students were probed on a variety of topics about the Earth system, including geologic time. A number of widely held preconceptions were uncovered on all four campuses, although scientific ideas appeared with greater frequency at the single private institution. Predominate non-scientific preconceptions included: 1) "Instantaneous" creation, wherein the Earth is formed with a modern-day surface appearance, although not necessarily including life. This idea is traced to religious ideas in about half of the cases. 2) Life existed when the Earth first formed. Approximately 40-70 percent of public students and 30 percent of private students believed life existed "when the Earth was formed". This life takes a variety of forms, including simple or single-celled life, water-born life, and life essentially identical to modern. 3) Experiential preconceptions. A variety of ideas possibly garnered from books, secondary school curriculum, film, and TV were prevalent. For instance, a number of ideas about the appearance of the Earth at formation are derivative of scientific ideas, such as the idea that a supercontinent (Pangea) existed, the Earth as covered with water or ice, and that algae were present at Earth's formation. Student interviews also revealed difficulty in extrapolating scientific concepts into a future context. For example, several students correctly showed the movement of continents from the past to present, but showed no change in position when queried about the appearance of the Earth's surface well into the future.
Charles Darwin and the origin of life.
Peretó, Juli; Bada, Jeffrey L; Lazcano, Antonio
2009-10-01
When Charles Darwin published The Origin of Species 150 years ago he consciously avoided discussing the origin of life. However, analysis of some other texts written by Darwin, and of the correspondence he exchanged with friends and colleagues demonstrates that he took for granted the possibility of a natural emergence of the first life forms. As shown by notes from the pages he excised from his private notebooks, as early as 1837 Darwin was convinced that "the intimate relation of Life with laws of chemical combination, & the universality of latter render spontaneous generation not improbable". Like many of his contemporaries, Darwin rejected the idea that putrefaction of preexisting organic compounds could lead to the appearance of organisms. Although he favored the possibility that life could appear by natural processes from simple inorganic compounds, his reluctance to discuss the issue resulted from his recognition that at the time it was possible to undertake the experimental study of the emergence of life.
The Drake Equation in an astrobiological context
NASA Astrophysics Data System (ADS)
Konesky, Gregory A.
2010-09-01
The Drake Equation was originally composed as an attempt to quantify the potential number of extraterrestrial civilizations in our Galaxy which we might be able to detect using a radio telescope. Since this equation was first formulated, nearly 50 years ago, we have discovered that life on Earth arose very early in its history, and has filled virtually every habitable, potentially extreme, niche available. This suggests that simple forms of life might be plentiful where possible, and can be observed remotely by atmospheric biosignatures in the host planet. We consider modifications to the Drake Equation to reflect this new understanding.
Darwin's warm little pond revisited: from molecules to the origin of life.
Follmann, Hartmut; Brownson, Carol
2009-11-01
All known cosmic and geological conditions and laws of chemistry and thermodynamics allow that complex organic matter could have formed spontaneously on pristine planet Earth about 4,000 mya. Simple gasses and minerals on the surface and in oceans of the early Earth reacted and were eventually organized in supramolecular aggregates and enveloped cells that evolved into primitive forms of life. Chemical evolution, which preceded all species of extant organisms, is a fact. In this review, we have concentrated on experimental and theoretical research published over the last two decades, which has added a wealth of new details and helped to close gaps in our previous understanding of this multifaceted field. Recent exciting progress in the molecular and genetic analyses of existing life, in particular microorganisms of ancient origin, even supports the possibility that a cellular, self-reproducing common ancestor might be assembled and resurrected in anaerobic cultures at some time in the future. Charles Darwin did not, and indeed, could not, address and specify the earliest phases of life which preceded the Origin of Species. However, in a famous letter, he sketched "a warm little pond with all sorts of... (chemicals, in which) ...a protein was chemically formed." We try to trace the impact of his charming clear-sighted metaphor up to the present time.
Darwin's warm little pond revisited: from molecules to the origin of life
NASA Astrophysics Data System (ADS)
Follmann, Hartmut; Brownson, Carol
2009-11-01
All known cosmic and geological conditions and laws of chemistry and thermodynamics allow that complex organic matter could have formed spontaneously on pristine planet Earth about 4,000 mya. Simple gasses and minerals on the surface and in oceans of the early Earth reacted and were eventually organized in supramolecular aggregates and enveloped cells that evolved into primitive forms of life. Chemical evolution, which preceded all species of extant organisms, is a fact. In this review, we have concentrated on experimental and theoretical research published over the last two decades, which has added a wealth of new details and helped to close gaps in our previous understanding of this multifaceted field. Recent exciting progress in the molecular and genetic analyses of existing life, in particular microorganisms of ancient origin, even supports the possibility that a cellular, self-reproducing common ancestor might be assembled and resurrected in anaerobic cultures at some time in the future. Charles Darwin did not, and indeed, could not, address and specify the earliest phases of life which preceded the Origin of Species. However, in a famous letter, he sketched “a warm little pond with all sorts of… (chemicals, in which) …a protein was chemically formed.” We try to trace the impact of his charming clear-sighted metaphor up to the present time.
Rapid fixation of methylene chloride by a macrocyclic amine.
Lee, Jung-Jae; Stanger, Keith J; Noll, Bruce C; Gonzalez, Carlos; Marquez, Manuel; Smith, Bradley D
2005-03-30
A simple macrocyclic amine is alkylated by methylene chloride to give a quaternary ammonium chloride salt. When methylene chloride is the solvent, the reaction exhibits pseudo-first-order kinetics, and the reaction half-life at 25.0 degrees C is 2.0 min. The reaction half-life for a structurally related, acyclic amine is approximately 50 000 times longer. Detailed calculations favor a mechanism where the methylene chloride associates with the macrocycle to form an activated prereaction complex. The macrocyclic nitrogen subsequently attacks the methylene chloride with a classic SN2 trajectory, and although the carbon-chlorine bond breaks, the chloride leaving group does not separate from the newly formed cationic macrocycle, such that the product is a tightly associated ion-pair. X-ray crystal structures of the starting amine and the product salt, as well as kinetic data, support this mechanism.
A Review of Ideas Concerning Life Origin
NASA Astrophysics Data System (ADS)
Gindilis, L. M.
2014-10-01
Since the times of Antiquity the and for a long time the idea of self-origination of life was the dominant one. It reappeared again after microorganisms were discovered (XVII century). The possibility of abiogenesis at microbial level was discussed for more than a century. Pateur demonstrated that spontaneous origination of microorganisms in sterile broth was due to those same microorganisms transported by dust particles. Thus proving that every form of life originates from the parental life form. So the question arises: how did the first microorganisms appear on the Earth. There are three possible versions: 1) accidental origination of a viable form; 2) primal organisms were transported to the Earth from outer space; 3) they were formed on the Earth in the process of prebiotic chemical evolution. We discuss the problems of prebiotic evolution from simple monomers up to living cells. An important item of nowadays conceptions of life origination is the hypothesis of the ancient world of RNA as possible precursor of life on Earth. The discovery in carbonaceous chondrites of traces of bacterial life evidences the existence of life in the Solar System even before the formation of the Earth. The idea of life as brought to the Earth out of Cosmos originated under the impression of self-origination hypothesis downfall. It went through several stages (Helmholtz, W. Thompson, XIX century; Arrhenius, early XX century; Hoyle and Wickramasinghe, second half of XX century) and presently evokes constantly growing interest. The panspermia theory does not solve the problem of origination of life, only moves it onto other planets. According to V.A. Mazur, the probability of accidental formation of RNA molecule is negligible not only on the Earth, but in the whole Universe over all the time span of its existence. But it is practically equal to unit in the domain formed at the inflation stage of the evolution of the Universe. A.D.Panov considered panspermia in the Galaxy at the level of prebiotic evolution products. The quantitative model he has brought forward increases life origination probability by many orders of magnitude in comparison with any isolated planet. In this model the life to originates simultaneously on all the planets with proper conditions on the same molecular basis, one and the same genetic code and the same chirality.
Singh, P C; Nautiyal, C S
2012-12-01
To prepare concentrated formulation of Trichoderma harzianum MTCC-3841 (NBRI-1055) with high colony forming units (CFU), long shelf life and efficient in root colonization by a simple scrapping method. NBRI-1055 spores scrapped from potato dextrose agar plates were used to prepare a concentrated formulation after optimizing carrier material, moisture content and spore harvest time. The process provides an advantage of maintaining optimum moisture level by the addition of water rather than dehydration. The formulation had an initial 11-12 log(10) CFU g(-1). Its concentrated form reduces its application amount by 100 times (10 g 100 kg(-1) seed) and provides 3-4 log(10) CFU seed(-1). Shelf life of the product was experimentally determined at 30 and 40 °C and predicted at other temperatures following Arrhenius equation. The concentrated formulation as compared to similar products provides an extra advantage of smaller packaging for storage and transportation, cutting down product cost. Seed application of the formulation recorded significant increase in plant growth promotion. Stable and effective formulation of Trichoderma harzianum NBRI-1055 was obtained by a simple scrapping method. A new method for the production of concentrated, stable, effective and cost efficient formulation of T. harzianum has been validated for seed application. © 2012 The Society for Applied Microbiology.
Kronish, Ian M; Carson, April P; Davidson, Karina W; Muntner, Paul; Safford, Monika M
2012-01-01
Depressive symptoms are associated with increased incident and recurrent cardiovascular events. In 2010, the American Heart Association published the Life's Simple 7, a metric for assessing cardiovascular health as measured by 4 health behaviors (smoking, physical activity, body mass index, diet) and 3 biological measures (cholesterol, blood pressure, glucose). The association between depressive symptoms and the Life's Simple 7 has not yet been explored. Data from 20,093 participants ≥45 years of age who enrolled in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study between 2003 and 2007 and who had complete data available on Life's Simple 7 components were used for these analyses. The prevalence of ideal, intermediate, and poor health on each Life's Simple 7 component and total Life's Simple 7 scores were compared between participants with and without depressive symptoms. Depressive symptoms were measured using the 4-item Centers for Epidemiologic Studies of Depression scale. Participants with depressive symptoms were more likely to have poor levels on each of the Life's Simple 7 components other than cholesterol [adjusted prevalence ratios (95% CI): smoking 1.41 (1.29-1.55); physical activity 1.38 (1.31-1.46); body mass index 1.09 (1.04-1.15); diet 1.08 (1.06-1.10); blood pressure 1.11 (1.02-1.21); glucose 1.24 (1.09-1.41)]. There was a graded association between increasing depressive symptoms and lower total Life's Simple 7 score. Depressive symptoms are associated with worse cardiovascular health on the overall Life's Simple 7 and on individual components representing both health behaviors and biological factors.
NASA Astrophysics Data System (ADS)
Nicholson, Arwen E.; Wilkinson, David M.; Williams, Hywel T. P.; Lenton, Timothy M.
2018-06-01
The search for habitable exoplanets inspires the question - how do habitable planets form? Planet habitability models traditionally focus on abiotic processes and neglect a biotic response to changing conditions on an inhabited planet. The Gaia hypothesis postulates that life influences the Earth's feedback mechanisms to form a self-regulating system, and hence that life can maintain habitable conditions on its host planet. If life has a strong influence, it will have a role in determining a planet's habitability over time. We present the ExoGaia model - a model of simple `planets' host to evolving microbial biospheres. Microbes interact with their host planet via consumption and excretion of atmospheric chemicals. Model planets orbit a `star' that provides incoming radiation, and atmospheric chemicals have either an albedo or a heat-trapping property. Planetary temperatures can therefore be altered by microbes via their metabolisms. We seed multiple model planets with life while their atmospheres are still forming and find that the microbial biospheres are, under suitable conditions, generally able to prevent the host planets from reaching inhospitable temperatures, as would happen on a lifeless planet. We find that the underlying geochemistry plays a strong role in determining long-term habitability prospects of a planet. We find five distinct classes of model planets, including clear examples of `Gaian bottlenecks' - a phenomenon whereby life either rapidly goes extinct leaving an inhospitable planet or survives indefinitely maintaining planetary habitability. These results suggest that life might play a crucial role in determining the long-term habitability of planets.
Resource recovery from end-of-life tyres in Greece: a field survey, state-of-art and trends.
Karagiannidis, A; Kasampalis, T
2010-06-01
Lack of consistent and available information for the entire tyre industry has often hindered adequate understanding of current and future issues that need to be addressed for improving the sustainable end-of-life tyre management. The aim of this paper is to review related best available technologies and techniques for Greece, ranging from simple mechanical processing, up to complex multistep, mechanochemical and/or thermal treatment. End-of-life tyre management guidelines in the form of a manual for supporting future entrepreneurs in this field are also discussed. Extensive data mining, classification and inventorying was performed, both in the field via questionnaires and in the literature, for the purpose of accurately determining Hellenic conditions, in order to pinpoint encountered problems, propose interventions and determine new entrepreneurship opportunities.
Thorpe, Charles; Jacobson, Brynna
2013-03-01
Anthony Giddens' The Politics of Climate Change represents a significant shift in the way in which he addresses ecological politics. In this book, he rejects the relevance of environmentalism and demarcates climate-change policy from life politics. Giddens addresses climate change in the technocratic mode of simple rather than reflexive modernization. However, Giddens' earlier sociological theory provides the basis for a more reflexive understanding of climate change. Climate change instantiates how, in high modernity, the existential contradiction of the human relationship with nature returns in new form, expressed in life politics and entangled with the structural contradictions of the capitalist state. The interlinking of existential and structural contradiction is manifested in the tension between life politics and the capitalist nation-state. This tension is key for understanding the failures so far of policy responses to climate change. © London School of Economics and Political Science 2013.
Techniques for optimal crop selection in a controlled ecological life support system
NASA Technical Reports Server (NTRS)
Mccormack, Ann; Finn, Cory; Dunsky, Betsy
1993-01-01
A Controlled Ecological Life Support System (CELSS) utilizes a plant's natural ability to regenerate air and water while being grown as a food source in a closed life support system. Current plant research is directed toward obtaining quantitative empirical data on the regenerative ability of each species of plant and the system volume and power requirements. Two techniques were adapted to optimize crop species selection while at the same time minimizing the system volume and power requirements. Each allows the level of life support supplied by the plants to be selected, as well as other system parameters. The first technique uses decision analysis in the form of a spreadsheet. The second method, which is used as a comparison with and validation of the first, utilizes standard design optimization techniques. Simple models of plant processes are used in the development of these methods.
Techniques for optimal crop selection in a controlled ecological life support system
NASA Technical Reports Server (NTRS)
Mccormack, Ann; Finn, Cory; Dunsky, Betsy
1992-01-01
A Controlled Ecological Life Support System (CELSS) utilizes a plant's natural ability to regenerate air and water while being grown as a food source in a closed life support system. Current plant research is directed toward obtaining quantitative empirical data on the regenerative ability of each species of plant and the system volume and power requirements. Two techniques were adapted to optimize crop species selection while at the same time minimizing the system volume and power requirements. Each allows the level of life support supplied by the plants to be selected, as well as other system parameters. The first technique uses decision analysis in the form of a spreadsheet. The second method, which is used as a comparison with and validation of the first, utilizes standard design optimization techniques. Simple models of plant processes are used in the development of these methods.
The structure and evolution of plankton communities
NASA Astrophysics Data System (ADS)
Longhurst, Alan R.
New understanding of the circulation of ancient oceans is not yet matched by progress in our understanding of their pelagic ecology, though it was the planktonic ecosystems that generated our offshore oil and gas reserves. Can we assume that present-day models of ecosystem function are also valid for ancient seas? This question is addressed by a study of over 4000 plankton samples to derive a comprehensive, global description of zooplankton community structure in modern oceans: this shows that copepods form only 50% of the biomass of all plankton, ranging from 70% in polar to 35% in tropical seas. Comparable figures are derived from 14 other taxonomic categories of zooplankton. For trophic groupings, the data indicate globally: geletinous predators - 14%; gelatinous herbivores - 4%; raptorial predators - 33%; macrofiltering herbivores - 20%; macrofiltering omnivores - 25%; and detritivores - 3%. A simple, idealized model for the modern pelagic ecosystem is derived from these percentages which indicates that metazooplankton are not the most important consumers of pico- and nano-plankton production which itself probably constitutes 90% of primary production in warm oceans. This model is then compared with candidate life-forms available in Palaeozoic and Mesozoic oceans to determine to what extent it is also valid for ancient ecosystems: it is concluded that it is probably unnecessary to postulate models fundamentally differing from it in order to accommodate the life-forms, both protozoic and metazoic, known to have populated ancient seas. Remarkably few life-forms have existed which cannot be paralleled in the modern ocean, which contains remarkably few life-forms which cannot be paralleled in the Palaeozoic ocean. As a first assumption, then, it is reasonable to assume that energy pathways were similar in ancient oceans to those we study today.
77 FR 76604 - Submission for OMB Review; Comment Request
Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-28
... currently approved collection. Title: Form 5304-SIMPLE; Form 5305-SIMPLE; Notice 98-4. Abstract: Forms 5304-SIMPLE and 5035-SIMPLE are used by an employer to permit employees to make salary reduction contributions to a savings incentive match plan (SIMPLE IRA) described in Code section 408(p). These forms are not...
Shelf life studies of common hazardous materials: An innovative approach to pollution prevention
DOE Office of Scientific and Technical Information (OSTI.GOV)
Farmanian, P.A.
1995-12-31
Hazardous chemical systems, ranging in form from simple materials to compounded products and complex natural mixtures, constitute an important asset in the Navy`s daily operations. These materials include but are not limited to paints, solvents, soaps, resins, adhesives, pesticides, printing materials, petroleum products, and photographic chemicals. The short-lived availability of hazardous materials that are suspected of or known to degrade over time imposes a unique burden on the Navy`s procurement and hazardous waste disposal systems. Hazardous Materials whose shelf life`s have expired are processed for disposal as hazardous wastes. In addition, these expired hazardous materials must be replaced with newmore » materials. Many shelf life codes are based solely on the recommendations of suppliers and are not critically subjected to scientific study. The important goal of this project is to conduct a comprehensive study of the degradation of a given hazardous material to determine the true shelf life.« less
Bazarganipour, Fatemeh; Taghavi, Seyed-Abdolvahab; Allan, Helen; Hosseini, Nazafarin; Khosravi, Ahmad; Asadi, Rahimeh; Salari, Shohreh; Dehghani, Raziyeh; Jamshidi, Zahra; Rezaei, Marziyeh; Saberian, Mansoreh; Javedan, Fatemeh; Salari, Zahra; Miri, Fahimeh
2017-10-01
To evaluate a simple acupressure protocol in LIV3 and LI4 acupoints in women with primary dysmenorrhea. This paper reports a randomized, single blinded clinical trial. 90 young women with dysmenorrhea were recruited to three groups to receive 20min acupressure every day in either LIV3 or LI4, or placebo points. Acupressure was timed five days before menstruation for three successive menstrual cycles. On menstruation, each participant completed the Wong Baker faces pain scale, and the quality of life short form -12 (QOL SF-12). Intensity and duration of pain between the three groups in the second and third cycles during the intervention (p<0.05) differed significantly. Significant differences were seen in all domains of QOL except for mental health (p=0.4), general health (p=0.7) and mental subscale component (p=0.12) in the second cycle, and mental health (p=0.9), and mental subscale component (p=0.14) in the third cycle. Performing the simple acupressure protocol is an effective method to decrease the intensity and duration of dysmenorrhea, and improve the QOL. Registration ID in IRCT: IRCT2016052428038N1. Copyright © 2017. Published by Elsevier Ltd.
A joint analysis of the Drake equation and the Fermi paradox
NASA Astrophysics Data System (ADS)
Prantzos, Nikos
2013-07-01
I propose a unified framework for a joint analysis of the Drake equation and the Fermi paradox, which enables a simultaneous, quantitative study of both of them. The analysis is based on a simplified form of the Drake equation and on a fairly simple scheme for the colonization of the Milky Way. It appears that for sufficiently long-lived civilizations, colonization of the Galaxy is the only reasonable option to gain knowledge about other life forms. This argument allows one to define a region in the parameter space of the Drake equation, where the Fermi paradox definitely holds (`Strong Fermi paradox').
Classifying Planets: Nature vs. Nurture
NASA Astrophysics Data System (ADS)
Beichman, Charles A.
2009-05-01
The idea of a planet was so simple when we learned about the solar system in elementary school. Now students and professional s alike are faced with confusing array of definitions --- from "Brown Dwarfs” to "Super Jupiters", from "Super Earths” to "Terrestrial Planets", and from "Planets” to "Small, Sort-of Round Things That Aren't Really Planets". I will discuss how planets might be defined by how they formed, where they are found, or by the life they might support.
How fast do living organisms move: Maximum speeds from bacteria to elephants and whales
NASA Astrophysics Data System (ADS)
Meyer-Vernet, Nicole; Rospars, Jean-Pierre
2015-08-01
Despite their variety and complexity, living organisms obey simple scaling laws due to the universality of the laws of physics. In the present paper, we study the scaling between maximum speed and size, from bacteria to the largest mammals. While the preferred speed has been widely studied in the framework of Newtonian mechanics, the maximum speed has rarely attracted the interest of physicists, despite its remarkable scaling property; it is roughly proportional to length throughout nearly the whole range of running and swimming organisms. We propose a simple order-of-magnitude interpretation of this ubiquitous relationship, based on physical properties shared by life forms of very different body structure and varying by more than 20 orders of magnitude in body mass.
Life and the Universe: From Astrochemistry to Astrobiology
NASA Technical Reports Server (NTRS)
Allamandola, Louis J.
2013-01-01
Great strides have been made in our understanding of interstellar material thanks to advances in infrared astronomy and laboratory astrophysics. Ionized polycyclic aromatic hydrocarbons (PAHs), shockingly large molecules by earlier astrochemical standards, are widespread and very abundant throughout much of the cosmos. In cold molecular clouds, the birthplace of planets and stars, interstellar atoms and molecules freeze onto extremely cold dust and ice particles forming mixed molecular ices dominated by simple species such as water, methanol, ammonia, and carbon monoxide. Within these clouds, and especially in the vicinity of star and planet forming regions, these ices and PAHs are processed by ultraviolet light and cosmic rays forming hundreds of far more complex species, some of biogenic interest. Eventually, these are delivered to primordial planets by comets and meteorites. As these materials are the building blocks of comets and related to carbonaceous micrometeorites, they are likely to be important sources of complex organic materials delivered to habitable planets (including the primordial Earth) and their composition may be related to the origin of life. This talk will focus on the chemical evolution of these cosmic materials and their relevance to astrobiology.
Humic First Theory: A New Theory on the Origin of Life
NASA Astrophysics Data System (ADS)
Daei, Mohammad Ali; Daei, Manijeh; Daei, Bijan
2017-04-01
In 1953, Miller & Urey through a brilliant experiment demonstrated that the building blocks of life could evolve in primitive earth conditions [1]. During the recent years scientists revealed that organic matters are not very rare compounds in comets, asteroids, and meteorites which have bombarded the ancient earth repeatedly [2]. So simple organic molecules on early earth could be quite enough to start chemical evolution and steadily, proceeded to the very simple form of life. Many theories have tried to explain how life emerged from non life, but failed, largely due to the lack of a distinct methodology. There is a huge gap between the simple building blocks, like amino acid, sugar, and lipid molecules, to a living cell with a very sophisticated structure and organization. It is unacceptable to fill this great distance, only by accidental reactions in a passive media (primitive soap) even, over a very long time. Obviously, manufacturing of a primitive cell required a natural factory with rather firm and resistant basement, plenty of organic and inorganic raw materials and qualified production line, plus some sources of energy. There were plenty of solar energy and water in the early Earth, but what about the other factors? Availability of essential minerals was not guaranteed at all, in primitive earth which covered with bare, dead rocks. While we are not able today, to multiply any microorganisms in ideal conditions of modern laboratory in the absence of only one of essential nutrients or elements, how can we expect primitive cells appear on early earth conditions without the support of soluble minerals and organic matters? Ideal production line must be active and protective, have catalyzing ability, could provide numerous opportunities for interaction between basic bio molecules (mainly RNA and proteins) and above all, have capability to react with different sources of energy. There are strong evidences that show only some form of stable, rich and active organic matter like modern "humic substances" could perform this great and complicated duty. A mass of warm, wet clay mixed with enough humic substances (HS) in suitable PH, could provide all above requirements, and promote biochemical evolution step by step toward a functional primitive cell. HS are fluorescent compounds and could transform UV radiation to usable light. In addition these protective materials could provide chemical energy plus balanced minerals and organic molecules. While everything in non living world is reducing energy, HS can collect more and more material and energy like a living organism. Fortunately, there are reliable evidences that HS could be accessible on ancient Earth. In fact Ziechman et al [7], in 1994 by finding humic material in Miller's experimental vessels proved that humic substances could be generated on early Earth conditions by polymerizing simple organic molecules. Our investigations show elemental selection and also chairal selection for life are proportionately tailored to Humic materials. For example nearly all heavy metals make insoluble compounds with HS, hence omitted from life processes. In contrast all essential elements have appropriate affinity and workability with HS. There is reliable evidence that shows HS prefer left amino acids and right sugars. As you see many signs and symptoms are referring to "humic substances" as the mother of life, at least on this planet.
The principle of cooperation and life's origin and evolution
NASA Technical Reports Server (NTRS)
Oro, J.; Armangue, G.; Mar, A.
1986-01-01
In simple terms a living entity is a negentropic system that replicates, mutates and evoluves. A number of suggestions have been made, such as directed panspermia, atmospheric photosynthesis, genetic overtaking from inorganic processes, etc., as alternative models to the accepted Oparin-Haldane-Urey model of the origin of life on Earth. This has probably occurred because in spite of tremendous advances in the prebiotic synthesis of biochemical compounds, the fundamental problem of the appearance of the first life--a primordial replicating cell-ancestral to all other forms of extant life, has remained elusive. This is indeed a reflection on the different fundamental nature of the problem involved. Regardless of which were the fundamental processes which occurred on the primitive Earth, it has to end up with the fundamental characteristics of an ancestral protocell. The problem of the emergence of the first ancestral cell was one of synergistic macromolecular cooperation, as it has been discussed by authors recently (COSPAR XXV Plenary Meeting). An analogous situation must have occurred at the time of the appearance of the first eucaryotic organism. Procaryotic life appeared probably during the first 600 million years of Earth history when the Earth was sufficiently cool and continually bombarded (in the late accretion period) by comets and minor bodies of the solar system, when the sea had not yet acquired its present form.
The limits of extremophilic life expanded under extraterrestrial environment-simulated experiments
NASA Astrophysics Data System (ADS)
Lage, C.; Dalmaso, G.; Teixeira, L.; Bendia, A.; Rosado, A.
2012-09-01
Astrobiology is a brand new area of science that seeks to understand the origin and dynamics of life in the universe. Several hypotheses to explain life in the cosmic context have been developed throughout human history, but only now technology has allowed many of them to be tested. Laboratory experiments have been able to show how chemical elements essential to life, carbon, nitrogen, oxygen and hydrogen combine in biologically important compounds. Interestingly, these compounds are found universally. As these compounds were combined to the point of originating cells and complex organisms is still a challenge to be unveiled by science. However, our 4.5 billion years-old solar system was born within a 10-billion years-old universe. Thus, simple cells like microorganisms may have had time to form in planets older than ours or other suitable molecular places in the universe. One hypothesis to explain the origin of life on Earth is called panspermia, which predicts that microbial life could have been formed in the universe billions of years ago, traveling between planets, and inseminating units of life that could have become more complex in habitable planets like ours. A project designed to test the viability of extremophile microorganisms exposed to simulated extraterrestrial environments is ongoing at the Carlos Chagas Filho Institute of Biophysics to test whether microbial life could withstand those inhospitable environments. Ultra-resistant (known or novel ones) microorganisms collected from terrestrial extreme environments, extremophiles, have been exposed to intense radiation sources simulating solar radiation (at synchrotron accelerators), capable of emitting in a few hours radiation equivalent of million years accumulated doses. The results obtained in these experiments reveal the interesting possibility of the existence of microbial life beyond Earth.
NASA Astrophysics Data System (ADS)
Lage, Claudia A. S.; Dalmaso, Gabriel Z. L.; Teixeira, Lia C. R. S.; Bendia, Amanda G.; Paulino-Lima, Ivan G.; Galante, Douglas; Janot-Pacheco, Eduardo; Abrevaya, Ximena C.; Azúa-Bustos, Armando; Pelizzari, Vivian H.; Rosado, Alexandre S.
2012-10-01
Astrobiology is a relatively recent scientific field that seeks to understand the origin and dynamics of life in the Universe. Several hypotheses have been proposed to explain life in the cosmic context throughout human history, but only now, technology has allowed many of them to be tested. Laboratory experiments have been able to show how chemical elements essential to life, such as carbon, nitrogen, oxygen and hydrogen combine in biologically important compounds. Interestingly, these compounds are ubiquitous. How these compounds were combined to the point of originating cells and complex organisms is still to be unveiled by science. However, our 4.5 billion years old Solar system appeared in a 10 billion years old Universe. Thus, simple cells such as micro-organisms may have had time to form in planets older than ours or in other suitable places in the Universe. One hypothesis related to the appearance of life on Earth is called panspermia, which predicts that microbial life could have been formed in the Universe billions of years ago, travelling between planets, and inseminating units of life that could have become more complex in habitable planets such as Earth. A project designed to test the viability of extremophile micro-organisms exposed to simulated extraterrestrial environments is in progress at the Carlos Chagas Filho Institute of Biophysics (UFRJ, Brazil) to test whether microbial life could withstand inhospitable environments. Radiation-resistant (known or novel ones) micro-organisms collected from extreme terrestrial environments have been exposed (at synchrotron accelerators) to intense radiation sources simulating Solar radiation, capable of emitting radiation in a few hours equivalent to many years of accumulated doses. The results obtained in these experiments reveal an interesting possibility of the existence of microbial life beyond Earth.
Protostars are Nature's Chemical Factories
NASA Technical Reports Server (NTRS)
Nuth, Joseph A. III; Johnson, Natasha M.
2005-01-01
H(2-2), N2 and CO are the most abundant molecular constituents in astrophysical environments, including protostellar nebulae. Although some organic molecules may be produced on very long timescales by the irradiation of ices formed on the cold surfaces of interstellar grains and these molecules may be an important source of raw materials leading to the origin of life on Earth, pre-solar organics could be swamped by the efficient conversion of nebular H2, N2 and CO to simple organic materials.
Preliminary psychometric testing of the Fox Simple Quality-of-Life Scale.
Fox, Sherry
2004-06-01
Although quality of life is extensively defined as subjective and multidimensional with both affective and cognitive components, few instruments capture important dimensions of the construct, and few are both conceptually congruent and user friendly for the clinical setting. The aim of this study was to develop and test a measure that would be easy to use clinically and capture both cognitive and affective components of quality of life. Initial item sources for the Fox Simple Quality-of-Life Scale (FSQOLS) were literature-based. Thirty items were compiled for content validity assessment by a panel of expert healthcare clinicians from various disciplines, predominantly nursing. Five items were removed as a result of the review because they reflected negatively worded or redundant items. The 25-item scale was mailed to 177 people with lung, colon, and ovarian cancer in various stages. Cancer types were selected theoretically, based on similarity in prognosis, degree of symptom burden, and possible meaning and experience. Of the 145 participants, all provided complete data on the FSQOLS. Psychometric evaluation of the FSQOLS included item-total correlations, principal components analysis with varimax rotation revealing two factors explaining 50% variance, reliability estimation using alpha estimates, and item-factor correlations. The FSQOLS exhibited significant convergent validity with four popular quality-of-life instruments: the Ferrans and Powers Quality of Life Index, the Functional Assessment of Cancer Therapy Scale, the Short-Form-36 Health Survey, and the General Well-Being Scale. Content validity of the scale was explored and supported using qualitative interviews of 14 participants with lung, colon and ovarian cancer, who were a subgroup of the sample for the initial instrument testing.
Neves, S P S; Funch, R; Conceição, A A; Miranda, L A P; Funch, L S
2016-06-01
A transect was used to examine the environmental and biological descriptors of a compact vegetation mosaic in the Chapada Diamantina in northeastern Brazil, including the floristic composition, spectrum of plant life forms, rainfall, and soil properties that defined areas of cerrado (Brazilian savanna), caatinga (seasonally dry tropical forest thorny, deciduous shrub/arboreal vegetation) and cerrado-caatinga transition vegetation. The floristic survey was made monthly from April/2009 to March/2012. A dendrogram of similarity was generated using the Jaccard Index based on a matrix of the species that occurred in at least two of the vegetation types examined. The proportions of life forms in each vegetation type were compared using the chi-square test. Composite soil samples were analyzed by simple variance (ANOVA) to examine relationships between soil parameters of each vegetation type and the transition area. The monthly precipitation levels in each vegetation type were measured and compared using the chi-square test. A total of 323 species of angiosperms were collected distributed in 193 genera and 54 families. The dendrogram demonstrated strong difference between the floristic compositions of the cerrado and caatinga, sharing 2% similarity. The chi-square test did not demonstrate any significant statistical differences between the monthly values of recorded rainfall. The organic matter and clay contents of the soilsin the caatinga increased while sand decreased, and the proportions of therophyte, hemicryptophyte, and chamaephyte life forms decreased and phanerophytes increased. We can therefore conclude that the floristic composition and the spectrum of life forms combined to define the cerrado and caatinga vegetation along the transect examined, with soil being the principal conditioning factor determining the different vegetation types, independent of precipitation levels.
Models of protocellular structures, functions and evolution
NASA Technical Reports Server (NTRS)
Pohorille, Andrew; New, Michael H.; DeVincenzi, Donald L. (Technical Monitor)
2000-01-01
The central step in the origin of life was the emergence of organized structures from organic molecules available on the early earth. These predecessors to modern cells, called 'proto-cells,' were simple, membrane bounded structures able to maintain themselves, grow, divide, and evolve. Since there is no fossil record of these earliest of life forms, it is a scientific challenge to discover plausible mechanisms for how these entities formed and functioned. To meet this challenge, it is essential to create laboratory models of protocells that capture the main attributes associated with living systems, while remaining consistent with known, or inferred, protobiological conditions. This report provides an overview of a project which has focused on protocellular metabolism and the coupling of metabolism to energy transduction. We have assumed that the emergence of systems endowed with genomes and capable of Darwinian evolution was preceded by a pre-genomic phase, in which protocells functioned and evolved using mostly proteins, without self-replicating nucleic acids such as RNA.
Rediscovering the art of healing connection by creating the Tree of Life poster.
Pipe, Teri Britt; Mishark, Kenneth; Hansen, Reverend Patrick; Hentz, Joseph G; Hartsell, Zachary
2010-06-01
The goal of this project was to provide a way for hospital staff to form meaningful therapeutic relationships with patients in the fast-paced hospital environment. Watson's Theory of Human Caring was the framework guiding the project. The Lifestory intervention was a Tree of Life poster depicting sources of encouragement and enjoyment, special memories, life lessons, family, and roots. Preintervention and postintervention measures included quality of life (QOL) and spirituality scales with established psychometrics. A one-sample t test was used to analyze data. Mean age of participants (n = 15) was 73.8. Ten (67%) patients reported the intervention positively affected their QOL. Improvements were noted in overall QOL (p = 0.05), as well as emotional (p = 0.005), physical (p = 0.02,) and spiritual well-being, as measured by the Expanded Version of the Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being Scale (p = 0.02). This simple Lifestory intervention was feasible and associated with improvement in several QOL dimensions in hospitalized older adults. Copyright 2010, SLACK Incorporated.
Finding the right rocks on Mars
NASA Astrophysics Data System (ADS)
Hargraves, R. B.; Knudsen, J. M.; Madsen, M. B.; Bertelsen, P.
Locating a rock on the surface of Mars that bears unambiguous evidence of the existence—prior or present—of life on that planet is, understandably, the “Holy Grail” of NASAs sample return missions. Remote recognition of such a rock on Mars will not be easy. We do know, however, that present in the Martian crust—especially in the “Southern highlands”—is rock carrying strong natural remanent magnetization (NRM). Characterization of such magnetized rock has profound implications for adding to our knowledge about the origin and early evolution of the Martian interior, lithosphere, atmosphere, and possibly even Martian life forms [Ward and Brownlee, 2000]. Moreover, it should be possible to recognize such rocks by use of a simple magnetic compass mounted on a Rover.
Viral ancestors of antiviral systems.
Villarreal, Luis P
2011-10-01
All life must survive their corresponding viruses. Thus antiviral systems are essential in all living organisms. Remnants of virus derived information are also found in all life forms but have historically been considered mostly as junk DNA. However, such virus derived information can strongly affect host susceptibility to viruses. In this review, I evaluate the role viruses have had in the origin and evolution of host antiviral systems. From Archaea through bacteria and from simple to complex eukaryotes I trace the viral components that became essential elements of antiviral immunity. I conclude with a reexamination of the 'Big Bang' theory for the emergence of the adaptive immune system in vertebrates by horizontal transfer and note how viruses could have and did provide crucial and coordinated features.
Viral Ancestors of Antiviral Systems
Villarreal, Luis P.
2011-01-01
All life must survive their corresponding viruses. Thus antiviral systems are essential in all living organisms. Remnants of virus derived information are also found in all life forms but have historically been considered mostly as junk DNA. However, such virus derived information can strongly affect host susceptibility to viruses. In this review, I evaluate the role viruses have had in the origin and evolution of host antiviral systems. From Archaea through bacteria and from simple to complex eukaryotes I trace the viral components that became essential elements of antiviral immunity. I conclude with a reexamination of the ‘Big Bang’ theory for the emergence of the adaptive immune system in vertebrates by horizontal transfer and note how viruses could have and did provide crucial and coordinated features. PMID:22069523
Battery energy storage sizing when time of use pricing is applied.
Carpinelli, Guido; Khormali, Shahab; Mottola, Fabio; Proto, Daniela
2014-01-01
Battery energy storage systems (BESSs) are considered a key device to be introduced to actuate the smart grid paradigm. However, the most critical aspect related to the use of such device is its economic feasibility as it is a still developing technology characterized by high costs and limited life duration. Particularly, the sizing of BESSs must be performed in an optimized way in order to maximize the benefits related to their use. This paper presents a simple and quick closed form procedure for the sizing of BESSs in residential and industrial applications when time-of-use tariff schemes are applied. A sensitivity analysis is also performed to consider different perspectives in terms of life span and future costs.
Battery Energy Storage Sizing When Time of Use Pricing Is Applied
Khormali, Shahab
2014-01-01
Battery energy storage systems (BESSs) are considered a key device to be introduced to actuate the smart grid paradigm. However, the most critical aspect related to the use of such device is its economic feasibility as it is a still developing technology characterized by high costs and limited life duration. Particularly, the sizing of BESSs must be performed in an optimized way in order to maximize the benefits related to their use. This paper presents a simple and quick closed form procedure for the sizing of BESSs in residential and industrial applications when time-of-use tariff schemes are applied. A sensitivity analysis is also performed to consider different perspectives in terms of life span and future costs. PMID:25295309
NASA Technical Reports Server (NTRS)
Saltsman, James F.; Halford, Gary R.
1988-01-01
A method is proposed (without experimental verification) for extending the total strain version of Strainrange Partitioning (TS-SRP) to predict the lives of thermomechanical fatigue (TMF) cycles. The principal feature of TS SRP is the determination of the time-temperature-waveshape dependent elastic strainrange versus life lines that are added subsequently to the classical inelastic strainrange versus life lines to form the total strainrange versus life relations. The procedure is based on a derived relation between failure and flow behavior. Failure behavior is represented by conventional SRP inelastic strainrange versus cyclic life relations, while flow behavior is captured in terms of the cyclic stress-strain response characteristics. Stress-strain response is calculated from simple equations developed from approximations to more complex cyclic constitutive models. For applications to TMF life prediction, a new testing technique, bithermal cycling, is proposed as a means for generating the inelastic strainrange versus life relations. Flow relations for use in predicting TMF lives would normally be obtained from approximations to complex thermomechanical constitutive models. Bithermal flow testing is also proposed as an alternative to thermomechanical flow testing at low strainranges where the hysteresis loop is difficult to analyze.
Protists and the Wild, Wild West of Gene Expression: New Frontiers, Lawlessness, and Misfits.
Smith, David Roy; Keeling, Patrick J
2016-09-08
The DNA double helix has been called one of life's most elegant structures, largely because of its universality, simplicity, and symmetry. The expression of information encoded within DNA, however, can be far from simple or symmetric and is sometimes surprisingly variable, convoluted, and wantonly inefficient. Although exceptions to the rules exist in certain model systems, the true extent to which life has stretched the limits of gene expression is made clear by nonmodel systems, particularly protists (microbial eukaryotes). The nuclear and organelle genomes of protists are subject to the most tangled forms of gene expression yet identified. The complicated and extravagant picture of the underlying genetics of eukaryotic microbial life changes how we think about the flow of genetic information and the evolutionary processes shaping it. Here, we discuss the origins, diversity, and growing interest in noncanonical protist gene expression and its relationship to genomic architecture.
The limits of life on Earth and searching for life on Mars
NASA Technical Reports Server (NTRS)
Nealson, K. H.
1997-01-01
Considerations of basic properties of bacteria such as size, structure, and metabolic versatility allow one to understand how these remarkable life-forms are so adaptable to environments previously thought to be uninhabitable. It is now appreciated that bacteria on Earth can utilize almost any redox couple that yields energy, taking advantage of this energy, while transforming the elements during metabolism. The ability to grow at the expense of inorganic redox couples allows the microbes to occupy niches not available to the more metabolically constrained eukaryotes. Furthermore, the simplicity of the bacterial structure allows them considerably more resistance to environmental variables (pH, salinity, temperature) that are toxic or lethal to more complex organisms. This information can be used to explain the predominance of prokaryotes in extreme environments on Earth, and to speculate as to simple types of metabolism and biogeochemical cycles that may exist on this planet, Mars, and perhaps other non-Earth environments.
The limits of life on Earth and searching for life on Mars.
Nealson, K H
1997-10-25
Considerations of basic properties of bacteria such as size, structure, and metabolic versatility allow one to understand how these remarkable life-forms are so adaptable to environments previously thought to be uninhabitable. It is now appreciated that bacteria on Earth can utilize almost any redox couple that yields energy, taking advantage of this energy, while transforming the elements during metabolism. The ability to grow at the expense of inorganic redox couples allows the microbes to occupy niches not available to the more metabolically constrained eukaryotes. Furthermore, the simplicity of the bacterial structure allows them considerably more resistance to environmental variables (pH, salinity, temperature) that are toxic or lethal to more complex organisms. This information can be used to explain the predominance of prokaryotes in extreme environments on Earth, and to speculate as to simple types of metabolism and biogeochemical cycles that may exist on this planet, Mars, and perhaps other non-Earth environments.
NASA Technical Reports Server (NTRS)
Sandford, Scott A.
2015-01-01
Many environments in space contain very low temperature mixed molecular ices that are exposed to ionizing radiation in the form of cosmic rays and high-energy photons. While traditional chemistry would not be expected to occur at the temperatures typical of these ices (T < 50 K), ionizing radiation can break bonds in the original molecules in the ices to form highly reactive ions and radicals. These ions and radicals are subsequently free to react despite the low temperatures of the original ices. Laboratory experiments, many of them carried out at the Astrochemistry Laboratory at NASA-Ames, show that the irradiation of ices made of even simple molecules like H2O, CO, CO2, CH4, NH3, etc. can result in the robust formation of large numbers of far more complex organic compounds. Many of these new products are of direct interest to astrobiology. For example, the irradiation of mixed molecular ices has been shown to produce amino acids, amphiphiles, quinones, sugars, heterocyclic compounds, and nucleobases, all molecular building blocks used by terrestrial life. Insofar as the presence of these materials plays a role in the origin of life on planets, this has profound implications for the potential abundance of life in the universe since these experiments simulate universal conditions that are expected to be found wherever new stars and planets form.
NASA Technical Reports Server (NTRS)
Crowe, Lois M.; Crowe, John H.
1989-01-01
Anhydrobiosis, or life without water is commonly demonstrated by a number of plants and animals. These organisms have the capacity to loose all body water, remain dry for various periods, and then be revived by rehydration. While in the anhydrobiotic state, these organisms become highly resistant to several environmental stresses such as extremely low temperatures, elevated temperatures, ionizing radiation, and high vacuum. Since water is commonly thought to be essential for life, survival of anhydrobiotic organisms with an almost total loss of water is examined. A search of literature reveal that many anhydrobiotic organisms make large quantities of trehalose or other carbohydrates. Laboratory experiments have shown that trehalose is able to stabilize and preserve microsomes of sarcoplasmic reticulum and artificial liposomes. It was demonstrated that trehalose and other disaccharides can interact directly with phosopipid headgroups and maintain membranes in their native configuration by replacing water in the headgroup region. Recent studies show that trehalose is an effective stabilizer of proteins during drying and that it does so by direct interaction with groups on the protein. If life that is able to withstand environmental extremes has ever developed on Mars, it is expected that such life would have developed some protective compounds which can stabilize macromolecular structure in the absence of water and at cold temperatures. On Earth, that role appears to be filled by carbohydrates that can stabilize both membrane and protein stuctures during freezing and drying. By analog with terrestrial systems, such life forms might develop resistance either during some reproductive stage or at any time during adult existence. If the resistant form is a developmental stage, the life cycle of the organism must be completed with a reasonable time period relative to time when environmental conditions are favorable. This would suggest that simple organisms with a short life cycle might be most sucessful.
Folsom, Aaron R; Shah, Amil M; Lutsey, Pamela L; Roetker, Nicholas S; Alonso, Alvaro; Avery, Christy L; Miedema, Michael D; Konety, Suma; Chang, Patricia P; Solomon, Scott D
2015-09-01
Many people may underappreciate the role of lifestyle in avoiding heart failure. We estimated whether greater adherence in middle age to American Heart Association's Life's Simple 7 guidelines—on smoking, body mass, physical activity, diet, cholesterol, blood pressure, and glucose—is associated with lower lifetime risk of heart failure and greater preservation of cardiac structure and function in old age. We studied the population-based Atherosclerosis Risk in Communities Study cohort of 13,462 adults ages 45-64 years in 1987-1989. From the 1987-1989 risk factor measurements, we created a Life's Simple 7 score (range 0-14, giving 2 points for ideal, 1 point for intermediate, and 0 points for poor components). We identified 2218 incident heart failure events using surveillance of hospital discharge and death codes through 2011. In addition, in 4855 participants free of clinical cardiovascular disease in 2011-2013, we performed echocardiography from which we quantified left ventricular hypertrophy and diastolic dysfunction. One in four participants (25.5%) developed heart failure through age 85 years. Yet, this lifetime heart failure risk was 14.4% for those with a middle-age Life's Simple 7 score of 10-14 (optimal), 26.8% for a score of 5-9 (average), and 48.6% for a score of 0-4 (inadequate). Among those with no clinical cardiovascular event, the prevalence of left ventricular hypertrophy in late life was approximately 40% as common, and diastolic dysfunction was approximately 60% as common, among those with an optimal middle-age Life's Simple 7 score, compared with an inadequate score. Greater achievement of American Heart Association's Life's Simple 7 in middle age is associated with a lower lifetime occurrence of heart failure and greater preservation of cardiac structure and function. Copyright © 2015 Elsevier Inc. All rights reserved.
An Experimental Framework for Generating Evolvable Chemical Systems in the Laboratory
NASA Astrophysics Data System (ADS)
Baum, David A.; Vetsigian, Kalin
2017-12-01
Most experimental work on the origin of life has focused on either characterizing the chemical synthesis of particular biochemicals and their precursors or on designing simple chemical systems that manifest life-like properties such as self-propagation or adaptive evolution. Here we propose a new class of experiments, analogous to artificial ecosystem selection, where we select for spontaneously forming self-propagating chemical assemblages in the lab and then seek evidence of a response to that selection as a key indicator that life-like chemical systems have arisen. Since surfaces and surface metabolism likely played an important role in the origin of life, a key experimental challenge is to find conditions that foster nucleation and spread of chemical consortia on surfaces. We propose high-throughput screening of a diverse set of conditions in order to identify combinations of "food," energy sources, and mineral surfaces that foster the emergence of surface-associated chemical consortia that are capable of adaptive evolution. Identification of such systems would greatly advance our understanding of the emergence of self-propagating entities and the onset of adaptive evolution during the origin of life.
Entropy and charge in molecular evolution--the case of phosphate
NASA Technical Reports Server (NTRS)
Arrhenius, G.; Sales, B.; Mojzsis, S.; Lee, T.; Bada, J. L. (Principal Investigator)
1997-01-01
Biopoesis, the creation of life, implies molecular evolution from simple components, randomly distributed and in a dilute state, to form highly organized, concentrated systems capable of metabolism, replication and mutation. This chain of events must involve environmental processes that can locally lower entropy in several steps; by specific selection from an indiscriminate mixture, by concentration from dilute solution, and in the case of the mineral-induced processes, by particular effectiveness in ordering and selective reaction, directed toward formation of functional biomolecules. Numerous circumstances provide support for the notion that negatively charged molecules were functionally required and geochemically available for biopoesis. Sulfite ion may have been important in bisulfite complex formation with simple aldehydes, facilitating the initial concentration by sorption of aldehydes in positively charged surface active minerals. Borate ion may have played a similar, albeit less investigated role in forming charged sugar complexes. Among anionic species, oligophosphate ions and charged phosphate esters are likely to have been of even more wide ranging importance, reflected in the continued need for phosphate in a proposed RNA world, and extending its central role to evolved biochemistry. Phosphorylation is shown to result in selective concentration by surface sorption of compounds, otherwise too dilute to support condensation reactions. It provides protection against rapid hydrolysis of sugars and, by selective concentration, induces the oligomerization of aldehydes. As a manifestation of life arisen, phosphate already appears in an organic context in the oldest preserved sedimentary record.
Rossetti, Valentina; Filippini, Manuela; Svercel, Miroslav; Barbour, A D; Bagheri, Homayoun C
2011-12-07
Filamentous bacteria are the oldest and simplest known multicellular life forms. By using computer simulations and experiments that address cell division in a filamentous context, we investigate some of the ecological factors that can lead to the emergence of a multicellular life cycle in filamentous life forms. The model predicts that if cell division and death rates are dependent on the density of cells in a population, a predictable cycle between short and long filament lengths is produced. During exponential growth, there will be a predominance of multicellular filaments, while at carrying capacity, the population converges to a predominance of short filaments and single cells. Model predictions are experimentally tested and confirmed in cultures of heterotrophic and phototrophic bacterial species. Furthermore, by developing a formulation of generation time in bacterial populations, it is shown that changes in generation time can alter length distributions. The theory predicts that given the same population growth curve and fitness, species with longer generation times have longer filaments during comparable population growth phases. Characterization of the environmental dependence of morphological properties such as length, and the number of cells per filament, helps in understanding the pre-existing conditions for the evolution of developmental cycles in simple multicellular organisms. Moreover, the theoretical prediction that strains with the same fitness can exhibit different lengths at comparable growth phases has important implications. It demonstrates that differences in fitness attributed to morphology are not the sole explanation for the evolution of life cycles dominated by multicellularity.
Directed Panspermia. 3. strategies and Motivation for Seeding Star-Forming Clouds
NASA Astrophysics Data System (ADS)
Mautner, Michael N.
1997-11-01
Microbial swarms aimed at star-forming regions of interstellar clouds can seed stellar associations of 10 - 100 young planetary systems. Swarms of millimeter size, milligram packets can be launched by 35 cm solar sails at 5E-4 c, to penetrate interstellar clouds. Selective capture in high-density planetary accretion zones of densities > 1E-17 kg m-3 is achieved by viscous drag. Strategies are evaluated to seed dense cloud cores, or individual protostellar condensations, accretion disks or young planets therein. Targeting the Ophiuchus cloud is described as a model system. The biological content, dispersed in 30 μm, 1E-10 kg capsules of 1E6 freeze-dried microorganisms each, may be captured by new planets or delivered to planets after incorporation first into carbonaceous asteroids and comets. These objects, as modeled by meteorite materials, contain biologically available organic and mineral nutrients that are shown to sustain microbial growth. The program may be driven by panbiotic ethics, predicated on: 1. The unique position of complex organic life amongst the structures of Nature; 2. Self-propagation as the basic propensity of the living pattern; 3. The biophysical unity humans with of the organic, DNA/protein family of life; and 4. Consequently, the primary human purpose to safeguard and propagate our organic life form. To promote this purpose, panspermia missions with diverse biological payloads will maximize survival at the targets and induce evolutionary pressures. In particular, eukaryotes and simple multicellular organisms in the payload will accelerate higher evolution. Based on the geometries and masses of star-forming regions, the 1E24 kg carbon resources of one solar system, applied during its 5E9 yr lifespan, can seed all newly forming planetary systems in the galaxy.
Measurement of Quality of Life III. From the IQOL Theory to the Global, Generic SEQOL Questionnaire
Ventegodt, Soren; Merrick, Joav; Andersen, Niels Jorgen
2003-01-01
The Danish Quality of Life Survey is based on the philosophy of life known as the integrative quality-of-life (IQOL) theory. It consists of eight different quality-of-life concepts, ranging from the superficially subjective via the deeply existential to the superficially objective (well being, satisfaction with life, happiness, meaning in life, biological order, realizing life potential, fulfillment of needs, and objective factors [ability of functioning and fulfilling societal norms]).This paper presents the work underlying the formulation of the theories of a good life and how these theories came to be expressed in a comprehensive, multidimensional, generic questionnaire for the evaluation of the global quality of life — SEQOL (self-evaluation of quality of life) — presented in full length in this paper. The instruments and theories on which the Quality of Life Survey was based are constantly being updated. It is an on-going process due to aspects such as human development, language, and culture. We arrived at eight rating scales for the quality of life that, guided by the IQOL theory, were combined into a global and generic quality-of-life rating scale. This was simplified to the validated QOL5 with only five questions, made for use in clinical databases. Unfortunately, the depth of human existence is to some extent lost in QOL5.We continue to aim towards greater simplicity, precision, and depth in the questions in order to explore the depths of human existence. We have not yet found a final form that enables us to fully rate the quality of life in practice. We hope that the several hundred questions we found necessary to adequately implement the theories of the Quality of Life Survey can be replaced by far fewer; ideally, only eight questions representing the eight component theories. These eight ideal questions have not yet been evaluated, and therefore they should not form the basis of a survey. However, the perspective is clear. If eight simple questions can accurately rate the quality of life as well as its depth, we have found an instrument of immense practical scope. PMID:14570988
Kim, Sook-Young; Sok, Sohyune R
2012-08-01
The objective of this study was to examine the perceived health status, family support and life satisfaction of older Korean adults and the relationships among them. This study was designed to be a descriptive correlation study using questionnaire. Subjects were 246 older people who were over 65 years of age in Seoul and Daegu metropolitan city, Korea. Measures were the Cornell Medical Index-Simple Korean Form to measure the perceived health status, the Family Support Instrument to measure the family support and the Standard Life Satisfaction Instrument for Korean people to measure the life satisfaction. Perceived health state was worse as average 3.3, family support was good as average 3.4 and life satisfaction was low as average 3.1. There were statistically significant positive correlations among perceived health state, family support and life satisfaction and between family support and life satisfaction. The predictors of life satisfaction in elderly were family support, age, monthly allowance and perceived health state. These factors explained 37.5% of the total variance. The major influencing factor was family support. This cross-sectional study provides preliminary evidence that to develop nursing strategy to increase family support of older Korean adults is needed. © 2012 Blackwell Publishing Asia Pty Ltd.
Life prediction modeling based on cyclic damage accumulation
NASA Technical Reports Server (NTRS)
Nelson, Richard S.
1988-01-01
A high temperature, low cycle fatigue life prediction method was developed. This method, Cyclic Damage Accumulation (CDA), was developed for use in predicting the crack initiation lifetime of gas turbine engine materials, where initiation was defined as a 0.030 inch surface length crack. A principal engineering feature of the CDA method is the minimum data base required for implementation. Model constants can be evaluated through a few simple specimen tests such as monotonic loading and rapic cycle fatigue. The method was expanded to account for the effects on creep-fatigue life of complex loadings such as thermomechanical fatigue, hold periods, waveshapes, mean stresses, multiaxiality, cumulative damage, coatings, and environmental attack. A significant data base was generated on the behavior of the cast nickel-base superalloy B1900+Hf, including hundreds of specimen tests under such loading conditions. This information is being used to refine and extend the CDA life prediction model, which is now nearing completion. The model is also being verified using additional specimen tests on wrought INCO 718, and the final version of the model is expected to be adaptable to most any high-temperature alloy. The model is currently available in the form of equations and related constants. A proposed contract addition will make the model available in the near future in the form of a computer code to potential users.
Possible and False Biomarkers from Space
NASA Technical Reports Server (NTRS)
Bernstein, Max P.
2004-01-01
The Search for life in the Solar System is one of NASA's main goals for the coming decade. We may never observe alien life directly; we or our robotic craft may always be removed from it by many years, or meters of crust. If we do find evidence of Life elsewhere in the Solar System it will probably be in form of chemical biomarkers, quintessentially biological molecules that indicate the presence of micro-organisms. What molecules would be truly indicative of alien life? Chlorophyll fragments, which are often used by geochemists are probably far too specific. Simpler molecules, such as fatty acids, amino acids and nucleo-bases might seem to be biomarkers, but they can form non-biotically in space. Alkyl substituted aromatics in ALH 84001 have been invoked as biomarkers, but they are not strong evidence in and of themselves. Understanding the range of nonbiological organic molecules which could act as false biomarkers in space is a prerequisite for any reasonable search for true biomarkers on other worlds. When simple organics arrive at the surface of a body like Europa, either from below or from space, how long do they survive and what do they make? How can we distinguish these from real biomarkers? In this talk I will present some ideas about what might be useful qualities to consider in a potential biomarker, and will ask for advice from the attendant geochemists.
Ocular Changes and Approaches of Ophthalmopathy in Basedow – Graves- Parry- Flajani Disease
SARACI, George; TRETA, Anamaria
2011-01-01
ABSTRACT Basedow-Graves disease is an autoimmune condition with multiple local and systemic aspects. Among these, oculopathy has a major impact on patient's life from both functional and esthetic point of view. Basedow-Graves oculopathy requires an appropriate positive and differential diagnosis using clinical and imagistic approaches. Treatment is always required in moderate or severe forms and it begins with simple general points and continues with medical and surgical therapies. Current article stresses upon the most characteristic clinical signs of thyroidian ophthalmopathy and the required current therapeutic approaches. PMID:22205899
Amagai, Noriko; Komagamine, Yuriko; Kanazawa, Manabu; Iwaki, Maiko; Jo, Ayami; Suzuki, Hiroyuki; Minakuchi, Shunsuke
2017-10-01
To investigate the combined effect of complete denture renewal and simple dietary advice. A randomized controlled trial was performed with edentulous patients who required new complete dentures. All participants received complete denture treatment. In addition, the intervention group received dietary advice in a pamphlet form, while the control group received advice pertaining to the care and maintenance of the dentures. The advice was given by dentists for each group. The participants' food intake was assessed at baseline and 3 months after intervention using a diet history questionnaire and an oral health related quality of life assessment measured using the Japanese version of the Oral Health Impact Profile for edentulous people (OHIP-EDENT-J). Among 70 participants who were randomized, 62 participants finished all parts of this trial. At baseline, there was no significant difference in the food intake between the two groups. At the 3-month assessment, the intervention group showed significantly greater intake of chicken (P=0.013), fish with bones (P=0.012), and carrots and pumpkins (P=0.025) compared to the control group. However, at baseline and at the 3-month assessment, there was no significant difference in the OHIP-EDENT-J scores between the groups, but the OHIP-EDENT-J scores significantly improved for both groups at the 3-month assessment. There were more significant improved dimensions of OHIP-EDENT-J in the intervention group than in the control group at the 3-month assessment. Simple dietary advice combined with complete denture treatment could improve food intake of edentulous patients. The present study suggests that brief dietary advice provided by dentists can improve food intake of edentulous elderly. This simply diet advice is much easier compared to customized forms, might enable normal dentists provide patients it. The result of this study broadens possibility of nutritional counseling in daily clinical practice. Copyright © 2017 Elsevier Ltd. All rights reserved.
The Origin of Universal Scaling in Biology from Molecules & Cells to Whales and Ecosystems
NASA Astrophysics Data System (ADS)
West, Geoffrey
2002-03-01
Life is the most complex physical system in the Universe manifesting an extraordinary diversity of form and function over an enormous scale ranging from the largest animals and plants to the smallest microbes. Yet, many of its most fundamental and complex phenomena scale with size in a surprisingly simple fashion. For example, metabolic rate (the power needed to sustain life) scales as the 3/4-power of mass over 27 orders of magnitude ranging from molecular and intra-cellular levels up through the smallest unicellular organisms to the largest animals and plants. Similarly, time-scales (such as lifespan and heart-rate) and sizes (such as the radius of a tree trunk or the density of mitochondria) change with size with exponents which are typically simple powers of 1/4. The phenomenology of these "laws" will be reviewed and a quantitative unified theory presented that explains their origin, including that of the universal 1/4-power. It is based on the fundamental observation that, regardless of size, almost all life is sustained, and ultimately constrained, by space-filling, fractal-like hierarchical branching networks which are optimised by the forces of natural selection. Integrated descriptions of the cardiovascular, respiratory and plant vascular systems will be presented as explicit examples. It will be shown how scaling universality can be related to an effective additional fourth spatial dimension of life. Extensions to growth, aging and mortality, ecosystems and the nature of evolution, including thermodynamic considerations and the concept of a universal molecular clock, will be discussed.
