Erscheinungsdatum: 03/2010, Medium: Taschenbuch, Einband: Kartoniert / Broschiert, Titel: MECHANISMS THAT AFFECT AGONISM AND RESOURCE ACQUISITION, Titelzusatz: The Influence of opponent size, shelter ownership, sex, reproductive state, and physiology on interactions in the rusty crayfish, Autor: Martin, Arthur, Verlag: VDM Verlag, Sprache: Englisch, Rubrik: Biologie // Sonstiges, Seiten: 136, Informationen: Paperback, Gewicht: 219 gr, Verkäufer: averdo
Erscheinungsdatum: 06.12.2010, Medium: Taschenbuch, Einband: Kartoniert / Broschiert, Titel: Neural Mechanisms of Color Vision, Titelzusatz: Double-Opponent Cells in the Visual Cortex, Auflage: Softcover reprint of hardcover 1st ed. 2002, Autor: Conway, Bevil Richard, Verlag: Springer US, Sprache: Englisch, Schlagworte: Neurologie und klinische Neurophysiologie // Zoologie und Tierwissenschaften, Rubrik: Allgemeinmedizin // Diagnostik, Therapie, Seiten: 160, Informationen: Paperback, Gewicht: 254 gr, Verkäufer: averdo
High Quality Content by WIKIPEDIA articles! In nuclear strategy, second strike capability is a country's assured ability to respond to a nuclear attack with powerful nuclear retaliation against the attacker. To have such an ability (and to convince the opponent of its viability) is considered vital in nuclear deterrence, as otherwise the other side might be tempted to try to win a nuclear war in one massive first strike against the opponent's own nuclear forces. The possession of second strike capabilities counters a first strike nuclear threat and can support a no first use nuclear strategy. Reciprocal second strike capabilities usually cause a mutual assured destruction defence strategy, though one side may have a lower level minimal deterrence response. An example of how second strike capability can be strengthened is the implementation of fail-deadly mechanisms.
The work in this book is concerned with examining the retinal contributions to human trichromatic colour vision. Chromatic processing at the retinal level was examined using the electroretinograms (ERGs) for which cone isolating stimuli were used to assess the nature of L and M cone inputs to cone-opponent mechanisms. From the experiments, It has been shown that the low (12Hz) and high (30Hz) temporal frequency flickering stimuli can isolate the chromatic and luminance processing mechanisms in the retina. For low temporal frequency ERGs, the L:M ratio was close to unity and L/M phase difference was close to 180°.For high temporal frequency ERGs, the L:M ratio was more than unity and L/M phase difference was close to 90°. In addition to this, the variation in L:M ratio across the retinal eccentricity was also examined. These results suggest, for the chromatic processing, L:M ratio is close to unity independent of retinal eccentricity and individuals. For the luminance processing, L:M ratio is more than unity and depends upon the region of the retina being stimulated. These findings indicate the maintenance of cone selective input for the chromatic processing across the human retina.
The discovery of a novel photoreceptor in the retina that participates in circadian phototransduction (how the retina converts light signals into neural signals) has opened up a new area of investigation. It is still not known whether human circadian phototransduction uses mechanisms similar to color vision, i.e., opponent mechanisms at a post-receptoral level. The primary goal of the study reporter here was to answer the question: does the circadian system respond to light in an additive manner, or is a spectral opponent mechanism also involved? A secondary goal of this work was to determine if the spectral sensitivity of nocturnal melatonin changes throughout the night. The findings in this book are a first step toward a better understanding of the mechanisms underlying circadian phototransduction in humans. The present results demonstrate that an opponent mechanism contributes to the spectral sensitivity to light for human melatonin suppression. In general, retinal stimulation of humans from monochromatic, or nearly monochromatic, light sources might result in data that cannot be generalized to polychromatic sources used in architectural lighting.
This book contains field and laboratory research that analyze how environmental and physiological factors influence agonistic interactions and the impact these interactions have on the development of dominance relationships and resource use. This book highlights the importance for understanding shelter availability, abundance, and quality in different natural systems to develop a clearer understanding that the impact of shelter use and preference, opponent size, and sex have on dominance relationships. Animals were also shown to exhibit different social behaviors during interactions. Male and female crayfish also engage one another in natural systems and make the choice to engage in agonistic bouts or mating behavior. Animals communicate during interactions and compete for both resources and mates that are essential for increasing an individual s fitness. Research on the underlying mechanisms that influence motivation can provide a clearer understanding of how to manipulate and alter aggression and the dominance relationships that are so prevalent in many animal systems.