bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling the Impacts of Climatic Change on Water Resources
Authors: Wardlaw R. B. , Hulme M. , Stuck A. Y.
Published: July 2007

Following the prolonged drought at the end of the 1980s in the south east of the UK, Anglian Water undertook (a) to review the reliable yields of their resource systems and (b) to investigate the potential risks associated with alternative future investment programmes. One of the major identifiable risks is climate change, and there is a clear need to understand how different scenarios of climate change could affect the reliable output of existing sources, and thereby affect investment programmes.

This paper highlights the approach which was adopted to model climate change impacts on rainfall, and on the limitations which exist for this type of assessment.
Groundwater Quality Monitoring: the Use of Flow‐Through Cells
Authors: Howsam P. , Thakoordin M.
Published: July 2007

The monitoring of groundwater quality is a necessary and growing activity for those concerned with groundwater resource protection. In order to gain a true understanding of changes occurring in the aquifer, it is important that monitoring is carried out properly and that reliable data are obtained. It would appear that appropriate procedures for measuring unstable groundwater quality parameters at the well‐head are not in common use. Field tests, with and without the utilization of a flow‐through cell, clearly demonstrate the differences in parameter values which can be recorded. For the measurement of dissolved oxygen, redox potential, and pH in the field, a flow‐through cell must be used, otherwise data are not likely to be of use. The use of a flow‐through cell also enhances purging and sampling procedures during the monitoring of other groundwater quality parameters.
Remote Sensing: Latest Developments and Uses
Authors: Redfern H. , Williams R. G.
Published: July 2007

This paper considers currently available airborne and satellite‐derived data suitable for monitoring coastal and river zones, and the potential offered by geographical information systems to manage this information. The main advantage of satellite data is the relatively low cost of acquisition over broad areas at regular intervals in time. Examples are (a) LANDSAT thematic mapper data and ‘satellite pour l'observation de la terre’multi‐spectral and panchromatic imagery which provide high resolution imagery for land‐use mapping and bathymetric analysis, (b) National Oceanic and Atmospheric Administration's advanced very high resolution radiometer which provides a synoptic view of sea surface temperature and meteorological conditions, and (c) European remote sensing satellites whose array of sensors provide information on wave characteristics and wind speed and direction. In the field of geographical information systems, the challenge is to create systems which can both store the large quantity of data available and incorporate models which can predict the effects of change to the environment.
Improved Guidelines for the Use of the Rising Air Float Technique for River Gauging
Authors: Toop C. J. , Webster P. , Hawnt R. J. E.
Published: July 2007

The rising air float technique is a method of river discharge measurement involving the release of air bubbles from a perforated pipe laid across the bed of a river. This paper describes field and laboratory analyses which seek to extend previous work and to assess the potential of the technique as an alternative for conventional methods of spot and continuous gauging.

The results have confirmed that the technique is a cheap, accurate and robust alternative to other methods of spot gauging, and is sensitive to the operating pressure, with a value of 10 psi producing an optimum bubble envelope at the surface. A major constraint to the implementation of the technique for continuous monitoring remains the procedure for automatic processing of a photographic image of the bubble envelope.

Guidelines are presented for the optimum configuration of equipment for both spot and continuous gauging.
Demands and Resources for Public Water Supplies in Scotland from 1991 to 2016
Authors: Anderson P.
Published: July 2007

This paper describes an assessment, which was carried out during 1994, of demands and resources for public water supplies in Scotland from 1991 to 2016. The assessment is the third in a series published by The Scottish Office – the two previous studies being carried out in 1973 and 1984. In the 1994 study, demands were assessed on a component basis from 1991 to 2016 in five‐year steps for each of the nine mainland and three islands councils. These were aggregated to give the all‐Scotland picture, and a sensitivity analysis was carried out to determine what effect any changes in underlying assumptions might have on the forecast demands; and a demand envelope was constructed.
Viscosity as a Criterion for Optimum Dosing of Polymers in Waterworks Sludges
Authors: Papavasilopoulos E. N.
Published: July 2007

This study was carried out to evaluate the use of viscosity measurements as a method of assessing the optimum use of organic polymers as conditioning agents in sludge dewatering. The study focused on sludge from the clarifiers of a water‐treatment works. In addition to viscosity measurements, the programme included an appraisal of other techniques for specifying dewater‐ability, e.g. the specific resistance to filtration, the capillary suction time and the electrical charge status via streaming‐current measurements.
The Role of Groundwater as a Strategic and Economic Asset in Northern Ireland
Authors: Robins N. S.
Published: July 2007

In Northern Ireland, groundwater contributes 77 Ml/d out of 700 Ml/d in public supply, and a further 31 Ml/d to private users. Of the latter, agriculture takes about 11 Ml/d and industry uses 18 Ml/d; a further 2 Ml/d are consumed by up to 15 000 people for rural domestic needs. Groundwater is a protected asset and, as such, its use should be maximized for both strategic and commercial gain. Increased demand on the public supply system by the year 2001 will involve no new major groundwater input, but private exploitation of groundwater will increase, particularly by the specialist industries such as electronics and water bottling.
Assessing the Flow Needs of Rivers
Authors: Evans D.
Published: July 2007

