Marine meiofaunal macroecology and paleoecology: microfossil Ostracoda and Foraminifera as models

Special Session 3: Ecological and Evolutionary Paradigms in Marine Biology and How Meiofauna can be Used to Address Them: no. SS3-9Conference Theme: Life in the Changing OceanSmall benthic organisms, meiofauna, have been investigated less intensively compared to larger macrofauna, resulting in greater taxonomic uncertainty and less census data accumulation. However, they are the most abundant and diverse group of (non-microbial) organisms in marine sediments. Hundreds of specimens and dozens of species can be obtained from small amount of sediment. Two taxa of meiofauna, the crustacean Ostracoda and protozoan Foraminifera are known as microfossils. Their microscopic-size …published_or_final_versio

Deep-sea biodiversity dynamics and faunal evolution throughout the Cenozoic

Special Session 5: Evolution in the Deep Sea: Origins, Adaptation and Diversity: no. SS5-3Conference Theme: Life in the Changing OceanMacroevolutionary history of deep-sea benthic ecosystem remains poorly understood because of limited and fragmentary distribution of deep-sea strata as outcrops on land and resulting limited availability of macrofossil data. Deep-sea sediment cores provide almost continuous sedimentary records from the Jurassic to the present of the last ~200 million years, of which Cenozoic record is especially complete, although macrofossils are rarely included there because only small amount of sediments are available from the sediment cores. Some small organisms with high fossilization potential known as microfossils are abundantly included in these deep-sea sediment cores, and thus provide us unique opportunity to investigate detailed macroevolutionary history throughout the …published_or_final_versio

Marine meiofaunal macroecology and paleoecology: microfossil Ostracoda and Foraminifera as models

Special Session 3: Ecological and Evolutionary Paradigms in Marine Biology and How Meiofauna can be Used to Address Them: no. SS3-9Conference Theme: Life in the Changing OceanSmall benthic organisms, meiofauna, have been investigated less intensively compared to larger macrofauna, resulting in greater taxonomic uncertainty and less census data accumulation. However, they are the most abundant and diverse group of (non-microbial) organisms in marine sediments. Hundreds of specimens and dozens of species can be obtained from small amount of sediment. Two taxa of meiofauna, the crustacean Ostracoda and protozoan Foraminifera are known as microfossils. Their microscopic-size …published_or_final_versio

The Spin Mass of an Electron Liquid

We show that in order to calculate correctly the {\it spin current} carried by a quasiparticle in an electron liquid one must use an effective "spin mass" $m_s$, that is larger than both the band mass, $m_b$, which determines the charge current, and the quasiparticle effective mass $m^*$, which determines the heat capacity. We present microscopic calculations of $m_s$ in a paramagnetic electron liquid in three and two dimensions, showing that the mass enhancement $m_s/m_b$ can be a very significant effect.Comment: 10 pages, 1 figur

The Effect of Acetaminophen on Oxidative Modification of Low-Density Lipoproteins in Hypercholesterolemic Rabbits

Oxidative modification of low-density lipoproteins (LDL) contributes to the pathology of atherosclerosis. Antioxidants may protect LDL against oxidative modification. Acetaminophen, a widely used analgesic and antipyretic agent, has significant antioxidant properties. However, there is little evidence to suggest that acetaminophen acts as an antioxidant for LDL oxidation in vivo. In this study, we investigated the in vivo effect of acetaminophen on LDL oxidation in hypercholesterolemic rabbits. The oxidative modification of LDL was identified by conjugated dienes and thiobarbituric acid-reactive substances (TBARS). In the cholesterol group which rabbits were fed a diet contained 1% g cholesterol for 8 weeks, TBARS contents and conjugated diene levels in the plasma and isolated LDL samples significantly increased compared with the control rabbits (p<0.05). However, in the cholesterol + acetaminophen group, the TBARS contents and conjugated diene levels were significantly lower than that of the cholesterol group (p<0.05). The results from in vitro studies also demonstrated that the LDL isolated from serum was oxidized by Cu++ ions and this oxidation reduced in the presence of acetaminophen. The reduced oxidative modification of LDL by acetaminophen may be of therapeutic value in preventing the development and progression of atherosclerosis

Why is the bandwidth of sodium observed to be narrower in photoemission experiments?

