bluuebunny/crossref_metadata_2025 huggingface dataset:
Criteria for Assessment of Functional Impairment in Patients with Cirrhosis of the Liver*
Authors: Bircher J. , Blankart R. , Halpern A. , Hacki W. , Laissue J. , Preisig R.
Published: September 2010

Abstract. Fourty‐seven patients with cirrhosis of the liver and 58 normal subjects were studied in order to find quantitative criteria to assess the severity of the functional impairment in this disease. The special investigations included hepatic haemodynamics, partial functions and liver volume, which was measured in frontal and right lateral scans. – In contrast to normal subjects liver volumes in cirrhosis were not correlated significantly with the body weight (r=–0.05), with the galactose elimination capacity (Tygstrup's method, r= 0.15) or with the sulfobromophthalein transport maximum (Wheeler's method, r=–0.40). Large livers, however, were associated with corresponding increases in splanchnic oxygen uptake (r= 0.74, P < 0.001), even though hepatic blood flow estimated with the indocyanine green infusion and extraction technique appeared to vary independently (r= 0.40, P > 0.05). – It may be inferred from these data that patients with cirrhosis can be further characterized on the basis of liver volume. Compared to small livers hepatomegaly shows a dissociation between oxygen uptake and functional capacity. Thus, with existing methods the severity of functional impairment in cirrhosis may be quantitatively investigated. Such information should be relevant for prognostic stratification and endpoint definition of therapeutic trials.
Effects of cardiac glycosides on 24‐h ambulatory blood pressure in healthy volunteers and patients with heart failure
Authors: Grossmann M. , Kirch W.
Published: September 2010

Blood pressure effects of cardiac glycosides in humans have been infrequently reported. Although direct infusion of ouabain or digoxin causes vasoconstriction, indirect effects of cardiac glycosides may have the opposite effect, owing to changes in sympatho‐vagal balance.

This paper summarises three studies on the effects of cardiac glycosides on circadian blood pressure, utilizing automatic 24‐h ambulatory blood pressure measurement (ABPM). In healthy volunteers, 10 days of oral digoxin or digitoxin caused decreases in diastolic blood pressure and heart rate during overnight sleep. No effect was detectable during daytime activities. In patients with heart failure (NYHA stage II), 7 days of oral digoxin also caused a decrease in diastolic blood pressure but only a small increase in systolic pressure during overnight sleep. Again, no effect was detectable during the day.

Cardiac glycosides have significant effects on blood pressure, which only appear during overnight sleep, i.e. a phase when sympathetic background activity is lowest. Regular daytime activities may ‘overwrite’ these effects. Effects of cardiac glycosides on blood pressure may have therapeutic impact, depending on the stage of heart failure and concomitant diseases.
Ambulatory blood pressure in heart failure
Authors: Jamieson M. J. , Jamieson C.
Published: September 2010

Ambulatory blood‐pressure monitoring (ABPM) is accepted in the evaluation and management of hypertension. The use of ABPM in heart failure has received considerably less attention. Many patients with advanced heart failure experience disabling fatigue, orthostatic dizziness and symptoms of coronary and cerebrovascular insufficiency that may relate to periods of hypotension. These may be exacerbated by vasodilator drug therapy and may be difficult to evaluate by casual clinic recordings. ABPM in heart failure may help in the following: (i) evaluating time‐dependent pharmacodynamic drug effects, such as peak and end‐of‐dose phenomena, tolerance and rebound; (ii) titrating ACE inhibitors and other drugs to highest‐tolerated doses; and (iii) correlating circadian blood‐pressure profiles with symptoms, quality of life, severity of heart failure, progression of ventricular and renal dysfunction, risks of stroke and myocardial infarction, and life expectancy. Devices for ABPM have been beset by problems of inaccuracy and unreliability. Standards for their manufacture and sale (including bench tests of accuracy against sphygmomanometry and intra‐arterial recordings, and field tests of reliability) have been devised independently by several agencies, including the British Hypertension Society (BHS) and US Association for the Advancement of Medical Instrumentation (AAMI). A joint BHS/AAMI set of guidelines is in preparation. These guidelines emphasize the suitability of ABPM devices for hypertensive patients and those under general anesthesia, and may not be applicable to ambulant individuals with heart failure and blood pressures at or below the lower end of the evaluated ranges. Prospective studies of the accuracy and reliability of ABPM devices, their clinical utility and research potential should be undertaken in patients with heart failure before their informal and uncontrolled use in this population becomes widespread.
Direct effect of statins on homocysteine‐induced endothelial adhesiveness: potential impact to human atherosclerosis
Authors: Lin C. P. , Chen Y. H. , Lin W. T. , Leu H. B. , Liu T. Z. , Huang S. L. , Chen J. W.
Published: September 2010

Background  Although homocysteine (HCY) is a risk factor for cardiovascular diseases, recent clinical trials failed to show the benefits by reducing plasma HCY. Alternative strategy with 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase inhibitors, statins, might be feasible. This study investigated HCY‐induced endothelial adhesiveness with mononuclear cells (MNCs) from patients with coronary artery disease (CAD). The direct endothelial protective effects of statins were also examined.