Human and environmental needs sometimes conflict: the more for the environment, the less for the people and vice versa. Environmental needs include soil water, wetlands, lakes, rivers and estuaries. The paper recognizes that all these aspects must be catered for, but focuses on the flow needs of rivers; in particular, it suggests a method to determine river‐flow targets which are objective, sustainable, integrated with river‐quality characteristics and economically justified. Such targets could help the Environment Agency to balance human and environmental water needs in a rational manner.
Welsh Water's Partnership Approach to Beating the Drought in North Wales
Authors: Morrison J. A. E.
Published: July 2007

This paper describes how Dwr Cymru – Welsh Water managed the drought of 1995–1996 in North Wales without restricting supplies to customers. The summer of 1995 experienced a major increase in the demand for water which, when combined with thirteen months of below‐average rainfall, meant that resources had to be skilfully managed, using control rules and minimizing leakage on the network. The subsequent winter replenishment of the resources was critical and, with over thirty scattered resources supplying North Wales, a variety of solutions had to be employed. A key to the successful implementation of the chosen solutions was the partnership approach adopted with interested parties such as angling clubs and the Environment Agency.

The paper outlines a variety of differing solutions which were adopted and identifies the role of partnership.
The Water Resources of Lima, Peru
Authors: La Touche M. C. D.
Published: July 2007

Lima, the capital city of Peru, depends for its water supply on the resources of the River Rimac and the alluvial aquifer above which the city is situated. This paper describes the limitations of the present supply and possible new sources which could be developed to augment the water supply in future.
Continual Assessment of the Groundwater Resources of Lima
Authors: Watkins M. D. , Evans D. A. , Lloyd J. W.
Published: July 2007

During recent years, Lima has increasingly had to depend upon the resources of the alluvial aquifer above which it is situated. This paper describes the computer modelling and other studies which were carried out to assess the sustainable yield of the aquifer.
Hydrological Data for Wetland Management
Authors: Hollis G. E. , Thompson J. R.
Published: July 2007

Hydrology is the prime control in wetland ecosystems, but little formal hydrological data are gathered in wetlands by hydrometric authorities. Normally, most of the hydrological data for wetlands can be obtained from informal sources, non‐hydrological organizations, the local population and archival information ‐ especially photographs. Some short‐term field monitoring can be useful in augmenting the large hydrological data sets which can be gathered ‐ even when initial enquiries yield minimum information. A case study from the North Kent Marshes is used to illustrate this fact.
The Quality of Shallow Groundwaters in Northern Ireland
Authors: Robins N. S.
Published: July 2007

Northern Ireland has a diverse range of rock types and lithologies which create small hydrogeological units, each with its own characteristics. The restricted geometry of these units permits only short and shallow groundwater flowpaths to develop, most with at least partial access to atmospheric oxygen. Each hydrogeological unit has a distinctive distribution of mineralization and major ions. In general, groundwater chemistry is stable with time, except for a few areas of intense agricultural activity where trends in nitrate nitrogen concentration are apparent. The relatively high rainfall in Northern Ireland dilutes surplus nutrients which, combined with year‐round moist soils with an active bacterial population, ensures that nitrate nitrogen concentrations are generally low.
Aquifer Recharge: An Operational Drought‐Management Strategy in North London
Authors: O'Shea M. J. , Sage R.
Published: July 2007

The North London Artificial Recharge scheme, which comprises thirty‐seven wells and boreholes, is designed to boost resources during a drought. All sources discharge groundwater either to the Lee Valley reservoirs or the New River during the abstraction, which avoids the need for expensive on‐site water treatment and significantly enhances the cost effectiveness of the scheme. Fully treated drinking water provides the source of gravity‐fed artificial‐recharge water, via the normal distribution system.

This paper describes the strategy which was introduced in 1997, in response to a deteriorating water‐resources situation. Abstraction occurred over a period of four months prior to the onset of autumnal winter rainfall. Daily abstraction rates peaked at 150 Ml/d, and a total of about 10 700 Ml were withdrawn.
Beach‐Profile Measurement, Theory and Analysis: Practical Guidance and Applied Case Studies
Authors: Cooper N. J. , Leggett D. J. , Lowe J. P.
Published: July 2007

Whilst beach‐profile surveying is a relatively long‐established and widely utilised shoreline monitoring technique, a considerable gap exists between theoretical and practical requirements from, and uses of, beach‐profile data. The paper bridges this gap by providing a summary of the key elements of beach‐profile measurement, theory and analysis. The benefits of applying these elements to practical coastal management are given in three case studies. The first case study presents results from beach‐profile analysis on a regional scale in East Anglia. The second case study applies both analytical and theoretical techniques to investigate erosional problems along a coastal bay in Jersey. The third case study assesses the performance of two major sand‐replenishment schemes in Poole Bay (on the south coast of England) based upon beach‐profile volumetric analyses. Most importantly, the paper demonstrates that beach‐profile measurement, theory and analysis can provide information of practical use in coastal management.
The Condition of Public Urban Parks and Greenspace in Britain
Authors: Reeves N.
Published: July 2007

Public urban parks and greenspaces are an important aspect of the urban environment. It was the UK that pioneered the concept of municipal parks in the nineteenth century, for reasons of improved public health and a better environment, in response to the creeping industrialisation of our towns and cities. For generations, public parks have contributed to the social, economic, environmental and cultural fabric of local communities, and it was local authorities which pioneered their provision, development and management. Such has been their success that almost every town and city has a public park or network of public greenspace, and they now account for about 20% of the developed land areas in England (13.5% in England and Wales). Their status and quality depends upon the good stewardship of local authorities. However, year‐on‐year budget cuts over the last thirty years, a lack of recognition of parks services in the Government's annual Standard Spending Assessment for local authorities, and the fact that provision of public parks is a non‐statutory service of local government have all contributed to their declining condition and status.

