Chrysosphaerella and the phytoplankton of the Little Sea, Dorset

The Little Sea is an 80-acre, shallow freshwater lake formed about a hundred years ago by sand-dunes cutting off a sea-inlet at Studland Bay, near Swanage. This work presents a general survey of the phytoplankton in the lake from October 1990 to December 1993. Many species were present throughout the year; others showed seasonal variations. Numerically, the diatoms, Monoraphidium and sometimes Rhodomonas, were the main constituents of the phytoplankton. One species of alga in the lake of particular interest is Chrysosphaerella longispina Lauterb. which, up to 1991, had only been recorded from five localities in Britain.

Plant nutrients and major ions in the Little Sea, Studland, Dorset

This short paper records some measurements made on the Little Sea, a shallow, coastal, acidic lake on Studland Heath, Dorset. The lake, formed about 100 years ago by dunes cutting off a sea inlet, has not received any input of agricultural fertilizers or other waste products for at least the last 30 years. It is a Site of Special Scientific Interest (SSSI). Samples of surface water were taken from the northern and southern ends of the lake at 3-monthly intervals, from July 1995 to April 1996. The first samples in July 1995 were taken during a period of drought; rain, sometimes very heavy, came in late September. With the exception of silicate, potassium and phosphate, there were no large changes in plant nutrient concentrations during the year. The concentration of nitrate-nitrogen was very low (close to the limits of analytical detection), but total phosphorus at ca. 30 mu g per litre was similar to concentrations found in some of the Cumbrian eutrophic lakes. The large number of algal species at low cell/colony concentrations suggested that the lake is mesotrophic. Sodium, chloride and magnesium in the lake water were close to the same proportions as those found in sea water. Dry and wet deposition of sea-salts on the lake surface and its catchment area probably is the major source of sodium, magnesium and chloride ions in the lake, and also accounts for about half of the mean potassium and sulphate concentrations.

Ground beetles and rove beetles be associated with temporary ponds in England

To date, research on the ecology and conservation of wetland invertebrates has concentrated overwhelmingly on fully aquatic organisms. Many of these spend part of their life-cycle in adjacent terrestrial habitats, either as pupae (water beetles) or as adults (mayflies, dragonflies, stoneflies, caddisflies and Diptera or true-flies). However, wetland specialist species also occur among several families of terrestrial insects (Williams & Feltmate 1992) that complete their whole life-cycle in the riparian zone or on emergent vegetation. There are 441 terrestrial invertebrate species which characteristically occur in riparian habitats along British rivers. Most of these species belong to two families of predatory beetles: the ground beetles (Carabidae) and the rove beetles (Staphylinidae). This paper describes the diversity of ground and rove beetles around ponds, summarises life-histories, hibernation strategies, and morphological and behavioural adaptions.

Concentrations of Polychlorinated Biphenyls (PCB’s), Chlorinated Pesticides, and Heavy Metals and Other Elements in Tissues of Belugas, Delphinapterus leucas, from Cook Inlet

