Comparing Charge Transport in Oligonucleotides: RNA:DNA Hybrids and DNA Duplexes.

Understanding the electronic properties of oligonucleotide systems is important for applications in nanotechnology, biology, and sensing systems. Here the charge-transport properties of guanine-rich RNA:DNA hybrids are compared to double-stranded DNA (dsDNA) duplexes with identical sequences. The conductance of the RNA:DNA hybrids is ∼10 times higher than the equivalent dsDNA, and conformational differences are determined to be the primary reason for this difference.

The Type II Secreted Lipase/Esterase LesA is a Key Virulence Factor Required for Xylella fastidiosa Pathogenesis in Grapevines.

Pierce's disease (PD) of grapevines is caused by Xylella fastidiosa (Xf), a xylem-limited gamma-proteobacterium that is responsible for several economically important crop diseases. The occlusion of xylem elements and interference with water transport by Xf and its associated biofilm have been posited as the main cause of PD symptom development; however, Xf virulence mechanisms have not been described. Analysis of the Xf secretome revealed a putative lipase/esterase (LesA) that was abundantly secreted in bacterial culture supernatant and was characterized as a protein ortholog of the cell wall-degrading enzyme LipA of Xanthomonas strains.

An engineered innate immune defense protects grapevines from Pierce disease.

We postulated that a synergistic combination of two innate immune functions, pathogen surface recognition and lysis, in a protein chimera would lead to a robust class of engineered antimicrobial therapeutics for protection against pathogens. In support of our hypothesis, we have engineered such a chimera to protect against the gram-negative Xylella fastidiosa (Xf), which causes diseases in multiple plants of economic importance. Here we report the design and delivery of this chimera to target the Xf subspecies fastidiosa (Xff), which causes Pierce disease in grapevines and poses a great threat to the wine-growing regions of California.

Participation of the Cowpea mosaic virus protease in eliciting extreme resistance.

Extreme resistance of Arlington line cowpea (Vigna unguiculata) to Cowpea mosaic virus (CPMV) is under control of a dominant locus designated Cpa. We transiently expressed, using Tomato bushy stunt virus (TBSV) vectors and Agrobacterium tumefaciens, in nearly isogenic Cpa/Cpa and cpa/cpa cowpea lines, sequences from RNA1, the larger of two CPMV genomic RNAs. Activation of a Cpa-specific response mapped to the CPMV 24K protease (24KPro).

Health care factors related to stage at diagnosis and survival among Medicare patients with colorectal cancer.

Background: With the growth in enrollment of Medicare patients in HMOs the effectiveness of care received by Medicare/HMO patients continues to be of concern. By considering the relationship of insurance to stage at diagnosis, this study inquires whether HMOs emphasize early diagnosis of colorectal cancer to a greater extent than FFS plans, if particular HMO types (group/nongroup models) are more successful in doing so, and how this pertains to survival.

Methods: Data for 1329 Medicare patients with colorectal cancer, diagnosed 1987 to 1993, and residing in northern California, were acquired from a population-based cancer registry.

Switching costs, price sensitivity and health plan choice.

We investigate the extent to which sensitivity to health plan premiums differs across individuals according to characteristics related to the cost of switching plans. Our results indicate substantial variation in price sensitivity related to expected health care costs: younger, healthier employees are between two and four times more sensitive to price than employees who are older and who have been recently hospitalized or diagnosed with cancer. We also find evidence of status quo bias: estimated premium elasticities are significantly higher for new hires than for incumbent employees.