Materials and methods  Circulating MNCs were isolated from 14 stable CAD patients and 7 age‐ and gender‐matched healthy subjects. Superoxide production of MNCs was determined by Ultra‐weak and luminol‐enhanced chemiluminescence. Human aortic endothelial cells (HAECs) were used for endothelial adhesiveness to MNCs or U937 human monocytic cells. Endothelial expression of vascular cell adhesion molecule‐1 (VCAM‐1) and intercellular adhesion molecule‐1 (ICAM‐1) were examined by Western blot.

Results  Superoxide production of MNCs and plasma HCY and high‐sensitive CRP levels were significantly increased in CAD patients than in healthy subjects. Stimulation with HCY enhanced the endothelial adhesiveness to MNCs from CAD patients or to U937 cells in a dose‐dependent manner, whereas it was obscure with MNCs from healthy subjects. HCY stimulated endothelial VCAM‐1 but not ICAM‐1 expression in a dose‐dependent manner. Monoclonal antibodies to VCAM‐1 attenuated HCY‐induced endothelial adhesiveness. Simvastatin or pravastatin significantly reduced HCY‐induced VCAM‐1 expression and endothelial adhesiveness to MNCs from CAD patients.

Conclusion  Circulating MNCs were activated in CAD patients, which was critical to HCY‐induced endothelial adhesiveness. Statins could directly reduce HCY‐induced endothelial‐MNC adhesion via VCAM‐1 inhibition, suggesting its potential implication in HCY‐related atherosclerosis disease.
Inland commercial fisheries management in France
Authors: Boisneau P. , Mennesson‐Boisneau C.
Published: September 2010

The French fisheries management regime is based on public and private ownership of fishing waters associated with a complex multilevel management system. A total of 730 operational commercial inland fisheries were examined by analysis of thematic interviews and questionnaires. Commercial fishermen are beginning to understand the nature of their own activity and its relationship to the concept of sustainable management. Nevertheless, fishermen have to face two major problems: first, they are poorly represented on decision making bodies where anglers are dominant, and secondly their activities are governed by two separate ministries. Opportunities for future development may lie in decision making at the catchment level.
Local owner‐based management of Finnish lake fisheries: social dimensions and power relations
Authors: Salmi P. , Muje K.
Published: September 2010

Traditionally most inland water bodies in Finland were privately owned as an extension of land ownership. Statutory fishery associations are responsible for local decision‐making on most lakes. Social dimensions have been tightly embedded in decision making by these associations. The local level of Finnish fisheries management has been subjected to a fundamental shift from locally based subsistence fishing and wide local participation in fisheries associations to a wide range of non‐local recreational demands and decreasing participation. In this paper the functionality of local resource management in the Finnish context of private ownership of fishing waters is studied, with focus on the social significance of local decision‐making and representation of user groups in the decision‐making process. The main material consists of personal thematic interviews with a range of fishermen, decision makers and other stakeholders in two lakes.
Co‐operative fisheries management of the cross border Lake Peipsi‐Pihkva
Authors: Vetemaa M. , Vaino V. , Saat T. , Kuldin S.
Published: September 2010

This paper focuses on the management and socio‐economic principles for allocation of the commercial fish resources of Lake Peipsi‐Pihkva. The fish resources of this cross border lake are very important both for Russia and Estonia. Recent changes in the Estonian and Russian economies, and the appearance of the state border dividing the lake, have resulted in deep changes in economic, social and legal issues related to the fishery. As the lake is now an international waterbody, the Intergovernmental Estonian–Russian Fishery Commission (ERFC) agreed for co‐operative management measures annually from 1994. The ERFC is responsible for all general decisions on management strategies and technical measures used in fishery management. The stocks of most commercial fish species in Lake Peipsi‐Pihkva are still abundant, and the economic status of the fishermen is relatively good. It may be concluded that co‐operative management of the Lake Peipsi‐Pihkva fisheries have been successful.
Combining creel intercept and mail survey methods to understand the human dimensions of local freshwater fisheries
Authors: Ditton R. B. , Hunt K. M.
Published: September 2010

Creel surveys were conducted by Texas Parks and Wildlife Department at two lakes were used as a means of sampling anglers for follow‐up mail surveys. After the collection of fisheries dependent data from fishing parties on randomly selected days, anglers were randomly selected and told of an forthcoming mail survey they would receive within 90 days. They were asked to provide their names and addresses on a confidential basis. The mail survey provided detailed coverage of the anglers intercepted (e.g. their social and demographic characteristics, level of fishing experience and involvement, experience preferences, consumptive orientation, management preferences, attitudes and satisfaction levels), characteristics of the trip when they were intercepted (i.e. trip length, party size and expenditures by location), and lake‐specific issues of concern to management. This add‐on methodology is described with particular attention to sample size considerations, creel intercept and mail survey procedures, recall bias, response rates and administrative concerns.
Economic evaluation of inland fisheries in England and Wales
Authors: Peirson G. , Tingley D. , Spurgeon J. , Radford A.
Published: September 2010

