Regulation and private participation in the water and sanitation sector

Private-sector participation is widely perceived to be the solution to the failure of many publicly owned and managed water utilities to operate efficiently and make the investments required to meet community needs. However, there are no guarantees that privatisation will actually yield the desired performance improvements. Simply converting a public-sector monopoly into a private one provides no competitive incentives for the utility to operate efficiently, make appropriate investments or respond to consumer demands. Likewise, privatisation per se need do little to improve sector performance if governments are unwilling or unable to tackle such underlying problems as overmanning, uneconomic water pricing policies, financing the provision of public and merit goods, and restricting over-intrusive political intervention.
Given the characteristics of the water and sanitation sector it is inevitable that some form of continued public regulation of the private companies will be necessary. The regulatory burden can be reduced by adopting a competitive form of privatisation, choosing a more competitive sector structure and devising an appropriate regulatory regime. However, it has to be recognised that there will be a trade-off between making a venture attractive to private firms and introducing a notionally 'ideal' regulatory system. Regulation, in practice, is as much about creating the conditions under which private firms can operate effectively and efficiently as it is about protecting specific customer and public interests.     

Linear features and butterflies: the importance of green lanes

Green lanes are unmetalled tracks between fields of variable width, which may be sunk below or raised above field level, and bounded on both sides by ‘grass’ banks, hedgerows or dry-stone walls. In the UK they have no unique planning status and have been overlooked as discrete landscape elements. Green lanes were surveyed for butterflies in 1997 on lowland arable farmland on the Trafford/north Cheshire border (Warburton) and on upland grassland in the Yorkshire Dales (Ribble Valley). At the lowland site the green lanes were bounded by vegetation and were compared with grass banks and single hedgerow field boundaries; at the upland farm, the green lanes were bounded by dry-stone walls and were compared with grass banks and single dry-stone walls. Data from earlier work on a largely arable farm (Manydown) in Hampshire in 1987 and 1988 were re-analysed to make comparisons between a green lane, the rides and glades of two coppiced woodlands, and the grass banks and single hedgerows surrounding arable fields. Green lanes, whether bounded by vegetation or stone were superior to other common farmland biotopes with the exception of woodland, in terms of both butterfly abundance and species richness.Multiple regression of the Warburton data indicated the importance of green lanes, adjacent habitat type, and nectar sources for species richness and butterfly abundance. The interior of green lanes had lower windspeeds, and more bramble nectar sources than hedgerows or grass banks. By their nature they occupy a larger area of uncropped land, and are subject to a reduced disturbance regime and reduced inputs of agrochemicals and fertilisers. Their value as biodiversity reservoirs in intensively managed land is likely to be high.     

大面积镜面电火花加工的实验研究

介绍了大面积镜面电火花加工法现状.通过改变混粉工作液中微粉的种类、浓度、加工参数以及加工面积进行了工艺试验.验证了混粉电火花加工的确能改善表面粗糙度.     

Competitive interactions and substratum preferences of two intertidal isopods

The intertidal isopods Gnorimosphaeroma oregonensis oregonensis (Dana) and Exosphaeroma amplicauda (Stimpson) are shown to have differing preferences for substratum particle-size categories. In field sampling, 80.9% of the total number of G. oregonensis oregonensis taken were present on substrata falling within a ?-4.2 to-3.8 diameter size-range, while 60.0% of E. amplicauda occupied the range ?-2.5 to-2.1. These relationships changed upon laboratory manipulation of density ratios, and suggest competitive interaction: when E. amplicauda is tested alone, the resultant preference assumes a greater niche breadth and overlap to that of the field. Introduction of G. oregonensis oregonensis produces a displacement of E. amplicauda, the degree being dependent upon their relative numerical strength. With an experimental ratio of 3:1 (G. oregonensis:E. amplicauda) there is a simulation of field densities, and the laboratory results approximate more closely the overlap in nature.     