This paper provides an assessment of the history, status and condition of public urban parks and greenspace, and discusses how these important assets can be rejuvenated to service the needs of present and future generations.
Evaluating Natural Attenuation of Groundwater Pollution from a Coal‐Carbonisation Plant: Developing a Local‐Scale Model using MODFLOW, MODTMR and MT3D
Authors: Davison R. M. , Lerner D. N.
Published: July 2007

The effluent from a former coal‐carbonisation plant in Nottinghamshire has contaminated the underlying aquifer with ammonium and organic compounds. In terms of flow and contamination, the site has experienced a complex history. MODFLOW has been used to unravel the past flow directions and to provide a basis for solute transport and biodegradation modelling. The modelling has shown that a fine grid is required to represent local flows to prevent incorrect site interpretations. A telescopic mesh technique was essential for this study to enable the site features to be adequately represented while including the regional hydrogeological influences. The influence of grid size to numerical dispersion was investigated for the MT3D computer program. The ‘method of characteristics’and ‘hybrid method of characteristics’modules of MT3D were found to be relatively free from numerical dispersion for all the grid sizes investigated. However, the ‘modified method of characteristics’suffered extensively, and a linear relationship between grid size and numerical dispersion was demonstrated for this complex model.
Managing Water Services Through Service Differentiation and Pricing in an African City
Authors: Njiru C. , Smout I. K. , Sansom K.
Published: July 2007

A key challenge for managers of water utilities in developing countries is to provide services to the rising urban population in a financially sustainable manner. The paper examines the management of water services in an African city which piloted service differentiation and pricing. Among the key findings was that substantial improvement in the provision of water services to the urban poor was attained. Cost recovery was achieved through innovative structuring of public/private partnerships, an appropriate pricing policy, and flexible payment systems. The project demonstrates that (a) by structuring service delivery with appropriate pricing, utilities could serve more customers (including people living in informal settlements) at affordable cost and achieve financial sustainability, and (b) service differentiation and appropriate pricing has the potential to improve urban water services in low‐income countries.
Neural Network Simulation of the Chemical Oxygen Demand Reduction in a Biological Activated‐Carbon Filter
Authors: Mohanty S. , Scholz M. , Slater M. J.
Published: July 2007

This paper is primarily aimed at encouraging further use of neural networks by the water‐ and wastewater treatment industry. The study demonstrates the principle of using a network method of simulating the performance of a biological activated‐carbon filter based on a biological water‐quality assessment and measurements of pH and dissolved oxygen during the bio‐regeneration mode with untreated river water. Protozoa, worms, rotifers, bacteria, fungi and algae were used as biological parameters. The neural network model could reasonably estimate the chemical oxygen demand reduction in an exhausted filter. The neural network model gave much better results than a second‐order polynomial regression model; however, a much larger database is required than is currently available.
The Influence of Water‐Column Mixing on Dissolved‐Oxygen Concentrations and Saline Stratification in the River Tawe Barrage, Wales, UK
Authors: Taylor S. L. , Morgan H. , O'Hara K. , Rutstein A. , Thomas K.
Published: July 2007

The Tawe barrage was an early amenity barrage, and studies after its construction showed a deterioration in water quality within the impounded area. The main concern was the effect of low dissolved‐oxygen concentrations upon the migrating salmonids during their passage upstream. An aeration/mixing system was chosen in a combination of diffusers and a propeller, which has proved to be capable of maintaining satisfactory water quality. However, additional diffusers need to be installed to (a) achieve a satisfactory concentration of dissolved oxygen at all points in the river and (b) complete the full scheme.
The UK Floods of 2000–2001: A Hydrometeorological Appraisal
Authors: Marsh T. J. , Dale M.
Published: July 2007

The protracted and widespread flooding, which was experienced across much of the UK during the autumn and winter of 2000–01, was the most severe since 1947. Catchments remained saturated for lengthy periods and the high flow regimes of many rivers were significantly redefined. There is no modern parallel to the magnitude of groundwater replenishment over the 2000–01 winter recharge season, and groundwater flooding was exceptionally protracted in the English lowlands. This paper examines the synoptic background to an extremely wet episode and uses a hydrological framework to document the magnitude, duration and extent of a flood episode outside the previous experience of the greater part of the population of England and Wales.
Public Attitudes to In‐House Water Recycling in England and Wales
Authors: Jeffrey P.
Published: July 2007