Arnoldt, Hinrich; Strogatz, Steven H; Timme, Marc
2015-01-01
It has been hypothesized that in the era just before the last universal common ancestor emerged, life on earth was fundamentally collective. Ancient life forms shared their genetic material freely through massive horizontal gene transfer (HGT). At a certain point, however, life made a transition to the modern era of individuality and vertical descent. Here we present a minimal model for stochastic processes potentially contributing to this hypothesized "Darwinian transition." The model suggests that HGT-dominated dynamics may have been intermittently interrupted by selection-driven processes during which genotypes became fitter and decreased their inclination toward HGT. Stochastic switching in the population dynamics with three-point (hypernetwork) interactions may have destabilized the HGT-dominated collective state and essentially contributed to the emergence of vertical descent and the first well-defined species in early evolution. A systematic nonlinear analysis of the stochastic model dynamics covering key features of evolutionary processes (such as selection, mutation, drift and HGT) supports this view. Our findings thus suggest a viable direction out of early collective evolution, potentially enabling the start of individuality and vertical Darwinian evolution.
The size distribution of inhabited planets
NASA Astrophysics Data System (ADS)
Simpson, Fergus
2016-02-01
Earth-like planets are expected to provide the greatest opportunity for the detection of life beyond the Solar system. However, our planet cannot be considered a fair sample, especially if intelligent life exists elsewhere. Just as a person's country of origin is a biased sample among countries, so too their planet of origin may be a biased sample among planets. The magnitude of this effect can be substantial: over 98 per cent of the world's population live in a country larger than the median. In the context of a simple model where the mean population density is invariant to planet size, we infer that a given inhabited planet (such as our nearest neighbour) has a radius r < 1.2r⊕ (95 per cent confidence bound). We show that this result is likely to hold not only for planets hosting advanced life, but also for those which harbour primitive life forms. Further, inferences may be drawn for any variable which influences population size. For example, since population density is widely observed to decline with increasing body mass, we conclude that most intelligent species are expected to exceed 300 kg.
Evolutionary Models for Simple Biosystems
NASA Astrophysics Data System (ADS)
Bagnoli, Franco
The concept of evolutionary development of structures constituted a real revolution in biology: it was possible to understand how the very complex structures of life can arise in an out-of-equilibrium system. The investigation of such systems has shown that indeed, systems under a flux of energy or matter can self-organize into complex patterns, think for instance to Rayleigh-Bernard convection, Liesegang rings, patterns formed by granular systems under shear. Following this line, one could characterize life as a state of matter, characterized by the slow, continuous process that we call evolution. In this paper we try to identify the organizational level of life, that spans several orders of magnitude from the elementary constituents to whole ecosystems. Although similar structures can be found in other contexts like ideas (memes) in neural systems and self-replicating elements (computer viruses, worms, etc.) in computer systems, we shall concentrate on biological evolutionary structure, and try to put into evidence the role and the emergence of network structure in such systems.
Functional traits and root morphology of alpine plants
Pohl, Mandy; Stroude, Raphaël; Buttler, Alexandre; Rixen, Christian
2011-01-01
Background and Aims Vegetation has long been recognized to protect the soil from erosion. Understanding species differences in root morphology and functional traits is an important step to assess which species and species mixtures may provide erosion control. Furthermore, extending classification of plant functional types towards root traits may be a useful procedure in understanding important root functions. Methods In this study, pioneer data on traits of alpine plant species, i.e. plant height and shoot biomass, root depth, horizontal root spreading, root length, diameter, tensile strength, plant age and root biomass, from a disturbed site in the Swiss Alps are presented. The applicability of three classifications of plant functional types (PFTs), i.e. life form, growth form and root type, was examined for above- and below-ground plant traits. Key Results Plant traits differed considerably among species even of the same life form, e.g. in the case of total root length by more than two orders of magnitude. Within the same root diameter, species differed significantly in tensile strength: some species (Geum reptans and Luzula spicata) had roots more than twice as strong as those of other species. Species of different life forms provided different root functions (e.g. root depth and horizontal root spreading) that may be important for soil physical processes. All classifications of PFTs were helpful to categorize plant traits; however, the PFTs according to root type explained total root length far better than the other PFTs. Conclusions The results of the study illustrate the remarkable differences between root traits of alpine plants, some of which cannot be assessed from simple morphological inspection, e.g. tensile strength. PFT classification based on root traits seems useful to categorize plant traits, even though some patterns are better explained at the individual species level. PMID:21795278
Geomorphology: the Shock of the Familiar
NASA Astrophysics Data System (ADS)
Dietrich, W. E.
2008-12-01
Everyone experiences landscapes and has a sense about how they work: water runs down hill, it erodes and carries sediments, and that's about it, right? Introductory earth science text books are uniformly qualitative about the field, and leave one with little sense of wonder, and certainly not "shock". But four shocks occur if one peels away the first impressions. First, landscapes are surprisingly similar: the same forms are repeated in virtually all environments, including under the ocean and on other planets. Second, we lack theory and mechanistic observations to answer many simple first-order questions, e.g. what controls the width of a river, how does rock type control hillslope form and erosion rate, or, is there a topographic signature of life. Third, there are unexpected connections between surface erosion, deep earth processes, and climate. And fourth, the field itself, despite having been a subject of study for well over 100 years, is currently experiencing a revolution of ideas and discoveries through new tools, observatories, centers, journals, books, contributions of researchers from other disciplines, and from a significant hiring of young researchers in geomorphology. Deep messages await discovery in the simple landforms surrounding us.
NASA Astrophysics Data System (ADS)
Mundhenk, T. Nathan; Ni, Kang-Yu; Chen, Yang; Kim, Kyungnam; Owechko, Yuri
2012-01-01
An aerial multiple camera tracking paradigm needs to not only spot unknown targets and track them, but also needs to know how to handle target reacquisition as well as target handoff to other cameras in the operating theater. Here we discuss such a system which is designed to spot unknown targets, track them, segment the useful features and then create a signature fingerprint for the object so that it can be reacquired or handed off to another camera. The tracking system spots unknown objects by subtracting background motion from observed motion allowing it to find targets in motion, even if the camera platform itself is moving. The area of motion is then matched to segmented regions returned by the EDISON mean shift segmentation tool. Whole segments which have common motion and which are contiguous to each other are grouped into a master object. Once master objects are formed, we have a tight bound on which to extract features for the purpose of forming a fingerprint. This is done using color and simple entropy features. These can be placed into a myriad of different fingerprints. To keep data transmission and storage size low for camera handoff of targets, we try several different simple techniques. These include Histogram, Spatiogram and Single Gaussian Model. These are tested by simulating a very large number of target losses in six videos over an interval of 1000 frames each from the DARPA VIVID video set. Since the fingerprints are very simple, they are not expected to be valid for long periods of time. As such, we test the shelf life of fingerprints. This is how long a fingerprint is good for when stored away between target appearances. Shelf life gives us a second metric of goodness and tells us if a fingerprint method has better accuracy over longer periods. In videos which contain multiple vehicle occlusions and vehicles of highly similar appearance we obtain a reacquisition rate for automobiles of over 80% using the simple single Gaussian model compared with the null hypothesis of <20%. Additionally, the performance for fingerprints stays well above the null hypothesis for as much as 800 frames. Thus, a simple and highly compact single Gaussian model is useful for target reacquisition. Since the model is agnostic to view point and object size, it is expected to perform as well on a test of target handoff. Since some of the performance degradation is due to problems with the initial target acquisition and tracking, the simple Gaussian model may perform even better with an improved initial acquisition technique. Also, since the model makes no assumption about the object to be tracked, it should be possible to use it to fingerprint a multitude of objects, not just cars. Further accuracy may be obtained by creating manifolds of objects from multiple samples.
Symmetrical polyhedra (simple crystal forms) as orbits of noncrystallographic point symmetry groups
NASA Astrophysics Data System (ADS)
Ovsetsina, T. I.; Chuprunov, E. V.
2017-09-01
Simple crystal forms are analyzed as the orbits of noncrystallographic point symmetry groups on a set of smooth or structured ("hatched") planes of crystal space. Polyhedra with symmetrically equivalent faces, obtained using noncrystallographic point symmetry groups, are considered. All possible versions of simple forms for all noncrystallographic groups are listed in a unified table.
On theoretical and experimental modeling of metabolism forming in prebiotic systems
NASA Astrophysics Data System (ADS)
Bartsev, S. I.; Mezhevikin, V. V.
Recently searching for extraterrestrial life attracts more and more attention However the searching hardly can be effective without sufficiently universal concept of life origin which incidentally tackles a problem of origin of life on the Earth A concept of initial stages of life origin including origin of prebiotic metabolism is stated in the paper Suggested concept eliminates key difficulties in the problem of life origin and allows experimental verification of it According to the concept the predecessor of living beings has to be sufficiently simple to provide non-zero probability of self-assembling during short in geological or cosmic scale time In addition the predecessor has to be capable of autocatalysis and further complication evolution A possible scenario of initial stage of life origin which can be realized both on other planets and inside experimental facility is considered In the scope of the scenario a theoretical model of multivariate oligomeric autocatalyst coupled with phase-separated particle is presented Results of computer simulation of possible initial stage of chemical evolution are shown Conducted estimations show the origin of autocatalytic oligomeric phase-separated system is possible at reasonable values of kinetic parameters of involved chemical reactions in a small-scale flow reactor Accepted statements allowing to eliminate key problems of life origin imply important consequence -- organisms emerged out of the Earth or inside a reactor have to be based on another different from terrestrial biochemical
Chemical approaches to carbon dioxide utilization for manned Mars missions
NASA Technical Reports Server (NTRS)
Hepp, Aloysius F.; Landis, Geoffrey A.; Kubiak, Clifford P.
1991-01-01
Use of resources available in situ is a critical enabling technology for a permanent human presence in space. A permanent presence on Mars, e.g., requires a large infrastructure to sustain life under hostile conditions. As a resource on Mars, atmospheric CO2 is as follows: abundant; available at all points on the surface; of known presence; chemically simple; and can be obtained by simple compression. Many studies focus on obtaining O2 and the various uses for O2 including life support and fuel; discussion of CO, the coproduct from CO2 fixation revolves around its uses as a fuel, being oxidized back to CO2. Several new proposals are studied for CO2 fixation through chemical, photochemical, and photoelectrochemical means. For example, the reduction of CO2 to hydrocarbons such as acetylene (C2H2) can be accomplished with H2. C2H2 has a theoretical vacuum specific impulse of approx. 375 secs. Potential uses were also studied of CO2, as obtained or further reduced to carbon, as a reducing agent in metal oxide processing to form metals or metal carbides for use as structural or power materials; the CO2 can be recycled to generate O2 and CO.
d'Orsi, G; Tinuper, P; Bisulli, F; Zaniboni, A; Bernardi, B; Rubboli, G; Riva, R; Michelucci, R; Volpi, L; Tassinari, C; Baruzzi, A
2004-01-01
Objectives: Little is known about the long term outcome of patients with periventricular nodular heterotopia (PNH) and epilepsy, particularly the course of seizures. This study investigated the electroclinical and prognostic features of 16 patients with PNH. Methods: Of 120 patients with epilepsy and malformations of cortical development, 16 had PNH. Of these, eight patients had periventricular nodules only (simple PNH) and eight also presented with other cortical or cerebral malformations (subcortical heterotopia; polymicrogyria; focal dysplasia; schizencephaly; cortical infolding; agenesis of the corpus callosum; mega cisterna magna and cerebellar atrophy) (PNH plus). All patients underwent clinical, neurophysiological, and MRI investigation. The mean follow up was 17.3 years (2–40 years). Results: Two electroclinical patterns emerged: (1) The first pattern, associated with simple PNH, was characterised by normal intelligence and seizures, usually partial, which began during the second decade of life. The seizures never became frequent and tended to disappear or become very rare. The EEG showed focal abnormalities. (2) The second pattern, associated with PNH plus, was characterised by mental retardation and seizures that began during the first decade of life. The seizures were very frequent in most cases and sudden drops were observed in six patients. Seizures were medically refractory in four patients. The EEG showed focal and bisynchronous abnormalities. Conclusions: Two groups of PNH patients with different electroclinical and neuroradiological features can be identified after a long term follow up. The presence of other types of cortical or cerebral malformations, in addition to periventricular nodules, determines a poor prognosis. PMID:15146004
Wittenberg, Philipp; Gan, Fah Fatt; Knoth, Sven
2018-04-17
The variable life-adjusted display (VLAD) is the first risk-adjusted graphical procedure proposed in the literature for monitoring the performance of a surgeon. It displays the cumulative sum of expected minus observed deaths. It has since become highly popular because the statistic plotted is easy to understand. But it is also easy to misinterpret a surgeon's performance by utilizing the VLAD, potentially leading to grave consequences. The problem of misinterpretation is essentially caused by the variance of the VLAD's statistic that increases with sample size. In order for the VLAD to be truly useful, a simple signaling rule is desperately needed. Various forms of signaling rules have been developed, but they are usually quite complicated. Without signaling rules, making inferences using the VLAD alone is difficult if not misleading. In this paper, we establish an equivalence between a VLAD with V-mask and a risk-adjusted cumulative sum (RA-CUSUM) chart based on the difference between the estimated probability of death and surgical outcome. Average run length analysis based on simulation shows that this particular RA-CUSUM chart has similar performance as compared to the established RA-CUSUM chart based on the log-likelihood ratio statistic obtained by testing the odds ratio of death. We provide a simple design procedure for determining the V-mask parameters based on a resampling approach. Resampling from a real data set ensures that these parameters can be estimated appropriately. Finally, we illustrate the monitoring of a real surgeon's performance using VLAD with V-mask. Copyright © 2018 John Wiley & Sons, Ltd.
Metz, Johan A Jacob; Staňková, Kateřina; Johansson, Jacob
2016-03-01
This paper should be read as addendum to Dieckmann et al. (J Theor Biol 241:370-389, 2006) and Parvinen et al. (J Math Biol 67: 509-533, 2013). Our goal is, using little more than high-school calculus, to (1) exhibit the form of the canonical equation of adaptive dynamics for classical life history problems, where the examples in Dieckmann et al. (J Theor Biol 241:370-389, 2006) and Parvinen et al. (J Math Biol 67: 509-533, 2013) are chosen such that they avoid a number of the problems that one gets in this most relevant of applications, (2) derive the fitness gradient occurring in the CE from simple fitness return arguments, (3) show explicitly that setting said fitness gradient equal to zero results in the classical marginal value principle from evolutionary ecology, (4) show that the latter in turn is equivalent to Pontryagin's maximum principle, a well known equivalence that however in the literature is given either ex cathedra or is proven with more advanced tools, (5) connect the classical optimisation arguments of life history theory a little better to real biology (Mendelian populations with separate sexes subject to an environmental feedback loop), (6) make a minor improvement to the form of the CE for the examples in Dieckmann et al. and Parvinen et al.
Where should one look for traces of life on Venus?
NASA Astrophysics Data System (ADS)
Vidmachenko, A. P.
2018-05-01
Now Venus is not very similar to a suitable place for living. It surface temperature exceeds 730 K, the pressure is 90 atmospheres, the cloud layer consists of sulfur dioxide, and the fog above cloud is a solution of sulfuric acid. But about 3 billion years ago, this planet among the Earth-type planets within the Solar System was perhaps the most suitable place for the existence of some form of life there. Measurements of the ratio of hydrogen isotopes in the atmosphere also showed that the planet once had much more water, and perhaps it was enough even for the oceans. In early years on Venus was similar to the earth's climate, have a satisfactory temperature and oceans of liquid water. That is, under the above conditions with moderate temperature, sufficient heat and liquid water, Venus would be quite suitable for the emergence of certain microorganisms and for the existence of primitive life there, especially in the oceans. One way to check whether the ancient Venus was once covered by the oceans is the study of the tremolite found on Earth. It is necessary to hope to find the tremolite at some depth below the surface of Venus. Also necessary to search for some biosignals in the form of petrified remains, of possibly simple thermophilic microorganisms. We believe that such an experiment can be prepared and technically carried out during the next decades.
Mars in the late Noachian: Evolution of a habitable surface environment
NASA Astrophysics Data System (ADS)
Johnson, Sarah Stewart
2008-10-01
This dissertation addresses whether simple life forms might have existed on Mars during the late Noachian epoch, and whether those life forms, or their traces, can be detected today. It begins by analyzing the ancient Martian climate in light of new evidence that sulfur chemistry played a prominent role in the planet's early evolution. It finds that sulfur-induced greenhouse warming could have periodically heated the planet enough to support liquid water, thereby creating warm, wet, clement conditions. Moreover, it finds that those warming pulses, while short-lived over geologic time, may have persisted for hundreds of years. If sulfur helped create environmental conditions capable of hosting life, however, it also created conditions that were adverse to sustaining it. In particular, dissipation of sulfur volatiles cooled the climate, and sulfur rainout contributed to the acidity of Martian surface waters. The dissertation therefore proceeds to analyze the potential for persistence and detection of life in terrestrial environments with Mars-like characteristics. It first investigates the potential for detecting ancient life by searching for lipid biomarkers in sulfur-rich acid salt lakes, concluding that a variety of biomarkers may be more resistant to decay than previously believed. It then analyzes soil samples from permafrost, discovering the oldest independently authenticated viable organisms ever found, and positing low-level metabolic activity and DNA repair as a survival mechanism in ancient cells. Finally, the dissertation uses deep sequencing to examine prokaryotic diversity in a terrestrial Mars-like river characterized by low pH and high concentrations of iron and sulfur, with results considered in light of the implications for life detection approaches incorporating new, in situ "PCR in a chip" technology. The dissertation concludes by proposing future work, including the ultimate goal of developing a life detection instrument for Mars. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)
Mineral Bionization - Surface Chemical Modeling of the Emergence of Life
NASA Astrophysics Data System (ADS)
Arrhenius, G.
2001-12-01
The earliest stages in entering an RNA-world require natural mechanisms that are capable of selective concentration of simple aldehydes from dilute solution in the environment (4), furthermore phosphorylation of the sequestered aldehydes (2) and their catalytic condensation to form, selectively, tetrose- (threose) or pentose- (ribose) phosphate (3); the latter representing the R in RNA. A variety of common positively charged sheet structure minerals (mixed valence double layer metal hydroxide minerals such as hydrotalcite and green rust) have proven to be remarkably capable of performing these crucial tasks under simplified natural conditions (1). These prebiotic model reactions have demonstrated plausible closure of the gap, previously thought to preclude the natural formation of nucleoside phosphates, the backbone components of the information carrying genetic material. Pioneering research by other workers (5) has demonstrated the feasibility of necessary further steps in the chain toward functional RNA; mineral (montmorillonite) catalyzed oligomerization of nucleotides, the formation of complementary RNA strands (6) and the enzymatic activity of RNA (ribozymes). These contributions have placed the initially conjectural concept of an initial RNA-world on an experimental footing. Remaining problems include the initial transfer of information to spontaneously forming RNA, sufficient to convey biofunctionallity (7). Also in this central problem mineral surface interactions may be speculated to play a natural role; a question that is open to experimental verification. References. 1. Pitsch, S.; Eschenmoser, A.; Gedulin, B.; Hui, S. and Arrhenius, G. Origins Life Evol. Biosphere, 1994, 24 (5), 389. 2. Kolb, V.; Zhang, S.; Xu, Y.; Arrhenius, G. Origins Life Evol. Biosphere, 1997, 27, 485. 3. Krishnamurthy, R.; Pitsch, S.; Arrhenius, G. Origins Life Evol. Biosphere, Origins Life Evol. Biosphere 1999, 29, 139 4. Pitsch, S.; Krishnamurthy, R.; Arrhenius, G. Helv. Chim. Acta. 2000, 83, 2398. 5. Ferris, J. P.; Ertem, G. J. J. Am. Chem. Soc. 1993, 115, 1270. 6. Orgel ,L.E. J. Theoretical Biol. 1986, 123, 127-149 7. Arrhenius, G; Life out of Chaos. In Palyi et al. eds. Fundamentals of Life, Elsevier, Paris, 2001
Life sciences flight experiments microcomputer
NASA Technical Reports Server (NTRS)
Bartram, Peter N.
1987-01-01
A promising microcomputer configuration for the Spacelab Life Sciences Lab. Equipment inventory consists of multiple processors. One processor's use is reserved, with additional processors dedicated to real time input and output operations. A simple form of such a configuration, with a processor board for analog to digital conversion and another processor board for digital to analog conversion, was studied. The system used digital parallel data lines between the boards, operating independently of the system bus. Good performance of individual components was demonstrated: the analog to digital converter was at over 10,000 samples per second. The combination of the data transfer between boards with the input or output functions on each board slowed performance, with a maximum throughput of 2800 to 2900 analog samples per second. Any of several techniques, such as use of the system bus for data transfer or the addition of direct memory access hardware to the processor boards, should give significantly improved performance.
Passivating Li-Ion Batteries in Orbit at the End of the Spacecraft's Life
NASA Astrophysics Data System (ADS)
Alcindor, Peter; Kimber, Rick; Remy, Stephane; Prevot, Didier
2014-08-01
International focus on the "Clean Space Initiative", as discussed at the ESA workshop "EoL Electrical Passivation" held on October 11th 2013 identified new legislation (REACh, RoHS and LOS). This paper concerns itself with the prevention of Li-ion battery explosion post end of mission as the spacecraft systems remain active well beyond the initial design expectations and beyond classical reliability design predictions. The main risks to Li-ion energy storage battery systems is the prevention of over charging and over discharging, both these scenarios result in the build up of internal pressure ultimately resulting in venting of high pressure gas. To warrant against such risk legislation requires that batteries are "Passivated" within the predictable life of the spacecraft systems. This paper proposes a simple method for the passivation of Li-ion batteries that relies only on the normal systems that form part of most present day spacecraft heritage.
KGCAK: a K-mer based database for genome-wide phylogeny and complexity evaluation.
Wang, Dapeng; Xu, Jiayue; Yu, Jun
2015-09-16
The K-mer approach, treating genomic sequences as simple characters and counting the relative abundance of each string upon a fixed K, has been extensively applied to phylogeny inference for genome assembly, annotation, and comparison. To meet increasing demands for comparing large genome sequences and to promote the use of the K-mer approach, we develop a versatile database, KGCAK ( http://kgcak.big.ac.cn/KGCAK/ ), containing ~8,000 genomes that include genome sequences of diverse life forms (viruses, prokaryotes, protists, animals, and plants) and cellular organelles of eukaryotic lineages. It builds phylogeny based on genomic elements in an alignment-free fashion and provides in-depth data processing enabling users to compare the complexity of genome sequences based on K-mer distribution. We hope that KGCAK becomes a powerful tool for exploring relationship within and among groups of species in a tree of life based on genomic data.
Gwathmey, Kelly G; Sadjadi, Reza; Horton, William B; Conaway, Mark R; Barnett-Tapia, Carolina; Bril, Vera; Russell, James W; Shaibani, Aziz; Mauermann, Michelle L; Hehir, Michael K; Kolb, Noah; Guptill, Jeffrey; Hobson-Webb, Lisa; Gable, Karissa; Raja, Shruti; Silvestri, Nicholas; Wolfe, Gil I; Smith, A Gordon; Malik, Rabia; Traub, Rebecca; Joshi, Amruta; Elliott, Matthew P; Jones, Sarah; Burns, Ted M
2018-06-05
We studied the performance of a 15-item, health-related quality-of-life polyneuropathy scale in the clinic setting in patients with diabetic distal sensorimotor polyneuropathy (DSPN). Patients with DSPN from 11 academic sites completed a total of 231 Chronic Acquired Polyneuropathy Patient-Reported Index (CAPPRI) scales during their clinic visits. Conventional and modern psychometric analyses were performed on the completed forms. Conventional and modern analyses generally indicated excellent psychometric properties of the CAPPRI in patients with DSPN. For example, the CAPPRI demonstrated unidimensionality and performed like an interval-level scale. Attributes of the CAPPRI for DSPN include ease of use and interpretation; unidimensionality, allowing scores to be summed; adequate coverage of disease severity; and the scale's ability to address relevant life domains. Furthermore, the CAPPRI is free and in the public domain. The CAPPRI may assist the clinician and patient with DSPN in estimating disease-specific quality of life, especially in terms of pain, sleep, psychological well-being, and everyday function. The CAPPRI may be most useful in the everyday clinical setting but merits further study in this setting, as well as the clinical trial setting. © 2018 American Academy of Neurology.
The mysterious age invariance of the planetary nebula luminosity function bright cut-off
NASA Astrophysics Data System (ADS)
Gesicki, K.; Zijlstra, A. A.; Miller Bertolami, M. M.
2018-05-01
Planetary nebulae mark the end of the active life of 90% of all stars. They trace the transition from a red giant to a degenerate white dwarf. Stellar models1,2 predicted that only stars above approximately twice the solar mass could form a bright nebula. But the ubiquitous presence of bright planetary nebulae in old stellar populations, such as elliptical galaxies, contradicts this: such high-mass stars are not present in old systems. The planetary nebula luminosity function, and especially its bright cut-off, is almost invariant between young spiral galaxies, with high-mass stars, and old elliptical galaxies, with only low-mass stars. Here, we show that new evolutionary tracks of low-mass stars are capable of explaining in a simple manner this decades-old mystery. The agreement between the observed luminosity function and computed stellar evolution validates the latest theoretical modelling. With these models, the planetary nebula luminosity function provides a powerful diagnostic to derive star formation histories of intermediate-age stars. The new models predict that the Sun at the end of its life will also form a planetary nebula, but it will be faint.
NASA Astrophysics Data System (ADS)
Dabiri, M.; Ghafouri, M.; Rohani Raftar, H. R.; Björk, T.
2018-03-01
Methods to estimate the strain-life curve, which were divided into three categories: simple approximations, artificial neural network-based approaches and continuum damage mechanics models, were examined, and their accuracy was assessed in strain-life evaluation of a direct-quenched high-strength steel. All the prediction methods claim to be able to perform low-cycle fatigue analysis using available or easily obtainable material properties, thus eliminating the need for costly and time-consuming fatigue tests. Simple approximations were able to estimate the strain-life curve with satisfactory accuracy using only monotonic properties. The tested neural network-based model, although yielding acceptable results for the material in question, was found to be overly sensitive to the data sets used for training and showed an inconsistency in estimation of the fatigue life and fatigue properties. The studied continuum damage-based model was able to produce a curve detecting early stages of crack initiation. This model requires more experimental data for calibration than approaches using simple approximations. As a result of the different theories underlying the analyzed methods, the different approaches have different strengths and weaknesses. However, it was found that the group of parametric equations categorized as simple approximations are the easiest for practical use, with their applicability having already been verified for a broad range of materials.
A causal framework for integrating contemporary and Vedic holism.
Kineman, John J
2017-12-01
Whereas the last Century of science was characterized by epistemological uncertainty; the current Century will likely be characterized by ontological complexity (Gorban and Yablonsky, 2013). Advances in Systems Theory by mathematical biologist Robert Rosen suggest an elegant way forward (Rosen, 2013). "R-theory" (Kineman, 2012) is a synthesis of Rosen's theories explaining complexity and life in terms of a meta-model for 'whole' systems (and their fractions) in terms of "5 th -order holons". Such holons are Rosen "modeling relations" relating system-dependent processes with their formative contexts via closed cycles of four archetypal (Aristotelian) causes. This approach has post-predicted the three most basic taxa of life, plus a quasi-organismic form that may describe proto, component, and ecosystemic life. R-theory thus suggests a fundamentally complex ontology of existence inverting the current view that complexity arises from simple mechanisms. This model of cyclical causality corresponds to the ancient meta-model described in the Vedas and Upanishads of India. Part I of this discussion (Kineman, 2016a) presented a case for associating Vedic philosophy with Harappan civilization, allowing interpretation of ancient concepts of "cosmic order" (Rta) in the Rig Veda, nonduality (advaita), seven-fold beingness (saptanna) and other forms of holism appearing later in the Upanishads. By deciphering the model of wholeness that was applied and tested in ancient times, it is possible to compare, test, and confirm the holon model as a mathematical definition of life, systemic wholeness, and sustainability that may be applied today in modern terms, even as a foundation for holistic science. Copyright © 2017 Elsevier Ltd. All rights reserved.
The impact of a low cost wheelchair on the quality of life of the disabled in the developing world.
Shore, Susan; Juillerat, Stephanie
2012-09-01
People with disabilities in the developing world do not have equal and adequate access to education, employment, or medical care. Their physical or mental condition, compounded by a lack of financial and technological resources, imposes a burden on both the family and the State. A wheelchair is a form of assistive technology which eases that burden for many. This study examines the impact of a simple, donated chair on the health, quality of life, and function of a subject population. Surveys were administered to 519 disabled recipients of a semi-rigid depot style wheelchair in 3 different countries at the time they received their chair and again after 12 months of use. Surveys evaluated physical and emotional health, functional independence, and lifestyle. On initial reports, 46.6% of subjects said they never left home, 52.3% were hospitalized one or more days/month, 70.3% reported daily pain, and 48.7% reported a negative mood state. Following 12 months of using the wheelchair, both the reported overall health rating and mood state increased by 20%; pain was significantly diminished. Although some areas in the ICF function measure improved more than others, the overall reported level of independence rose by 11%. A representative sample of the disabled in 3 countries of the world is socially isolated, in poor health, and with limited function. Receipt of a simple, depot style wheelchair significantly improved their quality of life, health indicators, and the ICF function measure following 12 months of use.
NASA Technical Reports Server (NTRS)
Pohorille, Andrew; Wilson, Michael A.
1995-01-01
Molecular dynamics computer simulations of the structure and functions of a simple membrane are performed in order to examine whether membranes provide an environment capable of promoting protobiological evolution. Our model membrane is composed of glycerol 1-monooleate. It is found that the bilayer surface fluctuates in time and space, occasionally creating thinning defects in the membrane. These defects are essential for passive transport of simple ions across membranes because they reduce the Born barrier to this process by approximately 40%. Negative ions are transferred across the bilayer more readily than positive ions due to favorable interactions with the electric field at the membrane-water interface. Passive transport of neutral molecules is, in general, more complex than predicted by the solubility-diffusion model. In particular, molecules which exhibit sufficient hydrophilicity and lipophilicity concentrate near membrane surfaces and experience 'interfacial resistance' to transport. The membrane-water interface forms an environment suitable for heterogeneous catalysis. Several possible mechanisms leading to an increase of reaction rates at the interface are discussed. We conclude that vesicles have many properties that make them very good candidates for earliest protocells. Some potentially fruitful directions of experimental and theoretical research on this subject are proposed.
Read, Thomas; Olkhov, Rouslan V; Williamson, E Diane; Shaw, Andrew M
2015-09-01
A unified approach to affinity screening for Fab and Fc interactions of an antibody for its antigen and FcγR receptor has been developed. An antigen array is used for the Fab affinity and cross-reactivity screening and protein A/G proxy is the FcγR receptor. The affinities are derived using a simple 1:1 binding model with a consistent error analysis. The association and dissociation kinetics are measured over optimised times for accurate determination. The Fab/Fc affinities are derived for ten antibodies: mAb-actin (mouse), pAb-BSA (sheep), pAb-collagen V (rabbit), pAb-CRP (goat), mAb-F1 (mouse), mAbs (mouse) 7.3, 12.3, 29.3, 36.3 and 46.3 raised against LcrV in Yersinia pestis. The rate of the dissociation of antigen-antibody complexes relates directly to their immunological function as does the Fc-FcγR complex and a new half-life plot has been defined with a Fab/Fc half-life range of 17-470 min. The upper half-life value points to surface avidity. Two antibodies that are protective as an immunotherapy define a Fab half-life >250 min and an Fc half-life >50 min as characteristics of ideal interactions which can form the basis of an antibody screen for immunotherapy.
Method for estimating the morphological significance of simple forms of crystals from X-ray data
DOE Office of Scientific and Technical Information (OSTI.GOV)
Treivus, E. B., E-mail: sbobr1@bk.ru
2010-09-15
When developing V.I. Mikheev and I.I. Shafranovskii's method for estimating the morphological significance of faces of different simple forms from X-ray reflection intensities, a way to approximately evaluate the morphological significance of simple forms on crystals from the structure amplitudes of the corresponding atomic planes is proposed. The potential for this approach is demonstrated by the examples of marcasite and zircon.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lukens, Wayne W.; Saslow, Sarah A.
Technetium-99 (Tc) is a problematic fission product that complicates the long-term disposal of nuclear waste due to its long half-life, high fission yield, and the environmental mobility of pertechnetate, its stable form in aerobic environments. One approach to preventing Tc contamination is through incorporation into durable waste forms based on weathering-resistant minerals such as rutile (titanium dioxide). Here, the incorporation of technetium into titanium dioxide by means of simple, aqueous chemistry is presented. X-ray absorption fine structure spectroscopy and diffuse reflectance spectroscopy indicate that Tc(IV) replaces Ti(IV) within the structure. Rather than being incorporated as isolated Tc(IV) ions, Tc ismore » present as pairs of edge-sharing Tc(IV) octahedra similar to molecular Tc(IV) complexes such as [(H2EDTA)TcIV](u-O)2. Technetium-doped TiO2 was suspended in deionized water under aerobic conditions, and the Tc leached under these conditions was followed for 8 months. The normalized release rate of Tc (LRTc) from the TiO2 particles is low (3×10-6 g m-2 d-1), which illustrates the potential utility of TiO2 as waste form. However, the small size of the as-prepared TiO2 nanoparticles results in estimated retention of Tc for 104 years, which is only a fraction of the half-life of Tc (2×10-5 years).« less
Thacker, Evan L.; Gillett, Sarah R.; Wadley, Virginia G.; Unverzagt, Frederick W.; Judd, Suzanne E.; McClure, Leslie A.; Howard, Virginia J.; Cushman, Mary
2014-01-01
Background Life's Simple 7 is a new metric based on modifiable health behaviors and factors that the American Heart Association uses to promote improvements to cardiovascular health (CVH). We hypothesized that better Life's Simple 7 scores are associated with lower incidence of cognitive impairment. Methods and Results For this prospective cohort study, we included REasons for Geographic And Racial Differences in Stroke (REGARDS) participants aged 45+ who had normal global cognitive status at baseline and no history of stroke (N=17 761). We calculated baseline Life's Simple 7 score (range, 0 to 14) based on smoking, diet, physical activity, body mass index, blood pressure, total cholesterol, and fasting glucose. We identified incident cognitive impairment using a 3‐test measure of verbal learning, memory, and fluency obtained a mean of 4 years after baseline. Relative to the lowest tertile of Life's Simple 7 score (0 to 6 points), odds ratios of incident cognitive impairment were 0.65 (0.52, 0.81) in the middle tertile (7 to 8 points) and 0.63 (0.51, 0.79) in the highest tertile (9 to 14 points). The association was similar in blacks and whites, as well as outside and within the Southeastern stroke belt region of the United States. Conclusions Compared with low CVH, intermediate and high CVH were both associated with substantially lower incidence of cognitive impairment. We did not observe a dose‐response pattern; people with intermediate and high levels of CVH had similar incidence of cognitive impairment. This suggests that even when high CVH is not achieved, intermediate levels of CVH are preferable to low CVH. PMID:24919926
Caleyachetty, Rishi; Echouffo-Tcheugui, Justin B; Muennig, Peter; Zhu, Wenyi; Muntner, Paul; Shimbo, Daichi
2015-07-15
The American Heart Association developed the Life's Simple 7 metric for defining cardiovascular health. Little is known about the association of co-occurring social risk factors on ideal cardiovascular health. Using data on 11,467 adults aged ≥25 years from the National Health and Nutrition Examination Survey 1999-2006, we examined the association between cumulative social risk and ideal cardiovascular health in US adults. A cumulative risk score (range 0 to 3 or 4) was created by summing four social risk factors (low family income, low education level, minority race, and single-living status). Ideal levels for each component in Life's Simple 7 (blood pressure, cholesterol, glucose, BMI, smoking, physical activity, and diet) were used to create an ideal Life's Simple 7 score [0-1 (low), 2, 3, 4, and 5-7 (high)]. Adults with low income (odds ratio [OR]=0.30 [95% CI 0.23-0.39]), low education [0.22 (0.16-0.28)], who are non-white (0.44 [0.36-0.54]) and single-living [0.79 (0.67-0.95)] were less likely to have 5-7 versus 0 ideal Life's Simple 7 scores after adjustment for age and sex. Adults were less likely to attain 5-7 versus 0 ideal Life's Simple 7 scores as exposure to the number of social risk factors increased [OR (95% CI) of 0.58 (0.49-0.68); 0.27 (0.21-0.35); and 0.19 (0.14-0.27) for cumulative social risk scores of 1, 2, and 3 or 4, respectively, each versus 0]. US adults with an increasing number of socially risk factors, were progressively less likely to attain ideal levels of cardiovascular health factors. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Schneider, Berenice; Cunha, Eduardo R.; Marchese, Mercedes; Thomaz, Sidinei M.
2018-01-01
Macrophyte assemblages are composed of species with different life forms and various ecological functions. Our aim was to investigate the potential environmental determinants of changes in the biomass of individual life forms and of the composition of the macrophyte assemblage in terms of life forms diversity. We sampled 23 waterbodies at low and high water levels in the Middle Paraná River floodplain. Macrophyte biomass samples were collected and classified in terms of life forms. We performed a redundancy analysis using the biomass of the various life forms to assess the importance of environmental variables to the composition of macrophyte life forms. Linear regressions were applied to investigate the environmental determinants of the biomasses of individual life forms. The degree of connectivity and the combination of depth, hydrology and nitrate were the main determinants of the composition in terms of life forms. The biomass of each individual life form was explained by different combinations of environmental variables, but the connectivity was the most important one. Our study shows that groups of species with similar life forms respond to environmental factors in particular ways, which might alter the biomass composition of life forms. Given that the ecosystem functioning depends on the functional characteristics of local communities, our findings about the relation between environmental changes and the community composition in terms of life forms (or functional composition) can be a helpful tool for predicting changes on ecosystem processes (such as nutrient cycling) against possible future scenarios. PMID:29515608
The mismeasure of machine: Synthetic biology and the trouble with engineering metaphors.
Boudry, Maarten; Pigliucci, Massimo
2013-12-01
The scientific study of living organisms is permeated by machine and design metaphors. Genes are thought of as the "blueprint" of an organism, organisms are "reverse engineered" to discover their functionality, and living cells are compared to biochemical factories, complete with assembly lines, transport systems, messenger circuits, etc. Although the notion of design is indispensable to think about adaptations, and engineering analogies have considerable heuristic value (e.g., optimality assumptions), we argue they are limited in several important respects. In particular, the analogy with human-made machines falters when we move down to the level of molecular biology and genetics. Living organisms are far more messy and less transparent than human-made machines. Notoriously, evolution is an opportunistic tinkerer, blindly stumbling on "designs" that no sensible engineer would come up with. Despite impressive technological innovation, the prospect of artificially designing new life forms from scratch has proven more difficult than the superficial analogy with "programming" the right "software" would suggest. The idea of applying straightforward engineering approaches to living systems and their genomes-isolating functional components, designing new parts from scratch, recombining and assembling them into novel life forms-pushes the analogy with human artifacts beyond its limits. In the absence of a one-to-one correspondence between genotype and phenotype, there is no straightforward way to implement novel biological functions and design new life forms. Both the developmental complexity of gene expression and the multifarious interactions of genes and environments are serious obstacles for "engineering" a particular phenotype. The problem of reverse-engineering a desired phenotype to its genetic "instructions" is probably intractable for any but the most simple phenotypes. Recent developments in the field of bio-engineering and synthetic biology reflect these limitations. Instead of genetically engineering a desired trait from scratch, as the machine/engineering metaphor promises, researchers are making greater strides by co-opting natural selection to "search" for a suitable genotype, or by borrowing and recombining genetic material from extant life forms. Copyright © 2013 Elsevier Ltd. All rights reserved.
Interfacial mechanisms for stability of surfactant-laden films
Chai, Chew; Àlvarez-Valenzuela, Marco A.; Tajuelo, Javier; Fuller, Gerald G.
2017-01-01
Thin liquid films are central to everyday life. They are ubiquitous in modern technology (pharmaceuticals, coatings), consumer products (foams, emulsions) and also serve vital biological functions (tear film of the eye, pulmonary surfactants in the lung). A common feature in all these examples is the presence of surface-active molecules at the air-liquid interface. Though they form only molecular-thin layers, these surfactants produce complex surface stresses on the free surface, which have important consequences for the dynamics and stability of the underlying thin liquid film. Here we conduct simple thinning experiments to explore the fundamental mechanisms that allow the surfactant molecules to slow the gravity-driven drainage of the underlying film. We present a simple model that works for both soluble and insoluble surfactant systems in the limit of negligible adsorption-desorption dynamics. We show that surfactants with finite surface rheology influence bulk flow through viscoelastic interfacial stresses, while surfactants with inviscid surfaces achieve stability through opposing surface-tension induced Marangoni flows. PMID:28520734
Life cycle assessment of energy and CO2 emissions for residential buildings in Jakarta, Indonesia
NASA Astrophysics Data System (ADS)
Surahman, U.; Kubota, T.; Wijaya, A.
2016-04-01
In order to develop low energy and low carbon residential buildings, it is important to understand their detailed energy profiles. This study provides the results of life cycle assessment of energy and CO2 emissions for residential buildings in Jakarta, Indonesia. A survey was conducted in the city in 2012 to obtain both material inventory and household energy consumption data within the selected residential buildings (n=300), which are classified into three categories, namely simple, medium and luxurious houses. The results showed that the average embodied energy of simple, medium and luxurious houses was 58.5, 201.0, and 559.5 GJ, respectively. It was found that total embodied energy of each house can be explained by its total floor area alone with high accuracy in respective house categories. Meanwhile, it was seen that operational energy usage patterns varied largely among house categories as well as households especially in the simple and medium houses. The energy consumption for cooling was found to be the most significant factor of the increase in operational energy from simple to luxurious houses. Further, in the life cycle energy, the operational energy accounted for much larger proportions of about 86-92% than embodied energy regardless of the house categories. The life cycle CO2 emissions for medium and luxurious houses were larger than that of simple houses by 2 and 6 times on average. In the simple houses, cooking was the largest contributor to the CO2 emissions (25%), while the emissions caused by cooling increased largely with the house category and became the largest contributors in the medium (26%) and luxurious houses (41%).
Simple mechanisms of early life - simulation model on the origin of semi-cells.
Klein, Adrian; Bock, Martin; Alt, Wolfgang
2017-01-01
The development of first cellular structures played an important role in the early evolution of life. Early evolution of life probably took place on a molecular level in a reactive environment. The iron-sulfur theory postulates the formation of cell-like structures on catalytic surfaces. Experiments show that H 2 S together with FeS and other metallic centers drive auto-catalytic surface reactions, in which organic molecules such as pyruvic and amino acids occur. It is questionable which mechanisms are needed to form cell-like structures under these conditions. To address this question, we implemented a model system featuring the fundamentals of molecular dynamics: heat, attraction, repulsion and formation of covalent bonds. Our basic model exhibits a series of essential processes: self-organization of lipid micelles and bilayers, formation of fluid filled cavities, flux of molecules along membranes, transport of energized groups towards sinks and whole colonies of cell-like structures on a larger scale. The results demonstrate that only a few features are sufficient for discovering hitherto non described phenomena of self-assembly and dynamics of cell-like structures as candidates for early evolving proto-cells. Significance statement The quest for a possible origin of life continues to be one of the most fascinating problems in biology. In one theoretical scenario, early life originated from a solution of reactive chemicals in the ancient deep sea, similar to conditions as to be found in thermal vents. Experiments have shown that a variety of organic molecules, the building blocks of life, form under these conditions. Based on such experiments, the iron-sulfur theory postulates the growth of cell-like structures at certain catalytic surfaces. For an explanation and proof of such a process we have developed a computer model simulating molecular assembly of lipid bilayers and formation of semi-cell cavities. The results demonstrate the possibility of cell-like self-organization under appropriate physico-chemical conditions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
ERIC Educational Resources Information Center
Edwards, Mark Evan; Weber, Bruce; Bernell, Stephanie
2007-01-01
An existing measure of food insecurity with hunger in the United States may serve as an effective indicator of quality of life. State level differences in that measure can reveal important differences in quality of life across places. In this study, we advocate and demonstrate two simple methods by which analysts can explore state-specific…
A Simple Universal Turing Machine for the Game of Life Turing Machine
NASA Astrophysics Data System (ADS)
Rendell, Paul
In this chapter we present a simple universal Turing machine which is small enough to fit into the design limits of the Turing machine build in Conway's Game of Life by the author. That limit is 8 symbols and 16 states. By way of comparison we also describe one of the smallest known universal Turing machines due to Rogozhin which has 6 symbols and 4 states.
Eaton, T; Young, P; Fergusson, W; Garrett, J E; Kolbe, J
2005-04-01
The negative impact of chronic obstructive pulmonary disease (COPD) on health-related quality of life (HRQL) is substantial. Measurement of HRQL is increasingly advocated in clinical practice; traditional outcome measures such as lung function are poorly responsive. However many HRQL tools are not user-friendly in the clinic setting. Hence HRQL is often neglected. The Dartmouth Cooperative Functional Assessment Charts (COOP) have the requisite attributes of a tool suitable for routine clinical practice: they are simple, reliable, quick and easy to perform and score and well accepted. We aimed to determine the reliability, validity and responsiveness of the COOP in patients with significant COPD. HRQL was assessed during a prospective, randomised, placebo-controlled, double-blind, 12 week cross-over interventional study of ambulatory oxygen in patients (n = 50) with COPD. Test-retest reliability of the COOP domains was only modest however it was measured over a 2 month period. Significant correlations ranging between 0.4 and 0.8 were observed between all comparable domains of the COOP and the Medical Outcomes Study 36-item Short-form Health Survey, Chronic Respiratory Questionnaire (CRQ) and Hospital Anxiety and Depression (HAD) scale. Following ambulatory oxygen significant improvements were noted in all CRQ and HAD domains. Several domains of the generic SF-36 (role emotional, social functioning, role-physical) showed significant improvements. Comparable domains of the COOP (social activities, feelings) also showed significant improvements. The COOP change in health domain improved very significantly. The COOP is a simple, reliable HRQL tool which proved valid and responsive in our study population of COPD patients and may have a valuable role in routine clinical practice.
... people experience while drifting off to sleep. These simple forms of myoclonus occur in normal, healthy persons ... people experience while drifting off to sleep. These simple forms of myoclonus occur in normal, healthy persons ...
Phenological sequences reveal aggregate life history response to climatic warming.
Post, Eric S; Pedersen, Christian; Wilmers, Christopher C; Forchhammer, Mads C
2008-02-01
Climatic warming is associated with organisms breeding earlier in the season than is typical for their species. In some species, however, response to warming is more complex than a simple advance in the timing of all life history events preceding reproduction. Disparities in the extent to which different components of the reproductive phenology of organisms vary with climatic warming indicate that not all life history events are equally responsive to environmental variation. Here, we propose that our understanding of phenological response to climate change can be improved by considering entire sequences of events comprising the aggregate life histories of organisms preceding reproduction. We present results of a two-year warming experiment conducted on 33 individuals of three plant species inhabiting a low-arctic site. Analysis of phenological sequences of three key events for each species revealed how the aggregate life histories preceding reproduction responded to warming, and which individual events exerted the greatest influence on aggregate life history variation. For alpine chickweed (Cerastium alpinum), warming elicited a shortening of the duration of the emergence stage by 2.5 days on average, but the aggregate life history did not differ between warmed and ambient plots. For gray willow (Salix glauca), however, all phenological events monitored occurred earlier on warmed than on ambient plots, and warming reduced the aggregate life history of this species by 22 days on average. Similarly, in dwarf birch (Betula nana), warming advanced flower bud set, blooming, and fruit set and reduced the aggregate life history by 27 days on average. Our approach provides important insight into life history responses of many organisms to climate change and other forms of environmental variation. Such insight may be compromised by considering changes in individual phenological events in isolation.
Gas Phase Chemistry and Molecular Complexity: How Far Do They Go?
NASA Astrophysics Data System (ADS)
Balucani, Nadia
2016-07-01
The accumulation of organic molecules of increasing complexity is believed to be an important step toward the emergence of life. But how massive organic synthesis could occur in primitive Earth, i.e. a water-dominated environment, is a matter of debate. Two alternative theories have been suggested so far: endogenous and exogenous synthesis. In the first theory, the synthesis of simple organic molecules having a strong prebiotic potential (simple prebiotic molecules SPMs, such as H2CO, HCN, HC3N, NH2CHO) occurred directly on our planet starting from simple parent molecules of the atmosphere, liquid water and various energy sources. Miller's experiment was a milestone in this theory, but it was later recognized that the complexity of a planet cannot be reproduced in a single laboratory experiment. Some SPMs have been identified in the N2-dominated atmosphere of Titan (a massive moon of Saturn), which is believed to be reminiscent of the primitive terrestrial atmosphere. As such, the atmosphere of Titan represents a planetary scale laboratory for the comprehension of SPM formation in an environment close enough to primitive Earth and is the current frontier in the endogenous theory exploration. In the exogenous theory, SPMs came from space, the carriers being comets, asteroids and meteorites. The rationale behind this suggestion is that plenty of SPMs have been observed in interstellar clouds (ISCs), including star-forming regions, and in small bodies like comets, asteroids and meteorites. Therefore, the basic idea is that SPMs were formed in the solar nebula, preserved during the early phases of the Solar System formation in the body of comets/asteroids/meteorites and finally delivered to Earth by cometary and meteoritic falls. In this contribution, the status of our knowledge on how SPMs can be formed in the gas phase, either in the primitive terrestrial atmosphere or in the cold nebula from which the Solar System originated, will be presented. Particular attention will be given to neutral-neutral reactions.
NASA Astrophysics Data System (ADS)
Aye, S. A.; Heyns, P. S.
2017-02-01
This paper proposes an optimal Gaussian process regression (GPR) for the prediction of remaining useful life (RUL) of slow speed bearings based on a novel degradation assessment index obtained from acoustic emission signal. The optimal GPR is obtained from an integration or combination of existing simple mean and covariance functions in order to capture the observed trend of the bearing degradation as well the irregularities in the data. The resulting integrated GPR model provides an excellent fit to the data and improves over the simple GPR models that are based on simple mean and covariance functions. In addition, it achieves a low percentage error prediction of the remaining useful life of slow speed bearings. These findings are robust under varying operating conditions such as loading and speed and can be applied to nonlinear and nonstationary machine response signals useful for effective preventive machine maintenance purposes.
Transients in the inhibitory driving of neurons and their postsynaptic consequences.
Segundo, J P; Stiber, M; Altshuler, E; Vibert, J F
1994-09-01
The presynaptic fiber at an inhibitory synapse on a pacemaker neuron was forced to generate transients, defined here as spike trains with a trend, unceasingly accelerating or slowing. Experiments were on isolated crayfish stretch receptor organs. Spike train analyses used tools and notions from conventional point processes and from non-linear dynamics. Pre- and postsynaptic discharges contrasted clearly in terms of rates and interspike intervals. The inhibitory train evolved monotonically and smoothly, following tightly the simple prescribed curves; it was uniform, exhibiting throughout a single and simple discharge form (i.e. interval patterning). The inhibited postsynaptic train alternately accelerated and slowed, not following tightly any simple curve; it was heterogeneous, exhibiting in succession several different and often complex discharge forms, and switching abruptly from one to another. The inhibited trains depended on the inhibitory transient's span, range and average slope. Accordingly, transients separated (not cuttingly) into categories with prolonged spans (over 1 s) and slow slopes (around 1/s2) and those with short spans (under 1 s) and fast slopes (around 30/s2). Special transients elicited postsynaptic discharges that reproduced it faithfully, e.g. accelerated with the transient and proportionately; no transient elicited postsynaptic discharges faithful to its mirror image. Crayfish synapses are prototypes, so these findings should be expected in any other junction, as working hypotheses at least. Implications involve the operation of neural networks, including the role of distortions and their compensation, and the underlying mechanisms. Transients have received little attention, most work on synaptic coding concentrating on stationary discharges. Transients are inherent to the changing situations that pervade everyday life, however, and their biological importance is self-evident. The different discharges encountered during a transient had strong similarities to the stationary forms reported for different pacemaker drivings that are called locking, intermittency, erratic and stammering; they were, in fact, trendy versions of these. Such forms appear with several synaptic drivings in the same order along the presynaptic rate scale; they may constitute basic building blocks for synaptic operation. In terms of non-linear science, it is as if the attractors postulated for stationary drivings remained strongly influential during the transients, though affected by the rate of change.
A comparison of simple global kinetic models for coal devolatilization with the CPD model
Richards, Andrew P.; Fletcher, Thomas H.
2016-08-01
Simulations of coal combustors and gasifiers generally cannot incorporate the complexities of advanced pyrolysis models, and hence there is interest in evaluating simpler models over ranges of temperature and heating rate that are applicable to the furnace of interest. In this paper, six different simple model forms are compared to predictions made by the Chemical Percolation Devolatilization (CPD) model. The model forms included three modified one-step models, a simple two-step model, and two new modified two-step models. These simple model forms were compared over a wide range of heating rates (5 × 10 3 to 10 6 K/s) at finalmore » temperatures up to 1600 K. Comparisons were made of total volatiles yield as a function of temperature, as well as the ultimate volatiles yield. Advantages and disadvantages for each simple model form are discussed. In conclusion, a modified two-step model with distributed activation energies seems to give the best agreement with CPD model predictions (with the fewest tunable parameters).« less
Inversion Concept of the Origin of Life
NASA Astrophysics Data System (ADS)
Kompanichenko, V. N.
2012-06-01
The essence of the inversion concept of the origin of life can be narrowed down to the following theses: 1) thermodynamic inversion is the key transformation of prebiotic microsystems leading to their transition into primary forms of life; 2) this transformation might occur only in the microsystems oscillating around the bifurcation point under far-from-equilibrium conditions. The transformation consists in the inversion of the balance "free energy contribution / entropy contribution", from negative to positive values. At the inversion moment the microsystem radically reorganizes in accordance with the new negentropy (i.e. biological) way of organization. According to this approach, the origin-of-life process on the early Earth took place in the fluctuating hydrothermal medium. The process occurred in two successive stages: a) spontaneous self-assembly of initial three-dimensional prebiotic microsystems composed mainly of hydrocarbons, lipids and simple amino acids, or their precursors, within the temperature interval of 100-300°C (prebiotic stage); b) non-spontaneous synthesis of sugars, ATP and nucleic acids started at the inversion moment under the temperature 70-100°C (biotic stage). Macro- and microfluctuations of thermodynamic and physico-chemical parameters able to sustain this way of chemical conversion have been detected in several contemporary hydrothermal systems. A minimal self-sufficient unit of life on the early Earth was a community of simplest microorganisms (not a separate microorganism).
The early atmosphere: a new picture.
Levine, J S
1986-01-01
Over the last several years, many of the fundamental ideas concerning the composition and chemical evolution of the Earth's early atmosphere have changed. While many aspects of this subject are clouded--either uncertain or unknown, a new picture is emerging. We are just beginning to understand how astronomical, geochemical, and atmospheric processes each contributed to the development of the gaseous envelope around the third planet from the sun some 4.6 billion years ago and how that envelope chemically evolved over the history of our planet. Simple compounds in that gaseous envelope, energized by atmospheric lightning and/or solar ultraviolet radiation, formed molecules of increasing complexity that eventually evolved into the first living systems on our planet. This process is called "chemical evolution" and immediately preceded biological evolution; once life developed and evolved, it began to alter the chemical composition of the atmosphere that provided the very essence of its creation. Photosynthetic organisms which have the ability to biochemically transform carbon dioxide and water to carbohydrates, which they use for food, produce large amounts of molecular oxygen (O2) as a by-product of the reaction. Atmospheric oxygen photochemically formed ozone, which absorbs ultraviolet radiation from the sun and shields the Earth's surface from this biologically lethal radiation. Once atmospheric ozone levels increased sufficiently, life could leave the safety of the oceans and go ashore for the first time. Throughout the history of our planet, there has been strong interaction between life and the atmosphere. Understanding our cosmic roots is particularly relevant as we embark on a search for life outside the Earth. At this very moment, several radio telescopes around the world are searching for extraterrestrial intelligence (SETI).
Heavy-ion induced genetic changes and evolution processes
NASA Technical Reports Server (NTRS)
Yang, C. H.; Craise, L. M.; Durante, M.; Mei, M.
1994-01-01
On Moon and Mars, there will be more galactic cosmic rays and higher radiation doses than on Earth. Our experimental studies showed that heavy ion radiation can effectively cause mutation and chromosome aberrations and that high Linear Energy Transfer (LET) heavy-ion induced mutants can be irreversible. Chromosome translocations and deletions are common in cells irradiated by heavy particles, and ionizing radiations are effective in causing hyperploidy. The importance of the genetic changes in the evolution of life is an interesting question. Through evolution, there is an increase of DNA content in cells from lower forms of life to higher organisms. The DNA content, however, reached a plateau in vertebrates. By increasing DNA content, there can be an increase of information in the cell. For a given DNA content, the quality of information can be changed by rearranging the DNA. Because radiation can cause hyperploidy, an increase of DNA content in cells, and can induce DNA rearrangement, it is likely that the evolution of life on Mars will be effected by its radiation environment. A simple analysis shows that the radiation level on Mars may cause a mutation frequency comparable to that of the spontaneous mutation rate on Earth. To the extent that mutation plays a role in adaptation, radiation alone on Mars may thus provide sufficient mutation for the evolution of life.
Life Test Approach for Refractory Metal/Sodium Heat Pipes
NASA Technical Reports Server (NTRS)
Martin, James J.; Reid, Robert S.
2006-01-01
Heat pipe life tests described in the literature have seldom been conducted on a systematic basis. Typically one or more heat pipes are built and tested for an extended period at a single temperature with simple condenser loading. This paper describes an approach to generate carefully controlled data that can conclusively establish heat pipe operating life with material-fluid combinations capable of extended operation. Approximately 10 years of operational life might be compressed into 3 years of laboratory testing through a combination of increased temperature and mass fluence. Two specific test series have been identified and include: investigation of long term corrosion rates based on the guidelines contained in ASTM G-68-80 (using 7 heat pipes); and investigation of corrosion trends in a cross correlation sequence at various temperatures and mass fluences based on a central composite test design (using 9 heat pipes). The heat pipes selected for demonstration purposes are fabricated from a Mo-44.5%Re alloy with a length of 0.3 meters and a diameter of 1.59 cm(to conserve material) with a condenser to evaporator length ratio of approximately 3. The wick is a crescent annular design formed from 400-mesh Mo-Re alloy material hot isostatically pressed to produce a final wick core of 20 microns or less.
Exercise in Patients on Dialysis: A Multicenter, Randomized Clinical Trial
Manfredini, Fabio; Mallamaci, Francesca; D’Arrigo, Graziella; Baggetta, Rossella; Bolignano, Davide; Torino, Claudia; Lamberti, Nicola; Bertoli, Silvio; Ciurlino, Daniele; Rocca-Rey, Lisa; Barillà, Antonio; Battaglia, Yuri; Rapanà, Renato Mario; Zuccalà, Alessandro; Bonanno, Graziella; Fatuzzo, Pasquale; Rapisarda, Francesco; Rastelli, Stefania; Fabrizi, Fabrizio; Messa, Piergiorgio; De Paola, Luciano; Lombardi, Luigi; Cupisti, Adamasco; Fuiano, Giorgio; Lucisano, Gaetano; Summaria, Chiara; Felisatti, Michele; Pozzato, Enrico; Malagoni, Anna Maria; Castellino, Pietro; Aucella, Filippo; Abd ElHafeez, Samar; Provenzano, Pasquale Fabio; Tripepi, Giovanni; Catizone, Luigi
2017-01-01
Previous studies have suggested the benefits of physical exercise for patients on dialysis. We conducted the Exercise Introduction to Enhance Performance in Dialysis trial, a 6-month randomized, multicenter trial to test whether a simple, personalized walking exercise program at home, managed by dialysis staff, improves functional status in adult patients on dialysis. The main study outcomes included change in physical performance at 6 months, assessed by the 6-minute walking test and the five times sit-to-stand test, and in quality of life, assessed by the Kidney Disease Quality of Life Short Form (KDQOL-SF) questionnaire. We randomized 296 patients to normal physical activity (control; n=145) or walking exercise (n=151); 227 patients (exercise n=104; control n=123) repeated the 6-month evaluations. The distance covered during the 6-minute walking test improved in the exercise group (mean distance±SD: baseline, 328±96 m; 6 months, 367±113 m) but not in the control group (baseline, 321±107 m; 6 months, 324±116 m; P<0.001 between groups). Similarly, the five times sit-to-stand test time improved in the exercise group (mean time±SD: baseline, 20.5±6.0 seconds; 6 months, 18.2±5.7 seconds) but not in the control group (baseline, 20.9±5.8 seconds; 6 months, 20.2±6.4 seconds; P=0.001 between groups). The cognitive function score (P=0.04) and quality of social interaction score (P=0.01) in the kidney disease component of the KDQOL-SF improved significantly in the exercise arm compared with the control arm. Hence, a simple, personalized, home-based, low-intensity exercise program managed by dialysis staff may improve physical performance and quality of life in patients on dialysis. PMID:27909047
10 CFR 436.23 - Estimated simple payback time.
Code of Federal Regulations, 2010 CFR
2010-01-01
... Methodology and Procedures for Life Cycle Cost Analyses § 436.23 Estimated simple payback time. The estimated simple payback time is the number of years required for the cumulative value of energy or water cost savings less future non-fuel or non-water costs to equal the investment costs of the building energy or...
