13,355 research outputs found
Genotypic characterisation of Giardia from domestic dogs in the USA
The first large-scale urban survey of Giardia infections in dogs was undertaken in the USA. It involved several locations in the Western United States with Giardia isolates from microscopy-positive samples characterised by multi-locus PCR and sequencing. A high prevalence of Giardia was confirmed in asymptomatic domestic dogs, and for the first time, provides evidence that zoonotic assemblages/subgroups of Giardia occur frequently in domestic dogs living in urban environments, and more frequently than the dog specific assemblages
The WIGGUM gene is required for proper regulation of floral meristem size in Arabidopsis
The study of cell division control within developing tissues is central to understanding the processes of pattern formation. The floral meristem of angiosperms gives rise to floral organs in a particular number and pattern. Despite its critical role, little is known about how cell division is controlled in the floral meristem, and few genes involved have been identified. We describe the phenotypic effects of mutations in WIGGUM, a gene required for control of cell proliferation in the floral and apical meristem of Arabidopsis thaliana. wiggum flowers contain more organs, especially sepals and petals, than found in wild-type flowers. This organ number phenotype correlates with specific size changes in the early floral meristem, preceding organ initiation. Genetic studies suggest that WIGGUM acts on a similar process but in a separate pathway than the CLAVATA1 and CLAVATA3 genes in meristem size regulation, and reveal interactions with other genes affecting meristem structure and identity. Analysis of double mutant phenotypes also reveals a role for WIGGUM in apical meristem function. We propose that WIGGUM plays a role in restricting cell division relative to cellular differentiation in specific regions of the apical and floral meristems
Occultation studies of planets and satellites: The occultation of epsilon Geminorum by Mars
The occultation of epsilon Geminorum by Mars on 1976 April 8 was observed at three wavelengths and 4 ms time resolution with the 91 cm telescope. Temperature, pressure, and number density profiles of the Martian atmosphere were obtained for both the immersion and emersion events. Within the altitude range of 50 to 80 km above the mean surface, the mean temperature is 145 K, and the profiles exhibit wavelike structures with a peak to peak amplitude of 35 K and a vertical scale of about 20 km. The ratio of the refractivity of the atmosphere at 4500 A and 7500 A, determined from the time shift of the light curves for these wavelengths, is consistent with the atmospheric composition measured by Viking 1, 15 weeks later. From the central flash - a bright feature in the light curve midway between immersion and emersion - an optical depth is found at 4500 A of 3.3 plus or minus 1.7 per km atm (about 0.23 per equivalent Martian air mass) for the atmosphere about 25 km above the mean surface, near the south polar region. This large value and its weak wavelength dependence rule out Rayleigh scattering as the principal cause of the observed extinction
Reply to the comment by C. Capan and K. Behnia on "Nernst effect in poor conductors and in the cuprate superconductors" (cond-mat/0501288)
The comment criticisms (cond-mat/0501288) are completely out of line with the
context of the commented theory (Phys. Rev. Lett. v.93, 217002 (2004)). The
comment neglected essential parts of the theory, which actually addressed all
relevant experimental observations. I argue that the coexistence of the large
Nernst signal and the insulating-like in-plane resistivity in underdoped
cuprates rules out the vortex scenario, but agrees remarkably well with our
theory.Comment: 1 page, 1 figur
Achievement Goal
Achievement goals are self-regulatory commitments that provide direction to individuals as they interpret and respond to competence-relevant situations. Four types of achievement goals have been the primary focus of the literature: Masteryapproach goals (master a task; improve over time), performance-approach goals (outperform others), mastery-avoidance goals (not fall short of mastering a task; not decline over time), and performance-avoidance goals (not be outperformed by others)
- …