This study, which is based on responses from over 300 individuals in England and Wales, explores how a willingness to use a water‐recycling system of specific configuration varies against a number of factors which are linked to system design, system scale, system context, and water‐conservation behaviour. Findings show that there is broad willingness to accept in‐house water recycling provided that public health is not compromised.
STAKEHOLDER INVOLVEMENT IN WATER‐RESOURCES PLANNING
Authors: Garis Y. de , Lutt N. , Tagg A.
Published: July 2007

This paper discusses experiences of consultation and participation in water‐resource planning studies in the Thames catchment. Two different case studies are presented and the challenges which were encountered are discussed. The authors conclude that, whilst the inclusion of stakeholders in the decision‐making process has clear benefits, the answers to questions such as (a) who to involve, (b) when to involve them, and (c) how to present information to them, are not always clear.
ESTIMATING URBAN LOADS OF NITROGEN TO GROUNDWATER
Authors: Lerner D. N.
Published: July 2007

Urban areas can impose significant loads of nitrogen, as ammonium or nitrate, onto the underlying groundwater. There are many sources of nitrogen pollution, including diffuse sources (parks and gardens), intense point sources (industrial chemical spills), and multi‐point sources (leaking sewers). Data on the loadings associated with the various sources are scarce, although an estimate of the overall load is available for Nottingham. For other cities, a total load could be estimated by factoring the Nottingham result, or by considering each component of the load separately. Both approaches are described, and the integrated method is recommended for its simplicity.
FLOOD MANAGEMENT, COMMUNITIES AND THE ENVIRONMENT: A STRATEGY FOR THE SOMERSET LEVELS AND MOORS
Authors: Hicklin A. J.
Published: July 2007

The Somerset Levels and Moors have been designated a ‘special protection area’under the EU Habitats Directive and a Ramsar wetland of international importance. Water management is important to their well being, but drainage to improve agricultural productivity has reduced habitat quality and biodiversity interest. Over the last decade, significant progress has been made towards halting and (in some areas) reversing the declining wetland flora and fauna. However, the UK Government's target of achieving favourable conservation status by 2010 is unlikely to be achieved without further change.

This paper examines the changes which are needed to achieve sustainable agricultural flood‐management and conservation objectives in Somerset as a model for wetlands in England and Wales. Agricultural policy and, in particular, the lack of cross‐compliance and limited discretionary modulation, is failing marginal areas such as the Somerset Levels and Moors; also, farmers and the environment are losing out. In order to ensure that objectives are clear and options and constraints are understood, increased dialogue between stakeholders is essential.
PLANNING SITE‐SPECIFIC WATER‐DEMAND MANAGEMENT STRATEGIES
Authors: Makropoulos C. K. , Butler D.
Published: July 2007

Water‐demand management is a pro‐active approach to water conservation, which considers water‐consumption ‘needs’as ‘demands’rather than requirements. Taking into account a variety of engineering strategies to reduce urban water consumption, this research discusses the use of a tool for developing a master plan for site‐specific implementation. The tool links the characteristics of urban areas (engineering, economic and social) with the applicability of particular water‐demand management strategies within a fuzzy logic framework, to provide spatially‐sensitive decision support ‐ both at a strategic and an application level. The initial results, under various user‐defined scenarios, are presented and discussed. It is argued that decision‐support tools are beneficial in assisting the water industry to move towards a more pro‐active approach to urban water management, similar to the approach which has already been adopted by the Telecommunication and Energy sector.
CONTROLLING AND MONITORING ANAEROBIC DIGESTERS FED WITH THERMALLY HYDROLYSED SLUDGE
Authors: Potts L. G. A. , Jolly M.
Published: July 2007

A sludge treatment centre has been constructed at Nigg sewage‐treatment works, Aberdeen to receive sewage sludge from a number of plants in the area. The sludge is treated to the USEPA Class A standard in a thermal‐hydrolysis plant in which it is heated to 165°C for 30 mins in batch reactors. The hydrolysed sludge, which contains 10–12% dry solids, is then pumped to an anaerobic digestion plant where the temperature is maintained at 39°C for a minimum of 15 days.

The commissioning and testing of the anaerobic digesters was different to those which are fed with untreated sludge, and the approach is outlined. The paper discusses (a) the digestion parameters which were monitored during start‐up, (b) the performance of the digesters throughout the commissioning and testing period, and (c) the quality of the dewatered sludge.
DESIGN AND PERFORMANCE OF SEPARATORS FOR THE TREATMENT OF HIGHWAY DRAINAGE
Authors: Muhammad N. , Wheatley A. D. , Anderson A. R.
Published: July 2007

Laboratory work to improve the performance of storm‐water separators, to meet new Environment Agency and European standards, is described in this paper. Residence‐time distribution testing, using particulate and dissolved tracers, was used to study the hydraulics of separation. Oil‐separation efficiency and head‐loss analysis was used to develop additional final coalescing filters to reduce oil concentrations in the discharge to less than 5 mg/l. Field tests found lower oil, but greater metal, concentrations in runoff compared with those previously reported. It is suggested that improved separators could provide part of a multi‐barrier design to improve the sustainability of removal of priority pollutants in highway runoff.
THE INCREASING EFFECTS OF ZEBRA MUSSELS ON WATER INSTALLATIONS IN ENGLAND
Authors: Elliott Paul , Aldridge David. C. , Moggridge Geoff D. , Chipps Michael
Published: July 2007