10 CFR 436.23 - Estimated simple payback time.
Code of Federal Regulations, 2014 CFR
2014-01-01
... Methodology and Procedures for Life Cycle Cost Analyses § 436.23 Estimated simple payback time. The estimated simple payback time is the number of years required for the cumulative value of energy or water cost savings less future non-fuel or non-water costs to equal the investment costs of the building energy or...
10 CFR 436.23 - Estimated simple payback time.
Code of Federal Regulations, 2011 CFR
2011-01-01
... Methodology and Procedures for Life Cycle Cost Analyses § 436.23 Estimated simple payback time. The estimated simple payback time is the number of years required for the cumulative value of energy or water cost savings less future non-fuel or non-water costs to equal the investment costs of the building energy or...
10 CFR 436.23 - Estimated simple payback time.
Code of Federal Regulations, 2013 CFR
2013-01-01
... Methodology and Procedures for Life Cycle Cost Analyses § 436.23 Estimated simple payback time. The estimated simple payback time is the number of years required for the cumulative value of energy or water cost savings less future non-fuel or non-water costs to equal the investment costs of the building energy or...
10 CFR 436.23 - Estimated simple payback time.
Code of Federal Regulations, 2012 CFR
2012-01-01
... Methodology and Procedures for Life Cycle Cost Analyses § 436.23 Estimated simple payback time. The estimated simple payback time is the number of years required for the cumulative value of energy or water cost savings less future non-fuel or non-water costs to equal the investment costs of the building energy or...
Ice Radiation Chemistry as a Source of Potential False Biomarkers on the Surface of Europa
NASA Technical Reports Server (NTRS)
Bernstein, Max P.; Sandford, Scott A.; Allamandola, Louis J.
2004-01-01
If we find evidence of Life elsewhere in the Solar System it will probably be in form of chemical biomarkers, quintessentially biological molecules that indicate the presence of micro-organisms. While molecules such as amino acids and nucleo-bases might seem to be biomarkers, and alkyl substituted aromatics have been invoked as such, they are not necessarily. These molecules are present in some meteorites and are expected to be present on the surface of other planets even in the absence of life. Understanding the range of non-biological organic molecules which could act as false biomarkers in space is a prerequisite for any reasonable search for true biomarkers on other worlds. Our experiments have shown that some organic molecules in meteorites that appear biological in nature are formed by energetic processing of extraterrestrial ices can account for amino acids, quinones and other functionalized aromatic compounds. In the past, such molecules have been proposed as biomarkers. For example, alkylated aromatics were invoked as biomarkers in the Alan Hills 84001 'Martian meteorite.' When simple organics arrive at the surface of a body like Europa, either from below or from space, how long do they survive and what do they make? How can we distinguish these from real biomarkers?
Simple, Flexible, Trigonometric Taper Equations
Charles E. Thomas; Bernard R. Parresol
1991-01-01
There have been numerous approaches to modeling stem form in recent decades. The majority have concentrated on the simpler coniferous bole form and have become increasingly complex mathematical expressions. Use of trigonometric equations provides a simple expression of taper that is flexible enough to fit both coniferous and hard-wood bole forms. As an illustration, we...
Homeopathic potentization based on nanoscale domains.
Czerlinski, George; Ypma, Tjalling
2011-12-01
The objectives of this study were to present a simple descriptive and quantitative model of how high potencies in homeopathy arise. The model begins with the mechanochemical production of hydrogen and hydroxyl radicals from water and the electronic stabilization of the resulting nanodomains of water molecules. The life of these domains is initially limited to a few days, but may extend to years when the electromagnetic characteristic of a homeopathic agent is copied onto the domains. This information is transferred between the original agent and the nanodomains, and also between previously imprinted nanodomains and new ones. The differential equations previously used to describe these processes are replaced here by exponential expressions, corresponding to simplified model mechanisms. Magnetic stabilization is also involved, since these long-lived domains apparently require the presence of the geomagnetic field. Our model incorporates this factor in the formation of the long-lived compound. Numerical simulation and graphs show that the potentization mechanism can be described quantitatively by a very simplified mechanism. The omitted factors affect only the fine structure of the kinetics. Measurements of pH changes upon absorption of different electromagnetic frequencies indicate that about 400 nanodomains polymerize to form one cooperating unit. Singlet excited states of some compounds lead to dramatic changes in their hydrogen ion dissociation constant, explaining this pH effect and suggesting that homeopathic information is imprinted as higher singlet excited states. A simple description is provided of the process of potentization in homeopathic dilutions. With the exception of minor details, this simple model replicates the results previously obtained from a more complex model. While excited states are short lived in isolated molecules, they become long lived in nanodomains that form coherent cooperative aggregates controlled by the geomagnetic field. These domains either slowly emit biophotons or perform specific biochemical work at their target.
Cao, Xia; Zhou, Jiansong; Yuan, Hong; Chen, Zhiheng
2015-12-21
The American Heart Association developed the Life's Simple 7 metric for defining cardiovascular health. Little is known, however, whether co-occurring reproductive factors, which affects endogenous oestrogen levels during a woman's life, also influences ideal cardiovascular health in postmenopausal women. Using data on a cross-sectional study with a convenience sample of 1,625 postmenopausal women (median age, 60.0 years) in a medical health checkup program at a general hospital in central south China 2013-2014, we examined the association between cumulative reproductive risk and ideal cardiovascular health in postmenopausal women. A cumulative risk score (range 0 to 4) was created by summing four reproductive risk factors (age at menarche, age at menopause, number of children, and pregnancy losses) present in each individual from binary variables in which 0 stands for favorable and 1 for less-than-favorable level. Ideal levels for each component in Life's Simple 7 (blood pressure, cholesterol, glucose, BMI, smoking, physical activity, and diet) were used to create an ideal Life's Simple 7 score [0-1 (low), 2, 3, 4, 5 and 6-7 (high)]. Participants with earlier age at menarche (odds ratio [OR] =0.42 [95 % CI 0.26-0.48]), earlier age at menopause [0.46 (0.32-0.58)], who have more than three children (0.42 [0.38-0.56]) and have history of pregnancy losses [0.76 (0.66-0.92)] were more likely to attain low (0-1) ideal Life's Simple 7 after adjustment for age. Participants were more likely to attain low (0-1) ideal Life's Simple 7 as exposure to the number of reproductive risk factors increased [OR (95 % CI) of 0.52 (0.42-0.66), 0.22 (0.16-0.26), and 0.16 (0.12-0.22) for cumulative reproductive risk scores of 1, 2, and 3 or 4, respectively, each versus 0]. The postmenopausal Chinese women with an increasing number of reproductive risk factors were progressively less likely to attain ideal levels of cardiovascular health factors.
... Solitary Kidney Your Kidneys & How They Work Simple Kidney Cysts What are simple kidney cysts? Simple kidney cysts are abnormal, fluid-filled ... that form in the kidneys. What are the kidneys and what do they do? The kidneys are ...
Lakshmanan, Anupama; Hauser, Charlotte A.E.
2011-01-01
In this study, we perform a morphological evaluation of the diverse nanostructures formed by varying concentration and amino acid sequence of a unique class of ultrasmall self-assembling peptides. We modified these peptides by replacing the aliphatic amino acid at the C-aliphatic terminus with different aromatic amino acids. We tracked the effect of introducing aromatic residues on self-assembly and morphology of resulting nanostructures. Whereas aliphatic peptides formed long, helical fibers that entangle into meshes and entrap >99.9% water, the modified peptides contrastingly formed short, straight fibers with a flat morphology. No helical fibers were observed for the modified peptides. For the aliphatic peptides at low concentrations, different supramolecular assemblies such as hollow nanospheres and membrane blebs were found. Since the ultrasmall peptides are made of simple, aliphatic amino acids, considered to have existed in the primordial soup, study of these supramolecular assemblies could be relevant to understanding chemical evolution leading to the origin of life on Earth. In particular, we propose a variety of potential applications in bioengineering and nanotechnology for the diverse self-assembled nanostructures. PMID:22016623
Radionuclides, radiotracers and radiopharmaceuticals for in vivo diagnosis
NASA Astrophysics Data System (ADS)
Wiebe, Leonard I.
Radioactive tracers for in vivo clinical diagnosis fall within a narrow, strictly-defined set of specifications in respect of their physical properties, chemical and biochemical characteristics, and (approved) medical applications. The type of radioactive decay and physical half-life of the radionuclide are immutable properties which, along with the demands of production and supply, limit the choice of radionuclides used in medicine to only a small fraction of those known to exist. In use, the biochemical and physiological properties of a radiotracer are dictated by the chemical form of the radionuclide. This chemical form may range from elemental, molecular or ionic, to complex compounds formed by coordinate or covalent bonding of the radionuclide to either simple organic or inorganic molecules, or complex macromolecules. Few of the radiotracers which are tested in model systems ever become radiopharmaceuticals in the strictest sense. Radionuclides, radiotracers and radiopharmaceuticals in use are reviewed. Drug legislation and regulations concerning drug manufacture, as well as hospital ethical constraints and legislation concerning unsealed sources of radiation must all be satisfied in order to translate a radiopharmaceutical from the laboratory to clinical use.
Development, triploblastism, physics of wetting and the Cambrian explosion.
Fleury, Vincent
2013-09-01
The Cambrian explosion is characterized by the sudden outburst of organized animal plans, which occurred circa 530 M years ago. Around that time, many forms of animal life appeared, including several which have since disappeared. There is no general consensus about "why" this happened, and why it had any form of suddenness. However, all organized animal plans share a common feature: they are triploblastic, i.e., composed of 3 layers of tissue, endoderm, ectoderm and mesoderm. I show here that, within simple hypotheses, the formation of the mesoderm has intrinsically a physical exponential dynamics, leading rapidly to triploblastism, and eventually, to animal formation. A novel physico-mathematical framework including epithelium-mesenchyme transition, visco-elastic constitutive equations, and conservation laws, is presented which allows one to describe gastrulation as a self-wetting phenomenon of a soft solid onto itself. This phenomenon couples differentiation and migration during gastrulation, and leads in a closed form to an exponential scaling law for the formation of the mesoderm. Therefore, the Cambrian explosion might have started, actually, by a true viscoelastic "explosion": the exponential run-away of mesenchymal cells.
Approximate stresses in 2-D flat elastic contact fretting problems
NASA Astrophysics Data System (ADS)
Urban, Michael Rene
Fatigue results from the cyclic loading of a solid body. If the body subject to fatigue is in contact with another body and relative sliding motion occurs between these two bodies, then rubbing surface damage can accelerate fatigue failure. The acceleration of fatigue failure is especially important if the relative motion between the two bodies results in surface damage without excessive surface removal via wear. The situation just described is referred to as fretting fatigue. Understanding of fretting fatigue is greatly enhanced if the stress state associated with fretting can be characterized. For Hertzian contact, this can readily be done. Unfortunately, simple stress formulae are not available for flat body contact. The primary result of the present research is the development of a new, reasonably accurate, approximate closed form expression for 2-dimensional contact stresses which has been verified using finite element modeling. This expression is also combined with fracture mechanics to provide a simple method of determining when a crack is long enough to no longer be affected by the contact stress field. Lower bounds on fatigue life can then easily be calculated using fracture mechanics. This closed form expression can also be used to calculate crack propagation within the contact stress field. The problem of determining the cycles required to generate an initial crack and what to choose as an initial crack size is unresolved as it is in non-fretting fatigue.
The RNA world and the origin of metabolic enzymes
Ralser, Markus
2014-01-01
An RNA world has been placed centre stage for explaining the origin of life. Indeed, RNA is the most plausible molecule able to form both a (self)-replicator and to inherit information, necessities for initiating genetics. However, in parallel with self-replication, the proto-organism had to obtain the ability to catalyse supply of its chemical constituents, including the ribonucleotide metabolites required to replicate RNA. Although the possibility of an RNA-catalysed metabolic network has been considered, it is to be questioned whether RNA molecules, at least on their own, possess the required catalytic capacities. An alternative scenario for the origin of metabolism involves chemical reactions that are based on environmental catalysts. Recently, we described a non-enzymatic glycolysis and pentose phosphate pathway-like reactions catalysed by metal ions [mainly Fe(II)] and phosphate, simple inorganic molecules abundantly found in Archaean sediments. While the RNA world can serve to explain the origin of genetics, the origin of the metabolic network might thus date back to constraints of environmental chemistry. Interestingly, considering a metal-catalysed origin of metabolism gives rise to an attractive hypothesis about how the first enzymes could have formed: simple RNA or (poly)peptide molecules could have bound the metal ions, and thus increased their solubility, concentration and accessibility. In a second step, this would have allowed substrate specificity to evolve. PMID:25109990
Membrane-Based Functions in the Origin of Cellular Life
NASA Technical Reports Server (NTRS)
Wilson, Michael A.
2003-01-01
How simple membrane peptides performed such essential proto-cellular functions as transport of ions and organic matter across membranes separating the interior of the cell from the environment, capture and utilization of energy, and transduction of environmental signals, is a key question in protobiological evolution. On the basis of detailed, molecular-level computer simulations we investigate how these peptides insert into membranes, self-assemble into higher-order structures and acquire functions. We have studied the insertion of an a-helical peptide containing leucine (L) and serine (S) of the form (LSLLLSL)S into a model membrane. The transmembrane state is metastable, and approximately 15 kcal/mol is required to insert the peptide into the membrane. Investigations of dimers formed by (LSLLLSL)S and glycophorin A demonstrate how the favorable free energy of helix association can offset the unfavorable free energy of insertion, leading to self- assembly of peptide helices in the membrane. An example of a self-assembled structure is the tetrameric transmembrane pore of the influenza virus M2 protein, which is an efficient and selective voltage-gated proton channel. Our simulations explain the gating mechanism and provide guidelines how to reengineering the channel to act as a simple proton pump. In general, emergence of integral membrane proteins appears to be quite feasible and may be easier to envision than the emergence of water-soluble proteins.
Reflexive convention: civil partnership, marriage and family.
Heaphy, Brian
2017-09-14
Drawing on an analysis of qualitative interview data from a study of formalized same-sex relationships (civil partnerships) this paper examines the enduring significance of marriage and family as social institutions. In doing so, it intervenes in current debates in the sociology of family and personal life about how such institutions are undermined by reflexivity or bolstered by convention. Against the backdrop of dominating sociological frames for understanding the links between the changing nature of marriage and family and same-sex relationship recognition, the paper analyses the diverse and overlapping ways (including the simple, relational, strategic, ambivalent and critical ways) in which same-sex partners reflexively constructed and engaged with marriage and family conventions. My analysis suggests that instead of viewing reflexivity and convention as mutually undermining, as some sociologists of family and personal life do, it is insightful to explore how diverse forms of reflexivity and convention interact in everyday life to reconfigure the social institutions of marriage and family, but do not undermine them as such. I argue the case for recognizing the ways in which 'reflexive convention', or reflexive investment in convention, contributes to the continuing significance of marriage and family as social institutions. © London School of Economics and Political Science 2017.
Ojofeitimi, E O
1984-01-01
One hundred and fourteen preschool school children and their 30 mothers from three selected villages in Ile-Ife, Nigeria were assessed for nutritional status using selected and sensitive anthropometric techniques. The mothers' dietary patterns, their perceptions as to components of a good quality of life, infants' immunization status and major cause of infant death were also examined. Approximately 56% of the children and 80% of the women were identified to be suffering from mild to moderate malnutrition. The major cause of infant death as reported by the mothers was high fever and convulsion. Practically all the children under 3 years had not received any form of immunization. Ability to have plenty of children, good health and money, were highly perceived as measures of essential components of quality of life by all the mothers, while 20% listed good feeding, housing, clothing, and only 7% listed potable water. The need for effective health services, regular home visits, supplementary feeding programmes for school children and an effective health education campaign on the importance of immunization and nutrition for rural people are discussed. The training of agricultural extension workers in the use of simple anthropometric techniques to identify covert malnutrition is also highlighted.
NASA Technical Reports Server (NTRS)
Blake, David; Vaniman, David; Bish, David; Morrison, David (Technical Monitor)
1994-01-01
A principal objective of Mars exploration is the search for evidence of past life which may have existed during an earlier clement period of Mars history. We would like to investigate the history of surface water activity (which is a requirement for all known forms of life) by identifying and documenting the distribution of minerals which require water for their formation or distribution. A knowledge of the mineralogy of the present Martian surface would help to identify areas which, due to the early activity of water, might have harbored ancient life. It would be desirable to establish the presence and characterize the distribution of hydrated minerals such as clays, and of minerals which are primarily of sedimentary origin such as carbonates, silica and evaporites. Mineralogy, which is more critical to exobiological exploration than is simple chemical analysis (absent the detection of organics), will remain unknown or will at best be imprecisely constrained unless a technique sensitive to mineral structure such as powder X-ray diffraction (XRD) is employed. Additional information is contained in the original extended abstract.
Griffith, Robert W
2009-12-01
Among various scenarios that attempt to explain how life arose, the RNA world is currently the most widely accepted scientific hypothesis among biologists. However, the RNA world is logistically implausible and doesn't explain how translation arose and DNA became incorporated into living systems. Here I propose an alternative hypothesis for life's origin based on cooperation between simple nucleic acids, peptides and lipids. Organic matter that accumulated on the prebiotic Earth segregated into phases in the ocean based on density and solubility. Synthesis of complex organic monomers and polymerization reactions occurred within a surface hydrophilic layer and at its aqueous and atmospheric interfaces. Replication of nucleic acids and translation of peptides began at the emulsified interface between hydrophobic and aqueous layers. At the core of the protobiont was a family of short nucleic acids bearing arginine's codon and anticodon that added this amino acid to pre-formed peptides. In turn, the survival and replication of nucleic acid was aided by the peptides. The arginine-enriched peptides served to sequester and transfer phosphate bond energy and acted as cohesive agents, aggregating nucleic acids and keeping them at the interface.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-28
... Request; Domestic Client Life-Cycle Multi-Purpose Forms AGENCY: International Trade Administration. ACTION... life-cycle with CS. CS is mandated by Congress to help U.S. organizations, particularly small and... Client Life-cycle Multi-Purpose Forms, previously titled Export Information Services Order Forms, are...
Thirty Simple Ideas for Interactive Whiteboards
ERIC Educational Resources Information Center
Adams, Caralee
2011-01-01
This article presents thirty simple ideas for interactive whiteboards and how IWB can make one's teaching life easier. These teaching ideas for the interactive whiteboard can be used by teachers every day. Tips for classroom management are also presented.
A Simple and Reliable Method of Design for Standalone Photovoltaic Systems
NASA Astrophysics Data System (ADS)
Srinivasarao, Mantri; Sudha, K. Rama; Bhanu, C. V. K.
2017-06-01
Standalone photovoltaic (SAPV) systems are seen as a promoting method of electrifying areas of developing world that lack power grid infrastructure. Proliferations of these systems require a design procedure that is simple, reliable and exhibit good performance over its life time. The proposed methodology uses simple empirical formulae and easily available parameters to design SAPV systems, that is, array size with energy storage. After arriving at the different array size (area), performance curves are obtained for optimal design of SAPV system with high amount of reliability in terms of autonomy at a specified value of loss of load probability (LOLP). Based on the array to load ratio (ALR) and levelized energy cost (LEC) through life cycle cost (LCC) analysis, it is shown that the proposed methodology gives better performance, requires simple data and is more reliable when compared with conventional design using monthly average daily load and insolation.
NASA Astrophysics Data System (ADS)
Siahaan, N. M.; Harahap, A. S.; Nababan, E.; Siahaan, E.
2018-02-01
This study aims to initiate sustainable simple housing system based on low CO2 emissions at Griya Martubung I Housing Medan, Indonesia. Since it was built in 1995, between 2007 until 2016 approximately 89 percent of houses have been doing various home renewal such as restoration, renovation, or reconstruction. Qualitative research conducted in order to obtain insights into the behavior of complex relationship between various components of residential life support environment that relates to CO2 emissions. Each component is studied by conducting in-depth interviews, observation of the 128 residents. The study used Likert Scale to measure residents’ perception about components. The study concludes with a synthesis describing principles for a sustainable simple housing standard that recognizes the whole characteristics of components. This study offers a means for initiating the practice of sustainable simple housing developments and efforts to manage growth and preserve the environment without violating social, economics, and ecology.
NASA Technical Reports Server (NTRS)
Mckay, Christopher P.
2016-01-01
Titan is the only world we know other than Earth that has a liquid on its surface. It has a thick atmosphere composed of nitrogen and methane with a thick organic haze. There are lakes, rain, and clouds of methane and ethane. Here, we address the question of carbon-based life living in Titan liquids. Photochemically produced organics, particularly acetylene, in Titan's atmosphere could be a source of biological energy when reacted with atmospheric hydrogen. Light levels on the surface of Titan are more than adequate for photosynthesis but the biochemical limitations due to the few elements available in the environment may lead only to simple ecosystems that only consume atmospheric nutrients. Life on Titan may make use of the trace metals and other inorganic elements produced by meteorites as they ablate in the atmosphere. It is conceivable that H2O molecules on Titan could be used in a biochemistry that is rooted in hydrogen bonds in a way that metals are used in enzymes by life on Earth. Previous theoretical work has shown possible membrane structures in Titan liquids, azotosomes, composed of small organic nitrogen compounds, such as acrylonitrile. The search for a plausible information molecule for life in Titan liquids remains an open research topic - polyethers have been considered and shown to be insoluble at Titan temperatures. Possible search strategies for life on Titan include looking for unusual concentrations of certain molecules reflecting biological selection. Homochirality is a special and powerful example of such biology selection. Environmentally, a depletion of hydrogen in the lower atmosphere may be a sign of metabolism. A discovery of life in liquid methane and ethane would be our first compelling indication that the Universe is full of diverse and wondrous life forms.
NASA Astrophysics Data System (ADS)
McKay, Christopher P.
2016-02-01
Titan is the only world we know, other than Earth, that has a liquid on its surface. It also has a thick atmosphere composed of nitrogen and methane with a thick organic haze. There are lakes, rain, and clouds of methane and ethane. Here, we address the question of carbon-based life living in Titan liquids. Photochemically produced organics, particularly acetylene, in Titan's atmosphere could be a source of biological energy when reacted with atmospheric hydrogen. Light levels on the surface of Titan are more than adequate for photosynthesis, but the biochemical limitations due to the few elements available in the environment may lead only to simple ecosystems that only consume atmospheric nutrients. Life on Titan may make use of the trace metals and other inorganic elements produced by meteorites as they ablate in its atmosphere. It is conceivable that H2O molecules on Titan could be used in a biochemistry that is rooted in hydrogen bonds in a way that metals are used in enzymes by life on Earth. Previous theoretical work has shown possible membrane structures, azotosomes, in Titan liquids, azotosomes, composed of small organic nitrogen compounds, such as acrylonitrile. The search for a plausible information molecule for life in Titan liquids remains an open research topic - polyethers have been considered and shown to be insoluble at Titan temperatures. Possible search strategies for life on Titan include looking for unusual concentrations of certain molecules reflecting biological selection. Homochirality is a special and powerful example of such biology selection. Environmentally, a depletion of hydrogen in the lower atmosphere may be a sign of metabolism. A discovery of life in liquid methane and ethane would be our first compelling indication that the universe is full of diverse and wondrous life forms.
McKay, Christopher P
2016-02-03
Titan is the only world we know, other than Earth, that has a liquid on its surface. It also has a thick atmosphere composed of nitrogen and methane with a thick organic haze. There are lakes, rain, and clouds of methane and ethane. Here, we address the question of carbon-based life living in Titan liquids. Photochemically produced organics, particularly acetylene, in Titan's atmosphere could be a source of biological energy when reacted with atmospheric hydrogen. Light levels on the surface of Titan are more than adequate for photosynthesis, but the biochemical limitations due to the few elements available in the environment may lead only to simple ecosystems that only consume atmospheric nutrients. Life on Titan may make use of the trace metals and other inorganic elements produced by meteorites as they ablate in its atmosphere. It is conceivable that H₂O molecules on Titan could be used in a biochemistry that is rooted in hydrogen bonds in a way that metals are used in enzymes by life on Earth. Previous theoretical work has shown possible membrane structures, azotosomes, in Titan liquids, azotosomes, composed of small organic nitrogen compounds, such as acrylonitrile. The search for a plausible information molecule for life in Titan liquids remains an open research topic-polyethers have been considered and shown to be insoluble at Titan temperatures. Possible search strategies for life on Titan include looking for unusual concentrations of certain molecules reflecting biological selection. Homochirality is a special and powerful example of such biology selection. Environmentally, a depletion of hydrogen in the lower atmosphere may be a sign of metabolism. A discovery of life in liquid methane and ethane would be our first compelling indication that the universe is full of diverse and wondrous life forms.
McKay, Christopher P.
2016-01-01
Titan is the only world we know, other than Earth, that has a liquid on its surface. It also has a thick atmosphere composed of nitrogen and methane with a thick organic haze. There are lakes, rain, and clouds of methane and ethane. Here, we address the question of carbon-based life living in Titan liquids. Photochemically produced organics, particularly acetylene, in Titan’s atmosphere could be a source of biological energy when reacted with atmospheric hydrogen. Light levels on the surface of Titan are more than adequate for photosynthesis, but the biochemical limitations due to the few elements available in the environment may lead only to simple ecosystems that only consume atmospheric nutrients. Life on Titan may make use of the trace metals and other inorganic elements produced by meteorites as they ablate in its atmosphere. It is conceivable that H2O molecules on Titan could be used in a biochemistry that is rooted in hydrogen bonds in a way that metals are used in enzymes by life on Earth. Previous theoretical work has shown possible membrane structures, azotosomes, in Titan liquids, azotosomes, composed of small organic nitrogen compounds, such as acrylonitrile. The search for a plausible information molecule for life in Titan liquids remains an open research topic—polyethers have been considered and shown to be insoluble at Titan temperatures. Possible search strategies for life on Titan include looking for unusual concentrations of certain molecules reflecting biological selection. Homochirality is a special and powerful example of such biology selection. Environmentally, a depletion of hydrogen in the lower atmosphere may be a sign of metabolism. A discovery of life in liquid methane and ethane would be our first compelling indication that the universe is full of diverse and wondrous life forms. PMID:26848689
Self-organized huddles of rat pups modeled by simple rules of individual behavior.
Schank, J C; Alberts, J R
1997-11-07
Starting at infancy and continuing throughout adult life, huddling is a major component of the behavioral repertoire of Norway rats (Rattus norvegicus). Huddling behavior maintains the cohesion of litters throughout early life, and in adulthood, it remains a consistent feature of social behavior of R. norvegicus. During infancy, rats have severely limited sensorimotor capabilities, and yet they are capable of aggregating and display a form of group regulatory behavior that conserves metabolic effort and augments body temperature regulation. The functions of huddling are generally understood as group adaptations, which are beyond the capabilities of the individual infant rat. We show, however, that huddling as aggregative or cohesive behavior can emerge as a self-organizing process from autonomous individuals following simple sensorimotor rules. In our model, two sets of sensorimotor parameters characterize the topotaxic responses and the dynamics of contact in 7-day-old rats. The first set of parameters are conditional probabilities of activity and inactivity given prior activity or inactivity and the second set are preferences for objects in the infant rat's environment. We found that the behavior of the model and of actual rat pups compare very favorably, demonstrating that the aggregative feature of huddling can emerge from the local sensorimotor interactions of individuals, and that complex group regulatory behaviors in infant rats may also emerge from self-organizing processes. We discuss the model and the underlying approach as a paradigm for investigating the dynamics of social interactions, group behavior, and developmental change.
Simplified Life-Cycle Cost Estimation
NASA Technical Reports Server (NTRS)
Remer, D. S.; Lorden, G.; Eisenberger, I.
1983-01-01
Simple method for life-cycle cost (LCC) estimation avoids pitfalls inherent in formulations requiring separate estimates of inflation and interest rates. Method depends for validity observation that interest and inflation rates closely track each other.
FUNDAMENTALS OF LIFE CYCLE ASSESSMENT AND OFF-THE-SHELF SOFTWARE DEMONSTRATION
As the name implies, Life Cycle Assesssment (LCA) evaluates the entire life cycle of a product, process, activity, or service, not just simple economics at the time of delivery. This course on LCA covers the following issues:
Basic principles of LCA for use in producing, des...
Trachtenberg, Shlomo; Schuck, Peter; Phillips, Terry M.; Andrews, S. Brian; Leapman, Richard D.
2014-01-01
Spiroplasma melliferum is a wall-less bacterium with dynamic helical geometry. This organism is geometrically well defined and internally well ordered, and has an exceedingly small genome. Individual cells are chemotactic, polar, and swim actively. Their dynamic helicity can be traced at the molecular level to a highly ordered linear motor (composed essentially of the proteins fib and MreB) that is positioned on a defined helical line along the internal face of the cell’s membrane. Using an array of complementary, informationally overlapping approaches, we have taken advantage of this uniquely simple, near-minimal life-form and its helical geometry to analyze the copy numbers of Spiroplasma’s essential parts, as well as to elucidate how these components are spatially organized to subserve the whole living cell. Scanning transmission electron microscopy (STEM) was used to measure the mass-per-length and mass-per-area of whole cells, membrane fractions, intact cytoskeletons and cytoskeletal components. These local data were fit into whole-cell geometric parameters determined by a variety of light microscopy modalities. Hydrodynamic data obtained by analytical ultracentrifugation allowed computation of the hydration state of whole living cells, for which the relative amounts of protein, lipid, carbohydrate, DNA, and RNA were also estimated analytically. Finally, ribosome and RNA content, genome size and gene expression were also estimated (using stereology, spectroscopy and 2D-gel analysis, respectively). Taken together, the results provide a general framework for a minimal inventory and arrangement of the major cellular components needed to support life. PMID:24586297
ERIC Educational Resources Information Center
Walters, William H.
2011-01-01
This study evaluates the effectiveness of simple and expert searches in Google Scholar (GS), EconLit, GEOBASE, PAIS, POPLINE, PubMed, Social Sciences Citation Index, Social Sciences Full Text, and Sociological Abstracts. It assesses the recall and precision of 32 searches in the field of later-life migration: nine simple keyword searches and 23…
Unusual Features of Crystal Structures of Some Simple Copper Compounds
ERIC Educational Resources Information Center
Douglas, Bodie
2009-01-01
Some simple copper compounds have unusual crystal structures. Cu[subscript 3]N is cubic with N atoms at centers of octahedra formed by 6 Cu atoms. Cu[subscript 2]O (cuprite) is also cubic; O atoms are in tetrahedra formed by 4 Cu atoms. These tetrahedra are linked by sharing vertices forming two independent networks without linkages between them.…
On determinant representations of scalar products and form factors in the SoV approach: the XXX case
NASA Astrophysics Data System (ADS)
Kitanine, N.; Maillet, J. M.; Niccoli, G.; Terras, V.
2016-03-01
In the present article we study the form factors of quantum integrable lattice models solvable by the separation of variables (SoVs) method. It was recently shown that these models admit universal determinant representations for the scalar products of the so-called separate states (a class which includes in particular all the eigenstates of the transfer matrix). These results permit to obtain simple expressions for the matrix elements of local operators (form factors). However, these representations have been obtained up to now only for the completely inhomogeneous versions of the lattice models considered. In this article we give a simple algebraic procedure to rewrite the scalar products (and hence the form factors) for the SoV related models as Izergin or Slavnov type determinants. This new form leads to simple expressions for the form factors in the homogeneous and thermodynamic limits. To make the presentation of our method clear, we have chosen to explain it first for the simple case of the XXX Heisenberg chain with anti-periodic boundary conditions. We would nevertheless like to stress that the approach presented in this article applies as well to a wide range of models solved in the SoV framework.
Simple and Inexpensive Quantification of Ammonia in Whole Blood
Ayyub, Omar B.; Behrens, Adam M.; Heligman, Brian T.; Natoli, Mary E.; Ayoub, Joseph J.; Cunningham, Gary; Summar, Marshall; Kofinas, Peter
2015-01-01
Quantification of ammonia in whole blood has applications in the diagnosis and management of many hepatic diseases, including cirrhosis and rare urea cycle disorders, amounting to more than 5 million patients in the United States. Current techniques for ammonia measurement suffer from limited range, poor resolution, false positives or large, complex sensor set-ups. Here we demonstrate a technique utilizing inexpensive reagents and simple methods for quantifying ammonia in 100 μl of whole blood. The sensor comprises a modified form of the indophenol reaction, which resists sources of destructive interference in blood, in conjunction with a cation-exchange membrane. The presented sensing scheme is selective against other amine containing molecules such as amino acids and has a shelf life of at least 50 days. Additionally, the resulting system has high sensitivity and allows for the accurate reliable quantification of ammonia in whole human blood samples at a minimum range of 25 to 500 μM, which is clinically for rare hyperammonemic disorders and liver disease. Furthermore, concentrations of 50 and 100 μM ammonia could be reliably discerned with p=0.0001. PMID:25936660
Origin of life: Primordial soup that cooks itself
NASA Astrophysics Data System (ADS)
Bracher, Paul J.
2015-04-01
The spontaneous syntheses of some of life's building blocks from simple precursors have previously been demonstrated in isolation. Now it has been shown that they might all emerge from just one set of ingredients.
Transportable Maps Software. Volume I.
1982-07-01
being collected at the beginning or end of the routine. This allows the interaction to be followed sequentially through its steps by anyone reading the...flow is either simple sequential , simple conditional (the equivalent of ’if-then-else’), simple iteration (’DO-loop’), or the non-linear recursion...input raster images to be in the form of sequential binary files with a SEGMENTED record type. The advantage of this form is that large logical records
Wu, Wenqing; Wang, Zhoubing; Wei, Yan; Zhang, Guanghua; Shi, Shenxun; Gao, Jingfang; Li, Youhui; Tao, Ming; Zhang, Kerang; Wang, Xumei; Gao, Chengge; Yang, Lijun; Li, Kan; Shi, Jianguo; Wang, Gang; Liu, Lanfen; Zhang, Jinbei; Du, Bo; Jiang, Guoqing; Shen, Jianhua; Liu, Ying; Liang, Wei; Sun, Jing; Hu, Jian; Liu, Tiebang; Wang, Xueyi; Miao, Guodong; Meng, Huaqing; Li, Yi; Hu, Chunmei; Li, Yi; Huang, Guoping; Li, Gongying; Ha, Baowei; Deng, Hong; Mei, Qiyi; Zhong, Hui; Gao, Shugui; Sang, Hong; Zhang, Yutang; Fang, Xiang; Yu, Fengyu; Yang, Donglin; Liu, Tieqiao; Chen, Yunchun; Hong, Xiaohong; Wu, Wenyuan; Chen, Guibing; Cai, Min; Song, Yan; Pan, Jiyang; Dong, Jicheng; Pan, Runde; Zhang, Wei; Shen, Zhenming; Liu, Zhengrong; Gu, Danhua; Wang, Xiaoping; Liu, Xiaojuan; Zhang, Qiwen; Li, Yihan; Chen, Yiping; Kendler, Kenneth S; Flint, Jonathan; Zhang, Zhen
2013-01-01
Dysthymia is a form of chronic mild depression that has a complex relationship with major depressive disorder (MDD). Here we investigate the role of environmental risk factors, including stressful life events and parenting style, in patients with both MDD and dysthymia. We ask whether these risk factors act in the same way in MDD with and without dysthymia. We examined the clinical features in 5,950 Han Chinese women with MDD between 30-60 years of age across China. We confirmed earlier results by replicating prior analyses in 3,950 new MDD cases. There were no significant differences between the two data sets. We identified sixteen stressful life events that significantly increase the risk of dysthymia, given the presence of MDD. Low parental warmth, from either mother or father, increases the risk of dysthymia. Highly threatening but short-lived threats (such as rape) are more specific for MDD than dysthymia. While for MDD more severe life events show the largest odds ratio versus controls, this was not seen for cases of MDD with or without dysthymia. There are increased rates of stressful life events in MDD with dysthymia, but the impact of life events on susceptibility to dysthymia with MDD differs from that seen for MDD alone. The pattern does not fit a simple dose-response relationship, suggesting that there are moderating factors involved in the relationship between environmental precipitants and the onset of dysthymia. It is possible that severe life events in childhood events index a general susceptibility to chronic depression, rather than acting specifically as risk factors for dysthymia.
Application of the Enabler to nuclear electric propulsion
NASA Astrophysics Data System (ADS)
Pierce, Bill L.
This paper describes a power system concept that provides the electric power for a baseline electric propulsion system for a piloted mission to Mars. A 10-MWe space power system is formed by coupling an Enabler reactor with a simple non-recuperated closed Brayton cycle. The Enabler reactor is a gas-cooled reactor based on proven reactor technology developed under the NERVA/Rover programs. The selected power cycle, which uses a helium-xenon mixture at 1920 K at the turbine inlet, is diagramed and described. The specific mass of the power system over the power range from 5 to 70 MWe is given. The impact of operating life on the specific mass of a 10-MWe system is also shown.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Seinfeld, John H.
This project addressed the following research need in the Atmospheric System Research (ASR) Science and Program Plan: "Measurements downwind of urban sources of aerosol particles and precursor gases have shown that the mass concentration of secondary organic aerosol (SOA) can be several-fold greater than can be explained on the basis of current model calculations using observed precursor concentrations. ASR will continue conducting laboratory experiments on both gas-phase and aqueous-phase SOA formation to characterize the particle formation and the organic gases that react to form new organic aerosol material on aerosol seeds. ASR will use these experiments to guide the developmentmore » of comprehensive chemical mechanisms... to guide the development of parameterizations that are simple enough to be applied to aerosol life cycle models."« less
Cellular Automata with Anticipation: Examples and Presumable Applications
NASA Astrophysics Data System (ADS)
Krushinsky, Dmitry; Makarenko, Alexander
2010-11-01
One of the most prospective new methodologies for modelling is the so-called cellular automata (CA) approach. According to this paradigm, the models are built from simple elements connected into regular structures with local interaction between neighbours. The patterns of connections usually have a simple geometry (lattices). As one of the classical examples of CA we mention the game `Life' by J. Conway. This paper presents two examples of CA with anticipation property. These examples include a modification of the game `Life' and a cellular model of crowd movement.
Bauer, A; Pawlby, S; Plant, D T; King, D; Pariante, C M; Knapp, M
2015-01-01
Depression in mothers during pregnancy and in the postnatal period has been recognized to have wide-ranging adverse impacts on offspring. Our study examines some of the outcomes and long-term economic implications experienced by offspring who have been exposed to perinatal depression. We analysed the effects of perinatal depression on child development outcomes of children at ages 11 and 16 years from the community-based South London Child Development Study. Economic consequences were attached to those outcomes through simple decision-analytic techniques, building on evidence from studies of epidemiology, health-related quality of life, public sector costs and employment. The economic analysis takes a life-course perspective from the viewpoints of the public sector, individual and society. Additional risks that children exposed to perinatal depression develop emotional, behavioural or cognitive problems ranged from 5% to 21%. In addition, there was a high risk (24%) that children would have special educational needs. We present results in the form of cost consequences attached to adverse child outcomes. For each child exposed to perinatal depression, public sector costs exceeded £3030, costs due to reduced earnings were £1400 and health-related quality of life loss was valued at £3760. Action to prevent or treat mothers' depression during pregnancy and after birth is likely to reduce public sector costs, increase earnings and improve quality of life for children who were exposed to the condition.
Study of interaction in silica glass via model potential approach
NASA Astrophysics Data System (ADS)
Mann, Sarita; Rani, Pooja
2016-05-01
Silica is one of the most commonly encountered substances in daily life and in electronics industry. Crystalline SiO2 (in several forms: quartz, cristobalite, tridymite) is an important constituent of many minerals and gemstones, both in pure form and mixed with related oxides. Cohesive energy of amorphous SiO2 has been investigated via intermolecular potentials i.e weak Van der Waals interaction and Morse type short-range interaction. We suggest a simple atom-atom based Van der Waals as well as Morse potential to find cohesive energy of glass. It has been found that the study of silica structure using two different model potentials is significantly different. Van der Waals potential is too weak (P.E =0.142eV/molecule) to describe the interaction between silica molecules. Morse potential is a strong potential, earlier given for intramolecular bonding, but if applied for intermolecular bonding, it gives a value of P.E (=-21.92eV/molecule) to appropriately describe the structure of silica.
Using Pipe Cleaners to Bring the Tree of Life to Life
ERIC Educational Resources Information Center
Halverson, Kristy L.
2010-01-01
Phylogenetic trees, such as the "Tree of Life," are commonly found in biology textbooks and are often used in teaching. Because students often struggle to understand these diagrams, I developed a simple, inexpensive classroom model. Made of pipe cleaners, it is easily manipulated to rotate branches, compare topologies, map complete lineages,…
Career/Life Planning for Divorced Women: An Overview.
ERIC Educational Resources Information Center
Kitabchi, Gloria; And Others
1979-01-01
Several programs designed to meet the needs of mature women could be adapted to meet the special needs of the mature divorced woman. Career counseling for the divorced client must address the specific emotional factors involved in divorce, and aim toward total life planning, not simple adjustment to a life crisis and job placement. (Author)
Tallman, Ruth
2014-06-01
In this paper, I argue that the 'modified youngest first' principle provides a morally appropriate criterion for making decisions regarding the distribution of scarce medical resources, and that it is morally preferable to the simple 'youngest first' principle. Based on the complete lives system's goal of maximizing complete lives rather than individual life episodes, I argue that essential to the value we see in complete lives is the first person value attributed by the experiencer of that life. For a life to be 'complete' or 'incomplete,' the subject of that life must be able to understand the concept of a complete life, to have started goals and projects, and to know what it would be for that life to be complete. As the very young are not able to do this, it can reasonably be said that their characteristically human lives have not yet begun, giving those accepting a complete lives approach good reason to accept the modified youngest first principle over a simple 'youngest first' approach. © 2012 John Wiley & Sons Ltd.
Life-history traits predict perennial species response to fire in a desert ecosystem
Shryock, Daniel F.; DeFalco, Lesley A.; Esque, Todd C.
2014-01-01
The Mojave Desert of North America has become fire-prone in recent decades due to invasive annual grasses that fuel wildfires following years of high rainfall. Perennial species are poorly adapted to fire in this system, and post-fire shifts in species composition have been substantial but variable across community types. To generalize across a range of conditions, we investigated whether simple life-history traits could predict how species responded to fire. Further, we classified species into plant functional types (PFTs) based on combinations of life-history traits and evaluated whether these groups exhibited a consistent fire-response. Six life-history traits varied significantly between burned and unburned areas in short (up to 4 years) or long-term (up to 52 years) post-fire datasets, including growth form, lifespan, seed size, seed dispersal, height, and leaf longevity. Forbs and grasses consistently increased in abundance after fire, while cacti were reduced and woody species exhibited a variable response. Woody species were classified into three PFTs based on combinations of life-history traits. Species in Group 1 increased in abundance after fire and were characterized by short lifespans, small, wind-dispersed seeds, low height, and deciduous leaves. Species in Group 2 were reduced by fire and distinguished from Group 1 by longer lifespans and evergreen leaves. Group 3 species, which also decreased after fire, were characterized by long lifespans, large non-wind dispersed seeds, and taller heights. Our results show that PFTs based on life-history traits can reliably predict the responses of most species to fire in the Mojave Desert. Dominant, long-lived species of this region possess a combination of traits limiting their ability to recover, presenting a clear example of how a novel disturbance regime may shift selective environmental pressures to favor alternative life-history strategies.
A study of stiffness, residual strength and fatigue life relationships for composite laminates
NASA Technical Reports Server (NTRS)
Ryder, J. T.; Crossman, F. W.
1983-01-01
Qualitative and quantitative exploration of the relationship between stiffness, strength, fatigue life, residual strength, and damage of unnotched, graphite/epoxy laminates subjected to tension loading. Clarification of the mechanics of the tension loading is intended to explain previous contradictory observations and hypotheses; to develop a simple procedure to anticipate strength, fatigue life, and stiffness changes; and to provide reasons for the study of more complex cases of compression, notches, and spectrum fatigue loading. Mathematical models are developed based upon analysis of the damage states. Mathematical models were based on laminate analysis, free body type modeling or a strain energy release rate. Enough understanding of the tension loaded case is developed to allow development of a proposed, simple procedure for calculating strain to failure, stiffness, strength, data scatter, and shape of the stress-life curve for unnotched laminates subjected to tension load.
77 FR 63925 - Proposed Collection; Comment Request
Federal Register 2010, 2011, 2012, 2013, 2014
2012-10-17
..., Savings Incentive Match Plan for Employees of Small Employers (SIMPLE)--Not for Use With a Designated Financial Institution; Form 5305-SIMPLE, Savings Incentive Match Plan for Employees of Small Employers (SIMPLE)--for Use With a Designated Financial Institution; Notice 98-4, Simple IRA Plan Guidance. DATES...
Synthesis of Large Molecules in Cometary Ice Analogs: Physical Properties
NASA Astrophysics Data System (ADS)
Dworkin, Jason; Sandford, S. A.; Allamandola, L. J.; Deamer, D. W.; Gillette, S. J.; Zare, R. N.
Comets and carbonaceous micrometeorites may have been important sources of volatiles on the early Earth; their organic composition may therefore be related to the origin of life. Ices on grains in molecular clouds contain a variety of simple molecules. Within the cloud and especially the presolar nebula, these icy grains would have been photoprocessed by ultraviolet light to produce more complex molecules. We are investigating the molecules that could have been generated in precometary ices. Experiments were conducted by forming a realistic interstellar ice (H_2^O, CH_3H, NH_3 and CO) at ~10 K under high vacuum irradiated UV by a hydrogen plasma lamp. The residue remaining after warming to room temperature was analyzed by HPLC and by several mass spectrometric methods. This material contains a variety of complex compounds with MS profiles resembling those found in IDPs and meteorites. Surface tension measurements show that an amphiphilic component is also present. These species do not appear in various controls or in unphotolyzed samples. In other experiments, the residues were dispersed in aqueous media for microscopy. The organic material forms 10-40 micrometer droplets that fluoresce (300-450 nm) under UV excitation and appear strikingly similar to those produced by extracts of the Murchison meteorite. Together, these results suggest a link between organic material synthesized on cold grains photochemically and compounds that may have contributed to the organic inventory of the primitive Earth. The amphiphilic properties of such compounds permit self-assembly into the membranous boundary structures required for the first forms of cellular life.
Solé, Ricard V.; Valverde, Sergi
2013-01-01
The emergence of complex multicellular systems and their associated developmental programs is one of the major problems of evolutionary biology. The advantages of cooperation over individuality seem well known but it is not clear yet how such increase of complexity emerged from unicellular life forms. Current multicellular systems display a complex cell-cell communication machinery, often tied to large-scale controls of body size or tissue homeostasis. Some unicellular life forms are simpler and involve groups of cells cooperating in a tissue-like fashion, as it occurs with biofilms. However, before true gene regulatory interactions were widespread and allowed for controlled changes in cell phenotypes, simple cellular colonies displaying adhesion and interacting with their environments were in place. In this context, models often ignore the physical embedding of evolving cells, thus leaving aside a key component. The potential for evolving pre-developmental patterns is a relevant issue: how far a colony of evolving cells can go? Here we study these pre-conditions for morphogenesis by using CHIMERA, a physically embodied computational model of evolving virtual organisms in a pre-Mendelian world. Starting from a population of identical, independent cells moving in a fluid, the system undergoes a series of changes, from spatial segregation, increased adhesion and the development of generalism. Eventually, a major transition occurs where a change in the flow of nutrients is triggered by a sub-population. This ecosystem engineering phenomenon leads to a subsequent separation of the ecological network into two well defined compartments. The relevance of these results for evodevo and its potential ecological triggers is discussed. PMID:23596506
76 FR 36583 - Submission for Review: Life Insurance Election, Standard Form 2817
Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-22
... OFFICE OF PERSONNEL MANAGEMENT Submission for Review: Life Insurance Election, Standard Form 2817... agencies the opportunity to comment on a revised information collection request (ICR) 3206-0230, Life... of the life insurance). Clearance of this form for use by active Federal employees is not required...
Humanizing Chemistry Education: From Simple Contextualization to Multifaceted Problematization
ERIC Educational Resources Information Center
Sjöström, Jesper; Talanquer, Vicente
2014-01-01
Chemistry teaching has traditionally been weakly connected to everyday life, technology, society, and history and philosophy of science. This article highlights knowledge areas and perspectives needed by the humanistic (and critical-reflexive) chemistry teacher. Different humanistic approaches in chemistry teaching, from simple contextualization…
Simple Köhler homogenizers for image-forming solar concentrators
NASA Astrophysics Data System (ADS)
Zhang, Weiya; Winston, Roland
2010-08-01
By adding simple Köhler homogenizers in the form of aspheric lenses generated with an optimization approach, we solve the problems of non-uniform irradiance distribution and non-square irradiance pattern existing in some image-forming solar concentrators. The homogenizers do not require optical bonding to the solar cells or total internal reflection surface. Two examples are shown including a Fresnel lens based concentrator and a two-mirror aplanatic system.
How a life-like system emerges from a simple particle motion law
Schmickl, Thomas; Stefanec, Martin; Crailsheim, Karl
2016-01-01
Self-structuring patterns can be observed all over the universe, from galaxies to molecules to living matter, yet their emergence is waiting for full understanding. We discovered a simple motion law for moving and interacting self-propelled particles leading to a self-structuring, self-reproducing and self-sustaining life-like system. The patterns emerging within this system resemble patterns found in living organisms. The emergent cells we found show a distinct life cycle and even create their own ecosystem from scratch. These structures grow and reproduce on their own, show self-driven behavior and interact with each other. Here we analyze the macroscopic properties of the emerging ecology, as well as the microscopic properties of the mechanism that leads to it. Basic properties of the emerging structures (size distributions, longevity) are analyzed as well as their resilience against sensor or actuation noise. Finally, we explore parameter space for potential other candidates of life. The generality and simplicity of the motion law provokes the thought that one fundamental rule, described by one simple equation yields various structures in nature: it may work on different time- and size scales, ranging from the self-structuring universe, to emergence of living beings, down to the emergent subatomic formation of matter. PMID:27901107
Plasma and collision processes of hypervelocity meteorite impact in the prehistory of life
NASA Astrophysics Data System (ADS)
Managadze, G.
2010-07-01
A new concept is proposed, according to which the plasma and collision processes accompanying hypervelocity impacts of meteorites can contribute to the arising of the conditions on early Earth, which are necessary for the appearance of primary forms of living matter. It was shown that the processes necessary for the emergence of living matter could have started in a plasma torch of meteorite impact and have continued in an impact crater in the case of the arising of the simplest life form. It is generally accepted that planets are the optimal place for the origin and evolution of life. In the process of forming the planetary systems the meteorites, space bodies feeding planet growth, appear around stars. In the process of Earth's formation, meteorite sizes ranged from hundreds and thousands of kilometres. These space bodies consisted mostly of the planetesimals and comet nucleus. During acceleration in Earth's gravitational field they reached hypervelocity and, hitting the surface of planet, generated powerful blowouts of hot plasma in the form of a torch. They also created giant-size craters and dense dust clouds. These bodies were composed of all elements needed for the synthesis of organic compounds, with the content of carbon being up to 5%-15%. A new idea of possible synthesis of the complex organic compounds in the hypervelocity impact-generated plasma torch was proposed and experimentally confirmed. A previously unknown and experimentally corroborated feature of the impact-generated plasma torch allowed a new concept of the prehistory of life to be developed. According to this concept the intensive synthesis of complex organic compounds arose during meteoritic bombardment in the first 0.5 billion years at the stage of the planet's formation. This most powerful and destructive action in Earth's history could have played a key role and prepared conditions for the origin of life. In the interstellar gas-dust clouds, the synthesis of simple organic matter could have been explained by an identical process occurring in the plasma torch of hypervelocity collisions between submicron size dust particles. It is assumed that the processes occurred in the highly unbalanced hot plasma simultaneously with the synthesis of simple and complicated organic compounds, thereby ensuring their ordering and assembly. Bona fide experimental evidence presented below indicates that the physical fields generated in the plasma environment in the process of the formation and expansion of the torch meet the main requirements toward “true” local chiral fields. These fields were very likely to be capable to trigger the initial, weak breaking of enantiomer symmetry and determine the “sign” of the asymmetry of the bioorganic world. These fields could have worked as “trapping” fields influencing spontaneous processes occurring in highly overheated and nonequilibrium plasma in the state that is far from the thermodynamical branch of equilibrium and may have contributed to the formation of an environment needed for the synthesis of homochiral molecular structures, which, in turn, were needed for the emergence of the primary forms of living matter. It has been shown experimentally that the plasma-chemical processes in the torch have high catalytic properties and assure the rise of the chemical reaction rates by 10-100 million times. In the process of the plasma flyaway this in turn can assure the fast formation of simple and complicated organic compounds, including hyper-branched polymers. It is possible to assume that predominantly inorganic substances from meteorites were used for the synthesis of complicated organic compounds on early Earth. A laboratory experiment with hypervelocity impact plasma torch modelling by a laser with a Q-switch mode has shown the possibility of high-molecular organic compound synthesis, with mass of approximately 5000 a.m.u. by meteorite impact with an effective diameter of 100 mkm. The target contained only H, C, N and O elements in inorganic forms. The approximation of the curve received in these experiments has shown that molecular structures comparable in mass with the protoviroid (a hypothetical primogenitor of the biosphere) and could have been synthesized as a result of the impact of a meteorite of a millimetre-size range. Observable characteristics of the synthesis processes suggest high catalytic activity of the plasma medium and high speed of plasma-chemical reactions, combined with ordering and assemblage processes. This suggests that the plasma torch with a huge local density of energy and matter may be the optimal medium for the synthesis of complex organic compounds needed for prebiotic evolution and the development of the primary form of living matter. A new view of the impact crater provides the most interesting and unexpected consequence of the concept proposed. When considering the problem, it became evident that at a prebiotic stage of evolution there should be an environment in which a photogenic creature could have survived. The crater of the meteoric impact, which is capable of producing ‘a primogenitor of the biosphere’ environment sated with organic matter, moderate temperature and water for considerable time and becoming ‘a life cradle’, appears to be such an environment. Having enormous energy, the meteorite impact is capable of injecting the newly created complicated organic compounds deep into the space body surfaces, including subsurface water reservoirs, such as Europe, Enchilada and Titan. In this case the meteorite impact has no natural alternative in the creation of initial conditions for the origin of extraterrestrial life. This possibility was confirmed by a laboratory impact model experiment, in which the plasma torch was created under the water surface. The concept proposed is based on physical processes occurring in nature and on experimental results of impact experiments and subsequent modelling of their analogues in laboratory conditions. Thus, the realizability and survivability of this concept should be taken as well grounded due to the simplicity and clarity of the physical processes.
NASA Technical Reports Server (NTRS)
Dworkin, Jason P.; Sandford, Scott A.; Deamer, David W.; Gillette, J. Seb; Zare, Richard N.; Allamandola, Louis J. (Technical Monitor)
1999-01-01
The combination of realistic laboratory simulations and infrared observations have revolutionized our understanding of interstellar dust and ice-the main component of comets. Since comets and carbonaceous micrometeorites may have been important sources of volatiles and carbon compounds on the early Earth, their organic composition may be related to the origin of life. Ices on grains in molecular clouds contain a variety of simple molecules. The D/H ratios of the comets Hale-Bopp and Hyakutake are consistent with a primarily interstellar ice mixture. Within the cloud and especially in the presolar nebula through the early solar system, these icy grains would have been photoprocessed by the ultraviolet producing more complex species such as hexamethylenetetramine, polyoxymethylenes, and simple keones. We reported at the 1999 Bioastronomy meeting laboratory simulations studied to identify the types of molecules which could have been generated in pre-cometary ices. Experiments were conducted by forming a realistic interstellar mixed-molecular ice (H2O, CH3OH, NH3 and CO) at approximately 10 K under high vacuum irradiated with UV light from a hydrogen plasma lamp. The gas mixture was typically 100:50:1:1, however when different ratios were used material with similar characteristics was still produced. The residue that remained after warming to room temperature was analyzed by HPLC, and by several mass spectrometric methods. This material contains a rich mixture of complex compounds with mass spectral profiles resembling those found in IDPs and meteorites. Surface tension measurements show that an amphiphilic component is also present. These species do not appear in various controls or in unphotolyzed samples. Residues from the simulations were also dispersed in aqueous media for microscopy. The organic material forms 10-40 gm diameter droplets that fluoresce at 300-450 nm under UV excitation. These droplets have a morphology and internal structure which appear strikingly similar to those produced by extracts of the Murchison meteorite. Together, these results suggest a link between organic material photochemically synthesized on the cold grains in dense, interstellar molecular clouds and compounds that may have contributed to the organic inventory of the primitive Earth. For example, the amphiphilic properties of such compounds permit self-assembly into the membranous boundary structures that required for the first forms of cellular life.
Microbial Extremophiles in Evolutionary Aspect
NASA Technical Reports Server (NTRS)
Pikuta, Elena V.; Hoover, Richard B.
2007-01-01
The microflora of the cryosphere of planet Earth provides the best analogs for life forms that might be found in the permafrost or polar ice caps of Mars, near the surface of the cometary nuclei, or in the liquid water beneath the ice crusts of icy moons of Jupiter and Saturn. For astrobiology the focus on the study alkaliphilic microorganisms was enhanced by the findings of abundant carbonates and carbonate globules rimmed with possibly biogenic magnetites in association with the putative microfossils in the ALH84001 meteorite. Although the ALH84001 "nanofossils" were to small and simple to be unambiguously recognized as biogenic, they stimulated Astrobiology research and studies of microbial extremophiles and biomarkers in ancient rocks and meteorites. Recent studies of CI and CM carbonaceous meteorites have resulted in the detection of the well-preserved mineralized remains of coccoidal and" filamentous microorganisms in cyanobacterial mats. Energy Dispersive X-ray Analysis has shown anomalous biogenic element ratios clearly indicating they are not recent biological contaminants. This paper reviews microbial extremophiles in context of their significance to Astrobiology and the evolution of life. Extremophilic microorganisms on Earth are models for life that might endure high radiation environments in the ice near the surface of comets or on the icy moons of Jupiter and Saturn and in the seafloor deep beneath the icy crusts of Europa and Enceladus.
Keeping the Air Clean and Safe: An Anthrax Smoke Detector
NASA Technical Reports Server (NTRS)
2005-01-01
Scientists at work in the Planetary Protection division at NASA s Jet Propulsion Laboratory (JPL) sterilize everything before blasting it to the Red Planet. They take great pains to ensure that all spacecraft are void of bacterial life, especially the microscopic bacteria that can live hundreds of years in their spore states. No one is quite sure what Earthly germs would do on Mars, but scientists agree that it is safest to keep the Martian terrain as undisturbed as possible. Errant Earth germs would also render useless the instruments placed on exploration rovers to look for signs of life, as the life that they registered would be life that came with them from Earth. A team at JPL, headed by Dr. Adrian Ponce, developed a bacterial spore-detection system that uses a simple and robust chemical reaction that visually alerts Planetary Protection crews. It is a simple air filter that traps micron-sized bacterial spores and then submits them to the chemical reaction. When the solution is then viewed under an ultraviolet light, the mixture will glow green if it is contaminated by bacteria. Scientists can then return to the scrubbing and cleaning stages of the sterilization process to remove these harmful bacteria. The detection system is the space-bound equivalent of having your hands checked for cleanliness before being allowed to the table; and although intended to keep terrestrial germs from space, this technology has awesome applications here on Mother Earth. The bacterial spore-detection unit can recognize anthrax and other harmful, spore-forming bacteria and alert people of the impending danger. As evidenced in the anthrax mailings of fall 2001 in the United States, the first sign of anthrax exposure was when people experienced flu-like symptoms, which unfortunately, can take as much as a week to develop after contamination. Anthrax cost 5 people their lives and infected 19 others; and the threat of bioterrorism became a routine concern, with new threats popping up nearly everyday. The attacks threatened the safety that so many Americans took for granted, as the very air that people breathed became suspect. Any building with a circulation system, where large groups congregate, was now a potential target.
