Antimicrobial and Anticancer Properties of Synthetic Peptides Derived from the Wasp Parachartergus fraternus

Agelaia-MPI and protonectin are antimicrobial peptides isolated from the wasp Parachartergus fraternus that show antimicrobial and neuroactive activities. Previously, two analogues of these peptides, neuroVAL and protonectin-F, were designed to reduce nonspecific toxicity and improve potency. Here, the three-dimensional structures of neuroVAL, protonectin and protonectin-F were determined by using circular dichroism and NMR spectroscopy. Antibacterial, antifungal, cytotoxic and hemolytic activities were tested for the parent peptides and analogues. All peptides showed moderate antimicrobial activity against Gram-positive bacteria, with agelaia-MPI being the most active. Protonectin and protonectin-F were found to be toxic to cancerous and noncancerous cell lines. Internalization experiments revealed that these peptides accumulate inside both cell types. By contrast, neuroVAL was nontoxic to all tested cells and was able to enter cells without accumulating. In summary, neuroVAL has potential as a nontoxic cell-penetrating peptide, while protonectin-F needs further modification to realize its potential as an antitumor peptide.     

A Large-Scale Grid-Based Hydrological Model of the Severn and Thames Catchments

This paper addresses the issues of scale and appropriate model complexity for large-scale hydrological models. A grid-based hydrological model, which employs the UK Meteorological Office Rainfall and Evaporation Calculation System, is applied to the Severn and Thames catchments using a grid scale of 40 km, and is shown to reproduce the observed mean annual runoff over a 10-year period to within 6% with no prior calibration. The variation in the model performance is strongly correlated with the linearity of the annual rainfall/runoff relationship and a climate index. At the monthly scale, runoff routing becomes significant, and the introduction of a two-parameter routeing algorithm significantly improves the monthly runoff simulations giving efficiencies of 90% and 88% for the Severn and Thames respectively. The results provide guidance to climate modellers looking for efficient and robust land-surface parameterizations, and indicate the potential application of such a modelling scheme to water resource managers.     

Refinements to the BOD Test

For about eighty years the biochemical oxygen demand (BOD) has remained one of the major indicators of organic pollution in the water industry.
Whilst many adaptations and refinements have been made over the last 2–3 decades, one of the most significant was to suppress nitrification by the addition of allylthiourea (ATU) at 0.5 mg/1, thus ensuring that only carbonaceous oxidation was measured. Evidence has accrued to show that, for some situations, this concentration is insufficient to fully suppress nitrification.
Poor stability is a problem with biochemical oxygen demand when samples have to be stored prior to analysis, and a method of storage is proposed which minimizes instability. As an empirical bioassay procedure, the accuracy of BOD can be poor compared with alternative methods such as chemical oxygen demand; and problems with incubator and refrigerator temperatures, the preparation of standards, and replacement batteries for dissolved-oxygen probes are discussed.
The aim of this paper is to show that these problems with biochemical oxygen demand can be eliminated, thereby retaining confidence in its use.     

BIOFILM FORMATION IN GRANULAR-BED FILTERS

A high microbiological quality of drinking water must be ensured to protect public health. The filtration techniques that are used in treating drinking water play an important role; however, a biofilm can form on granular-media filters and the accumulated bacteria can slough off and enter the filtered water.
The aim of this research was to examine (a) the potential for biofilm formation and detachment from filter sand, and (b) the effect of different backwash regimes on biofilm removal. During the operation of the filter, bacteria became attached to the sand media, particularly in the top 30 mm of the filter bed. A water-only backwash at 20% and 40% bed expansion demonstrated poor removal of biofilm throughout the depth of the bed. Collapse-pulsing is a more efficient method and results in a reduction in the number of bacteria in the filtered water.     

DETERMINATION OF SLUDGE COMPOST QUALITY BY BIOASSAY

The paper reports the progress on a plant germination and growth trial as part of Thames Water's quality-control procedure for sludge composting and recycling. The experiment was conducted by cultivating two types of plants in a greenhouse under controlled environmental conditions, using (a) standard peat-based multipurpose compost, (b) Terra Eco Systems multipurpose compost, and (c) woodchip-amended sludge compost.
Tomatoes and petunias were selected for the trial, and the varieties were first-generation (F) hybrid. Germinated seed counts were used to calculate germination percentages and germination values, to assess compost performance. Calculated germination values for tomato and petunias were 26.52 and 17.76 respectively for the peat-based compost: the values of tomato plants for Woodchip-amended compost and Terra Eco compost were 17.80 and 11.84 respectively; and for petunia, all composts performed similarly, with germination values ranging from 14.00 to 17.76. It was concluded that there were no significant differences between the petunia plants in three composts used in this trial.     

Precast Concrete Blocks for High-Velocity Flow Applications

Precast concrete blocks can be used as erosion protection to a surface subjected to high-velocity water, for example a dam spillway.
The paper describes model testing carried out on flat and wedge-shaped blocks in a purpose-designed facility at the University of Salford, where an open channel discharge intensity of 0.5 m²/s can be accelerated to a velocity of 7.5 m/s.
The failure modes of tied and untied flat concrete blocks have been investigated under different laying and bedding conditions. The model results are compared to the findings from prototype studies. Results from experiments on wedge-shaped blocks of a Soviet design are also presented and confirm the Russian experience that the wedge shape is inherently stable at large discharges, a block of 100-m thickness being stable under a discharge intensity of 20 m²/s.     

The Installation and Use of a Snow Pillow to Monitor Snow Water Equivalent

In February 1993, a snow pillow was installed at Widdibank Fell near Cow Green reservoir (in Upper Teesdale) to monitor snow water equivalent.
This paper describes existing snow-measurement techniques in the UK and the site-selection process and installation details for the snow pillow. Following a winter of more than 100 days with snow cover at the site, the success of the pillow in representing site and catchment snow conditions and in providing operationally useful snowmelt information for flood warning has been assessed.     

Impact of the River Maine Drainage Scheme on Hydro-Power Generation

A comparison is made between pre- and post-drainage scheme river flows recorded on the River Maine, Co. Antrim. A method of using five-year reference periods has been applied to the mean daily flows to smooth and eliminate, as far as possible, variations due to climatic changes.
Any loss of energy production which might have been due to changes in river flow was examined for turbine installations at a factory at Cullybackey. The quantities of usable water, and hence potential energy production, were calculated for each of the post-scheme five-year periods and compared with a pre-scheme five-year reference period. Any potential loss was then represented by a depreciation factor. It was found that no measurable loss of potential energy production has occurred on the River Maine in the post-scheme period.     

MEMBRANE BIOREACTORS AND CONSTRUCTED WETLANDS FOR TREATMENT OF RENDERING PLANT WASTEWATER

The performance of a novel industrial membrane bioreactor (MBR) comprising denitrification, nitrification and ultrafiltration for the secondary treatment of primary treated animal rendering wastewater has been compared with an experimental, low-cost and novel vertical-flow constructed wetland planted with Typha latifolia L. (Reedmace or Broad-leaved Cattail). The process wastewater followed pre-treatment by dissolved air flotation (DAF). The mean DAF effluent gave highly variable chemical oxygen demand (COD) and ammonia concentrations of 5816 (standard deviation (SD): 3005.0) and 614 (SD: 268.7) mg/l, respectively. The mean MBR effluent for COD and ammonia was 37 and 86 mg/l, respectively. The mean treatment performance of the constructed wetland for COD, ammonia and suspended solids was 205, 67 and 57 mg/l, respectively.