The zebra mussel, Dreissena polymorpha, is a major biofouling pest of water treatment works, irrigation systems and power stations in Europe and North America. This paper documents current problems associated with zebra mussels in English waterworks. Questionnaires and manual surveys conducted between 2001 and 2003 have revealed that over 30 water treatment works in England suffer problems associated with zebra mussels. Hundreds of tonnes of mussels are being removed each year from raw water intakes, pipelines and reservoirs. Problems have increased in. the last five years, due to a spread in the range of zebra mussels around England and the cessation of chemical treatment at the intakes of many treatment facilities during the 1990s. The importance of taking control of zebra mussels into account in planning new water supply schemes is highlighted.
ASSESSMENT OF THE APPLICATION OF TREATED WASTEWATER AND SEWAGE SLUDGE IN PRODUCTIVE AGRICULTURE: A CASE STUDY FROM NORTHERN JORDAN
Authors: Hussein I.A.J. , Abu‐Sharar T. M. , Mrayyan B.
Published: July 2007

With the rapid expansion of development in Jordan, more water resources are being consumed and, consequently, incremental quantities of wastewater and sewage sludge are being generated from wastewater treatment plants. These quantities will end up in streams, open ponds or one of the other environmental media, which can cause adverse impacts on human health and the environment. In the mean while, a country like Jordan faces a remarkable shortage of fresh water resources and poor soil. The best way to mitigate the adverse impacts and compensate the water budget and enrich the poor soil is through the proper utilization and management of treated wastewater and sewage sludge in the agricultural sector. One of the main obstacles to this is public rejection of this solution, largely due to lack of information.

The purpose of this paper was to examine the acceptability to the Jordanian farmers of the utilization of reclaimed wastewater and treated sewage sludge in their irrigation activities. The scope of this study considered two potential areas at the northern part of the country, where a representative sample of local farmers were interviewed. The results were very encouraging and positive signs of acceptability were shown at all levels. These results were analyzed and documented and the recommendations are developed at the end of this paper.
Maximizing power in seroepidemiological studies through the use of the proportional odds model
Authors: Capuano Ana W. , Dawson Jeffrey D. , Gray Gregory C.
Published: July 2007

Epidemiological studies of zoonotic influenza and other infectious diseases often rely upon analysis of levels of antibody titer. In most of these studies, the antibody titer data are dichotomized based on a chosen cut‐point and analyzed with a traditional binary logistic regression. However, cut‐points are often arbitrary, particularly those selected for rare diseases or for infections for which serologic assays are imperfect. Alternatively, the data can be left in the original form, as ordinal levels of antibody titer, and analyzed using the proportional odds model. We show why this approach yields superior power to detect risk factors. Additionally, we illustrate the advantages of using the proportional odds model with the analyses of zoonotic influenza antibody titer data.
A sensitive retroviral pseudotype assay for influenza H5N1‐neutralizing antibodies
Authors: Temperton Nigel J. , Hoschler Katja , Major Diane , Nicolson Carolyn , Manvell Ruth , Hien Vo Minh , Ha Do Quang , De Jong Menno , Zambon Maria , Takeuchi Yasuhiro , Weiss Robin A.
Published: July 2007

Background  The World Health Organisation (WHO) recommended the development of simple, safe, sensitive and specific neutralization assays for avian influenza antibodies. We have used retroviral pseudotypes bearing influenza H5 hemagglutinin (HA) as safe, surrogate viruses for influenza neutralization assays which can be carried out at Biosafety Level 2.

Results  Using our assay, sera from patients who had recovered from infection with influenza H5N1, and sera from animals experimentally immunized or infected with H5 tested positive for the presence of neutralizing antibodies to H5N1. Pseudotype neutralizing antibody titers were compared with titers obtained by hemagglutinin inhibition (HI) assays and microneutralization (MN) assays using live virus, and showed a high degree of correlation, sensitivity and specificity.

Conclusions  The pseudotype neutralization assay is as sensitive as horse erythrocyte HI and MN for the detection of antibodies to H5N1. It is safer, and can be applied in a high‐throughput format for human and animal surveillance and for the evaluation of vaccines.
The Product Space Conditions the Development of Nations
Authors: Hidalgo C. A. , Klinger B. , Barabási A.-L. , Hausmann R.
Published: July 2007

Economies grow by upgrading the products they produce and export. The technology, capital, institutions, and skills needed to make newer products are more easily adapted from some products than from others. Here, we study this network of relatedness between products, or “product space,” finding that more-sophisticated products are located in a densely connected core whereas less-sophisticated products occupy a less-connected periphery. Empirically, countries move through the product space by developing goods close to those they currently produce. Most countries can reach the core only by traversing empirically infrequent distances, which may help explain why poor countries have trouble developing more competitive exports and fail to converge to the income levels of rich countries.
Influence of Hepatitis B Virus X and Core Promoter Mutations on Hepatocellular Carcinoma among Patients Infected with Subgenotype C2
Authors: Shinkai Noboru , Tanaka Yasuhito , Ito Kiyoaki , Mukaide Motokazu , Hasegawa Izumi , Asahina Yasuhiro , Izumi Namiki , Yatsuhashi Hiroshi , Orito Etsuro , Joh Takashi , Mizokami Masashi
Published: July 2007