Recreational inland fisheries are recognized to have considerable socio‐economic benefits, not only for individuals participating directly but also for others in both local and wider communities. In England and Wales the Environment Agency (EA) has a duty to maintain, improve and develop inland fisheries. At present, there are no recent economic evaluations of the whole range of UK inland fisheries for the EA to refer to when confronted with resource issues. There is a particular need to explore the benefits of fisheries to the wider community, in order to secure more resources for management and protection of fisheries. Preliminary results from a multi‐modular project to study the economic values associated with recreational fisheries in England and Wales are presented. Topics examined included recreational anglers’ consumer surplus, general public non‐use values of fisheries, social benefits of recreational fishing and impacts of fisheries on local communities.
Regional socio‐economic importance of fisheries in Finland
Authors: Virtanen J. , Ahvonen A. , Honkanen A.
Published: September 2010

The total value of Finnish fisheries production in 1997 was almost FIM 2 billion. The bulk of this sum was from processing and wholesaling, but in terms of value added, somewhat more than half was contributed by the primary sector, i.e. fishing and fish farming. In economic terms, fisheries accounted for 0.1% of gross domestic product (GDP) in 1997 and the relative job creation capacity was 0.15%. This paper examines the structure of Finnish fisheries in terms of production value and employment. It also considers the level of dependency on fisheries and of value added along the production chain. The focus is on concentration of the industry and on input to the economy at the regional level. The concentration of fisheries and regional dependence on fisheries are assessed in absolute and relative terms. Examining employment and value added in these two ways enables the regional nature of fisheries to be shown in greater detail. The input of fisheries to the regional economy is examined by the share of value added and by location quotients. The location quotient compares an area’s share of a particular activity with that area’s share of some basic or aggregated phenomenon. The location quotient showed that fisheries have importance not only in the coastal area but also inland.
Assessment of salmon stocks and the use of management targets; a case study of the River Tamar, England
Authors: HENDRY K. , SAMBROOK H. , WATERFALL R.
Published: September 2010

Abstract  Over recent years the rod and net catch of Atlantic salmon, Salmo salar L., on the River Tamar in south‐west England has decreased markedly, resulting in a consistent failure to meet the minimum egg deposition target (conservation limit). Compliance with the target is by annual assessment using rod catch as the major input variable. Further analysis suggested a disproportionate deterioration in the rod fishery performance of the Tamar compared with rivers locally, regionally and nationally. A concomitant decrease in rod licence sales and fishing effort, above both national and regional trends was also evident. However, examination of juvenile electric fishing and adult fish counter data revealed a different trend for the past 10 years, indicating a stable fish population, albeit at a lower level of abundance than previously. The analyses suggested that without consideration of changes in effort and rod exploitation rate, rod catch alone is not a reliable indicator of stock abundance and hence should not be used as such in stock assessment.
Field protocol for assessing small obstacles to migration of brown trout Salmo trutta, and European grayling Thymallus thymallus: a contribution to the management of free movement in rivers
Authors: OVIDIO M. , CAPRA H. , PHILIPPART J.‐C.
Published: September 2010

Abstract  Between 1996 and 2004, adult brown trout, Salmo trutta L. (n = 40) and European grayling, Thymallus thymallus (L.) (n = 39) were radio‐tracked in three southern Belgium rivers to assess their capabilities to bypass various obstacles. During their upstream migrations individuals encountered different types of physical obstacles and successfully passed some under variable environmental conditions. The obstacles cleared by the fish were characterised based on a simple topographical description protocol and compared with tracking data. The ability of trout and grayling to pass different typologies of physical obstacles in natural river systems is discussed in the context of enabling their free movement in rivers.
Optimising Denil fishways for passage of small and large fishes
Authors: MALLEN‐COOPER M. , STUART I. G.
Published: September 2010

Abstract  An 8‐m long experimental fishway was trialled at three different slopes [8.3% (1:12), 14.3% (1:7) and 20% (1:5)] to examine the potential of the single‐plane Denil fishway for the passage of small‐ and large‐bodied native fishes in Australia. Fish between 45 and 630 mm ascended the fishway. The lowest slope enabled the full size range of bony herring Nematalosa erebi (Günther), from 45 to 350 mm fork length, to ascend the fishway successfully as well as a higher numerical proportion; 88% at the 8.3% slope compared with 31% at the 20% slope (fish numbers per trial = 33–3936). These results dispel the notion that Denil fishways are inherently poor for small fishes. Manipulating the design parameters of slope, length, width and possibly depth‐over‐breadth ratio enables Denil fishways to pass a wide size range of fish, which may greatly extend their present application and enable them to make a greater contribution to the rehabilitation of diverse fish communities.
Temperature‐sensing telemetry – possibilities for assessing the feeding ecology of marine mammals and their potential impacts on returning salmonid populations
Authors: BENDALL B. , MOORE A.
Published: September 2010