On The Sfr-M* Main Sequence Archetypal Star-Formation History And Analytical Models
NASA Astrophysics Data System (ADS)
Ciesla, Laure; Elbaz, David; Fensch, Jeremy
2017-06-01
From the evolution of the main sequence we can build the star formation history (SFH) of MS galaxies, assuming that they follow this relation all their life. We show that this SFH is not only a function of cosmic time but also involve the seed mass of the galaxy. We discuss the implications of this MS SFH on the stellar mass growth, and the entry in the passive region of the UVJ diagram, while the galaxy is still forming stars. We test the ability of different analytical SFH forms found in the literature to probe the SFR of all type of galaxies. Using a sample of GOODS-South galaxies, we show that these SFHs artificially enhance or create a gradient of age, parallel to the MS. A simple model of a MS galaxy, such as those expected from compaction or variation in gas accretion, undergoing some fluctuations provide does not predict such a gradient, that we show is due to SFH assumptions. We propose an improved analytical form, taking into account a flexibility in the recent SFH that we calibrate as a diagnostic to identify rapidly quenched galaxies from large photometric survey.
Johnson, Jeffrey R.; Baumsteiger, Jason; Zydlewski, Joseph D.; Hudson, J. Michael; Ardren, William R.
2010-01-01
Coastal cutthroat trout Oncorhynchus clarkii clarkii exhibit resident and migratory life history strategies that often occur sympatrically, but the relationship between these forms within a population is poorly characterized. Through use of passive integrated transponder technology, migratory and resident coastal cutthroat trout were identified in two lower Columbia River tributaries (Abernathy Creek and the Chinook River) separated by more than 80 km. Genetic data from 17 highly variable microsatellite loci were used to ascertain the genetic population structure of these life history forms within and between streams. No distinct genetic separation was observed between the life history forms within a stream, as assessed by four different statistical approaches: permutation tests based on the genetic differentiation index F ST, principal components analysis of individuals, analysis of molecular variance, and contingency tests of allele frequency heterogeneity. Genetic differences were an order of magnitude higher between stream samples (F ST > 0.03) than between life history forms within a stream (F ST < 0.003). The contingency test detected allele frequency differences between migratory and resident life history forms in Abernathy Creek (P = 0.001), but this result was influenced more by age-class structure than by reproductive isolation between life history forms. Results are consistent with a single, randomly mating population in each stream producing both migratory and resident life history forms. These data suggest that individual life history strategy in coastal cutthroat trout is predominantly determined by phenotypic plasticity rather than genotype.
A User-Friendly DNA Modeling Software for the Interpretation of Cryo-Electron Microscopy Data.
Larivière, Damien; Galindo-Murillo, Rodrigo; Fourmentin, Eric; Hornus, Samuel; Lévy, Bruno; Papillon, Julie; Ménétret, Jean-François; Lamour, Valérie
2017-01-01
The structural modeling of a macromolecular machine is like a "Lego" approach that is challenged when blocks, like proteins imported from the Protein Data Bank, are to be assembled with an element adopting a serpentine shape, such as DNA templates. DNA must then be built ex nihilo, but modeling approaches are either not user-friendly or very long and fastidious. In this method chapter we show how to use GraphiteLifeExplorer, a software with a simple graphical user interface that enables the sketching of free forms of DNA, of any length, at the atomic scale, as fast as drawing a line on a sheet of paper. We took as an example the nucleoprotein complex of DNA gyrase, a bacterial topoisomerase whose structure has been determined using cryo-electron microscopy (Cryo-EM). Using GraphiteLifeExplorer, we could model in one go a 155 bp long and twisted DNA duplex that wraps around DNA gyrase in the cryo-EM map, improving the quality and interpretation of the final model compared to the initially published data.
Green remediation. Tool for safe and sustainable environment: a review
NASA Astrophysics Data System (ADS)
Singh, Mamta; Pant, Gaurav; Hossain, Kaizar; Bhatia, A. K.
2017-10-01
Nowadays, the bioremediation of toxic pollutants is a subject of interest in terms of health issues and environmental cleaning. In the present review, an eco-friendly, cost-effective approach is discussed for the detoxification of environmental pollutants by the means of natural purifier, i.e., blue-green algae over the conventional methods. Industrial wastes having toxic pollutants are not able to eliminate completely by existing the conventional techniques; in fact, these methods can only change their form rather than the entire degradation. These pollutants have an adverse effect on aquatic life, such as fauna and flora, and finally harm human life directly or indirectly. Cyanobacterial approach for the removal of this contaminant is an efficient tool for sustainable development and pollution control. Cyanobacteria are the primary consumers of food chain which absorbed complex toxic compounds from environments and convert them to simple nontoxic compounds which finally protect higher food chain consumer and eliminate risk of pollution. In addition, these organisms have capability to solve secondary pollution, as they can remediate radioactive compound, petroleum waste and degrade toxins from pesticides.
Corrigendum: New Form of Kane's Equations of Motion for Constrained Systems
NASA Technical Reports Server (NTRS)
Roithmayr, Carlos M.; Bajodah, Abdulrahman H.; Hodges, Dewey H.; Chen, Ye-Hwa
2007-01-01
A correction to the previously published article "New Form of Kane's Equations of Motion for Constrained Systems" is presented. Misuse of the transformation matrix between time rates of change of the generalized coordinates and generalized speeds (sometimes called motion variables) resulted in a false conclusion concerning the symmetry of the generalized inertia matrix. The generalized inertia matrix (sometimes referred to as the mass matrix) is in fact symmetric and usually positive definite when one forms nonminimal Kane's equations for holonomic or simple nonholonomic systems, systems subject to nonlinear nonholonomic constraints, and holonomic or simple nonholonomic systems subject to impulsive constraints according to Refs. 1, 2, and 3, respectively. The mass matrix is of course symmetric when one forms minimal equations for holonomic or simple nonholonomic systems using Kane s method as set forth in Ref. 4.
Setaria viridis floral-dip: A simple and rapid Agrobacterium-medicated transformation method
USDA-ARS?s Scientific Manuscript database
Setaria viridis was recently described as a new monocotyledonous model species for C4 photosynthesis research and genetic transformation. It has biological attributes (rapid life cycle, small genome, diploid, short stature and simple growth requirements) that make it suitable for use as a model plan...
Efficient simple sealed-off CO laser at room temperature
NASA Astrophysics Data System (ADS)
Peters, P. J. M.; Witteman, W. J.; Zuidema, R. J.
1980-07-01
The paper reports a simple sealed-off CW CO laser with gold electrodes. A constant long-life output power of more than 29 W/m and a maximum efficiency of 15% at room temperature are reported. No auxiliary features, such as a palladium hydrogen extraction tube, are necessary.
Die Metamorphose des Polypen von Tripedalia cystophora (Cubozoa, Carybdeidae) in die Meduse
NASA Astrophysics Data System (ADS)
Werner, B.
1983-09-01
The life cycle of the Cubozoa is unique due to the complete metamorphosis of the sessible solitary polyp into one single medusa which starts a pelagic way of life. Contrary to the other metagenetic classes of Scyphozoa and Hydrozoa, the cubozoan polyp terminates its polypoid existence definitely when it metamorphosizes. Generally, the metamorphosis of the cubopolyp is characterized by the transformation of its simple, sac-like multiradial body into the tetraradial structures of the much more complicated medusa. The macroscopic phases of the metamorphosis of Tripedalia cystophora Conant are reviewed, and the internal developmental processes which effect and underlie the transformation are described in detail from new histological investigations. Only the oral pole of the polyp is involved in the active processes of transformation whereas the basal pole follows in a more passive way. The most important process is the invagination of a quadrangular furrow around the hypostome of the polyp by which (a) the subumbrellar room (bell cavity) of the developing medusa is formed, and (b) the four gastric pockets within the wall of the bell are folded off from the polyp's simple stomach. The description of the metamorphosis on the whole and the detailed comparison of the principal developmental processes provide evidence that medusa formation of Cubozoa is different from that of the other metagenetic classes of Scyphozoa and Hydrozoa. The systematic and evolutionary consequences as well as general aspects of medusa formation in the phylum Cnidaria are discussed in detail. In conclusion, the pelagic medusa generation has been “invented” by the ancestors of the recent metagenetic cnidarian classes three times independently.
West, Geoffrey B; Brown, James H
2005-05-01
Life is the most complex physical phenomenon in the Universe, manifesting an extraordinary diversity of form and function over an enormous scale from the largest animals and plants to the smallest microbes and subcellular units. Despite this many of its most fundamental and complex phenomena scale with size in a surprisingly simple fashion. For example, metabolic rate scales as the 3/4-power of mass over 27 orders of magnitude, from molecular and intracellular levels up to the largest organisms. Similarly, time-scales (such as lifespans and growth rates) and sizes (such as bacterial genome lengths, tree heights and mitochondrial densities) scale with exponents that are typically simple powers of 1/4. The universality and simplicity of these relationships suggest that fundamental universal principles underly much of the coarse-grained generic structure and organisation of living systems. We have proposed a set of principles based on the observation that almost all life is sustained by hierarchical branching networks, which we assume have invariant terminal units, are space-filling and are optimised by the process of natural selection. We show how these general constraints explain quarter power scaling and lead to a quantitative, predictive theory that captures many of the essential features of diverse biological systems. Examples considered include animal circulatory systems, plant vascular systems, growth, mitochondrial densities, and the concept of a universal molecular clock. Temperature considerations, dimensionality and the role of invariants are discussed. Criticisms and controversies associated with this approach are also addressed.
Exercise in Patients on Dialysis: A Multicenter, Randomized Clinical Trial.
Manfredini, Fabio; Mallamaci, Francesca; D'Arrigo, Graziella; Baggetta, Rossella; Bolignano, Davide; Torino, Claudia; Lamberti, Nicola; Bertoli, Silvio; Ciurlino, Daniele; Rocca-Rey, Lisa; Barillà, Antonio; Battaglia, Yuri; Rapanà, Renato Mario; Zuccalà, Alessandro; Bonanno, Graziella; Fatuzzo, Pasquale; Rapisarda, Francesco; Rastelli, Stefania; Fabrizi, Fabrizio; Messa, Piergiorgio; De Paola, Luciano; Lombardi, Luigi; Cupisti, Adamasco; Fuiano, Giorgio; Lucisano, Gaetano; Summaria, Chiara; Felisatti, Michele; Pozzato, Enrico; Malagoni, Anna Maria; Castellino, Pietro; Aucella, Filippo; Abd ElHafeez, Samar; Provenzano, Pasquale Fabio; Tripepi, Giovanni; Catizone, Luigi; Zoccali, Carmine
2017-04-01
Previous studies have suggested the benefits of physical exercise for patients on dialysis. We conducted the Exercise Introduction to Enhance Performance in Dialysis trial, a 6-month randomized, multicenter trial to test whether a simple, personalized walking exercise program at home, managed by dialysis staff, improves functional status in adult patients on dialysis. The main study outcomes included change in physical performance at 6 months, assessed by the 6-minute walking test and the five times sit-to-stand test, and in quality of life, assessed by the Kidney Disease Quality of Life Short Form (KDQOL-SF) questionnaire. We randomized 296 patients to normal physical activity (control; n =145) or walking exercise ( n =151); 227 patients (exercise n =104; control n =123) repeated the 6-month evaluations. The distance covered during the 6-minute walking test improved in the exercise group (mean distance±SD: baseline, 328±96 m; 6 months, 367±113 m) but not in the control group (baseline, 321±107 m; 6 months, 324±116 m; P <0.001 between groups). Similarly, the five times sit-to-stand test time improved in the exercise group (mean time±SD: baseline, 20.5±6.0 seconds; 6 months, 18.2±5.7 seconds) but not in the control group (baseline, 20.9±5.8 seconds; 6 months, 20.2±6.4 seconds; P =0.001 between groups). The cognitive function score ( P =0.04) and quality of social interaction score ( P =0.01) in the kidney disease component of the KDQOL-SF improved significantly in the exercise arm compared with the control arm. Hence, a simple, personalized, home-based, low-intensity exercise program managed by dialysis staff may improve physical performance and quality of life in patients on dialysis. Copyright © 2017 by the American Society of Nephrology.
Doolittle, W Ford; Brunet, Tyler D P
2016-04-01
A universal Tree of Life (TOL) has long been a goal of molecular phylogeneticists, but reticulation at the level of genes and possibly at the levels of cells and species renders any simple interpretation of such a TOL, especially as applied to prokaryotes, problematic.
ERIC Educational Resources Information Center
Fox, J. Lawrence
1972-01-01
Reviews ideas and evidence bearing on the origin of life. Shows that evidence to support modifications of Oparin's theories of the origin of biological constituents from inorganic materials is accumulating, and that the necessary components are readily obtained from the simple gases found in the universe. (AL)
Swann, Gregory; Byck, Gayle R; Dick, Danielle M; Aliev, Fazil; Latendresse, Shawn J; Riley, Brien; Kertes, Darlene; Sun, Cuie; Salvatore, Jessica E; Bolland, John; Mustanski, Brian
2014-06-01
In a community sample of low-income African American adolescents, we tested the interactive effects of variation in the mu 1 opioid receptor (OPRM1) gene and the occurrence of stressful life events on symptoms of depression. Interactive effects of 24 OPRM1 simple nucleotide polymorphisms (SNP) and adolescent report of stressful life events on depression were tested using multilevel regressions. SNPs were dummy coded to test both additive and dominate forms of coding. Five OPRM1 SNPs showed significant evidence of interaction with stressful life events to alter depression risk (or symptoms) after adjusting for multiple testing and the correlated nature of the SNPs. Follow-up analyses showed significant differences based on OPRM1 genotype at both lower and higher frequencies of stressful life events, suggesting that participants with a copy of the minor allele on OPRM1 SNPs rs524731, rs9478503, rs3778157, rs10485057, and rs511420 have fewer symptoms in low stress conditions but more symptoms in high stress conditions compared to major allele homozygotes. The genetic variants associated with depression in African American adolescents may not translate to other ethnic groups. This study is also limited in that only one gene that functions within a complex biological system is addressed. This current study is the first to find an interaction between OPRM1 and life stress that is associated with depression. It also addressed an understudied population within the behavioral genetics literature. Further research should test additional genes involved in the opioid system and expand the current findings to more diverse samples. Copyright © 2014 Elsevier B.V. All rights reserved.
Wu, Wenqing; Wang, Zhoubing; Wei, Yan; Zhang, Guanghua; Shi, Shenxun; Gao, Jingfang; Li, Youhui; Tao, Ming; Zhang, Kerang; Wang, Xumei; Gao, Chengge; Yang, Lijun; Li, Kan; Shi, Jianguo; Wang, Gang; Liu, Lanfen; Zhang, Jinbei; Du, Bo; Jiang, Guoqing; Shen, Jianhua; Liu, Ying; Liang, Wei; Sun, Jing; Hu, Jian; Liu, Tiebang; Wang, Xueyi; Miao, Guodong; Meng, Huaqing; Li, Yi; Hu, Chunmei; Li, Yi; Huang, Guoping; Li, Gongying; Ha, Baowei; Deng, Hong; Mei, Qiyi; Zhong, Hui; Gao, Shugui; Sang, Hong; Zhang, Yutang; Fang, Xiang; Yu, Fengyu; Yang, Donglin; Liu, Tieqiao; Chen, Yunchun; Hong, Xiaohong; Wu, Wenyuan; Chen, Guibing; Cai, Min; Song, Yan; Pan, Jiyang; Dong, Jicheng; Pan, Runde; Zhang, Wei; Shen, Zhenming; Liu, Zhengrong; Gu, Danhua; Wang, Xiaoping; Liu, Xiaojuan; Zhang, Qiwen; Li, Yihan; Chen, Yiping; Kendler, Kenneth S.; Flint, Jonathan; Zhang, Zhen
2013-01-01
Background Dysthymia is a form of chronic mild depression that has a complex relationship with major depressive disorder (MDD). Here we investigate the role of environmental risk factors, including stressful life events and parenting style, in patients with both MDD and dysthymia. We ask whether these risk factors act in the same way in MDD with and without dysthymia. Results We examined the clinical features in 5,950 Han Chinese women with MDD between 30–60 years of age across China. We confirmed earlier results by replicating prior analyses in 3,950 new MDD cases. There were no significant differences between the two data sets. We identified sixteen stressful life events that significantly increase the risk of dysthymia, given the presence of MDD. Low parental warmth, from either mother or father, increases the risk of dysthymia. Highly threatening but short-lived threats (such as rape) are more specific for MDD than dysthymia. While for MDD more severe life events show the largest odds ratio versus controls, this was not seen for cases of MDD with or without dysthymia. Conclusions There are increased rates of stressful life events in MDD with dysthymia, but the impact of life events on susceptibility to dysthymia with MDD differs from that seen for MDD alone. The pattern does not fit a simple dose-response relationship, suggesting that there are moderating factors involved in the relationship between environmental precipitants and the onset of dysthymia. It is possible that severe life events in childhood events index a general susceptibility to chronic depression, rather than acting specifically as risk factors for dysthymia. PMID:24386213
NASA Technical Reports Server (NTRS)
Burton, Aaron S.
2012-01-01
In this review, Saladino et al. present an intriguing hypothesis surrounding the role of formamide in the originsof life on Earth, backed by experimental results supporting each step from formamide to RNA polymers [1]. The overall premise is that, from formamide and inorganic phosphate, RNA molecules over 100 nucleotides in length canbe produced. In addition, many carboxylic acids likely relevant to prebiotic metabolism are formed along the way. Thus, from a rather simple organic molecule that has been observed in outer space (formamide), you can generatemany of the compounds necessary for the origins of life. However, because high temperatures (160 C) are requiredfor the formamide reactions, it remains unclear where the warm formamide scenario could have occurred.Low-temperature, aqueous hydrogen counter to the observation that all protein-catalyzed ligation and polymerization reactions of RNA and DNA requireactivated substrates. Detailed mechanistic studies of the reported reactions are warranted and could provide important insights for understanding the chemistry behind the origins of life.Because the authors have produced many of the experimental results supporting their hypothesis, they coulddemonstrate the validity of their hypothesis by converting formamide into 100 nucleotide RNA oligomers, usingthe products of one reaction as the reactants for the next reaction, under specific conditions plausible on the pre-bioticEarth. Such a demonstration would represent a milestone for our understanding of the origins of life.cyanide-based prebiotic chemistry that we know actually happened has beenshown to produce many of the molecules invoked in the formamide hypothesis: amino acids, carboxylic acids, sugaracids, and nucleobases have all been found in meteorites recovered on Earth [e.g. [24
Quality of Work Life and Organizational Climate of Schools Located along the Thai-Cambodian Borders
ERIC Educational Resources Information Center
Kitratporn, Poonsook; Puncreobutr, Vichian
2016-01-01
The purpose of the study is to measure the Quality of Work Life and Organizational Climate of Schools located along the Thai-Cambodian borders. The study intended to measure the relationship between the two underlying variables quality of work life and organizational climate. Simple random sample of 384 respondents were administrators and teachers…
Skill Acquisition and Use across the Life Course: Current Trends, Future Prospects
ERIC Educational Resources Information Center
Martin, Bill
2007-01-01
People's life pathways are no longer as predictable as they were in the second half of the 20th century. It is no longer as simple as moving from school to work, probably via tertiary education, to living independently, then getting married and starting a family. Changes in how people combine education with life-course transitions will influence…
The Game of Life Rules on Penrose Tilings: Still Life and Oscillators
NASA Astrophysics Data System (ADS)
Owens, Nick; Stepney, Susan
John Horton Conway's Game of Life is a simple two-dimensional, two state cellular automaton (CA), remarkable for its complex behaviour. That behaviour is known to be very sensitive to a change in the CA rules. Here we continue our investigations into its sensitivity to changes in the lattice, by the use of an aperiodic Penrose tiling lattice.
NASA Astrophysics Data System (ADS)
Race, Margaret
As citizens and decision makers of the future, today's students need to understand the nature of science and the implications of scientific discoveries and activities in a broad societal context. Astrobiology provides an opportunity to introduce students to real world decision-making involving cutting edge, multidisciplinary research topics that involve Earth, the solar system and beyond. Although textbooks and curricular materials may take years to develop, teachers can easily bring the latest astrobiological discoveries and hypotheses into the classroom in the form of case studies to complement science classes. For example, using basic biological, geological and chemical information from Earth and other planets, students can discuss the same questions that experts consider when planning a Mars Sample Return mission. How would you recognize extraterrestrial life? What would be the impact of bringing martian life to Earth? How should martian samples be handled and tested to determine whether they pose hazards to Earth's biota and ecosystems? If truly martian life exists, what are the implications for future human missions or colonies on the planet? What are the ethical and societal implications of discovering extraterrestrial life, whether in the solar system or beyond? What difference world it make if the extraterrestrial life is microbial and simple vs. intelligent and advanced? By integrating basic science concepts, up-to-date research findings, and information about laws, societal concerns, and public decision making, students can experience first-hand the kind of questions and challenges we're likely to face in the years ahead.
Towards ageing well: Use it or lose it: Exercise, epigenetics and cognition.
Rea, Irene Maeve
2017-08-01
More and more people are living into the 90s or becoming centenarians. But, the gift of increased 'age span' seldom equates with an improved 'health-span'. Governments across the world are expressing concern about the epidemic of chronic disease, and have responded by initiating policies that make prevention, reduction and treatment of chronic disease, a public health priority. But understanding, how to age long and well, with the avoidance of chronic disease and later life complex disease morbidity is challenging. While inherited genes have an undoubted role to play in the chance of maintaining good health or conversely a predilection to developing disease and chronic ill health, there is increasing evidence that behavioural and environmental life-style choices may contribute up to 50% of the variability of human lifespan. Physical exercise is readily available to everyone, and is a simple cheap and effective form of life-style intervention. Exercise appears to help maintain good health and to reduce the risk of developing chronic disease and ill health. Evidence suggests that physical activity improves well-being across many health domains through out life, continues to offer important health benefits in older age groups and tracks with a 'healthy ageing' profile. Although many of the molecular pathways remain to be fully identified, here we discuss how physical activity and exercise is understood to produce changes in the human epigenome, which have the potential to enhance cognitive and psychological health, improve muscular fitness, and lead to better ageing with improved quality of life in older age.
Kudubes, Asli Akdeniz; Bektas, Murat
2015-01-01
This study was planned in an attempt to develop a scale for the quality of life in pediatric oncology patients aged 7-12, with child and parents forms. In collecting the study data, we used the Child and Parent Information Form, Visual Quality of Life Scale, Scale for Quality of Life Pediatric Oncology Patients Aged 7-12 and the Scale for the Quality of Life in Pediatric Oncology Patients Aged 7-12 for Parents. We also used Pearson correlation analysis, the Cronbach alpha coefficient, factor analysis and ROC analysis for the study data. In this study, the total Cronbach alpha value of the parent form was 0.96, the total factor load being 0.54-0.90 and the total variance explained was 82.5%. The cutoff point of the parent form was 93 points. The total Cronbach alpha value for the child form was 0.96, with a total factor load of 0.55-0.91 and the total variance being explained was 78.3%. The cutoff point of the child form was 65 points. This study suggests that the Scale for Quality of Life in Pediatric Oncology Patients Aged 7-12 Child and Parents Forms are valid and reliable instruments in assessing the quality of life of children.
Nonmedical Uses of Antibiotics: Time to Restrict Their Use?
Meek, Richard William; Vyas, Hrushi; Piddock, Laura Jane Violet
2015-01-01
The global crisis of antibiotic resistance has reached a point where, if action is not taken, human medicine will enter a postantibiotic world and simple injuries could once again be life threatening. New antibiotics are needed urgently, but better use of existing agents is just as important. More appropriate use of antibiotics in medicine is vital, but the extensive use of antibiotics outside medical settings is often overlooked. Antibiotics are commonly used in animal husbandry, bee-keeping, fish farming and other forms of aquaculture, ethanol production, horticulture, antifouling paints, food preservation, and domestically. This provides multiple opportunities for the selection and spread of antibiotic-resistant bacteria. Given the current crisis, it is vital that the nonmedical use of antibiotics is critically examined and that any nonessential use halted. PMID:26444324
Nonmedical Uses of Antibiotics: Time to Restrict Their Use?
Meek, Richard William; Vyas, Hrushi; Piddock, Laura Jane Violet
2015-10-01
The global crisis of antibiotic resistance has reached a point where, if action is not taken, human medicine will enter a postantibiotic world and simple injuries could once again be life threatening. New antibiotics are needed urgently, but better use of existing agents is just as important. More appropriate use of antibiotics in medicine is vital, but the extensive use of antibiotics outside medical settings is often overlooked. Antibiotics are commonly used in animal husbandry, bee-keeping, fish farming and other forms of aquaculture, ethanol production, horticulture, antifouling paints, food preservation, and domestically. This provides multiple opportunities for the selection and spread of antibiotic-resistant bacteria. Given the current crisis, it is vital that the nonmedical use of antibiotics is critically examined and that any nonessential use halted.
SPIKE-2: a Practical Stirling Engine for Kilowatt Level Solar Power
NASA Technical Reports Server (NTRS)
Beale, W. T.
1984-01-01
Recent advances in the art of free piston Stirling engine design make possible the production of 1-10kW free piston Stirling linear alternator engine, hermetically sealed, efficient, durable and simple in construction and operation. Power output is in the form of single or three phase 60 Hz. AC, or DC. The three phase capability is available from single machines without need of external conditioning. Engine voltage control regains set voltage within 5 cycles in response to any load change. The existing SPIKE-2 design has an engine alternator efficiency of 25% at 650 C heater wall temperature and a service life of over three years in solar service. The same system can be scaled over a range of at least 100 watts to 25kW.
Dorian, Paul; Guerra, Peter G; Kerr, Charles R; O'Donnell, Suzan S; Crystal, Eugene; Gillis, Anne M; Mitchell, L Brent; Roy, Denis; Skanes, Allan C; Rose, M Sarah; Wyse, D George
2009-06-01
Atrial fibrillation (AF) is commonly associated with impaired quality of life. There is no simple validated scale to quantify the functional illness burden of AF. The Canadian Cardiovascular Society Severity in Atrial Fibrillation (CCS-SAF) scale is a bedside scale that ranges from class 0 to 4, from no effect on functional quality of life to a severe effect on life quality. This study was performed to validate the scale. In 484 patients with documented AF (62.2+/-12.5 years of age, 67% men; 62% paroxysmal and 38% persistent/permanent), the SAF class was assessed and 2 validated quality-of-life questionnaires were administered: the SF-36 generic scale and the disease-specific AFSS (University of Toronto Atrial Fibrillation Severity Scale). There is a significant linear graded correlation between the SAF class and measures of symptom severity, physical and emotional components of quality of life, general well-being, and health care consumption related to AF. Patients with SAF class 0 had age- and sex-standardized SF-36 scores of 0.15+/-0.16 and -0.04+/-0.31 (SD units), that is, units away from the mean population score for the mental and physical summary scores, respectively. For each unit increase in SAF class, there is a 0.36 and 0.40 SD unit decrease in the SF-36 score for the physical and mental components. As the SAF class increases from 0 to 4, the symptom severity score (range, 0 to 35) increases from 4.2+/-5.0 to 18.4+/-7.8 (P<0.0001). The CCS-SAF scale is a simple semiquantitative scale that closely approximates patient-reported subjective measures of quality of life in AF and may be practical for clinical use.
A simple finite element method for non-divergence form elliptic equation
Mu, Lin; Ye, Xiu
2017-03-01
Here, we develop a simple finite element method for solving second order elliptic equations in non-divergence form by combining least squares concept with discontinuous approximations. This simple method has a symmetric and positive definite system and can be easily analyzed and implemented. We could have also used general meshes with polytopal element and hanging node in the method. We prove that our finite element solution approaches to the true solution when the mesh size approaches to zero. Numerical examples are tested that demonstrate the robustness and flexibility of the method.
A simple finite element method for non-divergence form elliptic equation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mu, Lin; Ye, Xiu
Here, we develop a simple finite element method for solving second order elliptic equations in non-divergence form by combining least squares concept with discontinuous approximations. This simple method has a symmetric and positive definite system and can be easily analyzed and implemented. We could have also used general meshes with polytopal element and hanging node in the method. We prove that our finite element solution approaches to the true solution when the mesh size approaches to zero. Numerical examples are tested that demonstrate the robustness and flexibility of the method.
Forest, M G; Tardy, V; Nicolino, M; David, M; Morel, Y
2005-06-01
Congenital adrenal hyperplasia (CAH) is a family of autosomal recessive disorders caused by mutations in genes encoding the enzymes involved in one of the various steps of adrenal steroid synthesis. Steroid 21-hydroxylase deficiency (21-OHD) is responsible for over 95% of the 5 forms of CAH, and results due to enzymatic defect owing to mutation in the CYP21 gene. The disease has two major clinical presentations. The "classical" form is severe, and divided into a salt wasting (SW) and simple virilizing (SV) subgroups. In both, affected female fetuses undergo virilization of the external genitalia prenatally and present at birth with sexual ambiguity. In addition, in both sexes infants with SW CAH are at risk of life-threatening adrenal crisis without treatment. This is why it is so important to make a diagnosis and to counsel the families. The diagnosis is easy by measuring the plasma levels of 17-hydroxyprogesterone (17-OHP) in antenatal (amniotic fluid), or perinatal samples (peripheral blood). Confirmation by molecular genetic analysis is advised. The second form of 21-OHD is called "non classical" because the presentation is much less severe and the onset of clinical expression occurs long after birth, often in the peripubertal period, as non-specific symptoms of hyperandrogeny. The unambiguous diagnosis of the latter requires a simple short ACTH test, with the measurement of 17-OHP at 60 min. In both forms, the mutations on the gene CYP21 responsible for the disease are now well known and can be identified by molecular biology techniques. There is a good correlation between phenotypes and genotypes, due to variable amount of the 21-hydroxylase-enzyme activity left (null to 50-60%). SW, SV and NC forms are associated with distinct mutations or combination of mutations. Nowadays, by combining hormonal and molecular tests, it is possible to predict the clinical form of the disease in a given family in the context of a prenatal diagnosis, which can lead to a prenatal treatment. Therefore, 21-OHD genotyping also appears essential for a new approach of genetic counseling, prediction of clinical form after postnatal screening and to define the post-ACTH 17-OHP values indicating the cut-off lines between NC, heterozygote and normal subjects.
Doolittle, W. Ford; Brunet, Tyler D. P.
2016-01-01
A universal Tree of Life (TOL) has long been a goal of molecular phylogeneticists, but reticulation at the level of genes and possibly at the levels of cells and species renders any simple interpretation of such a TOL, especially as applied to prokaryotes, problematic. PMID:27078870
Economic Input-Output Life Cycle Assessment of Water Reuse Strategies in Residential Buildings
This paper evaluates the environmental sustainability and economic feasibility of four water reuse designs through economic input-output life cycle assessments (EIO-LCA) and benefit/cost analyses. The water reuse designs include: 1. Simple Greywater Reuse System for Landscape Ir...
Russell, Bayden D.; Harley, Christopher D. G.; Wernberg, Thomas; Mieszkowska, Nova; Widdicombe, Stephen; Hall-Spencer, Jason M.; Connell, Sean D.
2012-01-01
Most studies that forecast the ecological consequences of climate change target a single species and a single life stage. Depending on climatic impacts on other life stages and on interacting species, however, the results from simple experiments may not translate into accurate predictions of future ecological change. Research needs to move beyond simple experimental studies and environmental envelope projections for single species towards identifying where ecosystem change is likely to occur and the drivers for this change. For this to happen, we advocate research directions that (i) identify the critical species within the target ecosystem, and the life stage(s) most susceptible to changing conditions and (ii) the key interactions between these species and components of their broader ecosystem. A combined approach using macroecology, experimentally derived data and modelling that incorporates energy budgets in life cycle models may identify critical abiotic conditions that disproportionately alter important ecological processes under forecasted climates. PMID:21900317
Spatial and gender scenario of literate life expectancy at birth in India.
Chattopadhyay, Aparajita; Sinha, Kumar Chiman
2010-10-01
Measuring human quality of life is academically challenging. The human development index (HDI) substantially captures the overall country level status on human welfare. However, this index has some drawbacks. Therefore, Lutz composed a simple index in 1995 combining life expectancy and literacy, called literate life expectancy (LLE). LLE can be calculated for subpopulations depending on availability of data. This article captures the LLE in major states in India and the gender differences in LLE at rural and urban levels. The authors have tried to highlight the social development scenario in India and its major states by using this pure social indicator that intentionally does not use any economic measurement. The state scenario comprehensively depicts gender differentials in social development, and it calls for implementing development measures more seriously in states like Haryana, Bihar, Rajasthan, Madhya Pradesh, and Uttar Pradesh to reduce the gender gap. Being highly correlated with the HDI, the LLE index proves to be a very clear and simple comprehensive measure of social development for different subpopulations.
Simple Check Valves for Microfluidic Devices
NASA Technical Reports Server (NTRS)
Willis, Peter A.; Greer, Harold F.; Smith, J. Anthony
2010-01-01
A simple design concept for check valves has been adopted for microfluidic devices that consist mostly of (1) deformable fluorocarbon polymer membranes sandwiched between (2) borosilicate float glass wafers into which channels, valve seats, and holes have been etched. The first microfluidic devices in which these check valves are intended to be used are micro-capillary electrophoresis (microCE) devices undergoing development for use on Mars in detecting compounds indicative of life. In this application, it will be necessary to store some liquid samples in reservoirs in the devices for subsequent laboratory analysis, and check valves are needed to prevent cross-contamination of the samples. The simple check-valve design concept is also applicable to other microfluidic devices and to fluidic devices in general. These check valves are simplified microscopic versions of conventional rubber- flap check valves that are parts of numerous industrial and consumer products. These check valves are fabricated, not as separate components, but as integral parts of microfluidic devices. A check valve according to this concept consists of suitably shaped portions of a deformable membrane and the two glass wafers between which the membrane is sandwiched (see figure). The valve flap is formed by making an approximately semicircular cut in the membrane. The flap is centered over a hole in the lower glass wafer, through which hole the liquid in question is intended to flow upward into a wider hole, channel, or reservoir in the upper glass wafer. The radius of the cut exceeds the radius of the hole by an amount large enough to prevent settling of the flap into the hole. As in a conventional rubber-flap check valve, back pressure in the liquid pushes the flap against the valve seat (in this case, the valve seat is the adjacent surface of the lower glass wafer), thereby forming a seal that prevents backflow.
Dynamics of prebiotic RNA reproduction illuminated by chemical game theory
Yeates, Jessica A. M.; Hilbe, Christian; Zwick, Martin; Nowak, Martin A.; Lehman, Niles
2016-01-01
Many origins-of-life scenarios depict a situation in which there are common and potentially scarce resources needed by molecules that compete for survival and reproduction. The dynamics of RNA assembly in a complex mixture of sequences is a frequency-dependent process and mimics such scenarios. By synthesizing Azoarcus ribozyme genotypes that differ in their single-nucleotide interactions with other genotypes, we can create molecules that interact among each other to reproduce. Pairwise interplays between RNAs involve both cooperation and selfishness, quantifiable in a 2 × 2 payoff matrix. We show that a simple model of differential equations based on chemical kinetics accurately predicts the outcomes of these molecular competitions using simple rate inputs into these matrices. In some cases, we find that mixtures of different RNAs reproduce much better than each RNA type alone, reflecting a molecular form of reciprocal cooperation. We also demonstrate that three RNA genotypes can stably coexist in a rock–paper–scissors analog. Our experiments suggest a new type of evolutionary game dynamics, called prelife game dynamics or chemical game dynamics. These operate without template-directed replication, illustrating how small networks of RNAs could have developed and evolved in an RNA world. PMID:27091972
Dynamics of prebiotic RNA reproduction illuminated by chemical game theory.
Yeates, Jessica A M; Hilbe, Christian; Zwick, Martin; Nowak, Martin A; Lehman, Niles
2016-05-03
Many origins-of-life scenarios depict a situation in which there are common and potentially scarce resources needed by molecules that compete for survival and reproduction. The dynamics of RNA assembly in a complex mixture of sequences is a frequency-dependent process and mimics such scenarios. By synthesizing Azoarcus ribozyme genotypes that differ in their single-nucleotide interactions with other genotypes, we can create molecules that interact among each other to reproduce. Pairwise interplays between RNAs involve both cooperation and selfishness, quantifiable in a 2 × 2 payoff matrix. We show that a simple model of differential equations based on chemical kinetics accurately predicts the outcomes of these molecular competitions using simple rate inputs into these matrices. In some cases, we find that mixtures of different RNAs reproduce much better than each RNA type alone, reflecting a molecular form of reciprocal cooperation. We also demonstrate that three RNA genotypes can stably coexist in a rock-paper-scissors analog. Our experiments suggest a new type of evolutionary game dynamics, called prelife game dynamics or chemical game dynamics. These operate without template-directed replication, illustrating how small networks of RNAs could have developed and evolved in an RNA world.
Conceptual design and integration of a space station resistojet propulsion assembly
NASA Technical Reports Server (NTRS)
Tacina, Robert R.
1987-01-01
The resistojet propulsion module is designed as a simple, long life, low risk system offering operational flexibility to the space station program. It can dispose of a wide variety of typical space station waste fluids by using them as propellants for orbital maintenance. A high temperature mode offers relatively high specific impulse with long life while a low temperature mode can propulsively dispose of mixtures that contain oxygen or hydrocarbons without reducing thruster life or generating particulates in the plume. A low duty cycle and a plume that is confined to a small aft region minimizes the impacts on the users. Simple interfaces with other space station systems facilitate integration. It is concluded that there are no major obstacles and many advantages to developing, installing, and operating a resistojet propulsion module aboard the Initial Operational Capability (IOC) space station.
Kovic, Bruno; Guyatt, Gordon; Brundage, Michael; Thabane, Lehana; Bhatnagar, Neera; Xie, Feng
2016-01-01
Introduction There is an increasing number of new oncology drugs being studied, approved and put into clinical practice based on improvement in progression-free survival, when no overall survival benefits exist. In oncology, the association between progression-free survival and health-related quality of life is currently unknown, despite its importance for patients with cancer, and the unverified assumption that longer progression-free survival indicates improved health-related quality of life. Thus far, only 1 study has investigated this association, providing insufficient evidence and inconclusive results. The objective of this study protocol is to provide increased transparency in supporting a systematic summary of the evidence bearing on this association in oncology. Methods and analysis Using the OVID platform in MEDLINE, Embase and Cochrane databases, we will conduct a systematic review of randomised controlled human trials addressing oncology issues published starting in 2000. A team of reviewers will, in pairs, independently screen and abstract data using standardised, pilot-tested forms. We will employ numerical integration to calculate mean incremental area under the curve between treatment groups in studies for health-related quality of life, along with total related error estimates, and a 95% CI around incremental area. To describe the progression-free survival to health-related quality of life association, we will construct a scatterplot for incremental health-related quality of life versus incremental progression-free survival. To estimate the association, we will use a weighted simple regression approach, comparing mean incremental health-related quality of life with either median incremental progression-free survival time or the progression-free survival HR, in the absence of overall survival benefit. Discussion Identifying direction and magnitude of association between progression-free survival and health-related quality of life is critically important in interpreting results of oncology trials. Systematic evidence produced from our study will contribute to improvement of patient care and practice of evidence-based medicine in oncology. PMID:27591026
M"Health" for Higher Education
ERIC Educational Resources Information Center
Aburas, Abdurazzag A.; Ayran, Mujgan
2013-01-01
Better education is required better advanced tools to be used for students. Smart phone becomes main part of our daily life. New medical design interface is introduced for medicine student based mobile. The Graphic User Interface must be easy and simple. The main interface design issue for mobile is simple and easy to use. Human Mobile…
ERIC Educational Resources Information Center
Maryland State Dept. of Education, Baltimore.
This booklet is intended to help adults master the basic and life skill vocabulary needed to meet the simple communication demands of daily life. It is designed to assist adult basic education (ABE) teachers in the implementation of a competency-based learning system that emphasizes the integration of basic and life skills learning. The booklet…
ERIC Educational Resources Information Center
Montessori, Mario M.
2013-01-01
This simple, first-published article by Mario Montessori was written in Kodaikanal, India, and reveals a great Montessori truth that has never been so explicit: There are developmental stages for practical life that cross over into nature study and living experiences. Although more abstract, the second plane has a strong practical life component…
75 FR 49025 - Proposed Collection; Comment Request for Form 1120-L
Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-12
... Form 1120-L, U.S. Life Insurance Company Income Tax Return. DATES: Written comments should be received....gov . SUPPLEMENTARY INFORMATION: Title: U.S. Life Insurance Company Income Tax Return. OMB Number: 1545-0128. Form Number: 1120-L. Abstract: Life insurance companies are required to file an annual...
Favorite Demonstrations: Simple "Jack-in-the-Box" Demonstrations for Physical Science Courses.
ERIC Educational Resources Information Center
Cole, Theodor C. H.
1993-01-01
The demonstrations presented in this article relate to everyday life, address interdisciplinary aspects, and have implications for the life sciences. Topics of the demonstrations are electricity calculations, astronomy, electrolysis of water, ester synthesis from butyric acid and pentanol, catalysis, and minerals. (PR)
Life Narratives as a Pedagogy for Cultivating Critical Self-Reflection.
Kelly, Bridget Turner; Bhangal, Naseeb K
2018-09-01
This chapter provides a framework for using life narratives as a powerful pedagogy to move youth from simple reflection to critical self-reflection. This increases learner agency, generates counter-narratives that challenge dominant norms, and increases learners' awareness of positionality. © 2018 Wiley Periodicals, Inc.
Wang, Shu-Yao; A, Ji-Ye; Fei, Fei; Geng, Jian-Liang; Peng, Ying; Ouyang, Bing-Chen; Wang, Pei; Jin, Xiao-Liang; Zhao, Yu-Qing; Wang, Jian-Kun; Geng, Ting; Li, Yan-Jing; Huang, Wen-Zhe; Wang, Zhen-Zhong; Xiao, Wei; Wang, Guang-Ji
2017-10-01
Ginkgo diterpene lactones meglumine injection (GDLI) is a commercially available product used for neuroprotection. However, the pharmacokinetic properties of the prototypes and hydrolyzed carboxylic forms of the primary components in GDLI, i.e., ginkgolide A (GA), ginkgolide B (GB), and ginkgolide K (GK), have never been fully evaluated in beagle dogs. In this work, a simple, sensitive, and reliable method based on ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) was developed, and the prototypes and total amounts of GA, GB, and GK were determined in beagle dog plasma. The plasma concentrations of the hydrolyzed carboxylic forms were calculated by subtracting the prototype concentrations from the total lactone concentrations. For the first time, the pharmacokinetics of GA, GB, and GK were fully assessed in three forms, i.e., the prototypes, the hydrolyzed carboxylic forms, and the total amounts, after intravenous administration of GDLI in beagle dogs. It was shown that ginkgolides primarily existed in the hydrolyzed form in plasma, and the ratio of hydrolysates to prototype forms of GA and GB decreased gradually to a homeostatic ratio. All of the three forms of the three ginkgolides showed linear exposure of AUC to the dosages. GA, GB, and GK showed a constant half-life approximately 2.7, 3.4, and 1.2 h, respectively, which were consistent for the forms at three dose levels (0.3, 1.0, and 3.0 mg·kg -1 ) and after a consecutive injection of GDLI for 7 days (1.0 mg·kg -1 ). Copyright © 2017 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.
Tajiri, Shinichiro; Kanamaru, Taro; Kamada, Makoto; Makoto, Kamada; Konno, Tsutomu; Nakagami, Hiroaki
2010-01-04
The objective of the present work is to develop an extended-release dosage form of cevimeline. Two types of extended-release tablets (simple matrix tablets and press-coated tablets) were prepared and their potential as extended-release dosage forms were assessed. Simple matrix tablets have a large amount of hydroxypropylcellulose as a rate-controlling polymer and the matrix is homogeneous throughout the tablet. The press-coated tablets consisted of a matrix core tablet, which was completely surrounded by an outer shell containing a large amount of hydroxypropylcellulose. The simple matrix tablets could not sustain the release of cevimeline effectively. In contrast, the press-coated tablets showed a slower dissolution rate compared with simple matrix tablets and the release curve was nearly linear. The dissolution of cevimeline from the press-coated tablets was not markedly affected by the pH of the dissolution medium or by a paddle rotating speed over the range of 50-200 rpm. Furthermore, cevimeline was constantly released from the press-coated tablets in the gastrointestinal tract and the steady-state plasma drug levels were maintained in beagle dogs. These results suggested that the designed PC tablets have a potential for extended-release dosage forms.
Assessing predation risk: optimal behaviour and rules of thumb.
Welton, Nicky J; McNamara, John M; Houston, Alasdair I
2003-12-01
We look at a simple model in which an animal makes behavioural decisions over time in an environment in which all parameters are known to the animal except predation risk. In the model there is a trade-off between gaining information about predation risk and anti-predator behaviour. All predator attacks lead to death for the prey, so that the prey learns about predation risk by virtue of the fact that it is still alive. We show that it is not usually optimal to behave as if the current unbiased estimate of the predation risk is its true value. We consider two different ways to model reproduction; in the first scenario the animal reproduces throughout its life until it dies, and in the second scenario expected reproductive success depends on the level of energy reserves the animal has gained by some point in time. For both of these scenarios we find results on the form of the optimal strategy and give numerical examples which compare optimal behaviour with behaviour under simple rules of thumb. The numerical examples suggest that the value of the optimal strategy over the rules of thumb is greatest when there is little current information about predation risk, learning is not too costly in terms of predation, and it is energetically advantageous to learn about predation. We find that for the model and parameters investigated, a very simple rule of thumb such as 'use the best constant control' performs well.
A simple model for indentation creep
NASA Astrophysics Data System (ADS)
Ginder, Ryan S.; Nix, William D.; Pharr, George M.
2018-03-01
A simple model for indentation creep is developed that allows one to directly convert creep parameters measured in indentation tests to those observed in uniaxial tests through simple closed-form relationships. The model is based on the expansion of a spherical cavity in a power law creeping material modified to account for indentation loading in a manner similar to that developed by Johnson for elastic-plastic indentation (Johnson, 1970). Although only approximate in nature, the simple mathematical form of the new model makes it useful for general estimation purposes or in the development of other deformation models in which a simple closed-form expression for the indentation creep rate is desirable. Comparison to a more rigorous analysis which uses finite element simulation for numerical evaluation shows that the new model predicts uniaxial creep rates within a factor of 2.5, and usually much better than this, for materials creeping with stress exponents in the range 1 ≤ n ≤ 7. The predictive capabilities of the model are evaluated by comparing it to the more rigorous analysis and several sets of experimental data in which both the indentation and uniaxial creep behavior have been measured independently.
Soft currencies, cash economies, new monies: Past and present
Guyer, Jane I.
2012-01-01
Current variation in the forms of money challenges economic anthropologists and historians to review theory and comparative findings on multiple currency systems. There are four main sections to the paper devoted to (i) the present continuum of hard to soft currencies as an instance of multiplicity, including discussion of different combinations of the classic four functions of money, especially the relationship between store of value and medium of exchange; (ii) the logic of anthropological inquiry into multiple currency economies; (iii) the case of the monies of Atlantic Africa, applying the analytics of exchange rates as conversions to African transactions; and (iv) the return to economic life in a present day Nigerian economy lived in soft currency and cash. The paper identifies five findings that suggest foci for future research. (i) The widespread occurrence of conversions, which bring together ranking principles within transactions. (ii) Several types of positional ranking ranging from simple stepwise ordinal scales to iconic ordinality that creates a parabolic curve of value. (iii) Fictional units of account that serve to mediate both the memorization of nonreductive transactions and their nature as conversions. (iv) The importance of the temporal reach of what constitutes wealth: over the short run, the life span, intergenerational succession, and in (legal) perpetuity (as for corporate and sovereign debts and specified assets). (v) The social niches in which these qualities are brought together in transactional regimes. In conclusion, the paper returns to the exchange function of cash, soft currencies, and new money forms. PMID:22308423
Origin of the Hawaiian rainforest ecosystem and its evolution in long-term primary succession
NASA Astrophysics Data System (ADS)
Mueller-Dombois, D.; Boehmer, H. J.
2013-02-01
Born among volcanoes in the north central Pacific about 4 million years ago, the Hawaiian rainforest became assembled from spores of algae, fungi, lichens, bryophytes, ferns and from seeds of about 275 flowering plants that over the millenia evolved into ca. 1000 endemic species. Outstanding among the forest builders were the tree ferns (Cibotium spp.) and the 'Ōhi'a lehua trees (Metrosideros spp.), which still dominate the Hawaiian rainforest ecosystem today. The structure of this forest is simple. The canopy in closed mature rainforests is dominated by cohorts of Metrosideros polymorpha and the undergrowth by tree fern species of Cibotium. When a new lava flow cuts through this forest, kipuka are formed, i.e. islands of remnant vegetation. On the new volcanic substrate, the assemblage of plant life-forms is similar as during the evolution of this system. In open juvenile forests, a mat-forming fern, the uluhe fern (Dicranopteris lineraris) becomes established. It inhibits further regeneration of the dominant 'Ōhi'a tree, thereby reinforcing the cohort structure of the canopy guild. In the later part of its life cycle, the canopy guild breaks down often in synchrony. The trigger is hypothesized to be a climatic perturbation. After that disturbance the forest becomes reestablished in about 30-40 yr. As the volcanic surfaces age, they go from a mesotrophic to a eutrophic phase, reaching a biophilic nutrient climax by about 1-25 K yr. Thereafter, a regressive oligotrophic phase follows; the soils become exhausted of nutrients. The shield volcanoes break down. Marginally, forest habitats change into bogs and stream ecosystems. The broader 'Ōhi'a rainforest redeveloping in the more dissected landscapes of the older islands looses stature, often forming large gaps that are invaded by the aluminum tolerant uluhe fern. The 'Ōhi'a trees still thrive on soils rejuvenated from landslides and from Asian dust on the oldest (5 million year old) island Kaua'i but their stature and living biomass is greatly diminished.
de Heering, Adélaïde; Dormal, Giulia; Pelland, Maxime; Lewis, Terri; Maurer, Daphne; Collignon, Olivier
2016-11-21
Is a short and transient period of visual deprivation early in life sufficient to induce lifelong changes in how we attend to, and integrate, simple visual and auditory information [1, 2]? This question is of crucial importance given the recent demonstration in both animals and humans that a period of blindness early in life permanently affects the brain networks dedicated to visual, auditory, and multisensory processing [1-16]. To address this issue, we compared a group of adults who had been treated for congenital bilateral cataracts during early infancy with a group of normally sighted controls on a task requiring simple detection of lateralized visual and auditory targets, presented alone or in combination. Redundancy gains obtained from the audiovisual conditions were similar between groups and surpassed the reaction time distribution predicted by Miller's race model. However, in comparison to controls, cataract-reversal patients were faster at processing simple auditory targets and showed differences in how they shifted attention across modalities. Specifically, they were faster at switching attention from visual to auditory inputs than in the reverse situation, while an opposite pattern was observed for controls. Overall, these results reveal that the absence of visual input during the first months of life does not prevent the development of audiovisual integration but enhances the salience of simple auditory inputs, leading to a different crossmodal distribution of attentional resources between auditory and visual stimuli. Copyright © 2016 Elsevier Ltd. All rights reserved.
Solar Energy in the School Curriculum: Giving New Life to Old Science.
ERIC Educational Resources Information Center
Hibbert, Oliver D.
1984-01-01
Describes some simple solar energy experiments, reviews real life examples of solar energy, and lists areas where solar energy can fit into existing school science curricula. Instructions for making equipment needed, a discussion of recent developments in thermal systems and photovoltaics, and a bibliography are included. (JN)
Promoting Simple Living in a Materialistic Society.
ERIC Educational Resources Information Center
Beck, Lawrence; And Others
The American dream is a dream filled with inexhaustible resources, boundless opportunities, and untold wealth. Fueled by the "psychology of affluence"--a social attitude that encourages us to want and expect more of everything--the dream equates quality of life with material wealth and assumes that our fulfillment in life is independent…
1968-11-01
of the existence of other highly developed life forms. To begin with, the observable universe -- that is, the distance to which we can observe luminous...been around long enough that life forms as developed as our own could exist. Implicit in further dis- cussion are the assumptions that: 1. Planets... life will exist; 3. Our own history of past evolution and development is neither slow nor fast, but average and tyoical for life forms. (Ours is the
Plant/life form considerations in the rangeland hydrology and erosion model (RHEM)
USDA-ARS?s Scientific Manuscript database
Resilience of rangeland to erosion has largely been attributed to adequate plant cover; however, plant life/growth form, and individual species presence can have a dramatic effect on hydrologic and erosion dynamics on rangelands. Plant life/growth form refers to genetic tendency of a plant to grow i...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Specht, W.L.; Klaine, S.J.; Hook, D.D.
1996-01-01
Plants form the basis of all ecosystems including wetlands. Although they are the most abundant life form and are the primary producers for all other organisms, they have received the least attention when it comes to environmental matters. Higher plants have rarely been used in ecotoxicity testing and may not respond in the same manner as algae, which have been used more frequently. The introduction of hazardous waste materials into wetland areas has the potential to alter and damage the ecological processes in these ecosystems. Measuring the impact of these contaminants on higher plants is therefore important and needs furthermore » research. Higher plants are useful for detecting both herbicidal toxicity and heavy metal toxicity. For phytotoxicity tests to be practical they must be simple, inexpensive, yet sensitive to a variety of contaminants. A difference between seed germination and root elongation tests is that seed germination tests measure toxicity associated with soils directly, while root elongation tests consider the indirect effects of water-soluble constituents that may be present in site samples.« less
Nonenzymatic gluconeogenesis-like formation of fructose 1,6-bisphosphate in ice.
Messner, Christoph B; Driscoll, Paul C; Piedrafita, Gabriel; De Volder, Michael F L; Ralser, Markus
2017-07-11
The evolutionary origins of metabolism, in particular the emergence of the sugar phosphates that constitute glycolysis, the pentose phosphate pathway, and the RNA and DNA backbone, are largely unknown. In cells, a major source of glucose and the large sugar phosphates is gluconeogenesis. This ancient anabolic pathway (re-)builds carbon bonds as cleaved in glycolysis in an aldol condensation of the unstable catabolites glyceraldehyde 3-phosphate and dihydroxyacetone phosphate, forming the much more stable fructose 1,6-bisphosphate. We here report the discovery of a nonenzymatic counterpart to this reaction. The in-ice nonenzymatic aldol addition leads to the continuous accumulation of fructose 1,6-bisphosphate in a permanently frozen solution as followed over months. Moreover, the in-ice reaction is accelerated by simple amino acids, in particular glycine and lysine. Revealing that gluconeogenesis may be of nonenzymatic origin, our results shed light on how glucose anabolism could have emerged in early life forms. Furthermore, the amino acid acceleration of a key cellular anabolic reaction may indicate a link between prebiotic chemistry and the nature of the first metabolic enzymes.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-05-02
... (Veterans Mortgage Life Insurance Inquiry); Comment Request AGENCY: Veterans Benefits Administration... maintain Veterans Mortgage Life Insurance accounts. DATES: Written comments and recommendations on the... use of other forms of information technology. Title: Veterans Mortgage Life Insurance Inquiry, VA Form...
The action uncertainty principle and quantum gravity
NASA Astrophysics Data System (ADS)
Mensky, Michael B.
1992-02-01
Results of the path-integral approach to the quantum theory of continuous measurements have been formulated in a preceding paper in the form of an inequality of the type of the uncertainty principle. The new inequality was called the action uncertainty principle, AUP. It was shown that the AUP allows one to find in a simple what outputs of the continuous measurements will occur with high probability. Here a more simple form of the AUP will be formulated, δ S≳ħ. When applied to quantum gravity, it leads in a very simple way to the Rosenfeld inequality for measurability of the average curvature.
Structure and functions of simple membrane-water interfaces. [Abstract only
NASA Technical Reports Server (NTRS)
Pohorille, A.; Wilson, M. A.
1994-01-01
The structure and functions of the earliest ancestors of contemporary cells are focal points in studies of the origin of life. Probably the first cell-like structures were vesicles - closed, spheroidal structures with aqueous medium trapped inside. The membranous walls of vesicles were most likely bilayers composed of simple amphiphilic material available on early earth. The membrane studied was composed of glycerol 1-monooleate (GMO). Glycerol forms the polar head group and the oily tail contains 18 carbon atoms. All head groups have been found to be located in two narrow regions at the interfaces with water. The membrane interior, formed by the hydrophobic tails, is quite fluid with chain disorder increasing towards the center of the bilayer. These results are in agreement with x-ray and neutron scattering data from related bilayers. The width of the membrane is not constant, but fluctuates in time and space. Occasional thinning defects in the membrane, observed during the course of the simulations, may have a significant influence on rates of passive transport of small molecules across membranes. It has been found that water penetrates the head group region but not the oily interior of the membrane. Water molecules near the interface are oriented by dipoles of the head groups. The resulting electrostatic potential across the interface, determined in our simulations, has been found to be markedly larger than across the water-oil interface. This quantity has been implicated as the source of selectivity, with respect to the sign of the charge, as an ion approaches the interface and during transport of hydrophobic ions across membranes.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-12
... of Lapse--Government Life Insurance); Comment Request AGENCY: Veterans Benefits Administration... determine claimants' eligibility to reinstate lapsed Government Life Insurance policy. DATES: Written.... Notice of Lapse--Government Life Insurance, VA Form 29-389. b. Application for Reinstatement, VA Form 29...
A novel method of the image processing on irregular triangular meshes
NASA Astrophysics Data System (ADS)
Vishnyakov, Sergey; Pekhterev, Vitaliy; Sokolova, Elizaveta
2018-04-01
The paper describes a novel method of the image processing based on irregular triangular meshes implementation. The triangular mesh is adaptive to the image content, least mean square linear approximation is proposed for the basic interpolation within the triangle. It is proposed to use triangular numbers to simplify using of the local (barycentric) coordinates for the further analysis - triangular element of the initial irregular mesh is to be represented through the set of the four equilateral triangles. This allows to use fast and simple pixels indexing in local coordinates, e.g. "for" or "while" loops for access to the pixels. Moreover, representation proposed allows to use discrete cosine transform of the simple "rectangular" symmetric form without additional pixels reordering (as it is used for shape-adaptive DCT forms). Furthermore, this approach leads to the simple form of the wavelet transform on triangular mesh. The results of the method application are presented. It is shown that advantage of the method proposed is a combination of the flexibility of the image-adaptive irregular meshes with the simple form of the pixel indexing in local triangular coordinates and the using of the common forms of the discrete transforms for triangular meshes. Method described is proposed for the image compression, pattern recognition, image quality improvement, image search and indexing. It also may be used as a part of video coding (intra-frame or inter-frame coding, motion detection).
Organic chloramines in drinking water: An assessment of formation, stability, reactivity and risk.
How, Zuo Tong; Linge, Kathryn L; Busetti, Francesco; Joll, Cynthia A
2016-04-15
Although organic chloramines are known to form during the disinfection of drinking water with chlorine, little information is currently available on their occurrence or toxicity. In a recent in vitro study, some organic chloramines (e.g. N-chloroglycine) were found to be cytotoxic and genotoxic even at micromolar concentrations. In this paper, the formation and stability of 21 different organic chloramines, from chlorination of simple amines and amino acids, were studied, and the competition between 20 amino acids during chlorination was also investigated. For comparison, chlorination of two amides was also conducted. The formation and degradation of selected organic chloramines were measured using either direct UV spectroscopic or colorimetric detection. Although cysteine, methionine and tryptophan were the most reactive amino acids towards chlorination, they did not form organic chloramines at the chlorine to precursor molar ratios that were tested. Only 6 out of the 21 organic chloramines formed had a half-life of more than 3 h, although this group included all organic chloramines formed from amines. A health risk assessment relating stability and reactivity data from this study to toxicity and precursor abundance data from the literature indicated that only N-chloroglycine is likely to be of concern due to its stability, toxicity and abundance in water. However, given the stability of organic chloramines formed from amines, more information about the toxicity and precursor abundance for these chloramines is desirable. Copyright © 2016 Elsevier Ltd. All rights reserved.
The embryologic development of the human external auditory meatus. Preliminary report.
