Atomic force microscopy of an organic monolayer

Atomic force microscope images of polymerized monolayers of n-(2-aminoethyl)-10,12-tricosadiynamide revealed parallel rows of molecules with a side-by-side spacing of approximately equal to 0.5 nanometer. Forces used for imaging (10(-8) newton) had no observable effect on the polymer strands. These results demonstrate that atomic force microscope images can be obtained for an organic system.     

Pulse structure of the pulsating radio source in vulpecula

The pulses from the pulsating radio source at right ascension 19 hours 19 minutes, declination +22 degrees have the following characteristics: (i) they begin with a sharp leading edge; (ii) they terminate after 37 milliseconds; and (iii) they consist of three subpulses, the first of which is both the strongest and the best defined.     

Investigation of Johne's disease in Tasmanian fallow deer (Dama dama)

In 2012 when many sheep flocks in northern‐central Tasmania were experiencing a high prevalence of ovine Johne's disease, 34 wild adult fallow deer shot on or near infected properties were negative to microscopic Mptb lesions of the ileo‐caecal valve, terminal ileum and ileo‐caecal lymph nodes. This study demonstrated 95% confidence of detecting Johne's disease in this fallow deer population if ≥10% of animals were shedding Mycobacterium avium subsp. paratuberculosis in their faeces, or if ≥21% of animals were sub‐clinically infected.     

The impact of rising CO2 on ecosystem production

A fundamental property of green plants is that the rate of photosynthesis is dependent in the ambient CO₂ concentration. There is overwhelming experimental evidence that this effect increases plant production in most C₃ plants: hundreds of experiments with many species show that plant growth increases an average 30% to 40% for a doubling of the present normal ambient CO₂ concentration (Kimball, 1986). External environmental factors, such as temperature and the availability of nutrients, modify this response. The greatest stimulation of photosynthesis and growth can be expected to occur at high temperatures and much smaller responses at low temperature. Factors which restrict growth, such as low nutrients, will reduce but usually do not eliminate the stimulation of production with increasing CO₂ even when nitrogen is severly limiting. There are also reports of direct effects of ambient CO₂ concentration on dark respiration which show that there is an immediate reduction in the rate of CO₂ efflux or O₂ consumption when the CO₂ around plant tissues is increased. There have been very few longterm field studies of the effects of increased CO₂ on whole plants and ecosystem processes but the data from these studies are consistent in showing an increase in plant production with an increase in CO₂ concentration of the ambient air.     

Standardising multi-laboratory microsatellite data in Pacific salmon: an historical view of the future

Abstract –  For at least 15 years, multiple Pacific Rim Laboratories have cooperated to standardise the collection of Pacific salmon genetic data. For species such as Chinook salmon and chum salmon, allozyme electrophoretic data sets now include hundreds of populations sampled over multiple years throughout the north Pacific. More recently, microsatellite DNA markers have emerged as a new cornerstone of Pacific salmon genetic research. The allozyme experience provides at least two important lessons regarding shared, standardised databases. First, interlaboratory standardisation is sufficiently costly and time consuming that little progress is typically made in the absence of specific fishery management and conservation needs; thus immediate needs will direct future standardisation. Secondly, justified or not, there are significant concerns regarding intellectual propriety and other perceived privileges associated with unpublished genetic data that are shared among laboratories. This article describes challenges to genetic standardisation relative to new research goals, along with specific suggestions for meeting those challenges.