Abstract  Adult salmonids returning to the River Tees (north‐east England) tagged with temperature‐sensing acoustic transmitters provided some unexpected and novel information on the possible impact of seal predation at a tidal barrage 16 km from the sea. Predation events of tagged fish by seals were inferred by an increase in the temperature transmitted by the acoustic tags. Subsequent events of feeding or drinking by the seals were also inferred from further changes in temperature recorded by tags whilst in their stomachs. Rates of inferred predation on tagged individuals were high (47%). This is the first time that temperature‐sensing transmitters deployed inside wild salmonids have revealed instances of predation by, and subsequent feeding ecology of, marine mammals. The results are discussed in relation to the use of such technology in future studies attempting to address the interactions between marine mammals and their fish prey species.
Migration of rheophilic fish in the large lowland rivers Meuse and Rhine, the Netherlands
Authors: DE LEEUW J. J. , WINTER H. V.
Published: September 2010

Abstract Large‐scale migratory patterns of adult rheophilic fish [barbel,Barbus barbus(L.), chub,Leuciscus cephalus(L.), ide,Leuciscus idus(L.), nase,Chondrostoma nasus(L.)] were studied in relation to habitat quality and possible migration barriers in the lower rivers Meuse and Rhine, the Netherlands, using a telemetry system with transponders and detection stations based on inductive coupling. Most fish moved over short distances (<10 km), especially those residing in river stretches with high habitat diversity year‐round. About 16% of fish used river stretches over 50 km and two ide moved more than 200 km along free‐flowing river stretches. One‐third of barbel, chub and nase from a Weir‐regulated river stretch moved upstream during the spawning season to spawning habitats. Some fish resided in the areas immediately downstream of weirs and fishways during the spawning season, although it was unclear to what extent these observations reflected habitat choice or barriers to migration.
Efficiency of a fish lift for returning Atlantic salmon at a large‐scale hydroelectric complex in France
Authors: CROZE O. , BAU F. , DELMOULY L.
Published: September 2010

Abstract  This study describes the behaviour of radio‐tagged returning Atlantic salmon, Salmo salar L., at the Golfech‐Malause hydroelectric complex on the River Garonne, France. The particularity of this complex is that it is fitted with a fish lift, a type of fishway rarely tested for salmon. Only forty seven percent of salmon succeeded in passing. Frequenting of both the tailrace and the foot of the plant, where the lift was located, decreased rapidly during the blockage. Successful salmon spent proportionally more time near the entrance of the lift. The high mean number of visits to the lift entrance before upstream passage (51) suggested the lift was not sufficiently attractive. Evidence is also given of the difficulties specific to fish lifts that involve trapping fish: the V‐shaped entrance of the fish lift holding pool could inhibit salmon without even guaranteeing a non‐return effect.
Movements and habitat use of wild and stocked juvenile chub,Leuciscus cephalus(L.), in a small lowland river
Authors: BOLLAND J. D. , COWX I. G. , LUCAS M. C.
Published: September 2010

Abstract Stocking is a widespread management activity in inland fisheries, but the efficacy of such fishery enhancement measures is poorly understood. Radio‐telemetry was used to compare the movements and habitat selection of stocked, juvenile chub,Leuciscus cephalus(L.), with those of wild individuals in a small river in Eastern England. Thirty‐two wild juvenile chub (total for 2005 and 2006 combined) and 12 stocked, 1+ chub (2006) were surgically implanted with radio‐tags and tracked once per day for 1 month. Stocked chub did not disperse immediately after release, there was no evidence of reduced survival of stocked chub, and neither wild nor stocked chub were permanently displaced downstream of the study reach by high flows. Linear ranges of wild chub were, however, smaller than for stocked chub, movements were more frequent and larger for stocked fish (particularly during elevated flows), and differences in habitat use were found. The short‐term success of stocking cyprinids was demonstrated, whilst emphasising behavioural (movements and habitat use) differences between hatchery fish and wild counterparts, and the necessity for long‐term monitoring.
Migratory behaviour of adult chum salmon, Oncorhynchus keta, in a reconstructed reach of the Shibetsu River, Japan
Authors: MAKIGUCHI Y. , NII H. , NAKAO K. , UEDA H.
Published: September 2010

Abstract  During 2004–2006, 30 adult chum salmon, Oncorhynchus keta (Walbaum), were tagged with electromyogram (EMG) transmitters and depth/temperature loggers and tracked along both the channelised and reconstructed segments of the Shibetsu River, Japan to assess the effects of the river re‐meandering construction on upstream migration. Holding time of chum salmon in the reconstructed segment was longer than in the channelised segment. Further, greater diversity of physical condition in water velocity was observed in the reconstructed segment in 2005. Swimming speeds decreased during holding and often exceeded the critical swimming speed (Ucrit). It appears that the physical characteristics developed in the reconstructed segment may be suitable for holding of chum salmon. Further, swimming speed exceeding Ucrit prior to holding may be exhaustive so holding behaviour may be important for muscle recovery as well as for efficient swimming to reduce the energetic cost during upstream migration.
Survival and behaviour of European silver eel in late freshwater and early marine phase during spring migration
Authors: AARESTRUP K. , THORSTAD E. B. , KOED A. , JEPSEN N. , SVENDSEN J. C. , PEDERSEN M. I. , SKOV C. , ØKLAND F.
Published: September 2010