Nishimura, Y; Kumoi, T
1992-01-01
During the final period of embryogenesis, a funnel-shaped tube continues medially into the mesenchymal tissue forming a curved path. Although this may sound simple, the development occurring during early fetal life is in fact very complex. At first, ectodermal cells proliferate to fill the lumen of the meatus, forming the meatal plug, and then at 10 weeks the bottom of the plug extends in a disc-like fashion, so that in the horizontal plane the meatus is boot-shaped with a narrow neck and the sole of the meatal plug spreading widely to form the future tympanic membrane medially. At the same time, the plug in the proximal portion of the neck starts to be resorbed. In the 13-week fetus, the disc-like plug begins to show signs of its final destiny; the innermost surface of the plug in contact with the anlage of the malleus is ready to contribute to the formation of the tympanic membrane. In the 15-week fetus, the innermost portion of the disc-like plug splits, leaving a thin ectodermal cell layer of immature tympanic membrane. The neck of the boot forms the border between the primary and secondary meatus, and is the last part to split. In the 16.5-week fetus, the meatus is fully patent throughout its entire length, although the lumen is still narrow and curved. In the 18-week fetus, the meatus is already fully expanded to its complete form.
Life-history traits predict perennial species response to fire in a desert ecosystem
Shryock, Daniel F; DeFalco, Lesley A; Esque, Todd C
2014-01-01
The Mojave Desert of North America has become fire-prone in recent decades due to invasive annual grasses that fuel wildfires following years of high rainfall. Perennial species are poorly adapted to fire in this system, and post-fire shifts in species composition have been substantial but variable across community types. To generalize across a range of conditions, we investigated whether simple life-history traits could predict how species responded to fire. Further, we classified species into plant functional types (PFTs) based on combinations of life-history traits and evaluated whether these groups exhibited a consistent fire-response. Six life-history traits varied significantly between burned and unburned areas in short (up to 4 years) or long-term (up to 52 years) post-fire datasets, including growth form, lifespan, seed size, seed dispersal, height, and leaf longevity. Forbs and grasses consistently increased in abundance after fire, while cacti were reduced and woody species exhibited a variable response. Woody species were classified into three PFTs based on combinations of life-history traits. Species in Group 1 increased in abundance after fire and were characterized by short lifespans, small, wind-dispersed seeds, low height, and deciduous leaves. Species in Group 2 were reduced by fire and distinguished from Group 1 by longer lifespans and evergreen leaves. Group 3 species, which also decreased after fire, were characterized by long lifespans, large non-wind dispersed seeds, and taller heights. Our results show that PFTs based on life-history traits can reliably predict the responses of most species to fire in the Mojave Desert. Dominant, long-lived species of this region possess a combination of traits limiting their ability to recover, presenting a clear example of how a novel disturbance regime may shift selective environmental pressures to favor alternative life-history strategies. PMID:25247062
Historical Development of Origins Research
Lazcano, Antonio
2010-01-01
Following the publication of the Origin of Species in 1859, many naturalists adopted the idea that living organisms were the historical outcome of gradual transformation of lifeless matter. These views soon merged with the developments of biochemistry and cell biology and led to proposals in which the origin of protoplasm was equated with the origin of life. The heterotrophic origin of life proposed by Oparin and Haldane in the 1920s was part of this tradition, which Oparin enriched by transforming the discussion of the emergence of the first cells into a workable multidisciplinary research program. On the other hand, the scientific trend toward understanding biological phenomena at the molecular level led authors like Troland, Muller, and others to propose that single molecules or viruses represented primordial living systems. The contrast between these opposing views on the origin of life represents not only contrasting views of the nature of life itself, but also major ideological discussions that reached a surprising intensity in the years following Stanley Miller’s seminal result which showed the ease with which organic compounds of biochemical significance could be synthesized under putative primitive conditions. In fact, during the years following the Miller experiment, attempts to understand the origin of life were strongly influenced by research on DNA replication and protein biosynthesis, and, in socio-political terms, by the atmosphere created by Cold War tensions. The catalytic versatility of RNA molecules clearly merits a critical reappraisal of Muller’s viewpoint. However, the discovery of ribozymes does not imply that autocatalytic nucleic acid molecules ready to be used as primordial genes were floating in the primitive oceans, or that the RNA world emerged completely assembled from simple precursors present in the prebiotic soup. The evidence supporting the presence of a wide range of organic molecules on the primitive Earth, including membrane-forming compounds, suggests that the evolution of membrane-bounded molecular systems preceded cellular life on our planet, and that life is the evolutionary outcome of a process, not of a single, fortuitous event. PMID:20534710
Delayed massive hemothorax complicating simple rib fracture associated with diaphragmatic injury.
Chen, Chin-Li; Cheng, Yeung-Leung
2014-07-01
Traumatic hemothorax is potentially life threatening. Rib fractures are the commonest injury after chest trauma, which accounts for 10% of patients after trauma. A delayed massive hemothorax after simple rib fracture is rare. The possibility of delayed sequelae after chest trauma should be considered, and patients should be informed of this possibility. We present a case of this uncommon situation with delayed massive hemothorax caused by simple fracture of the lower ribs. Admission should be considered for close observation when presenting with fracture of the lower ribs because of the possibility of diaphragmatic injury or intra-abdominal injury, even if a simple rib fracture is found initially.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-13
... for Disability Insurance Benefits, Government Life Insurance) Activity: Comment Request. AGENCY... for Disability Insurance Benefits, Government Life Insurance, VA Form 29-357. OMB Control Number: 2900... VA Form 29-357 to file a claim for disability insurance on National Service Life Insurance and United...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-29
... Request; International Client Life-Cycle Multi-Purpose Forms AGENCY: International Trade Administration... aspects of an international organization's life-cycle with CS. CS is mandated by Congress to help U.S... trade events to U.S. organizations. The International Client Life-cycle Multi-Purpose Forms, previously...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-11-18
... for Disability Insurance Benefits, Government Life Insurance) Activity Under OMB Review AGENCY... INFORMATION: Title: Claim for Disability Insurance Benefits, Government Life Insurance, VA Form 29-357. OMB...: Policyholders complete VA Form 29-357 to file a claim for disability insurance on National Service Life...
Tsai, William; Lu, Qian
2017-10-01
Ambivalence over emotional expression (AEE) is the inner conflict of desiring emotion expression and fearing consequence of emotion expression. Few studies to date have examined the effects of AEE within an ethnic group that prioritizes emotional self-control. The present study examined the associations between AEE and well-being (viz., quality of life and depressive symptoms) as a function of acculturation among a sample of Chinese American breast cancer survivors. Ninety-six Chinese breast cancer survivors (M age = 54.64 years old, SD = 7.98) were recruited from Southern California. Participants filled out a paper-pen questionnaire containing the Ambivalence over Emotional Expression Questionnaire (AEQ), the Functional Assessment of Cancer Therapy-Breast (FACT-B), and the Center for Epidemiologic Studies Depression Scale-Short Form (CESD-10). Acculturation was a statistically significant moderator of the relations between AEE and depressive symptoms, and a statistically marginally significant moderator of the relations between AEE and quality of life. Simple slopes revealed that AEE was negatively associated with quality of life (B = -.45, p < .001) and depressive symptoms (B = .20, p < .001) for women with high acculturation, but not associated for women with low acculturation (Bs = -.15 and .04, ps > .05, for quality of life and depressive symptoms, respectively). These results suggest that less acculturated Chinese breast cancer survivors are protected by Chinese cultural values of emotional self-control and restraint, and thus do not experience the detrimental effects of AEE on their depressive symptoms and quality of life. Implications are discussed.
Natural Organohalogens: A New Frontier for Medicinal Agents?
NASA Astrophysics Data System (ADS)
Gribble, Gordon W.
2004-10-01
More than 4000 naturally occurring organohalogen compounds are known. These include a relatively small number of abiogenic organohalogens from volcanoes, forest fires, geothermal processes, and meteorites, and a very large number of biogenic organohalogens produced by myriad living organisms as part of their chemical makeup that serve as hormones, pheromones, repellents, and natural pesticides. From the chemically simple methyl chloride, methyl bromide, and chloroform to the structurally complex vancomycin, pyrroindomycin, and bastadins, the diversity of these organohalogens is unsurpassed among natural products. Most natural organohalogens contain chlorine (2300) or bromine (2100), but a significant number contain iodine (120) or fluorine (30). Several hundred marine natural products contain both chlorine and bromine. The present article focuses on newly discovered biogenic organohalogens, with an emphasis on those biologically active examples from marine organisms, bacteria, terrestrial plants, and higher life forms including humans.
Primordial soup was edible: abiotically produced Miller-Urey mixture supports bacterial growth.
Xie, Xueshu; Backman, Daniel; Lebedev, Albert T; Artaev, Viatcheslav B; Jiang, Liying; Ilag, Leopold L; Zubarev, Roman A
2015-09-28
Sixty years after the seminal Miller-Urey experiment that abiotically produced a mixture of racemized amino acids, we provide a definite proof that this primordial soup, when properly cooked, was edible for primitive organisms. Direct admixture of even small amounts of Miller-Urey mixture strongly inhibits E. coli bacteria growth due to the toxicity of abundant components, such as cyanides. However, these toxic compounds are both volatile and extremely reactive, while bacteria are highly capable of adaptation. Consequently, after bacterial adaptation to a mixture of the two most abundant abiotic amino acids, glycine and racemized alanine, dried and reconstituted MU soup was found to support bacterial growth and even accelerate it compared to a simple mixture of the two amino acids. Therefore, primordial Miller-Urey soup was perfectly suitable as a growth media for early life forms.
Does arthroscopic rotator cuff repair improve patients' activity levels?
Baumgarten, Keith M; Chang, Peter S; Dannenbring, Tasha M; Foley, Elaine K
2018-06-04
Rotator cuff repair decreases pain, improves range of motion, and increases strength. Whether these improvements translate to an improvement in a patient's activity level postoperatively remains unknown. The Shoulder Activity Level is a valid and reliable outcomes survey that can be used to measure a patient's shoulder-specific activity level. Currently, there are no studies that examine the effect of rotator cuff repair on shoulder activity level. Preoperative patient-determined outcomes scores collected prospectively on patients undergoing rotator cuff repair were compared with postoperative scores at a minimum of 2 years. These scores included the Shoulder Activity Level, Western Ontario Rotator Cuff Index, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, Single Assessment Numeric Evaluation, and simple shoulder test. Inclusion criteria were patients undergoing arthroscopic rotator cuff repair. Included were 281 shoulders from 273 patients with a mean follow-up of 3.7 years. The postoperative median Western Ontario Rotator Cuff Index (42 vs. 94), American Shoulder and Elbow Surgeons (41 vs. 95), Single Assessment Numeric Evaluation (30 vs. 95), and simple shoulder test (4 vs. 11) scores were statistically significantly improved compared with preoperative scores (P < .0001). The postoperative median Shoulder Activity Level score decreased compared with the preoperative score (12 vs. 11; P < .0001). Patients reported a statistically significant deterioration of their Shoulder Activity Level score after rotator cuff repair compared with their preoperative scores, although disease-specific and joint-specific quality of life scores all had statistically significantly improvement. This study suggests that patients generally have (1) significant improvements in their quality of life and (2) small deteriorations in activity level after arthroscopic rotator cuff repair. Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.
The RNA World: Life Before DNA and Protein
NASA Technical Reports Server (NTRS)
Joyce, Gerald F.
1993-01-01
All of the life that is known, all organisms that exist on Earth today or are known to have existed on Earth in the past, are of the same life form: a life form based on DNA and protein. It does not necessarily have to be that way. Why not have two competing life forms on this planet? Why not have biology as we know it and some other biology that occupies its own distinct niche? Yet that is not how evolution has played out. From microbes living on the surface of antarctic ice to tube worms lying near the deep-sea hydrothermal vents, all known organisms on this planet are of the same biology. Looking at the single known biology on Earth, it is clear that this biology could not have simply sprung forth from the primordial soup. The biological system that is the basis for all known. life is far too complicated to have arisen spontaneously. This brings us to the notion that something else something simpler, must have preceded life based on DNA and protein. One suggestion that has gained considerable acceptance over the past decade is that DNA and protein-based life was preceded by RNA-based life in a period referred to as the 'RNA world'. Even an RNA-based life form would have been fairly complicated - not as complicated as our own DNA- and protein-based life form - but far too complicated, according to prevailing scientific thinking, to have arisen spontaneously from the primordial soup. Thus, it has been argued that something else must have preceded RNA-based life, or even that there was a succession of life forms leading from the primordial soup to RNA-based life. The experimental evidence to support this conjecture is not strong because, after all, the origin of life was a historical event that left no direct physical record. However, based on indirect evidence in both the geological record and the phylogenetic record of evolutionary history on earth, it is possible to reconstruct a rough picture of what life was like before DNA and protein.
NASA Technical Reports Server (NTRS)
1972-01-01
A long life assurance program for the development of design, process, test, and application guidelines for achieving reliable spacecraft hardware was conducted. The study approach consisted of a review of technical data performed concurrently with a survey of the aerospace industry. The data reviewed included design and operating characteristics, failure histories and solutions, and similar documents. The topics covered by the guidelines are reported. It is concluded that long life hardware is achieved through meticulous attention to many details and no simple set of rules can suffice.
Life and the laundromat: reflections on dirty linen and everyday private life.
Lawler, J
1997-09-01
This is a paper in which I reflect on, and draw issues from, an unplanned ethnographic experience in a London laundromat. The concept of 'everyday life' has a kind of simple, even benign, quality. However, there are many events in everyday life that are complex and complicating. Everyday life can be mundane--boring even. But it can also confront and trouble us, even when it concerns such apparently ordinary matters like doing the laundry. This paper is about how the ordinary matters of everyday life can become problematic and how our involvement in them can confront us with dilemmas that are unwanted yet require our attention and judgement as participants in social life.
Schreiber, Ulrich; Mayer, Christian; Schmitz, Oliver J; Rosendahl, Pia; Bronja, Amela; Greule, Markus; Keppler, Frank; Mulder, Ines; Sattler, Tobias; Schöler, Heinz F
2017-01-01
The origin of life is still an unsolved mystery in science. Hypothetically, prebiotic chemistry and the formation of protocells may have evolved in the hydrothermal environment of tectonic fault zones in the upper continental crust, an environment where sensitive molecules are protected against degradation induced e.g. by UV radiation. The composition of fluid inclusions in minerals such as quartz crystals which have grown in this environment during the Archean period might provide important information about the first organic molecules formed by hydrothermal synthesis. Here we present evidence for organic compounds which were preserved in fluid inclusions of Archean quartz minerals from Western Australia. We found a variety of organic compounds such as alkanes, halocarbons, alcohols and aldehydes which unambiguously show that simple and even more complex prebiotic organic molecules have been formed by hydrothermal processes. Stable-isotope analysis confirms that the methane found in the inclusions has most likely been formed from abiotic sources by hydrothermal chemistry. Obviously, the liquid phase in the continental Archean crust provided an interesting choice of functional organic molecules. We conclude that organic substances such as these could have made an important contribution to prebiotic chemistry which might eventually have led to the formation of living cells.
ERIC Educational Resources Information Center
Braude, Stan
2007-01-01
In this article, the author describes a short activity which introduces third- to fifth-grade students to animal classification. The Tree of Animal Life activity is a simple, sorting exercise that can help them see a bigger picture. The activity sets the stage for learning about animal taxonomy and introduces the characteristics of various animal…
Big History or the 13800 million years from the Big Bang to the Human Brain
NASA Astrophysics Data System (ADS)
Gústafsson, Ludvik E.
2017-04-01
Big History is the integrated history of the Cosmos, Earth, Life, and Humanity. It is an attempt to understand our existence as a continuous unfolding of processes leading to ever more complex structures. Three major steps in the development of the Universe can be distinguished, the first being the creation of matter/energy and forces in the context of an expanding universe, while the second and third steps were reached when completely new qualities of matter came into existence. 1. Matter comes out of nothing Quantum fluctuations and the inflation event are thought to be responsible for the creation of stable matter particles in what is called the Big Bang. Along with simple particles the universe is formed. Later larger particles like atoms and the most simple chemical elements hydrogen and helium evolved. Gravitational contraction of hydrogen and helium formed the first stars und later on the first galaxies. Massive stars ended their lives in violent explosions releasing heavier elements like carbon, oxygen, nitrogen, sulfur and iron into the universe. Subsequent star formation led to star systems with bodies containing these heavier elements. 2. Matter starts to live About 9200 million years after the Big Bang a rather inconspicous star of middle size formed in one of a billion galaxies. The leftovers of the star formation clumped into bodies rotating around the central star. In some of them elements like silicon, oxygen, iron and many other became the dominant matter. On the third of these bodies from the central star much of the surface was covered with an already very common chemical compound in the universe, water. Fluid water and plenty of various elements, especially carbon, were the ingredients of very complex chemical compounds that made up even more complex structures. These were able to replicate themselves. Life had appeared, the only occasion that we human beings know of. Life evolved subsequently leading eventually to the formation of multicellular structures like plants, animals and fungi. 3. Matter starts to think A comet or an asteroid crashed into Earth about 66 million years ago, ending the dominance of dinosaurs. Small animals giving birth to living offspring were now able to evolve into a multitude of species, among them the primates. A group of primates migrated from Africa to other continents less than 100000 years ago. Their brain developed a special quality, self-conscience. This ability to reflect about oneself boosted their survival considerably. Man (Homo sapiens) had entered the scene, becoming one of the dominant species of this planet. Due to his immense ability today to handle matter and energy he has become something of a caretaker of planet Earth. Man is responsible for sustainable development for the good of his society and of the whole biosphere. If there is a fourth step in the history of the universe, discoveries in astrobiology may provide us with some clues in the next decades.
Sundseth, J; Kolstad, F; Johnsen, L G; Pripp, A H; Nygaard, O P; Andresen, H; Fredriksli, O A; Myrseth, E; Züchner, M; Zwart, J A
2015-10-01
The Neck Disability Index (NDI) is widely used as a self-rated disability score in patients with cervical radiculopathy. The purpose of this study was to evaluate whether the NDI score correlated with other assessments of quality of life and mental health in a specific group of patients with single-level cervical disc disease and corresponding radiculopathy. One hundred thirty-six patients were included in a prospective, randomized controlled clinical multicenter study on one-level anterior cervical discectomy with arthroplasty (ACDA) versus one-level anterior cervical discectomy with fusion (ACDF). The preoperative data were obtained at hospital admission 1 to 3 days prior to surgery. The NDI score was used as the dependent variable and correlation as well as regression analyses were conducted to assess the relationship with the short form-36, EuroQol-5Dimension-3 level and Hospital Anxiety and Depression Scale. The mean age at inclusion was 44.1 years (SD ±7.0, range 26-59 years), of which 46.3 % were male. Mean NDI score was 48.6 (SD = 12.3, minimum 30 and maximum 88). Simple linear regression analysis demonstrated a significant correlation between NDI and the EuroQol-5Dimension-3 level [R = -0.64, 95 % confidence interval (CI) -30.1- -19.8, p < 0.001] and to a lesser extent between NDI and the short form-36 physical component summary [R = -0.49, 95 % CI (-1.10- -0.58), p < 0.001] and the short form-36 mental component summary [R = -0.25, 95 % CI (-0.47- -0-09), p = 0.004]. Regarding NDI and the Hospital Anxiety and Depression Scale, a significant correlation for depression was found [R = 0.26, 95 % CI (0.21-1.73), p = 0.01]. Multiple linear regression analysis showed a statistically significant and the strongest correlation between NDI and the independent variables in the following order: EuroQol-5Dimension-3 level [R = -0.64, 95 % CI (-23.5- -7.9), p <0.001], short form-36 physical component summary [R = -0.41, 95 % CI (-0.93- -0.23), p = 0.001] and short form-36 mental component summary [R = -0.36, 95 % CI (-0.53- -0.15), p = 0.001]. The results from the present study show that the NDI correlated significantly with a different quality of life and mental health measures among patients with single-level cervical disc disease and corresponding radiculopathy.
NASA Technical Reports Server (NTRS)
Sankararaman, Shankar; Goebel, Kai
2013-01-01
This paper investigates the use of the inverse first-order reliability method (inverse- FORM) to quantify the uncertainty in the remaining useful life (RUL) of aerospace components. The prediction of remaining useful life is an integral part of system health prognosis, and directly helps in online health monitoring and decision-making. However, the prediction of remaining useful life is affected by several sources of uncertainty, and therefore it is necessary to quantify the uncertainty in the remaining useful life prediction. While system parameter uncertainty and physical variability can be easily included in inverse-FORM, this paper extends the methodology to include: (1) future loading uncertainty, (2) process noise; and (3) uncertainty in the state estimate. The inverse-FORM method has been used in this paper to (1) quickly obtain probability bounds on the remaining useful life prediction; and (2) calculate the entire probability distribution of remaining useful life prediction, and the results are verified against Monte Carlo sampling. The proposed methodology is illustrated using a numerical example.
Material Development and Meeting Learner's Need
ERIC Educational Resources Information Center
Aydin, Abdullah
2013-01-01
In this study, the aim was to show that learners' needs can be met using simple and cheap materials that can be found everywhere in 9th to 11th grade Chemistry courses. To this end, materials were developed using simple everyday life materials for 9th to 11th grade Chemistry courses. In the research, the project method was employed. The study was…
Reproductive efficiency and shade avoidance plasticity under simulated competition.
Fazlioglu, Fatih; Al-Namazi, Ali; Bonser, Stephen P
2016-07-01
Plant strategy and life-history theories make different predictions about reproductive efficiency under competition. While strategy theory suggests under intense competition iteroparous perennial plants delay reproduction and semelparous annuals reproduce quickly, life-history theory predicts both annual and perennial plants increase resource allocation to reproduction under intense competition. We tested (1) how simulated competition influences reproductive efficiency and competitive ability (CA) of different plant life histories and growth forms; (2) whether life history or growth form is associated with CA; (3) whether shade avoidance plasticity is connected to reproductive efficiency under simulated competition. We examined plastic responses of 11 herbaceous species representing different life histories and growth forms to simulated competition (spectral shade). We found that both annual and perennial plants invested more to reproduction under simulated competition in accordance with life-history theory predictions. There was no significant difference between competitive abilities of different life histories, but across growth forms, erect species expressed greater CA (in terms of leaf number) than other growth forms. We also found that shade avoidance plasticity can increase the reproductive efficiency by capitalizing on the early life resource acquisition and conversion of these resources into reproduction. Therefore, we suggest that a reassessment of the interpretation of shade avoidance plasticity is necessary by revealing its role in reproduction, not only in competition of plants.
Foundations of Swarm Intelligence: From Principles to Practice
2003-01-01
through the use of chemical substances known as pheromones which have a scent that decays over time through the process of evaporation [6, p. 26...These pheromones form the basis of what amounts to a clever, and apparently simple, communications and information storage and retrieval system. Since... pheromone strength or intensity decays over time, it also provides a very simple information processing mechanism that can implement forms of positive
A Simple Demonstration of Atomic and Molecular Orbitals Using Circular Magnets
ERIC Educational Resources Information Center
Chakraborty, Maharudra; Mukhopadhyay, Subrata; Das, Ranendu Sekhar
2014-01-01
A quite simple and inexpensive technique is described here to represent the approximate shapes of atomic orbitals and the molecular orbitals formed by them following the principles of the linear combination of atomic orbitals (LCAO) method. Molecular orbitals of a few simple molecules can also be pictorially represented. Instructors can employ the…
Interpretation of styles of simple stations in Korea
NASA Astrophysics Data System (ADS)
Hwang, Minhye; Shin, Yekyeong
2018-06-01
The purpose of this paper is to apply stylistic interpretation through the exterior of simple stations in Korea. Simple Station is a kind of railway stations. It was installed when there were not a lot of passengers and it was not necessary to operate the station at a high cost. It has minimal functions such as a waiting room, an office, an operating room, and toilets and was built between the 1910s and the 1960s. The form of the building is as simple as the name of "Simple Station". That is why the reading its style is easy and obvious. But it is also difficult to interpret because of the lack of stylistic evidences. Nevertheless, in the relationship between the station and the station tree, the concept of the Picturesque and Palladian Style are found. But it is still hard to distinguish whether the whole building style is Western or Japanese. Simple Station is one of the things that Japan has built as Western Culture in Korea during the Japanese colonial era, so it is natural that its style of form is complex.
Determinants of impaired quality of life in patients with fibrous dysplasia.
Majoor, Bas C J; Andela, Cornelie D; Bruggemann, Jens; van de Sande, Michiel A J; Kaptein, Ad A; Hamdy, Neveen A T; Dijkstra, P D Sander; Appelman-Dijkstra, Natasha M
2017-04-27
Fibrous dysplasia is a rare bone disorder, commonly associated with pain, deformity and fractures, which may significantly impact on quality of life. In this study we evaluate quality of life in patients with fibrous dysplasia using the Short Form-36 and the Brief Pain Inventory questionnaires. Data were compared with those of the general Dutch population. Out of 138 patients from a cohort of 255 patients with fibrous dysplasia that were sent questionnaires assessing quality of life and pain, the response rate was 70.3%, with 97 patients, predominantly female (65%), completing the questionnaires. Monostotic fibrous dysplasia was predominant (n = 62, 64%). Fibrous dysplasia patients had significantly lower quality of life outcome scores than the general Dutch population for all tested domains of the Short Form-36 except for the "Mental health" and the "Role emotional" domains. More severe forms of fibrous dysplasia, had the more severe Short-Form-36 quality of life outcomes, but there was no significant difference in Brief Pain Inventory domains between different subtypes of fibrous dysplasia. Quality of life was lower in patients with higher disease burden, as reflected by high skeletal burden scores (p = 0.003) and high levels of P1NP (p = 0.002). We demonstrate impairments in all domains of quality of life, except for 'Mental health' and 'Role emotional' domains, across the wide spectrum of fibrous dysplasia including its milder forms. We identified high skeletal burden scores, reflecting disease severity, as the most consistent predictor of impaired quality of life. Our findings hold significant clinical implications as they draw attention to the clinically unmet need to address quality of life issues in the management of patients with all subtypes of fibrous dysplasia, including its milder forms.
Multifunctional enzymes from reduced genomes - model proteins for simple primordial metabolism?
Seelig, Burckhard
2017-08-01
Billions of years of evolution have yielded today's complex metabolic networks driven by efficient and highly specialized enzymes. In contrast, the metabolism of the earliest cellular life forms was likely much simpler with only a few enzymes of comparatively low activity. It has been speculated that these early enzymes had low specificities and in turn were able to perform multiple functions. In this issue of Molecular Microbiology, Ferla et al. describe examples of enzymes that catalyze chemically distinct reactions while using the same active site. Most importantly, the authors demonstrated that the comparatively weak activities of these multifunctional enzymes are each physiologically relevant. These findings contrast with simply promiscuous enzyme activities, which have been described numerous times but are not physiologically relevant. Ferla et al. elegantly combined initial bioinformatics searches for enzyme candidates with sound kinetic measurements, evolutionary considerations and even structural discussions. The phenomenon of multifunctionality appears to be a mechanism for bacteria with reduced genomes to compensate for their lack of certain enzymes. In the broader context of evolution, these organisms could be considered living model systems to study features of long-extinct early cellular life. © 2017 John Wiley & Sons Ltd.
Use of edible films and coatings to extend the shelf life of food products.
Maftoonazad, Neda; Badii, Fojan
2009-06-01
The increased consumer demand for high quality, extended shelf life, ready to eat foods has initiated the development of several innovative techniques to keep their natural and fresh appearance as long as possible and at the same time render them safe. Packaging has been an important element in these preservation concepts for providing the appropriate (mechanical and functional) protection to the commodity. Since synthetic packaging materials contribute to the environmental pollution, edible coatings and packages have been proposed to replace or complement conventional packaging. Biodegradable and edible films and coatings are made from naturally occurring polymers and functional ingredients, and formed on the surface of food products. Edible films and coating have long been known to protect perishable food products from deterioration and reduce quality loss. These films should have acceptable sensory characteristics, appropriate barrier properties (CO(2), O(2), water, oil), microbial, biochemical and physicochemical stability, they should be safe, and be produced by simple technology in low cost. Also they can act as effective carrier for antioxidant, flavor, color, nutritional or anti-microbial additives. Patents on edible films and food products are also discussed in this article.
Study of flywheel energy storage for space stations
NASA Technical Reports Server (NTRS)
Gross, S.
1984-01-01
The potential of flywheel systems for space stations using the Space Operations Center (SOC) as a point of reference is discussed. Comparisons with batteries and regenerative fuel cells are made. In the flywheel energy storage concept, energy is stored in the form of rotational kinetic energy using a spinning wheel. Energy is extracted from the flywheel using an attached electrical generator; energy is provided to spin the flywheel by a motor, which operates during sunlight using solar array power. The motor and the generator may or may not be the same device. Flywheel energy storage systems have a very good potential for use in space stations. This system can be superior to alkaline secondary batteries and regenerable fuel cells in most of the areas that are important in spacecraft applications. Of special impotance relative to batteries, are high energy density (lighter weight), longer cycle and operating life, and high efficiency which minimizes the amount of orbital makeup fuel required. In addition, flywheel systems have a long shelf life, give a precise state of charge indication, have modest thermal control needs, are capable of multiple discharges per orbit, have simple ground handling needs, and have the potential for very high discharge rate. Major disadvantages are noted.
Bektas, Murat; Akdeniz Kudubes, Aslı; Ugur, Ozlem; Vergin, Canan; Demirag, Bengü
2016-06-01
This study aimed to develop the Scale for Quality of Life in Pediatric Oncology Patients Aged 13-18: Adolescent Form and Parent Form. We used the child and parent information form, Visual Quality of Life Scale, and our own scale, the Scale for Quality of Life in Pediatric Oncology Patients Aged 13-18: Adolescent Form and Parent Form. We finalized the 35-item scale to determine the items, received opinions from 14 specialists on the scale, and pilot-tested the scale in 25 children and their parents. We used Pearson correlation analysis, Cronbach α coefficient, factor analysis and receiver operating characteristics analysis to analyze the data. The total Cronbach α of the parent form was .97, the total factor load was .60-.97 and the total variance was 80.4%. The cutoff point of the parent form was 85.50. The total Cronbach α of the adolescent form was .98, the total factor load was .62-.96, and the total variance explained was 83.4%. The cutoff point of the adolescent form was 75.50. As a result of the parent form factor analysis, we determined the Kaiser-Meyer-Olkin coefficient as .83, the Barlett test χ(2) as 12,615.92; the factor coefficients of all items of the parent form ranged from .63 to .98. The factor coefficients of all items of the adolescent form ranged from .34 to .99. As a result of the adolescent form factor analysis, we determined the KMO as .79, and the Barlett test χ(2) as 13,970.62. Conclusively, we found that the adolescent form and the parent form were valid and reliable in assessing the children's quality of life. Copyright © 2016. Published by Elsevier B.V.
Towards an autopoietic redefinition of life.
Damiano, Luisa; Luisi, Pier Luigi
2010-04-01
In this paper we develop the autopoietic approach to the definition of the living developed by Maturana and Varela in the Seventies. Starting from very simple observations concerning the phenomenology of life, we propose a reformulation of the autopoietic original definition of life which integrates some of the contemporary criticism to it. Our definitional proposal, aiming to stimulate the further development of the autopoietic approach, expresses what remains implicit in the definition of the living originally given by Maturana and Varela: life, as self-production, is a process of cognitive coupling with the environment.
Simple method for experimentally testing any form of quantum contextuality
NASA Astrophysics Data System (ADS)
Cabello, Adán
2016-03-01
Contextuality provides a unifying paradigm for nonclassical aspects of quantum probabilities and resources of quantum information. Unfortunately, most forms of quantum contextuality remain experimentally unexplored due to the difficulty of performing sequences of projective measurements on individual quantum systems. Here we show that two-point correlations between binary compatible observables are sufficient to reveal any form of contextuality. This allows us to design simple experiments that are more robust against imperfections and easier to analyze, thus opening the door for observing interesting forms of contextuality, including those requiring quantum systems of high dimensions. In addition, it allows us to connect contextuality to communication complexity scenarios and reformulate a recent result relating contextuality and quantum computation.
26 CFR 1.401(a)-11 - Qualified joint and survivor annuities.
Code of Federal Regulations, 2011 CFR
2011-04-01
... must be at least the actuarial equivalent of the normal form of life annuity or, if greater, of any... 411(e)(2), which is a part of a plan providing for the payment of benefits in any form of a life... paragraph (c)(1) of this section has been made, life annuity benefits will be paid in a form having the...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-27
... of Lapse--Government Life Insurance) Activities Under OMB Review AGENCY: Veterans Benefits...--Government Life Insurance, VA Form 29-389. b. Application for Reinstatement, VA Form 29-389-1. OMB Control...-389 and 29-389-1 are used to inform claimants that their government life insurance has lapsed or will...
Some Remarks on Space-Time Decompositions, and Degenerate Metrics, in General Relativity
NASA Astrophysics Data System (ADS)
Bengtsson, Ingemar
Space-time decomposition of the Hilbert-Palatini action, written in a form which admits degenerate metrics, is considered. Simple numerology shows why D = 3 and 4 are singled out as admitting a simple phase space. The canonical structure of the degenerate sector turns out to be awkward. However, the real degenerate metrics obtained as solutions are the same as those that occur in Ashtekar's formulation of complex general relativity. An exact solution of Ashtekar's equations, with degenerate metric, shows that the manifestly four-dimensional form of the action, and its 3 + 1 form, are not quite equivalent.
Convergence to Diagonal Form of Block Jacobi-type Processes
NASA Astrophysics Data System (ADS)
Hari, Vjeran
2008-09-01
The main result of recent research on convergence to diagonal form of block Jacobi-type processes is presented. For this purpose, all notions needed to describe the result are introduced. In particular, elementary block transformation matrices, simple and non-simple algorithms, block pivot strategies together with the appropriate equivalence relations are defined. The general block Jacobi-type process considered here can be specialized to take the form of almost any known Jacobi-type method for solving the ordinary or the generalized matrix eigenvalue and singular value problems. The assumptions used in the result are satisfied by many concrete methods.
ERIC Educational Resources Information Center
Tatsumi, Tomoko; Ambridge, Ben; Pine, Julian M.
2018-01-01
This study aims to disentangle the often-confounded effects of input frequency and morphophonological complexity in the acquisition of inflection, by focusing on simple and complex verb forms in Japanese. Study 1 tested 28 children aged 3;3-4;3 on stative (complex) and simple past forms, and Study 2 tested 30 children aged 3;5-5;3 on completive…
NASA Astrophysics Data System (ADS)
Gao, Shuang; Zeng, Fei; Li, Fan; Wang, Minjuan; Mao, Haijun; Wang, Guangyue; Song, Cheng; Pan, Feng
2015-03-01
The search for self-rectifying resistive memories has aroused great attention due to their potential in high-density memory applications without additional access devices. Here we report the forming-free and self-rectifying bipolar resistive switching behavior of a simple Pt/TaOx/n-Si tri-layer structure. The forming-free phenomenon is attributed to the generation of a large amount of oxygen vacancies, in a TaOx region that is in close proximity to the TaOx/n-Si interface, via out-diffusion of oxygen ions from TaOx to n-Si. A maximum rectification ratio of ~6 × 102 is obtained when the Pt/TaOx/n-Si devices stay in a low resistance state, which originates from the existence of a Schottky barrier between the formed oxygen vacancy filament and the n-Si electrode. More importantly, numerical simulation reveals that the self-rectifying behavior itself can guarantee a maximum crossbar size of 212 × 212 (~44 kbit) on the premise of 10% read margin. Moreover, satisfactory switching uniformity and retention performance are observed based on this simple tri-layer structure. All of these results demonstrate the great potential of this simple Pt/TaOx/n-Si tri-layer structure for access device-free high-density memory applications.The search for self-rectifying resistive memories has aroused great attention due to their potential in high-density memory applications without additional access devices. Here we report the forming-free and self-rectifying bipolar resistive switching behavior of a simple Pt/TaOx/n-Si tri-layer structure. The forming-free phenomenon is attributed to the generation of a large amount of oxygen vacancies, in a TaOx region that is in close proximity to the TaOx/n-Si interface, via out-diffusion of oxygen ions from TaOx to n-Si. A maximum rectification ratio of ~6 × 102 is obtained when the Pt/TaOx/n-Si devices stay in a low resistance state, which originates from the existence of a Schottky barrier between the formed oxygen vacancy filament and the n-Si electrode. More importantly, numerical simulation reveals that the self-rectifying behavior itself can guarantee a maximum crossbar size of 212 × 212 (~44 kbit) on the premise of 10% read margin. Moreover, satisfactory switching uniformity and retention performance are observed based on this simple tri-layer structure. All of these results demonstrate the great potential of this simple Pt/TaOx/n-Si tri-layer structure for access device-free high-density memory applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr06406b
Senior Citizens' Personal Stories...Literacy through Narrative...Sharing the Richness of the Past.
ERIC Educational Resources Information Center
Lineberry, Colleen
Using simple writing strategies, senior citizens at an elder camp workshop collected memories in journals. In some cases, readings were used to trigger memories. The exercise enabled students to make connections between their own life experiences and the life experiences of others. Workshops encouraging participants to tell their own stories for…
ERIC Educational Resources Information Center
Homaei, Rezvan; Bozorgi, Zahra Dasht; Ghahfarokhi, Maryam Sadat Mirbabaei; Hosseinpour, Shima
2016-01-01
The purpose of the current study is to investigate the relationship between Optimism, Religiosity and Self-esteem with Marital Satisfaction and Life Satisfaction in married university students. The research method was a descriptive study kind of correlation. The sample group included 200 married students that were selected using a simple random…
Humic first, A new theory on the origin of life
NASA Astrophysics Data System (ADS)
Daei, Mohammad Ali; Daei, Manijeh
2016-04-01
In 1953, Miller &Urey through a brilliant experiment demonstrated that the building blocks of life could evolve in primitive earth conditions1. In recent years scientists revealed that organic matters are not very rare compounds in comets, asteroids, and meteorites2. These facts show simple organic molecules on early earth could be quite enough to start development of life. But, how? Many theorists have tried to explain how life emerged from non life, but failed2. There is a huge gap between the simple building blocks, like amino acid, sugar, and lipid molecules, to a living cell with a very sophisticated structure and organization. Obviously, creation of a cell needed a qualified production line which had to be durable and active, can gather all biochemical ingredients, protect them from degradation, have catalyzing ability, provide numerous opportunities for interaction between basic molecules, and above all, have capability to react to different sources of energy. We are sure this perfect factory was available on primitive earth and is nothing except humic substance! At the moment, HS, are doing nearly all of these duties, among the others, under your feet in agricultural soils4. What are humic substances? According to IHSS definition "Humic substances (HS) are major components of the natural organic matter (NOM) in soil and water as well as in geological organic deposits such as lake sediments, peats, brown coals, and shales5." They come from polymerization of organic molecules, but looking at them like a simple aggregation of different organic molecules, is a huge mistake6! It seems they do not come together except for making a capable structure! HS are the first organic machinery which appeared in proplanetary disk, more than four billion years ago. Derived from simple inorganic molecules, humic substances construct a firm intermediate structure which connects none life to life. In other word, life road pass over the humic bridge. This does not mean that necessarily they had extra terrestrial origin. In fact Ziechman et al7, in 1994 by finding humic material in Miller's experimental vessels proved that humic substances could be generate on early earth conditions by polymerizing simple organic molecules. Which evidences support our Ideas? 1- Suppose a wet land located in a warm area of primitive earth, covered with a layer of black humic materials, ready to action and reaction. Under this umbrella, basic molecules of life can interact freely and benefit from catalyzing and stimulating effects of HS. Amino and nucleic acid molecules may line up, grow, and develop mutually. Protein molecules can appear and do practices and before decaying a strand of nucleotides is ready to save their information and can rebuilt them for further practices. Thus, chemical evolution on a bed of humic acid can promote targeted, firmly and continuously towards a large network that be able to support a self replicating cell! We deliberately suggested, land and not the sea, as cradle of life. Because sodium, the most prevalent cation in oceans could not participate in primitive life, instead potassium played an important role. 2- There are strong evidences that show HS, really acted as the main elemental selector and even chairal selector for life on early earth. HS, show strong affinity and fast releasing tendency for macro nutrients (N, P, K).There is moderate affinity and releasing tendency for Ca, Mg, S. Also there is weak affinity and reluctance for liberating micronutrients. More interesting, HS generate insoluble compounds with nearly all toxic elements. As you see not only HS selected some and rejected other elements but also definite their proportions in the cell structure. 3- What is the reason of homochairality in living organism? As you know, none of previous theories in this field provided an easy explanation for this difficult and fundamental question. But, humic theory has a simple answer. Humic substances accepted some and rejected the other enantiomers, because their spatial structure dictate, as did so regarding elemental selection. References: 1- Miller, Stanly L." production of amino acid under possible primitive Earth conditions" Science 117:528.(may 1953) 2- Encyclopedia Britannica website "carbonaceous contrite" October 17, 2014 3- Shapiro, Robert " A simpler origin for life" Science American February 12 . 2007 4- Pettit, Robert, "organic matter, humus, humate, humic acid, fulvic acid humin: their importance in soil fertility and plant health" 5- International Humic Substances Society website, " What are humic substances" 6- Humic, Fulvic and microbial balance: organic soil conditioning, by William R. Jackson 1993, pag 165-167 7- Steinberg, Christian E.W "Ecology of humic substances in freshwater-determination from geochemistry to ecological niches" (2003)
ERIC Educational Resources Information Center
Rossi, Sergio; Benaglia, Maurizio; Brenna, Davide; Porta, Riccardo; Orlandi, Manuel
2015-01-01
A simple procedure to convert protein data bank files (.pdb) into a stereolithography file (.stl) using VMD software (Virtual Molecular Dynamic) is reported. This tutorial allows generating, with a very simple protocol, three-dimensional customized structures that can be printed by a low-cost 3D-printer, and used for teaching chemical education…
Rauk, Adam P; Guo, Kevin; Hu, Yanling; Cahya, Suntara; Weiss, William F
2014-08-01
Defining a suitable product presentation with an acceptable stability profile over its intended shelf-life is one of the principal challenges in bioproduct development. Accelerated stability studies are routinely used as a tool to better understand long-term stability. Data analysis often employs an overall mass action kinetics description for the degradation and the Arrhenius relationship to capture the temperature dependence of the observed rate constant. To improve predictive accuracy and precision, the current work proposes a least-squares estimation approach with a single nonlinear covariate and uses a polynomial to describe the change in a product attribute with respect to time. The approach, which will be referred to as Arrhenius time-scaled (ATS) least squares, enables accurate, precise predictions to be achieved for degradation profiles commonly encountered during bioproduct development. A Monte Carlo study is conducted to compare the proposed approach with the common method of least-squares estimation on the logarithmic form of the Arrhenius equation and nonlinear estimation of a first-order model. The ATS least squares method accommodates a range of degradation profiles, provides a simple and intuitive approach for data presentation, and can be implemented with ease. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.
A simplified life-cycle cost comparison of various engines for small helicopter use
NASA Technical Reports Server (NTRS)
Civinskas, K. C.; Fishbach, L. M.
1974-01-01
A ten-year, life-cycle cost comparison is made of the following engines for small helicopter use: (1) simple turboshaft; (2) regenerative turboshaft; (3) compression-ignition reciprocator; (4) spark-ignited rotary; and (5) spark-ignited reciprocator. Based on a simplified analysis and somewhat approximate data, the simple turboshaft engine apparently has the lowest costs for mission times up to just under 2 hours. At 2 hours and above, the regenerative turboshaft appears promising. The reciprocating and rotary engines are less attractive, requiring from 10 percent to 80 percent more aircraft to have the same total payload capability as a given number of turbine powered craft. A nomogram was developed for estimating total costs of engines not covered in this study.
Seafloor Fluid Flow and the Search for Extant Life: Escaping Earthly Prejudices
NASA Astrophysics Data System (ADS)
German, C. R.
2018-05-01
Despite decades of experience, ocean scientists on Earth continue to discover novel forms of seafloor fluid flow with the potential to host novel forms of life. Ocean Science can inform the search for life beyond Earth but should not dictate it.
Newton, P R; Naidoo, R; Brysiewicz, P
2015-09-19
Emergency medical services (EMS) are sometimes required to respond to cases that are later found not to be emergencies, resulting in high levels of inappropriate responses. This study evaluated the extent to which this occurs. All cases dispatched over 72 hours by the eThekwini EMS in Durban, South Africa, were prospectively enrolled in a quantitative descriptive study. Vehicle control forms containing dispatch data were matched and compared with patient report forms containing epidemiological and clinical data to describe the nature and extent of inappropriate responses based on patient need. Data were subjected to simple descriptive analysis, correlations and χ2 testing. A total of 1 385 cases met the study inclusion criteria. Marked variations existed between dispatch and on-scene priority settings, most notably in the highest priority 'red-code' category, which constituted >56% of cases dispatched yet accounted for <2% at the scene (p<0.001). Conversely, >80% of 'red-code' dispatches required a lower priority response. When comparing resource allocation according to patient interventional needs, >58% of cases required either no intervention or transport only and almost 36% required basic life support intervention only (p<0.001). Moreover, <12% of advanced life support dispatches were for patients found to be 'red code' at the scene. There is a significant mismatch between the dispatch of EMS resources and actual patient need in the eThekwini district, with significantly high levels of inappropriate emergency responses.
Matros, Andrea; Peshev, Darin; Peukert, Manuela; Mock, Hans-Peter; Van den Ende, Wim
2015-06-01
Substantial formation of reactive oxygen species (ROS) is inevitable in aerobic life forms. Due to their extremely high reactivity and short lifetime, hydroxyl radicals are a special case, because cells have not developed enzymes to detoxify these most dangerous ROS. Thus, scavenging of hydroxyl radicals may only occur by accumulation of higher levels of simple organic compounds. Previous studies have demonstrated that plant-derived sugars show hydroxyl radical scavenging capabilities during Fenton reactions with Fe(2+) and hydrogen peroxide in vitro, leading to formation of less detrimental sugar radicals that may be subject of regeneration to non-radical carbohydrates in vivo. Here, we provide further evidence for the occurrence of such radical reactions with sugars in planta, by following the fate of sucralose, an artificial analog of sucrose, in Arabidopsis tissues. The expected sucralose recombination and degradation products were detected in both normal and stressed plant tissues. Oxidation products of endogenous sugars were also assessed in planta for Arabidopsis and barley, and were shown to increase in abundance relative to the non-oxidized precursor during oxidative stress conditions. We concluded that such non-enzymatic reactions with hydroxyl radicals form an integral part of plant antioxidant mechanisms contributing to cellular ROS homeostasis, and may be more important than generally assumed. This is discussed in relation to the recently proposed roles for Fe(2+) and hydrogen peroxide in processes leading to the origin of metabolism and the origin of life. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.
Balance of flora, galt, and mucosal integrity.
Hanaway, Patrick
2006-01-01
It is clear that there is a dynamic relationship involving the gastrointestinal flora, environmental inputs (food and other nutrients), and the health of the immune system. Recent research has taught us a great deal about the role of diet and commensal bacteria in promoting health. It appears that Nobel Laureate Eli Metchnikov may have been correct in his assertion that live bacterial cultures are "the elixir of life". We are unlocking a number of secrets about immune system functioning, but we keep coming back to a simple intervention that has an ever-expanding opus of research to support it, and an extremely low toxicity ratio. Future studies will help us to clarify the best strains and the best dosages for individual patients and specific conditions. Assessment of commensal flora and a genomic scan for markers of immunologic dysregulation will be more accurate and more widely available. It appears, however, that the diagnostic and therapeutic tools we have to work with today can make a tremendous difference in reducing the burden of suffering for our patients. If "form follows function," as Buckminster Fuller was fond of saying, then the form of our immune system may be following the precise functions that our commensal flora is dictating. We have the opportunity to encourage breastfeeding, decrease unnecessary antibiotic and antimicrobial usage (especially in the first two years of life), improve oral tolerance with a healthy n-6/n-3 fatty acid ratio, and support the development of a healthy commensal flora. These actions on behalf of our immune systems will pay dividends for years to come.
Niklas, Karl J
2006-02-01
Life forms as diverse as unicellular algae, zooplankton, vascular plants, and mammals appear to obey quarter-power scaling rules. Among the most famous of these rules is Kleiber's (i.e. basal metabolic rates scale as the three-quarters power of body mass), which has a botanical analogue (i.e. annual plant growth rates scale as the three-quarters power of total body mass). Numerous theories have tried to explain why these rules exist, but each has been heavily criticized either on conceptual or empirical grounds. N,P-STOICHIOMETRY: Recent models predicting growth rates on the basis of how total cell, tissue, or organism nitrogen and phosphorus are allocated, respectively, to protein and rRNA contents may provide the answer, particularly in light of the observation that annual plant growth rates scale linearly with respect to standing leaf mass and that total leaf mass scales isometrically with respect to nitrogen but as the three-quarters power of leaf phosphorus. For example, when these relationships are juxtaposed with other allometric trends, a simple N,P-stoichiometric model successfully predicts the relative growth rates of 131 diverse C3 and C4 species. The melding of allometric and N,P-stoichiometric theoretical insights provides a robust modelling approach that conceptually links the subcellular 'machinery' of protein/ribosomal metabolism to observed growth rates of uni- and multicellular organisms. Because the operation of this 'machinery' is basic to the biology of all life forms, its allometry may provide a mechanistic explanation for the apparent ubiquity of quarter-power scaling rules.
Ricotta, Carlo; Pacini, Alessandra; Avena, Giancarlo
2002-01-01
We propose a measure of divergence from species to life-form diversity aimed at summarizing the ecological similarity among different plant communities without losing information on traditional taxonomic diversity. First, species and life-form relative abundances within a given plant community are determined. Next, using Rényi's generalized entropy, the diversity profiles of the analyzed community are computed both from species and life-form relative abundances. Finally, the speed of decrease from species to life-form diversity is obtained by combining the outcome of both profiles. Interestingly, the proposed measure shows some formal analogies with multifractal functions developed in statistical physics for the analysis of spatial patterns. As an application for demonstration, a small data set from a plant community sampled in the archaeological site of Paestum (southern Italy) is used.
Life's Late Digital Revolution and Why It Matters for the Study of the Origins of Life.
Baum, David A; Lehman, Niles
2017-08-25
The information contained in life exists in two forms, analog and digital. Analog information is manifest mainly in the differing concentrations of chemicals that get passed from generation to generation and can vary from cell to cell. Digital information is encoded in linear polymers such as DNA and RNA, whose side chains come in discrete chemical forms. Here, we argue that the analog form of information preceded the digital. Acceptance of this dichotomy, and this progression, can help direct future studies on how life originated and initially complexified on the primordial Earth, as well as expected trajectories for other, independent origins of complex life.
Energy survey study and report of hospitals in Chicago: South Suburban Hospital: Final report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1988-08-01
This study is part of a three-phased demonstration project to reduce energy consumption in hospitals through practical life-cycle/cost-effective modifications and alteration. Funds for the demonstration project are provided by the American Hospital Association (AHA), the Department of Energy (DOE), and the Department of Health and Human Services (DHHS). A thorough study and evaluation of all building systems is made to identify opportunities for reduction in energy consumption and to determine the most cost effective approaches to energy conservation. The primary objective of the study is to investigate and analyze energy usage of the facility and to identify all life cycle,more » cost-effective changes required to effect a reduction in energy consumption. For the purpose of economic evaluation of the energy conservation projects identified, life-cycle cost and simple payback periods are used. Energy conservation measures with simple payback periods exceeding five years were dismissed from further detailed study.« less
Significance of solvated electrons (e(aq)-) as promoters of life on earth.
Getoff, Nikola
2014-01-01
Based on the present state of knowledge a new hypothesis concerning the origin of life on Earth is presented, and emphasizes the particular significance of solvated electrons (e(aq)(-)). Solvated electrons are produced in seawater, mainly by (40)K radiation and in atmospheric moisture by VUV light, electrical discharges and cosmic ray. Solvated electrons are involved in primary chemical processes and in biological processes. The conversion of aqueous CO2 and CO into simple organic substances, the generation of ammonia from N2 and water, the formation of amines, amino acids and simple proteins under the action of e(aq)(-) has been experimentally proven. Furthermore, it is supposed that the generation of the primitive cell and equilibria of primitive enzymes are also realized due to the strong reducing property of e(aq)(-). The presented hypothesis is mainly founded on recently obtained experimental results. The involvement of e(aq)(-) in such mechanisms, as well as their action as an initiator of life is also briefly discussed.
Intrinsic and Extrinsic Aspects on Campylobacter jejuni Biofilms.
Melo, Roberta T; Mendonça, Eliane P; Monteiro, Guilherme P; Siqueira, Mariana C; Pereira, Clara B; Peres, Phelipe A B M; Fernandez, Heriberto; Rossi, Daise A
2017-01-01
Biofilm represents a way of life that allows greater survival of microorganisms in hostile habitats. Campylobacter jejuni is able to form biofilms in vitro and on surfaces at several points in the poultry production chain. Genetic determinants related to their formation are expressed differently between strains and external conditions are decisive in this respect. Our approach combines phylogenetic analysis and the presence of seven specific genes linked to biofilm formation in association with traditional microbiology techniques, using Mueller Hinton and chicken juice as substrates in order to quantify, classify, determine the composition and morphology of the biomass of simple and mixed biofilms of 30 C. jejuni strains. It also evaluates the inhibition of its formation by biocides commonly used in industry and also by zinc oxide nanoparticles. Genetic analysis showed high heterogeneity with the identification of 23 pulsotypes. Despite the diversity, the presence of flaA, cadF, luxS, dnaJ, htrA, cbrA , and sodB genes in all strains shows the high potential for biofilm formation. This ability was only expressed in chicken juice, where they presented phenotype of a strong biofilm producer, with a mean count of 7.37 log CFU/mL and an ultrastructure characteristic of mature biofilm. The composition of simple and mixed biofilms was predominantly composed by proteins. The exceptions were found in mixed biofilms with Pseudomonas aeruginosa , which includes a carbohydrate-rich matrix, lower ability to sessile form in chicken juice and compact architecture of the biofilm, this aspects are intrinsic to this species. Hypochlorite, chlorhexidine, and peracetic acid were more effective in controlling viable cells of C. jejuni in biofilm, but the existence of tolerant strains indicates exposure to sublethal concentrations and development of adaptation mechanisms. This study shows that in chicken juice C. jejuni presents greater potential in producing mature biofilms.
Kovic, Bruno; Guyatt, Gordon; Brundage, Michael; Thabane, Lehana; Bhatnagar, Neera; Xie, Feng
2016-09-02
There is an increasing number of new oncology drugs being studied, approved and put into clinical practice based on improvement in progression-free survival, when no overall survival benefits exist. In oncology, the association between progression-free survival and health-related quality of life is currently unknown, despite its importance for patients with cancer, and the unverified assumption that longer progression-free survival indicates improved health-related quality of life. Thus far, only 1 study has investigated this association, providing insufficient evidence and inconclusive results. The objective of this study protocol is to provide increased transparency in supporting a systematic summary of the evidence bearing on this association in oncology. Using the OVID platform in MEDLINE, Embase and Cochrane databases, we will conduct a systematic review of randomised controlled human trials addressing oncology issues published starting in 2000. A team of reviewers will, in pairs, independently screen and abstract data using standardised, pilot-tested forms. We will employ numerical integration to calculate mean incremental area under the curve between treatment groups in studies for health-related quality of life, along with total related error estimates, and a 95% CI around incremental area. To describe the progression-free survival to health-related quality of life association, we will construct a scatterplot for incremental health-related quality of life versus incremental progression-free survival. To estimate the association, we will use a weighted simple regression approach, comparing mean incremental health-related quality of life with either median incremental progression-free survival time or the progression-free survival HR, in the absence of overall survival benefit. Identifying direction and magnitude of association between progression-free survival and health-related quality of life is critically important in interpreting results of oncology trials. Systematic evidence produced from our study will contribute to improvement of patient care and practice of evidence-based medicine in oncology. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Application of cloud database in the management of clinical data of patients with skin diseases.
Mao, Xiao-fei; Liu, Rui; DU, Wei; Fan, Xue; Chen, Dian; Zuo, Ya-gang; Sun, Qiu-ning
2015-04-01
To evaluate the needs and applications of using cloud database in the daily practice of dermatology department. The cloud database was established for systemic scleroderma and localized scleroderma. Paper forms were used to record the original data including personal information, pictures, specimens, blood biochemical indicators, skin lesions,and scores of self-rating scales. The results were input into the cloud database. The applications of the cloud database in the dermatology department were summarized and analyzed. The personal and clinical information of 215 systemic scleroderma patients and 522 localized scleroderma patients were included and analyzed using the cloud database. The disease status,quality of life, and prognosis were obtained by statistical calculations. The cloud database can efficiently and rapidly store and manage the data of patients with skin diseases. As a simple, prompt, safe, and convenient tool, it can be used in patients information management, clinical decision-making, and scientific research.
Avian egg shape: Form, function, and evolution.
Stoddard, Mary Caswell; Yong, Ee Hou; Akkaynak, Derya; Sheard, Catherine; Tobias, Joseph A; Mahadevan, L
2017-06-23
Avian egg shape is generally explained as an adaptation to life history, yet we currently lack a global synthesis of how egg-shape differences arise and evolve. Here, we apply morphometric, mechanistic, and macroevolutionary analyses to the egg shapes of 1400 bird species. We characterize egg-shape diversity in terms of two biologically relevant variables, asymmetry and ellipticity, allowing us to quantify the observed morphologies in a two-dimensional morphospace. We then propose a simple mechanical model that explains the observed egg-shape diversity based on geometric and material properties of the egg membrane. Finally, using phylogenetic models, we show that egg shape correlates with flight ability on broad taxonomic scales, suggesting that adaptations for flight may have been critical drivers of egg-shape variation in birds. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.
Coarse-graining as a downward causation mechanism
NASA Astrophysics Data System (ADS)
Flack, Jessica C.
2017-11-01
Downward causation is the controversial idea that `higher' levels of organization can causally influence behaviour at `lower' levels of organization. Here I propose that we can gain traction on downward causation by being operational and examining how adaptive systems identify regularities in evolutionary or learning time and use these regularities to guide behaviour. I suggest that in many adaptive systems components collectively compute their macroscopic worlds through coarse-graining. I further suggest we move from simple feedback to downward causation when components tune behaviour in response to estimates of collectively computed macroscopic properties. I introduce a weak and strong notion of downward causation and discuss the role the strong form plays in the origins of new organizational levels. I illustrate these points with examples from the study of biological and social systems and deep neural networks. This article is part of the themed issue 'Reconceptualizing the origins of life'.
Utilizing traditional storytelling to promote wellness in American Indian communities.
Hodge, Felicia Schanche; Pasqua, Anna; Marquez, Carol A; Geishirt-Cantrell, Betty
2002-01-01
Utilizing storytelling to transmit educational messages is a traditional pedagogical method practiced by many American Indian tribes. American Indian stories are effective because they present essential ideas and values in a simple, entertaining form. Different story characters show positive and negative behaviors. The stories illustrate consequences of behaviors and invite listeners to come to their own conclusions after personal reflection. Because stories have been passed down through tribal communities for generations, listeners also have the opportunity to reconnect and identify with past tribal realities. This article reports on a research intervention that is unique in promoting health and wellness through the use of storytelling. The project utilized stories to help motivate tribal members to once more adopt healthy, traditional life-styles and practices. The authors present and discuss the stories selected, techniques used in their telling, the preparation and setting for the storytelling, and the involvement and interaction of the group.
Fabrication of Cantilever-Bump Type Si Probe Card
NASA Astrophysics Data System (ADS)
Park, Jeong-Yong; Lee, Dong-Seok; Kim, Dong-Kwon; Lee, Jong-Hyun
2000-12-01
Probe card is most important part in the test system which selects the good or bad chip of integrated circuit (IC) chips. Silicon vertical probe card is able to test multiple semiconductor chips simultaneously. We presented cantilever-bump type vertical probe card. It was fabricated by dry etching using RIE(reactive ion etching) technique and porous silicon micromachining using silicon direct bonded (SDB) wafer. Cantilevers and bumps were fabricated by isotropic etching using RIE@. 3-dimensional structures were formed by porous silicon micromachining technique using SDB wafer. Contact resistance of fabricated probe card was less than 2 Ω and its life time was more than 200,000 turns. The process used in this work is very simple and reproducible, which has good controllability in the tip dimension and spacing. It is expected that the fabricated probe card can reduce testing time, can promote productivity and enables burn-in test.
Drew, Mark S.
2016-01-01
Cutaneous melanoma is the most life-threatening form of skin cancer. Although advanced melanoma is often considered as incurable, if detected and excised early, the prognosis is promising. Today, clinicians use computer vision in an increasing number of applications to aid early detection of melanoma through dermatological image analysis (dermoscopy images, in particular). Colour assessment is essential for the clinical diagnosis of skin cancers. Due to this diagnostic importance, many studies have either focused on or employed colour features as a constituent part of their skin lesion analysis systems. These studies range from using low-level colour features, such as simple statistical measures of colours occurring in the lesion, to availing themselves of high-level semantic features such as the presence of blue-white veil, globules, or colour variegation in the lesion. This paper provides a retrospective survey and critical analysis of contributions in this research direction. PMID:28096807
Daigle, Jean-Christophe; Asakawa, Yuichiro; Beaupré, Mélanie; Vieillette, René; Laul, Dharminder; Trudeau, Michel; Zaghib, Karim
2017-12-13
Lithium titanium oxide (Li 4 Ti 5 O 12 )-based cells are a very promising battery technology for ultrafast-charge-discharge and long-cycle-life batteries. However, the surface reactivity of lithium titanium oxide in the presence of organic electrolytes continues to be a problem that may cause expansion of pouch cells. In this study, we report on the development of a simple and economical grafting method for forming hybrid polymer-Li 4 Ti 15 O 12 nanoparticles, which can be successfully applied in lithium-ion batteries. This method utilizes a low-cost and scalable hydrophobic polymer that is applicable in industrial processes. The hybrid materials demonstrated exceptional capability for preventing the degradation of cells in accelerated aging and operating over 150 cycles at 1C and 45 °C.