Hepatitis B virus (HBV) genotypes/subgenotypes and their related mutations in the HBV genome have been reported to be associated with hepatocellular carcinoma (HCC). To determine the HCC-associated mutations of the HBV genome in the entire X, core promoter, and precore/core regions, a cross-sectional control study was conducted comparing 80 Japanese patients infected with HBV C2 and suffering from HCC with 80 age-, sex-, and hepatitis B e antigen (HBeAg) status-matched patients without HCC (non-HCC group). Each HBeAg-positive group (31 with HCC; 29 without HCC) and HBeAg-negative group (49 with HCC; 51 without HCC) was also matched with respect to age and sex. The C1479, T1485, H1499, A1613, T1653, V1753, T1762/A1764, and A1896 mutations were frequent in this population. The prevalences of the T1653 mutation in the box α region and the V1753 and T1762/A1764 mutations in the basal core promoter region were significantly higher in the HCC group than in the non-HCC group (56% versus 30%, 50% versus 24%, and 91% versus 73% [
P
= 0.0013,
P
= 0.0010, and
P
= 0.0035, respectively]). The platelet count was significantly lower for the HCC group than for the non-HCC group (10.7 × 10
4
± 5.1 × 10
4
versus 17.3 × 10
4
± 5.1 × 10
4
platelets/mm
3
[
P
< 0.0001]). Regardless of HBeAg status, the prevalence of the T1653 mutation was higher in the HCC group (52% versus 24% [
P
= 0.036] for HBeAg-positive patients and 59% versus 33% [
P
= 0.029] for HBeAg-negative patients). In the multivariate analysis, the presence of T1653, the presence of V1753, and a platelet count of ≤10 × 10
4
/mm
3
were independent predictive factors for HCC (odds ratios [95% confidence intervals], 4.37 [1.53 to 12.48], 7.98 [2.54 to 25.10], and 24.39 [8.11 to 73.33], respectively). Regardless of HBeAg status, the T1653 mutation increases the risk of HCC in Japanese patients with HBV/C2.
Nasal
Staphylococcus aureus
Carriage Is Not a Risk Factor for Lower-Airway Infection in Young Cystic Fibrosis Patients
Authors: Ridder-Schaphorn Sabine , Ratjen Felix , Dübbers Angelika , Häberle Johannes , Falk Sabine , Küster Peter , Schuster Antje , Mellies Uwe , Löwe Brigitte , Reintjes Ralf , Peters Georg , Kahl Barbara C.
Published: July 2007

Staphylococcus aureus
is one of the first pathogens which often persistently infect the airways of cystic fibrosis (CF) patients. Nasal
S. aureus
carriage is a risk factor for
S. aureus
infections in non-CF patients. Topical treatment strategies successfully eradicate nasal
S. aureus
carriage, thereby decreasing
S. aureus
infection. A prospective longitudinal multicenter study was conducted to assess whether nasal carriage represents a risk factor for
S. aureus
colonization of the oropharynx in young CF patients. Cross-sectional analysis revealed a significantly higher prevalence of
S. aureus
-positive nasal (28/80 [35%] versus 20/109 [18%];
P
< 0.01) and oropharyngeal (35/80 [44%] versus 20/109 [18%];
P
< 0.001) cultures in children with CF compared to a control group. The first site of
S. aureus
detection was the nose in 6 patients and the oropharynx in 14 patients, respectively. Longitudinal analysis demonstrated a significantly higher
S. aureus
prevalence (61/62 [98%] versus 47/62 [76%];
P
< 0.001) and persistence (46/62 [74%] versus 31/62 [50%];
P
< 0.01) in the oropharynx than in the nose. In CF patients, the oropharynx, and not the nose, was the predominant site of
S. aureus
infection and persistence. Hence, it is unlikely that CF patients will benefit from topical treatment strategies to eradicate nasal carriage.
Prion Protein Expression Differences in Microglia and Astroglia Influence Scrapie-Induced Neurodegeneration in the Retina and Brain of Transgenic Mice
Authors: Kercher Lisa , Favara Cynthia , Striebel James F. , LaCasse Rachel , Chesebro Bruce
Published: July 2007

Activated microglia and astroglia are known to be involved in a variety of neurodegenerative diseases, including prion diseases. In the present experiments, we studied activation of astroglia and microglia after intraocular scrapie infection in transgenic mice expressing prion protein (PrP) in multiple cell types (tg7 mice) or in neurons only (tgNSE mice). In this model, scrapie infection and protease-resistant PrP deposition occurs in the retinas of both strains of mice, but retinal degeneration is observed only in tg7 mice. Our results showed that the retinas of tg7 and tgNSE mice both had astroglial activation with increased chemokine expression during the course of infection. However, only tg7 retinas exhibited strong microglial activation compared to tgNSE retinas, which showed little microglial activation by biochemical or morphological criteria. Therefore, microglial PrP expression might be required for scrapie-induced retinal microglial activation and damage. Furthermore, microglial activation preceded retinal neurodegeneration in tg7 mice, suggesting that activated microglia might contribute to the degenerative process, rather than being a response to the damage. Surprisingly, brain differed from retina in that an altered profile of microglial activation markers was upregulated, and the profiles in the two mouse strains were indistinguishable. Microglial activation in the brain was associated with severe brain vacuolation and neurodegeneration, leading to death. Thus, retinal and brain microglia appeared to differ in their requirements for activation, suggesting that different activation pathways occur in the two tissues.
Mechanistic Insights into the Cure of Prion Disease by Novel Antiprion Compounds
Authors: Webb Sarah , Lekishvili Tamuna , Loeschner Corinna , Sellarajah Shane , Prelli Frances , Wisniewski Thomas , Gilbert Ian H. , Brown David R.
Published: July 2007

