Spring Distribution of Ciliate Plankton in the Southeastern Yellow Sea in 2019

Ocean Science Journal - As planktonic ciliates have been recognized as important players in marine microbial food webs, relevant studies have been conducted in the western coastal waters of the...     

The 2007 Fox Creek landslide,Peace River Lowland,Alberta, Canada

Fox Creek is a small tributary of the Saddle River, a tributary of the Peace River in northwestern Alberta. It has several dormant landslides with degraded scarps and grabens. A new, reactivated landslide on the north bank of the Fox Creek occurred on 5 May 2007. The landslide formed two major sliding blocks. A rapid translational block slide, it mobilized 47 Mm³ of displaced materials, blocked the creek, and made a natural dam with a maximum height of 19 m at the tips of the displaced blocks. The rupture surfaces of the 2007 landslide were within the advance phase glaciolacustrine sediments. The residual friction angles are about 10° similar to those of the previous landslides in the Peace River Lowland. Precipitation and snow melt prior to the landslide are likely triggers of the 2007 Fox Creek landslide. The farmlands on the crest of the river valley and timber resources were impacted. The current landslide dam in Fox Creek does not have any evidence of seepage downstream; it may last for many years. Eventually, the creek will overtop and erode the dam. The same cycle of actions, landsliding, damming, and erosion will continue in the foreseeable future.     

Stress-Strain Behavior of Light-Weighted Soils

Unconfined and triaxial compression tests were carried out to examine the behavior of light-weighted soils (LWS) consisting of expanded polystyrene (EPS), dredged soils, and cement with respect to initial water content. The stress-strain behavior of LWS are analyzed with varying initial water content and silt contents of dredged soils, cement ratio, and confined stress. As initial water contents increase, the compressibility index increases and the preconsolidation pressure was vice versa. As initial water contents increase, the slope of stress-strain curve in elastic zone increases and strain rate at failure decreases and the strain rate at failure was not changed by the being of foams. As initial water contents increase, a compressive strength of LWS decreases. The decrement ratio of compressive strength of LWS with foams increases as cement content increases and initial water contents decreases. The compressive strength increases as silt contents increases.     

The CLIVAR C20C project: skill of simulating Indian monsoon rainfall on interannual to decadal timescales. Does GHG forcing play a role?

The ability of atmospheric general circulation models (AGCMs), that are forced with observed sea surface temperatures (SSTs), to simulate the Indian monsoon rainfall (IMR) variability on interannual to decadal timescales is analyzed in a multimodel intercomparison. The multimodel ensemble has been performed within the CLIVAR International “Climate of the 20th Century” (C20C) Project. This paper is part of a C20C intercomparison of key climate time series. Whereas on the interannual timescale there is modest skill in reproducing the observed IMR variability, on decadal timescale the skill is much larger. It is shown that the decadal IMR variability is largely forced, most likely by tropical sea surface temperatures (SSTs), but as well by extratropical and especially Atlantic Multidecadal Oscillation (AMO) related SSTs. In particular there has been a decrease from the late 1950s to the 1990s that corresponds to a general warming of tropical SSTs. Using a selection of control integrations from the World Climate Research Programme’s (WCRP’s) Coupled Model Intercomparison Project phase 3 (CMIP3), it is shown that the increase of greenhouse gases (GHG) in the twentieth century has not significantly contributed to the observed decadal IMR variability.     

Searching for strange attractor in wastewater flow

 Chaos is a complex and irregular world in contrast with simple and regular natures of linear systems. Scientists and engineers have invoked low-dimensional chaos for understanding the nature of real systems. In this study, the complex behavior of a daily wastewater flow and evidence of deterministic nonlinear dynamics are investigated. The analysis involves both a metric approach of the correlation dimension and a topological technique called the close returns plot. The estimation procedure of delay time and delay time window is reviewed using a new technique called the C–C method for the state space reconstruction. And both parameters are used for estimating the correlation dimension. As a result, the daily wastewater flow shows no evidence of chaotic dynamics, which implies that stochastic models rather than deterministic chaos may be more appropriate for representing an investigated series.     