Investigating the Effect of Damage Progression Model Choice on Prognostics Performance
NASA Technical Reports Server (NTRS)
Daigle, Matthew; Roychoudhury, Indranil; Narasimhan, Sriram; Saha, Sankalita; Saha, Bhaskar; Goebel, Kai
2011-01-01
The success of model-based approaches to systems health management depends largely on the quality of the underlying models. In model-based prognostics, it is especially the quality of the damage progression models, i.e., the models describing how damage evolves as the system operates, that determines the accuracy and precision of remaining useful life predictions. Several common forms of these models are generally assumed in the literature, but are often not supported by physical evidence or physics-based analysis. In this paper, using a centrifugal pump as a case study, we develop different damage progression models. In simulation, we investigate how model changes influence prognostics performance. Results demonstrate that, in some cases, simple damage progression models are sufficient. But, in general, the results show a clear need for damage progression models that are accurate over long time horizons under varied loading conditions.
Pathology of pulmonary aspergillomas.
Shah, Rajeev; Vaideeswar, Pradeep; Pandit, Shobhana P
2008-01-01
Aspergilloma refers to a fungal ball formed by saprophytic overgrowth of Aspergillus species and is seen secondary to cavitatory/cystic respiratory diseases. Paucity of clinical and pathological data of aspergilloma in India prompted us to analyze cases of aspergilloma over 15 years. The clinical features were recorded in all and correlated with detailed pathological examination. Aspergillomas were identified in 41 surgical excisions or at autopsy. There was male predominance; half the patients were in their fourth decade. Episodic hemoptysis was the commonest mode of presentation (85.4%). Forty aspergillomas were complex, occurring in cavitatory lesions (82.9%) or in bronchiectasis (14.6%). Simple aspergilloma was seen as an incidental finding in only one. Tuberculosis was the etiological factor in 31 patients, producing cavitatory or bronchiectatic lesions; other causes were chronic lung abscess and bronchiectasis (unrelated to tuberculosis). Surgical resections are endorsed in view of high risk of unpredictable, life-threatening hemoptysis.
The prospect of life on Jupiter.
NASA Technical Reports Server (NTRS)
Ponnamperuma, C.; Molton, P.
1973-01-01
We have simulated electrical discharges in the Jovian atmosphere, using anhydrous methane-ammonia mixtures, and shown the formation of simple aliphatic nitriles, amino-nitriles, and their oligomers. Including hydrogen sulfide in the gas mixture, it appears that sulfur-containing amino-nitriles are not formed, since the hydrolysate of the products did not contain the corresponding amino-acids. There is a strong analogy between these reactions and the classical spark reactions simulating the primitive earth's atmosphere. We are attempting a closer simulation of Jupiter's atmosphere by using appropriate temperature and pressure conditions. It seems that prebiotic synthesis on Jupiter may have reached an advanced state. As an alternative approach we have tested the survival ability of common terrestrial microorganisms in aqueous media at 102 atmospheres pressure and at 20 C in a simulated Jovian atmosphere. E. coli, S. marcescens, A. aerogenes, and B. subtilis will all tolerate 24 hr under these conditions with little death.
Differential calculus on quantized simple lie groups
NASA Astrophysics Data System (ADS)
Jurčo, Branislav
1991-07-01
Differential calculi, generalizations of Woronowicz's four-dimensional calculus on SU q (2), are introduced for quantized classical simple Lie groups in a constructive way. For this purpose, the approach of Faddeev and his collaborators to quantum groups was used. An equivalence of Woronowicz's enveloping algebra generated by the dual space to the left-invariant differential forms and the corresponding quantized universal enveloping algebra, is obtained for our differential calculi. Real forms for q ∈ ℝ are also discussed.
Gas and water recycling system for IOC vivarium experiments
NASA Technical Reports Server (NTRS)
Nitta, K.; Otsubo, K.
1986-01-01
Water and gas recycling units designed as one of the common experiment support system for the life science experiment facilities used in the Japanese Experiment Module are discussed. These units will save transportation and operation costs for the life science experiments in the space station. These units are also designed to have interfaces so simple that the connection to another life science experiment facilities such as the Research Animal Holding Facility developed by the Rockheed Missiles and Space Company can be easily done with small modification.
Epistemological issues in the study of microbial life: alternative terran biospheres?
Cleland, Carol E
2007-12-01
The assumption that all life on Earth today shares the same basic molecular architecture and biochemistry is part of the paradigm of modern biology. This paper argues that there is little theoretical or empirical support for this widely held assumption. Scientists know that life could have been at least modestly different at the molecular level and it is clear that alternative molecular building blocks for life were available on the early Earth. If the emergence of life is, like other natural phenomena, highly probable given the right chemical and physical conditions then it seems likely that the early Earth hosted multiple origins of life, some of which produced chemical variations on life as we know it. While these points are often conceded, it is nevertheless maintained that any primitive alternatives to familiar life would have been eliminated long ago, either amalgamated into a single form of life through lateral gene transfer (LGT) or alternatively out-competed by our putatively more evolutionarily robust form of life. Besides, the argument continues, if such life forms still existed, we surely would have encountered telling signs of them by now. These arguments do not hold up well under close scrutiny. They reflect a host of assumptions that are grounded in our experience with large multicellular organisms and, most importantly, do not apply to microbial forms of life, which cannot be easily studied without the aid of sophisticated technologies. Significantly, the most powerful molecular biology techniques available-polymerase chain reaction (PCR) amplification of rRNA genes augmented by metagenomic analysis-could not detect such microbes if they existed. Given the profound philosophical and scientific importance that such a discovery would represent, a dedicated search for 'shadow microbes' (heretofore unrecognized 'alien' forms of terran microbial life) seems in order. The best place to start such a search is with puzzling (anomalous) phenomena, such as desert varnish, that resist classification as 'biological' or 'nonbiological'.
Stressed Oxidation Life Prediction for C/SiC Composites
NASA Technical Reports Server (NTRS)
Levine, Stanley R.
2004-01-01
The residual strength and life of C/SiC is dominated by carbon interface and fiber oxidation if seal coat and matrix cracks are open to allow oxygen ingress. Crack opening is determined by the combination of thermal, mechanical and thermal expansion mismatch induced stresses. When cracks are open, life can be predicted by simple oxidation based models with reaction controlled kinetics at low temperature, and by gas phase diffusion controlled kinetics at high temperatures. Key life governing variables in these models include temperature, stress, initial strength, oxygen partial pressure, and total pressure. These models are described in this paper.
Evolution of complex fruiting-body morphologies in homobasidiomycetes.
Hibbett, David S; Binder, Manfred
2002-01-01
The fruiting bodies of homobasidiomycetes include some of the most complex forms that have evolved in the fungi, such as gilled mushrooms, bracket fungi and puffballs ('pileate-erect') forms. Homobasidiomycetes also include relatively simple crust-like 'resupinate' forms, however, which account for ca. 13-15% of the described species in the group. Resupinate homobasidiomycetes have been interpreted either as a paraphyletic grade of plesiomorphic forms or a polyphyletic assemblage of reduced forms. The former view suggests that morphological evolution in homobasidiomycetes has been marked by independent elaboration in many clades, whereas the latter view suggests that parallel simplification has been a common mode of evolution. To infer patterns of morphological evolution in homobasidiomycetes, we constructed phylogenetic trees from a dataset of 481 species and performed ancestral state reconstruction (ASR) using parsimony and maximum likelihood (ML) methods. ASR with both parsimony and ML implies that the ancestor of the homobasidiomycetes was resupinate, and that there have been multiple gains and losses of complex forms in the homobasidiomycetes. We also used ML to address whether there is an asymmetry in the rate of transformations between simple and complex forms. Models of morphological evolution inferred with ML indicate that the rate of transformations from simple to complex forms is about three to six times greater than the rate of transformations in the reverse direction. A null model of morphological evolution, in which there is no asymmetry in transformation rates, was rejected. These results suggest that there is a 'driven' trend towards the evolution of complex forms in homobasidiomycetes. PMID:12396494
A Simple Example of Radioactive Dating
ERIC Educational Resources Information Center
Brown, Todd
2014-01-01
Although nuclear half-life is vital to physics and physical science, and to sensitive societal issues from nuclear waste to the age of the Earth, a true lab on half-life is almost never done at the college or high school level. Seldom are students able to use radioactivity to actually date when an object came into being, as is done in this…
ERIC Educational Resources Information Center
Davis, Lorelei D.
1998-01-01
Saccharomyces cerevisiae provides an excellent tool for students to enter into inquiry-based science. This very simple organism is used to demonstrate that the principles governing life apply to all organisms. Students learn to design experiments using trypan blue and heat, build upon their findings with new experiments, and refine and repeat…
ERIC Educational Resources Information Center
Wilson, E. O., Ed.; Peter, Frances M., Ed.
The diversity of life forms is one of the greatest wonders of the planet earth. The biosphere is an intricate tapestry of interwoven life forms. This book offers an overall view of this biological diversity and carries an urgent warning about the rapid alteration and destruction of the environments that have fostered the diversity of life forms…
Influencing preferences for different types of causal explanation of complex events.
Klein, Gary; Rasmussen, Louise; Lin, Mei-Hua; Hoffman, Robert R; Case, Jason
2014-12-01
We examined preferences for different forms of causal explanations for indeterminate situations. Background: Klein and Hoffman distinguished several forms of causal explanations for indeterminate, complex situations: single-cause explanations, lists of causes, and explanations that interrelate several causes. What governs our preferences for single-cause (simple) versus multiple- cause (complex) explanations? In three experiments, we examined the effect of target audience, explanatory context, participant nationality, and explanation type. All participants were college students. Participants were given two scenarios, one regarding the U.S. economic collapse in 2007 to 2008 and the other about the sudden success of the U.S. military in Iraq in 2007. The participants were asked to assess various types of causal explanations for each of the scenarios, with reference to one or more purposes or audience for the explanations. Participants preferred simple explanations for presentation to less sophisticated audiences. Malaysian students of Chinese ethnicity preferred complex explanations more than did American students. The form of presentation made a difference: Participants preferred complex to simple explanations when given a chance to compare the two, but the preference for simple explanations increased when there was no chance for compari- son, and the difference between Americans and Malaysians disappeared. Preferences for explanation forms can vary with the context and with the audience, and they depend on the nature of the alternatives that are provided. Guidance for decision-aiding technology and training systems that provide explanations need to involve consideration of the form and depth of the accounts provided as well as the intended audience.
A new simple form of quark mixing matrix
NASA Astrophysics Data System (ADS)
Qin, Nan; Ma, Bo-Qiang
2011-01-01
Although different parametrizations of quark mixing matrix are mathematically equivalent, the consequences of experimental analysis may be distinct. Based on the triminimal expansion of Kobayashi-Maskawa matrix around the unit matrix, we propose a new simple parametrization. Compared with the Wolfenstein parametrization, we find that the new form is not only consistent with the original one in the hierarchical structure, but also more convenient for numerical analysis and measurement of the CP-violating phase. By discussing the relation between our new form and the unitarity boomerang, we point out that along with the unitarity boomerang, this new parametrization is useful in hunting for new physics.
Validation and reliability of the Turkish Utian Quality-of-Life Scale in postmenopausal women.
Abay, Halime; Kaplan, Sena
2016-04-01
There are a limited number of menopause-specific quality-of-life scales for the Turkish population. This study was conducted to evaluate the validity and reliability of the Turkish Utian Quality-of-Life Scale in postmenopausal women. The study group was comprised of 250 postmenopausal women who applied to a training and research hospital's menopause clinic in Turkey. A survey form and the Turkish Utian quality-of-Life Scale were used to collect data, and the Turkish version of Short Form-36 was used to evaluate reliability with an equivalent form. Language-validity, content-validity, and construct-validity methods were used to assess the validity of the scale, and Cronbach's α coefficient calculation and the equivalent-form reliability methods were used to assess the reliability of the scale. The Turkish Utian Quality-of-Life Scale was determined to be a valid and reliable instrument for measuring the quality of life of postmenopausal women. Confirmatory factor analysis demonstrates that the instrument fits well with 23 items and a four-factor model. The Cronbach's α coefficient for the quality-of-life domains were as follows: 0.88 overall, 0.79 health, 0.78 emotional, 0.76 sexual, and 0.75 occupational. Reliability of the instrument was confirmed through significant correlations between scores on the Turkish version of the Utian Quality-of-Life Scale and the Turkish version of the Short Form-36 (r = 0.745, P < 0.001). This research emphasizes that the Turkish Utian Quality-of-Life Scale is reliable and valid in postmenopausal women-it is a useful instrument for measuring quality of life during menopause.
A Simple System for the Early Detection of Breast Cancer
2016-07-01
AWARD NUMBER: W81XWH-14-1-0231 TITLE: A Simple System for Early Detection of Breast Cancer PRINCIPAL INVESTIGATOR: Stephen Johnston CONTRACTING...ADDRESS. 1. REPORT DATE July 2016 2. REPORT TYPE Annual 3. DATES COVERED 1Jul2015 - 30Jun2016 4. TITLE AND SUBTITLE A Simple System for the Early...Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39.18 W81XWH-14-1-0231 Abstract: We invented the immunosignature technology (IMS) as a simple , universal
Life Prediction for a CMC Component Using the NASALIFE Computer Code
NASA Technical Reports Server (NTRS)
Gyekenyesi, John Z.; Murthy, Pappu L. N.; Mital, Subodh K.
2005-01-01
The computer code, NASALIFE, was used to provide estimates for life of an SiC/SiC stator vane under varying thermomechanical loading conditions. The primary intention of this effort is to show how the computer code NASALIFE can be used to provide reasonable estimates of life for practical propulsion system components made of advanced ceramic matrix composites (CMC). Simple loading conditions provided readily observable and acceptable life predictions. Varying the loading conditions such that low cycle fatigue and creep were affected independently provided expected trends in the results for life due to varying loads and life due to creep. Analysis was based on idealized empirical data for the 9/99 Melt Infiltrated SiC fiber reinforced SiC.
Plant species and functional group combinations affect green roof ecosystem functions.
Lundholm, Jeremy; Macivor, J Scott; Macdougall, Zachary; Ranalli, Melissa
2010-03-12
Green roofs perform ecosystem services such as summer roof temperature reduction and stormwater capture that directly contribute to lower building energy use and potential economic savings. These services are in turn related to ecosystem functions performed by the vegetation layer such as radiation reflection and transpiration, but little work has examined the role of plant species composition and diversity in improving these functions. We used a replicated modular extensive (shallow growing- medium) green roof system planted with monocultures or mixtures containing one, three or five life-forms, to quantify two ecosystem services: summer roof cooling and water capture. We also measured the related ecosystem properties/processes of albedo, evapotranspiration, and the mean and temporal variability of aboveground biomass over four months. Mixtures containing three or five life-form groups, simultaneously optimized several green roof ecosystem functions, outperforming monocultures and single life-form groups, but there was much variation in performance depending on which life-forms were present in the three life-form mixtures. Some mixtures outperformed the best monocultures for water capture, evapotranspiration, and an index combining both water capture and temperature reductions. Combinations of tall forbs, grasses and succulents simultaneously optimized a range of ecosystem performance measures, thus the main benefit of including all three groups was not to maximize any single process but to perform a variety of functions well. Ecosystem services from green roofs can be improved by planting certain life-form groups in combination, directly contributing to climate change mitigation and adaptation strategies. The strong performance by certain mixtures of life-forms, especially tall forbs, grasses and succulents, warrants further investigation into niche complementarity or facilitation as mechanisms governing biodiversity-ecosystem functioning relationships in green roof ecosystems.
Plant Species and Functional Group Combinations Affect Green Roof Ecosystem Functions
Lundholm, Jeremy; MacIvor, J. Scott; MacDougall, Zachary; Ranalli, Melissa
2010-01-01
Background Green roofs perform ecosystem services such as summer roof temperature reduction and stormwater capture that directly contribute to lower building energy use and potential economic savings. These services are in turn related to ecosystem functions performed by the vegetation layer such as radiation reflection and transpiration, but little work has examined the role of plant species composition and diversity in improving these functions. Methodology/Principal Findings We used a replicated modular extensive (shallow growing- medium) green roof system planted with monocultures or mixtures containing one, three or five life-forms, to quantify two ecosystem services: summer roof cooling and water capture. We also measured the related ecosystem properties/processes of albedo, evapotranspiration, and the mean and temporal variability of aboveground biomass over four months. Mixtures containing three or five life-form groups, simultaneously optimized several green roof ecosystem functions, outperforming monocultures and single life-form groups, but there was much variation in performance depending on which life-forms were present in the three life-form mixtures. Some mixtures outperformed the best monocultures for water capture, evapotranspiration, and an index combining both water capture and temperature reductions. Combinations of tall forbs, grasses and succulents simultaneously optimized a range of ecosystem performance measures, thus the main benefit of including all three groups was not to maximize any single process but to perform a variety of functions well. Conclusions/Significance Ecosystem services from green roofs can be improved by planting certain life-form groups in combination, directly contributing to climate change mitigation and adaptation strategies. The strong performance by certain mixtures of life-forms, especially tall forbs, grasses and succulents, warrants further investigation into niche complementarity or facilitation as mechanisms governing biodiversity-ecosystem functioning relationships in green roof ecosystems. PMID:20300196
NASA Astrophysics Data System (ADS)
Carny, Ohad; Gazit, Ehud
2011-04-01
Any attempt to uncover the origins of life must tackle the known `blind watchmaker problem'. That is to demonstrate the likelihood of the emergence of a prebiotic system simple enough to be formed spontaneously and yet complex enough to allow natural selection that will lead to Darwinistic evolution. Studies of short aromatic peptides revealed their ability to self-assemble into ordered and stable structures. The unique physical and chemical characteristics of these peptide assemblies point out to their possible role in the origins of life. We have explored mechanisms by which self-assembling short peptides and RNA fragments could interact together and go through a molecular co-evolution, using diphenylalanine supramolecular assemblies as a model system. The spontaneous formation of these self-assembling peptides under prebiotic conditions, through the salt-induced peptide formation (SIPF) pathway was demonstrated. These peptide assemblies possess the ability to bind and stabilize ribonucleotides in a sequence-depended manner, thus increase their relative fitness. The formation of these peptide assemblies is dependent on the homochirality of the peptide monomers: while homochiral peptides (L-Phe-L-Phe and D-Phe-D-Phe) self-assemble rapidly in aqueous environment, heterochiral diastereoisomers (L-Phe-D-Phe and D-Phe-L-Phe) do not tend to self-assemble. This characteristic consists with the homochirality of all living matter. Finally, based on these findings, we propose a model for the role of short self-assembling peptides in the prebiotic molecular evolution and the origin of life.
Carny, Ohad; Gazit, Ehud
2011-04-01
Any attempt to uncover the origins of life must tackle the known 'blind watchmaker problem'. That is to demonstrate the likelihood of the emergence of a prebiotic system simple enough to be formed spontaneously and yet complex enough to allow natural selection that will lead to Darwinistic evolution. Studies of short aromatic peptides revealed their ability to self-assemble into ordered and stable structures. The unique physical and chemical characteristics of these peptide assemblies point out to their possible role in the origins of life. We have explored mechanisms by which self-assembling short peptides and RNA fragments could interact together and go through a molecular co-evolution, using diphenylalanine supramolecular assemblies as a model system. The spontaneous formation of these self-assembling peptides under prebiotic conditions, through the salt-induced peptide formation (SIPF) pathway was demonstrated. These peptide assemblies possess the ability to bind and stabilize ribonucleotides in a sequence-depended manner, thus increase their relative fitness. The formation of these peptide assemblies is dependent on the homochirality of the peptide monomers: while homochiral peptides (L-Phe-L-Phe and D-Phe-D-Phe) self-assemble rapidly in aqueous environment, heterochiral diastereoisomers (L-Phe-D-Phe and D-Phe-L-Phe) do not tend to self-assemble. This characteristic consists with the homochirality of all living matter. Finally, based on these findings, we propose a model for the role of short self-assembling peptides in the prebiotic molecular evolution and the origin of life.
Microscopic Observation of Self-Propagation of Calcifying Nanoparticles (Nanobacteria)
NASA Technical Reports Server (NTRS)
Mathew, Grace; McKay, David S.; Ciftcioglu, Neva
2007-01-01
Biologists typically define living organisms as carbon and water-based cellular forms with :self-replication" as the fundamental trait of the life process. However, this standard dictionary definition of life does not help scientists to categorize self-replicators like viruses, prions, proteons and artificial life. CNP also named nanobacteria were discovered in early 1990s as about 100 nanometer-sized bacteria-like particles with unique apatite mineral-shells around them, and found to be associated with pathological-calcification related diseases. Although CNP have been isolated and cultured from mammalian blood and diseased calcified tissues, and their biomineralizing properties well established, their biological nature and self-replicating capability have always been severely challenged. The terms "self-replication", "self-assembly" or "self-propagation" have been widely used for all systems including nanomachines, crystals, computer viruses and memes. In a simple taxonomy, all biological and non-biological "self replicators", have been classified into "living" or "nonliving" based on the properties of the systems and the amount of support they require to self-replicate. To enhance our understanding about self-replicating nature of CNP, we have investigated their growth in specific culture conditions using conventional inverted light microscope and BioStation IM, Nikon s latest time-lapse imaging system. Their morphological structure was examined using scanning (SEM) and transmission (TEM) electron microscopy. This present study, in conjunction with previous findings of metabolic activity, antibiotic sensitivity, antibody specificity, morphological aspects and infectivity, all concomitantly validate CNP as living self-replicators.
Diffusional transport and predicting oxidative failure during cyclic oxidation of beta-NiAl alloys
NASA Technical Reports Server (NTRS)
Nesbitt, J. A.; Vinarcik, E. J.; Barrett, C. A.; Doychak, J.
1992-01-01
Nickel aluminides (NiAl) containing 40-50 at. percent Al and up to 0.1 at. percent Zr have been studied following cyclic oxidation at 1200, 1300, 1350 and 1400 C. The selective oxidation of aluminum resulted in the formation of protective Al2O3 scales on each alloy composition at each temperature. However, repeated cycling eventually resulted in the gradual formation of less protective NiAl2O4. The appearance of the NiAl2O4, signaling the end of the protective scale-forming capability of the alloy, was related to the presence of gamma-prime-(Ni3Al) which formed as a result of the loss of aluminum from the sample. A simple methodology is presented to predict the protective life of beta-NiAl alloys. This method predicts the oxidative lifetime due to aluminum depletion when the aluminum concentration decreases to a critical concentration. The time interval preceding NiAl2O4 formation (i.e., the lifetime based on protective Al2O3 formation) and predicted lifetimes are compared and discussed. Use of the method to predict the maximum use temperature for NiAl-Zr alloys is also discussed.
'Yeast mail': a novel Saccharomyces application (NSA) to encrypt messages.
Rosemeyer, Helmut; Paululat, Achim; Heinisch, Jürgen J
2014-09-01
The universal genetic code is used by all life forms to encode biological information. It can also be used to encrypt semantic messages and convey them within organisms without anyone but the sender and recipient knowing, i.e., as a means of steganography. Several theoretical, but comparatively few experimental, approaches have been dedicated to this subject, so far. Here, we describe an experimental system to stably integrate encrypted messages within the yeast genome using a polymerase chain reaction (PCR)-based, one-step homologous recombination system. Thus, DNA sequences encoding alphabetical and/or numerical information will be inherited by yeast propagation and can be sent in the form of dried yeast. Moreover, due to the availability of triple shuttle vectors, Saccharomyces cerevisiae can also be used as an intermediate construction device for transfer of information to either Drosophila or mammalian cells as steganographic containers. Besides its classical use in alcoholic fermentation and its modern use for heterologous gene expression, we here show that baker's yeast can thus be employed in a novel Saccharomyces application (NSA) as a simple steganographic container to hide and convey messages. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.
Schreibersite: an effective catalyst in the formose reaction network
NASA Astrophysics Data System (ADS)
Pallmann, S.; Šteflová (neé Svobodová, J.; Haas, M.; Lamour, S.; Henß, A.; Trapp, O.
2018-05-01
We report on the ability of the meteoritic material schreibersite to catalyze the generation of higher sugars from simple carbohydrates in the formose reaction network. Since the analysis of carbonaceous meteorites like the Murchison meteorite it has become generally accepted that a substantial amount of organic material has been delivered to the early earth and, therefore, ought to be considered in scenarios for the origin(s) of life. Also for the open question of accessible phosphorus sources, an extraterrestrial material called schreibersite has been identified that is capable of releasing soluble and reactive phosphorus oxyanions that would react with organics to form for instance nucleotides and membrane associated molecules. We have reinvestigated this material using capillary electrophoresis to monitor its corrosion process in water and probed its ability to phosphorylate a wide range of organics. Although showing a poor reactivity of schreibersite, we have found that the material catalyzes the aldol reaction of small carbohydrates forming larger sugar molecules. This reaction in the formose reaction network is a prebiotically likely route to biologically relevant sugars. The results of our study present one of the first instances of connecting extraterrestrial material to prebiotic chemistry on the early earth.
Generalisation of physical habitat-discharge relationships
NASA Astrophysics Data System (ADS)
Booker, D. J.; Acreman, M. C.
2007-01-01
Physical habitat is increasingly used worldwide as a measure of river ecosystem health when assessing changes to river flows, such as those caused by abstraction. The major drawback with this approach is that defining precisely the relationships between physical habitat and flow for a given river reach requires considerable data collection and analysis. Consequently, widely used models such as the Physical Habitat Simulation (PHABSIM) system are expensive to apply. There is, thus, a demand for rapid methods for defining habitat-discharge relationships from simple field measurements. This paper reports the analysis of data from 63 sites in the UK where PHABSIM has been applied. The results demonstrate that there are strong relationships between single measurements of channel form and river hydraulics and the habitat available for target species. The results can form the basis of a method to estimate sensitivity of physical habitat to flow change by visiting a site at only one flow. Furthermore, the uncertainty in estimates reduces as more information is collected. This allows the user to select the level of investment in data collection appropriate for the desired confidence in the estimates. The method is demonstrated using habitat indicators for different life stages of Atlantic salmon, brown trout, roach and dace.
Scrunching: a novel escape gait in planarians
NASA Astrophysics Data System (ADS)
Cochet-Escartin, Olivier; Mickolajczyk, Keith J.; Collins, Eva-Maria S.
2015-10-01
The ability to escape a predator or other life-threatening situations is central to animal survival. Different species have evolved unique strategies under anatomical and environmental constraints. In this study, we describe a novel musculature-driven escape gait in planarians, ‘scrunching’, which is quantitatively different from other planarian gaits, such as gliding and peristalsis. We show that scrunching is a conserved gait among different flatworm species, underlying its importance as an escape mechanism. We further demonstrate that it can be induced by a variety of physical stimuli, including amputation, high temperature, electric shock and low pH. We discuss the functional basis for scrunching as the preferential gait when gliding is impaired due to a disruption of mucus production. Finally, we show that the key mechanical features of scrunching are adequately captured by a simple biomechanical model that is solely based on experimental data from traction force microscopy and tissue rheology without fit parameters. Together, our results form a complete description of this novel form of planarian locomotion. Because scrunching has distinct dynamics, this gait can serve as a robust behavioral readout for studies of motor neuron and muscular functions in planarians and in particular the restoration of these functions during regeneration.
The memory failures of everyday questionnaire (MFE): internal consistency and reliability.
Montejo Carrasco, Pedro; Montenegro, Peña Mercedes; Sueiro, Manuel J
2012-07-01
The Memory Failures of Everyday Questionnaire (MFE) is one of the most widely-used instruments to assess memory failures in daily life. The original scale has nine response options, making it difficult to apply; we created a three-point scale (0-1-2) with response choices that make it easier to administer. We examined the two versions' equivalence in a sample of 193 participants between 19 and 64 years of age. The test-retest reliability and internal consistency of the version we propose were also computed in a sample of 113 people. Several indicators attest to the two forms' equivalence: the correlation between the items' means (r = .94; p < .001) and the order of the items' frequencies (r = .92; p < .001). However, the correlation between global scores on the two forms was not very high (r = .67; p < .001). The results indicate this new version has adequate reliability and internal consistency (r(xx) = .83; p < .001; alpha = .83; p < .001) equivalent to those of the MFE 1-9. The MFE 0-2 provides a brief, simple evaluation, so we recommend it for use in clinical practice as well as research.
Simple method for forming thin-wall pressure vessels
NASA Technical Reports Server (NTRS)
Erickson, A. L.; Guist, L. R.
1972-01-01
Application of internal hydrostatic pressure to seam-welded circular cylindrical tanks having corner-welded, flat, circular ends forms large thin-walled high quality tanks. Form limits expansion of cylindrical portion of final tank while hemispherical ends develop freely; no external form or restraint is required to fabricate spherical tanks.
Ma, Wentao
2016-09-26
Although biology has achieved great successes in recent years, we have not got a clear idea on "what is life?" Actually, as explained here, the main reason for this situation is that there are two completely distinct aspects for "life", which are usually talked about together. Indeed, in respect to these two aspects: Darwinian evolution and self-sustaining, we must split the concept of life correspondingly, for example, by defining "life form" and "living entity", separately. For life's implementation (related to the two aspects) in nature, three mechanisms are crucial: the replication of DNA/RNA-like polymers by residue-pairing, the sequence-dependent folding of RNA/protein-like polymers engendering special functions, and the assembly of phospholipid-like amphiphiles forming vesicles. The notion "information" is significant for us to comprehend life phenomenon: the life form of a living entity can just be defined by its genetic information; Darwinian evolution is essentially an evolution of such information, transferred across generations. The in-depth analysis concerning the essence of life would improve our cognition in the whole field of biology, and may have a direct influence on its subfields like the origin of life, artificial life and astrobiology. This article was reviewed by Anthony Poole and Thomas Dandekar.
Service, Elisabet; Maury, Sini
2015-01-01
Working memory (WM) has been described as an interface between cognition and action, or a system for access to a limited amount of information needed in complex cognition. Access to morphological information is needed for comprehending and producing sentences. The present study probed WM for morphologically complex word forms in Finnish, a morphologically rich language. We studied monomorphemic (boy), inflected (boy+’s), and derived (boy+hood) words in three tasks. Simple span, immediate serial recall of words, in Experiment 1, is assumed to mainly rely on information in the focus of attention. Sentence span, a dual task combining sentence reading with recall of the last word (Experiment 2) or of a word not included in the sentence (Experiment 3) is assumed to involve establishment of a search set in long-term memory for fast activation into the focus of attention. Recall was best for monomorphemic and worst for inflected word forms with performance on derived words in between. However, there was an interaction between word type and experiment, suggesting that complex span is more sensitive to morphological complexity in derivations than simple span. This was explored in a within-subjects Experiment 4 combining all three tasks. An interaction between morphological complexity and task was replicated. Both inflected and derived forms increased load in WM. In simple span, recall of inflectional forms resulted in form errors. Complex span tasks were more sensitive to morphological load in derived words, possibly resulting from interference from morphological neighbors in the mental lexicon. The results are best understood as involving competition among inflectional forms when binding words from input into an output structure, and competition from morphological neighbors in secondary memory during cumulative retrieval-encoding cycles. Models of verbal recall need to be able to represent morphological as well as phonological and semantic information. PMID:25642181
NOAA Workforce Management Office
Request Forms Military Service Deposit Information NOAA Forms OPM Forms Performance Management Request Home Careers at NOAA Search Criteria Click to Search WORKFORCE MANAGEMENT OFFICE NATIONAL OCEANIC Federal Employees Health (FEHB) Life (FEGLI) Life Insurance and Active Duty Information Long Term Care
ERIC Educational Resources Information Center
Cinici, Ayhan
2013-01-01
The purpose of this study was a qualitative analysis of high school students' ideas about life cycle and life forms of the butterfly. For this purpose, open-ended questions and drawing methods were applied to 194 high school students from the ninth to eleventh grades and 14 to 16 years of age in Erzurum, Turkey. Students' drawings were categorised…
NASA Astrophysics Data System (ADS)
Szelepcsényi, Zoltán; Breuer, Hajnalka; Sümegi, Pál
2014-05-01
Nowadays more and more environmental lobbyists believe that climate change must be demonstrated in a new form. The estimated temperature increase can be realized more easily, if the emphasis is on ecological effects of the predicted temperature. For this reason a bioclimatic classification method was used to analyse the projected changes for the Carpathian Basin region. We applied the Holdridge life zone system, which is relatively simple, so our results can be used to inform the population. Holdridge developed a geometric model for climate classification which declares the relationship between classes (life zones) and climate indices (mean annual biotemperature, average total annual precipitation, potential evapotranspiration ratio). The necessary data for this study was derived from regional climate model (RCM) experiments of the ENSEMBLES project using the SRES A1B emission scenario. The temperature and precipitation data series were bias corrected for the selected RCM simulations. The target area of our investigations is the Carpathian Basin region. Life zones maps were created using the selected RCM simulations and their ensemble mean for the periods: 1961-1990 (T1), 2021-2050 (T2), 2061-2090 (T3). The spatial distribution of life zones and their temporal changes were investigated. According to our results the spatial pattern of life zones changes significantly from T1 to T3. It is possible that some types of life zones (e.g. boreal rain forest) will disappear; and some types (e.g. warm temperate thorn steppe) will appear in the target area. We determined those RCM simulations which predicted the maximum and minimum changes of the spatial pattern of life zones. Maps of T1 were compared to maps of T3 using Cohen's Kappa coefficient. Furthermore, relative extents, vertical distribution patterns and mean centres of life zones have been analysed. These parameters were defined for each decade and also for T1, T2 and T3. The temporal changes of the decadal values were analysed with Mann-Kendall trend test. Overall, our results predict that the mean centres of life zones will shift towards north in most cases. This research was supported by the European Union and the State of Hungary, co-financed by the European Social Fund in the framework of TÁMOP-4.2.4.A/ 2-11/1-2012-0001 'National Excellence Program'.
NASA Technical Reports Server (NTRS)
Jadaan, Osama
2001-01-01
Present capabilities of the NASA CARES/Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code include probabilistic life prediction of ceramic components subjected to fast fracture, slow crack growth (stress corrosion), and cyclic fatigue failure modes. Currently, this code has the capability to compute the time-dependent reliability of ceramic structures subjected to simple time-dependent loading. For example, in slow crack growth (SCG) type failure conditions CARES/Life can handle the cases of sustained and linearly increasing time-dependent loads, while for cyclic fatigue applications various types of repetitive constant amplitude loads can be accounted for. In real applications applied loads are rarely that simple, but rather vary with time in more complex ways such as, for example, engine start up, shut down, and dynamic and vibrational loads. In addition, when a given component is subjected to transient environmental and or thermal conditions, the material properties also vary with time. The objective of this paper is to demonstrate a methodology capable of predicting the time-dependent reliability of components subjected to transient thermomechanical loads that takes into account the change in material response with time. In this paper, the dominant delayed failure mechanism is assumed to be SCG. This capability has been added to the NASA CARES/Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code, which has also been modified to have the ability of interfacing with commercially available FEA codes executed for transient load histories. An example involving a ceramic exhaust valve subjected to combustion cycle loads is presented to demonstrate the viability of this methodology and the CARES/Life program.
Porpiglia, Francesco; Fiori, Cristian; Cavallone, Barbara; Morra, Ivano; Bertolo, Riccardo; Scarpa, Roberto Mario
2011-05-01
Laparoscopic simple prostatectomy has been proposed to treat large glands. To date groups have investigated the feasibility and perioperative results of laparoscopic simple prostatectomy but to our knowledge no study has focused on its complications and functional results at longer followup. We investigated complications and functional results in patients with a large prostate who were treated with laparoscopic simple prostatectomy and had at least 1 year of followup. From our prospectively maintained database we extracted data on 78 patients treated with laparoscopic simple prostatectomy at our institution who had at least 1 year of reported followup. Demographics, perioperative results, early and late complications, and functional results were evaluated. Followup was planned at 1, 3, 6 and 12 months, and every 6 months thereafter. Mean followup was 30 months. Grade III complications were recorded in 2 cases and late complications were reported in 4 (5%). Statistically significant differences were observed in the International Prostate Symptom Score, the International Prostate Symptom Score quality of life index and maximum urine flow when comparing preoperative and postoperative results. No significant differences were recorded in maximum urine flow or the International Prostate Symptom Score quality of life index during followup. Results suggest that laparoscopic simple prostatectomy is safe and effective even after a significant period, as indicated by the low complication rate and positive, stable functional results found during followup. In our opinion laparoscopic simple prostatectomy can be offered to patients as a valid treatment option for a large prostate at advanced laparoscopic centers. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
Bacillus Endospores - an ideal exobiological Tool
NASA Astrophysics Data System (ADS)
Moeller, R.; Horneck, G.
Exobiology investigations have one overall goal -- finding the answer to the question if Earth is the only possible place in our universe where life was created. For tackling this question a good approach is to use a simple and ubiquitous system like bacteria as used in BIOPAN and EXPOSE. Many of these microorganisms have the ability to form metabolic inactive continuous forms such as Bacillus endospores. These spores are highly resistant against a variety of environmental stresses, such as toxic chemical agents, desiccation, high and low pressure, high doses of ionising and UV radiation and temperature extremes such as heat or permafrost. They are ubiquitous, inhabit soils and rocks and are easily disseminated by wind and water. Therefore they are suitable test systems for studying several questions of astrobiology, such as the theory of Panspermia, planetary protection issues in connection with missions to Mars or Europa, or chances for life on past or present Mars. The strategies Bacillus sp. endospores have developed to survive harsh conditions include a desiccated spore core, an altered conformation of their DNA (A-form), high concentration of small acid-soluble proteins (SASPs) stabilising the DNA, dipicolinic acid (DPA) for stabilisation and protective spore coating layers. We have investigated the role of endogenous and exogenous pigments in the UV-resistance of Bacillus endospores by using spores of different degree and kind of pigmentation, i.e. white, grey or red spores (DSMZ culture collection). The spectral ranges of UV radiation represented those of the early or present UV radiation climate of Earth or Mars. It was found, that endogenous carotenoids, identified by spectrophotometrical analysis from a spore extract as well as in-situ by Raman spectroscopy, efficiently protect against UV-A radiation, whereas melanin was also protective against UV-C radiation. From these studied follows, that highly pigmented spores might survive even in an intense UV radiation climate, such as that on Mars or early Earth.
The emergence and early evolution of biological carbon-fixation.
Braakman, Rogier; Smith, Eric
2012-01-01
The fixation of CO₂ into living matter sustains all life on Earth, and embeds the biosphere within geochemistry. The six known chemical pathways used by extant organisms for this function are recognized to have overlaps, but their evolution is incompletely understood. Here we reconstruct the complete early evolutionary history of biological carbon-fixation, relating all modern pathways to a single ancestral form. We find that innovations in carbon-fixation were the foundation for most major early divergences in the tree of life. These findings are based on a novel method that fully integrates metabolic and phylogenetic constraints. Comparing gene-profiles across the metabolic cores of deep-branching organisms and requiring that they are capable of synthesizing all their biomass components leads to the surprising conclusion that the most common form for deep-branching autotrophic carbon-fixation combines two disconnected sub-networks, each supplying carbon to distinct biomass components. One of these is a linear folate-based pathway of CO₂ reduction previously only recognized as a fixation route in the complete Wood-Ljungdahl pathway, but which more generally may exclude the final step of synthesizing acetyl-CoA. Using metabolic constraints we then reconstruct a "phylometabolic" tree with a high degree of parsimony that traces the evolution of complete carbon-fixation pathways, and has a clear structure down to the root. This tree requires few instances of lateral gene transfer or convergence, and instead suggests a simple evolutionary dynamic in which all divergences have primary environmental causes. Energy optimization and oxygen toxicity are the two strongest forces of selection. The root of this tree combines the reductive citric acid cycle and the Wood-Ljungdahl pathway into a single connected network. This linked network lacks the selective optimization of modern fixation pathways but its redundancy leads to a more robust topology, making it more plausible than any modern pathway as a primitive universal ancestral form.
Grass meristems II: inflorescence architecture, flower development and meristem fate.
Tanaka, Wakana; Pautler, Michael; Jackson, David; Hirano, Hiro-Yuki
2013-03-01
Plant development depends on the activity of various types of meristems that generate organs such as leaves and floral organs throughout the life cycle. Grass species produce complex inflorescences and unique flowers. The grass inflorescence is composed of different types of branches, including a specialized branch called a spikelet. The spikelet is a special unit of the inflorescence and forms one to several florets, depending on the species. In the floret, floral organs such as perianth organs, carpels and stamens are formed. In Arabidopsis, because the inflorescence meristem (IM) forms the floral meristems (FMs) directly on its flanks, the change of meristem fate is relatively simple. In contrast, in grasses, different types of meristem, such as the IM, the branch meristem (BM), the spikelet pair meristem (SPM) in some grasses, the spikelet meristem (SM) and the FM, are responsible for the elaboration of their complex inflorescences and flowers. Therefore, sequential changes of meristem fate are required, and a number of genes involved in the specification of the fate of each meristem have been identified. In this review, we focus on the following issues concerning the fate of the reproductive meristems in two grass species, maize (Zea mays) and rice (Oryza sativa): (i) meristem regulation during inflorescence development; (ii) specification and fate change of the BM and the SM; (iii) determinacy of the FM; and (iv) communication between the meristem and lateral organs.
Fracture mechanics life analytical methods verification testing
NASA Technical Reports Server (NTRS)
Favenesi, J. A.; Clemmons, T. G.; Lambert, T. J.
1994-01-01
Verification and validation of the basic information capabilities in NASCRAC has been completed. The basic information includes computation of K versus a, J versus a, and crack opening area versus a. These quantities represent building blocks which NASCRAC uses in its other computations such as fatigue crack life and tearing instability. Several methods were used to verify and validate the basic information capabilities. The simple configurations such as the compact tension specimen and a crack in a finite plate were verified and validated versus handbook solutions for simple loads. For general loads using weight functions, offline integration using standard FORTRAN routines was performed. For more complicated configurations such as corner cracks and semielliptical cracks, NASCRAC solutions were verified and validated versus published results and finite element analyses. A few minor problems were identified in the basic information capabilities of the simple configurations. In the more complicated configurations, significant differences between NASCRAC and reference solutions were observed because NASCRAC calculates its solutions as averaged values across the entire crack front whereas the reference solutions were computed for a single point.
Applying the payoff time framework to carotid artery disease management.
Yuo, Theodore H; Roberts, Mark S; Braithwaite, R Scott; Chang, Chung-Chou H; Kraemer, Kevin L
2013-11-01
and Asymptomatic stenosis of the carotid arteries is associated with stroke. Carotid revascularization can reduce the future risk of stroke but can also trigger an immediate stroke. The objective was to model the generic relationship between immediate risk, long-term benefit, and life expectancy for any one-time prophylactic treatment and then apply the model to the use of revascularization in the management of asymptomatic carotid disease. In the "payoff time" framework, the possibility of losing quality-adjusted life-years (QALYs) because of revascularization failure is conceptualized as an "investment" that is eventually recouped over time, on average. Using this framework, we developed simple mathematical forms that define relationships between the following: perioperative probability of stroke (P); annual stroke rate without revascularization (r0); annual stroke rate after revascularization, conditional on not having suffered perioperative stroke (r1); utility levels assigned to the asymptomatic state (ua) and stroke state (us); and mortality rates (λ). In patients whose life expectancy is below a critical life expectancy (CLE = P/(1-P)r0-r1, the "investment" will never pay off, and revascularization will lead to loss of QALYs, on average. CLE is independent of utilities assigned to the health states if a rank ordering exists in which ua > us. For clinically relevant values (P = 3%, r0 = 1%, r1 = 0.5%), the CLE is approximately 6.4 years, which is longer than published guidelines regarding patient selection for revascularization. In managing asymptomatic carotid disease, the payoff time framework specifies a CLE beneath which patients, on average, will not benefit from revascularization. This formula is suitable for clinical use at the patient's bedside and can account for patient variability, the ability of clinicians who perform revascularization, and the particular revascularization technology that is chosen.
Sevoflurane therapy for life-threatening acute severe asthma: a case report.
Ruszkai, Zoltán; Bokrétás, Gergely Péter; Bartha, Péter Töhötöm
2014-10-01
Acute severe asthma is a life-threatening form of bronchial constriction in which the progressively worsening airway obstruction is unresponsive to the usual appropriate bronchodilator therapy. Pathophysiological changes restrict airflow, which leads to premature closure of the airway on expiration, impaired gas exchange, and dynamic hyperinflation ("air-trapping"). Additionally, patients suffering from asthma for a prolonged period of time usually have serious comorbidities. These conditions constitute a challenge during the treatment of this disease. Therapeutic interventions are designed to reduce airway resistance and improve respiratory status. To achieve therapeutic goals, appropriate bronchodilator treatment is indispensable, and mechanical ventilation under adequate sedation may also be required. The volatile anesthetic agent, sevoflurane, meets both criteria; therefore, its use can be beneficial and should be considered. A 67-yr-old Caucasian male presented with acute life-threatening asthma provoked by an assumed upper airway infection and non-steroidal anti-inflammatory drug antipyretics, complicated by chronic atrial fibrillation and hemodynamic instability. Due to frequent premature ventricular contractions, conventional treatment was considered unsafe and discontinued, and sevoflurane inhalation was initiated via the AnaConDa (Anaesthetic Conserving Device). Symptoms of life-threatening bronchospasm resolved, and the patient's respiratory status improved within hours. Adequate sedation was also achieved without any hemodynamic adverse effects. The volatile anesthetic agent, sevoflurane, is used widely in anesthesia practice. Its utility for treatment of refractory bronchospasm has been appreciated for years; however, its administration was difficult within the environment of the intensive care unit due to the need for an anesthesia machine and a scavenging system. The introduction of the AnaConDa eliminates these obstacles and makes the use of sevoflurane safe and simple. Our case report reveals the potential of sevoflurane as a "two-in-one" (bronchodilator and sedative) drug to treat a severe acute asthma attack.
NASA Astrophysics Data System (ADS)
Esteban, S. B.
Man has always wondered about the origins of humanity, life, and the world around him. The Earth crust is a vast and natural archive, and its rocks represent the pages of the most documented events in the geological past. These rocks hold large amounts of information about the Earth history, whose age is estimated to be 4,600 million years. Historical Geology seeks to bring together the knowledge of the origin of the Universe as well as the origin of Earth as a member of the Solar System. The Big Bang theory supposes that the Universe began with a huge explosion. In the Earth's history it is possible to differentiate the biological events from the physical ones. The physical events are geographical and environmental transformations. The biological events are related to life on Earth. There are evidences of biological processes back to 3,500 million years ago. At the beginning, the conditions on Earth were catastrophic and unstable. At this stage, the first signs of life were the molecules that started to take energy from the sunlight and the chemical products. It was not a simple accumulation of gradual biological forms, but was accompanied by episodic innovations that allowed increasing complexity and greater use of ecospace. Some of these innovations are shown by certain groups of primitive arthropods adapted to live in oxygen-poor, deep marine environments. These arthropods have been found in 500 million-year-old rocks in northwestern Argentina (provinces of Jujuy and La Rioja), indicating the presence of oxygen-poor seas in that region.
Shim, Jae-Hyun; Yoon, Sang-Young; Lee, Chang-Hoon; Doh, Jae-Won; Bae, Hack-Gun
2014-01-01
Objective We assessed the life-time prevalence (LTP) of chronic low back pain (LBP) in young Korean males. We also evaluated the relationship between lumbar spinal lesions and their health related quality-of-life (HRQOL). Methods A cross-sectional, self-reported survey was conducted in Korean males (aged 19-year-old) who underwent physical examinations for the conscript. We examined 3331 examinees in November 2014. We included 2411 subjects, who accepted to participate this study without any comorbidities. We interviewed using simple binary questions for their LBP experience and chronicity. HRQOL was assessed by Short-Form Health-Survey-36 (SF-36) in chronic LBP and healthy control groups. Radiological assessment was performed in chronic LBP group to determine whether there were any pathological causes of their symptoms. Results The LTP of chronic LBP was 13.4%. Most (71.7%) of them didn't have any lumbar spinal lesions (i.e., non-specific chronic LBP). The SF-36 subscale and summary scores were significantly lower in subjects with chronic LBP. Between specific and non-specific chronic LBP group, all physical and mental subscale scores were significantly lower in specific chronic LBP group, except mental health (MH) subscale score. In MH subscale and mental component summary score, statistical significant differences didn't appear between two groups (p=0.154, 0.126). Conclusion In Korean males 19 years of age, the LTP of chronic LBP was 13.4%, and more than two-thirds were non-specific chronic LBP. Chronic LBP had a significant impact on HRQOL. The presence of lumbar spinal pathoanatomical lesions affected mainly on the physical aspect of HRQOL. It influenced little on the mental health. PMID:25628807
Why Interstellar Ices Can Be Considered As Precursors For Prebiotic Chemistry
NASA Astrophysics Data System (ADS)
Hendecourt, Louis Le Sergeant d.; de Marcellus, Pierre; Meinert, Cornelia; Myrgorodska, Iuliia; Nahon, Laurent; Modica, Paola; Buhse, Thomas; Meierhenrich, Uwe J.
2015-08-01
Interstellar ices made of simple molecules (H2O, CO, CO2, CH3OH, NH3, CH4…) are abundant species observed in molecular clouds where stars and planetary systems form. Since the constitutive elements (H, O, C, N, S, P) are the most cosmically abundant and condensible, they favor the making of ices on grains. In the mantles formed, a rich organic chemistry develops, thanks to the protective nature of the grains. This chemistry leads to a high complexity. Radical chemistry generated by photo/thermo-chemical processes on the surfaces, leaves to the formation of organic residues as those produced in our laboratory using ice templates, and further studied, using methods that pertain mostly to analytical chemistry. The organic material formed may resemble the Soluble Organic Matter observed in pristine meteorites. From numerous amino acids [1], aldehydes and sugars [2] detected in these residues to chiral molecules and enantiomeric excesses produced by Vacuum Ultra-Violet Circularly Polarized Light from synchrotron radiation [3], one might seriously ask whether the chemistry of molecular clouds out of which stars, planetary systems and debris form, may not be seriously considered as the precursor of prebiotic chemistry in a given environment such as the surface of a telluric planet. I will present the general frame of these experiments in relation to the possibillity of feeding of the necessary prebiotic chemistry for the origin of life. Certainly, prebiotic chemistry is very different in itself than astrochemistry but the starting bricks issued from astrochemistry may well be necessary for the possibility of the emergence of life on planets under certain assumptions I will briefly discuss.REFERENCES[1] Meinert, C., Filippi, J.-J., de Marcellus, P., Le Sergeant d’Hendecourt, L. and Meierhenrich, U.J., ChemPlusChem, 77, 186-191 (2012).[2] de Marcellus, P., Meinert, C., Myrgorodska, I., Nahon, L., Buhse, T., Le Sergeantd’Hendecourt, L., Meierhenrich, U.J., PNAS, January 12th, 2015[3] Modica, P., Meinert, C. de Marcellus, Nahon, L., Meierhenrich, U.J., Le Sergeant d’Hendecourt, L. Astrophys.J, 788, 79
Origin of the Hawaiian rainforest and its transition states in long-term primary succession
NASA Astrophysics Data System (ADS)
Mueller-Dombois, D.; Boehmer, H. J.
2013-07-01
This paper addresses the question of transition states in the Hawaiian rainforest ecosystem with emphasis on their initial developments. Born among volcanoes in the north central Pacific about 4 million years ago, the Hawaiian rainforest became assembled from spores of algae, fungi, lichens, bryophytes, ferns and from seeds of about 275 flowering plants that over the millennia evolved into ca. 1000 endemic species. Outstanding among the forest builders were the tree ferns (Cibotium spp.) and the 'ōhi'a lehua trees (Metrosideros spp.), which still dominate the Hawaiian rainforest ecosystem today. The structure of this forest is simple. The canopy in closed mature rainforests is dominated by cohorts of Metrosideros polymorpha and the undergrowth by tree fern species of Cibotium. When a new lava flow cuts through this forest, kipuka are formed, i.e., islands of remnant vegetation. On the new volcanic substrate, the assemblage of plant life forms is similar to the assemblage during the evolution of this system. In open juvenile forests, a mat-forming fern, the uluhe fern (Dicranopteris linearis), becomes established. It inhibits further regeneration of the dominant 'ōhi'a tree, thereby reinforcing the cohort structure of the canopy guild. In the later part of its life cycle, the canopy guild breaks down often in synchrony. The trigger is hypothesized to be a climatic perturbation. After the disturbance, the forest becomes reestablished in about 30-40 yr. As the volcanic surfaces age, they go from a mesotrophic to a eutrophic phase, reaching a biophilic nutrient climax by about 1-25 K yr. Thereafter, a regressive oligotrophic phase follows; the soils become exhausted of nutrients. The shield volcanoes break down. Marginally, forest habitats change into bogs and stream ecosystems. The broader 'ōhi'a rainforest redeveloping in the more dissected landscapes of the older islands loses stature, often forming large gaps that are invaded by the aluminum tolerant uluhe fern. The 'ōhi'a trees still thrive on soils rejuvenated from landslides and from Asian dust on the oldest (5 million years old) island Kaua'i but their stature and living biomass is greatly diminished.
... person to repeat a simple sentence, like "The sky is blue." Is the person able to correctly ... to Your Doctor to Create a Plan The Life After Stroke Journey Every stroke recovery is different. ...
Evolution of finite-amplitude localized vortices in planar homogeneous shear flows
NASA Astrophysics Data System (ADS)
Karp, Michael; Shukhman, Ilia G.; Cohen, Jacob
2017-02-01
An analytical-based method is utilized to follow the evolution of localized initially Gaussian disturbances in flows with homogeneous shear, in which the base velocity components are at most linear functions of the coordinates, including hyperbolic, elliptic, and simple shear. Coherent structures, including counterrotating vortex pairs (CVPs) and hairpin vortices, are formed for the cases where the streamlines of the base flow are open (hyperbolic and simple shear). For hyperbolic base flows, the dominance of shear over rotation leads to elongation of the localized disturbance along the outlet asymptote and formation of CVPs. For simple shear CVPs are formed from linear and nonlinear disturbances, whereas hairpins are observed only for highly nonlinear disturbances. For elliptic base flows CVPs, hairpins and vortex loops form initially, however they do not last and break into various vortical structures that spread in the spanwise direction. The effect of the disturbance's initial amplitude and orientation is examined and the optimal orientation achieving maximal growth is identified.
Jenerette, Coretta; Dixon, Jane
2010-10-01
Ethnic and cultural norms influence an individual's assertiveness. In health care, assertiveness may play an important role in health outcomes, especially for predominantly minority populations, such as adults with sickle cell disease. Therefore, it is important to develop measures to accurately assess assertiveness. It is also important to reduce response burden of lengthy instruments while retaining instrument reliability and validity. The purpose of this article is to describe development of a shorter version of the Simple Rathus Assertiveness Schedule (SRAS). Data from a cross-sectional descriptive study of adults with sickle cell disease were used to construct a short form of the SRAS, guided by stepwise regression analysis. The 19-item Simple Rathus Assertiveness Scale-Short Form (SRAS-SF) had acceptable reliability (α = .81) and construct validity and was highly correlated with the SRAS (r = .98, p = .01). The SRAS-SF reduces response burden, while maintaining reliability and validity.
Leadership Begins at the End of Your Comfort Zone
ERIC Educational Resources Information Center
Ryder, Marilou
2013-01-01
The path one chooses in life may not always be an easy one. Through simple acts of failure and disappointment, the author learned a lot about her inspiration to become a leader and what it actually took to make them a reality. As a woman who had little confidence to handle major life changes, the author values every second of the experience.…
The Three Forms of Molecular Oxygen.
ERIC Educational Resources Information Center
Laing, Michael
1989-01-01
Finds that a logical application of the simple rules of the molecular orbital bonding theory for diatomic molecules predicted the existence of three spin isomers of the oxygen molecule: one triplet form with two unpaired electrons and two singlet forms with all electrons paired. (MVL)
A simple method for calculating the characteristics of the Dutch roll motion of an airplane
NASA Technical Reports Server (NTRS)
Klawans, Bernard B
1956-01-01
A simple method for calculating the characteristics of the Dutch roll motion of an airplane is obtained by arranging the lateral equations of motion in such form and order that an iterative process is quickly convergent.
Constraint Programming to Solve Maximal Density Still Life
NASA Astrophysics Data System (ADS)
Chu, Geoffrey; Petrie, Karen Elizabeth; Yorke-Smith, Neil
The Maximum Density Still Life problem fills a finite Game of Life board with a stable pattern of cells that has as many live cells as possible. Although simple to state, this problem is computationally challenging for any but the smallest sizes of board. Especially difficult is to prove that the maximum number of live cells has been found. Various approaches have been employed. The most successful are approaches based on Constraint Programming (CP). We describe the Maximum Density Still Life problem, introduce the concept of constraint programming, give an overview on how the problem can be modelled and solved with CP, and report on best-known results for the problem.
Nursing work life in acute care.
Brooks, Beth A; Anderson, Mary Ann
2004-01-01
The purpose of this project was to explore how acute care nurses in a midwestern state rate the quality of their work life. A simple random sample of 1500 registered nurses was surveyed. Data were collected using Brooks' Quality of Nursing Worklife Survey (Brooks BA. Development of an Instrument to Measure Quality of Nursing Work Life [unpublished doctoral dissertation]. Chicago: University of Illinois at Chicago; 2001). Findings suggested that nursing workload was too heavy, and there was not enough time todo the job well. This study revealed that there remain ongoing and fundamental work life concerns for staff nurses that the profession has neither addressed nor resolved in any meaningful, long-term way.
Advance Care Planning: is quality end of life care really that simple?
Johnson, Stephanie; Kerridge, Ian; Butow, Phyllis N; Tattersall, Martin H N
2017-04-01
The routine implementation of Advance Care Planning (ACP) is now a prominent feature of policy directed at improving end of life care in Australia. However, while complex ACP interventions may modestly reduce medical care at the end of life and enable more people to die at home or outside of acute hospital settings, existing legal, organisational, cultural and conceptual barriers limit the implementation and utility of ACP. We suggest that meaningful improvements in end of life care will not result from the institutionalisation of ACP but from more significant changes to the design and delivery of care. © 2017 Royal Australasian College of Physicians.
NASA Astrophysics Data System (ADS)
Sahlan, Muhamad; Raihani Rahman, Mohammad
2017-07-01
One of many applications of essential oils is as fragrance in perfumery. Menthol, benzyl acetate, and vanillin, each represents olfactive characteristic of peppermint leaves, jasmine flowers, and vanilla beans, are commonly used in perfumery. These components are highly volatile, hence the fragrance components will quickly evaporate resulting in short-lasting scent and low shelf life. In this research, said components have been successfully encapsulated simultaneously inside Polyvinyl Alcohol (PVA) using simple coacervation method to increase its shelf life. Optimization has been done using Central Composite Diagram with 4 independent variables, i.e. composition of menthol, benzyl acetate, vanillin, and tergitol 15-S-9 (as emulsifier). Encapsulation efficiency, loading capacity, and microcapsule size have been measured. In optimized composition of menthol (13.98 %w/w), benzyl acetate (14.75 %w/w), vanillin (17.84 %w/w), and tergitol 15-S-9 (13.4 %w/w) encapsulation efficiency of 97,34% and loading capacity of 46,46% have been achieved. Mean diameter of microcapsule is 20,24 μm and within range of 2,011-36,24 μm. Final product was achieved in the form of cross linked polyvinyl alcohol with hydrogel consistency and orange to yellow in color.
Engen, Steinar; Lande, Russell; Saether, Bernt-Erik
2011-10-01
We analyze weak fluctuating selection on a quantitative character in an age-structured population not subject to density regulation. We assume that early in the first year of life before selection, during a critical state of development, environments exert a plastic effect on the phenotype, which remains constant throughout the life of an individual. Age-specific selection on the character affects survival and fecundity, which have intermediate optima subject to temporal environmental fluctuations with directional selection in some age classes as special cases. Weighting individuals by their reproductive value, as suggested by Fisher, we show that the expected response per year in the weighted mean character has the same form as for models with no age structure. Environmental stochasticity generates stochastic fluctuations in the weighted mean character following a first-order autoregressive model with a temporally autocorrelated noise term and stationary variance depending on the amount of phenotypic plasticity. The parameters of the process are simple weighted averages of parameters used to describe age-specific survival and fecundity. The "age-specific selective weights" are related to the stable distribution of reproductive values among age classes. This allows partitioning of the change in the weighted mean character into age-specific components. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.