Abstract  The seaward migration of European silver eel Anguilla anguilla (L.) was studied during the late freshwater and early marine phase in River Gudenaa and Randers Fjord, Denmark, in the spring 2004. Migration was monitored in sections with different physical characteristics over a total distance of 46 km using automatic listening stations. Generally, eels quickly left the River Gudenaa (67% within 2 days) and stayed for up to 4.3 months (mean 1.7 months) in the inner fjord. This indicates a two‐step migration, with silver eels migrating out of the river in the spring, followed by a substantial residence period in the inner part of the fjord before continuing the migration. The results suggest that silver eel migration may not always be a direct journey to the ocean, but may include resident periods in coastal areas. The eels were subjected to a high mortality with less then 20% surviving out of the fjord. Fishing seemed to be the main reason for the mortality.
Larval fish assemblages and water mass structure off the oligotrophic south‐western Australian coast
Authors: MUHLING B. A. , BECKLEY L. E. , KOSLOW J. A. , PEARCE A. F.
Published: September 2010

Larval fish assemblages were sampled using replicated oblique bongo net tows along a five‐station transect extending from inshore (18 m depth) to offshore waters (1000 m depth) off temperate south‐western Australia. A total of 148 taxa from 93 teleost families were identified. Larvae of Gobiidae and Blenniidae were abundant inshore, while larvae of pelagic and reef‐dwelling families, such as Clupeidae, Engraulidae, Carangidae and Labridae were common in continental shelf waters. Larvae of oceanic families, particularly Myctophidae, Phosichthyidae and Gonostomatidae, dominated offshore assemblages. Multivariate statistical analyses revealed larval fish assemblages to have a strong temporal and spatial structure. Assemblages were distinct among seasons, and among inshore, continental shelf and offshore sampling stations. Inshore larval fish assemblages were the most seasonal, in terms of species composition and abundance, with offshore assemblages the least seasonal. However, larval fish assemblages were most closely correlated to water mass, with species distributions reflecting both cross‐shelf and along‐shore oceanographic processes and events. Similarity profile (SIMPROF) analysis suggested the presence of twelve distinct larval fish assemblages, largely delineated by water depth and season. The strength and position of the warm, southward flowing Leeuwin Current, and of the cool, seasonal, northward flowing Capes Current, were shown to drive much of the variability in the marine environment, and thus larval fish assemblages.
Integrated geological and geophysical exploration for concealed ores beneath cover in the Chaihulanzi goldfield, northern China
Authors: Liu Hongtao , Liu Jianming , Yu Changming , Ye Jie , Zeng Qingdong
Published: September 2010

An integrated geological and geophysical investigation was carried out in the near‐mine areas of the Chaihulanzi gold‐field, Inner Mongolia, northern China, to determine the south‐eastern strike extension of the principal mineralized shear system, in the search for new resources. In this case study, surface geophysical surveys played an important role in defining the mineralized structures beneath cover. A re‐investigation of the mine geology by observing the underground exposures of mineralization and its hosting structures, coupled with re‐evaluation and re‐examination of previous exploration data, revealed that the mineralization style at the Chaihulanzi gold‐field is not the skarn‐type as previously assumed, but is structurally controlled by an oblique‐sinistral shear structure. Moreover, a south‐eastward shallow‐plunging mineralized corridor within the principal mineralized shear system was also identified, implying that the ore‐forming fluid‐flow might move through the mineralizing system, from the south‐east at depth to the north‐west. These new geological findings imply that the mineralized shear system should extend much farther south‐eastwards along strike beneath cover, and thus a conceptual target area was proposed. A detailed geophysical survey program, involving the application of VLF‐EM, Stratagem EH4, CSAMT and gradient IP measurements, was carried out to test the validity of the conceptual target. Orientation surveys on the geologically known Line‐18 traverse revealed that VLF‐EM and Stratagem EH4 were the most effective methods of detecting the unseen mineralized system, whereas CSAMT could only provide low‐resolution data, and IP proved to be unsuitable in this environment due to the ubiquitous presence of graphite‐bearing schists in and around the mineralized system. A follow‐up systematic VLF‐EM survey highlighted the principal mineralized shear system as a linear conductive belt, tracing the principal mineralized system for a further 750 m of strike length beneath cover from the previous exploration limit (Line 18). Stratagem EH4 soundings over six parallel traverses perpendicular to the mineralized trend revealed that the principal mineralized shear structure extends for more than 500 m in the dip direction, a strong indication of the presence of potential deep mineralization under the surveyed area. Detailed modelling of the Stratagem EH4 sounding images provided well‐defined targets for test drilling. Subsequent test drilling on some of these targets returned encouraging results as several core‐intercepts of economic gold mineralization were encountered. This led to a more extensive drilling and underground prospecting program, focusing on deep mineralization south‐eastwards along the mineralized trend.
Analytical solution for the electric potential in arbitrary anisotropic layered media applying the set of Hankel transforms of integer order
Authors: Pervago E. , Mousatov A. , Shevnin V.
Published: September 2010

The analytical solution and algorithm for simulating the electric potential in an arbitrarily anisotropic multilayered medium produced by a point DC source is here proposed. The solution is presented as a combination of Hankel transforms of integer order and Fourier transforms based on the analytical recurrent equations obtained for the potential spectrum. For the conversion of the potential spectrum into the space domain, we have applied the algorithm of the Fast Fourier Transform for logarithmically spaced points. A comparison of the modelling results with the power‐series solution for two‐layered anisotropic structures demonstrated the high accuracy and computing‐time efficiency of the method proposed.