Prion diseases are fatal neurodegenerative disorders. Identification of possible therapeutic tools is important in the search for a potential treatment for these diseases. Congo red is an azo dye that has been used for many years to detect abnormal prion protein in the brains of diseased patients or animals. Congo red has little therapeutic potential for the treatment of these diseases due to toxicity and poor permeation of the blood-brain barrier. We have prepared two Congo red derivatives, designed without these liabilities, with potent activity in cellular models of prion disease. One of these compounds cured cells of the transmissible agent. The mechanism of action of these compounds is possibly multifactorial. The high affinity of Congo red derivatives, including compounds that are ineffective and are effective at the cure of prion disease, for abnormally folded prion protein suggests that the amyloidophylic property of these derivatives is not as critical to the mechanism of action as other effects. Congo red derivatives that are effective at the cure of prion disease increased the degradation of abnormal PrP by the proteasome. Therefore, the principal mechanism of action of the Congo red analogues was to prevent inhibition of proteasomal activity by PrPSc.
Co-axial horizontal stretching within extending orogens: the exhumation of HP rocks on Syros (Cyclades) revisited
Authors: Bond Clare E. , Butler Robert W. H. , Dixon John E.
Published: July 2007

Although the role of extensional tectonics in the exhumation of high-pressure metamorphic terranes is widely established, the kinematics of such deformation remains ambiguous. This paper outlines new field data from the Attic-Cycladic blueschist belt that suggest that distributed ductile strain plays a significant role in the extension and that, consequently, the role of major detachment faults may have been over-emphasized in previous studies. The high-pressure blueschist terrane (Ermoupolis Unit) of Syros shows abundant evidence of subhorizontal extension, manifest as layer boudinage and ductile thinning without the development of significant internal detachments. The deformation approximates to pure shear stretching that was heterogeneously distributed in space and time. Minor zones of asymmetric shear are interpreted not as through-going extensional shear zones but as structures that maintain compatibility between zones of differential stretching. The progression of deformation is charted through the systematic development of increasingly lower-pressure metamorphic assemblages. However, most of the decompression (potentially from 20 kbar to 6 kbar) occurred within the blueschist stability field, as the rocks were actively extending. Heterogeneous retrogression and concomitant deformation are believed to relate to the local chemistry and availability of hydrous fluids.
Strike-slip deformation within the Colombian Andes
Authors: Acosta Jorge , Velandia Francisco , Osorio Jairo , Lonergan Lidia , Mora Héctor
Published: July 2007

The Colombian Andes are characterized by a dominant NE structural trend, which is offset by ENE-trending right-lateral and NW-trending left-lateral structures. NE-trending faults are either dip-slip or oblique thrusts, generated as a result of a trans-pressive regime active since at least Palaeogene times. NW-trending faults are considered to be reactivated pre-Cretaceous extensional structures. Right-lateral shear on ENE-trending faults has resulted from oblique convergence between the Nazca Plate and the Northern Andes. Major changes in the geometry of the oblique-plate convergence between the Nazca and South American plates have generated the northward ‘escape’ of the Northern Andes and stress-strain partitioning within the mountain belt. These strike-slip structures have exerted important controls on sedimentation, source-rock distribution, fluid flow and ore mineralization during Cenozoic times. The interpretation of the Northern Andes as a mountain belt affected by strike-slip deformation provides a structural context in which to reassess the exploration plays.
The role of major fault zones in controlling the geometry and spatial organization of structures in the Zagros Fold-Thrust Belt
Authors: Sepehr M. , Cosgrove J. W.
Published: July 2007

The present-day morphology of the Zagros Fold-Thrust Belt is dominated by magnificent exposures of NW-SE-trending folds. This mountain belt is also characterized by a series of belt-parallel and belt-oblique (transfer) fault zones. Not all the fault zones have a clear exposure at the surface because of the presence of thick incompetent overlying sedimentary successions, but they can be identified from a study of the present-day seismicity of the belt and by the spatial organization of the overlying folds. The folds are not often cross-cut by the faults but plunge towards, or are deflected and end against, these blind transfer fault zones. As a result, shortening is accommodated by different fold trains on either side of the fault. This decoupling in turn causes the step-like offset of the major, belt-parallel thrust zones and the related topographic elements. These offsets occur on all scales, from regional (e.g. across the Kazerun and Izeh fault zones) to local. These transfer faults-lateral ramps may be influenced by pre-existing structures or by facies boundaries, which in particular influenced the Zagros Basin in the Cretaceous. In addition to controlling sedimentation and the compartmentalization of deformation, these fault zones also act as paths of fluid migration, as indicated by the present-day concentration of oil seepages and thermal or sulphur springs.
Interactions of transmembrane carbonic anhydrase, CAIX, with bicarbonate transporters
Authors: Morgan Patricio E. , Pastoreková Silvia , Stuart-Tilley Alan K. , Alper Seth L. , Casey Joseph R.
Published: July 2007

