The isolation and characterization of lysozyme from human foetal membranes: a comparison with the enzyme from other sources

Lysozyme (muramidase) was isolated from an acidic extract of human foetal membranes by adsorption and elution from octadecyl silica. It was further purified by gel-filtration and ion-exchange. The final product was homogeneous by high performance liquid chromatography (h.p.l.c.) and electrophoresis. It was indistinguishable from human milk lysozyme by all criteria investigated, including amino acid composition, electrophoretic mobility, retention time on h.p.l.c. and sequence of the first nine residues. Human uterine decidual tissue was shown to contain a similar concentration of lysozyme to foetal membranes. The enzyme was also present at lower concentrations in amnion, placenta and amniotic fluid.     

Soil N2O emissions with different reduced tillage methods during the establishment of Miscanthus in temperate grassland

An increase in renewable energy and the planting of perennial bioenergy crops is expected in order to meet global greenhouse gas (GHG) targets. Nitrous oxide (N₂O) is a potent greenhouse gas, and this paper addresses a knowledge gap concerning soil N₂O emissions over the possible “hot spot” of land use conversion from established pasture to the biofuel crop Miscanthus. The work aims to quantify the impacts of this land use change on N₂O fluxes using three different cultivation methods. Three replicates of four treatments were established: Miscanthus x giganteus (Mxg) planted without tillage; Mxg planted with light tillage; a novel seed‐based Miscanthus hybrid planted with light tillage under bio‐degradable mulch film; and a control of uncultivated established grass pasture with sheep grazing. Soil N₂O fluxes were recorded every 2 weeks using static chambers starting from preconversion in April 2016 and continuing until the end of October 2017. Monthly soil samples were also taken and analysed for nitrate and ammonium. There was no significant difference in N₂O emissions between the different cultivation methods. However, in comparison with the uncultivated pasture, N₂O emissions from the cultivated Miscanthus plots were 550%–819% higher in the first year (April to December 2016) and 469%–485% higher in the second year (January to October 2017). When added to an estimated carbon cost for production over a 10 year crop lifetime (including crop management, harvest, and transportation), the measured N₂O conversion cost of 4.13 Mg CO₂‐eq./ha represents a 44% increase in emission compared to the base case. This paper clearly shows the need to incorporate N₂O fluxes during Miscanthus establishment into assessments of GHG balances and life cycle analysis and provides vital knowledge needed for this process. This work therefore also helps to support policy decisions regarding the costs and benefits of land use change to Miscanthus.     

Differences in the diurnal and nocturnal use of intertidal feeding grounds by Redshank Tringa totanus

Capsule Redshank used more sites and had larger ranges at night than during the day.

Aims To determine whether there were differences in how wintering Redshank used intertidal feeding grounds during the day and night.

Methods The movements of 38 Redshank caught and radiotagged at two neighbouring sites on the Severn Estuary were monitored during four different study periods between January 1997 and October 1999.

Results Individuals used a greater number of sites at night than in the day (on average, two as opposed to one). Kernel home range analyses also indicated that individuals used larger core areas and home ranges at night. In addition, there was a significant difference between the sizes of ranges of birds caught at two neighbouring sites. One foraging site was almost entirely avoided during the day, probably due to disturbance from an adjacent heliport, but was used by the majority of individuals at night when the heliport was unused. This site was rich in invertebrates as a result of the high organic and nutrient input from a sewage outfall pipe. Redshank also used riverine mudflats less during the night, preferring more open mudflats – perhaps to avoid nocturnal predators.

Conclusions Comparison with previous studies suggests that the importance of sites predominantly used at night and the total extent of the areas used by waders may be underestimated by studies that rely on daytime surveys alone. It is important, therefore, that information on nocturnal distributions should be available to inform decisions on site management and protection.     

Simulated and observed fluxes of sensible and latent heat and CO2 at the WLEF-TV tower using SiB2.5

Three years of meteorological data collected at the WLEF‐TV tower were used to drive a revised version of the Simple Biosphere (SiB 2.5) Model. Physiological properties and vegetation phenology were specified from satellite imagery. Simulated fluxes of heat, moisture, and carbon were compared to eddy covariance measurements taken onsite as a means of evaluating model performance on diurnal, synoptic, seasonal, and interannual time scales. The model was very successful in simulating variations of latent heat flux when compared to observations, slightly less so in the simulation of sensible heat flux. The model overestimated peak values of sensible heat flux on both monthly and diurnal scales. There was evidence that the differences between observed and simulated fluxes might be linked to wetlands near the WLEF tower, which were not present in the SiB simulation. The model overestimated the magnitude of the net ecosystem exchange of CO₂ in both summer and winter. Mid‐day maximum assimilation was well represented by the model, but late afternoon simulations showed excessive carbon uptake due to misrepresentation of within‐canopy shading in the model. Interannual variability was not well simulated because only a single year of satellite imagery was used to parameterize the model.