The results of the apparent‐resistivity calculation for both traditional pole‐pole and tensor arrays above three‐layered sequence with an azimuthally anisotropic second layer are presented. The numerical simulations show that both arrays have the same sensitivity to the anisotropy parameters. This sensitivity depends significantly on the resistivity ratio between anisotropic and adjacent layers and increases for the models with a conductive second layer.
Anisotropic migration velocity analysis: Application to a data set from West Africa
Authors: Sarkar Debashish , Tsvankin Ilya
Published: September 2010

Although it is widely recognized that anisotropy can have a significant influence on the focusing and positioning of migrated reflection events, conventional depth imaging methods still operate with isotropic velocity fields. Here, we present an application of a 2D migration velocity analysis (MVA) algorithm, designed for factorized v(x, z) VTI (transversely isotropic with a vertical symmetry axis) media, to an offshore data set from West Africa. By approximating the subsurface with factorized VTI blocks, it is possible to decouple the spatial variations in the vertical velocity from the anisotropic parameters with minimal a priori information.

Since our method accounts for lateral velocity variation, it produces more accurate estimates of the anisotropic parameters than those previously obtained with time‐domain techniques. The values of the anellipticity parameter η found for the massive shales exceed 0.2, which confirms that ignoring anisotropy in the study area can lead to substantial imaging distortions, such as mis‐stacking and mispositioning of dipping events. While some of these distortions can be removed by using anisotropic time processing, further marked improvement in image quality is achieved by prestack depth migration with the estimated factorized VTI model. In particular, many fault planes, including antithetic faults in the shallow part of the section, are better focused by the anisotropic depth‐migration algorithm and appear more continuous. Anisotropic depth migration facilitates structural interpretation by eliminating false dips at the bottom of the section and improving the images of a number of gently dipping features.

One of the main difficulties in anisotropic MVA is the need to use a priori information for constraining the vertical velocity. In this case study, we successfully reconstructed the time–depth curve from reflection data by assuming that the vertical velocity is a continuous function of depth and estimating the vertical and lateral velocity gradients in each factorized block. If the subsurface contains strong boundaries with jumps in velocity, knowledge of the vertical velocity at a single point in a layer is sufficient for our algorithm to determine all relevant layer parameters.
Wavefield Migration plus Monte Carlo Imaging of 3D Prestack Seismic Data
Authors: Bonomi Ernesto , Brieger Leesa M. , Cazzola Luca , Zanoletti Francesco
Published: September 2010

Prestack wave‐equation migration has proved to be a very accurate shot‐by‐shot imaging tool. However, 3D imaging with this technique of a large field acquisition, especially one with hundreds of thousands of shots, is prohibitively costly. Simply adapting the technique to migrate many superposed shot‐gathers simultaneously would render 3D wavefield prestack migration cost‐effective but it introduces uncontrolled non‐physical interference among the shot‐gathers, making the final image useless. However, it has been observed that multishot signal interference can be kept under some control by averaging over many such images, if each multishot migration is modified by a random phase encoding of the frequency spectra of the seismic traces.

In this article, we analyse this technique, giving a theoretical basis for its observed behaviour: that the error of the image produced by averaging over M phase encoded migrations decreases as M−1. Furthermore, we expand the technique and define a general class of Monte‐Carlo encoding methods for which the noise variance of the average imaging condition decreases as M−1; these methods thus all converge asymptotically to the correct reflectivity map, without generating prohibitive costs.

The theoretical asymptotic behaviour is illustrated for three such methods on a 2D test case. Numerical verification in 3D is then presented for one such method implemented with a 3D PSPI extrapolation kernel for two test cases: the SEG–EAGE salt model and a real test constructed from field data.
A multigrid solver for 3D electromagnetic diffusion
Authors: Mulder W.A.
Published: September 2010

The performance of a multigrid solver for the time‐harmonic electromagnetic problem in geophysical settings is investigated. The frequencies are sufficiently small for waves travelling at the speed of light to be negligible, so that a diffusive problem remains. The discretization of the governing equations is obtained by the finite‐integration technique, which can be viewed as a finite‐volume generalization of Yee's staggered grid scheme. The resulting set of discrete equations is solved by a multigrid method.

