The objectives of this study were to determine the extent of absorption of functionalized
single-wall carbon nanotubes (SWCNTs) across the gut epithelial cells in Daphnia magna.
Several microscopic techniques were utilized, including micro-Raman spectroscopy, high-resolution
transmission electron microscopy (HRTEM) and selective area diffraction (SAD). In an
effort to examine the...
Full Text:
Daphnia magna
Edgington, A. J., Petersen, E. J., Herzing, A. A., Podila, R., Rao, A., & Klaine, S. J
The objectives of this study were to determine the extent of absorption of functionalized
single-wall carbon nanotubes (SWCNTs) across the gut epithelial cells in Daphnia magna.
Several microscopic techniques were utilized, including micro-Raman spectroscopy, high-resolution
transmission electron microscopy (HRTEM) and selective area diffraction (SAD). In an
effort to examine the...
The objectives of this study were to determine the extent of absorption of functionalized single-wall carbon nanotubes (SWCNTs) across the gut epithelial cells in Daphnia magna. Several microscopic techniques were utilized, including micro-Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM) and selective area diffraction (SAD). In an effort to examine the...
Stephen Biko was a black leader in South Africa who
died in police custody on September 12, 1977. Biko's death
echoed within the Republic of South Africa and around the
world, showing that racial tensions in that country were
severe. At his death he was a hero to the black...
The North Pacific humpback whale (Megaptera novaeangliae) population has been increasing at an average annual rate of ~6% since the early 1990s. In northern Southeast Alaska alone, there are now more whales than estimated for the entire North Pacific several decades ago. An understanding of how this growing population is...
The end of the Cold War brought about changes within international political relations that resulted in expanded interest in global civil society. Such developments, like globalization and democratization, have encouraged the growth of social and political organizations. Political scientists have found that these inter-governmental and non-governmental organizations have a significant...
The phylogenetic diversity of two continental shelf picoplankton
communities was examined by analyzing SSU (16S) ribosomal RNA (rRNA)
genes amplified from environmental DNA with bacterial-specific primers and
the polymerase chain reaction (PCR). Picoplankton populations collected from
the pycnocline (10 m) over the eastern continental shelf of the United States
near...
Oligotrophic bacteria are adapted to low nutrient concentrations. As most of the ocean is oligotrophic (low in nutrients), oligotrophic bacteria thrive in the ocean and make up the majority of planktonic cells. Because of this, oligotrophs are crucial to oceanic nutrient cycles. However, marine oligotrophic bacteria are dwarfed by their...
The study of diffusion coefficients of n-alkanes and other organic compounds in silicones is undertaken by gas-liquid chromatography. About 0. 3% of stationary phase is coated on glass bead support so that the only significant source of peak spreading is due to slow liquid phase mass transfer. Diffusion coefficients are...
Members of the SAR11 clade of heterotrophic α-proteobacteria are ubiquitous and abundant in the world's oceans where they are thought to play a pivotal role in the global carbon cycle. The first SAR11 bacterium cultivated in vitro, 'Candidatus Pelagibacter ubique' HTCC1062 (Ca. P. ubique), was isolated by dilution into sterile...
Continental shelves located along eastern boundary currents occupy relatively small volumes of the world’s oceans, yet are responsible for a large proportion of global primary production. The Oregon coast is among these ecosystems. Recent analyses of dissolved oxygen at shallow depths in the water column has suggested increasing episodes of...
Oceanic carbon cycling plays a major role in determining global atmospheric CO₂. A better understanding of dissolved organic matter and its constituents in the water column and how it affects marine carbon cycling is sought after. This study successfully measured osmolytes, low molecular zwitterionic compounds derived from amino acids, in...
Over 100 monthly bacterioplankton DNA samples, from each of the surface and 200 m depths at the Bermuda Atlantic Time-series Study (BATS) site, were analyzed for community assembly processes. Correlation networks, filtered for potential autocorrelation artifacts, were constructed for each depth. Network characteristics for the two depths were remarkably similar...
A specially designed gas chromatograph with both TCD and FID has
been tested for the measurement of the diffusion coefficients of methane and propane in helium. Knox's arrested elution technique(⁴) was used and yielded a value of 0.6431 cm²/sec averaged with the value
obtained by Yang and Hawkes(⁷). Values of...
SAR11 Alphaproteobacteria are the most abundant aerobic chemoheterotrophs in ocean surface waters. Previous studies have indicated SAR11 cells play an important role in marine carbon cycling and consume up to half of some common dissolved organic compounds, such as amino acids. During sequencing of the first SAR11 genome, genes for...
Our experiments aimed to investigate responses of the marine cyanobacteria Prochlorococcus and Synechococcus to toxic arsenic species, such as arsenate, and to understand cellular mechanisms that contribute to arsenic tolerance. We used two strains of Prochlorococcus, a high-light adapted MED4 and low-light adapted MIT9313, both axenic, for cultivation experiments. For...
SAR11 is a clade of marine bacteria that are the most abundant heterotrophs in ocean surface water. They play a significant role in marine carbon cycling. Although many culturing experiments have been done on SAR11, there was no research that focused on verifying the observations about inhibition of SAR11 growth...
Diffusion of short chain n-alkanes was found to be faster in the
polydimethylsilicone elastomer SE-30 than in the polydimethylsilicone
oil SF-96-2000. The opposite was true for the longer chain n-alkanes
suggesting that choice of stationary phase for gas chromatography
would depend on the chain length of sample components. The dependence...