Marsh Soils as Potential Sinks for Bacteroides Fecal Indicator Bacteria,Waccamaw National Wildlife Refuge,Georgetown, SC,USA

A soil core collected in a tidal freshwater marsh in the Waccamaw National Wildlife Refuge (Georgetown, SC) exuded a particularly strong odor of cow manure upon extrusion. In order to test for manure and determine its provenance, we carried out microbial source tracking using DNA markers for Bacteroides, a noncoliform, anaerobic bacterial group that represents a large proportion spectrum of the fecal population. Three core sections from 0–3 cm, 9–12 cm, and 30–33 cm were analyzed for the presence of Bacteroides. The ages of core sediments were estimated using ²¹⁰Pb and ¹³⁷Cs dating. All three core sections tested positive for Bacteroides DNA markers related to cow or deer feces. Because cow manure is stockpiled, used as fertilizer, and a source of direct contamination in the Great Pee Dee River/Winyah Bay watershed, it is very likely the source of the Bacteroides that was deposited on the marsh. The mid-points of the core sections were dated as follows: 0–3 cm, 2009; 9–12 cm, 1999, and 30–33 cm, 1961. The presence of Bacteroides at different depths/ages in the soil profile indicates that soils in tidal freshwater marshes are, at the least, capable of being short-term sinks for Bacteroides and, may have the potential to be long-term sinks of stable, naturalized populations.

     

Inflammation and collagenase production in rats with adjuvant arthritis reduced with 13-cis-retinoic acid

Oral administration of 13-cis-retinoic acid (40 or 160 milligrams per kilogram of body weight daily) significantly reduced the inflammation associated with developing and established adjuvant arthritis, an experimentally induced arthritis in rats that resembles human rheumatoid arthritis. The amount of collagenase secreted in tissue culture by adherent cells isolated from the inflamed joints of adjuvant rats treated with 13-cis-retinoic acid also decreased as compared to the amount secreted by cells from vehicle-treated adjuvant rats. Collagenase is important in the joint destruction accompanying rheumatoid arthritis. The successful use of retinoids in the treatment of this proliferative but nonmalignant disorder demonstrates a new application of these compounds.     

Revisiting carbon flux through the ocean's twilight zone

The oceanic biological pump drives sequestration of carbon dioxide in the deep sea via sinking particles. Rapid biological consumption and remineralization of carbon in the "twilight zone" (depths between the euphotic zone and 1000 meters) reduce the efficiency of sequestration. By using neutrally buoyant sediment traps to sample this chronically understudied realm, we measured a transfer efficiency of sinking particulate organic carbon between 150 and 500 meters of 20 and 50% at two contrasting sites. This large variability in transfer efficiency is poorly represented in biogeochemical models. If applied globally, this is equivalent to a difference in carbon sequestration of more than 3 petagrams of carbon per year.     

The RAR1 interactor SGT1, an essential component of R gene-triggered disease resistance

Plant disease resistance (R) genes trigger innate immune responses upon pathogen attack. RAR1 is an early convergence point in a signaling pathway engaged by multiple R genes. Here, we show that RAR1 interacts with plant orthologs of the yeast protein SGT1, an essential regulator in the cell cycle. Silencing the barley gene Sgt1 reveals its role in R gene-triggered, Rar1-dependent disease resistance. SGT1 associates with SKP1 and CUL1, subunits of the SCF (Skp1-Cullin-F-box) ubiquitin ligase complex. Furthermore, the RAR1-SGT1 complex also interacts with two COP9 signalosome components. The interactions among RAR1, SGT1, SCF, and signalosome subunits indicate a link between disease resistance and ubiquitination.     

Silicon device scaling to the sub-10-nm regime

In the next decade, advances in complementary metal-oxide semiconductor fabrication will lead to devices with gate lengths (the region in the device that switches the current flow on and off) below 10 nanometers (nm), as compared with current gate lengths in chips that are now about 50 nm. However, conventional scaling will no longer be sufficient to continue device performance by creating smaller transistors. Alternatives that are being pursued include new device geometries such as ultrathin channel structures to control capacitive losses and multiple gates to better control leakage pathways. Improvement in device speed by enhancing the mobility of charge carriers may be obtained with strain engineering and the use of different crystal orientations. Here, we discuss challenges and possible solutions for continued silicon device performance trends down to the sub-10-nm gate regimes.     