The convergence rate of the multigrid method decreased when the grid was stretched. The slower convergence rate of the multigrid method can be compensated by using bicgstab2, a conjugate‐gradient‐type method for non‐symmetric problems. In that case, the multigrid solver acts as a preconditioner. However, whereas the multigrid method provides excellent convergence with constant grid spacings, it performs less than satisfactorily when substantial grid stretching is used.
Seeing below the basalt – offshore Faroes
Authors: Gallagher Joseph W. , Dromgoole Peter W.
Published: September 2010

Exploration in the basalt covered areas of the Faroes offshore has always suffered from poor seismic imaging below the basalt. Long offset 2D and 3D seismic data were acquired and a significant improvement in the seismic image below top basalt has been achieved. Deep towing of the source and receiver cables helped by extending the seismic bandwidth towards lower frequencies. Bubble‐tuned rather than conventional peak‐tuned source arrays gave little, if any, incremental benefit. The improvement in the imaging comes primarily from the approach to processing the data. High frequencies (dominantly noise) are filtered out of the data early in the processing to concentrate on the low frequency data. Careful multiple removal is important with several passes of demultiple being applied to the data using both Surface‐Related Multiple Elimination (SRME) and Radon techniques. Velocity analysis is performed as an iterative process taking into account the geological model. Reprocessing legacy 2D surveys, acquired with wide‐ranging parameters, using these processing techniques improved these datasets significantly, indicating that sub‐basalt imaging seems to be more sensitive to processing than to the choice of acquisition parameters.
The spatial distribution of forest biomass in the Brazilian Amazon: a comparison of estimates
Authors: Houghton R. A. , Lawrence K. T. , Hackler J. L. , Brown Sandra
Published: September 2010

The amount of carbon released to the atmosphere as a result of deforestation is determined, in part, by the amount of carbon held in the biomass of the forests converted to other uses. Uncertainty in forest biomass is responsible for much of the uncertainty in current estimates of the flux of carbon from land‐use change. In the present contribution several estimates of forest biomass are compared for the Brazilian Amazon, based on spatial interpolations of direct measurements, relationships to climatic variables, and remote sensing data. Three questions were posed: First, do the methods yield similar estimates? Second, do they yield similar spatial patterns of distribution of biomass? And, third, what factors need most attention if we are to predict more accurately the distribution of forest biomass over large areas?

   The answer to the first two questions is that estimates of biomass for Brazil's Amazonian forests (including dead and belowground biomass) vary by more than a factor of two, from a low of 39 PgC to a high of 93 PgC. Furthermore, the estimates disagree as to the regions of high and low biomass. The lack of agreement among estimates confirms the need for reliable determination of aboveground biomass over large areas. Potential methods include direct measurement of biomass through forest inventories with improved allometric regression equations, dynamic modelling of forest recovery following observed stand‐replacing disturbances, and estimation of aboveground biomass from airborne or satellite‐based instruments sensitive to the vertical structure plant canopies.
Adaptive microevolutionary responses to simulated global warming inSimocephalus vetulus: a mesocosm study
Authors: VAN DOORSLAER WENDY , STOKS ROBBY , JEPPESEN ERIK , DE MEESTER LUC
Published: September 2010

Although several studies suggest the occurrence of microevolutionary responses that may allow local persistence of populations under global warming, rigorous experimental proof is lacking. Here, we combined the realism and rigid, replicated experimental design of a large‐scale mesocosm study where populations of the zooplankterSimocephalus vetuluswere exposed for 1 year to different global warming scenarios with a life table experiment under laboratory conditions at three temperatures that eliminated confounding, nongenetic factors. Our results provide solid proof for a rapid microevolutionary response to global warming in both survival and the subcomponents of individual performance (age at reproduction and number of offspring), which may allow populations ofS. vetulusto persist locally under predicted scenarios of global warming. Such microevolutionary responses may buffer changes in community structure under global warming and help explain the outcome of previous mesocosm studies finding only marginal effects of global warming at the community level.
Compositional similarity among urban floras within and across continents: biogeographical consequences of human‐mediated biotic interchange
Authors: LA SORTE FRANK A. , McKINNEY MICHAEL L. , PYŠEK PETR
Published: September 2010

Anthropogenic activities have weakened biogeographical barriers to dispersal resulting in the global spread and establishment of an increasing number of non‐native species. We examine the broad‐scale consequences of this phenomenon based on an analysis of compositional similarity across urban floras in the northeastern United States and Europe. We test the prediction that homogenization of species composition is uniquely defined within vs. between continents based on the time and place of origin of non‐native species. In this case, for archaeophytes and neophytes in Europe (introduced before and after ad 1500, respectively) and non‐native species originating from within and outside the United States. More species in urban floras were shared within than between continents. Within Europe, archaeophytes shared more species across urban floras compared with neophytes; strong associations were not observed for non‐native species across US urban floras. Between the two continents, non‐native species in the United States that originated from outside the United States shared species primarily with archaeophytes but also with European natives and neophytes. These results suggest that the direction of biotic interchange was unidirectional with species moving primarily from Europe to the United States with archaeophytes playing a primary and non‐native species originating from outside the two continents a secondary role as a homogenizing source. Archaeophytes, based on combination of biogeographical, evolutionary, and ecological factors in association with a long history of anthropogenic influence, appear to have played a prominent role in the continental and intercontinental homogenization of species composition. This suggests that the uniform homogenization of the Earth's biota is not imminent and is presently directed by a combination of biogeographically defined anthropogenic and historical factors.
Myelodysplastic features in patients with long‐term HIV infection and haemophilia
Authors: Katsarou O. , Terpos E. , Patsouris E. , Peristeris P. , Viniou N. , Kapsimali V. , Karafoulidou A.
Published: September 2010

