Deep-Sea Hydrothermal Vent Fauna: Evolution, Dispersal, Succession and Biogeography

Since their discovery in 1977, the ecological communities found at deep-sea hydrothermal vents have provided many surprises about life on Earth in extreme conditions and continue to instill much curiosity in scientists that study their systems as well as those simply interested in Earthʼs biodiversity. This review paper will attempt to provide a general overview of as many aspects of hydrothermal vents and their associated fauna as possible. The general geological processes that produce these systems and the chemosynthesis which sustains abundant life at these depths will first be covered. A basic overview of hydrothermal vent ecology, including some key organisms and general succession patterns will be taken up next. Dispersal ability, which plays a crucial role in facilitating the colonization of new habitat, structuring communities, and allowing for speciation through barriers to gene flow, will be considered. The biogeography of hydrothermal vent biotic assemblages globally will be an important topic and factors that influence it will be considered at length. Finally, what is currently known about the evolution of vent fauna will be briefly examined along with a theory which speculates on the origin of life on Earth at hydrothermal vents

If matter matters : navigating the moral implications of panpsychism

When you gaze at a sunset or taste a peach, there is a subjective feel to be had. This subjective "feel" is referred to as the qualitative character of experience. My goal is to argue that a certain ontological theory of the qualitative character of experience is more plausible than has been granted. The theory in question is called panpsychism. Roughly, panpsychists argue that in order to account for the qualitative character of experience, we must take the world to be, at its most fundamental level, "experiential." In slogan form, panpsychism might be summed up as "If humans are subjects of experience, then electrons are subjects of experience." There are three questions that the panpsychist proposal immediately raises. First: Why think that experiential phenomena cannot be novel phenomena but rather must be already present at the most fundamental levels of reality? Second: Precisely how are we to understand the claim that experiential phenomena are present at the fundamental level of reality? Third: Isn't it absurd to think that experiential phenomena are present at the fundamental level of reality--to think that there is something it is like to be an electron? I address each of these three questions in this thesis

Citizenship goes to the dogs

The conclusion I defend is that "domestic animals" have a moral claim to what I refer to as "basic citizenship rights," and that they do so for the same reason that "non-autonomous humans" do. I define each of these key terms. The bulk of this dissertation is structured around the following formal argument, which I refer to as the Political AMC, on account of its strategy being borrowed from the so-called Argument from Marginal Cases, or AMC: (P1) Non-rationally autonomous humans have an undefeated moral claim to basic citizenship rights. (P2) If non-rationally autonomous humans have an undefeated moral claim to basic citizenship rights, then possessing vulnerability and no decisive defeaters is a sufficient condition for having an undefeated claim to basic citizenship rights. (C1) Possessing vulnerability and no decisive defeaters is a sufficient condition for having a claim to basic citizenship rights. (P3) Domestic animals possess vulnerability and no decisive defeaters. (C2) Domestic animals have an undefeated claim to basic citizenship rights. The defense offered for Premise 2 is abductive--an inference to the best explanation-- and treated accordinglyIncludes bibliographical reference

Atlantic deep water provenance decoupled from atmospheric CO2 concentration during the lukewarm interglacials.

Ice core records show that atmospheric CO2 concentrations and Antarctic temperature were lower during the 'lukewarm interglacials' from 800 to 430 ka than the subsequent five interglacials. These different interglacial 'strengths' have been hypothesised to be controlled by Antarctic overturning circulation. How these variations in Antarctic overturning relate to Northern Atlantic overturning circulation, a major driver of Northern Hemisphere climate, is uncertain. Here we present a high-resolution record of authigenic neodymium isotopes-a water mass tracer that is independent of biological processes-and use it to reconstruct Atlantic overturning circulation during the last 800 kyr. This record reveals a similar proportion of North Atlantic Deep Water during the 'lukewarm interglacials' and the more recent interglacials. This observation suggests that the provenance of deep water in the Atlantic Ocean can be decoupled from ventilation state of the Southern Ocean and consequently the atmospheric concentration of carbon dioxide

Noncommutative symmetric functions and Laplace operators for classical Lie algebras

New systems of Laplace (Casimir) operators for the orthogonal and symplectic Lie algebras are constructed. The operators are expressed in terms of paths in graphs related to matrices formed by the generators of these Lie algebras with the use of some properties of the noncommutative symmetric functions associated with a matrix. The decomposition of the Sklyanin determinant into a product of quasi-determinants play the main role in the construction. Analogous decomposition for the quantum determinant provides an alternative proof of the known construction for the Lie algebra gl(N).Comment: 25 page

Haptic Noise Cancellation: Restoring Force Perception in Robotically-Assisted Beating Heart Surgery

Beating heart surgical methods have the potential to remove the need for the heart-lung machine and its attendant side effects, but must contend with the motion of the heart. Recent research in robotically-assisted surgery has produced a handheld, actuated in- strument that can track and compensate for heart motion; however, the reaction forces caused by the actuation mechanism make it dif- ficult for the surgeon to feel the heart during the operation, which can lead to unsafe tissue manipulation. This paper investigates an instrument design that negates reaction forces to the user by moving a counterweight out of phase with the moving mass of the actuator. The resulting instrument retains the tracking and motion compensa- tion abilities of the current instrument, but reduces reaction forces felt by the user by over 80%. Subjects used the new instrument in an in vitro beating heart surgical contact task and performance was compared to the previously existing instrument. The new in- strument provided a 28% increase in user force sensitivity and im- proved user reaction times by 51%, indicating that the new instru- ment greatly enhances force perception in beating heart tasks.Engineering and Applied Science

Assessing MyPlate Familiarity and Typical Meal Composition using Food Models in Children Aged 7-13

The Dietary Guidelines for Americans serve as a basis for developing federal nutrition education materials for the public, such as MyPlate. MyPlate is a visual cue that uses food groups as a guide to building healthy plates at mealtime. The objective of this study was to determine factors associated with child familiarity with MyPlate guidelines and to determine if typical meals met MyPlate guidelines using food models. A convenience sample of 250 children (aged 7-13 years) and their parent/guardian were recruited at a local science and history museum. Children viewed a picture of the MyPlate icon and were asked to identify the picture. Next, participants used a nine-inch plate to build a typical meal (meals that they would regularly consume) from a buffet of food and beverages models (>65 items to choose from). Research team members took photographs of the plates. A Registered Dietitian Nutritionist determined the percentage of plates that met MyPlate guidelines. Eighty-six percent of children recognized the MyPlate icon upon viewing the image; 7.6% could accurately identify the icon by name. When participants were asked to build a typical meal, however, only 3.43% met MyPlate guidelines. The results of this study suggest that despite being familiar with MyPlate, children built typical meals that did not meet MyPlate guidelines