The experimentally predicted narrowing in the bandwidth of sodium is interpreted in terms of the non-local self-energy effect on quasi-particle energies of the electron liquid. The calculated self-energy correction is a monotonically increasing function of the wavenumber variable. The usual analysis of photo-emission experiments assumes the final state energies on the nearly-free-electron-like model and hence it incorrectly ascribes the non-local self-energy correction to the final state energies to the occupied state energies, thus leading to a seeming narrowing in the bandwidth.Comment: 9 page

Earthquake-Induced Settlement in Soft Grounds

Earthquake-induced settlements in clay is derived from both undrained shear deformation and post-earthquake volume change. The former is assumed to be time-independent while the latter must be time-dependent. To determine the characteristics of cyclic-induced settlements, the authors have carried out a family of cyclic triaxial tests followed by drainage on the plastic marine clay. In every test, shear strain and excess pore pressure were measured during undrained stage and volume change was measured during dissipation of excess pore pressure. In the present study, in particular, the results from cyclic triaxial tests were formulated in order to predict the variations of pore pressure with number of load cycles. An excess pore pressure model was used together with the consolidation theory to evaluate the total settlements and their time-dependent variations due to dissipation of cyclic-induced pore pressure. The results of analysis using the proposed method provide a basis for evaluating the post-earthquake settlement in soft grounds

Human-induced marine ecological degradation: micropaleontological perspectives

We analyzed published downcore microfossil records from 150 studies and reinterpreted them from an ecological degradation perspective to address the following critical but still imperfectly answered questions: (1) How is the timing of human-induced degradation of marine ecosystems different among regions? (2) What are the dominant causes of human-induced marine ecological degradation? (3) How can we better document natural variability and thereby avoid the problem of shifting baselines of comparison as degradation progresses over time? The results indicated that: (1) ecological degradation in marine systems began significantly earlier in Europe and North America ( approximately 1800s) compared with Asia (post-1900) due to earlier industrialization in European and North American countries, (2) ecological degradation accelerated globally in the late 20th century due to post-World War II economic growth, (3) recovery from the degraded state in late 20th century following various restoration efforts and environmental regulations occurred only in limited localities. Although complex in detail, typical signs of ecological degradation were diversity decline, dramatic changes in total abundance, decrease in benthic and/or sensitive species, and increase in planktic, resistant, toxic, and/or introduced species. The predominant cause of degradation detected in these microfossil records was nutrient enrichment and the resulting symptoms of eutrophication, including hypoxia. Other causes also played considerable roles in some areas, including severe metal pollution around mining sites, water acidification by acidic wastewater, and salinity changes from construction of causeways, dikes, and channels, deforestation, and land clearance. Microfossils enable reconstruction of the ecological history of the past 10(2)-10(3) years or even more, and, in conjunction with statistical modeling approaches using independent proxy records of climate and human-induced environmental changes, future research will enable workers to better address Shifting Baseline Syndrome and separate anthropogenic impacts from background natural variability.published_or_final_versio

Temperature impacts on deep-sea biodiversity

Session - Climate Change ImpactsTemperature is considered to be a fundamental factor controlling biodiversity in marine ecosystems, but precisely what role temperature plays in modulating diversity is still not clear. The deep ocean, lacking light and in situ photosynthetic primary production, is an ideal model system to test the effects of temperature changes on biodiversity. Here we synthesize current knowledge on temperature–diversity relationships in the deep sea. Our results from both present and past deep-sea assemblages suggest that, when a wide range of deep-sea bottom-water temperatures is considered, a unimodal relationship exists between temperature and …published_or_final_versio