A model for genesis of transcription systems.
Burton, Zachary F; Opron, Kristopher; Wei, Guowei; Geiger, James H
2016-01-01
Repeating sequences generated from RNA gene fusions/ligations dominate ancient life, indicating central importance of building structural complexity in evolving biological systems. A simple and coherent story of life on earth is told from tracking repeating motifs that generate α/β proteins, 2-double-Ψ-β-barrel (DPBB) type RNA polymerases (RNAPs), general transcription factors (GTFs), and promoters. A general rule that emerges is that biological complexity that arises through generation of repeats is often bounded by solubility and closure (i.e., to form a pseudo-dimer or a barrel). Because the first DNA genomes were replicated by DNA template-dependent RNA synthesis followed by RNA template-dependent DNA synthesis via reverse transcriptase, the first DNA replication origins were initially 2-DPBB type RNAP promoters. A simplifying model for evolution of promoters/replication origins via repetition of core promoter elements is proposed. The model can explain why Pribnow boxes in bacterial transcription (i.e., (-12)TATAATG(-6)) so closely resemble TATA boxes (i.e., (-31)TATAAAAG(-24)) in archaeal/eukaryotic transcription. The evolution of anchor DNA sequences in bacterial (i.e., (-35)TTGACA(-30)) and archaeal (BRE(up); BRE for TFB recognition element) promoters is potentially explained. The evolution of BRE(down) elements of archaeal promoters is potentially explained.
Catalytic Role of Manganese Oxides in Prebiotic Nucleobases Synthesis from Formamide.
Bhushan, Brij; Nayak, Arunima; Kamaluddin
2016-06-01
Origin of life processes might have begun with the formation of important biomonomers, such as amino acids and nucleotides, from simple molecules present in the prebiotic environment and their subsequent condensation to biopolymers. While studying the prebiotic synthesis of naturally occurring purine and pyrimidine derivatives from formamide, the manganese oxides demonstrated not only good binding for formamide but demonstrated novel catalytic activity. A novel one pot manganese oxide catalyzed synthesis of pyrimidine nucleobases like thymine is reported along with the formation of other nucleobases like purine, 9-(hydroxyacetyl) purine, cytosine, 4(3 H)-pyrimidinone and adenine in acceptable amounts. The work reported is significant in the sense that the synthesis of thymine has exhibited difficulties especially under one pot conditions and also such has been reported only under the catalytic activity of TiO2. The lower oxides of manganese were reported to show higher potential as catalysts and their existence were favored by the reducing atmospheric conditions prevalent on early Earth; thereby confirming the hypothesis that mineral having metals in reduced form might have been more active during the course of chemical evolution. Our results further confirm the role of formamide as a probable precursor for the formation of purine and pyrimidine bases during the course of chemical evolution and origin of life.
The effects of distributed life cycles on the dynamics of viral infections.
Campos, Daniel; Méndez, Vicenç; Fedotov, Sergei
2008-09-21
We explore the role of cellular life cycles for viruses and host cells in an infection process. For this purpose, we derive a generalized version of the basic model of virus dynamics (Nowak, M.A., Bangham, C.R.M., 1996. Population dynamics of immune responses to persistent viruses. Science 272, 74-79) from a mesoscopic description. In its final form the model can be written as a set of Volterra integrodifferential equations. We consider the role of distributed lifespans and a intracellular (eclipse) phase. These processes are implemented by means of probability distribution functions. The basic reproductive ratio R(0) of the infection is properly defined in terms of such distributions by using an analysis of the equilibrium states and their stability. It is concluded that the introduction of distributed delays can strongly modify both the value of R(0) and the predictions for the virus loads, so the effects on the infection dynamics are of major importance. We also show how the model presented here can be applied to some simple situations where direct comparison with experiments is possible. Specifically, phage-bacteria interactions are analyzed. The dynamics of the eclipse phase for phages is characterized analytically, which allows us to compare the performance of three different fittings proposed before for the one-step growth curve.
Kokko, Hanna; Griffith, Simon C; Pryke, Sarah R
2014-10-22
The hawk-dove game famously introduced strategic game theory thinking into biology and forms the basis of arguments for limited aggression in animal populations. However, aggressive 'hawks' and peaceful 'doves', with strategies inherited in a discrete manner, have never been documented in a real animal population. Thus, the applicability of game-theoretic arguments to real populations might be contested. Here, we show that the head-colour polymorphism of red and black Gouldian finches (Erythrura gouldiae) provides a real-life example. The aggressive red morph is behaviourally dominant and successfully invades black populations, but when red 'hawks' become too common, their fitness is severely compromised (via decreased parental ability). We also investigate the effects of real-life deviations, particularly sexual reproduction, from the simple original game, which assumed asexual reproduction. A protected polymorphism requires mate choice to be sufficiently assortative. Assortative mating is adaptive for individuals because of genetic incompatibilities affecting hybrid offspring fitness, but by allowing red 'hawks' to persist, it also leads to significantly reduced population sizes. Because reductions in male contributions to parental care are generally known to lead to lower population productivity in birds, we expect zero-sum competition to often have wide ranging population consequences. © 2014 The Author(s) Published by the Royal Society. All rights reserved.
Benefits of a holistic breathing technique in patients on hemodialysis.
Stanley, Ruth; Leither, Thomas W; Sindelir, Cathy
2011-01-01
Health-related quality of life and heart rate variability are often depressed in patients on hemodialysis. This pilot program used a simple holistic, self-directed breathing technique designed to improve heart rate variability, with the hypothesis that improving heart rate variability would subsequently enhance health-related quality of life. Patient self-reported benefits included reductions in anxiety, fatigue, insomnia, and pain. Using holistic physiologic techniques may offer a unique and alternative tool for nurses to help increase health-related quality of life in patients on hemodialysis.
Simple Recipes for Prebiotic Soup: A High School or Undergraduate Chemistry Laboratory
NASA Astrophysics Data System (ADS)
Martinez-Meeler, Marisol; Aljinovic, Nika; Swain, Dorothy
2003-06-01
A lab activity demonstrating Stanley Miller‘s prebiotic soup experiments is described. This lab activity, which uses only simple, readily available materials and equipment, would be suitable for use in a high school or introductory college chemistry class. The activity starts by asking students to consider some of the debated issues surrounding research into the chemical origins of life on Earth. It continues by having the students set up a simple apparatus that sends an electrical spark through a mixture of methane, ammonia, and water. The experiment concludes (the following week) by having students analyze their reaction products and design their own variation on the experiment.
NASA Technical Reports Server (NTRS)
CraigMcClung, R.; Lee, Yi-Der; Cardinal, Joseph W.; Guo, Yajun
2012-01-01
The elastic stress intensity factor (SIF, commonly denoted as K) is the foundation of practical fracture mechanics (FM) analysis for aircraft structures. This single parameter describes the first-order effects of stress magnitude and distribution as well as the geometry of both structure/component and crack. Hence, the calculation of K is often the most significant step in fatigue analysis based on FM. This presentation will provide several reflections on the current state-of-the-art in SIF solution methods used for practical aerospace applications, including a brief historical perspective, descriptions of some recent and ongoing advances, and comments on some remaining challenges. Newman and Raju made significant early contributions to practical structural analysis by developing closed-form SIF equations for surface and corner cracks in simplified geometries, often based on empirical fits of finite element (FE) solutions. Those solutions (and others like them) were sometimes revised as new analyses were conducted or limitations discovered. The foundational solutions have exhibited striking longevity, despite the relatively "coarse" FE models employed many decades ago. However, in recent years, the accumulation of different generations of solutions for the same nominal geometry has led to some confusion (which solution is correct?), and steady increases in computational capabilities have facilitated the discovery of inaccuracies in some (not all!) of the legacy solutions. Some examples of problems and solutions are presented and discussed, including the challenge of maintaining consistency with legacy design applications. As computational power has increased, the prospect of calculating large numbers of SIF solutions for specific complex geometries with advanced numerical methods has grown more attractive. Fawaz and Andersson, for example, have been generating literally millions of new SIF solutions for different combinations of multiple cracks under simplified loading schemes using p-version FE methods. These data are invaluable, but questions remain about their practical use, because the tabular databases of key results needed to support practical life analysis can occupy gigabytes of storage for only a few classes of geometries. The prospect of using such advanced numerical methods to calculate in real time only those K solutions actually needed to support a specific crack growth analysis is also tempting, but the stark reality is that the computational cost is still so high that the approach is not practical except for specific, critical application problems. Some thoughts are offered about alternative paradigms. Compounding approaches are some of the earliest building blocks of SIF development for more complex geometries. These approaches are especially attractive because of their very low computational cost and their conceptual robustness; they are, in some ways, an intriguing contrast and complement to the brute-force numerical methods. In recent years, researchers at NRC-Canada have published remarkable results showing how compounding approaches can be used to generate accurate solutions for very difficult problems. Examples are provided of some successes--and some limitations--using this approach. These closed-form, tabulated numerical, and compounding approaches have typically been used for simple remote loading with simple load paths to the crack. However, many significant cracks occur in complex stress gradient fields. This is a job for weight function (WF) methods, where the arbitrary stress distribution on the crack plane in the corresponding uncracked body (typically determined using FE methods) is used to determine K. Several significant recent advances in WF methods and solutions are highlighted here. Fueled by advanced 3D numerical methods, many new solutions have been generated for classic geometries such as surface and corner cracks with wide ranges of geometrical validity. A new WF formulation has also be developed for part-through cracks considering the arbitrary stress gradients in all directions in the crack plane (so-called bivariant solutions). Basic WF methods have recently been combined with analytical expressions for crack plane stresses to develop a large family of accurate SIF solutions for corner, surface, and through cracks at internal or external notches with very wide ranges of shapes, sizes, acuities, and offsets. Finally, WF solutions are much faster than FE or boundary element solutions, but can still be much slower than simple closed-form solutions, especially for bivariant solutions that can require 2D numerical integration. Novel pre-integration and dynamic tabular methods have been developed that substantially increase the speed of these advanced WF solutions. The practical utility of advanced SIF methods, including both WF and direct numerical methods, is greatly enhanced if the FM life analysis can be directly and efficiently linked with digital models of the actual structure or component (e.g., FE models for stress analysis). Two recent advances of this type will be described. One approach directly interfaces the FM life analysis with the FE model of the uncracked component (including stress results). Through a powerful graphical user interface, simplified FM life models can be constructed (and visualized) directly on the component model, with the computer collecting the geometry and stress gradient information needed for the life calculation. An even more powerful paradigm uses expert logic to automatically build an optimum simple fracture model at any and every desired location in the component model, perform the life calculation, and even generate fatigue crack growth life contour maps, all with minimal user intervention. This paradigm has also been extended to the automatic calculation of fracture risk, considering uncertainty or variability in key input parameters such as initial crack size or location. Another new integrated approach links the engineering life analysis, the component model, and a 3D numerical fracture analysis built with the same component model to generate a table of SIF values at a specific location that can then be employed efficiently to perform the life calculation. Some attention must be given to verification and validation (V&V) issues and challenges: how good are these SIF solutions, how good is good enough, and does anyone believe the life answer? It is important to think critically about the different sources of error or uncertainty and to perform V&V in a hierarchal, building-block manner. Some accuracy issues for SIF solutions, for example, may actually involve independent material behavior issues, such as constraint loss effects for crack fronts near component surfaces, and can be a source of confusion. Recommendations are proposed for improved V&V approaches. This presentation will briefly but critically survey the range of issues and advances mentioned above, with a particular view towards assembling an integrated approach that combines different methods to create practical tools for real-world design and analysis problems. Examples will be selectively drawn from the recent literature, from recent enhancements in the NASGRO and DARWIN computer codes, and from previously unpublished research
76 FR 12417 - Proposed Collection; Comment Request for Form 8925
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-07
..., Public Law 104-13 (44 U.S.C. 3506(c)(2)(A)). Currently, the IRS is soliciting comments concerning Form 8925, Report of Employer-Owned Life Insurance Contracts. DATES: Written comments should be received on... . SUPPLEMENTARY INFORMATION: Title: Report of Employer-Owned Life Insurance Contracts. OMB Number: 1545-2089. Form...
Sunter, Jack D.; Benz, Corinna; Andre, Jane; Whipple, Sarah; McKean, Paul G.; Gull, Keith; Ginger, Michael L.; Lukeš, Julius
2015-01-01
ABSTRACT The cell shape of Trypanosoma brucei is influenced by flagellum-to-cell-body attachment through a specialised structure – the flagellum attachment zone (FAZ). T. brucei exhibits numerous morphological forms during its life cycle and, at each stage, the FAZ length varies. We have analysed FLAM3, a large protein that localises to the FAZ region within the old and new flagellum. Ablation of FLAM3 expression causes a reduction in FAZ length; however, this has remarkably different consequences in the tsetse procyclic form versus the mammalian bloodstream form. In procyclic form cells FLAM3 RNAi results in the transition to an epimastigote-like shape, whereas in bloodstream form cells a severe cytokinesis defect associated with flagellum detachment is observed. Moreover, we demonstrate that the amount of FLAM3 and its localisation is dependent on ClpGM6 expression and vice versa. This evidence demonstrates that FAZ is a key regulator of trypanosome shape, with experimental perturbations being life cycle form dependent. An evolutionary cell biology explanation suggests that these differences are a reflection of the division process, the cytoskeleton and intrinsic structural plasticity of particular life cycle forms. PMID:26148511
Bit by Bit: The Darwinian Basis of Life
Joyce, Gerald F.
2012-01-01
All known examples of life belong to the same biology, but there is increasing enthusiasm among astronomers, astrobiologists, and synthetic biologists that other forms of life may soon be discovered or synthesized. This enthusiasm should be tempered by the fact that the probability for life to originate is not known. As a guiding principle in parsing potential examples of alternative life, one should ask: How many heritable “bits” of information are involved, and where did they come from? A genetic system that contains more bits than the number that were required to initiate its operation might reasonably be considered a new form of life. PMID:22589698
ERIC Educational Resources Information Center
Stebbins, G. Ledyard
1973-01-01
Describes the basic logic behind the modern view of evolution theory. Despite gaps in fossil records, evidence is indicative of the origin of life from nonliving molecules and evolution of higher forms of life from simpler forms. (PS)
Astrobiological Research on Tardigrades: Implications for Extraterrestrial Life Forms
NASA Astrophysics Data System (ADS)
Horikawa, D. D.
2013-11-01
Tardigrades have been considered as a model for astrobiological studies based on their tolerance to extreme environments. Future research on tardigrades might provide important insight into the possibilities of existence of multicellular life forms.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ian Metzger, Jesse Dean
2010-12-31
This software requires inputs of simple water fixture inventory information and calculates the water/energy and cost benefits of various retrofit opportunities. This tool includes water conservation measures for: Low-flow Toilets, Low-flow Urinals, Low-flow Faucets, and Low-flow Showheads. This tool calculates water savings, energy savings, demand reduction, cost savings, and building life cycle costs including: simple payback, discounted payback, net-present value, and savings to investment ratio. In addition this tool also displays the environmental benefits of a project.
Jones, Jordan T; Carle, Adam C; Wootton, Janet; Liberio, Brianna; Lee, Jiha; Schanberg, Laura E; Ying, Jun; Morgan DeWitt, Esi; Brunner, Hermine I
2017-01-01
To validate the pediatric Patient-Reported Outcomes Measurement Information System short forms (PROMIS-SFs) in childhood-onset systemic lupus erythematosus (SLE) in a clinical setting. At 3 study visits, childhood-onset SLE patients completed the PROMIS-SFs (anger, anxiety, depressive symptoms, fatigue, physical function-mobility, physical function-upper extremity, pain interference, and peer relationships) using the PROMIS assessment center, and health-related quality of life (HRQoL) legacy measures (Pediatric Quality of Life Inventory, Childhood Health Assessment Questionnaire, Simple Measure of Impact of Lupus Erythematosus in Youngsters [SMILEY], and visual analog scales [VAS] of pain and well-being). Physicians rated childhood-onset SLE activity on a VAS and completed the Systemic Lupus Erythematosus Disease Activity Index 2000. Using a global rating scale of change (GRC) between study visits, physicians rated change of childhood-onset SLE activity (GRC-MD1: better/same/worse) and change of patient overall health (GRC-MD2: better/same/worse). Questionnaire scores were compared in support of validity and responsiveness to change (external standards: GRC-MD1, GRC-MD2). In this population-based cohort (n = 100) with a mean age of 15.8 years (range 10-20 years), the PROMIS-SFs were completed in less than 5 minutes in a clinical setting. The PROMIS-SF scores correlated at least moderately (Pearson's r ≥ 0.5) with those of legacy HRQoL measures, except for the SMILEY. Measures of childhood-onset SLE activity did not correlate with the PROMIS-SFs. Responsiveness to change of the PROMIS-SFs was supported by path, mixed-model, and correlation analyses. To assess HRQoL in childhood-onset SLE, the PROMIS-SFs demonstrated feasibility, internal consistency, construct validity, and responsiveness to change in a clinical setting. © 2016, American College of Rheumatology.
Learning to see, seeing to learn: visual aspects of sensemaking
NASA Astrophysics Data System (ADS)
Russell, Daniel M.
2003-06-01
When one says "I see," what is usually meant is "I understand." But what does it mean to create a sense of understanding a large, complex, problem, one with many interlocking pieces, sometimes ill-fitting data and the occasional bit of contradictory information? The traditional computer science perspective on helping people towards understanding is to provide an armamentarium of tools and techniques - databases, query tools and a variety of graphing methods. As a field, we have an overly simple perspective on what it means to grapple with real information. In practice, people who try to make sense of some thing (say, the life sciences, the Middle East, the large scale structure of the universe, their taxes) are faced with a complex collection of information, some in easy-to-digest structured forms, but with many relevant parts scattered hither and yon, in forms and shapes too difficult to manage. To create an understanding, we find that people create representations of complex information. Yet using representations relies on fairly sophisticated perceptual practices. These practices are in no way preordained, but subject to the kinds of perceptual and cognitive phenomena we see in every day life. In order to understand our information environments, we need to learn to perceive these perceptual elements, and understand when they do, and do not, work to our advantage. A more powerful approach to the problem of supporting realistic sensemaking practice is to design information environments that accommodate both the world"s information realities and people"s cognitive characteristics. This paper argues that visual aspects of representation use often dominate sensemaking behavior, and illustrates this by showing three sensemaking tools we have built that take advantage of this property.
Automated Oligopeptide Formation Under Simple Programmable Conditions
NASA Astrophysics Data System (ADS)
Suárez-Marina, I.; Rodriguez-Garcia, M.; Surman, A. J.; Cooper, G. J. T.; Cronin, L.
2017-07-01
Traditionally, prebiotic chemistry has investigated the formation of life's precursors under very specific conditions thought to be "plausible". Herein, we explore peptide formation studying several parameters at once by using an automated platform.
Heated Aluminum Tanks Resist Corrosion
NASA Technical Reports Server (NTRS)
Johnson, L. E.
1983-01-01
Simple expedient of heating foam-insulated aluminum alloy tanks prevents corrosion by salt-laden moisture. Relatively-small temperature difference between such tank and surrounding air will ensure life of tank is extended by many years.
How a life-like system emerges from a simplistic particle motion law.
Schmickl, Thomas; Stefanec, Martin; Crailsheim, Karl
2016-11-30
Self-structuring patterns can be observed all over the universe, from galaxies to molecules to living matter, yet their emergence is waiting for full understanding. We discovered a simple motion law for moving and interacting self-propelled particles leading to a self-structuring, self-reproducing and self-sustaining life-like system. The patterns emerging within this system resemble patterns found in living organisms. The emergent cells we found show a distinct life cycle and even create their own ecosystem from scratch. These structures grow and reproduce on their own, show self-driven behavior and interact with each other. Here we analyze the macroscopic properties of the emerging ecology, as well as the microscopic properties of the mechanism that leads to it. Basic properties of the emerging structures (size distributions, longevity) are analyzed as well as their resilience against sensor or actuation noise. Finally, we explore parameter space for potential other candidates of life. The generality and simplicity of the motion law provokes the thought that one fundamental rule, described by one simple equation yields various structures in nature: it may work on different time- and size scales, ranging from the self-structuring universe, to emergence of living beings, down to the emergent subatomic formation of matter.
NASA Technical Reports Server (NTRS)
Warmflash, D.; Larios-Sanz, M.; Fox, G. E.; McKay, D. S.
2002-01-01
To demonstrate the feasibility of two promising technologies, we have applied Enzyme-Linked Immunosorbent Assay (ELISA) as well as probes that target the 16S rRNA molecule to search for life in terrestrial soil samples, known to contain numerous life forms. Additional information is contained in the original extended abstract.
Spectrum analysis of radar life signal in the three kinds of theoretical models
NASA Astrophysics Data System (ADS)
Yang, X. F.; Ma, J. F.; Wang, D.
2017-02-01
In the single frequency continuous wave radar life detection system, based on the Doppler effect, the theory model of radar life signal is expressed by the real function, and there is a phenomenon that can't be confirmed by the experiment. When the phase generated by the distance between the measured object and the radar measuring head is л of integer times, the main frequency spectrum of life signal (respiration and heartbeat) is not existed in radar life signal. If this phase is л/2 of odd times, the main frequency spectrum of breath and heartbeat frequency is the strongest. In this paper, we use the Doppler effect as the basic theory, using three different mathematical expressions——real function, complex exponential function and Bessel's function expansion form. They are used to establish the theoretical model of radar life signal. Simulation analysis revealed that the Bessel expansion form theoretical model solve the problem of real function form. Compared with the theoretical model of the complex exponential function, the derived spectral line is greatly reduced in the theoretical model of Bessel expansion form, which is more consistent with the actual situation.
Let's do science with children
NASA Astrophysics Data System (ADS)
Paolini, Mara
2013-04-01
The school where I worked in 2011,was for primary school teachers-to-be. Classes were formed by a high number of students with a handicapped student in each class. The school was attended mainly by girls with low self-esteem and difficulties in fulfilling their homework. Moreover secondary school students often find science far from their world and rather boring. So helping them understand the relationship between science and everyday life, between chemistry and society was my main objective . Simple / elementary experiments were chosen : if presented and carried out with scientific method, they can prove very useful in the development of specific abilities, from simple observation to the more complex and vital ability to grasp cause and effect relation. I think that the direct observation of facts and phenomena is the foundation to stimulate the process of learning and abstracting experiments: A. The pressure as a force, the behavior of the hot and cold water. 1. the implosion of the can 2. the candle 3. the balloon and the bottle 4. the egg in the bottle Monitoring and evaluation The direct observation of students during operations and final written reports were the ways which was evaluated the project. Results of the project carried out: The students were able to use scientific language correctly, to explain the phenomenon to primary school children using their own ideas. they also devised a table where to list the experiments carried out
Student Annotation Form To Capture Reflections on Work Samples in Portfolios.
ERIC Educational Resources Information Center
Brookhart, Susan M.
Evidence is presented for the validity and reliability of a student annotation form used to collect student reflections on work samples in portfolios. The form was designed to be general enough to apply to many grades and subjects and simple enough for students at all levels to complete. The annotation forms asked students to indicate how…
Simple Elasticity Modeling and Failure Prediction for Composite Flexbeams
NASA Technical Reports Server (NTRS)
Makeev, Andrew; Armanios, Erian; OBrien, T. Kevin (Technical Monitor)
2001-01-01
A simple 2D boundary element analysis, suitable for developing cost effective models for tapered composite laminates, is presented. Constant stress and displacement elements are used. Closed-form fundamental solutions are derived. Numerical results are provided for several configurations to illustrate the accuracy of the model.
NASA Technical Reports Server (NTRS)
Dittman, R. A.; Marks, V.
1983-01-01
Management Information System, MIS, provides Life Sciences Projects Division at Johnson Space Center with automated system for project managment. MIS utilizes Tektronix 4027 color graphics display terminal and form-fillout capability. User interface with MIS data base is through series of forms.
Cross-Cultural Adaptation of the Physician Orders for Life-Sustaining Treatment Form to Brazil.
Mayoral, Vania F S; Fukushima, Fernanda B; Rodrigues, Aniela M; Carvalho, Raissa P; Carvalho, Larissa P; Pinheiro, Leandro A F V; Polegato, Bertha F; Minicucci, Marcos F; Bassett, Rick; Moss, Alvin H; Steinberg, Karl E; Vidal, Edison I O
2018-06-01
The Physician Orders for Life-Sustaining Treatment (POLST) paradigm is considered one of the most important strategies to respect patients' values at the end of life in the United States. The cross-cultural adaptation of POLST entailed several methodological considerations, which may be informative for international researchers who may also consider bringing POLST to their countries as a means to promote care at the end of life that is consistent with patients' preferences. To report the methods and outcome of the cross-cultural adaptation of the POLST form to Brazil. Cross-cultural adaptation study. Twenty physicians and 10 patients at a university hospital participated in the pilot tests. The cross-cultural adaptation process included choosing which existing POLST form(s) to use as a source, deciding the intended reading level, which healthcare professionals should be allowed to sign the form, and consultation with attorneys, bioethicists, and members of the National POLST Paradigm Task Force. Pilot tests occurred in two stages using different approaches. First, 20 physicians were trained about POLST and asked for any unclear aspects related to the form. Second, trained investigators completed POLST forms after engaging in advance care planning conversations with 10 hospitalized patients or patients' surrogates. This report provides a basis for future cross-cultural adaptations of POLST to other countries. The authors hope such new adaptations will broaden the possibilities of research using POLST and also may promote wider provision of care at the end of life that is consistent with patients' preferences.
Correlations of Life Form, Pollination Mode and Sexual System in Aquatic Angiosperms
Du, Zhi-Yuan; Wang, Qing-Feng
2014-01-01
Aquatic plants are phylogenetically well dispersed across the angiosperms. Reproductive and other life-history traits of aquatic angiosperms are closely associated with specific growth forms. Hydrophilous pollination exhibits notable examples of convergent evolution in angiosperm reproductive structures, and hydrophiles exhibit great diversity in sexual system. In this study, we reconstructed ancestral characters of aquatic lineages based on the phylogeny of aquatic angiosperms. Our aim is to find the correlations of life form, pollination mode and sexual system in aquatic angiosperms. Hydrophily is the adaptive evolution of completely submersed angiosperms to aquatic habitats. Hydroautogamy and maleflower-ephydrophily are the transitional stages from anemophily and entomophily to hydrophily. True hydrophily occurs in 18 submersed angiosperm genera, which is associated with an unusually high incidence of unisexual flowers. All marine angiosperms are submersed, hydrophilous species. This study would help us understand the evolution of hydrophilous pollination and its correlations with life form and sexual system. PMID:25525810
On the applicability of dialetheism and philosophy of identity to the definition of life
NASA Astrophysics Data System (ADS)
Kolb, Vera M.
2010-04-01
We have found that the principles of dialetheism, which state that some contradictions (typically at the limits of a system) may be true, and which amply demonstrate the limits of thought and conception, can be valuable in sorting out and clarifying some astrobiological problems that impede our ability to define life. The examples include the classification of viruses as alive or not alive, and the description of the transition zone for the abiotic-to-biotic transition. Dialetheism gives us the philosophical tool to state that the viruses may be both alive and not alive, and that chemical systems may exist that are both abiotic and biotic. We have extracted some philosophical principles of the identity and have applied them to the identity of living organisms and their life forms. The first and most important idea is that we should define an individual organism via its numerical identity. For each organism its identity will be in relation to itself. As the organism undergoes various changes during its development, and as it transitions from one to the next of its life forms, one can observe numerous qualitative differences between these life forms. Although the life forms change and the organism is in a flux, what remains constant is the numerical identity of the organism. If the organism reproduces, for example by a fission mode, then the daughter cells will have their own numerical identity. We can state that the life of an organism is a sum of all its life forms over the period of time of the existence of the organism. Reproduction, particularly by fission, represents an identity dilemma, but it can be resolved by Gallois' occasional identities theory.
NASA Astrophysics Data System (ADS)
Potashko, Oleksandr
Volcanoes engender life on heavenly bodies; they are pacemakers of life. All planets during their period of formation pass through volcanism hence - all planets and their satellites pass through the life. Tracks of life If we want to find tracks of life - most promising places are places with volcanic activity, current or past. In the case of just-in-time volcanic activity we have 100% probability to find a life. Therefore the most perspective “search for life” are Enceladus, Io and comets, further would be Venus, Jupiter’s satellites, Saturn’s satellites and first of all - Titan. Titan has atmosphere. It might be result of high volcanic activity - from one side, from other side atmosphere is a necessary condition development life from procaryota to eucaryota. Existence of a planet means that all its elements after hydrogen formed just there inside a planet. The forming of the elements leads to the formation of mineral and organic substances and further to the organic life. Development of the life depends upon many factors, e.g. the distance from star/s. The intensity of the processes of the element formation is inversely to the distance from the star. Therefore we may suppose that the intensity of the life in Mercury was very high. Hence we may detect tracks of life in Mercury, particularly near volcanoes. The distance from the star is only one parameter and now Titan looks very active - mainly due to interior reason. Its atmosphere compounds are analogous to comet tail compounds. Their collation may lead to interesting result as progress occurs at one of them. Volcanic activity is as a source of life origin as well a reason for a death of life. It depends upon the thickness of planet crust. In the case of small thickness of a crust the probability is high that volcanoes may destroy a life on a planet - like Noachian deluge. Destroying of the life under volcano influences doesn’t lead to full dead. As result we would have periodic Noachian deluge or nuclear winter. These events are known as extinctions or ice ages. The crust of a planet of the Earth group is formed at the outer edge of the body. The planets after asteroid belt like Jupiter or Saturn probably form their “crusts” in the centre of the body. Due to we may see internal kitchen of element forming in detail. This processes lead to the organic life, which we may detect at the atmospheres of Jupiter, Saturn, Neptune, and Pluto. But their satellites look like earth planet group - with outer crust. Huygens considered that God's wisdom and providence is clearest in the creation of life, and Earth holds no privileged position in the heavens that life must be universal. “Huygens” helps find life on Titan
Okun, Morris A; Kim, Ga Young
2016-01-01
One developmental task in emerging adulthood is finding meaning and purpose in life. Volunteering has been touted as one role that fosters purpose in life. We examined whether the association between frequency of volunteering and purpose in life varies with pleasure-based prosocial motivation and pressure-based prosocial motivation in a sample of 576 undergraduates, ages 18-22 years old. In a regression analysis predicting purpose in life, the frequency of volunteering by pleasure-based prosocial motivation by pressure-based prosocial motivation interaction effect was significant (p = .042). Simple slopes analyses revealed that frequency of volunteering was not significantly (p = .478) related to purpose in life among college students who were low in both pleasure-based and pressure-based prosocial motivation. The findings of the present study highlight the importance of prosocial motivation for understanding whether emerging adults' purpose in life will be enhanced by volunteering.
Holomorphic projections and Ramanujan’s mock theta functions
Imamoğlu, Özlem; Raum, Martin; Richter, Olav K.
2014-01-01
We use spectral methods of automorphic forms to establish a holomorphic projection operator for tensor products of vector-valued harmonic weak Maass forms and vector-valued modular forms. We apply this operator to discover simple recursions for Fourier series coefficients of Ramanujan’s mock theta functions. PMID:24591582
Chiral Determination of Amino Acids Using X-Ray Diffraction of Thin Films
NASA Technical Reports Server (NTRS)
Dragoi, D.; Kulleck, J.; Kanik, I.; Beegle, L. W.
2003-01-01
The astrobiological search for life, both extinct and extant, on other solar system bodies will take place via several planned lander missions to Mars Europa and Titan. The detection and identification of organic molecules that have been associated with life is a major technical challenge. Terrestrial life utilizes organic molecules, such as amino acids, as its basic building block. Amino acids can be synthesized by natural processes as is demonstrated by their detection in meteoritic material. In this process, the organic molecules are produced roughly in a even mixture of D and L forms. Biological process, however, can utilize almost uniquely one form or the other. In terrestrial biology, only the L-amino acids is common in biological processes. If signature of life existed elsewhere in the D form it then be concluded that life had evolutionary beginning on that body. Detection of an enantiomeric excess of L over D would also be a powerful sign that life had existed on that body at one time.
DNA as Genetic Material: Revisiting Classic Experiments through a Simple, Practical Class
ERIC Educational Resources Information Center
Malago, Wilson, Jr.; Soares-Costa, Andrea; Henrique-Silva, Flavio
2009-01-01
In 1928, Frederick Griffith demonstrated a transmission process of genetic information by transforming "Pneumococcus". In 1944, Avery et al. demonstrated that Griffith's transforming principle was DNA. We revisited these classic experiments in a practical class for undergraduate students. Both experiments were reproduced in simple, adapted forms.…
ERIC Educational Resources Information Center
Cepic, Mojca
2008-01-01
Light beams in wavy unclear water, also called underwater rays, and caustic networks of light formed at the bottom of shallow water are two faces of a single phenomenon. Derivation of the caustic using only simple geometry, Snell's law and simple derivatives accounts for observations such as the existence of the caustic network on vertical walls,…
75 FR 2545 - Call for Collaborating Partners for National Women's Health Week
Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-15
... expressions of interest by February 28, 2010. ADDRESSES: Expressions of interest, comments, and questions may... simple steps for a longer, healthier and happier life. For more information about National Women's Health...
Arakaki, Yoko; Fujiwara, Takayuki; Kawai-Toyooka, Hiroko; Kawafune, Kaoru; Featherston, Jonathan; Durand, Pierre M; Miyagishima, Shin-Ya; Nozaki, Hisayoshi
2017-12-06
The volvocine lineage, containing unicellular Chlamydomonas reinhardtii and differentiated multicellular Volvox carteri, is a powerful model for comparative studies aiming at understanding emergence of multicellularity. Tetrabaena socialis is the simplest multicellular volvocine alga and belongs to the family Tetrabaenaceae that is sister to more complex multicellular volvocine families, Goniaceae and Volvocaceae. Thus, T. socialis is a key species to elucidate the initial steps in the evolution of multicellularity. In the asexual life cycle of C. reinhardtii and multicellular volvocine species, reproductive cells form daughter cells/colonies by multiple fission. In embryogenesis of the multicellular species, daughter protoplasts are connected to one another by cytoplasmic bridges formed by incomplete cytokinesis during multiple fission. These bridges are important for arranging the daughter protoplasts in appropriate positions such that species-specific integrated multicellular individuals are shaped. Detailed comparative studies of cytokinesis between unicellular and simple multicellular volvocine species will help to elucidate the emergence of multicellularity from the unicellular ancestor. However, the cytokinesis-related genes between closely related unicellular and multicellular species have not been subjected to a comparative analysis. Here we focused on dynamin-related protein 1 (DRP1), which is known for its role in cytokinesis in land plants. Immunofluorescence microscopy using an antibody against T. socialis DRP1 revealed that volvocine DRP1 was localized to division planes during cytokinesis in unicellular C. reinhardtii and two simple multicellular volvocine species T. socialis and Gonium pectorale. DRP1 signals were mainly observed in the newly formed division planes of unicellular C. reinhardtii during multiple fission, whereas in multicellular T. socialis and G. pectorale, DRP1 signals were observed in all division planes during embryogenesis. These results indicate that the molecular mechanisms of cytokinesis may be different in unicellular and multicellular volvocine algae. The localization of DRP1 during multiple fission might have been modified in the common ancestor of multicellular volvocine algae. This modification may have been essential for the re-orientation of cells and shaping colonies during the emergence of multicellularity in this lineage.
Mathematical Modeling Of Life-Support Systems
NASA Technical Reports Server (NTRS)
Seshan, Panchalam K.; Ganapathi, Balasubramanian; Jan, Darrell L.; Ferrall, Joseph F.; Rohatgi, Naresh K.
1994-01-01
Generic hierarchical model of life-support system developed to facilitate comparisons of options in design of system. Model represents combinations of interdependent subsystems supporting microbes, plants, fish, and land animals (including humans). Generic model enables rapid configuration of variety of specific life support component models for tradeoff studies culminating in single system design. Enables rapid evaluation of effects of substituting alternate technologies and even entire groups of technologies and subsystems. Used to synthesize and analyze life-support systems ranging from relatively simple, nonregenerative units like aquariums to complex closed-loop systems aboard submarines or spacecraft. Model, called Generic Modular Flow Schematic (GMFS), coded in such chemical-process-simulation languages as Aspen Plus and expressed as three-dimensional spreadsheet.
Twelve essential tools for living the life of whole person health care.
Schlitz, Marilyn; Valentina, Elizabeth
2013-01-01
The integration of body, mind, and spirit has become a key dimension of health education and disease prevention and treatment; however, our health care system remains primarily disease centered. Finding simple steps to help each of us find our own balance can improve our lives, our work, and our relationships. On the basis of interviews with health care experts at the leading edge of the new model of medicine, this article identifies simple tools to improve the health of patients and caregivers.
Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-21
... Collection Request Title: Organ and Tissue Donor and Recipient Life Stories Form (OMB No. 0915-xxxx)--NEW... donation. Among the most visited pages on organdonor.gov are the donor and recipient life stories which in... voluntarily submit their stories to DoT via a standardized online form. The online form will be posted on...
Sharma, M; Shukla, Y
2009-11-01
The discovery of Precambrian microfossils in 1954 opened a new vista of investigations in the field of evolution of life. Although the Precambrian encompasses 87% of the earth's history, the pace of organismal evolution was quite slow. The life forms as categorised today in the three principal domains viz. the Bacteria, the Archaea and the Eucarya evolved during this period. In this paper, we review the advancements made in the Precambrian palaeontology and its contribution in understanding the evolution of life forms on earth. These studies have enriched the data base on the Precambrian life. Most of the direct evidence includes fossil prokaryotes, protists, advanced algal fossils, acritarchs, and the indirect evidence is represented by the stromatolites, trace fossils and geochemical fossils signatures. The Precambrian fossils are preserved in the form of compressions, impressions, and permineralized and biomineralized remains.
Power systems for future missions
NASA Technical Reports Server (NTRS)
Gill, S. P.; Frye, P. E.; Littman, Franklin D.; Meisl, C. J.
1994-01-01
A comprehensive scenario of future missions was developed and applicability of different power technologies to these missions was assessed. Detailed technology development roadmaps for selected power technologies were generated. A simple methodology to evaluate economic benefits of current and future power system technologies by comparing Life Cycle Costs of potential missions was developed. The methodology was demonstrated by comparing Life Cycle Costs for different implementation strategies of DIPS/CBC technology to a selected set of missions.
ERIC Educational Resources Information Center
Rickard, Angela
2014-01-01
Reflecting on my experience as a teacher and a lesbian in a second-level school in Ireland in the early 1990s, I use an auto-ethnographic approach first to explore some of the ways dominant narratives can silence, constrain and marginalise some people. Projecting forward to an imagined future, I draw on creative writing to "re-frame" how…
Death, Taxes and Advance Directives
D’Amore, J.D.; Jones, S.L.; Sittig, D.F.; Ness, R.B.
2014-01-01
Summary Suboptimal care at the end-of-life can be due to lack of access or knowledge of patient wishes. Ambiguity is often the result of non-standardized formats. Borrowing digital technology from other industries and using existing health information infrastructure can greatly improve the completion, storage, and distribution of advance directives. We believe several simple, low-cost adaptations to regional and federal programs can raise the standard of end-of-life care. PMID:25024771
The effect of microstructure, temperature, and hold-time on low-cycle fatigue of As HIP P/M Rene 95
NASA Technical Reports Server (NTRS)
Bashir, S.; Antolovich, S. D.
1984-01-01
The effects of microstructure, temperature, plastic strain range, and hold time on the low-cycle fatigue (LCF) life were studied for Rene 95, an important Ni base superalloy used in jet engine disks. It was shown that the life could be varied by approximately an order of magnitude at elevated temperatures by simple heat treatments. The life was largest for the microstructure that promoted the most homogeneous deformation mode. The results are explained using the concept of a synergistic interaction between the deformation mode and boundary oxidation.
ISSOL Meeting, Barcelona, Spain, 1993
NASA Technical Reports Server (NTRS)
Ferris, James P. (Editor)
1995-01-01
Topics in a conference on the origins of life and the evolution of the biosphere include the origin of chirality, prebiotic chemistry of small biomolecules, primitive polymer formation, RNA regulation and control. Early origins of life and the ecology of hydrothermal systems such as ocean floor vents and their simple organisms are examined. The process of mineral catalysis in Montmorillonite as a model for early metabolism is used. The origin of the genetic code and the development of branching in molecular structures of amino acids is described. Studies are reported of the effects of meteorite impact on early Earth life.
An analysis of life expectancy of airplane wings in normal cruising flight
NASA Technical Reports Server (NTRS)
Putnam, Abbott A
1945-01-01
In order to provide a basis for judging the relative importance of wing failure by fatigue and by single intense gusts, an analysis of wing life for normal cruising flight was made based on data on the frequency of atmospheric gusts. The independent variables considered in the analysis included stress-concentration factor, stress-load relation, wing loading, design and cruising speeds, design gust velocity, and airplane size. Several methods for estimating fatigue life from gust frequencies are discussed. The procedure selected for the analysis is believed to be simple and reasonably accurate, though slightly conservative.
The possibility of life proliferation from Enceladus
NASA Astrophysics Data System (ADS)
Czechowski, Leszek
2016-07-01
Enceladus is a medium sized icy satellite (MIS) of Saturn. MIS are built of mixtures of rocks and ices. According to [1]: "For life to have emerged […] on the early Earth, a sustained source of chemically transducible energy was essential. The serpentinization process is emerging as an increasingly likely source of that energy" (see also [2]). We consider here conditions for origin of life in the early Enceladus and later proliferation of the life. Mass of serpentinite: The serpentinization on the Earth is often considered with hydrothermal activity in neovolcanic zones along mid-oceanic spreading centers. However, only in small part the hydrothermal activity really occurs. A simple calculations (e.g. [3]) indicate that mass fraction of silicates in Enceladus is ~0.646, hence the total mass of its silicate is ~6.97 10^1^9 kg. [4] considered the process of differentiation and core forming in Enceladus. He found that the result of differentiation is a relatively cold core of loosely packed grains with water between them. The entire core of Enceladus was probably permeable. This could lead to formation of extensive hydrothermal convective systems. It indicates that total mass of serpententinized silicate in Enceladus could be larger than on the Earth. The evolution of temperature in the Enceladus interior for the first a few hundreds Myr is given in [4]. He found that the temperature allows for existing the life even in the center of the satellite. It is possible that for hundreds of Myr the conditions in Enceladus were more favorable for origin of life than on the Earth. Proliferation of life: The low gravity of the Enceladus and its volcanic activity make transport possible. Note that the low temperature of plumes from active region of Enceladus does not kill the organisms. The primitive bacteria could leave the Enceladus with volcanic jets in the same way as particles of the E ring. Other mechanisms could transport particles to terrestrial planets. Therefore it is possible that the Enceladus was a cradle of the life in the Solar System. References: [1] Russell, M. J., Hall, A. J., And Martin W. (2010). Geobiology (2010), 8, 355-371. [2] Izawa M.R.M. et al. (2010). Planet. Space Sci. 58, 583-591. [3] Abramov, O., Mojzsis, S.J., (2011) Icarus 213, 273-279. [4] Czechowski, L. (2014) Planet. Space Sci. 104, 185-199
Limits in the evolution of biological form: a theoretical morphologic perspective.
McGhee, George R
2015-12-06
Limits in the evolution of biological form can be empirically demonstrated by using theoretical morphospace analyses, and actual analytic examples are given for univalved ammonoid shell form, bivalved brachiopod shell form and helical bryozoan colony form. Limits in the evolution of form in these animal groups can be shown to be due to functional and developmental constraints on possible evolutionary trajectories in morphospace. Future evolutionary-limit research is needed to analyse the possible existence of temporal constraint in the evolution of biological form on Earth, and in the search for the possible existence of functional alien life forms on Titan and Triton that are developmentally impossible for Earth life.
Stardust: The Cosmic Seeds of Life
NASA Astrophysics Data System (ADS)
Kwok, Sun
How did life originate on Earth? For over 50 years, scientists believed that life was the result of chemistry involving simple molecules such as methane and ammonia cooking in a primordial soup. Recent space observations have revealed that old stars are capable of making very complex organic compounds. The stars then ejected the organics and spread them all over the Milky Way Galaxy. There is evidence that these organic dust particles actually reached the early Solar System. Through bombardments by comets and asteroids, the early Earth inherited significant amounts of star dust. Was the development of life assisted by the arrival of these extraterrestrial materials? In this book, we describe stunning discoveries in astronomy and solar system science over the last 10 years that resulted in a new perspective on the origin of life.
Jeon, S; Djian, P; Green, H
1998-01-20
Epidermal keratinocytes, late in their terminal differentiation, form cross-linked envelopes resistant to ionic detergent and reducing agent. Because the cross-linking process is catalyzed by the keratinocyte transglutaminase, the absence of active transglutaminase should result in failure of the keratinocyte to form a cross-linked envelope. Three keratinocyte strains bearing mutations in the keratinocyte transglutaminase were examined: two contained no detectable transglutaminase mRNA and none contained active enzyme. All three were unable to form cross-linked envelopes, either spontaneously in stratified cultures or upon induction with Ca2+. Although stratum corneum of normal humans and scales from patients with different ichthyotic diseases contain cross-linked envelopes, those from patients with transglutaminase-negative lamellar ichthyosis do not. Therefore, the disease due to the absence of transglutaminase may be readily distinguished from other ichthyotic disease by a simple test for cross-linked envelopes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Van Vleet, Mary J.; Misquitta, Alston J.; Stone, Anthony J.
Short-range repulsion within inter-molecular force fields is conventionally described by either Lennard-Jones or Born-Mayer forms. Despite their widespread use, these simple functional forms are often unable to describe the interaction energy accurately over a broad range of inter-molecular distances, thus creating challenges in the development of ab initio force fields and potentially leading to decreased accuracy and transferability. Herein, we derive a novel short-range functional form based on a simple Slater-like model of overlapping atomic densities and an iterated stockholder atom (ISA) partitioning of the molecular electron density. We demonstrate that this Slater-ISA methodology yields a more accurate, transferable, andmore » robust description of the short-range interactions at minimal additional computational cost compared to standard Lennard-Jones or Born-Mayer approaches. Lastly, we show how this methodology can be adapted to yield the standard Born-Mayer functional form while still retaining many of the advantages of the Slater-ISA approach.« less
BioFed: federated query processing over life sciences linked open data.
Hasnain, Ali; Mehmood, Qaiser; Sana E Zainab, Syeda; Saleem, Muhammad; Warren, Claude; Zehra, Durre; Decker, Stefan; Rebholz-Schuhmann, Dietrich
2017-03-15
Biomedical data, e.g. from knowledge bases and ontologies, is increasingly made available following open linked data principles, at best as RDF triple data. This is a necessary step towards unified access to biological data sets, but this still requires solutions to query multiple endpoints for their heterogeneous data to eventually retrieve all the meaningful information. Suggested solutions are based on query federation approaches, which require the submission of SPARQL queries to endpoints. Due to the size and complexity of available data, these solutions have to be optimised for efficient retrieval times and for users in life sciences research. Last but not least, over time, the reliability of data resources in terms of access and quality have to be monitored. Our solution (BioFed) federates data over 130 SPARQL endpoints in life sciences and tailors query submission according to the provenance information. BioFed has been evaluated against the state of the art solution FedX and forms an important benchmark for the life science domain. The efficient cataloguing approach of the federated query processing system 'BioFed', the triple pattern wise source selection and the semantic source normalisation forms the core to our solution. It gathers and integrates data from newly identified public endpoints for federated access. Basic provenance information is linked to the retrieved data. Last but not least, BioFed makes use of the latest SPARQL standard (i.e., 1.1) to leverage the full benefits for query federation. The evaluation is based on 10 simple and 10 complex queries, which address data in 10 major and very popular data sources (e.g., Dugbank, Sider). BioFed is a solution for a single-point-of-access for a large number of SPARQL endpoints providing life science data. It facilitates efficient query generation for data access and provides basic provenance information in combination with the retrieved data. BioFed fully supports SPARQL 1.1 and gives access to the endpoint's availability based on the EndpointData graph. Our evaluation of BioFed against FedX is based on 20 heterogeneous federated SPARQL queries and shows competitive execution performance in comparison to FedX, which can be attributed to the provision of provenance information for the source selection. Developing and testing federated query engines for life sciences data is still a challenging task. According to our findings, it is advantageous to optimise the source selection. The cataloguing of SPARQL endpoints, including type and property indexing, leads to efficient querying of data resources over the Web of Data. This could even be further improved through the use of ontologies, e.g., for abstract normalisation of query terms.
Life: Origin and evolution on Earth--How can we escape?
NASA Technical Reports Server (NTRS)
Markert, Clement L.; Krikorian, Abraham D.
1993-01-01
Exploitation of gene regulation rather than the creation of new genes has been predominantly responsible for the evolutionary advances in animals and plants that are widely recognized today. Until very recently it was not possible to examine life in the absence of gravity. We can now imagine forms of life in the universe adapting to circumstances different from those found on Earth. Our own life forms would surely become different in time if they were transferred to other planets with different conditions, including much lower or higher gravity.
Fern Gametophytes in Culture--A Simple System for Studying Plant Development and Reproduction.
ERIC Educational Resources Information Center
Dyer, A. F.
1983-01-01
Discusses fern life cycle and basic techniques for culturing fern gametophytes in the classroom. Also discusses investigations into the reproductive biology of ferns and into the early development of gametophytes. (JN)
77 FR 15371 - Announcement of Call for Collaborating Partners for National Women's Health Week
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-15
... expressions of interest by April 13, 2012. ADDRESSES: Expressions of interest, comments, and questions may be... simple steps for a longer, healthier, and happier life. For more information about National Women's...
Science in the Service of Religion: The Case of Islam.
ERIC Educational Resources Information Center
King, David A.
1990-01-01
Described is how scholars of medieval Islam used simple and adequate methods for regulating the calendar and prayer-times and for finding the sacred direction. Other applications of science to daily life are provided. (KR)
Code of Federal Regulations, 2010 CFR
2010-04-01
... of withdrawal and refund for variable life insurance contractholders required pursuant to Rule 6e-2... for Exemptions § 274.302 Form N-27I-1, notice of right of withdrawal and refund for variable life insurance contractholders required pursuant to Rule 6e-2 (§ 270.6e-2 of this chapter). [41 FR 47032, Oct. 27...
The cognitive domain of a glider in the game of life.
Beer, Randall D
2014-01-01
This article examines in some technical detail the application of Maturana and Varela's biology of cognition to a simple concrete model: a glider in the game of Life cellular automaton. By adopting an autopoietic perspective on a glider, the set of possible perturbations to it can be divided into destructive and nondestructive subsets. From a glider's reaction to each nondestructive perturbation, its cognitive domain is then mapped. In addition, the structure of a glider's possible knowledge of its immediate environment, and the way in which that knowledge is grounded in its constitution, are fully described. The notion of structural coupling is then explored by characterizing the paths of mutual perturbation that a glider and its environment can undergo. Finally, a simple example of a communicative interaction between two gliders is given. The article concludes with a discussion of the potential implications of this analysis for the enactive approach to cognition.
Chiral encoding may provide a simple solution to the origin of life
NASA Astrophysics Data System (ADS)
Brewer, Ashley; Davis, Anthony P.
2014-07-01
The route by which the complex and specific molecules of life arose from the 'prebiotic soup' remains an unsolved problem. Evolution provides a large part of the answer, but this requires molecules that can carry information (that is, exist in many variants) and can replicate themselves. The process is commonplace in living organisms, but not so easy to achieve with simple chemical systems. It is especially difficult to contemplate in the chemical chaos of the prebiotic world. Although popular in many quarters, the notion that RNA was the first self-replicator carries many difficulties. Here, we present an alternative view, suggesting that there may be undiscovered self-replication mechanisms possible in much simpler systems. In particular, we highlight the possibility of information coding through stereochemical configurations of substituents in organic polymers. We also show that this coding system leads naturally to enantiopurity, solving the apparent problem of biological homochirality.
SIMPL Systems, or: Can We Design Cryptographic Hardware without Secret Key Information?
NASA Astrophysics Data System (ADS)
Rührmair, Ulrich
This paper discusses a new cryptographic primitive termed SIMPL system. Roughly speaking, a SIMPL system is a special type of Physical Unclonable Function (PUF) which possesses a binary description that allows its (slow) public simulation and prediction. Besides this public key like functionality, SIMPL systems have another advantage: No secret information is, or needs to be, contained in SIMPL systems in order to enable cryptographic protocols - neither in the form of a standard binary key, nor as secret information hidden in random, analog features, as it is the case for PUFs. The cryptographic security of SIMPLs instead rests on (i) a physical assumption on their unclonability, and (ii) a computational assumption regarding the complexity of simulating their output. This novel property makes SIMPL systems potentially immune against many known hardware and software attacks, including malware, side channel, invasive, or modeling attacks.
How rare is complex life in the Milky Way?
Bounama, Christine; von Bloh, Werner; Franck, Siegfried
2007-10-01
An integrated Earth system model was applied to calculate the number of habitable Earth-analog planets that are likely to have developed primitive (unicellular) and complex (multicellular) life in extrasolar planetary systems. The model is based on the global carbon cycle mediated by life and driven by increasing stellar luminosity and plate tectonics. We assumed that the hypothetical primitive and complex life forms differed in their temperature limits and CO(2) tolerances. Though complex life would be more vulnerable to environmental stress, its presence would amplify weathering processes on a terrestrial planet. The model allowed us to calculate the average number of Earth-analog planets that may harbor such life by using the formation rate of Earth-like planets in the Milky Way as well as the size of a habitable zone that could support primitive and complex life forms. The number of planets predicted to bear complex life was found to be approximately 2 orders of magnitude lower than the number predicted for primitive life forms. Our model predicted a maximum abundance of such planets around 1.8 Ga ago and allowed us to calculate the average distance between potentially habitable planets in the Milky Way. If the model predictions are accurate, the future missions DARWIN (up to a probability of 65%) and TPF (up to 20%) are likely to detect at least one planet with a biosphere composed of complex life.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-08
... (Application for Ordinary Life Insurance) Activity Under OMB Review AGENCY: Veterans Benefits Administration... for Ordinary Life Insurance, Replacement Insurance for Modified Life Reduced at Age 65, National Service Life Insurance, VA Form 29-8485. b. Application for Ordinary Life Insurance, Replacement Insurance...
Necessary and sufficient conditions for R₀ to be a sum of contributions of fertility loops.
Rueffler, Claus; Metz, Johan A J
2013-03-01
Recently, de-Camino-Beck and Lewis (Bull Math Biol 69:1341-1354, 2007) have presented a method that under certain restricted conditions allows computing the basic reproduction ratio R₀ in a simple manner from life cycle graphs, without, however, giving an explicit indication of these conditions. In this paper, we give various sets of sufficient and generically necessary conditions. To this end, we develop a fully algebraic counterpart of their graph-reduction method which we actually found more useful in concrete applications. Both methods, if they work, give a simple algebraic formula that can be interpreted as the sum of contributions of all fertility loops. This formula can be used in e.g. pest control and conservation biology, where it can complement sensitivity and elasticity analyses. The simplest of the necessary and sufficient conditions is that, for irreducible projection matrices, all paths from birth to reproduction have to pass through a common state. This state may be visible in the state representation for the chosen sampling time, but the passing may also occur in between sampling times, like a seed stage in the case of sampling just before flowering. Note that there may be more than one birth state, like when plants in their first year can already have different sizes at the sampling time. Also the common state may occur only later in life. However, in all cases R₀ allows a simple interpretation as the expected number of new individuals that in the next generation enter the common state deriving from a single individual in this state. We end with pointing to some alternative algebraically simple quantities with properties similar to those of R₀ that may sometimes be used to good effect in cases where no simple formula for R₀ exists.
Hammer, Joseph H; Brenner, Rachel E
2017-07-14
This study extended our theoretical and applied understanding of gratitude through a psychometric examination of the most popular multidimensional measure of gratitude, the Gratitude, Resentment, and Appreciation Test-Revised Short form (GRAT-RS). Namely, the dimensionality of the GRAT-RS, the model-based reliability of the GRAT-RS total score and 3 subscale scores, and the incremental evidence of validity for its latent factors were assessed. Dimensionality measures (e.g., explained common variance) and confirmatory factor analysis results with 426 community adults indicated that the GRAT-RS conformed to a multidimensional (bifactor) structure. Model-based reliability measures (e.g., omega hierarchical) provided support for the future use of the Lack of a Sense of Deprivation raw subscale score, but not for the raw GRAT-RS total score, Simple Appreciation subscale score, or Appreciation of Others subscale score. Structural equation modeling results indicated that only the general gratitude factor and the lack of a sense of deprivation specific factor accounted for significant variance in life satisfaction, positive affect, and distress. These findings support the 3 pillars of gratitude conceptualization of gratitude over competing conceptualizations, the position that the specific forms of gratitude are theoretically distinct, and the argument that appreciation is distinct from the superordinate construct of gratitude.
Control of root meristem establishment in conifers.
Brunoni, Federica; Ljung, Karin; Bellini, Catherine
2018-06-19
The evolution of terrestrial plant life was made possible by the establishment of a root system, which enabled plants to migrate from aquatic to terrestrial habitats. During evolution, root organization has gradually progressed from a very simple to a highly hierarchical architecture. Roots are initiated during embryogenesis and branch afterwards through lateral root formation. Additionally, adventitious roots can be formed post-embryonically from aerial organs. Induction of adventitious roots forms the basis of the vegetative propagation via cuttings in horticulture, agriculture and forestry. This method, together with somatic embryogenesis, is routinely used to clonally multiply conifers. In addition to being utilized as propagation techniques, adventitious rooting and somatic embryogenesis have emerged as versatile models to study cellular and molecular mechanisms of embryo formation and organogenesis of coniferous species. Both formation of the embryonic root and the adventitious root primordia require the establishment of auxin gradients within cells that coordinate the developmental response. These processes also share key elements of the genetic regulatory networks that, for example, are triggering cell fate. This minireview gives an overview of the molecular control mechanisms associated with root development in conifers, from initiation in the embryo to post-embryonic formation in cuttings. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Rejniak, Katarzyna A.; Anderson, Alexander R.A.
2013-01-01
Simple epithelial tissues are organized as single layers of tightly packed cells that surround hollow lumens and form selective barriers separating different internal compartments of the body. The maintenance of epithelial structure and its function requires tight coordination and control of all the life processes of epithelial cells via cell-to-cell communication and signaling. These well-balanced cellular systems are, however, quite often disturbed by genetic or environmental cues that may lead to the formation of epithelial tumors (carcinomas). In fact, more than a half of all diagnosed tumors are initiated from epithelial cells. It is, therefore, important to gain a greater understanding of the factors that form and maintain the epithelial structure, as well as the features of the acinar structure that are modified during cancer development as observable in experimental and clinical research. We address these questions using the bio-mechanical model of the developing hollow epithelial acini introduced in Rejniak and Anderson (Bull. Math. Biol. 70:677–712, 2008). Here, we propose several scenarios involving various bio-mechanical interactions between neighboring cells that result in abnormal acinar development. Whenever possible, we compare our computational results with known experimental cases of mutant acini. PMID:18401665
Pimenta, Fernanda Batista; Pinho, Lucinéia; Silveira, Marise Fagundes; Botelho, Ana Cristina de Carvalho
2015-08-01
The profile of a sample population of elderly receiving treatment under the Family Health Strategy in the municipality of Teófilo Otoni, State of Minas Gerais, Brazil, is described, and the factors associated with diseases prevalence examined. Using simple random sampling, 385 elderly were interviewed using Form A and Elderly Form from the Primary Health Care Information System. The majority of the sample (83.1%) self-reported at least one disease, 69.9% had hypertension, and 17.7% had diabetes. Poisson regression analysis showed that the main factors associated with hypertension and other diseases were being non-white, having a low level of education, medication use, dental prosthesis use, and lack of a private health plan. The prevalence of diabetes was greater among women and individuals who depended on other people to live. It can be concluded that this sample population of elderly has a generally low socioeconomic status and are more susceptible to developing diseases, particularly hypertension. Diabetes should be controlled although had relatively low prevalence. It is suggested investments in structuring the health system network to provide adequate care for the elderly and in training health professionals to play an effective role in improving the quality of life of the elderly in Brazil.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Bin; Xu, Wu; Tao, Jinhui
Although the rechargeable lithium-oxygen (Li-O2) batteries have extremely high theoretical specific energy, the practical application of these batteries is still limited by the instability of their carbon-based air-electrode, Li metal anode, and electrolytes towards reduced oxygen species. Here we demonstrate a simple one-step in-situ electrochemical pre-charging strategy to generate thin protective films on both carbon nanotubes (CNTs) air-electrode and Li metal anode simultaneously under an inert atmosphere. Li-O2 cells after such pre-treatment demonstrate significantly extended cycle life of 110 and 180 cycles under the capacity-limited protocol of 1000 mAh g-1 and 500 mAh g-1, respectively, which is far more thanmore » those without pre-treatment. The thin-films formed from decomposition of electrolyte during in-situ electrochemical pre-charging process in an inert environment can protect both CNTs air-electrode and Li metal anode prior to conventional Li-O2 discharge/charge cycling where reactive reduced oxygen species are formed. This work provides a new approach for protections of carbon-based air-electrode and Li metal anode in practical Li-O2 batteries, and may also be applied to other battery systems.« less
Yu, Wei; Wang, Huwei; Qin, Lei; Hu, Junyang; Liu, Liang; Li, Baohua; Zhai, Dengyun; Kang, Feiyu
2018-05-23
Understanding the electrochemical property of superoxides in alkali metal oxygen batteries is critical for the design of a stable oxygen battery with high capacity and long cycle performance. In this work, a KO 2 -decorated binder-free cathode is fabricated by a simple and efficient electrochemical strategy. KO 2 nanoparticles are uniformly coated on the carbon nanotube film (CNT-f) through a controllable discharge process in the K-O 2 battery, and the KO 2 -decorated CNT-f is innovatively introduced into the Li-O 2 battery as the O 2 diffusion electrode. The Li-O 2 battery based on the KO 2 -decorated CNT-f cathode can deliver enhanced discharge capacity, reduced charge overpotential, and more stable cycle performance compared with the battery in the absence of KO 2 . In situ formed KO 2 particles on the surface of CNT-f cathode assist to form Li 2 O 2 nanosheets in the Li-O 2 battery, which contributes to the improvement of discharge capacity and cycle life. Interestingly, the analysis of KO 2 -decorated CNT-f cathodes, after discharge and cycle tests, reveals that the electrochemically synthesized KO 2 seems not a conventional electrocatalyst but a partially dissolvable and decomposable promoter in Li-O 2 batteries.