Tissues from Cook Inlet beluga whales, Delphinapterus leucas, that were collected as part of the Alaska Marine Mammal Tissue Archival Project were analyzed for polychlorinated biphenyls (PCB’s), chlorinated pesticides, and heavy metals and other elements. Concentrations of total PCB’s (ΣPCB’s), total DDT (ΣDDT), chlordane compounds, hexachlorobenzene (HCB), dieldrin, mirex, toxaphene, and hexachlorocyclohexane (HCH) measured in Cook Inlet beluga blubber were compared with those reported for belugas from two Arctic Alaska locations (Point Hope and Point Lay), Greenland, Arctic Canada, and the highly contaminated stock from the St. Lawrence estuary in eastern Canada. The Arctic and Cook Inlet belugas had much lower concentrations (ΣPCB’s and ΣDDT were an order of magnitude lower) than those found in animals from the St. Lawrence estuary. The Cook Inlet belugas had the lowest concentrations of all (ΣPCB’s aver-aged 1.49 ± 0.70 and 0.79 ± 0.56 mg/kg wet mass, and ΣDDT averaged 1.35 ± 0.73 and 0.59 ± 0.45 mg/kg in males and females, respectively). Concentrations in the blubber of the Cook Inlet males were significantly lower than those found in the males of the Arctic Alaska belugas (ΣPCB’s and ΣDDT were about half). The lower levels in the Cook Inlet animals might be due to differences in contaminant sources, food web differences, or different age distributions among the animals sampled. Cook Inlet males had higher mean and median concentrations than did females, a result attributable to the transfer of these compounds from mother to calf during pregnancy and during lactation. Liver concentrations of cadmium and mercury were lower in the Cook Inlet belugas (most cadmium values were <1 mg/kg and mercury values were 0.704–11.42 mg/kg wet mass), but copper levels were significantly higher in the Cook Inlet animals (3.97–123.8 mg/kg wet mass) than in Arctic Alaska animals and similar to those reported for belugas from Hudson Bay. Although total mercury levels were the lowest in the Cook Inlet population, methylmercury concentrations were similar among all three groups of the Alaska animals examined (0.34–2.11 mg/kg wet mass). As has been reported for the Point Hope and Point Lay belugas, hepatic concentrations of silver were re

Multidirectional movements of sportfish species between an estuarine no-take zone and surrounding waters of the Indian River Lagoon, Florida

We examined movement patterns of sportfish that were tagged in the northern Indian River Lagoon, Florida, between 1990 and 1999 to assess the degree of fish exchange between an estuarine no-take zone (NTZ) and surrounding waters. The tagged f ish were from seven species: red drum (Sciaenops ocellatus); black drum (Pogonias cromis); sheepshead (Archosargus probatocephalus); common snook (Centropomus undecimalis); spotted seatrout (Cynoscion nebulosus); bull shark (Carcharhinus leucas); and crevalle jack (Caranx hippos). A total of 403 tagged fish were recaptured during the study period, including 65 individuals that emigrated from the NTZ and 16 individuals that immigrated into the NTZ from surrounding waters of the lagoon. Migration distances between the original tagging location and the sites where emigrating fish were recaptured were from 0 to 150 km, and these migration distances appeared to be influenced by the proximity of the NTZ to spawning areas or other habitats that are important to specific life-history stages of individual species. Fish that immigrated into the NTZ moved distances ranging from approximately 10 to 75 km. Recapture rates for sportfish species that migrated across the NTZ boundary suggested that more individuals may move into the protected habitats than move out. These data demonstrated that although this estuarine no-take reserve can protect species from fishing, it may also serve to extract exploitable individuals from surrounding fisheries; therefore, if the no-take reserve does function to replenish surrounding fisheries, then increased egg production and larval export may be more important mechanisms of replenishment than the spillover of excess adults from the reserve into fishable areas.

Elements of the U.S. carbon budget: progress and preliminary results

This report outlines the approaches for estimating the carbon budget for the United States, a data rich subcontinental area, and presents an overview of problems encountered and preliminary results obtained.

Interference Competition and High Temperatures Reduce the Virulence of Fig Wasps and Stabilize a Fig-Wasp Mutualism

Fig trees are pollinated by fig wasps, which also oviposit in female flowers. The wasp larvae gall and eat developing seeds. Although fig trees benefit from allowing wasps to oviposit, because the wasp offspring disperse pollen, figs must prevent wasps fr

Ocean urea fertilization for carbon credits poses high ecological risks

The proposed plan for enrichment of the Sulu Sea, Philippines, a region of rich marine biodiversity, with thousands of tonnes of urea in order to stimulate algal blooms and sequester carbon is flawed for multiple reasons. Urea is preferentially used as a nitrogen source by some cyanobacteria and dinoflagellates, many of which are neutrally or positively buoyant. Biological pumps to the deep sea are classically leaky, and the inefficient burial of new biomass makes the estimation of a net loss of carbon from the atmosphere questionable at best. The potential for growth of toxic dinoflagellates is also high, as many grow well on urea and some even increase their toxicity when grown on urea. Many toxic dinoflagellates form cysts which can settle to the sediment and germinate in subsequent years, forming new blooms even without further fertilization. If large-scale blooms do occur, it is likely that they will contribute to hypoxia in the bottom waters upon decomposition. Lastly, urea production requires fossil fuel usage, further limiting the potential for net carbon sequestration. The environmental and economic impacts are potentially great and need to be rigorously assessed. (C) 2008 Elsevier Ltd. All rights reserved.