Brood neglect and contingent foraging behavior in a pelagic seabird

Among species where there is a risk to leaving offspring unattended, parents usually take alternating shifts guarding their young. However, they may occasionally exhibit brood neglect by leaving their offspring unattended at the nest. To investigate this phenomenon further, we examined the foraging behavior of the northern gannet (Morus bassanus) during chick-rearing. This species has a prolonged nestling period (13 weeks) and the single chick is usually guarded by one or other of its parents, because unattended chicks are frequently attacked by conspecifics. We tested the prediction that the foraging behavior of adults when they left their offspring alone at the nest (unattended trips) would differ in character to when adults left offspring with their partner (attended trips). Brood neglect typically occurred after a longer-than-average attendance period at the nest. Unattended trips were, on average, about half the duration of attended trips, and therefore much closer to the colony. There was also a difference in departure direction between attended and unattended trips, with unattended trips tending to be northeast of the colony. Chicks were fed by parents after both attended and unattended trips, but the frequency and the duration of unattended trips increased as chicks grew older whereas the duration of attended trips decreased as chicks grew. These results indicate that parents may be making a trade-off between risk of attack to their offspring and food-intake rate, and that the solution to this trade-off is dependent on chick age.Communicated by C. Brown     

Managing heather moorland: impacts of burning and cutting on Calluna regeneration

Heather regeneration following controlled burning and cutting of young and old heather stands was measured on twelve plots within the North York Moors National Park, UK. Rapid regeneration primarily from heather shoots, occurred in young heather stands and no significant differences were recorded between the two management treatments. Regeneration occurred more slowly in old heather stands and seedling growth was more rapid on the burnt plots. The results suggest that cutting promotes vegetative regeneration and burning promotes regeneration from seed. The implications for heather management are discussed.     

Albatross species demonstrate regional differences in North Pacific marine contamination.

Recent concern about negative effects on human health from elevated organochlorine and mercury concentrations in marine foods has highlighted the need to understand temporal and spatial patterns of marine pollution. Seabirds, long-lived pelagic predators with wide foraging ranges, can be used as indicators of regional contaminant patterns across large temporal and spatial scales. Here we evaluate contaminant levels, carbon and nitrogen stable isotope ratios, and satellite telemetry data from two sympatrically breeding North Pacific albatross species to demonstrate that (1) organochlorine and mercury contaminant levels are significantly higher in the California Current compared to levels in the high-latitude North Pacific and (2) levels of organochlorine contaminants in the North Pacific are increasing over time. Black-footed Albatrosses (Phoebastria nigripes) had 370-460% higher organochlorine (polychlorinated biphenyls [PCBs], dichlorodiphenyltrichloroethanes [DDTs]) and mercury body burdens than a closely related species, the Laysan Albatross (P. immutabilis), primarily due to regional segregation of their North Pacific foraging areas. PCBs (the sum of the individual PCB congeners analyzed) and DDE concentrations in both albatross species were 130-360% higher than concentrations measured a decade ago. Our results demonstrate dramatically high and increasing contaminant concentrations in the eastern North Pacific Ocean, a finding relevant to other marine predators, including humans.     

Demography and Population Viability of an Endangered Plant Species before and after Protection from Trampling

Land managers often suggest fencing to protect rare plant species from being trampled in heavily used recreation areas, but there are few documented examples of the efficacy of this strategy. In a 7-year demographic study we examined the reproduction, survival, and long-term viability of the endangered sentry milk-vetch (Astragalus cremnophylax var. cremnophylax) before and after protection from trampling. Demographic monitoring and population viability analyses indicated that the population has fluctuated during the 7 years. Before protection the population declined: 26% of individuals died, mortality surpassed natality, and age of first reproduction was significantly older than post-protection. Fifty-eight percent of the population was severely damaged. Population viability analyses of pre-protection years predicted that the population would go extinct within 100 years. Since protection, the population stabilized, grew, and declined again. Seedlings reached reproductive maturity more quickly. Recruitment increased and peaked in 1993 coincident with abundant precipitation, but again declined in 1994. The total numbers of undamaged plants surpassed the numbers of damaged plants. Models of the post-protection population predict stability. Multiple-linear regression analysis indicated that winter and spring precipitation were significantly correlated with lambda. Both "good" and "bad" climatic conditions occurred during the pre- and post-protection periods. Because of small population size and depauperate genetic diversity, climate will continue to influence population growth. Nevertheless, models indicate that where trampling and bad climatic conditions were coupled, extinction was accelerated. Recovery of sentry milk-vetch will depend on continued protection, augmentation, and environmental factors, although risk of extinction remains very high.