HIV‐related bone marrow changes are consistent with myelodysplastic features (MDF). Their pathogenesis may differ from primary myelodysplastic syndromes (MDS) and is associated with various factors including the virus itself or the antiretroviral therapy. In order to evaluate the differences between HIV‐related MDF and MDS, the morphological changes in peripheral blood and bone marrow, cytogenetic analysis and the response to anaemia treatment were studied in 158 HIV+ patients with haemophilia and the results were compared with those of 61 patients with primary MDS (31 with RA, 10 with RARS, 11 with RAEB, three with RAEB‐t and six with CMML). The eligibility criteria for patients with MDS were primary MDS, Hb levels < 10 g dL–1, and no significant organ disease. The peripheral blood and bone marrow examination revealed MDF in 44 HIV‐infected haemophilic patients (27.8%). The median time from seroconversion was 12.5 years and the mean time under AZT therapy was 44.1 months. Nineteen of these patients (43.1%) had Hb levels < 10 g dL–1, while neutropenia and thrombocytopenia were observed in 29.5% and 25%, respectively. Every patient of this study with Hb < 10 g dL–1 received erythropoietin (Epo). There were statistically significant morphological alterations between HIV‐related MDF and MDS: hypocellularity, plasmatocytosis and eosinophilia were more pronounced in HIV haemophiliacs with MDF, while dysplasia of erythroblasts, megakaryocytes and granulocytes was more frequent in MDS patients. No HIV haemophilic patient with MDF had more than 5% blasts in the bone marrow nor did any develop RAEB or acute leukaemia during the period of this study. The cytogenetic analysis was normal in HIV‐infected patients with haemophilia whereas 42.6% of patients with MDS had an abnormal karyotype. Complete erythroid response was achieved with Epo administration in 84.2% of HIV+ haemophilic patients with anaemia compared to 19.7% of patients with MDS. These data suggest that bone marrow changes in long‐term HIV patients have different characteristics from primary MDS and constitute the entity for which the name HIV‐myelopathy has been proposed in the literature.
Milder clinical presentation of haemophilia A with severe deficiency of factor VIII as measured by one‐stage assay
Authors: Ghosh K. , Shetty S. , Mohanty D.
Published: September 2010

During the course of investigations we encountered 11 patients with haemophilia A who had severe factor VIII deficiency as measured by one‐stage assay but had surprisingly mild clinical presentation. Four of these patients had either a brother, nephew or maternal uncle with severe clinical manifestations. Two patients had low protein S levels, and one was heterozygous for the factor V Leiden mutation. One patient had a combined deficiency of protein C and antithrombin III. Four patients had a two‐stage factor VIII assay value that was much higher than the one‐stage assay value. Five patients were heterozygous for the MTHFR gene C677T polymorphism, of whom two patients were also deficient for protein S and one had two‐stage factor assay values higher than the one‐stage assay values. The patient who was both factor VIII deficient and heterozygous for factor V Leiden had mild clinical presentation as compared to his maternal uncle who was only factor‐VIII deficient. The maternal cousin of the same patient was heterozygous for factor V Leiden and had suffered two thrombotic episodes. Thus, the present study advocates that the physiological inhibitors of blood coagulation also play an important role in cases of haemophilia A in the final outcome of haemostasis in vivo.
The responsibility of separating truth from myth to patient and family
Authors: Miller R.
Published: September 2010

The choice of treatment for patients with haemophilia is influenced by the availability of replacement products, evidence‐based knowledge and the beliefs of patients and their medical practitioners. Decisions are often restrained by wider political and domestic administrative directives to keep within budgetary limits. Issues about the optimal and most cost‐effective care still pose a challenge. When choosing treatments there are as yet no certain answers in many areas and myths can develop around a variety of issues. This article addresses the question of whose responsibility it is to separate truth from myth to patient and family, and suggests some basic counselling principles on which to base practice.
Rapidly destructive arthropathy of the hip in haemophilia
Authors: Ishiguro N. , Takagi H. , Ito T. , Oguchi T. , Takamatsu J. , Iwata H.
Published: September 2010

The aetiology of rapidly destructive arthropathy is still being debated. We report a 48‐year‐old male haemophiliac who exhibited hip arthropathy that was similar to rapidly destructive arthropathy. The hip joint was destroyed 6 months after the onset of symptoms. Results of clinical and laboratory examinations did not show any features of neuropathic, inflammatory or septic arthropathy, except for coagulopathy. Magnetic resonance imaging revealed an expansive joint capsule with synovial proliferation in the affected hip joint. Total hip arthroplasty was carried out successfully with total resection of the synovial tissue and joint capsule. A histological examination revealed bone necrosis, nonspecific inflammation, haemosiderosis and synovial hypertrophy. The recurrent bleeding into the hip joint induced pronounced inflammation with synovial proliferation and acute destruction of bony tissue.
Lack of evidence for increased inhibitor incidence in patients switched from plasma‐derived to recombinant factor VIII
Authors: Scharrer I. , Ehrlich H. J.
Published: September 2010

De novo inhibitor development is a rare event in PTPs switched from pdFVIII to rFVIII. Based on previously published data of clinical studies a change in FVIII product is unlikely to provoke inhibitor formation.