Effects of prior heavy exercise on V(over dot)O-2 kinetics during heavy exercise are related to changes in muscle activity

Burnley, M., Doust, J.H., Ball, D. and Jones, A.M. (2002) Effects of prior heavy exercise on VO2 kinetics during heavy exercise are related to changes in muscle activity. Journal of Applied Physiology 93, 167-174. RAE2008

Most Haunted and the Convergence of Traditional Belief and Popular Television

Koven, M. (2007). Most Haunted and the Convergence of Traditional Belief and Popular Television. Folklore. 118(2), pp.183-202. RAE2008

Analysis of Sequence Periodicity in E. coli Proteins: Empirical Investigation of the ?Duplication and Divergence? Theory of Protein Evolution

Gatherer, D., and McEwan, N.R. (2003). Analysis of sequence periodicity in E. coli proteins: empirical investigation of the 'duplication and divergence' theory of protein evolution. Journal of Molecular Evolution 57, 149-158. RAE2008

All-optical OFDM and distributed Raman amplification: Challenges to enable high capacities and extend reach

We review recent advances in all-optical OFDM technologies and discuss the performance of a field trial of a 2 Tbit/s Coherent WDM over 124 km with distributed Raman amplification. The results indicate that careful optimisation of the Raman pumps is essential. We also consider how all-optical OFDM systems perform favourably against energy consumption when compared with alternative coherent detection schemes. We argue that, in an energy constrained high-capacity transmission system, direct detected all-optical OFDM with 'ideal' Raman amplification is an attractive candidate for metro area datacentre interconnects with ~100 km fibre spans, with an overall energy requirement at least three times lower than coherent detection techniques.

Combining and choosing case base maintenance algorithms

Case-Based Reasoning (CBR) uses past experiences to solve new problems. The quality of the past experiences, which are stored as cases in a case base, is a big factor in the performance of a CBR system. The system's competence may be improved by adding problems to the case base after they have been solved and their solutions verified to be correct. However, from time to time, the case base may have to be refined to reduce redundancy and to get rid of any noisy cases that may have been introduced. Many case base maintenance algorithms have been developed to delete noisy and redundant cases. However, different algorithms work well in different situations and it may be difficult for a knowledge engineer to know which one is the best to use for a particular case base. In this thesis, we investigate ways to combine algorithms to produce better deletion decisions than the decisions made by individual algorithms, and ways to choose which algorithm is best for a given case base at a given time. We analyse five of the most commonly-used maintenance algorithms in detail and show how the different algorithms perform better on different datasets. This motivates us to develop a new approach: maintenance by a committee of experts (MACE). MACE allows us to combine maintenance algorithms to produce a composite algorithm which exploits the merits of each of the algorithms that it contains. By combining different algorithms in different ways we can also define algorithms that have different trade-offs between accuracy and deletion. While MACE allows us to define an infinite number of new composite algorithms, we still face the problem of choosing which algorithm to use. To make this choice, we need to be able to identify properties of a case base that are predictive of which maintenance algorithm is best. We examine a number of measures of dataset complexity for this purpose. These provide a numerical way to describe a case base at a given time. We use the numerical description to develop a meta-case-based classification system. This system uses previous experience about which maintenance algorithm was best to use for other case bases to predict which algorithm to use for a new case base. Finally, we give the knowledge engineer more control over the deletion process by creating incremental versions of the maintenance algorithms. These incremental algorithms suggest one case at a time for deletion rather than a group of cases, which allows the knowledge engineer to decide whether or not each case in turn should be deleted or kept. We also develop incremental versions of the complexity measures, allowing us to create an incremental version of our meta-case-based classification system. Since the case base changes after each deletion, the best algorithm to use may also change. The incremental system allows us to choose which algorithm is the best to use at each point in the deletion process.