Evolutionary construction by staying together and coming together.
Tarnita, Corina E; Taubes, Clifford H; Nowak, Martin A
2013-03-07
The evolutionary trajectory of life on earth is one of increasing size and complexity. Yet the standard equations of evolutionary dynamics describe mutation and selection among similar organisms that compete on the same level of organization. Here we begin to outline a mathematical theory that might help to explore how evolution can be constructive, how natural selection can lead from lower to higher levels of organization. We distinguish two fundamental operations, which we call 'staying together' and 'coming together'. Staying together means that individuals form larger units by not separating after reproduction, while coming together means that independent individuals form aggregates. Staying together can lead to specialization and division of labor, but the developmental program must evolve in the basic unit. Coming together can be creative by combining units with different properties. Both operations have been identified in the context of multicellularity, but they have been treated very similarly. Here we point out that staying together and coming together can be found at every level of biological construction and moreover that they face different evolutionary problems. The distinction is particularly clear in the context of cooperation and defection. For staying together the stability of cooperation takes the form of a developmental error threshold, while coming together leads to evolutionary games and requires a mechanism for the evolution of cooperation. We use our models to discuss simple aspects of the evolution of protocells, eukarya, multi-cellularity and animal societies. Copyright © 2012 Elsevier Ltd. All rights reserved.
Molecules from Clouds to Planets: Sweet Results from Alma
NASA Astrophysics Data System (ADS)
van Dishoeck, Ewine
2017-06-01
One of the most exciting developments in astronomy is the discovery of thousands of planets around stars other than our Sun. But how do these exo-planets form, and which chemical ingredients are available to build them? Thanks to powerful new telescopes, especially the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers are starting to address these age-old questions scientifically. Stars and planets are born in the cold and tenuous clouds between the stars in the Milky Way. In spite of the extremely low temperatures and densities, a surprisingly rich and interesting chemistry occurs in these interstellar clouds, as evidenced by the detection of more than 180 different molecules. Highly accurate spectroscopic data are key to their identification, and examples of the continued need and close interaction between laboratory work and astronomical observations will be given. ALMA now allows us to zoom in on solar system construction for the first time. Spectral scans of the birth sites of young stars contain tens of thousands of rotational lines. Water and a surprisingly rich variety of organic materials are found, including simple sugars and high abundances of deuterated species. How are these molecules formed? Can these pre-biotic molecules end up on new planets and form the basis for life elsewhere in the universe? Stay tuned for the latest analyses and also a comparison with recent results from the Rosetta mission to comet 67 P/C-G in our own Solar System.
Cimpoiasu, Vily M; Popa, Radu
2012-12-01
Biotic Abstract Dual Automata (BiADA), a novel simulation concept for studying the evolution of prebiotic order, has four main attributes. (1) The energy of each form of organization is the sum of two stocks: entropy-associated energy (E(s)) and free energy (E(g)), with dissimilar meaning, energy conductive, and energy exchange properties; (2) E(s) and E(g) have user-defined absolute values and are not derived from the relative thermodynamic parameters standard entropy and standard Gibbs free energy; (3) BiADA analyzes changes in both units of transformation and units of organization; and (4) BiADA-based models analyze forward and reverse transformations separately and the brut production of forms of organization. We discuss quantitative relationships between energy, information, and order parameters proposed in BiADA-based simulations. The example we show is that of a simple system with two forms of organization. The model monitors the energy flow and budget, the evolution of order and information capacity, and the energy cost of producing and maintaining the system's state. We show the effect of six prebiotic factors on the evolution of order and energy dissipative potential of the system. These are the initial state of the system, energy availability, the intrinsic energy conductivity, catalysis of "A to B" transformations, B autocatalysis, and the terminal heat sink. We discuss benefits of employing BiADA principles in the study of the origin of order in more complex networks.
High-resolution light microscopy of nanoforms
NASA Astrophysics Data System (ADS)
Vodyanoy, Vitaly; Pustovyy, Oleg; Vainrub, Arnold
2007-09-01
We developed a high resolution light imaging system. Diffraction gratings with 100 nm width lines as well as less than 100 nm size features of different-shaped objects are clearly visible on a calibrated microscope test slide (Vainrub et al., Optics Letters, 2006, 31, 2855). The two-point resolution increase results from a known narrowing of the central diffraction peak for the annular aperture. Better visibility and advanced contrast of the smallest features in the image are due to enhancement of high spatial frequencies in the optical transfer function. The imaging system is portable, low energy, and battery operated. It has been adapted to use in both transmitting and reflecting light. It is particularly applicable for motile nanoform systems where structure and functions can be depicted in real time. We have isolated micrometer and submicrometer particles, termed proteons, from human and animal blood. Proteons form by reversible seeded aggregation of proteins around proteon nucleating centers (PNCs). PNCs are comprised of 1-2nm metallic nanoclusters containing 40-300 atoms. Proteons are capable of spontaneous assembling into higher nanoform systems assuming structure of complicated topology. The arrangement of complex proteon system mimics the structure of a small biological cell. It has structures that imitate membrane and nucleolus or nuclei. Some of these nanoforms are motile. They interact and divide. Complex nanoform systems can spontaneously reduce to simple proteons. The physical properties of these nanoforms could shed some light on the properties of early life forms or forms at extreme conditions.
Quantifying biological integrity of California sage scrub communities using plant life-form cover.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hamada, Y.; Stow, D. A.; Franklin, J.
2010-01-01
The California sage scrub (CSS) community type in California's Mediterranean-type ecosystems supports a large number of rare, threatened, and endangered species, and is critically degraded and endangered. Monitoring ecological variables that provide information about community integrity is vital to conserving these biologically diverse communities. Fractional cover of true shrub, subshrub, herbaceous vegetation, and bare ground should fill information gaps between generalized vegetation type maps and detailed field-based plot measurements of species composition and provide an effective means for quantifying CSS community integrity. Remote sensing is the only tool available for estimating spatially comprehensive fractional cover over large extent, and fractionalmore » cover of plant life-form types is one of the measures of vegetation state that is most amenable to remote sensing. The use of remote sensing does not eliminate the need for either field surveying or vegetation type mapping; rather it will likely require a combination of approaches to reliably estimate life-form cover and to provide comprehensive information for communities. According to our review and synthesis, life-form fractional cover has strong potential for providing ecologically meaningful intermediate-scale information, which is unattainable from vegetation type maps and species-level field measurements. Thus, we strongly recommend incorporating fractional cover of true shrub, subshrub, herb, and bare ground in CSS community monitoring methods. Estimating life-form cover at a 25 m x 25 m spatial scale using remote sensing would be an appropriate approach for initial implementation. Investigation of remote sensing techniques and an appropriate spatial scale; collaboration of resource managers, biologists, and remote sensing specialists, and refinement of protocols are essential for integrating life-form fractional cover mapping into strategies for sustainable long-term CSS community management.« less
Zive, Dana M; Cook, Jennifer; Yang, Charissa; Sibell, David; Tolle, Susan W; Lieberman, Michael
2016-11-01
In April 2015, Oregon Health & Science University (OHSU) deployed a web-based, electronic medical record-embedded application created by third party vendor Vynca Inc. to allow real-time education, and completion of Physician Orders for Life Sustaining Treatment (POLST). Forms are automatically linked to the Epic Systems™ electronic health record (EHR) patient header and submitted to a state Registry, improving efficiency, accuracy, and rapid access to and retrieval of these important medical orders. POLST Forms, implemented in Oregon in 1992, are standardized portable medical orders used to document patient treatment goals for end-of-life care. In 2009, Oregon developed the first POLST-only statewide registry with a legislative mandate requiring POLST form signers to register the form unless the patient opts out. The Registry offers 24/7 emergency access to POLST Forms for Emergency Medical Services, Emergency Departments, and Acute Care Units. Because POLST is intended for those nearing end of life, immediate access to these forms at the time of an emergency is critical. Delays in registering a POLST Form may result in unwanted treatment if the paper form is not immediately available. An electronic POLST Form completion system (ePOLST) was implemented to support direct Registry submission. Other benefits of the system include single-sign-on, transmission of HL7 data for patient demographics and other relevant information, elimination of potential errors in form completion using internalized logic, built-in real-time video and text-based education materials for both patients and health care professionals, and mobile linkage for signature capture.
Learning in a Simple Motor System
ERIC Educational Resources Information Center
Broussard, Dianne M.; Kassardjian, Charles D.
2004-01-01
Motor learning is a very basic, essential form of learning that appears to share common mechanisms across different motor systems. We evaluate and compare a few conceptual models for learning in a relatively simple neural system, the vestibulo-ocular reflex (VOR) of vertebrates. We also compare the different animal models that have been used to…
Using Probabilistic Information in Solving Resource Allocation Problems for a Decentralized Firm
1978-09-01
deterministic equivalent form of HIQ’s problem (5) by an approach similar to the one used in stochastic programming with simple recourse. See Ziemba [38) or, in...1964). 38. Ziemba , W.T., "Stochastic Programs with Simple Recourse," Technical Report 72-15, Stanford University, Department of Operations Research
Investigating an Aerial Image First
ERIC Educational Resources Information Center
Wyrembeck, Edward P.; Elmer, Jeffrey S.
2006-01-01
Most introductory optics lab activities begin with students locating the real image formed by a converging lens. The method is simple and straightforward--students move a screen back and forth until the real image is in sharp focus on the screen. Students then draw a simple ray diagram to explain the observation using only two or three special…
A Simple Treatment of the Liquidity Trap for Intermediate Macroeconomics Courses
ERIC Educational Resources Information Center
Buttet, Sebastien; Roy, Udayan
2014-01-01
Several leading undergraduate intermediate macroeconomics textbooks now include a simple reduced-form New Keynesian model of short-run dynamics (alongside the IS-LM model). Unfortunately, there is no accompanying description of how the zero lower bound on nominal interest rates affects the model. In this article, the authors show how the…
24 CFR 954.300 - Eligible activities.
Code of Federal Regulations, 2010 CFR
2010-04-01
... is held in fee-simple title, land-trust, or long-term ground lease with a term at least equal to that... manufactured housing unit does not hold fee-simple title to the land on which the unit is located, the owner... purchase. (b) Forms of assistance. A grantee may invest HOME funds as equity investments, interest-bearing...
40 CFR 80.42 - Simple emissions model.
Code of Federal Regulations, 2014 CFR
2014-07-01
... (as measured under § 80.46) ETOH = Oxygen content of the fuel in question in the form of ethanol, in...) REGULATION OF FUELS AND FUEL ADDITIVES Reformulated Gasoline § 80.42 Simple emissions model. (a) VOC... VOC emissions from the fuel in question, in grams per mile, for VOC control region 1 during the summer...
40 CFR 80.42 - Simple emissions model.
Code of Federal Regulations, 2012 CFR
2012-07-01
... (as measured under § 80.46) ETOH = Oxygen content of the fuel in question in the form of ethanol, in...) REGULATION OF FUELS AND FUEL ADDITIVES Reformulated Gasoline § 80.42 Simple emissions model. (a) VOC... VOC emissions from the fuel in question, in grams per mile, for VOC control region 1 during the summer...
40 CFR 80.42 - Simple emissions model.
Code of Federal Regulations, 2013 CFR
2013-07-01
... (as measured under § 80.46) ETOH = Oxygen content of the fuel in question in the form of ethanol, in...) REGULATION OF FUELS AND FUEL ADDITIVES Reformulated Gasoline § 80.42 Simple emissions model. (a) VOC... VOC emissions from the fuel in question, in grams per mile, for VOC control region 1 during the summer...
Effects of Toy Crane Design-Based Learning on Simple Machines
ERIC Educational Resources Information Center
Korur, Fikret; Efe, Gülfem; Erdogan, Fisun; Tunç, Berna
2017-01-01
The aim of this 2-group study was to investigate the following question: Are there significant differences between scaffolded design-based learning controlled using 7 forms and teacher-directed instruction methods for the toy crane project on grade 7 students' posttest scores on the simple machines achievement test, attitude toward simple…
NASA Astrophysics Data System (ADS)
Iskandar, I.
2018-03-01
The exponential distribution is the most widely used reliability analysis. This distribution is very suitable for representing the lengths of life of many cases and is available in a simple statistical form. The characteristic of this distribution is a constant hazard rate. The exponential distribution is the lower rank of the Weibull distributions. In this paper our effort is to introduce the basic notions that constitute an exponential competing risks model in reliability analysis using Bayesian analysis approach and presenting their analytic methods. The cases are limited to the models with independent causes of failure. A non-informative prior distribution is used in our analysis. This model describes the likelihood function and follows with the description of the posterior function and the estimations of the point, interval, hazard function, and reliability. The net probability of failure if only one specific risk is present, crude probability of failure due to a specific risk in the presence of other causes, and partial crude probabilities are also included.
Other better versus self better in baboons: an evolutionary approach of social comparison
2017-01-01
Comparing oneself with others is an important characteristic of human social life, but the link between human and non-human forms of social comparison remains largely unknown. The present study used a computerized task presented in a social context to explore psychological mechanisms supporting social comparison in baboons and compare major findings with those usually observed in humans. We found that the effects of social comparison on subject's performance were guided both by similarity (same versus different sex) and by task complexity. Comparing oneself with a better-off other (upward comparison) increased performance when the other was similar rather than dissimilar, and a reverse effect was obtained when the self was better (downward comparison). Furthermore, when the other was similar, upward comparison led to a better performance than downward comparison. Interestingly, the beneficial effect of upward comparison on baboons' performance was only observed during simple task. Our results support the hypothesis of shared social comparison mechanisms in human and non-human primates. PMID:28539512
Birdsong dialect patterns explained using magnetic domains
NASA Astrophysics Data System (ADS)
Burridge, James; Kenney, Steven
2016-06-01
The songs and calls of many bird species, like human speech, form distinct regional dialects. We suggest that the process of dialect formation is analogous to the physical process of magnetic domain formation. We take the coastal breeding grounds of the Puget Sound white crowned sparrow as an example. Previous field studies suggest that birds of this species learn multiple songs early in life, and when establishing a territory for the first time, retain one of these dialects in order to match the majority of their neighbors. We introduce a simple lattice model of the process, showing that this matching behavior can produce single dialect domains provided the death rate of adult birds is sufficiently low. We relate death rate to thermodynamic temperature in magnetic materials, and calculate the critical death rate by analogy with the Ising model. Using parameters consistent with the known behavior of these birds we show that coastal dialect domain shapes may be explained by viewing them as low-temperature "stripe states."
A Multidimensional Ideal Point Item Response Theory Model for Binary Data.
Maydeu-Olivares, Albert; Hernández, Adolfo; McDonald, Roderick P
2006-12-01
We introduce a multidimensional item response theory (IRT) model for binary data based on a proximity response mechanism. Under the model, a respondent at the mode of the item response function (IRF) endorses the item with probability one. The mode of the IRF is the ideal point, or in the multidimensional case, an ideal hyperplane. The model yields closed form expressions for the cell probabilities. We estimate and test the goodness of fit of the model using only information contained in the univariate and bivariate moments of the data. Also, we pit the new model against the multidimensional normal ogive model estimated using NOHARM in four applications involving (a) attitudes toward censorship, (b) satisfaction with life, (c) attitudes of morality and equality, and (d) political efficacy. The normal PDF model is not invariant to simple operations such as reverse scoring. Thus, when there is no natural category to be modeled, as in many personality applications, it should be fit separately with and without reverse scoring for comparisons.
Design and implementation of an audio indicator
NASA Astrophysics Data System (ADS)
Zheng, Shiyong; Li, Zhao; Li, Biqing
2017-04-01
This page proposed an audio indicator which designed by using C9014, LED by operational amplifier level indicator, the decimal count/distributor of CD4017. The experimental can control audibly neon and holiday lights through the signal. Input audio signal after C9014 composed of operational amplifier for power amplifier, the adjust potentiometer extraction amplification signal input voltage CD4017 distributors make its drive to count, then connect the LED display running situation of the circuit. This simple audio indicator just use only U1 and can produce two colors LED with the audio signal tandem come pursuit of the running effect, from LED display the running of the situation takes can understand the general audio signal. The variation in the audio and the frequency of the signal and the corresponding level size. In this light can achieve jump to change, slowly, atlas, lighting four forms, used in home, hotel, discos, theater, advertising and other fields, and a wide range of USES, rU1h life in a modern society.
Prediction of primary somatosensory neuron activity during active tactile exploration
Campagner, Dario; Evans, Mathew Hywel; Bale, Michael Ross; Erskine, Andrew; Petersen, Rasmus Strange
2016-01-01
Primary sensory neurons form the interface between world and brain. Their function is well-understood during passive stimulation but, under natural behaving conditions, sense organs are under active, motor control. In an attempt to predict primary neuron firing under natural conditions of sensorimotor integration, we recorded from primary mechanosensory neurons of awake, head-fixed mice as they explored a pole with their whiskers, and simultaneously measured both whisker motion and forces with high-speed videography. Using Generalised Linear Models, we found that primary neuron responses were poorly predicted by whisker angle, but well-predicted by rotational forces acting on the whisker: both during touch and free-air whisker motion. These results are in apparent contrast to previous studies of passive stimulation, but could be reconciled by differences in the kinematics-force relationship between active and passive conditions. Thus, simple statistical models can predict rich neural activity elicited by natural, exploratory behaviour involving active movement of sense organs. DOI: http://dx.doi.org/10.7554/eLife.10696.001 PMID:26880559
Savage, Emilia Elizabeth; Wootten, Denise; Christopoulos, Arthur; Sexton, Patrick Michael; Furness, Sebastian George Barton
2013-04-01
Transient protein-protein interactions form the basis of signal transduction pathways in addition to many other biological processes. One tool for studying these interactions is bioluminescence resonance energy transfer (BRET). This technique has been widely applied to study signaling pathways, in particular those initiated by G protein-coupled receptors (GPCRs). These assays are routinely performed using transient transfection, a technique that has limitations in terms of assay cost and variability, overexpression of interacting proteins, vector uptake limited to cycling cells, and non-homogenous expression across cells within the assay. To address these issues, we developed bicistronic vectors for use with Life Technology's Gateway and flpIN systems. These vectors provide a means to generate isogenic cell lines for comparison of interacting proteins. They have the advantage of stable, single copy, isogenic, homogeneous expression with low inter-assay variation. We demonstrate their utility by assessing ligand-induced interactions between GPCRs and arrestin proteins.
Assembly and positioning of actomyosin rings by contractility and planar cell polarity
Sehring, Ivonne M; Recho, Pierre; Denker, Elsa; Kourakis, Matthew; Mathiesen, Birthe; Hannezo, Edouard; Dong, Bo; Jiang, Di
2015-01-01
The actomyosin cytoskeleton is a primary force-generating mechanism in morphogenesis, thus a robust spatial control of cytoskeletal positioning is essential. In this report, we demonstrate that actomyosin contractility and planar cell polarity (PCP) interact in post-mitotic Ciona notochord cells to self-assemble and reposition actomyosin rings, which play an essential role for cell elongation. Intriguingly, rings always form at the cells′ anterior edge before migrating towards the center as contractility increases, reflecting a novel dynamical property of the cortex. Our drug and genetic manipulations uncover a tug-of-war between contractility, which localizes cortical flows toward the equator and PCP, which tries to reposition them. We develop a simple model of the physical forces underlying this tug-of-war, which quantitatively reproduces our results. We thus propose a quantitative framework for dissecting the relative contribution of contractility and PCP to the self-assembly and repositioning of cytoskeletal structures, which should be applicable to other morphogenetic events. DOI: http://dx.doi.org/10.7554/eLife.09206.001 PMID:26486861
Genomics and the making of yeast biodiversity.
Hittinger, Chris Todd; Rokas, Antonis; Bai, Feng-Yan; Boekhout, Teun; Gonçalves, Paula; Jeffries, Thomas W; Kominek, Jacek; Lachance, Marc-André; Libkind, Diego; Rosa, Carlos A; Sampaio, José Paulo; Kurtzman, Cletus P
2015-12-01
Yeasts are unicellular fungi that do not form fruiting bodies. Although the yeast lifestyle has evolved multiple times, most known species belong to the subphylum Saccharomycotina (syn. Hemiascomycota, hereafter yeasts). This diverse group includes the premier eukaryotic model system, Saccharomyces cerevisiae; the common human commensal and opportunistic pathogen, Candida albicans; and over 1000 other known species (with more continuing to be discovered). Yeasts are found in every biome and continent and are more genetically diverse than angiosperms or chordates. Ease of culture, simple life cycles, and small genomes (∼10-20Mbp) have made yeasts exceptional models for molecular genetics, biotechnology, and evolutionary genomics. Here we discuss recent developments in understanding the genomic underpinnings of the making of yeast biodiversity, comparing and contrasting natural and human-associated evolutionary processes. Only a tiny fraction of yeast biodiversity and metabolic capabilities has been tapped by industry and science. Expanding the taxonomic breadth of deep genomic investigations will further illuminate how genome function evolves to encode their diverse metabolisms and ecologies. Copyright © 2015 Elsevier Ltd. All rights reserved.
Mazumder, B; Devi, Sasmita Rani
2008-07-01
Aluminum smelter plants employ Hall-Heroult electrolysis cells for electrolysis of molten cryolite to recover aluminum metal by electrolysis. These cells use carbon cathode blocks as a lining material inside. At the end of service life of the cells, pot lines are discarded and new carbon blocks are laid for fresh charging. These used carbon cathode blocks, known as spent pot liners, are heavily infested with toxic elements such as fluoride, cyanide, alkali, etc. Therefore, their disposal in open field poses great environmental risk. A simple process has been developed for decontamination of these spent pot liners and to recover its carbon value. The experiments indicated that this carbon, in the form of fine powder (around 20 micron in size) can absorb toxic elements like heavy metals, dyes, oils, etc. to a great extent and thus can be used for mitigating environmental pollution occuring due to various toxic wastes.
Kentner, David; Martano, Giuseppe; Callon, Morgane; Chiquet, Petra; Brodmann, Maj; Burton, Olga; Wahlander, Asa; Nanni, Paolo; Delmotte, Nathanaël; Grossmann, Jonas; Limenitakis, Julien; Schlapbach, Ralph; Kiefer, Patrick; Vorholt, Julia A; Hiller, Sebastian; Bumann, Dirk
2014-07-08
Shigella flexneri proliferate in infected human epithelial cells at exceptionally high rates. This vigorous growth has important consequences for rapid progression to life-threatening bloody diarrhea, but the underlying metabolic mechanisms remain poorly understood. Here, we used metabolomics, proteomics, and genetic experiments to determine host and Shigella metabolism during infection in a cell culture model. The data suggest that infected host cells maintain largely normal fluxes through glycolytic pathways, but the entire output of these pathways is captured by Shigella, most likely in the form of pyruvate. This striking strategy provides Shigella with an abundant favorable energy source, while preserving host cell ATP generation, energy charge maintenance, and survival, despite ongoing vigorous exploitation. Shigella uses a simple three-step pathway to metabolize pyruvate at high rates with acetate as an excreted waste product. The crucial role of this pathway for Shigella intracellular growth suggests targets for antimicrobial chemotherapy of this devastating disease.
Kentner, David; Martano, Giuseppe; Callon, Morgane; Chiquet, Petra; Brodmann, Maj; Burton, Olga; Wahlander, Asa; Nanni, Paolo; Delmotte, Nathanaël; Grossmann, Jonas; Limenitakis, Julien; Schlapbach, Ralph; Kiefer, Patrick; Vorholt, Julia A.; Hiller, Sebastian; Bumann, Dirk
2014-01-01
Shigella flexneri proliferate in infected human epithelial cells at exceptionally high rates. This vigorous growth has important consequences for rapid progression to life-threatening bloody diarrhea, but the underlying metabolic mechanisms remain poorly understood. Here, we used metabolomics, proteomics, and genetic experiments to determine host and Shigella metabolism during infection in a cell culture model. The data suggest that infected host cells maintain largely normal fluxes through glycolytic pathways, but the entire output of these pathways is captured by Shigella, most likely in the form of pyruvate. This striking strategy provides Shigella with an abundant favorable energy source, while preserving host cell ATP generation, energy charge maintenance, and survival, despite ongoing vigorous exploitation. Shigella uses a simple three-step pathway to metabolize pyruvate at high rates with acetate as an excreted waste product. The crucial role of this pathway for Shigella intracellular growth suggests targets for antimicrobial chemotherapy of this devastating disease. PMID:24958876
Possible complex organic compounds on Mars.
Kobayashi, K; Sato, T; Kajishima, S; Kaneko, T; Ishikawa, Y; Saito, T
1997-01-01
It is suggested that primitive Mars had somehow similar environments as primitive Earth. If life was born on the primitive earth using organic compounds which were produced from the early Earth environment, the same types of organic compounds were also formed on primitive Mars. Such organic compounds might have been preserved on Mars still now. We are studying possible organic formation on primitive and present Mars. A gaseous mixture of CO2, CO, N2 and H2O with various mixing ratios were irradiated with high energy protons (major components of cosmic rays). Hydrogen cyanide and formaldehyde were detected among volatile products, and yellow-brown-colored water-soluble non-volatile substances were produced, which gave amino acids after acid-hydrolysis. Major part of "amino acid precursors" were not simple molecules like aminonitriles, but complex compounds which eluted earlier than free amino acids in cation-exchange HPLC. These organic compounds should be major targets in the future Mars mission. Strategy for the detection of the complex organics on Mars will be discussed.
NASA Astrophysics Data System (ADS)
Le, Hang T. T.; Kalubarme, Ramchandra S.; Ngo, Duc Tung; Jang, Seong-Yong; Jung, Kyu-Nam; Shin, Kyoung-Hee; Park, Chan-Jin
2015-01-01
Aluminium doped lithium lanthanum titanate (A-LLTO) powders with various excess Li2O content are synthesized using a simple citrate gel method. The obtained A-LLTO powders show an agglomerated form, composed of nano-sized particles of 20-50 nm. The morphology and conductivity of the A-LLTO ceramics are largely affected by the content of excess Li2O. The highest total ionic conductivity of 3.17 × 10-4 S cm-1 is achieved for the A-LLTO sample containing 20% excess Li2O, exhibiting a vacancy content of 6%, and a total activation energy of 0.358 eV. The A-LLTO can act as a membrane to protect lithium metal from oxygen and other contaminants diffused through the oxygen electrode part. The Li-O2 cell employing the A-LLTO solid electrolyte shows a good cycle life of longer than 100 discharge-charge cycles, under the constant capacity mode of 300 mAh g-1.
Neuronal connectome of a sensory-motor circuit for visual navigation
Randel, Nadine; Asadulina, Albina; Bezares-Calderón, Luis A; Verasztó, Csaba; Williams, Elizabeth A; Conzelmann, Markus; Shahidi, Réza; Jékely, Gáspár
2014-01-01
Animals use spatial differences in environmental light levels for visual navigation; however, how light inputs are translated into coordinated motor outputs remains poorly understood. Here we reconstruct the neuronal connectome of a four-eye visual circuit in the larva of the annelid Platynereis using serial-section transmission electron microscopy. In this 71-neuron circuit, photoreceptors connect via three layers of interneurons to motorneurons, which innervate trunk muscles. By combining eye ablations with behavioral experiments, we show that the circuit compares light on either side of the body and stimulates body bending upon left-right light imbalance during visual phototaxis. We also identified an interneuron motif that enhances sensitivity to different light intensity contrasts. The Platynereis eye circuit has the hallmarks of a visual system, including spatial light detection and contrast modulation, illustrating how image-forming eyes may have evolved via intermediate stages contrasting only a light and a dark field during a simple visual task. DOI: http://dx.doi.org/10.7554/eLife.02730.001 PMID:24867217
Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-07
... prescribes the use of Form MA 8-7, Transmittal for Unemployment Insurance Materials. This simple check off... particularly interested in comments which: Evaluate whether the proposed collection of information is necessary...
Premenopausal women with recurrent urinary tract infections have lower quality of life.
Ennis, Siobhan S; Guo, Huifang; Raman, Lata; Tambyah, Paul A; Chen, Swaine L; Tiong, Ho Yee
2018-05-22
To examine the impact on quality of life of recurrent acute uncomplicated urinary tract infection among premenopausal Singaporean women, and to determine the risk factors for lower quality of life among these patients. A total of 85 patients with recurrent acute uncomplicated urinary tract infection who were referred to the Urology Department at the National University Hospital, Singapore, were prospectively recruited over a 3-year period to complete the validated Short Form 36 Health Survey version 1. In addition, demographic and clinical details including symptomology and medical history were analyzed for factors impacting quality of life. Short Form 36 Health Survey version 1 results were compared with published population norms. After adjusting for age, gender and race, recurrent acute uncomplicated urinary tract infection patients had significantly lower quality of life on seven out of eight Short Form 36 Health Survey version 1 domains when compared with age-, gender- and race-adjusted population norms for Singapore. Among those with recurrent acute uncomplicated urinary tract infection, those who also reported caffeine consumption had significantly lower Short Form 36 Health Survey version 1 scores than those who did not. Those who reported chronic constipation also had consistently lower Short Form 36 Health Survey version 1 scores across all domains. Recurrent acute uncomplicated urinary tract infection has a negative impact on the quality of life of premenopausal, otherwise healthy women. Recurrent acute uncomplicated urinary tract infection patients who also have chronic constipation or consume caffeine have lower quality of life than those who do not. More studies are required to understand the relationships between these common problems and risk factors. © 2018 The Japanese Urological Association.
Sagan Lecture: Spirit, Opportunity, and the Exploration of the Red Planet
NASA Astrophysics Data System (ADS)
Squyres, S.
2005-12-01
In January of 2004, twin robotic explorers named Spirit and Opportunity landed on Mars. Expected to last for 90 days, the two rovers have now been exploring the martian surface for more than a year and a half. Their objective is to search for evidence of past water on Mars, and to determine if Mars ever had conditions that would have been suitable for life. Spirit landed in Gusev Crater, a large impact crater in the southern highlands of Mars. Finding only basaltic lava on the crater floor, Spirit drove almost three kilometers to the base of the Columbia Hills, a small mountain range to the east of the landing site. There Spirit has ascended Husband Hill, the highest summit in the range, and has found strong evidence that the rocks there were modified long ago by water. Opportunity landed on Meridiani Planum, a smooth plateau near the martian equator, coming to rest in a small impact feature named Eagle Crater. Within Eagle Crater, Opportunity found compelling evidence for long-ago water on Mars. This evidence included 'blueberries': small concretions rich in hematite that precipitated from liquid water. It also included rocks that are made largely of sulfate salts, deposited when water evaporated away, and rocks that preserve ancient ripples that formed billions of years ago as water flowed over sand on Mars. The conditions long ago at Eagle Crater may have been suitable for some simple forms of life. Whether life could have developed there, however, is a much more difficult question. After leaving Eagle Crater, Opportunity drove eastward to Endurance Crater, a much larger crater that allowed access to deeper and older rocks which also proved to be blueberry-laden sulfate-rich sediments. Since leaving Endurance Crater, Opportunity has explored southward, driving more than five kilometers across the martian surface. The talk will provide an up-to-date summary of the mission of Spirit and Opportunity, from their initial conception through their launch, landing, and operations on the surface of Mars.
OʼConnor, Patrick J; Poudevigne, Mélanie S; Johnson, Kristen E; Brito de Araujo, Juliana; Ward-Ritacco, Christie L
2018-04-01
The aim of the study was to test whether the adoption of twice weekly, low-to-moderate intensity resistance training during weeks 22 to 34 of pregnancy can improve quality of life and mood. A parallel-group trial was conducted. Women in their second trimester (N = 134) were randomly assigned to 12 weeks of wait list, bimonthly pregnancy education classes, or twice weekly low-to-moderate intensity resistance training. Resistance training involved one abdominal exercise with no external load and five exercises (leg extension, leg press, arm lat pull, leg curl, and lumbar extension) with an external load that gradually progressed, and the total active exercise time during each exercise session was approximately 17 minutes. Quality of life and mood were measured before and after the interventions using the 36-item Short Form Health Survey and Profile of Mood States. Intent-to-treat mixed-model analyses of variance (3 groups by 2 times, pre- and postintervention) tested the hypothesis that outcomes would worsen for the controls and not change or improve for the resistance training group. The group by time interaction (F(2,131) = 3.144, η = .046, p = .046) for 36-item Short Form Health Survey vitality and subsequent simple main effects showed that scores were unchanged across time after resistance training (-1.8 (14.8)) but significantly decreased for the education (-6.44 (12.69), t = 3.408, df = 44, p = .001) and wait list (-9.11 (14.78), t = 4.135, df = 44, p < .001) groups, whereas posttest vitality scores for the pregnancy group (45.9 (16.9)) were significantly higher than the wait list (40.1 (16.3), t = 1.989, df = 87, p = .05) but not the education group (42.1 (15.4), p = .27). Profile of mood states fatigue scores showed a similar pattern. Adverse changes in symptoms of energy and fatigue during pregnancy are attenuated by adopting low-to-moderate intensity resistance training. Clinicaltrials.gov, NCT02557893.
Selcuk, Selcuk; Cam, Cetin; Asoglu, Mehmet Resit; Kucukbas, Mehmet; Arinkan, Arzu; Cikman, Muzaffer Seyhan; Karateke, Ates
2016-03-01
The impact of simple and radical hysterectomy on all aspects of pelvic floor dysfunctions was evaluated in current study. This retrospective cohort study included 142 patients; 58 women (40.8%) who have undergone simple, 41 (28.8%) radical hysterectomy, and 43 (30.2%) women without any surgical intervention to serve as the control group. The validated versions of the Urogenital Distress Inventory (UDI-6), Incontinence Impact Questionnaire (IIQ-7), Pelvic Floor and Incontinence Sexual Impact Questionnaire (PISQ-12), Wexner Incontinence Scale score and pelvic organ prolapse quantification (POP-Q) system were used in detailed evaluation of pelvic floor dysfunction. One-way ANOVA and Pearson's chi square tests were performed in statistical analysis. It was found that there were significant differences in irritative and obstructive scores of UDI-6 between Type III hysterectomy group and Type I hysterectomy group. In addition, patients of Type I hysterectomy had significant higher irritative and obstructive scores than the control group. Type III hysterectomy had the most significant deteriorating effect on sexual life, based on scores of PISQ-12 compared to both Type I hysterectomy group and control group. Hysterectomy results in detrimental effects on the quality of life (QoL) regarding all aspects of pelvic floor functions especially in women of radical hysterectomy. Urinary dysfunctional symptoms like urgency, obstruction and especially sexual problems are more bothersome and difficult to overcome. The impact of hysterectomy on QoL should be investigated as a whole and may be more profound than previously thought. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
... Inside Life Science > Bleach vs. Bacteria Inside Life Science View All Articles | Inside Life Science Home Page Bleach vs. Bacteria By Sharon Reynolds ... For Proteins, Form Shapes Function This Inside Life Science article also appears on LiveScience . Learn about related ...
From Ruthenium to Copper: A la carte Tools for the Synthesis of Molecules of Interest.
Monnier, Florian; Taillefer, Marc
2016-01-01
Well-defined ruthenium complexes and simple copper-ligand systems proved to be powerful catalysts for the construction of complex molecules from simple and abundant organic sources. In this account, chosen examples of reactions involving C-C bond formation catalyzed by [Ru(η(5)-C(5)H(5))-(CH(3)CN)(3)][PF(6)] will be presented. A practical synthesis of the versatile catalyst [Ru(η(5)-C(5)H(5))-(CH(3)CN)(3)][PF(6)] is also described via a simple and easy-handled procedure discovered in Geneva ten years ago. The second part of this review is focused on methodologies catalyzed by an association of a copper salt and a simple ligand for the formation of C-N, C-O and C-C bonds developed in our group in Montpellier. A brief overview of applications in life sciences and materials will conclude this article.
Fatigue-life distributions for reaction time data.
Tejo, Mauricio; Niklitschek-Soto, Sebastián; Marmolejo-Ramos, Fernando
2018-06-01
The family of fatigue-life distributions is introduced as an alternative model of reaction time data. This family includes the shifted Wald distribution and a shifted version of the Birnbaum-Saunders distribution. Although the former has been proposed as a way to model reaction time data, the latter has not. Hence, we provide theoretical, mathematical and practical arguments in support of the shifted Birnbaum-Saunders as a suitable model of simple reaction times and associated cognitive mechanisms.
[Morphology, biology and life-cycle of Plasmodium parasites].
Hommel, Marcel
2007-10-01
Laveran first discovered that an infectious agent was responsible for malaria by using a simple microscope, without the assistance of specific stains. Our knowledge of the Plasmodium life cycle and cellular biology has progressed with each technological advance, from Romanovsky staining and histology to electron microscopy, immunocytochemistry, molecular methods and modern imaging techniques. The use of bird, primate and rodent models also made a major contribution, notably in the development of antimalarial drugs that are still in use today.
Domanski, Cezary W
2004-01-01
This article unveils some previously unknown facts about the short life of Max Friedrich (1856-1887), the author in 1881 of the first PhD dissertation on experimental psychology, written under the supervision of Wilhelm Wundt: "On the Duration of Apperception for Simple and Complex Visual Stimuli." The article describes Friedrich's family background and life, professional career as a teacher, and works in psychology and mathematics. Copyright 2004 Wiley Periodicals, Inc.
Evaluation of an improved flotation device for infants and small children.
DOT National Transportation Integrated Search
1971-07-01
A simple, lightweight, life-support infant flotation device incorporating reliable self-righting, thermal protection and automatic self-ventilation is described This design concept utilizes prior data relative to the centers of gravity of infants and...
Signal relay during the life cycle of Dictyostelium.
Mahadeo, Dana C; Parent, Carole A
2006-01-01
A fundamental property of multicellular organisms is signal relay, the process by which information is transmitted from one cell to another. The integration of external information, such as nutritional status or developmental cues, is critical to the function of organisms. In addition, the spatial organizations of multicellular organisms require intricate signal relay mechanisms. Signal relay is remarkably exhibited during the life cycle of the social amoebae Dictyostelium discoideum, a eukaryote that retains a simple way of life, yet it has greatly contributed to our knowledge of the mechanisms cells use to communicate and integrate information. This chapter focuses on the molecules and mechanisms that Dictyostelium employs during its life cycle to relay temporal and spatial cues that are required for survival.
The role of boundary layer momentum advection in the mean location of the ITCZ
NASA Astrophysics Data System (ADS)
Dixit, Vishal; Srinivasan, J.
2017-08-01
The inter-tropical convergence zones (ITCZ) form closer to the equator during equinoxes while they form well away from the equator during the boreal summer. A simple three-way balance between the pressure gradients, Coriolis force and effective Rayleigh friction has been classically used to diagnose the location of maximum boundary layer convergence in the near equatorial ITCZ. If such a balance can capture the dynamics of off-equatorial convergence was not known. We used idealized aqua planet simulations with fixed, zonally symmetric sea surface temperature boundary conditions to simulate the near equatorial and off-equatorial ITCZ. As opposed to the convergence of inter-hemispheric flows in the near equatorial convergence, the off-equatorial convergence forms due to the deceleration of cross-equatorial meridional flow. The detailed momentum budget of the off-equatorial convergence zone reveals that the simple balance is not sufficient to capture the relevant dynamics. The deceleration of the meridional flow is strongly modulated by the inertial effects due to the meridional advection of zonal momentum in addition to the terms in the simple balance. The simple balance predicts a spurious near equatorial convergence and a consistent off-equatorial convergence of the meridional flow. The spurious convergence disappears when inertial effects are included in the balance. As cross equatorial meridional flow decelerates to form convergence, the inertial effects cancel the pressure gradient effects near the equator while they add away from the equator. The contribution to the off-equatorial convergence induced by the pressure gradients is significantly larger than the contribution due to the inertial effects and hence pressure gradients appear to be the primary factor in anchoring the strength and location of the off-equatorial convergence.
What Teachers Should Know about the Evolution-Intentional Design Debate on the Origin of Life.
ERIC Educational Resources Information Center
Brekke, Stewart E.
This paper discusses the beginning of life on Earth, the formation of life forms, evolution, and the origin of life. The paper suggests that how life first appeared on earth is not known and may never be known. (YDS)
Andréll, Paulin; Schultz, Tomas; Mannerkorpi, Kaisa; Nordeman, Lena; Börjesson, Mats; Mannheimer, Clas
2014-04-01
To compare health-related quality of life in 2 different populations with chronic pain: patients with fibromyalgia and patients with refractory angina pectoris. Previous separate studies have indicated that these patient groups report different impacts of pain on health-related quality of life. The Short-Form 36 was used to assess health- related quality of life. In order to adjust for age and gender differences between the groups, both patient groups were compared with age- and gender-matched normative controls. The difference in health-related quality of life between the 2 patient groups was assessed by transforming the Short-Form 36 subscale scores to a z-score. The patients with fibromyalgia (n = 203) reported poorer health-related quality of life in all the subscale scores of Short-Form 36 (p < 0.05-0.0001) than the patients with refractory angina (n = 146) when both groups were compared with their corresponding normal population (z-score). Patients with fibromyalgia experience greater impairment in health-related quality of life compared with the normal population than do patients with refractory angina pectoris, despite the fact that the latter have a potentially life-threatening disease. The great impairment in health- related quality of life in patients with fibromyalgia should be taken into consideration when planning rehabilitation.
What Possible Life Forms Could Exist on Other Planets: A Historical Overview
NASA Astrophysics Data System (ADS)
Raulin Cerceau, Florence
2010-04-01
Speculations on living beings existing on other planets are found in many written works since the Frenchman Bernard de Fontenelle spoke to the Marquise about the inhabitants of the solar system in his Entretiens sur la pluralité des mondes (1686). It was an entertainment used to teach astronomy more than real considerations about the habitability of our solar system, but it opened the way to some reflections about the possible life forms on other planets. The nineteenth century took up this idea again in a context of planetary studies showing the similarities as well as the differences of the celestial bodies orbiting our Sun. Astronomers attempted to look deeper into the problem of habitability such as Richard Proctor or Camille Flammarion, also well-known for their fine talent in popular writings. While the Martian canals controversy was reaching its height, they imagined how the living forms dwelling in other planets could be. Nowadays, no complex exo-life is expected to have evolved in our solar system. However, the famous exobiologist Carl Sagan and later other scientists, formulated audacious ideas about other forms of life in the light of recent discoveries in planetology. Through these few examples, this paper underlines the originality of each author’s suggestions and the evolution and contrast of ideas about the possible life forms in the universe.
What possible life forms could exist on other planets: a historical overview.
Raulin Cerceau, Florence
2010-04-01
Speculations on living beings existing on other planets are found in many written works since the Frenchman Bernard de Fontenelle spoke to the Marquise about the inhabitants of the solar system in his Entretiens sur la pluralité des mondes (1686). It was an entertainment used to teach astronomy more than real considerations about the habitability of our solar system, but it opened the way to some reflections about the possible life forms on other planets. The nineteenth century took up this idea again in a context of planetary studies showing the similarities as well as the differences of the celestial bodies orbiting our Sun. Astronomers attempted to look deeper into the problem of habitability such as Richard Proctor or Camille Flammarion, also well-known for their fine talent in popular writings. While the Martian canals controversy was reaching its height, they imagined how the living forms dwelling in other planets could be. Nowadays, no complex exo-life is expected to have evolved in our solar system. However, the famous exobiologist Carl Sagan and later other scientists, formulated audacious ideas about other forms of life in the light of recent discoveries in planetology. Through these few examples, this paper underlines the originality of each author's suggestions and the evolution and contrast of ideas about the possible life forms in the universe.
Using the Rasch Model to Determine Equivalence of Forms In the Trilingual Lollipop Readiness Test
ERIC Educational Resources Information Center
Lang, W. Steve; Chew, Alex L.; Crownover, Carol; Wilkerson, Judy R.
2007-01-01
Determining the cross-cultural equivalence of multilingual tests is a challenge that is more complex than simple horizontal equating of test forms. This study examines the functioning of a trilingual test of preschool readiness to determine the equivalence. Different forms of the test have previously been examined using classical statistical…
Extinguishment and Burnback Testing of Fire Fighting Agents
2005-09-26
resisting burnback for hydrocarbon fuel fires. Potential Aqueous Film Forming Foam ( AFFF ) replacements are required to exhibit an...simple, reliable test to evaluate the effectiveness of new foams being introduced into the market as potential Aqueous Film Forming Foam ( AFFF ...normal concentrations. Reference: Military Specification MIL-F-24385F, Fire Extinguishing Agent, Aqueous Film - Forming Foam
ERIC Educational Resources Information Center
Page, Judith L.; Horn, Donna
1985-01-01
Twelve preschoolers who had Down's Syndrome, hydrocephalus, or brain damage of unknown etiology and who functioned at early and late linguistic Stage I were asked to respond to commands in simple, complete adult forms and in incomplete, telegraphic child forms. Late Stage I Ss were superior in comprehension of all forms. (CL)
Work-life balance and welfare.
Evans, Lois; Young, Greg
2017-04-01
An online survey and focus groups were conducted, providing qualitative information on the work-life balance of psychiatrists and trainees in Australasia. An invitation to participate in an anonymous online welfare survey was emailed to all the Royal Australian and New Zealand College of Psychiatrists trainees, Fellows, and Affiliates. Following this, nine focus groups were held across Australia and New Zealand. Responses received were thematically analysed. The emergent patterns are presented in this report. Our research suggests that work-life balance can be subjectively and objectively measured. There are phases of good and bad work-life balance, depending on stage of career and other commitments. Work-life balance may be an indicator of the health of individuals and organisations. Due to its complexity, with intrinsic and extrinsic factors involved, solutions are unlikely to be simple. Further studies are needed to substantiate our findings.
Daily hemofiltration with a simplified method of delivery.
Zimmerman, Deborah L; Swedko, Peter J; Posen, Gerald A; Burns, Kevin D
2003-01-01
Observational studies of daily hemodialysis (HD) and intermittent hemofiltration (HF) therapy have been associated with improved outcomes for patients with endstage renal disease. We conducted a prospective study to evaluate the feasibility of daily HF as an alternative to intermittent HD using a simplified HF system (NxStage Medical). Each patient received 1 week of intermittent HD followed by 4 weeks of daily HF. Ringers lactate was used as the initial replacement solution; however, Hemosol LG2/L0 was used subsequently to simplify patient management. Changes in quality of life, nutrition, and laboratory values were assessed. Seven patients have completed 168 HF treatments with Hemosol. Their treatment time on HD was 232 minutes 3 days per week, and 132 minutes on HF 6 days per week. Single pool Kt/V per treatment for HD was 1.69 compared with 0.44 for HF (standard Kt/V 2.38 vs 1.93). Despite these weekly differences in urea clearance, potassium, calcium, phosphate, and nutrition remained stable. Beta-2 microglobulin tended to decline. All parameters of the Kidney Disease Quality of Life Instrument Short Form (KDQOL-SF) either remained stable or improved. In addition, blood pressure declined, allowing for a reduction in the number of antihypertensive medications. In summary, these preliminary data suggest that daily HF with this system is safe, simple, efficacious, and could potentially be used as a home based renal replacement therapy.
Intrinsic and Extrinsic Aspects on Campylobacter jejuni Biofilms
Melo, Roberta T.; Mendonça, Eliane P.; Monteiro, Guilherme P.; Siqueira, Mariana C.; Pereira, Clara B.; Peres, Phelipe A. B. M.; Fernandez, Heriberto; Rossi, Daise A.
2017-01-01
Biofilm represents a way of life that allows greater survival of microorganisms in hostile habitats. Campylobacter jejuni is able to form biofilms in vitro and on surfaces at several points in the poultry production chain. Genetic determinants related to their formation are expressed differently between strains and external conditions are decisive in this respect. Our approach combines phylogenetic analysis and the presence of seven specific genes linked to biofilm formation in association with traditional microbiology techniques, using Mueller Hinton and chicken juice as substrates in order to quantify, classify, determine the composition and morphology of the biomass of simple and mixed biofilms of 30 C. jejuni strains. It also evaluates the inhibition of its formation by biocides commonly used in industry and also by zinc oxide nanoparticles. Genetic analysis showed high heterogeneity with the identification of 23 pulsotypes. Despite the diversity, the presence of flaA, cadF, luxS, dnaJ, htrA, cbrA, and sodB genes in all strains shows the high potential for biofilm formation. This ability was only expressed in chicken juice, where they presented phenotype of a strong biofilm producer, with a mean count of 7.37 log CFU/mL and an ultrastructure characteristic of mature biofilm. The composition of simple and mixed biofilms was predominantly composed by proteins. The exceptions were found in mixed biofilms with Pseudomonas aeruginosa, which includes a carbohydrate-rich matrix, lower ability to sessile form in chicken juice and compact architecture of the biofilm, this aspects are intrinsic to this species. Hypochlorite, chlorhexidine, and peracetic acid were more effective in controlling viable cells of C. jejuni in biofilm, but the existence of tolerant strains indicates exposure to sublethal concentrations and development of adaptation mechanisms. This study shows that in chicken juice C. jejuni presents greater potential in producing mature biofilms. PMID:28769900
Biodiversity and evolution of the Myxozoa.
Canning, Elizabeth U; Okamura, Beth
2004-01-01
Myxozoans (phylum Myxozoa) are metazoan parasites utilizing invertebrate and (mainly) aquatic vertebrate hosts. They have in common with cnidarians the possession of virtually identical, highly complex organelles, namely the polar capsules in myxozoan spores, serving for attachment to new hosts and the nematocysts in surface epithelia of cnidarians, serving for food capture. Although myxozoan spores are multicellular, the simple trophic body forms of almost all species, reduced to syncytial plasmodia or single cells, reveal no clues to myxozoan ancestry or phylogenetic relationships. The myxozoan genus Buddenbrockia is one of only two known genera belonging to a clade which diverged early in the evolution of the Myxozoa. Today the Myxozoa are represented by two classes, the Myxosporea, containing all the better-known genera, which alternate between fish and annelids, and the Malacosporea, containing Buddenbrockia and Tetracapsuloides, parasitising bryozoans. The latter genus also infects salmonid fish, causing proliferative kidney disease (PKD). The enigmatic Buddenbrockia has retained some of its ancestral features in a body wall of two cell layers and a worm-like shape, maintained by four longitudinally-running muscle blocks, similar to a gutless nematode and suggestive of a bilaterian ancestry. Although some analyses of 18S rDNA sequences tend towards a cnidarian (diploblast) affinity for myxozoans, the majority of these studies place them within, or sister to, the Bilateria. The latter view is supported by their possession of central class Hox genes, so far considered to be synapomorphic for Bilateria. The simple body form is, therefore, an extreme example of simplification due to parasitism. Various hypotheses for the occurrence of identical complex organelles (nematocysts and polar capsules) in diploblast and triploblast phyla are evaluated: common ancestry, convergent evolution, gene transfer and, especially, endosymbiosis. A theory of the evolution of their digenetic life cycles is proposed, with the invertebrate as primary host and secondary acquisition of the vertebrate host serving for asexual population increase.
Life's origin: the cosmic, planetary and biological processes
NASA Technical Reports Server (NTRS)
Scattergood, T.; Des Marais, D.; Jahnke, L.
1987-01-01
From elements formed in interstellar furnaces to humans peering back at the stars, the evolution of life has been a long, intricate and perhaps inevitable process. Life as we know it requires a planet orbiting a star at just the right distance so that water can exist in liquid form. It needs a rich supply of chemicals and energy sources. On Earth, the combination of chemistry and energy generated molecules that evolved ways of replicating themselves and of passing information from one generation to the next. Thus, the thread of life began. This chart traces the thread, maintained by DNA molecules for much of its history, as it weaves its way through the primitive oceans, gaining strength and diversity along the way. Organisms eventually moved onto the land, where advanced forms, including humans, ultimately arose. Finally, assisted by a technology of its own making, life has reached back out into space to understand its own origins, to expand into new realms, and to seek other living threads in the cosmos.
Quality of Physician Orders for Life-Sustaining Treatment Forms Completed in Nursing Homes
Bressette, Matthew; Enguidanos, Susan
2017-01-01
Abstract Background: The physician orders for life-sustaining treatment (POLST) form allows seriously ill individuals to express their preferences for end-of-life treatments. Despite increased POLST use, little is known about the quality of completed forms. Objective: We examined the quality of POLST forms prepared for nursing home residents, including whether they had required signatures and clinically consistent care preferences. Design: We conducted a chart review of POLST forms for a sample of nursing home residents in California. Setting/Sample: We completed POLST audits for 938 residents in 13 nursing homes in Los Angeles. Measures: We recorded whether POLST forms were signed by both the patient (or proxy) and the physician, and whether the patient's treatment choices regarding resuscitation and medical intervention were consistent, as required by the California form. Results: Overall, 69.6% of audited POLST forms had at least one indicator of poor quality. Most lacked a required signature (15.8% lacked a physician signature and 17.4% lacked a patient/proxy signature) and 5.6% had conflicting treatment preferences. Conclusion: We found 30.4% of POLST forms for nursing home residents were not complete or documented clinically contradictory treatment preferences. Improvement in the quality of POLST forms is needed. PMID:27841953
Major evolutionary transitions in individuality
West, Stuart A.; Fisher, Roberta M.; Gardner, Andy; Kiers, E. Toby
2015-01-01
The evolution of life on earth has been driven by a small number of major evolutionary transitions. These transitions have been characterized by individuals that could previously replicate independently, cooperating to form a new, more complex life form. For example, archaea and eubacteria formed eukaryotic cells, and cells formed multicellular organisms. However, not all cooperative groups are en route to major transitions. How can we explain why major evolutionary transitions have or haven’t taken place on different branches of the tree of life? We break down major transitions into two steps: the formation of a cooperative group and the transformation of that group into an integrated entity. We show how these steps require cooperation, division of labor, communication, mutual dependence, and negligible within-group conflict. We find that certain ecological conditions and the ways in which groups form have played recurrent roles in driving multiple transitions. In contrast, we find that other factors have played relatively minor roles at many key points, such as within-group kin discrimination and mechanisms to actively repress competition. More generally, by identifying the small number of factors that have driven major transitions, we provide a simpler and more unified description of how life on earth has evolved. PMID:25964342
Origin and evolution of life on terrestrial planets.
Brack, A; Horneck, G; Cockell, C S; Bérces, A; Belisheva, N K; Eiroa, Carlos; Henning, Thomas; Herbst, Tom; Kaltenegger, Lisa; Léger, Alain; Liseau, Réne; Lammer, Helmut; Selsis, Franck; Beichman, Charles; Danchi, William; Fridlund, Malcolm; Lunine, Jonathan; Paresce, Francesco; Penny, Alan; Quirrenbach, Andreas; Röttgering, Huub; Schneider, Jean; Stam, Daphne; Tinetti, Giovanna; White, Glenn J
2010-01-01
The ultimate goal of terrestrial planet-finding missions is not only to discover terrestrial exoplanets inside the habitable zone (HZ) of their host stars but also to address the major question as to whether life may have evolved on a habitable Earth-like exoplanet outside our Solar System. We note that the chemical evolution that finally led to the origin of life on Earth must be studied if we hope to understand the principles of how life might evolve on other terrestrial planets in the Universe. This is not just an anthropocentric point of view: the basic ingredients of terrestrial life, that is, reduced carbon-based molecules and liquid H(2)O, have very specific properties. We discuss the origin of life from the chemical evolution of its precursors to the earliest life-forms and the biological implications of the stellar radiation and energetic particle environments. Likewise, the study of the biological evolution that has generated the various life-forms on Earth provides clues toward the understanding of the interconnectedness of life with its environment.
Atypical Brain Activation during Simple & Complex Levels of Processing in Adult ADHD: An fMRI Study
ERIC Educational Resources Information Center
Hale, T. Sigi; Bookheimer, Susan; McGough, James J.; Phillips, Joseph M.; McCracken, James T.
2007-01-01
Objective: Executive dysfunction in ADHD is well supported. However, recent studies suggest that more fundamental impairments may be contributing. We assessed brain function in adults with ADHD during simple and complex forms of processing. Method: We used functional magnetic resonance imaging with forward and backward digit spans to investigate…
2009-02-12
equivalent to usual printing or typescript . Can read either representations of familiar formulaic verbal exchanges or simple language containing only...read simple, authentic written material in a form equivalent to usual printing or typescript on subjects within a familiar context. Able to read with
Harold F. Haupt
1969-01-01
A simple gage on the lysimeter principle has been developed to provide continuous readings of the volume of water flowing from the base of a snowpack in the form of surface melt alone or rain percolate and surface melt combined. The data obtained show promise, after two seasons of being applicable in river flood forecasting, as well as in studies of snow hydrology....
Multiaxial Fatigue Damage Parameter and Life Prediction without Any Additional Material Constants
Yu, Zheng-Yong; Liu, Qiang; Liu, Yunhan
2017-01-01
Based on the critical plane approach, a simple and efficient multiaxial fatigue damage parameter with no additional material constants is proposed for life prediction under uniaxial/multiaxial proportional and/or non-proportional loadings for titanium alloy TC4 and nickel-based superalloy GH4169. Moreover, two modified Ince-Glinka fatigue damage parameters are put forward and evaluated under different load paths. Results show that the generalized strain amplitude model provides less accurate life predictions in the high cycle life regime and is better for life prediction in the low cycle life regime; however, the generalized strain energy model is relatively better for high cycle life prediction and is conservative for low cycle life prediction under multiaxial loadings. In addition, the Fatemi–Socie model is introduced for model comparison and its additional material parameter k is found to not be a constant and its usage is discussed. Finally, model comparison and prediction error analysis are used to illustrate the superiority of the proposed damage parameter in multiaxial fatigue life prediction of the two aviation alloys under various loadings. PMID:28792487
Multiaxial Fatigue Damage Parameter and Life Prediction without Any Additional Material Constants.
Yu, Zheng-Yong; Zhu, Shun-Peng; Liu, Qiang; Liu, Yunhan
2017-08-09
Based on the critical plane approach, a simple and efficient multiaxial fatigue damage parameter with no additional material constants is proposed for life prediction under uniaxial/multiaxial proportional and/or non-proportional loadings for titanium alloy TC4 and nickel-based superalloy GH4169. Moreover, two modified Ince-Glinka fatigue damage parameters are put forward and evaluated under different load paths. Results show that the generalized strain amplitude model provides less accurate life predictions in the high cycle life regime and is better for life prediction in the low cycle life regime; however, the generalized strain energy model is relatively better for high cycle life prediction and is conservative for low cycle life prediction under multiaxial loadings. In addition, the Fatemi-Socie model is introduced for model comparison and its additional material parameter k is found to not be a constant and its usage is discussed. Finally, model comparison and prediction error analysis are used to illustrate the superiority of the proposed damage parameter in multiaxial fatigue life prediction of the two aviation alloys under various loadings.
Search for and investigation of extraterrestrial forms of life
NASA Technical Reports Server (NTRS)
Rubin, A. B.
1975-01-01
Correct combinations of remote, analytic, and functional methods and measuring devices for detecting extraterrestrial life are elaborated. Considered are techniques and instruments available both on earth and aboard spacecraft and artificial planetary satellites. Emphasis is placed on the abiogenetic synthesis of organic compounds formed in photosynthesis on Mars.