Marcy: A chipping variety with resistance to common scab and the golden nematode

‘Marcy’ is a white-skinned, white-fleshed potato cultivar notable for its high yield, good chip color, and resistance to common scab and race Ro1 of the golden cyst nematode. It was selected from a cross made at Cornell University in 1990 between ‘Atlantic’ and Q155-3. Full-season marketable yields of Marcy have averaged 15% to 20% greater than Atlantic in 83 trials across New York, Maine, and Pennsylvania. Specific gravity of Marcy has averaged 0.008 less than Atlantic. Chip color out of 7 C storage in New York has been similar to ‘Pike’, but not as light as ‘Snowden’. Marcy tubers have an attractive oval shape, shallow eyes, and highly textured skin. Marcy was jointly released by the New York and Pennsylvania Agricultural Experiment Stations in 2002.     

Viral-derived DNA invasion and individual variation in an Indonesian population of large flying fox Pteropus vampyrus

Here, we performed next-generation sequencing (NGS) on six large flying foxes (Pteropus vampyrus) collected in Indonesia. Seventy-five virus species in the liver tissue of each specimen were listed. Viral homologous sequences in the bat genome were identified from the listed viruses. This finding provides collateral evidence of viral endogenization into the host genome. We found that two of the six specimens bore partial sequences that were homologous to the plant pathogens Geminiviridae and Luteoviridae. These sequences were absent in the P. vampyrus chromosomal sequences. Hence, plant viral homologous sequences were localized to the hepatocytes as extrachromosomal DNA fragments. Therefore, this suggests that the bat is a potential carrier or vector of plant viruses. The present investigation on wild animals offered novel perspectives on viral invasion, variation, and host interaction.     

Assessment of bovine mammary chemokine gene expression in response to lipopolysaccharide, lipotechoic acid + peptidoglycan, and CpG oligodeoxynucleotide 2135

During intramammary infections pathogen associated molecular patterns (PAMPs) induce an inflammatory response, recognized clinically as mastitis. Recognition of PAMPs by mammary cells leads to the production of the pro-inflammatory cytokines, TNF-α and IL-1β. These cytokines augment the secretion of various chemokines that are responsible for directing the host cellular immune response, and consequently the outcome of infection. Previous research has shown that gram-negative and gram-positive bacteria elicit different types of innate immune responses. The purpose of this study, therefore, was to characterize the expression of various chemokine genes in bovine mammary gland explants in response to lipopolysaccharide (LPS), peptidoglycan (PTG) combined with lipotechoic acid (LTA), and CpG oligodeoxynucleotide (CpG-ODN) 2135 representing gram-negative bacteria, gram-positive bacteria, and bacterial DNA, respectively, to determine if these PAMPs induce different chemokine gene expression patterns. Explants from 3 Holstein cows were cultured with 10 μg/mL of LPS, LTA + PTG, or CpG-ODN 2135 for 6 and 24 h. Total RNA was extracted and the expression of CXCL8, MCP-1, MCP-2, MCP-3, MIP1-α, and RANTES genes was measured by real-time polymerase chain reaction (RT-PCR). Lipopolysaccharide significantly induced MCP-1, MCP-2, and MCP-3 expression, and slightly increased CXCL8 gene expression. The combined PAMPs, LTA + PTG, on the other hand, significantly induced MCP-1 gene expression, and slightly increased MCP-3 expression. No significant expression differences for any of the chemokine genes were observed in explants stimulated with CpG-ODN 2135. These results demonstrate that PAMPs associated with different mastitis-causing pathogens induce chemokine-specific gene expression patterns that may contribute to different innate immune responses to bacteria.     

Identification of a locus for asynchronous heading in rice, <Emphasis Type="Italic">Oryza sativa</Emphasis> L.

We have identified a locus for asynchronous heading in rice. The length of heading period in a plant was measured as the indicator of asynchronous heading in 98 backcross inbred lines (BILs). These lines were derived using a single-seed descent method from a backcross of (japonica Nipponbare/indica Kasalath)/Nipponbare, and we used this mapping population in quantitative trait locus (QTL) analysis. We located a single QTL related to asynchronous heading (qah7) in the region of R2401–C39 on chromosome 7, and its contribution to the total variation was 0.14 (r²), with the positive effect due to the Kasalath allele. A near isogenic line (NILah7) that carries a Kasalath chromosomal segment corresponding to qah7 in the Nipponbare genetic background was selected and analyzed to identify a locus for asynchronous heading. The length of heading period in NILah7 was significantly longer (P < 0.001) than that in Nipponbare.