1,465 research outputs found

    Commentary on Moving Beyond Lip Service: The Clinical Reasoning Behind Practicing Strengths

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    Invited Commentary on Moving Beyond Lip Service: The Clinical Reasoning Behind Practicing Strength

    A search for biogenic trace gases in the atmosphere of Mars

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    The detection of certain trace gases in the atmosphere of Mars may serve as a possible indicator of microbial life on the surface of Mars. Candidate biogenic gases include methane CH4, ammonia NH3, nitrous oxide N2O, and several reduced sulfur species. Chemical thermodynamic equilibrium and photochemical calculations preclude the presence of these gases in any measurable concentrations in the atmosphere of Mars in the absence of biogenic production. A search for these gases utilizing either high resolution (spectral and spatial) spectroscopy from a Mars orbiter, such as the Observer, and or in situ measurements from a Mars lander or rover, is proposed

    Thirty Years After: The Science of the Viking Program and the Discovery of a 'New Mars'

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    Viking discovered a Mars that was very different from the Mars found by Mariner 4, 6 and 7. The new, exciting, more Earth-like Mars was hinted at by the Mariner 9 orbiter and confirmed by Viking. Viking discovered some very fundamental things about Mars. Viking discovered the presence of nitrogen in the atmosphere. A key ingredient needed for life. Viking made the first measurements of the isotopic composition of carbon, oxygen, nitrogen and the noble gases in the atmosphere of Mars. The ratio of 15N to 14N suggested that Mars may have lost more than 99% of the total mass of its atmosphere. The denser atmosphere in the past may explain the presence of flowing water earlier in the history of Mars first discovered by Mariner 9 with additional and higher spatial resolution examples provided by the Viking Orbiters. Viking did not measure organics or life at the surface of Mars. But, Viking did discover a surface unlike any other on the Solar System--a surface exhibiting very high chemical reactivity, most probably formed by the deposition of chemically active atmospheric gases, like hydrogen peroxide (H2O2) and ozone (O3), onto the surface of Mars

    The Exploration of Mars by Humans: Why Mars? Why Humans?

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    As we commemorate the 50th anniversary of Yuri Gagarin's historic flight in 1961, the first flight of a human in space, plans are underway for another historic human mission. Plans are being developed for a human mission to Mars. Once we reach Mars, the human species will become the first two-planet species. Both the Bush Administration (in 2004) and the Obama Administration (in 2010) proposed a human mission to Mars as a national goal of the United States

    The role of cVA and the Odorant binding protein Lush in social and sexual behavior in <i>Drosophila melanogaster</i>:cVA and social behavior

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    Social living is beneficial because it allows conspecifics to interact in ways that increase their chances of survival and reproduction. A key mechanism underlying these benefits is the ability to recognize conspecifics; thus, allowing the production of coordinated social interactions. Identification of such individuals is often through chemical communication: the individuals’ pheromonal profile indicates their sex, species and even past experiences. However we know little about how the chemosensory system of conspecifics detects and how the nervous system processes this information. One of the best documented pheromonal detection mechanism is that of cis-Vaccenyl Acetate (cVA) made by male Drosophila melanogaster and transferred to females during mating. Sensing of cVA by males inhibits courtship behavior towards already mated females. Sensing of cVA on other males also inhibits courtship and increases aggression. In this hybrid review/research article, we discuss the pheromonal system of Drosophila putting an emphasis on the molecular and cellular mechanisms involved in cVA sensing by the olfactory system, perception by the nervous system and ultimately the regulation of social interactions. The behavioral effect of cVA is context- as well as experience-dependent leading us to conclude that cVA plays a modulatory role in regulating social interactions rather than being a recognition pheromone. We also provide new behavioral data on the function of the Odorant Binding Protein Lush, which binds cVA in olfactory sensilla and help sensing this chemical. Our data indicate that lush may be involved in the sensing of additional pheromones to cVA and suggest the existence of a lush-independent cVA detecting system. Interpretation of our data in the light of our current knowledge about pheromonal recognition in Drosophila indicates that this system is still incompletely understood

    Humans to Mars: The Greatest Adventure in Human History

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    The reasons for a human mission to Mars are many and include (1) World technological leadership, (2) Enhanced national security, (3) Enhanced economic vitality, (4) The human urge to explore new and distant frontiers, (5) Scientific discovery (how did Mars evolve from an early Earth-like, hospitable planet to its present inhospitable state? Is there life on Mars?) (6) Inspiring the American public and the next generation of scientists and engineers (following the launch of Sputnik I by the USSR on October 4, 1957, the U. S. and the rest of the world witnessed a significant increase in the number of students going into science and engineering), (7) Develop new technologies for potential non-space spin-off applications, and, (8) Enhanced national prestige, etc. Other reasons for colonizing the Red Planet are more catastrophic in nature, including Mars as a safe haven for the survival of the human species in the event of an impact with a large asteroid (remember the demise of the dinosaurs 65-million years as a result of an asteroid impact!). Some have also suggested that the colonization of Mars may be a solution to the global exponential population explosion on our planet! A human mission to and the colonization of the Red Planet requires multi-disciplined expertise in many areas including engineering, technology, science, human health and medicine and the human psychological and behavior. To capture the relevant areas of needed expertise, we have invited a group of more than 70 U. S. and foreign experts in these areas, including astronauts, scientists, engineers, technologists, medical doctors, psychologists and economists to share their views and thoughts on a human mission to Mars

    Layered Social Network Analysis Reveals Complex Relationships in Kindergarteners.

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    The interplay between individuals forms building blocks for social structure. Here, we examine the structure of behavioral interactions among kindergarten classroom with a hierarchy-neutral approach to examine all possible underlying patterns in the formation of layered networks of "reciprocal" interactions. To understand how these layers are coordinated, we used a layered motif approach. Our dual layered motif analysis can therefore be thought of as the dynamics of smaller groups that tile to create the group structure, or alternatively they provide information on what the average child would do in a given local social environment. When we examine the regulated motifs in layered networks, we find that transitivity is at least partially involved in the formation of these layered network structures. We also found complex combinations of the expected reciprocal interactions. The mechanisms used to understand social networks of kindergarten children here are also applicable on a more general scale to any group of individuals where interactions and identities can be readily observed and scored

    The neurogenetics of group behavior in Drosophila melanogaster

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    Organisms rarely act in isolation. Their decisions and movements are often heavily influenced by direct and indirect interactions with conspecifics. For example, we each represent a single node within a social network of family and friends, and an even larger network of strangers. This group membership can affect our opinions and actions. Similarly, when in a crowd, we often coordinate our movements with others like fish in a school, or birds in a flock. Contributions of the group to individual behaviors are observed across a wide variety of taxa but their biological mechanisms remain largely unknown. With the advent of powerful computational tools as well as the unparalleled genetic accessibility and surprisingly rich social life of Drosophila melanogaster, researchers now have a unique opportunity to investigate molecular and neuronal determinants of group behavior. Conserved mechanisms and/or selective pressures in D. melanogaster can likely inform a much wider phylogenetic scale. Here, we highlight two examples to illustrate how quantitative and genetic tools can be combined to uncover mechanisms of two group behaviors in D. melanogaster: social network formation and collective behavior. Lastly, we discuss future challenges towards a full understanding how coordinated brain activity across many individuals gives rise to the behavioral patterns of animal societies
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