48 research outputs found
Molybdenum blue nano-rings: an effective catalyst for the partial oxidation of cyclohexane
Molybdenum blue (MB), a multivalent molybdenum oxide with a nano-ring morphology is well-known in analytical chemistry but, to date it has been largely ignored in other applications. In the present work, MB has been characterized by STEM-HAADF imaging for the first time, showing the nano-ring morphology of this complex molybdenum oxide and the ordered super-molecular framework crystals that can result from the self-assembly of these MB nano-ring units. The potential of MB as an oxidation catalyst has also been investigated, where it is shown to have excellent catalytic activity and stability in the selective oxidation of cyclohexane to cyclohexanol and cyclohexanone which are important intermediates in the production of nylon
Ammonia volatilization from field-applied animal slurry - the ALFAM model.
A statistical analysis of European ammonia (NH3) volatilization data (from Denmark, Italy, the Netherlands, Norway, Sweden, Switzerland and UK) collated in a database produced a model that is supported by theoretical considerations of the effect of explanatory variables (see www.alfam.dk). Volatilization could be described mathematically by a Michaelis-Menten-type equation, with the loss rates as the response variable (R2=80Ž Variables significantly affecting NH3 volatilization throughout Europe are soil water content, air temperature, wind speed, slurry type, dry matter content of slurry, total ammoniacal nitrogen content of slurry (TAN=NH3 NH4 ), application method and rate, slurry incorporation and measuring technique. The model was used to estimate the NH3 volatilization from typical cattle and pig slurries applied in Italy, England, Norway and Denmark. Climate observations from the following three periods in year 2000 were used as input: (1) 1 week before the normal sowing time for spring crops, (2) mid-season, and (3) 1 week after harvesting. There was little difference in the total NH3 volatilization from slurry applied in the three periods, principally due to interactions between soil water content and air temperature. The time from application to when 10␘f the applied TAN was lost was similar for countries in the south and north of Europe, primarily due to the low wind speeds counteracting the effect of higher air temperatures at the southern location. To reduce NH3 volatilization, the slurry should be incorporated faster in mid- and late-season than in the early spring, due to increasing air temperatures during the growing season
Filipins:The first antifungal "weed killers" identified from bacteria isolated from the trap-ant
Allomerus ants ensure that they have sufficient nitrogen in their diet by trapping and consuming other insects. In order to construct their traps, like the more extensively studied leaf cutter ants, they employ fungal farming. Pest management within these fungal cultures has been speculated to be due to the ants' usage of actinomycetes capable of producing antifungal compounds, analogous to the leafcutter ant mutualism. Here we report the first identification of a series of antifungal compounds, the filipins, and their associated biosynthetic genes isolated from a bacterium associated with this system
‘The sooner the better I could get out of there’: barriers to higher education access in Ireland
Physiological seawater adaptation in juvenile Atlantic salmon (Salmo salar) autumn migrants
1. About 25 % of juvenile Atlantic salmon (Salmo salar) migrating downstream in the River Frome in southern England do so in the autumn rather than in the spring. Here, we examine the physiological status of these fish with regard to those features that adapt them to sea water during the parr–smolt transformation (i.e. gill Na+K+ ATPase activity; the number, size and type of chloride cells on the gill lamellae; salinity tolerance and relative plasma thyroid levels).
2. Autumn migrants, and those fish which subsequently reside in the tidal reaches during the winter, are not sufficiently physiologically adapted to permit permanent or early, entry into the marine environment.
3. It is not known what proportion of autumn migrating fish survive and return to spawn as adults. If significant numbers do return, however, the production from tidal reach habitats must be taken into account in the development of salmon stock management strategies, especially monitoring and assessment programmes, and in the evaluation of factors affecting stocks
Mammals, agri-environment schemes and set-aside – what are the putative benefits?
1. The impacts of agricultural intensification on farmland wildlife have been the subject of increasing concern, particularly over the last two decades. Population declines have occurred for a number of mammalian species, sometimes drastically so, and changes in farming practice are believed to be significant contributory factors.
2. The major policy instruments for delivering environmental benefits on farmland are agri-environment schemes. These encourage farmers to adopt more environmentally sensitive farming practices to promote farmland biodiversity. Additionally, compulsory set-aside, which reduces agricultural surplus, could also have positive impacts on wildlife. In this paper we consider some of the putative benefits of agri-environment schemes and set-aside for mammals.
3. We review how establishment and management options within agri-environment schemes and set-aside might affect habitat resources for mammals. For example, conservation headlands increase plant and invertebrate resources within the crop edge for mammals such as wood mice. Grassy field margins can support communities of smaller mammals, and hedgerows may act as important commuting and hunting routes. Their potential will depend on factors such as seed mixtures used, timing and severity of cutting, and length of time they have been in place.
4. At a farm level, habitat heterogeneity may be increased through organic agriculture, which is supported by some agri-environment schemes. Studies suggest significant benefits to mammals, including wood mice and bats. However, it is increasingly recognized that effective conservation of farmland mammals must seek solutions at the landscape scale, addressing such issues as habitat connectivity between farms. One approach may be the better targeting of scheme agreements.
5. We suggest that agri-environment schemes and set-aside can contribute to the conservation of mammals on farmland. Recent policy changes are likely to have further positive impacts on farmland wildlife but appropriate mammal monitoring programmes must be developed rigorously to assess their effects