Association of some plasma membrane bicarbonate transporters with carbonic anhydrase enzymes forms a bicarbonate transport metabolon to facilitate metabolic CO2-HCO3− conversions and coupled HCO3− transport. The transmembrane carbonic anhydrase, CAIX, with its extracellular catalytic site, is highly expressed in parietal and other cells of gastric mucosa, suggesting a role in acid secretion. We examined in transfected HEK293 cells the functional and physical interactions between CAIX and the parietal cell Cl−/HCO3− exchanger AE2 or the putative Cl−/HCO3− exchanger SLC26A7. Coexpression of CAIX increased AE2 transport activity by 28 ± 7% and also activated transport mediated by AE1 and AE3 (32 ± 10 and 37 ± 9%, respectively). In contrast, despite a transport rate comparable to that of AE3, coexpressed CAIX did not alter transport associated with SLC26A7. The CAIX-associated increase of AE2 activity did not result from altered AE2 expression or cell surface processing. CAIX was coimmunoprecipitated with the coexpressed SLC4 polypeptides AE1, AE2, and AE3, but not with SLC26A7. GST pull-down assays with a series of domain-deleted forms of CAIX revealed that the catalytic domain of CAIX mediated interaction with AE2. AE2 and CAIX colocalized in human gastric mucosa, as indicated by coimmunofluorescence. This is the first example of a functional and physical interaction between a bicarbonate transporter and a transmembrane carbonic anhydrase. We conclude that CAIX can bind to some Cl−/HCO3− exchangers to form a bicarbonate transport metabolon.
Response Properties of Single Units in the Dorsal Nucleus of the Lateral Lemniscus of Decerebrate Cats
Authors: Davis Kevin A. , Lomakin Oleg , Pesavento Michael J.
Published: July 2007

The dorsal nucleus of the lateral lemniscus (DNLL) receives afferent inputs from many brain stem nuclei and, in turn, is a major source of inhibitory inputs to the inferior colliculus (IC). The goal of this study was to characterize the monaural and binaural response properties of neurons in the DNLL of unanesthetized decerebrate cat. Monaural responses were classified according to the patterns of excitation and inhibition observed in contralateral and ipsilateral frequency response maps. Binaural classification was based on unit sensitivity to interaural level differences. The results show that units in the DNLL can be grouped into three distinct types. Type v units produce contralateral response maps that show a wide V-shaped excitatory area and no inhibition. These units receive ipsilateral excitation and exhibit binaural facilitation. The contralateral maps of type i units show a more restricted I-shaped region of excitation that is flanked by inhibition. Type o maps display an O-shaped island of excitation at low stimulus levels that is bounded by inhibition at higher levels. Both type i and type o units receive ipsilateral inhibition and exhibit binaural inhibition. Units that produce type v maps have a low best frequency (BF), whereas type i and type o units have high BFs. Type v and type i units give monotonic rate-level responses for both BF tones and broadband noise. Type o units are inhibited by tones at high levels, but are excited by high-level noise. These results show that the DNLL can exert strong, differential effects in the IC.
Parameter Space Analysis Suggests Multi-Site Plasticity Contributes to Motor Pattern Initiation inTritonia
Authors: Calin-Jageman Robert J. , Tunstall Mark J. , Mensh Brett D. , Katz Paul S. , Frost William N.
Published: July 2007

This research examines the mechanisms that initiate rhythmic activity in the episodic central pattern generator (CPG) underlying escape swimming in the gastropod mollusk Tritonia diomedea. Activation of the network is triggered by extrinsic excitatory input but also accompanied by intrinsic neuromodulation and the recruitment of additional excitation into the circuit. To examine how these factors influence circuit activation, a detailed simulation of the unmodulated CPG network was constructed from an extensive set of physiological measurements. In this model, extrinsic input alone is insufficient to initiate rhythmic activity, confirming that additional processes are involved in circuit activation. However, incorporating known neuromodulatory and polysynaptic effects into the model still failed to enable rhythmic activity, suggesting that additional circuit features are also required. To delineate the additional activation requirements, a large-scale parameter-space analysis was conducted (∼2 × 106configurations). The results suggest that initiation of the swim motor pattern requires substantial reconfiguration at multiple sites within the network, especially to recruit ventral swim interneuron-B (VSI) activity and increase coupling between the dorsal swim interneurons (DSIs) and cerebral neuron 2 (C2) coupling. Within the parameter space examined, we observed a tendency for rhythmic activity to be spontaneous and self-sustaining. This suggests that initiation of episodic rhythmic activity may involve temporarily restructuring a nonrhythmic network into a persistent oscillator. In particular, the time course of neuromodulatory effects may control both activation and termination of rhythmic bursting.