Distribution and Acoustic Characteristics of Shallow Gas in the Korea Strait Shelf Mud off SE Korea

Shallow gas in the Korea Strait shelf mud (KSSM) off SE Korea, revealed by high-resolution subbottom profiles, is associated with acoustic blanking, acoustic turbidity, seepages with plumes in the water column, and seafloor depressions. The acoustic blanking, characterized by strong, consistent top reflection and wipeout below, is most dominant. The seaward edge of the acoustic blanking zone generally coincides with the 100-m water-depth contour, suggesting that the water depth (the pressure) may control the distribution of shallow gas. The acoustic turbidity, characterized by diffuse top reflection, is a dark smear, partially blanking the data below. The seepages with plumes, characterized by vertical smearing and disturbed seafloor, are seen only along the shallowest, landward edge of the acoustic blanking zone. This may suggest that the decreased gas solubility at shallow water depths, caused by the lowered pressure, increases the volume of free gas in the sediments, facilitating the gas escape. The seafloor depressions, interpreted as pockmarks, are accompanied by cone-shaped acoustic masking, which is probably the reflection from a narrow vent of gas. The gas-related acoustic anomalies appear to occur mostly in the upper, recent mud of the KSSM. Neither permeable beds nor faults, which can act as vertical migration pathways for deep thermogenic gas, are evident in the recent mud. We interpret that the bacterial degradation of organic matter in situ is the main source for the gas in the KSSM. The upwelling off SE Korea may be an important source for the increased organic matter in the area.     

Cloning and sequence analysis of the self-fertilizing fish Rivulus marmoratus immediate early gene c-fos

We have cloned the proto-oncogene c-fos from a self-fertilizing fish Rivulus marmoratus (Cyprinodontiformes, Rivulidae) after screening of R. marmoratus lambdaGEM-11 genomic DNA library, and sequenced over 12 kb including all exons, introns and the promoter region. The R. marmoratus c-fos gene consisted of one noncoding exon and four exons with high similarity to those of fugu and mammals. We sequenced approximately 7 kb of the R. marmoratus c-fos gene promoter region to gain a better understanding of the molecular anatomy of the immediate response of this gene upon cellular damage. In the promoter region, R. marmoratus c-fos gene has seven xenobiotic response elements (XREs) and eight metal response elements (MREs) as well as two estradiol (E2), 4 NFkappaB, 2 CarG, 2 prolactin (PRL) motifs and one pit1 site, while the 3'-UTR of this gene contains the estrogen response element (ERE). The seven XRE and eight MRE motifs raise the possibility of its regulation by exposure to environmental pollutants. In this paper, we discuss the gene structure of R. marmoratus c-fos gene and compare its promoter region with those of other organisms' c-fos genes. We propose its potential use in ecotoxicology.     

Cloning and sequence analysis of the self-fertilizing fish Rivulus marmoratus immediate early gene c-fos

We have cloned the proto-oncogene c-fos from a self-fertilizing fish Rivulus marmoratus (Cyprinodontiformes, Rivulidae) after screening of R. marmoratus λGEM-11 genomic DNA library, and sequenced over 12 kb including all exons, introns and the promoter region. The R. marmoratus c-fos gene consisted of one noncoding exon and four exons with high similarity to those of fugu and mammals. We sequenced ≈7 kb of the R. marmoratus c-fos gene promoter region to gain a better understanding of the molecular anatomy of the immediate response of this gene upon cellular damage. In the promoter region, R. marmoratus c-fos gene has seven xenobiotic response elements (XREs) and eight metal response elements (MREs) as well as two estradiol (E2), 4 NFκB, 2 CarG, 2 prolactin (PRL) motifs and one pit1 site, while the 3^′-UTR of this gene contains the estrogen response element (ERE). The seven XRE and eight MRE motifs raise the possibility of its regulation by exposure to environmental pollutants. In this paper, we discuss the gene structure of R. marmoratus c-fos gene and compare its promoter region with those of other organisms' c-fos genes. We propose its potential use in ecotoxicology.     

Structure of the subsurface counter current beneath the Tsushima warm current simulated by an ocean general circulation model

The subsurface counter current beneath the Tsushima Warm Current is simulated using a three-dimensional circulation model. The model well reproduces the counter current beneath the Tsushima Warm Current on the shelf break. The counter current appears as nearshore parts of the subsurface clockwise circulations from spring to early winter. The clockwise circulations are separated by developed shelves such as the Oki Spur and the Noto Peninsula, thus the counter current is not a continuous flow along the Japanese coast in this model. The vertical structure of the counter current can be explained by a density structure with the thermal wind relationship. The permanent and seasonal pycnoclines form mutually opposite horizontal density gradients near the Japanese coast in summer. Such a density structure results in a speed maximum of the counter current away from the bottom. It is remarkable that the second baroclinic mode is dominant in nearshore parts of the subsurface clockwise circulations in summer, which are attributed to the density structure. Similar density structures are also found in some coastal regions of the world oceans where subsurface counter currents are expected.